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Sample records for mo tc ru

  1. Metal-metal bonding and aromaticity in [M2(NHCHNH)3]2 (μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh).

    Science.gov (United States)

    Yan, Xiuli; Meng, Lingpeng; Sun, Zheng; Li, Xiaoyan

    2016-02-01

    The nature of M-M bonding and aromaticity of [M2(NHCHNH)3]2(μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh) was investigated using atoms in molecules (AIM) theory, electron localization function (ELF), natural bond orbital (NBO) and molecular orbital analysis. These analyses led to the following main conclusions: in [M2(NHCHNH)3]2(μ-E)2 (E = O, S; M = Nb, Mo, Tc, Ru, Rh), the Nb-Nb, Ru-Ru, and Rh-Rh bonds belong to "metallic" bonds, whereas Mo-Mo and Tc-Tc drifted toward the "dative" side; all these bonds are partially covalent in character. The Nb-Nb, Mo-Mo, and Tc-Tc bonds are stronger than Ru-Ru and Rh-Rh bonds. The M-M bonds in [M2(NHCHNH)3]2(μ-S)2 are stronger than those in [M2(NHCHNH)3]2(μ-O)2 for M = Nb, Mo, Tc, and Ru. The NICS(1)ZZ values show that all of the studied molecules, except [Ru2(NHCHNH)3]2(μ-O)2, are aromaticity molecules. O-bridged compounds have more aromaticity than S-bridged compounds. Graphical Abstract Left Molecular graph, and right electron localization function (ELF) isosurface of [M2(NHCHNH)3]2(μ-E)2(E = O, S; M = Nb, Mo, Tc, Ru, Rh).

  2. Beta decay of Tc-111 to Ru-111

    NARCIS (Netherlands)

    Pfeiffer, B; Lhersonneau, G; Dendooven, P; Honkanen, A; Huhta, M; Klockl, [No Value; Oinonen, M; Penttila, H; Persson, B.L.; Perajarvi, K; Wang, JC; Kratz, KL; Aysto, J

    1998-01-01

    The beta-decay of the very neutron-rich Tc-111 nucleus has been observed. A partial decay scheme of Ru-111 is presented, complementing the high-spin levels earlier reported in spontaneous fission work.

  3. Beta decay of {sup 111}Tc to {sup 111}Ru

    Energy Technology Data Exchange (ETDEWEB)

    Pfeiffer, B.; Kloeckl, I.; Kratz, K.L. [Mainz Univ. (Germany). Inst. fuer Kernchemie; Lhersonneauc, G.; Dendooven, P.; Honkanen, A.; Huhta, M.; Oinonen, M.; Penttilae, H.; Peraejaervi, K.; Wang, J.C.; Aeystoe, J. [Department of Physics, University of Jyvaeskylae, P.O.Box 35, FIN-40351 Jyvaeskylae (Finland); Persson, J.R. [School of Physics and Space Research, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    1998-05-01

    The {beta}-decay of the very neutron-rich {sup 111}Tc nucleus has been observed. A partial decay scheme of {sup 111}Ru is presented, complementing the high-spin levels earlier reported in spontaneous fission work. (orig.) With 1 fig., 2 tabs., 20 refs.

  4. Tc Generator Development: Up-to-Date Tc Recovery Technologies for Increasing the Effectiveness of Mo Utilisation

    Directory of Open Access Journals (Sweden)

    Van So Le

    2014-01-01

    Full Text Available A review on the Mo sources available today and on the Tc generators developed up to date for increasing the effectiveness of Mo utilisation is performed in the format of detailed description of the features and technical performance of the technological groups of the Mo production and Tc recovery. The latest results of the endeavour in this field are also surveyed in regard of the technical solution for overcoming the shortage of Mo supply. The technological topics are grouped and discussed in a way to reflect the similarity in the technological process of each group. The following groups are included in this review which are high specific activity Mo: the current issues of production, the efforts of more effective utilisation, and the high specific activity Mo-based Tc generator and Tc concentration units; low specific activity Mo: the Mo production based on neutron capture and accelerators and the direct production of Tc and the methods of increasing the specific activity of Mo using Szilard-Chalmers reaction and high electric power isotopic separator; up-to-date technologies of Tc recovery from low specific activity Mo: the solvent extraction-based Tc generator, the sublimation methods for Mo/Tc separation, the electrochemical method for Tc recovery, and the column chromatographic methods for Tc recovery. Besides the traditional Tc-generator systems, the integrated Tc generator systems (Tc generator column combined with postelution purification/concentration unit are discussed with the format of process diagram and picture of real generator systems. These systems are the technetium selective sorbent column-based generators, the high Mo-loading capacity column-based integrated Tc generator systems which include the saline-eluted generator systems, and the nonsaline aqueous and organic solvent eluent-eluted generator systems using high Mo-loading capacity molybdategel and recently developed sorbent columns. Tc concentration methods used in the

  5. Adsorption of formaldehyde and formyl intermediates on Pt, PtRu-, and PtRuMo-alloy surfaces: A density functional study

    Science.gov (United States)

    Cahyanto, Wahyu Tri; Shukri, Ganes; Agusta, Mohammad Kemal; Kasai, Hideaki

    2013-02-01

    Stable binding configuration for formaldehyde (H2CO) and formyl (HCO) adsorption on Pt, PtRu, and PtRuMo are studied within the frame of density functional theory (DFT). We address this study to investigate the role of Ru and Mo on the binding characteristic of formaldehyde and formyl adsorption with respect to interaction strength and charge analysis. Several binding conformation on all possible surface adsorption sites are considered in determining the most stable adsorption geometry on three surfaces. Our results show that the presence of Ru in PtRu and Mo in PtRuMo stabilize the formaldehyde and formyl, which are indicated by stronger bond strength. Further electronic structure analysis shows that the addition of Ru in PtRu and Mo in PtRuMo modifies the electronic structure of Pt's surface significantly. The presence of both impurities shifted the derived anti-bonding state - which is originally located below the fermi level in pure Pt surface - to be above the fermi level in PtRu and PtRuMo systems. This fact explains the stronger adsorption found on PtRu & PtRuMo as compared to pure Pt surface.

  6. Quality control studies of {sup 99}Mo used in {sup 99}Mo/{sup 99m}Tc generators produced at IPEN/CNEN-SP, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Said, Daphne S.; Brambilla, Tania P.; Matsuda, Margareth M.N.; Osso Junior, Joao A., E-mail: daphnesaid@usp.br, E-mail: taniabrambilla@yahoo.com.br, E-mail: mmatsuda@ipen.br, E-mail: jaosso@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    {sup 99m}Tc is the most used radionuclide in nuclear medicine. In Brazil, the {sup 99}Mo/{sup 99m}Tc generators are produced exclusively by the Center of Radiopharmacy at IPEN-CNEN/SP, by importing {sup 99}Mo from different suppliers. {sup 99}Mo (t{sub 1/2} = 66 h) is a fission product of {sup 235}U, therefore, it can be accompanied by several radioisotopes that are highly prejudicial for human health, demanding a strict quality control of this product for generators safe use. The European Pharmacopoeia established some parameters and limits that evaluate the quality of the solution of sodium [{sup 99}Mo]molybdate, that is used as raw material for generator's production. The European Pharmacopoeia also recommends some analytical methods to perform these evaluations, however, it has been observed difficulties on the implementation of these methods by the generator's producers. These difficulties are probably related to the lack of practicability of the proposed methods and the extensive list of utilized reagents. In this work some procedures of the European Pharmacopoeia's quality control method for {sup 99}Mo were evaluated. Different types of solid phase exchanger cartridges were tested for retention of {sup 99}Mo in 3 different conditions. Cartridges that presented percentages of retention higher than 90% were also tested for separation of {sup 99}Mo from possible contaminants (Ru e Te). The results shown that solid phase exchanger cartridges that presented percentages of retention of Mo higher than 90% also presented significant percentages of retention of Ru and Te. An alternative method for separation of {sup 99}Mo from {sup 131}I (other contaminant) are also proposed. (author)

  7. Electrochemical activation of nanostructured carbon-supported PtRuMo electrocatalyst for methanol oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Huerta, M.V., E-mail: mmartinez@icp.csic.e [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie 2, 28049 Madrid (Spain); Tsiouvaras, N.; Pena, M.A.; Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie 2, 28049 Madrid (Spain); Rodriguez, J.L.; Pastor, E. [Departamento de Quimica Fisica, Universidad de La Laguna, Astrofisico Francisco Sanchez s/n, 38071 Tenerife (Spain)

    2010-11-01

    The factors controlling the behavior and the stability of electrocatalysts based on Pt, Ru and Mo nanoparticles during exhaustive electrochemical treatment are examined. Along this treatment, it has been observed that in the case of ternary catalysts there are pronounced changes in the structure of their surface resulting in electrode activation for methanol and CO electrooxidation, whereas the activity of binary PtRu/C and PtMo/C catalysts decreases. Therefore, the role of both Ru and Mo is crucial for the electrochemical activation of the catalyst, though metal losses do occur during electrochemical process. For the first time a detailed study of this phenomenon is presented, including characterization by HRTEM, TXRF, XRD, electrochemical measurements and in situ Fourier transform infrared spectroscopy (FTIR). In order to get a deeper insight into the surface structure, chemical state, and stability of the electrocatalyst under reaction conditions, a combination of cyclic voltammetry, chronoamperometry and X-ray photoelectron spectroscopy (XPS) has been used. By comparing bulk and surface composition, our results point out to the key role of the geometric effect enhanced by previous reduction of the nanoparticles. At the end of the electrochemical treatment, Mo-PtRu/C catalysts surface was restructured with substantial enrichment in Pt and a less pronounced Mo surface enrichment, while Ru is incorporated into the Pt-Mo overlayer. These results underline the possibility of further optimization of the surface structure and composition producing PtRuMo nanoparticles with high methanol and CO oxidation activity.

  8. First decay scheme of {sup 113}Tc and identification of {sup 113}Ru{sup m}

    Energy Technology Data Exchange (ETDEWEB)

    Kurpeta, J.; Plochocki, A. [Warsaw Univ. (Poland). Inst. of Experimental Phys.; Lhersonneau, G.; Wang, J.C.; Dendooven, P.; Honkanen, A.; Huhta, M.; Oinonen, M.; Penttilae, H.; Peraejaervi, K.; Persson, J.R.; Aeystoe, J. [Department of Physics, University of Jyvaeskylae, P.O.Box. 35, FIN-40351, Jyvaeskylae (Finland)

    1998-07-01

    Very neutron-rich fission products of the mass chain A=113 obtained from the IGISOL on-line mass separator have been investigated by {gamma}{gamma} coincidence techniques and {gamma}-spectra multiscaling. Gamma-rays following {beta}-decay of {sup 113}Tc have been observed for the first time and a new 0.5 s isomeric state has been found in {sup 113}Ru. (orig.) With 3 figs., 1 tab., 9 refs.

  9. Methane Direct Conversion on Mo/ZSM-5 Catalysts Modified by Pd and Ru

    Institute of Scientific and Technical Information of China (English)

    Priscila Dias Sily; Fabio Bellot Noronha; Fabio Barboza Passos

    2006-01-01

    The effect of addition of Ru and Pd to Mo/HZSM-5 catalysts used in the dehydroaromatization of methane was investigated. Catalytic tests and temperature-programmed oxidation results showed that Pd-based catalysts were more selective to naphthalene and suffered strong deactivation. The presence of Ru improved the activity and stability, with a decrease in the carbonaceous deposit probably because of a mechanism of protection of the Mo2C surface.

  10. .sup.100Mo compounds as accelerator targets for production of .sup.99mTc

    Science.gov (United States)

    Richards, Vernal; Lapi, Suzanne

    2016-09-20

    Methods of synthesizing .sup.100Mo.sub.2C and .sup.99mTcO.sub.4.sup.- are disclosed. Methods of .sup.100Mo.sub.2C generation involve thermally carburizing .sup.100MoO.sub.3. Methods of .sup.99mTcO.sub.4 generation involve proton bombardment of .sup.100Mo.sub.2C in a cyclotron. Yields of .sup.99mTcO.sub.4 can be increased by sintering .sup.100Mo.sub.2C prior to bombardment. The methods also include recycling of .sup.100Mo.sub.2C to form .sup.100MoO.sub.3. SPECT images obtained using .sup.99mTcO.sub.4 generated by the disclosed methods are also presented.

  11. Role of thermal and photobeta decays in processes of nucleosynthesis of problematic p nuclei of {sup 113}In, {sup 115}Sn, {sup 92},{sup 94}Mo, and {sup 96},{sup 98}Ru in massive stars

    Energy Technology Data Exchange (ETDEWEB)

    Kopytin, I. V., E-mail: i-kopytin@yandex.ru; Hussain, Imad A. [Voronezh State University (Russian Federation)

    2013-04-15

    The temperature dependence of the rates of {sup 113}Cd {yields}{sup 113}In, {sup 115}In {yields}{sup 115}Sn, {sup 92}Zr{yields}{sup 92}Nb {yields}{sup 92}Mo, {sup 94}Zr{yields}{sup 94}Nb {yields}{sup 94}Mo, {sup 96}Mo {yields}{sup 96}Tc{yields}{sup 96}Ru, and {sup 98}Mo{yields}{sup 98}Tc{yields}{sup 98}Ru thermal beta transitions was studied at temperatures of massive-star matter in the range of 1 Multiplication-Sign 10{sup 8}-6 Multiplication-Sign 10{sup 9} K. These decays are the possible channel of synthesis of the p nuclei of {sup 113}In, {sup 115}Sn, {sup 92},{sup 94}Mo, and {sup 96},{sup 98}Ru. The abundances of these nuclei present a challenge for models that study the explosivemechanism of synthesis. The contribution of photobeta decay to the synthesis of the aforementioned p nuclei was estimated. It was shown that the channel of thermal beta decay for {sup 113}In, {sup 115}Sn, {sup 94}Mo, and {sup 98}Ru p nuclei and the channel of photobeta decay for the {sup 96}Mo p nucleus could be efficient at the high-temperature quasiequilibrium stage of massive-star evolution.

  12. A {sup 99m}Tc Generator using PZC for (n,{gamma}) {sup 99}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Adang, H.G.; Mutalib, A.; Suparman, I.; Hamid; Purwadi, B.; Pancoko, M.; Setiowati, S.; Yulianti, V.; Robertus, D.H. [Radioisotope Production Center, National Atomic Energy Agency Kawasan PUSPIPTEK, Serpong (Indonesia)

    1998-10-01

    The high performance adsorbent Poly Zirconium Compound (PZC) was produced by Department of Radioisotope, Japan Atomic Energy Research Institute. This compound was developed as an adsorbent for natural Mo (n,{gamma}) {sup 99}Mo-{sup 99m}Tc Generator. In the present paper, we report the performance of the PZC for a {sup 99m}Tc Generator which was focused on the yield, on elution profile and {sup 99}Mo breakthrough. (author)

  13. 99Mo/(99m)Tc separation: an assessment of technology options.

    Science.gov (United States)

    Dash, Ashutosh; Knapp, F F Russ; Pillai, M R A

    2013-02-01

    Several strategies for the effective separation of (99m)Tc from (99)Mo have been developed and validated. Due to the success of column chromatographic separation using acidic alumina coupled with high specific activity fission (99)Mo (F (99)Mo) for production of (99)Mo/(99m)Tc generators, however, most technologies until recently have generated little interest. The reduced availability of F (99)Mo and consequently the shortage of (99)Mo/(99m)Tc column generators in the recent past have resurrected interest in the production of (99)Mo as well as (99m)Tc by alternate routes. Most of these alternative production processes require separation techniques capable of providing clinical grade (99m)Tc from low specific activity (99)Mo or irradiated Mo targets. For this reason there has been renewed interest in alternate separation routes. This paper reviews the reported separation technologies which include column chromatography, solvent extraction, sublimation and gel systems that have been traditionally used for the fabrication of (99)Mo/(99m)Tc generator systems. The comparative advantage, disadvantage, and technical challenges toward adapting the emerging requirements are discussed. New developments such as solid-phase column extraction, electrochemical separation, extraction chromatography, supported liquid membrane (SLM) and thermochromatographic techniques are also being evaluated for their potential application in the changed scenario of providing (99m)Tc from alternate routes. Based on the analysis provided in this review, it appears that some proven separation technologies can be quickly resurrected for the separation of clinical grade (99m)Tc from macroscopic levels of reactor or cyclotron irradiated molybdenum targets. Furthermore, emerging technologies can be developed further to respond to the expected changing modes of (99m)Tc production.

  14. Successful Labeling of \\text{99mTc-MDP Using \\text{99mTc Separated from 99Mo Produced by 100Mo(n,2n)99Mo

    Science.gov (United States)

    Nagai, Yasuki; Hatsukawa, Yuichi; Kin, Tadahiro; Hashimoto, Kazuyuki; Motoishi, Shoji; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Sato, Yuichi; Kawauchi, Yukimasa; Sato, Norihito; Ohta, Akio; Yamabayashi, Hisamichi; Tanase, Masakazu; Fujisaki, Saburo; Teranaka, Tomoyuki; Takeuchi, Nobuhiro; Igarashi, Takashi

    2011-08-01

    We have for the first time succeeded in separating \\text{99mTc from a MoO3 sample irradiated with accelerator neutrons free from any radioactive impurities and in formulating \\text{99mTc-methylene diphosphonate (\\text{99mTc-MDP). 99Mo, the mother nuclide of \\text{99mTc, was produced by the 100Mo(n,2n)99Mo reaction using about 14 MeV neutrons provided by the 3H(d,n)4He reaction at the Fusion Neutronics Source of Japan Atomic Energy Agency. The \\text{99mTc was separated from 99Mo by sublimation and its radionuclide purity was confirmed to be higher than 99.99% by γ-spectroscopy. The labeling efficiency of \\text{99mTc-MDP was shown to be higher than 99% by thin-layer chromatography. These values exceed the United States Pharmacopeia requirements for a fission product, 99Mo. Consequently, a \\text{99mTc radiopharmaceutical preparation formed by using the mentioned 99Mo can be a promising substitute for the fission product 99Mo, which is currently produced using a highly enriched uranium target in aging research reactors. A longstanding problem to ensure a reliable and constant supply of 99Mo in Japan can be partially mitigated.

  15. Thermodynamics of ordered and disordered phases in the binary Mo-Ru system

    DEFF Research Database (Denmark)

    Kissavos, A.E.; Shallcross, Sam; Kaufman, L.;

    2007-01-01

    We have performed ab initio calculations of the mixing enthalpy for the Mo-Ru alloy system. Both completely random alloys on the fcc, bcc, and hcp lattices as well as ordered and partially ordered structures based on the hcp lattice and a sigma phase have been examined. Further, we have performed...

  16. Benchmark experiment for the cross section of the 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo reactions

    Science.gov (United States)

    Takács, S.; Ditrói, F.; Aikawa, M.; Haba, H.; Otuka, N.

    2016-05-01

    As nuclear medicine community has shown an increasing interest in accelerator produced 99mTc radionuclide, the possible alternative direct production routes for producing 99mTc were investigated intensively. One of these accelerator production routes is based on the 100Mo(p,2n)99mTc reaction. The cross section of this nuclear reaction was studied by several laboratories earlier but the available data-sets are not in good agreement. For large scale accelerator production of 99mTc based on the 100Mo(p,2n)99mTc reaction, a well-defined excitation function is required to optimise the production process effectively. One of our recent publications pointed out that most of the available experimental excitation functions for the 100Mo(p,2n)99mTc reaction have the same general shape while their amplitudes are different. To confirm the proper amplitude of the excitation function, results of three independent experiments were presented (Takács et al., 2015). In this work we present results of a thick target count rate measurement of the Eγ = 140.5 keV gamma-line from molybdenum irradiated by Ep = 17.9 MeV proton beam, as an integral benchmark experiment, to prove the cross section data reported for the 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo reactions in Takács et al. (2015).

  17. A practical {sup 99m}Tc generator using (n, {gamma}) {sup 99}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Tatenuma, Katsuyoshi; Ishikawa, Koji; Nishino, Mizuka; Hasegawa, Yoshio [KAKEN Co., Mito-Institute, Mito, Ibaraki (Japan); Kurosawa, Kiyoyuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Sekine, Toshiaki; Tanase, Masakazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-10-01

    For a new and practical {sup 99m}Tc generator using not (n, f){sup 99}Mo, but (n, {gamma}){sup 99}Mo, an inorganic polymer adsorbent framed with oxygen-zirconium-chlorine bonds with a high adsorption performance of Mo has been developed; the polymer adsorbent was named PZC. The amounts of {sup 99}Mo (Mo) adsorbed are stably more than 250 mg/g(PZC). But, the current experiments with 0.5 MBq to 1.85 GBq of {sup 99}Mo gave a subject that the breakthrough of {sup 99}Mo in the elution of {sup 99m}Tc from the adsorbent was 0.05-0.5 %, although the breakthrough of Zr was less than the detection limit of 5 x 10{sup -2} mg(Zr) to 1 g of PZC, and {sup 99m}Tc was eluted constantly with 78{+-}4%. To apply the adsorbent as a generator commercially in Japan, the {sup 99}Mo breakthroughed from the generator must be suppressed to less than 0.15 kBp({sup 99}Mo)/MBq({sup 99m}Tc) by law which is equivalent to 0.015 %, and the {sup 99}Mo breakthrough is controlled practically to less than 10{sup -2} of the law limit. In order to reduce the {sup 99}Mo breakthrough of PZC, we set an alumina column in series to the PZC column and examined the performance. Furthermore, several experiments to elucidate the mechanism of Mo adsorption to PZC were conducted where shapes of PZC irradiated by high flux {gamma} ray was observed. From the experimental results, it was cleared as follows; 1) The alumina column has a property of adsorbing {sup 99}Mo very effectively and of eluting {sup 99m}Tc very easily. By keeping an eluent saline at pH of 6 to 8 and using a small alumina column connected to PZC column, the breakthrough of {sup 99}Mo was reduced to approximately 0.003 % lower than the law limit and the high elution rates of {sup 99m}Tc were unchanged. 2) By irradiating PZC with the gamma rays up to 1 x 10{sup 9} rad, it was observed that the PZC was cracked, the size became smaller according to the fluences of gamma rays, and the destructive force of PZC was kept. On the other hand, by using the

  18. Assessment of Using 99Mo and 99mTc Isotopes in Kuwait Medical Sector.

    Science.gov (United States)

    Ali, Naser

    2016-04-01

    The Ministry of Health (MOH) in the state of Kuwait currently depends on importing the radioisotope molybdenum (Mo) in its isotopic form (Mo) to fulfill its demands. The present study was conducted on all nuclear medicine departments in the state of Kuwait. Daily, weekly, and monthly data were analyzed to statistically determine the current and future demands for the isotope Tc. This analysis was performed by collecting and analyzing data on MOH consumption of Tc for different diagnostic applications. The overall results indicate a partial decrease of 1.012% in the overall total demand for Tc up to the year 2018 for the state of Kuwait.

  19. Vibrational contributions to phase stability in the Mo-Ru system

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, Sean H.; Abrecht, David G.; Clark, Richard A.; Schwantes, Jon M.

    2016-12-01

    Density functional theory using the Perdew-Burke-Ernzerhof functional and the small displacement method was used to calculate the quasiharmonic phonon density of states (DOS) for 69 ordered structures in the Mo-Ru substitutional alloy system to estimate the effect of vibrational contributions to the free energy of formation. These structures were used to determine interaction parameters in the cluster expansion approximation up to triplet sets to incorporate the vibrational contribution into the configurational energy of formation for the randomly mixed system. The free energies calculated using this approximation are shown to resolve lingering disagreement between reported theoretical and experimental results, and the stabilizing effect of vibrational entropy is observed to improve theoretical predictions of the Mo-Ru phase diagram.

  20. Cyclotron Production of (99m)Tc using (100)Mo2C targets.

    Science.gov (United States)

    Richards, Vernal N; Mebrahtu, Efrem; Lapi, Suzanne E

    2013-10-01

    An investigative study of the (100)Mo (p,2n)(99m)Tc reaction on a medical cyclotron using (100)Mo2C is reported. This is the first report of this compound being used as a target for this reaction. (100)Mo2C, a refractory carbide with high thermal conductivity, properties which underscore its use on a cyclotron, was synthesized using (100)MoO3. Its ease of oxidation back to (100)MoO3 under air at elevated temperatures facilitates the use of thermo-chromatography, a high temperature gas phase separation technique for the separation and isolation of (99m)Tc. Activity yields for (99m)Tc averaged 84% of the calculated theoretical yields. Additionally, the percent recovery of MoO3, the precursor for Mo2C, was consistently high at 85% ensuring a good life cycle for this target material. The produced (99m)Tc was radio-chemically pure and easily labeled MDP for imaging purposes.

  1. Carbon-Supported PtRuMo Electrocatalysts for Direct Alcohol Fuel Cells

    Directory of Open Access Journals (Sweden)

    José L.G. Fierro

    2013-10-01

    Full Text Available The review article discusses the current status and recent findings of our investigations on the synthesis and characterization of carbon-supported PtRuMo electrocatalysts for direct alcohol fuel cells. In particular, the effect of the carbon support and the composition on the structure, stability and the activity of the PtRuMo nanoparticles for the electrooxidation of CO, methanol and ethanol have been studied. Different physicochemical techniques have been employed for the analysis of the catalysts structures: X-ray analytical methods (XRD, XPS, TXRF, thermogravimetry (TGA and transmission electron microscopy (TEM, as well as a number of electrochemical techniques like CO adsorption studies, current-time curves and cyclic voltammetry measurements. Furthermore, spectroscopic methods adapted to the electrochemical systems for in situ studies, such as Fourier transform infrared spectroscopy (FTIRS and differential electrochemical mass spectrometry (DEMS, have been used to evaluate the oxidation process of CO, methanol and ethanol over the carbon-supported PtRuMo electrocatalysts.

  2. Development of 99Mo/99mTc Generator System for Production of Medical Radionuclide 99mTc using a Neutron-activated 99Mo and Zirconium Based Material (ZBM as its Adsorbent

    Directory of Open Access Journals (Sweden)

    I. Saptiama

    2016-12-01

    Full Text Available Molybdenum produced from fission of U-235 is the most desirable precursor for 99Mo/99mTc generator system as it is non-carrier added and has high specific activity. However, in the last decade there has been short supply of 99Mo due to several constrains. Therefore, there have been many works performed for development of 99Mo/99mTc generator system using 99Mo which is not produced from either LEU or HEU. This report deals with development of 99Mo/99mTc generator system where zirconium-based material (ZBM is used as adsorbent of neutron-activated 99Mo. The system was prepared by firstly irradiating natural Mo in the G. A. Siwabessy reactor to produce neutron-activated 99Mo. The target was dissolved in NaOH 4N and then neutralized with 12 M HCl. The 99Mo solution was then mixed with a certain amount of ZBM followed by heating at 90°C for three hours to allow the 99Mo adsorbed on ZBM. The 99Mo-ZBM (9.36 GBq of 99Mo was Mo/ 4.2 g ZBM was packed on a fritz-glass column. This column was then fitted serially with an alumina column for trapping 99Mo breakthrough. The columns were then eluted daily with saline solution for up to one week. The yield of 99mTc was found to be between 53.7 – 74% (n= 5. All 99mTc eluates were clear solutions with pH of 5. Breakthrough of 99Mo in 99mTc eluates was found to be 0.031 ± 0.019 μCi 99Mo/ mCi 99mTc (n= 5 which was less than the maximum activity of 99Mo allowed in 99mTc solution ( 99%. Radiolabeling of this 99mTc towards methylene diphosphonate (MDP kit gave a radiolabelling efficiency of 99%. In summary, a new 99Mo/99mTc generator system that used neutron-activated 99Mo and ZBM as its adsorbent has been successfully prepared. The 99mTc produced from this new 99Mo/99mTc generator system attained the quality of 99mTc required for medical purposes.

  3. Diversification in the Supply Chain of (99)Mo Ensures a Future for (99m)Tc.

    Science.gov (United States)

    Cutler, Cathy S; Schwarz, Sally W

    2014-07-01

    The uncertain availability of (99m)Tc has become a concern for nuclear medicine departments across the globe. An issue for the United States is that currently it is dependent on a supply of (99m)Tc (from (99)Mo) that is derived solely by production outside the United States. Since the United States uses half the world's (99)Mo production, the U.S. (99)Mo supply chain would be greatly enhanced if a producer were located within the United States. The fragility of the old (99)Mo supply chain is being addressed as new facilities are constructed and new processes are developed to produce (99)Mo without highly enriched uranium. The conversion to low-enriched uranium is necessary to minimize the potential misuse of highly enriched uranium in the world for nonpeaceful means. New production facilities, new methods for the production of (99)Mo, and a new generator elution system for the supply of (99m)Tc are currently being pursued. The progress made in all these areas will be discussed, as they all highlight the need to embrace diversity to ensure that we have a robust and reliable supply of (99m)Tc in the future.

  4. The annealing effects on the micro-structure and properties of RuMoC films as seedless barrier for advanced Cu metallization

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Jianxiong; Liu, Bo, E-mail: liubo2009@scu.edu.cn, E-mail: gh.jiao@siat.ac.cn [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064 (China); Jiao, Guohua, E-mail: liubo2009@scu.edu.cn, E-mail: gh.jiao@siat.ac.cn; Lu, Yuanfu; Dong, Yuming [Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences, Shenzhen 518055 (China); The Chinese University of Hong Kong, Hong Kong (China); Li, Qiran [Institut d' Electronique Fondamentale, CNRS-Université Paris Sud UMR 8622, 91405 Orsay (France)

    2016-09-07

    100 nm thick RuMoC films and 5 nm thick RuMoC films with Cu capping have been deposited on Si(111) by magnetron co-sputtering with Ru and MoC confocal targets. The samples were subsequently annealed at temperatures ranging from 450 to 650 °C in vacuum at a pressure of 3 × 10{sup −4} Pa to study the annealing effects on the microstructures and properties of RuMoC films for advanced seedless Cu metallization applications. The sheet resistances, residual oxygen contents, and microstructures of the RuMoC films have close correlation with the doping contents of Mo and C, which can be easily controlled by the deposition power ratio of MoC versus Ru targets (DPR). When DPR was 0.5, amorphous RuMoC film (marked as RuMoC II) with low sheet resistances and residual oxygen contents was obtained. The fundamental relationship between the annealing temperatures with the microstructures and properties of the RuMoC films was investigated, and a critical temperature point was revealed at about 550 °C where the components and microstructures of the RuMoC II films changed obviously. Results indicated that below 550 °C, the RuMoC II films remained amorphous due to the well-preserved C-Ru and C-Mo bonds. However, above 550 °C, the microstructures of RuMoC II films transformed from amorphous to nano-composite structure due to the breakage of Ru-C bonds, while the supersaturated solid solution MoC segregated out along the grain boundaries of Ru, thus hindering the diffusion of Cu and O atoms. This is the main mechanism of the excellent thermal stability of the RuMoC films after annealing at high temperatures. The results indicated great prospects of amorphous RuMoC films in advanced seedless Cu metallization applications.

  5. Conceptual design of a new homogeneous reactor for medical radioisotope Mo-99/Tc-99m production

    Energy Technology Data Exchange (ETDEWEB)

    Liem, Peng Hong [Nippon Advanced Information Service (NAIS Co., Inc.) Scientific Computational Division, 416 Muramatsu, Tokaimura, Ibaraki (Japan); Tran, Hoai Nam [Chalmers University of Technology, Dept. of Applied Physics, Div. of Nuclear Engineering, SE-412 96 Gothenburg (Sweden); Sembiring, Tagor Malem [National Nuclear Energy Agency (BATAN), Center for Reactor Technology and Nuclear Safety, Kawasan Puspiptek, Serpong, Tangerang Selatan, Banten (Indonesia); Arbie, Bakri [PT MOTAB Technology, Kedoya Elok Plaza Blok DA 12, Jl. Panjang, Kebun Jeruk, Jakarta Barat (Indonesia)

    2014-09-30

    To partly solve the global and regional shortages of Mo-99 supply, a conceptual design of a nitrate-fuel-solution based homogeneous reactor dedicated for Mo-99/Tc-99m medical radioisotope production is proposed. The modified LEU Cintichem process for Mo-99 extraction which has been licensed and demonstrated commercially for decades by BATAN is taken into account as a key design consideration. The design characteristics and main parameters are identified and the advantageous aspects are shown by comparing with the BATAN's existing Mo-99 supply chain which uses a heterogeneous reactor (RSG GAS multipurpose reactor)

  6. Investigation of double beta decay of {sup 100}Mo to excited states of {sup 100}Ru

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R. [IPHC, UPL, CNRS/IN2P3, F-67037 Strasbourg (France); Augier, C. [LAL, Univ Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Barabash, A.S. [ITEP, Institute of Theoretical and Experimental Physics, 117218 Moscow (Russian Federation); Basharina-Freshville, A. [University College London, London WC1E 6BT (United Kingdom); Blondel, S. [LAL, Univ Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Blot, S. [University of Manchester, Manchester M13 9PL (United Kingdom); Bongrand, M. [LAL, Univ Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Brudanin, V. [JINR, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Busto, J. [CPPM, Université de Marseille, CNRS/IN2P3, F-13288 Marseille (France); Caffrey, A.J. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Čermák, P. [IEAP, Czech Technical University in Prague, CZ-12800 Prague (Czech Republic); Cerna, C. [CENBG, Université Bordeaux, CNRS/IN2P3, F-33175 Gradignan (France); Chapon, A. [LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, F-14050 Caen (France); Chauveau, E. [University of Manchester, Manchester M13 9PL (United Kingdom); Dragounová, L. [National Radiation Protection Institute, CZ-14000 Prague (Czech Republic); Duchesneau, D. [LAPP, Université de Savoie, CNRS/IN2P3, F-74941 Annecy-le-Vieux (France); Durand, D. [LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, F-14050 Caen (France); Egorov, V. [JINR, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Eurin, G. [LAL, Univ Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); University College London, London WC1E 6BT (United Kingdom); Evans, J.J. [University of Manchester, Manchester M13 9PL (United Kingdom); and others

    2014-05-15

    Double beta decay of {sup 100}Mo to the excited states of daughter nuclei has been studied using a 600 cm{sup 3} low-background HPGe detector and an external source consisting of 2588 g of 97.5% enriched metallic {sup 100}Mo, which was formerly inside the NEMO-3 detector and used for the NEMO-3 measurements of {sup 100}Mo. The half-life for the two-neutrino double beta decay of {sup 100}Mo to the excited 0{sub 1}{sup +} state in {sup 100}Ru is measured to be T{sub 1/2}=[7.5±0.6(stat)±0.6(syst)]⋅10{sup 20} yr. For other (0ν+2ν) transitions to the 2{sub 1}{sup +}, 2{sub 2}{sup +}, 0{sub 2}{sup +}, 2{sub 3}{sup +} and 0{sub 3}{sup +} levels in {sup 100}Ru, limits are obtained at the level of ∼(0.25–1.1)⋅10{sup 22} yr.

  7. Present status of {sup 99}Mo-{sup 99m}Tc generator in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Genka, Tsuguo [Japan Atomic Industrial Forum, Inc., Asia Cooperation Center, Tokyo (Japan)

    2003-03-01

    In Japan most of the demand of {sup 99m}Tc is relying on fission produced {sup 99}Mo imported from overseas. The (n, {gamma}) {sup 99}Mo-{sup 99m}Tc generator is not in the state of practical use but research and development are going on. Since 1995, Japan Atomic Energy Research Institute (JAERI) and Kaken Co. Ltd. have been collaborating to develop the Mo adsorbent material of poly zirconium compound (PZC) fit for so called (n, {gamma}) method. In 2000 the Kaken and the National Nuclear Energy Agency (BATAN) of Indonesia has facilitated to promote the technology of PZC based {sup 99m}Tc generator under the joint research agreement. Along with the cooperative experiments between two bodies, very promising results are coming out. Some of these results will be disclosed in the present workshop. (author)

  8. Homogeneous SLOWPOKE reactors for Mo-99/Tc-99m production in North America

    Energy Technology Data Exchange (ETDEWEB)

    Hilborn, J.W., E-mail: hilbovanw@sympatico.ca [Deep River, Ontario (Canada); Bonin, H.W. [Royal Military College of Canada, Kingston, Ontario (Canada)

    2014-07-01

    The 15 month shutdown of NRU in 2009 - 2010 caused an overall isotope shortage of approximately 30%; and in North America, the annual Tc-99m demand decreased from an estimated 20 million unit doses to about 15 million unit doses. Mo-99/Tc-99m is produced from HEU targets, irradiated in NRU for 11 days, and after chemical removal of uranium it is shipped to Nordion in Kanata, Ontario. Nordion further purifies the material and sends it to Lantheus Medical Imaging in the USA for manufacture of Mo-99 generators, which are then distributed to hundreds of hospital radiopharmacies throughout North America. One other American company, Covidien, manufactures and distributes Mo-99 generators like Lantheus, but they import bulk Mo-99 from Europe or South Africa. At the hospitals, Tc-99m is chemically extracted daily from the Mo-99 generators and loaded into syringes for immediate clinical use. Fortuitously, the 66 hour half-life of Mo-99 allows the replenishment of Tc-99m in the generator over a growth period of about 20 hours; and a generator can be 'milked' daily for up to two weeks. A more efficient model is the direct production and distribution of Tc-99m unit doses to regional hospitals from 10 'industrial' radiopharmacies located at existing licensed reactor sites in North America. A 20 kW homogeneous SLOWPOKE reactor at each site would deliver 15 litres of irradiated uranyl sulphate fuel solution daily to industrial-scale hot cells for extraction of Mo-99, which would be incorporated in large Mo-99/Tc-99m generators for extraction of Tc-99m five days a week; and the Low Enriched Uranium (LEU) would be recycled. Each automated hot-cell facility would be designed to load up to 7,000 Tc-99m syringes daily, for courier delivery to all of the Nuclear Medicine hospitals within a 3 hour average range by road transport. Typically, the delivered doses would be in the range 10 to 30 mCi. Assuming an average unit dose of 25 mCi at the hospital and 5 x 52

  9. Thermoelectric and structural properties of a new Chevrel phase: Ti 0.3Mo 5RuSe 8

    Science.gov (United States)

    McGuire, Michael A.; Schmidt, Anneliese M.; Gascoin, Franck; Jeffrey Snyder, G.; DiSalvo, Francis J.

    2006-07-01

    The new Chevrel phase Ti 0.3Mo 5RuSe 8 has been synthesized and characterized by quantitative microprobe analysis, powder X-ray diffraction, and high-temperature thermoelectric properties measurements. The thermoelectric properties of this compound are compared to the previously reported data for other related Chevrel phases. We report also the results of Rietveld analysis of powder X-ray diffraction data for Ti 0.3Mo 5RuSe 8. This compound adopts the rhombohedral Chevrel phase structure (space group R3¯, Z=3) with hexagonal lattice constants a=9.75430(25) Å and c=10.79064(40) Å. The low level of incorporation and low scattering power of Ti precluded the identification of the Ti positions, and Rietveld refinement was carried out only for the Mo 5RuSe 8 framework of Ti 0.3Mo 5RuSe 8 ( Rp=10.5%, Rwp=14.6%). Rietveld analysis was also used to refine the structure of the unfilled phase Mo 5RuSe 8 ( R3¯, Z=3, a=9.63994(8) Å, c=10.97191(11) Å, Rp=8.0%, Rwp=10.5%). Comparisons between the two structures are made.

  10. Study of gels of molybdenum with cerium in the preparation of generators of 99Mo - 99mTc

    OpenAIRE

    Vanessa Moraes; Bárbara Marczewski; Carla Roberta Dias; João Alberto Osso Junior

    2005-01-01

    99mTc has ideal nuclear properties for organ imaging in nuclear medicine, and it is obtained from the 99Mo-99mTc generator. Four different types of generators are available: chromatographic that uses 99Mo from fission of uranium; MEK solvent extraction; Tc2O7 sublimation; gel chromatographic. This work presents the preparation of gel generators of molybdenum with cerium and characterization of the gels: mass ratio between molybdenum and cerium, structure, size of particles and elution percent...

  11. Evaluation of Mo99 and Tc99m Productions Based on a High-Performance Cyclotron

    Directory of Open Access Journals (Sweden)

    J. Esposito

    2013-01-01

    Full Text Available Following preliminary feasibility studies which started at Legnaro National Laboratories (LNL in 2011, the Italian National Institute for Nuclear Physics (INFN research activities are underway aiming at the alternative, accelerator-driven, Mo99/Tc99m production routes. One of the most promising approaches is to use 100Mo-enriched (i.e., >99% molybdenum metallic targets, bombarded with high-beam-current, high-energy proton cyclotrons. In order to get a comprehensive map of radionuclides expected, a detailed theoretical investigation has been carried out using the TALYS-TENDL 2012 excitation functions extended up to (p,6n, (p,p5n, and (p,2p4n levels. A series of quality parameters have thus been calculated both at the end of beam (EOB and at longer times. Results point out that accelerator-99Mo is of limited interest for a possible massive production because of the quite low specific activity with respect to reactor-99Mo. Accelerator-Tc99m quality parameters (i.e., radionuclidic purity (RNP, isotopic purity (IP, and specific activities calculated are instead quite close to the generator-Tc. Calculations at 15, 20, and 25 MeV have thus been performed to assess the best operative irradiation condition for Tc99m production while minimizing both the short-lived and long-lived Tc contaminant radionuclides. Although present in minimum quantities, Tc contaminants may indeed have an impact either on the pharmaceutical labeling procedures or on contributing to patient radiation dose during the diagnostic procedures.

  12. Structural and mechanical properties of transition metal borides Nb2MB2 (M=Tc, Ru, and Os) under pressure

    Science.gov (United States)

    Li, Xiaofeng; Yan, Haiyan; Wei, Qun

    2016-10-01

    First-principle total energy calculations are employed to provide a fundamental understanding of the structural, mechanical, and electronic properties of transition metal borides Nb2MB2 (M=Tc, Ru, and Os) within the tetragonal superstructure P4/mnc structure. The mechanically and dynamically stabilities of three borides have been demonstrated by the elastic constants and phonons calculations under pressure. Among these three compounds, Nb2TcB2 exhibits the biggest bulk and Young's modulus, smallest Poission's ratio, and highest harness. Density of states of them revealed that the strong B-B, Nb-B and M-B covalent bonds are major driving forces for their high bulk and shear moduli as well as small Poisson's ratio.

  13. CO tolerant PtRu-MoO{sub x} nanoparticles supported on carbon nanofibers for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsiouvaras, N.; Pena, M.A.; Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie 2, 28049 Madrid (Spain); Martinez-Huerta, M.V. [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie 2, 28049 Madrid (Spain); Facultad de Quimicas, Universidad de La Laguna, Astrofisico Francisco Sanchez s/n, 38071, La Laguna, Tenerife (Spain); Moliner, R.; Lazaro, M.J. [Instituto de Carboquimica, CSIC, Miguel Luesma Castan 4, 50018 Zaragoza (Spain); Rodriguez, J.L.; Pastor, E. [Facultad de Quimicas, Universidad de La Laguna, Astrofisico Francisco Sanchez s/n, 38071, La Laguna, Tenerife (Spain)

    2009-01-15

    Novel nanostructured catalysts based on PtRu-MoO{sub x} nanoparticles supported on carbon nanofibers have been investigated for CO and methanol electrooxidation. Carbon nanofibers are prepared by thermocatalytic decomposition of methane (NF), and functionalized with HNO{sub 3} (NF.F). Electrocatalysts are obtained using a two-step procedure: (1) Pt and Ru are incorporated on the carbon substrates (Vulcan XC 72R, NF and NF.F), and (2) Mo is loaded on the PtRu/C samples. Differential electrochemical mass spectrometry (DEMS) analyses establish that the incorporation of Mo increases significantly the CO tolerance than respective binary counterparts. The nature of the carbon support affects considerably the stabilization of MoO{sub x} nanoparticles and also the performance in methanol electrooxidation. Accordingly, a significant increase of methanol oxidation is obtained in PtRu-MoO{sub x} nanoparticles supported on non-functionalized carbon nanofiber, in parallel with a large reduction of the Pt amount in comparison with binary counterparts and commercial catalyst. (author)

  14. Evaluation of Pakgen {sup 99m}Tc generators loaded with indigenous fission {sup 99}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Mushtaq, A.; Pervez, S.; Hussain, S.; Mirza, J.A.; Asif, M.; Siddique, M.U.; Khalid, U.; Khan, B.; Khalid, M. [Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan). Isotope Production Div.; Khan, M.M.

    2012-07-01

    Fission produced {sup 99}Mo/{sup 99m}Tc generators, called Pakgen, have been manufactured at the PINSTECH generator production facility since 2000 for nuclear medicine applications in Pakistan. These generators were loaded with fission {sup 99}Mo imported from NTP South Africa. Recently production of fission {sup 99}Mo has begun in the Molybdenum-99 Production Facility at PINSTECH. Prior to use in the clinic, eight sets of generators were produced, 23 GBq and 74 GBq at time of calibration, and they were subjected to various quality control procedures recommended in the pharmacopoeia to assess their performance. The elution profile, volume, activity, pH, radionuclidic, chemical, radiochemical and biological purity, and expiry time of the eluates were examined. Labeling efficiency tests were also carried out with a number of the more widely used in vivo radiopharmaceutical kits like DTPA, MDP and MIBI. Performance of {sup 99m}Tc generators loaded with locally produced and imported fission {sup 99}Mo was comparable, and the users of Pakgen generators were fully satisfied. The effect of a wet vs. a dry column on {sup 99m}Tc yields of generators loaded with low and high activity was also studied for the first time. (orig.)

  15. Targetry of MoO3 on a copper substrate for the no-carrier-added 94mTC production via 94Mo(p,n)94mTc reaction

    Institute of Scientific and Technical Information of China (English)

    SADEGHI Mahdi; KAKAVAND Tayeb; AREF Morteza; SARABADANI Parvin

    2009-01-01

    94mTc was produced via natMo(p,xn)94mTc reaction.Deposition of MoO3 on Cu substrate was carried out via two special sedimentation methods for the production of 94mTc.The 533 mg of MoO3,600 μL of collodium (nitrocellulose) and 3 mL of acetone were used to prepare a MoO3 layer of 11.69 cm2 and 45.81 mg.cm-2.Also,a MoO3 layer was prepared by 533 mg of MoO3,71.188 mg of methylcellulose and 4 mL of water.The targets were checked by SEM and thermal shock test.

  16. Performance tests on column materials for {sup 99}Mo-{sup 99m}Tc generator

    Energy Technology Data Exchange (ETDEWEB)

    Sombrito, E.Z.; Bulos, A.D.; Tangonan, M.C. [Chemistry Research Section, Atomic Research Div., Philippine Nuclear Research Inst., Quezon (Philippines)

    1998-10-01

    To meet the need of producing a {sup 99}Mo-{sup 99m}Tc generator, based on low specific activity reactor-produced {sup 99}Mo, different procedures for preparing zirconium molybdate gels were tested. Performance tests were done on molybdate gel columns prepared using the procedures developed by Vietnam and China, and recently, on a polyzirconium compound (PZC) prepared in Japan. The conditions for the batch drying of a large volume of the gel material were studied as well as the conditions in preparing a column to concentrate technetium-99m. The performance of PZC sample as column material for the generator was also evaluated. (author)

  17. Influence of the irradiation time on the activity of decay products during the cooling. Case: Mo-98 {yields} Mo-99 {yields} Tc-99m; Influencia del tiempo de irradiacion en la actividad de los productos de decaimiento durante el enfriamiento. Caso: Mo-98 {yields} Mo-99 {yields} Tc-99m

    Energy Technology Data Exchange (ETDEWEB)

    Reyes J, J.L.; Ruiz C, M.A.; Alanis M, J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    In this work the behavior of the activity in the cooling time of Mo-99, Tc-99 and Tc-99m obtained by Neutron activation of natural Mo is described. The analytical development is based on the application of the Laplace transform for resolving the balance equations. (Author)

  18. Preperation and performance of {sup 99}Mo/{sup 99m}Tc chromatographic column generator based on zirconium molybdosilicate

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, M.; Saber, H.M.; El-Sadek, A.A. [Atomic Energy Authority, Cairo (Egypt). Hot Labs. Center; Nassar, M.Y. [Benha Univ. (Egypt). Chemistry Dept.

    2016-08-01

    Zirconium molybdosilicate (ZrMoSi) gel prepared using {sup 99}Mo radiotracer via peroxo route was used as a base material for {sup 99}Mo/{sup 99m}Tc column generator. The {sup 99m}Tc elution yield and {sup 99}Mo breakthrough in the eluate were studied as a function of the pH-value of gel precipitation, gel drying temperature and Zr: Mo: Si molar ratio. Precipitation pH-value of 2, drying temperature of 100 C and Zr: Mo: Si molar ratio of 0.5: 0.5: 1 were found to be the optimum conditions achieving {sup 99m}Tc elution yield of 82% and {sup 99}Mo breakthrough of 1.0 x 10{sup -3}%. The gel prepared with the optimum conditions was characterized by BET surface area and pore size analyzer, IR spectroscopy, thermal analysis (TGA and DTA), XRD, XRF and FESEM. Technetium-99m eluted from the optimum ZrMoSi {sup 99}Mo/{sup 99m}Tc generator was found to have a high radiochemical purity (98% as {sup 99m}TcO{sub 4}{sup -}) and chemical purity meeting criteria of clinical grade.

  19. Magnetic properties and microstructure of FePt/MoC/CrRu films

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Jai-Lin, E-mail: tsaijl@dragon.nchu.edu.tw; Luo, Qi-Shao; Chen, Po-Ran; Tseng, Yun-Ting

    2015-05-15

    The FePt films with thickness of 4−10 nm were deposited on MoC/CrRu/glass at substrate temperature ranged from 260 to 410 °C by using magnetron sputtering and strong (001) textured FePt films were obtained at 380 °C and 410 °C. The multi-functional MoC conductive intermediate layer was used to resist the Cr diffusion and promote the epitaxial growth of the (001) textured FePt film which shows perpendicular magnetization and a linear-like in-plane magnetic loop. The out-of plane coercivity and shape of demagnetization curve were dominated by the ordering degree and perpendicular magnetic anisotropy which were increased with deposited temperature. The FePt film deposited at 290 °C shows continuous morphology and change to interconnected structure at 350 °C and finally form the island like structure at 380 °C and 410 °C. Each island contains many FePt grains and the smaller grains size was 12.2 nm which obtained at 5 nm thick FePt film. Perpendicular anisotropy of 1.1×10{sup 7} erg/cm{sup 3} and coercivity of 8.2 kOe have been demonstrated in 7 nm thick FePt film. - Highlights: • The MoC conductive intermediate layer was resisted the Cr diffusion. • The MoC layer promote the epitaxial growth of (001) textured FePt film. • The FePt film shows perpendicular magnetization on MoC layer.

  20. Cyclotron production of ⁹⁹mTc: recycling of enriched ¹⁰⁰Mo metal targets.

    Science.gov (United States)

    Gagnon, K; Wilson, J S; Holt, C M B; Abrams, D N; McEwan, A J B; Mitlin, D; McQuarrie, S A

    2012-08-01

    There is growing interest in the large scale cyclotron production of (99m)Tc via the (100)Mo(p,2n)(99m)Tc reaction. While the use and recycling of cyclotron-irradiated enriched molybdenum targets has been reported previously in the context of (94m)Tc production, to the best of our knowledge, previous recycling studies have been limited to the use of oxide targets. To facilitate reuse of high-power enriched (100)Mo targets, this work presents and evaluates a strategy for recycling of enriched metallic molybdenum. For the irradiated (100)Mo targets in this study, an overall metal to metal recovery of 87% is reported. Evaluation of "new" and "recycled" (100)Mo revealed no changes in the molybdenum isotopic composition (as measured via ICP-MS). For similar irradiation conditions of "new" and "recycled" (100)Mo, (i.e. target thicknesses, irradiation time, and energy), comparable levels of (94g)Tc, (95g)Tc, and (96g)Tc contaminants were observed. Comparable QC specifications (i.e. aluminum ion concentration, pH, and radiochemical purity) were also reported. We finally note that [(99m)Tc]-MDP images obtained by comparing MDP labelled with generator-based (99m)Tc vs. (99m)Tc obtained following the irradiation of recycled (100)Mo demonstrated comparable biodistribution. With the goal of producing large quantities of (99m)Tc, the proposed methodology demonstrates that efficient recycling of enriched metallic (100)Mo targets is feasible and effective.

  1. Preparation of a gel of zirconium molybdate for use in generators of {sup 99} Mo - {sup 99m} Tc prepared with {sup 99} Mo produced by the {sup 98} Mo(n,{gamma}){sup 99} Mo reaction

    Energy Technology Data Exchange (ETDEWEB)

    Osso Junior, Joao A.; Lima, Ana Lucia V.P.; Silva, Nestor C. da; Nieto, Renata C.; Velosa, Adriana C. de [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: jaosso@net.ipen.br

    1998-07-01

    IPEN develops a project concerning the preparation of a gel of Zirconium Molybdate for use in the generators of {sup 99} Mo-{sup 99m} Tc . {sup 99m} Tc is the most used radioisotope in nuclear medicine diagnosis procedures and nowadays the generators are being prepared with imported {sup 99} Mo, produced by {sup 235} U fission. The production of {sup 99} Mo by the {sup 98} Mo(n, {gamma}){sup 99} Mo reaction is now possible because of the power upgrade of IPEN's IEA-R1 reactor, from 2 to 5 MW. This work describes the preparation method of Zirconium Molybdate gel that will be used in the {sup 99} Mo-{sup 99m} Tc generators. The gel is prepared by the chemical reaction between Mo, in Mo O{sub 3} form, and Zr, in Zr O Cl{sub 2}.8H{sub 2}O form. After the reaction, the gel is filtered, dried and cracked with saline solution. The product is then loaded into glass columns for use as {sup 99m} Tc generator. The results showed the good quality of the gel prepared at laboratory level and of the generators evaluated. (author)

  2. Increased rigidly triaxial deformations in neutron-rich Mo, Ru isotopes

    Science.gov (United States)

    Liang, WuYang; Jiao, ChangFeng; Xu, FuRong; Fu, XiMing

    2016-09-01

    Pairing-deformation-frequency self-consistent crankingWoods-Saxon model is employed to investigate the triaxiality in the ground states of the neutron-rich even-even Mo, Ru isotopes. Deformation evolutions and transition probabilities have been studied, giving the triaxial shapes in their ground states. The kinematic moments of inertia have been calculated to illustrate the gradually rigid deformation. To understand the origin of the asymmetry shape in this region, we analyze the evolution of single-particle orbits with changing γ deformation. The present calculations reveal the importance of the triaxial deformation in describing not only static property, but also rotational behaviors in this mass region, providing significant probes into the shell structure around.

  3. On the 'artificial' nature of Tc and the 'carrier-free' nature of {sup 99m}Tc from {sup 99}Mo/{sup 99m}Tc generators

    Energy Technology Data Exchange (ETDEWEB)

    Alfassi, Zeev B. [Department of Nuclear Engineering, Ben Gurion University, Beer Sheva, 84105 (Israel)]. E-mail: alfassi@bgumail.bgu.ac.il; Groppi, Flavia [Universita degli Studi and INFN-Milano, LASA, Radiochemistry Laboratory Via F.lli Cervi 201, 20090 Segrate, Milan (Italy); Bonardi, Mauro L. [Interfaculty Reactor Institute Delft, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Goeij, Jeroen J.M. de [Interfaculty Reactor Institute Delft, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)

    2005-07-01

    Two widespread misconceptions regarding Tc are dealt with. First, it is shown that although primordial Tc has decayed completely, Tc is still present in nature due to natural processes, in addition to substantial man-made quantities. Thus, Tc cannot be considered as a purely artificial element. Second, it is shown that {sup 99m}Tc from {sup 99}Mo/{sup 99m}Tc generators is certainly not carrier-free (CF) and that, 'no-carrier-added' (NCA) is a more appropriate designation. As a quantitative measure of the amount of long-lived {sup 99g}Tc carrier present in {sup 99m}Tc preparations from generators, the Isotope Dilution Factor (IDF) is used and calculated for some practical situations.

  4. Synthesis and characterization of zirconium molybdates of {sup 99} Mo/{sup 99m} Tc generators; Sintesis y caracterizacion de molibdatos de zirconio de generadores {sup 99} Mo/{sup 99m} Tc

    Energy Technology Data Exchange (ETDEWEB)

    Contreras R, A.; Monroy G, F.; Diaz A, L.V. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The zirconium molybdates are gels which are used as cation exchangers in the production of {sup 99} Mo/{sup 99m} Tc generators. The synthesis method and the characterization of these gels by thermogravimetry, infrared spectroscopy and X-ray diffraction is presented with the purpose of finding which the factors are that influence in the efficiency of the {sup 99m} Tc production. The results show that the quantity of molecular water contained in gel, is possibly the cause of variations of the efficiencies of the {sup 99} Mo/{sup 99m} Tc generator. (Author)

  5. Bandgap renormalization and work function tuning in MoSe2/hBN/Ru(0001) heterostructures

    Science.gov (United States)

    Zhang, Qiang; Chen, Yuxuan; Zhang, Chendong; Pan, Chi-Ruei; Chou, Mei-Yin; Zeng, Changgan; Shih, Chih-Kang

    2016-12-01

    The van der Waals interaction in vertical heterostructures made of two-dimensional (2D) materials relaxes the requirement of lattice matching, therefore enabling great design flexibility to tailor novel 2D electronic systems. Here we report the successful growth of MoSe2 on single-layer hexagonal boron nitride (hBN) on the Ru(0001) substrate using molecular beam epitaxy. Using scanning tunnelling microscopy and spectroscopy, we found that the quasi-particle bandgap of MoSe2 on hBN/Ru is about 0.25 eV smaller than those on graphene or graphite substrates. We attribute this result to the strong interaction between hBN/Ru, which causes residual metallic screening from the substrate. In addition, the electronic structure and the work function of MoSe2 are modulated electrostatically with an amplitude of ~0.13 eV. Most interestingly, this electrostatic modulation is spatially in phase with the Moiré pattern of hBN on Ru(0001) whose surface also exhibits a work function modulation of the same amplitude.

  6. {sup 99}Mo/{sup 99m}Tc generators performances prepared from zirconium molybdate gels

    Energy Technology Data Exchange (ETDEWEB)

    Monroy-Guzman, Fabiola; Diaz-Archundia, Laura Veronica; Hernandez-Cortes, Sabino [Instituto Nacional de Investigaciones Nucleares, Estado de Mexico (Mexico)]. E-mail: fmg@nuclear.inin.mx

    2008-07-01

    {sup 99m}Tc may be produced from {sup 99}Mo/{sup 99m}Tc zirconium molybdate gel generators. These gels are part of the generator matrix and their chemical and physical characteristics directly influence the generator performances. In this work zirconium molybdate gels were synthesized under different preparation conditions and characterized by TGA, IR and INAA. Our goal was to investigate and correlate generator performance with the physical-chemical properties of the gel. The two factors studied were the molybdate solution pH and the preparation conditions of the zirconyl salt solutions. Several polymolybdate and zirconium species can be formed in solution which can inhibit or favor the zirconium molybdate gel formation or the insoluble polymolybdate-rich and zirconium oxy-hydroxide phases. The {sup 99}Mo/{sup 99m}Tc gel generator performance is directly correlated with gel structures. More regular network gels present lower generator performances compared to gels with more flexible random framework. The physico-chemical properties of the gels as well as their behavior as technetium-99m generators are presented and discussed. (author)

  7. An electrochemical procedure to concentrate {sup 99m}Tc availed from a zirconium [{sup 99}Mo] molybdate gel generator

    Energy Technology Data Exchange (ETDEWEB)

    Chakravarty, Rubel [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Sarkar, S.K. [Radiopharmaceuticals Laboratory, Board of Radiation and Isotope Technology, Navi Mumbai 400705 (India); Venkatesh, Meera [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Dash, Ashutosh, E-mail: adash@barc.gov.in [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2012-02-15

    Successful use of electrochemical method to concentrate {sup 99m}Tc obtained from a zirconium molybdate (Zr{sup 99}Mo) gel generator is reported. The process consists of electrodeposition of the {sup 99m}Tc in an oxalate bath on a small platinum electrode followed by recovery of {sup 99m}Tc in a small volume of normal saline. The overall recovery of {sup 99m}Tc was >90% with >99.99% radionuclidic purity and >99% radiochemical purity. The compatibility of the product in the preparation of {sup 99m}Tc labeled formulations such as {sup 99m}Tc-DMSA and {sup 99m}Tc-EC was found to be satisfactory in terms of high labeling yields (>98%). - Highlights: Black-Right-Pointing-Pointer Utility of electrochemical technique to concentrate {sup 99m}Tc obtained from an expired Zr{sup 99}Mo gel generator. Black-Right-Pointing-Pointer Optimization of experimental conditions for quantitative deposition of {sup 99m}Tc. Black-Right-Pointing-Pointer Evaluation of quality features of the concentrated {sup 99m}TcO{sub 4}{sup -} solution for radiopharmaceutical applications.

  8. First decay scheme of Tc-113 and identification of Ru-113(m)

    NARCIS (Netherlands)

    Kurpeta, J; Lhersonneau, G; Wang, JC; Dendooven, P; Honkanen, A; Huhta, M; Oinonen, M; Penttila, H; Perajarvi, K; Persson, B.L.; Plochocki, A; Aysto, J

    1998-01-01

    Very neutron-rich fission products of the mass chain A=113 obtained from the IGISOL on-line mass separator have been investigated by gamma gamma coincidence techniques and gamma-spectra multiscaling. Gamma-rays following beta-decay of Tc-113 have been observed for the first time and a new 0.5 s isom

  9. Production optimization of 99Mo/99mTc zirconium molybate gel generators at semi-automatic device: DISIGEG.

    Science.gov (United States)

    Monroy-Guzman, F; Rivero Gutiérrez, T; López Malpica, I Z; Hernández Cortes, S; Rojas Nava, P; Vazquez Maldonado, J C; Vazquez, A

    2012-01-01

    DISIGEG is a synthesis installation of zirconium (99)Mo-molybdate gels for (99)Mo/(99m)Tc generator production, which has been designed, built and installed at the ININ. The device consists of a synthesis reactor and five systems controlled via keyboard: (1) raw material access, (2) chemical air stirring, (3) gel dried by air and infrared heating, (4) moisture removal and (5) gel extraction. DISIGEG operation is described and dried condition effects of zirconium (99)Mo- molybdate gels on (99)Mo/(99m)Tc generator performance were evaluated as well as some physical-chemical properties of these gels. The results reveal that temperature, time and air flow applied during the drying process directly affects zirconium (99)Mo-molybdate gel generator performance. All gels prepared have a similar chemical structure probably constituted by three-dimensional network, based on zirconium pentagonal bipyramids and molybdenum octahedral. Basic structural variations cause a change in gel porosity and permeability, favouring or inhibiting (99m)TcO(4)(-) diffusion into the matrix. The (99m)TcO(4)(-) eluates produced by (99)Mo/(99m)Tc zirconium (99)Mo-molybdate gel generators prepared in DISIGEG, air dried at 80°C for 5h and using an air flow of 90mm, satisfied all the Pharmacopoeias regulations: (99m)Tc yield between 70-75%, (99)Mo breakthrough less than 3×10(-3)%, radiochemical purities about 97% sterile and pyrogen-free eluates with a pH of 6.

  10. Comparative study of {sup 99}Mo/{sup 99m}Tc generators at base of synthesized gels starting from {sup 99}Mo of activation and of fission; Estudio comparativo de generadores {sup 99}Mo/{sup 99m}Tc a base de geles sintetizados a partir de {sup 99}Mo de activacion y de fision

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, I.Z. [Universidad Autonoma del Estado de Mexico, Paseo Colon esq. Paseo Tollocan C.P. 50120, Toluca, Estado de Mexico (Mexico); Monroy G, F.; Rivero G, T.; Rojas N, P. [ININ, Carretera Me' xico -Toluca S/N C.P. 52045 La Marquesa Ocoyoacac Estado de Mexico (Mexico)]. e-mail: Liris_zoet@hotmail.com

    2007-07-01

    At the present time the more used and diffused radionuclide in nuclear medicine it is the Technetium 99 metastable ({sup 99}mTc) it is used for diagnostic and therapy. It is produced starting from molybdenum 99 ({sup 99}Mo), which is absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of {sup 99}Mo situation that forces to use high specific activities of {sup 99}Mo that it is obtained starting from the fission of the {sup 235}U. Given these conditions and limitations, new preparation procedures of {sup 99}Mo/{sup 99m}Tc generators, of low or medium specific activity, its have been developed, using gels of zirconium molybdates that incorporates until 30% in weight of {sup 99}Mo in the gel, and also conserve similar characteristics of quality and purity that those obtained by the traditional generator; reducing by this way the cost of production of the {sup 99m}Tc, when using {sup 99}Mo of low specific activity, in the preparation of {sup 99}Mo/{sup 99m}Tc generators. The radiochemical characteristics of the elution of {sup 99m}Tc, depends strongly on the gel preparation conditions. In particular, the present work has for object to determine the influence of the used type of {sup 99}Mo, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the quality of the {sup 99}Mo/{sup 99m}Tc generators. When diminishing the agitation air flow the efficiency it increases and in the radionuclide purity of the eluates and when using {sup 99}Mo of fission for the gels production it increases in an important way the elution efficiency, the radiochemical purity and radionuclide of the eluates of {sup 99m}Tc. (Author)

  11. Study of the viability of hydroxyapatite as matrix of the generator {sup 99} Mo/{sup 99m} Tc; Estudio de la viabilidad de la hidroxiapatita como matriz del generador {sup 99} Mo/{sup 99m} Tc

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar D, I.C.; Badillo A, V.E. [UAZ, Unidad Academica de Ciencias Quimicas, 98600 Guadalupe, Zacatecas (Mexico); Monroy G, F. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: itzelaguilar@hotmail.com

    2004-07-01

    The generator more used in the nuclear medicine it is the generator {sup 99} Mo / {sup 99} Tc. The separation of {sup 99}Mo and {sup 99m}Tc in the commercial generator is carried out on a column that contains alumina (Al{sub 2}0{sub 3}). The adsorbent proposed in this investigation work, the hydroxyapatite, is an insoluble solid considered within of the fixers of anions more important. To evaluate the efficiency of the hydroxyapatite in the separation of the Mo and the Tc they were carried out preliminary tests to know the likeness of the one been accustomed to by the molybdate ions (MoO{sub 4}{sup -2}) and the pertechnetate ions (Tc0{sub 4}{sup -}) in function of the value of the p H, in a solution of CaCI{sub 2} 0.01 M. For the study of the retention of the molybdate ion, it was used the radioisotope Mo-99 fission product, and for the pertechnetate ion it was used the Tc- 99 m radionuclide son of the Mo-99. The obtained results in a solution of CaCl{sub 2} 0.01 M to different values of p H of the solution, show that the fixation of the pertechnetate ions (TcO{sub 4}{sup -}) and the fixation of the molybdate ions (MoO{sub 4}{sup -2}), they present very different behaviors in the hydroxyapatite. The results indicate that the synthetic hydroxyapatite BIO-RAD retains to the molybdate ion to values of lightly acid p H (5-6), being the retention of the pertechnetate practically worthless. (Author)

  12. Comparative study of {sup 99}Mo/{sup 99m}Tc generators at base of synthesized gels starting from activation and fission {sup 99}Mo; Estudio comparativo de generadores {sup 99}Mo/{sup 99m}Tc a base de geles sintetizados a partir de {sup 99}Mo de activacion y de fision

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, I.Z. [UAEM, Paseo Colon esq. Paseo Tollocan, 50120 Toluca, Estado de Mexico (Mexico); Monroy G, F.; Rivero G, T.; Rojas N, P. [ININ, Carretera Mexico -Toluca S/N, 52045 La Marquesa Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: Liris_zoet@hotmail.com

    2007-07-01

    The {sup 99m}Tc is used for diagnostic and therapy. It is produced starting from {sup 99}Mo, absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of {sup 99}Mo with high specific activities of {sup 99}Mo, obtained from the {sup 235}U fission. Given these conditions and limitations, new preparation procedures of {sup 99}Mo/{sup 99m}Tc generators, its have been developed, using zirconium molybdates gels that incorporates until 30% of {sup 99}Mo, conserve similar characteristics of quality and purity that the traditional generator. The radiochemical characteristics of the {sup 99m}Tc elution, depend strongly on the gel preparation conditions. In particular, the present work has by object to determine the influence of the {sup 99}Mo used type, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the {sup 99}Mo/{sup 99m}Tc generators quality. When diminishing the flow of agitation air the efficiency it increases and in the radionuclide purity of the eluates and when using {sup 99}Mo from fission for the gels production it increases in an important way the elutriation efficiency, the radiochemical and radionuclide purity of the {sup 99m}Tc eluates. (Author)

  13. Comparison of Two Preparation Methods on Catalytic Activity and Selectivity of Ru-Mo/HZSM5 for Methane Dehydroaromatization

    Directory of Open Access Journals (Sweden)

    Lucia M. Petkovic

    2014-01-01

    Full Text Available Catalytic performance of Mo/HZSM5 and Ru-Mo/HZSM5 catalysts prepared by vaporization-deposition of molybdenum trioxide and impregnation with ammonium heptamolybdate was analyzed in terms of catalyst activity and selectivity, nitrogen physisorption analyses, temperature-programmed oxidation of carbonaceous residues, and temperature-programmed reduction. Vaporization-deposition rendered the catalyst more selective to ethylene and coke than the catalyst prepared by impregnation. This result was assigned to lower interaction of molybdenum carbide with the zeolite acidic sites.

  14. A new 2D monolayer BiXene, M2C (M = Mo, Tc, Os).

    Science.gov (United States)

    Sun, Weiwei; Li, Yunguo; Wang, Baotian; Jiang, Xue; Katsnelson, Mikhail I; Korzhavyi, Pavel; Eriksson, Olle; Di Marco, Igor

    2016-08-25

    The existence of BiXenes, a new family of 2D monolayers, is hereby predicted. Theoretically, BiXenes have 1H symmetry (P6[combining macron]m2) and can be formed from the 4d/5d binary carbides. As the name suggests, they are close relatives of MXenes, which instead have 1T symmetry (P3[combining macron]m1). The newly found BiXenes, as well as some new MXenes, are shown to have formation energies close to that of germanene, which suggests that these materials should be possible to be synthesised. Among them, we illustrate that 1H-Tc2C and 1T-Mo2C are dynamically stable at 0 K, while 1H-Mo2C, 1T-Tc2C, 1H-Os2C, and 1T-Rh2C are likely to be stabilised via strain or temperature. In addition, the nature of the chemical bonding is analysed, emphasizing that the covalency between the transition metal ions and carbon is much stronger in BiXenes than in MXenes. The emergence of BiXenes can not only open up a new era of conducting 2D monolayers, but also provide good candidates for carrier materials aimed at energy storage and spintronic devices that have already been unveiled in MXenes.

  15. Use of 99mTc from a commercial 99Mo/9mTc generator as yield tracer for the determination of 99Tc at low levels

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Jensen, Mikael; Nielsen, Sven Poul

    2007-01-01

    cartridges was investigated to purify the eluate to obtain a suitable Tc-99m tracer with low Tc-99 concentration. The activity ratio of Tc-99/Tc-99m in the prepared Tc-99m solution is lower than 15 x 10(-9), which is higher than the theoretical ratio of less than 10 x 10(-9). The possible reason is discussed......) 2007 Elsevier Ltd. All rights reserved....

  16. Distortion, interaction, and conceptual DFT perspectives of MO4-alkene (M = Os, Re, Tc, Mn) cycloadditions.

    Science.gov (United States)

    Ess, Daniel H

    2009-02-20

    The reaction pathways (including the transition states) of ethylene addition to osmium tetroxide (OsO(4), and amine ligated), rhenate (ReO(4)(-)), technetate (TcO(4)(-)), and permanganate (MnO(4)(-)) have been studied by qualitative and quantitative analyses. Distortion/interaction and absolutely localized energy decomposition analyses provide new insights into why the (3 + 2) pathway is highly preferred over the (2 + 2) pathway, the origin of rate enhancement from ligated base, and reactivity differences between OsO(4), ReO(4)(-), TcO(4)(-), and MnO(4)(-). The (2 + 2) transition state has a much larger barrier than the (3 + 2) transition state because (1) the Os-O bond is stretched significantly resulting in a larger distortion energy (DeltaE(d)(double dagger)) value and (2) the transition state interaction energy (DeltaE(i)(double dagger)) is destabilizing due to large exchange repulsions overwhelming stabilizing charge-transfer terms. Base ligation lowers osmium tetroxide and ethylene distortion energies due to the ground-state O-Os-O angle being predistorted from 110 degrees to 103 degrees. Because MO(4) distortion energies are comparable, reactivity differences between OsO(4), ReO(4)(-), TcO(4)(-), and MnO(4)(-) is shown to be a function of ethylene to MO(4) charge-transfer. This interaction also dictates the position of the transition state along the reaction coordinate and corresponds to the onset of a stabilizing DeltaE(i)(double dagger) value. The conceptual DFT hardness profile and hardness response show that the (3 + 2) reaction pathway may be classified as an "allowed" pathway while the (2 + 2) reaction coordinate is best designated as "forbidden".

  17. Cyclotron production of {sup 99m}Tc: Experimental measurement of the {sup 100}Mo(p,x){sup 99}Mo, {sup 99m}Tc and {sup 99g}Tc excitation functions from 8 to 18 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, Katherine, E-mail: kgagnon1@ualberta.ca [Edmonton PET Centre, Cross Cancer Institute, University of Alberta, Edmonton, AB (Canada); Benard, Francois [BC Cancer Agency, Vancouver, BC (Canada); Kovacs, Michael [Lawson Health Research Institute, London, ON (Canada); Ruth, Thomas J.; Schaffer, Paul [TRIUMF, Vancouver, BC (Canada); Wilson, John S.; McQuarrie, Steve A. [Edmonton PET Centre, Cross Cancer Institute, University of Alberta, Edmonton, AB (Canada)

    2011-08-15

    Introduction: The cyclotron-based {sup 100}Mo(p,2n){sup 99m}Tc transformation has been proposed as a viable alternative to the reactor based {sup 235}U(n,f){sup 99}Mo{yields}{sup 99m}Tc strategy for production of {sup 99m}Tc. Despite efforts to theoretically model the amount of ground-state {sup 99g}Tc present at end of bombardment for the (p,2n) reaction, experimental validation has yet to be performed. The co-production of {sup 99g}Tc may have important implications in both the subsequent radiopharmaceutical chemistry and patient dosimetry upon injection. Methods: To determine the extent of {sup 99g}Tc co-production, we have experimentally measured the {sup 100}Mo(p,x){sup 99}Mo, {sup 99m}Tc, and {sup 99g}Tc excitation functions in the 8-18 MeV range using a combination of natural abundance and 97.42% enriched {sup 100}Mo foils along with {gamma}-ray spectrometry and ICP-MS. Although the excitation functions for production of {sup 99}Mo and {sup 99m}Tc have been presented previously in the literature, to the best of our knowledge, this work presents the first experimental evaluation of the {sup 100}Mo(p,2n){sup 99g}Tc excitation function. Results: From the experimental cross-section measurements, the {sup 99m}Tc production yields and {sup 99m}Tc/{sup 99m+g}Tc nuclei ratio were calculated for various thick target irradiation conditions. Results suggest that TBq quantities of {sup 99m}Tc can be achieved with a {sup 99m}Tc/{sup 99m+g}Tc nuclei ratio that is on par with the current {sup 99}Mo/{sup 99m}Tc generator standard eluted at a 24-h frequency. Conclusion: These findings suggest that the cyclotron production of {sup 99m}Tc may be a feasible alternative to the current reactor-based production strategy.

  18. AB-INITIO STUDY OF BULK MODULUS AND CHARGE DENSITY OF CUBIC SrMO3 PEROVSKITES (M = Ti, Zr, Mo, Rh, Ru

    Directory of Open Access Journals (Sweden)

    AVINASH DAGA

    2012-03-01

    Full Text Available Bulk modulus & charge density of cubic SrMO3 perovskites (M = Ti, Zr, Mo, Rh & Ru have been investigated systematically using the first principle density functional calculations. Local density approximation (LDAmethod has been used to compute the two quantities for five perovskites. It is found that the calculated bulk modulus for all the transition metal oxides are in good agreement with the available experimental data and with other theoretical results previously reported in the literature. ABINIT computer code is used to carry out all the calculations. Charge density plots for all the five cubic SrMO3 perovskites have been drawn using MATLAB. The maximum and minimum values of charge density along with the corresponding reduced coordinates are reported for all the perovskites.

  19. Synthesis and irradiation of titanium molybdates used as matrices of the {sup 99} Mo/ {sup 99m} Tc generators; Sintesis e irradiacion de molibdatos de titanio utilizados como matrices de los generadores de {sup 99} Mo/ {sup 99m} Tc

    Energy Technology Data Exchange (ETDEWEB)

    Diaz V, H. [Facultad de Quimica, UAEM 50000 Toluca, Estado de Mexico (Mexico); Monroy G, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2005-07-01

    The {sup 99m} Tc is the radioisotope but used in nuclear medicine. Commercially it takes place starting from generators of {sup 99} Mo/{sup 99m} Tc, composed by a chromatography column padded of aluminium oxide of aluminum, where it is deposited the {sup 99} Mo, product of the fission of the {sup 235} U adsorbed and eluted, by means of a saline solution, in form of {sup 99m} TcO{sub 4}{sup -}. The production of {sup 99} Mo as a result of the fission, imposes radiochemical separations that generate significant quantities of radioactive waste of medium activity, and inflict elaborated radiochemical manipulation. Due to this, its have been carried out intense investigations to substitute the {sup 99} Mo fission product, by chemical compounds that produce {sup 99} Mo via the reaction {sup 98} Mo(n, {gamma}){sup 99} Mo. Presently work intends the use of gels of titanium molybdates like matrices of these generators. Titanium molybdates were synthesized starting from solutions TiCl{sub 3} and ammonium molybdates and it was studied the effect of the final pH of the gels, the concentration of the Ti{sup +3} and the influence of the laundry of these on the acting of generators. The best efficiencies and chemical purity, radiochemical and radionuclides of the gels like matrices of generators {sup 99} Mo/{sup 99m} Tc were gotten with the washed gel, elaborated with the solution of TiCI{sub 3} 0.35M, and to a final pH of 5.9 (Author)

  20. Feasibility studies towards future self-sufficient supply of the (99)Mo-(99m)Tc isotopes with Japanese accelerators.

    Science.gov (United States)

    Nakai, Kozi; Takahashi, Naruto; Hatazawa, Jun; Shinohara, Atsushi; Hayashi, Yoshihiko; Ikeda, Hayato; Kanai, Yasukazu; Watabe, Tadashi; Fukuda, Mitsuhiro; Hatanaka, Kichiji

    2014-01-01

    In order to establish a self-sufficient supply of (99m)Tc, we studied feasibilities to produce its parent nucleus, (99)Mo, using Japanese accelerators. The daughter nucleus, (99m)Tc, is indispensable for medical diagnosis. (99)Mo has so far been imported from abroad, which is separated from fission products generated in nuclear reactors using enriched (235)U fuel. We investigated (99m)Tc production possibilities based on the following three scenarios: (1) (99)Mo production by the (n, 2n) reaction by spallation neutrons at the J-PARC injector, LINAC; (2) (99)Mo production by the (p, pn) reaction at Ep = 50-80 MeV proton at the RCNP cyclotron; (3) (99m)Tc direct production with a 20 MeV proton beam from the PET cyclotron. Among these three scenarios, scenario (1) is for a scheme on a global scale, scenario (2) works in a local area, and both cases take a long time for negotiations. Scenario (3) is attractive because we can use nearly 50 PET cyclotrons in Japan for (99m)Tc production. We here consider both the advantages and disadvantages among the three scenarios by taking account of the Japanese accelerator situation.

  1. Feasibility studies towards future self-sufficient supply of the 99Mo-99mTc isotopes with Japanese accelerators

    Science.gov (United States)

    NAKAI, Kozi; TAKAHASHI, Naruto; HATAZAWA, Jun; SHINOHARA, Atsushi; HAYASHI, Yoshihiko; IKEDA, Hayato; KANAI, Yasukazu; WATABE, Tadashi; FUKUDA, Mitsuhiro; HATANAKA, Kichiji

    2014-01-01

    In order to establish a self-sufficient supply of 99mTc, we studied feasibilities to produce its parent nucleus, 99Mo, using Japanese accelerators. The daughter nucleus, 99mTc, is indispensable for medical diagnosis. 99Mo has so far been imported from abroad, which is separated from fission products generated in nuclear reactors using enriched 235U fuel. We investigated 99mTc production possibilities based on the following three scenarios: (1) 99Mo production by the (n, 2n) reaction by spallation neutrons at the J-PARC injector, LINAC; (2) 99Mo production by the (p, pn) reaction at Ep = 50–80 MeV proton at the RCNP cyclotron; (3) 99mTc direct production with a 20 MeV proton beam from the PET cyclotron. Among these three scenarios, scenario (1) is for a scheme on a global scale, scenario (2) works in a local area, and both cases take a long time for negotiations. Scenario (3) is attractive because we can use nearly 50 PET cyclotrons in Japan for 99mTc production. We here consider both the advantages and disadvantages among the three scenarios by taking account of the Japanese accelerator situation. PMID:25504230

  2. Theoretical spectroscopic constants for the low-lying states of the oxides and sulfides of Mo and Tc

    Science.gov (United States)

    Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.; Pettersson, Lars G. M.; Siegbahn, Per E. M.

    1989-01-01

    Spectroscopic results were determined for the ground and low-lying states of the oxides and sulfides of Mo and Tc, using the single-reference-based modified coupled pair functional method of Ahlrichs et al. (1985) and Chong et al. (1986) and the multireference-based state-averaged CASSCF/MRCI method. Spectroscopic constants, dipole moments, Mulliken populations, and radiative lifetimes were calculated for selected low-lying states of these molecular systems. The spectroscopy of the MoS and TcS molecules was found to be quite analogous to the corresponding oxides.

  3. Determination of 99Mo contamination in a nuclear medicine patient submitted to a diagnostic procedure with 99mTc

    Directory of Open Access Journals (Sweden)

    Bernardo Maranhão Dantas

    2005-10-01

    Full Text Available 99mTc is a radionuclide widely used for imaging diagnosis in nuclear medicine. In Brazil it is obtained by elution from 99Mo-99mTc generators supplied by the Nuclear Energy Research Institute (IPEN. The elution is carried out in radiopharmacy laboratories located in hospitals and clinics. Depending of the quality of the generator and conditions of use during the elution process, 99Mo can be extracted from the column of the generator, becoming a radionuclidic impurity of the eluate used for the obtention of the radiopharmaceutical to be administered to the patient. 99Mo emits high-energy photons and beta particles and its presence degrades the quality of the image and unnecessarily increases the radiation dose delivered to the patient. An in-vivo measurement technique was developed to verify the occurrence of internal contamination by 99Mo in nuclear medicine patients. Direct measurements were made in a volunteer who underwent myocardial scintigraphy with 99mTc-sestamibi. The results indicated the presence of internal contamination of the patien by 99Mot. The activity was tracked for several days, and an assessment of the radiation dose from the contaminant 99Mo was made.O 99mTc é um radionuclídeo largamente utilizado em diagnósticos por imagem em medicina nuclear. No Brasil, ele é obtido por eluição de um gerador de 99Mo-99mTc fornecido pelo IPEN. A eluição do gerador é feita nas clínicas onde se realizam os exames. Durante a eluição o 99Mo pode ser carreado da coluna, tornando-se uma impureza radionuclídica do eluato a ser utilizado para a obtenção do radiofármaco administrado ao paciente. O 99Mo emite fótons de alta energia e partículas beta, e sua presença, além de provocar degradação na qualidade da imagem do exame, aumenta desnecessariamente a dose de radiação no paciente. Assim, com o objetivo de verificar a possível ocorrência de contaminação interna por 99Mo em pacientes de medicina nuclear, foi desenvolvida

  4. Electrooxidation of H{sub 2}/CO on carbon-supported PtRuMo nanoparticles for polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsiouvaras, N.; Pena, M.A.; Fierro, J.L.G.; Martinez-Huerta, M.V. [CSIC, Madrid (Spain). Inst. de Catalisis y Petroleoquimica; Alcaide, F.; Alvarez, G. [CIDETEC-IK4, Donostia, San Sebastian (Spain)

    2010-07-01

    Ternary anodic PtRuMo catalysts have been prepared following a two step procedure. All catalysts prepared present PtRu metal loading of 30%wt and a Mo load of 0, 1, 2.5 and 5%wt supported on Vulcan XC 72R. Different physicochemical techniques have been employed for the analysis of the catalysts as well as electrochemical techniques in combination with FTIR for in situ studies. The fuel cell performance was evaluated at 80 C in a PEMFC fed with H{sub 2}/CO (10 ppm). Catalysts obtained exhibit good dispersion and small particle size (2.6 nm). FTIR results obtained in CO saturated confirm that lower amounts of CO are adsorbed on ternary catalysts compared with binary catalyst, whichever Mo composition was used. However, polarization curves of the catalysts show that the activity strongly depend on the composition, where PtRu-Mo(1%wt)/C displays the highest CO tolerance. (orig.)

  5. Optimization of the {sup 99m} Tc generator with hydrotalcite as support of {sup 99} Mo; Optimizacion del generador de {sup 99m} Tc con hidrotalcita como soporte del {sup 99} Mo

    Energy Technology Data Exchange (ETDEWEB)

    Aranda O, N

    2004-07-01

    In the last years, in the laboratories of the National Institute of Nuclear Investigations (ININ) its have been investigating to the hydrotalcite like a material of support of the {sup 99} Mo with the purpose of developing a new technetium generator. During the development of the investigations it has been demonstrated that when putting in contact to the HTC with an aqueous solution that contains anions of any type, the HTC re hydrate and the structure is regenerated to laminate of the hydrotalcite. If the present anions in the solution are molybdate anions (MoO{sub 4}{sup 2-}), these anions passed to be part of the structure of the hydrotalcite (HT-MoO{sub 4}). These anions can contain, in turn, {sup 99} Mo in their composition ({sup 99}MoO{sub 4}{sup 2-}) and equally they can pass to be part of the structure of the hydrotalcite forming the HT-{sup 99}MoO{sub 4}. When the HT-{sup 99}MoO{sub 4} is packed in a column, the {sup 99m}Tc that it takes place when decaying the {sup 99}Mo radioactively can separate the column using aqueous solution of NaCl. This way, in previous studies (Serrano, 2000) it was found that the aqueous solution of NaCl to 0.5% it is the but appropriate for elutriate at the {sup 99m}Tc from the column the yield of the elution of the {sup 99m}Tc was since high (98%) in the first elution, and the radionuclide contamination caused by the presence of {sup 99}Mo in the eluate it was low (<0.01%). In this investigation it was also found that the HTC has a high capacity to retain molybdate ions (255.1 mg of ions MoO{sub 4}{sup 2-} for gram of HTC). These facts, standing out the high capacity of the HTC to retain molybdate ions, they drove from a direct way to investigate the optimization of the generator of {sup 99m}Tc, with hydrotalcite like support of the {sup 99}Mo, using {sup 99}Mo of low specific activity. This finishes radioactive material it can be obtained by the irradiation of the {sup 98}Mo (in the chemical form of MoO{sub 3} or (NH{sub 4

  6. On the Highest Oxidation States of Metal Elements in MO4 Molecules (M = Fe, Ru, Os, Hs, Sm, and Pu).

    Science.gov (United States)

    Huang, Wei; Xu, Wen-Hua; Schwarz, W H E; Li, Jun

    2016-05-02

    Metal tetraoxygen molecules (MO4, M = Fe, Ru, Os, Hs, Sm, Pu) of all metal atoms M with eight valence electrons are theoretically studied using density functional and correlated wave function approaches. The heavier d-block elements Ru, Os, Hs are confirmed to form stable tetraoxides of Td symmetry in (1)A1 electronic states with empty metal d(0) valence shell and closed-shell O(2-) ligands, while the 3d-, 4f-, and 5f-elements Fe, Sm, and Pu prefer partial occupation of their valence shells and peroxide or superoxide ligands at lower symmetry structures with various spin couplings. The different geometric and electronic structures and chemical bonding types of the six iso-stoichiometric species are explained in terms of atomic orbital energies and orbital radii. The variations found here contribute to our general understanding of the periodic trends of oxidation states across the periodic table.

  7. Studies of techniques for the post-elution concentration of {sup 99}mTc obtained from gel type {sup 99}Mo/{sup 99}mTc generators; Estudos de tecnicas de concentracao da atividade de {sup 99}mTc eluido de geradores de {sup 99}Mo/{sup 99}mTc tipo gel

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Katia Noriko

    2009-07-01

    On average 80% of the radiopharmaceuticals used in Nuclear Medicine are labeled with {sup 99}mTc due to its physical properties and easy attainment through of {sup 99}Mo/{sup 99}mTc generators. The Directory of Radiopharmacy (DIRF) of IPEN-CNEN/SP developed a gel type chromatographic generator of MoZr with {sup 99}Mo produced by {sup 98}Mo(n,{gamma}){sup 99}Mo reaction that occurs at the IEA-R1 Nuclear Reactor. The gel is composed of zirconium molybdate with elution volume of 12 mL with an activity of 11100 MBq (300 mCi) producing a radioactive concentration of 925 MBq (25 mCi)/mL. The fission generator gives a higher radioactive concentration around 1850 MBq (50 mCi)/mL. The aim of this work is to study a system of post-elution concentration of {sup 99}mTc for the attainment of a high enough radioactive concentration to meet the demands of the market, with a proved quality. Two types of systems of post-elution concentration were developed: the single and the tandem. The most appropriate system for the gel generator of {sup 99}Mo/{sup 99}mTc, being at the same time sterile and vacuum automated, was the tandem system using Dionex 2.5 cc/QMA cartridges. The gel generator is eluted with 10 mL of solution of 0.1% NaCl and the pertechnetate anion is retained in the QMA cartridge and further eluted with 4 mL of saline. The process takes no more than 30 minutes. The elution efficiency of the system of concentration was 90 %. At the beginning of 2009 a global crisis in the supply of {sup 99}Mo took place making it necessary the development of alternative technologies for the production of {sup 99}Mo/{sup 99}mTc generators using fission produced {sup 99}Mo and the development of an appropriate method to extend the useful life of this generator. The results of this study showed that the same system developed for the post- concentration of the gel generator can be employed for the fission generator, using the tandem system, giving a concentration factor of 3 for the elution

  8. Selective-Area Growth of Thick Diamond Films Using Chemically Stable Masks of Ru/Au and Mo/Au

    Science.gov (United States)

    Nagase, Masanori; Watanabe, Katsumi; Umezawa, Hitoshi; Shikata, Shinichi

    2012-07-01

    Selective-area growth of diamond films in microwave-plasma chemical vapor deposition was performed using newly developed masks. By forming chemically stable masks made of Ru/Au or Mo/Au, which have high melting points, good adhesion to diamond, and difficulty in forming carbide compounds, patterned diamond films with a large thickness of 50 µm, a large area of 5 mm2, and a high orientation in the [001] direction were successfully grown on (001) diamond substrates without degradation of the crystal quality of masked areas.

  9. Preparation of {sup 99}Mo/{sup 99m}Tc generators based on {sup 99}Mo zirconium molybdates in the Gel Synthesis Device for Generators; Preparacion de generadores {sup 99}Mo/{sup 99m}Tc a base de {sup 99}Mo-molibdatos de zirconio en el DISIGEG

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, I. Z.; Monroy G, F.; Rivero G, T.; Rojas N, P. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)], e-mail: fabiola.monroy@inin.gob.mx

    2008-07-01

    The {sup 99m}Tc is used for diagnosis and therapy. It is produced commercially from {sup 99}Mo obtained from the fission of {sup 235}U, which is retained in chromatographic columns filled with alumina whose maximum capacity is 0.2%. Given these constraints new methods of preparation {sup 99}Mo/{sup 99m}Tc generators have been developed using zirconium molybdates gels containing up to 30% of Mo, which is part of the generator matrix, and retaining quality and purity similar characteristics to those commercial generators. The present study aims to determine the flow of agitation, temperature and drying time optimal to prepare {sup 99}Mo/{sup 99m}Tc generators based on {sup 99}Mo zirconium molybdates in the Gel Synthesis Device {sup 99}Mo/{sup 99m}Tc Generators designed and built by groups of the Radioactive Materials Research Laboratory and Automation and Instrumentation Department of the National Institute of Nuclear Research. (Author)

  10. Generator of {sup 99m} Tc with MnO{sub 2} as support of {sup 99} Mo; Generador de {sup 99m} Tc con MnO{sub 2} como soporte del {sup 99}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Granados C, F.; Serrano G, J. [Departamento de Quimica, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The generator of {sup 99m} Tc with MnO{sub 2} as support of {sup 99} Mo was studied. By mean of static experiments the retention of {sup 99} Mo in MnO{sub 2} in function of the stirring time and of the p H value of the solution of {sup 99} Mo. It was found that the {sup 99} Mo presents 100% of retention in MnO{sub 2} in the rank of p H 3-11 and the balance was reached before of 10 minutes. In dynamic conditions the retention of {sup 99} Mo in MnO{sub 2} at p H=5 was also higher: 99.72%. The generated {sup 99m} Tc can be separated from {sup 99} Mo, adsorbed in MnO{sub 2} packed in the column, using distilled water at p H=5 or NaCl solution at 0.9%. With saline solution the elution yields were greater than 80% and only an aliquot of 5 ml was necessary for obtaining this yield. The better results were obtained when the column was packed with 1 g of MnO{sub 2}. The water and the saline solution were passed through of the column with a flux of 1.25 ml/min. (Author)

  11. A comparison of rat SPECT images obtained using 99mTc derived from 99Mo produced by an electron accelerator with that from a reactor

    Science.gov (United States)

    Galea, R.; Wells, R. G.; Ross, C. K.; Lockwood, J.; Moore, K.; Harvey, J. T.; Isensee, G. H.

    2013-05-01

    Recent shortages of molybdenum-99 (99Mo) have led to an examination of alternate production methods that could contribute to a more robust supply. An electron accelerator and the photoneutron reaction were used to produce 99Mo from which technetium-99m (99mTc) is extracted. SPECT images of rat anatomy obtained using the accelerator-produced 99mTc with those obtained using 99mTc from a commercial generator were compared. Disks of 100Mo were irradiated with x-rays produced by a 35 MeV electron beam to generate about 1110 MBq (30 mCi) of 99Mo per disk. After target dissolution, a NorthStar ARSII unit was used to separate the 99mTc, which was subsequently used to tag pharmaceuticals suitable for cardiac and bone imaging. SPECT images were acquired for three rats and compared to images for the same three rats obtained using 99mTc from a standard reactor 99Mo generator. The efficiency of 99Mo-99mTc separation was typically greater than 90%. This study demonstrated the delivery of 99mTc from the end of beam to the end user of approximately 30 h. Images obtained using the heart and bone scanning agents using reactor and linac-produced 99mTc were comparable. High-power electron accelerators are an attractive option for producing 99Mo on a national scale.

  12. A comparison of rat SPECT images obtained using (99m)Tc derived from 99Mo produced by an electron accelerator with that from a reactor.

    Science.gov (United States)

    Galea, R; Wells, R G; Ross, C K; Lockwood, J; Moore, K; Harvey, J T; Isensee, G H

    2013-05-07

    Recent shortages of molybdenum-99 ((99)Mo) have led to an examination of alternate production methods that could contribute to a more robust supply. An electron accelerator and the photoneutron reaction were used to produce (99)Mo from which technetium-99m ((99m)Tc) is extracted. SPECT images of rat anatomy obtained using the accelerator-produced (99m)Tc with those obtained using (99m)Tc from a commercial generator were compared. Disks of (100)Mo were irradiated with x-rays produced by a 35 MeV electron beam to generate about 1110 MBq (30 mCi) of (99)Mo per disk. After target dissolution, a NorthStar ARSII unit was used to separate the (99m)Tc, which was subsequently used to tag pharmaceuticals suitable for cardiac and bone imaging. SPECT images were acquired for three rats and compared to images for the same three rats obtained using (99m)Tc from a standard reactor (99)Mo generator. The efficiency of (99)Mo-(99m)Tc separation was typically greater than 90%. This study demonstrated the delivery of (99m)Tc from the end of beam to the end user of approximately 30 h. Images obtained using the heart and bone scanning agents using reactor and linac-produced (99m)Tc were comparable. High-power electron accelerators are an attractive option for producing (99)Mo on a national scale.

  13. A new inorganic adsorbent of (n, {gamma}){sup 99}Mo for the practical {sup 99m}Tc generator

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Y.; Nishino, M. [Kaken Co., Asahi, Ibaraki (Japan). Functional Materials Inst.; Ishikawa, K.; Tatenuma, K.; Kurosawa, K.; Tanase, M.; Yamabayashi, H.

    1998-10-01

    Technetium-99m is used most widely in diagnostic nuclear medicine. By the milking procedure, it is normally eluted as the daughter nuclide from {sup 99}Mo adsorbed in an alumina column as a generator. Molybdenum-99 with high specific activity has been produced in large quantities from the fission of irradiated {sup 235}U. However, the production process involves the troublesome handling process of various fission products in the high radiation field and generates highly radioactive and poisonous wastes. To avoid these drawbacks, some gel generators have been proposed. They are of zirconium molybdate, zirconium molybdophosphate or titanium molybdate gel, which are able to be applied to {sup 99}Mo obtained easily by (n, {gamma}) reaction of natural Mo. However, it has become apparent that the gel has been prepared only under certain strict conditions such as concentrations and reaction temperature, and eventually the elution rate of {sup 99m}Tc was unstable because of any influences of the gel preparation conditions. We have developed and reported a new inorganic adsorbent (Polyinorganic Zirconium Compound: PZC) of {sup 99}Mo with a low specific activity obtained by (n, {gamma}) reaction to overcome the problems of gel generators above mentioned. PZC was prepared from ZrCl{sub 4} and isopropyl alcohol. The adsorbed amount of {sup 99}Mo (Mo) to PZC was about 200 mg/g-PZC, and the yield of {sup 99m}Tc was about 80%. And the breakthrough of {sup 99}Mo was less than 0.5%. In this paper, the properties of the improved PZC, performance of generators with {sup 99}Mo loaded from 0.5 to 470 MBq, and a method to reduce the breakthrough of {sup 99}Mo are described. (author)

  14. The preparation of {sup 99m}Tc from {sup 99}Mo-{sup 99m}Tc using Poly-Zirconium Compound (PZC)

    Energy Technology Data Exchange (ETDEWEB)

    Laohawilai, S. [Isotope Production Div., Office of Atomic Energy for Peace (Thailand)

    1998-10-01

    The process of for providing the {sup 99m}Tc-gel generator followed the protocol that received from Department of Radioisotopes, Tokai Research Establishment, JAERI. Sodium molybdate (molybdenum-99), pH 7 with concentration 20 mg/ml and activity nearly 1 mCi/ml was added into the adsorbent (PZC). The total activity of {sup 99}Mo was about 10 mCi and the heating time was varied from 3-18 hours at 70degC. The properties of the gel were studied for elution profile and elution efficiency. The molybdenum breakthrough in sodium pertechnetate (technetium-99m) was also performed. (author)

  15. Evaluation of '9{sup 9}Mo presence in eluates of {sup 99}mTc used in nuclear medicine; Avaliacao da presenca de {sup 99}Mo em eluatos de {sup 99m}Tc utilizados em medicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Bianca da Silva

    2010-07-01

    Tc-99m is used for diagnostic imaging in nuclear medicine through SPECT technique. It is obtained by the elution of {sup 99}Mo/{sup 99m}Tc generators. During the elution process {sup 99}Mo can be extracted becoming a radionuclidic impurity. One of the quality parameters of the eluate is the radionuclidic purity, MBT (molybdenum break through), defined as the ratio between {sup 99}Mo and {sup 99m}Tc activities in the eluate. The North-American and European pharmacopoeias restrict the {sup 99}Mo content, respectively, in 0.015 e 0.1% and, according to the International Atomic Energy Agency (IAEA), the activity ratio at the moment of administration of the radiopharmaceutical to the patient, should not exceed 0.015%. In Brazil, the control of such parameter is not obliged in official regulations. Thus, the objective of this work is to evaluate the occurrence of {sup 99}Mo in {sup 99m}Tc eluates. It was initially optimized a methodology to determine the activity of {sup 99}Mo in eluate samples. Efficiency curves were obtained for a NaI (Tl) 8'' x 4'' scintillation detector installed at the In Vivo Monitoring Laboratory (LABMIV-IRD). The methodology has been validated through the measurement of a {sup 99}Mo standard liquid source calibrated at the National Metrology Laboratory for Ionizing Radiation (LNMRI-IRD). The samples analyzed in this work were gently supplied by 5 Nuclear Medicine Clinics located in the city of Rio de Janeiro. The activities of {sup 99}mTc and {sup 99}Mo in those samples have been measured respectively at the clinics and at the LABMIV. By applying a standardized methodology, the ration between the activities were calculated. The results show that 147 out of 174 samples presented {sup 99}Mo activities above the minimum detectable activity of the technique. On the other hand, only 2 out of 147 samples surpassed the MBT limit suggested by the IAEA and have been detected in samples eluted from generators of 750 mCi. In one of the

  16. Mass measurements of very neutron-deficient Mo and Tc isotopes and their impact on rp process nucleosynthesis

    CERN Document Server

    Haettner, E; Audi, G; Blaum, K; Block, M; Eliseev, S; Fleckenstein, T; Herfurth, F; Heßberger, F P; Hofmann, S; Ketelaer, J; Ketter, J; Kluge, H -J; Marx, G; Mazzocco, M; Novikov, Yu N; Plaß, W R; Rahaman, S; Rauscher, T; Rodríguez, D; Schatz, H; Scheidenberger, C; Schweikhard, L; Sun, B; Thirolf, P G; Vorobjev, G; Wang, M; Weber, C; 10.1103/PhysRevLett.106.122501

    2011-01-01

    The masses of ten proton-rich nuclides, including the N=Z+1 nuclides 85-Mo and 87-Tc, were measured with the Penning trap mass spectrometer SHIPTRAP. Compared to the Atomic Mass Evaluation 2003 a systematic shift of the mass surface by up to 1.6 MeV is observed causing significant abundance changes of the ashes of astrophysical X-ray bursts. Surprisingly low alpha-separation energies for neutron-deficient Mo and Tc are found, making the formation of a ZrNb cycle in the rp process possible. Such a cycle would impose an upper temperature limit for the synthesis of elements beyond Nb in the rp process.

  17. Generator of {sup 99} Mo- {sup 99m} Tc at base of gels of titanium molybdates; Generador de {sup 99} Mo- {sup 99m} Tc a base de geles de molibdatos de titanio

    Energy Technology Data Exchange (ETDEWEB)

    Cortes R, O

    2004-07-01

    Commercially the generators of {sup 99m}Tc use a chromatographic column loaded with alumina where the {sup 99} Mo, product of fission of the {sup 235} U, it is retained and eluted the {sup 99m} TcO{sub 4} - by means of a saline solution. Among the limitations of this system, they are: the limited capacity of adsorption of the alumina (2 mg {sup 99} Mo/g alumina) and the production of significant quantities of radioactive waste of medium activity, product of the separation of the {sup 99} Mo and the rest of the products of fission of the {sup 235} U that impose, on the other hand, elaborated radiochemical manipulations. Given these limitations, new procedures of preparation of generators {sup 99} Mo/{sup 99m} Tc, of low or medium activity specify that keep the same characteristics of quality and purity that those obtained by the traditional generator, via the nuclear reaction {sup 98} Mo(n,r){sup 99} Mo, they have been and they continue being study object. A viable option for the production of generators of {sup 99m} Tc consists on using gels of titanium molybdates like matrixes of this generators. The gels are synthesized starting from solutions of TiCI{sub 4} and (NH{sub 4}){sub 2} MoO{sub 4} and irradiated later on. These gels allow to incorporate until 40% of Mo, with what is possible to obtain activities of up to 7.5 GBq/g {sup 99} Mo (200 mCi), avoiding the complex separation processes for their obtaining. Of capital importance they are the conditions of synthesis of the gels, which are presently study object work. Among the evaluated parameters they are: order of addition of the titanium solutions and molybdenum, molar ratio Ti:Mo, concentration of the solution of Ti, p H of the molybdates solution and laundry of those obtained gels, as well as the preparation of the columns. Trying to elucidate those structures of the synthesized materials, which are responsible for the properties of the corresponding generators, some techniques of such analysis were applied

  18. Substitution effects on superconducting and normal state properties in (Mo1-xTx)3Sb7, where T = Ru and Fe

    Science.gov (United States)

    Tran, V. H.

    2016-12-01

    The effects of Ru- and Fe-doping on the physical properties of Mo3Sb7 were studied by measuring ac-susceptibility, dc-magnetization, electrical resistivity and specific heat. It is found that single-phased (Mo{}1-xRu x )3Sb7 and (Mo{}1-xFe x )3Sb7 samples are obtained for the concentrations x ≤slant 0.1. In this concentration range, the lattice parameter shrinks with increasing dopant content. The substitution effects on the superconducting and normal state properties are completely different between two investigated systems. In the Ru-based solid solution alloys, the substitution enhances the superconducting parameters T c and H c2 and also benefits the spin-gap opening at {T}* ˜ 50 K. In contrast, in the Fe-substituted samples, there is a depression of both T c and H c2, accompanied by vanishing spin-gap and low-dimensional magnetic correlation. The substitution of the Mo atoms by Ru and Fe atoms suppresses the cubic-tetragonal distortion, but presumably favours the magnetic field to induce a magnetic order below T *.

  19. Study of gels of molybdenum with cerium in the preparation of generators of 99Mo - 99mTc

    Directory of Open Access Journals (Sweden)

    Vanessa Moraes

    2005-10-01

    Full Text Available 99mTc has ideal nuclear properties for organ imaging in nuclear medicine, and it is obtained from the 99Mo-99mTc generator. Four different types of generators are available: chromatographic that uses 99Mo from fission of uranium; MEK solvent extraction; Tc2O7 sublimation; gel chromatographic. This work presents the preparation of gel generators of molybdenum with cerium and characterization of the gels: mass ratio between molybdenum and cerium, structure, size of particles and elution percentage of 99mTc after irradiating the gels. Eight gels were prepared at the same temperature of 50 ºC with concentrations of NaOH of 2 and 4 mol/L, mass ratio of 0.31 and 0.38 and final pH of 3.5 and 4.5. The analysis of the results proved that these gels are not adequate for preparation of the generators of 99Mo-99mTc, since the elution percentages are low, when compared with the gel of molybdenum with zirconium.O 99mTc é o radiofármaco mais utilizado em Medicina Nuclear. Ele é obtido do gerador de 99Mo-99mTc e existem quatro tipos diferentes de geradores: cromatográfico que utiliza 99Mo de fissão; extração por solvente com MKT; sublimação do heptaóxido de tecnécio; cromatográfico tipo gel. Este trabalho apresenta a preparação de geradores tipo gel de molibdênio com cério, a caracterização desses géis com relação à quantidade de molibdênio e de cério, sua estrutura, tamanho das partículas e porcentagem de eluição do 99mTc após o gel ser irradiado. Foram preparados oito géis na temperatura de 50ºC com concentração de NaOH de 2 e 4 mol/L, relação de massa de 0,31 e 0,38 e pH final de 3,5 e 4,5. A análise dos resultados comprovou que esses géis não são adequados para preparação dos geradores de 99Mo-99mTc, já que as porcentagens de eluição são baixas, quando comparadas com o gel de molibdênio com zircônio.

  20. The Use of Sodium Hypochlorite Solution for (n,γ99Mo/99mTc Generator Based on Zirconium-Based Material (ZBM

    Directory of Open Access Journals (Sweden)

    I. Saptiama

    2015-08-01

    Full Text Available The many problems in preparing fission product 99Mo led into this work to develop 99Mo/99mTc generator using neutron-irradiated natural MoO3 targets and, more specifically, to develop a zirconium-based material (ZBM for chromatography columns that have an adsorption capacity of more than 100 mg Mo/g ZBM. This paper reports our recent experiments in the use of sodium hypochlorite solution of various concentrations to improve the yield of 99mTc in performance of (n,γ99Mo/99mTc generators based on the ZBM. The synthesized ZBM was coated with tetraethyl orthosilicate for improving the hardness of the material. The adsorption of [99Mo]molybdate into ZBM was carried out by reacting ZBM into [99Mo]molybdate solution at 90°C to form ZBM-[99Mo] molybdate. ZBM-[99Mo]molybdate was then packed into generator column, then eluted with 10 × 1 mL of saline followed by 1 × 5 mL of NaOCl solution. The NaOCl solution concentrations used were 0.5%; 1%; 3%; and 5% for each column, respectively. This study resulted in a ZBM which has a 99Mo adsorption capacity of 167.5 ± 3.4 mgMo/g ZBM, as well as in a yield eluate of 99mTc of up to 70%, and the find that the optimum NaOCl concentration was 3%. The use of sodium hypochlorite solution affected 99Mo breakthrough. The higher sodium hypochlorite concentration used, the more 99Mo breaktrough exist on 99mTc eluate.

  1. The synthesis of the light Mo and Ru isotopes how now, no need for an exotic solution?

    CERN Document Server

    Costa, V; Zappalà, R A; Arnould, M

    2000-01-01

    The most detailed calculations of the p-process call for its development in the O/Ne layers of Type II supernovae. In spite of their overall success in reproducing the solar system content of p-nuclides, they suggest a significant underproduction of the light Mo and Ru isotopes. On grounds of a model for the explosion of a 25 solar mass star with solar metallicity, we demonstrate that this failure might just be related to the uncertainties left in the rate of the 22Ne(alpha,n)25Mg neutron producing reaction. The latter indeed have a direct impact on the distribution of the s-process seeds for the p-process.

  2. The synthesis of the light Mo and Ru isotopes: how now, no need for an exotic solution?

    Science.gov (United States)

    Costa, V.; Rayet, M.; Zappalà, R. A.; Arnould, M.

    2000-06-01

    The most detailed calculations of the p-process call for its development in the O/Ne layers of Type II supernovae. In spite of their overall success in reproducing the solar system content of p-nuclides, they suggest a significant underproduction of the light Mo and Ru isotopes. On grounds of a model for the explosion of a 25 Msun star with solar metallicity, we demonstrate that this failure might just be related to the uncertainties left in the rate of the \\reac{22}{Ne}{\\alpha}{n}{25}{Mg} neutron producing reaction. The latter indeed have a direct impact on the distribution of the s-process seeds for the p-process.

  3. Structural optimization and physical properties of TcB3 and MoB3 at high-pressure: First-principles

    Science.gov (United States)

    Ying, Chun; Bai, Xiaowan; Du, Yungang; Zhao, Erjun; Lin, Lin; Hou, Qingyu

    2016-06-01

    The thermodynamic, mechanical and dynamic properties of TcB3 and MoB3 are systematically investigated at high-pressure by first-principles within density functional theory (DFT). The calculated formation enthalpies are negative for TcB3 with considered structures under the pressure range from 0 to 100 GPa. Triboride hP4-TcB3 (i.e., TcB3 in hP4-OsB3 type structure) has the lowest formation enthalpy of -1.44 eV under ambient condition. The largest shear modulus of 240 GPa and smallest Poisson’s ratio of 0.20 for oP16-TcB3 are comparable to those of 267 GPa and 0.15 for ReB2. The calculated elastic constants show that MB3 (M=Tc and Mo) are mechanically stable at ambient conditions, except for mP8-MoB3. The estimated high hardness of 33.4 and 33.1 GPa for oP16-TcB3 and hP4-TcB3, respectively, are reported for the first time. The calculated lattice parameters for MoB3 are in good agreement with the previously theoretical and experimental studies. Below 13 GPa, hP16-MoB3 and hR24-MoB3 are thermodynamically more favorable than MoB3 in other structures. A pressure-induced phase transition is predicted at 13 GPa from hP16-MoB3 and hR24-MoB3 to hP4-MoB3. Above 13 GPa, hP4-MoB3 becomes the thermodynamically most stable phase among MoB3 in considered structures. All compounds with considered structures are metallic, and the electronic structures of MB3 are governed by a strong hybridization between M-4d and B-2p states. The strong and directional covalent bonding between M-4d and B-2p as well as the strong interlayer interactions of boron layers are correlated to the high hardness of 38.0 and 38.4 GPa for hP16-MoB3 and hR24-MoB3, respectively.

  4. Concerning the electronic coupling of MoMo quadruple bonds linked by 4,4'-azodibenzoate and comparison with t2g 6-Ru(II) centers by 4,4'-azodiphenylcyanamido ligands.

    Science.gov (United States)

    Chisholm, Malcolm H; D'Acchioli, Jason S; Hadad, Christopher M; Patmore, Nathan J

    2006-12-25

    From the reactions between Mo2(O2CtBu)4 and each of terephthalic acid and 4,4'-azodibenzoic acid, the compounds [Mo2(O2CtBu)3]2(mu-O2CC6H4CO2) (1) and [Mo2(O2CtBu)3]2(mu-O2CC6H4N2C6H4CO2) (2) have been made and characterized by spectroscopic and electrochemical methods. Their electronic structures have been examined by computations employing density functional theory on model compounds where HCO2 substitutes for tBuCO2. On the basis of these studies, the two Mo2 units are shown to be only weakly coupled and the mixed-valence ions 1+ and 2+ to be valence-trapped and Class II and I, respectively, on the Robin-Day classification scheme for mixed-valence compounds. These results are compared to t2g6-Ru centers linked by 1,4-dicyanamidobenzene and azo-4,4'-diphenylcyanamido bridges for which the mixed-valence ions [Ru-bridge-Ru]5+ have been previously classified as fully delocalized, Class III [Crutchley et al. Inorg. Chem. 2001, 40, 1189; Inorg. Chem. 2004, 43, 1770], and on the basis of results described herein, it is proposed that the latter complex ion is more likely a mixed-valence organic radical where the bridge is oxidized and not the Ru(2+) centers.

  5. Effect of Zr:Mo ratio on {sup 99m}Tc generator performance based on zirconium molybdate gels

    Energy Technology Data Exchange (ETDEWEB)

    Monroy-Guzman, F. E-mail: fmg@nuclear.inin.mx; Diaz-Archundia, L.V.; Contreras Ramirez, A

    2003-07-01

    Zirconium molybdate gels have shown to be viable alternatives for preparation of {sup 99m}Tc generators using {sup 99}Mo produced by neutron activation. The aim of this work was to investigate the effect of the Zr:Mo molar ratio on the gel chemical structure and correlate it with the elution efficiency. A series of gels were prepared at Zr:Mo molar ratios from 0.5:1 to 2.3:1 and characterized by TGA, IR, XRD and UV. It was found that the variation of Zr:Mo ratio produces different polymolybdate arrangements on the octahedral units around to the zirconia which is mainly influenced by the water content. When the matrix molybdenum concentration was increased a lesser amount of water was found and the elution efficiencies were increased. However high elution efficiencies produce higher {sup 99}Mo breakthrough values. The gel formulation appears thus to be a compromise between the elution efficiency and the molybdenum breakthrough. The chemical-physical properties of these gels are presented and discussed.

  6. Production optimization of {sup 99}Mo/{sup 99m}Tc zirconium molybate gel generators at semi-automatic device: DISIGEG

    Energy Technology Data Exchange (ETDEWEB)

    Monroy-Guzman, F., E-mail: fabiola.monroy@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Rivero Gutierrez, T., E-mail: tonatiuh.rivero@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Lopez Malpica, I.Z.; Hernandez Cortes, S.; Rojas Nava, P.; Vazquez Maldonado, J.C. [Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac, 52750, Estado de Mexico (Mexico); Vazquez, A. [Instituto Mexicano del Petroleo, Eje Central Norte Lazaro Cardenas 152, Col. San Bartolo Atepehuacan, 07730, Mexico D.F. (Mexico)

    2012-01-15

    DISIGEG is a synthesis installation of zirconium {sup 99}Mo-molybdate gels for {sup 99}Mo/{sup 99m}Tc generator production, which has been designed, built and installed at the ININ. The device consists of a synthesis reactor and five systems controlled via keyboard: (1) raw material access, (2) chemical air stirring, (3) gel dried by air and infrared heating, (4) moisture removal and (5) gel extraction. DISIGEG operation is described and dried condition effects of zirconium {sup 99}Mo- molybdate gels on {sup 99}Mo/{sup 99m}Tc generator performance were evaluated as well as some physical-chemical properties of these gels. The results reveal that temperature, time and air flow applied during the drying process directly affects zirconium {sup 99}Mo-molybdate gel generator performance. All gels prepared have a similar chemical structure probably constituted by three-dimensional network, based on zirconium pentagonal bipyramids and molybdenum octahedral. Basic structural variations cause a change in gel porosity and permeability, favouring or inhibiting {sup 99m}TcO{sub 4}{sup -} diffusion into the matrix. The {sup 99m}TcO{sub 4}{sup -} eluates produced by {sup 99}Mo/{sup 99m}Tc zirconium {sup 99}Mo-molybdate gel generators prepared in DISIGEG, air dried at 80 Degree-Sign C for 5 h and using an air flow of 90 mm, satisfied all the Pharmacopoeias regulations: {sup 99m}Tc yield between 70-75%, {sup 99}Mo breakthrough less than 3 Multiplication-Sign 10{sup -3}%, radiochemical purities about 97% sterile and pyrogen-free eluates with a pH of 6. - Highlights: Black-Right-Pointing-Pointer {sup 99}Mo/{sup 99m}Tc generators based on {sup 99}Mo-molybdate gels were synthesized at a semi-automatic device. Black-Right-Pointing-Pointer Generator performances depend on synthesis conditions of the zirconium {sup 99}Mo-molybdate gel. Black-Right-Pointing-Pointer {sup 99m}TcO{sub 4}{sup -} diffusion and yield into generator depends on gel porosity and permeability. Black

  7. Evaluation of proton induced reactions on sup 1 sup 0 sup 0 Mo. New cross sections for production of sup 9 sup 9 sup m Tc and sup 9 sup 9 Mo

    CERN Document Server

    Takács, S; Tarkanyi, F; Hermanne, A; Sonck, M

    2003-01-01

    The use of the sup 9 sup 9 Mo -> sup 9 sup 9 sup m Tc generator in nuclear medicine is well established world wide. The production of the sup 9 sup 9 Mo (T sub 1 sub / sub 2 = 66 h) parent as a fission product of sup 2 sup 3 sup 5 U is largely based on the use of reactor technology. From the early 1990's accelerator based production methods to provide either direct produced sup 9 sup 9 sup m Tc or the parent sup 9 sup 9 Mo, were studied and suggested as potential alternatives to the reactor based production of sup 9 sup 9 Mo. A possible pathway for the charged particle production of sup 9 sup 9 sup m Tc and sup 9 sup 9 Mo is irradiation of molybdenum metal with protons via the reaction sup 1 sup 0 sup 0 Mo(p,2n) sup 9 sup 9 sup m Tc and sup 1 sup 0 sup 0 Mo(p,pn) sup 9 sup 9 Mo, respectively. The earlier published excitation functions show large differences in their maximum that result in large differences in the calculated yields. Study the excitation function for these proton-induced reactions was decided. ...

  8. Computer simulation and experimental investigation of Mo-99 yield in thick targets as a Tc-99m generator

    Science.gov (United States)

    Malykhina, T.; Torhovkin, O.

    2017-09-01

    The most important requirement for the production technology of radionuclides is to provide a high specific activity of the target nuclide as well as the full activity of the target. This problem can be solved by using a large volume of photonuclear targets, and then by the target nuclide radiochemical separation. Computer simulation and experimental study of the spatial distribution of the activity is carried out in this work for the molybdenum target. Optimal parameters of irradiation to achieve the maximum yield of isotopes Mo-99 (Tc-99m) from the molybdenum target have been found.

  9. Isomeric yield ratio for the [sup 95]Mo (p,n) [sup 95m,g]Tc reaction

    Energy Technology Data Exchange (ETDEWEB)

    Nagame, Y.; Baba, S. (Japan Atomic Energy Research Inst., Tokai-mura, Ibaraki (Japan). Dept. of Radioisotopes); Saito, T. (Osaka Univ., Toyonaka (Japan). Faculty of Science)

    1994-03-01

    Excitation functions and isomeric yield ratios for the [sup 95]Mo(p,n) (p,n) [sup 95m.g]Tc reactions up to E[sub p] = 28 MeV are analyzed with a statistical model. In the vicinity of the threshold energy E[sub p] [<=] 12 MeV, the experimental isomeric yield ratios are well reproduced by the calculations, while the calculation overestimates the experimental value beyond that energy. This suggests that the contribution of a pre-equilibrium process occurs above E[sub p] [approx] 12 MeV. The relationship between the isomeric yield ratio and compound nucleus spin distribution is discussed. (Author).

  10. Synthesis of alumina {sup 99}Mo-molybdate(VI) gel matrices and evaluation of {sup 99m}Tc elution performance

    Energy Technology Data Exchange (ETDEWEB)

    El-Absy, M.A.; El-Garhy, M.A.; Fasih, T.W.; El-Amir, M.A.; Ramadan, H.E. [Atomic Energy Authority, Cairo (Egypt). Radioactive Isotopes and Generators Dept.; El-Shahat, M.F. [Ain Shams Univ., Cairo (Egypt). Chemistry Dept.

    2015-05-01

    Synthesis of a novel alumina {sup 99}Mo-molybdate(VI) gel matrix of high Mo(VI) content and reproducible separation indices of the generated {sup 99m}Tc radionuclide are described and briefly discussed. Similar mixture solutes of aluminate and low specific activity {sup 99}Mo-molybdate(VI) anions in concentrated NaOH are prepared. Then, the solutes are acidified with concentrated HCl, HNO{sub 3} and/or H{sub 2}SO{sub 4} at pH 9.5-4.5. Physico-chemical investigations indicate that molybdate(VI) anions are strongly adsorbed onto in situ-precipitated pseudoboehmite from acidic solutions than from basic solutions. The maximum adsorption % of {sup 99}Mo (167 mg Mo/g matrix dried at 50 C) is achieved from the nitrate solution at pH 5.5. Separation of {sup 99m}Tc from the corresponding gel matrix with physiological saline solution exhibits high elution yield with a narrow elution profile and radionuclidic, radiochemical and chemical purity indices comparable with {sup 99m}Tc eluates from {sup 99}Mo/{sup 99m}Tc generators prepared by loading alumina with fission {sup 99}Mo.

  11. Radiochemical purity of Mo and Tc solution obtained after irradiation and dissolution of Mo-100-enriched and ultra-high-purity natural Mo disks

    Energy Technology Data Exchange (ETDEWEB)

    Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey D. [Argonne National Lab. (ANL), Argonne, IL (United States); Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-09-01

    Four irradiations of ultra-high-purity natural Mo targets and one irradiation using 97.4% Mo-100-enriched material were performed. The purpose of these irradiations was to determine whether the presence of Sn stabilizer in the H2O2 used for the dissolution of sintered Mo disks can affect the radiochemical purity of the final K2MoO4 in 5M KOH solution. Results from radiochemical purity tests performed using thin-layer paper chromatography show that even 2– 3× excess of Sn-stabilized H2O2 typically used for dissolution of sintered Mo disks did not affect the radiochemical purity of the final product.

  12. Influence of the electrolyte in the fixation of {sup 99} Mo in hydroxyapatite as matrix of the {sup 99} Mo/ {sup 99m} Tc generator; Influencia del electrolito en la fijacion de {sup 99} Mo en hidroxiapatita coma matriz del generador {sup 99} Mo/ {sup 99m} Tc

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez G, S.; Badillo A, V.E. [UAZ, Zacatecas (Mexico); Monroy G, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: s_vazgro@hotmail.com

    2005-07-01

    The more used isotope at the moment in the services of nuclear medicine in the world is the technetium-99m. The {sup 99m} Tc emitts gamma rays of 141 keV and it semi disintegration period is of six hours, given it short half life, to produce it is necessary to order generators that are systems that allow to separate periodically at the {sup 99m}Tc of the {sup 99} Mo by means of chromatographic techniques. In this work it is sought to evaluate the use of the hydroxyapatite, to separate molybdates {sup 99} MoO{sub 4}{sup 2} of pertechnetates {sup 99m}TcO{sub 4}{sup -} and to be able to determine if it is feasible their use for to build generators of {sup 99m} Tc. With this purpose preliminary tests to know the likeness of the hydroxyapatite for the molybdates in function of the pH value, in different solutions were carried out: one of NaCl 0.9%, NaCl 2% and CaCl{sub 2} 0.01 M. The obtained results in a NaCl 0.9% solution and at to 2% to different pH values of the solution, shows that the fixation of the molybdate ions (MoO{sub 4}{sup -2}) it is worthless to basic pH values of (9-11), as long as in solution of CaCI{sub 2} 0.01 M show a considerable retention of molybdate ions. (Author)

  13. Hartree-Fock-Bogoliubov calculation of ground state properties of even-even and odd Mo and Ru isotopes

    CERN Document Server

    Bassem, Y El

    2016-01-01

    In a previous work [Int. J. Mod. Phys. E 24, 1550073 (2015)], hereafter referred as paper I, we have investigated the ground-state properties of Nd, Ce and Sm isotopes within Hartree-Fock-Bogoliubov method with SLy5 skyrme force in which the pairing strength has been generalized with a new proposed formula. However, that formula is more appropriate for the region of Nd. In this work, we have studied the ground-state properties of both even-even and odd Mo and Ru isotopes. For this, we have used Hartree- Fock-Bogoliubov method with SLy4 skyrme force, and a new formula of the pairing strength which is more accurate for this region of nuclei. The results have been compared with available experimental data, the results of Hartree-Fock-Bogoliubov calculations based on the D1S Gogny effective nucleon-nucleon interaction and predictions of some nuclear models such as Finite Range Droplet Model (FRDM) and Relativistic Mean Field (RMF) theory.

  14. Oxygen reduction behavior of RuO{sub 2}/Ti, IrO{sub 2}/Ti and IrM (M: Ru, Mo, W, V) O{sub x}/Ti binary oxide electrodes in a sulfuric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Takasu, Yoshio; Yoshinaga, Norihiro; Sugimoto, Wataru [Department of Fine Materials Engineering, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda 386-8567 (Japan)

    2008-04-15

    Some oxide catalysts, such as RuO{sub 2}/Ti, IrO{sub 2}/Ti and IrM(M: Ru, Mo, W, V)O{sub x}/Ti binary oxide electrodes, were prepared by using a dip-coating method on a Ti substrate. Their catalytic behavior for the oxygen reduction reaction (ORR) was evaluated by cyclic voltammetry in 0.5 M H{sub 2}SO{sub 4} at 60 C. These catalysts were found to exhibit considerably high activity, and the most active one among them was Ir{sub 0.6}V{sub 0.4}O{sub 2}/Ti prepared at 450 C, showing onset potential for the ORR at about 0.86 V-0.90 (vs RHE). (author)

  15. Labeling of ceftriaxone for infective inflammation imaging using {sup 99m}Tc eluted from {sup 99}Mo/{sup 99m}Tc generator based on zirconium molybdate

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, M., E-mail: mmostafa95@yahoo.co [Radioactive Isotopes and Generators Department, Hot Labs Center, Atomic Energy Authority, P.O. Box 13759, Cairo (Egypt); Motaleb, M.A. [Labeled Compounds Department, Hot Labs Center, Atomic Energy Authority, P.O. Box 13759, Cairo (Egypt); Sakr, T.M. [Radioactive Isotopes and Generators Department, Hot Labs Center, Atomic Energy Authority, P.O. Box 13759, Cairo (Egypt)

    2010-10-15

    Zirconium molybdate gel was prepared by mixing {sup 99}Mo, produced from {sup 98}Mo(n,{gamma}) reaction and Zr solutions in nitrate media with excess H{sub 2}O{sub 2}, and used as the base material for {sup 99}Mo/{sup 99m}Tc generator. The prepared generator showed a good performance. {sup 99m}Tc eluted from the prepared generator passed the quality control tests with specifications meeting the requirements of European and US Pharmacopeias. The {sup 99m}Tc eluate was used for labeling of cephalosporin analogue, ceftriaxone, which was then assessed for infection imaging in a mouse model. {sup 99m}Tc-ceftriaxone was prepared at pH 9 with a radiochemical yield of 95{+-}2% by adding {sup 99m}Tc to 30 mg ceftriaxone in the presence of 50 {mu}g SnCl{sub 2}.2H{sub 2}O. Biodistribution studies in mice were carried out using experimentally induced infection in the left thigh using E. coli. Both thighs of the mice were dissected and counted to evaluate the ratio of bacterial infected thigh/contralateral thigh. {sup 99m}Tc-ceftriaxone showed high uptake in the infectious lesion (T/NT =5.6{+-}0.6 at 4 h post injection). The abscess to normal muscle ratio indicated that {sup 99m}Tc-ceftriaxone could be used for infection imaging. Besides, in vitro studies showed that {sup 99m}Tc-ceftriaxone can differentiate between bacterial infection and sterile inflammation.

  16. Sulphur-bridged ruthenium-molybdenum complexes: [(R-aapm)2Ru(-S)2 Mo(OH)2]. Synthesis, spectroscopic and electro-chemical characterization. R-aapm = 2-(arylazo)pyrimidine

    Indian Academy of Sciences (India)

    Prithwiraj Byabartta

    2006-03-01

    The reaction of ctc-[Ru(R-aapm)2Cl2] (1) with (NH4)2MoS4 in aqueous MeOH afforded redviolet mixed ligand complexes of the type [(R-aapm)2Ru(-S)2Mo(OH)2] (2a-2e) [R-aapm = 2-(arylazo) pyrimidine, -R-C6H4-N=N-C4H3NN, R = H (2a), Me (2b), Cl (2c), OMe (2d), NO2 (2e)]. In complexes (2a-2e) the terminal Mo=S bonds of the MoS$_{4}^{2-}$ unit get hydroxylated and the molybdenum ion is reduced from the starting MoVI in MoS$_{4}^{2-}$ to MoIV in the final product. The solution electronic spectra exhibit a strong MLCT band at 550-570 nm in DCM. The 1H NMR spectra confirms the geometry of the complexes as being that of cis-trans-cis isomers. Cyclic voltammograms show a Ru(III)/Ru(II) couple at 1.10-1.4 V, irreversible Mo(IV)/Mo(V) oxidations in the 1.66-1.72 V range, along with four successive reversible ligand reductions in the range -0.45-0.67 V (one electron), -0.82-1.12 V (one electron), -1.44-1.90 V (simultaneously two electrons).

  17. In-vivo study of the nuclear quadrupole interaction of99Mo (β- 99)Tc in nitrogenase of Klebsiella pneumoniaein nitrogenase of Klebsiella pneumoniae

    Science.gov (United States)

    Mottner, P.; Lerf, A.; Ni, X.; Butz, T.; Erfkamp, J.; Müller, A.

    1990-08-01

    We report on the first TDPAC-measurements of the nuclear quadrupole interaction (NQI) of (NQI) of99Mo(β-)99Tc in the nitrogenase of the bacteria Klebsiella pneumoniae. Because nitrogenase is the only Mo-containing enzyme in Klebsiella pneumoniae under the chosen conditions, no further isolation of this enzyme was necessary. The majority of the incorporated99Mo is subjected to a well defined NQI with ω=365(7) Mrad/s, η=1 and a reorientational correlation time of τcoττ≈10nsec and is attributed to the active site of the FeMo cofactor. During sample preparation we noted a pronounced affinity of the bacteria to99mTc.

  18. Predictions regarding the supply of 99Mo and 99mTc when NRU ceases production in 2018

    CERN Document Server

    Ross, C K

    2015-01-01

    The NRU reactor in Chalk River had been scheduled to stop producing medical isotopes by the end of 2016 but the Government of Canada recently announced that it will remain available to support isotope production until its operating license expires on 31 March, 2018. NRU has the capability of producing up to 80 % of the world's requirements for 99Mo but is presently producing less than 20 %. There are a number of initiatives underway, both within Canada and around the world, to find alternative ways of producing 99Mo or its daughter, 99mTc. We examine the status of the main proposals and conclude that it will be challenging for any of them to meet the required demand by the end of 2016. An additional year should be enough time for some of the proposals to complete the development of manufacturing facilities and achieve regulatory approval. It is likely that these operators will have enough production capability to make up for the shortfall when the NRU operating license expires.

  19. {sup 99m}Tc production on the basis of central generator and wasteless reactor Zr-Mo gel-technology

    Energy Technology Data Exchange (ETDEWEB)

    Savushikin, I.A.; Gourko, O.B. [National Academy of Sciences of Belarus, Minsk (Belarus). Joint Institute of Power Engineering and Nuclear Research-Sosny

    2004-07-01

    According to the current needs in production of {sup 99}Mo, the amount of radioactive waste from radiochemical processing of uranium targets can reach several tens millions GBq per year. The problem of management of long-lived radioactive wastes constrains the production of the radioisotope {sup 99}Mo by the uranium fission method. For developing countries, to which Belarus belongs too, such method of {sup 99m}Tc production is inapplicable because of complexity, high costs and problems of utilization of high activity wastes. Recently, a simpler and less expensive method of {sup 99m}Tc production based on the irradiation of the target from stable {sup 98}Mo has been developed. (orig.)

  20. PENGARUH REGENERASI KOLOM ALUMINA ASAM TERHADAP RECOVERY DAN KUALITAS 99mTc HASIL EKSTRAKSI PELARUT MEK DARI 99Mo HASIL AKTIVASI NEUTRON

    Directory of Open Access Journals (Sweden)

    Adang H G

    2017-01-01

    Full Text Available ABSTRAK PENGARUH REGENERASI KOLOM ALUMINA ASAM TERHADAP RECOVERY DAN KUALITAS 99mTc HASIL EKSTRAKSI PELARUT MEK DARI 99Mo HASIL AKTIVASI NEUTRON. Melalui kerjasama antara PTRR-BATAN, Chiyoda dan JAEA Jepang telah dilakukan pemurnian 99mTc dari 99Mo hasil aktivasi neutron dengan menggunakan metode kromatografi kolom alumina asam terhadap hasil ekstraksi MEK (Metil Etil Keton. Pemurnian 99mTc dengan metode kolom alumina asam hanya dapat digunakan satu kali dan pemurnian berikutnya harus diganti dengan kolom baru. Hal ini dinilai kurang praktis dan juga memerlukan biaya yang mahal. Dalam penelitian ini dicoba penggunaan kolom alumina asam untuk pemurnian 99mTc lebih dari satu kali dengan melakukan proses regenerasi dengan cara melewatkan larutan HNO3 0,1N setiap kali proses pemurnian selesai. Penelitian ini bertujuan untuk mendapatkan larutan 99mTc yang dapat digunakan untuk penandaan kit radiofarmaka. Parameter yang diamati dalam penelitian ini adalah recovery, profil elusi, pH, kemurnian radiokimia dan kemurnian radionuklida (lolosan 99Mo. Hasil penelitian yang dilakukan selama 5 hari telah diperoleh pH ~5, recovery > 60 %, kemurnian radiokimia > 95 % dan lolosan 99Mo tidak terdeteksi. Dari hasil perlakuan terhadap kolom alumina asam dengan larutan HNO3 0,1 N disimpulkan bahwa kolom alumina asam tidak perlu diganti setiap hari. Kata kunci: 99mTc, 99Mo, MEK, kolom alumina asam, kemurnian radiokimia. ABSTRACT Purification of 99mTc from 99Mo activation using acidic alumina column chromatography system from MEK (Methyl Ethyl Keton extraction has been carried out through cooperation between PTRR - BATAN, Chiyoda and JAEA Japan. This method has a limitation that acidic alumina column for purification of 99mTc can be used only once, for the next purification acidic alumina column should be replaced with new column, so it is less practical and also requires high cost. This study aims to obtain a 99mTc solution can be use for labelling of a

  1. Evaluation of the influence of pH in the efficiency of the {sup 99}Mo-{sup 99m}Tc at basis of zirconium molybdate; Evaluacion de la influencia de pH en la eficiencia del generador {sup 99}Mo-{sup 99m}Tc a base de molibdato de zirconio

    Energy Technology Data Exchange (ETDEWEB)

    Diaz A, L.V

    2003-07-01

    The {sup 99m}Tc are the radionuclide more used in the nuclear medicine, it is used for diagnostic and therapy, and he is commonly takes place by means of a generator {sup 99} Mo-{sup 99m}Tc, using molybdenum ({sup 99}Mo) product of the fission of the uranium, adsorbed over alumina. This generator imposes the use of high activities you specify of {sup 99} Mo, as well as of complex processes of separation of the one {sup 99} Mo, generating important quantities of radioactive waste of medium activity. As well as, the production of these generators, demands the use of reactors of great capacity that Mexico not it possesses, in such a way that, presently work is carried out a generator of {sup 99} Mo- {sup 99m} Tc, in the one which {sup 99} Mo taken place by the reaction {sup 98} Mo(n, {gamma}) {sup 99} Mo that it was part from a gel to base is used of molybdate and zirconium. It was found, therefore, to produce a generator {sup 99} Mo- {sup 99m}Tc with the help of gels of zirconium and molybdates with the same characteristics of quality and purity that those obtained by the one traditional generator and that it can be carried out under the conditions technical-economics prevailing in Mexico. Specifically, this work has been focused to the study of the effect caused by the variation of the one p H in the solutions of ZrOCl{sub 2} * 8H{sub 2}O (zirconil) and of molybdates, of the relationships molars zirconium : molybdenum (Zr:Mo), as well as the effect of the concentration variation, time of preparation and consequently p H of the ZrOCl{sub 2} * 8H{sub 2}O in the synthesis of the gel zirconium - {sup 99} molybdenum, on the efficiency of the generator and the quantity of {sup 99} Mo presents in the {sup 99m} Tc taken place by this means. The gel used for the production of {sup 99m}Tc will possess a discharge efficiency of recovery of {sup 99m}Tc and a contained first floor of pollutants, in particular smaller to 0.015% of {sup 99} Mo, main source of impurity radionuclide

  2. Synthesis, crystal structure, and electronic properties of high-pressure PdF2-type oxides MO2 (M = Ru, Rh, Os, Ir, Pt).

    Science.gov (United States)

    Shirako, Yuichi; Wang, Xia; Tsujimoto, Yoshihiro; Tanaka, Kie; Guo, Yanfeng; Matsushita, Yoshitaka; Nemoto, Yoshihiro; Katsuya, Yoshio; Shi, Youguo; Mori, Daisuke; Kojitani, Hiroshi; Yamaura, Kazunari; Inaguma, Yoshiyuki; Akaogi, Masaki

    2014-11-03

    The polycrystalline MO2's (HP-PdF2-type MO2, M = Rh, Os, Pt) with high-pressure PdF2 compounds were successfully synthesized under high-pressure conditions for the first time, to the best of our knowledge. The crystal structures and electromagnetic properties were studied. Previously unreported electronic properties of the polycrystalline HP-PdF2-type RuO2 and IrO2 were also studied. The refined structures clearly indicated that all compounds crystallized into the HP-PdF2-type structure, M(4+)O(2-)2, rather than the pyrite-type structure, M(n+)(O2)(n-) (n superconductivity nor a magnetic transition was detected down to a temperature of 2 K, unlike the case of 3d transition metal chalcogenide pyrites.

  3. New observation of 2{beta}2{nu} decay of {sup 100}Mo to the 0{sub 1}{sup +} level of {sup 100}Ru in the ARMONIA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Belli, P. [INFN, Sezione di Roma ' Tor Vergata' , I-00133, Rome (Italy); Bernabei, R., E-mail: rita.bernabei@roma2.infn.i [INFN, Sezione di Roma ' Tor Vergata' , I-00133, Rome (Italy); Dipartimento di Fisica, Universita di Roma ' Tor Vergata' , I-00133, Rome (Italy); Boiko, R.S. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Cappella, F. [INFN, Sezione di Roma ' La Sapienza' , I-00185, Rome (Italy); Cerulli, R. [INFN, Laboratori Nazionali del Gran Sasso, I-67010, Assergi (Aq) (Italy); Danevich, F.A. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); D' Angelo, S. [Dipartimento di Fisica, Universita di Roma ' Tor Vergata' , I-00133, Rome (Italy); Incicchitti, A. [INFN, Sezione di Roma ' La Sapienza' , I-00185, Rome (Italy); Kobychev, V.V.; Kropivyansky, B.N. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Laubenstein, M. [INFN, Laboratori Nazionali del Gran Sasso, I-67010, Assergi (Aq) (Italy); Nagornyi, P.G. [Chemical Department, Kyiv National Taras Shevchenko University, 01033 Kyiv (Ukraine); Nagorny, S.S. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Nisi, S. [INFN, Laboratori Nazionali del Gran Sasso, I-67010, Assergi (Aq) (Italy); Nozzoli, F. [Dipartimento di Fisica, Universita di Roma ' Tor Vergata' , I-00133, Rome (Italy); Poda, D.V. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Prosperi, D. [INFN, Sezione di Roma ' La Sapienza' , I-00185, Rome (Italy); Dipartimento di Fisica, Universita di Roma ' La Sapienza' , I-00185, Rome (Italy); Polischuk, O.G.; Tretyak, V.I.; Vyshnevskyi, I.M. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine)

    2010-11-30

    A sample of {sup 100}MoO{sub 3} powder with molybdenum enriched in {sup 100}Mo to 99.5% and mass of 1199 g was measured for 18120 h in a low-background set-up with 4 HP Ge detectors ({approx_equal}225 cm{sup 3} volume each one) deep underground (3600 m w.e.) at the Laboratori Nazionali del Gran Sasso of the INFN (Italy). The two {gamma} quanta of 540 keV and of 591 keV emitted in the deexcitation process after a 2{beta}2{nu} decay of {sup 100}Mo to the 0{sub 1}{sup +} excited level of {sup 100}Ru (E{sub exc}=1131 keV) are observed in the accumulated data both in coincidence and in the 1-dimensional sum spectrum. The measured half life is: T{sub 1/2}=6.9{sub -0.8}{sup +1.0}(stat.){+-}0.7(syst.)x10{sup 20} yr, well in agreement with positive results obtained in previous experiments. Moreover, the limit on charge non-conserving {beta} decay of {sup 100}Mo is also set: {tau}{sub CNC}>4.5x10{sup 19} yr at 90% C.L.; it corresponds to the limit on CNC admixture in weak currents: {epsilon}{sub {nu}}{sup 2}<2.9x10{sup -21}.

  4. New observation of 2β2ν decay of 100Mo to the 01+ level of 100Ru in the ARMONIA experiment

    Science.gov (United States)

    Belli, P.; Bernabei, R.; Boiko, R. S.; Cappella, F.; Cerulli, R.; Danevich, F. A.; d'Angelo, S.; Incicchitti, A.; Kobychev, V. V.; Kropivyansky, B. N.; Laubenstein, M.; Nagornyi, P. G.; Nagorny, S. S.; Nisi, S.; Nozzoli, F.; Poda, D. V.; Prosperi, D.; Polischuk, O. G.; Tretyak, V. I.; Vyshnevskyi, I. M.; Yurchenko, S. S.

    2010-11-01

    A sample of 100MoO 3 powder with molybdenum enriched in 100Mo to 99.5% and mass of 1199 g was measured for 18120 h in a low-background set-up with 4 HP Ge detectors ( ≃225 cm volume each one) deep underground (3600 m w.e.) at the Laboratori Nazionali del Gran Sasso of the INFN (Italy). The two γ quanta of 540 keV and of 591 keV emitted in the deexcitation process after a 2β2ν decay of 100Mo to the 01+ excited level of 100Ru ( E=1131 keV) are observed in the accumulated data both in coincidence and in the 1-dimensional sum spectrum. The measured half life is: T=6.9-0.8+1.0(stat.)±0.7(syst.)×10 yr, well in agreement with positive results obtained in previous experiments. Moreover, the limit on charge non-conserving β decay of 100Mo is also set: τ>4.5×10 yr at 90% C.L.; it corresponds to the limit on CNC admixture in weak currents: ɛν2<2.9×10.

  5. Study of the performance of gels of molybdenum containing several cations for the preparation of {sup 99}Mo and {sup 99m}Tc; Estudo do desempenho de geis de molibdenio formados com diferentes cations no preparo de geradores de {sup 99}Mo e {sup 99m}Tc

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Vanessa

    2005-07-01

    {sup 99m}Tc is the most employed radioisotope in Nuclear Medicine, due to its nuclear characteristics: short half-life (6.04 h); emission of low energy gamma ray (140 keV); no emission of {beta}{sup -}; generated by the radioactive decay of {sup 99}Mo (radioisotope generator system). {sup 99}Mo can be produced in cyclotron or nuclear reactor by the irradiation of {sup 235}U (n, f) {sup 99}Mo or by the {sup 98}Mo (n, {gamma}) {sup 90}Mo reaction. Four different kinds of generators of {sup 99m}Tc can be employed, based on the separation techniques: column chromatographic using alumina, with fission {sup 99}Mo; solvent extraction using methylethylketone; sublimation of technetium heptoxide; gel type chromatographic generator, that contains molybdenum. IPEN, aiming the nationalization of the {sup 99m}Tc generators production, developed a gel type generator that uses zirconium molybdate. Three types of gels are studied in the work: molybdenum gel with titanium, molybdenum gel with cerium and molybdenum gel with hafnium, that were compared with the molybdenum gel with zirconium. The variables studied in the gel preparation are: mass relation between Mo and the cation, NaOH concentration, temperature and final pH of the product. After the preparation, the gels are analysed in relation to the amount of Mo and the cation, structure and gel particle size. The gel is irradiated and later a generator system is prepared, and the elutions are analysed in order to measure the {sup 99m}Tc elution efficiency. The results showed that the molybdenum gel with titanium had the best performance in all analysis. (author)

  6. Study of the durability of the Ru-capped MoSi multilayer surface under megasonic cleaning

    Science.gov (United States)

    Kurtuldu, Hüseyin; Rastegar, Abbas; House, Matthew

    2012-11-01

    Because EUV masks lack of a pellicle, they are prone to particle contamination and must be cleaned frequently. Despite the relatively good resistance of the TaN absorber lines to pattern damage by megasonic cleaning, the Ru cap can be easily damaged by it. We demonstrate that the type and concentration of the dissolved gas are critical factors in determining the cavitation that eventually introduces pits on the surface of Ru-capped multilayer films. In particular, oxygen creates many more pits than CO2 under similar conditions. In this paper, we present the results of SEMATECH's extensive experimental studies of pit creation on Ru-capped multilayer EUV blanks by megasonics as a function of acoustic field power, gas type and concentration in ultra-pure water, and chemicals during sonication.

  7. Magnetic and electronic properties of La3 MO7 and possible polaron formation in hole-doped La3 MO7 (M  =  Ru and Os)

    Science.gov (United States)

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

    2017-03-01

    Oxides with 4d/5d transition metal ions are physically interesting for their particular crystalline structures as well as the spin–orbit coupled electronic structures. Recent experiments revealed a series of 4d/5d transition metal oxides R 3 MO7 (R: rare earth; M: 4d/5d transition metal) with unique quasi-one-dimensional M chains. Here first-principles calculations have been performed to study the electronic structures of La3OsO7 and La3RuO7. Our study confirm both of them to be Mott insulating antiferromagnets with identical magnetic order. The reduced magnetic moments, which are much smaller than the expected value for ideal high-spin state (3 t 2g orbitals occupied), are attributed to the strong p  ‑  d hybridization with oxygen ions, instead of the spin–orbit coupling. The Ca-doping to La3OsO7 and La3RuO7 can not only modulate the nominal carrier density but also affect the orbital order as well as the local distortions. The Coulombic attraction and particular orbital order would prefer to form polarons, which might explain the puzzling insulating behavior of doped 5d transition metal oxides. In addition, our calculations predict that the Ca-doping can trigger ferromagnetism in La3RuO7 but not in La3OsO7.

  8. Actual stage of the project for the preparation of a gel zirconium molybdate for use in the {sup 99} Mo/{sup 99m}Tc generators; Estagio atual do projeto de preparo do gel de molibdato de zirconio para uso nos geradores de {sup 99} Mo/{sup 99m}Tc

    Energy Technology Data Exchange (ETDEWEB)

    Osso Junior, Joao A.; Silva, Nestor C. da; Lima, Ana Lucia V.P.; Camargo, Fabio de; Nieto, Renata C.; Moraes, Vanessa; Landini, Liliane [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2002-07-01

    The project for the preparation of a gel of zirconium molybdate for use in the generators of {sup 99} Mo/{sup 99m}Tc is part of the program of radioisotope production nationalization carried out at IPEN. Nowadays {sup 99} Mo used in the generators distributed by the Instituted is imported and produced by {sup 235} U fission. This work describes the actual situation of the project, in which {sup 99} Mo is produced by the {sup 98} Mo(n,{gamma}){sup 99} Mo using IPEN's IEA-R1m reactor and further submitted to a chemical reaction with Zr under adequate conditions to produce the gel of zirconium molybdate. The results of the tests with the pilot plant will also be presented, and the results compared with those obtained at laboratory level, were some variables have been studied, such as: pH of the solution containing the gel, initial concentration of Mo and Zr, reaction temperature and addition order of the reagents. An estimative of the routine production of {sup 99} Mo/{sup 99m}Tc gel type generators will also be given. (author)

  9. Structures and magnetic properties of double perovskites A sub 2 LnMO sub 6 and 6H-perovskites Ba sub 3 LnRu sub 2 O sub 9 (A=Sr, Ba; Ln=Y, lanthanides; M=Nb, Ta, Ru)

    CERN Document Server

    Hinatsu, Y

    2003-01-01

    This account describes the synthesis, crystal structures and magnetic properties of double perovskites A sub 2 LnMO sub 6 and 6H-perovskites Ba sub 3 LnRu sub 2 O sub 9 (A=Sr, Ba; Ln=Y, lanthanides; M=Nb, Ta, Ru). The double perovskites A sub 2 LnMO sub 6 have two kinds of cations, Ln and M, in the B site of the perovskite ABO sub 3. These cations adopt the alternative ordered arrangement. Measurements of the magnetic susceptibility, specific heat, and powder neutron diffraction showed that all of the A sub 2 LnRuO sub 6 compounds exhibited an antiferromagnetic transition at low temperatures and a complex temperature dependence of the magnetic susceptibility below their transition temperatures. In these compounds, the magnetic interaction between the Ln (4f electrons) and Ru (4d electrons) ions via the Ln-O-Ru pathway contributes greatly to their magnetic cooperative phenomena. The structural and magnetic studies for the 6H-perovskites Ba sub 3 LnRu sub 2 O sub 9 show that the Ln cations occupy the corner-sha...

  10. Influence of the Ti concentration and of the Ti:Mo molar ratio, in the efficiency of the {sup 99} Mo - {sup 99m} Tc generator, at basis of gels of titanium molybdates; Influencia de la concentracion de Ti y de la relacion molar Ti:Mo, en la eficiencia del generador {sup 99} Mo - {sup 99m} Tc a base de geles de molibdatos de titanio

    Energy Technology Data Exchange (ETDEWEB)

    Cortes R, O.; Monroy G, F.; Martinez C, T. [Facultad de Quimica, UNAM, 04510 Mexico D.F. (Mexico)]. e-mail: ocielcr@hotmail.com

    2003-07-01

    The {sup 99m} Tc, continues being the radionuclide more used in nuclear medicine to world scale. The production of this radioisotope, is carried out by means of generators {sup 99} Mo/{sup 99m} Tc that get ready commercially with {sup 99} Mo of high specific activity, adsorbed in alumina (2 mg {sup 99} Mo/g alumina) and that they are elutriated every 23 hours. In an alternative way, it is intended to use gels of titanium molybdates, as matrices of this generators. The gels are synthesized starting from solutions of ammonium molybdates and of titanium tetrachloride in aqueous media. These gels allow to incorporate until 25% of molybdenum in their structure, being been able to use {sup 99} Mo of low specific activity that can be obtained starting from the reaction {sup 98} Mo (n, {gamma}) {sup 99} Mo. With the object of producing generators of medium activity, with the base of gels of titanium molybdates, intends in this work, to study the influence of two synthesis parameters of these gels: the concentration of the titanium solutions and the molar ratio Ti: Mo. The decrease of the concentration of the titanium solution, used during the synthesis of the gels, is converted in an efficiency decrease and radionuclide purity of the generators, as well as an increment so much of the volume of elutriation, as of the pH of the elutriates. The gels that contain an major number of titanium moles, regarding the molybdenum moles, present a greater radionuclide purity, but they diminish their efficiency. The best characteristics for the gels synthesis of titanium molybdates are: a molar ratio 1:1 for Ti and Mo, and to use solutions of titanium whose concentration is near at 1 M. (Author)

  11. Study of the titanium molybdate gel performance for {sup 99} Mo/{sup 99m}Tc generators utilization; Estudo do desempenho do gel de molibdenio com titanio para utilizacao nos geradores de {sup 99} Mo/{sup 99m}Tc

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Vanessa; Nieto, Renata C.; Camargo, Fabio de; Osso Junior, Joao A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2002-07-01

    {sup 99m}Tc is the most used radioisotope in Nuclear Medicine for kidney, brain, liver, lung and bone scans, due to its nuclear properties. It is produced from the radioactive decay of {sup 99} Mo, the basis for a radioisotope generator system. {sup 99} Mo can be produced by several nuclear reactions in nuclear reactors and cyclotrons. In this work, {sup 99} Mo will be produced by {sup 98} Mo (n, {gamma}) {sup 99} Mo reaction and a gel type chromatographic generator will be prepared, containing molybdenum and titanium. This study is part of the radioisotope production nationalization politics at IPEN-CNEN/SP. The gel type generator is prepared by mixing a titanium chloride solution at proper pH with molybdenum oxide dissolved at proper pH, with stirring and further filtration, drying and cracking of the gel. The following variables were studied: mass relation of Mo and Ti, NaOH concentration, temperature and final pH. The gel characterization consisted of particle size distribution and quantitative analysis of Mo and Ti. These results will be compared with those obtained with the gel containing Mo and Zr. (author)

  12. Microstructure and property of the Ti-24Al-15Nb-1.5Mo/TC11 joint welded by electron beam welding

    Institute of Scientific and Technical Information of China (English)

    Ying-ying Liu; Ze-kun Yao; Hong-zhen Guo; Hang-hang Yang

    2009-01-01

    The Ti-24Al-15Nb-1.5Mo alloy, in the as-forged and heat-treated states, was joined to the as-forged TC11 titanium alloy by electron beam welding with the heat inputs of 135 and 150 kJ/m. Then the microstructure and property of the Ti-24Al-15Nb-1.5Mo/TC11 welding interface were investigated. The results show that the phase constitution of the weld is not related to the heat input, and is mainly composed of α' phase. Moreover, the intermetallic phases of Ti_2AlNb, MoNb, Nb_3Al, and TiAl_3 are formed in the weld zone. Therefore, the microhardness value of the weld zone is higher than that of the other portions in the same sample. The profile of the weld is asymmetrically funnel-like. The grain sizes of the weld and its heat-affected zones are increased with increasing heat input. There is an obvious difference in the element content of the welding interface; only the alloying elements in the fusion zone reach a new balance during solidification.

  13. Performance study of molybdenum gels with titanium for preparation of {sup 99}Mo-{sup 99m}Tc generators; Estudo do desempenho de geis de molibdenio com titanio no preparo de geradores de {sup 99}Mo-{sup 99m}Tc

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Vanessa; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: vmoraes@ipen.br

    2005-07-01

    {sup 99m}Tc is the most used radioisotope in Nuclear Medicine, due to nuclear characteristics. It is obtained by the radioactive decay of {sup 99}Mo, generator of radioisotope system. When {sup 99}Mo is produced by the activation in reactor, the most used technique for the preparation of the generators is the gel type generator, which incorporates {sup 99}Mo to the gel that is insoluble, chemically inert to the solutions and with properties of ion exchange. Several countries had already studied this methodology, as is the case of Vietnam, India, China, Australian. This work has the objective of studying the performance and characterization of molybdenum gels with titanium. Four variables in the preparation of the gel were studied: mass ratio between Mo and Ti (1.80 and 2.25), concentration of NaOH (2 and 4 mol/L), final temperature (25 and 50 deg C) and pH (3.5 and 4.5). The prepared gels were analyzed with relation to the size of its particles, identification of its structure, amount of molybdenum, amount of titanium, profile of elution, pH of the elution, determination of the radioisotopes in the eluate and final radiochemical purity. The final result is a formularization of the gel with the best characteristics for posterior preparation of the generator of {sup 99m}Tc-{sup 99}Mo. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-15

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

  15. Influence of alumina phases on the molybdenum adsorption capacity and chemical stability for {sup 99}Mo/{sup 99m}Tc generators columns

    Energy Technology Data Exchange (ETDEWEB)

    Guedes-Silva, Cecilia C.; Ferreira, Thiago dos Santos; Paula, Carolina M. de; Otubo, Larissa, E-mail: cecilia.guedes@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Carvalho, Flavio M.S. [Universidade de Sao Paulo (IGC/USP), SP (Brazil). Instituto de Geociencias

    2016-07-15

    Technetium-{sup 99m} is the clinically most used radionuclide worldwide. Although many techniques can be applied to separate {sup 99}Mo and {sup 99m}Tc, the most commonly used method is the column chromatography with alumina as stationary phase. However, the alumina nowadays used has limited adsorption capacity of molybdate ions which implies the need to develop or improve materials to produce high specific activity generators. In this paper, alumina was obtained by a solid state method and heat treatments at different conditions. The powders had a microstructure with porous particles of γ, δ, θ and α-Al{sub 2}O{sub 3} phases as well as specific surface area between 36 and 312 m{sup 2} g{sup -1}. Most interesting results were reached by powders calcined at 900 deg C for 5 hours which had high chemical stability and a molybdenum adsorption capacity of 92.45 mg Mo per g alumina. (author)

  16. Electroless Ni-P-MoS2 Composite Coating on TC4 Titanium Alloy%TC4钛合金表面化学镀Ni-P-MoS2复合镀层

    Institute of Scientific and Technical Information of China (English)

    林翠; 吴群英; 赵晓斌

    2015-01-01

    研究了搅拌方式、表面活性剂种类及用量对Ni-P-MoS2复合镀层沉积速率、MoS2微粒复合量及分布的影响,借助三维视频显微镜、扫描电镜、能谱仪观察了复合镀层的形貌及镀层中各元素的含量与分布,研究了MoS2微粒在镀液中的活化与其沉积方式.结果表明,间歇搅拌保证镀液中的离子和微粒均匀分散的同时也减少了MoS2微粒的脱落,故能加快沉积速率,促进MoS2微粒含量的增加和均匀分布.在特性吸附和“空间位阻”效应的共同作用下,单一阳离子型表面活性剂的使用保证了镀层沉积速率和MoS2微粒复合量;由于阴阳离子表面活性的强烈相互作用,使得复配表面活性剂有利于MoS2微粒在复合镀层中的均匀分布.镀液中被活化的MoS2微粒通过搅拌和电场作用到达Ni-P层表面,而未被活化的MoS2微粒则仅依靠搅拌作用靠近Ni-P层表面,经催化作用,完全活化和部分活化MoS2微粒被Ni-P层完全或部分包裹,未被活化的MoS2微粒则吸附在Ni-P表面且易脱落.

  17. Synthesis and Characterization of the Chiral Skeleton Cluster [NiRuMo(CO)5(μ3-S)(η5-C5H5)(η5-C5H4COCH3)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The new chiral cluster [NiRuMo(CO)5(μ3-S)(η5-C5H5(5-C5H4COCH3)] 3 was synthesized by the reaction of precursor [CoRuMo(CO)8(μ3-S(η5-C5H4COCH3)] 1 with NiCp2 2 in refluxing THF. It was characterized by C/H elemental analysis, IR and 1H NMR. Molecular structure of cluster 3 was determined by single-crystal X-ray analyses. Crystal data: triclinic, space group Pī with the following crystallographic parameters: a = 7.9606(8), b = 8.5604(9), c = 14.779(2)A, = 93.908(2), = 105.057(2), = 101.463(2)°, C17H12O6MoNiRuS, Mr = 600.0(5), Z = 2, V = 945.5(2)A3, Dc = 2.108 g/cm3, = 2.568 mm-1, 2 max 2.00σ(I).

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

    KAUST Repository

    Peskov, Maxim

    2013-03-14

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

  19. Synthesis, structural characterization and antioxidant activity of some vanadium(IV), Mo(VI)/(IV) and Ru(II) complexes of pyridoxal Schiff base derivatives

    Science.gov (United States)

    Elsayed, Shadia A.; Noufal, Aya M.; El-Hendawy, Ahmed M.

    2017-09-01

    New complexes containing vanadium(IV), Mo(VI)/(IV) and Ru(II) derived from Schiff base of pyridoxal and S-benzyldithiocarbazate (H2pysb) or p-toluidine (Hpytol) have been prepared. The structures of the described compounds were elucidated by elemental analyses, spectroscopic techniques (IR, 1H NMR, UV-Vis and EPR) magnetism, molar conductivity and thermal analysis measurements. Their redox behaviors were also studied by cyclic voltammetry. The ligand H2pysb showed coordination to the metal ions in a dibasic tridenate manner through deprotonated phenolate oxygen, azomethine nitrogen and thiolate sulfur, while Hpytol behaved as monobasic bidentate through phenolate oxygen and azomethine nitrogen. The complexes were tested for their antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and the data obtained revealed that the scavenging activity of the complexes towards DPPH is high for the oxovanadium(IV) complexes with lower IC50 values which are comparable to ascorbic acid as a standard antioxidant. The EC50 concentration ratio together with other antioxidant parameters are also reported.

  20. Study and optimization of the conditions for the preparation of the gel of zirconium molybdate used in the sup 9 sup 9 Mo- sup 9 sup 9 sup m Tc generators

    CERN Document Server

    Silva, N C D

    2001-01-01

    The gel type generator of sup 9 sup 9 Mo- sup 9 sup 9 sup m Tc has been an important alternative for the supply of the most used radioisotope in clinical applications, sup 9 sup 9 sup m Tc. The objective of this work was to define the best preparation conditions of the gel that will allow the best performance of a sup 9 sup 9 Mo- sup 9 sup 9 sup m Tc gel type generator, from the study of the process variables that once defined, introduce them in the experimental procedure of the project under way at IPEN. Nowadays the sup 9 sup 9 Mo employed in the generators is imported and produced by sup 2 sup 3 sup 5 U fission. In the method here described, sup 9 sup 9 Mo was produced by the sup 9 sup 8 Mo(n,gamma) sup 9 sup 9 Mo reaction through the irradiation of MoO sub 3 at the IEA-R1m reactor, and further it was subjected to a chemical reaction with zirconium under adequate conditions in order to produce the zirconium molybdate gel. In order to study variables such as: reagent addition order, final pH of the solution...

  1. Electronic structures and properties of eight-coordinate metal-polyarsenic complexes MAs8n- (M = V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re).

    Science.gov (United States)

    Li, J; Wu, K

    2000-04-03

    The eight-coordinate early transition metal polyarsenic complexes, MAs(8)3- (M = V, Nb, Ta), MAs(8)2- (M = Cr, Mo, W), and MAs8- (M = Mn, Tc, Re), have been studied using density functional theory (DFT). The geometry optimizations of these complexes indicate that in the most stable structures the transition metal atoms are trapped in a crownlike cavity consisting of a zigzag eight-membered ring of As8 cluster. The scalar-relativistic effects and spin-orbit coupling effects on the electronic structures and energy levels were taken into account. The stabilities of gas-phase MAs8n- ions and bonding between the As8 ring and early transition metals are discussed on the basis of population analysis, atomization energies, and decomposition reaction energies. All these complex ions are found to be diamagnetic with notable HOMO-LUMO energy gaps. The vibrational frequencies and infrared absorption intensities of the MAs8n- series are predicted theoretically. Brief theoretical calculations of the similar MoA(8)2- pnictide ions indicate that the analogous P, Sb, and even Bi complexes are likely to be stable, whereas the crownlike MoN(8)2- is not a stable complex.

  2. Screening on binary Zr-1X (X = Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi) alloys with good in vitro cytocompatibility and magnetic resonance imaging compatibility.

    Science.gov (United States)

    Zhou, F Y; Qiu, K J; Li, H F; Huang, T; Wang, B L; Li, L; Zheng, Y F

    2013-12-01

    In this study, the microstructures, mechanical properties, corrosion behaviors, in vitro cytocompatibility and magnetic susceptibility of Zr-1X alloys with various alloying elements, including Ti, Nb, Mo, Cu, Au, Pd, Ag, Ru, Hf and Bi, were systematically investigated to explore their potential use in biomedical applications. The experimental results indicated that annealed Zr-1X alloys consisted entirely or primarily of α phase. The alloying elements significantly increased the strength and hardness of pure Zr and had a relatively slight influence on elastic modulus. Ru was the most effective enhancing element and Zr-1Ru alloy had the largest elongation. The results of electrochemical corrosion indicated that adding various elements to Zr improved its corrosion resistance, as indicated by the reduced corrosion current density. The extracts of the studied Zr-1X alloys produced no significant deleterious effects on osteoblast-like cells (MG 63), indicating good in vitro cytocompatibility. All except for Zr-1Ag alloy showed decreased magnetic susceptibility compared to pure Zr, and Zr-1Ru alloy had the lowest magnetic susceptibility value, being comparable to that of α' phase Zr-Mo alloy and Zr-Nb alloy and far lower than that of Co-Cr alloy and Ti-6Al-4V alloy. Among the experimental Zr-1X alloys, Zr-1Ru alloy possessing high strength coupled with good ductility, good in vitro cytocompatibility and low magnetic susceptibility may be a good candidate alloy for medical devices within a magnetic resonance imaging environment. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Chemical Coupling SERS Properties of Pyridine on Silver-Caged Metal Clusters M@Ag12 (M = V-, Nb-, Ta-, Cr, Mo, W, Mn+, Tc+, Re+)

    Science.gov (United States)

    Chen, Lei; Wang, Zhigang; Li, Zhengqiang; Zhang, Rui-Qin

    2017-07-01

    Using density functional theory, this work presents a comprehensive analysis of nonresonant surface-enhanced Raman scattering enhancement of pyridine on M@Ag12 (M = V-, Nb-, Ta-, Cr, Mo, W, Mn+, Tc+, Re+). Computational results indicate that the chemical enhancement of pyridine on M@Ag12 is closely associated with the charge properties of silver-caged clusters. Pyridine on negative clusters exhibits the strongest chemical enhancement with a factor of about 103, while the chemical enhancement is only about 102 for pyridine on neutral clusters and 10 for pyridine on positive clusters. The polarizability analyses elucidate the nature of the chemical enhancement that delocalized electrons of negative adsorption systems occupy higher molecular orbitals than those of neutral and positive adsorption systems, which can lead to stronger nonresonant chemical enhancement.

  4. Chemical Coupling SERS Properties of Pyridine on Silver-Caged Metal Clusters M@Ag12 (M = V-, Nb-, Ta-, Cr, Mo, W, Mn+, Tc+, Re+)

    Science.gov (United States)

    Chen, Lei; Wang, Zhigang; Li, Zhengqiang; Zhang, Rui-Qin

    2016-10-01

    Using density functional theory, this work presents a comprehensive analysis of nonresonant surface-enhanced Raman scattering enhancement of pyridine on M@Ag12 (M = V-, Nb-, Ta-, Cr, Mo, W, Mn+, Tc+, Re+). Computational results indicate that the chemical enhancement of pyridine on M@Ag12 is closely associated with the charge properties of silver-caged clusters. Pyridine on negative clusters exhibits the strongest chemical enhancement with a factor of about 103, while the chemical enhancement is only about 102 for pyridine on neutral clusters and 10 for pyridine on positive clusters. The polarizability analyses elucidate the nature of the chemical enhancement that delocalized electrons of negative adsorption systems occupy higher molecular orbitals than those of neutral and positive adsorption systems, which can lead to stronger nonresonant chemical enhancement.

  5. DFT investigation of electronic structures and magnetic properties of halides family MeHal3 (Me=Ti, Mo,Zr,Nb, Ru, Hal=Cl,Br,I) one dimensional structures

    Science.gov (United States)

    Kuzubov, A. A.; Kovaleva, E. A.; Popova, M. I.; Kholtobina, A. S.; Mikhaleva, N. S.; Visotin, M. A.; Fedorov, A. S.

    2017-10-01

    Using DFT GGA calculations, electronic structure and magnetic properties of wide family of transition metal trihalides (TMHal3) (Zr, Ti and Nb iodides, Mo, Ru, Ti and Zr bromides and Ti or Zr chlorides) are investigated. These structures consist of transition metal atoms chains surrounded by halides atoms. Chains are connected to each other by weak interactions. All TMHal3 compounds were found to be conductive along chain axis except of MoBr3 which is indirect gap semiconductor. It was shown that NbI3 and MoBr3 have large magnetic moments on metal atoms (1.17 and 1.81 μB, respectively) but other TMHal3 materials have small or zero magnetic moments. For all structures ferromagnetic and anti-ferromagnetic phases have almost the same energies. The causes of these properties are debated.

  6. Effects of co-doped Mo and W on catalytic performances of Ru-Se nano-cluster for oxygen reduction%Mo和W共掺杂对Ru-Se簇合物催化氧还原性能的影响

    Institute of Scientific and Technical Information of China (English)

    赵东江; 马松艳

    2014-01-01

    以过渡金属羰基化合物和硒粉为原料,采用低温回流技术在1,6-己二醇中合成了W和Mo共掺杂的Ru-Mo-W-Se纳米簇合物。利用SEM、XRD和旋转圆盘电极( RDE)技术表征了合成催化剂的形貌、结构和电催化性能。催化剂以六方结构的Rux簇为主相,同时形成无定形相,聚集颗粒高度分散。在氧气饱和的0.5 mol·dm-3 H2 SO4溶液中,Ru-W-Mo-Se催化剂对氧还原反应( ORR)表现出较高的催化活性和稳定性,开路电位为0.90 V( vs. NHE),耐甲醇能力比Ru-Se明显增强。在Tafel电位范围内,催化剂的交换电流密度为4.98×10-4 mA·cm-2,具有较好的催化动力学性能。%The Ru-W-Mo-Se nanometric cluster was synthesized by decarbonylation of transition metal carbonyl compounds in 1,6-hexanediol solvent containing dissolved selenium under refluxing conditions. The structure,morphology and electrocatalytic perform-ances of the as-prepared catalyst were characterized by SEM,XRD and rotating disk electrode( RDE) technique. The sample main-tained the hexagonal structure of Rux cluster as the main phase,formed an amorphous phase and presented a highly dispersed parti-cles. The catalyst demonstrated higher electrocatalytic activity, better stability and methanol tolerant than that of Ru-Se catalyst, showing an open circuit potential( OCP) of 0. 90 V( vs. NHE) in 0. 5 mol dm-3 H2 SO4 saturated with oxygen. The exchange current density was calculated to be 4. 98×10-4 mA cm-2 in Tafel potential region.

  7. Correlation factors for C-14, Cl-36, Ni-59, Ni-63, Mo-93, Tc-99, I-129 and Cs-135. In operational waste for SFR 1

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, Maria; Pettersson, Michael; Wiborgh, Marie (Kemakta AB, Stockholm (SE))

    2007-01-15

    The use of correlation factors is one possibility to estimate a reference radionuclide inventory for the purpose of safety assessment studies, when waste-type specific information is not at hand. The correlation factor approach requires that there is a correlation between the activity content of the difficult-to-measure nuclide and the key nuclide. A safety assessment of a future deep repository for low and intermediate level waste (SFL 3-5) was conducted during the second half of the 1990's. Within that project, correlation factors for estimating the inventory of radionuclides which are difficult to measure experimentally were developed. These factors have also partly been used to estimate a reference inventory for SFR 1. Based on a literature survey and recent reports published by SKB, it is concluded that new information is available making an update of some correlation factors relevant. For these radionuclides, reported data from estimations and measurements of radionuclide content and correlation factors in different types of radioactive wastes are summarised. The data is evaluated and updated correlation factors representative for fresh waste for eight radionuclides (C-14, Cl-36, Ni-59, Ni-63, Mo-93, Tc-99, I-129 and Cs-135) are suggested. New information from measurements in Swedish NPP has made it possible to define factors that are BWR and PWR specific for C-14, Ni-59 and Ni-63. The uncertainties in suggested data and the applicability of the correlation factors for estimates of the radionuclide content in operational waste are commented upon

  8. High performance Mo adsorbent PZC

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1998-10-01

    We have developed Mo adsorbents for natural Mo(n, {gamma}){sup 99}Mo-{sup 99m}Tc generator. Among them, we called the highest performance adsorbent PZC that could adsorb about 250 mg-Mo/g. In this report, we will show the structure, adsorption mechanism of Mo, and the other useful properties of PZC when you carry out the examination of Mo adsorption and elution of {sup 99m}Tc. (author)

  9. New observation of 2{beta}2{nu} decay of {sup 100}Mo to the 0{sup +}{sub 1} level of {sup 100}Ru in the ARMONIA{sup 1} experiment

    Energy Technology Data Exchange (ETDEWEB)

    Belli, P; Bernabei, R; D' Angelo, S; Nozzoli, F [Dipartimento di Fisica, Universita di Roma ' Tor Vergata' and INFN, Sezione di Roma ' Tor Vergata' , I-00133, Roma (Italy); Boiko, R S; Danevich, F A; Kobychev, V V; Kropivyansky, B N; Nagorny, S S; Poda, D V; Polischuk, O G; Tretyak, V I; Vyshnevskyi, I M [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Cappella, F; Incicchitti, A; Prosperi, D [Dipartimento di Fisica, Universita di Roma ' La Sapienza' and INFN, Sezione di Roma, I-00185, Roma (Italy); Cerulli, R; Laubenstein, M; Nisi, S [INFN, Laboratori Nazionali del Gran Sasso, I-67010 Assergi (Italy); Nagornyi, P G, E-mail: bernabei@roma2.infn.i [Chemical Department, Kyiv National Taras Shevchenko University, 01033 Kyiv (Ukraine)

    2010-01-01

    Sample of {sup 100}MoO{sub 3} with molybdenum enriched in {sup 100}Mo to 99.5% and mass of 1199 g was measured deep underground (3600 m w.e.) in the Laboratori Nazionali del Gran Sasso of INFN, Italy; during 17249 h with a low-background set-up with 4 HP Ge detectors. After 2{beta}2{nu} decay of {sup 100}Mo to the 0{sup +}{sub 1} excited level of {sup 100}Ru (E{sub exc} = 1131 keV), two {gamma} quanta of 540 keV and 591 keV should be emitted in deexcitation process. Both these {gamma}'s are observed in the accumulated data as in coincidence spectrum as well in 1-dimensional sum spectrum. Measured half life is T{sub 1/2} (7.0{sup +1.1}{sub -0.8}) x 10{sup 20} yr, in agreement with positive results obtained in previous experiments.

  10. Ligand dependence of metal-metal bonding in the d(3)d(3) dimers M(2)X(9)(n-) (M(III) = Cr, Mo, W; M(IV) = Mn, Tc, Re; X = F, Cl, Br, I).

    Science.gov (United States)

    Stranger, R; Turner, A; Delfs, C D

    2001-08-13

    The ligand dependence of metal-metal bonding in the d(3)d(3) face-shared M(2)X(9)(n-) (M(III) = Cr, Mo, W; M(IV) = Mn, Tc, Re; X = F, Cl, Br, I) dimers has been investigated using density functional theory. In general, significant differences in metal-metal bonding are observed between the fluoride and chloride complexes involving the same metal ion, whereas less dramatic changes occur between the bromide and iodide complexes and minimal differences between the chloride and bromide complexes. For M = Mo, Tc, and Re, change in the halide from F to I results in weaker metal-metal bonding corresponding to a shift from either the triple metal-metal bonded to single bonded case or from the latter to a nonbonded structure. A fragment analysis performed on M(2)X(9)(3-) (M = Mo, W) allowed determination of the metal-metal and metal-bridge contributions to the total bonding energy in the dimer. As the halide changes from F to I, there is a systematic reduction in the total interaction energy of the fragments which can be traced to a progressive destabilization of the metal-bridge interaction because of weaker M-X(bridge) bonding as fluoride is replaced by its heavier congeners. In contrast, the metal-metal interaction remains essentially constant with change in the halide.

  11. Equilibrium and pre-equilibrium calculations of cross-sections of (, ) reactions on 89Y, 90Zr and 94Mo targets used for the production of 89Zr, 90Nb and 94Tc positron-emitting radionuclides

    Indian Academy of Sciences (India)

    R Baldik; H Aytekin; E Tel

    2013-02-01

    In this study, the pre-equilibrium and equilibrium calculations of cross-sections of 89Y(, ), 90Zr$(p, xn)$ and 94Mo(, ) reactions, which were used for the production of 89Zr, 90Nb and 94Tc positron-emitting radioisotopes, have been investigated. Pre-equilibrium calculations have been performed at different proton incident energies by using the hybrid, geometry-dependent-hybrid and full exciton models. The Weisskopf–Ewing model is used for calculating the equilibrium effects at the same incident energies. The calculated results have been discussed and compared with the experimental results.

  12. Agostic interaction in the methylidene metal dihydride complexes H2MCH2 (M=Y, Zr, Nb, Mo, Ru, Th, or U).

    Science.gov (United States)

    Roos, Björn O; Lindh, Roland; Cho, Han-Gook; Andrews, Lester

    2007-07-19

    Multiconfigurational quantum chemical methods (complete active space self-consistent field (CASSCF)/second-order perturbation theory (CASPT2)) have been used to study the agostic interaction between the metal atom and H(C) in the methylidene metal dihydride complexes H2MCH2, where M is a second row transition metal or the actinide atoms Th or U. The geometry of some of these complexes is highly irregular due to the formation of a three center bond CH...M, where the electrons in the CH bond are delocalized onto empty or half empty orbitals of d- or f-type on the metal. No agostic interaction is expected when M=Y, where only a single bond with methylene can be formed, or when M=Ru, because of the lack of empty electron accepting metal valence orbitals. The largest agostic interaction is found in the Zr and U complexes.

  13. First principle research of possible HM-AFM in double perovskites A2MoOsO6 and A2TcReO6 (A = Si, Ge, Sn, and Pb) with group IVA elements set on the A-site position

    Science.gov (United States)

    Fuh, Huei-Ru; Liu, Yun-Ping; Wang, Yin-Kuo

    2013-05-01

    We calculated electronic structures of double perovskite structures of A2MoOsO6 and A2TcReO6 (A = Si, Ge, Sn, and Pb) based on the density functional theory which was carried out with a full structural optimization using generalized gradient approximation and taking into account the correlation effect (GGA + U). In GGA calculation, Pb2TcReO6 shows a half-metallic antiferromagnet (HM-AFM) characteristic, whereas Sn2MoOsO6, Pb2MoOsO6, and Sn2TcReO6 are nearly HM-AFMs. With GGA + U calculation, Sn2MoOsO6 and Pb2MoOsO6 become stable HM-AFM, but Sn2TcReO6 and Pb2TcReO6 changes HM-AFM into an antiferromagnetic insulator. The p-d hybridization between B(B')d-Op and double exchange interaction is the mean reason to result in the half-metallic and compensated ferrimagnetic phase.

  14. Nanoporous magnets of chiral and racemic [{Mn(HL)}2Mn{Mo(CN)7}2] with switchable ordering temperatures (TC = 85 K 106 K) driven by H2O sorption (L = N,N-dimethylalaninol).

    Science.gov (United States)

    Milon, Julie; Daniel, Marie-Christine; Kaiba, Abdellah; Guionneau, Philippe; Brandès, Stéphane; Sutter, Jean-Pascal

    2007-11-14

    Molecule-based solids represent a rare opportunity to combine, adjust, and interrelate structural and physical functionalities to develop multifunctional materials. Here we report on a series of porous supramolecular magnets whose magnetic properties are related to their sorption state. A family of magnets of the formula [{Mn(HL)(H2O)}2Mn{Mo(CN)7}2].2H2O have been obtained by assembling the heptacyano-metalate building unit {Mo(CN)7}4- with Mn(II) in the presence of protonated N,N-dimethylalaninol (L) as ligand, the latter being either as a racemic mixture or as a chiral R- or S-enantiomer. The resulting magnets possess an open framework structure and exhibit a TC with a switching behavior (TC = 85 K 106 K) as a function of the hydration state. Moreover, chiral magnets are formed with the optically active ligands. The H2O and gas (N2, CO2, CO) sorption features, the magnetic behavior of both the hydrated and dehydrated magnets, and the crystal structures of the hydrated chiral (S) and racemic magnets are described.

  15. Fiscal Year 2010 Summary Report on the Epsilon-Metal Phase as a Waste Form for 99 Tc

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, Denis M.; Crum, Jarrod V.; Buck, Edgar C.; Riley, Brian J.; Zumhoff, Mac R.

    2010-09-30

    Epsilon metal (ε-metal) is generated in nuclear fuel during irradiation. This metal consists of Pd, Ru, Rh, Mo, and some Te. These accumulate at the UO2 grain boundaries as small (ca 5 µm) particles. These metals have limited solubility in the acid used to dissolve fuel during reprocessing and in typical borosilicate glass. These must be treated separately to improve overall waste loading in glass. This low solubility and their survival in 2 Gy-old natural reactors led us to investigate them as a waste form for the immobilization of 99Tc and 107Pd, two very long-lived isotopes.

  16. 4-d magnetism: Electronic structure and magnetism of some Mo-based alloys

    Science.gov (United States)

    Liu, Yong; Bose, S. K.; Kudrnovský, J.

    2017-02-01

    We report results of a first-principles density-functional study of alloys of the 4 d -element Mo with group IV elements Si, Ge and Sn in zinc blende (ZB) and rock salt (RS) structures. The study was motivated by a similar study of ours based on the 4 d -element Tc, which showed the presence of half-metallic states with integer magnetic moment (1μB) per formula unit in TcX (X=C, Si, Ge) alloys. The calculated Curie temperatures for the ferromagnetic (FM) phases were low, around or less than 300 K. Searching for the possibility of 4 d -based alloys with higher Curie temperatures we have carried out the study involving the elements Mo, Ru and Rh. Among these the most promising case appears to be that involving the element Mo. Among the MoX (X=Si, Ge, Sn) alloys in ZB and RS structures, both MoGe and MoSn in ZB structures are found to possess an integer magnetic moment of 2μB per formula unit. ZB MoSn can be classified as a marginal/weak half-metal or a spin gapless semiconductor, while ZB MoGe would be best described as a gapless magnetic semiconductor. The calculated Curie temperatures are in the range 300-700 K. Considering the theoretical uncertainty in the band gaps due not only to the treatment of exchange and correlation effects, but density functional theory itself, these classifications may change somewhat, but both merit investigation from the viewpoint of potential spintronic application. Based on their higher Curie temperatures, Mo-based alloys would serve such purpose better than the previously reported Tc-based ones.

  17. MO-F-CAMPUS-I-05: Radiation Dosimetry of 99mTc-IDA-D-[c(RGDfK)]2, a SPECT Agent for Angiogenesis Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2015-06-15

    Purpose: Tc-99m labeled IDA-D-[c(RGDfK){sub 2} ( {sup 99m}Tc-RGD) is a recently developed radiotracer for gamma camera or single photon emission computed tomography (SPECT) imaging and promising agent for the visualization of angiogenesis. In this study, we investigated the internal radiation dosimetry of {sup 99m}Tc-RGD in humans. Methods: Six normal controls (F:M=4:2; 68.3±3.2 years; 56.5±10.7 kg) were participated in this study. Simultaneous anterior and posterior scans of whole-body were performed using dual head gamma camera system. Before the emission scan, transmission scan was performed just before injection of {sup 99m}Tc-RGD using Co-57 flood source. After an intravenous injection of 388.7±29.3 MBq of {sup 99m}Tc-RGD, six serial emission scans were performed at 0, 1, 2, 4, 8 and 24 hours post-injection. The anterior and posterior images were geometrically averaged and attenuation correction was applied using transmission scan image. Regions of interest (ROIs) were drawn on liver, gallbladder, kidneys, urinary bladder, spleen, brain, and large intestine. Time activity curves were obtained from serial emission scan and ROIs. The number of disintegrations per unit activity administered (residence time) were calculated from the area under the curve of time activity curves and injected dose of each patient. Finally, the radiation dose for each organ and effective doses were obtained using OLINDA/EXM 1.1 software and residence time. Results: High radiation doses were reported on renal and biliary excretion tracks such as urinary bladder wall, upper large intestine, kidneys, liver and gallbladder wall and their doses were 19.15±6.84, 19.28±4.78, 15.67±0.90, 9.13±1.71 and 9.09±2.03 µGy/MBq, respectively. The effective dose and effective dose equivalent were 5.08±0.53 and 7.11±0.58 µSv/MBq, respectively. Conclusion: We evaluated the radiation dose of 99mTc-RGD, which has an acceptable effective radiation dose compare to the other Tc-99m labeled radio-tracers.

  18. 钎焊工艺参数对C/C复合材料/Cu/Mo/TC4钎焊接头微观组织的影响%Effects of Brazing Parameters on Microstructures of C/C Composite/Cu/Mo/TC4 Brazed Joints

    Institute of Scientific and Technical Information of China (English)

    秦优琼; 于治水

    2012-01-01

    在钎焊温度为820~940℃,钎焊时间为1~30min的条件下,采用TiZrNiCu钎料、Cu/Mo复合中间层对C/C复合材料和TC4进行了钎焊实验.利用扫描电镜及能谱仪对接头的界面组织进行了研究.结果表明:在较低工艺参数下,Cu/C/C复合材料界面结构为Cu/Cu51Zr14/Ti2 (Cu,Ni)+ Ti(Cu,Ni)+ TiCu+ Cu2TiZr/TiC/C/C复合材料.随着工艺参数的提高,TiCu和Cu2TiZr反应相逐渐消失,Ti(Cu,Ni)2新相生成,此时的界面结构为Cu/Cu51Zr14/Ti2 (Cu,Ni)+ Ti(Cu,Ni)+Ti(Cu,Ni)2/TiC/C/C复合材料.钎焊工艺参数较高时界面结构为Cu/Cu51Zr14/Cu(s.s)+Ti(Cu,Ni)2/TiC/C/C复合材料.随着钎焊温度的增加以及保温时间的延长,界面反应层Cu51Zr14和TiC反应层厚度增加.%C/C composite and TC4 were brazed using TiZrNiCu filler metal and Cu/Mo composite in-terlayers at 820-940℃ for l-30min. The interfacial microstructures were investigated by scanning electron microscopy and electron energy spectrum analysis. The results showed that the sequence of the interface structure at low brazing parameters can be described as the following: Cu/Cu51Zr14/Ti2 (Cu, Ni)+Ti(Cu,Ni)+TiCu+Cu2TiZr/TiC/C/C composite. With the increased brazing parameter, TiCu and Cu2TiZr disappeared, and Ti(Cu,Ni)2 appeared. The interface structure was changed to Cu/Cu5i Zri4/Ti2 (Cu,Ni)+Ti(Cu,Ni)+ Ti(Cu,Ni)2/TiC/C/C composite. For high brazing parameters, the interface structure was composed of Cu/Cu51 Zr14/Cu(s. s) + Ti(Cu, Ni)2/TiC/C/C composite. The thickness of Cu51Zr14and TiC reaction layers increased with the increased brazing temperature and the prolonged holding time.

  19. Extraction of Tc(VII) and Re(VII) on TRU resin

    Energy Technology Data Exchange (ETDEWEB)

    Guerin, Nicolas; Riopel, Remi; Kramer-Tremblay, Sheila [Canadian Nuclear Laboratories (CNL), Chalk River, ON (Canada). Radiobiology and Health Branch; De Silva, Nimal; Cornett, Jack [Ottawa Univ., ON (Canada). Dept. of Earth and Environmental Sciences; Dai, Xiongxin [China Institute for Radiation Protection, Beijing (China)

    2017-06-01

    TRU resin can be used to rapidly and selectively extract Tc(VII) and Re(VII). The retention capacity curves of Tc(VII) and Re(VII) for HNO{sub 3}, HCl, H{sub 2}SO{sub 4} and H{sub 3}PO{sub 4} solutions were studied and prepared. Tc(VII) and Re(VII) were simultaneously extracted in 2 M H{sub 2}SO{sub 4} and 1.5 M H{sub 3}PO{sub 4} and were effectively separated from Mo(VI) and Ru(III). Tc(VII) and Re(VII) remained strongly bonded to the resin even after washing using a large volume of 2 M H{sub 2}SO{sub 4} at a relatively high flow rate. Also, they were both completely eluted from the resin using 15 mL of near boiling water, an eluent directly compatible for ICP-MS instrument measurements.

  20. [N(CH3)4]2[Mn(H2O)]3[Mo(CN)7](2).2H2O: a new high Tc cyano-bridged ferrimagnet based on the [MoIII(CN)7]4- building block and induced by counterion exchange.

    Science.gov (United States)

    Larionova, Joulia; Clérac, Rodolphe; Donnadieu, Bruno; Guérin, Christian

    2002-06-17

    The title compound was synthesized by slow diffusion of aqueous solutions containing K4[Mo(CN)7].2H2O, [Mn(H2O)6](NO3)2, and [N(CH3)4]Cl. The compound crystallized in monoclinic space group C2/c, a = 25.8546(14), b = 12.3906(7), c = 13.5382(7) A, beta = 116.4170 (10) degrees, Z = 4, R = 0.0353, wR2 = 0.0456. The MoIII site is surrounded by six -C-N-Mn linkages and one terminal cyano group in a distorted capped-prism fashion. There are two pentahedral MnII sites in the structure, both with four -N-C-Mo linkages and one water molecule. The anisotropic three-dimensional structure consists of connected corrugated gridlike sheet layers parallel to the bc plane. Tetramethylammonium counterions ([N(CH3)4]+) located between these layers seem to induce their distortion. The three-dimensional organization may also be viewed as interconnected octagonal channels propagated along the c axis. The void space of these channels is occupied by coordinated and crystalized water molecules. Temperature and field dependence of the magnetization in both the dc and ac modes have been measured on polycrystalline sample. These investigations have revealed that the compound ordered ferrimagnetically at Tc = 86 K, with a small hysteresis effect. These findings have been compared to those reported previously for three- and two-dimensional materials of the same family.

  1. Ru isotope heterogeneity in the solar protoplanetary disk

    Science.gov (United States)

    Fischer-Gödde, Mario; Burkhardt, Christoph; Kruijer, Thomas S.; Kleine, Thorsten

    2015-11-01

    Nucleosynthetic isotope anomalies in bulk chondrites and differentiated meteorites reflect variable proportions of isotopically diverse presolar components in bulk planetary bodies, but the origin of these heterogeneities is not well understood. Here, the Ru isotope composition of a comprehensive suite of iron meteorites and bulk samples of ordinary, enstatite and carbonaceous chondrites, as well as acid leachates and an insoluble residue of the Allende chondrite are examined using newly developed multi-collector inductively coupled plasma mass spectrometry techniques. Except for IAB iron meteorites and enstatite chondrites, all investigated meteorites show well-resolved Ru isotope anomalies. Of these, within-group Ru isotopic variations observed for samples from a given chemical group of iron meteorites reflect secondary neutron capture induced Ru isotope shifts during prolonged cosmic ray-exposure. After correction of these cosmogenic effects using Pt isotopes as a neutron-dose monitor, the remaining Ru isotope anomalies are nucleosynthetic in nature and are consistent with a deficit in s-process Ru in iron meteorite parent bodies. Similarly, Ru isotope anomalies in bulk ordinary and carbonaceous chondrites also reflect a deficiency in s-process Ru. The sequential dissolution of Allende reveals the presence of an HF-soluble s-process carrier, which is either an unidentified presolar phase or a component that incorporated s-process Ru liberated from SiC grains during nebular or parent body processes. We show that varying proportions of the s-process carrier identified in Allende resulted in the correlated Ru isotope anomalies observed for bulk meteorites, and that all meteorites (except possibly IAB irons and enstatite chondrites) are depleted in this s-process component relative to Ru from the Earth's mantle. Bulk meteorites exhibit correlated Ru and Mo isotope anomalies, reflecting variable deficits of a common s-process component, but some iron meteorites and

  2. β-delayed proton decay of 89Ru

    Institute of Scientific and Technical Information of China (English)

    李占奎; 徐树威; 于涌; 谢元祥; 王春芳; 邢建萍; 潘强岩; 胡青元; 李世红; 陈红艳; 张天梅

    2000-01-01

    89Ru was synthesized in the reaction of 58Ni (36Ar, 2p3n) on the basis of a "p-γ" coincidence measurement by using a He-jet tape transport system, and its p-delayed proton emission with a half-life of (1.1 ±0.2) s was investigated. The p-delayed proton spectrum of 89Ru populating the low-lying states in 88Mo was obtained, and the final state proton branching ratios to the low-lying 2+ and 4 + states in88Mo were estimated to be 100:6. Based on the statistical model calculations, the ground state spin of 89Ru was preliminarily assigned to be 5/2+ or 7/2±, and the mass excess of 89Ru was deduced to be -59.5 MeV.

  3. β-delayed proton decay of 89Ru

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    89Ru was synthesized in the reaction of 58Ni (36Ar, 2p3n) on the basis of a "p-γ" coincidence measurement by using a He-jet tape transport system, and its β-delayed proton emission with a half-life of (1.1±0.2) s was investigated. The β-delayed proton spectrum of 89Ru populating the low-lying states in 88Mo was obtained, and the final state proton branching ratios to the low-lying 2+ and 4+ states in 88Mo were estimated to be 100:6. Based on the statistical model calculations, the ground state spin of 89Ru was preliminarily assigned to be 5/2+ or 7/2±, and the mass excess of 89Ru was deduced to be -59.5 MeV.

  4. Development of fission Mo-99 production technology

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Ho; Choung, W. M.; Lee, K. I. and others

    2000-05-01

    Fission Mo-99 is the only parent nuclide of Tc-99m, an extremely useful tool for mdeical diagnosis, with an estimated usage of greater than 80% of nuclear medicine applicatons. HEU and LEU targets to optimize in HANARO irradiation condition suggested and designed for domestic production of fission Mo-99. The optimum process conditions are established in each unit process to meet quality requirements of fission Mo-99 products, and the results of performance test in combined process show Mo separation and purification yield of the above 97%. The concept of Tc generator production process is established, and the result of performance test show Tc production yield of 98.4% in Tc generator procuction process. The drafts is prepared for cooperation of technical cooperation and business investment with foreign country. Evaluation on economic feasibility is accompanied for fission Mo-99 and Tc-99m generator production.

  5. sup 9 sup 9 Tc atom counting by quadrupole ICP-MS. Optimisation of the instrumental response

    CERN Document Server

    Mas, J L; Garcia-Leon, M

    2002-01-01

    In this paper, an extensive work is done on the specific tune of a conventional ICP-MS for sup 9 sup 9 Tc atom counting. For this, two methods have been used and compared: the partial variable control method and the 5D Simplex method. Instrumental limits of detection of 0.2 and 0.8 ppt, respectively, were obtained. They are noticeably lower than that found with the automatic tune method of the spectrometer, 47 ppt, which shows the need of a specific tune when very low levels of sup 9 sup 9 Tc have to be determined. A study is presented on the mass interferences for sup 9 sup 9 Tc. Our experiments show that the formation of polyatomic atoms or refractory oxides as well as sup 9 sup 8 Mo hydrides seem to be irrelevant for sup 9 sup 9 Tc atom counting. The opposite occurs with the presence of isobaric interferences, i.e. sup 9 sup 9 Ru, and the effect of abundance sensitivity, or low-mass resolution, which can modify the response at m/z=99 to a non-negligible extent.

  6. Density functional investigation of metal-metal interactions in mixed-valence d2d3 (Cr, Mo, W) and d3d4 (Mn, Tc, Re) face-shared [M2Cl9]2- systems.

    Science.gov (United States)

    Cavigliasso, Germán; Comba, Peter; Stranger, Robert

    2004-10-18

    The molecular and electronic structures of mixed-valence face-shared (Cr, Mo, W) d(2)d(3) and (Mn, Tc, Re) d(3)d(4) [M(2)Cl(9)](2-) dimers have been calculated by density functional methods in order to investigate metal-metal bonding in this series. The electronic structures of these systems have been analyzed using potential energy curves for the broken-symmetry and other spin states arising from the d(2)d(3) and d(3)d(4) coupling modes. In (d(2)d(3)) [Mo(2)Cl(9)](2-) and [W(2)Cl(9)](2-), the global minimum has been found to be a spin-doublet state characterized by delocalization of the metal-based electrons in a multiple metal-metal bond (with a formal bond order of 2.5). In contrast, weak coupling between the metal centers and electron localization are favored in (d(2)d(3)) [Cr(2)Cl(9)](2-), the global minimum for this species being a ferromagnetic S = 5/2 state with a relatively long Cr-Cr separation. The (d(3)d(4)) [Re(2)Cl(9)](2-) system also exhibits a global minimum corresponding to a metal-metal bonded spin-doublet state with a formal bond order of 2.5, reflecting the electron-hole equivalence between d(2)d(3) and d(3)d(4) configurations. Double minima behavior is predicted for (d(3)d(4)) [Tc(2)Cl(9)](2-) and [Mn(2)Cl(9)](2-) due to two energetically close low-lying states (these being S = 3/2 and S = 5/2 states for the former, and S = 5/2 and S = 7/2 states for the latter). A comparison of computational results for the d(2)d(2), d(2)d(3), and d(3)d(3) [W(2)Cl(9)](z-) series and the d(3)d(3), d(3)d(4), and d(4)d(4) [Re(2)Cl(9)](z-) series indicates that the observed trends in metal-metal distances can only be rationalized if changes in both the strength of sigma bonding and metal-metal bond order are taken into consideration. These two factors act conjointly in the W series but in opposition to one another in the Re series. In the case of the [Cr(2)Cl(9)](z-) and [Mn(2)Cl(9)](z-) dimers, the metal-metal bond lengths are significantly shorter for mixed

  7. Sustained availability of 99mTc: possible paths forward.

    Science.gov (United States)

    Pillai, Maroor Raghavan Ambikalmajan; Dash, Ashutosh; Knapp, F F Russ

    2013-02-01

    The availability of (99m)Tc for single-photon imaging in diagnostic nuclear medicine is crucial, and current availability is based on the (99)Mo/(99m)Tc generator fabricated from fission-based molybdenum (F (99)Mo) produced using high enriched uranium (HEU) targets. Because of risks related to nuclear material proliferation, the use of HEU targets is being phased out and alternative strategies for production of both (99)Mo and (99m)Tc are being evaluated intensely. There are evidently no plans for replacement of the limited number of reactors that have primarily provided most of the (99)Mo. The uninterrupted, dependable availability of (99m)Tc is a crucial issue. For these reasons, new options being pursued include both reactor- and accelerator-based strategies to sustain the continued availability of (99m)Tc without the use of HEU. In this paper, the scientific and economic issues for transitioning from HEU to non-HEU are also discussed. In addition, the comparative advantages, disadvantages, technical challenges, present status, future prospects, security concerns, economic viability, and regulatory obstacles are reviewed. The international actions in progress toward evolving possible alternative strategies to produce (99)Mo or (99m)Tc are analyzed as well. The breadth of technologies and new strategies under development to provide (99)Mo and (99m)Tc reflects both the broad interest in and the importance of the pivotal role of (99m)Tc in diagnostic nuclear medicine.

  8. Effects of Promoters on a Ru/Sepiolite Catalyst for Carbon Dioxide Methanation

    Institute of Scientific and Technical Information of China (English)

    Laitao Luo; Songjun Li; Yan Ouyang

    2003-01-01

    In this work, CO2 methanation has been investigated over Ru-based catalysts. The effects of promoters on the activity, selectivity and reduction properties of the Ru/sepiolite catalyst were analyzed by kinetic and thermodynamic methods. The catalysts were characterized by means of TPD, and the results revealed that the addition of Mo, Mn or Co improved the properties of the Ru/sepiolite catalyst.The effects of promoters could affect the change of enthalpy, entropy and chemical potential.

  9. The geometrical structure, electronic structure and magnetism of bimetallic AunM2 (n=1, 2; M=Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd) clusters

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The geometrical structure, stability, magnetism, and electronic structure of bimetallic clusters AuM2 and Au2M2, where M are 4d transition metal elements, are investigated systematically by using the first-principles method based on density functional theory. The calculation results show that there is a large amount of low-energy isomers with the very similar structure. AuM2 and Au2M2 clusters display dramatic magnetism. The magnetic moment of the 4d element is either enhanced or weakened with respect to the bulk value, which is largely dependent on the orbital exchange-splitting.

  10. TC4合金等离子钼基合金化改性层摩擦磨损性能研究%Study on Wear Properties of Mo-based Plasma Alloying Layer on Ti6Al4V

    Institute of Scientific and Technical Information of China (English)

    秦林; 李哲; 赵琪; 唐宾

    2011-01-01

    Molybdenum alloying layer and compound layer of W-Mo, W-Mo-N was fabricated on the surface ofTi6A14V by double glow plasma surface alloying technique. The microstructure distribution and microhardness of compound layer was measured. The wear properties of compound layer were measured by ball-plate slipping wear machine. The results show that the microstructure Ti6A14V after molybdenum alloying, W-Mo and W-Mo-N alloying is satisfactory. The surface hardness of Ti6A14V improves at different extent after different treatments, and the microhardness in alloying layer decreases along the depth. The surface hardness of W-Mo-N alloying layer is highest, about 1504 HV, but the hardness of W-Mo-N and molybdenum alloying layer reduces rapidly, hi short slip distance, the molybdenum-modified layer gains the smallest friction coefficient among the there alloying layers. As the friction going, the friction coefficient of molybdenum-modified layer increases quickly, even higher than W-Mo alloying layer. Molybdenum-modified layer appears as abrasive wear and adhesive wear. W-Mo and W-Mo-N alloying reduces adherent phenomenon, especially the W-Mo-N alloying.%利用双层辉光等离子渗金属技术在Ti6Al4V(TC4)上制备钼基改性层以提高材料的摩擦磨损性能.对改性层的组织结构元素分布和显微硬度进行了测试,并采用球-盘滑动磨损试验机对渗层进行摩擦磨损性能测试.结果表明:Ti6Al4V合金表面经过渗Mo、W-Mo及W-Mo-N共渗都可以形成致密、均匀的表面合金改性层;通过三种表面改性后,钛合金的表面硬度都有不同程度提高,其中W-Mo-N共渗表面硬度提高最大,达1504 HV.在较短滑动距离内,渗钼改性层摩擦系数最小,W-Mo-N共渗次之,W-Mo共渗最大.随着摩擦的深入,渗钼改性层摩擦系数很快升高,超过W-Mo改性层.渗钼改性层磨损表现为磨粒磨损和粘着磨损,W-Mo和W-Mo-N共渗都降低了材料的粘着现象,W-Mo-N共渗最为显著.

  11. Oxidation resistance of Ru-capped EUV multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Bajt, S; Dai, Z; Nelson, E J; Wall, M A; Alameda, J; Nguyen, N; Baker, S; Robinson, J C; Taylor, J S; Clift, M; Aquila, A; Gullikson, E M; Edwards, N G

    2005-02-23

    Differently prepared Ru-capping layers, deposited on Mo/Si EUV multilayers, have been characterized using a suite of metrologies to establish their baseline structural, optical, and surface properties in as-deposited state. Same capping layer structures were tested for their thermal stability and oxidation resistance. Post-mortem characterization identified changes due to accelerated tests. The best performing Ru-capping layer structure was studied in detail with transmission electron microscopy to identify the grain microstructure and texture. This information is essential for modeling and performance optimization of EUVL multilayers.

  12. Determination of Tc-99 in radioactive wastes; Determinacion de Tc-99 en desechos radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Rivera S, A. A.

    2015-07-01

    Tc-99 is a fission product and one of the most important radionuclides from the view point of safety assessment for the disposal of radioactive waste because of its long half-life (2.1 x 10{sup 5} years) and high mobility in soil-water systems, if this is released into the environment in significant quantities can concentrate on plants and animals. Tc-99 is a pure beta emitter with a maximum energy of 292 KeV, so their quantification imposes destructive methods to be analyzed by liquid scintillation. Therefore the quantification of Tc-99 in ion exchange resins requires of the mineralization of these and separation of Tc-99 of other radioisotopes present in the resin. Therefore the object of this thesis is to develop a quantification method of Tc-99 content in spent exchange resins. So in order to track the behavior of technetium during digestion exchange resins and radiochemical separation, given its high volatility, in this work the {sup 99m}Tc is used. To determine the degree of mineralization of the resins, an analysis was performed by chromatography. Subsequently the method used to determine the percentage of {sup 99m}Tc aerosolized during mineralization of resin is described. After the method for the radiochemical separation of {sup 99m}Tc is presented by liquid-liquid extraction using crown ether as extractant; for this testing was performed by varying the molarity of the extractant, the ratio of solvent extractant, type of digestion of the resin and the presence of Sr-85, in order to study the behavior of {sup 99m}Tc in the presence of this radioisotope. Finally, a track beta spectra of a sample of {sup 99m}Tc eluted from a generator {sup 99}Mo/{sup 99m}Tc function of time was performed. (Author)

  13. Suppression of ferromagnetism and observation of quantum well states in epitaxial thin films of the cubic ruthenate BaRuO3

    Science.gov (United States)

    Burganov, Bulat; Paik, Hanjong; Shen, Kyle; Schlom, Darrell

    The pseudocubic perovskite ruthenates ARuO3, where A is alkaline earth metal, are correlated materials where Hund's coupling drives correlations and leads to a low coherence scale, large renormalization, and formation of local moments. The ferromagnetic BaRuO3 has an ideal cubic structure and a larger bandwidth, compared to its GdFeO3-distorted counterparts, CaRuO3 and SrRuO3. In stark contrast to SrRuO3, which is a Fermi liquid below TC, BaRuO3 exhibits critical fluctuations near TC that are enhanced under hydrostatic pressure, which suppresses the Fermi liquid coherence scale and TC and drives a crossover into non-FL regime. Here we use ARPES to characterize the momentum-resolved electronic structure of strained ultrathin BaRuO3 films grown in situ by molecular beam epitaxy. The films on STO (001) are metallic down to 2 u.c. thickness and manifest clearly defined subbands of well-defined quasiparticles which arise due to quantum confinement effects. We observe that the bands are moderately renormalized compared to bare GGA bands and discover that the ferromagnetism can be suppressed in the atomically thin limit. We discuss our results on BaRuO3 in the context of our recent ARPES studies of the other perovskite ruthenates, SrRuO3 and CaRuO3.

  14. Simulation of the direct production of 99mTc at a small cyclotron

    Science.gov (United States)

    Eslami, M.; Kakavand, T.

    2014-06-01

    Usually 99mTc is produced indirectly through generator 99Mo/99mTc. In the present study, the direct production of this radioisotope by charged particle irradiation was investigated using Monte Carlo method. After scouting of the reactions that produce 99mTc, excitation functions of these reactions were predicted by optical model components in the TALYS-1.6 code. Suitable energy range of projectile for this production was selected by spotting of maximum cross section and minimum impurity due to other emission channels. Then target geometry was designed based on stopping power calculation by the SRIM code. Thick target yield of 100Mo(p,2n)99mTc, 98Mo(p,γ)99mTc and natMo(p,x)99mTc reactions was predicted by the result of excitation function and stopping power calculations. Finally, 100Mo(p,2n)99mTc reaction was selected as a primary reaction for the direct production of 99mTc and its process was simulated by employing the MCNPX code to calculate the energy distribution of proton in the 100Mo target body and estimation of residual nuclei during irradiation. Good agreement was obtained between the experimental, the theoretical, and the simulation-based (analytical and directly) production yields. This study demonstrated that Monte Carlo provides a method for the design and optimization of targets for the radionuclide production purposes.

  15. Oxidation resistance and microstructure of Ru-capped extreme ultraviolet lithography multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Bajt, S; Dai, Z; Nelson, E J; Wall, M A; Alameda, J B; Nguyen, N; Baker, S L; Robinson, J C; Taylor, J S; Aquila, A; Edwards, N V

    2005-06-15

    The oxidation resistance of protective capping layers for extreme ultraviolet lithography (EUVL) multilayers depends on their microstructure. Differently prepared Ru-capping layers, deposited on Mo/Si EUVL multilayers, were investigated to establish their baseline structural, optical, and surface properties in as-deposited state. The same capping layer structures were then tested for their thermal stability and oxidation resistance. The best performing Ru-capping layer structure was analyzed in detail with transmission electron microscopy (TEM). As compared to other Ru capping layers preparations studied here it is the only one that shows grains with preferential orientation. This information is essential for modeling and performance optimization of EUVL multilayers.

  16. Effect of Transition Metals on Catalytic Performance of Ru/Sepiolite Catalyst for Methanation of Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    Laitao Luo; Songjun Li

    2004-01-01

    The effects of Mo, Mn and Zr transitional metals on the catalytic performance of Ru/sepiolite for CO2 methanation were investigated. The results indicated that addition of the transitional metals affected the activity of the Ru/sepiolite remarkably, and the activities of the catalysts were closely associated with the electronic state of the ruthenium surface. The addition of Mo increased the active surface area, the Ru dispersity, the number of active sites, and the resistance to poisoning. According to the Transition State Theory, when Mo is added into the Ru/sepiolite catalyst, the decrease in surface energy is at a cost of an increment in steric hindrance. When T ≤674 K, the energy factor was dominating, and resulted in a decreasing in the ratio of S(CH4)/S(CO). Otherwise, the steric factor dominated the reaction course.

  17. Study of the effect of irradiation of Mo targets at nuclear reactor; Estudo do efeito da irradiacao de alvos contendo Mo em reator nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Nieto, Renata C.; Lima, Ana Lucia V.P.; Silva, Nestor C. da; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2000-07-01

    The most used radioisotope in nuclear medicine is {sup 99m}Tc, in the {sup 99}Mo-{sup 99m}Tc generator form. {sup 99}Mo can be produced by several nuclear reactions in reactors and cyclotrons. The cyclotron production is not technically and economically viable. The production in the reactor can be done in two different ways: by the fission of {sup 235}U and by the {sup 98}Mo(n,{gamma}){sup 99}Mo reaction. A project for the production of {sup 99}Mo by the activation of Mo and the preparation of gel type generators is under development at the 'Instituto de Pesquisas Energeticas e Nucleares'. In the present work, the radionuclidic impurities produced in the activation of MoO{sub 3} , metallic Mo and Mo Zr gel were evaluated, as well as the radionuclidic purity of {sup 99m}Tc eluted from generators prepared. (author)

  18. Dibenzothiophene hydrodesulfurization over Ru promoted alumina based catalysts using in situ generated hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad, Yaseen; Shen, Chong; Li, Chunxi [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Lu, Yingzhou [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2011-02-15

    Catalytic hydrodesulfurization (HDS) of dibenzothiophene (DBT) was carried out in a temperature range of 320-400 C using in situ generated hydrogen coupled with the effect of selected organic additives for the first time. Four kinds of alumina based catalysts i.e. Co-Mo/Al{sub 2}O{sub 3}, Ni-Mo/Al{sub 2}O{sub 3}, Ru-Co-Mo/Al{sub 2}O{sub 3} and Ru-Ni-Mo/Al{sub 2}O{sub 3} were used for the desulfurization process, which were prepared following incipient impregnation method with fixed metal loadings (wt.%) of Co, Ni, Mo and Ru. The surface area, average pore diameter and pore volume distribution of the fresh and used catalysts were measured by N{sub 2} adsorption using BET method. Catalytic activity was investigated in a batch autoclave reactor in the complete absence of external hydrogen gas. Addition and mutual reaction of specific quantities of water and ethanol provided the necessary in situ hydrogen for the desulfurization reaction. Organic additives like diethylene glycol (DEG), phenol, naphthalene, anthracene, o-xylene, tetralin, decalin and pyridine did impinge the HDS activity of the catalysts in different ways. Liquid samples from reaction products were quantitatively analyzed by HPLC technique while qualitative analyses were made using GC-MS. Both of these techniques showed that Ni-based catalysts were more active than Co-based ones at all conditions. Moreover, incorporation of Ru to both Co and Ni-based catalysts greatly promoted desulfurization activity of these catalysts. DBT conversion of up to 84% was achieved with Ru-Ni-Mo/Al{sub 2}O{sub 3} catalyst at 380 C temperature for 11 h. Catalyst systems followed the HDS activity order as: Ru-Ni-Mo/Al{sub 2}O{sub 3}> Ni-Mo/Al{sub 2}O{sub 3}> Ru-Co-Mo/Al{sub 2}O{sub 3}> Co-Mo/Al{sub 2}O{sub 3} at all conditions. Cost effectiveness, mild operating conditions and reasonably high catalytic activity using in situ generated hydrogen mechanism proved our process to be useful for HDS of DBT. (author)

  19. Nitrogen Scattering at Ru Surfaces

    NARCIS (Netherlands)

    Zaharia, T.; Ueta, H.; Kleyn, A.W.; Gleeson, M.A.

    2013-01-01

    Results on the scattering of hyperthermal N2 molecules from bare and N-covered Ru(0001) surfaces are presented. These are compared with Ar scattering from the same surfaces as a reference nonreactive system. In the case of bare Ru(0001) the measured angular distributions are consistent with scatteri

  20. Nitrogen Scattering at Ru Surfaces

    NARCIS (Netherlands)

    Zaharia, T.; Ueta, H.; Kleyn, A. W.; Gleeson, M. A.

    2013-01-01

    Results on the scattering of hyperthermal N2 molecules from bare and N-covered Ru(0001) surfaces are presented. These are compared with Ar scattering from the same surfaces as a reference non-reactive system. In the case of bare Ru(0001) the measured angular distributions are consistent with scatter

  1. Nitrogen Scattering at Ru Surfaces

    NARCIS (Netherlands)

    Zaharia, T.; Ueta, H.; Kleyn, A.W.; Gleeson, M.A.

    2013-01-01

    Results on the scattering of hyperthermal N-2 molecules from bare and N-covered Ru(0001) surfaces are presented. These are compared with Ar scattering from the same surfaces as a reference non-reactive system. In the case of bare Ru(0001) the measured angular distributions are consistent with scatte

  2. Reactions of ethanol on Ru

    NARCIS (Netherlands)

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

    2012-01-01

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

  3. A review on the process technology for Mo-99 production

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Hoh; Yoo, Jae Hyung; Jung, Won Myung; Lee, Kyoo Il; Woo, Moon Sik; Hwang, Doo Sung; Kim, Yun Koo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-07-01

    Tc-99m is most frequently used in nuclear medical diagnostics because of its favourable nuclear properties and reasonable prices, and the demand of Tc-99m, is on the increase recently. Mo-99, the parent radionuclide of Tc-99m, is the only source of Tc-99m. This review described overall aspects of process technologies for Mo-99 production. Firstly, the chemical, physical and radioactive properties of Tc-99m, Mo-99 were examined to understand Mo-99 separation process. Also, the technology for Mo-99 production with both the neutron capture and nuclear fission method were examined. But the neutron capture method was scarcely used for large production of Mo-99 because of its low specific activity and high production cost. This review also described mainly process technologies in the nuclear fission method, fabrication and condition for irradiation of targets, transport and dissolution of targets irradiated, separation and purification of Mo-99, etc. Especially, for Mo-99 separation and purification process, the characteristics, merits and demerits of various processes, which have been developed in a few countries, were examined and analyzed. 30 figs., 16 tabs., 60 refs. (Author).

  4. Magnesium-molybdenum compounds as matrices of generators of {sup 99m} Tc; Compuestos de magnesio-molibdeno como matrices de generadores de {sup 99m} Tc

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez M, T.S.; Monroy G, F. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: thania_susana@terra.com.mx

    2004-07-01

    The generator system of radionuclides more diffused, and used in the world, it is the{sup 99}Mo / {sup 99m} Tc. These use {sup 99} Mo, product of fission of the {sup 235} U of very high specific activity, adsorbed on alumina (0.2% of {sup 99} Mo/gram of alumina). An alternative for the production of generators of low activity specifies, via the reaction {sup 98} Mo(n, {gamma}) {sup 99} Mo, it is based on the use of compounds with molybdates base, as matrices of the generators {sup 99} Mo / {sup 99m} Tc. In this work is proposed to develop a generator at base of compounds of magnesium molybdates that could be irradiated after its synthesis, given the short half life of the only radioisotope produced by magnesium: {sup 27} Mg (t{sub 1/2} = 9.46 m). In this work two parameters were studied, fundamental in the preparation of the magnesium molybdates, matrices of the generators {sup 99}Mo / {sup 99m}Tc, and their influence in the efficiency and radionuclide purity: the washing of the gels previous to its irradiation and the molar ratio Mo:Mg. The magnesium molybdates non washing presents bigger efficiencies (72%), but they don't fulfill a smaller percentage to 0.015% of {sup 99} Mo, neither with a radiochemical purity of 90%, except when the molar ratio Mo: Mg of 1:1.08 which provide the best results. (Author)

  5. Simulation of the direct production of {sup 99m}Tc at a small cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Eslami, M., E-mail: emohammad@znu.ac.ir [Department of Physics, Faculty of Science, Zanjan University, Zǝngan (Zanjan) (Iran, Islamic Republic of); Kakavand, T. [Department of Physics, Faculty of Science, Imam Khomeini International University, Qazvin (Iran, Islamic Republic of)

    2014-06-01

    Highlights: • The production yield was estimated for {sup 98,100,nat}Mo(p,x){sup 99m}Tc nuclear reactions. • MCNPX was used to calculate the proton energy distribution and secondary neutron flux. • The residual nuclei during the reactions were monitored as an alternative method. • Good agreement was obtained between experimental, theoretical and simulation-based yields. - Abstract: Usually {sup 99m}Tc is produced indirectly through generator {sup 99}Mo/{sup 99m}Tc. In the present study, the direct production of this radioisotope by charged particle irradiation was investigated using Monte Carlo method. After scouting of the reactions that produce {sup 99m}Tc, excitation functions of these reactions were predicted by optical model components in the TALYS-1.6 code. Suitable energy range of projectile for this production was selected by spotting of maximum cross section and minimum impurity due to other emission channels. Then target geometry was designed based on stopping power calculation by the SRIM code. Thick target yield of {sup 100}Mo(p,2n){sup 99m}Tc, {sup 98}Mo(p,γ){sup 99m}Tc and {sup nat}Mo(p,x){sup 99m}Tc reactions was predicted by the result of excitation function and stopping power calculations. Finally, {sup 100}Mo(p,2n){sup 99m}Tc reaction was selected as a primary reaction for the direct production of {sup 99m}Tc and its process was simulated by employing the MCNPX code to calculate the energy distribution of proton in the {sup 100}Mo target body and estimation of residual nuclei during irradiation. Good agreement was obtained between the experimental, the theoretical, and the simulation-based (analytical and directly) production yields. This study demonstrated that Monte Carlo provides a method for the design and optimization of targets for the radionuclide production purposes.

  6. Low-spin excitations in {sup 98}Ru

    Energy Technology Data Exchange (ETDEWEB)

    Radeck, Desiree; Albers, Michael; Bernards, Christian; Fransen, Christoph; Jolie, Jan; Muecher, Dennis [Institut fuer Kernphysik, Universitaet Koeln (Germany)

    2009-07-01

    In the context of collectivity in the A=100 mass region N=52 isotones were investigated in detail and phonon excitations - especially the mixed-symmetry (MS) states - were identified. In order to investigate how states with this MS character evolve with increasing valence neutron number N=54 isotones were studied. While in {sup 96}Mo the one-phonon MS state 2{sup +}{sub 1,ms} was identified, {sup 98}Ru shows a breakdown of vibrational structure above the two-phonon triplet and no candidate for the 2{sup +}{sub 1,ms} state was assigned. The recently investigated N=54 isotone {sup 100}Pd was explained well with an U{sub {pi}}{sub {nu}}(5) fit within the IBM-2. Furthermore, a candidate for the one-phonon MS2{sup +}{sub 1,ms} state was determined. To do further investigations on the N=54 isotone {sup 98}Ru - in particular regarding the breakdown of vibrational symmetry and the one-phonon MS excitation - an experiment was performed at the Cologne Tandem Accelerator using the HORUS spectrometer. The nuclei were populated by the reaction {sup 97}Mo({sup 3}He,2n){sup 98}Ru. By analysing the coincidence and {gamma}{gamma} angular correlation data the level scheme was extended and clarified by determining spins, multipole mixing ratios and branching ratios. The low-energy excitations of positive parity are discussed and compared to theoretical expectations. The results are compared with those for other N=54 isotones.

  7. Penning trap assisted decay spectroscopy of neutron-rich {sup 115}Ru

    Energy Technology Data Exchange (ETDEWEB)

    Kurpeta, J.; Plochocki, A.; Urban, W. [Warsaw University, Faculty of Physics, Warsaw (Poland); Elomaa, V.V.; Eronen, T.; Hakala, J.; Jokinen, A.; Karvonen, P.; Moore, I.; Penttilae, H.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Ronkainen, J.; Saastamoinen, A.; Sonoda, T.; Weber, C.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics (Finland)

    2007-03-15

    Exotic, neutron-rich {sup 111}Mo and {sup 115}Ru nuclei, produced in proton-induced fission of {sup 238}U target, were separated with the IGISOL mass separator. The separator was coupled to the JYFLTRAP Penning trap to select the ions of a single, desired element out of the isobaric IGISOL beam. Monoisotopic samples of {sup 115}Ru and {sup 111}Mo ions were observed with a microchannel plate detector after the trap or were implanted on a catcher foil for gamma- and beta-ray coincidence spectroscopy. In spite of short data taking time new gamma transitions were identified in the beta decay of very neutron-rich {sup 115}Ru. (orig.)

  8. Anomalous linear resistivity from ˜1 to 103K in Sr2RuO4-δ

    Science.gov (United States)

    Pavuna, Davor; Forró, László; Berger, Helmuth

    1999-09-01

    We discuss striking, linear resistivity in single crystals of Sr2RuO4-δ that persist over three decades of temperature, up to ˜1050K, while the superconductivity remains confined <1 K. This suggests that linear resistivity is not an exclusive feature of the N- state of high-Tc cuprates, but rather of all layered oxides, especially perovskites, possibly even independently of the magnitude of Tc.

  9. A new approach for manufacturing and processing targets to produce 99mTc with cyclotrons

    Science.gov (United States)

    Matei, L.; McRae, G.; Galea, R.; Niculae, D.; Craciun, L.; Leonte, R.; Surette, G.; Langille, S.; Louis, C. St.; Gelbart, W.; Abeysekera, B.; Johnson, R. R.

    2017-06-01

    The most important radioisotope for nuclear medicine is 99mTc. After the supply crisis of 99Mo starting in 2008, the availability of 99mTc became a worldwide concern. Alternative methods for producing the medical imaging isotope 99mTc are actively being developed around the world. The reaction 100Mo(p, 2n)99mTc provides a direct route that can be incorporated into routine production in nuclear medicine centers that possess medical cyclotrons for production of other isotopes, such as those used for Positron Emission Tomography. This paper describes a new approach for manufacturing targets for the (p, 2n) nuclear reaction on 100Mo and the foundation for the subsequent commercial separation and purification of the 99mTc produced. Two designs of targets are presented. The targets used to produce 99mTc are subject to a number of operational constraints.They must withstand the temperatures generated by the irradiation, accommodate temperature gradients from cooling system of the target, must be resilient and must be easily post-processed to separate the 99mTc. After irradiation, the separation of Tc from Mo was carried out using an innovative two-step approach. The process described in this paper can be automated with modules that easily fit in standard production hot cells found in nuclear medicine facilities.

  10. Validity of {sup 99m}Tc-DMSA renal uptake by planar posterior-view method in children

    Energy Technology Data Exchange (ETDEWEB)

    Tsukamoto, Eriko; Katoh, Chietsugu; Mochizuki, Takafumi; Shiga, Toru; Morita, Koichi; Tamaki, Nagara [Hokkaido Univ., Sapporo (Japan). School of Medicine; Itoh, Kazuo

    1999-12-01

    Renal uptake {sup 99m}Tc-DMSA has been quantified by various methods. The aim of this study is to obtain a normal value for {sup 99m}Tc-DMSA renal uptake calculated by the posterior view method and age variation, and to assess its clinical validity. Scintigrams of 238 children (0-12 years) with {sup 99m}Tc-DMSA were reviewed. All the children had a clinical history of primary vesicoureteral reflux and/or neurogenic bladder, ureteral or urethral anomalies. Their kidneys were divided into two groups, ''normal'' and abnormal'' according to their scintigraphic findings and split renal functions. Percent renal uptake per injected dose (% RU) was quantitated from planar images at 2 hours after injection of an age-adjusted dose (26-95 MBq) of {sup 99m}Tc-DMSA. Calculated total % RU, individual % UR of the right and left kidneys (mean{+-}sd) in patients with normal kidneys were 40.7{+-}5.0%, 20.2{+-}3.0%, 20.4{+-}2.7%, respectively. There was no significant correlation between % RU and age (r=0.231). Longitudinal variation in the % RU in 9 patients ranged from 1.2% to 18%. Our conventional method for quantifying % RU is simple, practical and feasible in routine clinical practice, especially for children under follow up. (author)

  11. Influence of Ruthenium doping on Structural and Morphological Properties of MoO3 Thin Films

    Directory of Open Access Journals (Sweden)

    S. D. Gothe

    2016-09-01

    Full Text Available The present work examines the effect of Ru doping on MoO3 thin films on steel substrate deposited by Sol-gel spin coat method. The annealing temperature was 6000C for pure MoO3 and 8000C for Ru doped thin films. The doping concentration of Ru was varied from 10 to 50wt%. The influence of Ru doping on structural and morphological properties of MoO3 thin films were studied. The XRD revealed that all films are highly crystalline in nature with monoclinic phase for molybdenum peaks. In the doped XRD pattern some new peaks were observed and are matched with ruthenium orthorhombic phase indicating an incorporation of dopant in pure molybdenum oxide. The same is confirmed with the compositional analysis by EDAX. The SEM images of the MoO3 resemble a rod like surface with porous morphology. Incorporation of Ru ions in molybdenum oxide decreases the length of the rods and vanishes after 40wt%. Tetragonal grain size increases from 20wt% of Ru and becomes maximum at 50wt% of Ru doped thin films

  12. Communication between remote moieties in linear Ru-Ru-Ru trimetallic cyanide-bridged complexes.

    Science.gov (United States)

    Pieslinger, German E; Albores, Pablo; Slep, Leonardo D; Coe, Benjamin J; Timpson, Cliff J; Baraldo, Luis M

    2013-03-18

    In this article, we report the structural, spectroscopic, and electrochemical properties of the cyanide-bridged complex salts trans-[(NC)Ru(II)(L)4(μ-CN)Ru(II)(py)4Cl]PF6 and trans-[Ru(II)(L)4{(μ-CN)Ru(II)(py)4Cl}2](PF6)2 (L = pyridine or 4-methoxypyridine). The mixed-valence forms of these compounds show a variety of metal-to-metal charge-transfer bands, including one arising from charge transfer between the remote ruthenium units. The latter is more intense when L = 4-methoxypyridine and points to the role of the bridging ruthenium unit in promoting mixing between the dπ orbitals of the terminal fragments.

  13. Effect of pressure on the Curie temperature of Mn2RuSn and Mn2PdSn

    Science.gov (United States)

    Adachi, Y.; Watanabe, T.; Kanomata, T.; Hayasaka, M.; Endo, K.; Nishihara, H.; Xu, X.; Kainuma, R.

    2017-04-01

    Effect of pressure on the Curie temperature TC of the Mn-rich Heusler alloys Mn2RuSn and Mn2PdSn has been investigated by measuring the temperature dependence of initial permeability at various pressures up to 10 kbar. It was found that the Curie temperatures of Mn2RuSn and Mn2PdSn decrease with increasing pressure. The pressure derivatives of TC were estimated to be -0.59 K/kbar for Mn2RuSn and -0.80 K/kbar for Mn2PdSn. On the basis of the experimental results, the relationship between the magnetic transition temperature and the Mn-Mn distance is discussed.

  14. Search for 2\\beta\\ decays of 96Ru and 104Ru by ultra-low background HPGe gamma spectrometry at LNGS: final results

    CERN Document Server

    Belli, P; Cappella, F; Cerulli, R; Danevich, F A; d'Angelo, S; Incicchitti, A; Kovtun, G P; Kovtun, N G; Laubenstein, M; Poda, D V; Polischuk, O G; Shcherban, A P; Solopikhin, D A; Suhonen, J; Tretyak, V I

    2013-01-01

    An experiment to search for double beta decay processes in 96Ru and 104Ru, which are accompanied by gamma rays, has been realized in the underground Gran Sasso National Laboratories of the I.N.F.N. (Italy). Ruthenium samples with masses of about (0.5-0.7) kg were measured with the help of ultra-low background high purity Ge gamma ray spectrometry. After 2162 h of data taking the samples were deeply purified to reduce the internal contamination of 40K. The last part of the data has been accumulated over 5479 h. New improved half life limits on 2\\beta+/\\epsilon \\beta+/2\\epsilon\\ processes in 96Ru have been established on the level of 10^{20} yr, in particular for decays to the ground state of 96Mo: T1/2(2\

  15. The {sup 99m}Tc generator using poly zirconium chloride (PZC)

    Energy Technology Data Exchange (ETDEWEB)

    Wan Anuar Wan Awang; Rehir Dahalan; Shaaban Kasim [Medical Technology Div., Malaysian Inst. for Nuclear Technology Research (MINT), Selangor (Malaysia)

    1998-10-01

    The {sup 99m}Tc generator system has been prepared using poly zirconium chloride (PZC) to replace alumina (Al{sub 2}O{sub 3}) as a adsorbent. The Mo-98 (MoO{sub 3}) was irradiated using our 1 MW TRIGA MARK II research reactor. The amount of Mo-99 adsorbed to the PZC has been studied and the yield from the elution was about 20%. (author)

  16. TC-2 Satellite Delivered

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    On April 18, 2005, TC-2, the second satellite of Double Star Program (DSP), which was jointly developed by CNSA and ESA, was approved to be delivered to the user after the on-board test and trial operation. The satellite is working well and the performance can meet the user's need. The satellite has collected large amount of valuable scientific data

  17. Round table on RU486.

    Science.gov (United States)

    Shallat, L

    1993-01-01

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

  18. Effect of Ru thickness on spin pumping in Ru/Py bilayer

    Energy Technology Data Exchange (ETDEWEB)

    Behera, Nilamani; Singh, M. Sanjoy; Chaudhary, Sujeet; Pandya, Dinesh K., E-mail: dkpandya@physics.iitd.ac.in; Muduli, P. K. [Department of Physics, Thin Film Laboratory, Indian Institute of Technology Delhi, New Delhi 110016 (India)

    2015-05-07

    We report the effect of Ru thickness (t{sub Ru}) on ferromagnetic resonance (FMR) line-width of Ru(t{sub Ru})/Py(23 nm) bilayer samples grown on Si(100)/SiO{sub 2} substrates at room temperature by magnetron sputtering. The FMR line-width is found to vary linearly with frequency for all thicknesses of Ru, indicating intrinsic origin of damping. For Ru thicknesses below 15 nm, Gilbert-damping parameter, α is almost constant. We ascribe this behavior to spin back flow that is operative for Ru thicknesses lower than the spin diffusion length in Ru, λ{sub sd}. For thicknesses >15 nm (>λ{sub sd}), the damping constant increases with Ru thickness, indicating spin pumping from Py into Ru.

  19. Pressure Induced Enhancement of Superconductivity in LaRu2P2

    Science.gov (United States)

    Li, Baoxuan; Lu, Pengchao; Liu, Jianzhong; Sun, Jian; Li, Sheng; Zhu, Xiyu; Wen, Hai-Hu

    2016-04-01

    To explore new superconductors beyond the copper-based and iron-based systems is very important. The Ru element locates just below the Fe in the periodic table and behaves like the Fe in many ways. One of the common thread to induce high temperature superconductivity is to introduce moderate correlation into the system. In this paper, we report the significant enhancement of superconducting transition temperature from 3.8 K to 5.8 K by using a pressure only of 1.74 ± 0.05 GPa in LaRu2P2 which has an iso-structure of the iron-based 122 superconductors. The ab-initio calculation shows that the superconductivity in LaRu2P2 at ambient pressure can be explained by the McMillan’s theory with strong electron-phonon coupling. However, it is difficult to interpret the enhancement of Tc versus pressure within this picture. Detailed analysis of the pressure induced evolution of resistivity and upper critical field Hc2(T) reveals that the increase of Tc with pressure may be accompanied by the involvement of extra electron-boson interaction. This suggests that the Ru-based system has some commonality as the Fe-based superconductors.

  20. Interference removals on Pd, Ru and Au with ICP-QQQ-MS in PGE RM

    Science.gov (United States)

    Nadeem Hussain Bokhari, Syed; Meisel, Thomas; Walkner, Christoph

    2015-04-01

    Gold and platinum group elements (PGE) are essential industrial precious metals with high world demand due to their unique properties. Struggle for natural exploration of PGE is on great pace and recycling from industrial wastes, electronics and catalytic convertor is on the rise for PGE supply chain. Along with these developments it is becoming more challenging for analytical chemists to determine gold and PGE out of complex matrix which causes severe interferences. The current state of art is online analysis coupled with chromatographic separation of interferences. The ICP-QQQ-MS Agilent 8800 has the capability of using multi tunes and mass shifts. We aim to remove interferences on Pd+ (for direct and isotope dilution analysis) Au+ and Ru+ in lieu of chemical separations. YO+, SrOH+, ZnAr+, NiAr+, ZrO+, CuAr+, MoO+ , Ru+and Cd+ are expected interferences on Pd+ while Au+ is interfered by TaO+, HfOH+, GdAr+ and 102Ru+ ,104Ru+ by 102Pd+ ,104Pd+ etc. Initial test were performed on pure solutions of 1mg/l (interfering elements): 1 ng/l (Pd, Ru & Au) respectively. The outcomes of initial tests were applied on PGE reference material (RM) WMG-1 and SARM-7 (digested with Na2O2 sintering). The results obtained show that YO+, SrOH+ interfere (104Pd,105Pd), 104 Ru+ on (104Pd), ZnAr+ has slight interference on (104Pd and106Pd), ZrO+, NiAr+, CuAr+ interferences are negligible, MoO+ has severe interference on (108Pd, 110Pd) and that Cd+ has severe isobaric interference on (106Pd,108Pd, 110Pd). These interference have been removed by formation of Pd(NH3)3+complex. The TaO+, HfOH+ and GdAr+ interferences on Au+ are best removed by formation of Au(NH3)+ and Au(NH3)2+ complexes. 102Pd+,104Pd+interference on 102Ru+ ,104Ru+ can be removed by formation of Ru(NH3)4+ and RuO+ compounds. The results obtained comply with certified values of RM. The developed method is being tested on low concentration PGE reference materials. References: Sugiyama, N. " Removal of complex spectral

  1. Re(VII) and Tc(VII) trioxo complexes stabilized by tridentate ligands and their potential use as radiopharmaceuticals

    NARCIS (Netherlands)

    Hahn, Eva M.; Casini, Angela; Kuehn, Fritz E.

    2014-01-01

    Tc(VII) and Re(VII) trioxo complexes are currently arousing interest because of their potential use as radiopharmaceuticals due to their hydrophilic character and stability in a biological environment. The radioactive isotopes Tc-99m and Re-188 are readily obtained from commercially available Mo-99/

  2. Enhancement of ferromagnetism by oxygen isotope substitution in strontium ruthenate SrRuO3

    Science.gov (United States)

    Kawanaka, Hirofumi; Aiura, Yoshihiro; Hasebe, Takayuki; Yokoyama, Makoto; Masui, Takahiko; Nishihara, Yoshikazu; Yanagisawa, Takashi

    2016-10-01

    The oxygen isotope effect of the ferromagnetic transition in itinerant ferromagnet strontium ruthenate SrRuO3 with a Curie temperature Tc of 160 K is studied. We observed for the first time a shift of ∆Tc ~ 1 K by oxygen isotope substitution of 16O → 18O in SrRuO3 by precise measurements of DC and AC magnetizations. The results surprisingly lead to the noteworthy inverse isotope effect with negative coefficient α = -∂ lnTc/∂ lnM. The Raman spectra indicate that the main vibration frequency of 16O at 363 cm-1 shifts to 341 cm-1 following oxygen isotope substitution 18O. This shift is remarkably consistent with the Debye frequency being proportional to ∝ 1√M where M is the mass of an oxygen atom. The positive isotope shift of ∆Tc can be understood by taking account of the electron-phonon interaction.

  3. Critical Behaviour of Sintered SrRuO3

    Institute of Scientific and Technical Information of China (English)

    侯登录; 姜恩永; 李凤舞; 白海力; 周学志; Henry KUNKEL; Gwyn WILLIAMS

    2002-01-01

    From the measurements of the ac susceptibility of SrRuO3, we determine the critical temperature Tc = 159.7 ±0.2 K and critical exponents δ= 2.50 + 0.15 (from the critical isotherm) or δ= 3.17 ± 0.20 (from magnetization versus magnetic field at Curie temperature), γ + β= 1.50 ± 0.05 (from the temperature dependence of the internal field of the crossover line), and γ= 0.96 ± 0.05 (from the temperature dependence of the susceptibility along the same line). These exponent values are very close to those predicted by the mean field model.

  4. Next generation nanolithography based on Ru/Be and Rh/Sr multilayer optics

    Directory of Open Access Journals (Sweden)

    N. I. Chkhalo

    2013-08-01

    Full Text Available A prospective move to 10.5 and 11.2 nm wavelengths, as an alternative to 6.7 and 13.5 nm, for next generation nanolithography is discussed. Ten-mirror optical systems based on Ru/Be, Mo/Be, Rh/Sr, Mo/Si, and La/B multilayers were compared for efficiency at their working wavelengths. It is shown that a transition to 10.5 nm and 11.2 nm may be a solution to the problem of increasing performance and resolution of a projection system.

  5. Separation of [(99m)Tc]pertechnetate and molybdate using polyethylene glycol coated C18 and C30 resins.

    Science.gov (United States)

    Andersson, J D; Wilson, J S; Romaniuk, J A; McEwan, A J B; Abrams, D N; McQuarrie, S A; Gagnon, K

    2016-04-01

    Hydrophobic adsorbents such as C18 and C30 were coated with PEG and subsequently used for the separation of Mo/Tc. The most effective resin for adsorbing PEG was the C18-U resin, which demonstrated a coating capacity of 97.6±2.8mg PEG per g of resin. The ability to adsorb pertechnetate was proportional to the amount of PEG coated on the hydrophobic resin. The [(99m)Tc]pertechnetate recovery during the separation of cyclotron produced (99m)Tc from (100)Mo was 91.8±0.3% (n=2). The resultant product met relevant USP monograph specifications.

  6. Current status and future of Mo-99 supply

    Energy Technology Data Exchange (ETDEWEB)

    Ponsard, Bernard [Belgian Nuclear Research Center (SCK.CEN), Mol (Belgium). AIPES Reactors and Isotopes Working Group

    2016-01-15

    The global supply of Mo-99 relies on a limited number of research reactors and processing facilities. Its production is essential as medical diagnostic imaging techniques using Tc-99m account for approximately 80% of all nuclear medicine procedures worldwide. The short half-life's of the radioisotopes requires a continuous supply. Several severe disruptions have been experienced over the past decade. Fortunately, the situation encouraged the industry to develop new projects and new production routes. The current status of Mo-99 supply is described and the efforts made to achieve a reliable Tc-99m availability for nuclear medicine is summarized.

  7. Photo-transmutation of {sup 100}Mo to {sup 99}Mo with Laser-Compton Scattering Gamma-ray

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jiyoung; Rehman, Haseeb ur; Kim, Yonghee [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    This paper presents a photonuclear transmutation method using laser Compton scattering (LCS) gamma-ray beam. Potential production rate (reaction rate) of 99Mo using the photonuclear (γ,n) reaction is evaluated. Rigorous optimization of the LCS spectrum has also been performed to maximize production of the 99Mo. Cyclotron proton accelerators are used worldwide to produce many short-living medical isotopes. However, few are capable of producing Mo-99 and none are suitable for producing more than a small fraction of the required amounts. More than 90% of the world's demand of 99Mo is sourced from five nuclear reactors. Two of these reactors have already been decommissioned and the rest are more than 45 years old. Relatively short half-life of the parent 99Mo requires continuous re-supply to meet the requirements of medical industry. Therefore, there is an urgent need to produce the 99Mo and 99mTc isotopes by alternative ways. One such alternative is giant dipole resonance (GDR) based photonuclear transmutation of 100Mo to 99Mo. For 99Mo production with the LCS photons using GDR-based (γ,n) reaction, the gamma-ray energy should be around 15 MeV. This study indicates that optimization of LCS spectrum by varying the electron and laser energies within practical limits can enhance the transmutation of Mo-100 to M-99 quite significantly. It has been found that irradiation time should be rather short, e.g., less than 6 hours, to maximize the weekly production of Mo-99 in the GDR-based Mo-99 production facility using the LCS photons. The analysis shows that production of 99Mo using a high-performance LCS facility offers a potentially-promising alternative for the production of 99mTc.

  8. Formation of graphene on Ru(0001) surface

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  9. On the viability of cyclometalated Ru(II) complexes as dyes in DSSC regulated by COOH group, a DFT study.

    Science.gov (United States)

    Wang, Jian; Bai, Fu-Quan; Xia, Bao-Hui; Feng, Lu; Zhang, Hong-Xing; Pan, Qing-Jiang

    2011-02-14

    The Ru(II) complexes [Ru(bpp)(dcbpy)Cl](+) (1), [Ru(tcbpp)(bpy)Cl](+) (2), and [Ru(tc'bpp)(bpy)Cl](+) (3) (bpp = 2,6-bis(N-pyrazolyl)pyridine, dcbpy = 4,4'-dicarboxyl-bipyridine, bpy = bipyridine, tcbpp = 4-carboxyl-2,6-bis(2-carboxyl-N-pyrazolyl)pyridine, tc'bpp = 4-carboxyl-2,6-bis(4-carboxyl-N-pyrazolyl)pyridine) are studied theoretically using density functional theory (DFT) techniques to explore their properties as dye in a solar cell. The calculated geometry structure and absorption spectrum of 1 are consistent with its experimental results. The calculation results indicate which sites the COOH groups attach to can significantly influence the electronic structure of the complex. By migrating the COOH groups from the bpy ligand in 1 to bpp ligand in 2 and 3, the nature of LUMO changes from bpy-localized to bpp dominated. The calculated low-lying absorptions at λ > 370 nm of the three complexes are categorized as metal-to-ligand charge-transfer (MLCT) transitions and the transition terminates at the orbital populated by the COOH appended ligand. The atomic spin density analysis also indicates that the ligand which is modified by the COOH groups is the ideal spot for the captured electron to situate. It can be predicted that the performance of 2 and 3 in the dye-sensitized solar cell can be enhanced as compared with 1.

  10. Specific heat, differential susceptibility and electrical resistivity of PrX2 (X = Ir, Pt, Rh and Ru) laves phase compounds at temperatures 1.4 K < T < 40 K

    Science.gov (United States)

    van Dongen, J. C. M.; van der Linden, H. W. M.; Greidanus, F. J. A. M.; Nieuwenhuys, G. J.; Mydosh, J. A.; Buschow, K. H. J.

    1980-01-01

    Specific heat and differential susceptibility data of PrX 2 (X = Ir, Pt, Rh, and Ru) compounds reveal phase transitions at Tc = (11.2 ± 0.5) K, (7.7 ± 0.5) K, (7.9 ± 0.5) K and (33.9 ± 0.5) K for X = Ir, Pt, RhandRu, resp. The electrical resistivity drops markedly below Tc, and the dϱ/d T versus T curve is similar to that of the specific heat.

  11. Reappraisal of Tc-99m DMSA scintigraphy for follow up in children with vesicoureteral reflux

    Energy Technology Data Exchange (ETDEWEB)

    Tsukamoto, Eriko; Morita, Koichi; Katoh, Chietsugu; Nakada, Kunihiro; Nonomura, Katsuya; Kakizaki, Hidehiro; Koyanagi, Tomohiko; Tamaki, Nagara [Hokkaido Univ., Sapporo (Japan). School of Medicine; Itoh, Kazuo

    1999-12-01

    We reviewed Tc-99m DMSA scintigraphy in children with vesicoureteral reflux (VUR) in order to assess whether repeated Tc-99m DMSA scans are necessary for the follow up of these patients. Ninety-seven children who were followed up for more than one year (1-7.4 years, average 2.8 years) after the first DMSA scan were included in the study. Fifty-one patients had been diagnosed as primary VUR and 46 as secondary VUR. Age at the first examination ranged from 0 to 14 years (average 5.1 years). Planar images were taken 2 hours after injection. The % renal uptake per injected dose (% RU) was calculated from posterior images. Kidneys in 11 patients (11.3%) changed morphologically during the follow up. Of these, new photon deficient areas (PD) were detected in only 4 patients (4.1%). All of these 4 patients had neurogenic bladder and were managed with self-catheterization. Of the remaining 7 patients, cortical thinning progressed in 5 patients (5.2%) and PDs resolved in 3 patients (3.1%). In one of these 7 patients, PD resolved in one kidney and cortical thinning progressed in the contralateral kidney. Of 97 patients reviewed, % RU decreased more than 20% during the follow up in 6 patients (6.2%). All were diagnosed as secondary VUR due to neurogenic bladder. % RU decreased only in the contracted kidneys at the initial scan. Two of them underwent renal transplantation because of severe renal failure. In conclusion, new PD rarely developed and % RU decreased in only a few patients during the follow up of children with VUR. Repeated Tc-99m DMSA scintigraphy therefore seems to have little benefit in the follow up of children with VUR. It should be performed in selected patients with high risk of urinary tract infection or renal failure. (author)

  12. Layered perovskite-related ruthenium oxychlorides: crystal structure of two new compounds Ba 5Ru 2Cl 2O 9 and Ba 6Ru 3Cl 2O 12

    Science.gov (United States)

    Tancret, N.; Roussel, P.; Abraham, F.

    2004-03-01

    Single crystals of the title compounds were prepared using a BaCl 2 flux and investigated by X-ray diffraction methods using Mo Kα radiation and a charge coupled device (CCD) detector. The crystal structures of these two new compounds were solved and refined in the hexagonal symmetry with space group P6 3/ mmc, a=5.851(1) Å, c=25.009(5) Å, ρcal=4.94 g cm -3, Z=2 to a final R1=0.069 for 20 parameters with 312 reflections for Ba 5Ru 2Cl 2O 9 and space group P 3¯m1 , a=5.815(1) Å, c=14.915(3) Å, ρcal=5.28 g cm -3, Z=1 to a final R1=0.039 for 24 parameters with 300 reflections for Ba 6Ru 3Cl 2O 12. The structure of Ba 5Ru 2Cl 2O 9 is formed by the periodic stacking along [001] of three hexagonal close-packed BaO 3 layers separated by a double layer of composition Ba 2Cl 2. The BaO 3 stacking creates binuclear face-sharing octahedra units Ru 2O 9 containing Ru(V). The structure of Ba 6Ru 3Cl 2O 12 is built up by the periodic stacking along [001] of four hexagonal close-packed BaO 3 layers separated by a double layer of composition Ba 2Cl 2. The ruthenium ions with a mean oxidation degree +4.67 occupy the octahedral interstices formed by the four layers hexagonal perovskite slab and then constitute isolated trinuclear Ru 3O 12 units. These two new oxychlorides belong to the family of compounds formulated as [Ba 2Cl 2][Ba n+1 Ru nO 3 n+3 ], where n represents the thickness of the octahedral string in hexagonal perovskite slabs.

  13. Scanning tunnelling microscope studies of growth of RuO2(110) thin layer on Ru(0001)

    Institute of Scientific and Technical Information of China (English)

    Zhang Han-Jie; Lü Bin; Lu Yun-Hao; Huang Han; Li Hai-Yang; Bao Shi-Ning; He Pei-Mo

    2006-01-01

    This paper reports that the growth of RuO2(110) thin layer growth on Ru(0001) has been investigated by means of scanning tunnelling microscope (STM). The STM images showed a domain structure with three rotational domains of RuO2(110) rotated by an angle of 120°. The as-grown RuO2(110) thin layer is expanded from the bulk-truncated RuCO2(110) due to the large mismatch between RuCO2(110) and the Ru(0001) substrate. The results also indicate that growth of RuO2(110) thin layer on the Ru(0001) substrate by oxidation tends first to formation of the Ru-O (oxygen) chains in the [001] direction of RuO2(110).

  14. Evaluation of nanostructured Pt-Ru catalyst for application in DMFC

    Energy Technology Data Exchange (ETDEWEB)

    Ocampo, A.L.; Gamboa, S.A. [Centro de Investigacion en Energia-UNAM, Morelos (Mexico); Sebastien, P.J. [Centro de Investigacion en Energia-UNAM, Morelos (Mexico)]|[Chiapas Politecnica Univ., Chiapas (Mexico); Morgado, J.; Montoya, J.A. [IMP, Eje Central Lazaro Cardenas, (Mexico); Savadogo, O. [Ecole Polytechnique, Montreal, PQ (Canada). Laboratoire d' electrochimie et de materiaux energetiques

    2006-07-01

    Slow methanol oxidation kinetics and the poisoning of the anode catalyst are the major factors that limit the performance of the direct methanol fuel cell (DMFC). Catalysts with higher catalytic activity are needed in order to overcome these challenges. Although platinum (Pt) is a good catalyst for methanol oxidation, it can be highly affected by carbon monoxide (CO) reaction intermediates. Superior catalytic activity occurs in Pt based alloys, such as platinum ruthenium (Pt-Ru), platinum molybdenum (Pt-Mo), platinum tin (Pt-Sn), and platinum osmium (Pt-Os). This is due to the bifunctional mechanism and/or by the electronic effect, which indicates a promotional effect of the alloyed metal on Pt. The most studied binary system is the Pt-Ru (ruthenium), which has shown the best catalytic activity. There are many factors that influence the physical properties and the electrochemical performance of the Pt-Ru catalyst. These include the preparation method; the atomic ratio between platinum and ruthenium; the nature of the catalyst support; and, an optional heat treatment. Other important factors such as the particle size, the morphology, the electrochemically active area, and the crystalline phase influence the physical properties. In this study, nanostructured Pt-Ru catalysts were fabricated and evaluated physicochemically and electrochemically for its use in direct methanol fuel cell (DMFC). The catalysts were synthesized from the carbonyl compounds of Pt and Ru via a pyrolysis-condensation reaction. The high resolution results showed a homogenous distribution of the nanostructured catalysts on Vulcan support. The catalyst was evaluated by XRD, HRTEM, electrochemical impedance spectroscopy and the methanol oxidation on the catalyst was studied using volt-amperometry. The performance of the catalyst was found to be similar or better than the commercial one. It was concluded that it is possible to synthesize Pt-Ru/C with good morphological characteristics and improve it

  15. Thermodynamic assessment of the Al-Ru system

    CSIR Research Space (South Africa)

    Prins, SN

    2003-03-01

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

  16. Predicting Single-Layer Technetium Dichalcogenides (TcX₂, X = S, Se) with Promising Applications in Photovoltaics and Photocatalysis.

    Science.gov (United States)

    Jiao, Yalong; Zhou, Liujiang; Ma, Fengxian; Gao, Guoping; Kou, Liangzhi; Bell, John; Sanvito, Stefano; Du, Aijun

    2016-03-01

    One of the least known compounds among transition metal dichalcogenides (TMDCs) is the layered triclinic technetium dichalcogenides (TcX2, X = S, Se). In this work, we systematically study the structural, mechanical, electronic, and optical properties of TcS2 and TcSe2 monolayers based on density functional theory (DFT). We find that TcS2 and TcSe2 can be easily exfoliated in a monolayer form because their formation and cleavage energy are analogous to those of other experimentally realized TMDCs monolayer. By using a hybrid DFT functional, the TcS2 and TcSe2 monolayers are calculated to be indirect semiconductors with band gaps of 1.91 and 1.69 eV, respectively. However, bilayer TcS2 exhibits direct-bandgap character, and both TcS2 and TcSe2 monolayers can be tuned from semiconductor to metal under effective tensile/compressive strains. Calculations of visible light absorption indicate that 2D TcS2 and TcSe2 generally possess better capability of harvesting sunlight compared to single-layer MoS2 and ReSe2, implying their potential as excellent light-absorbers. Most interestingly, we have discovered that the TcSe2 monolayer is an excellent photocatalyst for splitting water into hydrogen due to the perfect fit of band edge positions with respect to the water reduction and oxidation potentials. Our predictions expand the two-dimensional (2D) family of TMDCs, and the remarkable electronic/optical properties of monolayer TcS2 and TcSe2 will place them among the most promising 2D TMDCs for renewable energy application in the future.

  17. Selective oxidation of methylamine over zirconia supported Pt-Ru, Pt and Ru catalysts

    Institute of Scientific and Technical Information of China (English)

    Aiying Song; Gongxuan Lu

    2015-01-01

    Pt–Ru, Pt and Ru catalysts supported on zirconia were prepared by impregnation method and were tested in se-lective oxidation of methylamine (MA) in aqueous media. Among three catalysts, Ru/ZrO2 was more active than Pt/ZrO2 while Pt–Ru/ZrO2 demonstrated the best catalytic activity due to the fact that Pt addition efficiently pro-moted the dispersion of active species in bimetallic catalyst. Therefore, the~100%TOC conversion and N2 selec-tivity were achieved over Pt–Ru/ZrO2, Pt/ZrO2 and Ru/ZrO2 catalysts at 190, 220 and 250 °C, respectively.

  18. Adsorption and electron-induced polymerization of methyl methacrylate on Ru(1010).

    Science.gov (United States)

    Hedhili, M N; Yakshinskiy, B V; Wasielewski, R; Ciszewski, A; Madey, T E

    2008-05-01

    The adsorption and electron irradiation of methyl methacrylate (MMA) on a Ru(1010) surface have been studied using x-ray photoelectron spectroscopy (XPS), temperature programmed desorption (TPD), and low energy ion scattering. TPD analysis indicates that a monolayer of MMA chemisorbs and dissociates on the Ru(1010) surface. The reaction products observed upon heating include H(2), CO, CO(2), and a small amount of MMA. Physisorbed multilayers of MMA desorb at temperatures around 170 K. Electron irradiation of physisorbed MMA at 140 K leads to a modification of the MMA film: The XPS spectra show an increase in thermal stability of the film with retention of the MMA structure, and indicate that electron irradiation induces polymerization. An increase in the electron bombardment fluence induces a degradation of the formed polymerized species and leads to the accumulation of carbon on the Ru surface. These results are relevant to the accumulation of carbon on surfaces of Ru films that serve as capping layers on MoSi multilayer mirrors used in extreme ultraviolet lithography.

  19. Effect of Ru-substitution on electrical and magnetocaloric properties of Nd0.5Ca0.5MnO3

    Science.gov (United States)

    Krishnamoorthi, C.; Barik, S. K.; Mahendiran, R.

    2011-01-01

    It is shown that the charge-orbital ordered antiferromagnetic insulating state of the parent compound (y=0) in Nd0.5Ca0.5Mn1-yRuyO3 (y=0, 0.03, 0.05, & 0.10) series is destabilized and a ferromagnetic metallic state is induced by Ru substitution as small as 3%. The ferromagnetic transition temperature (TC) increases with Ru content from 215 K (y=0.03) to 255 K (y=0.10). The magnetic entropy change (ΔSm) of y=0 changes sign from negative to positive as the temperature is lowered below the charge ordering temperature. However, ΔSm is negative and exhibits a peak close to TC in Ru-doped samples. The peak values of ΔSm are -0.33, -3.8, -3.6, and -3.5 J kg-1 K-1 for y=0, 0.03, 0.05, & 0.10 respectively, for a field change of ΔH=5 T. The relative cooling power (RCP) decreases with increasing Ru content from 268 J/kg for x=0.03 to 234 J/kg for x=0.10 for ΔH=5 T whereas the y=0 sample shows 17 J/kg. The large RCP and ΔSm found in Ru-substituted samples will be interesting for magnetic refrigeration below room temperature.

  20. Presentation of test cases TC-2A, TC-2B, TC-2C, TC-2D - Twodimensional, incompressible, wall flows with separation

    DEFF Research Database (Denmark)

    Scheel Larsen, Poul

    1988-01-01

    The four test cases comprise the backfacing step at high Re-number (TC-2A) and low Re-number (TC-2B), a low Re-number boundary layer flow past a thin obstacle, fence-on-wall (TC-2C), and a high Re-number developed channel flow past a squareobstacle (TC-2D). Geometry, test conditions and available...

  1. Nanoscale decomposition of Nb-Ru-O

    Science.gov (United States)

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

    2016-11-01

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

  2. PHARMACOKINETICS OF RU486 IN RABBITS

    Institute of Scientific and Technical Information of China (English)

    ZHANGMing-Hua; CHUYun-Hong; LIQui; CHANGLi-Min; FANGZhen; JINGZuao-Ying

    1989-01-01

    Intravaginal release of contraceptive steroid by avoiding the first-pass effect may provide a suitable route of administration, thus leading to higher bioavailabilities. RU486 is significantly metabolizlcd by the first-pass metabolism. We have studied its pharmacokinetics

  3. A fast and simple dose-calibrator-based quality control test for the radionuclidic purity of cyclotron-produced 99mTc

    Science.gov (United States)

    Tanguay, J.; Hou, X.; Esquinas, P.; Vuckovic, M.; Buckley, K.; Schaffer, P.; Bénard, F.; Ruth, T. J.; Celler, A.

    2015-11-01

    Cyclotron production of {{}99\\text{m}} Tc through the 100Mo(p,2n){{}99\\text{m}} Tc reaction channel is actively being investigated as an alternative to reactor-based 99Mo generation by nuclear fission of 235U. Like most radioisotope production methods, cyclotron production of {{}99\\text{m}} Tc will result in creation of unwanted impurities, including Tc and non-Tc isotopes. It is important to measure the amounts of these impurities for release of cyclotron-produced {{}99\\text{m}} Tc (CPTc) for clinical use. Detection of radioactive impurities will rely on measurements of their gamma (γ) emissions. Gamma spectroscopy is not suitable for this purpose because the overwhelming presence of {{}99\\text{m}} Tc and the count-rate limitations of γ spectroscopy systems preclude fast and accurate measurement of small amounts of impurities. In this article we describe a simple and fast method for measuring γ emission rates from radioactive impurities in CPTc. The proposed method is similar to that used to identify 99Mo breakthrough in generator-produced {{}99\\text{m}} Tc: one dose calibrator (DC) reading of a CPTc source placed in a lead shield is followed by a second reading of the same source in air. Our experimental and theoretical analysis show that the ratio of DC readings in lead to those in air are linearly related to γ emission rates from impurities per MBq of {{}99\\text{m}} Tc over a large range of clinically-relevant production conditions. We show that estimates of the γ emission rates from Tc impurities per MBq of {{}99\\text{m}} Tc can be used to estimate increases in radiation dose (relative to pure {{}99\\text{m}} Tc) to patients injected with CPTc-based radiopharmaceuticals. This enables establishing dosimetry-based clinical-release criteria that can be tested using commercially-available dose calibrators. We show that our approach is highly sensitive to the presence of {{}93\\text{g}} Tc, {{}93\\text{m}} Tc, {{}94\\text{g}} Tc, {{}94\\text{m}} Tc

  4. Water-stable fac-{TcO₃}⁺ complexes - a new field of technetium chemistry.

    Science.gov (United States)

    Braband, Henrik

    2011-01-01

    The development of technetium chemistry has been lagging behind that of its heavier congener rhenium, primarily because the inherent radioactivity of all Tc isotopes has limited the number of laboratories that can study the chemistry of this fascinating element. Although technetium is an artificial element, it is not rare. Significant amounts of the isotope (99)Tc are produced every day as a fission byproduct in nuclear power plants. Therefore, a fundamental understanding of the chemistry of (99)Tc is essential to avoid its release into the environment. In this article the chemistry of technetium at its highest oxidation state (+VII) is reviewed with a special focus on recent developments which make water-stable complexes of the general type [TcO(3)(tacn-R)](+) (tacn-R = 1,4,7-triazacyclononane or derivatives) accessible. Complexes containing the fac-{TcO(3)}(+) core display a unique reactivity. In analogy to [OsO(4)] and [RuO(4)], complexes containing the fac-{TcO(3)}(+) core undergo with alkenes metal-mediated, vicinal cis-dihydroxylation reactions (alkene-glycol interconversion) in water via a (3+2)-cycloaddition reaction. Therefore, water-stable fac-{(99m)TcO(3)}(+) complexes pave the way for a new labeling strategy for radiopharmaceutical applications, based on (3+2)-cycloaddition reactions. This new concept for the labeling of biomolecules with small [(99m)TcO(3)(tacn-R)](+)-type complexes by way of a (3+2)-cycloaddition with alkenes is discussed in detail. The herein reported developments in high-valent technetium chemistry create a new field of research with this artificial element. This demonstrates the potential of fundamental research to provide new impetus of innovation for the development of new methods for radiopharmaceutical applications.

  5. Fission-Produced (99)Mo Without a Nuclear Reactor.

    Science.gov (United States)

    Youker, Amanda J; Chemerisov, Sergey D; Tkac, Peter; Kalensky, Michael; Heltemes, Thad A; Rotsch, David A; Vandegrift, George F; Krebs, John F; Makarashvili, Vakho; Stepinski, Dominique C

    2017-03-01

    (99)Mo, the parent of the widely used medical isotope (99m)Tc, is currently produced by irradiation of enriched uranium in nuclear reactors. The supply of this isotope is encumbered by the aging of these reactors and concerns about international transportation and nuclear proliferation. Methods: We report results for the production of (99)Mo from the accelerator-driven subcritical fission of an aqueous solution containing low enriched uranium. The predominately fast neutrons generated by impinging high-energy electrons onto a tantalum convertor are moderated to thermal energies to increase fission processes. The separation, recovery, and purification of (99)Mo were demonstrated using a recycled uranyl sulfate solution. Conclusion: The (99)Mo yield and purity were found to be unaffected by reuse of the previously irradiated and processed uranyl sulfate solution. Results from a 51.8-GBq (99)Mo production run are presented.

  6. GASIFICATION TEST RUN TC06

    Energy Technology Data Exchange (ETDEWEB)

    Southern Company Services, Inc.

    2003-08-01

    This report discusses test campaign TC06 of the Kellogg Brown & Root, Inc. (KBR) Transport Reactor train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Reactor is an advanced circulating fluidized-bed reactor designed to operate as either a combustor or a gasifier using a particulate control device (PCD). The Transport Reactor was operated as a pressurized gasifier during TC06. Test run TC06 was started on July 4, 2001, and completed on September 24, 2001, with an interruption in service between July 25, 2001, and August 19, 2001, due to a filter element failure in the PCD caused by abnormal operating conditions while tuning the main air compressor. The reactor temperature was varied between 1,725 and 1,825 F at pressures from 190 to 230 psig. In TC06, 1,214 hours of solid circulation and 1,025 hours of coal feed were attained with 797 hours of coal feed after the filter element failure. Both reactor and PCD operations were stable during the test run with a stable baseline pressure drop. Due to its length and stability, the TC06 test run provided valuable data necessary to analyze long-term reactor operations and to identify necessary modifications to improve equipment and process performance as well as progressing the goal of many thousands of hours of filter element exposure.

  7. Study of the retention and release of {sup 99m} Tc in several chromatographic columns through the elution with different solvents; Estudo da retencao e liberacao do tecnecio metaestavel ({sup 99m} Tc) em diversas colunas cromatograficas usando diferentes solventes

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Katia N.; Osso Junior, Joao A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: norisuzuki6@yahoo.com.br

    2005-07-01

    About 80% of the radiopharmaceuticals used in Nuclear Medicine is labelled with {sup 99m} Tc due to its physical properties such as short half-life of 6h, gamma photon emission of 140 keV and easy attainment through generators of {sup 99}Mo/{sup 99m} Tc. The Center of Radiopharmacy (CR) of the IPEN-CNEN/SP developed a type generator production of {sup 99}Mo/{sup 99m} Tc through the reaction {sup 98}Mo(n,a) {sup 99}Mo that it occurs in the nuclear reactor IEA-R1 of the IPEN-CNEN/SP, using the technique of elution of a gel of zirconium molybdate for the production of a MoZr gel type chromatographic generator. Although all the efforts used in the study of optimization of the conditions of preparation of the gel of MoZr, this generator possess a low to medium specific activity (925 MBq/mL) lower than the fission generator (1850 MBq/mL) used currently for the Brazilian medical costumers, as expected by this technology. The main objective of this work is the study of the retention and release of {sup 99m}-Tc in several chromatographic columns through the elution with different solvents. This is the first step for the attainment of a radioactive concentration of {sup 99m} Tc in order to attend the demand of the market without losing the quality and proving its clinical effectiveness. The initial results of adsorption and elution of {sup 99m} Tc from ion exchanging columns with different solvents will be presented. (author)

  8. Measurement of the 92,93,94,100Mo(g,n) reactions by Coulomb Dissociation

    CERN Document Server

    Göbel, K; Altstadt, S; Alvarez-Pol, H; Aksouh, F; Aumann, T; Babilon, M; Behr, K-H; Benlliure, J; Berg, T; Böhmer, M; Boretzky, K; Brünle, A; Beyer, R; Casarejos, E; Chartier, M; Cortina-Gil, D; Chatillon, A; Pramanik, U Datta; Deveaux, L; Elvers, M; Elze, T W; Emling, H; Erhard, M; Ershova, O; Fernandez-Dominguez, B; Geissel, H; Górska, M; Heftrich, T; Heil, M; Hellstroem, M; Ickert, G; Johansson, H; Junghans, A R; Käppeler, F; Kiselev, O; Klimkiewicz, A; Kratz, J V; Kulessa, R; Kurz, N; Labiche, M; Langer, C; Bleis, T Le; Lemmon, R; Lindenberg, K; Litvinov, Y A; Maierbeck, P; Movsesyan, A; Müller, S; Nilsson, T; Nociforo, C; Paar, N; Palit, R; Paschalis, S; Plag, R; Prokopowicz, W; Reifarth, R; Rossi, D M; Schnorrenberger, L; Simon, H; Sonnabend, K; Sümmerer, K; Surówka, G; Vretenar, D; Wagner, A; Walter, S; Waluś, W; Wamers, F; Weick, H; Weigand, M; Winckler, N; Winkler, M; Zilges, A

    2013-01-01

    The Coulomb Dissociation (CD) cross sections of the stable isotopes 92,94,100Mo and of the unstable isotope 93Mo were measured at the LAND/R3B setup at GSI Helmholtzzentrum f\\"ur Schwerionenforschung in Darmstadt, Germany. Experimental data on these isotopes may help to explain the problem of the underproduction of 92,94Mo and 96,98Ru in the models of p-process nucleosynthesis. The CD cross sections obtained for the stable Mo isotopes are in good agreement with experiments performed with real photons, thus validating the method of Coulomb Dissociation. The result for the reaction 93Mo(g,n) is especially important since the corresponding cross section has not been measured before. A preliminary integral Coulomb Dissociation cross section of the 94Mo(g,n) reaction is presented. Further analysis will complete the experimental database for the (g,n) production chain of the p-isotopes of molybdenum.

  9. Enhanced 99 Tc retention in glass waste form using Tc(IV)-incorporated Fe minerals

    Energy Technology Data Exchange (ETDEWEB)

    Um, Wooyong; Luksic, Steven A.; Wang, Guohui; Saslow, Sarah; Kim, Dong-Sang; Schweiger, Michael J.; Soderquist, Chuck Z.; Bowden, Mark E.; Lukens, Wayne W.; Kruger, Albert A.

    2017-11-01

    Technetium (99Tc) immobilization by doping into iron oxide mineral phases may alleviate the problems with Tc volatility during vitrification of nuclear waste. Reduced Tc, Tc(IV), substitutes for Fe(III) in the crystal structure by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation of Fe oxide minerals. Two Tc-incorporated Fe minerals (Tc-goethite and Tc-magnetite/maghemite) were prepared and tested for Tc retention in glass melt samples at temperatures between 600 – 1,000 oC. After being cooled, the solid glass specimens prepared at different temperatures were analyzed for Tc oxidation state using Tc K-edge XANES. In most samples, Tc was partially oxidized from Tc(IV) to Tc(VII) as the melt temperature increased. However, Tc retention in glass melt samples prepared using Tc-incorporated Fe minerals were moderately higher than in glass prepared using KTcO4 because of limited and delayed Tc volatilization.

  10. Reactivity of diaminogermylenes with ruthenium carbonyl: Ru3Ge3 and RuGe2 derivatives.

    Science.gov (United States)

    Cabeza, Javier A; García-Álvarez, Pablo; Polo, Diego

    2011-07-04

    The nature of the products of the reactions of [Ru(3)(CO)(12)] with diaminogermylenes depends upon the volume and the cyclic or acyclic structure of the latter. Thus, the triruthenium cluster [Ru(3){μ-Ge(NCH(2)CMe(3))(2)C(6)H(4)}(3)(CO)(9)], which has a planar Ru(3)Ge(3) core and an overall C(3h) symmetry, has been prepared in quantitative yield by treating [Ru(3)(CO)(12)] with an excess of the cyclic 1,3-bis(neo-pentyl)-2-germabenzimidazol-2-ylidene in toluene at 100 °C, but under analogous reaction conditions, the acyclic and bulkier Ge(HMDS)(2) (HMDS = N(SiMe(3))(2)) quantitatively leads to the mononuclear ruthenium(0) derivative [Ru{Ge(HMDS)(2)}(2)(CO)(3)]. Mixtures of products have been obtained from the reactions of [Ru(3)(CO)(12)] with the cyclic and very bulky 1,3-bis(tert-butyl)-2-germaimidazol-2-ylidene under various reaction conditions. The Ru(3)Ge(3) and RuGe(2) products reported in this paper are the first ruthenium complexes containing diaminogermylene ligands.

  11. Ru-NQR Study for Novel Phase Transition in CeRu2Al10

    Science.gov (United States)

    Matsumura, Masahiro; Tomita, Naoya; Matsuoka, Junichirou; Kishimoto, Yasuki; Kato, Harukazu; Kitagawa, Kentaro; Nishioka, Takashi; Tanida, Hiroshi; Sera, Masafumi

    2014-10-01

    We have performed Ru-NQR measurements on CeRu2Al10 exhibiting novel phase transition at an abnormally high temperature T0 = 27.3 K and on NdRu2Al10 with a magnetic transition temperature Tm = 2.4 K as a reference RKKY system. The splitting of the NQR line due to internal fields below T0 shows a mean-field-like monotonic increase, indicating no change in the magnetic structure below T0. The internal field strength is one order larger than those at Al sites in CeRu2Al10, and is comparable to that at the Ru site in NdRu2Al10 despite the sevenfold smaller magnitude of the 4f moment, being indicative of an enhanced conduction electron polarization at the Ru site. One of the causes of the high T0 might be the enhanced exchange coupling through the Ce-Ru-Ce path mediated by the enhanced conduction electron polarization. Being similar to that in the Al site, the nuclear spin-lattice relaxation rate 1/T1 shows a gap-like decrease below T0 without enhancement owing to a critical slowing down at T0, in contrast to the mean field 2nd-order transition.

  12. Ru(0) and Ru(II) nitrosyl pincer complexes: structure, reactivity, and catalytic activity.

    Science.gov (United States)

    Fogler, Eran; Iron, Mark A; Zhang, Jing; Ben-David, Yehoshoa; Diskin-Posner, Yael; Leitus, Gregory; Shimon, Linda J W; Milstein, David

    2013-10-07

    Despite considerable interest in ruthenium carbonyl pincer complexes and their substantial catalytic activity, there has been relatively little study of the isoelectronic ruthenium nitrosyl complexes. Here we describe the synthesis and reactivity of several complexes of this type as well as the catalytic activity of complex 6. Reaction of the PNP ligand (PNP = 2,6-bis((t)Bu2PCH2)pyridine) with RuCl3(NO)(PPh3)2 yielded the Ru(II) complex 3. Chloride displacement by BAr(F-) (BAr(F-) = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate) gave the crystallographicaly characterized, linear NO Ru(II) complex 4, which upon treatment with NaBEt3H yielded the Ru(0) complexes 5. The crystallographically characterized Ru(0) square planar complex 5·BF4 bears a linear NO ligand located trans to the pyridilic nitrogen. Further treatment of 5·BF4 with excess LiOH gave the crystallographicaly characterized Ru(0) square planar, linear NO complex 6. Complex 6 catalyzes the dehydrogenative coupling of alcohols to esters, reaching full conversion under air or under argon. Reaction of the PNN ligand (PNN = 2-((t)Bu2PCH2)-6-(Et2NCH2)pyridine) with RuCl3(NO)(H2O)2 in ethanol gave an equilibrium mixture of isomers 7a and 7b. Further treatment of 7a + 7b with 2 equivalent of sodium isopropoxide gave the crystallographicaly characterized, bent-nitrosyl, square pyramidal Ru(II) complex 8. Complex 8 was also synthesized by reaction of PNN with RuCl3(NO)(H2O)2 and Et3N in ethanol. Reaction of the "long arm" PN(2)N ligand (PN(2)N = 2-((t)Bu2PCH2-)-6-(Et2NCH2CH2)pyridine) with RuCl3(NO)(H2O)2 in ethanol gave complex 9, which upon treatment with 2 equiv of sodium isopropoxide gave complex 10. Complex 10 was also synthesized directly by reaction of PN(2)N with RuCl3(NO)(H2O)2 and a base in ethanol. A noteworthy aspect of these nitrosyl complexes is their preference for the Ru(0) oxidization state over Ru(II). This preference is observed with both aromatized and dearomatized pincer ligands, in

  13. Influence of the electronic structures on the heterogeneous photoelectrocatalytic performance of Ti/Ru{sub x}Sn{sub 1-x}O{sub 2} electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhijie, E-mail: 1061739408@qq.com [College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian 350108 (China); Zhu, Junqiu, E-mail: zhujunqiu@xmut.edu.com [School of Chemical Engineering and Materials Science, Quanzhou Normal University, Quanzhou, Fujian 362000 (China); Zhang, Shuai, E-mail: 601314274@qq.com [College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian 350108 (China); Shao, Yanqun, E-mail: yqshao1989@163.com [College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian 350108 (China); Lin, Deyuan, E-mail: lindeyuan_fj@126.com [Electric Power Research Institute of State Grid Fujian Electric Power Co. Ltd., Fuzhou 350007 (China); Zhou, Jianfeng, E-mail: 1277018923@qq.com [College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian 350108 (China); Chen, Yunxiang, E-mail: rogerchen@163.com [Electric Power Research Institute of State Grid Fujian Electric Power Co. Ltd., Fuzhou 350007 (China); Tang, Dian, E-mail: diantang@fzu.edu.cn [College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian 350108 (China)

    2017-07-05

    Highlights: • Ti/Ru{sub x}Sn{sub 1-x}O{sub 2} electrodes possessed photocatalytic and electrocatalytic activity were prepared by thermal decomposition method. • The effect of electronic structure on electronic conductivity, electrocatalytic and photocatalytic activity were studied. • The photoelectric-synergistic catalytic activity of the Ti/Ru{sub x}Sn{sub 1-x}O{sub 2} electrodes was studied upon UV irradiation. • The Ti/Ru{sub 0.05}Sn{sub 0.95}O{sub 2} electrode has good catalytic activity and excellent stability. - Abstract: DSA-type Ti/Ru{sub x}Sn{sub 1-x}O{sub 2} electrodes were prepared by thermal decomposition method as photoelectrocatalysts (PECs) and extensively characterized by various sophisticated techniques. First-principles calculations was employed to study the effects of Ru content on the electronic structures of the Ru{sub x}Sn{sub 1-x}O{sub 2} coatings. The photoelectric-synergistic catalytic activity of the Ti/Ru{sub x}Sn{sub 1-x}O{sub 2} electrodes was evaluated for the degradation of methyl orange (MO) in aqueous solution. The results show that the RuO{sub 2}−SnO{sub 2} solid solution could be formed. The band gaps of the Ru{sub x}Sn{sub 1-x}O{sub 2} coatings gradually decreased and eventually turned into metallic conductivity with the increase of ruthenium content. As a PEC electrode, reducing band gap is helpful to improve electronic conductivity and the electrocatalytic activity, but not always advantageous to increase the photocatalytic activity. Because too narrow band gap will sacrifice the photogenerated charge carriers and thus reduce photocatalytic activity of the electrode. In our experiments, the rate constant of Ti/Ru{sub 0.05}Sn{sub 0.95}O{sub 2} electrode increased with increasing Ru content and exhibited the maximum rate for 5% Ru loading. The stability test showed the photoelectrocatalytic activity of the Ti/Ru{sub 0.05}Sn{sub 0.95}O{sub 2} electrode almost had no attenuation after 100 h photoelectrolysis, revealing

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  16. Assessment of the direct cyclotron production of (99m)Tc: An approach to crisis management of (99m)Tc shortage.

    Science.gov (United States)

    Rovais, Mohammad Reza Aboudzadeh; Aardaneh, Khosro; Aslani, Gholamreza; Rahiminejad, Ali; Yousefi, Kamran; Boulouri, Fatemeh

    2016-06-01

    Nowadays, the cyclotron production of technetium-99m ((99m)Tc) has been increased, due to the worldwide (99m)Tc generator shortage. In the present work, an improved strategy for the production of (99m)Tc, using the proton irradiation of the enriched (100)Mo was developed. The performance of this method in terms of the production yield, chemical purity, radiochemical purity, as well as radionuclide purity was evaluated. The average production yield was measured to be 356MBqμA(-1)h(-1). A good agreement was found between the calculated production yield and the experimental one. The radiochemical separation and total recovery yields of (99m)Tc were 92% and 69%, respectively. The radiochemical and the radionuclide purities of the (99m)Tc were 99% and >99.99% at the end of purification, respectively. The results of quality control tests (QC) support the concept that cyclotron-produced (99m)Tc is suitable for preparation of USP-compliant.

  17. Excitation function and isomeric ratio of Tc-isotopes from the {sup 93}Nb(α, xn) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kim, G.N., E-mail: gnkim@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Naik, H. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Rediochemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 400085 (India); Zaman, M. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Yang, S.-C.; Song, T.-Y. [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Guin, R.; Das, S.K. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India)

    2015-03-15

    The excitation functions of {sup 94–96}Tc isotopes and independent isomeric ratios of {sup 93m, g}Tc, {sup 94m, g}Tc, and {sup 95m, g}Tc from the {sup 93}Nb(α, xn) reaction within the energy range below 40 MeV have been determined by using a stacked-foil activation and an off-line γ-ray spectrometric technique at the Variable Energy Cyclotron Center, Kolkota, India. The excitation function of {sup 94–96}Tc in the {sup 93}Nb(α, xn) reaction was also calculated by using the computer code TALYS 1.6. The present data are found to be in general agreement with the literature data but have similar trend with some deviation from calculated data of the TALYS 1.6 code. The isomeric ratios of {sup 93m, g}Tc, {sup 94m, g}Tc, and {sup 95m, g}Tc in the {sup 93}Nb(α, xn) reactions from the present work and literature data were compared with similar data in the {sup 93}Nb({sup 3}He, xn) and {sup 96}Mo(p, xn) reactions. In all the three reactions, the isomeric ratios increase with the increasing excitation energy. However, at all excitation energies, the isomeric ratios of {sup 93m, g}Tc, {sup 94m, g}Tc, and {sup 95m, g}Tc in the {sup 93}Nb(α, xn) and {sup 93}Nb({sup 3}He, xn) reactions are higher than those in the {sup 96}Mo(p, xn) reactions, which indicate the role of input angular momentum besides excitation energy. Above the excitation energy of 35–55 MeV, the isomeric ratios of {sup 95m, g}Tc, {sup 94m, g}Tc, and {sup 93m, g}Tc decrease in all the {sup 93}Nb(α, xn), {sup 93}Nb({sup 3}He, xn) and {sup 96}Mo(p, xn) reactions. This decreasing trend at higher excitation energy indicates the starting of pre-equilibrium reaction, which depends on the target, projectile, and type of reaction products.

  18. Uranium ferromagnet with negligible magnetocrystalline anisotropy: U4Ru7Ge6

    Science.gov (United States)

    Vališka, Michal; Diviš, Martin; Sechovský, Vladimír

    2017-02-01

    Strong magnetocrystalline anisotropy (MA) is a well-known property of uranium compounds. The almost isotropic ferromagnetism in U4Ru7Ge6 reported in this paper represents a striking exception. We present results for magnetization, ac susceptibility, thermal expansion, specific heat, and electrical resistivity measurements performed on a U4Ru7Ge6 single crystal at various temperatures and magnetic fields; we discuss the results in relation to first-principles electronic structure calculations. U4Ru7Ge6 behaves as an itinerant 5 f -electron ferromagnet (TC=10.7 K , μS=0.85 μB/f .u . at 1.9 K ). The ground-state easy magnetization direction is along the [111] axis of the cubic lattice. The anisotropy field μ0Ha along the [001] direction is only about 0.3 T , which is at least three orders of magnitude smaller than for other U ferromagnets. At Tr=5.9 K the easy magnetization direction changes to [001], and remains [001] up to TC. This transition is due to a change in magnetic symmetry, and is quite apparent in the low-field magnetization, ac susceptibility, and thermal expansion data, whereas only weak anomalies are observed at Tr in the temperature dependence of the specific heat and electrical resistivity. The magnetoelastic interaction induces a rhombohedral (tetragonal) distortion of the paramagnetic cubic crystal lattice in the case of the [111] ([001]) easy magnetization direction. The rhombohedral distortion is connected with two crystallographically inequivalent U sites. Our density functional theory calculations, including spin-orbit interaction (SOI) of the U 5 f electrons, also produces two inequivalent U sites, because SOI leads to a reduction of the symmetry of the former cubic structure. The calculated ground state is in agreement with the experimentally observed [111] easy magnetization direction. The first excited state has moments along the [001] direction, which agrees with the moment orientation for T >Tr . The energy of the first excited state is

  19. Specific heat, resistivity, and AC susceptibility of the cubic PrX 2 compounds (X = Pt, Ru, Ir, Rh)

    Science.gov (United States)

    Greidanus, F. J. A. M.; Nieuwenhuys, G. J.; de Jongh, L. J.; Huiskamp, W. J.; Capel, H. W.; Buschow, K. H. J.

    1983-04-01

    Specific-heat, differential-susceptibility and electrical-resistivity measurements on PrX 2 (X = Ir, Pt, Rh, Ru) compounds reveal phase transitions at Tc = 11.2±0.5 K, 7.7±0.5 K, 7.9±0.5 Kand 33.9±0.5 K for X = Ir, Pt, Rh, and Ru, respective ly. From earlier neutron inelastic scattering experiments, the crystalline electric field levels of these compounds have been determined. The specific-heat results are compared with the results of a mean-field calculation, assuming bilinear exchange interactions. The presence of broad secondary maxima in the temperature dependence of the specific heat of PrRh 2, PrRu 2 and especially PrIr 2 can qualitatively be explained by the presence of biquadratic (quadrupolar) interactions. The behaviour of the susceptibility is in agreement with ferromagnetic ordering. The electrical resistivity drops markedly below Tc, and the dϱ/d T versus T curve is similar to that of the specific heat.

  20. Al 2O 3 supported Ru catalysts prepared by thermolysis of Ru 3(CO) 12 for catalytic wet air oxidation

    Science.gov (United States)

    Yu, Chaoying; Zhao, Peiqing; Chen, Gexin; Hu, Bin

    2011-06-01

    Low loading catalysts Ru/γ-Al 2O 3 and Ru-Ce/γ-Al 2O 3 were prepared by thermolysis of Ru 3(CO) 12 on γ-Al 2O 3. The catalysts were characterized by XPS, XRD and SEM. Two new Ru species (Ru A and Ru B) were detected during the Ru 3(CO) 12 decomposition process due to chemical interaction with the active OH groups on the surface of Al 2O 3 support, and the reduction of them can lead to more dispersed metallic phases. The sample was completely decomposed at 673 K in H 2, and RuO 2 was formed with minor amounts of Ru 0. When the temperature was increased to 773 K to heat the sample, the ratio of Ru 0 to RuO 2 increased. However, after the addition of CeO 2, only RuO 2 was detected on surface. The catalysts exhibited high activities in Catalytic Wet Air Oxidation (CWAO) of different organic compounds at high concentration such as isopropyl alcohol, phenol, acetic acids and N,N-dimethylformamide, which is attributed to the better dispersion of Ru particles and the addition of CeO 2 further enhanced number of effectively active sites on the cluster-derived catalyst surface.

  1. Shape transitions in neutron-rich Ru isotopes: spectroscopy of 109,110,111,112Ru

    Energy Technology Data Exchange (ETDEWEB)

    Hua, H; Cline, D; Hayes, A B; Teng, R; Riley, D; Clark, R M; Fallon, P; Goergen, A; Macchiavelli, A O; Vetter, K

    2005-06-29

    The spectroscopy of neutron-rich {sup 109,110,111,112}Ru nuclei was studied by measuring the prompt {gamma} rays originated from fission fragments, produced by the {sup 238}U({alpha},f) fusion-fission reaction, in coincidence with the detection of both fragments. For {sup 109,111}Ru, both the negative-parity (h{sub 11/2} orbitals) and positive-parity (g{sub 7/2} and/or d{sub 5/2} orbitals) bands were extended to substantially higher spin and excitation energy than known previously. The ground-state and {gamma}-vibrational bands of {sup 110,112}Ru also were extended to higher spin, allowing observation of the second band crossing at the rotational frequency of {approx}450 keV in {sup 112}Ru, which is {approx}50 keV above the first band crossing. At a similar rotational frequency, the first band crossing for the h{sub 11/2} band in {sup 111}Ru was observed, which is absent in {sup 109}Ru. These band crossings most likely are caused by the alignment of the g{sub 9/2} proton pair. This early onset of the band crossing for the aligned {pi}g{sub 9/2} orbitals may be evidence of a triaxial shape transition from prolate to oblate occurring in {sup 111}Ru. The data together with a comparison of cranked shell model predictions are presented.

  2. The Distribution of Tc in Purex

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Tc is an important fission product (fission yield of 99Tc is 6.13%) and has complex chemical behavior. It distributes in many flows of Purex. The influence of Tc can be ignored in military plutonium production reactor because the burning up of it is very low and the production of Tc is little. The burning up of PWR is much deeper and the production of Tc is much higher than the former so the tendency and controlling of Tc in Purex causes popular consideration. The main reason for that is the peculiar chemical property of Tc. Tc co-extracts with Zr, U and Pu in 1A cell and effect the separation of U or Pu in 1B cell by consuming large amount of reductants and

  3. Superconducting bolometers: high-Tc and low-Tc

    Science.gov (United States)

    Richards, Paul L.

    1991-07-01

    A description is given of recent work at Berkeley on superconducting detectors and mixers for infrared and millimeter wavelengths. The first report is a review article which summarizes the status of development of superconducting components for infrared and millimeter wave receivers. Next, a report is given on measurements and theoretical modeling of the absorptivity (surface resistance) of high quality epitaxial films of the high-Tc superconductor YBCO from 750 GHz to 21 THz. The next report describes measurements of the thermal boundary resistance between YBCO films and various substrates. This resistance is much larger than expected from the acoustic impedance mismatch model and gives a thermal time constant in the nanosecond range for typical YBCO films. Reports are also included on the design and experimental performance of two different types of high-Tc bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna coupled microbolometer. The properties of a low-Tc microbolometer are also described. The last reports describe accurate measurements and also theoretical modeling of an SIS quasi-particle waveguide mixer for W-band which uses very high quality Ta junctions. The best mixer noise is only 1.3 times the quantum limit. Both the mixer gain and the noise are in quantitative agreement with the quantum theory.

  4. A computerized compact module for separation of (99m)Tc-radionuclide from molybdenum.

    Science.gov (United States)

    Chattopadhyay, Sankha; Barua, Luna; De, Anirban; Saha Das, Sujata; Kuniyil, Remashan; Bhaskar, Partha; Pal, Sasanka Shekhar; Sarkar, Sishir Kumar; Das, Malay Kanti

    2012-11-01

    An automated closed cycle module for the separation and recovery of various isotopes, radioactive or non-radioactive, using solvent extraction and column chromatography techniques, and in particular, for separation and recovery of (99m)Tc from low-medium specific activity (99)Mo, is described. The module may also be applicable for separation of (99m)Tc produced in a cyclotron. The module is safe and reliable to avoid human interference and hazards posed by handling of radioactive and hazardous chemicals. The entire system of automation includes a user-friendly PC based graphical user interface (GUI) that actually supervises the process via an embedded system based electronic controller.

  5. Introduction to Theoretical Surface Science

    Science.gov (United States)

    2007-07-01

    111), (100) and (110) surfaces in the fcc structure even for the hcp metals Y, Zr, Tc and Ru and for the bcc metals Nb and Mo. (a) surface energy in eV...surface energies have been calculated for the fcc structure , even for the hcp metals Y, Zr, Tc and Ru and for the bcc metals Nb and Mo. The surface

  6. Temperature-induced transformation of electrochemically formed hydrous RuO2 layers over Ru(0001) model electrodes

    Science.gov (United States)

    Krause, Philipp P. T.; Camuka, Hava; Leichtweiss, Thomas; Over, Herbert

    2016-07-01

    Hydrous RuO2 reveals excellent performance both as a supercapacitor and as a heterogeneous oxidation catalyst. Molecular understanding of these processes needs, however, a model system with preferably low structural and morphological complexity. This goal is partly accomplished here by using single crystalline Ru(0001) as a template on which hydrous RuO2 is electrochemically formed. The hydrous RuO2 layers on Ru(0001) and their temperature induced transformation under ultra high vacuum (UHV) conditions are comprehensively characterized by scanning electron microscopy and X-ray photoemission spectroscopy. The hydrous RuO2 layer grows with an intricate morphology governed by the presence of step bunching regions of the Ru(0001) surface. Upon annealing to 200 °C in UHV the hydrous RuO2 layer transforms mostly into flat metallic Ru islands and occasionally into (100) and (111) oriented RuO2 particles aligned along the high symmetry direction of Ru(0001).Hydrous RuO2 reveals excellent performance both as a supercapacitor and as a heterogeneous oxidation catalyst. Molecular understanding of these processes needs, however, a model system with preferably low structural and morphological complexity. This goal is partly accomplished here by using single crystalline Ru(0001) as a template on which hydrous RuO2 is electrochemically formed. The hydrous RuO2 layers on Ru(0001) and their temperature induced transformation under ultra high vacuum (UHV) conditions are comprehensively characterized by scanning electron microscopy and X-ray photoemission spectroscopy. The hydrous RuO2 layer grows with an intricate morphology governed by the presence of step bunching regions of the Ru(0001) surface. Upon annealing to 200 °C in UHV the hydrous RuO2 layer transforms mostly into flat metallic Ru islands and occasionally into (100) and (111) oriented RuO2 particles aligned along the high symmetry direction of Ru(0001). Electronic supplementary information (ESI) available. See DOI: 10

  7. Biochemistry of derivatives of amino acid with (/sup 103/Ru)ruthenocene. Comparison with /sup 131/I-hippuran

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, M.; Park, I.-H.

    1986-01-01

    The potential radiopharmaceuticals: ruthenocenoyl alanine, ruthenocenoyl methionine, 1'methyl-ruthenocenoyl glycine and its esters were labelled with /sup 103/Ru starting from the analogous ferrocene compounds. In a series of tests in mice and rats these substances were compared with hippuran and ruppuran (=ruthernocenoyl glycine, a ruthenocene-amino acid analogue of hippuran). The organ distribution of these compounds was measured at various times after injection. Kidney concentrations of 1'-methyl-ruthenocenoyl glycine and its esters were found to be extremely high, followed by a rapid excretion. In contrast with these compounds, ruthenocenoyl methionine indicated a significantly greater affinity for liver than for kidney, but not for pancreas. Ruthenocenoyl alanine exhibits a high affinity for tumor cells. The advantages of /sup 97/Ru labelled radiopharmaceuticals compared with sup(99m)Tc or /sup 123/I//sup 131/I labelled compounds are discussed.

  8. Low-temperature specific heat and magnetic properties of the filled skutterudite ferromagnet NdRu4As12

    Science.gov (United States)

    Rudenko, A.; Henkie, Z.; Cichorek, T.

    2016-09-01

    We present the low-temperature specific heat and magnetic properties of the filled skutterudite compound NdRu4As12 that exhibits a ferromagnetic transition at TC ≃ 2.3 K . Magnetic entropy considerations point at a quartet ground state of the Nd3+ ions. Deep in the ferromagnetic state, the heat capacity shows a Schottky anomaly that we ascribe to the Zeeman splitting in the presence of a molecular field. Comparison of the specific heats of NdRu4As12 and its Os-based homologue near their Curie temperatures supports our earlier observation suggesting an unusual lowering of the Th cubic point symmetry in the latter filled skutterudite.

  9. Quantitative analysis of relationships between irradiation parameters and the reproducibility of cyclotron-produced (99m)Tc yields.

    Science.gov (United States)

    Tanguay, J; Hou, X; Buckley, K; Schaffer, P; Bénard, F; Ruth, T J; Celler, A

    2015-05-21

    Cyclotron production of (99m)Tc through the (100)Mo(p,2n) (99m)Tc reaction channel is actively being investigated as an alternative to reactor-based (99)Mo generation by nuclear fission of (235)U. An exciting aspect of this approach is that it can be implemented using currently-existing cyclotron infrastructure to supplement, or potentially replace, conventional (99m)Tc production methods that are based on aging and increasingly unreliable nuclear reactors. Successful implementation will require consistent production of large quantities of high-radionuclidic-purity (99m)Tc. However, variations in proton beam currents and the thickness and isotopic composition of enriched (100)Mo targets, in addition to other irradiation parameters, may degrade reproducibility of both radionuclidic purity and absolute (99m)Tc yields. The purpose of this article is to present a method for quantifying relationships between random variations in production parameters, including (100)Mo target thicknesses and proton beam currents, and reproducibility of absolute (99m)Tc yields (defined as the end of bombardment (EOB) (99m)Tc activity). Using the concepts of linear error propagation and the theory of stochastic point processes, we derive a mathematical expression that quantifies the influence of variations in various irradiation parameters on yield reproducibility, quantified in terms of the coefficient of variation of the EOB (99m)Tc activity. The utility of the developed formalism is demonstrated with an example. We show that achieving less than 20% variability in (99m)Tc yields will require highly-reproducible target thicknesses and proton currents. These results are related to the service rate which is defined as the percentage of (99m)Tc production runs that meet the minimum daily requirement of one (or many) nuclear medicine departments. For example, we show that achieving service rates of 84.0%, 97.5% and 99.9% with 20% variations in target thicknesses requires producing on average

  10. Hydrogen-induced mitigation of O on Ru(1010): a density-functional study.

    Science.gov (United States)

    Yakovkin, I N

    2009-07-21

    The reaction of hydrogen with oxygen adsorbed on an Ru(1010) surface has been studied by density-functional calculations and kinetic Monte Carlo simulations. In agreement with experiment, it has been found that molecular hydrogen does not react with adsorbed O. In contrast, the hydrogenation of oxygen by an atomic H beam occurs spontaneously and results in the formation of adsorbed OH molecules. Subsequent impinging H-atoms can either initiate the formation of water, which readily desorbs at room temperature thus removing the O from the surface, or lead to formation and desorption of H2. It is the latter channel that hinders, at 300 K, a complete removal of O from Ru capping layers on Si/Mo mirrors for extreme ultraviolet radiation. The estimated height of the barrier for the Langmuir-Hinshelwood reaction between adsorbed H and OH, 0.92 eV, and related position of the H2O peak in model desorption spectra (approximately 320 K) are consistent with recent experiments. The H2 desorption peak appears at higher temperature, approximately 350 K, so that in the range from 320 to 330 K adsorbed hydrogen atoms will react predominantly with OH. Hence, the present simulations predict that an efficient removal of the chemisorbed O from Ru capping layers can be achieved by heating the surface to 320-330 K in a molecular hydrogen atmosphere.

  11. A general route for RuO2 deposition on metal oxides from RuO4

    DEFF Research Database (Denmark)

    Kleiman-Shwarsctein, Alan; Laursen, Anders Bo; Cavalca, Filippo;

    2012-01-01

    A novel method for the deposition of RuO2 from RuO4(g) on diverse metal oxides has been developed by grafting dopamine onto the otherwise un-reactive metal oxide surface. Oxygen evolution reaction on TiO2 and the photoelectrochemical improvement of WO3 by deposition of RuO2 are just a few examples...

  12. Electrooxidation of CO on Ru(0001) and RuO2(100) Electrode Surfaces

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The electrooxidation of CO on Ru (0001) and RuO2 (100) electrode surfaces were characterized by cyclic voltammetry, AES and RHEED. The CO adlayer was first partially oxidized at 0.8 V, which is controlled by the attack of oxygen species toward the Ru(0001) surface. The remaining CO adlayer oxidation at 0.55 V is related to the combination of CO molecules with oxygen species already located on the surface. In contrast, successive peaks on RuO2(100) at 0.4 V and 0.72 V are observed, which shows that CO molecules can directly react with two different lattice-oxygen on the surface to carbon dioxide.

  13. Feasibility studies of producing {sup 99} Mo by capture in the IEA-R1 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Concilio, Roberta; Mendonca, Arlindo Gilson; Maiorino, Jose Rubens [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: maiorino@net.ipen.br; amendon@net.ipen.br

    1998-07-01

    Everyday the production of {sup 99} Mo for {sup 99m} Tc generators, becomes more necessary, whose properties are ideal for medical diagnosis. This works presents a description and an analysis of the production of {sup 99} Mo by radioactive capture at {sup 98} Mo using the research reactor IEA-R1 in 5 MW and operating 5 days a week, referring to the use of targets, separation methods, total and specific activity attained and its limitations. (author)

  14. Chemically mediated diffusion of d-metals and B through Si and agglomeration at Si-on-Mo interfaces

    NARCIS (Netherlands)

    T. Tsarfati,; Zoethout, E.; van de Kruijs, R.; F. Bijkerk,

    2009-01-01

    Chemical diffusion and interlayer formation in thin layers and at interfaces is of increasing influence in nanoscopic devices, such as nanoelectronics and reflective multilayer optics. Chemical diffusion and agglomeration at interfaces of thin Ru, Mo, Si, and B4C layers have been studied with x-ray

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

    Institute of Scientific and Technical Information of China (English)

    MAO Ping; ZHANG Zhi-Gang; PAN Li-Yang; XU Jun; CHEN Pei-Yi

    2009-01-01

    @@ Stacked ruthenium (Ru) nanocrystals (NCs) are formed by rapid thermal annealing for the whole gate stacks and embedded in memory structure, which is compatible with conventional CMOS technology. Ru NCs with high density (3×1012 cm-2 ), small size (2-4 nm) and good uniformity both in aerial distribution and morphology are formed. Attributed to the higher surface trap density, a memory window of 5.2 V is obtained with stacked Ru NCs in comparison to that of 3.5 V with single-layer samples. The stacked Ru NCs device also exhibits much better retention performance because of Coulomb blockade and vertical uniformity between stacked Ru NCs.

  16. Carbon coated face-centered cubic Ru-C nanoalloys.

    Science.gov (United States)

    Zhao, Zhisheng; Meng, Chuanmin; Li, Peifang; Zhu, Wenjun; Wang, Qianqian; Ma, Yanming; Shen, Guoyin; Bai, Ligang; He, Hongliang; He, Duanwei; Yu, Dongli; He, Julong; Xu, Bo; Tian, Yongjun

    2014-09-07

    Carbon-encapsulated ruthenium-carbon (Ru-C) nanoalloys were synthesized by dynamic shocks. The Ru-C alloy shows a new fcc structure different from the original hcp structure of metal Ru. This fcc phase is assigned to a Ru32C4 solid solution with a lattice parameter of 3.868(2) Å and a bulk modulus KT0 of 272(12) GPa. The small amount of carbon in the solid solution enhances the thermodynamic and chemical stabilities with respect to pure Ru, as well as induces changes in the electronic properties, which have direct applications in improving the material's catalytic activity and selectivity.

  17. CO oxidation on fully oxygen covered Ru(0001)

    DEFF Research Database (Denmark)

    Sljivancanin, Zeljko; Hammer, Bjørk

    2010-01-01

    We present a reaction mechanism for CO oxidation at the Ru(0001)-(1×1) surface. By means of density-functional theory studies, we compare the reactivity of flat and stepped regions of the Ru(0001). We find that at saturation oxygen coverage, where the flat parts are unreactive toward CO adsorption...... an intricate reaction pathway for CO adsorption and CO2 formation exists at the monatomic Ru step. By suggesting an efficient mechanism for CO oxidation on nonoxidic Ru, our results offer an explanation for the controversy in the experimental literature regarding how nonoxidic Ru may be as active in CO...

  18. Pt Ru/C electrocatalysts prepared using electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio Furtunato da; Oliveira Neto, Almir; Pino, Eddy Segura; Brandalise, Michele; Linardi, Marcelo; Spinace, Estevam Vitorio [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: espinace@ipen.br

    2007-10-15

    Pt Ru/C electrocatalysts (carbon-supported Pt Ru nanoparticles) were prepared submitting water/ethylene glycol mixtures containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The electrocatalysts were characterized by energy dispersive X ray analysis (EDX), X ray diffraction (XRD) and cyclic voltammetry and tested for methanol electro-oxidation aiming fuel cell application. The obtained Pt Ru/C electrocatalysts showed superior performance for methanol electro-oxidation at room temperature compared to commercial Pt Ru/C electrocatalyst. (author)

  19. Valence modulations in CeRuSn

    NARCIS (Netherlands)

    Feyerherm, R.; Dudzik, E.; Prokeš, K.; Mydosh, J.A.; Huang, Y.K.; Pöttgen, R.

    2014-01-01

    CeRuSn exhibits an extraordinary room temperature structure at 300 K with the coexistence of two types of Ce ions, namely trivalent Ce3+ and intermediate-valent Ce(4−δ)+, in a metallic environment. The ordered arrangement of these two Ce types on specific crystallographic sites results in a doubling

  20. Electroreflectance study of RuSe 2

    Science.gov (United States)

    Huang, Y. S.; Lin, S. S.; Sheu, J. S.; Shen, W. M.; Pollak, Fred H.

    1990-12-01

    We report the first electrolyte-electroreflectance (EER) study of a RuSe 2 single crystal in the photon energy region of 0.9-5.5 eV. The EER spectrum exhibits differential like structure in the vicinity of interband transitions. The transition energies are determined accurately. A probable energy-band structure is constructed.

  1. Ruthenium redox equilibria: 1. Thermodynamic stability of Ru(III and Ru(IV hydroxides

    Directory of Open Access Journals (Sweden)

    Igor Povar

    2016-04-01

    Full Text Available On the basis of the selected thermodynamic data for Ru(III and Ru(IV compounds in addition to original thermodynamic and graphical approach used in this paper, the thermodynamic stability areas of sparingly soluble hydroxides as well as the repartition of their soluble and insoluble chemical species towards the solution pH and initial concentrations of ruthenium in heterogeneous mixture solid phase–saturated solution have been investigated. By means of the ΔG–pH diagrams, the areas of thermodynamic stability of Ru(III and Ru(IV hydroxides have been established for a number of analytical concentrations in heterogeneous mixtures. The diagrams of heterogeneous and homogeneous chemical equilibria have been used for graphical representation of complex equilibria in aqueous solutions containing Ru(III and Ru(IV. The obtained results, based on the thermodynamic analysis and graphic design of the calculated data in the form of the diagrams of heterogeneous chemical equilibria, are in good agre­ement with the available experimental data.

  2. Lubiprostone: RU 0211, SPI 0211.

    Science.gov (United States)

    2005-01-01

    Lubiprostone [RU 0211, SPI 0211] is a bicyclic fatty acid that acts as a chloride channel opener, increasing intestinal water secretion. Lubiprostone, an orally-administered formulation, is one of a series of functional fatty acid compounds discovered by Dr Ryuji Ueno, and is currently undergoing development for the treatment of constipation, constipation-predominant irritable bowel syndrome (IBS-C) and postoperative ileus with Sucampo Pharmaceutical's. Lubiprostone activates a specific chloride channel (CLC2) on cells lining the gut, thereby naturally increasing intestinal fluid secretion. The increased fluid level softens the stool, promotes spontaneous bowel movements, and reduces abdominal discomfort/pain and bloating. The chloride channel is a protein that controls cell membrane transport of chloride ion. Lubiprostone acts on the ClC-2 chloride channel, which is located in the apical intestinal membrane. In November 2004, Takeda Pharmaceuticals entered into a collaboration and licensing agreement for Lubiprostone with Sucampo Pharmaceuticals for the treatment of chronic constipation and constipation-predominant Irritable Bowel Syndrome (c-IBS). Under the terms of the agreement, Takeda received the right to market the product in the US and Canada, while Sucampo reserved the co-promotion rights for these countries. Takeda's wholly-owned US subsidiary, Takeda Pharmaceuticals North America Inc., will sell lubiprostone once the product is approved by the US FDA. Takeda will also receive an option for marketing rights in other territories, including Japan and Europe. Takeda and Sucampo agreed on the exclusive manufacturing and supply of Lubiprostone by R-Tech Ueno, Ltd, a member of the Sucampo Group. Sucampo has the potential to receive up to dollar US 210 million in initial and milestone payments, some of which are contingent upon the successful achievement of several milestones. Takeda will fund a major part of development costs not only for chronic constipation

  3. Properties of Superconducting Mo, Mo2n and Trilayer Mo2n-Mo-Mo2n Thin Films

    Science.gov (United States)

    Barrentine, E. M.; Stevenson, T. R.; Brown, A. D.; Lowitz, A. E.; Noroozian, O.; U-Yen, K.; Eshan, N.; Hsieh, W. T.; Moseley, S. H.; Wollack, E. J.

    2014-01-01

    We present measurements of the properties of thin film superconducting Mo, Mo2N and Mo2N/Mo/Mo2N trilayers of interest for microwave kinetic inductance detector (MKID) applications. Using microwave resonator devices, we investigate the transition temperature, energy gaps, kinetic inductance, and internal quality factors of these materials. We present an Usadel-based interpretation of the trilayer transition temperature as a function of trilayer thicknesses, and a 2-gap interpretation to understand the change in kinetic inductance and internal resonance quality factor (Q) as a function of temperature.

  4. Preparation of zirconium molybdate gel for use in {sup 99m}Tc generators: definition of the preparation method at laboratory level; Preparacao do gel de molibdato de zirconio para uso nos geradores de {sup 99m}Tc: definicao do metodo de preparacao a nivel de laboratorio

    Energy Technology Data Exchange (ETDEWEB)

    Osso Junior, Joao A.; Lima, Ana Lucia V.P.; Silva, Nestor C. da; Nieto, Renata C.; Velosa, Adriana C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1999-11-01

    IPEN develops a project concerning the preparation of a gel of Zirconium Molybdate for use in the generators of {sup 99} Mo {sup 99m} Tc. {sup 99}`m Tc is the most used radioisotope in Nuclear Medicine diagnosis procedures and nowadays the generators are being prepared with imported {sup 99} Mo, produced by {sup 235} U fission. The production of {sup 99} Mo(n,{gamma}){sup 99} Mo reaction is now possible because of the power upgrade of IPEN`s IEA-R1 reactor, from 2 to 5 MW. This work describes the preparation method of Zirconium Molybdate gel that will be used in the {sup 99} Mo {sup 99}`m Tc generators. The gel is prepared by the chemical reaction between Mo, in Mo O{sub 3} form, and Zr, in Zr O Cl{sub 2} 8 H{sub 2} O form. After the reaction, the gel is filtered, dried and cracked with saline solution. The product is then loaded into glass columns for use as {sup 99m} Tc generator. The results showed the good quality of the gel prepared at laboratory level and of the generators evaluated. (author) 3 refs., 2 figs.

  5. Reinvestigation of the beta-decay of {sup 110}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.C.; Dendooven, P.; Hankonen, S.; Huikari, J.; Jokinen, A.; Kolhinen, V.S.; Lhersonneau, G.; Nieminen, A.; Peraejaervi, K.; Rinta-Antila, S.; Aeystoe, J. [Department of Physics, University of Jyvaeskylae, FIN-40351, Jyvaeskylae (Finland)

    2004-01-01

    The beta-decay of the neutron-rich nucleus {sup 110}Mo, separated by the IGISOL on-line mass separator from other fission products, has been investigated by using beta-gamma and gamma-gamma coincidence techniques. The decay scheme of {sup 110}Mo has been revised, including 3 new excited states and 7 new {gamma} transitions in {sup 110}Tc. The {beta}-feedings were measured and log ft values and B(GT) values were deduced based on a Q{sub {beta}}-value from systematics. Three excited 1{sup +} states in {sup 110}Tc fed by spin-flip allowed-unhindered beta transitions were identified. The deduced beta-decay strengths are compared with the Gamow-Teller strength distribution obtained from a macroscopic-microscopic calculation. The role of the asymptotic quantum numbers in the context of the allowed beta-decay is discussed. (orig.)

  6. Development of Tyrosine-Based Radiotracer Tc99m-N4-Tyrosine for Breast Cancer Imaging

    Directory of Open Access Journals (Sweden)

    Fan-Lin Kong

    2012-01-01

    Full Text Available The purpose of this study was to develop an efficient way to synthesize Tc99m-O-[3-(1,4,8,11-tetraazabicyclohexadecane-propyl]-tyrosine (Tc99m-N4-Tyrosine, a novel amino acid-based radiotracer, and evaluate its potential in breast cancer gamma imaging. Precursor N4-Tyrosine was synthesized using a 5-step procedure, and its total synthesis yield was 38%. It was successfully labeled with Tc99m with high radiochemical purity (>95%. Cellular uptake of Tc99m-N4-Tyrosine was much higher than that of Tc99m-N4 and the clinical gold standard 18F-2-deoxy-2-fluoro-glucose (18F-FDG in rat breast tumor cells in vitro. Tissue uptake and dosimetry estimation in normal rats revealed that Tc99m-N4-Tyrosine could be safely administered to humans. Evaluation in breast tumor-bearing rats showed that although Tc99m-N4-Tyrosine appeared to be inferior to 18F-FDG in distinguishing breast tumor tissue from chemical-induced inflammatory tissue, it had high tumor-to-muscle uptake ratios and could detect breast tumors clearly by planar scintigraphic imaging. Tc99m-N4-Tyrosine could thus be a useful radiotracer for use in breast tumor diagnostic imaging.

  7. (99m)Tc-DMSA absolute and relative renal uptake in cats: procedure and normal values.

    Science.gov (United States)

    Vandermeulen, Eva; Ham, Hamphrey R; Dobbeleir, André A; De Sadeleer, Carlos; Piepsz, Amy; Waelbers, Tim; Vermeire, Simon T; Slegers, Guido; Peremans, Kathelijne Y

    2011-06-01

    In this study we investigated the influence of technical factors (positioning, background (BG) correction and attenuation correction) on qualitative and quantitative (absolute (AU) and relative (RU) uptake) assessment of feline kidneys with (99m)technetium labelled dimercaptosuccinic acid ((99m)Tc-DMSA). Eleven healthy adult cats were included. Influence of BG and depth correction on quantitative assessment was evaluated. Depth correction was based on the geometric mean method (using dorsal and ventral images) and the use of two standards placed over each individual kidney. Visual evaluation showed superiority of dorsal and ventral over lateral positioning due to increased separation of the kidneys permitting region of interest (ROI) placement without overlap. No apparent influence of BG correction was found for RU. However, AU was systematically overestimated without BG correction. Depth correction did not seem to affect RU in most cases, however, in some cats the differences were not negligible. The values for AU without depth correction were lower compared to depth corrected values.

  8. A Molybdenum(0) Isocyanide Analogue of Ru(2,2'-Bipyridine)3 (2+) : A Strong Reductant for Photoredox Catalysis.

    Science.gov (United States)

    Büldt, Laura A; Guo, Xingwei; Prescimone, Alessandro; Wenger, Oliver S

    2016-09-05

    We report the first homoleptic Mo(0) complex with bidentate isocyanide ligands, which exhibits metal-to-ligand charge transfer ((3) MLCT) luminescence with quantum yields and lifetimes similar to Ru(bpy)3 (2+) (bpy=2,2'-bipyridine). This Mo(0) complex is a very strong photoreductant, which manifests in its capability to reduce acetophenone with essentially diffusion-limited kinetics as shown by time-resolved laser spectroscopy. The application potential of this complex for photoredox catalysis was demonstrated by the rearrangement of an acyl cyclopropane to a 2,3-dihydrofuran, which is a reaction that requires a reduction potential so negative that even the well-known and strongly reducing Ir(2-phenylpyridine)3 photosensitizer cannot catalyze it. Our study thus provides the proof-of-concept for the use of chelating isocyanides to obtain Mo(0) complexes with long-lived (3) MLCT excited states that are applicable to unusually challenging photoredox chemistry.

  9. Synthesis and Crystal Structure of [CpRu(η5-C5H5)(dppc)Cl][PF6

    Institute of Scientific and Technical Information of China (English)

    WU Xiang-Hua; YU Guang-Ao; MENG Xiang-Gao; CHEN Yan; REN Yong; LIU Sheng-Hua

    2006-01-01

    The title complex [Ru(η5-C5H5)(dppc)Cl][PF6] has been synthesized by the reaction of [Ru(η5-C5H5)(PPh3)2Cl] with [dppc][PF6] (1,1'-bis(diphenylphosphino)cobaltocenium hexaflurophospate) in CH2Cl2, and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 15.754(8), b =13.704(7), c=19.120(10) (A),β=106.148(9)°, V=3965(4) (A)3, Z=4, C40H35Cl3CoF6P3Ru, Mr=988.94, Dc=1.657 g/cm3, F(000) = 1984 and μ(MoKα) = 1.181 mm-1. The final R = 0.0425 and wR = 0.1001 for 7002 independent reflections. The title complex shows a mononuclear Ru(Ⅱ)capped by an η5-Cp ring, a chelating η2-dppc and a terminal chloride to assume a three-legged piano-stool configuration.

  10. The electrical and magnetic properties of ferromagnetic-superconducting compound Ru(Gd1.5-xPrxCe0.5Sr2Cu2O10-δ

    Directory of Open Access Journals (Sweden)

    A Khajehnezhad

    2009-08-01

    Full Text Available   Coexistence of superconductivity and magnetic ordering or their mutually exclusive existence in solids is one of the fundamental problems of solid state physics. To determine the effect of Pr substitution for Gd on electrical and magnetic properties of RuGd1.5Ce0.5Sr2Cu2O10-δ (Ru-1222, Ru(Gd1.5-xPrxCe0.5Sr2Cu2O10-δ with x=0.0, 0.01, 0.03, 0.03 3 , 0.04, 0.05, 0.06, 0.1 have been prepared by the standard solid-state reaction technique. The XRD patterns for various x have been obtained to show their phase purity. The resistivity and magnetoresistivity of samples have been measured at various temperatures and different magnetic fields up to 1.5T . Superconductivity and magnetic parameters such as superconducting transition temperature Tc and magnetic transition Tirr, have been obtained through resistivity curves. The sharp decrease in Tc with x in Ru(Gd1.5-xPrxCe0.5Sr2Cu2O10-δ shows competition between pair breaking by magnetic impurity, hole doping because of different valance of ions, difference in ionic radii and oxygen stoichiometry, which affect on superconducting transition. In Pr substitution for Gd, the small difference between Gd3+ and Pr3+,4+ ionic radii decreases the mean Ru-Ru distance, and as a result, the magnetic exchange interaction can become stronger with increasing x. Both Tc and Tirr decrease with external magnetic field .

  11. Contact and Support Considerations in the Hydrogen Evolution Reaction Activity of Petaled MoS2 Electrodes.

    Science.gov (United States)

    Finn, Shane T; Macdonald, Janet E

    2016-09-28

    Petaled MoS2 electrodes grown hydrothermally from Mo foils are found to have an 800 nm, intermediate, MoSxOy layer. Similar petaled MoS2 films without this intermediate layer are grown on Au. X-ray photoelectron and Raman spectroscopies and transmission electron microscopy indicate the resulting petaled multilayer MoS2 films are frayed and exhibit single-layer, 1T-MoS2 behavior at the edges. We compare the electrocatalytic hydrogen evolution reaction activity via linear sweep voltammetry with Tafel analysis as well as the impedance properties of the electrodes. We find that petaled MoS2/Au and petaled MoS2/Mo exhibit comparable overpotential to 10 mA cm(-2) at -279 vs -242 mV, respectively, and similar Tafel slopes of ∼68 mV/decade indicating a similar rate-determining step. The exchange current normalized to the geometric area of petaled MoS2/Au (0.000921 mA cm(-2)) is 3 times smaller than that of petaled MoS2/Mo (0.00290 mA cm(-2)), and is attributed to the lower petal density on the Au support. However, Au supports increase the turnover frequency per active site of petaled MoS2 to 0.48 H2 Mo(-1) s(-1) from 0.25 H2 Mo(-1) s(-1) on Mo supports. Both petaled MoS2 films have nearly ohmic contacts to their supports with uncompensated resistivity Ru of <2.5 Ω·cm(2).

  12. Magnesium-molybdenum compounds as matrixes of {sup 99m} Tc generators; Compuestos de magnesio-molibdeno como matrices de generadores de {sup 99m} Tc

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez M, T.S

    2005-07-01

    In order to finding new production alternatives of {sup 99}Mo/ {sup 99m}Tc generators, easy to produce and with high elutriation efficiencies, it is proposed in this work to develop a generator with basis of magnesium and molybdenum that could be irradiated after their synthesis, given the short half life of the only radioisotope produced by the magnesium: {sup 27} Mg (t{sub 1/2} = 9.46 m). It is necessary to mention that have not been reported works in relation to this type of compound, being then important to carry out basic studies on the formation and behavior of these in relation to their matrix functions of those generated of {sup 99} Mo/ {sup 99m} Tc. In this work it was determined the effect that has, the magnesium salt used in the synthesis of those molybdenum-magnesium compounds, the molar ratio Mo: Mg, the concentration of the magnesium salt, the pH of the used ammonium molybdates in the synthesis of the final compounds and the washing of the molybdates of synthesized magnesium, in the performance of the {sup 99} Mo/ {sup 99m} Tc generators. Parameters like the elutriation efficiency, the radionuclide purity, radiochemical and chemical of the eluates and their pH, were determined in each case, also its were characterized the synthesized compounds using: neutron activation analysis (NAA), X-ray diffraction (XRD) and scanning electron microscopy of high vacuum (SEM), besides of complementary techniques: infrared spectroscopy (IR), and thermal gravimetric analysis (TGA). (Author)

  13. Dilatometric study of the metamagnetic and ferromagnetic phases in the triple-layered Sr4Ru3O10 system

    Science.gov (United States)

    Schottenhamel, W.; Abdel-Hafiez, M.; Fittipaldi, R.; Granata, V.; Vecchione, A.; Hücker, M.; Wolter, A. U. B.; Büchner, B.

    2016-10-01

    High-resolution thermal expansion and magnetostriction measurements were performed on single crystalline Sr4Ru3O10 in the temperature range T =2 -200 K and magnetic fields up to 12 T. Signatures of the ferromagnetic phase transition at Tc˜102 K were found in the lattice expansion of both the c axis and the a b plane. Due to the layered crystal structure the effects are, however, strongly anisotropic. Further distinct anomalies are visible in the lower temperature region, which could be correlated with the metamagnetic transition at T*˜50 K. By relating the changes of the thermal expansion at the ferromagnetic transition to those of the heat capacity via the Ehrenfest relation, a strong volumetric pressure dependence of d Tc/d p ˜-8.5 K/GPa has been revealed.

  14. Results of four one-day electron-accelerator irradiations of enriched Mo-100 targets for the production of Mo-99

    Energy Technology Data Exchange (ETDEWEB)

    Chemerisov, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Bailey, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Heltemes, T. [Argonne National Lab. (ANL), Argonne, IL (United States); Jonah, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, R. [Argonne National Lab. (ANL), Argonne, IL (United States); Makarashvili, V. [Argonne National Lab. (ANL), Argonne, IL (United States); Tkac, P. [Argonne National Lab. (ANL), Argonne, IL (United States); Rotsch, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Virgo, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, G. F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-01

    A series of four one-day irradiations was conducted with 100Mo-enriched disk targets. After irradiation, the enriched disks were removed from the target and dissolved. The resulting solution was processed using a NorthStar RadioGenix™ 99mTc generator either at Argonne National Laboratory or at the NorthStar Medical Radioisotopes facility. Runs on the RadioGenix system produced inconsistent analytical results for 99mTc in the Tc/Mo solution. These inconsistencies were attributed to the impurities in the solution or improper column packing. During the irradiations, the performance of the optic transitional radiation (OTR) and infrared cameras was tested in high radiation field. The OTR cameras survived all irradiations, while the IR cameras failed every time. The addition of X-ray and neutron shielding improved camera survivability and decreased the number of upsets.

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

    Science.gov (United States)

    Kim, Woo-Hee; Park, Sang-Joon; Son, Jong-Yeog; Kim, Hyungjun

    2008-01-30

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

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

    Science.gov (United States)

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

    2015-06-01

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

  17. Mifepristone (RU 486) treatment of meningiomas.

    OpenAIRE

    Lamberts, S.W.; Tanghe, H L; Avezaat, C J; Braakman, R; Wijngaarde, R.; Koper, J. W.; de Jong, H

    1992-01-01

    Meningiomas are common brain tumours which are generally benign, well circumscribed and slow growing. In a minority of patients complete surgical removal is not possible and re-growth of tumour tissue is a major clinical problem. Most meningiomas contain progesterone receptors. The anti-progestational drug mifepristone (RU 486) binds to these receptors. Ten patients were treated with 12 recurrent or primary "inoperable" meningiomas, all of whom had shown recent neuroradiological and/or ophtha...

  18. Structure and magnetism in S r1 -xAxTc O3 perovskites: Importance of the A -site cation

    Science.gov (United States)

    Reynolds, Emily; Avdeev, Maxim; Thorogood, Gordon J.; Poineau, Frederic; Czerwinski, Kenneth R.; Kimpton, Justin A.; Yu, Michelle; Kayser, Paula; Kennedy, Brendan J.

    2017-02-01

    The S r1 -xB axTc O3 (x =0 , 0.1, 0.2) oxides were prepared and their solid-state and magnetic structure studied as a function of temperature by x-ray and neutron powder diffraction. The refined Tc moments at room temperature and Néel temperatures for B a0.1S r0.9Tc O3 and B a0.2S r0.8Tc O3 were 2.32 (14 ) μβ and 2.11 (13 ) μβ and 714 ∘C and 702 ∘C , respectively. In contrast to expectations, the Néel temperature in the series S r1 -xAxTc O3 decreases with increasing Ba content. This observation is consistent with previous experimental measurements for the two series A M O3 (M =Ru , Mn; A =Ca , Sr, Ba) where the maximum magnetic ordering temperature was observed for A =Sr . Taken with these previous results the current work demonstrates the critical role of the A -site cation in the broadening of the π* bandwidth and ultimately the magnetic ordering temperature.

  19. The physical properties of Gd3Ru: A real candidate for a practical cryogenic refrigerator

    Science.gov (United States)

    Monteiro, J. C. B.; dos Reis, R. D.; Gandra, F. G.

    2015-05-01

    The magnetization, the specific heat, and the magnetocaloric effect (MCE) for Gd3Ru are presented as function of temperature at different magnetic fields. The results show a maximum entropy change - Δ S = 30 J/kg K @ 5 T, which is the highest value for the R3M compounds. With a non-hysteretic transition of first order type at TC = 54 K, it presents a temperature change ΔTmax = 5.7 K around 59 K with a refrigerating cooling power of 700 J/kg and these results are comparable to values found for giant MCE materials. This compound is stable and able to operate at temperatures between 90 K and 40 K with a minimum - Δ S = 5 J/kg K. These figures were obtained by sweeping the magnetic field without using sample preparation routines. This methodology is appropriate to evaluate the MCE for the cycling process of a cryogenic magnetic refrigerator.

  20. Melt-textured GdSr 2RuCu 2O 8 samples: preliminary results

    Science.gov (United States)

    Gombos, M.; Vecchione, A.; Ciancio, R.; Sisti, D.; Uthayakumar, S.; Pace, S.

    2004-08-01

    The superposition of strongly anisotropic magnetic and superconducting properties, expected in Gd1212 (GdSr 2RuCu 2O 8), makes relevant the fabrication of oriented samples of macroscopic size by melt-texturing techniques. Starting from 1 cm diameter pellets we have grown top-seeded melt-textured samples using MgO seeds. X-ray diffraction analysis shows that a certain degree of orientation is present in our samples. Large oriented domains of millimetre size were observed by polarised light optical microscopy, larger domains are expected by optimisation of growth parameters and seed. Images show even a homogeneous distribution of Gd1210 precipitates with a mean size of a few micrometres. Resistivity measurements show a 12 K wide superconductive transition with Tc onset at about 40 K, optimisation of annealing treatments are expected to reduce this width.

  1. Pt Ru/C electrocatalysts prepared using electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

    Pt Ru/C electrocatalysts (carbon-supported Pt Ru nanoparticles) were prepared submitting water/ethylene glycol solutions containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The water/ethylene glycol ratio (v/v) was evaluated as synthesis parameters. The Pt Ru/C electrocatalysts were prepared with a nominal Pt:Ru atomic ratio of 50:50 and were characterized by energy dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) and tested for methanol electro-oxidation using cyclic voltammetry and chronoamperometry. The obtained Pt Ru/C electrocatalysts showed the typical fcc structure of platinum-ruthenium alloys and the electrocatalytic activity depends on the water/ethylene glycol ratio used in the preparation.

  2. Tc-99 Ion Exchange Resin Testing

    Energy Technology Data Exchange (ETDEWEB)

    Valenta, Michelle M.; Parker, Kent E.; Pierce, Eric M.

    2010-08-01

    Pacific Northwest National Laboratory was contracted by CHPRC to evaluate the release of 99Tc from spent resin used to treat water from well 299-W15-765 and stored for several years. The key questions to be answered are: 1) does 99Tc readily release from the spent ion exchange resin after being in storage for several years; 2) if hot water stripping is used to remove the co-contaminant carbon tetrachloride, will 99Tc that has been sequestered by the resin be released; and 3) can spent resin be encapsulated into a cementitious waste form; if so, how much 99Tc would be released from the weathering of the monolith waste form? The results from the long term stability leach test results confirm that the resin is not releasing a significant amount of the sequestered 99Tc, evident by the less than 0.02% of the total 99Tc loaded being identified in the solution. Furthermore, it is possible that the measured 99Tc concentration is the result of 99Tc contained in the pore spaces of the resin. In addition to these results, analyses conducted to examine the impact of hot water on the release of 99Tc suggest that only a small percentage of the total is being released. This suggest that hot water stripping to remove carbon tetrachloride will not have a significant affect on the resin’s ability to hold-on to sequestered 99Tc. Finally, encapsulation of spent resin in a cementitious material may be a viable disposal option, but additional tests are needed to examine the extent of physical degradation caused by moisture loss and the effect this degradation process can have on the release of 99Tc.

  3. Development of production of {sup 99}Mo from LEU target

    Energy Technology Data Exchange (ETDEWEB)

    Adang, H.G.; Mutalib, A.; Lubis, H. [Radioisotope Production Centre, National Atomic Energy Agency, Kawasan Puspiptek, Serpong (Indonesia)] [and others

    1998-10-01

    {sup 99}TC, the most popular radioisotope in nuclear medicine, is daughter of {sup 99}Mo. {sup 99}Mo is produced in research reactor by irradiating of high enriched uranium (HEU). However, in recent year, strict regulation that has been implemented by USA DOE and NPT has led to the difficulty in getting HEU. Therefore, BATAN has tried to develop the production of {sup 99}Mo by using low enriched uranium (LEU). The research involves the use of LEU in the production of {sup 99}Mo. This research was started in 1994 by joint-research between BATAN and Argonne National Laboratory USA. This program is divided into three research groups. The first group emphasizes its research on fabrication of LEU foil that is going to be irradiated. The second group studies the irradiation`s aspects and physical characteristic of irradiated LEU foils. The third group studies the radiochemical separation process of fission product {sup 99}Mo from solution of irradiated LEU foils. There are five steps that are carried out in studying of radiochemical separation of {sup 99}Mo from irradiated LEU. First is designing a dissolver that is going to be used in dissolving of LEU foil and testing its reliability. Second is dissolving LEU in the new design dissolver. Third is evaluation the modified of Cintichem`s radiochemical separation process of {sup 99}Mo from LEU. Forth is modifying the Cintichem`s radiochemical separation process of {sup 99}Mo from the solution of irradiated LEU. And fifth is using the modified of Cintichem`s radiochemical separation process for separation {sup 99}Mo from solution of irradiated LEU. The first through the forth steps of experiments were already carried out and will be reported in this workshop, whereas the fifth step of experiment is going to be conducted in February 1998. (author)

  4. Electron transfer dynamics of peptide-derivatized Ru(II) -polypyridyl complexes on nanocrystalline metal oxide films.

    Science.gov (United States)

    Hanson, Kenneth; Wilger, Dale J; Jones, Sean T; Harrison, Daniel P; Bettis, Stephanie E; Luo, Hanlin; Papanikolas, John M; Waters, Marcey L; Meyer, Thomas J

    2013-01-01

    The performance of dye-sensitized solar and photoelectrochemical cells is strongly dependent on the electron transfer events at the electrode-sensitizer interface. Surface-bound peptides derivatized with chromophores have not been used in dye-sensitized solar and photoelectrochemical cells, but they have properties for these applications that could be advantageous by exploiting secondary structure and the attachment of multiple chromophores. In this manuscript, we have investigated structure-property relationships for three metallopeptide-based assemblies to solution and chemically bound to nanocrystalline MO(2) (M = Ti, Zr) films. A particular interest was exploring the influence of increasing separation distance between a common chromophore, [Ru(bpy)(2) (4-Me-4'-(NHCO)bpy)](2+) , and the underlying oxide substrate on excited and ground state electron transfer. Rates of Ru(II) oxidation to Ru(III) at the interface were measured by cyclic voltammetry on fluorine-doped tin oxide and cross-surface electron transfer on TiO(2) . Excited state injection by [Ru(III) (bpy)(2) (bpy(-) )](2+) was monitored by transient absorption and time-resolved emission. There are discernible trends in the electron transfer rate data with approximated, fully extended distances between the [Ru(bpy)(2) (4-Me-4'-(NHCO)bpy)](2+) sites and the interface. However, the distance dependences that are observed are smaller than anticipated, a result consistent with a lack of ordered secondary structure in the surface-bound peptide chains and a distribution of local orientations. For the surface-bound excited states, only a small fraction undergo quenching by electron transfer to TiO(2) , presumably from those oriented near the surface.

  5. Evidence for a spin pseudogap in the normal state of superconducting Mo{sub 3}Sb{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Tran, V H; Miiller, W [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, PO Box 1410, 50-950 Wroclaw (Poland); Hillier, A D; Adroja, D T [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Oxfordshire OX11 0QX (United Kingdom); Bukowski, Z [Laboratory for Solid State Physics, ETH Zuerich, 8093 Zuerich (Switzerland)

    2009-12-02

    Using muon spin relaxation (muSR) and inelastic neutron scattering (INS) we have investigated the normal state of the superconductor Mo{sub 3}Sb{sub 7} and the reference compound Ru{sub 3}Sn{sub 7}. The muSR experiments on Ru{sub 3}Sn{sub 7} reveal static and relatively slow dynamic relaxations, which are ascribed to a random static nuclear dipole field and thermally activated muon motion, respectively. INS experiments on Ru{sub 3}Sn{sub 7}, on the other hand, reveal three phononic excitations at 11, 18 and 23 meV, substantiating the assertion of Einstein and Debye oscillations derived from the specific heat and electrical resistivity data. The distinct difference in the muSR as well as INS spectra between Ru{sub 3}Sn{sub 7} and Mo{sub 3}Sb{sub 7} provides strong evidence for a magnetic/electronic nature of the phase transition at T{sup *} = 50 K in the Mo-based compound. On the basis of the muSR and INS data, the energy spin pseudogap of 150(10) K was estimated. The observed weak magnetism in the dynamic susceptibility chi{sup ''}(Q,omega) and residual longitudinal field relaxation at 5 K imply a static ordering or quantum fluctuations.

  6. Td-MoTe2: A possible topological superconductor

    Science.gov (United States)

    Luo, X.; Chen, F. C.; Zhang, J. L.; Pei, Q. L.; Lin, G. T.; Lu, W. J.; Han, Y. Y.; Xi, C. Y.; Song, W. H.; Sun, Y. P.

    2016-09-01

    We measured the magnetoresistivity properties of Td-MoTe2 single crystal under the magnetic field up to 33 T. By analyzing the Shubnikov-de Haas oscillations of the longitudinal resistance Δρxx, a linear dependence of the Landau index n on 1/B is obtained. The intercept of the Landau index plot is 0.47, which is between 3/8 and 1/2. This clearly reveals a nontrivial π Berry's phase, which is a distinguished feature of the surface state in Td-MoTe2 single crystal. Accompanied by the superconductivity observed at TC = 0.1 K, Td-MoTe2 may be a promising candidate of the topological superconductor and opens a door to study the relationship between the superconductivity and topological physics.

  7. Ruthenium redox equilibria 1. Thermodynamic stability of Ru(III) and Ru(IV) hydroxides

    OpenAIRE

    Igor Povar; Oxana Spinu

    2016-01-01

    On the basis of the selected thermodynamic data for Ru(III) and Ru(IV) compounds in addition to original thermodynamic and graphical approach used in this paper, the thermodynamic stability areas of sparingly soluble hydroxides as well as the repartition of their soluble and insoluble chemical species towards the solution pH and initial concentrations of ruthenium in heterogeneous mixture solid phase–saturated solution have been investigated. By means of the ΔG–pH diagrams, the areas of therm...

  8. Sideward flow of $K^{+}$ mesons in Ru+Ru and Ni+Ni reactions near threshold

    CERN Document Server

    Crochet, Philippe; Wisniewski, K; Leifels, Y; Andronic, A; Averbeck, R; Devismes, A; Finck, C; Gobbi, A; Hartmann, O; Hildenbrand, K D; Koczón, P; Kress, T; Kutsche, R; Reisdorf, W; Schull, D; Alard, J P; Barret, V; Basrak, Z; Bastid, N; Belyaev, I; Bendarag, A; Berek, G; Caplar, R; Cindro, N; Dupieux, P; Dzelalija, M; Eskef, M; Fodor, Z; Grishkin, Yu L; Hong, B; Kecskeméti, J; Kim, Y J; Kirejczyk, M; Korolija, M; Kotte, R; Kowalczyk, M; Lebedev, A; Lee, K S; Man'ko, V I; Merlitz, H; Mohren, S; Moisa, D; Neubert, W; Nyanin, A; Pelte, D; Petrovici, M; Plettner, C; Rami, F; De Schauenburg, B; Seres, Z; Sikora, B; Sim, K S; Simion, V; Siwek-Wilczynska, K; Smolyankin, V T; Somov, A; Stockmeier, M R; Stoicea, G; Vasilev, M A; Wagner, P; Wohlfarth, D; Yang, J T; Yushmanov, I E; Zhilin, A V

    2000-01-01

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

  9. Lanthanum-Promoted Ru/Sepiolite in Ammonia Synthesis

    Institute of Scientific and Technical Information of China (English)

    Le Zhiping; Lin Jianxin; Yu Xiujin; Huang Yueyu; Wei Kemei

    2005-01-01

    A new kind of Ru supported on sepiolite catalyst with La as promoter for ammonia synthesis was prepared. The effects of reaction conditions on catalytic activity were discussed. The result shows that La is an effective promoter for sepiolite-supported Ru based catalyst. When the load of Ru is 5% (mass fraction), and the molar ratio of La/Ru is 1.5, under the condition of 10 MPa 450 ℃ 20000 h-1, the ammonia synthesis rate is 38.5 mmol NH3·g-1·h-1.

  10. MoS₂ decoration by Mo-atoms and the MoS₂-Mo-graphene heterostructure: a theoretical study.

    Science.gov (United States)

    Kvashnin, D G; Sorokin, P B; Seifert, G; Chernozatonskii, L A

    2015-11-21

    Here we propose a completely new covalent heterostructure based on graphene and self-decorated MoS2 monolayers. Detailed investigation of the decoration process of the MoS2 surface by Mo adatoms was performed using first principles DFT methods. Comparison between valence-only and semicore pseudopotentials was performed to correctly describe the interaction between Mo adatoms and the MoS2 surface. It was found that self-decoration by Mo atoms is favorable from an energetic point of view. We studied in detail various decoration paths of Mo atoms on the MoS2 surface. The strong variation of electronic properties after the decoration of MoS2 was found. The impact of the presence of Mo adatoms on the electronic properties of the graphene/MoS2 heterostructure was shown.

  11. Studies of post-elution concentration of {sup 99m}-Tc eluted from a gel type chromatographic generator

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Katia N.; Osso Junior, Joao Alberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: norisuzuki6@yahoo.com.br; jaosso@ipen.br

    2007-07-01

    The radiopharmaceuticals most used in Diagnostic Nuclear Medicine are those labeled with the metastable technetium ({sup 99m}Tc) due to its ideal physical properties of decay (t{sub 1/2} 6.01 h, E{gamma} 140 keV), low cost and availability facilitated through the commercial generator {sup 99}Mo /{sup 99m}Tc. This radionuclide is formed by the {beta}{sup -} decay of {sup 99}Mo adsorbed on an alumina column of the generator and collected in the form of sodium pertechnetate (Na{sup 99m}TcO{sub 4}) by elution with saline solution (0.9%). The Radiopharmacy Center (CR) of the IPEN-CNEN/SP developed a gel type chromatographic generator of MoZr with {sup 99}Mo produced by {sup 98}Mo(n, {gamma}){sup 99}Mo reaction that occurs in IEA-R1 Nuclear Reactor. The gel is composed of zirconium molybdate with elution volume of 12 ml with an activity of 11100 MBq (300 mCi) producing a radioactive concentration of 925 MBq (34 mCi) / ml. The fission generator gives a higher radioactive concentration around 1850 MBq (69 mCi) / ml. The aim of this work is to study a system of post-elution concentration using ion exchange cartridges in tandem (cation - anion) for the attainment of a high enough radioactive concentration to meet the demand of market, with a proved quality. This system of concentration will be made based in the technique of solid phase extraction (SPE) using commercial cartridges of extraction, which contains the solid phase and eluent saline solution (0.9%). As the eluent results of this system used in the gel generator of MoZr will be compared with the fission generator currently produced by IPEN-CNEN/SP. (author)

  12. TC-1 Satellite of DSP Delivered

    Institute of Scientific and Technical Information of China (English)

    SunQing

    2004-01-01

    TC-1 satellite of Double Star Program (DSP), a near-earth equatorial satellite, was delivered to the representative of the end user, the Research Center for Space Science and Application under the Chinese Academy of Sciences (CAS) on April 12, 2004, which symbolized that TC-1 satellite was put into operation formally.

  13. Microstructure and magnetic properties of FePt film with combined MoC/(Mg-X)O (X=Cu, Ni, Co) intermediate layers

    Science.gov (United States)

    Tsai, Jai-Lin; Tzeng, Jie-Lin; Hu, Keng-Chun; Li, Hsu-Kang; Pan, Zu-Yu; Chang, Yuan-Shuo; Liao, Chang-Chun

    2017-01-01

    The magnetic properties and microstructure of FePt films grown on MoC layer and MoC/(Mg-X)O (X=Cu, Ni, Co) combined intermediate layers were studied. The (Mg-X)O (X=Cu, Ni, Co) layer with thickness of 5 nm was deposited on CrRu seed layer at 395 °C. The CrRu (200) texture was enhanced which may due to well grains growth in specific orientation and small lattice mismatch with (Mg-X)O (X=Cu, Ni, Co). Finally, the FePt/MoC layers were deposited on (Mg-X)O layer at 425 °C. Using MoC/MgCuO combined intermediate layers, the rocking width of FePt (001) and CrRu (200) diffraction peak were changed from 7.1° to 6.1°, and 5.7° to 3.8°, respectively. For MoC/MgCoO dual intermediate layers, the rocking width of FePt (001) and CrRu (200) diffraction peak were 6.7° and 4.1°. The FePt/MoC/MgCoO film illustrates perpendicular magnetic anisotropy with out-of plane coercivity of 9.3 kOe which is higher than FePt film deposited on MoC layer (8.5 kOe) and the in-plane loops is linear. From microstructure, the FePt grains were more separated on MoC/(Mg-X)O (X=Cu, Ni, Co) combined intermediate layers.

  14. Enhanced metallic properties of SrRuO3 thin films via kinetically controlled pulsed laser epitaxy

    Science.gov (United States)

    Thompson, J.; Nichols, J.; Lee, S.; Ryee, S.; Gruenewald, J. H.; Connell, J. G.; Souri, M.; Johnson, J. M.; Hwang, J.; Han, M. J.; Lee, H. N.; Kim, D.-W.; Seo, S. S. A.

    2016-10-01

    Metal electrodes are a universal element of all electronic devices. Conducting SrRuO3 (SRO) epitaxial thin films have been extensively used as electrodes in complex-oxide heterostructures due to good lattice mismatches with perovskite substrates. However, when compared to SRO single crystals, SRO thin films have shown reduced conductivity and Curie temperatures (TC), which can lead to higher Joule heating and energy loss in the devices. Here, we report that high-quality SRO thin films can be synthesized by controlling the plume dynamics and growth rate of pulsed laser epitaxy (PLE) with real-time optical spectroscopic monitoring. The SRO thin films grown under the kinetically controlled conditions, down to ca. 16 nm in thickness, exhibit both enhanced conductivity and TC as compared to bulk values, due to their improved stoichiometry and a strain-mediated increase of the bandwidth of Ru 4d electrons. This result provides a direction for enhancing the physical properties of PLE-grown thin films and paves a way to improved device applications.

  15. Scintillating 99Tc Selective Ion Exchange Resins

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell Greenhalgh; Richard D. Tillotson

    2012-07-01

    Scintillating technetium (99Tc) selective ion exchange resins have been developed and evaluated for equilibrium capacities and detection efficiencies. These resins can be utilized for the in-situ concentration and detection of low levels of pertechnetate anions (99TcO4-) in natural waters. Three different polystyrene type resin support materials were impregnated with varying amounts of tricaprylmethylammonium chloride (Aliquat 336) extractant, several different scintillating fluors and wavelength shifters. The prepared resins were contacted batch-wise to equilibrium over a wide range of 99TcO4- concentrations in natural water. The measured capacities were used to develop Langmuir adsorption isotherms for each resin. 99Tc detection efficiencies were determined and up to 71.4 ± 2.6% was achieved with some resins. The results demonstrate that a low level detection limit for 99TcO4- in natural waters can be realized.

  16. Stability Limits of the Liquid Phase in the Layered Mo/Pb/Mo, Mo/Bi/Mo and Mo/In/Mo Film Systems

    Directory of Open Access Journals (Sweden)

    S.I. Petrushenko

    2016-12-01

    Full Text Available The results of the study of supercooling of the fusible metals films between the continuous layers of molybdenum during the crystallization are given. Due to an original in situ technique based on the changes of resistance of samples during heating and cooling directly in the vacuum chamber the values of supercooling in Mo/Pb/Mo, Mo/Bi/Mo, Mo/In/Mo films are determined and the influence of the morphological structure of the bismuth inclusions on the temperature and nature of its supercooled melt crystallization has been found. The substrate temperature change during the condensation of samples, accompanied by a corresponding change in their microstructure, allows realizing both avalanche and diffuse crystallization and changing of supercooling value in the range of 60 to 180 K in Mo/Bi/Mo films.

  17. Microstructural analysis and Transport Properties of MoO and MoC nanostructures prepared by focused electron beam-induced deposition

    Science.gov (United States)

    Makise, Kazumasa; Mitsuishi, Kazutaka; Shimojo, Masayuki; Shinozaki, Bunju

    2014-07-01

    By electron-beam-induced deposition, we have succeeded in the direct fabrication of nanowires of molybdenum oxide (MoOx) and molybdenum carbide (MoC) on a SiO2 substrate set in a scanning electron microscope. In order to prepare MoOx specimens of high purity, a precursor gas of molybdenum hexacarbonyl [Mo(CO)6] is used, mixed with oxygen gas. On the other hand, MoC is grown by mixing H2O gas with the precursor gas. The electrical transport properties of the nanowires are investigated by the DC four-terminal method. A highly resistive MoOx nanowire prepared from an as-deposited specimen by annealing in air shows nonlinear current-voltage characteristics and a high photoconductivity. The resistivity ρ of an as-deposited amorphous MoC (a-MoC) nanowire takes its maximum at a temperature T ~ 10 K and decreases to ~ 0 with decreasing temperature. This behavior of ρ(T) indicates the possible occurrence of superconductivity in a-MoC nanowires. The characteristic of ρ(T) below the superconducting transition temperature Tc ~ 4 K can be well explained by the quantum phase-slip model with a coherence length ξ(0) ~ 8 nm at T = 0.

  18. Spin polarization effect for Tc2 molecule

    Institute of Scientific and Technical Information of China (English)

    Yan Shi-Ying; Zhu Zheng-He

    2004-01-01

    Density functional method (DFT) (B3p86) of Gaussian98 has been used to optimize the structure of the Tc2 molecule. The result shows that the ground state for Tc2 molecule is an 11-multiple state and its electronic configuration is 11∑- g, which shows the spin polarization effect of Tc2 molecule of a transition metal element for the first time.Meanwhile, we have not found any spin pollution because the wavefunction of the ground state does not mingle with wavefunctions of higher energy states. So, that the ground state for Tc2 molecule is an 11-multiple state is indicative of the spin polarization effect of Tc2 molecule of a transition metal element: that is, there exist 10 parallel spin electrons. The non-conjugated electron is greatest in number. These electrons occupy different spacious tracks, so that the energy of Tc2 molecule is minimized. It can be concluded that the effect of parallel spin of the Tc2 molecule is larger than the effect of the conjugated molecule, which is obviously related to the effect of electron d delocalization.In addition, the Murrell-Sorbie potential functions with the parameters for the ground state 11∑- g and other states of Tc2 molecule are derived. Dissociation energy De for the ground state of Tc2 molecule is 2.266eV, equilibrium bond length Re is 0.2841nm, vibration frequency ωe is 178.52cm-1. Its force constants f2, f3, and f4 are 0.9200aJ.nm-2,-3.5700aJ.nm-3, 11.2748aJ.nm-4 respectively. The other spectroscopic data for the ground state of Tc2 molecule ωexe,Be, αe are 0.5523cm- 1, 0.0426cm- 1, 1.6331 × 10-4cm- 1 respectively.

  19. Los Alamos National Laboratory Support for Commercial U.S. Production of 99Mo without the Use of Highly Enriched Uranium

    Energy Technology Data Exchange (ETDEWEB)

    Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-04

    There is currently a serious shortage of 99Mo, from which to generate the medically significant isotope 99mTc. Most of the world's supply comes from the fission of highly enriched uranium targets--this is a proliferation concern. This document focuses on the technology involved in two alternative methods: electron accelerator production of 99Mo from the 100Mo(γ,n)99Mo reaction and production of 99Mo as a fission product in a subcritical, DT accelerator-driven low enriched uranium salt solution.

  20. $\\it{Ab-initio}$ calculations of electric field gradient in Ru compounds and their implication on the nuclear quadrupole moments of $^{99}$Ru and $^{101}$Ru

    Indian Academy of Sciences (India)

    S N MISHRA

    2017-08-01

    The nuclear quadrupole moments, $\\mathcal{Q}$, for the ground and first excited states in $^{99}$Ru and ground state of $^{101}$Ru have been determined by comparing the experimentally observed quadrupole interaction frequencies $\\mathcal{ν_{Q}}$ with calculated electric field gradient (EFG) for a large number of Ru-based compounds. The $\\it{ab-initio}$ calculations of EFG were performed using the all-electron augmented plane wave + local orbital (APW + lo) method of the density functional theory (DFT). From the slope of the linear correlation between theoretically calculated EFGs and experimentally observed $\\mathcal{ν_{Q}}$, we obtain the quadrupole moment for the $(5/2^{+})$ ground state in $^{99}$Ru and $^{101}$Ru as 0.0734(17) b and 0.431(14) b respectively, showing excellent agreement with the values reported in literature. For $3/2^{+}$, the quadrupole moment of the first excited state in $^{99}$Ru is obtained as +0.203(3) b, which is considerably lower than the commonly accepted literature value of +0.231(12) b. The results presented in this paper would be useful for the precise determination of quadrupole moment of high spin states in other Ru isotopes and is likely to stimulate further shell model calculations for an improved understanding of nuclear shape in these nuclei.

  1. Ab-initio calculations of electric field gradient in Ru compounds and their implication on the nuclear quadrupole moments of ^{99}Ru and ^{101}Ru

    Science.gov (United States)

    Mishra, S. N.

    2017-08-01

    The nuclear quadrupole moments, Q, for the ground and first excited states in ^{99}Ru and ground state of ^{101}Ru have been determined by comparing the experimentally observed quadrupole interaction frequencies ν _Q with calculated electric field gradient (EFG) for a large number of Ru-based compounds. The ab-initio calculations of EFG were performed using the all-electron augmented plane wave + local orbital (APW + lo) method of the density functional theory (DFT). From the slope of the linear correlation between theoretically calculated EFGs and experimentally observed ν _Q, we obtain the quadrupole moment for the (5/2^+) ground state in ^{99}Ru and ^{101}Ru as 0.0734(17) b and 0.431(14) b respectively, showing excellent agreement with the values reported in literature. For 3/2^+, the quadrupole moment of the first excited state in ^{99}Ru is obtained as +0.203(3) b, which is considerably lower than the commonly accepted literature value of +0.231(12) b. The results presented in this paper would be useful for the precise determination of quadrupole moment of high spin states in other Ru isotopes and is likely to stimulate further shell model calculations for an improved understanding of nuclear shape in these nuclei.

  2. MoEDAL expands

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    The MoEDAL collaboration deployed a test array of 18 plastic Nuclear Track Etch Detector (NTD) stacks – covering an area of 1 m2 – in the MoEDAL/VELO cavern at Point 8 of the LHC ring in November 2009. This small array was supplemented by a further 110 stacks this past January. The MoEDAL test array, which now covers an area of 8 m2, will reveal its secrets early in 2013. The full MoEDAL detector will be installed in the next long shutdown of the LHC in 2013.   View of the MoEDAL detectors installed at Point 8 of the LHC ring in January 2011. MoEDAL (Monopole and Exotics Detector At the LHC), the seventh LHC experiment, was approved by the CERN Research Board at the end of 2009. Its goal is to search for very specific exotics such as highly ionising massive stable (or pseudo-stable) particles with conventional electrical charge and magnetic monopoles. “The main LHC experiments are designed to detect conventionally charged particles, with conventional ionisation patte...

  3. Anticorrelation between polar lattice instability and superconductivity in the Weyl semimetal candidate MoTe2

    Science.gov (United States)

    Takahashi, H.; Akiba, T.; Imura, K.; Shiino, T.; Deguchi, K.; Sato, N. K.; Sakai, H.; Bahramy, M. S.; Ishiwata, S.

    2017-03-01

    The relation between the polar structural instability and superconductivity in a Weyl semimetal candidate MoTe2 has been clarified by finely controlled physical and chemical pressure. The physical pressure as well as the chemical pressure, i.e., the Se substitution for Te, enhances the superconducting transition temperature Tc at around the critical pressure where the polar structure transition disappears. From the heat capacity and thermopower measurements, we ascribe the significant enhancement of Tc at the critical pressure to a subtle modification of the phonon dispersion or the semimetallic band structure upon the polar-to-nonpolar transition. On the other hand, the physical pressure, which strongly reduces the interlayer distance, is more effective on the suppression of the polar structural transition and the enhancement of Tc as compared with the chemical pressure, which emphasizes the importance of the interlayer coupling on the structural and superconducting instability in MoTe2.

  4. Study of the Pt/Ru(0001) Interface

    DEFF Research Database (Denmark)

    Godowski, Jan P; Li, Zhe Shen; Bork, Jakob

    2007-01-01

    The growth process of platinum on Ru(0001) near room temperature was characterized using photoelectron spectroscopy of high resolution. The binding energy position and intensity of the Pt 4f7/2 and Ru 3d5/2 core levels as well as the shape and structure of the valence band spectra corresponding t...

  5. Ru Nanoframes with an fcc Structure and Enhanced Catalytic Properties.

    Science.gov (United States)

    Ye, Haihang; Wang, Qingxiao; Catalano, Massimo; Lu, Ning; Vermeylen, Joseph; Kim, Moon J; Liu, Yuzi; Sun, Yugang; Xia, Xiaohu

    2016-04-13

    Noble-metal nanoframes are of great interest to many applications due to their unique open structures. Among various noble metals, Ru has never been made into nanoframes. In this study, we report for the first time an effective method based on seeded growth and chemical etching for the facile synthesis of Ru nanoframes with high purity. The essence of this approach is to induce the preferential growth of Ru on the corners and edges of Pd truncated octahedra as the seeds by kinetic control. The resultant Pd-Ru core-frame octahedra could be easily converted to Ru octahedral nanoframes of ∼2 nm in thickness by selectively removing the Pd cores through chemical etching. Most importantly, in this approach the face-centered cubic (fcc) crystal structure of Pd seeds was faithfully replicated by Ru that usually takes an hcp structure. The fcc Ru nanoframes showed higher catalytic activities toward the reduction of p-nitrophenol by NaBH4 and the dehydrogenation of ammonia borane compared with hcp Ru nanowires with roughly the same thickness.

  6. Dramatic destabilization of the Ru(0001) surface upon oxygen adsorption

    Science.gov (United States)

    Reuter, K.; Ganduglia-Pirovano, M. V.; Scheffler, M.; Stampfl, C.

    2000-03-01

    Under high oxygen pressures, where most other transition metal surfaces typically form inert surface oxides, Ru(0001) displays the highest rates for oxidation reactions. This unusual behavior has been attributed to the fact that Ru can exist in different oxidation states and to the ease with which its surface can be loaded with high concentrations of subsurface oxygen. Yet, recent experiments have also indicated that high oxygen loads in the subsurface region destabilize Ru(0001) and lead to the emission of RuOx (xA. Böttcher, H. Conrad and H. Niehus, J. Chem. Phys. (submitted).). We perform density functional theory calculations to gain a fundamental understanding of the O-Ru bond in on-surface as well as subsurface oxygen phases. After completion of a full monolayer coverage on the surface, Ru(0001) is found to strongly bind even up to another full monolayer in the sites directly below the first substrate layer. In agreement with the experimental findings, this highly loaded O-Ru-O fringe is then relatively instable against lift-off, which might lead to either RuOx fragmentation or restructuring. The relation between charge transfer towards the oxygen and bond formation, as well as substrate destabilization is discussed.

  7. Electronic structure of Fe- vs. Ru-based dye molecules

    DEFF Research Database (Denmark)

    Johnson, Phillip S.; Cook, Peter L.; Zegkinoglou, Ioannis;

    2013-01-01

    In order to explore whether Ru can be replaced by inexpensive Fe in dye molecules for solar cells, the differences in the electronic structure of Fe- and Ru-based dyes are investigated by X-ray absorption spectroscopy and first-principles calculations. Molecules with the metal in a sixfold...

  8. Electrical transport and magnetic behaviors of La0.67Sr0.33Mn1-xBxO3 (B = Cr, Ru)

    Science.gov (United States)

    Acharya, Deepshikha; Bhargav, Abhinav; Tank, Tejas M.; Sanyal, Sankar P.

    2016-05-01

    Polycrystalline samples of La0.67Sr0.33Mn1-xCrxO3 (with x=0, 0.05 and 0.1) and La0.67Sr0.33Mn1-xRuxO3 (with x = 0.05 and 0.1) were synthesized using the conventional solid state reaction route and found single phase in nature. Electrical resistivity measurements as a function of temperature in range 5 K-400 K and as a function of magnetic field up to 5 Tesla were performed using d.c. four-probe method. Magnetization data were acquired as a function of temperature in a range 10 K-400 K with an applied magnetic field of 500 Oe. When Mn is partially substituted by Cr and Ru the system displays dramatic changes in the electrical transport behavior and shows double-peaked feature in resistivity curve. Both Cr and Ru substitutions effectively reduce insulator-metal transition (TP) and paramagnetic-ferromagnetic transition (TC) temperatures implying that there might exist FM interaction between Mn+3 and Cr+3 as well Mn+3 and Ru+4. The largest low-temperature magnetoresistance (MR%) is attributed to grain boundary effects and difference in size disorder for Cr and Ru substituted compounds.

  9. Bifunctional electrocatalysis in pt-ru nanoparticle systems.

    Science.gov (United States)

    Roth, C; Benker, N; Theissmann, R; Nichols, R J; Schiffrin, D J

    2008-03-04

    Pt-Ru alloys are prominent electrocatalysts in fuel cell anodes as they feature a very high activity for the oxidation of reformate and methanol. The improved CO tolerance of these alloys has been discussed in relation to the so-called ligand and bifunctional mechanisms. Although these effects have been known for many years, they are still not completely understood. A new approach that bridges the gap between single crystals and practical catalysts is presented in this paper. Nanoparticulate model systems attached to an oxidized glassy carbon electrode were prepared by combining both ligand-stabilized and spontaneously deposited Pt and Ru nanoparticles. These electrodes showed very different voltammetric responses for CO and methanol oxidation. The cyclic voltammograms were deconvoluted into contributions attributed to Pt, Ru, and Pt-Ru contact regions to quantify the contribution of the latter to the bifunctional mechanism. Scanning transmission electron microscopy confirmed the proximity of Pt and Ru nanoparticles in the different samples.

  10. EFFECT OF MIFEPRISTONE (RU486) ON MARKERS OF ENDOMETRIAL RECEPTIVITY

    Institute of Scientific and Technical Information of China (English)

    武捷; 王龙生; 程捷; 王介东

    2003-01-01

    Objective To study the effect of single and low dose of RU486 on endometrial receptivity of healthy women. Methods A total of 5 healthy women were followed for one control and one treatment cycle. In the treatment cycle, a dose of 10 mg RU486 was administered on day luteinizing hormone (LH)-2. In both the control and treatment cycle, an endometrial biopsy was obtained on LH+7. These biopsies were assessed by immunohistochemical analysis to find the difference in expression of integrins and progesterone receptor (PR) between the control and treatment cycle. Results The treatment with RU486 increased the expression of α1 and α4 subunits of integrin in glandular epithelial cells, but did not influence β3 subunit. Moreover, the normal down-regulation of PR in epitherial cell nuclei was inhibited by 10 mg RU486. Conclusion Single dose of 10 mg RU486 impairs the establishment of endometrial receptivity on time.

  11. PtRu/C electrocatalysts prepared using {gamma}-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F.; Neto, Almir Oliveira; Pino, Eddy S.; Linardi, Marcelo; Spinace, Estevam V. [Instituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP, Av. Professor Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo, SP (Brazil)

    2007-07-10

    PtRu/C electrocatalysts (carbon-supported PtRu nanoparticles) were prepared submitting water/ethylene glycol solutions containing Pt(IV) and Ru(III) ions and the carbon support to {gamma}-irradiation. The water/ethylene glycol ratio (v/v) and the total dose (kGy) were evaluated as synthesis parameters. The electrocatalysts were characterized by energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and cyclic voltammetry and tested for methanol electro-oxidation aiming fuel cell application. The obtained PtRu/C electrocatalysts were more active for methanol electro-oxidation than the commercial PtRu/C electrocatalyst at ambient temperature and the electrocatalytic activity depends on the water/ethylene glycol ratio used in the preparation. (author)

  12. Chemical Tuning of Magnetic Properties through Ru/Rh Substitution in Th7Fe3-type FeRh6-nRunB3 (n = 1-5) Series.

    Science.gov (United States)

    Shankhari, Pritam; Misse, Patrick R N; Mbarki, Mohammed; Park, Hyounmyung; Fokwa, Boniface P T

    2017-01-03

    The new quaternary boride series FeRh6-nRunB3 (n = 1-5) was synthesized by arc melting and characterized by powder and single-crystal X-ray diffraction (XRD), energy-dispersive X-ray analysis, and superconducting quantum interference device magnetometry. Single-crystal structure refinement showed the distribution of the iron atoms in two of three possible crystallographic 4d metal sites in the structure (Th7Fe3-type, space group P63mc). Rietveld refinements of the powder XRD data indicated single-phase synthesis of all the members. A linear decrease of the lattice parameters and the unit cell volume with increasing Ru content was found, indicating Vegard's behavior. Susceptibility measurements show decreasing Curie temperature and magnetic moment (μa(5T)) recorded at 5 T with increasing Ru content from TC = 295 K and μa(5T) = 3.35 μB (FeRh5RuB3) to TC = 205 K and μa(5T) = 0.70 μB (FeRhRu5B3). The measured coercivities lie between 1.0 and 2.2 kA/m indicating soft to semihard magnetic materials.

  13. Contribution of energy-gap in the ferromagnetic spin-wave spectrum on magnetocaloric parameters of CeRu(2)Ge(2).

    Science.gov (United States)

    Samanta, Tapas; Das, I; Banerjee, S

    2009-01-14

    A study of the magnetocaloric effect has been performed on a polycrystalline CeRu(2)Ge(2) compound, which exhibits an antiferromagnetic ordering below T(N) = 8.3 K and enters into a ferromagnetic ground state at T(C) = 7.4 K. The origins of the magnetocaloric parameters (the isothermal entropy change: -ΔS and the adiabatic temperature change: ΔT(ad)) of the CeRu(2)Ge(2) compound below T(C) have been analyzed. A sharp decrease in -ΔS has been observed below T(C). However, the ΔT(ad) does not fall as sharply as -ΔS with decreasing temperature in the corresponding temperature region. This behavior results in an additional value of ΔT(ad) at low temperature, which originates from the exponential decrease of the magnetic contribution of specific heat associated with an increase of energy-gap in the ferromagnetic spin-wave spectrum with the application of magnetic field.

  14. Fischer–Tropsch Synthesis: Effect of Reducing Agent for Aqueous-Phase Synthesis Over Ru Nanoparticle and Supported Ru Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Pendyala, Venkat Ramana Rao [Univ. of Kentucky, Lexington, KY (United States); Shafer, Wilson D. [Univ. of Kentucky, Lexington, KY (United States); Jacobs, Gary [Univ. of Kentucky, Lexington, KY (United States); Graham, Uschi M. [Univ. of Kentucky, Lexington, KY (United States); Khalid, Syed [Brookhaven National Lab. (BNL), Upton, NY (United States); Davis, Burtron H. [Univ. of Kentucky, Lexington, KY (United States)

    2014-12-27

    The effect of the reducing agent on the performance of a ruthenium nanoparticle catalyst was investigated during aqueous-phase Fischer–Tropsch synthesis using a 1 L stirred tank reactor in the batch mode of operation. For the purpose of comparison, the activity and selectivity of NaY zeolite supported Ru catalyst were also studied. NaBH4 and hydrogen were used as reducing agents in our study, and hydrogen reduced catalysts exhibited higher activities than the NaBH4 reduced catalysts, because of higher extent of reduction and a relatively lower tendency toward agglomeration of Ru particles. The Ru nanoparticle catalyst displayed higher activities than the NaY zeolite supported Ru catalyst for both reducing agents. NaBH4 reduced catalysts are less active and the carbon dioxide selectivity is higher than the hydrogen reduced catalysts. The activity of the supported Ru catalyst (Ru/NaY) was 75 % of that of the Ru nanoparticle catalyst, and has the benefit of easy wax/catalyst slurry separation by filtration. Finally, the hydrogen reduced supported Ru catalyst exhibited superior selectivity towards hydrocarbons (higher C5+ selectivity and lower selectivity to methane) than all other catalysts tested.

  15. On linear resistivity from ~1 to 103 K in Sr2RuO4 - δ single crystals grown by flux technique

    Science.gov (United States)

    Berger, H.; Forró, L.; Pavuna, D.

    1998-03-01

    We report transport measurements on single crystals of Sr2RuO4 - δ, grown by the flux technique. The temperature dependence of the Hall coefficient is similar to the one measured in cuprates, and the linear resistivity persists up to ~1000 K, while the superconductivity remains confined below 1 K. This suggests that the linear temperature dependence of resistivity is not an exclusive signature of the anomalous normal state of high-Tc cuprates but rather of layered oxides in general, especially single-layer perovskites, possibly independently of the magnitude of the superconducting temperature. In addition, such Sr2RuO4 - δ may be used as a broad-range thermometer.

  16. Formalizing BPEL-TC Through ?-Calculus

    Directory of Open Access Journals (Sweden)

    Preeti Marwaha

    2013-07-01

    Full Text Available WS-BPEL is way to define business processes that interact with external entities through webservice operations using WSDL. We have proposed BPEL-TC, an extension to existing WS-BPEL whichuses temporally customized Web Services (WSDL-TC as a model for process decomposition and assembly.WSDL-TC handles both backward compatible and incompatible changes and also maintains variousversions of the artifacts that results due to changes over time and customizations desired by the users. Inthis paper, we are using pi-calculus to formalize Business Process Execution Language- TemporalCustomization (BPEL-TC process. π -calculus is a model of computation for concurrent systems alongwith changing connectivity of interactive systems. Pi-calculus is an extension of the process algebra CCS,with added mobility to CCS while preserving its algebraic properties.

  17. Direct 99m Tc labeling of Herceptin (trastuzumab) by 99m Tc(I) tricarbonyl ion.

    Science.gov (United States)

    Chen, Wan-Jou; Yen, Chao-Liang; Lo, Su-Tang; Chen, Kuo-Ting; Lo, Jem-Mau

    2008-03-01

    By simply incubating Herceptin (trastuzumab) with [99m Tc(CO)3(OH2)3]+ ion in saline, a significant yield of 99m Tc-labeled trastuzumab was found to be achievable. The effective labeling may be based on that trastuzumab is inherent with endogenous histidine group to which 99m Tc(I) tricarbonyl ion can be strongly bound. For practical 99m Tc labeling processing, trastuzumab was purified beforehand from the commercial product, Herceptin (Genentech) via size exclusion chromatography to remove the excipient, alpha-histidine and a high-labeled yield could be obtained by incubating the purified trastuzumab with [99m Tc(CO)3(OH2)3]+. Retention of bioactivity of the 99m Tc(I)-labeled trastuzumab was validated using a cell binding test.

  18. Technetium Removal Using Tc-Goethite Coprecipitation

    Energy Technology Data Exchange (ETDEWEB)

    Um, Wooyong; Wang, Guohui; Jung, Hun Bok; Peterson, Reid A.

    2013-11-18

    This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory for the U.S. Department of Energy (DOE) EM-31 Support Program (EMSP) subtask, “Low temperature waste forms coupled with technetium removal using an alternative immobilization process such as Fe(II) treated-goethite precipitation” to increase our understanding of 99Tc long-term stability in goethite mineral form and the process that controls the 99Tc(VII) reduction and removal by the final Fe (oxy)hydroxide forms. The overall objectives of this task were to 1) evaluate the transformation process of Fe (oxy)hydroxide solids to the more crystalline goethite (α-FeOOH) mineral for 99Tc removal and 2) determine the mechanism that limits 99Tc(IV) reoxidation in Fe(II)-treated 99Tc-goethite mineral and 3) evaluate whether there is a long-term 99Tcoxidation state change for Tc sequestered in the iron solids.

  19. Superconductivity in Y6Tr4Al43 (Tr = Nb, Mo, Ta) with Peanut-Shaped Cage Structure

    Science.gov (United States)

    Kase, Naoki; Satoh, Ryoh; Nakano, Tomohito; Takeda, Naoya

    2016-10-01

    Superconductivity is discovered in Y6Tr4Al43 (Tr = Nb, Mo, Ta) with a peanut-shaped cage structure at Tc = 0.86, 0.75, and 0.68 K, respectively. The superconducting state is revealed by performing electrical resistivity and specific heat measurements. The upper critical field is obtained to be 0.22 (Nb), 0.175 (Mo), and 0.15 T (Ta). A specific heat jump provides evidence of bulk superconductivity in these compounds.

  20. Compatibility of RuO2 electrodes with PZT ceramics

    Indian Academy of Sciences (India)

    K T Jacob; G Rajitha; V S Saji

    2009-06-01

    Because of its high electrical conductivity and good diffusion barrier properties ruthenium dioxide (RuO2) is a good electrode material for use with ferroelectric lead zirconate–titanate (PZT) solid solutions. Under certain conditions, RuO2 can react with PZT to form lead ruthenate (Pb2Ru2O6.5) during processing at elevated temperatures resulting in lead depletion from PZT. The standard Gibbs energies of formation of RuO2 and Pb2Ru2O6.5 and activities of components of the PZT solid solution have been determined recently. Using this data along with older thermodynamic information on PbZrO3 and PbTiO3, the stability domain of Pb2Ru2O6.5 is computed as a function of PZT composition, temperature and oxygen partial pressure in the gas phase. The results show PbZrO3-rich compositions are more prone to react with RuO2 at all temperatures. Increasing temperature and decreasing oxygen partial pressure suppress the reaction. Graphically displayed are the reaction zones as a function of oxygen partial pressure and PZT composition at temperatures 973, 1173 and 1373 K.

  1. Structure and electrical properties of epitaxial SrRuO3 thin films controlled by oxygen partial pressure

    Science.gov (United States)

    Sun, Yan; Zhong, Ni; Zhang, Yuan-Yuan; Qi, Rui-Juan; Huang, Rong; Tang, Xiao-Dong; Yang, Ping-Xiong; Xiang, Ping-Hua; Duan, Chun-Gang

    2016-12-01

    SrRuO3 (SRO) thin films have been grown on (001)-oriented SrTiO3 substrate under various oxygen partial pressures (PO2). A typical step-and-terrace surface morphology and coherent epitaxy characteristics are found in the SRO films for high oxygen pressure growth (PO2 ≥ 10 Pa). Under such high PO2, SRO films exhibit metallic behavior over a temperature range of 10 K ≤ T ≤ 300 K. A detailed study on the transport properties of the metallic SRO films reveals that the resistivity (ρ) follows the law ρ(T)-ρ0 ∝ Tx (x = 0.5, 1.5, or 2). Below ferromagnetic transition temperature (Tc), ρ(T) follows T2 dependence below 30 K and T1.5 dependence at T > 30 K, respectively. This result demonstrates that a transition between the Fermi-liquid (FL) and non-Fermi-liquid (NFL) behavior occurs at ˜30 K. Furthermore, ρ(T) follows T0.5 dependence at T > Tc in the paramagnetic metal state. We have found that the FL to NFL transitions as well as the ferromagnetic transition are corresponding to the abnormal peaks in the magnetoresistance curves, suggesting the coupling of electronic and magnetic properties. The transition temperature of FL to NFL for metallic SRO films is almost independent on PO2, while Tc slightly increases with PO2.

  2. Incorporation of M(H2O)6(2+) between layers {M(H2O)2Ru2(CO3)4Cl2}n(2n-) (M = Zn, Mn): syntheses, structures and magnetic properties.

    Science.gov (United States)

    Liu, Bin; Jia, Yan-Yan; Yang, Huai-Qing; Yang, Jian-Hui; Xue, Gang-Lin

    2013-12-28

    Isostructural heterometallic diruthenium carbonates KM(H2O)6[M(H2O)2Ru2(CO3)4Cl2]·4H2O [M = Zn (1) and Mn (2)] were synthesized from the reaction of the precursors [Ru2(CO3)4Cl2](5-) and transitional metal ions in aqueous solution. Complexes 1 and 2 show layered structures in which Ru2(II,III) units are linked by four octahedral environment M(H2O)2(2+) ions in a cross fashion and vice versa giving a negative bimetallic square grid layer {M(H2O)2Ru2(CO3)4Cl2}n(3n-). M(H2O)6(2+) ions, linked by K(+) forming zigzag chain {KM(H2O)6}n(3+), are located in the void spaces between the layers. The adjacent bimetallic carbonate layers are connected with K-O and K-Cl bonds, and hydrogen bonding, forming a supramolecular 3D framework structure. Their magnetic properties were characterized in detail, and intralayer ferromagnetic coupling between the Ru2 dimer and Mn(2+) ion, as well as long-range ordering (Tc = 5.2 K) coexistence of domain movement behavior were observed for complex 2.

  3. Fabrication of solvent extraction apparatus for {sup 99m}Tc production

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ul Jae; Han, H. S.; Cho, U. G.; Kim, S. D.; Jung, Y. J.; Shin, H. Y.; Hong, S. B. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-03-01

    To automatic extraction apparatus for {sup 99M}Tc separation from {sup 99}Mo formed by (n,r) nuclear reaction was developed. This system can be mainly divided into the operation part and the control part. The operation part consists of the follow instruments, such as lead shield unit, which contains a mixing vessel for extraction and phases separation, 3 glass bottles for supplying of different liquids, cation resin column for impurities removal, alumina column for {sup 99M}Tc absorption, membrane filter for purification, etc. The control part consists of the aluminum chassis, industrial computer systems with monitor, control board, user-defined operations panel, etc. The system can be operated automatically or manually. This technical report described overall aspects of the elements and operating method for the apparatus, and will be helpful for the system maintenance and troubleshooting. 28 figs. (Author)

  4. RoMo

    DEFF Research Database (Denmark)

    Pedersen, Esben Warming; Hornbæk, Kasper

    2011-01-01

    In TUIs, physical/digital conflicts can occur when the digital model does not match the model implied by the spatial lay- out of tangibles. We show how tangible tabletop interfaces (TTI) can be modified to allow robot movement of tangi- bles, thereby avoiding conflicts. We present RoMo, an open...

  5. PREFACE: 2014 Joint IMEKO TC1-TC7-TC13 Symposium: Measurement Science Behind Safety and Security

    Science.gov (United States)

    Sousa, João A.; Ribeiro, Álvaro S.; Filipe, Eduarda

    2015-02-01

    The 2014 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium was organized by RELACRE - Portuguese Association of Accredited Laboratories and the Portuguese Society for Metrology, on 3-5 September 2014. The work of this symposium is reported in this volume. The scope of the symposium includes the main topics covered by the above Technical Committees: - TC1 Education and Training in measurement and Instrumentation - TC7 Measurement Science - TC13 Measurements in Biology and Medicine The effort towards excellence of previous events, in this well established series, is maintained. There has been a special focus on measurement science behind safety and security, with the aim of highlighting the interdisciplinary character of measurement science and the importance of metrology in our daily lives. The discussion was introduced by keynote lectures on measurement challenges in biometrics, health monitoring and social sciences, to promote useful interactions with scientists from different disciplines. The Symposium was attended by experts working in these areas from 18 countries, including USA, Japan and China, and provided a useful forum for them to share and exchange their work and ideas. In total over fifty papers are included in the volume, organized according to the presentation sessions. Each paper was independently peer-reviewed by two reviewers from a distinguished international panel. The Symposium was held in Funchal, capital of Madeira Islands, known as the Atlantic Pearl. This wonderful Atlantic archipelago, formed by Madeira and Porto Santo islands, discovered in the 14th century, was chosen to host the 2014 IMEKO TC1-TC7-TC13 Joint Symposium ''Measurement Science behind Safety and Security''. It was the first territory discovered by the Portuguese sailors, when set out to discover a new world, in an epic journey where instrumentation and quality of measurement played a central role in the success of the enterprise, and gave an

  6. Coexistence of magnetic order, heavy fermion and intermediate valence behaviour in Ce{sub 7}X{sub 3} (X=Ni, Ru, Pd, Pt, Ir and Rh)

    Energy Technology Data Exchange (ETDEWEB)

    Trovarelli, O. [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche; Sereni, J.G. [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche; Schmerber, G. [IPCMS-GEMM, 23 rue du Loess, 67037 Strasbourg (France); Kappler, J.P. [IPCMS-GEMM, 23 rue du Loess, 67037 Strasbourg (France)

    1995-02-01

    Low temperature specific heat, AC magnetic susceptibility and magnetization measurements were performed on the Ce{sub 7}X{sub 3} compounds (X=Ni, Ru, Rh, Pd, Ir and Pt). They exhibit coexistence of magnetic order (MO), heavy fermion (HF) and intermediate valence (IV) behaviour and the results are interpreted in terms of the three Ce sublattices (1Ce{sub I}, 3Ce{sub II} and 3Ce{sub III}) present in the Th{sub 7}Fe{sub 3}-type structure. From entropic considerations it is found that sublattice Ce{sub III} presents an IV behaviour in all these compounds and Ce{sub II} show MO or have a HF behaviour depending on the Ce-ligand electronic structure. The Ce{sub I} atoms (more than 6A distant from each other) exhibit MO only when the Ce{sub II} sublattice provides a high density of electronic states. ((orig.)).

  7. Fabrication of metal nanoclusters on graphene grown on Ru(0001)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hui; FU Qiang; CUI Yi; TAN DaLi; BAO XinHe

    2009-01-01

    Monolayer graphene was epitaxially grown on Ru(0001) through exposure of the Ru(0001) to ethylene at room temperature followed by annealing in ultrahigh vacuum at elevated temperatures. The resulting graphene structures were studied by scanning tunneling microscopy (STM), X-ray photoelectron spec-troscopy (XPS), and ultraviolet photoelectron spectroscopy (UPS). The graphene/Ru(0001) surface was used as a periodic template for growth of metal nanoclusters. Highly dispersed Pt clusters with well controlled size and spatial distribution were fabricated on the surface.

  8. Ordered Porous Pd Octahedra Covered with Monolayer Ru Atoms.

    Science.gov (United States)

    Ge, Jingjie; He, Dongsheng; Bai, Lei; You, Rui; Lu, Haiyuan; Lin, Yue; Tan, Chaoliang; Kang, Yan-Biao; Xiao, Bin; Wu, Yuen; Deng, Zhaoxiang; Huang, Weixin; Zhang, Hua; Hong, Xun; Li, Yadong

    2015-11-25

    Monolayer Ru atoms covered highly ordered porous Pd octahedra have been synthesized via the underpotential deposition and thermodynamic control. Shape evolution from concave nanocube to octahedron with six hollow cavities was observed. Using aberration-corrected high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy, we provide quantitative evidence to prove that only a monolayer of Ru atoms was deposited on the surface of porous Pd octahedra. The as-prepared monolayer Ru atoms covered Pd nanostructures exhibited excellent catalytic property in terms of semihydrogenation of alkynes.

  9. Anelastic characterization and superconducting properties of RuSr2GdCu2O8+δ

    Directory of Open Access Journals (Sweden)

    Jurelo, A. R.

    2008-08-01

    Full Text Available Since the discovery of the high Tc superconductors, many researches have been carried out on the different properties of these materials, especially on the transition temperature into the superconducting state. The rutheno-cuprates belong to a new class of composites, which were synthesized for the first time by Bauernfeind in 1995. Bernhard and collaborators discovered, in 1999, the coexistence of the ferromagnetism and the superconductivity in this phase, which is known as antagonistic phenomenon in the electromagnetism due to spin-charge interactions established in these states. However, the physical nature of the superconducting and magnetic states is still very obscure. The non-stoichiometric (interstitial oxygen is considered as a possible cause for the non-uniformity of the sample properties. In this paper, results of mechanical spectroscopy in Ru-1212 samples are presented showing complex anelastic spectra, which were attributed to the mobility of the interstitial oxygen atoms in the Ru-1212 lattice.Desde el descubrimiento de los superconductores de alta Tc, muchas investigaciones han sido realizadas sobre las diferentes propiedades de estos materiales, especialmente sobre la temperatura de transición dentro del estado superconductor. Los cupratos de rutenio pertenecen a una nueva clase de compositos, los cuales fueron sintetizados por primera vez por Bauernfeind en 1995. Bernhard y colaboradores descubrieron, en 1999, la coexistencia del ferromagnetismo y la superconductividad en esta fase, lo cual es conocido como un fenómeno antagonistico en el electromagnetismo debido a las interacciones spin-carga establecidas en estos estados. Sin embargo, la naturaleza física de los estados superconductores y magnéticos aun no son muy claros. El oxigeno no-estequiométrico (intersticial es considerado como una causa de la no-uniformidad de las propiedades de la muestra. En este articulo, los resultados de espectroscopia mecánica en muestras

  10. Preparation of Sm–Ru bimetallic alloy films on Ru(0001) surface by vapour-deposition and annealing

    Indian Academy of Sciences (India)

    G Ranga Rao; H Nozoye

    2001-12-01

    Sm–Ru intermetallic surface alloy films were prepared by vacuum deposition and annealing of rare earth Sm on single crystal Ru(0001) surface. The Ru 3 and Sm 3 core level spectra clearly show the formation of surface alloy layers. XPS measurements on surface alloy film revealed an induced peak in the Ru3 region at lower binding energy by 1 eV compared to the bulk Ru (elemental) suggesting an electronic effect of alloying and Sm–Ru bond formation. The Sm 35/2 photoemission peak of Sm film consists of strong features characteristic of Sm(II) with electron configuration 46 (5\\ 6)2 and Sm(III) with electron configuration 46 (5\\ 6)3. It is observed that the Sm(II) feature decreases in intensity upon alloy formation with surface Ru atoms. Oxidation of these films with carbon monoxide indicates alloy breakdown due to the oxidation of Sm atoms selectively. Alloy oxidation also shows a clear shift of Sm 35/2 feature.

  11. Submonolayered Ru Deposited on Ultrathin Pd Nanosheets used for Enhanced Catalytic Applications.

    Science.gov (United States)

    Zhang, Zhicheng; Liu, Ye; Chen, Bo; Gong, Yue; Gu, Lin; Fan, Zhanxi; Yang, Nailiang; Lai, Zhuangchai; Chen, Ye; Wang, Jie; Huang, Ying; Sindoro, Melinda; Niu, Wenxin; Li, Bing; Zong, Yun; Yang, Yanhui; Huang, Xiao; Huo, Fengwei; Huang, Wei; Zhang, Hua

    2016-12-01

    Ultrathin Pd nanosheets (NSs) coated with submonolayered Ru, referred to as Pd@Ru NSs, are synthesized via a seed-mediated growth method. The underpotential deposition can be the driving force for the formation of Pd@Ru NSs. The Pd@Ru NSs exhibit superior catalytic properties in the reduction of 4-nitrophenol and the semihydrogenation of 1-octyne, compared to the pure Pd NSs and Ru NSs.

  12. Methanol Electrooxidation on Smooth Platinum Modified with Ru: the Influence of Ru Coverage and Potentials on Oxidative Current and Products

    Institute of Scientific and Technical Information of China (English)

    WANG, Hong-Sen

    2003-01-01

    Methanol oxidation on smooth Pt electrode modified with different coverage of Ru was studied using cyclic voltammetry and potential step combined with differential electrochemical mass spectroscopy. The current efficiency of formed CO2 was calculated from faraday current and ion current of m/z = 44. The results show that Ru modified Pt electrode with the coverage of ca. 0.3 has the highest catalytic activity for methanol electrooxidation, I.e. Faraday current and the current efficiency of CO2at the low potentials reach to the maximum. In addition, Ru loses its co-catalytic properties at the high potentials.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  14. Mechanistic Insight of Bivalent Compound 21MO as Potential Neuroprotectant for Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    John M. Saathoff

    2016-03-01

    Full Text Available We have recently developed a bivalent strategy to provide novel compounds that potentially target multiple risk factors involved in the development of Alzheimer’s disease (AD. Our previous studies employing a bivalent compound with a shorter spacer (17MN implicated that this compound can localize into mitochondria and endoplasmic reticulum (ER, thus interfering with the change of mitochondria membrane potential (MMP and Ca2+ levels in MC65 cells upon removal of tetracycline (TC. In this report, we examined the effects by a bivalent compound with a longer spacer (21MO in MC65 cells. Our results demonstrated that 21MO suppressed the change of MMP, possibly via interaction with the mitochondrial complex I in MC65 cells. Interestingly, 21MO did not show any effects on the Ca2+ level upon TC removal in MC65 cells. Our previous studies suggested that the mobilization of Ca2+ in MC65 cells, upon withdraw of TC, originated from ER, so the results implicated that 21MO may preferentially interact with mitochondria in MC65 cells under the current experimental conditions. Collectively, the results suggest that bivalent compounds with varied spacer length and cell membrane anchor moiety may exhibit neuroprotective activities via different mechanisms of action.

  15. Partial phase diagram of Pd-Ag-Ru-Gd quaternary system

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    On the basis of the Ag-Pd-Gd, Ag-Ru-Gd and Pd-Ru-Gd ternary systems, the partial phase diagram of Pd-Ag-Ru-Gd(Gd<25% atom fraction) quaternary system has been studied by means of X-ray diffraction analysis, differential thermal analysis, electron probe microanalysis and optical microscopy.The 700℃ isothermal sections of the Ag-Pd-5Ru-Gd, Ag-Pd-20Ru-Gd and Ag-Pd-50Ru-Gd (Gd≤25%atom fraction) phase diagrams were determined respectively. And the 700℃ isothermal section of the PdAg-Ru-Gd (Gd≤25% atom fraction) quaternary system phase diagram was finally irferred. The section consists of four single-phase regions: solid solution Pd(Ag), (Ru), Pd3Gd and Ag51 Gd14; five two-phase regions: Pd(Ag) + (Ru), Pd(Ag) + Ag51 Gd14 , (Ru) + Ag51 Gd14 , Pd(Ag) + Pd3Gd and (Ru) +Pd3Gd; three three-phase regions: Pd(Ag) + Pd3Gd+ (Ru), Pd(Ag) + Ag51Gd14 + (Ru) and (Ru) +Ag51Gd14 + Pd3Gd; one four-phase region Pd(Ag) + (Ru) + Ag51Gd14 + Pd3Gd. No new quaternary intermetallic phase is found.

  16. On the kinetics of the hydrogen evolution reaction on Ni-MoOx composite catalysts in alkaline solutions

    Directory of Open Access Journals (Sweden)

    Jović Borka M.

    2012-01-01

    Full Text Available MoO3 particles were co-deposited with Ni onto smooth or rough Ni supports from modified Watt’s baths of different compositions. Morphology and composition of the electrodeposits were characterized by means of cyclic voltammetry, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. The electrocatalytic activity of the composite catalysts for H2 evolution in alkaline solutions was determined by quasi-stationary polarization curves. Activity increases with MoOx content in the Ni deposit up to a limiting value. Composite Ni-MoOx catalyst performed high catalytic activity, similar to that of commercial Ni-RuO2 catalyst. Stability tests showed that Ni-MoOx codeposits are stable under condition of constant current and exhibit excellent tolerance to repeated short-circuiting.

  17. Annealing of RuO 2 and Ru Bottom Electrodes and Its Effects on the Electrical Properties of (Ba,Sr)TiO 3 Thin Films

    Science.gov (United States)

    Ahn, Joon-Hyung; Choi, Won-Youl; Lee, Won-Jae; Kim, Ho-Gi

    1998-01-01

    Crystalline structures and surface morphologies of annealed RuO2 and Ru thin films were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The annealing was performed in oxygen and argon ambient and high vacuum in the temperature range of 400 800° C. In oxygen ambient annealing, the surface morphology was drastically changed due to the evaporation of ruthenium dioxides in the form of RuO3 and RuO4. Annealed RuO2 thin film in vacuum was reduced to the Ru metal phase. The actual variation of RuO2 bottom electrodes during the deposition of (Ba,Sr)TiO3 (BST) thin films and the effects of the thermal stability of bottom electrodes on electrical properties of BST thin films deposited on RuO2/SiO2/Si were also investigated.

  18. Study of Ru{sub 2}VGe and Ru{sub 2}VSb: High-spin polarized and half-metallic Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, Idris Hamid; Gupta, Dinesh C. [Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior – 474011 (India)

    2015-06-24

    Electronic and magnetic properties of Ru{sub 2}VGe and Ru{sub 2}VSb have been investigated by ab-initio. The optimized equilibrium lattice parameters were found to be 6.032 Å for Ru{sub 2}VGe and 6.272 Å for Ru{sub 2}VSb. Both the materials have ferromagnetic ground states and V mainly contributes to the magnetic properties in these materials. The highly spin-polarized half-metallic materials have integral magnetic moments of 1.0 µ{sub B} for Ru{sub 2}VGe and 2.0 µ{sub B} for Ru{sub 2}VSb with an energy gap of 0.095 eV for Ru2VGe and 0.186 eV for Ru{sub 2}VSb in the spin-down channel.

  19. Development of more efficacious Tc-99m organ imaging agents for use in nuclear medicine by analytical characterization of radiopharmaceutical mixtures. Progress report, May 1, 1981-April 30, 1982

    Energy Technology Data Exchange (ETDEWEB)

    Heineman, W.R.; Deutsch, E.A.

    1981-12-01

    The objectives of this year's research were to develop a method for rapidly determining TcO/sub 4//sup -/ in /sup 99/Mo//sup 99m/Tc generator eluates, to improve the ability to chromatographically determine individual Tc-HEDP complexes in radiopharmaceuticals, and to investigate the effects of TcO/sub 4//sup -/ concentration and electrochemical reduction on the types and relative amounts of Tc-HEDP complexes present in a radiopharmaceutical formulation. A rapid and sensitive high performance liquid chromatographic (HPLC) method for the quantitative determination of pertechnetate (TcO/sub 4//sup -/) was developed. This HPLC-based analysis may be of considerable utility in assessing the history and function of /sup 99/MO/sup 99m/Tc generators as well as in the routine analysis of reduced technetium radiopharmaceuticals for the presence of undesired TcO/sub 4//sup -/. Encouraging results were obtained on a dimethyl amine column using aqueous (NH/sub 4/)/sub 2/SO/sub 4/ as the mobile phase. The preparation of Tc(NaBH/sub 4/) HEDP radiopharmaceutical analogues using varying concentrations of total TcO/sub 4//sup -/ shows a dramatic effect in the number and distribution of Tc-HEDP complexes over a TcO/sub 4//sup -/ concentration range of 10/sup -2/ to 10/sup -8/M. These results suggest that total TcO/sub 4//sup -/ concentration is an important parameter to be considered in the preparation of a specific Tc-HEDP complex to improve skeletal imaging. The preparation of Tc(electrode) HEDP radiopharmaceutical analogues by using electrochemical reduction was explored. The resulting solutions contain Tc-HEDP complexes that are tentatively identified as being the same complexes formed by NaBH/sub 4/ reduction, although the relative concentrations of these complexes are quite different with the two modes of reduction. Thus, electrochemical reduction shows promise as a viable route to the preparation of specific Tc-HEDP complexes for improved skeletal imaging.

  20. Dissociation of CH4 on Ni(111) and Ru(0001)

    DEFF Research Database (Denmark)

    Egeberg, Rasmus; Ullmann, S.; Alstrup, I.

    2002-01-01

    to clarify to what extent a similar effect is present in these systems. The apparent activation energies found were 74 +/- 10 and 51 +/- 6 kJ/mol on Ni(1 1 1) and Ru(0 0 0 1) respectively. On neither Ru(0 0 0 1) nor Ni(1 1 1) did we observe a significant decrease of the overall sticking coefficient when...... the terraces, Finally we have observed a large promotion of the sticking probability of CH4 on Ru(0 0 0 1) by increasing the surface temperature at a fixed gas temperature thus lending support to a mechanism where the dissociation of methane takes place over Ru atoms displaced normal to the surface....

  1. Isospin Distribution of Fragments in Reaction 96Ru+96Ru, 96Ru+96Zr, 96Zr+96Ru, and 96Zr+96Zr at Beam Energy 400 AMeV

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The isospin distribution of particles and fragments in collisions 96Ru+96Ru, 96Ru+96Zr, 96Zr+96Ru, and 96Zr+96Zr at beam energy 400 AMeV is studied with isospin dependent QMD model. We find the rapidity distribution of difference between neutron-proton number in neutron rich nucleus-nucleus collisions at intermediate energies is sensitive to the isospin dependent part of nuclear potential. The study of the N/Z ratio of nucleons, light charged particles (LCP) and intermediate mass fragments (IMF) shows that the isospin dependent part of nuclear potential drives IMF to be more isospin symmetric and emitted nucleons to be more neutron rich. We also study the time evolution of the isospin distribution

  2. Local structure and magneto-transport in Sr 2FeMoO 6 oxides

    Science.gov (United States)

    Liscio, F.; Bardelli, F.; Meneghini, C.; Mobilio, S.; Ray, Sugata; Sarma, D. D.

    2006-05-01

    Double perovskite oxides Sr 2FeMoO 6 have attracted a great interest for their peculiar magneto-transport properties, and, in particular, for the large values of low-field magneto-resistance (MR) which remains elevated even at room temperature, thanks to their high Curie temperature ( Tc > 400 K). These properties are strongly influenced by chemical cation disorder, that is by the relative arrangement of Fe and Mo on their sublattices: the regular alternation of Fe and Mo enhances the MR and saturation magnetization. On the contrary the disorder generally depresses the magnetization and worsen the MR response. In this work the X-ray absorption fine structure (XAFS) technique has been employed in order to probe the cation order from a local point of view. XAFS spectra were collected at the Fe and Mo K edges on Sr 2FeMoO 6 samples with different degree of long-range chemical order. The XAFS results prove that a high degree of short-range cation order is preserved, despite the different long-range order: the Fe-Mo correlations are always preferred over the Fe-Fe and Mo-Mo ones in the perfectly ordered as well as in highly disordered samples.

  3. Development of industrial-scale fission {sup 99}Mo production process using low enriched uranium target

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Kon; Lee, Jun Sig [Radioisotope Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Beyer, Gerd J. [Grunicke Strasse 15, Leipzig (Germany)

    2016-06-15

    Molybdenum-99 ({sup 99}Mo) is the most important isotope because its daughter isotope, technetium-99m ({sup 99}mTc), has been the most widely used medical radioisotope for more than 50 years, accounting for > 80% of total nuclear diagnostics worldwide. In this review, radiochemical routes for the production of {sup 99}Mo, and the aspects for selecting a suitable process strategy are discussed from the historical viewpoint of {sup 99}Mo technology developments. Most of the industrial-scale {sup 99}Mo processes have been based on the fission of {sup 235}U. Recently, important issues have been raised for the conversion of fission {sup 99}Mo targets from highly enriched uranium to low enriched uranium (LEU). The development of new LEU targets with higher density was requested to compensate for the loss of {sup 99}Mo yield, caused by a significant reduction of {sup 235}U enrichment, from the conversion. As the dramatic increment of intermediate level liquid waste is also expected from the conversion, an effective strategy to reduce the waste generation from the fission {sup 99}Mo production is required. The mitigation of radioxenon emission from medical radioisotope production facilities is discussed in relation with the monitoring of nuclear explosions and comprehensive nuclear test ban. Lastly, the {sup 99}Mo production process paired with the Korea Atomic Energy Research Institute's own LEU target is proposed as one of the most suitable processes for the LEU target.

  4. Potassium-oxygen interactions on a Ru(001) surface

    Energy Technology Data Exchange (ETDEWEB)

    Hrbek, J.; Shek, M.L.; Xu, G.Q. (Brookhaven National Lab., Upton, NY (United States)); Sham, T.K. (Univ. of Western Ontario, London, Ontario (Canada))

    1992-10-01

    The interaction of potassium with oxygen has been examined using synchrotron-based photoemission and NEXAFS, thermal desorption, work function measurements, and isotope exchange. Potassium coverages on Ru(001) surface ranging from monolayer to multilayer were investigated. Oxygen coadsorbed with potassium at 80 K forms a potassium-dioxygen complex, where both peroxide and superoxide ions were identified. The complex has high thermal stability on the Ru(001) surface, decomposing and desorbing at T > 900 K. 52 refs., 14 figs., 2 tabs.

  5. Oxidation of Mg adsorbed on Ru(001): A photoemission study

    Energy Technology Data Exchange (ETDEWEB)

    Malik, I.J.; Hrbek, J. (Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)); Shek, M. (National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States)); Bzowski, A.; Kristof, P.; Sham, T.K. (Department of Chemistry, University of Western Ontario, London, Ontario NA6 5B7 (Canada))

    1992-07-01

    We studied the interaction of oxygen with Mg overlayers adsorbed on Ru(001). Soft x-ray synchrotron radiation was used to explore photoemission from the valence band, the O 2{ital p}, O 2{ital s}, and Mg 2{ital p} levels, as well as intra- and interatomic Auger processes. The photoemission results are complemented by thermal desorption data. The O/Mg/Ru system shows photoemission features characteristic of molecular orbitals of a dioxygen species.

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

    DEFF Research Database (Denmark)

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

    1998-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thanh Nam

    2015-07-01

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

  8. Insights into Stabilization of the 99TcVO Core for Synthesis of 99TcVO Compounds

    Energy Technology Data Exchange (ETDEWEB)

    McGregor, Donna; Burton-Pye, Benjamin P.; Lukens, Wayne W.; Howell, Robertha C.; Francesconi, Lynn C.

    2014-01-01

    Synthesis of technetium-99 (99Tc; t1/2: 2.1 105 years, max: 253 keV) materials is of importance in studies of the nuclear fuel cycle where Tc is a major fission product (6percent thermal yield from 235U and 239Pu), in understanding radioactive tank waste composition, and in identifying 99mTc compounds for nuclear medicine imaging. One of the most useful synthetic starting materials, (NBu4)TcOCl4, is susceptible to disproportionation in water to form TcO4 and TcIV species, especially TcO2 2H2O. This unwanted reaction is especially problematic when working with ligands bearing hard donor atoms, such as oxygen, where the stability with the soft TcV=O3+ core may be low. Polyoxometalates (POMs) are such ligands. They possess defect sites with four hard oxygen atoms and show low (ca. 108) stability constants with transition metals. Tc complexes of POMs are molecular-level models for Tc metal oxide solid-state materials and can provide information on coordination and redox environments of metal oxides that stabilize low-valent Tc. In order to synthesize pure Tc POM complexes [TcVO(1-P2W17O61)]7 (TcVO-1) and [TcVO(2-P2W17O61)]7 (TcVO-2) from (NBu4)TcOCl4, we have identified strategies that minimize formation of TcIV species and optimize the formation of pure TcV species. The parameters that we consider are the amount of ethylene glycol, which is employed as a transfer ligand to prevent hydrolysis of (NBu4)TcOCl4, and the precipitating agent. The TcIV species that contaminates the non-optimized syntheses is likely a TcIV -oxido-bridged dimer [TcIV-(-O)2-TcIV]. We also employ a novel procedure where the 2 ligand is photoactivated and reduced (in the presence of a sacrificial electron donor) to subsequently reduce TcVIIO4 to an isolatable TcVO-2 product that is remarkably free of TcIV.

  9. Prospects of zero Schottky barrier height in a graphene-inserted MoS{sub 2}-metal interface

    Energy Technology Data Exchange (ETDEWEB)

    Chanana, Anuja; Mahapatra, Santanu [Nano-Scale Device Research Laboratory, Department of Electronic Systems Engineering, Indian Institute of Science (IISc) Bangalore, Bangalore 560012 (India)

    2016-01-07

    A low Schottky barrier height (SBH) at source/drain contact is essential for achieving high drive current in atomic layer MoS{sub 2}-channel-based field effect transistors. Approaches such as choosing metals with appropriate work functions and chemical doping are employed previously to improve the carrier injection from the contact electrodes to the channel and to mitigate the SBH between the MoS{sub 2} and metal. Recent experiments demonstrate significant SBH reduction when graphene layer is inserted between metal slab (Ti and Ni) and MoS{sub 2}. However, the physical or chemical origin of this phenomenon is not yet clearly understood. In this work, density functional theory simulations are performed, employing pseudopotentials with very high basis sets to get insights of the charge transfer between metal and monolayer MoS{sub 2} through the inserted graphene layer. Our atomistic simulations on 16 different interfaces involving five different metals (Ti, Ag, Ru, Au, and Pt) reveal that (i) such a decrease in SBH is not consistent among various metals, rather an increase in SBH is observed in case of Au and Pt; (ii) unlike MoS{sub 2}-metal interface, the projected dispersion of MoS{sub 2} remains preserved in any MoS{sub 2}-graphene-metal system with shift in the bands on the energy axis. (iii) A proper choice of metal (e.g., Ru) may exhibit ohmic nature in a graphene-inserted MoS{sub 2}-metal contact. These understandings would provide a direction in developing high-performance transistors involving heteroatomic layers as contact electrodes.

  10. Enantioselective Michael reaction catalyzed by well-defined chiral ru amido complexes: isolation and characterization of the catalyst intermediate, ru malonato complex having a metal-carbon bond.

    Science.gov (United States)

    Watanabe, Masahito; Murata, Kunihiko; Ikariya, Takao

    2003-06-25

    Chiral Ru amido complexes promote asymmetric Michael addition of malonates to cyclic enones, leading to Michael adducts with excellent ee's, in which the chiral Ru amido complexes react with malonates to give isolable catalyst intermediates, chiral Ru malonato complexes bearing a metal bound C-nucleophile.

  11. Tropical Cyclone Prediction Using COAMPS-TC

    Science.gov (United States)

    2014-09-01

    Oceanography | Vol. 27, No.3104 S P E C I A L I S S U E O N N AV Y O P E R AT I O N A L M O D E L S Tropical Cyclone Prediction Using COAMPS...Ocean/ Atmosphere Mesoscale Prediction System for Tropical Cyclones (COAMPS®-TC) has been developed for prediction of tropical cyclone track, structure...and intensity. The COAMPS-TC has been tested in real time in both uncoupled and coupled modes over the past several tropical cyclone seasons in

  12. Enhancement of Solar Fuel Production Schemes by Using a Ru,Rh,Ru Supramolecular Photocatalyst Containing Hydroxide Labile Ligands.

    Science.gov (United States)

    Rogers, Hannah Mallalieu; Arachchige, Shamindri M; Brewer, Karen J

    2015-11-16

    Polyazine-bridged Ru(II)Rh(III)Ru(II) complexes with two halide ligands, Cl(-) or Br(-), bound to the catalytically active Rh center are efficient single-component photocatalysts for H2O reduction to H2 fuel, with the coordination environment on Rh impacting photocatalysis. Herein reported is a new, halide-free Ru(II)Rh(III)Ru(II) photocatalyst with OH(-) ligands bound to Rh, further enhancing the photocatalytic reactivity of the structural motif. H2 production experiments using the photocatalyst bearing OH(-) ligands at Rh relative to the analogues bearing halides at Rh in solvents of varying polarity (DMF, CH3CN, and H2O) suggest that ion pairing with halides deactivates photocatalyst function, representing an exciting phenomenon to exploit in the development of catalysts for solar H2 production schemes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. CTLA-4 (CD152) enhances the Tc17 differentiation program.

    Science.gov (United States)

    Pick, Jonas; Arra, Aditya; Lingel, Holger; Hegel, J Kolja; Huber, Magdalena; Nishanth, Gopala; Jorch, Gerhard; Fischer, Klaus-Dieter; Schlüter, Dirk; Tedford, Kerry; Brunner-Weinzierl, Monika C

    2014-07-01

    Although CD8(+) T cells that produce IL-17 (Tc17 cells) have been linked to host defense, Tc17 cells show reduced cytotoxic activity, which is the characteristic function of CD8(+) T cells. Here, we show that CTLA-4 enhances the frequency of IL-17 in CD8(+) T cells, indicating that CTLA-4 (CD152) specifically promotes Tc17 differentiation. Simultaneous stimulation of CTLA-4(+/+) and CTLA-4(-/-) T cells in cocultures and agonistic CTLA-4 stimulation unambiguously revealed a cell-intrinsic mechanism for IL-17 control by CTLA-4. The quality of CTLA-4-induced Tc17 cells was tested in vivo, utilizing infection with the facultative intracellular bacterium Listeria monocytogenes (LM). Unlike CTLA-4(+/+) Tc17 cells, CTLA-4(-/-) were nearly as efficient as Tc1 CTLA-4(+/+) cells in LM clearance. Additionally, adoptively transferred CTLA-4(-/-) Tc17 cells expressed granzyme B after rechallenge, and produced Tc1 cytokines such as IFN-γ and TNF-α, which strongly correlate with bacterial clearance. CTLA-4(+/+) Tc17 cells demonstrated a high-quality Tc17 differentiation program ex vivo, which was also evident in isolated IL-17-secreting Tc17 cells, with CTLA-4-mediated enhanced upregulation of Tc17-related molecules such as IL-17A, RORγt, and IRF-4. Our results show that CTLA-4 promotes Tc17 differentiation that results in robust Tc17 responses. Its inactivation might therefore represent a central therapeutic target to enhance clearance of infection.

  14. Kinetics of reduction of a RuO2(110) film on Ru by atomic hydrogen

    NARCIS (Netherlands)

    Ugur, D.; Storm, A.J.; Verberk, R.; Brouwer, J.C.; Sloof, W.G.

    2013-01-01

    The kinetics and the mechanism of reduction of a RuO2(110) film, grown thermally on a Ru(0001) surface, has been studied in the temperature range of 60-200 °C by using an atomic hydrogen flux of 2 × 1019 at. H m-2 s-1. The reduction kinetics is dominated by the creation of oxygen vacancies at the su

  15. Enhancement of perpendicular magnetic anisotropy and coercivity in ultrathin Ru/Co/Ru films through the buffer layer engineering

    Science.gov (United States)

    Kolesnikov, Alexander G.; Stebliy, Maxim E.; Ognev, Alexey V.; Samardak, Alexander S.; Fedorets, Aleksandr N.; Plotnikov, Vladimir S.; Han, Xiufeng; Chebotkevich, Ludmila A.

    2016-10-01

    We present results on a study of the interplay between microstructure and the magnetic properties of ultrathin Ru/Co/Ru films with perpendicular magnetic anisotropy (PMA). To induce PMA in the Co layer, we experimentally determined thicknesses of the buffer and capping layers of Ru. The maximum value of PMA was observed for the Co thickness of 0.9 nm with the 3 nm thick capping layer. The effective anisotropy field (H eff) and coercive force (H c) of the Co layer are very sensitive to the Ru buffer layer thickness (t b). The values of H eff and H c increase approximately by two and ten times, correspondingly, when t b changes from 6 to 20 nm, owing to an increase in volume fraction of the crystalline phase as a result of the grains’ growth. PMA is found to be mainly enhanced by elastic strains induced by the lattice mismatch on the Ru/Co and Co/Ru interfaces, leading to the deformation of the Co lattice. The surface impact is determined to be less than 10% of the magneto-elastic contribution to the effective anisotropy. Observation of the magnetic domain structure by means of polar Kerr microscopy reveals that out-of-plane magnetization reversal occurs through the nucleation, growth, and annihilation of domains, where the average size drastically rises with the increasing t b.

  16. Preparation of (99m)Tc carbonyl DTPA-bevacizumab and its bioevaluation in a melanoma model.

    Science.gov (United States)

    Kameswaran, Mythili; Pandey, Usha; Sarma, Haladhar Dev; Samuel, Grace

    2014-11-01

    The objective of this study was to explore the potential of (99m)Tc carbonyl labeled DTPA-bevacizumab as a tumor imaging agent. Bevacizumab (Avastin) is a humanized monoclonal antibody (MoAb) that inhibits the vascular endothelial growth factor (VEGF). Bevacizumab was conjugated with paraisothiocyanatobenzyl diethylenetriamine pentaacetic acid (p-SCN-Bn-DTPA) and subsequently radiolabeled with (99m)Tc via the (99m)Tc carbonyl synthon. The radioconjugate after purification was characterized by SE-HPLC and its in vitro stability was determined by histidine challenge experiments. Biodistribution studies to determine the uptake by tumors were carried out in melanoma model. The radiochemical purity of (99m)Tc carbonyl labeled antibody was >98 %. The radiolabeled antibody exhibited good stability in the histidine challenge experiments up to 24 h when stored at 37 °C. Biodistribution studies in mice bearing melanoma showed significant tumor uptake (6.9 ± 2.2 % ID/g at 24 h p.i.) which was reduced to 1.6 ± 0.4 % ID/g on co-injection with cold Bevacizumab. The (99m)Tc carbonyl-DTPA-bevacizumab conjugate with good radiochemical purity, excellent stability and good specificity for VEGF indicates its potential as a radioimmunoscintigraphy agent for various cancers.

  17. Effect of Electron Irradiation on Superconductivity in Single Crystals of Ba(Fe_{1−x}Ru_{x}_{2}As_{2} (x=0.24

    Directory of Open Access Journals (Sweden)

    R. Prozorov

    2014-11-01

    Full Text Available A single crystal of isovalently substituted Ba(Fe_{1−x}Ru_{x}_{2}As_{2} (x=0.24 is sequentially irradiated with 2.5 MeV electrons up to a maximum dose of 2.1×10^{19} e^{−}/cm^{2}. The electrical resistivity is measured in situ at T=22  K during the irradiation and ex situ as a function of temperature between subsequent irradiation runs. Upon irradiation, the superconducting transition temperature T_{c} decreases and the residual resistivity ρ_{0} increases. We find that electron irradiation leads to the fastest suppression of T_{c} compared to other types of artificially introduced disorder, probably due to the strong short-range potential of the pointlike irradiation defects. A more detailed analysis within a multiband scenario with variable scattering potential strength shows that the observed T_{c} versus ρ_{0} is fully compatible with s_{±} pairing, in contrast to earlier claims that this model leads to a too rapid suppression of T_{c} with scattering.

  18. Study on Chemisorption and Desorption of Hydrogen and Nitrogen on Ru-based Ammonia Synthesis Catalyst

    Institute of Scientific and Technical Information of China (English)

    祝一锋; 李小年

    2003-01-01

    The effects of promoters K,Ba,Sm,on the chemisorption and desorption of hydrogen and nitrogen,dispersion of metallic Ru and catalytic activity of active carbon(AC) supported ruthenium catalyst for ammonia synthesis have been studied by means of pulse chromatography,temperature-programmed desorption,and activity test,Promoters K,Ba and Sm increased the activity of Ru/AC catalysts for ammonia synthesis significantly,and particularly,potassium exhibited the best promotion on the activity because of the strong electronic donation to metallic Ru.Much higher activity can be obtained for Ru/AC catalyst with binary or triple promoters.The activity of Ru/AC catalyst is dependent on the adsorption of hydrogen and nitrogen.The high activity of catalyst could be ascribed to strong dissociation of nitrogen on the catalyst surface.Strong adsorption of hydrogen would inhibit the adsorption of nitrogen,resulted in decrease of the catalytic activity.Ru/AC catalyst promoted by Sm2O3 shows the best dispersion of metallic Ru,since the partly reduced SmO2 on the surface modifies the morphology of active sites and favors the dispersion of metallic Ru.The activity of Ru/AC catalysts is in accordance to the corresponding amount of nitrogen chemisorption and the desorption activation enery of nitrogen.The desorption activation energy for nitrogen decreases in the order of Ru>Ru-Ba>Ru-Sm>Ru-Bs-Sm>Ru-K>Ru-K-Bm>Ru-K-Ba>Ru-K-Ba-Sm,just opposite to the order or catalytic activity,suggesting that the ammonia synthesis over Ru-based catalyst is controlled by the step of dissociation of nitrogen.

  19. Atomic hydrogen interaction with Ru(1010).

    Science.gov (United States)

    Vesselli, E; Comelli, G; Rosei, R

    2004-05-01

    The interaction of atomic hydrogen with clean and deuterium precovered Ru(1010) was studied by means of temperature-programmed desorption (TPD) spectroscopy. Compared to molecular hydrogen experiments, after exposure of the clean surface to gas-phase atomic hydrogen at 90 K, two additional peaks grow in the desorption spectra at 115 and 150 K. The surface saturation coverage, determined by equilibrium between abstraction and adsorption reactions, is 2.5 monolayers. Preadsorbed deuterium abstraction experiments with gas-phase atomic hydrogen show that a pure Eley-Rideal mechanism is not involved in the process, while a hot atom (HA) kinetics describes well the reaction. By least-squares fitting of the experimental data, a simplified HA kinetic model yields an abstraction cross section value of 0.5 +/- 0.2 angstroms2. The atomic hydrogen interaction with an oxygen precovered surface was also studied by means of both TPD and x-ray photoelectron spectroscopy: oxygen hydrogenation and water production take place already at very low temperature (90 K).

  20. Face to phase with RU Lupi

    CERN Document Server

    Gahm, Gösta F; Walter, Frederick M; Petrov, Peter P; Herczeg, Gregory J

    2013-01-01

    We present new results on the classical T Tauri star RU Lupi based on three observing runs collecting high-resolution spectra, complementary NIR spectra, multicolour photometric data, and X-ray observations. The photospheric absorption lines are weakened. This veiling becomes extremely strong on occasion, and we show that this effect is due to narrow emission lines that fill in the photospheric lines. The blue-shifted wings in the optical emission lines of He I, attributed to a stellar wind, are remarkably stable in equivalent width. In contrast, the red-shifted wings change dramatically in strength depending on rotational phase. From the pattern of variability we infer that these wings originate in accreting gas close to the star, and that the accretion funnels are bent and trail the hot spot. Forbidden emission lines are very stable over the entire observing period and originate in the disk wind. A system of narrow blue-shifted absorption features seen in lines of Ca II and Na I can be traced to a disk wind...

  1. Imaging studies of breast cancer xenografts. Monoclonal anti-mucin antibodies BM-7 and 12H12 labeled with {sup 99m}TC; Immunszintigraphie xenotransplantierter Mammakarzinome. {sup 99m}Tc-markierte monoklonale Anti-Muzinantikoerper BM-7 und 12H12

    Energy Technology Data Exchange (ETDEWEB)

    Bruemmendorf, T.H. [Onkologisches Labor, Universitaetsfrauenklinik, Heidelberg (Germany); Kaul, S. [Onkologisches Labor, Universitaetsfrauenklinik, Heidelberg (Germany); Schuhmacher, J. [Onkologisches Labor, Universitaetsfrauenklinik, Heidelberg (Germany); Baum, R.P. [Radiologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum, Heidelberg (Germany); Kliveny, G. [Onkologisches Labor, Universitaetsfrauenklinik, Heidelberg (Germany); Matys, R. [Onkologisches Labor, Universitaetsfrauenklinik, Heidelberg (Germany); Eichler, A. [Onkologisches Labor, Universitaetsfrauenklinik, Heidelberg (Germany); Gueckel, B.; Beldermann, F.; Bastert, G.

    1995-10-01

    The present study was undertaken to evaluate the correlation of the favourable in vitro characteristics of the anit-mucin Mabs 12H12 and BM-7 with high tumor accumulation in vivo. They were labeled with {sup 99m}Tc; their biodistribution in nude mice bearing mammary tumor xenograft AR was examined and immunoscintigraphy was performed after 24 h. {sup 99m}Tc-labeling of the Mabs 12H12 and BM-7 led to tumor uptakes of 20.7% and 8.8% ID/g, respectively, after 48 h. Tumor-to-muscle ratios were 31 (12H12) and 18 (BM-7). Tumor xenografts were clearly visualized in immunoscintigrams. Combination of Mab 12H12 and {sup 99m}Tc provides high tumor-to-tissue ratios shortly after administration. (orig.) [Deutsch] Gegenstand dieser Arbeit waren tierexperimentelle Untersuchungen zur Biodistribution und Immunszintigraphie der Anti-Muzin-MoAbs 12H12 und BM-7 in thymusaplastischen Nacktmaeusen mit xenotransplantierten humanen Mammakarzinomen. Die MoAb waren mit {sup 99m}Tc markiert; ihre Biodistribution wurde im Tiermodell 24 und 48 h nach i. v. Injektion untersucht. Die {sup 99m}Tc-Markierungen der MoAbs 12H12 und BM-7 fuehrten zu einer Tumoranreicherung von 20,7% bzw. 8,8% ID/g und zu Tumor/Muskel-Quotienten von 31 bzw. 18 nach 48 h. Immunszintigraphisch liess sich mit beiden MoAbs nach 24 h das Mammakarzinom AR gut darstellen. Die beiden MoAbs erfahren im Tiermodell eine schnelle Tumoraufnahme und rasche Blut-Clearance. (orig.)

  2. General report of TC 106: Unsaturated soils

    NARCIS (Netherlands)

    Jommi, C.

    2013-01-01

    This general report summarises the contributions on unsaturated soil mechanics submitted to the Discussion Session of TC106 – Unsaturated soils –at the 18th International Conference on Soil Mechanics and Geotechnical Engineering held in Paris in September 2013. The thirty-five papers collected under

  3. General report of TC 106: Unsaturated soils

    NARCIS (Netherlands)

    Jommi, C.

    2013-01-01

    This general report summarises the contributions on unsaturated soil mechanics submitted to the Discussion Session of TC106 – Unsaturated soils –at the 18th International Conference on Soil Mechanics and Geotechnical Engineering held in Paris in September 2013. The thirty-five papers collected under

  4. Grain boundaries in high-Tc superconductors

    NARCIS (Netherlands)

    Hilgenkamp, H.; Mannhart, J.

    2002-01-01

    Since the first days of high-Tc superconductivity, the materials science and the physics of grain boundaries in superconducting compounds have developed into fascinating fields of research. Unique electronic properties, different from those of the grain boundaries in conventional metallic supercondu

  5. Layered ruthenium hexagonal perovskites: The new series [Ba 2Br 2-2x(CO 3) x][Ba n+1Ru nO 3n+3] with n=2, 3, 4, 5

    Science.gov (United States)

    Kauffmann, Matthieu; Roussel, Pascal; Abraham, Francis

    2007-07-01

    Single crystals of the title compounds were prepared by solid state reactions from barium carbonate and ruthenium metal using a BaBr 2 flux and investigated by X-ray diffraction method using Mo(Kα) radiation and a Charge Coupled Device (CCD) detector. A structural model for the term n=2, Ba 5Ru 2Br 2O 9 ( 1) was established in the hexagonal symmetry, space group P6 3/ mmc, a=5.8344(2) Å, c=25.637(2) Å, Z=2. Combined refinement and maximum-entropy method (MEM) unambiguously show the presence of CO 32- ions in the three other compounds ( 2, 3, 4). Their crystal structures were solved and refined in the trigonal symmetry, space group P3¯ml, a=5.8381(1) Å, c=15.3083(6) Å for the term n=3, Ba 6Ru 3Br 1.54(CO 3) 0.23O 12 ( 2), and space group R3¯m, a=5.7992(1) Å, c=52.866(2) Å and a=5.7900(1) Å, c=59.819(2) Å for the terms n=4, Ba 7Ru 4Br 1.46(CO 3) 0.27O 15 ( 3), and n=5, Ba 8Ru 5Br 1.64(CO 3) 0.18O 18 ( 4), respectively. The structures are formed by the periodic stacking along [0 0 1] of ( n+1) hexagonal close-packed [BaO 3] layers separated by a double layer of composition [Ba 2Br 2-2x(CO 3) x]. The ruthenium atoms occupy the n octahedral interstices created in the hexagonal perovskite slabs and constitute isolated dimers Ru 2O 9 of face-shared octahedra (FSO) in 1 and isolated trimers Ru 3O 12 of FSO in 2. In 3 and 4, the Ru 2O 9 units are connected by corners either directly ( 3) or through a slab of isolated RuO 6 octahedra ( 4) to form a bidimensional arrangement of RuO 6 octahedra. These four oxybromocarbonates belong to the family of compounds formulated [Ba 2Br 2-2x(CO 3) x][Ba n+1Ru nO 3n+3] where n represents the thickness of the octahedral string in hexagonal perovskite slabs. These compounds are compared to the oxychloride series.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-15

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

  7. TC81201F MPEG2 decoder LSI; MPEG2 decoder LSI TC81201F

    Energy Technology Data Exchange (ETDEWEB)

    Kitagaki, K. [Toshiba Corp., Tokyo (Japan)

    1996-04-01

    The moving picture expert group 2 (MPEG2) decoder LSI series have been developed, in order to meet needs for diversifying multi-media systems. MPEG2 is an international standard for coding moving pictures, capable of compressing large quantities of moving picture data. Therefore, the decoder LSI for the MPEG2 signals is also a key device to realize the multi-media systems. The system needs are diversifying, as seen in different audio codes for DVD`s and digital satellite broadcasting systems (DBS`s). The company has developed, based on decoder LSI T9556 announced in 1994, TC81200F for mass production, TC81201F optimized for the DVD system and TC81211F as the one-chip device for MPEG1 decoder. Chip cost and system cost of TC81201F are reduced by optimizing functions and circuits, and by reducing external memories. 4 refs., 4 figs., 1 tab.

  8. Fabrication of atomized uranium dispersion targets for fission mo production

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Moonsoo; Ryu, Ho Jin; Park, Jong Man; Kim, Chang Kyu; Lee, Jong Hyeon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    Among radioisotopes for medical diagnosis, Tc-99m is most widely used. Mo-99 produced from nuclear fission of uranium in research reactors is the key radioisotopes for Tc-99m generators. Generally, major producers of Mo-99 still use targets containing highly enriched uranium (HEU). However, the international non-proliferation policy emphasizes the minimization of the use of HEU in medical radioisotopes production nowadays. Therefore, low enriched uranium (LEU) targets have been developed by casting and crushing of UAl{sub 2} compounds. The UAl{sub 2} particle dispersed target has a lower U-235 density when compared to HEU targets. In order to improve the low production efficiency of LEU targets, target designers try to develop high uranium density targets with LEU. KAERI has proposed that high density uranium alloys, instead of UAl{sub 2}, can be used as dispersing particles in an aluminum matrix. While it is very difficult to fabricate uranium alloys powder by grinding or crushing, spherical powder of uranium alloys can be produced easily by centrifugal atomization. Mini-size targets with 3, 6, and 9 g-U/cc were fabricated in this study to investigate the feasibility of high density targets with atomized uranium particles. The microstructural changes after thermal treatments were observed to analyze the interaction behavior of uranium particles and aluminum matrix.

  9. Development Of ABEC Column For Separation Of Tc-99 From Northstar Dissolved Target Solution

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Dominique C. [Argonne National Lab. (ANL), Argonne, IL (United States); Bennett, Megan E. [Argonne National Lab. (ANL), Argonne, IL (United States); Naik, Seema R. [Argonne National Lab. (ANL), Argonne, IL (United States); ling, lei [Argonne National Lab. (ANL), Argonne, IL (United States); Wang, N-H. Linda [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-12-01

    Batch and column breakthrough experiments were performed to determine isotherms and mass-transfer parameters for adsorption of Tc on aqueous biphasic extraction chromatographic (ABEC) sorbent in two solutions: 200 g/L Mo, 5.1 M K+, 1 M OH-, and 0.1 M NO3- (Solution A) and 200 g/L Mo, 9.3 M K+, 5 M OH-, and 0.1 M NO3- (Solution B). Good agreement was found between the isotherm values obtained by batch and column breakthrough studies for both Solutions A and B. Potassium-pertechnetate intra-particle diffusivity on ABEC resin was estimated by VERSE simulations, and good agreement was found among a series of column-breakthrough experiments at varying flow velocities, column sizes, and technetium concentrations. However, testing of 10 cc cartridges provided by NorthStar with Solutions A and B did not give satisfactory results, as significant Tc breakthrough was observed and ABEC cartridge performance varied widely among experiments. These different experimental results are believed to be due to inconsistent preparation of the ABEC resin prior to packing and/or inconsistent packing.

  10. Th1 Th2, Tc1 Tc2 cells of patients with otolaryngological diseases

    Directory of Open Access Journals (Sweden)

    Nobuo Ohta

    2004-01-01

    Full Text Available Cytokines are important regulatory mediators secreted by T cells and other immunoactive cells. Based on the cytokine synthesis patterns, CD4 T cells can often be classified into at least two populations with different immune regulatory functions. The Th1 cells, producing interleukin (IL-2 and interferon (IFN-γ, are often associated with cell-mediated immune responses such as delayed type hypersensitivity (DTH, whereas Th2 cells, secreting IL-4, IL-5 and IL-13, usually provide B cell help and enhance allergic reactions. Naïve CD8 T cells, similar to CD4 T cells, can differentiate into at least two subsets of cytolytic effector cells with distinct cytokine patterns. The Tc1 cells secrete a Th 1 - like cytokine pattern, including IL-2 and IFN-γ. The Tc2 cells produce Th2 cytokines, including IL-4, IL-5 and 11—10. There is increasing evidence that Th1/Th2 and Tc1/Tc2 cytokine imbalance has been of patho- genetic importance in various diseases, such as allergic and autoimmune diseases. The present review article focuses on the evidence that the imbalance of Th1/Th2 and Tc1/Tc2 cytokines plays an important role in various otolaryngological diseases, such as Kimura's disease, Wegener's granulomatosism, acute perceptive hearing loss and Meniere's disease. It is concluded that the predominance of Th 1 or Th2 and Tc1 or Tc2 cells may contribute to the mechanism in the pathogenesis of these otolaryngological diseases.

  11. High-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles for phenol hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chao [The Key Laboratory of Fuel Cell Technology of Guangdong Province and The Key Laboratory for New Energy of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Yang, Xu [Key Laboratory of Renewable Energy, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou (China); Yang, Hui; Huang, Peiyan; Song, Huiyu [The Key Laboratory of Fuel Cell Technology of Guangdong Province and The Key Laboratory for New Energy of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China); Liao, Shijun, E-mail: chsjliao@scut.edu.cn [The Key Laboratory of Fuel Cell Technology of Guangdong Province and The Key Laboratory for New Energy of Guangdong Universities, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou (China)

    2014-10-01

    Graphical abstract: The addition of Ru could significantly improve the performance of the mesoporous silica nanoparticles supported PdRu/MSN catalyst, which showed over 5 times higher mass activity than the mono-Pd/MSN towards the liquid-phase hydrogenation of phenol. The improved dispersion and the electronic interaction contributed to the enhanced catalytic activity for the catalyst towards phenol hydrogenation. - Highlights: • PdRu bimetal catalyst supported on mesoporous silica nanoparticles was prepared. • The average sizeof PdRu alloy is smaller than that of mono-Pd. • The addition of Ru to Pd modulates the electronic properties between Pd and Ru. • PdRu/MSN catalyst shows superior activity on phenol hydrogenation than Pd/MSN. • PdRu/MSN catalyst shows good selectivity for cyclohexanol to some extent. - Abstract: A high-performance PdRu bimetallic catalyst supported on mesoporous silica nanoparticles (MSN), PdRu/MSN, was prepared by a facile impregnation–hydrogen reduction method. It was found that PdRu/MSN showed 5 times higher activity than that of Pd/MSN towards the liquid-phase hydrogenation of phenol. The catalysts were characterized comprehensively by multiple techniques, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and hydrogen temperature program reduction (TPR). It was revealed that adding Ru could effectively improve the Pd dispersion and promote the electronic interaction between the Pd and Ru, both of which contribute to enhancing the catalytic activity.

  12. High density plasma reactive ion etching of Ru thin films using non-corrosive gas mixture

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Su Min; Garay, Adrian Adalberto; Lee, Wan In; Chung, Chee Won, E-mail: cwchung@inha.ac.kr

    2015-07-31

    Inductively coupled plasma reactive ion etching (ICPRIE) of Ru thin films patterned with TiN hard masks was investigated using a CH{sub 3}OH/Ar gas mixture. As the CH{sub 3}OH concentration in CH{sub 3}OH/Ar increased, the etch rates of Ru thin films and TiN hard masks decreased. However, the etch selectivity of Ru films on TiN hard masks increased and the etch slope of Ru film improved at 25% CH{sub 3}OH/Ar. With increasing ICP radiofrequency power and direct current bias voltage and decreasing process pressure, the etch rates of Ru films increased, and the etch profiles were enhanced without redeposition on the sidewall. Optical emission spectroscopy and X-ray photoelectron spectroscopy were employed to analyze the plasma and surface chemistry. Based on these results, Ru thin films were oxidized to RuO{sub 2} and RuO{sub 3} compounds that were removed by sputtering of ions and the etching of Ru thin films followed a physical sputtering with the assistance of chemical reaction. - Highlights: • Etching of Ru films in CH{sub 3}OH/Ar was investigated. • High selectivity and etch profile with high degree of anisotropy were obtained. • XPS analysis was examined to identify the etch chemistry. • During etching Ru was oxidized to RuO{sub 2} and RuO{sub 3} can be easily sputtered off.

  13. Gizmopolitan. O cómo reconciliar la femineidad y los videojuegos

    Directory of Open Access Journals (Sweden)

    Susana Tosca

    2012-04-01

    Full Text Available Este artículo examina Gizmopolitan, una revista femenina producida por fans cuyo tema central es cómo ser una mujer en Azeroth (el nombre del mundo en que se desarrolla el juego de rol online World of Warcraft. El análisis de esta revista revela interesantes aspectos de la relación dialéctica entre los videojuegos, el género de los jugadores y el contenido producido por fans.Digital Culture/ Mobile Communication Group. Universidad IT de Co-penhague. Rued Langgaards Vej 7, 2300 Copenhague (Dinamarca

  14. The Single State Dominance Hypothesis and the Two-Neutrino Double Beta Decay of Mo100

    CERN Document Server

    Simkovic, F; Semenov, S V

    2001-01-01

    The hypothesis of the single state dominance (SSD) in the calculation of the two-neutrino double beta decay of Mo100 is tested by exact consideration of the energy denominators of the perturbation theory. Both transitions to the ground state as well as to the 0+ and 2+ excited states of the final nucleus Ru100 are considered. We demonstrate, that by experimental investigation of the single electron energy distribution and the angular correlation of the outgoing electrons, the SSD hypothesis can be confirmed or ruled out by a precise two-neutrino double beta decay measurement (e.g. by NEMO III collaboration).

  15. Tc Chemistry in HLW: Role of Organic Complexants

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Nancy S.; Conradsen, Steven D.

    2003-06-01

    Tc complexation with organic compounds in tank waste plays a significant role in the redox chemistry of Tc and the partitioning of Tc between the supernatant and sludge components in waste tanks. These processes need to be understood so that strategies to effectively remove Tc from high-level nuclear waste prior to waste immobilization can be developed and so that long-term consequences of Tc remaining in residual waste after sludge removal can be evaluated. Only limited data on the stability of Tc-organic complexes exists and even less thermodynamic data on which to develop predictive models of Tc chemical behavior is available. To meet these challenges we are conducting a research program to study to develop thermodynamic data on Tc-organic complexation over a wide range of chemical conditions. We will attempt to characterize Tc-speciation in actual tank waste using state-of-the-art analytical organic chemistry, separations, and speciation techniques to validate our model. On the basis of such studies we will develop credible model of Tc chemistry in HLW that will allow prediction of Tc speciation in tank waste and Tc behavior during waste pretreatment processing and in waste tank residuals.

  16. 质子数Z分别位于Ru之上和之下的A∼(100∼126)丰中子原子核三轴形变在原子核形状变迁和共存中的重要作用%Imp ortance of Triaxiality in Shap e Transitions and Co existence in A ∼100 to 126 Neutron-rich Nuclei with Z Beyond and Below Ru

    Institute of Scientific and Technical Information of China (English)

    罗亦孝; 杨韵颐; 朱胜江; 刘艳鑫; 焦长峰; 梁午阳; 石跃; 许甫荣; 孙阳; 刘少华; N. T. Brewer; J. H. Hamilton; I. Y. Lee; G.M. Ter-Akopian; A. V. Daniel; Yu. Oganessian; M. A. Stoyer; R. Donangelo; 马文超; J. O. Rasmussen; A.V. Ramayya; S. Frauendorf; 王恩宏; J. K. Hwang; 王建国; 李红洁

    2015-01-01

    基于Ru (Z=44)丰中子同位素中存在最大三轴形变的理论预言和实验证据,综述了近年来Rh (Z=45), Pd (Z=46), Ag (Z=47), Cd (Z=48)(质子数Z位于Ru,Z=44之上)及Zr (Z=40), Nb (Z=41), Mo (Z=42), Tc (Z=43)(质子数Z位于Ru,Z=44之下)的A∼(100∼126)丰中子同位素中关于三轴形变的形状变迁和形状共存系统性研究的重要进展。252 Cf自发裂变瞬发γ射线γ-γ-γ三重符合、特别是新建立的γ-γ-γ-γ四重符合数据的系统观测和研究,在Ru, Pd, Cd和Nb丰中子同位素中显著扩展或首次观测到了一系列能带,为这个核区原子核形状的研究提供了新的、重要的实验数据。联系此前报道的有关进展,使用PES, TRS, PSM, CCCSM和SCTAC理论模型计算拟合新的实验数据,在该核区沿同中素和同位素链,并随自旋和激发能变化各自由度,跟踪原子核形状渐进变化,获得了新的系统性研究成果,显著扩展和深化了人们对原子核形状变迁和形状共存的认知。  对于Ru及其上的Rh (Z=45), Pd (Z=46), Ag (Z=47)和Cd (Z=48)丰中子同位素的研究表明:Rh丰中子核具有比最大值稍小的三轴形变,γ=−28°,并在103–106 Rh同位素链上鉴别出了手征对称破缺;在三轴形变核112Ru和114Pd(N =68)中发现了三轴原子核的摆动运动,该摆动运动也可能在114Ru (N =70)中存在;观察到了从具有最大三轴形变的110,112 Ru 中手征破缺到稍小三轴形变的112,114,116 Pd 中扰动的手征破缺的过渡;在较软的Ag 核中观察到了丰富的谱学结构,在104,105Ag 中鉴别出了可能的手征对称破缺,在较重的115,117Ag 中提出了趋于三轴形变的γ软度;具有小形变的Cd核的能级结构被解释为准粒子耦合、准转动和软三轴形变;最近的库伦激发的研究提供了Z=50, N=82满壳附近122,124,126 Cd 核中出现核集体性的实验和理论证据;上述研究成果展现出

  17. Rahasäru veeretas viisimünti / Inna Grünfeldt

    Index Scriptorium Estoniae

    Grünfeldt, Inna, 1961-

    2008-01-01

    Folkloorifestival Viru Säru, mille teemaks seekord "Raha, rikkus ja vaesus", katsus Kadrinas kavasid. Žüriisse kuulusid Viru Säru kunstiline juht Igor Tõnurist, rahvamuusik Margus Veenre ja rahvatantsujuht Angela Arraste. Ka nende arvamused kavade kohta

  18. Mismatched uptake of Tc-99m-ECD and Tc-99m-HMPAO in subacute cerebral infarction: Tc-99m-ECD for viability and Tc-99m-HMPAO for flow restoration

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D. S.; Hyun, I. Y.; Kim, S. K. [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)] [and others

    1997-07-01

    Tc-99m-HMPAO reflects tissue perfusion but Tc-99m-ECD uptake is affected by tissue viability in addition to tissue perfusion which the varied state of cellular retention of Tc-99m-ECD reflects. Luxuriously perfused area on Tc-99m-HMPAO SPECT implies that this cortex was already reperfused either spontaneously or after thrombolysis and that accompanied paralysis of vascular reactivity in those zones warms progressive deterioration. We tried to find out if we can use sequential Tc-99m-ECD/Tc-99m-HMPAO SPECT to reveal cortical perfusion and severity and range of risky areas of cerbral cortex despite reperfusion in sub-acute infarction. In 13 patients (M ; F =7 : 6, mean age 57 (range: 26-84)) with cortical (n=12) and basal ganglia infarction (1), we performed sequential Tc-99m-ECD/Tc-99m-HMPAO SPECT at the same position. At first, 555 MBq of Tc-99m-ECD was injected and imaged and then 1110 MBq of Tc-99m-HMPAO was injected again and imaged with the patients in situ, and the first image (Tc-99m-ECD) and the subtracted image (2nd- 1st : Tc-99m-HMPAO) were compared slice by slice. Study was done from 3 days to 31 days (16{+-}9) after ictus. Tc-99m-ECD uptake was always less than or equal to Tc-99m-HMPAO uptake at the lesion in all cases. Luxury perfusion was prominent in four patients. Mismatched uptake was found in 10 patients. Severity of mismatch showed diverse spectrum and was ranged from total middle cerebral artery territory (1 case) to peripheral thin zones around infarction (2 cases). The other 7 showed intermediate amount of tissues with mismatch , i.e., Tc-99m-ECD defects where Tc-99m-HMPAO uptake is in part increased, normal or decreased. Upon discharge, patients having more uptake with Tc-99m-ECD predicted improvement. Patients having mismatched uptake went dichotomous way. In conclusion, Tc-99m-ECD/Tc-99m-HMPAO sequential SPECT is feasible and reveal both tissue perfusion (Tc-99m-HMPAO ) and discrepant Tc-99m-ECD uptake probably reflecting viability in acute

  19. Photoelectrochemistry of Pristine Mono- and Few-Layer MoS2.

    Science.gov (United States)

    Velický, Matěj; Bissett, Mark A; Woods, Colin R; Toth, Peter S; Georgiou, Thanasis; Kinloch, Ian A; Novoselov, Kostya S; Dryfe, Robert A W

    2016-03-09

    Two-dimensional crystals are promising building blocks for the new generation of energy materials due to their low volume, high surface area, and high transparency. Electrochemical behavior of these crystals determines their performance in applications such as energy storage/conversion, sensing, and catalysis. Nevertheless, the electrochemistry of an isolated monolayer of molybdenum disulfide, which is one of the most promising semiconducting crystals, has not been achieved to date. We report here on photoelectrochemical properties of pristine monolayer and few-layer basal plane MoS2, namely the electron transfer kinetics and electric double-layer capacitance, supported by an extensive physical and chemical characterization. This enables a comparative qualitative correlation among the electrochemical data, MoS2 structure, and external illumination, although the absolute magnitudes of the electron transfer and capacitance are specific to the redox mediator and electrolyte used in these measurements ([Ru(NH3)6](3+/2+) and LiCl, respectively). Our work shows a strong dependence of the electrochemical properties on the number of MoS2 layers and illumination intensity and proves that an effective interlayer charge transport occurs in bulk MoS2. This highlights the exciting opportunities for tuning of the electrochemical performance of MoS2 through modification of its structure, external environment, and illumination.

  20. Elementary Steps of Syngas Reactions on Mo2C(001): Adsorption Thermochemistry and Bond Dissociation

    Energy Technology Data Exchange (ETDEWEB)

    Medford, Andrew

    2012-02-16

    Density functional theory (DFT) and ab initio thermodynamics are applied in order to investigate the most stable surface and subsurface terminations of Mo{sub 2}C(001) as a function of chemical potential and in the presence of syngas. The Mo-terminated (001) surface is then used as a model surface to evaluate the thermochemistry and energetic barriers for key elementary steps in syngas reactions. Adsorption energy scaling relations and Broensted-Evans-Polanyi relationships are established and used to place Mo{sub 2}C into the context of transition metal surfaces. The results indicate that the surface termination is a complex function of reaction conditions and kinetics. It is predicted that the surface will be covered by either C{sub 2}H{sub 2} or O depending on conditions. Comparisons to transition metals indicate that the Mo-terminated Mo{sub 2}C(001) surface exhibits carbon reactivity similar to transition metals such as Ru and Ir, but is significantly more reactive towards oxygen.

  1. PREFACE: 2013 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium: Measurement Across Physical and Behavioural Sciences

    Science.gov (United States)

    Battista Rossi, Giovanni; Crenna, Francesco; Belotti, Vittorio

    2013-09-01

    The 2013 Joint IMEKO (International Measurement Confederation) TC1-C7-TC13 was organised by the University of Genova - DIME/MEC, Measurement Laboratory, Italy, on 4-6 September 2013. The work of this symposium is reported in this volume. The scope of the symposium includes the main topics covered by the above Technical Committees: TC1 Education and Training in Measurement and Instrumentation TC7 Measurement Science TC13 Measurements in Biology and Medicine This is in keeping with the tradition set by the previous events of this well established series. There has been a special focus on measurement across physical and behavioural sciences, with the aim of highlighting the interdisciplinary character of measurement science and of promoting constructive interactions with scientists in other disciplines. The discussion was introduced by keynote lectures on measurement challenges in psychophysics, psychometrics and quantum physics. The symposium was attended by experts working in these areas from 18 countries, including USA, Australia and Japan, and provided a useful forum for them to share and exchange their work and ideas. In total over sixty papers are included in the volume, organised according to the presentation sessions. Each paper was independently peer-reviewed by two reviewers from a distinguished international panel. The Symposium was held in Genova, which was the European Capital of Culture in 2004, and took place in Palazzo Ducale, an important historical building whose construction started in the 13th century, and that has been the house of the Duke of Genova from the 14th century. Genova, whose name comes from the Latin word 'Janua' (meaning 'door', as January is the door month of the year), has been regarded over the centuries as a door connecting Europe with the different countries and cultures of the Mediterranean basin and thus was an appropriate site for an international symposium involving different and new scientific visions and approaches to

  2. Bottom-up fabrication of graphene nanostructures on Ru(1010).

    Science.gov (United States)

    Song, Junjie; Zhang, Han-jie; Cai, Yiliang; Zhang, Yuxi; Bao, Shining; He, Pimo

    2016-02-01

    Investigations on the bottom-up fabrication of graphene nanostructures with 10, 10'-dibromo-9, 9'-bianthryl (DBBA) as a precursor on Ru(1010) were carried out using scanning tunnelling microscopy (STM) and density functional theory (DFT) calculations. Upon annealing the sample at submonolayer DBBA coverage, N = 7 graphene nanoribbons (GNRs) aligned along the [1210] direction form. Higher DBBA coverage and higher annealing temperature lead to the merging of GNRs into ribbon-like graphene nanoflakes with multiple orientations. These nanoflakes show different Moiré patterns, and their structures were determined by DFT simulations. The results showed that GNRs possess growth preference on the Ru(1010) substrate with a rectangular unit cell, and GNRs with armchair and zigzag boundaries are obtainable. Further DFT calculations suggest that the interaction between graphene and the substrate controls the orientations of the graphene overlayer and the growth of graphene on Ru(1010).

  3. Atomic states and properties of Ru-electrocatalyst

    Institute of Scientific and Technical Information of China (English)

    PENG Hong-jian; XIE You-qing; WEI De-liang

    2006-01-01

    Using the one-atom theory(OA), the atomic states of Ru-electrocatalyst with hcp structure was determined as [Kr](4dn)3.78(4dc)2.22(5sc)1.77(5sf)0.23. The potential curve, elasticity and the temperature dependence of linear thermal expansion coefficient and bulk modulus of hcp-Ru were calculated quantitatively. The atomic states of this metal with fcc and bcc structure and liquid state were also studied. According to its atomic states, the relationship between the atomic states and catalytic performance was explained qualitatively and these supplied Ru-metal and electrocatalyst with complete data for optimum designation in accordance with metal material systematic sicence.

  4. Shock compaction of high- Tc superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Weir, S.T.; Nellis, W.J.; McCandless, P.C.; Brocious, W.F. (Lawrence Livermore National Lab., CA (USA)); Seaman, C.L.; Early, E.A.; Maple, M.B. (California Univ., San Diego, La Jolla, CA (USA). Dept. of Physics); Kramer, M.J. (Ames Lab., IA (USA)); Syono, Y.; Kikuchi, M. (Tohoku Univ., Sendai (Japan))

    1990-09-01

    We present the results of shock compaction experiments on high-{Tc} superconductors and describe the way in which shock consolidation addresses critical problems concerning the fabrication of high J{sub c} bulk superconductors. In particular, shock compaction experiments on YBa{sub 2}Cu{sub 3}O{sub 7} show that shock-induced defects can greatly increase intragranular critical current densities. The fabrication of crystallographically aligned Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} samples by shock-compaction is also described. These experiments demonstrate the potential of the shock consolidation method as a means for fabricating bulk high-{Tc} superconductors having high critical current densities.

  5. Synthesis, characterization and structural control of nano crystalline molybdenum oxide MoO{sub 3} single phase by low cost technique

    Energy Technology Data Exchange (ETDEWEB)

    Afify, H.H.; Hassan, S.A. [Solid State Department, Physics Division, National Research Centre, 33 El Bohouthst. (fromer El Tahrirst.), Dokki, P.O. 12622, Giza (Egypt); Abouelsayed, A., E-mail: as.abouelsayed@gmail.com [Spectroscopy Department, Physics Division, National Research Centre, 33 El Bohouthst. (fromer El Tahrirst.), Dokki, P.O. 12622, Giza (Egypt); Demian, S.E. [Solid State Department, Physics Division, National Research Centre, 33 El Bohouthst. (fromer El Tahrirst.), Dokki, P.O. 12622, Giza (Egypt); Zayed, H.A. [Physics Department, Faculty of Girls for Art, Sciences and Education, Ain Shams University (Egypt)

    2016-06-15

    Thermodynamically stable α- MoO{sub 3} thin film is prepared without any other phases of the molybdenum oxides. Simple and low coast spray pyrolysis technique is used. Growth conditions are optimized to produce pure α- MoO{sub 3} with controlled crystallite size and surface morphology. Small angle (GAXRD) diffractometer is used to elucidate the structure. Profile shape function (PSF) model is made for the experimental data. WinFit software is going first to fit (PSF) to use the refined profile parameters for determination of crystallite size and internal residual strain. The (GAXRD) patterns prove the existence of α- MoO{sub 3} only with layered structure, indicated by the appearance of only (0k0). The calculated crystallite sizes and the strain are found to range from 10 to 28 nm and 0.28%–0.05% respectively. Ultraviolet and Visible transmission measurements were performed over a wavelength range 190–2500 nm on the MoO{sub 3} thin films synthesized by spray pyrolysis technique at different substrate temperature. The two sub-bands corresponds to the electronic transition between the molybdenum oxidation states Mo{sup 4+}, Mo{sup 5+} and Mo{sup 6+} are observed. Quantitative information on the temperature-induced blue shift of the sub-bands was obtained by fitting the spectra with Lorentz functions. The transition from Mo{sup 5+} to Mo{sup 6+} oxidation states show a blue shift up to Tc = 325 °C. Above Tc, the transition Mo{sup 5+} to Mo{sup 6+} increases more drastically, resulting in an anomaly in the temperature-induced shift at Tc. The anomaly can be attributed to the amorphous-to-crystalline phase transition at 325 °C. In addition, both refractive index and extinction coefficient are calculated as a function of substrate temperature. - Highlights: • Single phase α-MoO{sub 3} nano crystalline MoO{sub 3} thin films have been synthesized. • Amorphous-to-crystalline phase transition occurs at 325 °C for MoO{sub 3} thin films. • A clear

  6. Ternary Pt-Ru-Ni catalytic layers for methanol electrooxidation prepared by electrodeposition and galvanic replacement

    OpenAIRE

    Athanasios ePapaderakis; Nikolaos ePliatsikas; Chara eProchaska; Kalliopi M. Papazisi; Balomenou, Stella P.; Dimitrios eTsiplakides; Panagiotis ePatsalas; Sotiris eSotiropoulos

    2014-01-01

    Ternary Pt-Ru-Ni deposits on glassy carbon substrates, Pt-Ru(Ni)/GC, have been formed by initial electrodeposition of Ni layers onto glassy carbon electrodes, followed by their partial exchange for Pt and Ru, upon their immersion into equimolar solutions containing complex ions of the precious metals. The overall morphology and composition of the deposits has been studied by SEM microscopy and EDS spectroscopy. Continuous but nodular films have been confirmed, with a Pt ÷ Ru ÷ Ni % bulk atomi...

  7. Molecularly imprinted Ru complex catalysts integrated on oxide surfaces.

    Science.gov (United States)

    Muratsugu, Satoshi; Tada, Mizuki

    2013-02-19

    Selective catalysis is critical for the development of green chemical processes, and natural enzymes that possess specialized three-dimensional reaction pockets with catalytically active sites represent the most sophisticated systems for selective catalysis. A reaction space in an enzyme consists of an active metal center, functional groups for molecular recognition (such as amino acids), and a surrounding protein matrix to prepare the reaction pocket. The artificial design of such an integrated catalytic unit in a non-enzymatic system remains challenging. Molecular imprinting of a supported metal complex provides a promising approach for shape-selective catalysis. In this process, an imprinted cavity with a shape matched to a template molecule is created in a polymer matrix with a catalytically active metal site. In this Account, we review our studies on molecularly imprinted metal complex catalysts, focusing on Ru complexes, on oxide surfaces for shape-selective catalysis. Oxide surface-attached transition metal complex catalysts not only improve thermal stability and catalyst dispersion but also provide unique catalytic performance not observed in homogeneous precursors. We designed molecularly imprinted Ru complexes by using surface-attached Ru complexes with template ligands and inorganic/organic surface matrix overlayers to control the chemical environment around the active metal complex catalysts on oxide surfaces. We prepared the designed, molecularly imprinted Ru complexes on SiO(2) surfaces in a step-by-step manner and characterized them with solid-state (SS) NMR, diffuse-reflectance (DR) UV-vis, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller isotherm (BET), X-ray fluorescence (XRF), and Ru K-edge extended X-ray absorption fine structure (EXAFS). The catalytic performances of these Ru complexes suggest that this process of molecular imprinting facilitates the artificial integration of catalytic functions at surfaces. Further advances such

  8. Line Nodes and Time Reversal Symmetry Breaking in p-wave Sr2RuO4

    Science.gov (United States)

    Annett, Jf; Gyorffy, Bl; Litak, G.; Wysokinski, Ki

    2001-03-01

    The superconductor Sr_2RuO4 exhibits broken time reversal symmetry and has a contant Knight shift below Tc. These experiments suggest a pairing state of the ^3He-A type, d(k) = (k_x+ik_y)hatz. On the other hand specific heat measurements of Nishizaki Maeno and Mao (J. Phys. Soc. Japan 69, 572 (2000)) imply that the gap has line nodes. To resolve this contradiction we calculate the energy gap and heat capacity in several alternative scenarios for the pairing interaction. We find that on-site Hunds rule exchange cannot produce the observed T_c. Nearest neighbour spin independent attraction leads to d-wave pairing, while nearest neighbour parallel spin interaction leads to a p-wave state with no line nodes. However we can also obtain a state with line nodes on the alpha-beta Fermi surface sheets, and time reversal symmetry breaking on the gamma sheet. We discuss the possible physical origin of this state and the comparison with available experimental data.

  9. Superplastic Deformation of TC6 Alloy

    Directory of Open Access Journals (Sweden)

    DING Ling

    2016-12-01

    Full Text Available The superplastic tensile tests of TC6 alloy were conducted in the temperature range of 800-900℃ by using the maximum m value superplasticity deformation (Max m SPD method and the constant strain rate deformation method at the strain rate range of 0.0001-0.1 s-1. The stress-strain curve of the tensile tests was obtained and the microstructure near the fracture were analyzed by metallographic microscope. The result shows that the superplasticity of TC6 alloy is excellent, and the elongation increases first and then decreases with the increase of strain rate or temperature. When the temperature is 850℃ and strain rate is 0.001 s-1 at constant stain rate tensile tests, the elongation reaches up to 993%. However, the elongation using Max m SPD method at 850℃ is 1353%. It is shown that the material can achieve better superplasticity by using Max m SPD tensile compared to constant stain rate tensile under the same temperature. The superplastic deformation of TC6 alloy can enhance the dynamic recrystallization behavior significantly, the dynamic recrystallization behavior is promoted when strain rate and temperature are increased.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

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

    DEFF Research Database (Denmark)

    Dahl, Søren; Logadottir, Ashildur; Egeberg, Rasmus

    1999-01-01

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

  12. New superconductors from granular to high T$_{c}$

    CERN Document Server

    Deutscher, Guy

    2006-01-01

    How new are the high Tc superconductors, as compared to the conventional low Tc ones? In what sense are these oxides different from regular metals in their normal state? How different is the mechanism for high Tc superconductivity from the well-known electron-phonon interaction that explains so well superconductivity in metals and alloys? What are the implications of the new features of the high Tc oxides for their practical applications? This book aims to give some answers to those questions, drawing particularly on similarities between the high Tc oxides and granular superconductors, which also present a maximum of their critical temperature near the metal-insulator transition.

  13. New superconductors from granular to high T$_{c}$

    CERN Document Server

    Deutscher, Guy

    2017-01-01

    How new are the high Tc superconductors, as compared to the conventional low Tc ones? In what sense are these oxides different from regular metals in their normal state? How different is the mechanism for high Tc superconductivity from the well-known electron-phonon interaction that explains so well superconductivity in metals and alloys? What are the implications of the new features of the high Tc oxides for their practical applications? This interesting book aims to provide some answers to those questions, drawing particularly on similarities between the high Tc oxides and granular superconductors, which also present a short coherence length, a small superfluid density and an inhomogeneous structure.

  14. RuBee and RFID A confidential summary,May 2009

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

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

  15. Synthesis and Crystal Structure of [ Cp* Ru(η6- C6H5B Ph3)

    Institute of Scientific and Technical Information of China (English)

    YIN Jun; GUAN Jin-Tao; YU Guang-Ao; LIU Sheng-Hua

    2005-01-01

    The title complex [Cp*Ru(η6-C6H5BPh3)] has been synthesized by the reaction of [Cp*Ru(H2O)(NBD)]BF4 with H2 and NaBPh4, and its crystal structure was determined by singlecrystal X-ray diffraction analysis. It crystallizes in triclinic, space group P(1) with a = 11.0610(10), b = 11.2317(10), c = 12.3633(11) (A), α = 81.419(2), β = 67.8370(10), γ = 88.370(2)°, V= 1405.9(2) (A)3,Z= 2, C34H35BRu, Mr= 555.50, Dc = 1.312 g/cm3, F(000) = 576 and μ(MoKa) = 0.577 mm-1. The final R and wR are 0.0559 and 0.1483, respectively for 4365 observed reflections with I > 2σ(Ⅰ). In the title complex, the four phenyl rings bonded to the B atom are deposited in a tetrahedral geometry,and one of the phenyl rings is η6-bonded to ruthenium.

  16. The half-life of the 1437 keV 11/2 sup - state in sup 97 Mo

    Energy Technology Data Exchange (ETDEWEB)

    Kostova, L.G.; Andrejtscheff, W.; Kostov, L.K. (Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. za Yadrena Izsledvaniya i Yadrena Energetika); Funke, L.; Will, E. (Zentralinstitut fuer Kernforschung, Rossendorf (Germany)); Vdovin, A.I. (Joint Inst. for Nuclear Research, Dubna (Russia))

    1992-05-01

    Using the ({alpha}, n) reaction, the half-life of the first 11/2{sup -} level in {sup 97}Mo has been determined as T{sub 1/2}(1437.0 keV)=2.5{+-}0.3 ns by means of the pulsed beam method. The experimentally obtained B(M2) value between the h{sub 11/2} and g{sub 7/2} configurations in {sup 97}Mo has been satisfactorily described within the quasiparticle-phonon model using g{sub s}{sup eff}=0.6 g{sub s}{sup free} c{sub s}. Similar calculations and comparisons with experimental data have been performed also for {sup 95,99}Mo as well as for {sup 99}Ru and {sup 101}Pd. (orig.).

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

    Directory of Open Access Journals (Sweden)

    Ning Gan

    2011-08-01

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

  18. Superconductivity in Potassium-Doped Metallic Polymorphs of MoS2.

    Science.gov (United States)

    Zhang, Renyan; Tsai, I-Ling; Chapman, James; Khestanova, Ekaterina; Waters, John; Grigorieva, Irina V

    2016-01-13

    Superconducting layered transition metal dichalcogenides (TMDs) stand out among other superconductors due to the tunable nature of the superconducting transition, coexistence with other collective electronic excitations (charge density waves), and strong intrinsic spin-orbit coupling. Molybdenum disulfide (MoS2) is the most studied representative of this family of materials, especially since the recent demonstration of the possibility to tune its critical temperature, Tc, by electric-field doping. However, just one of its polymorphs, band-insulator 2H-MoS2, has so far been explored for its potential to host superconductivity. We have investigated the possibility to induce superconductivity in metallic polytypes, 1T- and 1T'-MoS2, by potassium (K) intercalation. We demonstrate that at doping levels significantly higher than that required to induce superconductivity in 2H-MoS2, both 1T and 1T' phases become superconducting with Tc = 2.8 and 4.6 K, respectively. Unusually, K intercalation in this case is responsible both for the structural and superconducting phase transitions. By adding new members to the family of superconducting TMDs, our findings open the way to further manipulate and enhance the electronic properties of these technologically important materials.

  19. The Nanostructuring of Atomically Flat Ru(0001) upon Oxidation and Reduction

    Science.gov (United States)

    Goriachko, A.; Over, H.

    2016-12-01

    The O/Ru(0001) system is widely studied due to its rich phase variety of various stoichiometry and atomic arrangements, including the formation of a RuO2/Ru(0001) oxide layer. Apart from homogeneous ruthenium surfaces in certain oxidation states, also strongly heterogeneous surfaces can exist due to oxidation state's variation at the nanoscale. We report on a scanning tunneling microscopy (STM) study of the nanostructuring of the oxidized Ru(0001) surface as a result of its interaction with molecular oxygen at elevated temperatures and subsequent reduction of a resulting RuO2 film by CO or HCl molecules from the gas phase in high-vacuum environment.

  20. STUDY ON POLYMER- Ru- Co BIMETALLIC COMPLEXES CATALYSTS Ⅱ. X-RAY PHOTOELECTRON SPECTROSCOPIC ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    ZONG Huijuan; TANG Qi; CHEN Zonghan; JIANG Yingyan

    1991-01-01

    Polymer-Ru-Co bimetallic complexes have been examined by X-ray photoelectron spectroscopy.The catalyst is highly active only when the mole ratio of Co/Ru is 4:3. The activity of catalysts does not depend on the total Co/Ru ratio, but on the surface stoichiometry of Co and Ru. When the relative intensities of Co2p and Ru3d of XP S peaks are close to each other and both are high, the catalyst exhibits its maximum activity.The mechanism of catalytic hydroformylation has been discussed.

  1. Väike Hüüru ja suur Laagri

    Index Scriptorium Estoniae

    Nirk, Lia

    2016-01-01

    Laagri keskuses asuva Saue vallaraamatukogu ning Hüüru külaseltsi vahel sõlmiti 2014. a. raamleping, mille alusel vallaraamatukogu maksab külaseltsile raamatukoguteenuse osutamise eest ja raamatukoguhoidjaks on MTÜ palgatud kultuuritöötaja

  2. Registration of 'RU9101001'/'Katy' recombinant inbred lines of rice

    Science.gov (United States)

    The cross of RU9101001/'Katy' rice (Oryza sativa L.) was used to develop a mapping population consisting of 238 F9 generation recombinant inbred lines of rice (Oryza sativa L.) (GSOR100361 to GSOR100600). This population has been used to map major genes that provide resistance to the rice blast pat...

  3. Photoacoustic characterization of n-RuSe2 semiconductor pellets

    Science.gov (United States)

    Bernal-Alvarado, J.; Vargas-Luna, M.; Solorza-Feria, O.; Mondragón, R.; Alonso-Vante, N.

    2000-09-01

    Using the open photoacoustic cell technique, a set of physical properties for a semiconductor (n-RuSe2) in powder form was measured. According to the Dramicanin theoretical model, charge carriers transport parameters (bulk and surface) and the effective thermal diffusivity were obtained.

  4. Hydrogen mediated transport of Sn to Ru film surface

    NARCIS (Netherlands)

    Faradzhev, N.; Sidorkin, V.

    2009-01-01

    The authors report on the interaction of atomic hydrogen with Sn and thin Ru film at room temperature. The study is done using a combination of photoelectron and low energy ion scattering spectroscopies as well as scanning electron microscopy. The adsorption of hydrogen on a Sn surface leads to the

  5. Hydrogen mediated transport of Sn to Ru film surface

    NARCIS (Netherlands)

    Faradzhev, N.; Sidorkin, V.

    2009-01-01

    The authors report on the interaction of atomic hydrogen with Sn and thin Ru film at room temperature. The study is done using a combination of photoelectron and low energy ion scattering spectroscopies as well as scanning electron microscopy. The adsorption of hydrogen on a Sn surface leads to the

  6. Dissociation of CH4 on Ni(111) and Ru(0001)

    DEFF Research Database (Denmark)

    Egeberg, Rasmus; Ullmann, S.; Alstrup, I.;

    2002-01-01

    the steps were passivated with Au. On Ni(111) sputtering the surface at 500 K with no subsequent annealing increased the initial sticking but at higher coverages this effect vanished. We interpret these results as due to the steps on both surfaces being blocked by carbon species leaving them inaccessible...... to impinging CH4 molecules. We conclude that in these types of experiments steps play a minor role for CH4 dissociation on Ru(0 0 0 1) and Ni(l 1 1). In a temperature programmed oxidation reaction we observe that carbon from the steps of Ru(0 0 0 1) leaves the surface at lower temperatures than carbon from...... the terraces, Finally we have observed a large promotion of the sticking probability of CH4 on Ru(0 0 0 1) by increasing the surface temperature at a fixed gas temperature thus lending support to a mechanism where the dissociation of methane takes place over Ru atoms displaced normal to the surface....

  7. Chemical fingerprinting of algaenans using RuO4 degradation

    NARCIS (Netherlands)

    Blokker, P.; Ende, H. van den; Leeuw, J.W. de; Versteegh, G.J.M.; Sinninghe Damsté, J.S.

    2006-01-01

    The freshwater green microalgae, Oocystus solitaria Wittrock f. maior Wille, Pediastrum braunii Wartmann, Pediastrum kawraiskyi Schmidle, Sorastrum spinulosum Na¨geli and Coelastrum reticulatum (Dangeard) Senn were investigated with respect to the presence of algaenan and the corresponding RuO4 chem

  8. Photoinduced energy- and electron-transfer processes in dinuclear Ru(II)-Os(II), Ru(II)-Os(III), and Ru(III)-Os(II) trisbipyridine complexes containing a shape-persistent macrocyclic spacer.

    Science.gov (United States)

    Venturi, Margherita; Marchioni, Filippo; Ferrer Ribera, Belén; Balzani, Vincenzo; Opris, Dorina M; Schlüter, A Dieter

    2006-01-16

    The PF6- salt of the dinuclear [(bpy)2Ru(1)Os(bpy)2]4+ complex, where 1 is a phenylacetylene macrocycle which incorporates two 2,2'-bipyridine (bpy) chelating units in opposite sites of its shape-persistent structure, was prepared. In acetonitrile solution, the Ru- and Os-based units display their characteristic absorption spectra and electrochemical properties as in the parent homodinuclear compounds. The luminescence spectrum, however, shows that the emission band of the Ru(II) unit is almost completely quenched with concomitant sensitization of the emission of the Os(II) unit. Electronic energy transfer from the Ru(II) to the Os(II) unit takes place by two distinct processes (k(en) = 2.0x10(8) and 2.2x10(7) s(-1) at 298 K). Oxidation of the Os(II) unit of [(bpy)2Ru(1)Os(bpy)2]4+ by Ce(IV) or nitric acid leads quantitatively to the [(bpy)2Ru(II)(1)Os(III)(bpy)2]5+ complex which exhibits a bpy-to-Os(III) charge-transfer band at 720 nm (epsilon(max) = 250 M(-1) cm(-1)). Light excitation of the Ru(II) unit of [(bpy)2Ru(II)(1)Os(III)(bpy)2]5+ is followed by electron transfer from the Ru(II) to the Os(III) unit (k(el,f) = 1.6x10(8) and 2.7x10(7) s(-1)), resulting in the transient formation of the [(bpy)2Ru(III)(1)Os(II)(bpy)2]5+ complex. The latter species relaxes to the [(bpy)2Ru(II)(1)Os(III)(bpy)2]5+ one by back electron transfer (k(el,b) = 9.1x10(7) and 1.2x10(7) s(-1)). The biexponential decays of the [(bpy)2*Ru(II)(1)Os(II)(bpy)2]4+, [(bpy)2*Ru(II)(1)Os(III)(bpy)2]5+, and [(bpy)2Ru(III)(1)Os(II)(bpy)2]5+ species are related to the presence of two conformers, as expected because of the steric hindrance between hydrogen atoms of the pyridine and phenyl rings. Comparison of the results obtained with those previously reported for other Ru-Os polypyridine complexes shows that the macrocyclic ligand 1 is a relatively poor conducting bridge.

  9. Microstructure and phase transformation behavior of Mo-MoSi2 gradient material

    Institute of Scientific and Technical Information of China (English)

    Ying-Yi Zhang; Yun-Gang Li; Yong-Hong Qi; Xue-Feng Shi

    2015-01-01

    Mo-MoSi2 gradient coating on Mo substrate was prepared by siliconizing process,using the polysilicon as silicon atoms.The gradient layer was analyzed by the experimental results,theoretical analysis,and thermodynamic calculation.The silicon,molybdenum content of gradient coating shows a gradual change regulation.The reaction between silicon and molybdenum is most likely to generate Mo5Si3,then MoSi2,finally Mo3Si,but when the silicon content is excessive,the Mo5Si3 and Mo3Si will react with silicon and generate MoSi2.The gradient layer is mainly constituted by Si and MoSi2,only about 1/10 gradient layer is constituted by Mo5Si3 and Mo3Si,and the stable existences of Mo5Si3 and Mo3Si are mainly determined by the silicon content.Along the Mo substrate to the surface of the coating,the phase compo sition of gradient coating changes as follows:Mo → transition layer,Mo (main phase) + Mo3Si + Mo5Si3 →intermediate layer,and MoSi2 (main phase)+ Mo5Si3 + Si → surface layer MoSi2 (main phase)+ Si,and the experimental temperature has no effect on phase composition of gradient coating.

  10. Evidence for conventional superconducting behavior in noncentrosymmetric Mo3Al2C

    Science.gov (United States)

    Bonalde, I.; Kim, H.; Prozorov, R.; Rojas, C.; Rogl, P.; Bauer, E.

    2011-10-01

    We report on measurements of the magnetic penetration depth of polycrystalline samples of nonmagnetic Mo3Al2C (Tc=9 K) without inversion symmetry. Two previous specific-heat measurements in this compound found different anomalous peaks in the low-temperature limit. One of these peaks was attributed to the superconducting transition at 3 K of the impurity phase Mo2C. We argue here that the second anomalous peak may be caused by the superconducting transition of SiC:Al at 1.45 K, another impurity phase possibly present in Mo3Al2C samples. The temperature-independent behavior of the penetration depth observed below 0.5 K is taken as firm evidence for the presence of a nodeless superconducting gap in Mo3Al2C. Numerical calculations using the BCS expression for the penetration depth give qualitative support for an isotropic energy gap in Mo3Al2C. The present results suggest that Mo3Al2C is a conventional s-wave superconductor, although two-gap or anisotropic-gap superconductivity cannot be ruled out.

  11. Spectroscopic, Electrochemical and Computational Characterisation of Ru Species Involved in Catalytic Water Oxidation: Evidence for a [RuV(O)(Py2Metacn)] Intermediate

    OpenAIRE

    Casadevall, Carla; Codolà Duch, Zoel; Costas Salgueiro, Miquel; Lloret Fillol, Julio

    2016-01-01

    A new family of ruthenium complexes based on the N-pentadentate ligand Py2Metacn (N-methyl-N′,N′′-bis(2-picolyl)-1,4,7-triazacyclononane) has been synthesised and its catalytic activity has been studied in the water-oxidation (WO) reaction. We have used chemical oxidants (ceric ammonium nitrate and NaIO4) to generate the WO intermediates [RuII(OH2)(Py2Metacn)]2+, [RuIII(OH2)(Py2Metacn)]3+, [RuIII(OH)(Py2Metacn)]2+ and [RuIV(O)(Py2Metacn)]2+, which have been characterised spectroscopically. Th...

  12. 24Na and 99mTc Tracers Applied to the Characterization of Liquid-Solid Fluidized Bed and Hydraulic Transport Reactors

    OpenAIRE

    Fauquex, P.-F.; Flaschel, E.; Do, H. P.; Friedli, C.; Lerch, P.; Renken, A.

    1983-01-01

    For the characterization of fluidized bed- and hydraulic transport reactors, two radiotracer techniques have been developed permitting the study of mixing phenomena in flowing liquids as well as in beds of fluidized particulate solids. For labelling the aqueous phase, a 99mTc containing solution obtained by means of a 99Mo isotopic generator has been used. The silica gel employed for fluidization has been activated by thermal neutrons to yield a 24Na tracer derived from its natural sodium con...

  13. Mechanism of -O-O- bond activation and catalysis by RuIII-pac complexes (pac = polyaminocarboxylate)

    Indian Academy of Sciences (India)

    Debabrata Chatterjee

    2012-11-01

    This paper presents the mechanistic aspects of the -O-O- bond activation by the Ru-pac (pac = polyaminocarboxylate) complex leading to the formation of various catalytic active species, viz. [RuIII(pac)(OOH)]2−, [RuIV(pac)(OH)]− and [RuV(pac)(O)]−, and their reactivity towards oxidation of a few organic compounds.

  14. Mechanism of RuO2 crystallization in borosilicate glass: an original in situ ESEM approach.

    Science.gov (United States)

    Boucetta, Hassiba; Podor, Renaud; Stievano, Lorenzo; Ravaux, Johann; Carrier, Xavier; Casale, Sandra; Gossé, Stéphane; Monteiro, Amélie; Schuller, Sophie

    2012-03-19

    Ruthenium, a fission product arising from the reprocessing of spent uranium oxide (UOX) fuel, crystallizes in the form of acicular RuO(2) particles in high-level waste containment glass matrices. These particles are responsible for significant modifications in the physicochemical behavior of the glass in the liquid state, and their formation mechanisms are a subject of investigation. The chemical reactions responsible for the crystallization of RuO(2) particles with acicular or polyhedral shape in simplified radioactive waste containment glass are described. In situ high-temperature environmental scanning electron microscopy (ESEM) is used to follow changes in morphology and composition of the ruthenium compounds formed by reactions at high temperature between a simplified RuO(2)-NaNO(3) precursor and a sodium borosilicate glass (SiO(2)-B(2)O(3)-Na(2)O). The key parameter in the formation of acicular or polyhedral RuO(2) crystals is the chemistry of the ruthenium compound under oxidized conditions (Ru(IV), Ru(V)). The precipitation of needle-shaped RuO(2) crystals in the melt might be associated with the formation of an intermediate Ru compound (Na(3)Ru(V)O(4)) before dissolution in the melt, allowing Ru concentration gradients. The formation of polyhedral crystals is the result of the direct incorporation of RuO(2) crystals in the melt followed by an Ostwald ripening mechanism.

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

    KAUST Repository

    Liu, Xin

    2012-01-01

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

  16. Electronic structures and vibrational properties of coronene on Ru(0001): first-principles study

    Institute of Scientific and Technical Information of China (English)

    Zhang Yu-Yang; Du Shi-Xuan; Gao Hong-Jun

    2012-01-01

    We calculate the configurations,electronic structures,vibrational properties at the coronene/Ru(0001) interface,and adsorption of a single Pt atom on coronene/Ru(0001) based on density functional theory calculations.The geometric structures and electronic structures of the coronene on Ru(0001) are compared with those of the graphene/Ru(0001).The results show that the coronene/Ru(0001) can be a simplified model system used to describe the interaction between graphene and ruthenium.Further calculations of the vibrational properties of coronene molecule adsorbed on Ru(0001)suggest that the phonon properties of differently corrugated regions of graphene on Ru(0001) are different.This model system is also used to investigate the selective adsorption of Pt atoms on graphene/Ru(0001).The configurations of Pt on coronene/Ru(0001) with the lowest binding energy give clues to explain the experimental observation that a Pt cluster selectively adsorbs on the second highest regions of graphene/Ru(0001).This work provides a simple model for understanding the adsorption properties and vibrational properties of graphene on Ru(0001) substrate.

  17. Bifunctional MoO3-WO3/Ag/MoO3-WO3 Films for Efficient ITO-Free Electrochromic Devices.

    Science.gov (United States)

    Dong, Wenjie; Lv, Ying; Xiao, Lili; Fan, Yi; Zhang, Nan; Liu, Xingyuan

    2016-12-14

    Dielectric-metal-dielectric (DMD) trilayer films, served as both electrochromic (EC) film and transparent conductor (TC), have exhibited great potential application in low-cost, ITO-free electrochromic devices (ECDs). However, recent reports on the DMD-based ECDs revealed that the response time and the optical modulation properties were not very satisfactory. Here, the mixed MoO3-WO3 materials were first introduced as the dielectric layer to construct an EC-TC bifunctional MoO3-WO3/Ag/MoO3-WO3 (MWAMW) film, which demonstrates strong and broad-band optical modulation in the visible light region, fast color-switching time (2.7 s for coloration and 4.1 s for bleaching), along with high coloration efficiency (70 cm(2) C(-1)). The electrical structure and electrochemical reaction kinetics analysis revealed that the improved EC performances are associated with the increased electron intervalence transition together with the fast charge-transfer and ion-diffusion dynamics.

  18. Atomic layer deposition of Ru from CpRu(CO)(2)Et using O-2 gas and O-2 plasma

    NARCIS (Netherlands)

    Leick, N.; Verkuijlen, R. O. F.; Lamagna, L.; Langereis, E.; Rushworth, S.; Roozeboom, F.; M. C. M. van de Sanden,; Kessels, W. M. M.

    2011-01-01

    The metalorganic precursor cyclopentadienylethyl(dicarbonyl)ruthenium (CpRu(CO)(2)Et) was used to develop an atomic layer deposition (ALD) process for ruthenium. O-2 gas and O-2 plasma were employed as reactants. For both processes, thermal and plasma-assisted ALD, a relatively high growth-per-cycle

  19. Laser-Induced Fluorescence Spectroscopy of Two Ruthenium-Bearing Molecules: RuF and RuCl

    Science.gov (United States)

    Zarringhalam, Hanif; Adam, Allan G.; Linton, Colan; Tokaryk, Dennis W.

    2017-06-01

    This work extends the electronic spectroscopy of RuF, and reports on what we believe is the first observation of RuCl. Both molecules have been created in a laser-ablation molecular beam apparatus at UNB, and their spectra have been detected by laser-induced fluorescence. In the low-resolution survey of RuF from 400 to 770 nm, five bands were detected in the blue, green and infrared regions of the electromagnetic spectrum. Four of them were rotationally analyzed from high-resolution data. The three bands in the green region are associated with the ^4Γ_{11/2}-X^4Φ_{9/2} system first observed by Steimle et al. A new ^4Δ_{7/2}-X^4Φ_{9/2} transition in the blue region was also detected. Two high-resolution bands of RuCl were rotationally analyzed, and the ground state was also found to be X^4Φ_{9/2}. The data provide detailed structural information about the molecules, such as bond lengths, vibrational frequencies, isotopic structure, spin-orbit interactions and hyperfine interactions. T. C. Steimle, W. Virgo and T. Ma, J. Chem. Phys. 124 024309 (2006).

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

    CSIR Research Space (South Africa)

    Modibedi, M

    2009-06-01

    Full Text Available Pt-Ru-P was prepared by the chemical reduction method using sodium hypophoshite as a reducing agent on Vulcan XC 72 and multi-walled carbon nano-tubes (MWCNTs). Sodium citrate was added as the stabilizer during electro-catalyst preparation...

  1. Structural investigations in BaFe(2-x)Ru(x)As2 as a function of Ru and temperature.

    Science.gov (United States)

    Sharma, Shilpam; Bharathi, A; Vinod, K; Sundar, C S; Srihari, V; Sen, Smritijit; Ghosh, Haranath; Sinha, Anil K; Deb, S K

    2015-02-01

    We present the results of synchrotron X-ray diffraction (XRD) measurements on powdered single-crystal samples of BaFe(2-x)Ru(x)As2, as a function of Ru content, and as a function of temperature, across the spin-density wave transition in BaFe(1.9)Ru(0.1)As2. The Rietveld refinements reveal that with Ru substitution, while the a-axis increases, the c-axis decreases. In addition, the variation of positional coordinates of As (z(As)), the Fe-As bond length and the As-Fe-As bond angles have also been determined. In the sample with x = 0.1, temperature-dependent XRD measurements indicate that the orthorhombicity shows the characteristic increase with a decrease in temperature, below the magnetic transition. It is seen that the c-axis, the As-Fe-As bond angles, Fe-As bond length and positional coordinates of the As show definite anomalies close to the structural transition. The observed anomalies in structural parameters are analysed in conjunction with restricted geometric optimization of the structure using ab initio electronic structure calculations.

  2. Automated direct assay system for RU38486, an antiprogesterone-antiglucocorticoid agent, and its metabolites using high performance liquid chromatography.

    Directory of Open Access Journals (Sweden)

    Nagoshi,Kazusuke

    1991-04-01

    Full Text Available An automated direct assay system using high performance liquid chromatography was developed for the measurement of RU38486 and its three metabolites (RU42698, RU42848, RU42633 in human serum. Serum concentrations of these compounds were measured up to 144 h following single oral administration of 200 (200 mg group, n = 3 or 400 mg (400 mg group, n = 3 of RU38486 to healthy female volunteers. The serum half-lives (200 mg group-400 mg group of RU38486, RU42698, RU42848 and RU42633 were 31.8-33.1 h, 41.2-39.3 h, 33.9-36.6 h and 29.2-36.6 h, respectively. Our system could quantify them easily and simultaneously, and was considered to be valuable in studies on the relationship between the pharmacokinetics and the clinical effects of RU38486.

  3. Influence of Ti(4+) on the electrochemical performance of Li-rich layered oxides - high power and long cycle life of Li2Ru1-xTixO3 cathodes.

    Science.gov (United States)

    Kalathil, Abdul Kareem; Arunkumar, Paulraj; Kim, Da Hye; Lee, Jong-Won; Im, Won Bin

    2015-04-01

    Li-rich layered oxides are the most attractive cathodes for lithium-ion batteries due to their high capacity (>250 mAh g(-1)). However, their application in electric vehicles is hampered by low power density and poor cycle life. To address these, layered Li2Ru0.75Ti0.25O3 (LRTO) was synthesized and the influence of electroinactive Ti(4+) on the electrochemical performance of Li2RuO3 was investigated. LRTO exhibited a reversible capacity of 240 mAh g(-1) under 14.3 mA g(-1) with 0.11 mol of Li loss after 100 cycles compared to 0.22 mol of Li for Li2Ru0.75Sn0.25O3. More Li(+) can be extracted from LRTO (0.96 mol of Li) even after 250 cycles at 143 mA g(-1) than Li2RuO3 (0.79 mol of Li). High reversible Li extraction and long cycle life were attributed to structural stability of the LiM2 layer in the presence of Ti(4+), facilitating the lithium diffusion kinetics. The versatility of the Li2MO3 structure may initiate exploration of Ti-based Li-rich layered oxides for vehicular applications.

  4. Retention of 99mTc-DMSA(III) and 99mTc-nanocolloid in different syringes affects imaging quality.

    Science.gov (United States)

    Bauwens, Matthias; Pooters, Ivo; van der Pol, Jochen; Mottaghy, Felix M; van Kroonenburgh, Marinus

    2014-04-01

    (99m)Tc-dimercaptosuccinic acid [DMSA(III)] and colloidal human serum albumin ((99m)Tc-nanocolloid) are widely used radiopharmaceuticals. Recently, in our institution we encountered image quality problems in DMSA scans after changing the brand of syringes we were using, which triggered us to look into the adsorption properties of syringes from different brands for (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid. We also describe a clinical case in which adsorption of (99m)Tc-DMSA(III) caused inferior imaging quality. DMSA and nanocolloid were labeled with (99m)Tc following manufacturer guidelines. After synthesis, syringes with (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid were stored for 15, 30, 60, and 120 min. We evaluated Luer Lock syringes manufactured by different brands such as Artsana, Henke-Sass-Wolf, B. Braun Medical N.V., CODAN Medizinische Geräte GmbH & Co KG, Becton Dickinson and Company, and Terumo Europe. Adsorption of (99m)Tc-DMSA(III) and (99m)Tc-nanocolloid was acceptably low for all syringes (image quality--for example, in DMSA scans using pediatric radiopharmaceutical doses. It is advised to check the compatibility of any radiopharmaceutical with syringes as an integral part of the quality assurance program.

  5. Fabrication of MgFe2O4/MoS2 Heterostructure Nanowires for Photoelectrochemical Catalysis.

    Science.gov (United States)

    Fan, Weiqiang; Li, Meng; Bai, Hongye; Xu, Dongbo; Chen, Chao; Li, Chunfa; Ge, Yilin; Shi, Weidong

    2016-02-16

    A novel one-dimensional MgFe2O4/MoS2 heterostructure has been successfully designed and fabricated. The bare MgFe2O4 was obtained as uniform nanowires through electrospinning, and MoS2 thin film appeared on the surface of MgFe2O4 after further chemical vapor deposition. The structure of the MgFe2O4/MoS2 heterostructure was systematic investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectrometry (XPS), and Raman spectra. According to electrochemical impedance spectroscopy (EIS) results, the MgFe2O4/MoS2 heterostructure showed a lower charge-transfer resistance compared with bare MgFe2O4, which indicated that the MoS2 played an important role in the enhancement of electron/hole mobility. MgFe2O4/MoS2 heterostructure can efficiently degrade tetracycline (TC), since the superoxide free-radical can be produced by sample under illumination due to the active species trapping and electron spin resonance (ESR) measurement, and the optimal photoelectrochemical degradation rate of TC can be achieved up to 92% (radiation intensity: 47 mW/cm(2), 2 h). Taking account of its unique semiconductor band gap structure, MgFe2O4/MoS2 can also be used as an photoelectrochemical anode for hydrogen production by water splitting, and the hydrogen production rate of MgFe2O4/MoS2 was 5.8 mmol/h·m(2) (radiation intensity: 47 mW/cm(2)), which is about 1.7 times that of MgFe2O4.

  6. sup 99m Tc renal tubular function agents: Current status

    Energy Technology Data Exchange (ETDEWEB)

    Eshima, D.; Fritzberg, A.R.; Taylor, A. Jr. (Emory Univ. School of Medicine, Atlanta, GA (USA))

    1990-01-01

    Orthoiodohippuric (OIH) acid labeled with 131I is a widely used renal radiopharmaceutical agent and has been the standard radiopharmaceutical agent for the measurement of effective renal plasma flow (EPRF). Limitations to the routine clinical use of 131I OIH are related to the suboptimal imaging properties of the 131I radionuclide and its relatively high radiation dose. 123I has been substituted for 131I; however, its high cost and short shelf-life have limited its widespread use. Recent work has centered on the development of a new 99mTc renal tubular function agent, which would use the optimal radionuclidic properties and availability of 99mTc and combine the clinical information provided by OIH. The search for a suitable 99mTc renal tubular function agent has focused on the diamide dithiolate (N2S2), the paraaminohippuric iminodiacetic acid (PAHIDA), and the triamide mercaptide (N3S) donor ligand systems. To date, the most promising 99mTc tubular function agent is the N3S complex: 99mTc mercaptoacetyltriglycine (99mTc MAG3). Studies in animal models in diuresis, dehydration, acid or base imbalance, ischemia, and renal artery stenosis demonstrate that 99mTc MAG3 behaves similarly to 131I OIH. A simple kit formulation is available that yields the 99mTc MAG3 complex in high radiochemical purity. Studies in normal subjects and patients indicate that 99mTc MAG3 is an excellent 99mTc renal tubular agent, but its plasma clearance is only 50% to 60% that of OIH. In an effort to develop an improved 99mTc renal tubular function agent, changes have been made in the core N3S donor ligand system, but to date no agent has been synthesized that is clinically superior to 99mTc MAG3. 61 references.

  7. Magnetic properties of Ce-Nd-Fe-Mo alloys and their nitrides

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, C; Pinkerton, FE

    2014-11-01

    New quaternary alloys of Ce-1 xNdxFe12 Mo-y(y) with x=0, 0.2, 0.4, 0.6, 0.8, 1 and y=0, 1.5, 2 have been prepared and magnetically hardened by melt spinning. X-ray diffraction indicates that the as-spun materials exhibit the tetragonal ThMn12-type structure. Prior to nitriding, the coercivity H-ci is less than 0.6 kOe in all alloys and is independent of Nd content, while the magnetization 4 pi M-19 (measured in an applied held of 19 kOe) and Curie temperature T-c increase with added Nd content x. The effects of nitriding pressure P, time t, and temperature TOR magnetic properties have been carefully evaluated on NdFe10Mo2 in order to identify the optimal nitriding parameters. The optimized nitriding profile was subsequently adopted to nitride the remaining samples. After nitrogenation, T-c and 4 pi M-19 have been substantially enhanced primarily due to the increased Fe-Fe exchange from nitrogen induced lattice dilation. Benefitting from the positive contribution from Nd, H-ci has been greatly improved in the Nd containing samples. As a result, Ce0.2Nd0.8Fe10Mo2 nitride features H-ci=2.9 kOe and (BH)(max) = 1.6 MGOe and Ce0.2Nd0.8Fe10.5Mo1.5 nitride demonstrates H-ci=2.5 kOe, (BH)(max) = 1.5 MGOe at room temperature, and T-c=337 degrees C. which are substantial advancements compared to the pure Ce based ThMn12-type materials previously reported. (C) 2014 Published by Elsevier B.V.

  8. Effect of Mo content on thermal and mechanical properties of Mo–Ru–Rh–Pd alloys

    Energy Technology Data Exchange (ETDEWEB)

    Masahira, Yusuke [Division of Sustainable Energy and Environment Engineering, Graduate School of Engineering, Osaka University (Japan); Ohishi, Yuji, E-mail: ohishi@see.eng.osaka-u.ac.jp [Division of Sustainable Energy and Environment Engineering, Graduate School of Engineering, Osaka University (Japan); Kurosaki, Ken; Muta, Hiroaki [Division of Sustainable Energy and Environment Engineering, Graduate School of Engineering, Osaka University (Japan); Yamanaka, Shinsuke [Division of Sustainable Energy and Environment Engineering, Graduate School of Engineering, Osaka University (Japan); Research Institute of Nuclear Engineering, University of Fukui (Japan); Komamine, Satoshi; Fukui, Toshiki; Ochi, Eiji [Japan Nuclear Fuel Limited (Japan)

    2015-01-15

    Metallic inclusions are precipitated in irradiated oxide fuels. The composition of the phases varies with the burnup and the conditions such as temperature gradients and oxygen potential of the fuel. In the present work, Mo{sub x/(0.7+x)} (Ru{sub 0.5}Rh{sub 0.1}Pd{sub 0.1}){sub (0.7)/(0.7+x)} (x = 0, 0.05, 0.1, 0.15, 0.2, and 0.25) alloys were prepared by arc melting, followed by annealing in a high vacuum. The thermal and mechanical properties of the alloys such as elastic moduli, Debye temperature, micro-Vickers hardness, electrical resistivity, and thermal conductivity have been evaluated to elucidate the effect of Mo content on these physical properties of the alloys. The alloys with lower Mo contents show higher thermal conductivity. The thermal conductivity of the alloy with x = 0 is almost twice of that of the alloy with x = 0.25. The thermal conductivities of the alloys are dominated by electronic contribution, which has been evaluated using the Wiedemann–Franz–Lorenz relation from the electrical resistivity data. It is confirmed that the variation of the Mo contents of the alloys considerably affects the mechanical and thermal properties of the alloys.

  9. Crystal Structures, Stabilities, Electronic Properties, and Hardness of MoB2: First-Principles Calculations.

    Science.gov (United States)

    Ding, Li-Ping; Shao, Peng; Zhang, Fang-Hui; Lu, Cheng; Ding, Lei; Ning, Shu Ya; Huang, Xiao Fen

    2016-07-18

    On the basis of the first-principles techniques, we perform the structure prediction for MoB2. Accordingly, a new ground-state crystal structure WB2 (P63/mmc, 2 fu/cell) is uncovered. The experimental synthesized rhombohedral R3̅m and hexagonal AlB2, as well as theoretical predicted RuB2 structures, are no longer the most favorite structures. By analyzing the elastic constants, formation enthalpies, and phonon dispersion, we find that the WB2 phase is thermodynamically and mechanically stable. The high bulk modulus B, shear modulus G, low Poisson's ratio ν, and small B/G ratio are benefit to its low compressibility. When the pressure is 10 GPa, a phase transition is observed between the WB2-MoB2 and the rhombohedral R3̅m MoB2 phases. By analyzing the density of states and electron density, we find that the strong covalent is formed in MoB2 compounds, which contributes a great deal to its low compressibility. Furthermore, the low compressibility is also correlated with the local buckled structure.

  10. Synthesis of the d,I-HM-PAO and formulation of nucleo-equipment for the obtention of {sup 99m} Tc-(d,I)-HM-PAO; Sintesis del d,I-HM-PAO y formulacion de nucleo-equipos para la obtencion de {sup 99m} Tc-(d,I)-HM-PAO

    Energy Technology Data Exchange (ETDEWEB)

    Lezama C, J.; Ferro F, G.; Alcazar A, P

    1991-09-15

    Most brain imaging radiopharmaceuticals are conventional hydrophilic compounds that are excluded from entering the normal brain by an intact blood-brain barrier (BBB). Under pathologic conditions, the barrier is disrupted and radiotracer concentrates in the leisure for positive identification. {sup 99m} Tc- hexa methyl propylene amine oxime ({sup 99} {sup m} Tc-HM-PAO) is a newer-type lipophilic agent that enter the normal brain through an intact BBB. Studies with this agent offer the promise of measuring cerebral perfusion in the normal and diseased brain. In this paper we present the synthesis and Tc-99m labelling of d,I-HM-PAO. The synthesis of the ligand was carried out by condensation of two molecular equivalents of butanedione monoxime with one molecular equivalent of 1,3 propanediamine provided a bis imine intermediate, which was reduced with sodium borohydride to get the meso and d,I diastereoisomers of HM-PAO. Separation of these was achieved by fractional crystallization. {sup 99m} Tc-(d,I)HM-PAO was obtained by stannous ion reduction of Mo-99/Tc-99m generator eluate in the presence of the ligand. Complex radiochemical purity was determined by instant thin layer chromatography and paper chromatography. Finally, we obtained {sup 99m} Tc-(d,I)HM-PAO with a high radiochemical yield, in excess of 90%. However, for subsequent clinical studies the preparation has to be done a few minutes before application because our product has a low stability. (Author)

  11. Impeding 99Tc(IV) mobility in novel waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mal Soon; Um, Wooyong; Wang, Guohui; Kruger, Albert A.; Lukens, Wayne W.; Rousseau, Roger J.; Glezakou, Vassiliki Alexandra

    2016-06-30

    Technetium (99Tc) is a long-lived radioactive fission product whose mobility in the subsurface is largely governed by its oxidation state1. Immobilization of Tc in mineral substrates is crucial for radioactive waste management and environmental remediation. Tc(IV) incorporation in spinels2, 3 has been proposed as a novel method to increase Tc retention in glass waste forms. However, experiments with Tc-magnetite under high temperature and oxic conditions showed re-oxidation of Tc(IV) to volatile pertechnetate Tc(VII)O4-.4, 5 Here we address this problem with large-scale ab initio molecular dynamics simulations and propose that elevated temperatures, 1st row transition metal dopants can significantly enhance Tc retention in the order Co > Zn > Ni. Experiments with doped spinels at T=700 ºC provided quantitative confirmation of increased Tc retention in the same order predicted by theory. This work highlights the power of modern state-of-the-art simulations to provide essential insights and generate bottom-up design criteria of complex oxide materials at elevated temperatures.

  12. IEC TC104工作动态

    Institute of Scientific and Technical Information of China (English)

    陈洁

    2000-01-01

    @@1 IECTC104简介 IEC TC104是由原来的IEC TC50(环境试验技术委员会)和IEC TC75(环境条件的分类分级委员会)两个技术委员会于1997年6月合并组成的一个技术委员会,其全称为“环境条件、分类和试验方法技术委员会”。 IEC TC104的工作范围是:

  13. 99mTc-ciprofloxacin for diagnosis of bacterial infection

    Science.gov (United States)

    Aungurarat, A.; Ngamprayad, T.; Dangprasert, M.; Phumkem, S.; Jowanaridhi, B.

    2015-05-01

    Preparation of 99mTc-ciprofloxacin for diagnosis of bacterial infection was investigated by varying factors which affected this compound. The optimum conditions for preparation of 99mTc-ciprofloxacin and a lyophilized kit for Tc-99m labelling were studied. The results from biodistribution study showed that the percentages of the injected dose per gram tissues of infected area at 1 and 3 hours after injection were around 0.25-0.56. 99mTc-ciprofloxacin was found sterile, pyrogen-free and non-toxic. Radiochemical purity was greater than 90% with greater than 6 hours of stability.

  14. Direct {sup 99m}Tc labeling of Herceptin (trastuzumab) by {sup 99m}Tc(I) tricarbonyl ion

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.-J.; Yen, C.-L.; Lo, S.-T.; Chen, K.-T. [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lo, J.-M. [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China)], E-mail: jmlo@mx.nthu.edu.tw

    2008-03-15

    By simply incubating Herceptin (trastuzumab) with [{sup 99m}Tc(CO){sub 3}(OH{sub 2}){sub 3}]{sup +} ion in saline, a significant yield of {sup 99m}Tc-labeled trastuzumab was found to be achievable. The effective labeling may be based on that trastuzumab is inherent with endogenous histidine group to which {sup 99m}Tc(I) tricarbonyl ion can be strongly bound. For practical {sup 99m}Tc labeling processing, trastuzumab was purified beforehand from the commercial product, Herceptin (Genentech) via size exclusion chromatography to remove the excipient, {alpha}-histidine and a high-labeled yield could be obtained by incubating the purified trastuzumab with [{sup 99m}Tc(CO){sub 3}(OH{sub 2}){sub 3}]{sup +}. Retention of bioactivity of the {sup 99m}Tc(I)-labeled trastuzumab was validated using a cell binding test.

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

    Directory of Open Access Journals (Sweden)

    Yangchuan Xing

    2009-09-01

    Full Text Available Carbon nanotubes (CNTs have been investigated in recent years as a catalyst support for proton exchange membrane fuel cells. Improved catalyst activities were observed and attributed to metal-support interactions. We report a study on the kinetics of methanol electro-oxidation on CNT supported Pt-Ru alloy nanoparticles. Alloy catalysts with different compositions, Pt53Ru47/CNT, Pt69Ru31/CNT and Pt77Ru23/CNT, were prepared and investigated in detail. Experiments were conducted at various temperatures, electrode potentials, and methanol concentrations. It was found that the reaction order of methanol electro-oxidation on the PtRu/CNT catalysts was consistent with what has been reported for PtRu alloys with a value of 0.5 in methanol concentrations. However, the electro-oxidation reaction on the PtRu/CNT catalysts displayed much lower activation energies than that on the Pt-Ru alloy catalysts unsupported or supported on carbon black (PtRu/CB. This study provides an overall kinetic evaluation of the PtRu/CNT catalysts and further demonstrates the beneficial role of CNTs.

  16. Expanding the knowledge of the geographic distribution of Trypanosoma cruzi TcII and TcV/TcVI genotypes in the Brazilian Amazon.

    Science.gov (United States)

    Lima, Valdirene Dos Santos; Xavier, Samanta Cristina das Chagas; Maldonado, Irene Fabíola Roman; Roque, André Luiz Rodrigues; Vicente, Ana Carolina Paulo; Jansen, Ana Maria

    2014-01-01

    Trypanosoma cruzi infection is a complex sylvatic enzooty involving a wide range of animal species. Six discrete typing units (DTUs) of T. cruzi, named TcI to TcVI, are currently recognized. One unanswered question concerning the epidemiology of T. cruzi is the distribution pattern of TcII and hybrid DTUs in nature, including their virtual absence in the Brazilian Amazon, the current endemic area of Chagas disease in Brazil. Herein, we characterized biological samples that were collected in previous epizootiological studies carried out in the Amazon Basin in Brazil. We performed T. cruzi genotyping using four polymorphic genes to identify T. cruzi DTUs: mini-exon, 1f8, histone 3 and gp72. This analysis was conducted in the following biological samples: (i) two T. cruzi isolates obtained by culturing of stools from the triatomine species Rhodnius picttipes and (ii) five serum samples from dogs in which trypomastigotes were observed during fresh blood examination. We report for the first time the presence of TcII and hybrid DTUs (TcV/TcVI) in the Amazon region in mixed infections with TcI. Furthermore, sequencing of the constitutive gene, gp72, demonstrated diversity in TcII even within the same forest fragment. These data show that TcII is distributed in the five main Brazilian biomes and is likely more prevalent than currently described. It is very probable that there is no biological or ecological barrier to the transmission and establishment of any DTU in any biome in Brazil.

  17. Magnetic, electronic, high-spin polarization and half-metallic properties of Ru2VGe and Ru2VSb Heusler alloys: An FP-LAPW study

    Science.gov (United States)

    Gupta, Dinesh C.; Bhat, Idris H.

    2015-01-01

    Electronic and magnetic properties of Ru2VGe and Ru2VSb have been calculated using full potential linearized augmented plane wane method. The optimized equilibrium lattice constants in stable Fm-3m configuration were found to be 6.032 Å for Ru2VGe and 6.272 Å for Ru2VSb. Spin-resolved calculations show that V mainly contributes to the magnetic properties in these materials. The materials follow the Slater-Pauling rule and hence have integral magnetic moments which is due to 100% spin polarization at Fermi energy. The calculated total magnetic moments per unit cell were found to be 1.0 μB for Ru2VGe and 2.0 μB for Ru2VSb. Both the materials having ferromagnetic ground state, exhibit half-metallicity with an energy gap in the spin-down channel of 0.095 eV for Ru2VGe and 0.186 eV for Ru2VSb.

  18. Crystal structure of the Nd(Ru{sub 0.6}Ge{sub 0.4}){sub 2} and ErRuGe compounds

    Energy Technology Data Exchange (ETDEWEB)

    Rizzoli, C.; Sologub, O.; Salamakha, P

    2003-02-17

    Using X-ray powder and single crystal diffraction, the crystal structures of the Nd(Ru{sub 0.6}Ge{sub 0.4}){sub 2} and ErRuGe compounds were investigated. The compounds belong to the KHg{sub 2} and TiNiSi type structure, respectively.

  19. Indole cyanation via C-H bond activation under catalysis of Ru(Ⅲ)-exchanged NaY zeolite (RuY) as a recyclable catalyst

    Institute of Scientific and Technical Information of China (English)

    Alireza Khorshidi

    2012-01-01

    Selective 3-cyanation of indoles was achieved under heterogeneous catalysis of Ru(Ⅲ)-exchanged NaY zeolite (RuY) as a recyclable catalyst,in combination with K4[Fe(CN)6] as a nontoxic,slow cyanide releasing agent.Under the aforementioned conditions,good yields of the desired products were obtained.

  20. 99Tc Process Monitoring System In-Lab Performance Characterization

    Energy Technology Data Exchange (ETDEWEB)

    O' Hara, Matthew J.; Niver, Cynthia M.

    2014-01-01

    Executive Summary A 99Tc Process Monitoring (Tc-Mon) System has been designed and built for deployment at the recently constructed 200 West Pump & Treat (200W P&T) Plant in the 200 West Area ZP-1 Operable Unit of the Hanford Site. The plant is operated by CH2M Hill Plateau Remediation Company (CHPRC). The Tc-Mon system was created through collaboration between Pacific Northwest National Laboratory (PNNL) and Burge Environmental, Inc. The new system’s design has been optimized based on experience from an earlier field test (2011) of a prototype system at the 200W-ZP-1 Interim Pump & Treat Plant. A portion of the new 200W P&T Plant is dedicated to removal of 99Tc from contaminated groundwater in the 200 West Area. 99Tc, as the pertechnetate anion (99TcO4-), is remediated through delivery of water into two trains (Trains A and B) of three tandem extraction columns filled with Purolite A530E resin. The resin columns cannot be regenerated; therefore, once they have reached their maximum useful capacity, the columns must be disposed of as radioactive waste. The Tc-Mon system’s primary duty will be to periodically sample and analyze the effluents from each of the two primary extraction columns to determine 99Tc breakthrough. The Tc-Mon system will enable the CH2M Hill Plateau Remediation Company (CHPRC) to measure primary extraction column breakthrough on demand. In this manner, CHPRC will be able to utilize each extraction column to its maximum capacity. This will significantly reduce column disposal and replacement costs over the life of the plant. The Tc-Mon system was constructed by Burge Environmental, Inc. and was delivered to PNNL in June 2013 for setup and initial hardware and software performance testing in the 325 Building. By early July, PNNL had initiated an in-laboratory performance characterization study on the system. The objective was to fully calibrate the system and then evaluate the quality of the analytical outputs 1) against a series of clean

  1. Magnetotransport properties of Mo substituted La0.7Ca0.3Mn1-xMoxO3 perovskites

    Science.gov (United States)

    Chen, Jenq-Wei; Rao, G. Narsinga

    2016-03-01

    We studied the effects of Mo substitution on the structural, transport, and magnetic properties of the La0.7Ca0.3Mn1-xMoxO3 (x ≤ 0.1) samples. Powder X-ray diffraction analysis reveals that the samples studied crystallize in the orthorhombic structure with space group Pbnm. Both particle size and morphology change significantly as the Mo content x varies. The metal-insulator transition temperature (TMI) and Curie temperature (TC) decrease monotonically as x increases. Magnetization data reveal that long-range FM ordering persists in all samples and the saturation moment decreases linearly as x increases. The smaller depression rate of dTC/dx observed is mainly ascribed to the increased amount of Mn2+ ions with Mo doping, which opens the FM coupling between Mn2+-O-Mn3+ in the samples.

  2. High-Tc superconducting quantum interference device recordings of spontaneous brain activity: Towards high-Tc magnetoencephalography

    Science.gov (United States)

    Öisjöen, F.; Schneiderman, J. F.; Figueras, G. A.; Chukharkin, M. L.; Kalabukhov, A.; Hedström, A.; Elam, M.; Winkler, D.

    2012-03-01

    We have performed single- and two-channel high transition temperature (high-Tc) superconducting quantum interference device (SQUID) magnetoencephalography (MEG) recordings of spontaneous brain activity in two healthy human subjects. We demonstrate modulation of two well-known brain rhythms: the occipital alpha rhythm and the mu rhythm found in the motor cortex. We further show that despite higher noise-levels compared to their low-Tc counterparts, high-Tc SQUIDs can be used to detect and record physiologically relevant brain rhythms with comparable signal-to-noise ratios. These results indicate the utility of high-Tc technology in MEG recordings of a broader range of brain activity.

  3. Preparation and stability of the {sup 99m} Tc-HNE{sub 2} radiopharmaceutical; Preparacion y estabilidad del radiofarmaco {sup 99m} TC-HNE{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Estrada T, J

    2002-07-01

    conjugate the solid phase extraction was used, using the C-18 sep-pak cartridges. The native peptide and the conjugate were characterized by High Performance Liquid Chromatography (HPLC) using a molecular exclusion column for YMC-Pack Diol-60 peptides, phosphates buffer 0.1 M p H= 7.4 at a flux 1.5 ml/min; integrated to a diode arrangement detector to obtain the UV spectra and a radioactivity detector for obtaining the radio chromatograms of the compounds in study, verifying that the different bifunctional agents will be separate appropriately from the peptide, once formed the conjugate peptide, the labelling with {sup 99m} Tc was realized using sodium pertechnetates (NaTcO{sub 4}) eluted from a {sup 99}Mo/{sup 99m} Tc generator and as a reducer agent stannous chloride. The In vitro stability tests were realized measuring the radiochemical purity of the radio peptide in Instant Thin Layer Chromatography with silica-gel (ITLC-SG), NaCl 0.9% and acetone as eluent systems at different time intervals in solutions of different cysteine concentration. These tests indicated the trans chelation grade of the {sup 99m} Tc metal. In the In vivo evaluations the stability of the {sup 99m} Tc-HNE-2 was obtained when it was realized the biodistribution in normal mice of the balb-c stock. The obtained results show a radiochemical purity of 95.05 % {+-} 2.81% for the {sup 99m} Tc-DTPA-HNE-2 conjugates and 51.45% {+-} 3.2% for {sup 99m} Tc-HYNIC-HNE-2 even as tricine as colligand was used. The In vivo and In vitro stability tests of the radio conjugates show that the radio complexes are keeping whole at least during 24 hours (In vitro) time in which passing for half life of the {sup 99m} Tc radionuclide and 30 min (In vivo). Since the radio conjugates prepared with DTPA were obtained with radiochemical purities adequate for its use in scintillography, it is necessary as a future work to realize the biodistribution kinetics as in healthy animals as in models with induced infectious processes

  4. Preparation and stability of the {sup 99m} Tc-HNE{sub 2} radiopharmaceutical; Preparacion y estabilidad del radiofarmaco {sup 99m} TC-HNE{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Estrada T, J

    2002-07-01

    conjugate the solid phase extraction was used, using the C-18 sep-pak cartridges. The native peptide and the conjugate were characterized by High Performance Liquid Chromatography (HPLC) using a molecular exclusion column for YMC-Pack Diol-60 peptides, phosphates buffer 0.1 M p H= 7.4 at a flux 1.5 ml/min; integrated to a diode arrangement detector to obtain the UV spectra and a radioactivity detector for obtaining the radio chromatograms of the compounds in study, verifying that the different bifunctional agents will be separate appropriately from the peptide, once formed the conjugate peptide, the labelling with {sup 99m} Tc was realized using sodium pertechnetates (NaTcO{sub 4}) eluted from a {sup 99}Mo/{sup 99m} Tc generator and as a reducer agent stannous chloride. The In vitro stability tests were realized measuring the radiochemical purity of the radio peptide in Instant Thin Layer Chromatography with silica-gel (ITLC-SG), NaCl 0.9% and acetone as eluent systems at different time intervals in solutions of different cysteine concentration. These tests indicated the trans chelation grade of the {sup 99m} Tc metal. In the In vivo evaluations the stability of the {sup 99m} Tc-HNE-2 was obtained when it was realized the biodistribution in normal mice of the balb-c stock. The obtained results show a radiochemical purity of 95.05 % {+-} 2.81% for the {sup 99m} Tc-DTPA-HNE-2 conjugates and 51.45% {+-} 3.2% for {sup 99m} Tc-HYNIC-HNE-2 even as tricine as colligand was used. The In vivo and In vitro stability tests of the radio conjugates show that the radio complexes are keeping whole at least during 24 hours (In vitro) time in which passing for half life of the {sup 99m} Tc radionuclide and 30 min (In vivo). Since the radio conjugates prepared with DTPA were obtained with radiochemical purities adequate for its use in scintillography, it is necessary as a future work to realize the biodistribution kinetics as in healthy animals as in models with induced infectious processes

  5. Self-assembly of Ru4 and Ru8 assemblies by coordination using organometallic Ru(II2 precursors: Synthesis, characterization and properties

    Directory of Open Access Journals (Sweden)

    Sankarasekaran Shanmugaraju

    2012-02-01

    Full Text Available Coordination-driven self-assembly of binuclear half-sandwich p-cymene ruthenium(II complexes [Ru2(μ-η4-C2O4(MeOH2(η6-p-cymene2](O3SCF32 (1a or [Ru2(μ-η4-N,N'-diphenyloxamidato(MeOH2(η6-p-cymene2](O3SCF32 (1b separately with an imidazole-based tetratopic donor L in methanol affords two tetranuclear metallamacrocycles 2a and 2b, respectively. Conversely, the similar combination of L with 2,5-dihydroxy-1,4-benzoquinonato (dhbq bridged binuclear complex [Ru2(μ-η4-C6H2O4(MeOH2(η6-p-cymene2](O3SCF32 (1c in 1:2 molar ratio resulted in an octanuclear macrocyclic cage 2c. All the self-assembled macrocycles 2a–2c were isolated as their triflate salts in high yields and were characterized fully by multinuclear (1H, 13C and 19F NMR, infrared (IR and electrospray ionization mass spectrometry (ESIMS. In addition, the molecular structure of macrocycle 2a was established unequivocally by single-crystal X-ray diffraction analysis and adopts a tetranuclear rectangular geometry with the dimensions of 5.53 Å × 12.39 Å. Furthermore, the photo- and electrochemical properties of these newly synthesized assemblies have been studied by using UV–vis absorption and cyclic voltammetry analysis.

  6. Was photosynthetic RuBisCO recruited by acquisitive evolution from RuBisCO-like proteins involved in sulfur metabolism?

    Science.gov (United States)

    Ashida, Hiroki; Danchin, Antoine; Yokota, Akiho

    2005-01-01

    Genome analyses have revealed that the genomes of non-photosynthetic bacteria including Bacillus subtilis code for proteins similar to the large subunit of RuBisCO (called RuBisCO-like protein (RLP)). This raises a fundamental question as to their functional relationship to photosynthetic RuBisCO. Recently, we identified the RLP of B. subtilis as the 2,3-diketo-5-methylthiopentyl-1-phosphate enolase in the methionine salvage pathway. In this mini-review, we suggest functional and evolutionary links between B. subtilis RLP and photosynthetic RuBisCO. Furthermore, we propose that photosynthetic RuBisCOs evolved from RLPs similar to that found in B. subtilis.

  7. A rechargeable hydrogen battery based on Ru catalysis.

    Science.gov (United States)

    Hsu, Shih-Fan; Rommel, Susanne; Eversfield, Philipp; Muller, Keven; Klemm, Elias; Thiel, Werner R; Plietker, Bernd

    2014-07-01

    Apart from energy generation, the storage and liberation of energy are among the major problems in establishing a sustainable energy supply chain. Herein we report the development of a rechargeable H2 battery which is based on the principle of the Ru-catalyzed hydrogenation of CO2 to formic acid (charging process) and the Ru-catalyzed decomposition of formic acid to CO2 and H2 (discharging process). Both processes are driven by the same catalyst at elevated temperature either under pressure (charging process) or pressure-free conditions (discharging process). Up to five charging-discharging cycles were performed without decrease of storage capacity. The resulting CO2/H2 mixture is free of CO and can be employed directly in fuel-cell technology.

  8. Metamagnetic domains in [Co/Pt]/Ru multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Kiselev, N.S. [IFW Dresden (Germany); Donetsk Inst. for Physics and Technology (Russian Federation); Bran, C.; Wolff, U.; Schultz, L.; Bogdanov, A.N.; Neu, V.; Roessler, U.K. [IFW Dresden (Germany); Hellwig, O. [Hitachi GST, San Jose (United States)

    2009-07-01

    In antiferromagnetically coupled superlattices with perpendicular anisotropy, a magnetic field induces a cascade of reorientation transitions accompanied by metamagnetic multidomain states. For a micromagnetic model, we derive equilibrium sizes of stripe and bubble metamagnetic domains as functions of the antiferromagnetic exchange, magnetic field, and geometrical parameters of the multilayers. Magnetic phase diagrams display three different types of metamagnetic domains which separate the ferrimagnetic state from the antiferromagnetic and the saturated ferromagnetic state, and from ferrostripe phases. Experimental investigations have been carried out for an antiferromagnetically coupled [(Co/Pt){sub 8}Co/Ru]{sub 18} superlattice. Magnetic force microscopy (MFM) imaging in a magnetic fields reveals peculiarities of the nucleation and evolution of metamagnetic domains. Theoretical analysis of MFM data and the magnetization curves gives a consistent description of the magnetization processes in [Co/Pt]/Ru multilayers. Demagnetization processes starting from the multidomain metamagnetic states lead to specific remanents states, namely metamagnetic band and bubble topological defects.

  9. Novel Ru - K/Carbon Nanotubes Catalyst for Ammonia Synthesis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel ammonia synthesis catalyst, potassium-promoted ruthenium supported on carbon nanotubes, was developed. It was found that the Ru-K/carbon nanotubes catalyst had higher activity for ammonia synthesis ( 20.85 ml NH 3 /h/g-cat ) than the Ru-K/fullerenes ( 13.3 ml NH 3 /h/g-cat ) at atmospheric ressure and 623 K. The catalyst had activity even at 473 K, and had the highest activity ( 23.46 ml NH 3 /h/g-cat ) at 643 K. It was suggested that the multi-walled structure favored the electron transfer, the hydrogen-storage and the hydrogen-spill which were favorable to ammonia synthesis.

  10. Espalhamento Thomson no tiroide compacto TC-1

    OpenAIRE

    Luiz Angelo Berni

    1996-01-01

    Resumo: Pela primeira vez foi instalado o diagnóstico de espalhamento Thomson no Toróide Compacto TC-1 da Unicamp. Primeiramente o diagnóstico foi realizado com uma única passagem do laser de rubi ( energia: 3 J -duração: 40 ns ) pelo plasma com injeção axial e radial do laser e observado a 90° .Com a injeção axial obtivemos uma densidade de (4,3 ± 0,7)x1021 m-3 e uma temperatura eletrônica de ( 8 ± 3) eV. Estes resultados foram confirmados com a geometria radial de injeção do laser com uma d...

  11. Standardization of 99mTc.

    Science.gov (United States)

    Sahagia, Maria

    2006-01-01

    The radioactivity of 99mTc was standardized by the 4piPC-gamma coincidence method with two different modes. One is using coincidences between (119.5-142.6)keV conversion electrons and K X-rays, and the other is coincidences between the 2.13 keV conversion electrons and 140.5 keVgamma-rays. The background of the K X-ray peak and the sensitivity of the proportional counter (PC) to 140 keV gamma-rays were the main sources of uncertainties in the first case and low detection efficiency for conversion electrons in the second case. General coincidence equations were written, with specific forms, for the three measurement variants, including literature variant. Comparison with the ionization chamber calibration is reported.

  12. RILEM TC ISR Summer 2015 Activity Report

    Energy Technology Data Exchange (ETDEWEB)

    Le Pape, Yann [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-01

    With aging infrastructures, instances of Alkali Silica Reaction (ASR) and Delayed Ettringite Formation (DEF), broadly covered under the term Internal Swelling Reaction (ISR), are increasingly being detected. They have been observed in bridges, dams, and most recently in nuclear power plants. Concrete swelling may result in bridge partial failure, dams with structural cracks and misaligned turbine shafts, and locked slice gates. For nuclear reactors micro-cracks may cause increased gas permeability which will jeopardize the containment integrity and may decrease the residual structural resistance under accidental loading. This TC, which limits its activity to structures with known expansive concrete, seeks to address two complementary but fundamental questions: a) What is the kinetics of the reaction and b) How would it affect the integrity of the structure (serviceability and strength) and thus establish a science based prognostic to the structure owner.

  13. Olefin hydroformylation catalysis with RuCl2(DMSO4.

    Directory of Open Access Journals (Sweden)

    Marisela Reyes*

    2008-05-01

    Full Text Available The RuCl2(DMSO4 complex was used as catalytic precursor in olefin hydroformylation reactions, giving good percent yield and better selectivity for linear aldehydes. The reactions were tested in homogeneous medium and biphasic organic solvent/ water systems. The substrates tried were 1-hexene, cyclohexene, 2-methyl-2-pentene, 2,3-dimethyl-2-butene; binary mixtures and synthetic naphtha and real naphtha. The activity is better for linear olefins compared with substituted olefins.

  14. Comparing Ru and Fe-catalyzed olefin metathesis.

    Science.gov (United States)

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

    2014-08-01

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

  15. 95Mo NMR: hyperfine interactions in MoO3, MoS2, MoSe2 Mo3Se4, MoSi2 and Mo2C.

    Science.gov (United States)

    Bastow, T J

    1998-10-01

    Nuclear hyperfine interactions have been obtained by nuclear magnetic resonance (NMR) for 95Mo in a number of binary Mo compounds, both insulators and metals, which illustrate the interplay between nuclear quadrupole and chemical (Knight) shift terms. The insulating phases are characterised by nuclear spin lattice relaxation times greater than 100 s, demonstrating the ineffectiveness of indirect phonon Raman relaxation for these compounds.

  16. TC17 titanium alloy laser melting deposition repair process and properties

    Science.gov (United States)

    Liu, Qi; Wang, Yudai; Zheng, Hang; Tang, Kang; Li, Huaixue; Gong, Shuili

    2016-08-01

    Due to the high manufacturing cost of titanium compressor blisks, aero engine repairing process research has important engineering significance and economic value. TC17 titanium alloy is a rich β stable element dual α+β phase alloy whose nominal composition is Ti-5Al-2Sn-2Zr-4Mo-4Cr. It has high mechanical strength, good fracture toughness, high hardenability and a wide forging-temperature range. Through a surface response experiment with different laser powers, scanning speeds and powder feeding speeds, the coaxial powder feeding laser melting deposition repair process is studied for the surface circular groove defects. In this paper, the tensile properties, relative density, microhardness, elemental composition, internal defects and microstructure of the laser-repaired TC17 forging plate are analyzed. The results show that the laser melting deposition process could realize the form restoration of groove defect; tensile strength and elongation could reach 1100 MPa and 10%, which could reach 91-98% that of original TC17 wrought material; with the optimal parameters (1000 W-25 V-8 mm/s), the microhardness of the additive zone, the heat-affected zone and base material is evenly distributed at 370-390 HV500. The element content difference between the additive zone and base material is less than ±0.15%. Due to the existence of the pores 10 μm in diameter, the relative density could reach 99%, which is mainly inversely proportional to the powder feeding speed. The repaired zone is typically columnar and dendrite crystal, and the 0.5-1.5 mm-deep heat-affected zone in the groove interface is coarse equiaxial crystal.

  17. Core-level photoemission from alkali metals on Ru(001)

    Energy Technology Data Exchange (ETDEWEB)

    Shek, M. (Department of Physics, Hunter College of The City University of New York, New York, New York 10021 (USA)); Hrbek, J. (Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973-5000 (USA)); Sham, T.K. (Department of Chemistry, University of Western Ontario, London, Ontario, Canada NA65B7 (Canada)); Xu, G. (Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973-5000 (USA))

    1990-02-15

    We report soft-x-ray photoemission results on the core-level binding energies of Li, Na, K, and Cs adsorbed on Ru(001). For all four alkali metals, the saturated alkali-metal--Ru interface core level and the second- (surface-) layer core-level binding energies differ by as much as 0.85--1.25 eV. Surface versus bulklike core-level shifts are reported for Li, K, and Cs, which are 0.55 eV for Li and {similar to}0.25 eV for the other two. For increasing coverages of Li, Na, and K in direct contact with Ru, there are significant decreases in the core-level binding energies, the total shift ranging from {similar to}{minus}1.25 eV for Li to {similar to}{minus}0.80 eV for K; the shift for Cs is small and the reasons for the deviation are discussed. A comparison between our observations and the prediction from the thermodynamic model of Johannson and Martensson is also given.

  18. Aluminum thin film growth on a Ru(0001) surface

    Science.gov (United States)

    Ceballos, G.; Theis, M.; Pelzer, Th.; Schick, M.; Rangelov, G.; Wandelt, K.

    1995-07-01

    The growth of thin Al films on a Ru(0001) substrate has been investigated by means of AES, LEED, TDS, and PAX measurements. A plot of the Ru and Al AES intensities versus evaporation time for a deposition temperature of 300 K reveals a distinct break at θAl = 1, while for higher coverages the Ru intensity decays exponentially indicating a three-dimensional growth of Al clusters. From this behavior we deduce a Stranski-Krastanov growth mechanism. This behavior persists up to 650 K. For higher deposition temperatures a diffusion of Al into the substrate and a partial desorption of the Al film is found. At low Al coverage the LEED pattern reveals an initial film growth with Al(111) structure and an expansion of the interatomic spacing of 2% compared to the Al(111) bulk plane. This superstructure persisted up to ˜ 2.5 ML. In the submonolayer regime CO and Xe TD-spectra as well as Xe 4d PAX-spectra suggest together with LEED an island growth.

  19. Optical spectroscopy of RU Cam, a pulsating carbon star

    CERN Document Server

    Kipper, Tonu

    2007-01-01

    We analysed the high resolution spectra of a RU Cam, classified as W Vir type star. The atmospheric parameters of RU Cam were estimated Teff=5250K and log g=1.0. The hydrogen deficiency of RU Cam was not confirmed. The iron abundance, [Fe/H]=-0.37, is close to the solar one. Abundances of most other elements are also close to normal. We found considerable excesses of carbon and nitrogen: [C/Fe]=+0.98, [N/Fe]=+0.60. The carbon to oxygen ratio is C/O$\\ge$1. The carbon isotopic abundance ratio is equal to C^12/C^13=4.5. For sodium a moderate overabundance Na/Fe=+0.55 was obtained. For two moments of observations we found close heliocentric velocity values, Vr=-21.7+/-0.8 and -23.1+/-1.0 km/s. Both spectra contain a peculiar feature - an emission component of NaI doublet which location agrees with the radial velocity from the bulk of metallic lines. For our two observing moments we found no dependence of radial velocities on the formation depth or on excitation energy for metallic lines.

  20. Reactivity of periodically rippled graphene grown on Ru(0001)

    Energy Technology Data Exchange (ETDEWEB)

    Borca, B; Calleja, F; Hinarejos, J J; Vazquez de Parga, A L; Miranda, R [Departamento de Fisica de la Materia Condensada, Universidad Autonoma de Madrid, Cantoblanco, E-28049 Madrid (Spain)

    2009-04-01

    We report here the reactivity of epitaxial graphene islands and complete monolayers on Ru(0001) towards molecular oxygen and air. The graphene is prepared by thermal decomposition of ethylene molecules pre-adsorbed on an Ru(0001) surface in an ultra-high vacuum chamber. The graphene layer presents a periodically rippled structure that is dictated by the misfit between graphene and Ru(0001) lattice parameters. The periodic ripples produce spatial charge redistribution in the graphene and modifies its electronic structure around the Fermi level. In order to investigate the reactivity of graphene we expose graphene islands to a partial pressure of oxygen and following the evolution of the surface by STM during the exposure. For the exposure to air we removed the sample from the UHV chamber and we re-introduce it after several hours, taking STM images before and after. The surface areas not covered by the graphene islands present a dramatic change but the graphene structure, even the borders of the islands, remain intact. In the case of a complete graphene monolayer the exposure to oxygen or to air does not affect or destroy the rippled structure of the graphene monolayer.

  1. DETERMINATION AND APPLICATION OF LARSON-MILLER PARAMETER FOR HEAT RESISTANT STEEL 12Cr1MoV AND 15CrMo

    Institute of Scientific and Technical Information of China (English)

    R.C.Yang; K.Chen; H.X.Feng; H.Wang

    2004-01-01

    Based on the analysis and processing on relative empirical formula and data, C-values in Larson-Miller (P) expression, P = T(C + lg t), have determined for pearlitic heat resistant steel 12Cr1Mo V and 15CrMo(20.62 and 20. 30). The simulation experiments of high temperature aging, heated from 1.5 to 873 hours, have been designed and performed for its verification. And in combination with published information and the present nearly quantitative works, it has further been verified that both the degradations of microstructures and mechanical properties show a good accuracy and practicability using the Larson-Miller parameter with the present determined C-values. Finally, the effects of carbon content on C-value are analyzed by the empirical electron theory of solids and molecules (EET).

  2. Ruthenocuprates RuSr2(Eu,Ce)2Cu2O10-y: Intrinsic magnetic multilayers

    Science.gov (United States)

    Živković, I.; Hirai, Y.; Frazer, B. H.; Prester, M.; Drobac, D.; Ariosa, D.; Berger, H.; Pavuna, D.; Margaritondo, G.; Felner, I.; Onellion, M.

    2002-04-01

    We report ac susceptibility data on RuSr2(Eu,Ce)2Cu2O10-y (Ru-1222, Ce content x=0.5 and 1.0), RuSr2GdCu2O8 (Ru-1212), and SrRuO3. Both Ru-1222 (x=0.5, 1.0) sample types exhibit unexpected magnetic dynamics in low magnetic fields: logarithmic time relaxation, switching behavior, and ``inverted'' hysteresis loops. Neither Ru-1212 nor SrRuO3 exhibit such magnetic dynamics. The results are interpreted as evidence of the complex magnetic order in Ru-1222. We propose a specific multilayer model to explain the data, and note that superconductivity in the ruthenocuprate is compatible with both the presence and absence of the magnetic dynamics.

  3. Evaluation of the absorbed dose to the kidneys due to Tc{sup 99m} (DTPA) / Tc{sup 99m} (Mag3) and Tc{sup 99m} (Dmsa); Evaluacion de la dosis absorbida en los rinones debido al Tc{sup 99m} (DTPA) / Tc{sup 99m} (MAG3) y Tc{sup 99m} (DMSA)

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez A, M.; Murillo C, F.; Castillo D, C.; Rocha J, J.; Sifuentes D, Y.; Sanchez S, P. [Universidad Nacional de Trujillo, Av. Juan Pablo II s/n, Trujillo (Peru); Idrogo C, J.; Marquez P, F., E-mail: marvva@hotmail.com [Instituto Nacional de Enfermedades Neoplasicas, Av. Angamos 2520, Lima (Peru)

    2015-10-15

    The absorbed dose in the kidneys of adult patients has been assessed using the biokinetics of radiopharmaceuticals containing Tc{sup 99m} (DTPA) / Tc{sup 99m} (Mag3) or Tc{sup 99m} (Dmsa).The absorbed dose was calculated using the formalism MIRD and the Cristy-Eckerman representation for the kidneys. The absorbed dose to the kidneys due to Tc{sup 99m} (DTPA) / Tc{sup 99m} (Mag3), are given by 0.00466 mGy.MBq{sup -1} / 0.00339 mGy.MBq{sup -1}. Approximately 21.2% of the absorbed dose is due to the bladder (content) and the remaining tissue, included in biokinetics of Tc{sup 99m} (DTPA) / Tc{sup 99m} (Mag3). The absorbed dose to the kidneys due to Tc{sup 99m} (Dmsa) is 0.17881 mGy.MBq{sup -1}. Here, 1.7% of the absorbed dose is due to the bladder, spleen, liver and the remaining tissue, included in biokinetics of Tc{sup 99m} (Dmsa). (Author)

  4. Accumulation of 99m TC-methylene diphosphonate radiotracer in ...

    African Journals Online (AJOL)

    Accumulation of 99m TC-methylene diphosphonate radiotracer in rat's forelimb. ... by gamma camera 2 h after the injection of 99mTc-MDP via the tail vein. ... can be used for survey radioactivity examination in different bones of the forelimb.

  5. Electron Spin Pairing in High-Tc Superconductors

    Institute of Scientific and Technical Information of China (English)

    郭卫; 韩汝珊

    2001-01-01

    An electron pairing theory based on effective electron spin coupling mediated by antiferromagnetically correlated local moments is presented to account for high-Tc phenomena. We show that Kondo scattering and the suppression of the antiferromagnetic superexchange between Cu2+ moments lead to local triplet pairing, the mechanism underlying high-Tc superconductivity.

  6. Theoretical Modeling of 99 Tc NMR Chemical Shifts

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Gabriel B.; Andersen, Amity; Washton, Nancy M.; Chatterjee, Sayandev; Levitskaia, Tatiana G.

    2016-09-06

    Technetium (Tc) displays a rich chemistry due to the wide range of oxidation states (from -I to +VII) and ability to form coordination compounds. Determination of Tc speciation in complex mixtures is a major challenge, and 99Tc NMR spec-troscopy is widely used to probe chemical environments of Tc in odd oxidation states. However interpretation of the 99Tc NMR data is hindered by the lack of reference compounds. DFT computations can help fill this gap, but to date few com-putational studies have focused on 99Tc NMR of compounds and complexes. This work systematically evaluates the inclu-sion small percentages of Hartree-Fock exchange correlation and relativistic effects in DFT computations to support in-terpretation of the 99Tc NMR spectra. Hybrid functionals are found to perform better than their pure GGA counterparts, and non-relativistic calculations have been found to generally show a lower mean absolute deviation from experiment. Overall non-relativistic PBE0 and B3PW91 calculations are found to most accurately predict 99Tc NMR chemical shifts.

  7. Muscle localization of Tc-99m MDP after exertion

    Energy Technology Data Exchange (ETDEWEB)

    Valk, P.

    1984-09-01

    Very high muscle uptake of Tc-99m MDP was seen two days after the start of a program of vigorous weight-lifting exercises. Localization of Tc-99m bone tracer in muscle that has been damaged by exertion may be a more common phenomenon than is recognized at present.

  8. Mo-Si alloy development

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.T.; Heatherly, L.; Wright, J.L. [Oak Ridge National Lab., TN (United States)

    1996-06-01

    The objective of this task is to develop new-generation corrosion-resistant Mo-Si intermetallic alloys as hot components in advanced fossil energy conversion and combustion systems. The initial effort is devoted to Mo{sub 5}-Si{sub 3}-base (MSB) alloys containing boron additions. Three MSB alloys based on Mo-10.5Si-1.1B (wt %), weighing 1500 g were prepared by hot pressing of elemental and alloy powders at temperatures to 1600{degrees}C in vacuum. Microporosities and glassy-phase (probably silicate phases) formations are identified as the major concerns for preparation of MSB alloys by powder metallurgy. Suggestions are made to alleviate the problems of material processing.

  9. Orientation-Dependent Oxygen Evolution on RuO2 without Lattice Exchange

    DEFF Research Database (Denmark)

    Stoerzinger, Kelsey A.; Diaz-Morales, Oscar; Kolb, Manuel

    2017-01-01

    RuO2 catalysts exhibit record activities toward the oxygen evolution reaction (OER), which is crucial to enable efficient and sustainable energy storage. Here we examine the RuO2 OER kinetics on rutile (110), (100), (101), and (111) orientations, finding (100) the most active. We assess the poten......RuO2 catalysts exhibit record activities toward the oxygen evolution reaction (OER), which is crucial to enable efficient and sustainable energy storage. Here we examine the RuO2 OER kinetics on rutile (110), (100), (101), and (111) orientations, finding (100) the most active. We assess...... work, suggesting lattice oxygen is not exchanged in catalyzing OER on crystalline RuO2 surfaces. This hypothesis is supported by the correlation of activity with the number of active Ru-sites calculated by density functional theory, where more active facets bind oxygen more weakly. This new...

  10. Pt-Ru Catalysts Prepared by a Modified Polyol Process for Direct Methanol Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Junmin; ZHU Fangfang; ZHANG Kunhua; LIU Weiping; GUAN Weiming

    2012-01-01

    Supported PtRu/C catalysts used in direct methanol fuel cells (DMFCs) were prepared by a new modified polyol method.Transmission electron microscopy (TEM),X-ray diffraction (XRD) and cyclic voltammograms (CVs) were carried out to characterize the morphology,composition and the electrochemical properties of the PtRu/C catalyst.The results revealed that the PtRu nanoparticles with small average particle size (≈2.5 nm),and highly dispersed on the carbon support.The PtRu/C catalyst exhibited high catalytic activity and anti-poisoned performance than that of the JM PtRu/C.It is imply that the modified polyol method is efficient for PtRu/C catalyst preparation.

  11. Kinetic study of methanol oxidation on Pt2Ru3/C catalyst in the alkaline media

    Directory of Open Access Journals (Sweden)

    A. V. TRIPKOVIC

    2007-11-01

    Full Text Available The interaction of acridine orange (AO with double-stranded (ds The electrochemical oxidation of methanol in NaOH solution was examined on a thin film Pt2Ru3/C electrode. The XRD pattern revealed that the Pt2Ru3 alloy consisted of a solid solution of Ru in Pt and a small amount of Ru or a solid solution of Pt in Ru. It was shown that in alkaline solution, the difference in activity between Pt/C and Pt2Ru3/C is significantly smaller than in acid solution. It is proposed that the reaction follows a quasi bifunctional mechanism. The kinetic parameters indicated that the chemical reaction between adsorbed COad and OHad species could be the rate limiting step.

  12. A Comparative Study of 99mTc-YIGSR and 99mTc-MIBI Uptake in Tumor Cells

    Institute of Scientific and Technical Information of China (English)

    HU Jia; LAN Xiaoli; ZHANG Yongxue; GAO Zairong; WU Jun

    2005-01-01

    To investigate a new kind of tumor tracer 99mTc-YIGSR developed from a five amino structure (YIGSR) of the Laminin -chain,which can bind to the laminin receptors of tumor specifically, and radiolabeled with MAG3. (1) Preparation of the 99m Tc-YIGSR probe: with S-Acetly-NH3-MAG3as the chelator and with proper reductants YIGSR was labeled with 99mTc; (2) Cell culture and viability measurement: EAC was maintained in RPMI 1640 supplemented with calf serum; the trypan blue exclusion was applied to calculate the cell viability; (3) Study of the cell dynamic: The EACs uptake of 99mTc-YIGSR and99mTc-MIBI was observed at 37 ℃ and 22 ℃, respectively. (1)The labeling efficiencies of 99mTc-YIGSR and99mTc-MIBI were (62±3) % and (96±2) %, respectively; (2) The cell viability was declined with time of incubation; (3) At 37 ℃, the EACS uptake of 99mTc-YIGSR and99mTc-MIBI reached the peak of (43. 16±2.4) % and (24.4±1.8) % at 60min, respectively; and at 22 ℃, the highest uptake was (26.5±2.1) % and (9. 47±1.9) % at 60min, respectively. The in vitro study suggests that 99mTc-YIGSR is superior to 99mTc-MIBI in cell uptake and has potential value in tumor imaging.

  13. Comparison of relative renal function measured with either 99m Tc-DTPA or 99m Tc-EC dynamic scintigraphies with that measured with 99m Tc-DMSA static scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Domingues, F.C.; Fujikawa, G.Y.; Decker, H.; Alonso, G.; Pereira, J.C.; Duarte, P.S. [Centro de Diagnostico Fleury, Sao Paulo, SP (Brazil). Secao de Medicina Nuclear; Sao Paulo Univ. (USP), SP (Brazil). Escola de Saude Publica. Dept. de Epidemiologia]. E-mail: paulo.duarte@fleury.com.br

    2006-07-15

    Objective: The aim of this study was to compare the renal function measured with either {sup 99m}Tc-DTPA or {sup 99m}Tc-EC dynamic scintigraphies with that measured using {sup 99m}Tc-DMSA static scintigraphy. Methods: the values of relative renal function measured in 111 renal dynamic scintigraphies performed either with {sup 99m}Tc-DTPA (55 studies) or with {sup 99m}Tc-EC (56 studies) were compared with the relative function measured using {sup 99m}Tc-DMSA static scintigraphy performed within a 1-month period. The comparisons were performed using Wilcoxon signed rank test. The number of {sup 99m}Tc-DTPA and {sup 99m}Tc-EC studies that presented relative renal function different by more than 5% from that measured with {sup 99m}Tc-DMSA, using chi square test were also compared. Results: the relative renal function measured with {sup 99m}Tc-EC is not statistically different from that measured with {sup 99m}Tc-DMSA (p = 0.97). The relative renal function measured with {sup 99m}Tc-DTPA was statistically different from that measured using {sup 99m}Tc-DMSA, but with a borderline statistical significance (p = 0.05). The number of studies with relative renal function different by more than 5% from that measured with {sup 99m}Tc-DMSA is higher for the {sup 99m}Tc-DTPA scintigraphy (p 0.04) than for {sup 99m}Tc-EC. Conclusion: the relative renal function measured with {sup 99m}Tc-EC dynamic scintigraphy is comparable with that measured with {sup 99m}Tc-DMSA static scintigraphy, while the relative renal function measured with {sup 99m}Tc-DTPA dynamic scintigraphy presents a significant statistical difference from that measured with {sup 99m}Tc-DMSA static scintigraphy. (author)

  14. Comparison of relative renal function measured with either 99mTc-DTPA or 99mTc-EC dynamic scintigraphies with that measured with 99mTc-DMSA static scintigraphy

    Directory of Open Access Journals (Sweden)

    F. C. Domingues

    2006-08-01

    Full Text Available OBJECTIVE: The aim of this study was to compare the renal function measured with either 99mTc-DTPA or 99mTc-EC dynamic scintigraphies with that measured using 99mTc-DMSA static scintigraphy. METHODS: the values of relative renal function measured in 111 renal dynamic scintigraphies performed either with 99mTc-DTPA (55 studies or with 99mTc-EC (56 studies were compared with the relative function measured using 99mTc-DMSA static scintigraphy performed within a 1-month period. The comparisons were performed using Wilcoxon signed rank test. The number of 99mTc-DTPA and 99mTc-EC studies that presented relative renal function different by more than 5% from that measured with 99mTc-DMSA, using chi square test were also compared. RESULTS: the relative renal function measured with 99mTc-EC is not statistically different from that measured with 99mTc-DMSA (p = 0.97. The relative renal function measured with 99mTc-DTPA was statistically different from that measured using 99mTc-DMSA, but with a borderline statistical significance (p = 0.05. The number of studies with relative renal function different by more than 5% from that measured with 99mTc-DMSA is higher for the 99mTc-DTPA scintigraphy (p = 0.04 than for 99mTc-EC. CONCLUSION: the relative renal function measured with 99mTc-EC dynamic scintigraphy is comparable with that measured with 99mTc-DMSA static scintigraphy, while the relative renal function measured with 99mTc-DTPA dynamic scintigraphy presents a significant statistical difference from that measured with 99mTc-DMSA static scintigraphy.

  15. RuPd, RuCo, PdCo and RuPdCo materials as candidates for cathode catalyzers in PEM fuel cells; Materiales RuPd, RuCo, PdCo y RuPdCo como candidatos a catalizadores catodicos en celdas de combustible tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Leyva Noyola, Fatima; Solorza Feria, Omar [Centro de Investigacion y Estudios Superiores del IPN, Mexico, D.F. (Mexico)]. E-mail: fleyva@cinvestav.mx

    2009-09-15

    This work reports on the catalytic activity of RuPd, RuCo, PdCo and RuPdCo material for oxygen reduction reaction (ORR). These materials were synthesized using chemical reduction with NaBH{sub 4} as a reducing agent in THF, in ambient temperature and pressure conditions. The evaluation of the catalytic activity was done using cyclic voltamperometry (CV) and rotary disc electrode (RDE) in H{sub 2}SO{sub 4} 0.5 M. The kinetic results showed that the electrochemical reaction involves 4 electrons and the transfer of the first electron is the determinant stage. The values of {alpha}, i0 and the Tafel slope were very similar for the four materials studied, around 0.4, 5x10{sup -6} mA cm{sup -2} and 60 mV dec-1, respectively. Although these values are less than those reported for nanostructured platinum, they are better than those reported for other materials such as pure Pd, which enables them to be considered as cathode catalysts for a proton exchange membrane fuel cell. [Spanish] En este trabajo se reporta la actividad catalitica de los materiales RuPd, RuCo, PdCo y RuPdCo para la reaccion de reduccion de oxigeno (RRO). Estos materiales fueron sintetizados por el metodo de reduccion quimica, usando NaBH{sub 4} como agente reductor en THF, en condiciones de temperatura y presion ambiental. La evaluacion de la actividad catalitica fue realizada usando Voltamperometria Ciclica (VC) y Electrodo Disco Rotatorio (EDR) en H{sub 2}SO{sub 4} 0.5 M. Los resultados cineticos mostraron que la reaccion electroquimica procede por la via de 4 electrones y la etapa determinante es la transferencia del primer electron. Los valores de {alpha}, i0 y pendiente de Tafel fueron muy similares para los 4 materiales estudiados, siendo estos de alrededor de 0.4, 5x10{sup -6} mA cm{sup -2} y 60 mV dec{sup -1}, respectivamente. Sin embargo, aun cuando estos valores son menores que los reportados para platino nanoestructurado, son mejores que los reportados para otros materiales como el Pd puro

  16. Dipole strength distribution below the giant dipole resonance in {sup 92}Mo, {sup 98}Mo and {sup 100}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Rusev, G.Y.

    2006-07-01

    Investigations of the dipole-strength distributions in {sup 92}Mo, {sup 98}Mo and {sup 100}Mo were carried out by means of the method of nuclear resonance fluorescence. The low-lying excitations in the nuclides {sup 92}Mo, {sup 98}Mo and {sup 100}Mo have been studied in photon-scattering experiments at an electron energy of 6 MeV at the ELBE accelerator and at electron energies from 3.2 to 3.8 MeV at the Dynamitron accelerator. Five levels were observed in {sup 92}Mo. Five levels in {sup 98}Mo and 14 in {sup 100}Mo were identified for the first time in the energy range from 2 to 4 MeV. Dipole-strength distributions up to the neutron-separation energies in the nuclides {sup 92}Mo, {sup 98}Mo and {sup 100}Mo have been investigated at the ELBE accelerator. Because of the possible observation of transitions in the neighboring nuclei produced via ({gamma},n) reaction, additional measurements at electron energies of 8.4 and 7.8 MeV, below the neutron-separation energy, were performed on {sup 98}Mo and {sup 100}Mo, respectively. The number of transitions assigned to {sup 92}Mo, {sup 98}Mo and {sup 100}Mo is 340, 485 and 499, respectively, the main part of them being dipole transitions. Statistical properties of the observed transitions are obtained. The continuum contains the ground-state transitions as well as the branching transitions to the low-lying levels and the subsequent deexcitations of these levels. (orig.)

  17. Level structure of 89Mo

    Science.gov (United States)

    García-Bermúdez, G.; Cardona, M. A.; Ribas, R. V.; Filevich, A.; Achterberg, E.; Szybisz, L.

    1993-10-01

    The level structure of 89Mo has been studied with the 60Ni(32S,2pn) reaction at 110 MeV beam energy. Mainly two bands of γ rays depopulating states of probable spin-parity values ranging up to (27/2)+ were determined from the excitation function, neutron and γ-γ coincidences, and γ-ray angular distributions. The high-spin states of 89Mo show a scheme very similar to that of the 87Zr isotone. The interpretation of these states in terms of the three neutron-hole configuration (νg9/2)-3 and core-excited states is discussed.

  18. Stability, structural, elastic and electronic properties of RuN polymorphs from first-principles calculations

    Science.gov (United States)

    Bannikov, V. V.; Shein, I. R.; Ivanovskii, A. L.

    2010-05-01

    First-principles FLAPW-GGA calculations for six possible polymorphs of ruthenium mononitride RuN indicate that the most stable structure is that of zinc blende rather than the rock salt structure recently reported for synthesized RuN samples. The elastic, electronic properties and the features of chemical bonds of zinc-blende RuN polymorph were investigated and discussed in detail.

  19. Phototoxicity of strained Ru(ii) complexes: is it the metal complex or the dissociating ligand?

    Science.gov (United States)

    Azar, Daniel F; Audi, Hassib; Farhat, Stephanie; El-Sibai, Mirvat; Abi-Habib, Ralph J; Khnayzer, Rony S

    2017-07-27

    A photochemically dissociating ligand in Ru(bpy)2(dmphen)Cl2 [bpy = 2,2'-bipyridine; dmphen = 2,9-dimethyl-1,10-phenanthroline] was found to be more cytotoxic on the ML-2 Acute Myeloid Leukemia cell line than Ru(bpy)2(H2O)2(2+) and prototypical cisplatin. Our findings illustrate the potential potency of diimine ligands in photoactivatable Ru(ii) complexes.

  20. A Novel Ultrafine Ru-B Amorphous Alloy Catalyst for Glucose Hydrogenation to Sorbitol

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An ultrafine Ru-B amorphous alloy catalyst was prepared by chemical reduction with KBH4 in aqueous solution, which exhibited perfect selectivity to sorbitol (~100%) and very high activity during the liquid phase glucose hydrogenation, much higher than the corresponding crystallized Ru-B, the pure Ru powder, and Raney Ni catalysts. The correlation of the catalytic activity to both the structural and surface electronic characteristics was discussed briefly.

  1. Radiolabeling of annexin A5 with {sup 99m}Tc: comparison of HYNIC-Tc vs. iminothiolane-Tc-tricarbonyl conjugates

    Energy Technology Data Exchange (ETDEWEB)

    Biechlin, Marie-Laure [Faculte de Medecine Lyon-Sud (EA 3738), 69921 Oullins (France); Radiopharmacie, Centre Hospitalier de Chambery, 73000 Chambery (France)], E-mail: marie.laure.biechlin@ch-chambery.fr; Bonmartin, Alain; Gilly, Francois-Noel [Faculte de Medecine Lyon-Sud (EA 3738), 69921 Oullins (France); Fraysse, Marc [Radiopharmacie, Centre Hospitalier Lyon Sud, 69495 Pierre-Benite (France); Moulinet d' Hardemare, Amaury du [Departement de Chimie Moleculaire, Equipe de Chimie Inorganique Redox et Biomimetique, Universite Joseph Fourier-Grenoble I (DCM UMR 5250, ICMG), 38041 Grenoble cedex 9 (France)], E-mail: amaury.d-hardemare@ujf-grenoble.fr

    2008-08-15

    In the perspective of expanding the use of annexin A5 (anx A5) as radioactive tracer of cell death in vivo, we recently described its radiolabeling with {sup 99m}Tc-tricarbonyl [{sup 99m}Tc(H{sub 2}O){sub 3}(CO){sub 3}]{sup +} via the mercaptobutyrimidyl group (anx A5-SH). The aim of the present article was to compare this new method with the HYNIC strategy (anx A5-HYNIC), recognized at present as the reference for the radiolabeling of proteins with {sup 99m}Tc. Similar radiolabeling yields and better chemical stability were obtained with the [anx A5-SH-{sup 99m}Tc-tricarbonyl] complex. Since the [anx A5-HYNIC-{sup 99m}Tc(tricine){sub 2}] conjugate shows isomeric forms which can affect the biological properties whereas [anx A5-SH-{sup 99m}Tc-tricarbonyl] is less or not prone to such drawback, the latter seems superior to the former. Furthermore, (anx A5-SH) is readily obtained via commercial sources of Traut's reagent whereas (anx A5-HYNIC) is not. The results provide encouraging evidence in the development of anx A5-labeled reagent for apoptose imaging.

  2. Structural, spectroscopic, and multiconfigurational quantum chemical investigations of the electron-rich metal-metal triple-bonded Tc(2)X(4)(PMe(3))(4) (X = Cl, Br) complexes.

    Science.gov (United States)

    Poineau, Frederic; Forster, Paul M; Todorova, Tanya K; Gagliardi, Laura; Sattelberger, Alfred P; Czerwinski, Kenneth R

    2010-07-19

    The compounds Tc(2)Cl(4)(PMe(3))(4) and Tc(2)Br(4)(PMe(3))(4) were formed from the reaction between (n-Bu(4)N)(2)Tc(2)X(8) (X = Cl, Br) and trimethylphosphine. The Tc(II) dinuclear species were characterized by single-crystal XRD, UV-visible spectroscopy, and cyclic voltammetry techniques, and the results are compared to those obtained from density functional theory and multiconfigurational (CASSCF/CASPT2) quantum chemical studies. The compound Tc(2)Cl(4)(PMe(3))(4) crystallizes in the monoclinic space group C2/c [a = 17.9995(9) A, b = 9.1821(5) A, c = 17.0090(9) A, beta = 115.4530(10) degrees ] and is isostructural to M(2)Cl(4)(PMe(3))(4) (M = Re, Mo, W) and to Tc(2)Br(4)(PMe(3))(4). The metal-metal distance (2.1318(2) A) is similar to the one found in Tc(2)Br(4)(PMe(3))(4) (2.1316(5) A). The calculated molecular structures of the ground states are in excellent agreement with the structures determined experimentally. Calculations of effective bond orders for Tc(2)X(8)(2-) and Tc(2)X(4)(PMe(3))(4) (X = Cl, Br) indicate stronger pi bonds in the Tc(2)(4+) core than in Tc(2)(6+) core. The electronic spectra were recorded in benzene and show a series of low intensity bands in the range 10 000-26 000 cm(-1). Assignment of the bands as well as computing their excitation energies and intensities were performed at both TD-DFT and CASSCF/CASPT2 levels of theory. Calculations predict that the lowest energy band corresponds to the delta* --> sigma* transition, the difference between calculated and experimental values being 228 cm(-1) for X = Cl and 866 cm(-1) for X = Br. The next bands are attributed to delta* --> pi*, delta --> sigma*, and delta --> pi* transitions. The cyclic voltammograms exhibit two reversible waves and indicate that Tc(2)Br(4)(PMe(3))(4) exhibits more positive oxidation potentials than Tc(2)Cl(4)(PMe(3))(4.) This phenomenon is discussed and ascribed to stronger metal (d) to halide (d) back bonding in the bromo complex. Further analysis indicates that Tc

  3. Pressure-induced superconductivity and structural transitions in Ba(Fe0.9Ru0.1)2As2

    Science.gov (United States)

    Uhoya, Walter O.; Tsoi, Georgiy M.; Vohra, Yogesh K.; Sefat, Athena S.; Weir, Samuel T.

    2014-03-01

    Electrical transport and structural characterizations of isoelectronically substituted Ba(Fe0.9Ru0.1)2As2 have been performed as a function of pressure up to ~30 GPa and temperature down to ~10 K using designer diamond anvil cell. Similar to undoped members of the AFe2As2 (A = Ca, Sr, Ba) family, Ba(Fe0.9Ru0.1)2As2 shows anomalous a-lattice parameter expansion with increasing pressure and a concurrent ThCr2Si2 type isostructural (I4/mmm) phase transition from tetragonal (T) phase to a collapsed tetragonal (cT) phase occurring between 12 and 17 GPa where the a is maximum. Above 17 GPa, the material remains in the cT phase up to 30 GPa at 200 K. The resistance measurements show evidence of pressure-induced zero resistance that may be indicative of high-temperature superconductivity for pressures above 3.9 GPa. The onset of the resistive transition temperature decreases gradually with increasing pressure before completely disappearing for pressures above ~10.6 GPa near the T-cT transition. We have determined the crystal structure of the high-Tc phase of Ru-doped BaFe2As2 to remain as tetragonal (I4/mmm) by analyzing the X-ray diffraction pattern obtained at 10 K and 9.7 ± 0.7 GPa, as opposed to inferring the structural transition from electrical resistance measurement, as in a previous report [S.K. Kim, M.S. Torikachvili, E. Colombier, A. Thaler, S.L. Bud'ko, P.C. Canfield, Phys. Rev. B 84, 134525 (2011)].

  4. Spontaneous deposition of Ru on Pt (100: morphological and electrochemical studies. Preliminary results of ethanol oxidation at Pt(100/Ru

    Directory of Open Access Journals (Sweden)

    Colle Vinicius D.

    2003-01-01

    Full Text Available In the present work ruthenium was deposited in submonolayer amounts on Pt(100 by spontaneous deposition at several deposition times. The Pt (100/Ru surfaces were analyzed using ex-situ STM to image the deposits characteristic of ruthenium on Pt (100. It was observed the formation of ruthenium islands with diameters between 1.0 and 4.5 nm with bi-atomic thickness in the center of the islands. A homogeneous distribution of the ruthenium islands on the platinum terraces was found, with no preferential deposition on steps or surface defect sites. The ruthenium coverage degree had been calculated by the decrease of charge of the hydrogen adsorption-desorption peaks in the cyclic voltammograms of the Pt(100/Ru electrodes. The Pt(100/Ru electrodes with a ruthenium coverage degree of ca. 0.3 showed a high activity for the ethanol electrooxidation. The electrochemical experimental results support strongly the bifunctional mechanism for the enhanced ethanol oxidation.

  5. Anomalous magnetic fluctuations in superconducting Sr2RuO4 revealed by 101Ru nuclear spin-spin relaxation

    Science.gov (United States)

    Manago, Masahiro; Yamanaka, Takayoshi; Ishida, Kenji; Mao, Zhiqiang; Maeno, Yoshiteru

    2016-10-01

    We carried out 101Ru nuclear quadrupole resonance (NQR) measurement on superconducting (SC) Sr2RuO4 under zero magnetic field (H =0 ) and found that the nuclear spin-spin relaxation rate 1 /T2 is enhanced in the SC state. The 1 /T2 measurement in the SC state under H =0 is effective for detecting slow magnetic fluctuations parallel to the quantized axis of the nuclear spin. Our results indicate that low-energy magnetic fluctuations perpendicular to the RuO2 plane emerge when the superconductivity sets in, which is consistent with the previous 17O-NQR result that the nuclear spin-lattice relaxation rate 1 /T1 of the in-plane O site exhibits anomalous behavior in the SC state. The enhancement of the magnetic fluctuations in the SC state is unusual and suggests that the fluctuations are related to the unconventional SC pairing. We suggest that this phenomenon is a consequence of the spin degrees of freedom of the spin-triplet pairing.

  6. Materials selection for a transport packaging of Mo-99

    Energy Technology Data Exchange (ETDEWEB)

    Hara, Debora H.S.; Lucchesi, Raquel F.; Mancini, Victor A.; Rossi, Jesualdo L., E-mail: debora_hara@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Fiore, Marina [Universidade de Sao Paulo (USP), SP (Brazil). Departamento de Engenharia Metalurgica e de Materiais. Escola Politecnica

    2015-07-01

    The radiopharmaceuticals are radioactive isotopes used in nuclear medicine for more accurate diagnosis and treatment of diseases or dysfunctions. Currently, the most important radionuclide for the preparation of radiopharmaceuticals for diagnostic purposes is technetium-99m ({sup 99m}Tc), a product of the radioactive decay of molybdenum-99 (Mo-99). The aim of this work was the materials selection that can enable the manufacture of a package for Mo-99 transport with the aid of CES EduPack program and the methodology developed by Ashby. The ESTAR program was used to check the occurrence of Bremsstrahlung and the XCOM program was used to calculate the attenuation coefficient of gamma radiation from some of the selected materials for the shield; after, the thickness required for radiation shielding was calculated. From the results, the materials selected as potential candidates for the manufacture of the shielding were the tungsten alloys. Related to the thermal insulation and the impact protection, woods, plywoods and particle boards stand out. With regard to internal and external coatings, the selected materials focus on groups of steels and nickel alloys. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.; Lister, C.J.; Morss, L.R. [and others

    1995-08-01

    Partial level schemes for {sup 108,110,112}Ru, and {sup 114}Ru about which nothing was previously known, were determined from the measurement of prompt, triple-gamma coincidences in {sup 248}Cm fission fragments. A 5-mg {sup 249}Cm source, mixed with 65-mg KCl and pressed in the form of a 7-mm diameter pellet, was used for the experiment. Prompt {gamma} rays emitted from the fission fragments were detected with the Eurogam array at Daresbury, which at that time consisted of 45 Compton suppressed Ge detectors and 5 LEPS spectrometers. Transitions in Ru were identified by gating on {gamma} rays in the complementary Te fragments. Figure I-25 shows the technique used to identify the previously unknown transitions in {sup 114}Ru and its partial level scheme. High spin states up to spin 10 h were observed and the {gamma}-ray branching ratios were determined. The ratios of electric quadrupole transition probabilities deduced from the experimental branching ratios were found to be in good agreement with the predictions of a simple model of rigid triaxial rotor. Our analysis shows that gamma deformation in Ru isotopes is increasing with the neutron number and the gamma value for {sup 112}Ru and {sup 114}Ru is {approximately} 25 degrees. This is one of the highest gamma values encountered in nuclei, suggesting soft triaxial shapes for {sup 112}Ru and {sup 114}Ru. The results of this investigation were published.

  8. Thermal stability of RuO sub 2 -based bottom electrodes during various ambient annealings

    CERN Document Server

    Ahn, J H; Choi, G P; Choi, W Y; Kim, H G; Lee, W J; Yoon, S G

    1999-01-01

    RuO sub 2 thin films were prepared on SiO sub 2 /Si, TiN/SiO sub 2 /Si and Ru/poly-Si by using DC magnetron sputtering. The annealing of the RuO sub 2 -based bottom electrodes was performed in oxygen and argon ambients and in high vacuum in the temperature range of 400 .deg. C approx 800 .deg. C. In oxygen-ambient annealing, the surface morphology was drastically changed due to the evaporation of ruthenium dioxides in the form of RuO sub 3 and RuO sub 4. The RuO sub 2 thin film annealed in high vacuum was reduced to the Ru metal phase. Evaporation and reduction of the RuO sub 2 thin films could actually be observed during the deposition of (Ba,Sr)TiO sub 3 thin films. oxygen diffusion through the RuO sub 2 /diffusion barrier/poly-Si structures is also discussed

  9. Magnetic properties and spin polarization of Ru doped half metallic CrO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    West, Kevin G.; Dao, Nam N. H.; Lu, Jiwei, E-mail: jl5tk@virginia.edu [Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Osofsky, Michael; Mazin, I. I. [Naval Research Laboratory, Washington, DC 20375 (United States); Wolf, Stuart A. [Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Department of Physics, University of Virginia, Charlottesville, Virginia 22904 (United States)

    2015-07-06

    Chromium dioxide (CrO{sub 2}) is a half metal that is of interest for spintronic devices. It has not been synthesized through traditional physical vapor deposition (PVD) techniques because of its thermodynamic instability in low oxygen pressures. Epitaxial thin films of Ru doped tetragonal rutile CrO{sub 2} were synthesized by a PVD technique. The as-deposited Ru{sub x}Cr{sub 1−x}O{sub 2} was ferrimagnetic with the saturation magnetization moment showing a strong dependence on the Ru concentration. Curie temperature as high as 241 K has been obtained for ∼23 at. % Ru. The Ru substitution increased the electrical conductivity by increasing the minority spin concentration. The spin polarization was found to be as high as 70% for 9 at. % Ru and decreased to ∼60% with Ru concentrations up to ∼44 at. %, which is determined by the Fermi velocities of the majority and minority spins. First principle calculations were performed to understand the effect of Ru content on the properties of CrO{sub 2}. The PVD processes of Ru doped CrO{sub 2} could lead to the practical applications of the high spin polarization of CrO{sub 2} in spintronic devices.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  11. Research on Repair of TC11 Titanium Alloy Components by Laser Melting Deposition Process%TC11钛合金零件的激光熔化沉积修复研究

    Institute of Scientific and Technical Information of China (English)

    宫新勇; 刘铭坤; 李岩; 张永忠

    2012-01-01

    结合飞机起动机钛合金叶轮的修复需要,研究了Ti-6Al-3.5Mo-1.8Zr-0.23Si(TC11)钛合金激光熔化沉积修复工艺及界面的组织与力学性能.结果表明,激光熔化沉积TC11钛合金及界面重熔区具有典型的魏氏组织特征,基体热影响区组织逐渐由魏氏组织向双态组织过渡;激光熔化沉积TC11钛合金的抗拉强度高于界面过渡区及基体,而塑性稍低于基体.通过采用逐点熔化沉积的方法对叶轮受损叶片进行了修复,经加工检验后通过了超转试验考核,实现了装机应用.%To repair the titanium alloy impeller for airplane starter, laser melting deposited Ti-6Al-3.5Mo-l.8Zr-0.23Si(TCll) titanium alloys, as well as the microstructure and properties of the interface, are investigated. The results indicate that the deposited TC11 titanium alloys and the interfacial re-melted layer present a typical Widmanstatten structure and the heat affected zone (HAZ) within the substrate changes gradually from Widmanstatten to duplex microstructure. Compared to the interface transition zone and the substrate, the as-deposited TC11 alloy possesses higher tensile strength and lower ductility. The damaged impeller blades are repaired by laser melting deposition in a point-by-point way. After machining and checking, the repaired impeller passes the over speed test and comes into real use.

  12. Characterization of a trinuclear ruthenium species in catalytic water oxidation by Ru(bda)(pic)2 in neutral media.

    Science.gov (United States)

    Zhang, Biaobiao; Li, Fei; Zhang, Rong; Ma, Chengbing; Chen, Lin; Sun, Licheng

    2016-06-30

    A Ru(III)-O-Ru(IV)-O-Ru(III) type trinuclear species was crystallographically characterized in water oxidation by Ru(bda)(pic)2 (H2bda = 2,2'-bipyridine-6,6'-dicarboxylic acid; pic = 4-picoline) under neutral conditions. The formation of a ruthenium trimer due to the reaction of Ru(IV)[double bond, length as m-dash]O with Ru(II)-OH2 was fully confirmed by chemical, electrochemical and photochemical methods. Since the oxidation of the trimer was proposed to lead to catalyst decomposition, the photocatalytic water oxidation activity was rationally improved by the suppression of the formation of the trimer.

  13. Performance of TcI/TcVI/TcII Chagas-Flow ATE-IgG2a for universal and genotype-specific serodiagnosis of Trypanosoma cruzi infection

    Science.gov (United States)

    Alessio, Glaucia Diniz; de Araújo, Fernanda Fortes; Côrtes, Denise Fonseca; Sales Júnior, Policarpo Ademar; Lima, Daniela Cristina; Gomes, Matheus de Souza; do Amaral, Laurence Rodrigues; Xavier, Marcelo Antônio Pascoal; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis; de Lana, Marta

    2017-01-01

    Distinct Trypanosoma cruzi genotypes have been considered relevant for patient management and therapeutic response of Chagas disease. However, typing strategies for genotype-specific serodiagnosis of Chagas disease are still unavailable and requires standardization for practical application. In this study, an innovative TcI/TcVI/TcII Chagas Flow ATE-IgG2a technique was developed with applicability for universal and genotype-specific diagnosis of T. cruzi infection. For this purpose, the reactivity of serum samples (percentage of positive fluorescent parasites-PPFP) obtained from mice chronically infected with TcI/Colombiana, TcVI/CL or TcII/Y strain as well as non-infected controls were determined using amastigote-AMA, trypomastigote-TRYPO and epimastigote-EPI in parallel batches of TcI, TcVI and TcII target antigens. Data demonstrated that “α-TcII-TRYPO/1:500, cut-off/PPFP = 20%” presented an excellent performance for universal diagnosis of T. cruzi infection (AUC = 1.0, Se and Sp = 100%). The combined set of attributes “α-TcI-TRYPO/1:4,000, cut-off/PPFP = 50%”, “α-TcII-AMA/1:1,000, cut-off/PPFP = 40%” and “α-TcVI-EPI/1:1,000, cut-off/PPFP = 45%” showed good performance to segregate infections with TcI/Colombiana, TcVI/CL or TcII/Y strain. Overall, hosts infected with TcI/Colombiana and TcII/Y strains displayed opposite patterns of reactivity with “α-TcI TRYPO” and “α-TcII AMA”. Hosts infected with TcVI/CL strain showed a typical interweaved distribution pattern. The method presented a good performance for genotype-specific diagnosis, with global accuracy of 69% when the population/prototype scenario include TcI, TcVI and TcII infections and 94% when comprise only TcI and TcII infections. This study also proposes a receiver operating reactivity panel, providing a feasible tool to classify serum samples from hosts infected with distinct T. cruzi genotypes, supporting the potential of this method for universal and genotype

  14. Transport properties of Heusler compounds Ru{sub 2}CrGe and Ru{sub 2}CrSn under high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Okada, H; Koyama, K; Watanabe, K [High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, Sendai (Japan); Kusakari, Y; Kanomata, T [Faculty of Engineering, Tohoku Gakuin University, Tagajo (Japan); Matsuoka, E; Onodera, H, E-mail: hironari@imr.tohoku.ac.j [Department of Physics, Graduate School of Science, Sendai (Japan)

    2009-03-01

    We have performed the specific heat and the electrical resistivity measurements under high magnetic fields for Heusler compounds Ru{sub 2}CrGe and Ru{sub 2}CrSn. We found that the electrical resistivity for Ru{sub 2}CrGe shows an upturn in the vicinity of 130 K and changes a metallic to a semiconducting-like behavior with decreasing temperature. By applying magnetic field, a negative magnetoresistance was observed below 200 K. On the other hand, the electrical resistivity for Ru{sub 2}CrSn shows a semimetallic-like behavior. The results of the electrical resistivity in Ru{sub 2}CrGe suggest that the compound has a gap-like structure in the electronic structure at the Fermi level. Moreover, it was found that another phase transition occurs in Ru{sub 2}CrGe and Ru{sub 2}CrSn, in addition to the magnetic transition.

  15. Targeting human telomeric G-quadruplex DNA and inhibition of telomerase activity with [(dmb2Ru(obipRu(dmb2](4+.

    Directory of Open Access Journals (Sweden)

    Shuo Shi

    Full Text Available Inhibition of telomerase by inducing/stabilizing G-quadruplex formation is a promising strategy to design new anticancer drugs. We synthesized and characterized a new dinuclear complex [(dmb2Ru(obipRu(dmb2](4+ (dmb = 4,4'-dimethyl-2,2'-bipyridine, obip = (2-(2-pyridylimidazo[4,5-f][1,10]phenanthroline with high affinity for both antiparallel and mixed parallel / antiparallel G-quadruplex DNA. This complex can promote the formation and stabilize G-quadruplex DNA. Dialysis and TRAP experiments indicated that [(dmb2Ru(obipRu(dmb2](4+ acted as an excellent telomerase inhibitor due to its obvious selectivity for G-quadruplex DNA rather than double stranded DNA. In vitro co-culture experiments implied that [(dmb2Ru(obipRu(dmb2](4+ inhibited telomerase activity and hindered cancer cell proliferation without side effects to normal fibroblast cells. TUNEL assay indicated that inhibition of telomerase activity induced DNA cleavage further apoptosis in cancer cells. Therefore, Ru(II complex represents an exciting opportunity for anticancer drug design by specifically targeting cancer cell G-quadruplexes DNA.

  16. Measurement of target and double-spin asymmetries for the e<mo>→>p<mo>→mo><mo>→mo>eπ<mo>+mo><mo>(n)> reaction in the nucleon resonance region at low Q2

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, X.; Adhikari, K. P.; Bosted, P.; Deur, A.; Drozdov, V.; El Fassi, L.; Kang, Hyekoo; Kovacs, K.; Kuhn, S.; Long, E.; Phillips, S. K.; Ripani, M.; Slifer, K.; Smith, L. C.; Adikaram, D.; Akbar, Z.; Amaryan, M. J.; Anefalos Pereira, S.; Asryan, G.; Avakian, H.; Badui, R. A.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Briscoe, W. J.; Bültmann, S.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Chen, J. -P.; Chetry, T.; Choi, Seonho; Ciullo, G.; Clark, L.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Crede, V.; D' Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Djalali, C.; Dodge, G. E.; Dupre, R.; Egiyan, H.; El Alaoui, A.; Elouadrhiri, L.; Eugenio, P.; Fanchini, E.; Fedotov, G.; Fersch, R.; Filippi, A.; Fleming, J. A.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Gleason, C.; Golovach, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guler, N.; Guo, L.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jenkins, D.; Jiang, H.; Jo, H. S.; Joosten, S.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Lanza, L.; Lenisa, P.; Livingston, K.; MacGregor, I. J. D.; Markov, N.; McKinnon, B.; Mirazita, M.; Mokeev, V.; Movsisyan, A.; Munevar, E.; Munoz Camacho, C.; Murdoch, G.; Nadel-Turonski, P.; Net, L. A.; Ni, A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Paremuzyan, R.; Park, K.; Pasyuk, E.; Peng, P.; Pisano, S.; Pogorelko, O.; Price, J. W.; Puckett, A. J. R.; Raue, B. A.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schumacher, R. A.; Sharabian, Y. G.; Skorodumina, Iu.; Smith, G. D.; Sokhan, D.; Sparveris, N.; Stankovic, I.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Tian, Ye; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zhang, J.; Zonta, I.

    2016-10-01

    We report measurements of target- and double-spin asymmetries for the exclusive channel e<mo>→>p<mo>→mo><mo>→mo>eπ<mo>+mo><mo>(n)> in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH3 target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3, and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low Q2 range from 0.0065 to 0.35 (GeV/c)2. The Q2 access was made possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low as 6 degrees. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis prediction from SAID, and the dynamic model DMT. In many kinematic regions our results, in particular results on the target asymmetry, help to constrain the polarization-dependent components of these models.

  17. Pr16Mo21O56

    Directory of Open Access Journals (Sweden)

    Patrick Gougeon

    2011-05-01

    Full Text Available The structure of hexadecapraseodymium henicosamolybdenum hexapentacontaoxide, Pr16Mo21O56, is isotypic with other rare earth representatives of formula type RE16Mo21O56 (RE = La, Ce, Nd. It is characterized by Mo10O18iO8a units (where i = inner and a = apical O atoms containing bioctahedral Mo10 clusters and octahedral MoO6 units that share some of their O atoms to form the Mo–O framework. The two independent Mo10 cluster units are centred at Wyckoff positions 2b and 2c and have point-group symmetry overline{1}. The Mo atom of the MoO6 unit is likewise situated at an inversion centre (2d. The eight crystallographically different Pr3+ cations occupy irregular voids in the framework with coordination numbers to the O atoms varying between 8 and 11.

  18. {sup 99m}Tc-sestamibi. Clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Bucerius, Jan [Maastricht Univ. Medical Center (Netherlands). Dept. of Nuclear Medicine and Cardiovascular Research Institute Maastricht; Ahmadzadehfar, Hojjat; Biersack, Hans-Juergen (eds.) [Universitaetsklinikum Bonn (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    2012-07-01

    {sup 99m}Tc-sestamibi is a single-photon emission computed tomography (SPECT) radiotracer that was introduced into clinical routine for myocardial perfusion imaging more than two decades ago. Although today the main application of {sup 99m}Tc-sestamibi SPECT remains the imaging of myocardial perfusion, it is also an accepted and well-proven imaging technique for a variety of oncologic and non-oncologic applications, including brain, breast, and thyroid cancer and thyroid and parathyroid adenoma. Its efficacy in a range of indications ensures that {sup 99m}Tc-sestamibi SPECT will remain widely used despite the rapid diffusion of 18F-FDG PET. {sup 99m}Tc-Sestamibi - Clinical Applications provides a detailed and informative overview of almost all the oncologic and non-oncologic applications of {sup 99m}Tc-sestamibi SPECT, including several relatively rare indications. Different disease-related protocols for {sup 99m}Tc-sestamibi SPECT are presented, and for each disease a comprehensive summary of the relevant pathology and epidemiology is provided. Throughout, there is a strong emphasis on the practical aspects of use of this popular tracer, including instructions for the preparation of several commercially available tracer kits. Clinical practitioners will find this book to be an invaluable guide to the application and benefits of {sup 99m}Tc-sestamibi SPECT in both the inpatient and the outpatient setting. (orig.)

  19. Tc-99m Ciprofloxacin SPECT of Pulmonary Tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Kyung; Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of); Yoon, Min Ki [Good Samaritan Hospital, Pohang (Korea, Republic of); Choe, Won Sick [Kangbuk Samsung Hospital, Seoul (Korea, Republic of)

    2010-06-15

    Tc-99m ciprofloxacin is available for imaging infection. However, there has been no study on employing single photon emission computed tomography (SPECT) with using Tc-99m ciprofloxacin to image active pulmonary tuberculosis. Therefore, we conducted this study to assess the efficacy of Tc-99m ciprofloxacin SPECT for imaging active pulmonary tuberculosis. Twenty-one participants were enrolled in this prospective study. They were divided into two groups according to the clinical and radiological assessment. Group one (Gr. 1) consisted of five normal volunteers and six patients with inactive pulmonary tuberculosis. Group two (Gr. 2) consisted of ten patients with active pulmonary tuberculosis. SPECT was performed 3 h after injecting 555 MBq (15 mCi) of Tc-99m ciprofloxacin. The findings of Tc-99m ciprofloxacin SPECT were interpreted by a nuclear medicine specialist and then the results were analyzed according to the patients' clinical and radiological classifications. The results of Tc-99m ciprofloxacin SPECT were as follows: eight true-positive cases, ten true-negative cases, one false-positive case and two false-negative cases. The sensitivity and specificity was 80.0% and 90.0%, respectively. The positive predictive value was 88.9% and the negative predictive value was 83.3%. Conclusions Tc-99m ciprofloxacin SPECT is feasible for imaging active pulmonary tuberculosis. It is a useful nuclear-imaging method for discriminating between the active and inactive tuberculosis states in patients with a past medical history of pulmonary tuberculosis.

  20. Impeding 99Tc(IV) mobility in novel waste forms

    Science.gov (United States)

    Lee, Mal-Soon; Um, Wooyong; Wang, Guohui; Kruger, Albert A.; Lukens, Wayne W.; Rousseau, Roger; Glezakou, Vassiliki-Alexandra

    2016-06-01

    Technetium (99Tc) is an abundant, long-lived radioactive fission product whose mobility in the subsurface is largely governed by its oxidation state. Tc immobilization is crucial for radioactive waste management and environmental remediation. Tc(IV) incorporation in spinels has been proposed as a novel method to increase Tc retention in glass waste forms during vitrification. However, experiments under high-temperature and oxic conditions show reoxidation of Tc(IV) to volatile pertechnetate, Tc(VII). Here we examine this problem with ab initio molecular dynamics simulations and propose that, at elevated temperatures, doping with first row transition metal can significantly enhance Tc retention in magnetite in the order Co>Zn>Ni. Experiments with doped spinels at 700 °C provide quantitative confirmation of the theoretical predictions in the same order. This work highlights the power of modern, state-of-the-art simulations to provide essential insights and generate theory-inspired design criteria of complex materials at elevated temperatures.

  1. Unconventional high-Tc superconductivity in fullerides.

    Science.gov (United States)

    Takabayashi, Yasuhiro; Prassides, Kosmas

    2016-09-13

    A3C60 molecular superconductors share a common electronic phase diagram with unconventional high-temperature superconductors such as the cuprates: superconductivity emerges from an antiferromagnetic strongly correlated Mott-insulating state upon tuning a parameter such as pressure (bandwidth control) accompanied by a dome-shaped dependence of the critical temperature, Tc However, unlike atom-based superconductors, the parent state from which superconductivity emerges solely by changing an electronic parameter-the overlap between the outer wave functions of the constituent molecules-is controlled by the C60 (3-) molecular electronic structure via the on-molecule Jahn-Teller effect influence of molecular geometry and spin state. Destruction of the parent Mott-Jahn-Teller state through chemical or physical pressurization yields an unconventional Jahn-Teller metal, where quasi-localized and itinerant electron behaviours coexist. Localized features gradually disappear with lattice contraction and conventional Fermi liquid behaviour is recovered. The nature of the underlying (correlated versus weak-coupling Bardeen-Cooper-Schrieffer theory) s-wave superconducting states mirrors the unconventional/conventional metal dichotomy: the highest superconducting critical temperature occurs at the crossover between Jahn-Teller and Fermi liquid metal when the Jahn-Teller distortion melts.This article is part of the themed issue 'Fullerenes: past, present and future, celebrating the 30th anniversary of Buckminster Fullerene'.

  2. Optimization of the Processing of Mo Disks

    Energy Technology Data Exchange (ETDEWEB)

    Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States); Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States); Stepinski, Dominique [Argonne National Lab. (ANL), Argonne, IL (United States); Makarashvili, Vakhtang [Argonne National Lab. (ANL), Argonne, IL (United States); Harvey, James [NorthStar Medical Technologies, LLC, Madison, WI (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    The objective of this work is to decrease the processing time for irradiated disks of enriched Mo for the production of 99Mo. Results are given for the dissolution of nonirradiated Mo disks, optimization of the process for large-scale dissolution of sintered disks, optimization of the removal of the main side products (Zr and Nb) from dissolved targets, and dissolution of irradiated Mo disks.

  3. Asialoglycoprotein receptor targeted imaging using Tc-99m galactosylated chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, E. M.; Jeong, H. J.; Kim, B. C.; Kim, C. K [Wonkang University College of Medicine, Iksan (Korea, Republic of)

    2004-07-01

    The asialoglycoprotein receptor (ASGP-R) is expressed on liver hepatocytes. Chitosan conjugates of galactose have shown to be specifically taken up by liver parenchymal cells via ASGP-R. In this study, Tc-99m hydrazino nicotinamide (HYNIC)-galactosylated chitosan (HYNIC-GC) was synthesized and evaluated as a targeted agent for the imaging of hepatocytes. GC was obtained after coupling of lactobionic acid as the galactose moiety and coupled with HYNIC. HYNIC-GC was radiolabeled with Tc-99m using stannous chloride and tricine as reducing agent and coligand respectively. Hepatic uptake property of Tc-99m HYNIC-GC was studied in female Balb/C mouse. Tc-99m HYNIC--GC and Tc-99m HYNIC-Chitosan as a control were intravenously injected into mice. Receptor binding was identified by coinjection with 50 mM and 80mM free galactose respectively. Biodistribution was determined at three different time points. The level of galactose substitution was 7.6%. Labeling efficiency was >90% both in vitro and serum up to 24 h. Tc-99m HYNIC-GC injected via tail vein of mice showed high selectivity of liver. On the other hands, Tc-99m HC without galactose group showed low uptake (Fig. 1A, 1B). Hepatic uptake of Tc-99m HYNIC-GC was dramatically blocked by 50 mM and 80 mM free galactose coinjection (Fig. 1C, 1D). The liver accumulated about 14 percent injected dose per gram (%ID/g) up to 120 min after injection. Tc-99m HYNIC-GC showed specific and rapid targeting to liver. It is a promising specific radiopharmaceutical with potential applications in the imaging of liver parenchymal cells.

  4. Ternary Pt-Ru-Ni catalytic layers for methanol electrooxidation prepared by electrodeposition and galvanic replacement

    Directory of Open Access Journals (Sweden)

    Athanasios ePapaderakis

    2014-06-01

    Full Text Available Ternary Pt-Ru-Ni deposits on glassy carbon substrates, Pt-Ru(Ni/GC, have been formed by initial electrodeposition of Ni layers onto glassy carbon electrodes, followed by their partial exchange for Pt and Ru, upon their immersion into equimolar solutions containing complex ions of the precious metals. The overall morphology and composition of the deposits has been studied by SEM microscopy and EDS spectroscopy. Continuous but nodular films have been confirmed, with a Pt÷Ru÷Ni % bulk atomic composition ratio of 37÷12÷51 (and for binary Pt-Ni control systems of 47÷53. Fine topographical details as well as film thickness have been directly recorded using AFM microscopy. The composition of the outer layers as well as the interactions of the three metals present have been studied by XPS spectroscopy and a Pt÷Ru÷Ni % surface atomic composition ratio of 61÷12÷27 (and for binary Pt-Ni control systems of 85÷15 has been found, indicating the enrichment of the outer layers in Pt; a shift of the Pt binding energy peaks to higher values was only observed in the presence of Ru and points to an electronic effect of Ru on Pt. The surface electrochemistry of the thus prepared Pt-Ru(Ni/GC and Pt(Ni/GC electrodes in deaerated acid solutions (studied by cyclic voltammetry proves the existence of a shell consisting exclusively of Pt-Ru or Pt. The activity of the Pt-Ru(Ni deposits towards methanol oxidation (studied by slow potential sweep voltammetry is higher from that of the Pt(Ni deposit and of pure Pt; this enhancement is attributed both to the well-known Ru synergistic effect due to the presence of its oxides but also (based on the XPS findings to a modification effect of Pt electronic properties.

  5. Synthesis and unexpected reactivity of [Ru(6 -cymene)Cl2 (PPh2 Cl)], leading to [Ru(6 -cymene)Cl2 (PPh2H)] and [Ru(6-cymene)Cl2 (PPh2OH)] complexes

    Indian Academy of Sciences (India)

    Arun Kumar Pandiakumar; Ashoka G Samuelson

    2015-08-01

    The reaction of [Ru(6-cymene)Cl2]2 and PPh2Cl in the ratio 1:2 gives a stable [Ru(6-cymene) Cl2(PPh2Cl)] complex. Attempts to make the cationic [Ru(6-cymene)Cl(PPh2Cl)2]Cl with excess PPh2Cl and higher temperatures led to adventitious hydrolysis and formation of [Ru(6-cymene)Cl2 (PPh2OH)]. Attempts to make a phosphinite complex by reacting [Ru(6-cymene)Cl2]2 with PPh2Cl in the presence of an alcohol results in the reduction of PPh2Cl to give [Ru(6-cymene)Cl2(PPh2H)] and the expected phosphinite. The yield of the hydride complex is highest when the alcohol is 1-phenyl-ethane-1,2-diol. All three half-sandwich complexes are characterized by X-ray crystallography. Surprisingly, the conversion of chlorodiphenylphosphine to diphenylphosphine is mediated by 1-phenyl-ethane-1,2-diol even in the absence of the ruthenium half-sandwich precursor.

  6. QTAIM analysis of the bonding in Mo-Mo bonded dimolybdenum complexes.

    Science.gov (United States)

    Van der Maelen, Juan F; Cabeza, Javier A

    2012-07-02

    A number of local and integral topological parameters of the electron density of relevant bonding interactions in the binuclear molybdenum complexes [Mo(2)Cl(8)](4-), [Mo(2)(μ-CH(3)CO(2))(4)], [Mo(2)(μ-CF(3)CO(2))(4)], [Mo(2)(μ-CH(3)CO(2))(4)Br(2)](2-), [Mo(2)(μ-CF(3)CO(2))(4)Br(2)](2-), [Mo(2)(μ-CH(3)CO(2))(2)Cl(4)](2-), [Mo(2)(μ-CH(3)CO(2))(2)(μ-Cl)(2)Cl(4)](2-), and [Mo(2)(μ-Cl)(3)Cl(6)](3-) have been calculated and interpreted under the perspective of the quantum theory of atoms in molecules (QTAIM). These data have allowed a comparison between related but different atom-atom interactions, such as different Mo-Mo formal bond orders, ligand-unbridged versus Cl-bridged, CH(3)CO(2)-bridged, and CF(3)CO(2)-bridged Mo-Mo interactions, and Mo-Cl(terminal) and Mo-Cl(bridge) versus Mo-Br and Mo-O interactions. Calculations carried out using nonrelativistic and relativistic approaches afforded similar results.

  7. Thermal Diffusivity of Ordered Double Perovskite A2FeMoO6 (A = Ca, Sr and Ba)

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-Jun; HUANG Qiao-Jian; NIU Dong-Lin; XU Sheng; ZHANG Shu-Yi

    2004-01-01

    @@ Thermal diffusivity has been investigated in ordered double perovskite Sr2FeMoO6 by means of transient surface grating technique in the temperature range of 300-450 K. The thermal diffusivity shows an appreciable decrease from 39mm2/s at 300 K to 37mm2/s at 360K in the ferromagnetic phase, and then steeply drops to 10mm2/s with further increasing temperature above the critical temperature Tc ~ 380 K. Such an abrupt decrease of the thermal diffusivity has been ascribed to the structural phase transition at Tc. We further investigate the lattice effect on the thermal diffusivity in A2FeMoO6 (A = Ca, Sr and Ba) by substitution of Ca2+ or Ba2+ ions for Sr2+ions at 300K. We find that the thermal diffusivity increases from 35mm2/s for A = Ca to 41 mm2/s for A = Ba.Considering the change of the Fe-O-Mo bond angle from 152.4° for A = Ca to 180° for A = Ba, the increased thermal diffusivity for Ba compound has been ascribed to the enhanced hybridization between transition-metal d and oxygen p states due to the larger Fe-O-Mo bond angle and hence the wider one-electron bandwidth W.

  8. Development of multilayer perceptron networks for isothermal time temperature transformation prediction of U-Mo-X alloys

    Energy Technology Data Exchange (ETDEWEB)

    Johns, Jesse M.; Burkes, Douglas

    2017-07-01

    In this work, a multilayered perceptron (MLP) network is used to develop predictive isothermal time-temperature-transformation (TTT) models covering a range of U-Mo binary and ternary alloys. The selected ternary alloys for model development are U-Mo-Ru, U-Mo-Nb, U-Mo-Zr, U-Mo-Cr, and U-Mo-Re. These model’s ability to predict 'novel' U-Mo alloys is shown quite well despite the discrepancies between literature sources for similar alloys which likely arise from different thermal-mechanical processing conditions. These models are developed with the primary purpose of informing experimental decisions. Additional experimental insight is necessary in order to reduce the number of experiments required to isolate ideal alloys. These models allow test planners to evaluate areas of experimental interest; once initial tests are conducted, the model can be updated and further improve follow-on testing decisions. The model also improves analysis capabilities by reducing the number of data points necessary from any particular test. For example, if one or two isotherms are measured during a test, the model can construct the rest of the TTT curve over a wide range of temperature and time. This modeling capability reduces the cost of experiments while also improving the value of the results from the tests. The reduced costs could result in improved material characterization and therefore improved fundamental understanding of TTT dynamics. As additional understanding of phenomena driving TTTs is acquired, this type of MLP model can be used to populate unknowns (such as material impurity and other thermal mechanical properties) from past literature sources.

  9. KINETIKA HIDRODESULFURISASI DIBENZOTHIOPHENE (HDS DBT MENGGUNAKAN KATALIS NiMo/γ-Al2O3

    Directory of Open Access Journals (Sweden)

    Subagjo Subagjo

    2014-12-01

    Full Text Available Evaluasi kinetika reaksi hidrodesulfurisasi (HDS dibenzothiophene dan simulasi nafta hydrotreater yang berada di PT. PERTAMINA Refinery Unit II Dumai menggunakan katalis NiMo/Al2O3 hasil pengembangan telah dilakukan. Kinetika reaksi HDS DBT dilakukan dalan sistem reaktor batch dengan variasi temperatur 280-320oC dan tekanan 30 bar. Data kinetika diolah dengan persamaan hukum pangkat (law power dan persamaan kinetik mekanistik (Langmuir Hinshelwood, LH. Berdasarkan model hukum pangkat, kinetika HDS DBT menggunakan NiMo/Al2O3 hasil pengembangan merupakan  orde satu  terhadap DBT dengan konstanta Arhenius  sebesar 165633 detik-1 dan energi aktivasi 69017 J/mol (16,56 kkal/mol. Model LH yang cocok untuk reaksi HDS DBT menggunakan NiMo/Al2O3 hasil pengembangan adalah model LH yang mengilustrasikan adanya kompetisi antara reaktan DBT dan H2 pada tipe pusat aktif yang sama, dengan DBT teradsorb secara kuat sedangkan H2 teradsorpsi secara lemah. Energi aktifasi dan konstanta Arhenius berdasarkan model LH ini ini berturut-turut adalah 81409 J/mol (19,34 kkal/mol dan 1658133 s-1. Dengan menggunakan persamaan laju reaksi hukum pangkat, model memberikan hasil konversi sulfur yang sama dengan hasil keluaran reaktor nafta hydrotreater RU II-Dumai, yaitu mencapai 98%.

  10. Dissociative sticking of CH4 on Ru(0001)

    DEFF Research Database (Denmark)

    Nielsen, Jane Hvolbæk; Holmblad, Peter Mikal; Chorkendorff, Ib

    1999-01-01

    In this study the CH4 dissociation probability on Ru(0001) is found for various translational and vibrational energies. The absolute sticking values are determined from King and Wells experiments and carbon uptake curves. The carbon amount is determined from the recombination signal of carbon...... with oxygen obtained after the beam exposure when heating in an oxygen atmosphere. The measured sticking coefficient of CH4 is strongly enhanced both by increasing the translational and the vibrational energy of the CH4 molecule. A model is applied to the data and an estimate of the thermal activation energy...

  11. Triaxiality near the 110Ru ground state from Coulomb excitation

    Science.gov (United States)

    Doherty, D. T.; Allmond, J. M.; Janssens, R. V. F.; Korten, W.; Zhu, S.; Zielińska, M.; Radford, D. C.; Ayangeakaa, A. D.; Bucher, B.; Batchelder, J. C.; Beausang, C. W.; Campbell, C.; Carpenter, M. P.; Cline, D.; Crawford, H. L.; David, H. M.; Delaroche, J. P.; Dickerson, C.; Fallon, P.; Galindo-Uribarri, A.; Kondev, F. G.; Harker, J. L.; Hayes, A. B.; Hendricks, M.; Humby, P.; Girod, M.; Gross, C. J.; Klintefjord, M.; Kolos, K.; Lane, G. J.; Lauritsen, T.; Libert, J.; Macchiavelli, A. O.; Napiorkowski, P. J.; Padilla-Rodal, E.; Pardo, R. C.; Reviol, W.; Sarantites, D. G.; Savard, G.; Seweryniak, D.; Srebrny, J.; Varner, R.; Vondrasek, R.; Wiens, A.; Wilson, E.; Wood, J. L.; Wu, C. Y.

    2017-03-01

    A multi-step Coulomb excitation measurement with the GRETINA and CHICO2 detector arrays was carried out with a 430-MeV beam of the neutron-rich 110Ru (t1/2 = 12 s) isotope produced at the CARIBU facility. This represents the first successful measurement following the post-acceleration of an unstable isotope of a refractory element. The reduced transition probabilities obtained for levels near the ground state provide strong evidence for a triaxial shape; a conclusion confirmed by comparisons with the results of beyond-mean-field and triaxial rotor model calculations.

  12. Helium, neon and argon diffraction from Ru(0001).

    Science.gov (United States)

    Minniti, M; Díaz, C; Fernández Cuñado, J L; Politano, A; Maccariello, D; Martín, F; Farías, D; Miranda, R

    2012-09-05

    We present an experimental and theoretical study of He, Ne and Ar diffraction from the Ru(0001) surface. Close-coupling calculations were performed to estimate the corrugation function and the potential well depth in the atom-surface interaction in all three cases. DFT (density functional theory) calculations, including van der Waals dispersion forces, were used to validate the close-coupling results and to further analyze the experimental results. Our DFT calculations indicate that, in the incident energy range 20-150 meV, anticorrugating effects are present in the case of He and Ar diffraction, whereas normal corrugation is observed with Ne beams.

  13. Comparing Ru and Fe-catalyzed olefin metathesis

    KAUST Repository

    Poater, Albert

    2014-01-01

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

  14. Is the methanation reaction over Ru single crystals structure dependent?

    DEFF Research Database (Denmark)

    Vendelbo, Søren Bastholm; Johansson, Martin; Nielsen, Jane Hvolbæk;

    2011-01-01

    The influence of monoatomic steps and defects on the methanation reaction over ruthenium has been investigated. The experiments are performed on a Ru(0 1 54) ruthenium single crystal, which contains one monoatomic step atom for each 27 terrace atoms. The methanation activity is measured at one ba...... front-side of the crystal is poisoned faster than the entire crystal containing more defects. We also observe that additional sputtering of the well-defined front-side increases the reactivity measured on the surface. Based on this, we conclude that the methanation reaction takes place...

  15. Extended collective bands in neutron-rich 109Ru

    Institute of Scientific and Technical Information of China (English)

    DING Huai-Bo; ZHU Sheng-Jiang; J.H. Hamilton; A.V. Ramayya; J. K. Hwang; K. Li; S.H. Liu; Y.X. Luo; J.O. Rasmussen; C.T. Goodin; I. Y. Lee; WANG Jian-Guo; CHE Xing-Lai; GU Long

    2009-01-01

    Levels in the neutron-rich 109Ru have been studied by observing the prompt γ-rays following the spontaneous fission fragments of 252Cf. The ground state band and the negative parity bands have been confirmed and extended. A positive parity band with the band head level at 332.5 keV is newly identified and suggested as a single-neutron excitation band built on the 7/2+ [404] Nilsson orbital. Some structural characteristics of these bands are discussed.

  16. THz-Pulse-Induced Selective Catalytic CO Oxidation on Ru

    Science.gov (United States)

    LaRue, Jerry L.; Katayama, Tetsuo; Lindenberg, Aaron; Fisher, Alan S.; Ã-ström, Henrik; Nilsson, Anders; Ogasawara, Hirohito

    2015-07-01

    We demonstrate the use of intense, quasi-half-cycle THz pulses, with an associated electric field component comparable to intramolecular electric fields, to direct the reaction coordinate of a chemical reaction by stimulating the nuclear motions of the reactants. Using a strong electric field from a THz pulse generated via coherent transition radiation from an ultrashort electron bunch, we present evidence that CO oxidation on Ru(0001) is selectively induced, while not promoting the thermally induced CO desorption process. The reaction is initiated by the motion of the O atoms on the surface driven by the electric field component of the THz pulse, rather than thermal heating of the surface.

  17. Synthesis of hierarchical MoO2/MoS2 nanofibers for electrocatalytic hydrogen evolution

    Science.gov (United States)

    Rheem, Youngwoo; Han, Yosep; Lee, Kyu Hwan; Choi, Sung-Mook; Myung, Nosang V.

    2017-03-01

    Perpendicularly attached MoS2 nanosheets on MoO2 conductive nanofibers were synthesized by combining electrospinning, calcination, and sulfurization processes. Compared to randomly stacked MoS2 nanosheets on MoO2 nanofiber, they show greater hydrogen evolution reaction (HER) performance (i.e., onset potential of ‑180 mV versus normal hydrogen electrode with the Tafel slope of 59 mV dec‑1). HER performance decreases with increasing MoS2 nanocrystal size.

  18. Investigation of Novel Electrocatalysts for Metal Supported Solid Oxide Fuel Cells - Ru:GDC

    DEFF Research Database (Denmark)

    Sudireddy, Bhaskar Reddy; Nielsen, Jimmy; Thydén, Karl Tor Sune

    2015-01-01

    The electrochemical performance and stability of the planar metal supported solid oxide fuel cells (MS-SOFC) with two different electrocatalytically active materials, namely, Ni:GDC and Ru:GDC were investigated. Ru:GDC with an ASR of 0.322 Ωcm2 performed better than Ni:GDC with an ASR of 0.453 Ωc...

  19. Lutidine-derived Ru-CNC hydrogenation pincer catalysts with versatile coordination properties

    NARCIS (Netherlands)

    Filonenko, Georgy A.; Cosimi, Elena; Lefort, Laurent; Conley, Matthew P.; Copéret, Christophe; Lutz, Martin|info:eu-repo/dai/nl/304828971; Hensen, Emiel J M; Pidko, Evgeny A.

    2014-01-01

    Lutidine-derived bis-N-heterocyclic carbene (NHC) ruthenium CNC-pincer complexes (Ru-CNC's) were prepared. Depending on the synthetic procedure, normal (1, 2) or mixed normal/abnormal NHC-complexes (3) are formed. In the presence of phosphazene base, Ru-CNC complexes activate nitriles to give ketimi

  20. A PHARMACOKINETIC STUDY ON RU 486 AND ITS METABOLITES AFTER ORAL ADMINISTRATION AT VARIOUS DOSES

    Institute of Scientific and Technical Information of China (English)

    SHIYong-En; YEZhi-Hou; HEChang-Hai; ZHANGGuo-Qin; XUJian-Qiu; BAJXiu-Mei

    1989-01-01

    The purpose of the present study is to obtain pharmacokinetic parameters of RU486 and its metabolites and then to find out an optimal regimen of the compound for termination of human early pregnancy. Plasma levels of RU486 and its metabolites,