A novel Meloidogyne graminicola effector, MgMO237, interacts with multiple host defence-related proteins to manipulate plant basal immunity and promote parasitism.

Science.gov (United States)

Chen, Jiansong; Hu, Lili; Sun, Longhua; Lin, Borong; Huang, Kun; Zhuo, Kan; Liao, Jinling

2018-02-27

Plant-parasitic nematodes can secrete effector proteins into the host tissue to facilitate their parasitism. In this study, we report a novel effector protein, MgMO237, from Meloidogyne graminicola, which is exclusively expressed within the dorsal oesophageal gland cell and markedly up-regulated in parasitic third-/fourth-stage juveniles of M. graminicola. Transient expression of MgMO237 in protoplasts from rice roots showed that MgMO237 was localized in the cytoplasm and nucleus of the host cells. Rice plants overexpressing MgMO237 showed an increased susceptibility to M. graminicola. In contrast, rice plants expressing RNA interference vectors targeting MgMO237 showed an increased resistance to M. graminicola. In addition, yeast two-hybrid and co-immunoprecipitation assays showed that MgMO237 interacted specifically with three rice endogenous proteins, i.e. 1,3-β-glucan synthase component (OsGSC), cysteine-rich repeat secretory protein 55 (OsCRRSP55) and pathogenesis-related BetvI family protein (OsBetvI), which are all related to host defences. Moreover, MgMO237 can suppress host defence responses, including the expression of host defence-related genes, cell wall callose deposition and the burst of reactive oxygen species. These results demonstrate that the effector MgMO237 probably promotes the parasitism of M. graminicola by interacting with multiple host defence-related proteins and suppressing plant basal immunity in the later parasitic stages of nematodes. © 2018 BSPP AND JOHN WILEY & SONS LTD.

Effect of temperature for synthesizing single-walled carbon nanotubes by catalytic chemical vapor deposition over Mo-Co-MgO catalyst

International Nuclear Information System (INIS)

Niu Zhiqiang; Fang Yan

2008-01-01

The influence of temperature on synthesizing single-walled carbon nanotubes (SWCNTs) by catalytic chemical vapor deposition of methane over Mo-Co-MgO catalyst was studied by Transmission Electron Microscope (TEM) and Raman scattering. The Mo-Co-MgO bimetallic catalyst was prepared by decomposing the mixture of magnesium nitrate, ammonium molybdate, citric acid, and cobalt nitrate. The results show that Mo-Co-MgO bimetallic catalyst is effective to synthesize SWCNTs. By using Mo-Co-MgO bimetallic catalyst, generation of SWCNTs even at 940 K was demonstrated. The optimum temperature of synthesizing SWCNTs over Mo-Co-MgO bimetallic catalyst may be about 1123 K. At 1123 K, the diameters of SWCNTs are in the range of 0.75-1.65 nm. The content of SWCNTs is increased with the increase of temperature below 1123 K and the carbon yield rate is also increased with the increase of synthesis temperature. Therefore, the amount of SWCNTs increases with the increase of temperature below 1123 K. However, above 1123 K, the content of SWCNTs is decreased with the increase of temperature; therefore, it is not effective to increase the amount of SWCNTs through increasing synthesis temperature above 1123 K

Variations of force constants, M-O distances and bond order in solid solutions between Ba/sub 2/MgUO/sub 6/ and Ba/sub 2/MgWO/sub 6/

Energy Technology Data Exchange (ETDEWEB)

Kemmler-Sack, S; Fadini, A [Tuebingen Univ. (Germany, F.R.). Inst. fuer Chemie

1977-12-01

In solid solutions between the 1:1 ordered perovskites Ba/sub 2/MgUO/sub 6/ and Ba/sub 2/MgWO/sub 6/ (system Ba/sub 2/MgUsub(1-x)Wsub(x)O/sub 6/) the force constants of the UO/sub 6/ and WO/sub 6/ octahedras are variied. The valence force constants fsub(MO) tend to adjust for each x. The bond order and the M-O distances are reported as well.

Tunnel magnetoresistance in thermally robust Mo/CoFeB/MgO tunnel junction with perpendicular magnetic anisotropy

Directory of Open Access Journals (Sweden)

B. Fang

2015-06-01

Full Text Available We report on tunnel magnetoresistance and electric-field effect in the Mo buffered and capped CoFeB/MgO magnetic tunnel junctions (MTJs with perpendicular magnetic anisotropy. A large tunnel magnetoresistance of 120% is achieved. Furthermore, this structure shows greatly improved thermal stability and stronger electric-field-induced modulation effect in comparison with the Ta/CoFeB/MgO-based MTJs. These results suggest that the Mo-based MTJs are more desirable for next generation spintronic devices.

Oxidative dehydrogenation of propane with K-MoO3/MgAl2O4 ...

Indian Academy of Sciences (India)

with potassium addition due to interaction with MoO3 sites. For this reason total ... in recent years.1–3 In ODH of propane reaction, there ... heptamolybdate (Merck), dissolved in water and Mg- .... Alkali metal promotion slows down the reduc-.

Epitaxial (100)-oriented Mo/V superlattice grown on MgO(100) by dcMS and HiPIMS

International Nuclear Information System (INIS)

Shayestehaminzadeh, S.; Magnusson, R.L.; Gislason, H.P.; Olafsson, S.

2013-01-01

Epitaxial (100)-oriented Mo/V superlattices have been grown by High Power Impulse Magnetron Sputtering (HiPIMS) and dc Magnetron Sputtering (dcMS) on single-crystalline MgO(100) substrates at growth temperatures ranging from 30 °C to 600 °C. Superlattice bilayer period of Mo/V around 12/12 monolayers and 15 repeat periods was studied. This study aims to investigate the effect of the HiPIMS process on reducing the growth temperature of Mo/V superlattices using the high energy ionized Mo, V species in the HiPIMS plasma. In one case, the Mo layer was only grown with the HiPIMS process and V layer grown using the dcMS process while in another both layers were grown with the HiPIMS process. The as-deposited films were characterized by X-ray reflection and diffraction techniques. The dcMS process was found to give superior superlattice growth at high growth temperatures while a mixed Mo HiPIMS and V dcMS process gives better result at lower growth temperatures (300 °C). Room temperature growth reveals that neither the mixed Mo HiPIMS and V dcMS process nor the pure HiPIMS for both materials can produce better result compared to the pure dcMS process, which gives a relatively better result. - Highlights: • Epitaxial (100)-oriented Mo/V superlattices have been grown by HiPIMS and dcMS on MgO(100) for various temperatures. • The study was aimed to investigate the effect of ionized HiPIMS process onlowering the growth temperature. • The dcMS process was found to give superior superlattice growth at high growth temperature. • The mixed Mo HiPIMS and V dcMS process gives best result at lower growth temperatures

Microstructural Characterization of a Mg Matrix U-Mo Dispersion Fuel Plate Irradiated in the Advanced Test Reactor to High Fission Density: SEM Results

Science.gov (United States)

Keiser, Dennis D.; Jue, Jan-Fong; Miller, Brandon D.; Gan, Jian; Robinson, Adam B.; Medvedev, Pavel G.; Madden, James W.; Moore, Glenn A.

2016-06-01

Low-enriched (U-235 RERTR-8 experiment at high temperature, high fission rate, and high power, up to high fission density. This paper describes the results of the scanning electron microscopy (SEM) analysis of an irradiated fuel plate using polished samples and those produced with a focused ion beam. A follow-up paper will discuss the results of transmission electron microscopy (TEM) analysis. Using SEM, it was observed that even at very aggressive irradiation conditions, negligible chemical interaction occurred between the irradiated U-7Mo fuel particles and Mg matrix; no interconnection of fission gas bubbles from fuel particle to fuel particle was observed; the interconnected fission gas bubbles that were observed in the irradiated U-7Mo particles resulted in some transport of solid fission products to the U-7Mo/Mg interface; the presence of microstructural pathways in some U-9.1 Mo particles that could allow for transport of fission gases did not result in the apparent presence of large porosity at the U-7Mo/Mg interface; and, the Mg-Al interaction layers that were present at the Mg matrix/Al 6061 cladding interface exhibited good radiation stability, i.e. no large pores.

Transitions in Al-like, Mg-like and Na-like Kr and Mo, observed in the JET tokamak

Energy Technology Data Exchange (ETDEWEB)

Jupen, C; Denne, B; Martinson, I [JET Joint Undertaking, Abingdon, Oxon (UK)

1990-05-01

Spectra of highly ionized Kr and Mo, emitted from the JET tokamak plasmas, have been recorded in the region 30-335 A. Detailed analysis of the n=3, {Delta}n=0 transitions in Kr XXIV-XXVI and Mo XXX-XXXII has resulted in a number of new spectral classifications. Some isoelectronic regularities for Al-like and Mg-like ions are discussed. (orig.).

High-activity MgO-supported CoMo Hydrodesulfurization Catalysts Prepared by Non-aqueous Impregnation

Czech Academy of Sciences Publication Activity Database

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

2015-01-01

Roč. 162, JAN 2015 (2015), s. 430-436 ISSN 0926-3373 R&D Projects: GA ČR GAP106/11/0902 Institutional support: RVO:67985858 Keywords : CoMo/MgO * benzothiophene hydrodesulfurization * non-aqueous impregnation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 8.328, year: 2015

New structural family of ternary molybdates NaA3R(MoO4)5, where A is Mg, Mn, Co or Ni and R is Al, In, Cr or Fe

International Nuclear Information System (INIS)

Kozhevnikova, N.M.; Kotova, I.Yu

1998-01-01

Ternary NaA 3 R(MoO 4 ) 5 molybdates belonging to a new structural family are produced by crystallization from melted solution and by solid-phase synthesis method. NaMg 3 In(MoO 4 ) 5 , NaNi 3 Al(MoO 4 ) 5 and NaCo 3 Al(MoO 4 ) 5 single crystals are grown. Crystallographic and thermal characteristics of NaA 3 R(MoO 4 ) 5 are determined. Structural similarities in MgMoO 4 , NaIn(MoO 4 ) 2 , Na 2 Mg(MoO 4 ) 6 and NaA 3 R(MoO 4 ) 5 series are revealed [ru

Electrochemical performance of La-doped Sr{sub 2}MgMoO{sub 6-{delta}} in natural gas

Energy Technology Data Exchange (ETDEWEB)

Ji, Yuan [Texas Materials Institute, ETC 9.102, The University of Texas at Austin, Austin, TX 78712 (United States); College of Physics, Jilin University, 2519 Jiefang Road, Changchun 130023, Jilin Province (China); Huang, Yun-Hui; Goodenough, John B. [Texas Materials Institute, ETC 9.102, The University of Texas at Austin, Austin, TX 78712 (United States); Ying, Jie-Rong [Texas Materials Institute, ETC 9.102, The University of Texas at Austin, Austin, TX 78712 (United States); Institute of Nuclear and New Energy Technology, Tsinghua University, P.O. Box 1021, Beijing 102201 (China)

2007-08-15

Modification of the double perovskite Sr{sub 2}MgMoO{sub 6-{delta}} by La substitution has shown that Sr{sub 2-x}La{sub x}MgMoO{sub 6-{delta}} with 0.6 {<=} x {<=} 0.8 has better performance as the anode of a solid oxide fuel cell. With a Sr{sub 1.2}La{sub 0.8}MgMoO{sub 6-{delta}} anode, LSGM electrolyte, SrCo{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} cathode, and a La{sub 0.5}Ce{sub 0.4}O{sub 1.7-{delta}} buffer layer between the anode and the electrolyte, a maximum power density of 550 mW/cm{sup 2} has been obtained for a SOFC operating on wet methane (3%H{sub 2}O) at 800 C. The performance of the SOFC using C{sub 2}H{sub 6} fuel, like that of CH{sub 4}, changes little on switching from dry C{sub 2}H{sub 6} to 3% H{sub 2}O/C{sub 2}H{sub 6}, but improvement with wet C{sub 3}H{sub 8} shows that some steam will need to be added to a moderately desulfurized natural-gas fuel. (author)

Model surface studies of metal oxides: Adsorption of water and methanol on ultrathin MgO films on Mo(100)

International Nuclear Information System (INIS)

Wu, M.; Estrada, C.A.; Corneille, J.S.; Goodman, D.W.

1992-01-01

Model surface studies of magnesium oxide have been carried out using surface sensitive techniques. Ultrathin MgO films have been synthesized under ultrahigh vacuum (UHV) conditions by thermally evaporating Mg onto Mo(100) in the presence of oxygen. Low-energy electron diffraction (LEED) studies indicate that the MgO films grow epitaxially with the (100) face of MgO oriented parallel to Mo(100). The MgO films, prepared under optimum synthesis conditions, have essentially one-to-one stoichiometry, are nearly free from pointlike surface defects, and have properties essentially identical to those of bulk, single-crystal MgO. Adsorption of water and methanol onto the MgO films has been studied using high-resolution electron energy-loss spectroscopy (HREELS) and temperature programmed desorption (TPD). In order to circumvent the difficulty associated with intense multiple surface optical phonon (Fuchs--Kliewer modes) losses, a new approach to acquisition of HREELS data has been demonstrated. This new approach enables the direct observation of weak loss features due to excitation of the adsorbates without serious interference from multiple phonon losses. Our HREELS studies show that water and methanol undergo heterolytic dissociation, leading to the formation of hydroxyl and methoxy species, respectively

A Structural Study on the Foaming Behavior of CaO-SiO2-MO (MO = MgO, FeO, or Al2O3) Ternary Slag System

Science.gov (United States)

Park, Youngjoo; Min, Dong Joon

2017-12-01

The foaming index of the CaO-SiO2-MO (MO = MgO, FeO, or Al2O3) ternary slag system with a fixed CaO/SiO2 ratio is measured to understand the effect of the ionic structure. At 1773 K (1500 °C), the foaming index of the slag increases with Al2O3 addition and decreases with MgO or FeO addition at a fixed CaO/SiO2 ratio. It is verified that the previous correlation between the foaming index and the physical properties could also be valid for the CaO-SiO2-(MgO or Al2O3) system. Raman spectroscopy for the CaO/SiO2 = 1.0 slag is applied to explain the foaming behavior from an ionic structural perspective. From the ionic structural viewpoint, the fractional change in each silicate anion unit is identified by de-convoluted Raman spectra. The Raman spectra indicate that the silicate network structure is polymerized with Al2O3 as an aluminosilicate structure; in contrast, de-polymerization occurs by MgO or FeO addition. Furthermore, the relationship between the silicate structure and the thermodynamic stability function is discussed. Since the ionic structure of the molten slag affects various physical/thermodynamic properties, the foaming behavior could be successfully interpreted from the ionic structural viewpoint.

Superconductivity in dense Mg1–xMxB2 (M= Zr, Nb, Mo; x= 0⋅ 05 ...

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science; Volume 28; Issue 3. Superconductivity in dense Mg1–MB2 (M = Zr, Nb, Mo; = 0.05) materials sintered under pressure. S Kalavathi C Divakar. Superconductors Volume 28 Issue 3 June 2005 pp 249-252 ...

Electronic transitions and band offsets in C60:SubPc and C60:MgPc on MoO3 studied by modulated surface photovoltage spectroscopy

International Nuclear Information System (INIS)

Fengler, S.; Dittrich, Th.; Rusu, M.

2015-01-01

Electronic transitions at interfaces between MoO 3 layers and organic layers of C 60 , SubPc, MgPc, and nano-composite layers of SubPc:C 60 and MgPc:C 60 have been studied by modulated surface photovoltage (SPV) spectroscopy. For all systems, time dependent and modulated SPV signals pointed to dissociation of excitons at the MoO 3 /organic layer interfaces with a separation of holes towards MoO 3 . The highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps (E HL ) of C 60 , SubPc, and MgPc and the effective E HL of SubPc:C 60 and MgPc:C 60 were measured. The offsets between the LUMO (ΔE L ) or HOMO (ΔE H ) bands were obtained with high precision and amounted to 0.33 or 0.73 eV for SubPc:C 60 , respectively, and to −0.33 or 0.67 eV for MgPc:C 60 , respectively. Exponential tails below E HL and most pronounced sub-bandgap transitions were characterized and ascribed to disorder and transitions from HOMO bands to unoccupied defect states

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)

Cyclic Oxidation of High Mo, Reduced Density Superalloys

Directory of Open Access Journals (Sweden)

James L. Smialek

2015-11-01

Full Text Available Cyclic oxidation was characterized as part of a statistically designed, 12-alloy compositional study of 2nd generation single crystal superalloys as part of a broader study to co-optimize density, creep strength, and cyclic oxidation. The primary modification was a replacement of 5 wt. % W by 7% or 12% Mo for density reductions of 2%–7%. Compositions at two levels of Mo, Cr, Co, and Re were produced, along with a midpoint composition. Initially, polycrystalline vacuum induction samples were screened in 1100 °C cyclic furnace tests using 1 h cycles for 200 h. The behavior was primarily delimited by Cr content, producing final weight changes of −40 mg/cm2 to −10 mg/cm2 for 0% Cr alloys and −2 mg/cm2 to +1 mg/cm2 for 5% Cr alloys. Accordingly, a multiple linear regression fit yielded an equation showing a strong positive Cr effect and lesser negative effects of Co and Mo. The results for 5% Cr alloys compare well to −1 mg/cm2, and +0.5 mg/cm2 for Rene′ N4 and Rene′ N5 (or Rene′ N6, respectively. Scale phases commonly identified were Al2O3, NiAl2O4, NiTa2O6, and NiO, with (Ni,CoMoO4 found only on the least resistant alloys having 0% Cr and 12% Mo. Scale microstructures were complex and reflected variations in the regional spallation history. Large faceted NiO grains and fine NiTa2O6 particles distributed along NiAl2O4 grain boundaries were typical distinctive features. NiMoO4 formation, decomposition, and volatility occurred for a few high Mo compositions. A creep, density, phase stability, and oxidation balanced 5% Cr, 10% Co, 7% Mo, and 3% Re alloy was selected to be taken forward for more extensive evaluations in single crystal form.

Novel Mg-Doped SrMoO3 Perovskites Designed as Anode Materials for Solid Oxide Fuel Cells

Directory of Open Access Journals (Sweden)

Vanessa Cascos

2016-07-01

Full Text Available SrMo1−xMxO3−δ (M = Fe and Cr, x = 0.1 and 0.2 oxides have been recently described as excellent anode materials for solid oxide fuel cells at intermediate temperatures (IT-SOFC with LSGM as the electrolyte. In this work, we have improved their properties by doping with aliovalent Mg ions at the B-site of the parent SrMoO3 perovskite. SrMo1−xMgxO3−δ (x = 0.1, 0.2 oxides have been prepared, characterized and tested as anode materials in single solid-oxide fuel cells, yielding output powers near 900 mW/cm−2 at 850 °C using pure H2 as fuel. We have studied its crystal structure with an “in situ” neutron power diffraction (NPD experiment at temperatures as high as 800 °C, emulating the working conditions of an SOFC. Adequately high oxygen deficiencies, observed by NPD, together with elevated disk-shaped anisotropic displacement factors suggest a high ionic conductivity at the working temperatures. Furthermore, thermal expansion measurements, chemical compatibility with the LSGM electrolyte, electronic conductivity and reversibility upon cycling in oxidizing-reducing atmospheres have been carried out to find out the correlation between the excellent performance as an anode and the structural features.

Magnesium-Molybate Compounds as Matrix for 99Mo/99mTc Generators

Directory of Open Access Journals (Sweden)

Fabiola Monroy-Guzman

2011-01-01

Full Text Available This work reports the preparation of a 99mTc generator based on conversion of 99Mo produced by neutron irradiation, into insoluble magnesium 99Mo-molybdates compounds as matrix. The effect of magnesium salt types and concentration, Mg:Mo molar ratios, pH of molybdate solutions, eluate volume as well as the addition order of molybdate and magnesium solutions’ influences on the final 99mTc were evaluated. Polymetalates and polymolybdates salts either crystallized or amorphous were obtained depending on the magnesium salt and Mg:Mo molar ratio used in matrix preparation. 99Mo/99mTc generator production based on magnesium-99Mo molybdate compounds allow reduction of preparation time and eliminates the use of specialized installations. The best generator performances were attained using matrices prepared from 0.1 mol/L MgCl2·6H2O solutions, ammonium molybdate solutions at pH 7 and at a Mg:Mo molar ratio of 1:1.

Sorption of {sup 99}MoO{sub 4}{sup 2-} ions on commercial hydrotalcites

Energy Technology Data Exchange (ETDEWEB)

Serrano, J.; Gonzalez, H.; Lopez, H.; Aranda, N.; Granados, F.; Bulbulian, S. [Delegacion Miguel Hidalgo, Mexico (Mexico). Instituto Nacional de Investigaciones Nucleares

2005-07-01

{sup 99}MoO{sub 4}{sup 2-} sorption behavior on 3 commercial hydrotalcites, produced by Sasol Chemie, was studied through batch experiments. Only one of them showed high sorption capacity. This product, the MG70 was identified by XRD diffraction analysis as hydrotalcite (Mg{sub 6}Al{sub 2}(OH){sub 16}CO{sub 3} x 4H{sub 2}O), while the other two, MG50 and MG30, were identified mainly as magnesium aluminum hydroxide hydrate, MgAl{sub 2}(OH){sub 14} x 3H{sub 2}O. Calcined MG70 (CMG70) was used to retain about 298.17{+-}8.3 mg of {sup 99}Mo-MoO{sub 4}{sup 2-} (MG70-{sup 99}MoO{sub 4}). When this material was packed in a glass column, the generated {sup 99m}Tc was eluted by using NaCl or HNO{sub 3} aqueous solutions. Saline solutions eluted {sup 99m}Tc with considerable amounts of {sup 99}Mo while 0.1 M HNO{sub 3} eluted {sup 99m}Tc together with a such small amount of {sup 99}Mo that the {sup 99}Mo {mu}Ci/{sup 99m}Tc mCi ratios are close to the value recommended by the American Pharmacopeia. (orig.)

Spectroscopic study of anomalous solubility effect of molybdenum trioxide in water in the presence of MgO

International Nuclear Information System (INIS)

Bunin, V.M.; Karelin, A.I.; Solov'eva, L.N.

1992-01-01

Mechanism of MoO 3 dissolution in water in the presence of MgO was investigated by the methods of raman spectroscopy and infrared spectroscopy. Dissolution of MoO 3 proceeds through formation of MgMoO 4 . Its interaction with MoO 3 excess results to formation of magnesium dimolybdate MgMo 2 O 7

Synthesis and X-ray examination of ternary molybdates, KAIn(MoO4)3 (A - Mg, Mn)

International Nuclear Information System (INIS)

Smirnyagina, N.N.; Khazheeva, Z.I.; Kozhevnikova, N.M.; Alekseev, F.P.; Mokhosoev, M.V.

1985-01-01

The interaction in ternary salt systems K 2 MoO 4 -AMoO 4 -In 2 (MoO 4 ) 3 is studied in the 200-1000 deg temperature range. The triangulation is performed. The formation of new ternary molybdates of the KAIn(MoO 4 ) 3 composition is established. They are investigated with the methods of differential thermal analysis and roentgenography. It is found that KMgIn(MoO 4 ) 3 and KMnIn(MoO 4 ) 3 compounds are isostructural and crystallize in monoclinic crystal system. Elementary cell parameters for KMgIn((MoO 4 ) 3 are a=9.753(7); b=9.282(6); c=13.583(9) A; β=94.1(1) deg; for KMnIn(MoO 4 ) 3 - a=9.80(2); b=9.28(1); c=13.64(2) A; β=94.7(1) A; cells of such dimensions contain four formula units of the above composition. Crystal densities calculated for KMgIn(MoO 4 ) 3 and KMnIn(MnO 4 ) 3 are 3.56 and 3.69 g/cm 3 , respectively

Nanostructured Mo-based electrode materials for electrochemical energy storage.

Science.gov (United States)

Hu, Xianluo; Zhang, Wei; Liu, Xiaoxiao; Mei, Yueni; Huang, Yunhui

2015-04-21

The development of advanced energy storage devices is at the forefront of research geared towards a sustainable future. Nanostructured materials are advantageous in offering huge surface to volume ratios, favorable transport features, and attractive physicochemical properties. They have been extensively explored in various fields of energy storage and conversion. This review is focused largely on the recent progress in nanostructured Mo-based electrode materials including molybdenum oxides (MoO(x), 2 ≤ x ≤ 3), dichalconides (MoX2, X = S, Se), and oxysalts for rechargeable lithium/sodium-ion batteries, Mg batteries, and supercapacitors. Mo-based compounds including MoO2, MoO3, MoO(3-y) (0 energy storage systems because of their unique physicochemical properties, such as conductivity, mechanical and thermal stability, and cyclability. In this review, we aim to provide a systematic summary of the synthesis, modification, and electrochemical performance of nanostructured Mo-based compounds, as well as their energy storage applications in lithium/sodium-ion batteries, Mg batteries, and pseudocapacitors. The relationship between nanoarchitectures and electrochemical performances as well as the related charge-storage mechanism is discussed. Moreover, remarks on the challenges and perspectives of Mo-containing compounds for further development in electrochemical energy storage applications are proposed. This review sheds light on the sustainable development of advanced rechargeable batteries and supercapacitors with nanostructured Mo-based electrode materials.

Biogas reforming over multi walled carbon nanotubes with Co-Mo/MgO nanoparticles

Science.gov (United States)

Khavarian, Mehrnoush; Mohamed, Abdul Rahman

2017-12-01

The utilization of biogas for the production of valuable chemicals is among the very important processes in the energy research field. The most suitable process for biogas reforming is dry reforming of methane. An obvious drawback is the variable composition of biogas rather than the stoichiometrically equimolar quantities of methane and carbon dioxide. Moreover, activating the methane and carbon dioxide molecules in the reforming reaction provides many challenges in exploring new concepts and opportunities for development of unique catalysts. In the present work, the catalytic activity behavior of Co-Mo-MgO/multi-walled carbon nanotubes (MWCNTs) nanocomposite in dry reforming was investigated with different CO2/CH4 feed ratio to evaluate the performance of this catalyst for biogas reforming reaction. It was found that conversions of methane and carbon dioxide were greatly influenced by the feed gas ratio. The CH4 and CO2 conversions are 83 % and 87 % at the reaction temperature of 825 °C, GHSV of 175 L/h.gcat and CO2/CH4 feed ratio of unity. The minimum carbon deposition rate is observed at the CO2/CH4 feed ratio of 0.6 which is 0.080 gc/gcat-h.

Effect of unlabelled monoclonal antibody (MoAb) on biodistribution of /sup 111/Indium labelled (MoAb)

Energy Technology Data Exchange (ETDEWEB)

Lamki, L M; Murray, J L; Rosenblum, M G; Patt, Y Z; Babaian, Richard; Unger, M W

1988-08-01

We have evaluated immunoscintigraphy in cancer patients using four /sup 111/In-labelled murine monoclonal antibodies (MoAb): 96.5 (anti-P97 of melanoma), ZME-018 (anti-high molecular weight antibody of melanoma), ZCE-025 (anti-CEA for colon cancer) and PAY-276 (anti-prostatic acid phosphatase for prostatic cancer). The effect of increasing the doses of unlabelled MoAb (co-infused with 1 mg labelled MoAb) on the relative body distribution of each labelled MoAb was assessed. Localization in the liver decreased significantly in all cases, with increasing MoAb dose, except for ZME-018. Localization in other organs increased significantly as the liver activity decreased. The spleen activity, however, fell in the case of MoAb ZME-018. Blood-pool activity increased with MoAb dose in all four MoAbs. These findings correlated with the rise in the detection rate of metastases, the plasma half-life, and other pharmacokinetic parameters. However, the dose level at which this correlation occurred varied with each antibody. These data demonstrate the co-infusion of unlabelled MoAb with /sup 111/In-labelled MoAb could alter the organ distribution, pharmacokinetics and tumour uptake in a favourable manner, though the degree to which this occurs depends on the antibody in question.

Voltage profile, structural prediction, and electronic calculations for MgxMo6S8

CSIR Research Space (South Africa)

Kganyago, KR

2003-03-01

Full Text Available the binary Mo6S8 and MgAMo6S8 ~see Table III!, the Mo-Mo distances decrease by (0.521)%. This decrease corresponds to an an- isotropic contraction of the Mo6 octahedron. The Mo cluster of the rhombohedral compounds forms an elongated octahe- dron of symmetry...

PENGARUH TEMPERATUR DAN IRADIASI TERHADAP INTERDIFUSI PARTIKEL BAHAN BAKAR JENIS U−7Mo/Al

Directory of Open Access Journals (Sweden)

Maman Kartaman Ajiriyanto

2016-06-01

Full Text Available ABSTRAK PENGARUH TEMPERATUR DAN IRADIASI TERHADAP INTERDIFUSI PARTIKEL BAHAN BAKAR JENIS U−7Mo/Al. Paduan U−7Mo/Al memiliki potensi besar sebagai bahan bakar reaktor riset, tetapi bahan bakar ini memiliki beberapa kekurangan antara lain dapat membentuk interaction layer pada antarmuka pada saat proses fabrikasi maupun iradiasi di reaktor melalui mekaniame difusi. Penelitian ini dilakukan untuk mengetahui terjadinya interaction layer yang disebabkan oleh interdifusi atau diffusion couple paduan U−7Mo dengan pelat AlMg2 yang dipanaskan pada temperatur 500 °C dan 550 °C selama 24 jam dalam tungku arc furnace dan tungku DTA pada temperatur 30 °C hingga 1400 °C. Hasil pengamatan mikrostruktur menggunakan Scanning Electron Microscope (SEM pada sampel diffusion couple hasil pemanasan pada temperatur 500 °C belum terlihat adanya interaction layeratau pembentukan fasa baru antara partikel U−Mo dan matriks Al. Sementara itu, pemanasan pada temperatur 550 °C telah terjadi interdifusi paduan U−7Mo dengan pelat AlMg2 menghasilkan senyawa (U,MoAlx pada antarmuka atau interface. Hal ini didukung oleh hasil analisis DTA menunjukkan bahwa paduan U−7Mo/Al pada 500 °C mempunyai kompatibilitas panas yang baik, tetapi diatas temperatur 550 °C telah terjadi perubahan fasa a + d menjadi a + g. Pemanasan hingga 679,14 °C terjadi fasa metastabil U(Al,Mox dan selanjutnya mengalami proses interdifusi dengan leburan uranium membentuk interaction layer berupa aglomerat senyawa UAlx (UAl4, UAl3 danUAl2. Aglomerat yang terbentuk dari proses pemanasan secara diffusion couple maupun dalam tungku DTA dibandingkan dengan aglomerat yang terbentuk akibat proses iradiasi. Bahan bakar paduan U−7Mo/Al yang diradiasi dengan burn up 58% mengalami interdifusi antara U−7Mo dengan matriks Al menghasilkan fasa metastabil U(Al,Mox yang berubah menjadi layer (U,MoAl7, presipitat UMo2Al20, (UMoAl3−Al dan membentuk boundary atau aglomerat UAlx (UAl4, UAl3 danUAl2

Near-UV and blue wavelength excitable Mg{sub 0.6}Ca{sub 2.16}Mo{sub 0.2}W{sub 0.8}O{sub 6}: Eu{sub 0.12}{sup 3+}/Na{sub 0.12}{sup +} high efficiency red phosphors

Energy Technology Data Exchange (ETDEWEB)

Khanna, A. [Smart Lighting Engineering Research Center, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Electrical Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Dutta, P.S., E-mail: duttap@rpi.edu [Smart Lighting Engineering Research Center, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Electrical Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

2015-05-15

Red phosphors with narrow emission around 615 nm (with FWHM~5–10 nm) having chemical compositions of A{sub 0.6}Ca{sub 2.16}Mo{sub 0.2}W{sub 0.8}O{sub 6}: Eu{sub 0.12}{sup 3+}/Na{sub 0.12}{sup +} (A=Mg, Sr) have been found to exhibit the highest luminescence amongst the molybdate–tungstate family when excited by sources in the 380–420 nm wavelength range. Thus they are most suitable for enhancing color rendering index and lowering color temperature in phosphor converted white LEDs (pc-WLEDs) with near-UV/blue LED excitation sources. The excitation band edge in the near UV/blue wavelength in the reported phosphor has been attributed to the coordination environment of the transition metal ion (Mo{sup 6+}, W{sup 6+}) and host crystal structure. Furthermore the quantum efficiency of the phosphors has been enhanced by adjusting activator concentration, suitable compositional alloying using substitutional alkaline earth metal cations and charge compensation mechanisms. - Graphical abstract: The charge transfer excitation of orthorhombic Mg{sub 0.6}Ca{sub 2.16}Mo{sub 0.2}W{sub 0.8}O{sub 6}: Eu{sub 0.12}{sup 3+}/Na{sub 0.12}{sup +} is significantly higher than tetragonal CaMoO{sub 4}: Eu{sup 3+} phosphors making Mg{sub 0.6}Ca{sub 2.16}Mo{sub 0.2}W{sub 0.8}O{sub 6}: Eu{sub 0.12}{sup 3+}/Na{sub 0.12}{sup +} prime candidates for fabrication of warm white phosphor-converted LEDs. - Highlights: • LED excitable Mg{sub 0.6}Ca{sub 2.16}Mo{sub 0.2}W{sub 0.8}O{sub 6}: Eu{sub 0.12}{sup 3+}/Na{sub 0.12}{sup +} phosphors were synthesized. • These phosphors are 10 times more intense than CaMoO{sub 4}: Eu{sup 3+} red phosphors. • Their intensity and efficiency were enhanced by materials optimization techniques. • Such techniques include compositional alloying, charge compensation, etc.

Labelling of MoAb with 153SmH1ETA: Preliminary results

International Nuclear Information System (INIS)

Ferro-Flores, G.; De, F.; Ramirez, M.; Pedraza-Lopez, M.; Tendilla, J.I.; Melendez-Alafort, L.; Murphy, C.A.

2001-01-01

A method to label MoAb with Sm-153 using 1,5,9,13-tetraazacyclohexadecane N,N',N'',N''' tetraacetic acid (H 4 ETA) as a bifunctional chelator was developed. H 4 ETA and SmH 1 ETA were synthesized in our laboratory and characterized by IR spectroscopy, TGA (thermogravimetric analysis), SEM (Scattering Electronic Microscopy), EDAX (Elemental Dispersion Analysis by X-rays) and EPR (Electron Paramagnetic Resonance) at 6 K. The 153 SmH 1 ETAMoAb was prepared by a simple incubation of the MoAb ior cea1, and the 153 SmH 1 ETA complex at neutral pH and at room temperature for 24 h. The specific activity of the labelled antibody was 111 MBq/mg (3 mCi/mg). Sm-153(III) is commercially available with specific activities up to 318.2 GBq/mg. Therefore, under the conditions described above 153 SmH 1 ETA labelled MoAb could be obtained with specific activity up to 1.14 GBq/mg (30.7 mCi/mg). (author)

Influence of H2O and H2S on the Composition, Activity, and Stability of Sulfided Mo, CoMo, and NiMo Supported on MgAl2O4 for Hydrodeoxygenation of Ethylene Glycol

DEFF Research Database (Denmark)

Dabros, Trine Marie Hartmann; Gaur, Abhijeet; Pintos, Delfina Garcia

2018-01-01

In this work, density functional theory (DFT), catalytic activity tests, and in-situ X-ray absorption spectroscopy (XAS) was performed to gain detailed insights into the activity and stability of MoS2, Ni-MoS2, and Co-MoS2 catalysts used for hydrodeoxygenation (HDO) of ethylene glycol upon...

Absence of traditional magnetoresistivity mechanisms in Sr2FeMoO6 thin films grown on SrTiO3, MgO and NdGaO3 substrates.

Science.gov (United States)

Saloaro, M; Majumdar, S; Huhtinen, H; Paturi, P

2012-09-12

Magnetoresistive double perovskite Sr(2)FeMoO(6) thin films were grown with two different deposition pressures on SrTiO(3), MgO and NdGaO(3) substrates by pulsed laser deposition and thorough structural, magnetic and magneto-transport characterization was made. According to x-ray diffraction, all the films were phase pure and fully textured. Indication of substrate dependent strain and low angle grain boundaries was found, especially in films on MgO. Both the deposition pressure and the choice of the substrate have a strong influence on the saturation magnetization, M(s), and Curie temperature, T(C). The structural and magnetic data indicate the presence of anti-site disorder (ASD) in the films. The temperature dependence of resistivity showed semiconductive behaviour at temperatures below 100 K and metallic behaviour at higher temperatures. The semiconductive behaviour was found to increase with increasing ASD. In good quality films, up to 12% negative magnetoresistance (MR) was observed and films grown on MgO and NGO substrates also showed low field MR. However, the most significant observation of this study was that the magnetoresistivity of these Sr(2)FeMoO(6) thin films could not be explained with any traditional MR mechanism, but carried the clear signature of superposition of different mechanisms, in particular low angle grain boundary tunnelling and suppression of antiferromagnetically ordered domains under a magnetic field.

Cyclil Oxidation Behaviors of MoSi2 with Different Relative Density

Institute of Scientific and Technical Information of China (English)

YAN Jianhui; ZHANG Houan; TANG Siwen; XU Jianguang

2008-01-01

The influence of different relative density on the cyclic oxidation behaviors of MoSi2 at 1 273 K were studied. "Pesting" was not found in all MoSi2 materials after being oxidized for 480 h. All samples exhibited continuous mass gain during the oxidation process. The mass gains of MoSi2 with the lowest relative density (78.6%) and the highest relative density (94.8%) are increased by 8.15 mg·cm2 and 3.48 mg·cm-2, respectively. The surface of the material with lower relative density formed a loose, porous and discontinuous oxidation scale, which accelerated oxygen diffusion and aggravated the oxidation process. However, a dense scale in the material with higher relative density is formed, which acts a diffusion barrier to the oxygen atoms penetrating into the matrix. The high temperature oxidation resistance of MoSi2 can be improved by increasing its relative density.

MoO3 incorporation in magnesium aluminosilicate glasses

International Nuclear Information System (INIS)

Tan, Shengheng; Ojovan, Michael I.; Hyatt, Neil C.; Hand, Russell J.

2015-01-01

Molybdate has a very low solubility in silicate and borosilicate glass systems and its excess presence in nuclear waste glass can cause the formation of a readily soluble “yellow phase”. In this study, the incorporation of molybdenum oxide (MoO 3 ) in a magnesium aluminosilicate glass system has been investigated. The prepared glasses show a higher than 90% molybdenum retention rate and up to 5.34 mol% (12.28 wt%) MoO 3 can be incorporated into these glasses without causing visible phase separation. The incorporation of MoO 3 increases glass density, decreases glass transition and crystallisation temperatures and intensifies Raman bands assigned to vibrations of MoO 4 2− units. When excess molybdate is added liquid–liquid phase separation and crystallisation occurs. The separated phase is spherical, 200–400 nm in diameter and randomly dispersed. Based on powder X-ray diffraction, Raman spectroscopy and transmission electron microscopy, the separated phase is identified as MgMoO 4

Development of Molybdenum Adsorbent for 99Mo/99mTc Radioisotope Generator Based on Irradiated Natural Molybdenum

International Nuclear Information System (INIS)

Rohadi Awaludin; Hotman Lubis; Sriyono; Abidin; Herlina; Endang Sarmini; Indra Saptiama; Hambali

2011-01-01

Preparation of 99 Mo/ 99m Tc radioisotope generator using irradiated natural molybdenum requires an adsorbent with high absorption capacity. Zirconium-based materials (ZBM), adsorbent with adsorption capacity of about 183 mg(Mo) / g(adsorbent), has been successfully synthesized. However, the adsorbent was easily broken in the Mo adsorption process due to many fractures in the grain. To increase the hardness, the material was immersed in tetraethyl orthosilicate (TEOS) and coated by TEOS flow in a column. The hardness test results showed that the ZBM with TEOS treatment was not broken when immersed into the Mo solution. Observations using SEM showed that the fractures formed on the ZBM were successfully removed by TEOS treatment. Measurements using EDS showed that after TEOS treatment, the silicon was detected and the oxygen content increased in the material surface. Adsorption test results showed that the TEOS immersion decreased the adsorption capacity of molybdenum from 183 to 79.8 mg of Mo per gram of adsorbent. The TEOS flow-in a column gave material with relatively high adsorption capacity, 140 mgMo per gram adsorbent. The content of Silicon in the surface was lower than that of adsorbent immersed in TEOS. (author)

Magneto-optical and electromagnetic studies of core connectivity and weak-link behaviour in Cu/MgB2 and Ni/MgB2 wires and tapes

International Nuclear Information System (INIS)

Polyanskii, A; Beilin, V; Felner, I; Tsindlekht, M I; Yashchin, E; Dul'kin, E; Galstyan, E; Roth, M; Senkowicz, B; Hellstrom, E

2004-01-01

Critical current density, ac susceptibility (real part χ' and magneto-optical (MO) imaging were used to characterize round wire and tapes made from pre-reacted MgB 2 powder by the powder-in-tube method. Magnetic susceptibility measurements indicated the existence of large-scale weak-link networks in the cores of as-deformed Ni/MgB 2 and Cu/MgB 2 wires and tapes. As-deformed samples showed a two-step transition in χ' versus T traces as evidence of weak links in the tape core. The first heat treatment (HT) of as-deformed tapes led to a sharp susceptibility transition, very strong connection in the tape core as seen in MO images, and high critical current. A second rolling of an as-sintered tape induced a network of defects in the brittle core and gave rise to χ' curve broadening, but did not result in a two-step transition. These data show that deformation-induced cracks are not the primary source of weak-link behaviour. A large decrease in transport current was also registered in this sample. The second HT, for 30 min, restored the sharp magnetic transition and high transport current. Alternating areas of strong and weak connection in the tape core have been observed on MO images. Fast heating and cooling of the as-deformed tape with no dwell time at the maximum temperature resulted in a strongly linked core with a sharp transition and increased transport current. After fast HT, no mechanical defects were observed in MO images. Such fast transformation could be explained by rapid sintering due to highly strained MgB 2 grains

Diffusion barrier performances of thin Mo, Mo-N and Mo/Mo-N films between Cu and Si

International Nuclear Information System (INIS)

Song Shuangxi; Liu Yuzhang; Mao Dali; Ling Huiqin; Li Ming

2005-01-01

In this work, we have studied the diffusion barrier performances of Mo, Mo-N and Mo/Mo-N metallization layers deposited by sputtering Mo in Ar/N 2 atmospheres, respectively. Samples were subsequently annealed at different temperatures ranging from 400 to 800 deg C in vacuum condition. The film properties and their suitability as diffusion barriers and protective coatings in silicon devices were characterized using four-point probe measurement, X-ray diffractometry, scanning electron microscopy, Auger electron spectroscopy and transmission electron microscopy analyses. Experimental results revealed that the Mo (20 nm)/Mo-N (30 nm) layer was able to prevent the diffusion reaction between Cu and Si substrate after being annealed at 600 deg C for 30 min. The adhesion between layers and the content of N atoms are the key parameters to improve the properties of Mo-based barrier materials. The Mo layer interposed between Cu and Mo-N diluted the high nitrogen concentration of the barrier and so enhanced the barrier performances

Use of multivariate statistical tool for data processing in the analysis of Cu, Cr, Fe, Pb, Mo and Mg in lubricating oil by LIBS

International Nuclear Information System (INIS)

Alves, Luana F.N.; Sarkis, Jorge E.S.; Bordon, Isabela C.A.C.

2015-01-01

Analysis of industrial lubricants is widely used for monitoring and predicting maintenance requirements in a broad range of mechanical systems. Laser induced breakdown spectroscopy has been used to evaluate the potentiality of the technique for the determination of metals in lubricating oils. Prior to quantitative analysis, the LIBS system was calibrated using standard samples containing the elements investigated (Cu, Cr, Fe, Pb, Mo and Mg). This study presents the usefulness of multivariate statistical techniques for evaluation and interpretation of large complex data sets in order to get more information about concentration of metals in oils lubricants is related to engine wear. (author)

Incidência de ocratoxina A em café torrado e moído e em café solúvel consumido na cidade de Belo Horizonte, MG

Directory of Open Access Journals (Sweden)

PRADO Guilherme

2000-01-01

Full Text Available A ocorrência de ocratoxina A foi verificada em amostras de café solúvel e café torrado e moído, comercializados em Belo Horizonte/MG, no período de outubro/1998 a maio/1999. O método usado para a determinação de ocratoxina A foi a cromatografia líquida de alta eficiência (CLAE em combinação com cromatografia de imunoafinidade. Os valores de recuperação e coeficiente de variação de ocratoxina A foram superiores a 73% e inferiores 15%, respectivamente. As amostras de café solúvel e café torrado e moído, continham níveis de ocratoxina A entre 0,31 e 1,78ng/g e 0,99 e 5,87ng/g, respectivamente. Os resultados revelaram que o café não apresenta níveis de contaminação significativos.

Microstructure and properties of MoSi2-MoB and MoSi2-Mo5Si3 molybdenum silicides

International Nuclear Information System (INIS)

Schneibel, J.H.; Sekhar, J.A.

2003-01-01

MoSi 2 -based intermetallics containing different volume fractions of MoB or Mo 5 Si 3 were fabricated by hot-pressing MoSi 2 , MoB, and Mo 5 Si 3 powders in vacuum. Both classes of alloys contained approximately 5 vol.% of dispersed silica phase. Additions of MoB or Mo 5 Si 3 caused the average grain size to decrease. The decrease in the grain size was typically accompanied by an increase in flexure strength, a decrease in the room temperature fracture toughness, and a decrease in the hot strength (compressive creep strength) measured around 1200 deg. C, except when the Mo 5 Si 3 effectively became the major phase. Oxidation measurements on the two classes of alloys were carried out in air. Both classes of alloys were protected from oxidation by an in-situ adherent scale that formed on exposure to high temperature. The scale, although not analyzed in detail, is commonly recognized in MoSi 2 containing materials as consisting mostly of SiO 2 . The MoB containing materials showed an increase in the scale thickness and the cyclic oxidation rate at 1400 deg. C when compared with pure MoSi 2 . However, in contrast with the pure MoSi 2 material, oxidation at 1400 deg. C began with a weight loss followed by a weight gain and the formation of the protective silica layer. The Mo 5 Si 3 containing materials experienced substantial initial weight losses followed by regions of small weight changes. Overall, the MoB and Mo 5 Si 3 additions to MoSi 2 tended to be detrimental for the mechanical and oxidative properties

Fabrication of blue luminescent MoS{sub 2} quantum dots by wet grinding assisted co-solvent sonication

Energy Technology Data Exchange (ETDEWEB)

Ali, Junaid; Siddiqui, Ghayas Uddin [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of); Choi, Kyung Hyun, E-mail: amm@jejunu.ac.kr [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of); Jang, Yunseok [Department of Printed Electronics, Korea Institute of Machinery & Materials, Daejeon, Republic of Korea (Korea, Republic of); Lee, Kangtaek [Department of Chemical and Biomolecular Engineering, Yonsei University (Korea, Republic of)

2016-01-15

Molybdenum disulfide (MoS{sub 2}) belongs to transition-metal dichalcogenides (TMDs) family and has vital position among 2D materials. Here, an efficient strategy for the synthesis of zero-dimensional MoS{sub 2} quantum dots (QDs) has been represented. This strategy consists of wet grinding of pristine MoS{sub 2} in N-methyl-2-pyrrolidone (NMP) followed by sonication in NMP and 1,2-dichlorobenzene (o-DCB). The efficacy of this approach to synthesize MoS{sub 2} QDs has been reported by analyzing the as synthesized MoS{sub 2} QDs by different characterization techniques such as high resolution transmission electron microscopy, energy dispersive x-ray spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, Fourier transform infrared spectroscopy and UV–vis spectroscopy. The concentration (yield) of as synthesized MoS{sub 2} QDs was found to be 7 mg mL{sup −1}. Most of the MoS{sub 2} QDs were measured around 2–5 nm in size. The as synthesized MoS{sub 2} QDs showed distinct blue luminescence upon UV excitation. - Highlights: • Synthesis of MoS{sub 2} quantum dots. • Wet grinding of MoS{sub 2} flakes for 6 h in NMP. • Ultrasonication of MoS{sub 2} in NMP and DCB. • Particle size 2–5 nm and concentration 7 mg/ml. • MoS{sub 2} QDs showed blue luminescence.

99Mo production by 100Mo(n,2n)99Mo using accelerator neutrons

International Nuclear Information System (INIS)

Sato, Nozomi; Kawabata, Masako; Nagai, Yasuki; Hashimoto, Kazuyuki; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji; Kin, Tadahiro; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Minato, Futoshi; Iwamoto, Osamu; Iwamoto, Nobuyuki; Hashimoto, Shintaro

2013-01-01

We proposed a new route to produce a medical radioisotope 99 Mo by the 100 Mo(n,2n) 99 Mo reaction using accelerator neutrons. A high-quality 99 Mo with a minimum level of radioactive waste can be obtained by the proposed reaction. The decay product of 99 Mo, 99m Tc, is separated from 99 Mo by the sublimation method. The proposed route could bring a major breakthrough in the solution of ensuring a constant and reliable supply of 99 Mo. (author)

MoO{sub 3} incorporation in magnesium aluminosilicate glasses

Energy Technology Data Exchange (ETDEWEB)

Tan, Shengheng; Ojovan, Michael I.; Hyatt, Neil C.; Hand, Russell J.

2015-03-15

Molybdate has a very low solubility in silicate and borosilicate glass systems and its excess presence in nuclear waste glass can cause the formation of a readily soluble “yellow phase”. In this study, the incorporation of molybdenum oxide (MoO{sub 3}) in a magnesium aluminosilicate glass system has been investigated. The prepared glasses show a higher than 90% molybdenum retention rate and up to 5.34 mol% (12.28 wt%) MoO{sub 3} can be incorporated into these glasses without causing visible phase separation. The incorporation of MoO{sub 3} increases glass density, decreases glass transition and crystallisation temperatures and intensifies Raman bands assigned to vibrations of MoO{sub 4}{sup 2−} units. When excess molybdate is added liquid–liquid phase separation and crystallisation occurs. The separated phase is spherical, 200–400 nm in diameter and randomly dispersed. Based on powder X-ray diffraction, Raman spectroscopy and transmission electron microscopy, the separated phase is identified as MgMoO{sub 4}.

Nanostructured metal oxides: promise opportunity and challenge to develop clinically useful 99Mo/99mTc generators using (n, gamma)99Mo

International Nuclear Information System (INIS)

Dash, Ashutosh

2014-01-01

The role of 99m Tc diagnostic nuclear medicine needs hardly to be reiterated. Today, it is the most widely used radionuclide for single photon emission computed tomography (SPECT) imaging procedures. The current strategy of availing 99m Tc is ensured from column chromatographic 99 Mo/ 99m Tc generators using a bed of acidic alumina. While the column chromatographic 99 Mo/ 99m Tc generator constitute a successful exemplar of availing 99m Tc, the limited capacity of alumina (2-20 mg Mo per g of alumina) for taking up molybdate ions necessitates the use of 99 Mo of the highest specific activity available, as can be found in fission produced 99 Mo (F 99 Mo). In order to reduce dependence of F 99 Mo, the scope of using low specific activity (n,γ) 99 Mo along with high capacity adsorbent is an interesting prospect. In this context, the scope of using nanomaterials as a viable adsorbent seemed attractive by virtue of their huge surface to volume ratios, altered physical properties, tailored surface chemistry, favorable adsorption characteristics, and enhanced surface reactivity resulting from the nanoscale dimensions. This emerging class of adsorbent represents an innovative paradigm and is expected to play an important role in the development of 99 Mo/ 99m Tc generators adaptable to the existing and foreseeable demands. This talk outlines a critical assessment on the role of nanostructured metal oxides, recent developments, the contemporary status, and key challenges and apertures to the near future. (author)

Production of carbon nanotubes: Chemical vapor deposition synthesis from liquefied petroleum gas over Fe-Co-Mo tri-metallic catalyst supported on MgO

Energy Technology Data Exchange (ETDEWEB)

Setyopratomo, P., E-mail: puguh-sptm@yahoo.com; Wulan, Praswasti P. D. K., E-mail: wulanmakmur@gmail.com; Sudibandriyo, M., E-mail: msudib@che.ui.ac.id [Chemical Engineering Department, University of Indonesia, Depok Campus, Depok 16424 (Indonesia)

2016-06-03

Carbon nanotubes were produced by chemical vapor deposition method to meet the specifications for hydrogen storage. So far, the various catalyst had been studied outlining their activities, performances, and efficiencies. In this work, tri-metallic catalyst consist of Fe-Co-Mo supported on MgO was used. The catalyst was prepared by wet-impregnation method. Liquefied Petroleum Gas (LPG) was used as carbon source. The synthesis was conducted in atmospheric fixed bed reactor at reaction temperature range 750 – 850 °C for 30 minutes. The impregnation method applied in this study successfully deposed metal component on the MgO support surface. It found that the deposited metal components might partially replace Mg(OH){sub 2} or MgO molecules in their crystal lattice. Compare to the original MgO powder; it was significant increases in pore volume and surface area has occurred during catalyst preparation stages. The size of obtained carbon nanotubes is ranging from about 10.83 nm OD/4.09 nm ID up to 21.84 nm OD/6.51 nm ID, which means that multiwall carbon nanotubes were formed during the synthesis. Yield as much as 2.35 g.CNT/g.catalyst was obtained during 30 minutes synthesis and correspond to carbon nanotubes growth rate of 0.2 μm/min. The BET surface area of the obtained carbon nanotubes is 181.13 m{sup 2}/g and around 50 % of which is contributed by mesopores. Micropore with half pore width less than 1 nm contribute about 10% volume of total micro and mesopores volume of the carbon nanotubes. The existence of these micropores is very important to increase the hydrogen storage capacity of the carbon nanotubes.

Preparation of MoB and MoB-MoSi2 composites by combustion synthesis in SHS mode

International Nuclear Information System (INIS)

Yeh, C.L.; Hsu, W.S.

2007-01-01

Combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) was carried out in the Mo-B and Mo-B-Si systems for the preparation of molybdenum boride MoB and the composite of MoB-MoSi 2 from elemental powder compacts. Under a preheating temperature above 150 deg. C , the reaction of Mo with boron in the sample compact of Mo:B = 1:1 is characterized by a planar combustion front propagating in a self-sustaining and steady manner. As the preheating temperature or sample compaction density increased, combustion temperature was found to increase and the propagation rate of the combustion front was correspondingly enhanced. Moreover, the XRD analysis provides evidence of yielding nearly single-phase α-MoB from the Mo-B sample at equiatomic stoichiometry. In the synthesis of MoB-MoSi 2 composites, the starting stoichiometry of the Mo-B-Si powder compact was varied so as to produce the final composites containing 20-80 mol% MoB. It was also found the increase of flame-front velocity and combustion temperature with increasing MoB content formed in the composite. The composition analysis by XRD shows excellent conversion from the Mo-B-Si powder compact to the MoB-MoSi 2 composite through the SHS reaction; that is, in addition to a small amount of Mo 5 Si 3 , the as-synthesized composite is composed entirely of MoB and MoSi 2

Microstructure, mechanical property, corrosion behavior, and in vitro biocompatibility of Zr-Mo alloys.

Science.gov (United States)

Zhou, F Y; Wang, B L; Qiu, K J; Li, L; Lin, J P; Li, H F; Zheng, Y F

2013-02-01

In this study, the microstructure, mechanical properties, corrosion behaviors, and in vitro biocompatibility of Zr-Mo alloys as a function of Mo content after solution treatment were systemically investigated to assess their potential use in biomedical application. The experimental results indicated that Zr-1Mo alloy mainly consisted of an acicular structure of α' phase, while ω phase formed in Zr-3Mo alloy. In Zr-5Mo alloy, retained β phase and a small amount of precipitated α phase were observed. Only the retained β phase was obtained in Zr-10Mo alloy. Zr-1Mo alloy exhibited the greatest hardness, bending strength, and modulus among all experimental Zr-Mo alloys, while β phase Zr-10Mo alloy had a low modulus. The results of electrochemical corrosion indicated that adding Mo into Zr improved its corrosion resistance which resulted in increasing the thermodynamic stability and passivity of zirconium. The cytotoxicity test suggested that the extracts of the studied Zr-Mo alloys produced no significant deleterious effect to fibroblast cells (L-929) and osteoblast cells (MG 63), indicating an excellent in vitro biocompatibility. Based on these facts, certain Zr-Mo alloys potentially suitable for different biomedical applications were proposed. Copyright © 2012 Wiley Periodicals, Inc.

Sign system choice influence on the substance formation forecast in A2MoO4-B2(MoO4)3 and A2MoO4-CMoO4 systems

International Nuclear Information System (INIS)

Manzanov, Yu.E.; Lutsik, V.I.; Mokhosoev, M.V.

1987-01-01

Three sign spaces were used for forecasting compound formation in A 2 MoO 4 -B 2 (MoO 4 ) 3 (5:1 ratio, where A-Li, Na, K, Rb, Cs; B-Al, In, Ga, Sc, Cr, Fe, Bi, La, Nd, Sm-Lu, Y) and A 2 MoO 4 -CMoO 4 (1:2 ratio, where A-Li, Na, K, RB, Cs, Tl; C-Mg, Ca, Sr, Ba, Cu, Zn, Cd, Pd, Mn, Co, Ni) systems: 1-electron distribution on energy shells of cations and their valency; 2-the type of incomplete electron shell, charge of cations, three first ionization potentials, standard heat capacity, ionic radius of cations; 3-standard formation enthalpy and standard entropy, oxide melting points and ionic radius of cations. It is shown that sign space, related with thermodynamic properties of oxides contains data, necessary for forecasting interaction in molybdate systems. This enables to improve reliability of forecasting

Structure of β-TlMo2P3O13

International Nuclear Information System (INIS)

Costentin, G.; Borel, M.M.; Grandin, A.; Leclaire, A.; Raveau, B.

1991-01-01

Thallium molybdenum triphosphate, TlMo 2 P 3 O 13 , M r =679.16, monoclinic, P2 1 /c, a=9.7536 (3), b=19.0640 (16), c=6.3945 (7) A, β=107.099 (7) 0 , V=1136 (2) A 3 , Z=4, D m not measured, D x =4.08 Mg m -3 , λ(MoKα)=0.71073 A, μ=16.90 mm -1 , F(000)=314, T=293 K, 951 reflections, R=0.047, ωR=0.047. The lattice is built up from MoO 6 , PO 4 and P 2 O 7 groups delimiting tunnels where the Tl + ions are located. The title compound is isotyopic with β-KMo 2 P 3 O 13 . (orig.)

Measurement of target and double-spin asymmetries for the mo>→>p<mo>→→eπ+(n)> reaction in the nucleon resonance region at low $Q^2$

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 mo>→>p<mo>→→eπ+(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.

Electronic structures of B1 MoN, fcc Mo2N, and hexagonal MoN

International Nuclear Information System (INIS)

Ihara, H.; Kimura, Y.; Senzaki, K.; Kezuka, H.; Hirabayashi, M.

1985-01-01

The electronic structures of B1 MoN, fcc Mo 2 N, and hexagonal MoN were observed by photoelectron spectroscopic measurement. The B1-MoN phase has been predicted to be a high-T/sub c/ superconductor because of a large density of states at Fermi level. The observed electronic structure of the stoichiometric B1-MoN phase is different from that of the real B1-MoN type. The nitrogen excess B1-MoN/sub x/ (x> or =1.3) phase, however, shows the B1-type electronic structure. This is explained by the occurrence of a nitrogen vacancy in the apparent stoichiometric B1 phase and the occupation of the nitrogen vacancy in the nitrogen-excess B1 phase. This property is related to the previously reported low T/sub c/ of the B1-MoN crystals

Surface Modifications with Laser Synthesized Mo Modified Coating

Science.gov (United States)

Sun, Lu; Chen, Hao; Liu, Bo

2013-01-01

Mg-Cu-Al was first used to improve the surface performance of TA15 titanium alloys by means of laser cladding technique. The synthesis of hard composite coating on TA15 titanium alloy by laser cladding of Mg-Cu-Al-B4C/Mo pre-placed powders was investigated by means of scanning electron microscope, energy dispersive spectrometer and high resolution transmission electron microscope. Experimental results indicated that such composite coating mainly consisted of TiB2, TiB, TiC, Ti3Al and AlCuMg. Compared with TA15 alloy substrate, an improvement of wear resistance was observed for this composite coating due to the actions of fine grain, amorphous and hard phase strengthening.

Preparation of Sr2(MgMo)1-xRuxO6 ceramics for use in a solid oxide fuel cell anode

International Nuclear Information System (INIS)

Bezerra, Matheus Eiji Ohno; Florio, Daniel Zanetti de; Fonseca, Fabio Coral

2016-01-01

Full text: Solid Oxide Fuel Cells are the most efficient devices known for the direct conversion of fuels into electric energy. Such devices have advanced steadily and are already available for specific applications such as portable power and residential stationary generation. The main objective of this work is the development of anodes for SOFC operating directly with renewable fuels, without the addition of water and using strategic fuels such as ethanol and natural gas. Specifically, a family of mixed ionic-electronic compounds has been investigated: the double perovskites with compositions Sr 2 (MgMo) 1-x Ru x O 6 with x = 0; 1; 2; 5; 10 e 20 at.%. This material has been synthesized by polymeric precursor method. The resins were prepared by combining stoichiometric amounts of the starting solutions. The resulting solution was heated treated under magnetic stirring. The thermal decomposition of the polymeric resin was studied by means of simultaneous thermogravimetric and differential scanning calorimetry up to 1500 °C with heating and cooling rates of 10 °/min in Ar. The thermal decomposition result shows mass loss up to, approximately, 900 °C. However X-ray diffraction analyses of the powder heat treated at 900 °C and 1200 °C presents a considerable content of an undesiderate phase (SrMoO 4 ). According to the literature for similar compounds a thermal treatment under reduction conditions could be necessary to obtain the double perovskites single phase. After this treatment the material will be characterized regarding its electrical properties. The expected results will contribute to advance both the understanding of the mixed ionic electronic ceramics and the SOFC technology using renewable fuels. (author)

Effect of hydrogen on the growth and morphology of single wall carbon nanotubes synthesized on a Fe-Mo/MgO catalytic system

Energy Technology Data Exchange (ETDEWEB)

Biris, Alexandru R. [National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj Napoca, RO-3400 (Romania)], E-mail: biris@oc1.itim-cj.ro; Li Zhongrui; Dervishi, Enkeleda [Applied Science Department, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Nanotechnology Center, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Lupu, Dan [National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj Napoca, RO-3400 (Romania); Xu Yang; Saini, Viney [Applied Science Department, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Nanotechnology Center, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Watanabe, Fumiya [Nanotechnology Center, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Biris, Alexandru S. [Applied Science Department, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States); Nanotechnology Center, University of Arkansas at Little Rock, 2801 S. University Ave, Little Rock, AR 72204 (United States)], E-mail: asbiris@ualr.edu

2008-04-21

Single wall carbon nanotubes were synthesized from thermal pyrolysis of methane on a Fe-Mo/MgO catalyst by radio frequency catalytic chemical vapor deposition (RF-CVD) using argon as a carrier gas. Controlled amounts of hydrogen (H{sub 2}/CH{sub 4}=0-1 v/v) were introduced in separate experiments along with the carbon source. The properties and morphology of the synthesized single wall carbon nanotubes were monitored by transmission electron microscopy, Raman scattering, and thermogravimetric analysis. The nanotubes with the highest crystallinity were obtained with H{sub 2}/CH{sub 4}=0.6. By monitoring the Radial Breathing Modes present in the Raman spectra of the single-wall carbon nanotube samples, the variation of the structural and morphological properties of the carbon nanotubes with the flow level of hydrogen, reflect changes of the catalyst systems induced by the presence of hydrogen.

Processing of Mo-Si-B intermetallics by extrusion and oxidation properties of the extruded Tl-MoSi2-MoB Systems

International Nuclear Information System (INIS)

Summers, Eric

1999-01-01

An extrusion process was developed that is able to consistently produce large quantities of Mo-Si-B rods without the presence of defects. Binder removal from the extruded rods was studied in detail and it was determined that heating rates on the order of 0.02degree/minute (1.2degree/hour) are necessary to remove the binder without the formation of defects. This low heating rate resulted in debinding times in excess of 70 hours (∼ 3 days). Wicking was investigated as a means to decrease the time necessary for binder removal. Using 0.05microm alumina powder as a wicking agent, binder removal times were reduced to 10 hours with heating rates up to 1degree/minute employed without defect formation. Once the extrusion process was complete the oxidation properties of the Tl-MoSi 2 -MoB extruded phase assemblage was investigated. It was determined that this composition exhibits catastrophic oxidation or pesting in the temperature range of 660--760 C, resulting in the material turning to dust. Outside of this temperature range the composition is oxidatively stable. Continuous mass measurements were taken at 1,300, 1,450, and 1,600 C to determine the oxidation rate constants of this material. Parabolic rate constants of 6.9 x 10 -3 , 1.3 x 10 -3 , and 9.1 x 10 -3 mg 2 /cm 4 /hr were determined for 1,300, 1,450, and 1,600 C respectively

Proton-oxygen conductivity in substituted perovskites ATi0.95Mo0.05O3-α (A = Ca, Sr, Ba; M = Sc, Mg) in the reducing hydrogen-containing atmospheres

International Nuclear Information System (INIS)

Gorelov, V.P.; Balakireva, V.B.; Sharova, N.V.

1999-01-01

Electric conductivity depending on temperature, oxygen partial pressure, as well as the number of t i ion transfer and transfer hydrogen numbers in the perovskites ATi 0.95 Mo 0.05 O 3-α (A = Ca, Sr, Ba; M = Sc, Mg) in reducing hydrogen-containing atmospheres in the temperature range of 450-850 deg C have been measured. With the temperature decrease t i increases reaching 1.0 at a temperature of 550 deg C for all compositions. Proton conductivity under conditions of assumed concomitant transfer of either O 2- or OH - has been ascertained [ru

Measurement and Estimation of the 99Mo Production Yield by 100Mo(n,2n)99Mo

Science.gov (United States)

Minato, Futoshi; Tsukada, Kazuaki; Sato, Nozomi; Watanabe, Satoshi; Saeki, Hideya; Kawabata, Masako; Hashimoto, Shintaro; Nagai, Yasuki

2017-11-01

We, for the first time, measured the yield of 99Mo, the mother nuclide of 99mTc used in nuclear medicine diagnostic procedures, produced by the 100Mo(n,2n)99Mo reaction with accelerator neutrons. The neutrons with a continuous energy spectrum from the thermal energy up to about 40 MeV were provided by the C(d,n) reaction with 40 MeV deuteron beams. It was proved that the 99Mo yield agrees with that estimated by using the latest data on neutrons from the C(d,n) reaction and the evaluated cross section of the 100Mo(n,2n)99Mo reaction given in the Japanese Evaluated Nuclear Data Library. On the basis of the agreement, a systematic calculation was carried out to search for an optimum condition that enables us to produce as much 99Mo as possible with a good 99Mo/100Mo value from an economical point of view. The calculated 99Mo yield from a 150 g 100MoO3 sample indicated that about 30% of the demand for 99Mo in Japan can be met with a single accelerator capable of 40 MeV, 2 mA deuteron beams. Here, by referring to an existing 18F-fluorodeoxyglucose (FDG) distribution system we assumed that 99mTc radiopharmaceuticals formed after separating 99mTc from 99Mo can be delivered to hospitals from a radiopharmaceutical company within 6 h. The elution of 99mTc from 99Mo twice a day would meet about 50% of the demand for 99Mo.

Electric field enhanced adsorption and diffusion of adatoms in MoS{sub 2} monolayer

Energy Technology Data Exchange (ETDEWEB)

Shi, Wenwu [School of Physical Electronics, Center for Public Security Information and Equipment Integration Technology, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Wang, Zhiguo, E-mail: zgwang@uestc.edu.cn [School of Physical Electronics, Center for Public Security Information and Equipment Integration Technology, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Li, Zhijie [School of Physical Electronics, Center for Public Security Information and Equipment Integration Technology, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Fu, Y.Q., E-mail: richard.fu@northumbria.ac.uk [School of Physical Electronics, Center for Public Security Information and Equipment Integration Technology, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Faculty of Engineering and Environment, University of Northumbria, Newcastle upon Tyne, NE1 8ST (United Kingdom)

2016-11-01

A new phenomenon, electric field enhanced adsorption and diffusion of lithium, magnesium and aluminum ions in a MoS{sub 2} monolayer, was investigated using density functional theory in this study. With the electric field increased from 0 to 0.8 V/Å, the adsorption energies of the Li, Mg and Al atoms in the MoS{sub 2} monolayer were decreased from −2.01 to −2.49 eV, from −0.80 to −1.28 eV, and −2.71 to −3.01 eV, respectively. The corresponding diffusion barriers were simultaneously decreased from 0.23 to 0.08 eV, from 0.15 to 0.10 eV, and 0.24 to 0.21 eV for the Li, Mg and Al ions, respectively. We concluded that the external electric field can increase the charging speed of rechargeable ion batteries based on the MoS{sub 2} anode materials. - Highlights: • Effect of electric field on the adsorption and diffusion were investigated. • Adsorption energies of the adatoms in the MoS{sub 2} monolayer were enhanced. • Diffusion barriers of the adatoms in the MoS{sub 2} monolayer were decreased. • Electric field can be used to realize a fast charging rate of rechargeable ion batteries.

Express and low-cost microwave synthesis of the ternary Chevrel phase Cu{sub 2}Mo{sub 6}S{sub 8} for application in rechargeable magnesium batteries

Energy Technology Data Exchange (ETDEWEB)

Murgia, Fabrizio; Antitomaso, Philippe; Stievano, Lorenzo; Monconduit, Laure [Institut Charles Gerhardt de Montpellier (ICGM, UMR 5253CNRS Université de Montpellier), 2, Place Eugène Bataillon, CC1502, 34095 Montpellier cedex 5 (France); Réseau sur le Stockage Electrochimique de l' Energie (RS2E,FR 3459CNRS), 33, Rue Saint-Leu, 80039 Amiens cedex (France); Berthelot, Romain, E-mail: romain.berthelot@umontpellier.fr [Institut Charles Gerhardt de Montpellier (ICGM, UMR 5253CNRS Université de Montpellier), 2, Place Eugène Bataillon, CC1502, 34095 Montpellier cedex 5 (France); Réseau sur le Stockage Electrochimique de l' Energie (RS2E,FR 3459CNRS), 33, Rue Saint-Leu, 80039 Amiens cedex (France)

2016-10-15

The ternary Chevrel phase Cu{sub 2}Mo{sub 6}S{sub 8} was successfully synthetized using a simple and cost-effective solid-state microwave-assisted reaction. While solid-state routes require days of high-temperature treatment under inert atmosphere, highly pure and crystalline Cu{sub 2}Mo{sub 6}S{sub 8} could be obtained in only 400 s from this precursor, the Chevrel binary phase Mo{sub 6}S{sub 8} was then obtained by copper removal through acidic leaching, and was evaluated as a positive electrode material for Mg-battery. The electrochemical performance in half-cell configuration shows reversible capacity exceeding 80 mAh/g, which is comparable to previous works carried out with materials synthesized by conventional high-temperature solid-state routes. - Graphical abstract: Ultrafast micro-wave synthesis of Chevrel phase Cu{sub 2}Mo{sub 6}S{sub 8} towards Mo{sub 6}S{sub 8} as positive electrode of Mg-battery. - Highlights: • Chevrel phase Cu{sub 2}Mo{sub 6}S{sub 8} is synthesized by fast microwave-assisted solid-state reaction. • Highly-pure and well-crystalline Cu{sub 2}Mo{sub 6}S{sub 8} is obtained. • Mo{sub 6}S{sub 8} obtained from leaching is tested as a positive electrode for Mg batteries.

Mass spectrometric determination of stability of gaseous BaMoO2, Ba2MoO4, Ba2MoO5, Ba2Mo2O8 molecules

International Nuclear Information System (INIS)

Kudin, L.S.; Balduchchi, Dzh.; Dzhil'i, G.; Gvido, M.

1982-01-01

During the mass spectrometric investigation of BaCrO 4 evaporation Cr + , Ba + , BaO + main ions are recorded as well as BaMoO 4 + , BaMoO 3 + , BaMoO 2 + , BaMoO + , BaMoO 4 + , Ba 2 MoO 5 + , BaMo 2 O 8 + ions - the products of ionization of three-component (Ba, Mo, M) molecules, forming as a result of substance chemical interaction with the material of an effusion cell (Mo). Heats of formation of BaMoO 2 , Ba 2 MoO 4 , Ba 2 MoO 5 and Ba 2 Mo 2 O 8 molecules which constituted - 577+-70, -1343+-115, -1464+-70, -2393+-90 k J/mol respectively are determined on the base of the analysis of curves of ionisation efficiency and of reaction heats Ba 2 MoO 5 =BaO+BaMoO 4 , ΔH 0 0 =322+-60 kJ/mol Ba 2 Mo 2 O 8 =2BaMoO 4 , ΔH 0 0 =351+-80 kJ/mol calculated with the use of third low of thermodynamics [ru

99Mo Yield Using Large Sample Mass of MoO3 for Sustainable Production of 99Mo

Science.gov (United States)

Tsukada, Kazuaki; Nagai, Yasuki; Hashimoto, Kazuyuki; Kawabata, Masako; Minato, Futoshi; Saeki, Hideya; Motoishi, Shoji; Itoh, Masatoshi

2018-04-01

A neutron source from the C(d,n) reaction has the unique capability of producing medical radioisotopes such as 99Mo with a minimum level of radioactive waste. Precise data on the neutron flux are crucial to determine the best conditions for obtaining the maximum yield of 99Mo. The measured yield of 99Mo produced by the 100Mo(n,2n)99Mo reaction from a large sample mass of MoO3 agrees well with the numerical result estimated with the latest neutron data, which are a factor of two larger than the other existing data. This result establishes an important finding for the domestic production of 99Mo: approximately 50% of the demand for 99Mo in Japan could be met using a 100 g 100MoO3 sample mass with a single accelerator of 40 MeV, 2 mA deuteron beams.

Preparation and Oxidation Resistance of Mo-Si-B Coating on Nb-Si Based Alloy Surface

Directory of Open Access Journals (Sweden)

PANG Jie

2018-02-01

Full Text Available Mo-Si-B coating was prepared on Nb-Si alloys to improve the high-temperature oxidation. The influence of the halide activators (NaF and AlF3 on Si-B co-depositing to obtain Mo-Si-B coating on Nb-Si alloys was analyzed by thermochemical calculations. The results show that NaF proves to be more suitable than AlF3 to co-deposit Si and B. Then Mo-Si-B can be coated on Nb-Si based alloys using detonation gun spraying of Mo followed by Si and B co-deposition. The fabricated coatings consist of outer MoSi2 layer with fine boride phase and inner unreacted Mo layer. The mass gain of the Mo-Si-B coating is 1.52mg/cm2 after oxidation at 1250℃ for 100h. The good oxidation resistance results in a protective borosilicate scale formed on the coating.

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.)

Impact of Reduced Graphene Oxide on MoS2 Grown by Sulfurization of Sputtered MoO3 and Mo Precursor Films (Postprint)

Science.gov (United States)

2016-05-26

1,2 intercalation assisted exfoliation,8–11 physical vapor deposition (PVD),12,13 and a wet chemistry approach involving thermal decomposition of a... annealed MoO3, MoS2 films S1 (MoS2 using Mo precursor), S2 (MoS2 using MoO3 precursor), S1r (MoS2 using Mo pre- cursor and rGO), and S2r (MoS2 using...MoO3 precursor and rGO). The annealed MoO3 (a) shows Mo(IV) peaks which are indicative of MoO2, and Mo(VI) peaks that occur when MoO3 is present. Both

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.

Production of $^{99}$?? and $^{99m}$Tc in the $^{100}$Mo($\\gamma, n$) Photonuclear Reaction at the Electron Accelerator - MT-25 Microtron

CERN Document Server

Sabelnikov, A V; Gustova, M V; Dmitriev, S N

2004-01-01

$^{99}$Mo was obtained in the $^{100}$Mo($\\gamma, n$) reaction at the electron accelerator - MT-25 microtron of the LNR. A foil of $^{\\rm nat}$Mo(9.6{\\%} $^{100}$Mo) and $^{100}$MoO$_{3}$ powder (100{\\%} ^{100}$Mo) were used as targets. The $^{99}$Mo radiation yield under experimental conditions amounted to 3.2 kBq/$\\mu $A$\\cdot $h$\\cdot $mg of $^{100}$Mo. The $^{99m}$Tc isolation from the target material and other radioactive impurities was realized by means of ion exchange. A possibility of use of the $^{99}$Mo/$^{99m}$Tc generator based on molybdenumcarbonyl was investigated. The radioactive impurity content in the final $^{99m}$Tc preparations did not exceed 10$^{-5}$ Bq/Bq.

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

Reaction layer between U-7WT%Mo and Al alloys in chemical diffusion couples

International Nuclear Information System (INIS)

Mirandou, M.; Granovsky, M.; Ortiz, M.; Balart, S.; Arico, S.; Gribaudo, L.

2005-01-01

Several failures in U-Mo dispersion fuel plates like pillowing and large porosities have been reported during irradiation experiments. These failures have been assigned to the formation of a large (U-Mo)/Al interaction product under high operating conditions. The modification of the matrix by alloying Al to change the interaction layer and improve its irradiation behavior, has been proposed. This paper reports diffusion experiments performed between U-7wt%Mo and various Al alloys containing Mg and / or Si. By the use of Optical Microscopy, SEM and X-Ray diffraction, it was found that with a concentration of 5.2wt% or 7.1 wt%Si the interaction layer is constituted mainly by (U,Mo)(Si,Al) 3 and no (U,Mo)Al 4 is detected. As part of the studies of properties of the U-Mo alloys the time for isothermal transformation start at different temperatures of the γ phase is being evaluated for the present U-7wt%Mo alloy. These results are used to plan the future diffusion program that will include diffusion under irradiation at CNEA RA3 reactor. (author)

Origin of unusual HREE-Mo-rich carbonatites in the Qinling orogen, China.

Science.gov (United States)

Song, Wenlei; Xu, Cheng; Smith, Martin P; Kynicky, Jindrich; Huang, Kangjun; Wei, Chunwan; Zhou, Li; Shu, Qihai

2016-11-18

Carbonatites, usually occurring within intra-continental rift-related settings, have strong light rare earth element (LREE) enrichment; they rarely contain economic heavy REE (HREE). Here, we report the identification of Late Triassic HREE-Mo-rich carbonatites in the northernmost Qinling orogen. The rocks contain abundant primary HREE minerals and molybdenite. Calcite-hosted fluid inclusions, inferred to represent a magmatic-derived aqueous fluid phase, contain significant concentrations of Mo (~17 ppm), reinforcing the inference that these carbonatitic magmas had high Mo concentrations. By contrast, Late Triassic carbonatites in southernmost Qinling have economic LREE concentrations, but are depleted in HREE and Mo. Both of these carbonatite types have low δ 26 Mg values (-1.89 to -1.07‰), similar to sedimentary carbonates, suggesting a recycled sediment contribution for REE enrichment in their mantle sources. We propose that the carbonatites in the Qinling orogen were formed, at least in part, by the melting of a subducted carbonate-bearing slab, and that 10 Ma younger carbonatite magmas in the northernmost Qinling metasomatized the thickened eclogitic lower crust to produce high levels of HREE and Mo.

Impact of reduced graphene oxide on MoS{sub 2} grown by sulfurization of sputtered MoO{sub 3} and Mo precursor films

Energy Technology Data Exchange (ETDEWEB)

Pacley, Shanee, E-mail: shanee.pacley@us.af.mil; Brausch, Jacob; Beck-Millerton, Emory [U.S. Air Force Research Laboratory (AFRL)/Wright Patterson Air Force Base, Wright Patterson, Ohio 45433-7707 (United States); Hu, Jianjun; Jespersen, Michael [University of Dayton Research Institute, 300 College Park, Dayton, Ohio 45469 (United States); Hilton, Al [Wyle Laboratories, 4200 Colonel Glenn Hwy, Beavercreek, Ohio 45431 (United States); Waite, Adam [University Technology Corporation, 1270 N Fairfield Rd., Beavercreek, Ohio 45432 (United States); Voevodin, Andrey A. [Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle, Denton, Texas 76203 (United States)

2016-07-15

Monolayer molybdenum disulfide (MoS{sub 2}), a two dimensional semiconducting dichalcogenide material with a bandgap of 1.8–1.9 eV, has demonstrated promise for future use in field effect transistors and optoelectronics. Various approaches have been used for MoS{sub 2} processing, the most common being chemical vapor deposition. During chemical vapor deposition, precursors such as Mo, MoO{sub 3}, and MoCl{sub 5} have been used to form a vapor reaction with sulfur, resulting in thin films of MoS{sub 2}. Currently, MoO{sub 3} ribbons and powder, and MoCl{sub 5} powder have been used. However, the use of ribbons and powder makes it difficult to grow large area-continuous films. Sputtering of Mo is an approach that has demonstrated continuous MoS{sub 2} film growth. In this paper, the authors compare the structural properties of MoS{sub 2} grown by sulfurization of pulse vapor deposited MoO{sub 3} and Mo precursor films. In addition, they have studied the effects that reduced graphene oxide (rGO) has on MoS{sub 2} structure. Reports show that rGO increases MoS{sub 2} grain growth during powder vaporization. Herein, the authors report a grain size increase for MoS{sub 2} when rGO was used during sulfurization of both sputtered Mo and MoO{sub 3} precursors. In addition, our transmission electron microscopy results show a more uniform and continuous film growth for the MoS{sub 2} films produced from Mo when compared to the films produced from MoO{sub 3}. Atomic force microscopy images further confirm this uniform and continuous film growth when Mo precursor was used. Finally, x-ray photoelectron spectroscopy results show that the MoS{sub 2} films produced using both precursors were stoichiometric and had about 7–8 layers in thickness, and that there was a slight improvement in stoichiometry when rGO was used.

Nanoparticles of superconducting γ-Mo2N and δ-MoN

International Nuclear Information System (INIS)

Gomathi, A.; Sundaresan, A.; Rao, C.N.R.

2007-01-01

We have been able to prepare nanoparticles (∼4 nm diameter) of cubic γ-Mo 2 N by a simple procedure involving the reaction of MoCl 5 with urea at 873 K. The nanoparticles show a superconducting transition around 6.5 K. The γ-Mo 2 N nanoparticles are readily transformed to nanoparticles of δ-MoN with a slightly larger diameter on heating in a NH 3 atmosphere at 573 K. Phase-pure δ-MoN obtained by this means shows a superconducting transition around 5 K. - Graphical abstract: TEM image of the γ-Mo 2 N particles with the inset showing the resistivity of the sample as a function of temperature

Microwave effects on NiMoS and CoMoS single-sheet catalysts.

Science.gov (United States)

Borges, I; Silva, Alexander M; Modesto-Costa, Lucas

2018-05-04

Single-sheet nanoclusters of MoS 2 , NiMoS or CoMoS are widely used in hydrodesulfurization (HDS) catalysis in the petroleum industry. In HDS reactions under microwave irradiation, experiments indirectly pointed out that for pristine MoS 2 reaction rates are accelerated because hot spots are generated on the catalyst bed. In this work, we investigated NiMoS and CoMoS isolated single-sheet substituted catalysts before and after thiophene adsorption focusing on quantifying the effect of microwave irradiation. For that purpose, density functional theory (DFT) molecular charge densities of each system were decomposed according to the distributed multipole analysis (DMA) of Stone. Site dipole values of each system were directly associated with a larger or smaller interaction with the microwave field according to a proposed general approach. We showed that microwave enhancement of HDS reaction rates can occur more efficiently in the CoMoS and NiMoS promoted clusters compared to pristine MoS 2 in the following order: CoMoS > NiMoS > MoS 2 . The atomic origin of the catalyst hot spots induced by microwaves was clearly established in the promoted clusters.

Electronic structure of structural open derivatives of the [Mo6X14]2- cluster: [Mo5Cl13]2- and [Mo4I11]2-

International Nuclear Information System (INIS)

Miessner, H.; Korol'kov, D.V.

1983-01-01

The electronic structure of structural open derivatives of the [Mo 6 X 14 ] 2 - -cluster [Mo 5 Cl 13 ] 2 - and [Mo 4 I 11 ] 2 - has been studied by the EHMO method. In [Mo 5 Cl 13 ] 2 - 9 occupied MO's with dominant Mo4d character are responsible for the formation of the 8 metal-metal bonds. In [Mo 4 I 11 ] 2 - the stronger covalent character of the Mo-I bonds affects the localization and the energy of molecular orbitals and also the charge distribution. The metal-metal bonds are formed by 8 MO's containing considerable participation of halogen AO's contrary to the chloride cluster. There is no bonding between the Mo atoms at the wing tips of the Mo 4 butterfly and the reason for decreasing the dihedral angle between the Mo 3 planes in [Mo 4 I 11 ] 2 - compared with the octahedral angle is apparently the stabilization of the whole system (Mo-Mo and Mo-I bonds). The unpaired electron occupies in both clusters a slightly antibonding (with regard to the Mo-Mo bonds) orbital. (author)

Perfil do geoturista do Parque Estadual da Serra do Rola-Moça (MG)

OpenAIRE

Fonseca Filho, Ricardo Eustáquio; Universidade Federal de Ouro Preto, Ouro Preto, MG; Ribeiro, Gabriela Sousa; Circuito Turístico Montanhas e Fé, MG

2016-01-01

O Parque Estadual da Serra do Rola-Moça (PESRM) é uma unidade de conservação de Proteção Integral em Minas Gerais, com características geológicas e geomorfológicas que o caracterizam como um geossítio do Geoparque do Quadrilátero Ferrífero, com alto potencial para o geoturismo. A pesquisa teve por objetivo conhecer o perfil do visitante do PESRM, na tentativa de identificar se há entre os visitantes potenciais geoturistas. A metodologia incluiu revisão bibliográfica e digital, e trabalho de c...

Phase relations in the M2MoO4 - Ag2MoO4 - Hf(MoO4)2 (M=Li, Na) systems

International Nuclear Information System (INIS)

Bazarova, Zh.G.; Bazarov, B.G.; Balsanova, L.V.

2002-01-01

The M 2 MoO 4 - Ag 2 MoO 4 - Hf(MoO 4 ) 2 (M=Li, Na) systems were studied by X-ray diffraction and differential thermal analyses in the subsolidus area (450 - 500 Deg C) for the first time. The formation of the binary compound with the variable composition Li 4-x Hf 1+0.2x (MoO 4 ) 4 (0 ≤ x ≤ 0.6) in the Li 2 MoO 4 - Hf(MoO 4 ) 2 system and the ternary molybdates Li 4 Ag 2 Hf(MoO 4 ) 5 (S 1 ) and Na 2 Ag 2 Hf(MoO 4 ) 4 (S 2 ) was established and the thermal characteristics of the prepared compounds were examined. The new binary molybdate Ag 2 Hf(MoO 4 ) 3 was prepared by the reaction between Ag 2 MoO 4 and Hf(MoO 4 ) 2 [ru

Phase formation in the Li2MoO4–K2MoO4–In2(MoO4)3 system and crystal structures of new compounds K3InMo4O15 and LiK2In(MoO4)3

International Nuclear Information System (INIS)

Khal’baeva, Klara M.; Solodovnikov, Sergey F.; Khaikina, Elena G.; Kadyrova, Yuliya M.; Solodovnikova, Zoya A.; Basovich, Olga M.

2012-01-01

XRD study of solid-phase interaction in the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system was performed. The boundary K 2 MoO 4 –In 2 (MoO 4 ) 3 system is an non-quasibinary join of the K 2 O–In 2 O 3 –MoO 3 system where a new polymolybdate K 3 InMo 4 O 15 isotypic to K 3 FeMo 4 O 15 was found. In the structure (a=33.2905(8), b=5.8610(1), c=15.8967(4) Å, β=90.725(1)°, sp. gr. C2/c, Z=8, R(F)=0.0407), InO 6 octahedra, Mo 2 O 7 diortho groups and MoO 4 tetrahedra form infinite ribbons {[In(MoO 4 ) 2 (Mo 2 O 7 )] 3− } ∞ along the b-axis. Between the chains, 8- to 10-coordinate potassium cations are located. A subsolidus phase diagram of the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system was constructed and a novel triple molybdate LiK 2 In(MoO 4 ) 3 was revealed. Its crystal structure (a=7.0087(2), b=9.2269(3), c=10.1289(3) Å, β=107.401(1)°, sp. gr. P2 1 , Z=2, R(F)=0.0280) contains an open framework of vertex-shared MoO 4 tetrahedra, InO 6 octahedra and LiO 5 tetragonal pyramids with nine- and seven-coordinate potassium ions in the framework channels. - Graphical abstract: Exploring the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system showed its partial non-quasibinarity and revealed new compounds K 3 InMo 4 O 15 (isotypic to K 3 FeMo 4 O 15 ) and LiK 2 In(MoO 4 ) 3 which were structurally studied. An open framework of the latter is formed by vertex-shared MoO 4 tetrahedra, InO 6 octahedra and LiO 5 tetragonal pyramids. Highlights: ► Subsolidus phase relations in the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system were explored. ► The K 2 MoO 4 –In 2 (MoO 4 ) 3 system is a non-quasibinary join of the K 2 O–In 2 O 3 –MoO 3 system. ► New compounds K 3 InMo 4 O 15 and LiK 2 In(MoO 4 ) 3 were obtained and structurally studied. ► K 3 InMo 4 O 15 is isotypic to K 3 FeMo 4 O 15 and carries bands of InO 6 , MoO 4 and Mo 2 O 7 units. ► An open framework of LiK 2 In(MoO 4 ) 3 is formed by polyhedra MoO 4 , InO 6 and LiO 5 .

ITO-free flexible organic photovoltaics with multilayer MoO3/LiF/MoO3/Ag/MoO3 as the transparent electrode

International Nuclear Information System (INIS)

Chen, Shilin; Dai, Yunjie; Zhang, Hongmei; Zhao, Dewei

2016-01-01

We present efficient flexible organic photovoltaics (OPVs) with multiple layers of molybdenum oxide (MoO 3 )/LiF/MoO 3 /Ag/MoO 3 as the transparent electrode, where the thin Ag layer yields high conductivity and the dielectric layer MoO 3 /LiF/MoO 3 has high transparency due to optical interference, leading to improved power conversion efficiency compared with indium tin oxide (ITO) based devices. The MoO 3 contacting organic active layer is used as a buffer layer for good hole extraction. Thus, the multilayer MoO 3 /LiF/MoO 3 /Ag/MoO 3 can improve light transmittance and also facilitate charge carrier extraction. Such an electrode shows excellent mechanical bendability with a 9% reduction of efficiency after 1000 cycles of bending due to the ductile nature of the thin metal layer and dielectric layer used. Our results suggest that the MoO 3 /LiF/MoO 3 /Ag/MoO 3 multilayer electrode is a promising alternative to ITO as an electrode in OPVs. (paper)

Optimization of the Pd-Fe-Mo Catalysts for Oxygen Reduction Reaction in Proton-Exchange Membrane Fuel Cells

International Nuclear Information System (INIS)

Lee, Yeayeon; Jang, Jeongseok; Lee, Jin Goo; Jeon, Ok Sung; Kim, Hyeong Su; Hwang, Ho Jung; Shul, Yong Gun

2016-01-01

Highlights: • Pd-Mo-Fe catalysts show high catalytic activity and stability for oxygen-reduction reactions in acid media. • The optimum compositions were 7.5:1.5:1.0 for Pd-Fe-Mo, and the optimum temperatures were 500 °C. • The Pd-Fe-Mo catalysts were successfully applied to the PEMFC cathode, showing ∼500 mA cm −1 at 0.6 V. • The lattice constant was strongly related to the activity and stability of the catalysts for oxygen-reduction reactions. - Abstract: Highly active and durable non-platinum catalysts for oxygen-reduction reaction (ORR) have been developed for energy conversion devices such as proton-exchange membrane fuel cells (PEMFCs). In this study, Pd-Fe-Mo catalyst is reported as a non-platinum catalyst for ORR. The atomic ratio and annealing temperatures are controlled on the catalysts to understand interplay between their physical and chemical properties and electrochemical activities. The Pd-Fe-Mo catalyst optimized with 7.5:1.5:1.0 of the atomic ratio and 500 °C of the annealing temperature shows 32.18 mA mg −1 PGM (PGM: platinum group metal) of the kinetic current density at 0.9 V for ORR, which is comparable to that of commercial Pt/C catalyst. The current density is degraded to 6.20 mA mg −1 PGM after 3000 cycling of cyclic voltammetry, but it is greatly enhanced value compared to other non-platinum catalysts. In actual application to PEMFCs, the 20% Pd-Fe-Mo catalyst supported on carbons exhibits a high performance of 506 mA cm −2 at 0.6 V. The results suggest that the Pd-Fe-Mo catalyst can be a good candidate for non-platinum ORR catalysts.

Thermal expansion studies on Th(MoO4)2, Na2Th(MoO4)3 and Na4Th(MoO4)4

International Nuclear Information System (INIS)

Keskar, Meera; Krishnan, K.; Dahale, N.D.

2008-01-01

Thermal expansion behavior of Th(MoO 4 ) 2 , Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 was studied under vacuum in the temperature range of 298-1123 K by high temperature X-ray diffractometer. Th(MoO 4 ) 2 was synthesized by reacting ThO 2 with 2 mol of MoO 3 , at 1073 K in air and Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 were prepared by reacting Th(MoO 4 ) 2 with 1 and 2 mol of Na 2 MoO 4 , respectively at 873 K in air. The XRD data of Th(MoO 4 ) 2 was indexed on orthorhombic system where as XRD data of Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 were indexed on tetragonal system. The lattice parameters and cell volume of all the three compounds, fit into polynomial expression with respect to temperature, showed positive thermal expansion (PTE) up to 1123 K. The average value of thermal expansion coefficients for Th(MoO 4 ) 2 , Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 were determined from the high temperature data

Preparation of clinical-scale 99Mo/99mTc column generator using neutron activated low specific activity 99Mo and nanocrystalline γ-Al2O3 as column matrix.

Science.gov (United States)

Chakravarty, Rubel; Ram, Ramu; Dash, Ashutosh; Pillai, M R A

2012-10-01

Preparation of clinical-scale (99)Mo/(99m)Tc generator using (n,γ) activated low specific activity (99)Mo and nanocrystalline γ-Al(2)O(3) as a high capacity sorbent matrix is attempted. Nanocrystalline γ-Al(2)O(3) was synthesized by 'solid state mechanochemical' reaction of aluminum nitrate with ammonium bicarbonate. Experimental parameters were optimized to effectively separate (99m)Tc from (99)Mo using this sorbent as the column matrix. The performance features of a 13 GBq (350 mCi) (99)Mo/(99m)Tc generator using this sorbent and (99)Mo produced by (n,γ) route having specific activity 12.9-18.5 GBq/g were evaluated for 10 days. The sorbent possessed the requisite selectivity for (99)Mo and demonstrated a maximum sorption capacity of 200 ± 5mg Mo/g, which is ~10 times higher than that of ordinary acidic alumina. The overall yield of (99m)Tc was >80%, with radionuclidic purity >99.99% and radiochemical purity >99%. The yield of (99m)Tc varied from 7.8 to 2.1 GBq in the eluate for the six days of operation of the generator. The radioactive concentration of (99m)Tc eluted was adequate for the formulation of radiopharmaceuticals. The performance of the generator remained consistent over an extended period of 10 days. The eluted (99m)Tc was suitable for the formulation of (99m)Tc-DMSA and (99m)Tc-EC resulting in high radiolabeling yields (>98%). The effectiveness of γ-Al(2)O(3) as a new generation sorbent in the development of clinically useful (99)Mo/(99m)Tc generator using low specific activity (99)Mo and yielding (99m)Tc with adequate radioactive concentration and high purity suitable for formulation of radiopharmaceuticals is demonstrated. Copyright © 2012 Elsevier Inc. All rights reserved.

Ternary system of Na2MoO4-Cs2MoO4-MoO3

International Nuclear Information System (INIS)

Zueva, V.P.; Shabanova, A.N.; Drobasheva, T.I.

1982-01-01

Using the methods of thermal analysis interaction of components in ternary system Na 2 MoO 4 -Cs 2 MoO 4 -MoO 3 has been studied. Crystallization surface consists of nine fields belonging to initial components and compounds of lateral sides. Triangulation of the system is carried out and the character of nonvariant points is clarified, the temperature of 360 deg C corresponds to low-melting eutectics

[Smoļenskas-Rīgas aktis 13. gs.-14. gs. pirmā puse : kompleksa "Moscowitica-Ruthenica" dokumenti par Smoļenskas un Rīgas attiecībām = Смоленско-рижские акты XIII в.-первая половина XIV в. : документ�

Index Scriptorium Estoniae

Levans, Andris, 1968-

2011-01-01

Arvustus: Smoļenskas-Rīgas aktis 13. gs.-14. gs. pirmā puse : kompleksa "Moscowitica-Ruthenica" dokumenti par Smoļenskas un Rīgas attiecībām = Смоленско-рижские акты XIII в.-первая половина XIV в. : документы комплекса Moscowitica-Ruthenica об отношениях Смоленска и Риги /koostajad Leksanders Ivanovs, Anatolijs Kuzņcovs. Vēstures avoti ; 6 (Riga: Latvijas Valsts vēstures arcīva izdevniecība, 2009)

Preparation and characterization of iron(III) 99Mo-molybdate(VI) gels for the assessment of 99mTc elution performance

International Nuclear Information System (INIS)

Amin, Mahmoud; Fasih, Tharwat W.; El-Absy, Mohamed A.

2018-01-01

New iron(III) 99 Mo-molybdate(VI) gels (Fe 99 Mo) of high Mo content were prepared by the precipitation/filtration method. 99 Mo-MoO 3 dissolved in NaOH was added to aqueous solutions of Fe(NO 3 ) 3 at Mo/Fe mole fractions ∝2.21 and 1.99 with continuous stirring at ambient room temperature. Two different Fe 99 Mo were precipitated from the mixed solutions adjusted at pH 2 and 4.7. The amount of water of hydration increased with the increasing the gel settling time and pH of the mixed solution. The matrices were characterized by radiometric, XRD, SEM, XRF, FT-IR, TGA, and DTA measurements. Small chromatographic columns of 2.0 g Fe 99 Mo containing ≥800 mg Mo tagged with 740 MBq 99 Mo were eluted with 5 mL saline solution. Highly reproducible 99m Tc elution indices suitable for preparation of 99 Mo/ 99m Tc generators were achieved from generator supported with 0.5 g Al 2 O 3 filter. Elution performance of 99m Tc radionuclide was highly dependent on the gel structural properties.

Microstructure and tribological properties of NiMo/Mo2Ni3Si intermetallic 'in-situ' composites

International Nuclear Information System (INIS)

Gui Yongliang; Song Chunyan; Yang Li; Qin Xiaoling

2011-01-01

Research highlights: → Wear resistant NiMo/Mo 2 Ni 3 Si intermetallic 'in-situ' composites was fabricated successfully with Mo-Ni-Si powder blends as the starting materials. Microstructure of the NiMo/Mo 2 Ni 3 Si composites consists of Mo 2 Ni 3 Si primary dendrites, binary intermetallic phase NiMo and small amount of Ni/NiMo eutectics structure. The NiMo/Mo 2 Ni 3 Si composites exhibited high hardness and outstanding tribological properties under room-temperature dry-sliding wear test conditions which were attributed to the covalent-dominant strong atomic bonds and excellent combination of strength and ductility and toughness. - Abstract: Wear resistant NiMo/Mo 2 Ni 3 Si intermetallic 'in-situ' composites with a microstructure of ternary metal silicide Mo 2 Ni 3 Si primary dendritic, the long strip-like NiMo intermetallic phase, and a small amount of Ni/NiMo eutectics structure were designed and fabricated using molybdenum, nickel and silicon elemental powders. Friction and wear properties of NiMo/Mo 2 Ni 3 Si composites were evaluated under different contact load at room-temperature dry-sliding wear test conditions. Microstructure, worn surface morphologies and subsurface microstructure were characterized by OM, XRD, SEM and EDS. Results indicate that NiMo/Mo 2 Ni 3 Si composites have low fiction coefficient, excellent wear resistance and sluggish wear-load dependence. The dominant wear mechanisms of NiMo/Mo 2 Ni 3 Si composites are soft abrasion and slightly superficial oxidative wear.

Influence of basic properties of Mg,Al-mixed oxides on their catalytic activity in knoevenagel condensation between benzaldehyde and phenylsulfonylacetonitrile

Directory of Open Access Journals (Sweden)

Caridad Noda Pérez

2009-01-01

Full Text Available The catalytic performance of Mg,Al-mixed oxides (MO20, MO25 and MO33 derived from hydrotalcites was evaluated in the Knoevenagel reaction between benzaldehyde and phenylsulfonylacetonitrile at 373 and 383 K. The best results were obtained for the sample MO20 that presented the highest basic sites density and external area and the smallest crystallite sizes. The relative amount of basic sites with weak to intermediate strength also played an important role on catalytic performance. By increasing the catalyst content from 1 to 5 wt.% at 383 K, a complete conversion of the reactants is attained, producing α-phenylsulfonylcinnamonitrile with a selectivity of 100%.

A Temperature Window for the Synthesis of Single-Walled Carbon Nanotubes by Catalytic Chemical Vapor Deposition of CH4over Mo2-Fe10/MgO Catalyst

Directory of Open Access Journals (Sweden)

Yu Ouyang

2009-01-01

Full Text Available Abstract A temperature window for the synthesis of single-walled carbon nanotubes by catalytic chemical vapor deposition of CH4over Mo2-Fe10/MgO catalyst has been studied by Raman spectroscopy. The results showed that when the temperature is lower than 750 °C, there were few SWCNTs formed, and when the temperature is higher than 950 °C, mass amorphous carbons were formed in the SWCNTs bundles due to the self-decomposition of CH4. The temperature window of SWCNTs efficient growth is between 800 and 950 °C, and the optimum growth temperature is about 900 °C. These results were supported by transmission electron microscope images of samples formed under different temperatures. The temperature window is important for large-scale production of SWCNTs by catalytic chemical vapor deposition method.

In-situ fabrication of MoSi2/SiC–Mo2C gradient anti-oxidation coating on Mo substrate and the crucial effect of Mo2C barrier layer at high temperature

International Nuclear Information System (INIS)

Liu, Jun; Gong, Qianming; Shao, Yang; Zhuang, Daming; Liang, Ji

2014-01-01

MoSi 2 /SiC–Mo 2 C gradient coating on molybdenum was in situ prepared with pack cementation process by two steps: (1) carburizing with graphite powder to obtain a Mo 2 C layer on Mo substrate, and (2) siliconizing with Si powder to get a composite MoSi 2 /SiC layer on the upper part of Mo 2 C layer. The microstructure and elemental distribution in the coating were investigated with scanning electron microscopy (SEM), backscattered electron (BSE), energy dispersive spectroscopy (EDS), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Cyclic oxidation tests (at 500 °C, 1200 °C, 1400 °C and 1600 °C) demonstrated excellent oxidation resistance for the gradient composite coating and the mass loss was only 0.23% in 60 min at 1600 °C. XRD, EPMA, thermal dynamic and phase diagram analyses indicated that the Mo 2 C barrier layer played the key role in slowing down the diffusion of C and Si toward inner Mo substrate at high temperature and principally this contributed to the excellent anti-oxidation for Mo besides the outer MoSi 2 /SiC composite layer.

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...

Solution chemistry of Mo(III) and Mo(IV): Thermodynamic foundation for modeling localized corrosion

International Nuclear Information System (INIS)

Wang Peiming; Wilson, Leslie L.; Wesolowski, David J.; Rosenqvist, Joergen; Anderko, Andrzej

2010-01-01

To investigate the behavior of molybdenum dissolution products in systems that approximate localized corrosion environments, solubility of Mo(III) in equilibrium with solid MoO 2 has been determined at 80 deg. C as a function of solution acidity, chloride concentration and partial pressure of hydrogen. The measurements indicate a strong increase in solubility with acidity and chloride concentration and a weak effect of hydrogen partial pressure. The obtained results have been combined with literature data for systems containing Mo(III), Mo(IV), and Mo(VI) in solutions to develop a comprehensive thermodynamic model of aqueous molybdenum chemistry. The model is based on a previously developed framework for simulating the properties of electrolyte systems ranging from infinite dilution to solid saturation or fused salt limit. To reproduce the measurements, the model assumes the presence of a chloride complex of Mo(III) (i.e., MoCl 2+ ) and hydrolyzed species (MoOH 2+ , Mo(OH) 2 + , and Mo(OH) 3 0 ) in addition to the Mo 3+ ion. The model generally reproduces the experimental data within experimental scattering and provides a tool for predicting the phase behavior and speciation in complex, concentrated aqueous solutions. Thus, it provides a foundation for simulating the behavior of molybdenum species in localized corrosion environments.

Enhanced Selectivity and Uptake Capacity of CO2 and Toluene Adsorption in Co0.5 M0.33 MoS4 (M= Sb or Y) Chalcogels by Impregnated Metal Salts

KAUST Repository

Adhiam, Fatima Abdullah Ahmed

2017-11-17

The synthesis of metal chalcogenide aerogels Co0.5M0.33MoS4 (M= Sb or Y) by the sol-gel method is reported. In this system, the building blocks [MoS4]2− chelated with Co2+ and (Sb3+) or (Y3+) salts in nonaqueous solvents forming amorphous networks with a gel property. The chalcogels obtained after supercritical drying have BET surface areas of 176 m2 g−1 (Co0.5Sb0.33MoS4) and 145 m2 g−1 (Co0.5Y0.33MoS4). Electron microscopy and physisorption studies reveal that the new materials are porous with wide pore size distribution and average pore width of 16 nm. These chalcogels show higher adsorption capacity of toluene vapor (Co0.5Sb0.33MoS4: 387 mg g−1) and (Co0.5Y0.33MoS4: 304 mg g−1) over cyclohexane vapor and high selectivity of CO2 over CH4 or H2, Co0.5Sb0.33MoS4 (CO2/H2: 80 and CO2/CH4: 21), Co0.5Y0.33MoS4 (CO2/H2: 27 and CO2/CH4: 15). We also demonstrated that the impregnation of various metal species like Li+, Mg2+, and Ni2+ significantly enhanced the uptake capacity and selectivity of toluene and CO2 adsorptions in the chacogels.

Spectrophotometric and potentiometric studies of oxidation of Mo(III) by Mo(VI) in phosphoric acid medium

Energy Technology Data Exchange (ETDEWEB)

Kumar, A; Verma, G S.P. [Ranchi Coll. (India). Dept. of Chemistry

1975-12-01

Oxidation of Mo(III) (green) by Mo(VI) in an inert atmosphere and in orthophosphoric acid medium at various acid concentrations is reported. Potentiometric and spectrophotometric data suggest that oxidation of Mo(III) proceeds to Mo(V) through a binuclear species Mo(III) Mo(IV) absorbing at 400 nm. The formation of this species is facilitated at high acid concentrations. It is further found that quantitative conversion of Mo(III) into Mo(V) takes place at fairly high acid concentrations. In high phosphoric acid concentrations, solution of Mo(III) has been found to be oxidized to Mo(VI) by air and hence this can be used as a good oxygen absorber.

Transfer matrix approach to electron transport in monolayer MoS2/MoO x heterostructures

Science.gov (United States)

Li, Gen

2018-05-01

Oxygen plasma treatment can introduce oxidation into monolayer MoS2 to transfer MoS2 into MoO x , causing the formation of MoS2/MoO x heterostructures. We find the MoS2/MoO x heterostructures have the similar geometry compared with GaAs/Ga1‑x Al x As semiconductor superlattice. Thus, We employ the established transfer matrix method to analyse the electron transport in the MoS2/MoO x heterostructures with double-well and step-well geometries. We also considere the coupling between transverse and longitudinal kinetic energy because the electron effective mass changes spatially in the MoS2/MoO x heterostructures. We find the resonant peaks show red shift with the increasing of transverse momentum, which is similar to the previous work studying the transverse-momentum-dependent transmission in GaAs/Ga1‑x Al x As double-barrier structure. We find electric field can enhance the magnitude of peaks and intensify the coupling between longitudinal and transverse momentums. Moreover, higher bias is applied to optimize resonant tunnelling condition to show negative differential effect can be observed in the MoS2/MoO x system.

Phase formation in the Li2MoO4-Rb2MoO4-Ln2(MoO4)3 systems and the properties of LiRbLn2(MoO4)4

International Nuclear Information System (INIS)

Basovich, O.M.; Khajkina, E.G.; Vasil'ev, E.V.; Frolov, A.M.

1995-01-01

Phase equilibria within subsolidus range of ternary salt systems Li 2 MoO 4 -Rb 2 MoO 4 -Ln 2 (MoO 4 ) 4 (Ln - Nd, Er) are analyzed. Formation of ternary molybdate LiRbNd 2 (MoO 4 ) 4 is proved along LiNd(MoO 4 ) 2 -RbNd(MoO 4 )-2 cross-section. Phase diagram of this cross-section is plotted. Similar compounds are synthesized for Ln = La-Eu. The parameters of their monoclinic elementary cells are determined. Luminescent properties of LiRbLa 2 (MoO 4 ) 4 -Nd 3+ are studied. 17 refs., 4 figs., 2 tabs

Stacking change in MoS2 bilayers induced by interstitial Mo impurities.

Science.gov (United States)

Cortés, Natalia; Rosales, Luis; Orellana, Pedro A; Ayuela, Andrés; González, Jhon W

2018-02-01

We use a theoretical approach to reveal the electronic and structural properties of molybdenum impurities between MoS 2 bilayers. We find that interstitial Mo impurities are able to reverse the well-known stability order of the pristine bilayer, because the most stable form of stacking changes from AA' (undoped) into AB' (doped). The occurrence of Mo impurities in different positions shows their split electronic levels in the energy gap, following octahedral and tetrahedral crystal fields. The energy stability is related to the accommodation of Mo impurities compacted in hollow sites between layers. Other less stable configurations for Mo dopants have larger interlayer distances and band gaps than those for the most stable stacking. Our findings suggest possible applications such as exciton trapping in layers around impurities, and the control of bilayer stacking by Mo impurities in the growth process.

Rapid water disinfection using vertically aligned MoS_2 nanofilms and visible light

International Nuclear Information System (INIS)

Liu, Chong; Kong, Desheng; Hsu, Po-Chun; Yuan, Hongtao; Lee, Hyun-Wook

2016-01-01

Here, solar energy is readily available in most climates and can be used for water purification. However, solar disinfection of drinking water (SODIS) mostly relies on ultraviolet light, which represents only 4% of total solar energy, and this leads to slow treatment speed. The development of new materials that can harvest visible light for water disinfection, and speed up solar water purification, is therefore highly desirable. Here, we show that few-layered vertically aligned MoS_2 (FLV-MoS_2) films can be used to harvest the whole spectrum of visible light (~ 50% of solar energy) and achieve highly efficient water disinfection. The bandgap of MoS_2 was increased from 1.3 eV to 1.55 eV by decreasing the domain size, which allowed the FLV-MoS_2 to generate reactive oxygen species (ROS) for bacterial inactivation in water. The FLV-MoS_2 showed ~15 times better log inactivation efficiency of indicator bacteria compared to bulk MoS_2, and much faster inactivation of bacteria under both visible light and sunlight illumination compared to widely used TiO_2. Moreover, by using a 5 nm copper film on top of the FLV-MoS_2 as a catalyst to facilitate electron-hole pair separation and promote the generation of ROS, the disinfection rate was further increased 6 fold. With our approach, we achieved water disinfection of >99.999% inactivation of bacteria in 20 minutes with a small amount of material (1.6 mg/L) under simulated visible light.

Rapid water disinfection using vertically aligned MoS2 nanofilms and visible light

International Nuclear Information System (INIS)

Liu, Chong; Kong, Desheng; Hsu, Po-Chun; Yuan, Hongtao; Lee, Hyun-Wook

2016-01-01

In most climates, solar energy is readily available and can be used for water purification. But, solar disinfection of drinking water mostly relies on ultraviolet light, which represents only 4% of the total solar energy, and this leads to a slow treatment speed. Therefore, the development of new materials that can harvest visible light for water disinfection, and so speed up solar water purification, is highly desirable. Here we show that few-layered vertically aligned MoS_2 (FLV-MoS_2) films can be used to harvest the whole spectrum of visible light (~50% of solar energy) and achieve highly efficient water disinfection. The bandgap of MoS_2 was increased from 1.3 to 1.55 eV by decreasing the domain size, which allowed the FLV-MoS_2 to generate reactive oxygen species (ROS) for bacterial inactivation in the water. The FLV-MoS_2 showed a ~15 times better log inactivation efficiency of the indicator bacteria compared with that of bulk MoS_2, and a much faster inactivation of bacteria under both visible light and sunlight illumination compared with the widely used TiO_2. Moreover, by using a 5 nm copper film on top of the FLV-MoS_2 as a catalyst to facilitate electron–hole pair separation and promote the generation of ROS, the disinfection rate was increased a further sixfold. Here, we achieved water disinfection of >99.999% inactivation of bacteria in 20 min with a small amount of material (1.6 mg l–1) under simulated visible light.

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)

Spectrophotometric and potentiometric studies of oxidation of Mo(III) by Mo(VI) in phosphoric acid medium

International Nuclear Information System (INIS)

Kumar, Arvind; Verma, G.S.P.

1975-01-01

Oxidation of Mo(III) (green) by Mo(VI) in an inert atmosphere and in orthophosphoric acid medium at various acid concentrations is reported. Potentiometric and spectrophotometric data suggest that oxidation of Mo(III) proceeds to Mo(V) through a binuclear species Mo(III) Mo(IV) absorbing at 400 nm. The formation of this species is facilitated at high acid concentrations. It is further found that quantitative conversion of Mo(III) into Mo(V) takes place at fairly high acid concentrations. In high phosphoric acid concentrations, solution of Mo(III) has been found to be oxidized to Mo(VI) by air and hence this can be used as a good oxygen absorber. (author)

Influence of the Ti concentration and of the Ti:Mo molar ratio, in the efficiency of the 99 Mo - 99m Tc generator, at basis of gels of titanium molybdates

International Nuclear Information System (INIS)

Cortes R, O.; Monroy G, F.; Martinez C, T.

2003-01-01

The 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 99 Mo/ 99m Tc that get ready commercially with 99 Mo of high specific activity, adsorbed in alumina (2 mg 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 99 Mo of low specific activity that can be obtained starting from the reaction 98 Mo (n, γ) 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)

Spent 99Mo/99mTc generator as an economical source of 99Mo

International Nuclear Information System (INIS)

El-Kolaly, M.T.

1990-01-01

An improved method for utilization and purification of 99 Mo from spent 90 Mo/ 99m Tc generators has been described. After washing the generator with saline to remove the generated 99m Tc, followed by 2 mL 5 M NaOH containing a few drops of H 2 O 2 , the 99 Mo was quantitatively eluted from the generator with 5 mL 5 M NaOH. The alkaline eluate containing 99 Mo was contaminated with partially dissolved alumina. In the present method, an anion-exchange resin Dowex 1 x 8 column was used for purification of 99 Mo from the contaminating alumina. The resultant 99 Mo was of high purity and contained 3+ /mL 99 Mo solution, as estimated by atomic absorption. (author)

Study of the activation of targets containing Mo for the production of 99Mo by the 98Mo(n,γ)99Mo nuclear reaction and the behaviour of the radionuclidic impurities of the process

International Nuclear Information System (INIS)

Nieto, Renata Correa

1998-01-01

The most used radioisotope in Nuclear Medicine is 99m Tc, in the 99 Mo- 99m Tc generator form. 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 235 U and by 98 Mo(n,γ) 99 Mo reaction. A project for the production of 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 3 and MoZr gel were evaluated, and these represent the two possible ways of preparing the gel of MoZr. A target of metallic Mo was also studied. The radionuclidic purity of 99m Tc eluted from generators prepared in these ways was also measured and compared with the generators prepared with fission 99 Mo. The results showed that, by all the parameters analysed, the best way of preparing the generator of 99 Mo - 99m Tc is the irradiation of MOO 3 and further preparation of the gel and the generators. (author)

Interstitial Mo-Assisted Photovoltaic Effect in Multilayer MoSe2 Phototransistors.

Science.gov (United States)

Kim, Sunkook; Maassen, Jesse; Lee, Jiyoul; Kim, Seung Min; Han, Gyuchull; Kwon, Junyeon; Hong, Seongin; Park, Jozeph; Liu, Na; Park, Yun Chang; Omkaram, Inturu; Rhyee, Jong-Soo; Hong, Young Ki; Yoon, Youngki

2018-03-01

Thin-film transistors (TFTs) based on multilayer molybdenum diselenide (MoSe 2 ) synthesized by modified atmospheric pressure chemical vapor deposition (APCVD) exhibit outstanding photoresponsivity (103.1 A W -1 ), while it is generally believed that optical response of multilayer transition metal dichalcogenides (TMDs) is significantly limited due to their indirect bandgap and inefficient photoexcitation process. Here, the fundamental origin of such a high photoresponsivity in the synthesized multilayer MoSe 2 TFTs is sought. A unique structural characteristic of the APCVD-grown MoSe 2 is observed, in which interstitial Mo atoms exist between basal planes, unlike usual 2H phase TMDs. Density functional theory calculations and photoinduced transfer characteristics reveal that such interstitial Mo atoms form photoreactive electronic states in the bandgap. Models indicate that huge photoamplification is attributed to trapped holes in subgap states, resulting in a significant photovoltaic effect. In this study, the fundamental origin of high responsivity with synthetic MoSe 2 phototransistors is identified, suggesting a novel route to high-performance, multifunctional 2D material devices for future wearable sensor applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of a gel of zirconium molybdate for use in the generators of 99 Mo - 99m Tc prepared with 99 Mo produced by the 98 Mo(n,γ)99 Mo reaction

International Nuclear Information System (INIS)

Osso Junior, Joao A.; Lima, Ana Lucia V.P.; Silva, Nestor C. da; Nieto, Renata C.; Velosa, Adriana C. de

1998-01-01

IPEN develops a project concerning the preparation of a gel of Zirconium Molybdate for use in the generators of 99 Mo- 99m Tc . 99m Tc is the most used radioisotope in nuclear medicine diagnosis procedures and nowadays the generators are being prepared with imported 99 Mo, produced by 235 U fission. The production of 99 Mo by the 98 Mo(n, γ) 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 99 Mo- 99m Tc generators. The gel is prepared by the chemical reaction between Mo, in Mo O 3 form, and Zr, in Zr O Cl 2 .8H 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 99m Tc generator. The results showed the good quality of the gel prepared at laboratory level and of the generators evaluated. (author)

Edge termination of MoS2 and CoMoS catalyst particles

DEFF Research Database (Denmark)

Byskov, Line Sjolte; Nørskov, Jens Kehlet; Clausen, B. S.

2000-01-01

The edge termination of MoS2 and CoMoS catalyst particles is studied by density functional calculations. We show that for structures without vacancies Mo-terminated edges have the lowest edge energies. Creation of vacancies, which are believed to be active sites in these catalyst systems, leads...

SURFACE MODIFICATIONS WITH LASER SYNTHESIZED Mo MODIFIED COATING

OpenAIRE

LU SUN; HAO CHEN; BO LIU

2013-01-01

Mg–Cu–Al was first used to improve the surface performance of TA15 titanium alloys by means of laser cladding technique. The synthesis of hard composite coating on TA15 titanium alloy by laser cladding of Mg–Cu–Al–B4C/Mo pre-placed powders was investigated by means of scanning electron microscope, energy dispersive spectrometer and high resolution transmission electron microscope. Experimental results indicated that such composite coating mainly consisted of TiB2, TiB, TiC, Ti3Al and AlCuMg. ...

Influences of Different Components on Agglomeration Behavior of MoS2 During Oxidation Roasting Process in Air

Science.gov (United States)

Wang, Lu; Zhang, Guo-Hua; Wang, Jing-Song; Chou, Kuo-Chih

2016-08-01

An agglomeration of the furnace charge always takes place during the oxidation roasting process of molybdenite concentrate (with the main component of MoS2) in multiple hearth furnaces, which greatly affects the production process and furnace service life. In the present work, a preliminary study about the influence of various components on the agglomeration phenomenon of pure MoS2 have been carried out. The results show that reaction temperature, impurity content, and air flow rate have significant effects on the agglomeration extent. Meanwhile, the impurity type added into the pure MoS2 plays a crucial role. It was found that CaO and MgO have a stronger sulfur-fixing effect and that the desulphurization of the roasted product was uncompleted. It was also concluded that the agglomeration is due to the formation of low-melting-point eutectics, including that between MoO3 and impurities and that between MoO3 and Mo4O11. It is suggested that decreasing the impurities contents, especially K, Cu, Pb, and Fe, is an effective method for reducing the extent of agglomeration.

Enhanced production of prodigiosin by Serratia marcescens MO-1 using ram horn peptone.

Science.gov (United States)

Kurbanoglu, Esabi Basaran; Ozdal, Murat; Ozdal, Ozlem Gur; Algur, Omer Faruk

2015-06-01

This work addresses the production of prodigiosin from ram horn peptone (RHP) using MO-1, a local isolate in submerged culture. First, a novel gram-negative and rod-shaped bacterial strain, MO-1, was isolated from the body of the grasshopper (Poecilemon tauricola Ramme 1951), which was collected from pesticide-contaminated fields. Sequence analysis of 16S rDNA classified the microbe as Serratia marcescens. The substrate utilization potential (BIOLOG) and fatty acid methyl ester profile (FAME) of S. marcescens were also determined. The effect of RHP on the production of prodigiosin by S. marcescens MO-1 was investigated, and the results showed that RHP supplementation promoted the growth of MO-1 and increased the production of prodigiosin. A concentration of 0.4% (w/v) RHP resulted in the greatest yield of prodigiosin (277.74 mg/L) after 48 h when mannitol was used as the sole source of carbon. The pigment yield was also influenced by the types of carbon sources and peptones. As a result, RHP was demonstrated to be a suitable substrate for prodigiosin production. These results revealed that prodigiosin could be produced efficiently by S. marcescens using RHP.

Enhanced production of prodigiosin by Serratia marcescens MO-1 using ram horn peptone

Directory of Open Access Journals (Sweden)

Esabi Basaran Kurbanoglu

2015-06-01

Full Text Available This work addresses the production of prodigiosin from ram horn peptone (RHP using MO-1, a local isolate in submerged culture. First, a novel gram-negative and rod-shaped bacterial strain, MO-1, was isolated from the body of the grasshopper (Poecilemon tauricola Ramme 1951, which was collected from pesticide-contaminated fields. Sequence analysis of 16S rDNA classified the microbe as Serratia marcescens. The substrate utilization potential (BIOLOG and fatty acid methyl ester profile (FAME of S. marcescens were also determined. The effect of RHP on the production of prodigiosin by S. marcescens MO-1 was investigated, and the results showed that RHP supplementation promoted the growth of MO-1 and increased the production of prodigiosin. A concentration of 0.4% (w/v RHP resulted in the greatest yield of prodigiosin (277.74 mg/L after 48 h when mannitol was used as the sole source of carbon. The pigment yield was also influenced by the types of carbon sources and peptones. As a result, RHP was demonstrated to be a suitable substrate for prodigiosin production. These results revealed that prodigiosin could be produced efficiently by S. marcescens using RHP.

Polymer-Derived Ceramic Functionalized MoS2 Composite Paper as a Stable Lithium-Ion Battery Electrode

Science.gov (United States)

David, L.; Bhandavat, R.; Barrera, U.; Singh, G.

2015-04-01

A facile process is demonstrated for the synthesis of layered SiCN-MoS2 structure via pyrolysis of polysilazane functionalized MoS2 flakes. The layered morphology and polymer to ceramic transformation on MoS2 surfaces was confirmed by use of electron microscopy and spectroscopic techniques. Tested as thick film electrode in a Li-ion battery half-cell, SiCN-MoS2 showed the classical three-stage reaction with improved cycling stability and capacity retention than neat MoS2. Contribution of conversion reaction of Li/MoS2 system on overall capacity was marginally affected by the presence of SiCN while Li-irreversibility arising from electrolyte decomposition was greatly suppressed. This is understood as one of the reasons for decreased first cycle loss and increased capacity retention. SiCN-MoS2 in the form of self-supporting paper electrode (at 6 mg.cm-2) exhibited even better performance, regaining initial charge capacity of approximately 530 mAh.g-1 when the current density returned to 100 mA.g-1 after continuous cycling at 2400 mA.g-1 (192 mAh.g-1). MoS2 cycled electrode showed mud-cracks and film delamination whereas SiCN-MoS2 electrodes were intact and covered with a uniform solid electrolyte interphase coating. Taken together, our results suggest that molecular level interfacing with precursor-derived SiCN is an effective strategy for suppressing the metal-sulfide/electrolyte degradation reaction at low discharge potentials.

Deoxygenation of glycolaldehyde and furfural on Mo2C/Mo(100)

Science.gov (United States)

McManus, Jesse R.; Vohs, John M.

2014-12-01

The desire to produce fuels and chemicals in an energy conscious, environmentally sympathetic approach has motivated considerable research on the use of cellulosic biomass feedstocks. One of the major challenges facing the utilization of biomass is finding effective catalysts for the efficient and selective removal of oxygen from the highly-oxygenated, biomass-derived platform molecules. Herein, a study of the reaction pathways for the biomass-derived platform molecule furfural and biomass-derived sugar model compound glycolaldehyde provides insight into the mechanisms of hydrodeoxygenation (HDO) on a model molybdenum carbide catalyst, Mo2C/Mo(100). Using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS), it was found that the Mo2C/Mo(100) catalyst was active for selective deoxygenation of the aldehyde carbonyl by facilitating adsorption of the aldehyde in an η2(C,O) bonding configuration. Furthermore, the catalyst showed no appreciable activity for furanic ring hydrogenation, highlighting the promise of relatively inexpensive Mo2C catalysts for selective HDO chemistry.

Effect of Mo/B atomic ratio on the properties of Mo2NiB2-based cermets

International Nuclear Information System (INIS)

Xie, Lang; Li, XiaoBo; Zhang, Dan; Yi, Li; Gao, XiaoQing; Xiangtan Univ.

2015-01-01

Using three elementary substances, Mo, Ni, and amorphous B as raw materials, four series of Mo 2 NiB 2 -based cermets with the Mo/B atomic ratio ranging from 0.9 to 1.2 were successfully prepared via reaction sintering. The effect of Mo/B atomic ratio on the microstructure and properties was studied for the cermets. The results indicate that there is a strong correlation between the Mo/B atomic ratio and properties. The transverse rupture strength of the cermets increases with an increase in Mo/B ratio and shows a maximum value of 1 872 MPa at an Mo/B atomic ratio of 1.1 and then decreases with increasing Mo/B atomic ratio. The hardness and the corrosion resistance of the cermets increase monotonically with an increase in Mo/B atomic ratio. In Mo-rich cermets with an atomic ratio of Mo/B above 1.1, a small amount Ni-Mo intermetallic compound is found precipitated at the interface of Mo 2 NiB 2 grains.

In-situ fabrication of MoSi{sub 2}/SiC–Mo{sub 2}C gradient anti-oxidation coating on Mo substrate and the crucial effect of Mo{sub 2}C barrier layer at high temperature

Energy Technology Data Exchange (ETDEWEB)

Liu, Jun [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Gong, Qianming, E-mail: gongqianming@mail.tsinghua.edu.cn [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Shao, Yang; Zhuang, Daming [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Liang, Ji [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)

2014-07-01

MoSi{sub 2}/SiC–Mo{sub 2}C gradient coating on molybdenum was in situ prepared with pack cementation process by two steps: (1) carburizing with graphite powder to obtain a Mo{sub 2}C layer on Mo substrate, and (2) siliconizing with Si powder to get a composite MoSi{sub 2}/SiC layer on the upper part of Mo{sub 2}C layer. The microstructure and elemental distribution in the coating were investigated with scanning electron microscopy (SEM), backscattered electron (BSE), energy dispersive spectroscopy (EDS), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Cyclic oxidation tests (at 500 °C, 1200 °C, 1400 °C and 1600 °C) demonstrated excellent oxidation resistance for the gradient composite coating and the mass loss was only 0.23% in 60 min at 1600 °C. XRD, EPMA, thermal dynamic and phase diagram analyses indicated that the Mo{sub 2}C barrier layer played the key role in slowing down the diffusion of C and Si toward inner Mo substrate at high temperature and principally this contributed to the excellent anti-oxidation for Mo besides the outer MoSi{sub 2}/SiC composite layer.

Facile synthesis of stable structured MoS{sub 2}-Mo-CNFs heteroarchitecture with enhanced hydrogen evolution

Energy Technology Data Exchange (ETDEWEB)

Mo, Qionghua [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Faculty of Material and Energy, South West University, Chongqing 400700 (China); Yao, Yucen [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Liu, Bitao, E-mail: liubitao007@163.com [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Peng, Lingling; Yan, Hengqing; Hou, Zhupei; Wang, Jun [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Lin, Yue, E-mail: linyue@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026 (China)

2017-06-01

3D structured MoS{sub 2} are grown in-situ on Mo particles embedded carbon nanofibers (CNFs) via a hydrothermal method. Due to this special structure, the bonding and effective electron delivery between CNFs and MoS{sub 2} are both enhanced, and which will exhibits a better hydrogen evolution activity. The onset potential of this MoS{sub 2}-Mo-CNFs catalyst will decreased to 60 mV compared to the 90 mV for the MoS{sub 2}-CNFs. And its current density nearly no change with 5000 cycles which is better than the 32.3% decrease of MoS{sub 2}-CNFs at η = 300 mV (V vs RHE). - Highlights: • Newly structured MoS{sub 2}-Mo-CNFs with effectively connection between MoS{sub 2} and CNFs successfully synthesized. • This structure can enhance the charge transfer and significantly increase electrocatalytic efficiency. • Nearly no HER activity loss after 5000 CV cycles.

Interdiffusion between U(Mo,Pt) or U(Mo,Zr) and Al or Al A356 alloy

International Nuclear Information System (INIS)

Komar Varela, C.; Mirandou, M.; Arico, S.; Balart, S.; Gribaudo, L.

2009-01-01

Solid state reactions in chemical diffusion couples U-7 wt.%Mo-0.9 wt.%Pt/Al at 580 deg. C and U-7 wt.%Mo-0.9 wt.%Pt/Al A356 alloy, U-7 wt.%Mo-1 wt.%Zr/Al and U-7 wt.%Mo-1 wt.%Zr/Al A356 alloy at 550 deg. C were characterized. Results were obtained from optical and scanning electron microscopy, electron probe microanalysis and X-ray diffraction. The UAl 3, UAl 4 and Al 20 Mo 2 U phases were identified in the interaction layers of γU(Mo,Pt)/Al and γU(Mo,Zr)/Al diffusion couples. Al 43 Mo 4 U 6 ternary compound was also identified in γU(Mo,Zr)/Al due to the decomposition of γU(Mo,Zr) phase. The U(Al,Si) 3 and U 3 Si 5 phases were identified in the interaction layers of γU(Mo,Pt)/Al A356 and γU(Mo,Zr)/Al A356 diffusion couples. These phases are formed due to the migration of Si to the interaction layer. In the diffusion couple U(Mo,Zr)/Al A356, Zr 5 Al 3 phase was also identified in the interaction layer. The use of synchrotron radiation at Brazilian Synchrotron Light Laboratory (LNLS, CNPq, Campinas, Brazil) was necessary to achieve a complete crystallographic characterization.

Experimental cross-sections for proton-induced nuclear reactions on Mo-nat

Czech Academy of Sciences Publication Activity Database

Červenák, Jaroslav; Lebeda, Ondřej

2016-01-01

Roč. 380, AUG (2016), s. 32-49 ISSN 0168-583X R&D Projects: GA MŠk(CZ) LM2011019 Institutional support: RVO:61389005 Keywords : cross-sections * excitation functions * proton-induced nuclear reactions * natural molybdenum * Mo-99 * Tc-99m * Tc96m+g * Tc-95m * thick target yields * U-120M cyclotron Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.109, year: 2016

On the reduction of orthorhombic MoO3 to MoO2

International Nuclear Information System (INIS)

Delannay, F.

1982-01-01

Electron diffraction shows evidence of topotactic orientation relationships between the original MoO 3 crystal and MoO 2 crystals formed under mild reduction conditions. These relationships differ from previously published literature data. A possible mechanism of formation of the [100] strings of edge sharing octahedra in the MoO 2 structure is tentatively proposed. (author)

Cu4Pr6(MoO4)11-Pr2(MoO4)3 system

International Nuclear Information System (INIS)

Arzumanyan, G.A.

1982-01-01

Existence boundaries and Dalton compositions (CuPr(MoO 4 ) 2 , CuPr 3 (MoO 4 ) 5 ) of solid solutions that in the mojority are of shcheelite dsitored structure have been determined in the Cu 4 Pr 6 (MoO 4 ) 11 -Pr 2 (MoO 4 ) 3 system. It has been revealed that regions of homogeneity near the CuPr(MoO 4 ) 2 composition have a horseshoeshaped profile

The modulation of Schottky barriers of metal-MoS2 contacts via BN-MoS2 heterostructures.

Science.gov (United States)

Su, Jie; Feng, Liping; Zhang, Yan; Liu, Zhengtang

2016-06-22

Using first-principles calculations within density functional theory, we systematically studied the effect of BN-MoS2 heterostructure on the Schottky barriers of metal-MoS2 contacts. Two types of FETs are designed according to the area of the BN-MoS2 heterostructure. Results show that the vertical and lateral Schottky barriers in all the studied contacts, irrespective of the work function of the metal, are significantly reduced or even vanish when the BN-MoS2 heterostructure substitutes the monolayer MoS2. Only the n-type lateral Schottky barrier of Au/BN-MoS2 contact relates to the area of the BN-MoS2 heterostructure. Notably, the Pt-MoS2 contact with n-type character is transformed into a p-type contact upon substituting the monolayer MoS2 by a BN-MoS2 heterostructure. These changes of the contact natures are ascribed to the variation of Fermi level pinning, work function and charge distribution. Analysis demonstrates that the Fermi level pinning effects are significantly weakened for metal/BN-MoS2 contacts because no gap states dominated by MoS2 are formed, in contrast to those of metal-MoS2 contacts. Although additional BN layers reduce the interlayer interaction and the work function of the metal, the Schottky barriers of metal/BN-MoS2 contacts still do not obey the Schottky-Mott rule. Moreover, different from metal-MoS2 contacts, the charges transfer from electrodes to the monolayer MoS2, resulting in an increment of the work function of these metals in metal/BN-MoS2 contacts. These findings may prove to be instrumental in the future design of new MoS2-based FETs with ohmic contact or p-type character.

Phase formation in the Li2MoO4–Rb2MoO4–Fe2(MoO4)3 system and crystal structure of a novel triple molybdate LiRb2Fe(MoO4)3

International Nuclear Information System (INIS)

Khal'baeva, Klara M.; Solodovnikov, Sergey F.; Khaikina, Elena G.; Kadyrova, Yuliya M.; Solodovnikova, Zoya A.; Basovich, Olga M.

2013-01-01

X-ray investigation of solid state interaction of the components in the Li 2 MoO 4 –Rb 2 MoO 4 –Fe 2 (MoO 4 ) 3 system was carried out, and a subsolidus phase diagram of the said system was constructed. The subsystem Rb 2 MoO 4 –LiRbMoO 4 –RbFe(MoO 4 ) 2 was shown to be non-quasiternary. Formation of a novel triple molybdate LiRb 2 Fe(MoO 4 ) 3 was established, conditions of solid state synthesis and crystallization of the compound were found. Its crystal structure (orthorhombic, space group Pnma, Z=4, a=24.3956(6), b=5.8306(1), c=8.4368(2) Å) represents a new structure type and includes infinite two-row ribbons ([Fe(MoO 4 ) 3 ] 3− ) ∞ parallel to the b axis and composed of FeO 6 octahedra, terminal Mo(3)O 4 tetrahedra, and bridge Mo(1)O 4 and Mo(2)O 4 tetrahedra connecting two or three FeO 6 octahedra. The ribbons are connected to form 3D framework via corner-sharing LiO 4 tetrahedra. Rubidium cations are 11- and 13-coordinated and located in cavities of this heterogeneous polyhedral framework. - Graphical abstract: Exploring the Li 2 MoO 4 –Rb 2 MoO 4 –Fe 2 (MoO 4 ) 3 system showed its partial non-quasiternarity and revealed a new compound LiRb 2 Fe(MoO 4 ) 3 which was structurally studied. - Highlights: • The Li 2 MoO 4 –Rb 2 MoO 4 –Fe 2 (MoO 4 ) 3 system study revealed a new compound LiRb 2 Fe(MoO 4 ) 3 . • Its structure of a new type includes ribbons of FeO 6 octahedra and MoO 4 tetrahedra. • The ribbons are connected into a 3D framework via corner-sharing LiO 4 tetrahedra

Preparation and characterization of iron(III) {sup 99}Mo-molybdate(VI) gels for the assessment of {sup 99m}Tc elution performance

Energy Technology Data Exchange (ETDEWEB)

Amin, Mahmoud; Fasih, Tharwat W.; El-Absy, Mohamed A. [Egyptian Atomic Energy Authority, Cairo (Egypt)

2018-04-01

New iron(III) {sup 99}Mo-molybdate(VI) gels (Fe{sup 99}Mo) of high Mo content were prepared by the precipitation/filtration method. {sup 99}Mo-MoO{sub 3} dissolved in NaOH was added to aqueous solutions of Fe(NO{sub 3}){sub 3} at Mo/Fe mole fractions ∝2.21 and 1.99 with continuous stirring at ambient room temperature. Two different Fe{sup 99}Mo were precipitated from the mixed solutions adjusted at pH 2 and 4.7. The amount of water of hydration increased with the increasing the gel settling time and pH of the mixed solution. The matrices were characterized by radiometric, XRD, SEM, XRF, FT-IR, TGA, and DTA measurements. Small chromatographic columns of 2.0 g Fe{sup 99}Mo containing ≥800 mg Mo tagged with 740 MBq {sup 99}Mo were eluted with 5 mL saline solution. Highly reproducible {sup 99m}Tc elution indices suitable for preparation of {sup 99}Mo/{sup 99m}Tc generators were achieved from generator supported with 0.5 g Al{sub 2}O{sub 3} filter. Elution performance of {sup 99m}Tc radionuclide was highly dependent on the gel structural properties.

Successful labeling of 99mTc-MDP using 99mTc separated from 99Mo produced by 100Mo(n,2n)99Mo

International Nuclear Information System (INIS)

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

2011-01-01

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

Development of 99mTc extraction techniques from 99Mo by (n,γ) reaction

International Nuclear Information System (INIS)

Kimura, Akihiro; Hori, Naohiko; Tsuchiya, Kunihiko; Ishihara, Masahiro; Yamabayashi, Hisamichi; Tanase, Masakazu; Fujisaki, Saburo; Sato, Yuichi

2010-11-01

Investigation of production method of 99 Mo by (n, γ) reaction, where the processing is relatively simple and generating less amount of radioactive waste, is conducted in the Neutron Irradiation and Testing Reactor Center. The 99 Mo is adsorbed to highly efficient adsorbent PZC after neutron irradiation and 99m Tc is eluted. However, radioactivity concentration of the 99m Tc solution obtained from PZC column loaded with 99 Mo derived by (n, γ) method is lower than that obtained from alumina column with 99 Mo by (n, f) method due to extremely low specific activity of (n, f) 99 Mo. Therefore, it is necessary to develop technique for increasing the amount of 99 Mo and the 99m Tc solution of high radioactivity concentration (minimum: 1Ci/ cm 3 ). In this study, the preliminary fabrication tests using high density MoO 3 pellets were carried out to increase the production of 99 Mo. The method of concentrating 99m Tc solution through solvent extraction with MEK was investigated and a device for this concentration process was also developed. In the preliminary tests of the MoO 3 pellets, the pellets having high density were successfully fabricated by the SPS method. Additionally, it was ascertained that the pellets can be dissolved with 6M-NaOH solution completely. The test for 99 Mo adsorption followed by 99m Tc elution using PZC was carried out. As the result, amount of Mo adsorbed to 1g-PZC was about 250mg, and 99m Tc yield was about 80%. In the concentration test using Re solution instead of 99m Tc solution, it was ascertained that the concentration efficiency is higher than 80% of the theoretical value. A concentration device for 99m Tc solution could be realized based on the method employed in the present experiments. The outcomes of development of 99m Tc extraction techniques from 99 Mo by (n,γ) reaction was reviewed in this paper, and the contents were presented in the 3rd International Symposium on Material Test Reactors. (author)

Geochemical element mobility during the hydrothermal alteration in the Tepeoba porphyry Cu-Mo-Au deposits at Balikesir, NW Turkey

Science.gov (United States)

Abdelnasser, Amr; Kiran Yildirim, Demet; Doner, Zeynep; Kumral, Mustafa

2016-04-01

The Tepeoba porphyry Cu-Mo-Au deposit represents one of the important copper source and mineral deposits in the Anatolian tectonic belt at Balikesir province, NW Turkey. It considered as a vein-type deposit locally associated with intense hydrothermal alteration within the brecciation, quartz stockwork veining, and brittle fracture zones in the main host rock that represented by hornfels, as well as generally related to the shallow intermediate to silicic intrusive Eybek pluton. Based on the field and geologic relationships and types of ore mineral assemblages and the accompanied alteration types, there are two mineralization zones; hypogene (primary) and oxidation/supergene zones are observed associated with three alteration zones; potassic, phyllic, and propylitic zones related to this porphyry deposit. The phyllic and propylitic alterations locally surrounded the potassic alteration. The ore minerals related to the hypogene zone represented by mostly chalcopyrite, Molybdenite, and pyrite with subordinate amount of marcasite, enargite, and gold. On the other hand they include mainly cuprite with chalcopyrite, pyrite and gold as well as hematite and goethite at the oxidation/supergene zone. This study deals with the quantitative calculations of the mass/volume changes (gains and losses) of the major and trace elements during the different episodes of alteration in this porphyry deposit. These mass balance data reveal that the potassic alteration zone that the main Cu- and Mo-enriched zone, has enrichment of K, Si, Fe, and Mg, and depletion of Na referring to replacement of plagioclase and amphibole by K-feldspar, sericite and biotite. While the propylitic alteration that is the main Mo- and Au-enriched zone is accompanied with K and Na depletion with enrichment of Si, Fe, Mg, and Ca forming chlorite, epidote, carbonate and pyrite. On the other hand the phyllic alteration that occurred in the outer part around the potassic alteration, characterized by less amount

Evaluation of highly loaded low specific activity 99Mo on alumina column as 99mTc generator

International Nuclear Information System (INIS)

Asif, M.; Mushtaq, A.

2010-01-01

Adsorption behavior of molybdate on acidic alumina was studied at boiling water bath temperature (∼100 deg C). Various parameters affecting the adsorption of molybdenum, such as pH, amount of molybdenum, incubation period, etc., were determined. A 99m Tc generator was prepared by adsorbing low specific activity 99 Mo (150 mg) on 1 g alumina. Elutions were carried out with saline. Performance of the generator such as 99 Mo breakthrough, aluminum contents, pH, elution profile, radiochemical purity, and labeling efficiency of kits were checked. (author)

Lattice structures and electronic properties of MO/MoSe2 interface from first-principles calculations

Science.gov (United States)

Zhang, Yu; Tang, Fu-Ling; Xue, Hong-Tao; Lu, Wen-Jiang; Liu, Jiang-Fei; Huang, Min

2015-02-01

Using first-principles plane-wave calculations within density functional theory, we theoretically studied the atomic structure, bonding energy and electronic properties of the perfect Mo (110)/MoSe2 (100) interface with a lattice mismatch less than 4.2%. Compared with the perfect structure, the interface is somewhat relaxed, and its atomic positions and bond lengths change slightly. The calculated interface bonding energy is about -1.2 J/m2, indicating that this interface is very stable. The MoSe2 layer on the interface has some interface states near the Fermi level, the interface states are mainly caused by Mo 4d orbitals, while the Se atom almost have no contribution. On the interface, Mo-5s and Se-4p orbitals hybridize at about -6.5 to -5.0 eV, and Mo-4d and Se-4p orbitals hybridize at about -5.0 to -1.0 eV. These hybridizations greatly improve the bonding ability of Mo and Se atom in the interface. By Bader charge analysis, we find electron redistribution near the interface which promotes the bonding of the Mo and MoSe2 layer.

Effects of Mo Content on Microstructure and Mechanical Property of PH13-8Mo Martensitic Precipitation-Hardened Stainless Steel

Science.gov (United States)

Yubing, Pei; Tianjian, Wang; Zhenhuan, Gao; Hua, Fan; Gongxian, Yang

This paper introduces the effects of Mo content on microstructure and mechanical property of PH13-8Mo martensitic precipitation-hardened stainless steel which is used for LP last stage blade in steam turbine. Thermodynamic software Thermo-Calc has been used to calculate precipitation temperature and the mass fraction of precipitated phases in PH13-8Mo steel with different Mo content. The result shows that when the mass of Mo is below 0.6wt.%, chi-phase mu-phase and sigma-phase could disappear. The microstructure and mechanical property of high Mo PH13-8Mo (Mo=0.57wt.%) and low Mo PH13-8Mo (Mo=2.15wt.%)have been investigated in different heat treatments. The investigations reveal that austenitizing temperature decrease with the reduce of Mo content, so the optimum solution temperature for low Mo PH13-8Mo is lower than that for high Mo PH13-8Mo.The influence of solution temperature on grain size is weakened with the increase of Mo content, Mo rich carbides could retard coarsening of grain. An enormous amount of nano-size uniformly distributed β-NiAl particles are found in both kinds of steels using transmission electron microscopy, they are the most important strengthening phase in PH13-8Mo.

Effect of 67Cu and 99Mo labeled tetrathiomolybdate on the distribution of 67Cu, Cu, and 99Mo in bile fractions in sheep

International Nuclear Information System (INIS)

Gooneratne, R.; Laarveld, B.; Christensen, D.

1989-01-01

The effect of intravenous administration of 67 Cu and 99 Mo labeled tetrathiomolybdate (TTM) on the appearance of 67 Cu, stable Cu, and 99 Mo in gel chromatographic fractions of bile was examined in sheep fed either 5 or 35 mg Cu kg-1 DM. Peak excretory periods of biliary 67 Cu, stable Cu, and 99 Mo were observed at 30 min-1.25 hr, 2-3 hr, and 11-13 hr after 67 Cu and after 99 Mo labeled TTM. Sephadex G-75 gel filtration of bile samples collected at 1, 3, and 12 hr after 67 Cu administration revealed two major protein peaks of molecular weights of greater than 80,000 (peak I) and 7,000 (peak II) containing both 67 Cu and Cu. But the ratio of 67 Cu in the two peaks varied with time of bile collection. The ratio of areas of peak I:II 1 hr after 67 Cu administration was approximately 0.48; at 3 hr, 0.62, and at 12 hr 1.35. Tetrathiomolybdate administration increased both 67 Cu and stable Cu in bile by severalfold and induced a major shift of Cu into the higher molecular weight protein fraction. The experiments confirm the effectiveness of TTM as a ''decoppering'' agent. Furthermore, TTM not only promoted bile Cu excretion, but it also increased the incorporation of Cu into the macromolecular fraction. This may limit enterohepatic circulation of biliary Cu and thereby cause an overall Cu depletion and a negative Cu balance

Uniform Pt Nanoparticles Incorporated into Reduced Graphene Oxides with MoO_3 as Advanced Anode Catalysts for Methanol Electro-oxidation

International Nuclear Information System (INIS)

Hao, Yanfei; Wang, Xudan; Zheng, Yuanyuan; Shen, Jianfeng; Yuan, Junhua; Wang, Ai-jun; Niu, Li; Huang, Shengtang

2016-01-01

Highlights: • Pt nanoparticles were uniformly deposited on graphene with MoO_3. Their size can be tuned by controlling MoO_3 loading. These Pt catalysts are high active on methanol oxidation. They also show high tolerance to CO poisoning. - Abstract: Pt nanoparticles (NPs) were uniformly deposited on the reduced graphene oxides (RGOs) by one-pot thermoreduction strategy with assist of MoO_3. MoO_3 can significantly reduce the size of Pt NPs on RGOs. These Pt NPs can be averaged to be 3.0 to 4.1 nm with MoO_3 loading from 27.4 to 8.8%. Without MoO_3, the size of Pt NPs can reach up to 15.2 nm. In addition, MoO_3 in Pt-MoO_3/RGO catalysts conducts a surface-confined reversible electron transfer. And the Pt-MoO_3/RGO catalysts show strong resistance to CO poisoning and high activity towards methanol oxidation reaction (MOR). Among these Pt-based catalysts, Pt-MoO_3/RGO catalysts with 16.5% MoO_3 loading possess a largest MOR current up to 610 mA mg"−"1 Pt with a smallest deteriorate rate of 0.000425 s"−"1 polarizing for 5000 s at 0.65 V. These results demonstrate commercial feasibility for Pt catalysts to reduce significantly the amount of precious metals Pt in parallel to maintain a high MOR activity and CO tolerance.

Comparative study of NiW, NiMo and MoW prepared by mechanical alloying

International Nuclear Information System (INIS)

Gonzalez, G.; Sagarzazu, A.; Villalba, R.; Ochoa, J.

2007-01-01

The present work concern the amorphisation process induced by mechanical alloying in the NiW, NiMo and MoW systems. The alloys chosen combine a group of transition elements varying from very similar atomic radius and electronic valences (MoW) to different ones (NiW and NiMo). The three systems achieved an amorphous state after 50 h of milling. The mechanism of amorphisation proposed for NiW and NiMo was the combined effect of an excess concentration of the solute atoms entering into the structure of one of the elements and a critical concentration of defects. Continuous formation of an amorphous phase at the interface of the crystalline phase was observed during the process. MoW seems to amorphize by continuous reduction of grain size down to a critical value where the amorphisation takes place

Phase relations in the systems M2MoO4-Cr2(MoO4)3-Zr(MoO4)2 (M=Li, Na, or Rb)

International Nuclear Information System (INIS)

Bazarov, B.G.; Chimitova, O.D.; Bazarova, Ts.T.; Arkhincheeva, S.I.; Bazarova, Zh.G.

2008-01-01

Phase equilibria in the systems M 2 MoO 4 -Cr 2 (MoO 4 ) 3 -Zr(MoO 4 ) 2 (M=Li, Na, or Rb) were investigated by X-ray powder diffraction analysis, DTA, and IR spectroscopy. The subsolidus structure of the phase diagrams of the systems under study was established. Two phases are formed in the Rb 2 MoO 4 -Cr 2 (MoO 4 ) 3 -Zr(MoO 4 ) 2 system with the molar ratios of the starting components equal to 5:1:1 (S 2 ) and 1:1:1 (S 1 ). Proceeding from isostructural character of Rb 5 FeHf(MoO 4 ) 6 and S 2 , the unit cell parameters are determined for S 2 [ru

Synthesis and characterization of MgO nanocrystals for biosensing applications

Energy Technology Data Exchange (ETDEWEB)

Li, Hongji [Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry & Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China); Li, Mingji, E-mail: limingji@163.com [Tianjin Key Laboratory of Film Electronic and Communication Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Qiu, Guojun [Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry & Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China); Li, Cuiping; Qu, Changqing; Yang, Baohe [Tianjin Key Laboratory of Film Electronic and Communication Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China)

2015-05-25

Highlights: • MgO nanocrystals were prepared using DC arc plasma jet CVD method. • The growth time does not exceed 10 min in process of the synthesis. • The samples were found to consist of cubic MgO nanobelts and nanosheets. • Nanocrystals contain contacts, rough edges, vacancies, and doping defects. • The samples exhibited excellent electrochemical biosensing properties. - Abstract: MgO nanocrystals were prepared using a simple direct current arc plasma jet chemical vapor deposition method. Magnesium nitrate was used as source material and Mo film was used as a substrate and catalyst. The high-temperature plasma produced ensured rapid synthesis of the MgO nanocrystals. The as-prepared nanocrystals were characterized by field-emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, energy-dispersive spectroscopy, Fourier transform infrared spectrometry, ultraviolet–visible spectrophotometry, and photoluminescence measurements. The as-synthesized samples were found to consist of cubic MgO nanobelts and nanosheets with large surface areas and low coordination oxide ions, and contained numerous contacts, rough edges, vacancies, and doping defects. The nanostructures exhibited excellent electrochemical sensing properties with high-sensing sensitivity toward ascorbic acid. Their high electrocatalytic activity was attributed to the effect of defects and the surface electron transfer ability of the one-dimensional MgO nanobelts.

Preparation of Sr{sub 2}(MgMo){sub 1-x}Ru{sub x}O{sub 6} ceramics for use in a solid oxide fuel cell anode

Energy Technology Data Exchange (ETDEWEB)

Bezerra, Matheus Eiji Ohno; Florio, Daniel Zanetti de [Universidade Federal do ABC (UFABC), SP (Brazil); Fonseca, Fabio Coral, E-mail: matheus.eiji@aluno.ufabc.edu.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2016-07-01

Full text: Solid Oxide Fuel Cells are the most efficient devices known for the direct conversion of fuels into electric energy. Such devices have advanced steadily and are already available for specific applications such as portable power and residential stationary generation. The main objective of this work is the development of anodes for SOFC operating directly with renewable fuels, without the addition of water and using strategic fuels such as ethanol and natural gas. Specifically, a family of mixed ionic-electronic compounds has been investigated: the double perovskites with compositions Sr{sub 2}(MgMo){sub 1-x}Ru{sub x}O{sub 6} with x = 0; 1; 2; 5; 10 e 20 at.%. This material has been synthesized by polymeric precursor method. The resins were prepared by combining stoichiometric amounts of the starting solutions. The resulting solution was heated treated under magnetic stirring. The thermal decomposition of the polymeric resin was studied by means of simultaneous thermogravimetric and differential scanning calorimetry up to 1500 °C with heating and cooling rates of 10 °/min in Ar. The thermal decomposition result shows mass loss up to, approximately, 900 °C. However X-ray diffraction analyses of the powder heat treated at 900 °C and 1200 °C presents a considerable content of an undesiderate phase (SrMoO{sub 4}). According to the literature for similar compounds a thermal treatment under reduction conditions could be necessary to obtain the double perovskites single phase. After this treatment the material will be characterized regarding its electrical properties. The expected results will contribute to advance both the understanding of the mixed ionic electronic ceramics and the SOFC technology using renewable fuels. (author)

Optimization of the 99m Tc generator with hydrotalcite as support of 99 Mo

International Nuclear Information System (INIS)

Aranda O, N.

2004-01-01

, which doesn't take place in Mexico and it has to be cared from Canada, at a cost of $361 USD for Ci. Presently work the results are described obtained when investigating the use of the 99 Mo of low specific activity for the optimization of the generator of 99m Tc using hydrotalcite with different molar ratio of x (x = Al 3+ /(AI 3+ + Mg 2+ )) like support of the 99 Mo. (Author)

Photoluminescence of MoS2 Prepared by Effective Grinding-Assisted Sonication Exfoliation

Directory of Open Access Journals (Sweden)

Jing-Yuan Wu

2014-01-01

Full Text Available Exfoliation of bulk molybdenum disulfide (MoS2 using sonication in appropriate solvent is a promising route to large-scale preparation of few-layered or monolayered crystals. Grinding-assisted sonication exfoliation was used for preparing monolayered MoS2 nanosheets from natural mineral molybdenite. By controlling the sonication time, larger crystallites could be further exfoliated to smaller as well as thinner nanosheets without damaging their structures. The concentration of 1.6 mg mL−1 of final solution could be achieved. Several microscopic techniques like scanning electron microscopy, transmission electron microscopy, and atomic force microscopy were employed to evaluate the exfoliation results. Strong photoluminescence with the peak centered at 440 nm was also observed in the resulting dispersion which included several small lateral-sized (~3 nm nanostructures.

Effect of aqueous solution and load on the formation of DLC transfer layer against Co-Cr-Mo for joint prosthesis.

Science.gov (United States)

Guo, Feifei; Zhou, Zhifeng; Hua, Meng; Dong, Guangneng

2015-09-01

Diamond-like carbon (DLC) coating exhibits excellent mechanical properties such as high hardness, low friction and wear, which offer a promising solution for the metal-on-metal hip joint implants. In the study, the hydrogen-free DLC coating with the element Cr as the interlay addition was deposited on the surface of the Co-Cr-Mo alloy by a unbalanced magnetron sputtering method. The coating thickness was controlled as 2 µm. Nano-indentation test indicated the hardness was about 13 GPa. DLC coated Co-Cr-Mo alloy disc against un-coated Co-Cr-Mo alloy pin (spherical end SR9.5) comprised the friction pairs in the pin-on-disc tribotest under bovine serum albumin solution (BSA) and physiological saline(PS).The tribological behavior under different BSA concetrations(2-20 mg/ml), and applied load (2-15N) was investigated.DLC transfer layer did not form under BSA solution, even though different BSA concetration and applied load changed. The coefficient of friction(COF) under 6 mg/ml BSA at 10 N was the lowest as 0.10. A higher COF of 0.13 was obtained under 20 mg/ml BSA. The boundary absorption layer of protein is the main factor for the counterparts. However, the continous DLC transfer layer was observed under PS solution, which make a lower COF of 0.08. Copyright © 2015 Elsevier Ltd. All rights reserved.

Corrosive sliding wear behavior of laser clad Mo2Ni3Si/NiSi intermetallic coating

International Nuclear Information System (INIS)

Lu, X.D.; Wang, H.M.

2005-01-01

Many ternary metal silicides such as W 2 Ni 3 Si, Ti 2 Ni 3 Si and Mo 2 Ni 3 Si with the topologically closed-packed (TCP) hP12 MgZn 2 type Laves phase crystal structure are expected to have outstanding wear and corrosion resistance due to their inherent high hardness and sluggish temperature dependence and strong atomic bonds. In this paper, Mo 2 Ni 3 Si/NiSi intermetallic coating was fabricated on substrate of an austenitic stainless steel AISI321 by laser cladding using Ni-Mo-Si elemental alloy powders. Microstructure of the coating was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS). Wear resistance of the coating is evaluated under corrosive sliding wear test condition. Influence of corrosion solutions on the wear resistance of the coating was studied and the wear mechanism was discussed based on observations of worn surface morphology. Results showed that the laser clad Mo 2 Ni 3 Si/NiSi composite coating have a fine microstructure of Mo 2 Ni 3 Si primary dendrites and the interdendritic Mo 2 Ni 3 Si/NiSi eutectics. The coating has excellent corrosive wear resistance compared with austenitic stainless steel AISI321 under acid, alkaline and saline corrosive environments

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.

Holey Reduced Graphene Oxide Coupled with an Mo2 N-Mo2 C Heterojunction for Efficient Hydrogen Evolution.

Science.gov (United States)

Yan, Haijing; Xie, Ying; Jiao, Yanqing; Wu, Aiping; Tian, Chungui; Zhang, Xiaomeng; Wang, Lei; Fu, Honggang

2018-01-01

An in situ catalytic etching strategy is developed to fabricate holey reduced graphene oxide along with simultaneous coupling with a small-sized Mo 2 N-Mo 2 C heterojunction (Mo 2 N-Mo 2 C/HGr). The method includes the first immobilization of H 3 PMo 12 O 40 (PMo 12 ) clusters on graphite oxide (GO), followed by calcination in air and NH 3 to form Mo 2 N-Mo 2 C/HGr. PMo 12 not only acts as the Mo heterojunction source, but also provides the Mo species that can in situ catalyze the decomposition of adjacent reduced GO to form HGr, while the released gas (CO) and introduced NH 3 simultaneously react with the Mo species to form an Mo 2 N-Mo 2 C heterojunction on HGr. The hybrid exhibits superior activity towards the hydrogen evolution reaction with low onset potentials of 11 mV (0.5 m H 2 SO 4 ) and 18 mV (1 m KOH) as well as remarkable stability. The activity in alkaline media is also superior to Pt/C at large current densities (>88 mA cm -2 ). The good activity of Mo 2 N-Mo 2 C/HGr is ascribed to its small size, the heterojunction of Mo 2 N-Mo 2 C, and the good charge/mass-transfer ability of HGr, as supported by a series of experiments and theoretical calculations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, structure and optical properties of two isotypic crystals, Na3MO4Cl (M=W, Mo)

International Nuclear Information System (INIS)

Han, Shujuan; Bai, Chunyan; Zhang, Bingbing; Yang, Zhihua; Pan, Shilie

2016-01-01

Two isotypic compounds, Na 3 MO 4 Cl (M = W, Mo) have been obtained from the high temperature solution, and their structures were determined by single-crystal X-ray diffraction. Both of them crystallize in the space group P4/nmm of tetragonal system with the unit cells: a=7.5181(15), c=5.360(2) for Na 3 WO 4 Cl and a=7.4942(12), c=5.3409(18) for Na 3 MoO 4 Cl. The structure exhibits a 3D network built up by the ClNa 6 groups, and the MO 4 groups reside in the tunnels of the 3D network. The structural similarities and differences between Na 3 MO 4 Cl (M=W, Mo) and Sr 3 MO 4 F (M=Al, Ga) have been discussed. Meanwhile, detailed structure comparison analyses between Na 3 MO 4 Cl (M=W, Mo) and Na 3 MO 4 F (M=W, Mo) indicate that the different connection modes of ClNa 6 and FNa 6 make Na 3 MO 4 Cl and Na 3 MO 4 F crystallize in different structures. The IR spectra were used to verify the validity of the structure. The diffuse reflectance spectra show that the UV absorption edges are about 249 nm (4.99 eV) and 265 nm (4.69 eV) for Na 3 WO 4 Cl and Na 3 MoO 4 Cl, respectively. In addition, the first-principles theoretical studies are also carried out to aid the understanding of electronic structures and linear optical properties. - Graphical abstract: Two isotypic compounds, Na 3 MO 4 Cl (M=W, Mo) have been obtained from the high temperature solution. Both of them crystallize in the space group P4/nmm of tetragonal system. The structure exhibits a 3D network built up by the ClNa 6 groups, and the MO 4 groups reside in the tunnels of the 3D network. - Highlights: • Structure and properties of Na 3 MO 4 Cl (M=W, Mo) are reported for the first time. • They show a 3D network built by ClNa 6 , and WO 4 lies in the tunnels of the network. • IR spectra were used to verify the validity of the structure. • Band structures and density of states have been calculated.

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.

Development on UO3-K2O and MoO3-K2O binary systems and study of UO2MoO4-MoO3 domain within UO3-MoO3-K2O ternary system

International Nuclear Information System (INIS)

Dion, C.; Noel, A.

1983-01-01

This paper confirms the previous study on the MoO 3 -K 2 O system, and constitutes a clarity of the UO 3 -K 2 O system. Four distinct uranates VI with alkaline metal/uranium ratio's 2, 1, 0,5 and 0,285 exist. Preparation conditions and powder diffraction spectra of these compounds are given. Additional informations relative to K 2 MoO 4 allotropic transformations are provided. Study of UO 2 MoO 4 -K 2 MoO 4 diagram has brought three new phases into prominence: (B) K 6 UMo 4 O 18 incongruently melting point, (E) K 2 UMo 2 O 10 congruently melting and (F) K 2 U 3 Mo 4 O 22 incongruently melting point. Within MoO 3 -K 2 MoO 4 -UO 2 MoO 4 ternary system, no new phase is found. The general appearance of ternary liquidus and crystallization fields of several compounds are given. These three new compounds become identified with these of UO 2 MoO 4 -Na 2 MoO 4 binary system [fr

Investigation of BaMoO4-Ln2(MoO4)3 systems (Ln = Nd, Sm, Yb)

International Nuclear Information System (INIS)

Vakulyuk, V.V.; Evdokimov, A.A.; Khomchenko, G.P.

1982-01-01

Using the methods of X-ray phase and differential-thermal analyses phase ratios in the systems BaMoO 4 -Ln 2 (MoO 4 ) 3 (Ln=Nd, Sm, Yb); BaNd 2 (MoO 4 ) 4 -MaGd 2 (MoO 4 ) are studied. Unit cell parameters and the character of melting of the compounds BaLn 2 (MoO 4 ) 4 are specified. Effect of growth conditions on laminated nature of BaGd 2 (MoO 4 ) 4 monocrystals is studied

Study of Mo (VI Removal from Aqueous Solution: Application of Different Mathematical Models to Continuous Biosorption Data

Directory of Open Access Journals (Sweden)

Fatemeh Kafshgari

2013-01-01

Full Text Available Molybdenum (VI biosorption process was investigated by marine algae Cystoseria indica pretreated with 0.1 M CaCl2 solution in a packed bed column. The biosorbent was characterized by FTIR, BET and SEM analyses. The results showed that Mo (VI ions should be chelated with the hydroxyl, carboxyl and amine groups of the biomass. The effects of inlet metal concentration and flow rate on biosorption process were investigated and the experimental breakthrough curves were obtained. Results showed that the maximum biosorption capacity of Ca-pretreated C. indica for Mo (VI was found to be 18.32 mg/g at optimum flow rate of (1.4 mL/min. The controlled-rate step shifted from external to internal mass transfer limitations, as the flow rate increased. Also, it was observed that the breakthrough and exhaustion time decreased from 17.14 hr to 9.05 hr and from 0.006 h to 0.002 hr respectively, with the increase of flow rate from 0.7 to 2.1 ML/min. The increase in the initial concentration of Mo (VI solution from 30 to 95 ml min-1 increases the adsorption capacity from 18.32 to 30.19 mg/g and decreases the percentage of Mo (VI removal from 61 to 38%. Also, the treated volume was the greatest (1.42 L at the lowest inlet concentration. Column data obtained under different conditions were described using the Thomas, Yoon and Nelson, Yan and Belter models. The breakthrough curve predictions by Belter model were found to be very satisfactory.

Systems Tl2MoO4-E(MoO4)2, where E=Zr or Hf, and the crystal structure of Tl8Hf(MoO4)6

International Nuclear Information System (INIS)

Bazarov, B.G.; Bazarova, Ts.T.; Fedorov, K.N.; Bazarova, Zh.G.; Chimitova, O.D.; Klevtsova, R.F.; Glinskaya, L.A.

2006-01-01

Systems Tl 2 MoO 4 -E(MoO 4 ) 2 (E=Zr, Hf) were studied by X-ray diffraction, differential thermal analysis and IR spectroscopy. Formation of Tl 8 E(MoO 4 ) 6 and Tl 2 E(MoO 4 ) 2 compounds was established. Phase T-x diagrams of the Tl 2 MoO 4 -Zr(MoO 4 ) 2 system were constructed. Monocrystals were grown, and structure of Tl 8 Hf(MoO 4 ) 6 was studied. The compound is crystallized in monoclinic syngony with elementary cell parameters a=9.9688(6), b=18.830(1), c=7.8488(5) A, β=108.538(1) Deg, Z=2, sp. gr. C2/m. The isolated group [HfMo 6 O 24 ] 8- is responsible for fundamental fragment of the structure. Three varieties of crystallographically independent Tl-polyhedra fill space evenly between fragments [HfMo 6 O 24 ] 8- forming three-dimensional form [ru

Phase equilibria in the Tl2MoO4–R2(MoO43–Zr(MoO42 (R = Al, Cr systems: synthesis, structure and properties of new triple molybdates Tl5RZr(MoO46 and TlRZr0.5(MoO43

Directory of Open Access Journals (Sweden)

V. G. Grossman

2017-12-01

Full Text Available The Tl2MoO4–R2(MoO43–Zr(MoO42 (R = Al, Cr systems were studied in the subsolidus region using X-ray powder diffraction and differential scanning calorimetric (DSC analysis. Quasi-binary joins were revealed, and triangulation was carried out. New ternary molybdates: Tl5RZr(MoO46 (5:1:2 and TlRZr0.5(MoO43 (1:1:1 (R = Al, Cr were prepared. The unit cell parameters for the new compounds were calculated.

Hydrothermal Synthesis of MoO2 and Supported MoO2 Cata-lysts for Oxidative Desulfurization of Dibenzothiophene

Institute of Scientific and Technical Information of China (English)

Wang Danhong; Zhang Jianyong; Liu Ni; Zhao Xin; Zhang Minghui

2014-01-01

A novel method for obtaining spherical MoO2 nanoparticles and SiO2-Al2O3 supported MoO2 by hydrothermal reduction of Mo (VI) species was studied. The obtained MoO2 catalysts show very high catalytic activity in the oxidative desulfurization (ODS) process. The effect of hydrothermal temperature and crystallization temperature on ODS activity was investigated. The ODS activity of supported MoO2 catalysts with various MoO2 contents were also investigated. The mecha-nism for formation of MoO2 involving oxalic acid was proposed.

Phase equilibria in the CdMoO4-Gd2(MoO4)3 system

International Nuclear Information System (INIS)

Tunik, T.A.; Fedorov, N.F.; Razumovskij, S.N.

1980-01-01

The constitutional diagram of the CdMoO 4 -Cd 2 (MoO 4 ) 3 system has been plotted using statistical and dynamic methods as well as a complex of instrumental analysis procedures. Three major phases have been found to occur in the systems, viz.: CdMoO 4 based solid solutions that crystallize in the range from 0 to 25 mol.percent of Cd 2 (MoO 4 ) 3 and pass in transit the two-phase narrow region becoming then solid solutions having a distorted scheelite structure and existing in concentrations from 40 to 65 mol.% of Cd 2 (MoO 4 ) 3 . The entire range, in which the Cd 2 (MoO 4 ) 3 solid solutions can exist, amounts to less than 5 mol.%. Certain crystallochemical constants of the phases that occur in the system have been determined [ru

Integral data test of HENDL1.0/MG and visualBUS with neutronics shielding experiments. Pt.1

International Nuclear Information System (INIS)

Gao Chunjing; Deng Tieru; Xu Dezheng; Li Jingjing; Wu Yican

2004-01-01

HENDL1.0/MG, a multi-group working library of the Hybrid Evaluated Nuclear Data Library, was home-developed by the FDS Team of ASIPP (Institute of Plasma Physics, Chinese Academy of Sciences) on the basis of several national data libraries. To validate and qualify the process of producing HENDL1.0/MG, simulating calculations of a series of existent spherical shell benchmark experiments (Al, Mo, Co, Ti, Mn, W, Be and V) have been performed with HENDL1.0/MG and the multifunctional neutronics code system named VisualBUS home-developed also by FDS Team. (authors)

Interdiffusion between U-Mo alloys and Al

International Nuclear Information System (INIS)

Mirandou, M.I.; Balart, S.N.; Ortiz, M.; Granovsky, M.S.; Hofman, G.L.

2002-01-01

During the fabrication and/or irradiation of the dispersion fuel elements, the fuel particles react with the surrounding Al matrix. This reaction results in the formation of a zone consisting of intermetallic compounds. The low thermal conductivity of these compounds has a major effect on the fuel temperature as well as on the swelling of the fuel. Interdiffusion between U-Mo/Al is being investigated using chemical diffusion couples. In this paper the first results obtained with optical and scanning electron microscope, electron microprobe and X-Ray diffraction are presented. Investigation of the effect on the formation of the interdiffusion zone of small additions of Mg to Al is the primary purpose of this study. (author)

Measurement of formation cross-section of 99Mo from the 98Mo(n,γ) and 100Mo(n,2n) reactions.

Science.gov (United States)

Badwar, Sylvia; Ghosh, Reetuparna; Lawriniang, Bioletty M; Vansola, Vibha; Sheela, Y S; Naik, Haladhara; Naik, Yeshwant; Suryanarayana, Saraswatula V; Jyrwa, Betylda; Ganesan, Srinivasan

2017-11-01

The formation cross-section of medical isotope 99 Mo from the 98 Mo(n,γ) reaction at the neutron energy of 0.025eV and from the 100 Mo(n,2n) reaction at the neutron energies of 11.9 and 15.75MeV have been determined by using activation and off-line γ-ray spectrometric technique. The thermal neutron energy of 0.025eV was used from the reactor critical facility at BARC, Mumbai, whereas the average neutron energies of 11.9 and 15.75MeV were generated using 7 Li(p,n) reaction in the Pelletron facility at TIFR, Mumbai. The experimentally determined cross-sections were compared with the evaluated nuclear data libraries of ENDF/B-VII.1, CENDL-3.1, JENDL-4.0 and JEFF-3.2 and are found to be in close agreement. The 100 Mo(n,2n) 99 Mo reaction cross-sections were also calculated theoretically by using TALYS-1.8 and EMPIRE-3.2 computer codes and compared with the experimental data. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cinética e equilíbrio de adsorção dos oxiânions Cr (VI, Mo (VI e Se (VI pelo sal de amônio quaternário de quitosana Kinetics and equilibrium of adsorption of oxyanions Cr (VI, Mo (VI and Se (VI by quaternary ammonium chitosan salt

Directory of Open Access Journals (Sweden)

Viviane A. Spinelli

2005-07-01

Full Text Available O sal quaternário de quitosana foi sintetizado com cloreto de glicidil trimetil amônio. A modificação química foi caracterizada por espectrometria no IV, RMN de 13C e ¹H, e mmol/g de grupos quaternários presentes na matriz polimérica por condutimetria. A remoção de Cr (VI, Mo (VI e Se (VI, em meio aquoso, foi investigada em processo de batelada. A adsorção mostrou ser dependente do pH para o Cr (VI e Se (VI, com um pH ótimo de adsorção, entre 4,0 a 6,0. Para o Mo (VI a adsorção manteve-se quase constante no intervalo de pH entre 4,0 e 11,5. O modelo de isoterma de Langmuir descreveu melhor os dados de equilíbrio na faixa de concentração investigada. No presente estudo, um grama do sal quaternário de quitosana reticulado com glutaraldeído adsorveu 68,3 mg de Cr, 63,4 mg de Mo e 90,0 mg de Se. A velocidade de adsorção, no processo, segue a equação cinética de pseudo segunda-ordem, sendo que o equilíbrio para os três íons foi alcançado próximo aos 200 minutos. A análise dispersiva de raios-X para o Cr (VI mostrou que o principal mecanismo de adsorção é a troca iônica entre os íons Cl- da superfície do polímero pelos oxiânions. O trocador aniônico apresentou a seguinte ordem de seletividade: Cr (VI > Mo (VI > Se (VI.Quaternary chitosan salt was synthesized in the presence of glycidyl trimetyl ammonium chloride. The polymer was characterized by spectroscopic techniques: infrared, 13C and ¹H NMR, while the amount of quaternary ammonium groups was obtained by condutimetry. The removal of Cr (VI, Mo (VI and Se (VI from aqueous solutions was carried out in batch adsorption processes. The process seemed to be pH dependent for Cr (VI and Se (VI with an optimum pH ranging from 4.0 to 6.0; while for Mo (VI the adsorption remained almost constant within the range between 4.0 and 11.5. The Langmuir isotherm model provided the best fit of the equilibrium data over the whole concentration investigated. In the experiment

Comparitive study of fluorescence lifetime quenching of rhodamine 6G by MoS2 and Au-MoS2

Science.gov (United States)

Shakya, Jyoti; Kasana, Parath; Mohanty, T.

2018-04-01

Time resolved fluorescence study of Rhodamine 6G (R6G) in the presence of Molybdenum disulfide (MoS2) nanosheets and gold doped MoS2 (Au-MoS2) have been carried out and discussed. We have analyzed the fluorescence decay curves of R6G and it is observed that Au-MoS2 is a better fluorescence lifetime quencher as compare to MoS2 nanosheets. Also, the energy transfer efficiency and energy transfer rate from R6G to MoS2 and Au-MoS2 has been calculated and found higher for Au-MoS2.

Demonstration of resonant photopumping of Mo VII by Mo XII for a VUV laser near 600 Angstrom

International Nuclear Information System (INIS)

Ilcisin, K.J.; Aumayr, F.; Schwob, J.L.; Suckewer, S.

1993-09-01

We present data of experiments on the resonant photopumping of Mo VII by Mo XII as a method of generating a coherent VUV source near 600 angstrom. The experiment is based on a scheme proposed by Feldman and Reader in which the 4p 6 -- 4p 5 6s transition in Mo VII in resonantly photopumped by the 5s 2 S 1/2 -- 4p 2 P 1/2 transition in Mo XII. Results of the laser produced plasma experiments show the successful enhancement of the population of the Mo VII 4p 5 6s upper lasing level when pumped by an adjacent Mo VII plasma. No enhancement was seen in a control experiment where the Mo VII plasma was pumped by a Zr X plasma. Improvements of the intensity of the Mo XII pump source, achieved using an additional pump laser, lead to the generation of a population inversion for the VUV transition

Quenching Mo optical losses in CIGS solar cells by a point contacted dual-layer dielectric spacer: a 3-D optical study.

Science.gov (United States)

Rezaei, Nasim; Isabella, Olindo; Vroon, Zeger; Zeman, Miro

2018-01-22

A 3-D optical modelling was calibrated to calculate the light absorption and the total reflection of fabricated CIGS solar cells. Absorption losses at molybdenum (Mo) / CIGS interface were explained in terms of plasmonic waves. To quench these losses, we assumed the insertion of a lossless dielectric spacer between Mo and CIGS, whose optical properties were varied. We show that such a spacer with low refractive index and proper thickness can significantly reduce absorption in Mo in the long wavelength regime and improve the device's rear reflectance, thus leading to enhanced light absorption in the CIGS layer. Therefore, we optimized a realistic two-layer MgF 2 / Al 2 O 3 dielectric spacer to exploit (i) the passivation properties of ultra-thin Al 2 O 3 on the CIGS side for potential high open-circuit voltage and (ii) the low refractive index of MgF 2 on the Mo side to reduce its optical losses. Combining our realistic spacer with optically-optimized point contacts increases the implied photocurrent density of a 750 nm-thick CIGS layer by 10% for the wavelengths between 700 and 1150 nm with respect to the reference cell. The elimination of plasmonic resonances in the new structure leads to a higher electric field magnitude at the bottom of CIGS layer and justifies the improved optical performance.

The recovery of 99Mo from solutions of irradiated Uranium using a column with nanoparticles of Titanium Dioxide

International Nuclear Information System (INIS)

Androne, G. E.; Petre, M.; Lazar, C. G.

2016-01-01

Molyibdenum-99 (T½ = 66.02 h) decays by beta emission to 99 Tcm (T½ = 6.02 h). The latter nuclide is used in many nuclear medicine applications. The 99 Mo is produced from irradiated high (HEU) or low (LEU) enriched uranium. In this work a sensitive and selective method for recovering Mo from uranium solution, using a column with titanium dioxide nanoparticles, is developed. The titanium dioxide (TiO 2 ) nanoparticles were synthesized via sol-gel method using titanium tetra-chloride as starting material and urea as a reacting medium. A 40 ml uranium solution containing 450 g/L uranyl nitrate, 1 M HNO 3 , and 4 mg Mo was loaded on a column containing 6 g of TiO 2 sorbent at 75°C. After loading, the column was washed with 1 M HNO 3 and H 2 O. Mo was stripped from the column with 0.1 M NaOH at 25°C. The ICP-MS results indicate that 80-95% of the initial mass of Mo was loaded on the column, and 90-94% of this quantity was recovered in the strip fraction. (authors)

Ternary CoS{sub 2}/MoS{sub 2}/RGO electrocatalyst with CoMoS phase for efficient hydrogen evolution

Energy Technology Data Exchange (ETDEWEB)

Liu, Yan-Ru; Shang, Xiao [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Gao, Wen-Kun [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Dong, Bin, E-mail: dongbin@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Chi, Jing-Qi; Li, Xiao; Yan, Kai-Li; Chai, Yong-Ming [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Yun-Qi, E-mail: liuyq@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Chen-Guang [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China)

2017-08-01

Highlights: • Ternary CoS{sub 2}/MoS{sub 2}/RGO with CoMoS phase as electrocatalyst for HER was prepared. • CoMoS phase have the metallic nature and highly intrinsic activity for HER. • RGO support ensures good distribution of CoMoS phase and enhances the conductivity. • The introduction of CoMoS and RGO may be a novel strategy for efficient HER of MoS{sub 2}. - Abstract: CoMoS phase with metallic character plays crucial role on enhancing the activity of MoS{sub 2} electrocatalysts for hydrogen evolution reaction (HER). However, only Co atoms located in the edges of MoS{sub 2} can create CoMoS phase, so it is a challenge to obtain CoMoS phase with homogeneous distribution limited by the layered MoS{sub 2} and doping method of Co. Herein, we reported a simple one-pot hydrothermal method to prepare novel ternary CoS{sub 2}/MoS{sub 2}/RGO with CoMoS phase for HER using reduced graphene oxide (RGO) as support. XPS proves the formation of CoMoS phase, implying the enhanced activity for HER. RGO support ensures the well distribution of CoMoS phase and enhances the conductivity of CoS{sub 2}/MoS{sub 2}/RGO. Compared to CoS{sub 2}/RGO, MoS{sub 2}/RGO and CoS{sub 2}/MoS{sub 2}, the obtained CoS{sub 2}/MoS{sub 2}/RGO shows superior activity for HER with an onset overpotential of −80 mV (vs. RHE), small Tafel slope of 56 mV dec{sup −1}, high exchange current density of 11.4 μA cm{sup −2} and rigid electrochemical durability. The enhanced performances for HER may be ascribed to the formation of CoMoS phase with high activity and the existence of RGO support with good electrical conductivitys in ternary CoS{sub 2}/MoS{sub 2}/RGO. Therefore, the introduction of CoMoS phase and RGO into MoS{sub 2} could effectively enhance electrocatalytic properties for HER.

On-stack two-dimensional conversion of MoS2 into MoO3

Science.gov (United States)

Yeoung Ko, Taeg; Jeong, Areum; Kim, Wontaek; Lee, Jinhwan; Kim, Youngchan; Lee, Jung Eun; Ryu, Gyeong Hee; Park, Kwanghee; Kim, Dogyeong; Lee, Zonghoon; Lee, Min Hyung; Lee, Changgu; Ryu, Sunmin

2017-03-01

Chemical transformation of existing two-dimensional (2D) materials can be crucial in further expanding the 2D crystal palette required to realize various functional heterostructures. In this work, we demonstrate a 2D ‘on-stack’ chemical conversion of single-layer crystalline MoS2 into MoO3 with a precise layer control that enables truly 2D MoO3 and MoO3/MoS2 heterostructures. To minimize perturbation of the 2D morphology, a nonthermal oxidation using O2 plasma was employed. The early stage of the reaction was characterized by a defect-induced Raman peak, drastic quenching of photoluminescence (PL) signals and sub-nm protrusions in atomic force microscopy images. As the reaction proceeded from the uppermost layer to the buried layers, PL and optical second harmonic generation signals showed characteristic modulations revealing a layer-by-layer conversion. The plasma-generated 2D oxides, confirmed as MoO3 by x-ray photoelectron spectroscopy, were found to be amorphous but extremely flat with a surface roughness of 0.18 nm, comparable to that of 1L MoS2. The rate of oxidation quantified by Raman spectroscopy decreased very rapidly for buried sulfide layers due to protection by the surface 2D oxides, exhibiting a pseudo-self-limiting behavior. As exemplified in this work, various on-stack chemical transformations can be applied to other 2D materials in forming otherwise unobtainable materials and complex heterostructures, thus expanding the palette of 2D material building blocks.

Geochronology of the Thompson Creek Mo Deposit: Evidence for the Formation of Arc-related Mo Deposits

Science.gov (United States)

Lawrence, C. D.; Coleman, D. S.; Stein, H. J.

2016-12-01

The Thompson Creek Mo deposit in central ID, has been categorized as an arc-related Mo deposit due to the location, grade of Mo, and relative lack of enrichments in F, Rb, and Nb, compared to the Climax-type Mo deposits. Geochronology from this arc-related deposit provides an opportunity to compare and contrast magmatism, and mineralization to that in Climax-type deposits. Distinct pulses of magmatism were required to form the Thompson Creek Mo deposit, which is consistent with recent geochronology from Climax-type deposits. Molybdenite Re-Os geochronology from five veins requires at least three pulses of magmatism and mineralization between 89.39 +/- 0.37 and 88.47 +/- 0.16 Ma. Zircon U-Pb ages from these mineralized samples overlap with molybdenite mineralization, but show a much wider range (91.01 +/- 0.37 to 87.27 +/- 0.69). Previous work from Climax-type Mo deposits suggest a correlation between a super eruption, and the subsequent rapid (<1 Ma) onset, and completion of Mo mineralizing intrusions. The longer life (3-4 Ma) for the Thompson Creek Mo deposit suggests that the mineralizing intrusions for arc-related Mo deposits may not need to have as high [Mo] as the Climax-type deposits. This study also finds a shift in the source of magmatism from the pre- to syn-mineralizing intrusions. Zircons from pre-mineralizing intrusions have much higher (15-60 pg) concentrations of radiogenic Pb than zircons from mineralized intrusions, which all have less than 15 pg, though whole rock [U] are similar.

Magnetoresistance in Co/2D MoS2/Co and Ni/2D MoS2/Ni junctions.

Science.gov (United States)

Zhang, Han; Ye, Meng; Wang, Yangyang; Quhe, Ruge; Pan, Yuanyuan; Guo, Ying; Song, Zhigang; Yang, Jinbo; Guo, Wanlin; Lu, Jing

2016-06-28

Semiconducting single-layer (SL) and few-layer MoS2 have a flat surface, free of dangling bonds. Using density functional theory coupled with non-equilibrium Green's function method, we investigate the spin-polarized transport properties of Co/2D MoS2/Co and Ni/2D MoS2/Ni junctions with MoS2 layer numbers of N = 1, 3, and 5. Well-defined interfaces are formed between MoS2 and metal electrodes. The junctions with a SL MoS2 spacer are almost metallic owing to the strong coupling between MoS2 and the ferromagnets, while those are tunneling with a few layer MoS2 spacer. Both large magnetoresistance and tunneling magnetoresistance are found when fcc or hcp Co is used as an electrode. Therefore, flat single- and few-layer MoS2 can serve as an effective nonmagnetic spacer in a magnetoresistance or tunneling magnetoresistance device with a well-defined interface.

Determination of Mo- and Ca-isotope ratios in Ca100MoO4 crystal for AMoRE-I experiment

Science.gov (United States)

Karki, S.; Aryal, P.; Kim, H. J.; Kim, Y. D.; Park, H. K.

2018-01-01

The first phase of the AMoRE (Advanced Mo-based Rare process Experiment) is to search for neutrinoless double-beta decay of 100Mo with calcium molybdate (Ca100MoO4) crystals enriched in 100Mo and depleted in 48Ca using a cryogenic technique at Yangyang underground laboratory in Korea. It is important to know 100Mo- and 48Ca-isotope ratios in Ca100MoO4 crystal to estimate half-life of 100Mo decays and to 2 νββ background from 48Ca. We employed the ICP-MS (Inductive Coupled Plasma Mass Spectrometer) to measure 100Mo- and 48Ca-isotope ratios in Ca100MoO4 crystal. The measured results for 100Mo- and 48Ca-isotope ratios in the crystal are (94 . 6 ± 2 . 8) % and (0 . 00211 ± 0 . 00006) %, respectively, where errors are included both statistical and systematic uncertainties.

Postirradiation tensile properties of Mo and Mo alloys irradiated with 600 MeV protons

International Nuclear Information System (INIS)

Mueller, G.V.; Gavillet, D.; Victoria, M.; Martin, J.L.

1994-01-01

Tensile specimens of pure Mo and Mo-5 Re, Mo-41 Re and TZM alloys have been irradiated with 600 MeV protons in the PIREX facility at 300 and 660 K to 0.5 dpa. Results of the postirradiation tensile testing show a strong radiation hardening and a severe loss of ductility for all the materials tested at room temperature. ((orig.))

MoMoSat -- Mobile Service for Monitoring with GeoNotes via Satellite

Energy Technology Data Exchange (ETDEWEB)

Niemeyer, Irmgard [Forschungszentrum Juelich (Germany). Programme Group Systems Analysis and Technology Evaluation (STE); Jonas, Karl [Univ. of Applied Science Bonn-Rhein-Sieg, Sankt Augustin (Germany). FhG FOKUS CC SATCom; Horz, Alexander [horz informatik, Sankt Augustin (Germany); Wettschereck, Dietrich; Schmidt, Dirk [DIALOGIS GmbH, Bonn (Germany)

2003-05-01

The MoMoSat service will enable mobile end-users to view, manage, annotate, and communicate mapbased information in the field. The handled information exists of a huge volume of raster (satellite or aerial images) and vector data (i.e. street networks, cadastral maps or points of interest), as well as text-specific geo-referenced textual notes (the so-called 'GeoNotes') and real-time voice. A secure real-time communication between mobile units and the primary data store is an essential task of the MoMoSat service. The basic information is stored in the primary database that is accessible through a virtual private network (VPN) and cached at a server at a base station in order to ensure data availability. The base station may be installed in a car or another mobile vehicle. The two servers will periodically communicate with each other via secure satellite communication in order to check for updates. The base station supplies the relevant GIS data for the mobile units (people or even robots in the field at remote solutions). The communication between the mobile units is based on a peer-to-peer wireless local area network (WLAN) architecture. The mobile units are equipped with mobile computers (i.e. laptop, tablet PC or PDA) combined with a satellite-based positioning system (GPS) that enables them to request the proper geographic data sets from yhe base station's map server. An interactive mapping software shows the actual location on the map and allows the user to navigate (zoom, pan) through the high-resolution map display. The user can switch 'on' or 'off' several thematic layers (i.e. street network or points of interest) on the map. The software also supports collaborative aspects of MoMoSat by offering tools for the management of the GeoNotes that can be visualized by categories. The user can extend the existing GeoNotes with his personnel comments or create new GeoNotes by defining categories, recipients and the level of

A 14-mo zinc-supplementation trial in apparently healthy Chilean preschool children.

Science.gov (United States)

Ruz, M; Castillo-Duran, C; Lara, X; Codoceo, J; Rebolledo, A; Atalah, E

1997-12-01

Apparently healthy preschool children (46 boys, 52 girls) aged 27-50 mo from low socioeconomic conditions who attended daycare centers in Santiago participated in a 14-mo long double-blind zinc supplementation trial. Unlike most previous studies, no additional inclusion criteria such as short stature or slow growth rate were considered. Subjects were pair matched according to sex and age and randomly assigned to two experimental groups: the supplemented group, which received 10 mg Zn/d, and the placebo group. Selected anthropometric, clinical, dietary, biochemical, and functional indexes were determined at the beginning of the study and after 6 and 14 mo of intervention. Actual dietary zinc intake was 66% of the recommended dietary allowance. Height gain after 14 mo was on average 0.5 cm higher in the supplemented group (P = 0.10). The response, however, was different between sexes. Boys from the supplemented group gained 0.9 cm more than those in the placebo group (P = 0.045). No effect was seen in girls. Although no significant differences were observed in the rest of the variables studied, trends (0.05 < P < 0.10) in the supplemented group compared with the placebo group for increased midarm muscle area in boys, improved response to tuberculin, and reduced rates of parasite reinfestation were noted. We conclude that in preschool children of low socioeconomic status, zinc is a limiting factor in the expression of growth potential.

New measurement of excitation functions for (p,x) reactions on Mo-nat with special regard to the formation of Tc-95m, Tc96m+g, Tc-99m and Mo-99

Czech Academy of Sciences Publication Activity Database

Lebeda, Ondřej; Pruszynski, M.

2010-01-01

Roč. 68, č. 12 (2010), s. 2355-2365 ISSN 0969-8043 Institutional research plan: CEZ:AV0Z10480505 Keywords : Cross-sections * Tc-99m * Mo-99 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.999, year: 2010

The fracture toughness and DBTT of MoB particle-reinforced MoSi2 composites

International Nuclear Information System (INIS)

Xiong Zhi; Wang Gang; Jiang Wan

2005-01-01

The room temperature fracture toughness and the high temperature DBTT of MoB particle-reinforced MoSi 2 composites were investigated using Vickers indentation technique and MSP testing method, respectively. Modified small punch (MSP) test is a method for evaluation of mechanical properties using very small specimens, and it's appropriate for the determination of strength and DBTT. It was found that the approximate fracture toughness of the composite is 1.3 times that of monolithic MoSi 2 , and its DBTT is 100 C higher than that of monolithic MoSi 2 materials. Cracks deflection is a probable mechanism responsible for this behavior. (orig.)

Theoretical prediction of high electron mobility in multilayer MoS2 heterostructured with MoSe2

Science.gov (United States)

Ji, Liping; Shi, Juan; Zhang, Z. Y.; Wang, Jun; Zhang, Jiachi; Tao, Chunlan; Cao, Haining

2018-01-01

Two-dimensional (2D) MoS2 has been considered to be one of the most promising semiconducting materials with the potential to be used in novel nanoelectronic devices. High carrier mobility in the semiconductor is necessary to guarantee a low power dissipation and a high switch speed of the corresponding electronic device. Strain engineering in 2D materials acts as an important approach to tailor and design their electronic and carrier transport properties. In this work, strain is introduced to MoS2 through perpendicularly building van der Waals heterostructures MoSe2-MoS2. Our first-principles calculations demonstrate that acoustic-phonon-limited electron mobility can be significantly enhanced in the heterostructures compared with that in pure multilayer MoS2. It is found that the effective electron mass and the deformation potential constant are relatively smaller in the heterostructures, which is responsible for the enhancement in the electron mobility. Overall, the electron mobility in the heterostructures is about 1.5 times or more of that in pure multilayer MoS2 with the same number of layers for the studied structures. These results indicate that MoSe2 is an excellent material to be heterostructured with multilayer MoS2 to improve the charge transport property.

MoDnm1 Dynamin Mediating Peroxisomal and Mitochondrial Fission in Complex with MoFis1 and MoMdv1 Is Important for Development of Functional Appressorium in Magnaporthe oryzae.

Directory of Open Access Journals (Sweden)

Kaili Zhong

2016-08-01

Full Text Available Dynamins are large superfamily GTPase proteins that are involved in various cellular processes including budding of transport vesicles, division of organelles, cytokinesis, and pathogen resistance. Here, we characterized several dynamin-related proteins from the rice blast fungus Magnaporthe oryzae and found that MoDnm1 is required for normal functions, including vegetative growth, conidiogenesis, and full pathogenicity. In addition, we found that MoDnm1 co-localizes with peroxisomes and mitochondria, which is consistent with the conserved role of dynamin proteins. Importantly, MoDnm1-dependent peroxisomal and mitochondrial fission involves functions of mitochondrial fission protein MoFis1 and WD-40 repeat protein MoMdv1. These two proteins display similar cellular functions and subcellular localizations as MoDnm1, and are also required for full pathogenicity. Further studies showed that MoDnm1, MoFis1 and MoMdv1 are in complex to regulate not only peroxisomal and mitochondrial fission, pexophagy and mitophagy progression, but also appressorium function and host penetration. In summary, our studies provide new insights into how MoDnm1 interacts with its partner proteins to mediate peroxisomal and mitochondrial functions and how such regulatory events may link to differentiation and pathogenicity in the rice blast fungus.

Studies of the effect of irradiation in a nuclear reactor, of targets containing Mo used for the preparation of 99Mo gel, material that constitutes the 99Mo - 99mTc generators

International Nuclear Information System (INIS)

Nieto, Renata Correa

2004-01-01

The most used radioisotope in Nuclear Medicine is 99m Tc, obtained in the 99 Mo - 99m Tc generator form. 99 Mo can be produced by several nuclear reactions in Cyclotron and Reactor. The production in Cyclotron is not technically and commercially feasible. The production in Nuclear Reactor can be made in two ways: 235 U fission and 99 Mo (n,γ) 99 Mo reaction. A project aiming the production of 99 Mo by activation of Mo is under way at IPEN, producing a gel type MoZr generator. There are two ways of preparing the gel and the generators: by irradiating MoO 3 and preparing the gel or by the preparation of the gel and further irradiation. This work consists in the study of the irradiation effects in several targets containing Mo for the production of 99 Mo by the 98 Mo (n,γ) 99 Mo reaction and further preparation of the gel for use as a gel type 99 Mo - 99m Tc generator. Three rinds of gel were studied: zirconium, titanium and cerium molybdate, and their morphology, infrared structure and elution yield of 99m Tc were analysed. The best results were achieved with the generators prepared with MoZr post formed gel, with amorphous structure and better elution yields. The pre formed gel induced crystallinity and worst performance of the generators. (author)

Ternary alloying study of MoSi2

International Nuclear Information System (INIS)

Yi, D.; Li, C.; Akselsen, O.M.; Ulvensoen, J.H.

1998-01-01

Ternary alloying of MoSi 2 with adding a series of transition elements was investigated by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). Iron, Co, Ni, Cr, V, Ti, and Nb were chosen as alloying elements according to the AB 2 structure map or the atomic size factor. The studied MoSi 2 base alloys were prepared by the arc melting process from high-purity metals. The EDS analysis showed that Fe, Co, and Ni have no solid solubility in as-cast MoSi 2 , while Cr, V, Ti, and Nb exhibit limited solid solubilities, which were determined to be 1.4 ± 0.7, 1.4 ± 0.4, 0.4 ± 0.1, and 0.8 ± 0.1. Microstructural characterization indicated that Mo-Si-M VIII (M VIII = Fe, Co, Ni) and Mo-Si-Cr alloys have a two-phase as-cast microstructure, i.e., MoSi 2 matrix and the second-phase FeSi 2 , CoSi, NiSi 2 , and CrSi 2 , respectively. In as-cast Mo-Si-V, Mo-Si-Ti, and Mo-Si-Nb alloys, besides MoSi 2 and C40 phases, the third phases were observed, which have been identified to be (Mo, V) 5 Si 3 , TiSi 2 , and (Mo, Nb) 5 Si 3

Substutited molybdates of bismuth on a basis of Bi13Mo5O34±δ: production and properties

Directory of Open Access Journals (Sweden)

Z. A. Mikhailovskaya

2014-11-01

Full Text Available The present work is devoted to the investigation of the methods of a synthesis and properties of the one of the most interesting one-dimensional oxygen –ion conductors, the Bi13Mo5O34±δ –based complex oxides. The general compositions of these bismuth molybdates are Bi13Mo5-хMeхO34-δ, and Bi13-yMeyMo5O34-δ, with Me = Mg, Ca, Sr, Ba (IIA group and Co, Fe, Ni (Fe triade. The samples have been synthesized using conventional ceramic technology. The powders and pellets of the bismuth molybdates were studied by X-Ray diffraction, scanning electron microscopy, laser dispersion, dilatometry, atom absorption and inductively-coupled plasma atomic emission spectrometry. Electrical conductivity has been studied using impedance spectroscopy method.

Physicochemical investigation of Bi2MoO6 solid-phase interaction with Sm2MoO6

International Nuclear Information System (INIS)

Khajkina, E.G.; Kovba, L.M.; Bazarova, Zh.G.; Khal'baeva, K.M.; Khakhinov, V.V.; Mokhosoev, M.V.

1986-01-01

Bi 2 MoO 6 -Sm 2 MoO 6 interaction in the temperature range of 700-1000 deg C is studied using X-ray phase analysis and vibrational spectroscopy. Formation of monoclinic solid solutions based on γ'-Bi 2 MoO 6 and B 2-x Sm x MoO 6 varied composition phase with α-Ln 2 MoO 6 structure which homogeneity region extent at 1000 deg C constitutes ∼ 50 mol % (0.7≤x≤1.7) is stated. Crystallographic characteristics of the synthesized phases are determined

AMORE Mo-99 Spike Test Results

Energy Technology Data Exchange (ETDEWEB)

Youker, Amanda J. [Argonne National Lab. (ANL), Argonne, IL (United States); Krebs, John F. [Argonne National Lab. (ANL), Argonne, IL (United States); Quigley, Kevin J. [Argonne National Lab. (ANL), Argonne, IL (United States); Byrnes, James P. [Argonne National Lab. (ANL), Argonne, IL (United States); Rotsch, David A [Argonne National Lab. (ANL), Argonne, IL (United States); Brossard, Thomas [Argonne National Lab. (ANL), Argonne, IL (United States); Wesolowski, Kenneth [Argonne National Lab. (ANL), Argonne, IL (United States); Alford, Kurt [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-09-27

With funding from the National Nuclear Security Administrations Material Management and Minimization Office, Argonne National Laboratory (Argonne) is providing technical assistance to help accelerate the U.S. production of Mo-99 using a non-highly enriched uranium (non-HEU) source. A potential Mo-99 production pathway is by accelerator-initiated fissioning in a subcritical uranyl sulfate solution containing low enriched uranium (LEU). As part of the Argonne development effort, we are undertaking the AMORE (Argonne Molybdenum Research Experiment) project, which is essentially a pilot facility for all phases of Mo-99 production, recovery, and purification. Production of Mo-99 and other fission products in the subcritical target solution is initiated by putting an electron beam on a depleted uranium (DU) target; the fast neutrons produced in the DU target are thermalized and lead to fissioning of U-235. At the end of irradiation, Mo is recovered from the target solution and separated from uranium and most of the fission products by using a titania column. The Mo is stripped from the column with an alkaline solution. After acidification of the Mo product solution from the recovery column, the Mo is concentrated (and further purified) in a second titania column. The strip solution from the concentration column is then purified with the LEU Modified Cintichem process. A full description of the process can be found elsewhere [1–3]. The initial commissioning steps for the AMORE project include performing a Mo-99 spike test with pH 1 sulfuric acid in the target vessel without a beam on the target to demonstrate the initial Mo separation-and-recovery process, followed by the concentration column process. All glovebox operations were tested with cold solutions prior to performing the Mo-99 spike tests. Two Mo-99 spike tests with pH 1 sulfuric acid have been performed to date. Figure 1 shows the flow diagram for the remotely operated Mo-recovery system for the AMORE project

Decay of 99Mo

International Nuclear Information System (INIS)

Dickens, J.K.; Love, T.A.

1976-01-01

Relative intensities for K x-rays and gamma rays emanating from 99 Mo in equilibrium with its 99 Tc* daughter have been measured using several Ge photon detectors. Combining these intensities with an evaluated set of electron-conversion coefficients has provided a set of absolute intensities for the observed gamma rays. The absolute intensity for the dominant 140.5-keV gamma ray in 99 Tc was determined to be 90.7 +- 0.6/100 99 Mo disintegrations for 99 Mo decay in equilibrium with decay of the 99 Tc* daughter

High pressure effect on MoS2 and MoSe2 single crystals grown by ...

Indian Academy of Sciences (India)

Unknown

tetrahedral anvil apparatus up to 5 GPa. In this paper we report room temperature resistance mea- surements as a function of pressure on MoS2 and MoSe2 single crystals. In each case the resistance decreases un- der pressure due to an increase in the carrier concentration. 2. Experimental. Single crystals of MoS2 and ...

Hydrothermal synthesis of 3D hierarchical flower-like MoSe{sub 2} microspheres and their adsorption performances for methyl orange

Energy Technology Data Exchange (ETDEWEB)

Tang, Hua, E-mail: tanghua@mail.ujs.edu.cn; Huang, Hong; Wang, Xiaoshuai; Wu, Kongqiang; Tang, Guogang; Li, Changsheng

2016-08-30

Highlights: • 3D hierarchical flower-like MoSe{sub 2} microspheres have been fabricated via a hydrothermal method. • A possible evolution process of 3D hierarchical flower-like MoSe{sub 2} microspheres was discussed. • Flower-like MoSe{sub 2} microspheres exhibit excellent adsorption properties for dye methyl orange removal from aqueous solution. - Abstract: In this paper, we report a facile and versatile modified hydrothermal method for synthesis of three-dimensional (3D) hierarchical flower-like MoSe{sub 2} microspheres using selenium powders and sodium molybdate as raw materials. The as-prepared MoSe{sub 2} was investigated for application as an adsorbent for the removal of dye contaminants from water. Power X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscope (XPS) and N{sub 2} adsorption-desorption analysis were carried out to study the microstructure of the as-synthesized product. A possible growth mechanism of MoSe{sub 2} flower-like microspheres was preliminarily proposed on the basis of observation of a time-dependent morphology evolution process. Moreover, the MoSe{sub 2} sample exhibited good adsorption properties, with maximum adsorption capacity of 36.91 mg/g for methyl orange. The adsorption process of methyl orange on 3D hierarchical flower-like MoSe{sub 2} microspheres was systematically investigated, which was found to obey the pseudo-second-order rate equation and Langmuir adsorption model.

Measurement of Mo-99 column activity in the evaluation of Mo-99/Tc-99m generator

International Nuclear Information System (INIS)

Kuster, Z.

1994-01-01

In order to calculate the real elution efficiency of Mo-99/Tc-99m generator the Mo-99 content on the column has to be previously determined. As found in this work, the external measurement of Mo-99-column activity by means of Geiger-Mueller counter is a simple, fast and reliable method. Generally, Mo-99-column is placed slightly out of the center of the generator; therefore the externally measured flux of photons (φ) is an angular-dependent function. If the thickness of the lead container is radially uniform, the flux measured at some distance from the generator (which is rotated in 2π/3 steps) is given by the equation φ = A (1 + Bcos (α-2π(i - 2)/3)) -1 , i=1,2 or 3 (Eq.1) where A is a numerical constant depending on the Mo-99-column activity, B is a numerical constant depending on the Mo-99- column position within the lead container, the angle α depends on the initial orientation of the generator. A total of 20 generator were studied. The measured Mo-99-column activities (Capintec dose calibrator) were in the range 13.1- 35.11 GBq. Contrary to the findings of Vinberg and Kristensen (Eur J Nucl Med 1/1976(219), values of A (Eq. 1) are in good correlation (r 2 =0.9794) with the measured Mo-99-column activities. (author)

Highly flexible, conductive and transparent MoO3/Ag/MoO3 multilayer electrode for organic photovoltaic cells

International Nuclear Information System (INIS)

Abachi, T.; Cattin, L.; Louarn, G.; Lare, Y.; Bou, A.; Makha, M.; Torchio, P.

2013-01-01

MoO 3 /Ag/MoO 3 (MAM) multilayer structures were deposited by vacuum evaporation on polyethylene terephthalate (PET) substrate. We demonstrate that, as in the case of glass substrate, the sheet resistance of such structures depends significantly on the Ag film deposition rate. When it is deposited between 0.2 and 0.4 nm/s, an Ag thickness of 11 nm allows achieving sheet resistance of 13 Ω/sq and an averaged transmission of 74%. A study of the influence of the PET substrate on the optimum MoO 3 thicknesses was done. A good qualitative agreement between the theoretical calculations of the variation of the optical transmittance of the MoO 3 /Ag/MoO 3 structures is obtained. The optimum MAM structures MoO 3 (17.5 nm)/Ag (11 nm)/MoO 3 (35 nm) has a factor of merit F M = 4.21 10 −3 (Ω/sq) −1 . Proven by the scotch test the MAM structures exhibit a good adhesion to the PET substrates. The MAM structures were also submitted to bending tests. For outer bending, the samples exhibit no variation of their resistance value, while for inner bending there is a small increase of the resistance of the MAM structures. However this increasing is smaller than that exhibited by Indium Tin Oxide. When the PET/MAM structures are used as anode in organic photovoltaic cells, it is shown that the need to use thicker Ag films inside the multilayer and to cover the MAM with Au to obtain promising Current density vs Voltage characteristics is due to the heating of the PET substrate during the deposition process. - Highlights: • MoO 3 /Ag/MoO 3 structures deposited on polyethylene terephthalate substrate. • MoO 3 /Ag/MoO 3 structures deposited by vacuum evaporation. • The Ag deposition rate influences the properties of the structures. • The MoO 3 /Ag/MoO 3 optimum structure has a factor of merit F M = 4.21 10 −3 (Ω/sq) −1 . • The MoO 3 /Ag/MoO 3 structures exhibit a high flexibility

A new approach to quantification of DTPA incorporation into monoclonal antibodies (MoAbs) labeled by the cyclic anhydride DTPA method

International Nuclear Information System (INIS)

Wang, T.S.T.; Ng, A.K.; Fawwaz, R.A.; Alsedairy, S.; Alderson, P.O.

1985-01-01

A method for determining the ratio of DTPA molecules attached per molecule of Ab was developed and used to examine the immunoreactivity of different Abs as a function of the amount of incorporated DTPA. The bicyclic anhydride of DTPA[2-C-14]acetic acid (BADTPA-C-14) was synthesized by reacting DTPA[2-C-14]acetic acid (1mCi/mmo1) and acetic anhydride. BADTPA-C-14 then was reacted with a MoAb to a melanoma associated antigen (MA) and to a MoAb to human HLA class II antigen (HLA) at 2mg/m1 of MoAb concentration, at MoAb to BADTPA-C-14 ratios (mmo1/mmo1) of l:1, 1:10, 1:00, l:200. The conjugate was dialyzed exhaustively against HEPES at pH 7.0. The MoAb concentration was measured at 280mm of uv; the DTPA/MoAb ratio was calculated based on the specific activity of BADTPA-C-14, and the immunoreactivity was assessed by direct cell-binding to melanoma, the HLA antigen and control (lymphoma) cells. Percent binding to the lymphoid cell line was less than 3%. The authors' results demonstrated a method for directly determining the number of DTPA molecules attached to a MOAb, and demonstrated variations in immunoreactivity as the number of DTPA groups per MoAb is altered

EXAFS study of Mo2N and Mo nitrides supported on zeolites

International Nuclear Information System (INIS)

Liu Zhenlin; Meng Ming; Fu Yilu; Jiang Ming; Hu Tiandou; Xie Yaning; Liu Tao

2002-01-01

In the present study, the reaction is applied to prepare molybdenum nitrides with high surface area, and zeolites are used as supports. The EXAFS of the Mo K-absorption edge is measured and the change of coordination environment of Mo atoms before and after the nitridation is revealed

Study of methodologies for quality control of 99Mo used in 99Mo/99mTc generators

International Nuclear Information System (INIS)

Said, Daphne de Souza

2016-01-01

99m Tc is the most used radionuclide in nuclear medicine. In Brazil, the 99 Mo/ 99m Tc generators are exclusively produced by Radiopharmacy Center at IPEN-CNEN/ SP, by importing 99 Mo from different suppliers. 99 Mo (t 1/2 = 66 h) is a fission product of 235 U and it can have radionuclidic impurities that are prejudicial for human health. For safe use of generators, it is necessary to perform the evaluation of 99 Mo by quality control tests in order to assess if 99 Mo complies with the specifications. The European Pharmacopoeia (EP) presents a monograph for evaluation of the quality of the [ 99 Mo] solution as sodium molybdate,that is used as raw material for 99 Mo/ 99m Tc generators production, including specification parameters (identification, radiochemical purity and radionuclidic purity), analysis methods and limits. However, it has been observed difficulties on the execution and implementation of these methods by the generators producers, with a few literature about this subject, probably due to complexity of the proposed methods. In this work, many quality control parameters of 99 Mo described in the EP monograph were evaluated. Separation methods for 99M o from its radionuclidic impurities by solid phase extraction (SPE) and TLC were studied. After SPE separation, the quantification of metals by ICP-OES to evaluate the percentage of retention of Mo and the percentage of recovery of Ru, Te and Sr using different types of cartridges were proposed, replacing radiotracers use. It was observed that the specific type of SPE cartridge recommended by the EP for separation of 99 Mo presented low recoveries for Ru, compared to other available anion exchange SPE cartridges. 99 Mo samples from different worldwide suppliers were analyzed. It was observed that quantification of 103 Ru in 99 Mo samples with decay time higher than 4 weeks is possible. An alternative method for separation of 131 I from 99 Mo showed promising results by TLC. The quantification of beta and

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)

MoS2 quantum dots@TiO2 nanotube composites with enhanced photoexcited charge separation and high-efficiency visible-light driven photocatalysis

Science.gov (United States)

Zhao, Fenfen; Rong, Yuefei; Wan, Junmin; Hu, Zhiwen; Peng, Zhiqin; Wang, Bing

2018-03-01

MoS2 quantum dots (QDs) that are 5 nm in size were deposited on the surface of ultrathin TiO2 nanotubes (TNTs) with 5 nm wall thickness by using an improved hydrothermal method to form a MoS2 QDs@TNT visible-light photocatalyst. The ultrathin TNTs with high percentage of photocatalytic reactive facets were fabricated by the commercially available TiO2 nanoparticles (P25) through an improved hydrothermal method, and the MoS2 QDs were acquired by using a surfactant-assisted technique. The novel MoS2 QDs@TNT photocatalysts showed excellent photocatalytic activity with a decolorization rate of 92% or approximately 3.5 times more than that of pure TNTs for the high initial concentration of methylene blue solution (20 mg l-1) within 40 min under visible-light irradiation. MoS2 as the co-catalysts favored the broadening of TNTs into the visible-light absorption scope. The quantum confinement and edge effects of the MoS2 QDs and the heterojunction formed between the MoS2 QDs and TNTs efficiently extended the lifetime of photoinduced charges, impeded the recombination of photoexcited electron-hole pairs, and improved the visible-light-driven high-efficiency photocatalysis.

Measurement of the molar heat capacities of MoO2 and MoO3 from 350 to 950 K

International Nuclear Information System (INIS)

Inaba, H.; Miyahara, K.; Naito, K.

1984-01-01

Molar heat capacities of MoO 2 and MoO 3 were measured in the range between 350 and 950 K by means of adiabatic scanning calorimetry. For MoO 2 , a sharp heat-capacity anomaly with a molar enthalpy change of (178 +- 24) J.mol -1 and a molar entropy change of (0.207 +- 0.028) J.K -1 .mol -1 was observed at 865 K, which had not been detected by drop calorimetry. For MoO 3 , two heat-capacity anomalies with molar enthalpy changes of (88 +- 21) and (60 +- 36) J.mol -1 were found at 808 K and 857 K, respectively; neither anomaly had been detected by the drop method. The lattice molar heat capacities of MoO 2 and MoO 3 are estimated as Csub(l,m)(MoO 2 ) = D(469 K/T) + E(578 K/T) + E(876 K/T) and Csub(l,m)(MoO 3 ) = D(208 K/T) + 2E(488 K/T) + E(1170 K/T), where D(x) and E(x) are the Debye and Einstein functions, respectively. The temperature coefficient of the electronic molar heat capacity of MoO 2 is estimated as (6.0 +- 0.5) mJ.K -2 .mol -1 . The excess heat capacity in MoO 3 found at higher temperatures is interpreted as being due to vacancy formation with a molar activation energy of (98 +-5) kJ.mol -1 . The origin of the heat-capacity anomalies is inferred as arising from the slight movement of distorted MoO 6 octahedra in the MoO 2 and MoO 3 structures. (author)

Carbon and Mo transformations during the synthesis of mesoporous Mo2C/carbon catalysts by carbothermal hydrogen reduction

Science.gov (United States)

Wang, Haiyan; Liu, Shida; Liu, Bing; Montes, Vicente; Hill, Josephine M.; Smith, Kevin J.

2018-02-01

The synthesis of mesoporous Mo2C/carbon catalysts by carbothermal hydrogen reduction is reported. Petroleum coke (petcoke) was activated with KOH at 800 °C to obtain high surface area microporous activated petcoke (APC; 2000 m2/g). The APC was wet impregnated with ammonium heptamolybdate (AHM: 10 wt% Mo), dried and reduced in H2 at temperatures from 400 to 800 °C, to yield Mo2C/APC catalysts. Increased reduction temperature increased the Mo2C yield and the mesoporous volume of the Mo2C/APC. At a reduction temperature of 750 °C the mesopore volume of the catalyst doubled compared to the APC support and accounted for 37% of the total pore volume. Maintaining the final CHR temperature for 90 min further increased the Mo2C yield and mesoporosity of the catalyst. The role of Mo2C in the catalytic hydrogenation of the APC and mesopore generation is demonstrated. The activity of the Mo2C/carbon catalysts in the hydrodeoxygenation of 4-methyl phenol increased with increased CHR temperature and catalyst mesoporosity.

Vertical MoSe2-MoO x p-n heterojunction and its application in optoelectronics

Science.gov (United States)

Chen, Xiaoshuang; Liu, Guangbo; Hu, Yunxia; Cao, Wenwu; Hu, PingAn; Hu, Wenping

2018-01-01

The hybrid n-type 2D transition-metal dichalcogenide (TMD)/p-type oxide van der Waals (vdW) heterojunction nanosheets consist of 2D layered MoSe2 (the n-type 2D material) and MoO x (the p-type oxide) which are grown on SiO2/Si substrates for the first time via chemical vapor deposition technique, displaying the regular hexagon structures with the average length dimension of sides of ˜8 μm. Vertical MoSe2-MoO x p-n heterojunctions demonstrate obviously current-rectifying characteristic, and it can be tuned via gate voltage. What is more, the photodetector based on vertical MoSe2-MoO x heterojunctions displays optimal photoresponse behavior, generating the responsivity, detectivity, and external quantum efficiency to 3.4 A W-1, 0.85 × 108 Jones, and 1665.6%, respectively, at V ds = 5 V with the light wavelength of 254 nm under 0.29 mW cm-2. These results furnish a building block on investigating the flexible and transparent properties of vdW and further optimizing the structure of the devices for better optoelectronic and electronic performance.

99Mo production using MoO3 pellets obtained by mechanical compression and heat treatment

International Nuclear Information System (INIS)

Rojas, Jorge; Mendoza, Pablo; Lopez, Alcides

2014-01-01

This paper shows the results of the MoO 3 pellets fabrication by mechanical compression and the heat treatment method (MCHT) in order to optimize the production of 99 Mo in the RACSO Nuclear Center. The effects of polyvinyl alcohol (PVA) as binder are assessed by heat treatment of pellets in air atmosphere, evaluating the elimination process with increasing temperature and solubility in 5N NaOH. The results show that the pellets fabrication technique is suitable because fulfills the required technical specifications, allows to irradiate 50 % more of 98 Mo mass and facilitate a safer radiological handling of the irradiated MoO 3 . (authors).

Achieving tunable doping of MoSe2 based devices using GO@MoSe2 heterostructure

Science.gov (United States)

Maji, Tuhin Kumar; Tiwary, Krishna Kanhaiya; Karmakar, Debjani

2017-05-01

Doping nature of MoSe2, one of the promising Graphene analogous device material, can be tuned by controlling the concentration of functional groups in Graphene oxide (GO)@MoSe2 heterostructure. In this study, by first-principles simulation, we have observed that GO can be used as a carrier injection layer for MoSe2, where n or p type carriers are introduced within MoSe2 layer depending on the type and concentration of functional moieties in it. Both n and p-type Schottky barrier height modulations are investigated for different modeled configurations of the heterostructure. This combinatorial heterostructure can be a promising material for future electronic device application.

Microstructural defects modeling in the Al-Mo system

International Nuclear Information System (INIS)

Pascuet, Maria I.; Fernandez, Julian R.; Monti, Ana M.

2006-01-01

In this work we have utilized computer simulation techniques to study microstructural defects, such as point defects and interfaces, in the Al-Mo alloy. Such alloy is taken as a model to study the Al(fcc)/U-Mo(bcc) interface. The EAM interatomic potential used has been fitted to the formation energy and lattice constant of the AlMo 3 intermetallic. Formation of vacancies for both components Al and Mo and anti-sites, Al Mo and Mo Al , as well as vacancy migration was studied in this structure. We found that the lowest energy defect complex that preserves stoichiometry is the antisite pair Al Mo +Mo Al , in correspondence with other intermetallics of the same structure. Our results also suggest that the structure of the Al(fcc)/Mo(bcc) interface is unstable, while that of the Al(fcc)/Al 5 Mo interface is stable, as observed experimentally. (author) [es

Development of improved HP/IP rotor material 2% CrMoNiWV (23 CrMoNiWV 88)

International Nuclear Information System (INIS)

Wiemann, W.

1989-01-01

The new 2% CrMoNiWV steel has a sufficient strength level, a very good creep (rupture) behaviour and an excellent toughness behaviour for a creep resistant steel. Even after long time high temperature exposure the toughness degradation is so small that it is still better than this of best 1% CrMo(Ni)V steels. The fatigue behaviour is well comparable to this of 1% CrMo(Ni)V. The 2% CrMoNiWV steel has the capability to substitute the traditional 1% CrMo(Ni)V. (orig.) With 26 annexes

Electrical characteristics of multilayer MoS2 FET's with MoS2/graphene heterojunction contacts.

Science.gov (United States)

Kwak, Joon Young; Hwang, Jeonghyun; Calderon, Brian; Alsalman, Hussain; Munoz, Nini; Schutter, Brian; Spencer, Michael G

2014-08-13

The electrical properties of multilayer MoS2/graphene heterojunction transistors are investigated. Temperature-dependent I-V measurements indicate the concentration of unintentional donors in exfoliated MoS2 to be 3.57 × 10(11) cm(-2), while the ionized donor concentration is determined as 3.61 × 10(10) cm(-2). The temperature-dependent measurements also reveal two dominant donor levels, one at 0.27 eV below the conduction band and another located at 0.05 eV below the conduction band. The I-V characteristics are asymmetric with drain bias voltage and dependent on the junction used for the source or drain contact. I-V characteristics of the device are consistent with a long channel one-dimensional field-effect transistor model with Schottky contact. Utilizing devices, which have both graphene/MoS2 and Ti/MoS2 contacts, the Schottky barrier heights of both interfaces are measured. The charge transport mechanism in both junctions was determined to be either thermionic-field emission or field emission depending on bias voltage and temperature. On the basis of a thermionic field emission model, the barrier height at the graphene/MoS2 interface was determined to be 0.23 eV, while the barrier height at the Ti/MoS2 interface was 0.40 eV. The value of Ti/MoS2 barrier is higher than previously reported values, which did not include the effects of thermionic field emission.

Development of Mo recycle technique from generator materials

Energy Technology Data Exchange (ETDEWEB)

Tanimoto, Masataka; Kurosawa, Makoto; Kimura, Akihiro; Nishikata, Kaori; Tsuchiya, Kunihiko [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan); Kakei, Sadanori; Yoshinaga, Hideo [Taiyo Koko Corp., Ako Laboratory, Ako, Hyogo (Japan)

2012-03-15

The domestic {sup 99}Mo production by the (n,{gamma}) method is proposed in JMTR because of low amount of radioactive wastes and easy {sup 99}Mo/{sup 99m}Tc production process. For the development of domestic production, it is necessary to use the enriched {sup 98}MoO{sub 3}, which is very expensive, for high specific activity of {sup 99}Mo. A large amount of used PZC/PTC embraced {sup 98}Mo is also generated after the decay of {sup 99}Mo. JAEA and Taiyo Koko is proposed to recover molybdenum from the used PZC/PTC for an effective use of resources and reduction of radioactive wastes. Preliminary experiments of Mo recycling with un-irradiated MoO{sub 3} were carried out by the elution and sublimation methods. From the results, Mo recovery rate from the PZC/PTC was more than 95% by two kinds of methods. The prospects are bright for Mo recycle and reduction of radioactive wastes using these methods. (author)

Investigation of the fabrication process of hot-worked stainless-steel and Mo sheathed PbMo6 S8 wires

International Nuclear Information System (INIS)

Yamasaki, H.; Kimura, Y.

1988-01-01

Stainless-steel and Mo sheathed PbMo 6 S 8 wires have been fabricated by hot working from modified PbS, Mo, and MoS 2 mixed powders which were prepared by reacting Pb, Mo, and S at 530 0 C. Critical current densities were investigated for different preparation conditions, and it is revealed that obtaining continuous current path between PbMo 6 S 8 grains is the most important factor to achieve high critical current density. The J/sub c/ value of 2.8 x 10 4 Acm 2 (8 T), 7.8 x 10 3 Acm 2 (15 T), and 1.3 x 10 3 Acm 2 (23 T) was observed for the PbMo 6 S/sub 7.0/ wire heat treated at 700 0 C.copic

Effect of Mo addition on the electrocatalytic activity of Pt-Sn-Mo/C for direct ethanol fuel cells

International Nuclear Information System (INIS)

Lee, Eungje; Murthy, Arun; Manthiram, Arumugam

2011-01-01

Carbon-supported Pt-Sn-Mo electrocatalysts have been synthesized by a polyol reduction method and characterized for ethanol electro-oxidation reaction (EOR). While the percent loading of the synthesized nanoparticles on the carbon support is higher than 35%, energy dispersive spectroscopy (EDS) reveals that the Mo contents in the nanoparticle catalysts are lower than the nominal value, indicating incomplete reduction of the Mo precursor. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses reveal that the Sn and Mo exist as oxide phases at the surface layers of the nanoparticles and the degree of alloying is very low. The electrochemical properties of the electrocatalysts have been evaluated by cyclic voltammetry (CV) and chronoamperometry. The catalytic activity for EOR decreases in the order PtSnMo 0.6 /C > PtSnMo 0.4 /C > PtSn/C. Single cell direct ethanol fuel cell (DEFC) tests also confirm that the PtSnMo 0.6 /C anode catalyst exhibit better performance than the PtSn/C anode catalyst. An analysis of the electrochemical data suggests that the incorporation of Mo to Pt-Sn enhances further the catalytic activity for EOR.

Phase formation in the Rb2MoO4-Li2MoO4-Hf(MoO4)2 system and the crystal structure of Rb5(Li1/3Hf5/3)(MoO4)6

International Nuclear Information System (INIS)

Solodovnikov, S.F.; Zolotova, E.S.; Balsanova, L.V.; Bazarov, B.G.; Bazarova, Zh.G.

2003-01-01

Phase formation in the Rb 2 MoO 4 -Li 2 MoO 4 -Hf(MoO 4 ) 2 system is studied in subsolidus region in air by the method of crossing sections. Three ternary molybdates are detected in the system. Compositions of two of them are corroborated by selection of isostructural analogues [ru

Thermal and x-ray studies on Tl2U(MoO4)3 and Tl4U(MoO4)4

International Nuclear Information System (INIS)

Dahale, N.D.; Keskar, Meera; Kulkarni, N.K.; Singh Mudher, K.D.

2006-01-01

In the quaternary Tl-U(IV)-Mo-O system, two new compounds namely Tl 2 U(MoO 4 ) 3 and Tl 4 U(MoO 4 ) 4 were prepared and characterized by powder X-ray diffraction and thermal methods. These compounds were prepared by solid state reactions of Tl 2 MoO 4 , UMoO 5 and MoO 3 in the required stoichiometric ratio at 500 deg C in evacuated sealed quartz ampoule. The XRD data of Tl 2 U(MoO 4 ) 3 and Tl 4 U(MoO 4 ) 4 were indexed on orthorhombic cell. TG curves of Tl 2 U(MoO 4 ) 3 and Tl 4 U(MoO 4 ) 4 did not show any weight change up to 700 deg C in an inert atmosphere. During heating in an inert atmosphere, Tl 2 U(MoO 4 ) 3 and Tl 4 U(MoO 4 ) 4 showed endothermic Dta peaks due to melting of the compounds at 519 and 565 deg C, respectively. (author)

Synthesis of MoS2 and MoO2 for their applications in H2 generation and lithium ion batteries: a review

International Nuclear Information System (INIS)

Zhao Yufei; Zhang Yuxia; Yang Zhiyu; Yan Yiming; Sun Kening

2013-01-01

Scientists increasingly witness the applications of MoS 2 and MoO 2 in the field of energy conversion and energy storage. On the one hand, MoS 2 and MoO 2 have been widely utilized as promising catalysts for electrocatalytic or photocatalytic hydrogen evolution in aqueous solution. On the other hand, MoS 2 and MoO 2 have also been verified as efficient electrode material for lithium ion batteries. In this review, the synthesis, structure and properties of MoS 2 and MoO 2 are briefly summarized according to their applications for H 2 generation and lithium ion batteries. Firstly, we overview the recent advancements in the morphology control of MoS 2 and MoO 2 and their applications as electrocatalysts for hydrogen evolution reactions. Secondly, we focus on the photo-induced water splitting for H 2 generation, in which MoS 2 acts as an important co-catalyst when combined with other semiconductor catalysts. The newly reported research results of the significant functions of MoS 2 nanocomposites in photo-induced water splitting are presented. Thirdly, we introduce the advantages of MoS 2 and MoO 2 for their enhanced cyclic performance and high capacity as electrode materials of lithium ion batteries. Recent key achievements in MoS 2 - and MoO 2 -based lithium ion batteries are highlighted. Finally, we discuss the future scope and the important challenges emerging from these fascinating materials. (review)

Diodes based on semi-insulating CdTe crystals with Mo/MoO{sub x} contacts for X- and γ-ray detectors

Energy Technology Data Exchange (ETDEWEB)

Maslyanchuk, O.; Kulchynsky, V.; Solovan, M. [Chernivtsi National University, Chernivtsi (Ukraine); Gnatyuk, V. [Institute of Semiconductor Physics, NAS of Ukraine, Kyiv (Ukraine); Potiriadis, C. [Greek Atomic Energy Commission, Attiki (Greece); Kaissas, I. [Greek Atomic Energy Commission, Attiki (Greece); Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki (Greece); Brus, V. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany)

2017-03-15

This paper reports on the possible applications of molybdenum oxide (Mo/MoO{sub x}) contacts in combination with semi-insulating CdTe crystals. The electrical contacts to p-type Cl-doped CdTe crystals were formed by the deposition of molybdenum oxide and pure molybdenum thin films by the DC reactive magnetron sputtering. Electrical properties of the prepared Mo-MoO{sub x}/p-CdTe/MoO{sub x}-Mo surface-barrier structures were investigated at different temperatures. It is shown that the rapid growth of the reverse current with increasing bias voltage higher than 10 V is caused by the space-charge limited currents. Spectrometric properties of the Mo-MoO{sub x}/p-CdTe/MoO{sub x}-Mo structures have been also analyzed. It is revealed that the developed heterojunction has shown promising characteristics for its practical application in X- and γ-ray radiation detector fabrication. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Phase formation in the K2MoO4-Lu2(MoO4)3-Hf(MoO4)2 system and the structural study of triple molybdate K5LuHf(MoO4)6

International Nuclear Information System (INIS)

Romanova, E.Yu.; Bazarov, B.G.; Tushinova, Yu.L.; Fedorov, K.N.; Bazarova, Zh.G.; Klevtsova, R.F.; Glinskaya, L.A.

2007-01-01

Interactions in the ternary system K 2 MoO 4 -Lu 2 (MoO 4 ) 3 -Hf(MoO 4 ) 2 have been studied by X-ray powder diffraction and differential thermal analysis. A new triple (potassium lutetium hafnium) molybdate with the 5 : 1 : 2 stoichiometry has been found. Monocrystals of this molybdate have been grown. Its X-ray diffraction structure has been refined (an X8 APEX automated diffractometer, MoK α radiation, 1960 F(hkl), R = 0.0166). The trigonal unit cell has the following parameters: a = 10.6536(1) A, c = 37.8434(8) A, V=3719.75(9) A, Z = 6, space group R3-bar c. The mixed 3D framework of the structure is built of Mo tetrahedra sharing corners with two independent (Lu,Hf)O 6 octahedra. Two sorts of potassium atoms occupy large framework voids [ru

Three-Dimensional Heterostructures of MoS 2 Nanosheets on Conducting MoO 2 as an Efficient Electrocatalyst To Enhance Hydrogen Evolution Reaction

KAUST Repository

Nikam, Revannath Dnyandeo

2015-10-05

Molybdenum disulfide (MoS) is a promising catalyst for hydrogen evolution reaction (HER) because of its unique nature to supply active sites in the reaction. However, the low density of active sites and their poor electrical conductivity have limited the performance of MoS in HER. In this work, we synthesized MoS nanosheets on three-dimensional (3D) conductive MoO via a two-step chemical vapor deposition (CVD) reaction. The 3D MoO structure can create structural disorders in MoS nanosheets (referred to as 3D MoS/MoO), which are responsible for providing the superior HER activity by exposing tremendous active sites of terminal disulfur of S2 (in MoS) as well as the backbone conductive oxide layer (of MoO) to facilitate an interfacial charge transport for the proton reduction. In addition, the MoS nanosheets could protect the inner MoO core from the acidic electrolyte in the HER. The high activity of the as-synthesized 3D MoS/MoO hybrid material in HER is attributed to the small onset overpotential of 142 mV, a largest cathodic current density of 85 mA cm, a low Tafel slope of 35.6 mV dec, and robust electrochemical durability.

Three-Dimensional Heterostructures of MoS 2 Nanosheets on Conducting MoO 2 as an Efficient Electrocatalyst To Enhance Hydrogen Evolution Reaction

KAUST Repository

Nikam, Revannath Dnyandeo; Lu, Ang-Yu; Sonawane, Poonam Ashok; Kumar, U. Rajesh; Yadav, Kanchan; Li, Lain-Jong; Chen, Yit Tsong

2015-01-01

Molybdenum disulfide (MoS) is a promising catalyst for hydrogen evolution reaction (HER) because of its unique nature to supply active sites in the reaction. However, the low density of active sites and their poor electrical conductivity have limited the performance of MoS in HER. In this work, we synthesized MoS nanosheets on three-dimensional (3D) conductive MoO via a two-step chemical vapor deposition (CVD) reaction. The 3D MoO structure can create structural disorders in MoS nanosheets (referred to as 3D MoS/MoO), which are responsible for providing the superior HER activity by exposing tremendous active sites of terminal disulfur of S2 (in MoS) as well as the backbone conductive oxide layer (of MoO) to facilitate an interfacial charge transport for the proton reduction. In addition, the MoS nanosheets could protect the inner MoO core from the acidic electrolyte in the HER. The high activity of the as-synthesized 3D MoS/MoO hybrid material in HER is attributed to the small onset overpotential of 142 mV, a largest cathodic current density of 85 mA cm, a low Tafel slope of 35.6 mV dec, and robust electrochemical durability.

Controllable Growth of Monolayer MoS2 and MoSe2 Crystals Using Three-temperature-zone Furnace

Science.gov (United States)

Zheng, Binjie; Chen, Yuanfu

2017-12-01

Monolayer molybdenum disulfide (MoS2) and molybdenum diselenide (MoSe2) have attracted a great attention for their exceptional electronic and optoelectronic properties among the two dimensional family. However, controllable synthesis of monolayer crystals with high quality needs to be improved urgently. Here we demonstrate a chemical vapor deposition (CVD) growth of monolayer MoS2 and MoSe2 crystals using three-temperature-zone furnace. Systematical study of the effects of growth pressure, temperature and time on the thickness, morphology and grain size of crystals shows the good controllability. The photoluminescence (PL) characterizations indicate that the as-grown monolayer MoS2 and MoSe2 crystals possess excellent optical qualities with very small full-width-half-maximum (FWHM) of 96 me V and 57 me V, respectively. It is comparable to that of exfoliated monolayers and reveals their high crystal quality. It is promising that our strategy should be applicable for the growth of other transition metal dichalcogenides (TMDs) monolayer crystals.

Phase transitions in alloys of the Ni-Mo system

International Nuclear Information System (INIS)

Ustinovshikov, Y.; Shabanova, I.

2011-01-01

Graphical abstract: The structure of Ni-20 at.% Mo and Ni-25 at.% Mo alloys was studied by methods of TEM and XPS. It is shown that at high temperatures the tendency toward phase separation takes place in the alloys and crystalline bcc Mo particles precipitate in the liquid solution. At 900 deg. C and below, the tendency toward ordering leads to the dissolution of Mo particles and precipitation of the particles of Ni 3 Mo, Ni 2 Mo or Ni 4 Mo chemical compounds. Highlights: → 'Chemical' phase transition 'ordering-phase separation' is first discovered in alloys of the Ni-Mo system. → It is first shown that the phase separation in the alloys studied begins at temperatures above the liquidus one. → The formation of Ni 3 Mo from A1 has gone through the intervening stage of the Ni 4 Mo and Ni 2 Mo coexistence. - Abstract: The structure of Ni-20 at.% Mo and Ni-25 at.% Mo alloys heat treated at different temperatures was studied by the method of transmission electron microscopy. X-ray photoelectron spectroscopy was used to detect the sign of the chemical interaction between Ni and Mo atoms at different temperatures. It is shown that at high temperatures the tendency toward phase separation takes place. The system of additional reflections at positions {1 1/2 0} on the electron diffraction patterns testifies that the precipitation of crystalline bcc Mo particles begins in the liquid solution. At 900 deg. C and below, the tendency toward ordering leads to the precipitation of the particles of the chemical compounds. A body-centered tetragonal phase Ni 4 Mo (D1 a ) is formed in the Ni-20 at.% Mo alloy. In the Ni-25 at.% Mo alloy, the formation of the Ni 3 Mo (D0 22 ) chemical compound from the A1 solid solution has gone through the intervening stage of the Ni 4 Mo (D1 a ) and Ni 2 Mo (Pt 2 Mo) formation.

X-ray and electron microscopy investigation of the topotactic transformation of MoO3 into MoO2

International Nuclear Information System (INIS)

Bertrand, O.; Dufour, L.C.

1980-01-01

The reduction of MoO 3 is investigated by X-ray analysis and electron microscopy from MoO 3 (010) platelets between 1000 A and 5 mm long. In all cases, the following orientation relationship between both lattices is found: [100] 2 parallel [010] 3 , [122] 2 parallel [100] 3 . [-12-2] 2 parallel [001] 3 . MoO 3 crystallites twinning and misorientation are discussed in relation with the particular importance of [101] 3 directions in MoO 3 preserved in the transformation and becoming [010] 2 of MoO 2 . A model for this topotactic reduction is proposed where the reaction develops layer (010) 3 by layer (010) 3 to form [20-1] 2 type planes in MoO 2 structure. Data on the kinetics of the boundary moving in [010] 3 direction are also presented. (author)

PENGARUH SERBUK U-Mo HASIL PROSES MEKANIK DAN HYDRIDE – DEHYDRIDE – GRINDING MILL TERHADAP KUALITAS PELAT ELEMEN BAKAR U-Mo/Al

Directory of Open Access Journals (Sweden)

Supardjo Supardjo

2015-07-01

Full Text Available PENGARUH SERBUK U-Mo HASIL PROSES MEKANIK DAN HYDRIDE – DEHYDRIDE – GRINDING MILL TERHADAP KUALITAS PELAT ELEMEN BAKAR U-Mo/Al. Penelitian bahan bakar U-7Mo/Al tipe pelat dilakukan dalam rangka pengembangan bahan bakar U3Si2/Al untuk mendapatkan bahan bakar baru yang memiliki densitas uranium lebih tinggi, stabil selama digunakan sebagai bahan bakar di dalam reaktor dan mudah dilakukan proses olah ulangnya. Lingkup penelitian meliputi pembuatan: paduan U-7Mo dengan teknik peleburan, pembuatan serbuk U-7Mo dengan dikikir dan hydride - dehydride - grinding mill, IEB U-7Mo/Al dengan teknik kompaksi pada tekanan 20 bar, dan PEB U-7Mo/Al dengan teknik pengerolan panas pada temperatur 425oC. Paduan U-7Mo hasil proses peleburan cukup homogen, berat jenis 16,34 g/cm3 dan bersifat ulet, kemudian dibuat menjadi serbuk dengan cara dikikir dan hydride - dehydride - grinding mill. Serbuk U-7Mo hasil proses kikir berbentuk pipih, kontaminan Fe cukup tinggi, sedangkan serbuk hasil proses hydride - dehydride - grinding mill, cenderung equiaxial dengan kontaminan yang rendah. Kedua jenis serbuk U-7Mo tersebut digunakan sebagai bahan baku pembuatan IEB U-7Mo/Al dan PEB U-7Mo/Al dengan densitas uranium 7 gU/cm3 dan diperoleh produk dengan kualitas yang hampir sama. Hasil uji IEB U-7Mo/Al berukuran 25 x 15 x 3,15±0,05 mm, tidak terdapat cacat/retak, distribusi U-7Mo di dalam matriks cukup homogen dan tidak terdapat pengelompokan/aglomerasi U-7Mo yang berdimensi >1 mm. PEB U-7Mo/Al hasil pengerolan dengan tebal akhir 1,45 mm, memiliki ketebalan meat rerata 0,60 mm dan tebal kelongsong 0,4 mm dan terdapat 1 titik pengukuran kelongsong dengan ketebalan 0,15 mm. Dengan membandingkan penggunaan kedua jenis serbuk U-7Mo tersebut, IEB U-7Mo/Al dan PEB U-7Mo/Al yang dihasilkan memiliki kualitas hampir sama. Namun demikian penggunaan serbuk U- 7Mo hasil proses hydride - dehydride - grinding mill lebih baik karena proses pengerjaannya lebih cepat dan impuritas dalam

Microstructure investigation of NiAl-Cr(Mo) interface in a directionally solidified NiAl-Cr(Mo) eutectic alloyed with refractory metal

International Nuclear Information System (INIS)

Chen, Y.X.; Cui, C.Y.; Guo, J.T.; Li, D.X.

2004-01-01

The microstructure of a directionally solidified NiAl-Cr(Mo) eutectic alloyed with refractory metal in as-processed and heat-treated states has been studied by means of scanning electron microscopy and high resolution electron microscopy (HREM). The microstructure of the NiAl-Cr(Mo) eutectic was characterized by lamellar Cr(Mo) phases embedded within NiAl matrix with common growth direction of . The interface between NiAl and lamellar Cr(Mo) did not have any transition layers. Misfit dislocations were observed at the NiAl-Cr(Mo) interface. In addition to lamellar Cr(Mo) phases, coherent Cr(Mo, Ni, Al) precipitates and NiAl precipitates were also observed in the NiAl matrix and lamellar Cr(Mo) phases, respectively. After hot isostatic pressing and heat treatment, the NiAl-Cr(Mo) interfaces became smooth and straight. Square array of misfit dislocations was directly observed at the (0 0 1) interface between NiAl and Cr(Mo, Ni, Al) precipitate. The configuration of misfit dislocation network showed a generally good agreement with prediction based on the geometric O-lattice model

Intermediate report of MoReMo. Modelling resilience for maintenance and outage

Energy Technology Data Exchange (ETDEWEB)

Oedewald, P.; Macchi, L. (VTT Technical Research Centre of Finland (Finland)); Axelsson, C. (Ringhals AB, Vattenfall AB (Sweden)); Eitrheim, M.H.R. (Institute for Energy Technology (Norway))

2012-02-15

Resilience Engineering (RE) is a new approach to safety that helps organisations and individuals adapt to unforeseen events and long-term changes. Such an approach is needed by nuclear power plants (NPPs) as they face demanding modification projects, high staff turnover and increased pressures to maintain and improve safety. The goal of the Modelling Resilience for Maintenance and Outage (MoReMO) project is to develop and test models and methods to identify and analyse resilience in safety-critical activities in natural everyday settings. In 2011, we have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. The project has collected data through observations, interviews and document reviews at two NPPs. Together, the four approaches have provided valuable insights for understanding the rationale behind work practices, their effects on safety, and the support of flexibility and adaptability. In 2012, the MoReMO project will complete the data collection and integrate results on how resilience can be operationalized in practical safety management tools for the companies. (Author)

Intermediate report of MoReMo. Modelling resilience for maintenance and outage

International Nuclear Information System (INIS)

Oedewald, P.; Macchi, L.; Axelsson, C.; Eitrheim, M.H.R.

2012-02-01

Resilience Engineering (RE) is a new approach to safety that helps organisations and individuals adapt to unforeseen events and long-term changes. Such an approach is needed by nuclear power plants (NPPs) as they face demanding modification projects, high staff turnover and increased pressures to maintain and improve safety. The goal of the Modelling Resilience for Maintenance and Outage (MoReMO) project is to develop and test models and methods to identify and analyse resilience in safety-critical activities in natural everyday settings. In 2011, we have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. The project has collected data through observations, interviews and document reviews at two NPPs. Together, the four approaches have provided valuable insights for understanding the rationale behind work practices, their effects on safety, and the support of flexibility and adaptability. In 2012, the MoReMO project will complete the data collection and integrate results on how resilience can be operationalized in practical safety management tools for the companies. (Author)

First-principles study of van der Waals interactions in MoS2 and MoO3

International Nuclear Information System (INIS)

Peelaers, H; Van de Walle, C G

2014-01-01

Van der Waals interactions play an important role in layered materials such as MoS 2 and MoO 3 . Within density functional theory, several methods have been developed to explicitly include van der Waals interactions. We compare the performance of several of these functionals in describing the structural and electronic properties of MoS 2 and MoO 3 . We include functionals based on the local density or generalized gradient approximations, but also based on hybrid functionals. The coupling of the semiempirical Grimme D2 method with the hybrid functional HSE06 is shown to lead to a very good description of both structural and electronic properties. (paper)

Controlled synthesis of MoO3 microcrystals by subsequent calcination of hydrothermally grown pyrazine–MoO3 nanorod hybrids and their photodecomposition properties

International Nuclear Information System (INIS)

Rajagopal, S.; Nataraj, D.; Khyzhun, O.Y.; Djaoued, Yahia; Robichaud, Jacques; Kim, Chang-Koo

2013-01-01

We present our results on successful synthesis of pyrazine–MoO 3 nanorod hybrids by using pyrazine and MoO 3 nanorods. On the first stage, MoO 3 nanorods were grown hydrothermally and, on the second stage, their mixture with pyrazine was again involved in a hydrothermal reaction to produce organic–inorganic hybrids. To understand the growth mechanism of the hybrids we varied time and temperature of the hydrothermal process. Intercalation of pyrazine was confirmed through X-ray diffraction analysis, X-ray photoelectron spectroscopy, X-ray emission spectroscopy, scanning electron microscopy methods. Upon calcinations, pyrazine was deintercalated, i.e. removed from the MoO 3 hybrid system, and the MoO 3 nanorods were found to bind together resulting in formation of MoO 3 microslabs with increased surface area. Photodecomposition performance of the MoO 3 nanorods, pyrazine–MoO 3 hybrids and MoO 3 microcrystals was studied against Procion Red MX-5B textile dye. A high photodecomposition performance was found to decrease when going from MoO 3 nanorods to MoO 3 microcrystal and, further, to pyrazine–MoO 3 hybrids. - Graphical abstract: Display Omitted - Highlights: • High aspect ratio MoO 3 nanorods were prepared through a new hydrothermal method. • Hybrids of pyrazine–MoO 3 were formed by intercalating pyrazine into MoO 3 nanorods. • Intercalation of pyrazine was confirmed in X-ray spectroscopic analysis. • After calcinations, MoO 3 crystal was retained by binding MoO 3 nanorods together. • High photodegradation performance was noticed from MoO 3 nanorods

Effet du Mg et des oligo-éléments sur le comportement de cinq variétés d'arachides (Arachis hypogeae L.

Directory of Open Access Journals (Sweden)

Lumpungu, K.

1987-01-01

Full Text Available Effect of magnesium and trace elements on the development of five groundnut varieties (Arachis hypogeae L.. A study of Mg and certain minor elements (B, Cu, Fe, Mn, Mo and Zn given by seed imbibition has been conducted. The results have shown that the effect of Mg and minor elements on the growth, yield (pods and seeds and lipids content of the seeds depend on the variety and rate of Mg and minor elements application.

Biodistribution of 99Mo in rats

International Nuclear Information System (INIS)

Souza, Raphael Sancho Sisley de; Ribeiro, Bianca da Silva; Dantas, Ana Leticia Almeida; Dantas, Bernardo Maranhao; Bernardo Filho, Mario

2009-01-01

The modification of 99 Mo standard metabolism in the presence of MDP would alter the dosimetry of this radionuclide in nuclear medicine patients. Therefore, the objective of this work is to evaluate the influence of MDP in the biodistribution of 99 Mo. Wistar rats were divided in two groups of six animals, being inoculated respectively 99 Molibdate and 99 Mo+MDP via plex ocular. The biodistribution study was carried out after 10 and 120 minutes respectively. The organs were counted with a NaI(Tl) detector. The uptake values did not present significant differences among the groups. An in vitro study through planar chromatography was carried out to determine the affinity between molybdenum and MDP. The results show that 99 Mo has low affinity both to propanone and NaCl-0.9% solution. However, 99 Mo in the presence of MDP presented affinity to NaCl-0.9% solution and low affinity to propanone suggesting that 99 Mo was bound to MDP under the conditions of the experiment. (author)

Synthesis of Fine Mo2C Powder from Prereduced Mo in Undiluted CH4 Flow

Science.gov (United States)

Cetinkaya, S.; Eroglu, S.

2017-10-01

The carburization behavior of prereduced Mo was investigated in undiluted CH4 flow at 900-1000 K. Prior to the experiments, equilibrium thermodynamic analysis was carried out in the Mo-C-H system. The products were characterized by mass measurement, x-ray diffraction and scanning electron microscopy techniques. A single Mo2C phase was obtained within 45 min, 5 min, and 2.5 min at 900 K, 950 K, and 1000 K, respectively, at CH4 contents higher than the predicted ones. The reasons for this behavior were discussed in terms of CH4 stability, open tube flow, and self-created atmosphere in the powder bed. The fractional conversion-time curves indicated that the carburization kinetics followed a linear rate law. The Mo2C crystallite size (26-37 nm) and platelet thickness (50-100 nm) were found to be smaller than those of the parent Mo phase. These findings were attributable to the defects formed as a result of stresses associated with the reduction and the carburization.

MgO melting curve constraints from shock temperature and rarefaction overtake measurements in samples preheated to 2300 K

OpenAIRE

Fat'yanov, Oleg V.; Asimow, P. D.

2014-01-01

Continuing our effort to obtain experimental constraints on the melting curve of MgO at 100-200 GPa, we extended our target preheating capability to 2300 K. Our new Mo capsule design holds a long MgO crystal in a controlled thermal gradient until impact by a Ta flyer launched at up to 7.5 km/s on the Caltech two-stage light-gas gun. Radiative shock temperatures and rarefaction overtake times were measured simultaneously by a 6-channel VIS/NIR pyrometer with 3 ns time resolution. The majority ...

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).

Solid state reactions of MoO3 and Na2MoO4 with (U.85,Ce.15)O2x

International Nuclear Information System (INIS)

Dahale, N.D.; Keskar, Meera; Singh Mudher, K.D.; Chawla, K.L.

1999-01-01

(U .85 ,Ce .15 )MoO 6-x was prepared by the solid state reactions of (U .85 ,Ce .15 )O 2±x with MoO 3 in air at 600 deg C. Solid state reactions of Na 2 MoO 4 with (U .85 ,Ce .15 )MoO 6.x up to 550 deg C in air led to the formation of Na 2 (U .85 ,Ce .15 )Mo 2 O 10-x and Na 2 (U .85 , Ce .15 ) 2 Mo 3 O 16-x . These compounds were characterised by x-ray and thermal methods. The x-ray powder data of (U .85 , Ce .15 ) MoO 6-x were indexed on monoclinic system whereas, data of Na 2 (U .85 ,Ce .15 ) Mo 2 O 10-x and Na 2 (U .85 ,Ce .15 ) 2 Mo 3 O 16-x were indexed on orthorhombic and monoclinic system respectively. (author)

Cobalt internal standard for Ni to assist the simultaneous determination of Mo and Ni in plant materials by high-resolution continuum source graphite furnace atomic absorption spectrometry employing direct solid sample analysis.

Science.gov (United States)

de Babos, Diego Victor; Bechlin, Marcos André; Barros, Ariane Isis; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta; de Oliveira, Silvana Ruella

2016-05-15

A new method is proposed for the simultaneous determination of Mo and Ni in plant materials by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS), employing direct solid sample analysis (DSS) and internal standardization (IS). Cobalt was used as internal standard to minimize matrix effects during Ni determinations, enabling the use of aqueous standards for calibration. Correlation coefficients for the calibration curves were typically better than 0.9937. The performance of the method was checked by analysis of six plant certified reference materials, and the results for Mo and Ni were in agreement with the certified values (95% confidence level, t-test). Analysis was made of different types of plant materials used as renewable sources of energy, including sugarcane leaves, banana tree fiber, soybean straw, coffee pods, orange bagasse, peanut hulls, and sugarcane bagasse. The concentrations found for Mo and Ni ranged from 0.08 to 0.63 ng mg(-1) and from 0.41 to 6.92 ng mg(-1), respectively. Precision (RSD) varied from 2.1% to 11% for Mo and from 3.7% to 10% for Ni. Limits of quantification of 0.055 and 0.074 ng were obtained for Mo and Ni, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Non-stoichiometry in the KMo2P3O12-tunnel structure: The oxide K0.75MoNbP3O12

International Nuclear Information System (INIS)

Leclaire, A.; Borel, M.M.; Grandin, A.; Raveau, B.

1990-01-01

K 0.75 MoNbP 3 O 12 , M r =503.009, orthorhombic, Pbcm, a=8.8518 (5), b=9.1453 (11), c=12.5174 (11) A, V=1013.3 (3) A 3 , Z=4, D x =3.300 Mg m -3 , λ(Mo Kα)=0.71073 A, μ=3.13 mm -1 , F(000)=953, T=294 K, R=0.029, wR=0.033 for 1235 observed reflections. This compound is isostructural with KMo 2 P 3 O 12 -type oxides. Its framework is built up from MoO 6 octahedra and PO 4 tetrahedra which delimit tunnels running along b. Different from KMo 2 P 3 O 12 , the tunnels are partly occupied by the potassium ions which are distributed at random. (orig.)

Effect of Cs and Li atom adsorption on MgO: Secondary emission and work function

International Nuclear Information System (INIS)

Bagraev, N.T.; Borisov, V.L.

1980-01-01

Adsorption of Cs and Li atoms on the surface of single crystal magnesium oxide films has been investigated using Auger, LEED and contact difference techniques. A decreased work function for a single crystal MgO film grown on the Mo (100) face was observed to be accompanied by an increased secondary electron emission yield shown to be due to a larger escape depth for secondary electrons. LEED showed well ordered layers of adsorbed Cs on the MgO film surface. A model to explain the behaviour of Cs atoms on the film surface is proposed. It is shown that the stability of the Cs coating is not dependent on a prolonged bombardment of the film by incident electron beams of high current density. Depositing and implanting of thin single crystal MgO films with Li were found to result in an increased secondary electron emission yield, with Li adsorption on the MgO film surface being disordered. (orig.)

Study of different absorbent materials for the preparation of generator systems of 99Mo - 99mTc and 188W-188Re

International Nuclear Information System (INIS)

Lopes, Paula Regina Corain; Osso Junior, Joao Alberto

2009-01-01

Amongst some currently radioisotopes, 99m Tc and 188 Re present adequate decay properties for use in Nuclear Medicine. In the current times the most diagnosis examinations are performed with 99m Tc and 188 Re is one radioisotope of potential use in therapy techniques. The objective of this work consists of determining the capacity of some adsorbent materials for retention of molybdenum and tungsten, aiming the optimization of generator systems of 99 Mo- 99m Tc and 188 W- 188 Re with suitable characteristics for application in Nuclear Medicine. Known amounts, in mass, of molybdenum and tungsten were percolated through different chromatographic columns containing different commercial adsorbent materials such as: PZC (poly-zirconium compound), acid alumina and calcinated alumina used in the routine preparation of 99 Mo- 99m Tc generators at IPEN. The tungsten ( 188 W), as well the PZC used in this project, supplied by Russia and Japan, respectively, through the International Atomic Energy Agency (IAEA) and used without any previous preparation. Also trace amounts of 99 Mo and 188 W were added to the initial solutions and the generators were assembled. The 99 Mo- 99m Tc generators were then eluted with known volumes of 0.9% NaCl solution every 24 hours whereas the 188 W- 188 Re generators were eluted every 48 hours. The eluted samples were analyzed by Gamma Spectroscopy and later submitted to quality control evaluation. The results showed that the PZC presents superior retention capacity for Mo of 97.50mg Mo/gPZC, higher than in acid and calcinated alumina, however the elution efficiency at lower pHs is not so high. With regards to the experiments carried out with 188 W and alumina, it was verified that the elution efficiency of 188 Re was not reproducible and the retention capacity of W was 90.23mgW/gAl 2 O 3 at pH 7. (author)

Experimental determination of the Mo isotope fractionation factor between metal and silicate liquids

Science.gov (United States)

Hin, R. C.; Burkhardt, C.; Schmidt, M. W.; Bourdon, B.

2011-12-01

The conditions and chemical consequences of core formation have mainly been reconstructed from experimentally determined element partition coefficients between metal and silicate liquids. However, first order questions such as the mode of core formation or the nature of the light element(s) in the Earth's core are still debated [1]. In addition, the geocentric design of most experimental studies leaves the conditions of core formation on other terrestrial planets and asteroids even more uncertain than for Earth. Through mass spectrometry, records of mass-dependent stable isotope fractionation during high-temperature processes such as metal-silicate segregation are detectable. Stable isotope fractionation may thus yield additional constrains on core formation conditions and its consequences for the chemical evolution of planetary objects. Experimental investigations of equilibrium mass-dependent stable isotope fractionation have shown that Si isotopes fractionate between metal and silicate liquids at temperatures of 1800°C and pressures of 1 GPa, while Fe isotopes leave no resolvable traces of core formation processes [2,3]. Molybdenum is a refractory and siderophile trace element in the Earth, and thus much less prone to complications arising from mass balancing core and mantle and from potential volatile behaviour than other elements. To determine equilibrium mass-dependent Mo isotope fractionation during metal-silicate segregation, we have designed piston cylinder experiments with a basaltic silicate composition and an iron based metal with ~8 wt% Mo, using both graphite and MgO capsules. Metal and silicate phases are completely segregated by the use of a centrifuging piston cylinder at ETH Zurich, thus preventing analysis of mixed metal and silicate signatures. Molybdenum isotope compositions were measured using a Nu Instruments 1700 MC-ICP-MS at ETH Zurich. To ensure an accurate correction of analytical mass fractionation a 100Mo-97Mo double spike was admixed

Normal and grazing incidence pulsed laser deposition of nanostructured MoSx hydrogen evolution catalysts from a MoS2 target

Science.gov (United States)

Fominski, V. Yu.; Romanov, R. I.; Fominski, D. V.; Dzhumaev, P. S.; Troyan, I. A.

2018-06-01

Pulsed laser ablation of a MoS2 target causes enhanced splashing of the material. So, for MoSx films obtained by pulsed laser deposition (PLD) in the conventional normal incidence (NI) configuration, their typical morphology is characterized by an underlying granular structure with an overlayer of widely dispersed spherical Mo and MoSx particles possessing micro-, sub-micro- and nanometer sizes. We investigated the possibility of using high surface roughness, which occurs due to particle deposition, as a support with a large exposed surface area for thin MoSx catalytic layers for the hydrogen evolution reaction (HER). For comparison, the HER performance of MoSx layers formed by grazing incidence (GI) PLD was studied. During GI-PLD, a substrate was placed along the direction of laser plume transport and few large particles loaded the substrate. The local structure and composition of thin MoSx layers formed by the deposition of the vapor component of the laser plume were varied by changing the pressure of the buffer gas (argon, Ar). In the case of NI-PLD, an increase in Ar pressure caused the formation of quasi-amorphous MoSx (x ≥ 2) films that possessed highly active catalytic sites on the edges of the layered MoS2 nanophase. At the same time, a decrease in the deposition rate of the MoSx film appeared due to the scattering of the vapor flux by Ar molecules during flux transport from the target to the substrate. This effect prevented uniform deposition of the MoSx catalytic film on the surface of most particles, whose deposition rate was independent of Ar pressure. The scattered vapor flux containing Mo and S atoms was a dominant source for MoSx film growth during GI-PLD. The thickness and composition distribution of the MoSx film on the substrate depended on both the pressure of the buffer gas and the distance from the target. For 1.0-2.5 cm from the target, the deposition rate was quite sufficient to form S-enriched quasi-amorphous MoSx (2.5 < x < 6) catalytic

Study on Mo(V) species, location and adsorbates interactions in MoH-SAPO-34 by employing ESR and electron spin-echo modulation spectroscopies

International Nuclear Information System (INIS)

Back, Gern Ho; Jang, Chang Ki; Ru, Chang Kuk; Cho, Young Hwan; So, Hyun Soo; Larry, Keven

2002-01-01

A solid-state reaction of MoO 3 with as-synthesized H-SAPO-34 generated paramagnetic Mo(V) species. The dehydration resulted in weak Mo(V) species, and subsequent activation resulted in the formation of Mo(V) species such as Mo(V) 5c and Mo(V) 6c that are characterized by ESR. The data of ESR and ESEM show the oxomolybdenum species, to be (MoO 2 ) + or (MoO) 3+ . The (MoO 2 ) + species seems to be more probable. Since H-SAPO-34 has a low framework negative charge, (MoO) 3+ with a high positive charge can not be easily stabilized. A solution reaction between the solution of silico-molybdic acid and calcined H-SAPO-34 resulted in only MoO + 2 species. A rhombic ESR signal is observed on adsorption of D 2 O, CD 3 OH, CH 3 CH 2 OD and ND 3 . The Location and coordination structure of Mo(V) species has been determined by three-pulse electron spin-echo modulation data and their simulations. After the adsorption of methanol, ethylene, ammonia, and water for MoH-SAPO-34, three molecules, one and one molecule, respectively, are directly coordinated to (MoO 2 ) +

Computational identification of MoRFs in protein sequences.

Science.gov (United States)

Malhis, Nawar; Gsponer, Jörg

2015-06-01

Intrinsically disordered regions of proteins play an essential role in the regulation of various biological processes. Key to their regulatory function is the binding of molecular recognition features (MoRFs) to globular protein domains in a process known as a disorder-to-order transition. Predicting the location of MoRFs in protein sequences with high accuracy remains an important computational challenge. In this study, we introduce MoRFCHiBi, a new computational approach for fast and accurate prediction of MoRFs in protein sequences. MoRFCHiBi combines the outcomes of two support vector machine (SVM) models that take advantage of two different kernels with high noise tolerance. The first, SVMS, is designed to extract maximal information from the general contrast in amino acid compositions between MoRFs, their surrounding regions (Flanks), and the remainders of the sequences. The second, SVMT, is used to identify similarities between regions in a query sequence and MoRFs of the training set. We evaluated the performance of our predictor by comparing its results with those of two currently available MoRF predictors, MoRFpred and ANCHOR. Using three test sets that have previously been collected and used to evaluate MoRFpred and ANCHOR, we demonstrate that MoRFCHiBi outperforms the other predictors with respect to different evaluation metrics. In addition, MoRFCHiBi is downloadable and fast, which makes it useful as a component in other computational prediction tools. http://www.chibi.ubc.ca/morf/. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Ordering in rapidly solidified Ni/sub 2/Mo

International Nuclear Information System (INIS)

Kulkarni, U.D.; Dey, G.K.; Banerjee, S.

1988-01-01

Ordering processes in the Ni-Mo system have been a subject of several investigations. Although the ordering behaviour of the Ni/sub 4/Mo and the Ni/sub 3/Mo has been examined in detail, no such study has been reported in the case of the Ni/sub 2/Mo alloy. The lack of experimental work on ordering transformations in Ni/sub 2/Mo is presumably due to the difficulty in obtaining a single phase fcc alloy of this composition. Enhanced solid solubility of Mo in Ni, which accompanies rapid solidification processing (RSP) makes the formation of such a phase possible. The ordering processes in Ni-Mo based alloys show several remarkable features. Firstly, the alloy (15 - 28 at % Mo) quenched from the α -phase filed exhibit a short range order (SRO) characterized by the presence of intensity maxima at /1 1/2 0/ fcc positions of the reciprocal space. This state of SRO has been attributed to the occurrence of 1 1/2 O spinodal ordering in the system. Secondly, the transformation from the state of SRO to the equilibrium/metastable coherent long range ordered (LRO) structures appears to take place in a continuous manner at relatively low temperatures of aging. Three different coherent LRO structures, namely: the equilibrium Ni/sub 4/Mo (prototype structure D1/sub a/) and the metastable Ni/sub 3/Mo (DO/sub 22/) and Ni/sub 2/Mo (Pt/sub 2/Mo) structures have reported to evolve from the SRO alloy, depending upon the aging treatment and the composition of the alloy

Fission 99Mo production technology

International Nuclear Information System (INIS)

Miao Zengxing; Luo Zhifu; Ma Huimin; Liang Yufu; Yu Ningwen

2003-01-01

This paper describes a production technology of fission 99 Mo in the Department Isotope, CIAE. The irradiation target is tubular U-Al alloy containing highly enriched uranium. The target is irradiated in the swimming pool reactor core. The neutron flux is about 4x10 13 /cm 2 .sec. The production scale is 3.7-7.4 TBq (100-200Ci) of fission 99 Mo per batch. Total recovery of 99 Mo is more than 70%. The production practice proves that the process and equipment are safe and reliable. (author)

Effect of support on the activity of MoVCeZr catalyst for propane ammoxidation reaction

International Nuclear Information System (INIS)

Anita Ramli; Farinaa Md Jamil; Ishak Ahmad

2010-01-01

Mixed metal oxide catalysts based on Mo-V have been known as the most active and selective in the ammoxidation of propane to ACN. A series of MoVCeZr (5 % wt/ wt) supported with MOR, TiO 2 and MgO have been prepared by incipient wetness impregnation method for propane ammoxidation reaction to ACN. The catalyst was calcined in a two step calcination process in static air between 350 - 600 degree Celsius for 10 hour. The surface area and pore size of these catalysts were measured using physical adsorption of nitrogen following Brunauer, Emmet and Teller (BET) equation. The textural and morphological of these catalysts were determined using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). The activities of all catalysts were tested using a fixed-bed reactor with online gas chromatography (GC) at 420 degree Celsius and atmospheric pressure in the presence of 0.5 ml catalyst with composition consisting of 5.8:7:17.4 (propane: ammonia: air) and helium as carrier to give a total flow of 120 ml. Result shows that MoVCeZr support gives a better conversion due to the surface area and pore size characteristic of the catalyst. (author)

Resonant photoelectron spectroscopy at the Mo 4p→4d absorption edge in MoS2

International Nuclear Information System (INIS)

Lince, J.R.; Didziulis, S.V.; Yarmoff, J.A.

1991-01-01

A systematic study has been conducted of the resonant behavior of the valence-band photoelectron spectrum of MoS 2 for hν=26--70 eV, spanning the Mo 4p→4d transition region. A broad Fano-like resonance appears at ∼42 eV in the constant-initial-state (CIS) intensity plot of the d z 2 peak near the valence-band maximum [∼2 eV binding energy (BE)], confirming its predominantly Mo 4d character. A second shoulder on the higher-hν side of the maximum in the d z 2 CIS intensity plot is suggested to result from transitions to unoccupied states in the 5sp band ∼10 eV above E F , by comparison with a partial-yield spectrum and previous inverse-photoemission data. The region of the valence band in the range 3--4.5-eV BE also exhibits resonant behavior, indicating Mo 4d character, although somewhat less than for the d z 2 peak. The 5--7-eV BE range does not exhibit resonance behavior at the Mo 4p edge and, therefore, contains negligible Mo 4d character. A feature at ∼30 eV in the CIS intensity plot for the 5--7-eV BE range could not be definitively assigned in this study, but may be due to a resonance between direct photoemission and a process involving absorption and autoionization of electronic states that contain Mo 5s and 5p character

Creep and shrinkage of Mo(Ni)

International Nuclear Information System (INIS)

Kaysser, W.A.; Hofmann-Amtenbrink, M.; Petzow, G.

1984-01-01

To avoid some of the errors inherent in a quantitative interpretation of shrinkage of powder compacts as Mo-Ni, other experiments were looked for, where the influence of Ni on the material transport properties of Mo could be measured semi-quantitatively during heating up to temperature and subsequent isothermal annealing. The bending of thin Mo foils under small loads was found to be an experimental arrangement, where variations in stress, in Ni-concentration and in intrinsic material properties could be realized. The results of these creep experiments will be compared in a qualitative sense with sintering experiments in Mo-Ni done under similar conditions as the creep experiments

Study of the water-gas shift reaction on Mo2C/Mo catalytic coatings for application in microstructured fuel processors

NARCIS (Netherlands)

Rebrov, E.V.; Kuznetsov, S.A.; Croon, de M.H.J.M.; Schouten, J.C.

2007-01-01

The activity and stability of two types of molybdenum carbide coatings deposited on molybdenum substrates (Mo2C/Mo) were compared in the water-gas shift reaction at 513–631 K. The activity of the Mo2C/Mo coatings obtained by carburization of preoxidized molybdenum substrates in a CH4/H2 mixture at

IEA Mobility Model (MoMo) and its use in the ETP 2008

International Nuclear Information System (INIS)

Fulton, Lew; Cazzola, Pierpaolo; Cuenot, Francois

2009-01-01

The IEA published 'Energy Technology Perspectives' (ETP) in June 2008. That document reports on IEA scenarios for baseline and low-CO 2 alternative scenarios to 2050, across the energy economy. The study included creating scenarios for transport, using the IEA Mobility Model (MoMo). This paper reports on the transport-related ETP scenarios and describes the model used in the analysis. According to the ETP Baseline scenario, world transport energy use and CO 2 emissions will more than double by 2050. In the most challenging scenario, called 'BLUE', transport emissions are reduced by 70% in 2050 compared to their baseline level in that year (and about 25% below their 2005 levels). There are several versions of the BLUE scenario, but all involve: a 50% or greater improvement in LDV efficiency, 30-50% improvement in efficiency of other modes (e.g. trucks, ships and aircraft), 25% substitution of liquid fossil fuels by biofuels, and considerable penetration of electric and/or fuel-cell vehicles. In the second half of this paper, an overview of the MoMo model is provided. Details on the complete analysis are contained in the ETP 2008 document, available at (www.iea.org). Details of the LDV fuel economy analysis are contained in a separate paper in this collection.

Behavior of methyl orange and orange 10 (orange G) in the presence of hydrotalcite type compounds of Mg/Al and Mg/Fe; Comportamiento de naranja de metilo y naranja 10 (orange G) en presencia de compuestos tipo hidrotalcita de mg/Al y Mg/Fe

Energy Technology Data Exchange (ETDEWEB)

Cruz N, G.

2015-07-01

This work is focused on studying the sorption capacity of methyl orange dye (Nm) and orange 10 (N-10) in the presence of hydrotalcite type compounds of Mg/Al and Mg/Fe uncalcined and calcined previously at 500 degrees Celsius. Sorption isotherms were determined and the study of the kinetics of sorption was performed. The materials were characterized before and after sorption processes of these dyes by X-ray diffraction, scanning electron microscopy, the specific surface area determination by the Brunauer-Emmett-Teller method, thermogravimetry coupled to mass and infrared spectrometry. The hydrotalcite type compounds reported in this paper were prepared in the laboratory and their acronyms are: HTMgAlG1, HTMgAlMO, HTMgFeG1 and HTMgFeG2. Note that in this work the best conditions for preparing compounds of Mg/Fe were found. From patterns of X-ray diffraction was identified the typical crystal structure of the hydrotalcite type compounds. By scanning electron microscopy the morphology could be determined in the form of flakes characteristics of these compounds. Likewise with elemental analysis of energy dispersive X-ray spectroscopy the presence of Mg, Al, Fe and C, elements of interest for this study was determined. The compounds presented a specific surface area relatively high from 80 to 120 m{sup 2}/g. Thermogravimetry results presented spectra of mass loss very characteristic associated to water losses, dehydroxylation and decarboxylation. The characteristic bands of water and carbonate were assigned by infrared spectroscopy and the bands corresponding to the dyes sulfonates were identified only for the calcined materials. The sorption capacities found of these compounds were as follows: for Nm in the compound HTMgAlG1 uncalcined was 17.82 mg/g for an initial concentration of 200 mg/L and for calcined (HTMgAlMOcal) of 99.8 mg/g with and initial concentration of 1000 mg/L. Moreover, the sorption capacity of the dye N-10 in this same material was 17.92 mg/g and 99

Single Phase Melt Processed Powellite (Ba,Ca) MoO{sub 4} For The Immobilization Of Mo-Rich Nuclear Waste

Energy Technology Data Exchange (ETDEWEB)

Brinkman, Kyle [Savannah River Site (SRS), Aiken, SC (United States); Marra, James [Savannah River Site (SRS), Aiken, SC (United States); Fox, Kevin [Savannah River Site (SRS), Aiken, SC (United States); Reppert, Jason [Savannah River Site (SRS), Aiken, SC (United States); Crum, Jarrod [Paci fic Northwest National Laboratory , Richland, WA (United States); Tang, Ming [Los Alamos National Laboratory , Los Alamos, NM (United States)

2012-09-17

Crystalline and glass composite materials are currently being investigated for the immobilization of combined High Level Waste (HLW) streams resulting from potential commercial fuel reprocessing scenarios. Several of these potential waste streams contain elevated levels of transition metal elements such as molybdenum (Mo). Molybdenum has limited solubility in typical silicate glasses used for nuclear waste immobilization. Under certain chemical and controlled cooling conditions, a powellite (Ba,Ca)MoO{sub 4} crystalline structure can be formed by reaction with alkaline earth elements. In this study, single phase BaMoO{sub 4} and CaMoO{sub 4} were formed from carbonate and oxide precursors demonstrating the viability of Mo incorporation into glass, crystalline or glass composite materials by a melt and crystallization process. X-ray diffraction, photoluminescence, and Raman spectroscopy indicated a long range ordered crystalline structure. In-situ electron irradiation studies indicated that both CaMoO{sub 4} and BaMoO{sub 4} powellite phases exhibit radiation stability up to 1000 years at anticipated doses with a crystalline to amorphous transition observed after 1 X 10{sup 13} Gy. Aqueous durability determined from product consistency tests (PCT) showed low normalized release rates for Ba, Ca, and Mo (<0.05 g/m{sup 2}).

U-Mo fuel qualification program in HANARO

International Nuclear Information System (INIS)

Lee, K.H.; Lee, C.S.; Kim, H.R.; Kuk, I.H.; Kim, C.K.

2000-01-01

Atomized U-Mo fuel has shown good performance from the results of previous out-of-pile tests and post-irradiation examinations. A qualification program of rod type U-Mo fuel is in progress and the fuel will be irradiated in HANARO. 6 gU/cm 3 U-7Mo, U-8Mo and U-9Mo are considered in this program. The laboratory test results of porosity, mechanical property, thermal conductivity, and thermal compatibility test are discussed in this paper. In parallel with this qualification program, the feasibility study on the core conversion from the present U 3 Si fuel to U-Mo in HANARO will be initiated to provide technical bases for the policy making. Several options of core conversion for HANARO are proposed and each option will be addressed briefly in terms of the operation policy, fuel management, and licensing of HANARO. (author)

On the coexistence of copper-molybdenum bronzes: CuxMoO3 (0.2 yMoO3-z (0.1 2-O quasi-ternary system

International Nuclear Information System (INIS)

Warner, T.E.; Skou, E.M.

2010-01-01

Two copper-molybdenum bronzes: Cu y MoO 3-z (0.1 x MoO 3 (0.2 3 at 600 o C under argon in Pt crucibles. Powder XRD showed that the material with global composition '0.1Cu.MoO 3 ' comprises ∼Cu 0.15 MoO 3 and MoO 3 ; whilst '0.2Cu.MoO 3 ' comprises ∼Cu 0.15 MoO 3 and ∼Cu 0.23 MoO 3 . DTA performed on '0.2Cu.MoO 3 ' reveals a reversible solid state phase transition ∼520 o C under argon. Reacting equimolar amounts of Cu 2 O and MoO 2 at 600 o C in a Cu crucible under argon yields: Cu 6 Mo 5 O 18 , Cu and MoO 2 . A tentative subsolidus Cu-MoO 2 -O isothermal (∼25 o C) phase diagram under argon is drawn from these data. Oxidation states of Cu and Mo within this system are discussed.

DFT study of the reactions of Mo and Mo with CO2 in gas phase

Indian Academy of Sciences (India)

understanding the mechanism of second-row metal reacting with CO2. The minimum energy ... et al.18 performed an IR study on the reaction of laser- ablated Mo atom .... indicate that the weak electrostatic interaction between. Mo. + and CO2 ...

A facile route to large-scale synthesis MoO2 and MoO3 as electrode materials for high-performance supercapacitors

International Nuclear Information System (INIS)

Xuan, H.C.; Du, Y.W.; Zhang, Y.Q.; Xu, Y.K.; Li, H.; Han, P.D.; Wang, D.H.

2016-01-01

MoO 3 and MoO 2 materials have been successfully synthesized by thermal decomposition of ammonium paramolybdate in air and a sealed quartz tube, respectively. The microstructure of as-synthesized MoO 3 is composed of irregular lamellar plates with a plate thickness around 100 nm and MoO 2 has the larger grain size with lamellar plates connected with each other. A maximum specific capacitance of 318 F/g at 0.5 A/g is obtained for MoO 2 prepared in a closed environment. On the other hand, the sample MoO 3 exhibits excellent rate capacity with specific capacitances of 218, 209, 196, 188, 176, and 160 F/g at current densities of 0.5, 1, 2, 3, 4, and 5 A/g, respectively. These results pave the way to consider MoO 3 and MoO 2 as prospective materials for energy-storage applications. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

New insights into the structure and mode of action of Mo-CBP3, an antifungal chitin-binding protein of Moringa oleifera seeds.

Directory of Open Access Journals (Sweden)

Adelina B Batista

Full Text Available Mo-CBP3 is a chitin-binding protein purified from Moringa oleifera Lam. seeds that displays inhibitory activity against phytopathogenic fungi. This study investigated the structural properties and the antifungal mode of action of this protein. To this end, circular dichroism spectroscopy, antifungal assays, measurements of the production of reactive oxygen species and microscopic analyses were utilized. Mo-CBP3 is composed of 30.3% α-helices, 16.3% β-sheets, 22.3% turns and 30.4% unordered forms. The Mo-CBP3 structure is highly stable and retains its antifungal activity regardless of temperature and pH. Fusarium solani was used as a model organism for studying the mechanisms by which this protein acts as an antifungal agent. Mo-CBP3 significantly inhibited spore germination and mycelial growth at 0.05 mg.mL-1. Mo-CBP3 has both fungistatic and fungicidal effects, depending on the concentration used. Binding of Mo-CBP3 to the fungal cell surface is achieved, at least in part, via electrostatic interactions, as salt was able to reduce its inhibitory effect. Mo-CBP3 induced the production of ROS and caused disorganization of both the cytoplasm and the plasma membrane in F. solani cells. Based on its high stability and specific toxicity, with broad-spectrum efficacy against important phytopathogenic fungi at low inhibitory concentrations but not to human cells, Mo-CBP3 has great potential for the development of new antifungal drugs or transgenic crops with enhanced resistance to phytopathogens.

Development of fission Mo-99 production technology

Energy Technology Data Exchange (ETDEWEB)

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

2001-05-01

This R and D project is planed to supply domestic demands of Mo-99 through fission route, and consequently this project will be expected to rise up utilization of HANARO and KAERI's capability for marketing extension into domestic and oversea radiopharmaceutical market. HEU and LEU target types are decided and designed for fission Mo-99 production in domestic. Experimental study of target fabrication technology was performed and developed processing equipments. And conceptual design of target loading/unloading in/from HANARO device are performed. Tracer test of Mo-99 separation and purification process was performed, test results reach to Mo-99 recovery yield above 80% and decontamination factor above 1600. Combined Mo-99 separation and purification process was decided for hot test scheduled from next year, and performance test was performed. Conceptual design for modification of existing hot cell for fission Mo-99 production facility was performed and will be used for detail design. Assumption for the comparison of LEU and HEU target in fission Mo-99 production process were suggested and compared of merits and demerits in view of fabrication technology and economy feasibility.

Development of fission Mo-99 production technology

International Nuclear Information System (INIS)

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

2001-05-01

This R and D project is planed to supply domestic demands of Mo-99 through fission route, and consequently this project will be expected to rise up utilization of HANARO and KAERI's capability for marketing extension into domestic and oversea radiopharmaceutical market. HEU and LEU target types are decided and designed for fission Mo-99 production in domestic. Experimental study of target fabrication technology was performed and developed processing equipments. And conceptual design of target loading/unloading in/from HANARO device are performed. Tracer test of Mo-99 separation and purification process was performed, test results reach to Mo-99 recovery yield above 80% and decontamination factor above 1600. Combined Mo-99 separation and purification process was decided for hot test scheduled from next year, and performance test was performed. Conceptual design for modification of existing hot cell for fission Mo-99 production facility was performed and will be used for detail design. Assumption for the comparison of LEU and HEU target in fission Mo-99 production process were suggested and compared of merits and demerits in view of fabrication technology and economy feasibility

Measurements of emissivities on JT-60 first wall materials (inconel 625, Mo, TiC-coated Mo)

International Nuclear Information System (INIS)

Nakamura, Hiroo; Shimizu, Masatsugu; Makino, Toshiro; Kunitomo, Takeshi.

1985-02-01

To evaluate heat removal performance of JT-60 first wall, emissivities and reflectivities on Inconel 625, Mo, TiC coated Mo with optically smooth surface and actual surface are measured at temperature from a room temperature to 1300 K. Spectra are measured in the rnage of wave lengthes from 0.34 μm to 20 μm. Actual surfaces are machined/pickled surfaces for Inconel 625, electro-polished surfaces for molybdenum, and as-coated surfaces for TiC-coated molybdenum. Results of Inconel 625 and molybdenum with oplically smooth surfaces are examined by a two-electrons-type dispersion model of optical constants. Electronic constants of the equation are given and formulated in order to correlates the macroscopic properties of the radiative heat transfer. Total emissivities, obtained from the spectral emissivities of optically smooth surface, are 0.13(RT) -- 0.21(1300 K) for Inconel 625, 0.035(RT) -- 0.18(1300 K) for Mo, and 0.053(RT) for TiC-coated Mo. Moreover, total emissivities of the actual surface at a room temperature are 0.35(Inconel 625), 0.124(Mo), and 0.073(TiC-coated Mo). Large dependence of the emissivities on temperature and wave length shows that the model including these dependences is necessary for an accurate evaluation of the radiative heat transfer. (author)

Study of the dynamics of the MoO2-Mo2C system for catalytic partial oxidation reactions

Science.gov (United States)

Cuba Torres, Christian Martin

On a global scale, the energy demand is largely supplied by the combustion of non-renewable fossil fuels. However, their rapid depletion coupled with environmental and sustainability concerns are the main drivers to seek for alternative energetic strategies. To this end, the sustainable generation of hydrogen from renewable resources such as biodiesel would represent an attractive alternative solution to fossil fuels. Furthermore, hydrogen's lower environmental impact and greater independence from foreign control make it a strong contender for solving this global problem. Among a wide variety of methods for hydrogen production, the catalytic partial oxidation offers numerous advantages for compact and mobile fuel processing systems. For this reaction, the present work explores the versatility of the Mo--O--C catalytic system under different synthesis methods and reforming conditions using methyl oleate as a surrogate biodiesel. MoO2 exhibits good catalytic activity and exhibits high coke-resistance even under reforming conditions where long-chain oxygenated compounds are prone to form coke. Moreover, the lattice oxygen present in MoO2 promotes the Mars-Van Krevelen mechanism. Also, it is introduced a novel beta-Mo2C synthesis by the in-situ formation method that does not utilize external H2 inputs. Herein, the MoO 2/Mo2C system maintains high catalytic activity for partial oxidation while the lattice oxygen serves as a carbon buffer for preventing coke formation. This unique feature allows for longer operation reforming times despite slightly lower catalytic activity compared to the catalysts prepared by the traditional temperature-programmed reaction method. Moreover, it is demonstrated by a pulse reaction technique that during the phase transformation of MoO2 to beta-Mo2C, the formation of Mo metal as an intermediate is not responsible for the sintering of the material wrongly assumed by the temperature-programmed method.

Controlled formation of MoSe{sub 2} by MoN{sub x} thin film as a diffusion barrier against Se during selenization annealing for CIGS solar cell

Energy Technology Data Exchange (ETDEWEB)

Jeon, Chan-Wook [School of Chemical Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of); Cheon, Taehoon [School of Materials Science and Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of); Center for Core Research Facilities, DaeguGyeongbuk Institute of Science & Technology, Daegu (Korea, Republic of); Kim, Hangil [School of Materials Science and Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of); Kwon, Min-Su [School of Chemical Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of); Kim, Soo-Hyun [School of Materials Science and Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of)

2015-09-25

Highlights: • Mo/MoN{sub x}/Mo multilayer was investigated as a back contact for CIGS solar cell. • The MoN{sub x} protected the underlying Mo layer during high temperature selenization. • The formation of MoSe{sub 2} layer was precisely controlled. • The diffusion barrier performance of MoN{sub x} against Se was evaluated using TEM analysis. - Abstract: This study investigated the interfacial reactions and electrical properties of a Mo single layer and Mo/MoN{sub x}/Mo multilayer during high temperature selenization annealing. The Mo single layer was converted easily to MoSe{sub 2}, which was 7 times thicker than the Mo layer consumed ∼900 nm, by selenization at 460 °C for 10 min and the sheet resistance increased 8 fold compared to that of the as-deposited Mo film. On the other hand, in the Mo/MoN{sub x}/Mo structure, transmission electron microscopy (TEM) showed that the MoSe{sub 2} transformation was localized only in the top Mo layer and the bottom Mo layer was completely unaffected, even after selenization at 560 °C. The sheet resistance of the multilayer was relatively unchanged by selenization. This suggests that the MoN{sub x} layer performed well as a diffusion barrier against Se and the thickness of MoSe{sub 2} can be controlled precisely by adjusting the top Mo layer thickness. Furthermore, TEM and energy dispersive spectroscopy analysis showed that the selenized multilayer consisted of MoSe{sub 2}/Mo/MoN{sub x}/Mo, in which the top Mo layer of 60 nm was not fully converted to MoSe{sub 2} and 20 nm was left unreacted. The residual Mo interlayer located at the interface of MoSe{sub 2} and MoN{sub x} is believed to be beneficial for the ohmic contact of the selenized multilayer.

An experimental study: Role of different ambient on sulfurization of MoO{sub 3} into MoS{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Kumar, Prabhat, E-mail: prabhat89k@gmail.com; Singh, Megha; Sharma, Rabindar K.; Reddy, G.B.

2016-06-25

Molybdenum disulfide (MoS{sub 2}) nanostructured thin films (NTFs) were synthesised by sulfurizing MoO{sub 3} NTFs using three different non-conventional methods (named methods 1–3). Method 1 uses sulfur vapors, second employs H{sub 2}S/Ar gas and third adopts plasma of H{sub 2}S/Ar gas. HRTEM revealed formation of core–shell nanostructures with maximum shell thickness obtained in method 3. The samples showed uniform nanoflakes (NFs) throughout substrate, revealed by SEM, same as their precursor MoO{sub 3.} XRD and Raman analysis disclosed crystalline MoS{sub 2} and degree of crystallinity was greatest in case of sulfurization in plasma ambient. Quantitative analysis of sulfurized films carried out by XPS shows presence of MoS{sub 2} in all three methods with percentage found to be 18%, 87% and ∼100% respectively. The effect of sulfurizing ambient on its efficiency to convert MoO{sub 3} into MoS{sub 2} has been studied and it was found out that plasma ambient has resulted in high quality of MoS{sub 2} NTFs based on parameters as crystallinity, purity, uniformity and stoichiometry control. - Highlights: • Comparison of three non-conventional methods of sulfurization. • Parameters used for comparison are crystallinity, purity, sulfurized thickness, uniformity and stoichiometry. • H{sub 2}S/Ar plasma based method came out to be best among other techniques. • A soft template reactions for sulfurization of MoO{sub 3} nanoflake is proposed.

MoEDAL: Passive but no less active

CERN Multimedia

MoEDAL Collaboration

2015-01-01

Relying almost completely on passive detectors, MoEDAL is a pioneering experiment designed to search for highly ionising avatars of new physics, such as magnetic monopoles or massive (pseudo-)stable charged particles. The first test detectors were deployed at LHC Point 8 in 2012 and analysed in 2013, and the full MoEDAL detector was installed in the winter of 2014 to start data-taking during Run 2 this year.   The image shows the MoEDAL detector systems installed at Point 8 of the LHC. MoEDAL’s groundbreaking physics programme defines over 30 scenarios that yield potentially revolutionary insights into such fundamental questions as: are there extra dimensions or new symmetries? Does magnetic charge exist? What is the nature of dark matter? And how did the big bang develop? MoEDAL's purpose is to meet such far-reaching challenges at the frontier of the field. Having reached its final configuration in winter 2014, MoEDAL now consists of ten layers of plastic attached to the ...

Applicability of Sol-Gel Derived Adsorbent for the Production of (n,f) 99Mo Generator

International Nuclear Information System (INIS)

Lee, Jun-Sig; Lee, Jong-Sup; Park, Ul-Jae; Son, Kwang-Jae; Han, Hyon-Soo; Kim, Myung Sic; Koo, Sung Chan; Chung, Young-Ju

2007-01-01

High performance adsorbents as the column material for (n,γ) 99 Mo/ 99 mTc and 188 W/ 188 Re generators have been developed at KAERI. These adsorbents should have enough loading capacities to produce such generators with high activities as the loading isotopes are not carrier-free. In this regard, the adsorbents are synthesized by sol-gel processing in which the ligand density can easily be adjusted and maximized. The marginal capacity of such adsorbents should be higher than 200 mg/g for molybdenum. From the previous works, the sol-gel processing techniques are adequately applied to meet the criteria. Further studies are being undertaken to employ the adsorbents for the production of high capacity (n,f) 99 Mo/ 99 mTc. Domestically, a private company has lined up the production facility of the molybdenum generator in the activity range of 300 ∼ 1,000 mCi/ea. The column elements are composed of manganese oxide doped on silica and alumina at the backup layer. In this column, the manganese oxide is the main reactive layer to retain (n,f) 99 Mo. The sol-gel derived adsorbent, in this study, is employed as the replacement of the manganese oxide doped silica in the column and tested for the loading efficiency of (n,f) 99 Mo, elution of 99 mTc, labeling property of the eluted 99 mTc. The same loading and elution procedures as the commercial production are applied for the tests and quality controls

Phase equilibria of the Mo-Al-Ho ternary system

Energy Technology Data Exchange (ETDEWEB)

Li, Yitai; Chen, Xiaoxian; Liu, Hao [Guangxi Univ., Nanning (China). College of Materials Science and Engineering; Guangxi Univ., Nanning (China). Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials; Zhan, Yongzhong [Guangxi Univ., Nanning (China). College of Materials Science and Engineering; Guangxi Univ., Nanning (China). Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials; Guangxi Univ., Nanning (China). Center of Ecological Collaborative Innovation for Aluminum Industry

2017-08-15

Investigation into the reactions and phase equilibria of transition metal elements (i.e. Mo, Zr, Cr, V and Ti), Al and rare earths is academically and industrially important for the development of both refractory alloys and lightweight high-temperature materials. In this work, the equilibria of the Mo-Al-Ho ternary system at 773 K have been determined by using X-ray powder diffraction and scanning electron microscopy equipped with energy dispersive X-ray analysis. A new ternary phase Al{sub 4}Mo{sub 2}Ho has been found and the other ternary phase Al{sub 43}Mo{sub 4}Ho{sub 6} is observed. Ten binary phases in the Al-Mo and Al-Ho systems, including Al{sub 17}Mo{sub 4} rather than Al{sub 4}Mo, have been determined to exist at 773 K. The homogeneity ranges of AlMo{sub 3} and Al{sub 8}Mo{sub 3} phase are 7.5 at.% and 1 at.%, respectively. According to the phase-disappearing method, the maximum solubility of Al in Mo is about 16 at.%.

Faceted MoS2 nanotubes and nanoflowers

International Nuclear Information System (INIS)

Deepak, Francis Leonard; Mayoral, Alvaro; Yacaman, Miguel Jose

2009-01-01

A simple synthesis of novel faceted MoS 2 nanotubes (NTs) and nanoflowers (NFs) starting from molybdenum oxide and thiourea as the sulphur source is reported. The MoS 2 nanotubes with the faceted morphology have not been observed before. Further the as-synthesized MoS 2 nanotubes have high internal surface area. The nanostructures have been characterized by a variety of electron microscopy techniques. It is expected that these MoS 2 nanostrutures will find important applications in energy storage, catalysis and field emission.

Catalytic upgrading of oleic acid into biofuel using Mo modified zeolite supported Ni oxalate catalyst functionalized with fluoride ion

International Nuclear Information System (INIS)

Ayodele, O.B.; Abbas, Hazzim F.; Daud, Wan Mohd Ashri Wan

2014-01-01

Highlights: • Modification of zeolite with freshly prepared molybdenum oxalate. • Functionalization of Ni oxalate with HF and incorporation into Mo modified zeolite. • Characterization of synthesized Mo modified zeolite supported Ni oxalate catalyst. • Deoxygenation of oleic acid with the synthesized zeolite supported catalyst. • Reusability study on the synthesized zeolite supported catalyst. - Abstract: In this study, fluoride ion functionalized nickel oxalate supported on molybdenum modified zeolite (NiMoFOx/Zeol) catalyst was synthesized, characterized and tested on the hydrodeoxygenation (HDO) of oleic acid (OA) into paraffinic fuel. The NiMoFOx/Zeol characterization results confirmed the presence of both Ni and Mo as well as the formation of NiMoO 4 which is a highly HDO reactive specie at 2θ value of 43.6° according to the XRD result. NiMoFOx/Zeol also showed loss in crystallinity and reduction in the average particle size leading to increase in the pore volume and specific surface area due to the combined effects of fluoride ion presence, oxalic acid functionalization and calcination. The effect of temperature, pressure and NiMoFOx/Zeol loading studied showed that initial increase in their values increased the yield of the target fractions until some points where reduction was observed. The best observed experimental conditions to hydrodeoxygenate 40 g (∼45 mL) of OA into 75% n-C 18 and 23% i-C 18 were 360 °C, 30 mg NiMoFOx/Zeol loading and 20 bar using 100 mL H 2 /min. The presence of i-C 18 was due to the functionalization of the catalyst with fluoride ion. The catalyst reusability result displayed excellent qualities with marginal loss of only 2% in activity after third reuse due to the improved synthesis protocol that employed organometallic precursor. The results are strongly encouraging for further studies toward industrialization of HDO process

Development and utilization of the inorganic polymer materials for {sup 99}Mo-{sup 99m}Tc and {sup 188}W-{sup 188}Re generator based on (n, gamma) method

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Kosuke; Ishikawa, Koji; Terunuma, Hitoshi; Hasegawa, Yoshio; Tatenuma, Katsuyoshi [KAKEN Co., Mito, Ibaraki (Japan)

2003-03-01

A molybdenum (Mo) adsorbent called PZC (Poly Zirconium Compound) with high efficiency of Mo adsorption has been developed in order to generate {sup 99m}Tc from {sup 99}Mo produced from natural Mo by (n, gamma) method. The {sup 99m}Tc generator using PZC has cleared mostly the technical subjects. By the results of many experiments, cold and hot test with {sup 99}Mo activity from low level (10{sup 5} Bq) to high level (10{sup 10} Bq), it has been confirmed that the PZC method can be practically applied for the (n, gamma) {sup 99}Mo-{sup 99m}Tc generator. From the reasons that PZC has the ability and many merits such as high adsorption capacity (>250 mg-Mo/g-PZC) of Mo, high elution yield (av. 80%) of {sup 99m}Tc, the low breakthrough (<0.05 kBq-{sup 99m}Mo/MBq-{sup 99m}Tc) of {sup 99}Mo and others, the current (n, fission) {sup 99m}Tc generator utilizing {sup 99}Mo produced from enriched uranium will be taken the place by PZC method. In this paper, the practicability of PZC and a newly developed functional material PTC(Poly Titanium Compound) as the (n, gamma) {sup 99}Mo-{sup 99m}Tc generator, and an ability of PZC as the {sup 188}W-{sup 188}Re generator will be shown. (author)

Preparation, biodistribution, and dosimetry of 188Re-Labeled MoAb ior cea1 and its f(ab')2 fragments by avidin-biotin strategy

International Nuclear Information System (INIS)

Ferro-Flores, Guillermina; Pimentel-Gonzalez, Gilmara; Gonzalez-Zavala, Maria Antonia; Murphy, Consuelo Arteaga de; Melendez-Alafort, Laura; Tendilla, Jose I.; Croft, Barbara Y.

1999-01-01

The biotinylated monoclonal antibody (MoAb) ior cea1 and its F(ab') 2 fragments were labeled with Re-188 by combination of avidin-biotin strategy. 188 Re-MoAb, 188 Re-MoAb-biotin, 188 Re-F(ab') 2 , and 188 Re-F(ab') 2 -biotin preparations were produced for these studies with specific activities of 1.30±0.18 GBq/mg and from instant freeze-dried kit formulations using ethane-1-hydroxy-1,1-diphosphonic acid (EHDP) as a weak competing ligand. There were no significant differences (p>0.05) between the biodistribution in mice of biotinylated and unbiotinylated 188 Re-labeled immunoconjugates. When avidin was injected as a chase after injection of 188 Re-MoAb-biotin or 188 Re-F(ab') 2 -biotin, the blood radioactivity level decreased approximately 75% (cumulated activity) and the effective dose decreased almost 25% with respect to that of the radioimmunoconjugates in which the chase effect was not used. Our results suggest that 188 Re-labeled biotinylated MoAb ior cea1 and its F(ab') 2 fragments prepared by this method are stable complexes in vivo

Effect of Mo2C/(Mo2C + WC) weight ratio on the microstructure and mechanical properties of Ti(C,N)-based cermet tool materials

International Nuclear Information System (INIS)

Xu, Qingzhong; Zhao, Jun; Ai, Xing; Qin, Wenzhen; Wang, Dawei; Huang, Weimin

2015-01-01

To optimize the Mo 2 C content in Ti(C,N)-based cermet tool materials used for cutting the high-strength steel of 42CrMo (AISI 4140/4142 steel), the cermets with different Mo 2 C/(Mo 2 C + WC) weight ratios were prepared. And the microstructure and mechanical properties of cermets were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and measurements of transverse rupture strength (TRS), Vickers hardness (HV) and fracture toughness (K IC ). The results indicate that the Mo 2 C/(Mo 2 C + WC) ratios have great influences on the microstructure features and mechanical properties of Ti(C,N)-based cermets. When the Mo 2 C/(Mo 2 C + WC) ratio increases, the Ti(C,N) grains become finer with smaller black cores surrounded by thinner rims, and the structure of cermets tends to be more compact with smaller binder mean free path. Owing to the medium grains and moderate rims, the cermets with a Mo 2 C/(Mo 2 C + WC) ratio of 0.4 exhibit better mechanical properties, and can be chosen as the tool material for machining 42CrMo steel due to the lower Mo content. - Highlights: • Mo 2 C/(Mo 2 C + WC) ratios affect microstructure and mechanical properties of cermets. • Grains become fine and structure of cermets tends to be compact with raised Mo 2 C. • The cermets with a Mo 2 C/(Mo 2 C + WC) ratio of 0.4 can be used to machine 42CrMo steel

Oxygen permeability of transition metal-containing La(Sr,PrGa(MgO3-δ ceramic membranes

Directory of Open Access Journals (Sweden)

Frade, J. R.

2004-08-01

Full Text Available Acceptor-type doping of perovskite-type La1-xSrxGa0.80-yMgyM0.20O3-δ (x = 0-0.20, y = 0.15-0.20, M = Fe, Co, Ni leads to significant enhancement of ionic conductivity and oxygen permeability due to increasing oxygen vacancy concentration. The increase in strontium and magnesium content is accompanied, however, with increasing role of surface exchange kinetics as permeation-limiting factor. At temperatures below 1223 K, the oxygen permeation fluxes through La(SrGa(Mg,MO3-δ membranes with thickness less than 1.5 mm are predominantly limited by the exchange rates at membrane surface. The oxygen transport in transition metal-containing La(SrGa(MgO3-δ ceramics increase in the sequence Co El dopado aceptor de cerámicas tipo perovskita La1-xSrxGa0.80-yMgyM0.20O3-δ (x = 0-0.20, y = 0.15-0.20, M = Fe, Co, Ni da lugar a una mejora significativa de la conductividad iónica y de la permeabilidad al oxígeno debido al aumento de la concentración de vacantes de oxígeno. Sin embargo, el aumento de la cantidad de estroncio y magnesio viene acompañado de un aumento de la participación de las cinéticas de intercambio superficial como factor limitante de la permeabilidad. A temperaturas por debajo de 1223 K la permeabilidad al flujo de oxígeno a través de las membranas de La(SrGa(Mg,MO3-δ con espesor menor de 1.5 mm está limitado principalmente por las velocidades de intercambio en la superficie de la membrana. El transporte de oxígeno en las cerámicas La(SrGa(MgO3-δ que contienen M aumenta en la secuencia Co < Fe < Ni. La conductividad iónica en estas fases es, sin embargo, menor que en la de los compuestos La1-xSrxGa1-yMgyO3-δ. El mayor nivel de permeabilidad de oxígeno, comparable a la de las fases basadas en La(SrFe(CoO3 y La2NiO4, se observa para las membranas de La0.90Sr0.10Ga0.65Mg0.15Ni0.20O3-δ. Los coeficientes de dilatación térmica medios de las cerámicas La(SrGa(Mg,MO3-δ en aire son del orden de (11.6–18.4 × 10-6 K-1 a 373

Single-layer MoS2 electronics.

Science.gov (United States)

Lembke, Dominik; Bertolazzi, Simone; Kis, Andras

2015-01-20

CONSPECTUS: Atomic crystals of two-dimensional materials consisting of single sheets extracted from layered materials are gaining increasing attention. The most well-known material from this group is graphene, a single layer of graphite that can be extracted from the bulk material or grown on a suitable substrate. Its discovery has given rise to intense research effort culminating in the 2010 Nobel Prize in physics awarded to Andre Geim and Konstantin Novoselov. Graphene however represents only the proverbial tip of the iceberg, and increasing attention of researchers is now turning towards the veritable zoo of so-called "other 2D materials". They have properties complementary to graphene, which in its pristine form lacks a bandgap: MoS2, for example, is a semiconductor, while NbSe2 is a superconductor. They could hold the key to important practical applications and new scientific discoveries in the two-dimensional limit. This family of materials has been studied since the 1960s, but most of the research focused on their tribological applications: MoS2 is best known today as a high-performance dry lubricant for ultrahigh-vacuum applications and in car engines. The realization that single layers of MoS2 and related materials could also be used in functional electronic devices where they could offer advantages compared with silicon or graphene created a renewed interest in these materials. MoS2 is currently gaining the most attention because the material is easily available in the form of a mineral, molybdenite, but other 2D transition metal dichalcogenide (TMD) semiconductors are expected to have qualitatively similar properties. In this Account, we describe recent progress in the area of single-layer MoS2-based devices for electronic circuits. We will start with MoS2 transistors, which showed for the first time that devices based on MoS2 and related TMDs could have electrical properties on the same level as other, more established semiconducting materials. This

Interface morphology of Mo/Si multilayer systems with varying Mo layer thickness studied by EUV diffuse scattering.

Science.gov (United States)

Haase, Anton; Soltwisch, Victor; Braun, Stefan; Laubis, Christian; Scholze, Frank

2017-06-26

We investigate the influence of the Mo-layer thickness on the EUV reflectance of Mo/Si mirrors with a set of unpolished and interface-polished Mo/Si/C multilayer mirrors. The Mo-layer thickness is varied in the range from 1.7 nm to 3.05 nm. We use a novel combination of specular and diffuse intensity measurements to determine the interface roughness throughout the multilayer stack and do not rely on scanning probe measurements at the surface only. The combination of EUV and X-ray reflectivity measurements and near-normal incidence EUV diffuse scattering allows to reconstruct the Mo layer thicknesses and to determine the interface roughness power spectral density. The data analysis is conducted by applying a matrix method for the specular reflection and the distorted-wave Born approximation for diffuse scattering. We introduce the Markov-chain Monte Carlo method into the field in order to determine the respective confidence intervals for all reconstructed parameters. We unambiguously detect a threshold thickness for Mo in both sample sets where the specular reflectance goes through a local minimum correlated with a distinct increase in diffuse scatter. We attribute that to the known appearance of an amorphous-to-crystallization transition at a certain thickness threshold which is altered in our sample system by the polishing.

Synthesis and electrochemical properties of tin-doped MoS{sub 2} (Sn/MoS{sub 2}) composites for lithium ion battery applications

Energy Technology Data Exchange (ETDEWEB)

Lu, Lin; Min, Feixia; Luo, Zhaohui; Wang, Shiquan, E-mail: wsqhao@126.com [Hubei University, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules (China); Teng, Fei [Nanjing University of Information Science and Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Sciences and Engineering (China); Li, Guohua [Zhejiang University of Technology, School of Chemical Engineering and Materials Science (China); Feng, Chuanqi [Hubei University, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules (China)

2016-12-15

SnO{sub 2}-MoO{sub 3} composites were synthesized by using (NH{sub 4}){sub 6}Mo{sub 7}O{sub 24}·4H{sub 2}O and SnCl{sub 2}·2H{sub 2}O as raw materials through a simple solvothermal method followed by pyrolysis. Tin-doped MoS{sub 2} (Sn/MoS{sub 2}) flowers have been synthesized by a solvothermal method followed with annealing in Ar(H{sub 2}) atmosphere, with SnO{sub 2}-MoO{sub 3}, thioacetamide (TAA), and urea as starting materials. The doping and the content of Sn-doping play crucial roles in the morphology and electrochemical performance of the MoS{sub 2}. As anode materials for lithium ion battery (LIB), all Sn/MoS{sub 2} composites exhibit both higher reversible capacity and better cycling performance at current density of 200 mA g{sup −1}, compared with MoS{sub 2} without Sn doping. The achieved discharge capacity for Sn/MoS{sub 2} composites is above 1000 mAh g{sup −1} after 100 cycles with nearly 100% coulombic efficiency. The doping of metal Sn in MoS{sub 2} can improve the conductivity of MoS{sub 2} and significantly enhance its electrochemical properties. The good electrochemical performance suggests that the Sn/MoS{sub 2} composite could be a promising candidate as a novel anode material for LIB application. Our present work provides a new approach to the fabrication of anode materials for LIB applications.

K(MoO24O3(AsO4

Directory of Open Access Journals (Sweden)

Raja Jouini

2013-06-01

Full Text Available A new compound with a non-centrosymmetric structure, potassium tetrakis[dioxomolybdenum(IV] arsenate trioxide, K(MoO24O3(AsO4, has been synthesized by a solid-state reaction. The [(MoO24O3(AsO4]+ three-dimensional framework consists of single arsenate AsO4 tetrahedra, MoO6 octahedra, MoO5 bipyramids and bioctahedral units of edge-sharing Mo2O10 octahedra. The [Mo2O8]∞ octahedral chains running along the a-axis direction are connected through their corners to the AsO4 tetrahedra, MoO6 octahedra and MoO5 bipyramids, so as to form large tunnels propagating along the a axis in which the K+ cations are located. This structure is compared with compounds containing M2O10 (M = Mo, V, Fe dimers and with those containing M2O8 (M = V chains.

Structural, morphological, and optical characterizations of Mo, CrN and Mo:CrN sputtered coatings for potential solar selective applications

Science.gov (United States)

Ibrahim, Khalil; Mahbubur Rahman, M.; Taha, Hatem; Mohammadpour, Ehsan; Zhou, Zhifeng; Yin, Chun-Yang; Nikoloski, Aleksandar; Jiang, Zhong-Tao

2018-05-01

Mo, CrN, and Mo:CrN sputtered coatings synthesized onto silicon Si(100) substrates were investigated as solar selective surfaces and their potential applications in optical devices. These coatings were characterized using XRD, SEM, UV-vis, and FTIR techniques. XRD investigation, showed a change in CrN thin film crystallite characteristic due to Mo doping. Compared to the CrN coating, the Mo:CrN film has a higher lattice parameter and lower grain size of 4.19 nm and 106.18 nm, respectively. FESEM morphology confirmed the decrement in Mo:CrN crystal size due to Mo doping. Optical analysis showed that in the visible range of the solar spectrum, the CrN coatings exhibit the highest solar absorptance of 66% while the lowest thermal emittance value of 5.67 was recorded for the CrN coating doped with Mo. Consequently, the highest solar selectivity of 9.6, and the energy band-gap of 2.88 eV were achieved with the Mo-doped CrN coatings. Various optical coefficients such as optical absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constants, and energy loss functions of these coatings were also estimated from the optical reflectance data recorded in the wavelength range of 190-2300 nm.

Cyclic tensile response of Mo-27 at% Re and Mo-0.3 at% Si solid solution alloys

Energy Technology Data Exchange (ETDEWEB)

Yu, X.J.; Kumar, K.S., E-mail: Sharvan_Kumar@brown.edu

2016-10-31

Stress-controlled uniaxial cyclic tensile tests were conducted on binary Mo-27 at% Re and Mo-0.3 at% Si solid solutions as a function of temperature and compared against the previously reported cyclic response of pure Mo. The Mo-27 at% Re alloy with a recrystallized grain size of ~30 µm was evaluated in the temperature range 25 °C–800 °C at R=0.1 and stress range that was 80% of the ultimate tensile strength (UTS); a peak in fatigue life was observed between 300 °C and 500 °C. The decrease in fatigue life at the higher temperatures of 700 °C and 800 °C is attributed to dynamic strain aging. Transmission electron microscopy of the cyclically-deformed alloy revealed parallel bands of dislocation at room temperature that transitioned to a uniform cell structure at 500 °C and back to orthogonal planar arrays at 800 °C. The as-extruded Mo-0.3 at% Si alloy was evaluated from 25 °C to 1200 °C and showed superior fatigue life and ratcheting strain resistance as compared to pure Mo and the Mo-27 at% Re alloy (within the temperature range where data were available for comparison). The superior resistance is attributed to the high density of dislocations within the material in this mostly unrecrystallized state rather than Si in solid solution. Above 800 °C, the ratcheting strain increases and fatigue life decreases rapidly with increasing temperature and is associated with dynamic recovery.

Plasma-assisted synthesis of MoS2

Science.gov (United States)

Campbell, Philip M.; Perini, Christopher J.; Chiu, Johannes; Gupta, Atul; Ray, Hunter S.; Chen, Hang; Wenzel, Kevin; Snyder, Eric; Wagner, Brent K.; Ready, Jud; Vogel, Eric M.

2018-03-01

There has been significant interest in transition metal dichalcogenides (TMDs), including MoS2, in recent years due to their potential application in novel electronic and optical devices. While synthesis methods have been developed for large-area films of MoS2, many of these techniques require synthesis temperatures of 800 °C or higher. As a result of the thermal budget, direct synthesis requiring high temperatures is incompatible with many integrated circuit processes as well as flexible substrates. This work explores several methods of plasma-assisted synthesis of MoS2 as a way to lower the synthesis temperature. The first approach used is conversion of a naturally oxidized molybdenum thin film to MoS2 using H2S plasma. Conversion is demonstrated at temperatures as low as 400 °C, and the conversion is enabled by hydrogen radicals which reduce the oxidized molybdenum films. The second method is a vapor phase reaction incorporating thermally evaporated MoO3 exposed to a direct H2S plasma, similar to chemical vapor deposition (CVD) synthesis of MoS2. Synthesis at 400 °C results in formation of super-stoichiometric MoS2 in a beam-interrupted growth process. A final growth method relies on a cyclical process in which a small amount of Mo is sputtered onto the substrate and is subsequently sulfurized in a H2S plasma. Similar results could be realized using an atomic layer deposition (ALD) process to deposit the Mo film. Compared to high temperature synthesis methods, the lower temperature samples are lower quality, potentially due to poor crystallinity or higher defect density in the films. Temperature-dependent conductivity measurements are consistent with hopping conduction in the plasma-assisted synthetic MoS2, suggesting a high degree of disorder in the low-temperature films. Optimization of the plasma-assisted synthesis process for slower growth rate and better stoichiometry is expected to lead to high quality films at low growth temperature.

On the Mo-Papas equation

Science.gov (United States)

Aguirregabiria, J. M.; Chamorro, A.; Valle, M. A.

1982-05-01

A new heuristic derivation of the Mo-Papas equation for charged particles is given. It is shown that this equation cannot be derived for a point particle by closely following Dirac's classical treatment of the problem. The Mo-Papas theory and the Bonnor-Rowe-Marx variable mass dynamics are not compatible.

XPS study of organic/MoO3 hybrid thin films for aldehyde gas sensors. Correlation between average Mo valance and sensitivity

International Nuclear Information System (INIS)

Itoh, Toshio; Matsubara, Ichiro; Shin, Woosuck; Izu, Noriya; Nishibori, Maiko

2010-01-01

We investigate the formaldehyde gas sensing properties of poly(5,6,7,8-tetrahydro-1-naphthylamine)-intercalated MoO 3 thin films ((PTHNA) x MoO 3 ). The resistance responses of (PTHNA) x MoO 3 to formaldehyde increase with increasing intercalation temperature. X-ray photoelectron spectroscopy reveals that the molar ratio of Mo 5+ decreases with increasing intercalation temperature. (author)

O aktualnim paradigmama javnog prava kao katalizatorima odnosa ustavnog i upravnog prava

OpenAIRE

Bačić, Arsen; Bačić, Petar

2017-01-01

U tekstu se prikazuju neke nove paradigme koje najizravnije ukazuju na organsku i vitalnu vezu ustavnog i upravnog prava unutar kompleksa javnog prava. Stajalište autora je da primjeri ''vladavine'' (governance), ''administrativnog konstitucionalizma'' (administrative constitutionalism), zatim ''libertarijanskog administrativnog prava'' (libertarian administrative law)... demonstriraju dinamični proces artikulacije suvremenog javnog prava i njegove adaptacije političkom procesu suvremene drža...

Physical properties of monolithic U8 wt.%-Mo

Science.gov (United States)

Hengstler, R. M.; Beck, L.; Breitkreutz, H.; Jarousse, C.; Jungwirth, R.; Petry, W.; Schmid, W.; Schneider, J.; Wieschalla, N.

2010-07-01

As a possible high density fuel for research reactors, monolithic U8 wt.%-Mo ("U8Mo") was examined with regard to its structural, thermal and electric properties. X-ray diffraction by the Bragg-Brentano method was used to reveal the tetragonal lattice structure of rolled U8Mo. The specific heat capacity of cast U8Mo was determined by differential scanning calorimetry, its thermal diffusivity was measured by the laser flash method and its mass density by Archimedes' principle. From these results, the thermal conductivity of U8Mo in the temperature range from 40 °C to 250 °C was calculated; in the measured temperature range, it is in good accordance with literature data for UMo with 8 and 9 wt.% Mo, is higher than for 10 wt.% Mo and lower than for 5 wt.% Mo. The electric conductivity of rolled and cast U8Mo was measured by a four-wire method and the electron based part of the thermal conductivity calculated by the Wiedemann-Frantz law. Rolled and cast U8Mo was irradiated at about 150 °C with 80 MeV 127I ions to receive the same iodine ion density in the damage peak region as the fission product density in the fuel of a typical high flux reactor after the targeted nuclear burn-up. XRD analysis of irradiated U8Mo showed a change of the lattice parameters as well as the creation of UO 2 in the superficial sample regions; however, a phase change by irradiation was not observed. The determination of the electron based part of the thermal conductivity of the irradiated samples failed due to high measurement errors which are caused by the low thickness of the damage region in the ion irradiated samples.

An alternative route for the preparation of the medical isotope 99Mo from the 238U(γ, f) and 100Mo(γ, n) reactions

International Nuclear Information System (INIS)

Naik, H.; Goswami, A.; Suryanarayana, S.V.; Jagadeesan, K.C.; Thakare, S.V.; Joshi, P.V.; Nimje, V.T.; Mittal, K.C.; Venugopal, V.; Kailas, S.

2013-01-01

The radionuclide 99 Mo, which has a half-life of 65.94 h was produced from 238 U(γ, f) and 100 Mo(γ, n) reactions using a 10 MeV electron linac at EBC, Kharghar Navi-Mumbai, India. This has been investigated since the daughter product 99m Tc is very important from a medical point of view and can be produced in a generator from the parent 99 Mo. The activity of 99 Mo was analyzed by a γ-ray spectrometric technique using a HPGe detector. From the detected γ-rays activity of 140.5 and 739.8 keV, the amount of 99 Mo produced was determined. For comparison, the amount of 99 Mo from 238 U(γ, f) and 100 Mo(γ, n) reactions was also estimated using the experimental photon flux from 197 Au(γ, n) 196 Au reaction. The amount of 99 Mo from the detected γ-lines is in agreement with the estimated value for 238 U(γ, f) and 100 Mo(γ, n) reactions. The production of 99 Mo activity from 238 U(γ, f) and 100 Mo(γ, n) reactions is a relevant and novel approach, which provides alternative routes to 235,238 U(n, f) and 98 Mo(n, γ) reactions, circumventing the need for a reactor. The viability and practicality of the 99 Mo production from the 238 U(γ, f) and 100 Mo(γ, n) reactions alternative to 235,238 U(n, f) and 98 Mo(n, γ) reactions has been emphasize. An estimate has been also arrived based on the experimental data of present work to fulfill the requirement of DOE. (author)

Structural transformation of MoO3 nanobelts into MoS2 nanotubes

International Nuclear Information System (INIS)

Deepak, Francis Leonard; Mayoral, Alvaro; Yacaman, Miguel Jose

2009-01-01

The structural transformation of MoO 3 nanobelts into MoS 2 nanotubes using a simple sulfur source has been reported. This transformation has been extensively investigated using electron microscopic and spectroscopic techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), and energy-dispersive X-ray analysis (SEM-EDAX and TEM-EDX). The method described in this report will serve as a generic route for the transformation of other oxide nanostructures into the chalcogenide nanostructures. (orig.)

A first principle Comparative study of electronic and optical properties of 1H –MoS2 and 2H –MoS2

International Nuclear Information System (INIS)

Kumar, Ashok; Ahluwalia, P.K.

2012-01-01

First principle calculations of electronic and optical properties of monolayer MoS 2 , so called 1H –MoS 2 , is performed which has emerged as a new direct band gap semiconductor. Before calculations of the properties of 1H –MoS 2 , we have calculated structural parameters, electronic properties (electronic band structure and electronic density of states) and frequency dependent optical response (real and imaginary part of dielectric function, energy loss function, absorption and reflectance spectra) of 2H –MoS 2 and compared with existing experimental results and found that our calculated results are in very good agreements with experimental results. To compare the dielectric functions of bulk (2H –MoS 2 ) and monolayer (1H –MoS 2 ) phases we have further extended these calculations to the single layer MoS 2 (1H –MoS 2 ) which is analogous to graphene. Structural parameters of 1H –MoS 2 are found very close to its bulk 2H –MoS 2 . We find direct electronic band gap at ‘K’ high symmetry point as compared to indirect band gap in its bulk 2H – MoS2. Our calculated dielectric function for 1H – MoS2 shows structure at nearly same energy positions as compared to 2H – MoS2 with additional structure at 3.8 eV. Also additional well defined energy loss peaks revealing the plasmonic resonances at 15.7 eV and 16.0 eV for E vector perpendicular and parallel to c axis respectively for 1H – MoS2 have been found, which are the signatures of surface plasmons at these energies. -- Highlights: ► Structural parameters of 2H-MoS2 and 1H-MoS2 are nearly identical. ► States around the Fermi energy are mainly due to the metal d states. ► Strong hybridization between Mo-d and S-p states below the Fermi energy has been found. ► Optical spectra of 2H-MoS2 finds very good agreements with experimental optical spectra. ► The band gap is found to be direct for 1H-MoS2 as compared to indirect for 2H-MoS2.

Phase transformations in Mo-doped FINEMETs

Energy Technology Data Exchange (ETDEWEB)

Silveyra, Josefina M., E-mail: jsilveyra@fi.uba.a [Lab. de Solidos Amorfos, INTECIN, FIUBA-CONICET, Paseo Colon 850, (C1063ACV) Buenos Aires (Argentina); Illekova, Emilia; Svec, Peter; Janickovic, Dusan [Institute of Physics SAS, Dubravska cesta 9, 845 11 Bratislava (Slovakia); Rosales-Rivera, Andres [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales (Colombia); Cremaschi, Victoria J. [Lab. de Solidos Amorfos, INTECIN, FIUBA-CONICET, Paseo Colon 850, (C1063ACV) Buenos Aires (Argentina)

2010-06-15

In this paper, the phase transformations occurring during the crystallization process of FINEMETs in which Nb has been gradually replaced by Mo have been studied by a variety of techniques including DSC, DTA, TGA, XRD and TEM. The thermal stability of the alloy was deteriorated as a consequence of Mo's smaller atomic size. The gradual replacement of Nb by Mo reduced the onset temperature of Fe-Si and of the borides. The Curie temperature of the amorphous phase slightly decreased from 594 K for x=0 to 587 K for x=3. The borides compounds Fe{sub 2}B and Fe{sub 23}B{sub 6} as well as the (Nb,Mo){sub 5}Si{sub 3} phase were found to precipitate in the second and third crystallization.

Ligand bridging-angle-driven assembly of molecular architectures based on quadruply bonded Mo-Mo dimers.

Science.gov (United States)

Li, Jian-Rong; Yakovenko, Andrey A; Lu, Weigang; Timmons, Daren J; Zhuang, Wenjuan; Yuan, Daqiang; Zhou, Hong-Cai

2010-12-15

A systematic exploration of the assembly of Mo2(O2C-)4-based metal-organic molecular architectures structurally controlled by the bridging angles of rigid organic linkers has been performed. Twelve bridging dicarboxylate ligands were designed to be of different sizes with bridging angles of 0, 60, 90, and 120° while incorporating a variety of nonbridging functional groups, and these ligands were used as linkers. These dicarboxylate linkers assemble with quadruply bonded Mo-Mo clusters acting as nodes to give 13 molecular architectures, termed metal-organic polygons/polyhedra with metal cluster node arrangements of a linear shape, triangle, octahedron, and cuboctahedron/anti-cuboctahedron. The syntheses of these complexes have been optimized and their structures determined by single-crystal X-ray diffraction. The results have shown that the shape and size of the resulting molecular architecture can be controlled by tuning the bridging angle and size of the linker, respectively. Functionalization of the linker can adjust the solubility of the ensuing molecular assembly but has little or no effect on the geometry of the product. Preliminary gas adsorption, spectroscopic, and electrochemical properties of selected members were also studied. The present work is trying to enrich metal-containing supramolecular chemistry through the inclusion of well-characterized quadruply bonded Mo-Mo units into the structures, which can widen the prospect of additional electronic functionality, thereby leading to novel properties.

Tetracarbonylbis(η5-cyclopentadienylbis(diphenylphosphinedimolybdenum(Mo—Mo hexane solvate

Directory of Open Access Journals (Sweden)

David R. Tyler

2008-07-01

Full Text Available The title compound, [Mo2(C5H52(C12H11P2(CO4]·C6H14, is a centrosymmetric Mo complex in which two Mo atoms are connected by an Mo—Mo bond [3.2072 (12 Å]. Each Mo atom is coordinated by an η5-cyclopentadienyl ligand, two carbonyl ligands and a diphenylphosphine ligand in a piano-stool fashion.

Room-temperature superparamagnetism due to giant magnetic anisotropy in Mo S defected single-layer MoS2

Science.gov (United States)

Khan, M. A.; Leuenberger, Michael N.

2018-04-01

Room-temperature superparamagnetism due to a large magnetic anisotropy energy (MAE) of a single atom magnet has always been a prerequisite for nanoscale magnetic devices. Realization of two dimensional (2D) materials such as single-layer (SL) MoS2, has provided new platforms for exploring magnetic effects, which is important for both fundamental research and for industrial applications. Here, we use density functional theory (DFT) to show that the antisite defect (Mo S ) in SL MoS2 is magnetic in nature with a magnetic moment μ of  ∼2 μB and, remarkably, exhibits an exceptionally large atomic scale MAE =\\varepsilon\\parallel-\\varepsilon\\perp of  ∼500 meV. Our calculations reveal that this giant anisotropy is the joint effect of strong crystal field and significant spin–orbit coupling (SOC). In addition, the magnetic moment μ can be tuned between 1 μB and 3 μB by varying the Fermi energy \\varepsilonF , which can be achieved either by changing the gate voltage or by chemical doping. We also show that MAE can be raised to  ∼1 eV with n-type doping of the MoS2:Mo S sample. Our systematic investigations deepen our understanding of spin-related phenomena in SL MoS2 and could provide a route to nanoscale spintronic devices.

Structural relaxation and colour in the spinel-magnesiochromite (MgAl2O4-MgCr2O4) and gahnite-zincochromite (ZnAl2O4-ZnCr2O4) solid solution series

Science.gov (United States)

Hålenius, U.; Andreozzi, G. B.; Skogby, H.

2009-04-01

.5 %, respectively, is determined. Based on a Cr-O bond distance for the CrO6 polyhedron in magnesiochromite and zincochromite of 1.995 and 1.991 Å respectively (O'Neill and Dollase, 1994) and applying the ligand field relationship 10Dq?C×R-5 (R equals the M-O distance of the MO6-polyhedron), Cr-O bond distances in gahnite and spinel with Cr-contents at trace levels are determined to 1.959 and 1.969 Å, respectively. These M-O bond distances are considerably longer than the M-O distances determined for end member gahnite and spinel by XRD-methods (1.9137 and 1.9280 Å, respectively; O'Neill and Dollase, 1994) and shows that there is considerable structural relaxation of M-O bonds in the two present spinel series. The relaxation parameter, ɛ, determined from the optical absorption spectra is 0.59 and 0.63 for the ZnAl2-2xCr2xO4 and MgAl2-2xCr2xO4 and series, respectively. These values are lower than those suggested from X-ray absorption spectroscopy (Juhin et al. 2007), which may be explained by second nearest neighbour interactions. In contrast to what may be expected, the interelectronic repulsion parameter, B, for V ICr3+ decreases with increasing Cr-content and apparent Cr-O bond length in both of the present spinel series . This indicates that interactions between Cr-atoms in neighbouring octahedra become important at increasing Cr-content and result in more covalent Cr-O bonds. This in turn suppresses the energy of 4A2g -4T2g (4F) transition (and calculated 10Dq-values) in octahedrally coordinated Cr3+. Consequently, the values of structural relaxation parameters determined from the optical absorption spectra must be regarded as minimum numbers. Literature Juhin, A., Calas, G., Cabaret, D. and Galoisy, L. (2007): Structural relaxation around Cr3+ in MgAl2O4. Physical Review, B76, 054105. O'Neill, H.St.C. and Dollase, W.A. (1994): Crystal structures and cation distributions in simple spinels from powder XRD structure refinements: MgCr2O4, ZnCr2O4, Fe3O4 and the temperature

Diversification of 99Mo/99mTc separation: non–fission reactor production of 99Mo as a strategy for enhancing 99mTc availability.

Science.gov (United States)

Pillai, Maroor R A; Dash, Ashutosh; Knapp, Furn F Russ

2015-01-01

This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo by decay and avoids proliferation as well as waste management issues associated with fission-produced (99)Mo.

PREPARATION AND CATALYTIC ACTIVITY FOR ISOPROPYL BENZENE CRACKING OF Co, Mo AND Co/Mo-Al2O3-PILLARED MONTMORILLONITE CATALYSTS

Directory of Open Access Journals (Sweden)

Hasanudin Hasanudin

2010-06-01

Full Text Available It has been prepared Co, Mo and Co/Mo-Al2O3-pillared montmorillonite catalysts using montmorillonite clay  as raw material. The structure and porosity of the catalysts were determined using N2 adsorption-desorption and FT-IR spectroscopy analysis methods. Isopropyl benzene cracking using these catalysts were used to test the catalytic activity and performance of Co, Mo and Co/Mo-Al2O3-pillared montmorillonites.  Characterization results showed that pillarization resulted in the increase of the total pore volume and specific surface area of the clay. Meanwhile, transition metals (Co, Mo and Co/Mo loaded on Al2O3-pillared monmorillonites could increase the catalytic activity of the catalysts for isopropyl benzene cracking significantly.   Keywords: pillared monmorillonite, isopropyl benzene  and cracking catalyst

Double molybdates in Li2MoO4 - Na2MoO4 - H2O system at 25 grad C

International Nuclear Information System (INIS)

Karov, Z.G.; Mirzoev, R.S.; Makitova, D.D.; Zhilova, S.B.; Podnek, A.G.; Urusova, R.Kh.

1989-01-01

Solubility in Li 2 MoO 4 - Na 2 MoO 4 - H 2 O system at 25 deg C is first stuied. Formation of two Li 2 MoO 4 · Na 2 MoO 4 · 4H 2 O and Li 2 MoO 4 · 3Na 2 MoO 4 · 12H 2 O compounds in a system is ascertained. Density, refractive index, viscosity, surface tension, electric conductivity and pH of saturated solutions are determined. Isothermes of mole volume, equivalent and reduced electric conductivity and seeming mole volume of salts sum in solutions are calculated. All these properties adequtely confirm the character of components interaction in a system determined by solubility method. Crystallhydrates of binary molybdates are separated, indentified and studied

Effects of Mo on microstructure of as-cast 28 wt.% Cr–2.6 wt.% C–(0–10) wt.% Mo irons

Energy Technology Data Exchange (ETDEWEB)

Imurai, S. [Department of Physics and Materials Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thanachayanont, C.; Pearce, J.T.H. [National Metal and Materials Technology Center, Pathumthani 12120 (Thailand); Tsuda, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Chairuangsri, T., E-mail: tchairuangsri@gmail.com [Department of Industrial Chemistry, Chiang Mai University, Chiang Mai 50200 (Thailand)

2014-04-01

Microstructures of as-cast 28 wt.% Cr–2.6 wt.% C irons containing (0–10) wt.% Mo with the Cr/C ratio of about 10 were studied and related to hardness. The experimental irons were cast into dry sand molds. Microstructural investigation was performed by light microscopy, X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectrometry. It was found that the iron with about 10 wt.% Mo was eutectic/peritectic, whereas the others with less Mo content were hypoeutectic. The matrix in all irons was austenite, partly transformed to martensite during cooling. Mo addition promoted the formation of M{sub 23}C{sub 6} and M{sub 6}C. At 1 wt.% Mo, multiple eutectic carbides including M{sub 7}C{sub 3}, M{sub 23}C{sub 6} and M{sub 6}C were observed. M{sub 23}C{sub 6} existed as a transition zone between eutectic M{sub 7}C{sub 3} and M{sub 6}C, indicating a carbide transition as M{sub 7}C{sub 3}(M{sub 2.3}C) → M{sub 23}C{sub 6}(M{sub 3.8}C) → M{sub 6}C. At 6 wt.% Mo, multiple eutectic carbides including M{sub 7}C{sub 3} and M{sub 23}C{sub 6} were observed together with fine cellular/lamellar M{sub 6}C aggregates. In the iron with 10 wt.% Mo, only eutectic/peritectic M{sub 23}C{sub 6} and M{sub 6}C were found without M{sub 7}C{sub 3}. Mo distribution to all carbides has been determined to be increased from ca. 0.4 to 0.7 in mass fraction as the Mo content in the irons was increased. On the other hand, Cr distribution to all carbides is quite constant as ca. 0.6 in mass fraction. Mo addition increased Vickers macro-hardness of the irons from 495 up to 674 HV{sub 30}. High Mo content as solid-solution in the matrix and the formation of M{sub 6}C or M{sub 23}C{sub 6} aggregates were the main reasons for hardness increase, indicating potentially improved wear performance of the irons with Mo addition. - Highlights: • Mo promoted the formation of M{sub 23}C{sub 6} and M{sub 6}C in the irons with Cr/C ratio of about 10

Irradiation performance of U-Mo-Ti and U-Mo-Zr dispersion fuels in Al-Si matrixes

Energy Technology Data Exchange (ETDEWEB)

Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Hofman, G.L. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Robinson, A.B.; Wachs, D.M. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Ryu, H.J.; Park, J.M.; Yang, J.H. [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

2012-08-15

Performance of U-7 wt.%Mo with 1 wt.%Ti, 1 wt.%Zr or 2 wt.%Zr, dispersed in an Al-5 wt.%Si alloy matrix, was investigated through irradiation tests in the ATR at INL and HANARO at KAERI. Post-irradiation metallographic features show that the addition of Ti or Zr suppresses interaction layer growth between the U-Mo and the Al-5 wt.%Si matrix. However, higher fission gas swelling was observed in the fuel with Zr addition, while no discernable effect was found in the fuel with Ti addition as compared to U-Mo without the addition. Known to have a destabilizing effect on the {gamma}-phase U-Mo, Zr, either as alloy addition or fission product, is ascribed for the disadvantageous result. Considering its benign effect on fuel swelling, with slight disadvantage from neutron economy point of view, Ti may be a better choice for this purpose.

Influence of Mo/MoSe{sub 2} microstructure on the damp heat stability of the Cu(In,Ga)Se{sub 2} back contact molybdenum

Energy Technology Data Exchange (ETDEWEB)

Theelen, Mirjam, E-mail: mirjam.theelen@tno.nl [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Delft University of Technology, Photovoltaic Materials and Devices, Mekelweg 4, 2628 CD Delft (Netherlands); Harel, Sylvie [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Verschuren, Melvin [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Tomassini, Mathieu [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Hovestad, Arjan [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Barreau, Nicolas [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Berkum, Jurgen van [Philips Innovation Services, High Tech Campus 11, 5656 AE Eindhoven (Netherlands); Vroon, Zeger [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Zeman, Miro [Delft University of Technology, Photovoltaic Materials and Devices, Mekelweg 4, 2628 CD Delft (Netherlands)

2016-08-01

The degradation behavior of Mo/MoSe{sub 2} layers have been investigated using damp heat exposure. The two studied molybdenum based films with different densities and microstructures were obtained by lifting off Cu(In,Ga)Se{sub 2} layers from a bilayer molybdenum stack on soda lime glass. Hereby, a glass/Mo/MoSe{sub 2} was obtained, which resembles the back contact as present in Cu(In,Ga)Se{sub 2} solar cells. The samples were degraded for 150 h under standard damp heat conditions and analyzed before, during and after degradation. It was observed that the degradation resulted in the formation of needles and molybdenum oxide layers near the glass/Mo and the Mo/Cu(In,Ga)Se{sub 2} interfaces. X-ray Photoelectron Spectroscopy measurements have shown that the sodium was also present at the surface of the degraded material and it is proposed that the degraded material consists mostly of MoO{sub 3} with intercalated Na{sup +}. This element has likely migrated from the soda lime glass. This intercalation process could have led to the formation of Na{sub x}MoO{sub 3} ‘molybdenum bronze’ following this redox reaction: xNa{sup +} + MoO{sub 3} + xe{sup −} ↔ Na{sub x}MoO{sub 3} It is proposed that the formed oxide layer contains Na{sub x}MoO{sub 3} with different Na{sup +} contents and different grades of conductivity. This intercalation process can also explain the high mobility of Na{sup +} via the grain boundaries in molybdenum. It was also observed that the molybdenum film with a top layer deposited at a high pressure is more susceptible for damp heat degradation. - Highlights: • SLG/high pressure Mo/low pressure Mo/MoSe{sub 2} stacks were exposed to damp heat. • Molybdenum deposited at low pressure retained the best reflectivity and conductivity. • Damp heat exposure leads to a Na{sub x}MoO{sub 3}/Mo multilayer structure. • The Na{sub x}MoO{sub 3} probably consists of Na{sup +} intercalated in a (reduced) MoO{sub 3} matrix. • Intercalation can explain the

Photochemical studies of alkylammonium molybdates. Part 12. O→Mo charge-transfer triplet-states-initiated self-assembly to {Mo154} ring- and tube-molybdenum-blues

Science.gov (United States)

Yamase, T.; Prokop, P.; Arai, Y.

2003-08-01

The chemically induced dynamic electron-spin-polarization technique is employed in order to investigate the primary steps of the photoredox reaction between polyoxomolybdates and alkylammonium cations as both proton and electron-donors in solutions. An observation of emissive electron-spin-polarization signals of alkylamino radical cations for the photoredox reaction between polyoxomolybdates and alkylammonium cations in solutions reveals that the O→Mo ligand-to-metal charge-transfer triplet states are involved in the transfers of both proton and electron from alkylammonium cation to polyoxomolybdate anions. Prolonged photolysis of aqueous solutions containing [Mo36O112(H2O)16]8-, [iPrNH3]+, and LaCl3 at pH 1.0 leads to formation of two kinds of {Mo154} molybdenum-blues, [Mo28VMo126VIO462H28(H2O)70]·156.5H2O (1) and [iPrNH3]8 [Mo28VMo126VIO458H12(H2O)66]·127H2O (2), which were X-ray crystallographically characterized. The former exhibits the intact car-tire-shaped {Mo154} ring structure (with thickness of about 1.1 nm and with outer- and inner-rings of approximately 3.5- and 2.3-nm diameters, respectively) derived formally from the dehydrated cyclic heptamerization of four-electron reduced building blocks of {Mo22} (≡[Mo4VMo18VIO70H12(H2O)10]) with overall symmetry of D7d. The anion for the latter, [Mo28VMo126VIO458H12(H2O)66]8- (2a), exhibits a nanotube structure of {Mo154} rings, each inner ring of which contains a bis(μ-oxo)-linkaged [MoO2(μ-O)(μ-H2O)MoO2]2+ unit replacing one of seven [Mo(H2O)O2(μ-O)Mo(H2O)O2]2+linker units. The neighboring {Mo154} rings are connected by six Mo-O-Mo bridge between inner-rings consisting of 7 head- and 14 linkers-MoO6 octahedra for each.

Mo isotope fractionation during hydrothermal evolution of porphyry Cu systems

Science.gov (United States)

Shafiei, Behnam; Shamanian, GholamHossein; Mathur, Ryan; Mirnejad, Hassan

2015-03-01

We present Mo isotope compositions of molybdenite types from three successive stages of ore deposition in several porphyry copper deposits of the Kerman region, Iran. The data provide new insights into controlling processes on Mo isotope fractionation during the hydrothermal evolution of porphyry systems. The Mo isotope compositions of 27 molybdenite samples show wide variations in δ97Mo ranging from -0.37 to +0.92 ‰. The data reveal that molybdenites in the early and transitional stages of mineralization (preferentially 2H polytypes; δ97Mo mean = 0.35 ‰) have higher δ97Mo values than late stage (mainly 3R polytypes; δ97Mo mean = 0.02 ‰) molybdenites. This trend suggests that fractionation of Mo isotopes occurred in high-temperature stages of mineralization and that hydrothermal systems generally evolve towards precipitation of molybdenite with lower δ97Mo values. Taking into account the genetic models proposed for porphyry Cu deposits along with the temperature-dependent fractionation of Mo isotope ratios, it is proposed that large variations of Mo isotopes in the early and the transitional stages of ore deposition could be controlled by the separation of the immiscible ore-forming fluid phases with different density, pH, and ƒO2 properties (i.e., brine and vapor). The fractionation of Mo isotopes during fluid boiling and Rayleigh distillation processes likely dominates the Mo isotope budget of the remaining ore-forming fluids for the late stage of mineralization. The lower δ97Mo values in the late stage of mineralization can be explained by depletion of the late ore-forming hydrothermal solutions in 97Mo, as these fluids have moved to considerable distance from the source. Finally, the relationship observed between MoS2 polytypes (2H and 3R) and their Mo isotopic compositions can be explained by the molecular vibration theory, in which heavier isotopes are preferentially partitioned into denser primary 2H MoS2 crystals.

Coke formation during the hydrotreatment of bio-oil using NiMo and CoMo catalysts

NARCIS (Netherlands)

Kadarwati, Sri; Hu, Xun; Gunawan, Richard; Westerhof, Roel; Gholizadeh, Mortaza; Hasan, M. D.Mahmudul; Li, Chun-Zhu

2017-01-01

This study aims to investigate the coke formation during the hydrotreatment of bio-oil at low temperature. The catalytic hydrotreatment of bio-oil produced from the pyrolysis of mallee wood was carried out using pre-sulphided NiMo and CoMo catalysts at a temperature range of 150–300 °C. Our results

Ion-induced secondary electron emission, optical and hydration resistant behavior of MgO, Mg–Mo–O and Mg–Ce–O thin films

International Nuclear Information System (INIS)

Kumar, Ashok; Thota, Subhash; Deva, Dinesh; Kumar, Jitendra

2014-01-01

Optical transmittance, hydration resistance and secondary electron emission characteristics of e-beam evaporated pure and Mo- or Ce-containing MgO thin films have been investigated. While the increased grain size and pyramidal columnar morphology following incorporation of molybdenum and cerium in MgO are responsible for the excellent discharge characteristics, emergence of neutral {100} and {110} MgO surfaces preferentially give rise to high optical transmittance (∼ 92–100%) and stability against hydration. Further, addition of Mo (or Ce) in MgO causes significant increase in defect density which, in turn, enhances the photoluminescence (PL) emission from 5-, 4- and 3-coordination sites. The changes lead to lowering of the breakdown voltage and hence improvement in the secondary electron emission (SEE) efficiency. These facts have been supported by ion-induced SEE yield (γ) deduced from the a.c. breakdown voltage observed, taking neon as a discharge gas, and determined semi-empirically as well with Hagstrum's theory based on Auger neutralization process using (i) band offset parameters and surface band gap data derived from X-ray photoelectron spectroscopy signal and (ii) information of defect energy levels obtained from photoluminescence (PL) measurements. The experimental values of neon ion-induced SEE yield (γ) are found to be 0.35, 0.42 and 0.39 for MgO, Mg–Mo–O (x = 0.035) and Mg–Ce–O (x = 0.01) thin films, respectively. - Highlights: • Higher hydration resistance • Increased photoluminescence emission • Higher secondary electron emission

Comparative study of 99Mo/99mTc generators at base of synthesized gels starting from activation and fission 99Mo

International Nuclear Information System (INIS)

Lopez M, I.Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

2007-01-01

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

Quality control studies of 99Mo used in 99Mo/99mTc generators produced at IPEN/CNEN-SP, Brazil

International Nuclear Information System (INIS)

Said, Daphne S.; Brambilla, Tania P.; Matsuda, Margareth M.N.; Osso Junior, Joao A.

2015-01-01

99m Tc is the most used radionuclide in nuclear medicine. In Brazil, the 99 Mo/ 99m Tc generators are produced exclusively by the Center of Radiopharmacy at IPEN-CNEN/SP, by importing 99 Mo from different suppliers. 99 Mo (t 1/2 = 66 h) is a fission product of 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 [ 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 99 Mo were evaluated. Different types of solid phase exchanger cartridges were tested for retention of 99 Mo in 3 different conditions. Cartridges that presented percentages of retention higher than 90% were also tested for separation of 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 99 Mo from 131 I (other contaminant) are also proposed. (author)

Development of fission Mo-99 production technology

International Nuclear Information System (INIS)

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

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.

Monolayer MoS2 heterojunction solar cells

KAUST Repository

Tsai, Menglin

2014-08-26

We realized photovoltaic operation in large-scale MoS2 monolayers by the formation of a type-II heterojunction with p-Si. The MoS 2 monolayer introduces a built-in electric field near the interface between MoS2 and p-Si to help photogenerated carrier separation. Such a heterojunction photovoltaic device achieves a power conversion efficiency of 5.23%, which is the highest efficiency among all monolayer transition-metal dichalcogenide-based solar cells. The demonstrated results of monolayer MoS 2/Si-based solar cells hold the promise for integration of 2D materials with commercially available Si-based electronics in highly efficient devices. © 2014 American Chemical Society.

Grotrian diagrams for highly ionized molybdenum Mo VI through Mo XLII

International Nuclear Information System (INIS)

Shirai, Toshizo; Sugar, J.; Wiese, W.L.

1997-07-01

Grotrian diagrams are presented to provide graphical overviews for 1,930 spectral lines of highly ionized molybdenum, Mo VI through Mo XLII. In the usual diagram display such as that by Bashkin and Stoner (North-Holland, Amsterdam, 1975), the density of transitions is often too high to allow each transition to be drawn separately. Here in our modified diagrams, the transitions are also represented by lines connecting the upper and lower energy levels, but the lower energy levels are extended and repeated for successive configurations as needed. As a sequence, dense packing is avoided and all lines in a multiplet can be accommodated. (author)

Intercalation of Si between MoS2 layers

Directory of Open Access Journals (Sweden)

Rik van Bremen

2017-09-01

Full Text Available We report a combined experimental and theoretical study of the growth of sub-monolayer amounts of silicon (Si on molybdenum disulfide (MoS2. At room temperature and low deposition rates we have found compelling evidence that the deposited Si atoms intercalate between the MoS2 layers. Our evidence relies on several experimental observations: (1 Upon the deposition of Si on pristine MoS2 the morphology of the surface transforms from a smooth surface to a hill-and-valley surface. The lattice constant of the hill-and-valley structure amounts to 3.16 Å, which is exactly the lattice constant of pristine MoS2. (2 The transitions from hills to valleys are not abrupt, as one would expect for epitaxial islands growing on-top of a substrate, but very gradual. (3 I(V scanning tunneling spectroscopy spectra recorded at the hills and valleys reveal no noteworthy differences. (4 Spatial maps of dI/dz reveal that the surface exhibits a uniform work function and a lattice constant of 3.16 Å. (5 X-ray photo-electron spectroscopy measurements reveal that sputtering of the MoS2/Si substrate does not lead to a decrease, but an increase of the relative Si signal. Based on these experimental observations we have to conclude that deposited Si atoms do not reside on the MoS2 surface, but rather intercalate between the MoS2 layers. Our conclusion that Si intercalates upon the deposition on MoS2 is at variance with the interpretation by Chiappe et al. (Adv. Mater. 2014, 26, 2096–2101 that silicon forms a highly strained epitaxial layer on MoS2. Finally, density functional theory calculations indicate that silicene clusters encapsulated by MoS2 are stable.

Behavior of methyl orange and orange 10 (orange G) in the presence of hydrotalcite type compounds of Mg/Al and Mg/Fe

International Nuclear Information System (INIS)

Cruz N, G.

2015-01-01

This work is focused on studying the sorption capacity of methyl orange dye (Nm) and orange 10 (N-10) in the presence of hydrotalcite type compounds of Mg/Al and Mg/Fe uncalcined and calcined previously at 500 degrees Celsius. Sorption isotherms were determined and the study of the kinetics of sorption was performed. The materials were characterized before and after sorption processes of these dyes by X-ray diffraction, scanning electron microscopy, the specific surface area determination by the Brunauer-Emmett-Teller method, thermogravimetry coupled to mass and infrared spectrometry. The hydrotalcite type compounds reported in this paper were prepared in the laboratory and their acronyms are: HTMgAlG1, HTMgAlMO, HTMgFeG1 and HTMgFeG2. Note that in this work the best conditions for preparing compounds of Mg/Fe were found. From patterns of X-ray diffraction was identified the typical crystal structure of the hydrotalcite type compounds. By scanning electron microscopy the morphology could be determined in the form of flakes characteristics of these compounds. Likewise with elemental analysis of energy dispersive X-ray spectroscopy the presence of Mg, Al, Fe and C, elements of interest for this study was determined. The compounds presented a specific surface area relatively high from 80 to 120 m 2 /g. Thermogravimetry results presented spectra of mass loss very characteristic associated to water losses, dehydroxylation and decarboxylation. The characteristic bands of water and carbonate were assigned by infrared spectroscopy and the bands corresponding to the dyes sulfonates were identified only for the calcined materials. The sorption capacities found of these compounds were as follows: for Nm in the compound HTMgAlG1 uncalcined was 17.82 mg/g for an initial concentration of 200 mg/L and for calcined (HTMgAlMOcal) of 99.8 mg/g with and initial concentration of 1000 mg/L. Moreover, the sorption capacity of the dye N-10 in this same material was 17.92 mg/g and 99.4 mg

Excitation functions of the 98Mo+d reactions

International Nuclear Information System (INIS)

Zarubin, P.P.; Padalko, V.Yu.; Khrisanfov, Yu.V.; Lebedev, P.P.; Podkopaev, Yu.N.

The excitation functions of the 98 Mo+d reactions were studied. The energy dependence of (d,p),(d,n) and (d,α) reactions was investigated by the activation analysis. The energies of deuterons in the range (6-12) MeV were determined by means of the aluminium filters. 98 Mo foils with surface densities of 1.02, 0.23 and 0.14 mgxcm -2 with 98 Mo enrichment of 94.1% were used as targets. The gamma spectra were measured by a Ge(Li) detector. The 98 Mo(d,p) 99 Mo reaction excitation function was determined via detection of 739 and 181 keV γ-radiation of 99 Mo (Tsub(1/2)=66.47h); 140 keV γ-radiation of 99 Tc (Tsub(1/2)=6h) was detected for the 98 Mo(d,n) 99 Tc reaction excitation function determination and 460, 568, 1091, 1200 and 1492 keV γ-quanta of 96 Nb (Tsub(1/2)=23.35h) - for the 98 Mo(d,α) 96 Nb reaction. In the excitation function the wide extremum was observed at Esub(d) approximately 10 MeV. The ratio of cross sections σsup(m)(d,n)/σ(d,p) on the 98 Mo target was determined. The ratio σsup(m)(d,n)/σ(d,p) was found to be decreasing function of the deuteron energy. The relative cross sections were determined with an accuracy of +-5%, while for the absolute values of cross sections the accuracy was +-15%

OPAL: prediction of MoRF regions in intrinsically disordered protein sequences.

Science.gov (United States)

Sharma, Ronesh; Raicar, Gaurav; Tsunoda, Tatsuhiko; Patil, Ashwini; Sharma, Alok

2018-06-01

Intrinsically disordered proteins lack stable 3-dimensional structure and play a crucial role in performing various biological functions. Key to their biological function are the molecular recognition features (MoRFs) located within long disordered regions. Computationally identifying these MoRFs from disordered protein sequences is a challenging task. In this study, we present a new MoRF predictor, OPAL, to identify MoRFs in disordered protein sequences. OPAL utilizes two independent sources of information computed using different component predictors. The scores are processed and combined using common averaging method. The first score is computed using a component MoRF predictor which utilizes composition and sequence similarity of MoRF and non-MoRF regions to detect MoRFs. The second score is calculated using half-sphere exposure (HSE), solvent accessible surface area (ASA) and backbone angle information of the disordered protein sequence, using information from the amino acid properties of flanks surrounding the MoRFs to distinguish MoRF and non-MoRF residues. OPAL is evaluated using test sets that were previously used to evaluate MoRF predictors, MoRFpred, MoRFchibi and MoRFchibi-web. The results demonstrate that OPAL outperforms all the available MoRF predictors and is the most accurate predictor available for MoRF prediction. It is available at http://www.alok-ai-lab.com/tools/opal/. ashwini@hgc.jp or alok.sharma@griffith.edu.au. Supplementary data are available at Bioinformatics online.

Coordination of {Mo142} Ring to La3+ Provides Elliptical {Mo134La10} Ring with a Variety of Coordination Modes

Directory of Open Access Journals (Sweden)

Eri Ishikawa

2009-12-01

Full Text Available A28-electron reduced C2h-Mo-blue 34Ǻ outer ring diameter circular ring, [Mo142O429H10(H2O49(CH3CO25(C2H5CO2]30- (≡{Mo142(CH3CO25(C2H5CO2} comprising eight carboxylate-coordinated (with disorder {Mo2} linkers and six defect pockets in two inner rings (four and three for each, respectively, reacts with La3+ in aqueous solutions at pH 3.5 to yield a 28-electron reduced elliptical Ci-Mo-blue ring of formula [Mo134O416H20(H2O46{La(H2O5}4{La(H2O7}4{LaCl2(H2O5}2]10- (≡{Mo134La10}, isolated as the Na10[Mo134O416H20(H2O46{La(H2O5}4{La(H2O7}4{LaCl2(H2O5}2]·144 H2O Na+ salt. The elliptical structure of {Mo134La10} showing 36 and 31 Å long and short axes for the outer ring diameters is attributed to four (A-D modes of LaO9/LaO7Cl2 tricapped-trigonal-prismatic coordination (TTP geometries. Two different LaO2(H2O7 and one LaO2(H2O2Cl2 TTP geometries (as A-C modes for each of two inner rings result from the coordination of all three defect pockets of the inner ring for {Mo142(CH3CO25(C2H5CO2}, and two LaO4(H2O5 TTP geometries (as D mode result from the displacement of two (acetate/propionate-coordinated binuclear {Mo2} linkers with La3+ in each inner ring. The isothermal titration calorimetry (ITC of the ring modification from circle to ellipsoid, showing the endothermic reaction of [La3+]/[{Mo142(CH3CO25(C2H5CO2}] = 6/1 with DH = 22 kJ×mol-1, DS = 172 J×K-1×mol-1, DG = −28 kJ×mol-1, and K = 9.9 ´ 104 M-1 at 293 K, leads to the conclusion that the coordination of the defect pockets to La3+ precedes the replacement of the {Mo2} linkers with La3+. 139La- NMR spectrometry of the coordination of {Mo142(CH3CO25(C2H5CO2} ring to La3+ is also discussed.

A modified {sup 99} Mo- {sup 99} Tc generator on Zirconium molybdo- phosphate-{sup 99} Mo gel. Vol. 3

Energy Technology Data Exchange (ETDEWEB)

El-Kolaly, M T; Talaat, H [Labelled Compounds Department, Cairo (Egypt); Botros, N [Radioistspe and Generator Department, Radioisotope Production and Sealed Source Division, Hot Laboratories Center, Atomic Energy Authority, Cairo (Egypt)

1996-03-01

A modified {sup 99} Mo - {sup 99} Tc gel generator is described. The new generator is based on the use of zirconium molybdophosphate - {sup 99} Mo gel in which {sup 99} Mo chemically combined in the gel structure, where {sup 99m}Tc can be easily eluted with distilled water or saline. The gel was prepared via chemical reaction between zirconyl chloride and molybdophosphate - {sup 99} Mo solution. The PH of the reaction mixture was adjusted with NaOH. Different gels have been prepared by varying the molar ratio of Mo:Zr:p. The PH and time of digeston on complete gel formation was also investigated in order to optimize the condition of gel preparation. Molybdophosphate {sup 32} P solution was used to determine the phosphorous content in the gel and in the {sup 99m}Tc eluate. The temperature and time of drying of the gel and their effect on {sup 99m}Tc elution efficiency were also studied. From the data obtained, the optimum conditions for routine production of {sup 99} Mo - {sup 99m}Tc generator are presented and discussed. 2 figs., 6 tabs.

Theoretical calculations of valence states in Fe-Mo compounds

International Nuclear Information System (INIS)

Estrada, F; Navarro, O; Noverola, H; Suárez, J R; Avignon, M

2014-01-01

The half-metallic ferromagnetic double perovskite compound Sr 2 FeMoO 6 is considered as an important material for spintronic applications. It appears to be fundamental to understand the role of electronic parameters controlling the half-metallic ground state. Fe-Mo double perovskites usually present some degree of Fe/Mo disorder which generally increases with doping. In this work, we study the valence states of Fe-Mo cations in the off-stoichiometric system Sr 2 Fe 1+x Mo 1−x O 6 (−1 ≤ x ≤ 1/3) with disorder. Our results for Fe and Mo valence states are obtained using the Green functions and the renormalization perturbation expansion method. The model is based on a correlated electron picture with localized Fe-spins and conduction Mo-electrons interacting with the local spins via a double-exchange-type mechanism

Feasibility study on mass production of (n,γ)99Mo

International Nuclear Information System (INIS)

Jun, Byung Jin; Tanimoto, Masataka; Kimura, Akihiro; Hori, Naohiko; Izumo, Hironobu; Tsuchiya, Kunihiko

2011-01-01

The world is currently suffering from a severe shortage of 99 Mo and various efforts have been given for its availability. The (n,γ) method is one of candidates for the alternative supply of 99 Mo. The only but critical shortage of (n,γ) 99 Mo is its extremely low specific activity, which gives inconveniency in the extraction of 99m Tc and is consequently converted to additional cost. Potential technologies which make the (n,γ) 99 Mo competitive by reducing the additional cost are already available. It is expected that verification of such technologies is much easy and cost effective compared to any other options known for the alternative 99 Mo production. Because Japan and Korea import all 99 Mo from long distance, the cost benefit of local (n,γ) 99 Mo production in these countries is especially large. If five high flux reactors in China, Japan and Korea are utilized for the cross backup supply of (n,γ) 99 Mo, stable availability of 99 Mo in the region can be secured. Therefore, it is necessary to evaluate its feasibility on (n,γ) 99 Mo production in the Asia region. In this report, we studied feasibility of the mass (n,γ) 99 Mo production from viewpoints of global and regional status of 99 Mo demand and supply, competitiveness with other production methods, requirements and flow of the 99 Mo, production capability, cost, convenience in usage, and alternative technologies to overcome its shortage. (author)

A Survey On Mean Glandular Dose From Full-Field Digital Mammography Systems, Operate Using Mo/ Mo And W/Rh Target/ Filter Combinations

International Nuclear Information System (INIS)

Noriah Jamal; Siti Selina Abdul Hamid; Humairah Samad Cheung; Siti Kamariah Che Mohamed; Ellyda Muhammed Nordin; Radhiana Hassan; Rehir Dahalan

2013-01-01

We had conducted a survey on Mean Glandular Dose (MGD) from Full-Field Digital Mammography systems (FFDM) operate using Molybdenum/ Molybdenum (Mo/ Mo) and Tungsten/ Rhodium (W/ Rh) target/ filter combinations. A survey was carried out at two randomly selected mammography centres in Malaysia, namely National Cancer Society and International Islamic University of Malaysia. The first centre operates using a W/ Rh, while the second centre operates using an Mo/ Mo target/ filter combinations. On the basis of recorded information, data on mammographic views, MGD, age and Compressed Breast Thickness (CBT) were recorded for 100 patients, for each mammographic centre respectively. The MGD data were analyzed for variation with age group, with 5 years increment. The MGD data were also analyzed for variation with CBT, with 5 mm increment. We found that for both CC and MLO views, FFDM systems operated using Mo/ Mo and W/ Rh target/ filter combinations present the same trend on MGD. The average MGD decreases as age increases. While average MGD increases with the increasing of CBT. However, FFDM system operates using Mo/ Mo gives higher MGD as compared with FFDM system operates using W/ Rh. (author)

Oxygen potential of a prototypic Mo-cermet fuel containing plutonium oxide

Energy Technology Data Exchange (ETDEWEB)

Miwa, Shuhei, E-mail: miwa.shuhei@jaea.go.jp [Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki, 311-1393 (Japan); Osaka, Masahiko [Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki, 311-1393 (Japan); Nozaki, Takahiro; Arima, Tatsumi; Idemitsu, Kazuya [Kyushu University, 744 Motooka Nishi-ku, Fukuoka, 819-0395 (Japan)

2015-10-15

Oxygen potential of a prototypic Mo-cermet fuel containing 50 vol.% PuO{sub 2−x} were investigated by the thermogravimetric analysis in the temperature range from 1273 K to 1473 K. It was shown that the oxygen potential and oxidation rate of the Mo-cermet were the same as those of pure PuO{sub 2−x} below the oxygen potential of Mo/MoO{sub 2} oxidation reaction. The same features of the Mo-cermet sample containing 50 vol.% PuO{sub 2−x} with those of pure PuO{sub 2−x} were discussed in terms of the microstructure. - Highlights: • Oxygen potential of Mo-cermet fuel was investigated by thermogravimetric analysis. • It was the same as that of pure PuO{sub 2−x} below the oxygen potential for Mo/MoO{sub 2}. • Gradual oxidation of Mo matrix occurred only above the oxygen potential for Mo/MoO{sub 2}. • Mo matrix and PuO{sub 2−x} in Mo-cermet fuel can thus be thermochemically individual.

Oxygen potential of a prototypic Mo-cermet fuel containing plutonium oxide

International Nuclear Information System (INIS)

Miwa, Shuhei; Osaka, Masahiko; Nozaki, Takahiro; Arima, Tatsumi; Idemitsu, Kazuya

2015-01-01

Oxygen potential of a prototypic Mo-cermet fuel containing 50 vol.% PuO_2_−_x were investigated by the thermogravimetric analysis in the temperature range from 1273 K to 1473 K. It was shown that the oxygen potential and oxidation rate of the Mo-cermet were the same as those of pure PuO_2_−_x below the oxygen potential of Mo/MoO_2 oxidation reaction. The same features of the Mo-cermet sample containing 50 vol.% PuO_2_−_x with those of pure PuO_2_−_x were discussed in terms of the microstructure. - Highlights: • Oxygen potential of Mo-cermet fuel was investigated by thermogravimetric analysis. • It was the same as that of pure PuO_2_−_x below the oxygen potential for Mo/MoO_2. • Gradual oxidation of Mo matrix occurred only above the oxygen potential for Mo/MoO_2. • Mo matrix and PuO_2_−_x in Mo-cermet fuel can thus be thermochemically individual.

Preparation of 99Mo/99mTc generators based on 99Mo zirconium molybdates in the Gel Synthesis Device for Generators

International Nuclear Information System (INIS)

Lopez M, I. Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

2008-01-01

The 99m Tc is used for diagnosis and therapy. It is produced commercially from 99 Mo obtained from the fission of 235 U, which is retained in chromatographic columns filled with alumina whose maximum capacity is 0.2%. Given these constraints new methods of preparation 99 Mo/ 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 99 Mo/ 99m Tc generators based on 99 Mo zirconium molybdates in the Gel Synthesis Device 99 Mo/ 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)

Few-layer MoS2 as nitrogen protective barrier

Science.gov (United States)

Akbali, B.; Yanilmaz, A.; Tomak, A.; Tongay, S.; Çelebi, C.; Sahin, H.

2017-10-01

We report experimental and theoretical investigations of the observed barrier behavior of few-layer MoS2 against nitrogenation. Owing to its low-strength shearing, low friction coefficient, and high lubricity, MoS2 exhibits the demeanor of a natural N-resistant coating material. Raman spectroscopy is done to determine the coating capability of MoS2 on graphene. Surface morphology of our MoS2/graphene heterostructure is characterized by using optical microscopy, scanning electron microscopy, and atomic force microscopy. In addition, density functional theory-based calculations are performed to understand the energy barrier performance of MoS2 against nitrogenation. The penetration of nitrogen atoms through a defect-free MoS2 layer is prevented by a very high vertical diffusion barrier, indicating that MoS2 can serve as a protective layer for the nitrogenation of graphene. Our experimental and theoretical results show that MoS2 material can be used both as an efficient nanocoating material and as a nanoscale mask for selective nitrogenation of graphene layer.

Adsorption of DNA/RNA nucleobases onto single-layer MoS2 and Li-Doped MoS2: A dispersion-corrected DFT study

Science.gov (United States)

Sadeghi, Meisam; Jahanshahi, Mohsen; Ghorbanzadeh, Morteza; Najafpour, Ghasem

2018-03-01

The kind of sensing platform in nano biosensor plays an important role in nucleic acid sequence detection. It has been demonstrated that graphene does not have an intrinsic band gap; therefore, transition metal dichalcogenides (TMDs) are desirable materials for electronic base detection. In the present work, a comparative study of the adsorption of the DNA/RNA nucleobases [Adenine (A), Cytosine (C) Guanine (G), Thymine (T) and Uracil (U)] onto the single-layer molybdenum disulfide (MoS2) and Li-doped MoS2 (Li-MoS2) as a sensing surfaces was investigated by using Dispersion-corrected Density Functional Theory (D-DFT) calculations and different measure of equilibrium distances, charge transfers and binding energies for the various nucleobases were calculated. The results revealed that the interactions between the nucleobases and the MoS2 can be strongly enhanced by introducing metal atom, due to significant charge transfer from the Li atom to the MoS2 when Lithium is placed on top of the MoS2. Furthermore, the binding energies of the five nucleobases were in the range of -0.734 to -0.816 eV for MoS2 and -1.47 to -1.80 eV for the Li-MoS2. Also, nucleobases were adsorbed onto MoS2 sheets via the van der Waals (vdW) force. This high affinity and the renewable properties of the biosensing platform demonstrated that Li-MoS2 nanosheet is biocompatible and suitable for nucleic acid analysis.

Converting MMSE to MoCA and MoCA 5-minute protocol in an educationally heterogeneous sample with stroke or transient ischemic attack.

Science.gov (United States)

Wong, Adrian; Black, Sandra E; Yiu, Stanley Y P; Au, Lisa W C; Lau, Alexander Y L; Soo, Yannie O Y; Chan, Anne Y Y; Leung, Thomas W H; Wong, Lawrence K S; Kwok, Timothy C Y; Cheung, Theodore C K; Leung, Kam-Tat; Lam, Bonnie Y K; Kwan, Joseph S K; Mok, Vincent C T

2018-05-01

The Montreal Cognitive Assessment (MoCA) is psychometrically superior over the Mini-mental State Examination (MMSE) for cognitive screening in stroke or transient ischemic attack (TIA). It is free for clinical and research use. The objective of this study is to convert scores from the MMSE to MoCA and MoCA-5-minute protocol (MoCA-5 min) and to examine the ability of the converted scores in detecting cognitive impairment after stroke or TIA. A total of 904 patients were randomly divided into training (n = 623) and validation (n = 281) samples matched for demography and cognition. MMSE scores were converted to MoCA and MoCA-5 min using (1) equipercentile method with log-linear smoothing and (2) Poisson regression adjusting for age and education. Receiver operating characteristics curve analysis was used to examine the ability of the converted scores in differentiating patients with cognitive impairment. The mean education was 5.8 (SD = 4.6; ranged 0-20) years. The entire spectrum of MMSE scores was converted to MoCA and MoCA-5 min using equipercentile method. Relationship between MMSE and MoCA scores was confounded by age and education, and a conversion equation with adjustment for age and education was derived. In the validation sample, the converted scores differentiated cognitively impaired patients with area under receiver operating characteristics curve 0.826 to 0.859. We provided 2 methods to convert scores from the MMSE to MoCA and MoCA-5 min based on a large sample of patients with stroke or TIA having a wide range of education and cognitive levels. The converted scores differentiated patients with cognitive impairment after stroke or TIA with high accuracy. Copyright © 2018 John Wiley & Sons, Ltd.

Thermal spreading of MoO3 in H-ZY

International Nuclear Information System (INIS)

Mosqueira, L.; Angeles-Chavez, C.; Torres-Garcia, E.

2011-01-01

Research highlights: → Molybdenum oxo-species were formed during thermally driven migration on H-ZY. → Oxo-species were identified according to the edge energy (E g ) values of bulk molybdenum oxide reference compounds. → The migration occurred via MoO 2 (OH) 2 species leading first to (MoO 4 ) 2- and (Mo 2 O 7 ) 2- formation, and finally of (Mo 7 O 24 ) 6- . - Abstract: This work provides a structural, optical and kinetics approach to the molybdenum oxo-species formed during thermally driven migration on H-ZY starting from mechanical mixtures with MoO 3 . The samples were characterized as a function of time of treatment by UV-vis diffuse reflectance, X-ray diffraction, N 2 adsorption and scanning transmission electron microscopy (STEM). Local analysis of elemental compositions obtained from linear scan of characteristic X-ray signal show a direct evidence of molybdenum presence into the zeolite crystals. Ultraviolet absorption spectra were used to determine both the kinetics of the spreading and the speciation of MoO x in the H-ZY. Besides MoO 3 , three surface molybdenum oxo-species were identified according to the edge energy (E g ) values of bulk molybdenum oxide reference compounds. This study shows that the tetrahedral species prevailed on H-ZY. This is consistent with limitations in the migration and growth of MoO x in the channel structure of the zeolite. Kinetic study suggest that migration of MoO x in the H-ZY at low temperature (ca. 723 K) occurs across the formation and diffusion of hydrated species such as MoO 2 (OH) 2 , which interact with the zeolite and form monomeric and dimeric structures (like (MoO 4 ) 2- and (Mo 2 O 7 ) 2- ). Migration of MoO x species in the H-ZY studied is significant even at 723 K and after very short periods of treatment (<5 min).

Electron microscopy studies on MoS2 nanocrystals

DEFF Research Database (Denmark)

Hansen, Lars Pilsgaard

Industrial-style MoS2-based hydrotreating catalysts are studied using electron microscopy. The MoS2 nanostructures are imaged with single-atom sensitivity to reveal the catalytically important edge structures. Furthermore, the in-situ formation of MoS2 crystals is imaged for the first time....

Measurement of the Single Top Quark Production Cross Section and mo stretchy='false'>|mo>Vtb stretchy='false'>|mo> in Events with One Charged Lepton, Large Missing Transverse Energy, and Jets at CDF

Energy Technology Data Exchange (ETDEWEB)

Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d’Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D’Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D’Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hirschbuehl, D.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W. -M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.

2014-12-31

We report a measurement of single top quark production in proton-antiproton collisions at a center-of-mass energy of smo>=>1.96 TeV using a data set corresponding to 7.5 fbmo>->1 of integrated luminosity collected by the Collider Detector at Fermilab. We select events consistent with the single top quark decay process tmo stretchy="false">→mo>Wb stretchy="false">→mo>ℓ>νb by requiring the presence of an electron or muon, a large imbalance of transverse momentum indicating the presence of a neutrino, and two or three jets including at least one originating from a bottom quark. An artificial neural network is used to discriminate the signal from backgrounds. We measure a single top quark production cross section of 3.04mo>->0.53mo>+>0.57 pb and set a lower limit on the magnitude of the coupling between the top quark and bottom quark mo stretchy="false">|mo

Thermophysical properties of Na2Th (MoO4)3 (s) and Na4Th (MoO4)4 (s)

International Nuclear Information System (INIS)

Dash, Smruti; Rakshit, S.K.; Singh, Ziley; Keskar, Meera; Dahale, N.D.

2009-01-01

The heat capacity of Na 2 Th (MoO 4 ) 3 (s) and Na 4 Th (MoO 4 ) 4 (s) have been measured by differential scanning calorimeter in the temperature range 318 to 845 K. The corresponding values are: C p,m (Na 2 Th (MoO 4 ) 3 ,s,T) (JK-1 mol-1) 368.710+ 1.0 10-1 (T/K) - 4950267 (K/T)2 (318 ≤ T (K) ≤ 845). C p,m (Na 4 Th (MoO 4 ) 4 ,s,T) (JK-1 mol-1) = 638.761+ 5.12 10-3 (T/K) - 12691691 (K/T)-2 (318 ≤ T (K) ≤ 845). Experimental heat capacity values for Na 2 Th (MoO 4 ) 3 (s) match reasonably well with that of additive oxide values. But C p,m (T) values of Na 4 Th (MoO 4 ) 4 (s) deviates substantially from the additive oxide values above 700 K. The uncertainty of the measurements reported in this study is calculated to be within 1 to 3 % . (author)

Towards a uniform and large-scale deposition of MoS2 nanosheets via sulfurization of ultra-thin Mo-based solid films.

Science.gov (United States)

Vangelista, Silvia; Cinquanta, Eugenio; Martella, Christian; Alia, Mario; Longo, Massimo; Lamperti, Alessio; Mantovan, Roberto; Basset, Francesco Basso; Pezzoli, Fabio; Molle, Alessandro

2016-04-29

Large-scale integration of MoS2 in electronic devices requires the development of reliable and cost-effective deposition processes, leading to uniform MoS2 layers on a wafer scale. Here we report on the detailed study of the heterogeneous vapor-solid reaction between a pre-deposited molybdenum solid film and sulfur vapor, thus resulting in a controlled growth of MoS2 films onto SiO2/Si substrates with a tunable thickness and cm(2)-scale uniformity. Based on Raman spectroscopy and photoluminescence, we show that the degree of crystallinity in the MoS2 layers is dictated by the deposition temperature and thickness. In particular, the MoS2 structural disorder observed at low temperature (<750 °C) and low thickness (two layers) evolves to a more ordered crystalline structure at high temperature (1000 °C) and high thickness (four layers). From an atomic force microscopy investigation prior to and after sulfurization, this parametrical dependence is associated with the inherent granularity of the MoS2 nanosheet that is inherited by the pristine morphology of the pre-deposited Mo film. This work paves the way to a closer control of the synthesis of wafer-scale and atomically thin MoS2, potentially extendable to other transition metal dichalcogenides and hence targeting massive and high-volume production for electronic device manufacturing.

The Microstructure of Multi-wire U-Mo Monolithic Fuel

Energy Technology Data Exchange (ETDEWEB)

Lee, Yoon Sang; Park, Eun Kee; Cho, Woo Hyoung; Park, Jong Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-10-15

In order to use low-enriched uranium (LEU) instead of highly enriched uranium (HEU) for high performance research reactors, the reduced enrichment for research and test reactors (RERTR) program is developing high uranium density fuel such as U-Mo/Al dispersion fuel. U-Mo alloys have an excellent irradiation performance when compared to other uranium alloys or compounds. But the results from the post-irradiation examination of the U-Mo/Al dispersion fuels indicate that an interaction between the U-Mo alloy fuel and the Al matrix phases occurs readily during an irradiation and it is sensitively dependent on the temperature. In order to lessen these severe interactions, a concept of a multi-wire type fuel was proposed. The fuel configuration is that three to six U-Mo fuel wires (1.5 mm {approx} 2 mm in diameter) are symmetrically arranged at the periphery side in the Al matrix as shown. This multi-wire fuels showed very good fuel performance during the KOMO-3 irradiation test. At the KOMO-3 test, the specimen of the multi-wire fuels were U-7Mo/Al and U-7Mo-1Si/Al. In this study we investigate the microstructure change of the U-7Mo and U-7Mo-1Ti with some variation of annealing conditions. In addition to this, we want to check the effect of adding Ti element to U-7Mo on the gamma phase stability

Gold nanoparticles on MoS2 layered crystal flakes

International Nuclear Information System (INIS)

Cao, Wei; Pankratov, Vladimir; Huttula, Marko; Shi, Xinying; Saukko, Sami; Huang, Zhongjia; Zhang, Meng

2015-01-01

Inorganic layered crystal MoS 2 is considered as one of the most promising and efficient semiconductor materials for future transistors, photoelectronics, and electrocatalysis. To boost MoS 2 -based material applications, one direction is to grow physically and chemically reactive nanoparticles onto MoS 2 . Here we report on a simple route to synthesis crystalized MoS 2 –Au complexes. The gold nanoparticles were grown on MoS 2 flakes through a wet method in the oxygen free environment at room temperature. Nanoparticles with diameters varying from 9 nm to 429 nm were controlled by the molar ratios of MoS 2 and HAuCl 4 precursors. MoS 2 host flakes keep intrinsic honeycomb layered structures and the Au nanoparticles cubic-center crystal microstructures. From product chemical states analysis, the synthesis was found driven by redox reactions between the sulphide and the chloroauric acid. Photoluminescence measurement showed that introducing Au nanoparticles onto MoS 2 stacks substantially prompted excitonic transitions of stacks, as an analogy for doping Si wafers with dopants. Such composites may have potential applications in wide ranges similar as the doped Si. - Highlights: • The Au nanoparticles were decorated on MoS 2 in oxygen free ambiences via a wet method. • The Au nanoparticles are size-controllable and crystalized. • Chemical reaction scheme was clarified. • The MoS 2 –Au complexes have strong photoluminescent properties

Study of different absorbent materials for the preparation of generator systems of {sup 99}Mo - {sup 99m}Tc and {sup 188}W-{sup 188}Re

Energy Technology Data Exchange (ETDEWEB)

Lopes, Paula Regina Corain; Osso Junior, Joao Alberto, E-mail: paulinhacorain@usp.b, E-mail: jaosso@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2009-07-01

Amongst some currently radioisotopes, {sup 99m}Tc and {sup 188}Re present adequate decay properties for use in Nuclear Medicine. In the current times the most diagnosis examinations are performed with {sup 99m}Tc and {sup 188}Re is one radioisotope of potential use in therapy techniques. The objective of this work consists of determining the capacity of some adsorbent materials for retention of molybdenum and tungsten, aiming the optimization of generator systems of {sup 99}Mo-{sup 99m}Tc and {sup 188}W-{sup 188}Re with suitable characteristics for application in Nuclear Medicine. Known amounts, in mass, of molybdenum and tungsten were percolated through different chromatographic columns containing different commercial adsorbent materials such as: PZC (poly-zirconium compound), acid alumina and calcinated alumina used in the routine preparation of {sup 99}Mo-{sup 99m}Tc generators at IPEN. The tungsten ({sup 188}W), as well the PZC used in this project, supplied by Russia and Japan, respectively, through the International Atomic Energy Agency (IAEA) and used without any previous preparation. Also trace amounts of {sup 99}Mo and {sup 188}W were added to the initial solutions and the generators were assembled. The {sup 99}Mo-{sup 99m}Tc generators were then eluted with known volumes of 0.9% NaCl solution every 24 hours whereas the {sup 188}W-{sup 188}Re generators were eluted every 48 hours. The eluted samples were analyzed by Gamma Spectroscopy and later submitted to quality control evaluation. The results showed that the PZC presents superior retention capacity for Mo of 97.50mg Mo/gPZC, higher than in acid and calcinated alumina, however the elution efficiency at lower pHs is not so high. With regards to the experiments carried out with {sup 188}W and alumina, it was verified that the elution efficiency of {sup 188}Re was not reproducible and the retention capacity of W was 90.23mgW/gAl{sub 2}O{sub 3} at pH 7. (author)

NMR and XAS Study of Fe-Mo Double Perovskites

International Nuclear Information System (INIS)

Zajac, D.A.; Kapusta, C.; Borowiec, M.; Sikora, M.; Marquina, C.; Blasco, J.; Ibarra, M.R.

2005-01-01

The results of NMR and XAS measurements of the A 2 FeMoO 6 double perovskites (DP) (A 2 =Sr 2 , SrBa, Ba 2 , Ca 2 ) at the Fe and Mo K edges are reported and the information on the individual site electronic and magnetic properties is analysed. The compounds studied belong to the family of materials exhibiting a high field '' colossal '' magnetoresistance as well as a low field '' giant '' magnetoresistance. Magnetoresistive properties of the compounds arise from their half-metallicity, i.e. only one spin direction being populated in the conduction band, which consists of overlapping spin down 3d Fe, 2p O and 4d Mo electron bands. Within the model, a spin-down electron undergoes a fast hopping through unoccupied oxygen 2p orbitals between Fe 3+ (3d 5 - spin up) and Mo 6+ (4d 0 ) ionic cores. This mechanism implicates an anti-parallel coupling of the Fe and Mo spins and leads to non-integer magnetic moments and a metallic character below TC. The interaction, in analogy with the '' double exchange '' (DE) in manganites, is called '' double exchange-like '' interaction. The superexchange interaction (SE) is also expected to be present, resulting also in an anti-parallel coupling of 3d Fe 3+ and 4d Mo 5+ spins through occupied oxygen 2p orbitals. The insulating character of SE is connected with an increase of the tilt angle of the Fe-O-Mo bond, which is related to a change of the structural tolerance factor f and results in structural distortions. The molybdenum NMR measurements revealed the existence of a non-integer magnetic moment at Mo and Fe, which can be attributed to the DE-like interaction. However, experiments using Moessbauer spectroscopy have shown the existence of two Fe ionisation states - with integer (SE) and non integer (DE) magnetic moments. The 95 Mo and 97 Mo NMR measurements on A 2 FeMoO 6 (A 2 =Sr 2 , SrBa, Ba 2 , Ca 2 ) presented in this work show different values of the Mo hyperfine field and the corresponding magnetic moment. This is attributed

Cyanide-limited complexation of molybdenum(III): synthesis of octahedral [Mo(CN)(6)](3-) and cyano-bridged [Mo(2)(CN)(11)](5-).

Science.gov (United States)

Beauvais, Laurance G; Long, Jeffrey R

2002-03-13

Octahedral coordination of molybdenum(III) is achieved by limiting the amount of cyanide available upon complex formation. Reaction of Mo(CF(3)SO(3))(3) with LiCN in DMF affords Li(3)[Mo(CN)(6)] x 6DMF (1), featuring the previously unknown octahedral complex [Mo(CN)(6)](3-). The complex exhibits a room-temperature moment of mu(eff) = 3.80 mu(B), and assignment of its absorption bands leads to the ligand field parameters Delta(o) = 24800 cm(-1) and B = 247 cm(-1). Further restricting the available cyanide in a reaction between Mo(CF(3)SO(3))(3) and (Et(4)N)CN in DMF, followed by recrystallization from DMF/MeOH, yields (Et(4)N)(5)[Mo(2)(CN)(11)] x 2DMF x 2MeOH (2). The dinuclear [Mo(2)(CN)(11)](5-) complex featured therein contains two octahedrally coordinated Mo(III) centers spanned by a bridging cyanide ligand. A fit to the magnetic susceptibility data for 2, gives J = -113 cm(-1) and g = 2.33, representing the strongest antiferromagnetic coupling yet observed through a cyanide bridge. Efforts to incorporate these new complexes in magnetic Prussian blue-type solids are ongoing.

A facile route to large-scale synthesis MoO{sub 2} and MoO{sub 3} as electrode materials for high-performance supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Xuan, H.C.; Du, Y.W. [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024 (China); Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093 (China); Zhang, Y.Q.; Xu, Y.K.; Li, H.; Han, P.D. [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024 (China); Wang, D.H. [Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093 (China)

2016-09-15

MoO{sub 3} and MoO{sub 2} materials have been successfully synthesized by thermal decomposition of ammonium paramolybdate in air and a sealed quartz tube, respectively. The microstructure of as-synthesized MoO{sub 3} is composed of irregular lamellar plates with a plate thickness around 100 nm and MoO{sub 2} has the larger grain size with lamellar plates connected with each other. A maximum specific capacitance of 318 F/g at 0.5 A/g is obtained for MoO{sub 2} prepared in a closed environment. On the other hand, the sample MoO{sub 3} exhibits excellent rate capacity with specific capacitances of 218, 209, 196, 188, 176, and 160 F/g at current densities of 0.5, 1, 2, 3, 4, and 5 A/g, respectively. These results pave the way to consider MoO{sub 3} and MoO{sub 2} as prospective materials for energy-storage applications. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Electrochemical behavior of Ni-Mo electro catalyst for water electrolysis

Energy Technology Data Exchange (ETDEWEB)

Fernandez V, S. M.; Ordonez R, E. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Cabanas M, G. [IPN, Centro de Nanociencias y Micro y Nanotecnologias, A. P. 75-874, 07300 Mexico D. F. (Mexico); Solorza F, O., E-mail: suilma.fernandez@inin.gob.m [IPN, Centro de Investigacion y de Estudios Avanzados, Departamento de Quimica, A. P. 14-740, 07000 Mexico D. F. (Mexico)

2010-07-01

Nickel-molybdenum based electrocatalysts were synthesized in organic media for the hydrogen evolution reaction and oxygen evolution reaction in alkaline media. The structure, morphology and chemical composition of the catalysts were evaluated by X-ray diffraction, scanning electron microscopy and Aas. Results revealed nanocrystalline powder materials with Ni{sub 0.006}Mo, Ni{sub 0.1}Mo and Ni Mo compositions. The best performance for hydrogen evolution reaction, was obtained on Ni{sub 0.1}Mo electrode, whereas Ni Mo was for the oxygen evolution reaction. Results suggest that the material with 1:1 stoichiometric ratio could be considered as a promising electro catalyst for oxygen evolution reaction. This nanocrystalline powder is formed by Ni{sub 2}Mo{sub 3}O{sub 8} and a crystalline structure attributed to the possible formation of a Ni Mo cluster, becomes NiMoO{sub 4} after thermal treatment at 1073 K in air. The Ni Mo 1:1 cluster catalyst presented electrochemical stability during the oxygen evolution reaction. (Author)

Electrochemical behavior of Ni-Mo electro catalyst for water electrolysis

International Nuclear Information System (INIS)

Fernandez V, S. M.; Ordonez R, E.; Cabanas M, G.; Solorza F, O.

2010-01-01

Nickel-molybdenum based electrocatalysts were synthesized in organic media for the hydrogen evolution reaction and oxygen evolution reaction in alkaline media. The structure, morphology and chemical composition of the catalysts were evaluated by X-ray diffraction, scanning electron microscopy and Aas. Results revealed nanocrystalline powder materials with Ni 0.006 Mo, Ni 0.1 Mo and Ni Mo compositions. The best performance for hydrogen evolution reaction, was obtained on Ni 0.1 Mo electrode, whereas Ni Mo was for the oxygen evolution reaction. Results suggest that the material with 1:1 stoichiometric ratio could be considered as a promising electro catalyst for oxygen evolution reaction. This nanocrystalline powder is formed by Ni 2 Mo 3 O 8 and a crystalline structure attributed to the possible formation of a Ni Mo cluster, becomes NiMoO 4 after thermal treatment at 1073 K in air. The Ni Mo 1:1 cluster catalyst presented electrochemical stability during the oxygen evolution reaction. (Author)

Tunneling in BP-MoS2 heterostructure

Science.gov (United States)

Liu, Xiaochi; Qu, Deshun; Kim, Changsik; Ahmed, Faisal; Yoo, Won Jong

Tunnel field effect transistor (TFET) is considered to be a leading option for achieving SS mV/dec. In this work, black phosphorus (BP) and molybdenum disulfide (MoS2) heterojunction devices are fabricated. We find that thin BP flake and MoS2 form normal p-n junctions, tunneling phenomena can be observed when BP thickness increases to certain level. PEO:CsClO4 is applied on the surface of the device together with a side gate electrode patterned together with source and drain electrodes. The Fermi level of MoS2 on top of BP layer can be modulated by the side gating, and this enables to vary the MoS2-BP tunnel diode property from off-state to on-state. Since tunneling is the working mechanism of MoS2-BP junction, and PEO:CsClO4\\ possesses ultra high dielectric constant and small equivalent oxide thickness (EOT), a low SS of 55 mV/dec is obtained from MoS2-BP TFET. This work was supported by the Global Research Laboratory and Global Frontier R&D Programs at the Center for Hybrid Interface Materials, both funded by the Ministry of Science, ICT & Future Planning via the National Research Foundation of Korea (NRF).

Effect of Mo{sub 2}C/(Mo{sub 2}C + WC) weight ratio on the microstructure and mechanical properties of Ti(C,N)-based cermet tool materials

Energy Technology Data Exchange (ETDEWEB)

Xu, Qingzhong; Zhao, Jun, E-mail: zhaojun@sdu.edu.cn; Ai, Xing; Qin, Wenzhen; Wang, Dawei; Huang, Weimin

2015-11-15

To optimize the Mo{sub 2}C content in Ti(C,N)-based cermet tool materials used for cutting the high-strength steel of 42CrMo (AISI 4140/4142 steel), the cermets with different Mo{sub 2}C/(Mo{sub 2}C + WC) weight ratios were prepared. And the microstructure and mechanical properties of cermets were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and measurements of transverse rupture strength (TRS), Vickers hardness (HV) and fracture toughness (K{sub IC}). The results indicate that the Mo{sub 2}C/(Mo{sub 2}C + WC) ratios have great influences on the microstructure features and mechanical properties of Ti(C,N)-based cermets. When the Mo{sub 2}C/(Mo{sub 2}C + WC) ratio increases, the Ti(C,N) grains become finer with smaller black cores surrounded by thinner rims, and the structure of cermets tends to be more compact with smaller binder mean free path. Owing to the medium grains and moderate rims, the cermets with a Mo{sub 2}C/(Mo{sub 2}C + WC) ratio of 0.4 exhibit better mechanical properties, and can be chosen as the tool material for machining 42CrMo steel due to the lower Mo content. - Highlights: • Mo{sub 2}C/(Mo{sub 2}C + WC) ratios affect microstructure and mechanical properties of cermets. • Grains become fine and structure of cermets tends to be compact with raised Mo{sub 2}C. • The cermets with a Mo{sub 2}C/(Mo{sub 2}C + WC) ratio of 0.4 can be used to machine 42CrMo steel.

PRoMoTo 2013 proceedings

OpenAIRE

Bishop, Judith; Tillmann, Nikolai; Puder, Arno; Naik, Vinayak

2013-01-01

Programming for Mobile and Touch (PRoMoTo'13) was held at the 2013 ACM SIGPLAN conference on Systems, Programming, Languages and Applications (SPLASH 2013), October 2013 in Indianapolis, USA. Submissions for this event were invited in the general area of mobile and touch-oriented programming languages and programming environments, and teaching of programming for mobile devices. These are proceedings of the PRoMoTo'13.

Synthesis and characterization of MoO3 films by acid hydrolysis of K2Mo4O13

International Nuclear Information System (INIS)

Hernan, L.; Morales, J.

1989-01-01

The behaviour of K 2 Mo 4 O 13 heated under reflux in an acid medium has been studied. A metastable polymorphic MoO 3 phase crystallizing in the hexagonal system was obtained. Lengthy treatment led to the formation of orthorhombic MoO 3 with the (010) planes perfectly oriented parallel to the substrate. SEM images do not support a topotactic mechanism for the successive transformations. The reactions involved probably take place through the polymerization of discrete units formed in the bulk solution

The Tribological Performance of CrMoN/MoS2 Solid Lubrication Coating on a Piston Ring

Directory of Open Access Journals (Sweden)

Yuelan Di

2017-05-01

Full Text Available In order to improve the tribological properties of an engine piston ring and enhance its service life, magnetron sputtering technology and low temperature ion sulphurizing treatment technology were used to prepare CrMoN/MoS2 solid lubricant coating on the surface of an engine piston ring. The morphologies and compositions of the surface and cross-section of the sulfuration layer were analyzed by field emission scanning electron microscopy (FESEM, and wear property under high load, high speed and high temperature conditions were tested by a SRV®4 friction and wear testing machine. The results show that the CrMoN/MoS2 composite coatings appear as a dense grain structure, and the coating is an ideal solid lubrication layer that possesses an excellent high temperature wear resistance, reducing the engine operating temperature abrasion effectively and prolonging the service life of the engine.

Energy dispersive X-ray fluorescence analysis with Bragg polarized Mo radiation. Energiedispersive Roentgenfluoreszenzanalyse mit Bragg-polarisierter Mo Strahlung

Energy Technology Data Exchange (ETDEWEB)

Gloeckl, H

1983-01-01

The aim of introducing energy dispersive analysis into X-ray fluorescence analysis is to suppress background from the Bremsstrahlung spectrum and the characteristic radiation without an undue reduction of the signal. The variant under consideration uses linearly polarization radiation obtained after a Bragg reflection,under delta = 90/sup 0/. In an introductory part, Bragg reflection, fluorescence and strong radiation are considered quantitatively with respect to counting statistics and detection limits. In the experimental part two combinations are describe, of a Ta crystal with a Cr tube and of a Mo crystal with a Mo tube. Details of adjustment, sample preparation and calibration and detection limits are given. The pros and cons of the Ta/Cr and the Mo/Mo are contrasted and proposals for further improvements are given.

Characterization of the interaction layer in diffusion couples U-Mo-Zr/Al and U-Mo-Zr/Al-A356 at 550 C degrees; Caracterizacion de la zona de interaccion en pares de difusion a 550 grados C U-Mo-Zr/Al y U-Mo-Zr/Al-A356

Energy Technology Data Exchange (ETDEWEB)

Komar Varela, Carolina; Arico, Sergio; Mirandou, Marcela; Balart, Silvia; Gribaudo, Luis [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Materiales; com, carolinakomar@gmail

2007-07-01

Out-of-pile diffusion experiments were performed between U-7 wt.% Mo-1 wt.% Zr and Al or Al A356 (7,1 wt.% Si) at 550 C degrees. In this work morphological characterization and phase identification on both interaction layers are presented. They were carried out by the use of different techniques: optical and scanning electron microscopy, X-ray diffraction and WDS microanalysis. In the interaction layer U-7 wt.% Mo-1 wt.% Zr/Al, the phases UAl{sub 3}, UAl{sub 4}, Al{sub 20}Mo{sub 2}U and Al{sub 43}Mo{sub 4}U{sub 6} were identified. Similar results in the interaction layer of the U-7 % Mo/Al at 580 C degrees were previously obtained. In the interaction layer U-7 wt.% Mo-1 wt.% Zr/Al A356, the phases U(Al,Si){sub 3} with 25 at.% Si and Si{sub 5}U{sub 3} were identified. This last phase, with a higher Si concentration, was identified with X-ray diffraction synchrotron radiation performed at the National Synchrotron Light Laboratory, Campinas, Brazil. (author) [Spanish] Se realizaron experiencias fuera de reactor en pares de difusion quimica U-7 % Mo-1 % Zr/Al y U-7 % Mo-1 % Zr/Al A356. En este trabajo se presentan los resultados de la caracterizacion morfologica e identificacion de fases presentes en la zona de interaccion que se forma al ser sometidos a un tratamiento isotermico de 1,5 h a 550 grados C. Las tecnicas utilizadas fueron: microscopia optica y electronica de barrido, difraccion de rayos X y microanalisis cuantitativo por sonda electronica. En la zona de interaccion correspondiente al par U-7 % Mo-1 % Zr/Al se identificaron las fases UAl{sub 3}, UAl{sub 4}, Al{sub 20}Mo{sub 2}U y Al{sub 43}Mo{sub 4}U{sub 6}. Estas cuatro fases fueron identificadas en pares U-7 % Mo/Al a 580 grados C en trabajos anteriores. En la zona de interaccion correspondiente al par U-7 % Mo-1 % Zr/Al A356 se identificaron las fases U(Al,Si){sub 3} (con una concentracion de 25 %at.Si) y Si{sub 5}U{sub 3}. Este compuesto rico en Si solo pudo ser identificado mediante la utilizacion de

MoOx modified ZnGaO based transparent conducting oxides

Science.gov (United States)

Dutta, Titas; Gupta, P.; Bhosle, V.; Narayan, J.

2009-03-01

We report here the growth of high work function bilayered structures of thin MoOx (2.0MoOx layer, molybdenum exists in Mo4+, Mo5+, and Mo6+ oxidation states, and the ratio of (Mo4++Mo5+) to Mo6+ was determined to be ˜2:1. The bilayer films showed good optical transparency (≥80%) and low resistivity of ˜10-4 Ω cm. Different transport behavior of the MoOx/ZnGa0.05O films grown at different Ts (substrate temperature) was observed in temperature-dependent resistivity measurements. The bilayer film at higher Ts showed metallic conductivity behavior down to 113 K. Moreover, a blueshift of the absorption edge in the transmission spectrum was observed with the increase in Ts, indicating an increase in the carrier concentration. It was observed that the ZnGa0.05O films with ultrathin MoOx (˜1-2 nanometers) overlayer showed a higher work function (varying from 4.7 to 5.1 eV) as compared to the single layer ZnGa0.05O film work function (˜4.4 eV). A correlation between the surface work function and MoOx layer thickness is observed. The higher work function of the MoOx overlayer is envisaged to improve the transport of the carriers across the heterojunction in a solid state device, thus resulting an increase in device efficiency.

Using molybdenum depleted in 95Mo in UMo fuel

International Nuclear Information System (INIS)

Bakker, K.; Wijtsma, F.; Bos, A.; Mol, C.; Rakhorst, H.; Bretscher, M.; Hofman, G.; Snelgrove, J.

2002-01-01

In recent years significant interest was gained in UMo fuel to be used in Material Test Reactors. This interest was induced by the fact that UMo fuel is mechanically stable, even at high uranium concentrations and high U-burnup. These properties are required in order to use Low Enriched Uranium (LEU) and still be able to achieve high flux and burnup values and, thus, to facilitate the conversion from High Enriched Uranium (HEU) to LEU. Neutronics computations have shown that, although the Mo concentration in UMo fuel is not very high (about 5 - 10w%), the neutron absorption cross sections of natural Mo are sufficiently high to have a considerable negative impact on the reactivity of this UMo fuel. In the present research the neutron absorption cross sections of natural Mo are discussed and the option to reduce the cross section of molybdenum by depleting the Mo in 95 Mo is described. Finally the economic consequences of using Mo depleted in 95 Mo are briefly discussed

Electronic structure investigation of MoS2 and MoSe2 using angle-resolved photoemission spectroscopy and ab initio band structure studies.

Science.gov (United States)

Mahatha, S K; Patel, K D; Menon, Krishnakumar S R

2012-11-28

Angle-resolved photoemission spectroscopy (ARPES) and ab initio band structure calculations have been used to study the detailed valence band structure of molybdenite, MoS(2) and MoSe(2). The experimental band structure obtained from ARPES has been found to be in good agreement with the theoretical calculations performed using the linear augmented plane wave (LAPW) method. In going from MoS(2) to MoSe(2), the dispersion of the valence bands decreases along both k(parallel) and k(perpendicular), revealing the increased two-dimensional character which is attributed to the increasing interlayer distance or c/a ratio in these compounds. The width of the valence band and the band gap are also found to decrease, whereas the valence band maxima shift towards the higher binding energy from MoS(2) to MoSe(2).

Computation of beam quality parameters for Mo/Mo, Mo/Rh, Rh/Rh, and W/Al target/filter combinations in mammography

International Nuclear Information System (INIS)

Kharrati, Hedi; Zarrad, Boubaker

2003-01-01

A computer program was implemented to predict mammography x-ray beam parameters in the range 20-40 kV for Mo/Mo, Mo/Rh, Rh/Rh, and W/Al target/filter combinations. The computation method used to simulate mammography x-ray spectra is based on the Boone et al. model. The beam quality parameters such as the half-value layer (HVL), the homogeneity coefficient (HC), and the average photon energy were computed by simulating the interaction of the spectrum photons with matter. The checking of this computation was done using a comparison of the results with published data and measured values obtained at the Netherlands Metrology Institute Van Swinden Laboratorium, National Institute of Standards and Technology, and International Atomic Energy Agency. The predicted values with a mean deviation of 3.3% of HVL, 3.7% of HC, and 1.5% of average photon energy show acceptable agreement with published data and measurements for all target/filter combinations in the 23-40 kV range. The accuracy of this computation can be considered clinically acceptable and can allow an appreciable estimation for the beam quality parameters

Mixed moderate thermophilic bioleaching of Cu, Mo and Re from molybdenite concentrate: effects of silver ion, medium and energy sources

Directory of Open Access Journals (Sweden)

Hadi Abdollahi

2017-12-01

Full Text Available This study evaluates the effects of different additives such as silver ion, medium and energy sources on the efficiency of mixed moderate thermophilic bioleaching approach to extract Cu, Mo and Re from molybdenite concentrate containing 0.98% Cu, 1.56% Fe, 53.84% Mo, and 0.055% Re. Molybdenite was the major phase of Mo-bearing mineral and chalcopyrite, covellite and pyrite were distinguished as minor phases. The higher copper extraction was obtained in tests with silver additives in all types and quantities rather than tests without silver ion. Kinetic of copper dissolution varied in these experiments and depended on the types and amounts of silver, and other supplemented additives such as ferric ion. There was no clear difference in the copper extraction by various culture media and 100% of Cu was dissolved after 30 days of treatment, using 50 mg/L of silver nitrate as additives. In the best condition and without silver additives, maximum 60% of copper was extracted even in the presence of energy sources such as sulfur, ferrous and ferric ions. In the most effective test with initial pH 1.57, 50 mg/L silver nitrate, and 50 g/L ferric sulfate, 100% of copper was dissolved in less than a week with highest kinetics rate. Molybdenum and rhenium extraction had the same tends with redox potential graph. By increasing the redox potential to the 550-600mV, molybdenite started to dissolve and finally, molybdenum and rhenium were extracted 2% and 9.53% in the best condition; respectively.

Creep Rupture Analysis and Life Estimation of 1.25Cr-0.5Mo, 2.25Cr-1Mo and Modified 9Cr-1Mo Steel: A Comparative Study

Science.gov (United States)

Roy, Prabir Kumar

2018-04-01

This paper highlights a comparative assessment of creep life of 1.25Cr-0.5Mo, 2.25Cr-1Mo and modified 9Cr-1Mo steels based on accelerated creep rupture tests. Creep rupture test data have been analysed and creep life of the above mentioned materials have been assessed using Larson Miller parameter at the stress levels of 60 and 42 MPa for different temperatures. Limiting steam temperatures for minimum design life of 105 h at 42 and 60 MPa for the above mentioned steels have also been calculated. Microstructural studies for the three above mentioned steels are also done.

Stable MoS2 Field-Effect Transistors Using TiO2 Interfacial Layer at Metal/MoS2 Contact

KAUST Repository

Park, Woojin

2017-09-07

Molybdenum disulphide (MoS2) is an emerging 2-dimensional (2D) semiconductor for electronic devices. However, unstable and low performance of MoS2 FETs is an important concern. In this study, inserting an atomic layer deposition (ALD) titanium dioxide (TiO2) interfacial layer between contact metal and MoS2 channel is suggested to achieve more stable performances. The reduced threshold voltage (VTH) shift and reduced series resistance (RSD) were simultaneously achieved.

Gold atoms and clusters on MgO(100) films; an EPR and IRAS study

Science.gov (United States)

Yulikov, M.; Sterrer, M.; Risse, T.; Freund, H.-J.

2009-06-01

Single gold atoms deposited on single crystalline MgO(1 0 0) films grown on Mo(1 0 0) are characterized by electron paramagnetic resonance spectroscopy as well as IR spectroscopy using CO as probe molecules. In this article we describe the first angular dependent measurements to determine the principal hyperfine components of a secondary hyperfine interaction, namely, with 17O of the MgO. The values determined here are in perfect agreement with theoretical expectations and corroborate the previously reported binding mechanism of Au atoms on the oxygen anions of the MgO terrace. The temperature dependent EPR data reveal an onset of Au atom mobility at about 80 K while the formation of Au particles occurs only above 125 K. By an analysis of the EPR line width in combination with STM measurements it is possible to deduce an increase of the interatomic distance above 80 K. The Au/CO complexes show a somewhat smaller temperature stability as compared to the Au atoms. The observed thermal stability is in perfect agreement with theoretical predictions for CO desorption.

Atomic structure calculations of Mo XV-XL

International Nuclear Information System (INIS)

Kubo, Hirotaka; Sugie, Tatsuo; Shiho, Makoto; Suzuki, Yasuo; Ishii, Keishi; Maeda, Hikosuke.

1986-06-01

Energy levels and oscillator strengths were calculated for Mo XV - Mo XL. The computer program for atomic structure calculation, developed by Dr. Robert D. Cowan, Los Alamos National Laboratory, was used in the present work. The scaled energy parameters were empirically determined from the observed spectral data. We present wavelengths and transition probabilities of Mo XV-XL. Energy levels and spectral patterns are presented in figures that are useful for the identification of spectral lines. (author)

Phase diagrams for the M2MoO4–Ln2(MoO43–Hf(MoO42 systems, where M = Li–Cs, Tl and Ln = La–Lu

Directory of Open Access Journals (Sweden)

Zh. G. Bazarova

2017-12-01

Full Text Available In this paper, the results of systematic studies of complex molybdate systems M2MoO4–Ln2(MoO43–Hf(MoO42 (M = Li–Cs, Tl; Ln = La–Lu are presented. Subsolidus phase diagrams of ternary systems were constructed and new triple molybdates were obtained. The optimum synthesis conditions for poly- and monocrystalline form were determined. According to single-crystal data, the structure of one of the representatives of triple molybdates was determined.

Effect of monoclonal antibodies (MoAb) to class I and class II HLA antigens on lectin- and MoAb OKT3-induced lymphocyte proliferation.

Science.gov (United States)

Akiyama, Y; Zicht, R; Ferrone, S; Bonnard, G D; Herberman, R B

1985-04-01

We have examined the effect of several monoclonal antibodies (MoAb) to monomorphic determinants of class II HLA antigens, and MoAb to monomorphic determinants of class I HLA antigens and to beta-2-microglobulin (beta 2-mu) on lectin- and MoAb OKT3-induced proliferation of human peripheral blood mononuclear cells (PBMNC) and cultured T cells (CTC). Some, but not all, anti-class II HLA MoAb inhibited the proliferative response of PBMNC to MoAb OKT3 and pokeweed mitogen (PWM). The degree of inhibitory effect varied considerably. This effect was not limited to anti-class II HLA MoAb since anti-class I HLA MoAb and anti-beta 2-mu MoAb also inhibited MoAb OKT3- or PWM-induced proliferative responses. In contrast, the response of PBMNC to phytohemagglutinin (PHA) and concanavalin A (Con A) was not blocked by any anti-class II HLA MoAb. However, some anti-class II HLA MoAb also inhibited the proliferative response of CTC plus allogeneic peripheral blood adherent accessory cells (AC) to PHA or Con A as well as to MoAb OKT3 or PWM. This may be attributable to the substantially greater class II HLA antigen expression by CTC than by fresh lymphocytes. Pretreatment of either CTC or AC with anti-class II HLA MoAb inhibited OKT3-induced proliferation. In contrast, pretreatment of CTC, but not AC, with anti-class I HLA MoAb inhibited the proliferative response of CTC to OKT3. Pretreatment of CTC with anti-class I HLA MoAb inhibited PHA-, Con A and PWM-induced proliferation, to a greater degree than the anti-class II HLA MoAb. It appears as if lymphocyte activation by different mitogens exhibits variable requirements for the presence of cells expressing major histocompatibility determinants. Binding of Ab to membrane markers may interfere with lymphocyte-AC cooperation, perhaps by inhibiting binding of mitogens to their receptors or by interfering with lymphocyte and AC function. We also have examined the role of class II HLA antigens on CTC by depleting class II HLA-positive cells

Characterization of interaction between U-Mo alloy and Al diffusion-couple

International Nuclear Information System (INIS)

Liu Yunming; Yin Changgeng; Sun Changlong; Chen Jiangang; Sun Xudong

2011-01-01

In this paper, the interaction behavior of U-Mo/Al was studied with the diffusion-couple method, and the couple was continuously jointed by hot-pressing with special device. Annealing experiments were accomplished in a vacuum hot-pressing furnace, and at 550∼570℃ for 5∼21 hours. The results show that the morphology and composition of interaction Layer depend on the interaction layer thickness. The content of U (Mo) and Al is mutational at the interface of U-Mo/interaction layer/Al. The layer close to U-Mo side is mainly composed of product (U, Mo)Al 3 , while the Al side is composed of (U, Mo)Al 4 and UMO 2 Al 20 . Diffusion process of U-Mo/Al is Al immigrating over the Al/U-Mo original interface into U-Mo side and reacting with U-Mo, subsequently the interaction layer is growing into Al. (authors)

Insights into highly improved solar-driven photocatalytic oxygen evolution over integrated Ag3PO4/MoS2 heterostructures

Science.gov (United States)

Cui, Xingkai; Yang, Xiaofei; Xian, Xiaozhai; Tian, Lin; Tang, Hua; Liu, Qinqin

2018-04-01

Oxygen evolution has been considered as the rate-determining step in photocatalytic water splitting due to its sluggish four-electron half-reaction rate, the development of oxygen-evolving photocatalysts with well-defined morphologies and superior interfacial contact is highly important for achieving high-performance solar water splitting. Herein, we report the fabrication of Ag3PO4/MoS2 nanocomposites and, for the first time, their use in photocatalytic water splitting into oxygen under LED light illumination. Ag3PO4 nanoparticles were found to be anchored evenly on the surface of MoS2 nanosheets, confirming an efficient hybridization of two semiconductor materials. A maximum oxygen-generating rate of 201.6 mol L-1 g-1 h-1 was determined when 200 mg MoS2 nanosheets were incorporated into Ag3PO4 nanoparticles, which is around 5 times higher than that of bulk Ag3PO4. Obvious enhancements in light-harvesting property, as well as electron-hole separation and charge transportation are revealed by the combination of different characterizations. ESR analysis verified that more active oxygen-containing radicals generate over illuminated Ag3PO4/MoS2 composite photocatalysts rather than irradiated Ag3PO4. The improvement in oxygen evolution performance of Ag3PO4/MoS2 composite photocatalysts is ascribed to wide spectra response in the visible-light region, more efficient charge separation and enhanced oxidation capacity in the valence band (VB). This study provides new insights into the design and development of novel composite photocatalytic materials for solar-to-fuel conversion.

Mo-Mo Quintuple Bond is Highly Reactive in H-H, C-H, and O-H σ-Bond Cleavages Because of the Polarized Electronic Structure in Transition State.

Science.gov (United States)

Chen, Yue; Sakaki, Shigeyoshi

2017-04-03

The recently reported high reactivity of the Mo-Mo quintuple bond of Mo 2 (N ∧ N) 2 (1) {N ∧ N = μ-κ 2 -CH[N(2,6-iPr 2 C 6 H 3 )] 2 } in the H-H σ-bond cleavage was investigated. DFT calculations disclosed that the H-H σ-bond cleavage by 1 occurs with nearly no barrier to afford the cis-dihydride species followed by cis-trans isomerization to form the trans-dihydride product, which is consistent with the experimental result. The O-H and C-H bond cleavages by 1 were computationally predicted to occur with moderate (ΔG° ⧧ = 9.0 kcal/mol) and acceptable activation energies (ΔG° ⧧ = 22.5 kcal/mol), respectively, suggesting that the Mo-Mo quintuple bond can be applied to various σ-bond cleavages. In these σ-bond cleavage reactions, the charge-transfer (CT Mo→XH ) from the Mo-Mo quintuple bond to the X-H (X = H, C, or O) bond and that (CT XH→Mo ) from the X-H bond to the Mo-Mo bond play crucial roles. Though the HOMO (dδ-MO) of 1 is at lower energy and the LUMO + 2 (dδ*-MO) of 1 is at higher energy than those of RhCl(PMe 3 ) 2 (LUMO and LUMO + 1 of 1 are not frontier MO), the H-H σ-bond cleavage by 1 more easily occurs than that by the Rh complex. Hence, the frontier MO energies are not the reason for the high reactivity of 1. The high reactivity of 1 arises from the polarization of dδ-type MOs of the Mo-Mo quintuple bond in the transition state. Such a polarized electronic structure enhances the bonding overlap between the dδ-MO of the Mo-Mo bond and the σ*-antibonding MO of the X-H bond to facilitate the CT Mo→XH and reduce the exchange repulsion between the Mo-Mo bond and the X-H bond. This polarized electronic structure of the transition state is similar to that of a frustrated Lewis pair. The easy polarization of the dδ-type MOs is one of the advantages of the metal-metal multiple bond, because such polarization is impossible in the mononuclear metal complex.

Micronutrients (B, Co, Cu, Fe, Mn, Mo, and Zn) content in made tea (Camellia sinensis L.) and tea infusion with health prospect: A critical review.

Science.gov (United States)

Karak, Tanmoy; Kutu, Funso Raphael; Nath, Jyoti Rani; Sonar, Indira; Paul, Ranjit Kumar; Boruah, Romesh Kumar; Sanyal, Sandip; Sabhapondit, Santanu; Dutta, Amrit Kumar

2017-09-22

Tea (Camellia sinensis L.) is a perennial acidophilic crop, and known to be a nonalcoholic stimulating beverage that is most widely consumed after water. The aim of this review paper is to provide a detailed documentation of selected micronutrient contents, viz. boron (B), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), and zinc (Zn) in made tea and tea infusion. Available data from the literature were used to calculate human health aspect associated with the consumption of tea infusion. A wide range of micronutrients reported in both made tea and tea infusion could be the major sources of micronutrients for human. The content of B, Co, Cu, Fe, Mn, Mo, and Zn in made tea are ranged from 3.04 to 58.44 μg g -1 , below detectable limit (BDL) to 122.4 μg g -1 , BDL to 602 μg g -1 , 0.275 to 13,040 μg g -1 , 0.004 to 15,866 μg g -1 , 0.04 to 570.80 μg g -1 and 0.01 to 1120 μg g -1 , respectively. Only 3.2 μg L -1 to 7.25 mg L -1 , 0.01 μg L -1 to 7 mg L -1 , 3.80 μg L -1 to 6.13 mg L -1 , 135.59 μg L -1 -11.05 mg L -1 , 0.05 μg L -1 to 1980.34 mg L -1 , 0.012 to 3.78 μg L -1 , and 1.12 μg L -1 to 2.32 μg L -1 of B, Co, Cu, Fe, Mn, Mo, and Zn, respectively, are found in tea infusion which are lower than the prescribed limit of micronutrients in drinking water by World Health Organization. Furthermore, micronutrient contents in tea infusion depend on infusion procedure as well as on the instrument used for analysis. The proportion of micronutrients found in different tea types are 1.0-88.9% for B, 10-60% for Co, 2.0-97.8% for Cu, 67.8-89.9% for Fe, 71.0-87.4% for Mn, 13.3-34% for Mo, and 34.9-83% for Zn. From the results, it can also be concluded that consumption of three cups of tea infusion per day does not have any adverse effect on human health with respect to the referred micronutrients rather got beneficial effects to human.

Development of the Mo loading apparatus for adsorbing high level 99Mo to PZC and packing in 99mTc generator column

International Nuclear Information System (INIS)

Hishinuma, Yukio; Ohmori, Hiroyuki; Noguchi, Tuneyuki; Tatenuma, Katsuyoshi; Genka, Tsuguo; Machi, Sueo

2006-01-01

For developing the automatic system to produce the PZC- 99m Tc generator column based on (n, gamma) method, we developed and fabricated the proto-type apparatus for semi hot test to prepare and pack PZC adsorbed 99 Mo produced by (n, gamma) method into the generator column; PZC is Mo adsorbent with practical performance for (n, gamma) 99m Tc generator with high 99 Mo adsorption and high 99m Tc elution. For conducting the constant supply and delivery of 99m Tc generator, it is necessary to establish the technology of (n, gamma) method 99m Tc generator using PZC and to develop the fabrication system for 99 Mo loading to PZC and packing the 99m Tc generator column. By the reason, we are developing the Mo loading apparatus. In order to automatically conduct the process of 99 Mo adsorption to PZC and PZC- 99 Mo packing into the generator column, based on one channel system developed by JAERI-KAKEN at 3 years ago, an advanced automatic loading system functioned with 8 channels was developed as FNCA project proceeded by the core with Kaken Co. and JAIF for realizing a mass production of 99m Tc generators, and moreover the Japanese patent regarding the PZC- 99m Tc generator including the automatic loading system of 99 Mo to PZC and making 99m Tc generator columns has already been applied with joint applicants of BATAN and Kaken Co. Regarding the multi-type Mo loading apparatus mentioned above, we set it up in a hot of BATAN at December 2003 year. In this report, we will introduce mainly about the multi-channel automatic loading system of 99 Mo. (author)

Elevated Temperature Tensile Tests on DU–10Mo Rolled Foils

Energy Technology Data Exchange (ETDEWEB)

Schulthess, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2014-09-01

Tensile mechanical properties for uranium-10 wt.% molybdenum (U–10Mo) foils are required to support modeling and qualification of new monolithic fuel plate designs. It is expected that depleted uranium-10 wt% Mo (DU–10Mo) mechanical behavior is representative of the low enriched U–10Mo to be used in the actual fuel plates, therefore DU-10Mo was studied to simplify material processing, handling, and testing requirements. In this report, tensile testing of DU-10Mo fuel foils prepared using four different thermomechanical processing treatments were conducted to assess the impact of foil fabrication history on resultant tensile properties.

Characterisation of electrodeposited and heat-treated Ni-Mo-P coatings

Energy Technology Data Exchange (ETDEWEB)

Melo, Regis L.; Casciano, Paulo N.S.; Correia, Adriana N.; Lima-Neto, Pedro de, E-mail: pln@ufc.br [Departamento de Quimica Analitica e Fisico-Quimica, Universidade Federal do Ceara, Fortaleza, CE (Brazil)

2012-07-01

The electrodeposition, hardness and corrosion resistance properties of Ni-Mo-P coatings were investigated. Characterisations of the electrodeposited coatings were carried out using scanning electron microscopy, X-ray diffraction and energy dispersive X-ray analysis techniques. Corrosion tests were performed at room temperature in 10-1 mol dm-3 NaCl solutions and by potentiodynamic linear polarisation. Amorphous Ni-Mo-P coatings were successfully obtained by electrodeposition using direct current. The coating composition showed to be dependent on the bath composition, current density and bath temperature. Both P and Mo contents contribute for the hardness properties of the Ni-Mo-P coatings and the absence of cracks is a requirement to produce electrodeposited Ni-Mo-P coatings with good hardness properties. The hardness values increase with heat-treatment temperature due to the precipitation of Ni, Ni{sub 3}P and NiMo phases during the heat treatment. The corrosion resistance of the electrodeposited Ni-Mo-P amorphous coatings increases with P content in the layer. Among the electrodeposited Ni-Mo-P amorphous coatings, Ni{sub 78}Mo{sub 10}P{sub 12} presented the best hardness and corrosion-resistance properties. The results showed that the addition of P is beneficial for the hardness and corrosion resistance properties of the Ni-Mo-based coatings. (author)

Toroidal deuteron accelerator for Mo-98 neutron activation

Energy Technology Data Exchange (ETDEWEB)

Araujo, Wagner L., E-mail: wagner.leite@ifnmg.edu.br, E-mail: tprcampos@pq.cnpq.br [Instituto Federal do Norte de Minas Gerais (IFN-MG), Montes Claros, MG (Brazil); Campos, Tarcisio P.R. Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

2017-07-01

The radionuclide Tc-{sup 99m} is the most useful radioisotope in nuclear medicine. It can be produced by the Mo-99 beta minus decay. Mo-99 has often been produced in a high- flux nuclear reactor through radioactive neutron capture reactions on Mo-98. The present paper provides a preliminary design of a toroidal transmutation system (TTS) based on a toroidal compact deuteron accelerator, which can provide the Mo-98 transmutation into Mo-99. This system is essentially composed of a multi-aperture plasma electrode and a target, submitted to 180 kV, where a positive deuteron beam is accelerated toward a titanium-target loaded with deuterium in which nuclear d-d fusion reactions are induced. The Particle Studio package of the Computer Simulation Technology (CST) software was applied to design, simulate and optimize the deuteron beam on the target. MCNP code provided to neutronic analysis. Based on electromagnetic and neutronic simulations, the neutron yield and reaction rates were estimated. The simulated data allowed appraising the Mo-99 activity. A TTS, in a specific configuration, could produce a total deuterium current of 1.6 A at the target and a neutron yield of 10{sup 13} n.s{sup -1}. In a arrangement of 30 column samples, TTS provides 230 mCi s{sup -1} Mo{sup 99} in each column, which represents 80% of Tc-99m in secular equilibrium. As conclusion, the system holds potential for generating Mo-99 and Tc-99m in a suitable activity in secular equilibrium. (author)

Toroidal deuteron accelerator for Mo-98 neutron activation

International Nuclear Information System (INIS)

Araujo, Wagner L.; Campos, Tarcisio P.R. Universidade Federal de Minas Gerais

2017-01-01

The radionuclide Tc- 99m is the most useful radioisotope in nuclear medicine. It can be produced by the Mo-99 beta minus decay. Mo-99 has often been produced in a high- flux nuclear reactor through radioactive neutron capture reactions on Mo-98. The present paper provides a preliminary design of a toroidal transmutation system (TTS) based on a toroidal compact deuteron accelerator, which can provide the Mo-98 transmutation into Mo-99. This system is essentially composed of a multi-aperture plasma electrode and a target, submitted to 180 kV, where a positive deuteron beam is accelerated toward a titanium-target loaded with deuterium in which nuclear d-d fusion reactions are induced. The Particle Studio package of the Computer Simulation Technology (CST) software was applied to design, simulate and optimize the deuteron beam on the target. MCNP code provided to neutronic analysis. Based on electromagnetic and neutronic simulations, the neutron yield and reaction rates were estimated. The simulated data allowed appraising the Mo-99 activity. A TTS, in a specific configuration, could produce a total deuterium current of 1.6 A at the target and a neutron yield of 10 13 n.s -1 . In a arrangement of 30 column samples, TTS provides 230 mCi s -1 Mo 99 in each column, which represents 80% of Tc-99m in secular equilibrium. As conclusion, the system holds potential for generating Mo-99 and Tc-99m in a suitable activity in secular equilibrium. (author)

Mo-99 production by fission and future projections

International Nuclear Information System (INIS)

Carranza, E.C.; Novello, A.; Bronca, M.; Cestau, D.; Bavaro, R.; Centurion, R.; Bravo, C.; Bronca, P.; Gualda, E.; Fraguas, F.; Giomi, A.; Ivaldi, L.

2012-01-01

Description of the I-131 and Mo-99 production process: The process starts with the irradiation of uranium-aluminum mini plates in the RA-3, Argentinean Reactor No.3, Ezeiza Atomic Center. In a nuclear reactor there is a constant flow of neutrons and when a neutron with proper energy impacts on a nucleus of U-235, it is absorbed at the same time generate an unstable configuration nuclear. For this reason, the nucleus formed is fission, getting two different atoms. Approximately 6% of the fissions produce Mo-99 and 3% produce I-131; the percentage remaining corresponds to formation of atoms without interest for use in medicine. In conclusion, the objective of the process developed in the Fission Plant, is starting from uranium mini plates, separate the Mo-99 and I-131 generated, the remaining elements formed. - Evolution of Mo-99 Production in the last 10 years: The Fission Mo-99 Plant Production begins routine production of Mo-99 in 1985, using targets made of uranium enriched at 90% U-235. In the 1990s, global concern regarding the use of highly enriched uranium, due to non-proliferation issues, caused the interruption of supply of nuclear material (HEU enriched at 90% of U-235). Following this, Argentina developed target based on low-enriched uranium (less than 20% U-235), becoming in 2002 the first country in the world to produce Mo-99 with LEU targets. From 2002 to date, the activity produced of Mo-99 has been tripled annually (author)

Synthesis of nanometre-thick MoO3 sheets

Science.gov (United States)

Kalantar-Zadeh, Kourosh; Tang, Jianshi; Wang, Minsheng; Wang, Kang L.; Shailos, Alexandros; Galatsis, Kosmas; Kojima, Robert; Strong, Veronica; Lech, Andrew; Wlodarski, Wojtek; Kaner, Richard B.

2010-03-01

The formation of MoO3 sheets of nanoscale thickness is described. They are made from several fundamental sheets of orthorhombic α-MoO3, which can be processed in large quantities via a low cost synthesis route that combines thermal evaporation and mechanical exfoliation. These fundamental sheets consist of double-layers of linked distorted MoO6 octahedra. Atomic force microscopy (AFM) measurements show that the minimum resolvable thickness of these sheets is 1.4 nm which is equivalent to the thickness of two double-layers within one unit cell of the α-MoO3 crystal.

A sensitive electrochemical sensor for in vitro detection of parathyroid hormone based on a MoS2-graphene composite

Science.gov (United States)

Kim, Hyeong-U.; Kim, Hye Youn; Kulkarni, Atul; Ahn, Chisung; Jin, Yinhua; Kim, Yeongseok; Lee, Kook-Nyung; Lee, Min-Ho; Kim, Taesung

2016-10-01

This paper reports a biosensor based on a MoS2-graphene (MG) composite that can measure the parathyroid hormone (PTH) concentration in serum samples from patients. The interaction between PTH and MG was analysed via an electrochemical sensing technique. The MG was functionalized using L-cysteine. Following this, PTH could be covalently immobilized on the MG sensing electrode. The properties of MG were evaluated using scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectrometry. Following optimization of immobilized materials—such as MG, PTH, and alkaline phosphatase (ALP)—the performance of the MG sensor was investigated via cyclic voltammetry, to assess its linearity, repeatability, and reproducibility. Electrochemical impedance spectroscopy was performed on graphene oxide (GO) and MG-modified electrodes to confirm the capture of a monoclonal antibody (MAb) targeting PTH. Furthermore, the ALP-PTH-MG sensor exhibits a linear response towards PTH from artificial serum over a range of 1-50 pg mL-1. Moreover, patient sera (n = 30) were evaluated using the ALP-PTH-MG sensor and compared using standard equipment (Roche E 170). The P-value is less than 0.01 when evaluated with a t-test using Welch’s correction. This implies that the fabricated sensor can be deployed for medical diagnosis.

Fixation Of Mo In Uranium Leach Liquor By Activated Carbon

International Nuclear Information System (INIS)

Mainar, S.; Guswita, A.; Erni, R.A.; Susilaningtyas

1996-01-01

The use of activated carbon for Mo fixation by bulk system is reported. Several factors influencing the fixation process were examined, including contact time, carbon particle size, carbon porosity and the effect of other elements present in Mo containing solutions. Experimental data showed that an adsorption equilibrium of Mo on of activated carbon and 0,85 to 1,18 mm of carbon particle size under forced-convection mass transfer in 100 ml solution that contains + 0,56 m mol of Mo and +. 0,25 m mol Of U was reached after 6 hours period. Under those conditions, about 0,50 m mol of Mo and 0,026 m mol of U were adsorbed into carbon. High concentration of rare earth elements decreased Mo adsorption, hence, the use of activated carbon was not effective to separate Mo from the digestion liquor of Rirang are where Mo was adsorbed, into the carbon + 34,5 %

Development of Commercial-scale Fission Mo-99 Production System

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung-Kon; Lee, Suseung; Hong, Soon-Bog; Jang, Kyung-Duk; Park, Ul Jael; Lee, Jun Sig [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

These days, worldwide {sup 99} Mo supply is not only insufficient but also unstable. Because, most of the main {sup 99}Mo production reactors are more than years old and suffered from frequent and unscheduled shutdown. Therefore, movement to replace old reactors to keep stable supply is now active. Under these conditions, KAERI (Korea Atomic Energy Research Institute) is developing LEU-based fission {sup 99}Mo production process which is connected to the new research reactor (Kijang New Research Reactor, KJRR), which is being constructed in Gijang, Busan, Korea. Historically, the most fission {sup 99}Mo producers have been used highly enriched uranium (HEU) targets so far. However, to reduce the use of HEU in private sector for non-proliferation, {sup 99}Mo producers are forced to convert their HEU-based process to use low enriched uranium (LEU) targets. Economic impact of a target conversion from HEU to LEU is significant. In this study, fission {sup 99}Mo process with non-irradiated LEU targets was presented except separation and purification steps. Pre- and post-irradiation tests of the fission {sup 99}Mo target will be done in 4th quarter of 2016. For the fission Mo production process development, hot experiments with irradiated LEU targets will be done in 4th quarter of 2016. Then, verification of the production process with quality control will be followed until the commercial production of fission {sup 99}Mo scheduled in 2019.

A novel three dimensional semimetallic MoS{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Tang, Zhen-Kun [Beijing Computational Science Research Center, Beijing 100084 (China); Departments of Physics and Electronics, Hengyang Normal University, Hengyang 421008 (China); Zhang, Hui; Liu, Li-Min, E-mail: limin.liu@csrc.ac.cn [Beijing Computational Science Research Center, Beijing 100084 (China); Liu, Hao [Chengdu Green Energy and Green Manufacturing Technology R and D Center, Chengdu, Sichuan 610207 (China); Lau, Woon-Ming [Beijing Computational Science Research Center, Beijing 100084 (China); Chengdu Green Energy and Green Manufacturing Technology R and D Center, Chengdu, Sichuan 610207 (China)

2014-05-28

Transition metal dichalcogenides (TMDs) have many potential applications, while the performances of TMDs are generally limited by the less surface active sites and the poor electron transport efficiency. Here, a novel three-dimensional (3D) structure of molybdenum disulfide (MoS{sub 2}) with larger surface area was proposed based on first-principle calculations. 3D layered MoS{sub 2} structure contains the basal surface and joint zone between the different nanoribbons, which is thermodynamically stable at room temperature, as confirmed by first principles molecular dynamics calculations. Compared the two-dimensional layered structures, the 3D MoS{sub 2} not only owns the large surface areas but also can effectively avoid the aggregation. Interestingly, although the basal surface remains the property of the intrinsic semiconductor as the bulk MoS{sub 2}, the joint zone of 3D MoS{sub 2} exhibits semimetallic, which is derived from degenerate 3d orbitals of the Mo atoms. The high stability, large surface area, and high conductivity make 3D MoS{sub 2} have great potentials as high performance catalyst.

Homogenization of compacted blends of Ni and Mo powders

International Nuclear Information System (INIS)

Lanam, R.D.; Yeh, F.C.H.; Rovsek, J.E.; Smith, D.W.; Heckel, R.W.

1975-01-01

The homogenization behavior of compacted blends of Ni and Mo powders was studied primarily as a function of temperature, mean compact composition, and Mo powder particle size. All compact compositions were in the Ni-rich terminal solid-solution range; temperatures were between 950 and 1200 0 C (in the region of the phase diagram where only the Mo--Ni intermediate phase forms); average Mo particle sizes ranged from 8.4 mu m to 48 mu m. Homogenization was characterized in terms of the rate of decrease of the amounts of the Mo-rich terminal solid-solution phase and the Mo--Ni intermediate phase. The experimental results were compared to predictions based upon the three-phase, concentric-sphere homogenization model. In general, agreement between experimental data and model predictions was fairly good for high-temperature treatments and for compact compositions which were not close to the solubility limit of Mo in Ni. Departures from the model are discussed in terms of surface diffusion contributions to homogenization and non-uniform mixing effects. (U.S.)

Na2MoO2As2O7

Directory of Open Access Journals (Sweden)

Raja Jouini

2012-12-01

Full Text Available Disodium molybdenum dioxide diarsenate, Na2MoO2As2O7, has been synthesized by a solid-state reaction. The structure is built up from MoAs2O12 linear units sharing corners to form a three-dimensional framework containing tunnels running along the a-axis direction in which the Na+ cations are located. In this framework, the AsV atoms are tetrahedrally coordinated and form an As2O7 group. The MoVI atom is displaced from the center of an octahedron of O atoms. Two Na+ cations are disordered about inversion centres. Structural relationships between different compounds: A2MoO2As2O7 (A = K, Rb, AMOP2O7 (A = Na, K, Rb; M = Mo, Nb and MoP2O7 are discussed.

Oxidation of atomically thin MoS2 on SiO2

Science.gov (United States)

Yamamoto, Mahito; Cullen, William; Einstein, Theodore; Fuhrer, Michael

2013-03-01

Surface oxidation of MoS2 markedly affects its electronic, optical, and tribological properties. However, oxidative reactivity of atomically thin MoS2 has yet to be addressed. Here, we investigate oxidation of atomic layers of MoS2 using atomic force microscopy and Raman spectroscopy. MoS2 is mechanically exfoliated onto SiO2 and oxidized in Ar/O2 or Ar/O3 (ozone) at 100-450 °C. MoS2 is much more reactive to O2 than an analogous atomic membrane of graphene and monolayer MoS2 is completely etched very rapidly upon O2 treatment above 300 °C. Thicker MoS2 (> 15 nm) transforms into MoO3 after oxidation at 400 °C, which is confirmed by a Raman peak at 820 cm-1. However, few-layer MoS2 oxidized below 400 °C exhibits no MoO3 Raman mode but etch pits are formed, similar to graphene. We find atomic layers of MoS2 shows larger reactivity to O3 than to O2 and monolayer MoS2 transforms chemically upon O3 treatment even below 100 °C. Work supported by the U. of Maryland NSF-MRSEC under Grant No. DMR 05-20741.

Carbon potential measurement on the Mo-MoC0.47 system by methane - hydrogen equilibration

International Nuclear Information System (INIS)

Ananthasivan, K.; Kaliappan, I.; Chandramouli, V.; Anthonysamy, S.; Vasudeva Rao, P.R.; Mathews, C.K.

1993-01-01

Uranium plutonium mixed carbides are potential candidate fuel materials for liquid metal cooled fast breeder reactors. The carbon potential of the fuel is an important thermochemical property which strongly influences the carbon transport between the clad and the fuel. The carbon potential of the fuel is altered during irradiation of the fuel in the reactor. This is due to the formation of various fission products and their binary and ternary carbides. Molybdenum is a fission product with a high yield which can alter the carbon potential of the fuel. The present work forms part of our studies on the carbon potential measurements in the U - Mo - C ternary system. The carbon potential of the Mo-Mo 2 C couple measured by the methane hydrogen gas equilibration technique is presented here and the results are compared with the values cited in the literature. (author)

Absorption spectra of CsNd(MoO4)2 and CsGd(MoO4)2-Nd3+ crystals in strong magnetic fields

International Nuclear Information System (INIS)

Gorban', I.S.; Kozeeva, L.P.; Slobodyanyuk, A.V.; Shevchenko, V.A.

1987-01-01

The comparison of the electronic structure of Nd 3+ in CsNd(MoO 4 ) 2 and CsGd(MoO 4 ) 2 - Nd 3+ crystals is made. It is established that in these crystals the activator centers, mainly, of the certain type with the symmetry of the local environment C 2 are formed. The absorption spectra of self-activated CsNd(MoO 4 ) 2 crystal differ from spectra of CsGd(MoO 4 ) 2 - Nd 3+ by the presence of the vibrating structure. The Stark splittings of energy levels of Nd 3+ in the investigated crystalline matrices are more sensitive to the environment effect than the Zeeman ones. The ground state of Nd 3+ ion in CsNd(MoO 4 ) 2 and CsGd(MoO 4 ) 2 molybdates is characterized by the similar values of g-factors

Vedinių su priesaga *-mo- raida

Directory of Open Access Journals (Sweden)

Saulius Ambrazas

2011-12-01

Full Text Available DEVELOPMENT OF DERIVATIVES WITH THE SUFFIX *-mo-SummaryAdjectives with the suffix *-mo- have been formed from substantives (cf. Lith. tólimas / tólymas and Latv. dial. tuôl’eims ‘distant’; Pruss. *auktimas ‘high’; Skr. agrimá- ‘the first, who is at the head’ and verbs (cf. Lith. dial. ãpsukmas ‘sewn round’, pliùkšmas ‘deflated, limp’; OLith. laimas ‘happy’ and Pruss. etnīstislaims (gnadenreich III 631; Lith. liñksmas and Latv. lìksms ‘merry, gay, joyfull’, Gmc. *werma- ‘warm’, Skr. bhīmá- ‘terrible, frightfull’, Toch. A, B cämpamo- ‘well-to-do, rich’, Hitt. kišamma- ‘combed’ from the Late Proto-Indo-European. The gratest part of them became participles in the Baltic, Slavic and Albanian languages.On the other hand, the use of derivatives with the suffix *-mo- in the position of abstract nouns is also very old, cf. semanticaly concretized and derivationaly indissoluble abstract noun, in herited from Proto-Indo-European, Lith. dmas (dmai, Latv. dũmi, Pruss. dumis (rauch E 39, Slav. *dymъ, Latv. fūmus, Skr. dhūmó- ‘smoke’ and Gk. θῡ‑μός with abstract meaning ‘soal, vitality, passion,    need’ : dhe-/dh-/dhū- ‘blow; breathe; choke; smoke; rush; disperse; whirl, move, stir’.In the East Baltic languages abstract nouns with the derived suffixes, based on *-mo-, became productive, cf. nomina actionis with *-i-mo- in Lithuanian (cf. gyvẽnimas ‘life’ and corresponding derivatives with *-u-mo- in Latvian (cf. ìeradums ‘custom, habit’.

Co-Processing of Jatropha-Derived Bio-Oil with Petroleum Distillates over Mesoporous CoMo and NiMo Sulfide Catalysts

Directory of Open Access Journals (Sweden)

Shih-Yuan Chen

2018-02-01

Full Text Available The co-processing of an unconventional type of Jatropha bio-oil with petroleum distillates over mesoporous alumina-supported CoMo and NiMo sulfide catalysts (denoted CoMo/γ-Al2O3 and NiMo/γ-Al2O3 was studied. Either a stainless-steel high-pressure batch-type reactor or an up-flow fixed-bed reaction system was used under severe reaction conditions (330–350 °C and 5–7 MPa, similar to the conditions of the conventional diesel hydrodesulfurization (HDS process. To understand the catalytic performance of the mesoporous sulfide catalysts for co-processing, we prepared two series of oil feedstocks. First, model diesel oils, consisting of hydrocarbons and model molecules with various heteroatoms (sulfur, oxygen, and nitrogen were used for the study of the reaction mechanisms. Secondly, low-grade oil feedstocks, which were prepared by dissolving of an unconventional type of Jatropha bio-oil (ca. 10 wt % in the petroleum distillates, were used to study the practical application of the catalysts. Surface characterization by gas sorption, spectroscopy, and electron microscopy indicated that the CoMo/γ-Al2O3 sulfide catalyst, which has a larger number of acidic sites and coordinatively unsaturated sites (CUS on the mesoporous alumina framework, was associated with small Co-incorporated MoS2-like slabs with high stacking numbers and many active sites at the edges and corners. In contrast, the NiMo/γ-Al2O3 sulfide catalyst, which had a lower number of acidic sites and CUS on mesoporous alumina framework, was associated with large Ni-incorporated MoS2-like slabs with smaller stacking numbers, yielding more active sites at the brims and corresponding to high hydrogenation (HYD activity. Concerning the catalytic performance, the mesoporous CoMo/γ-Al2O3 sulfide catalyst with large CUS number was highly active for the conventional diesel HDS process; unfortunately, it was deactivated when oxygen- and nitrogen-containing model molecules or Jatropha bio

ITO-free organic light-emitting diodes with MoO3/Al/MoO3 as semitransparent anode fabricated using thermal deposition method

International Nuclear Information System (INIS)

Lu, Hsin-Wei; Huang, Ching-Wen; Kao, Po-Ching; Chu, Sheng-Yuan

2015-01-01

Highlights: • In this paper, the structure of the proposed devices is substrate (glass; polyethersulfone (PES))/anode (MoO 3 /Al/MoO 3 ; MoO 3 /Al)/α-naphthylphenylbiphenyl diamine (NPB) (40 nm)/tris (8-hydroxyquinoline) aluminum (Alq3) (60 nm)/LiF (1 nm)/Al (150 nm). • The optical transmittance of the metal layer was enhanced by depositing metal oxidation (MoO 3 ) and metal (Al) layers. • The optimized films show the typical sheet resistance of 7 Ω/sq and a high transmittance of 70% at 550 nm. • The indium-tin-oxide (ITO)-free OLEDs with the fabricated composite anodes on a glass substrate exhibited the high luminance and current efficiency of 21,750 cd/m 2 and 3.18 cd/A, respectively. • The bending effects on PES substrate by depositing metal oxidation (MoO 3 ) and metal (Al) layers were also investigated. • MoO 3 covering the Al layer modifies the surface of the electrode and enhances the durability. The surface roughness of the bi-layer films was higher than that of the tri-layer films. Therefore, OLEDs with OMO anode outperform those with bi-layer films anode. - Abstract: In this paper, semitransparent electrodes with the structure substrate/MoO 3 /Al/MoO 3 (OMO) were fabricated via the thermal deposition method for use as the anode in organic light-emitting diodes (OLEDs). The optical transmittance of the metal layer was enhanced by depositing metal oxidation (MoO 3 ) and metal (Al) layers. The optimal thickness of the Al thin films was determined to be 15 nm for high optical transmittance and good electrical conductivity. The optimized films show the typical sheet resistance of 7 Ω/sq and a high transmittance of 70% at 550 nm. The indium-tin-oxide (ITO)-free OLEDs with the fabricated composite anodes on a glass substrate exhibited the high luminance and current efficiency of 21,750 cd/m 2 and 3.18 cd/A, respectively. In addition, bending effects on the polyethersulfone (PES) substrate/MoO 3 /Al/MoO 3 and PES substrate/MoO 3 /Al structures were

U-Mo/Al-Si interaction: Influence of Si concentration

International Nuclear Information System (INIS)

Allenou, J.; Palancher, H.; Iltis, X.; Cornen, M.; Tougait, O.; Tucoulou, R.; Welcomme, E.; Martin, Ph.; Valot, C.; Charollais, F.; Anselmet, M.C.; Lemoine, P.

2010-01-01

Within the framework of the development of low enriched nuclear fuels for research reactors, U-Mo/Al is the most promising option that has however to be optimised. Indeed at the U-Mo/Al interfaces between U-Mo particles and the Al matrix, an interaction layer grows under irradiation inducing an unacceptable fuel swelling. Adding silicon in limited content into the Al matrix has clearly improved the in-pile fuel behaviour. This breakthrough is attributed to an U-Mo/Al-Si protective layer around U-Mo particles appeared during fuel manufacturing. In this work, the evolution of the microstructure and composition of this protective layer with increasing Si concentrations in the Al matrix has been investigated. Conclusions are based on the characterization at the micrometer scale (X-ray diffraction and energy dispersive spectroscopy) of U-Mo7/Al-Si diffusion couples obtained by thermal annealing at 450 deg. C. Two types of interaction layers have been evidenced depending on the Si content in the Al-Si alloy: the threshold value is found at about 5 wt.% but obviously evolves with temperature. It has been shown that for Si concentrations ranging from 2 to 10 wt.%, the U-Mo7/Al-Si interaction is bi-layered and the Si-rich part is located close to the Al-Si for low Si concentrations (below 5 wt.%) and close to the U-Mo for higher Si concentrations. For Si weight fraction in the Al alloy lower than 5 wt.%, the Si-rich sub-layer (close to Al-Si) consists of U(Al, Si) 3 + UMo 2 Al 20 , when the other sub-layer (close to U-Mo) is silicon free and made of UAl 3 and U 6 Mo 4 Al 43 . For Si weight concentrations above 5 wt.%, the Si-rich part becomes U 3 (Si, Al) 5 + U(Al, Si) 3 (close to U-Mo) and the other sub-layer (close to Al-Si) consists of U(Al, Si) 3 + UMo 2 Al 20 . On the basis of these results and of a literature survey, a scheme is proposed to explain the formation of different types of ILs between U-Mo and Al-Si alloys (i.e. different protective layers).

Teens join the MoEDAL collaboration

CERN Multimedia

Stephanie Hills

2013-01-01

The principal investigator for any institute joining an experimental collaboration is generally a self-assured researcher with evident leadership skills and an in-depth knowledge of their subject gained over many years. Katherine Evans fits the brief in every respect, except that she is 17 years old and her research institute is the Langton Star Centre, based at the Simon Langton Grammar School for Boys. The school has just joined the MoEDAL experiment.   Teacher Becky Parker (left) with two students from the Simon Langton Grammar School for Boys in the MoEDAL experimental area. MoEDAL, the latest LHC experiment has detectors located close to the interaction point of the LHCb experiment. This new experiment is designed to search for the highly ionizing avatars of new physics at the LHC, specifically the magnetic monopole or dyon and other highly ionizing stable massive particles from a number of beyond-the-Standard-Model scenarios. MoEDAL was approved in 2010 and is due to start taking data i...

Mo-99 supply issues: Status report and lessons learned

International Nuclear Information System (INIS)

Ponsard, B.

2010-01-01

The worldwide supply of 99 Mo relies on a limited number of research reactors and processing facilities. Its production is essential for the nuclear medicine as 99m Tc, obtained from 99 Mo/ 99m Tc generators, is used in about 80% of the diagnostic nuclear imaging procedures. These applications represent yearly approximately 30 million examinations worldwide. The short half-life's of 99 Mo (66 hours) and its daughter 99m Tc (6 hours) require a regular supply of 99 Mo/ 99m Tc generators to hospitals or central radiopharmacies. Currently, there are only five nuclear reactors involved in the production of 99 Mo on industrial scale: NRU (Canada), HFR (Netherlands), BR2 (Belgium), OSIRIS (France) and SAFARI (South Africa). They irradiate highly enriched uranium targets for the production of about 95% of the available 99 Mo by four processing facilities: AECL/MDS NORDION (Canada), COVIDIEN (Netherlands), IRE (Belgium) and NTP (South Africa). However, these ageing reactors are subject to unscheduled shutdowns and longer maintenance periods making the 99 Mo supply chain vulnerable and unreliable. Several severe disruptions have been experienced since the fall 2005 due to the occurrence of problems at different stages of the supply chain: reactor outages, release of activity from processing facilities, recall of 99 Mo/ 99m Tc generators by the manufacturers, ... It is not expected that the situation will improve significantly in the near future. Therefore, several workshops have been organized in 2009 by the OECD Nuclear Energy Agency (NEA), the International Atomic Energy Agency (IAEA) and the Association of Imaging Producers and Equipment Suppliers (AIPES) to define measures that should be taken to secure the 99 Mo supply in the short, medium and long term. This paper summarizes the current status of the 99 Mo supply, discusses the ongoing plans for additional 99 Mo production capacity and outlines the issues for a reliable global supply chain. (author)

Tailored MoS2 nanorods: a simple microwave assisted synthesis

Science.gov (United States)

Reshmi, S.; Akshaya, M. V.; Satpati, Biswarup; Roy, Anupam; Basu, Palash Kumar; Bhattacharjee, K.

2017-11-01

We report here the synthesis of MoS2 nanostructures by a simple liquid phase exfoliation of MoS2 powder in organic solvents followed by microwave treatment. The probe sonication and the microwave treatment play an important role in rolling and curling of the MoS2 nanosheets to give rise to MoS2 spheres and rod/tube like-structures with diameter approximately 150-200 nm. The MoS2 nanorods formed in this fashion are hollow inside with a wall thickness of 15-20 nm and the length of the nanorods is found in the order of several micrometers. Synthesis of such tailored MoS2 nanorods by liquid phase exfoliation is not yet reported. Our observations suggest the 2H phase of bulk MoS2 remains preserved in the nanostructures with high crystalline quality.

Amorphous-crystalline transition studied in hydrated MoO3

International Nuclear Information System (INIS)

Camacho-Lopez, M.A.; Haro-Poniatowski, E.; Lartundo-Rojas, L.; Livage, J.; Julien, C.M.

2006-01-01

In this work we study the thermal behavior of hydrated MoO 3 synthesized via acidification of sodium molybdate. MoO 3 .nH 2 O (n = 1.4) amorphous compound was heated in air at increasing temperatures in order to obtain the crystalline MoO 3 phase. We have studied the structural changes as a function of annealing temperature by Raman spectroscopy. A statistical study to determine the average size of the crystallites at each annealing step has been realized by scanning electron microscopy. Results show that the hydrated MoO 3 .1.4H 2 O glass transforms in an amorphous MoO 3 .0.7H 2 O phase prior to its crystallization, while the sample heated at 500 deg. C crystallizes into the orthorhombic α-MoO 3 phase with micro-crystallites having an average size of 6.8 μm