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Sample records for iron lead molybdenum

  1. Effect of molybdenum and iron supply on molybdenum (99Mo) and iron (59Fe) uptake and activity of certain enzymes in tomato plants grown in sand culture

    International Nuclear Information System (INIS)

    Chatterjee, C.; Agarwala, S.C.

    1979-01-01

    Tomato (Lycopersicon esculentum Mill. var. Marglobe) plants were raised under controlled sand culture to study the interaction of molybdenum and iron supply on the uptake of molybdenum and iron and activity of certain enzymes affected by iron and/or molybdenum supply. Iron deficiency caused a decrease in the molybdenum uptake and accentuated the effect of molybdenum deficiency in reducing the uptake and more so the translocation of molybdenum from roots to shoots, thus inducing more severe molybdenum deficiency. The deficiency of iron and molybdenum decreased the activity of catalase, succinate dehydrogenase and nitrate reductase, the most marked decrease being found in plants supplied with both iron and molybdenum at low levels. Changes in the activities of nitrate reductase and catalase can be attributed to the interaction of iron and molybdenum supply in their absorption and translocation. (auth.)

  2. Analysis of molybdenum, chromium, vanadium and iron by polarographic techniques

    International Nuclear Information System (INIS)

    Al-Zand, T.K.

    1986-01-01

    The application of direct current Tast polarograph, differential pulse polarography and phase-selective alternative current Tast polarography to the problem of determining molybdenum, chromium, vanadium and iron in various supporting electrolytes is reported. The effect of the supporting electrolyte on the wave/peak potential and sensitivity of the metal ion have been examined. The polarographic methods were applied for simultaneous determination of chromium (3)/chromium (6), vanadium (4), vanadium (5) and iron (2)/iron (3) in different supporting electrolytes

  3. Sulfidation of alumina-supported iron and iron-molybdenum oxide catalysts

    NARCIS (Netherlands)

    Ramselaar, W.L.T.M.; Crajé, M.W.J.; Hadders, R.H.; Gerkema, E.; Beer, de V.H.J.; Kraan, van der A.M.

    1990-01-01

    The transition of alumina-supported iron and iron-molybdenum catalysts from the oxidic precursor to the sulfided catalysts was systematically studied by means of in-situ Mössbauer spectroscopy at room temperature. This enabled the adjudgement of various sulfidic phases in the sulfided catalysts. The

  4. Iron binary and ternary coatings with molybdenum and tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Yar-Mukhamedova, Gulmira, E-mail: gulmira-alma-ata@mail.ru [Institute Experimental and Theoretical Physics Al-Farabi Kazakh National University, 050038, Al-Farabi av., 71, Almaty (Kazakhstan); Ved, Maryna; Sakhnenko, Nikolay; Karakurkchi, Anna; Yermolenko, Iryna [National Technical University “Kharkov Polytechnic Institute”, Kharkov (Ukraine)

    2016-10-15

    Highlights: • High quality coatings of double Fe-Mo and ternary Fe-Mo-W electrolytic alloys can be produced both in a dc and a pulsed mode. • Application of unipolar pulsed current allows receiving an increased content of the alloying components and their more uniform distribution over the surface. • It is established that Fe-Mo and Fe-Mo-W coatings have an amorphous structure and exhibit improved corrosion resistance and microhardness as compared with the steel substrate due to the inclusion molybdenum and tungsten. - Abstract: Electrodeposition of Fe-Mo-W and Fe-Mo layers from a citrate solution containing iron(III) on steel and iron substrates is compared. The utilization of iron(III) compounds significantly improved the electrolyte stability eliminating side anodic redox reactions. The influence of concentration ratios and electrodeposition mode on quality, chemical composition, and functional properties of the alloys is determined. It has been found that alloys deposited in pulse mode have more uniform surface morphology and chemical composition and contain less impurities. Improvement in physical and mechanical properties as well as corrosion resistance of Fe-Mo and Fe-Mo-W deposits when compared with main alloy forming metals is driven by alloying components chemical passivity as well as by alloys amorphous structure. Indicated deposits can be considered promising materials in surface hardening technologies and repair of worn out items.

  5. Structural and electrical properties of iron molybdenum phosphate glasses

    International Nuclear Information System (INIS)

    De Oliveira, R.S.; Quixada-Ceara, Univ. Estadual do Ceara; De Paiva, J.A.C.; De Araujo, M.A.B.; Sombra, A. S.B.

    1998-01-01

    iron molybdenum phosphate glasses (xMoO 3 ·(0.6 - x)P 2 O 5 ·0.4Li 2 O) : yFe 2 O 2 with 0≤x≤ 0.6 and y = 0.03 (mol%) prepared in ambient atmosphere using the melt quenching technique were studied by using DC electrical conductivity, 57 Fe Moessbauer and infrared spectroscopies. The Dc conductivity depends on the MoO 3 concentration x. It was observed that, with increasing x, the ratio Fe 2+ /(Fe 3+ + Fe 2+ ) and the Dc conductivity increase. Infrared spectroscopy and X-ray powder diffraction indicate that a Li 2 MoO 4 crystalline phase is present for high MoO 3 content samples (x = 0.5, 0.6)

  6. Lead-iron phosophate glass

    International Nuclear Information System (INIS)

    Sales, B.C.; Boatner, L.A.

    1988-01-01

    The lead-iron phosphate nuclear waste glasses (LIPNWG) are the subject of the present chapter. They were discovered in 1984 while the authors were attempting to find a sintering aid for certain types of crystalline monazite ceramic high-level nuclear waste forms. In the present chapter, the term waste glass is synonymous with nuclear waste glass (NWG), and the acronym LIP is often used for lead-iron phosphate. Lead-iron phosphate glasses, like many of the previously studied phosphate glasses, are corrosion resistant in aqueous solutions at temperatures below 100 degrees C, and they can be melted and poured at temperatures that are relatively low in comparison with the processing temperatures required for current silicate glass compositions. Unlike the phosphate glasses investigated previously, however, LIPNWGs do not suffer from alteration due to devitrification during realistic and readily, achievable cooling periods. Additionally, lead-iron phosphate glass melts are not nearly as corrosive as the sodium phosphate melts investigated during the 1960s; and, therefore, they can be melted and processed using crucibles made from a variety of materials

  7. Effect of dispersed particles of calcium fluoride on the molybdenum solubility in iron

    International Nuclear Information System (INIS)

    Shvejkin, G.P.; Antsiferov, V.N.; Postnikov, V.S.

    1981-01-01

    The results of the investigation of compositions containing 20 at% Mo and 12 vol.% CaF 2 are presented. The sample diffractograms of compositions Fe+20 at% Mo and (Fe+20 at% Mo)+12 vol.% CaF 2 are given. It is shown that the introduction of calcium fluoride results in formation of continuos series of solid solutions of molybdenum in iron. The results of X-ray diffraction investigations on exceeding solubility limit of molybdenum in iron in the presence of calcium fluoride are confirmed

  8. Adhesive wear of iron chromium nickel silicon manganese molybdenum niobium alloys with duplex structure

    International Nuclear Information System (INIS)

    Lugscheider, E.; Deppe, E.; Ambroziak, A.; Melzer, A.

    1991-01-01

    Iron nickel chromium manganese silicon and iron chromium nickel manganese silicon molybdenum niobium alloys have a so-called duplex structure in a wide concentration range. This causes an excellent resistance to wear superior in the case of adhesive stress with optimized concentrations of manganese, silicon, molybdenum and niobium. The materials can be used for welded armouring structures wherever cobalt and boron-containing alloy systems are not permissible, e.g. in nuclear science. Within the framework of pre-investigations for manufacturing of filling wire electrodes, cast test pieces were set up with duplex structure, and their wear behavior was examined. (orig.) [de

  9. Iron Sulfur and Molybdenum Cofactor Enzymes Regulate the Drosophila Life Cycle by Controlling Cell Metabolism

    Science.gov (United States)

    Marelja, Zvonimir; Leimkühler, Silke; Missirlis, Fanis

    2018-01-01

    Iron sulfur (Fe-S) clusters and the molybdenum cofactor (Moco) are present at enzyme sites, where the active metal facilitates electron transfer. Such enzyme systems are soluble in the mitochondrial matrix, cytosol and nucleus, or embedded in the inner mitochondrial membrane, but virtually absent from the cell secretory pathway. They are of ancient evolutionary origin supporting respiration, DNA replication, transcription, translation, the biosynthesis of steroids, heme, catabolism of purines, hydroxylation of xenobiotics, and cellular sulfur metabolism. Here, Fe-S cluster and Moco biosynthesis in Drosophila melanogaster is reviewed and the multiple biochemical and physiological functions of known Fe-S and Moco enzymes are described. We show that RNA interference of Mocs3 disrupts Moco biosynthesis and the circadian clock. Fe-S-dependent mitochondrial respiration is discussed in the context of germ line and somatic development, stem cell differentiation and aging. The subcellular compartmentalization of the Fe-S and Moco assembly machinery components and their connections to iron sensing mechanisms and intermediary metabolism are emphasized. A biochemically active Fe-S core complex of heterologously expressed fly Nfs1, Isd11, IscU, and human frataxin is presented. Based on the recent demonstration that copper displaces the Fe-S cluster of yeast and human ferredoxin, an explanation for why high dietary copper leads to cytoplasmic iron deficiency in flies is proposed. Another proposal that exosomes contribute to the transport of xanthine dehydrogenase from peripheral tissues to the eye pigment cells is put forward, where the Vps16a subunit of the HOPS complex may have a specialized role in concentrating this enzyme within pigment granules. Finally, we formulate a hypothesis that (i) mitochondrial superoxide mobilizes iron from the Fe-S clusters in aconitase and succinate dehydrogenase; (ii) increased iron transiently displaces manganese on superoxide dismutase, which

  10. Iron Sulfur and Molybdenum Cofactor Enzymes Regulate the Drosophila Life Cycle by Controlling Cell Metabolism

    Directory of Open Access Journals (Sweden)

    Zvonimir Marelja

    2018-02-01

    Full Text Available Iron sulfur (Fe-S clusters and the molybdenum cofactor (Moco are present at enzyme sites, where the active metal facilitates electron transfer. Such enzyme systems are soluble in the mitochondrial matrix, cytosol and nucleus, or embedded in the inner mitochondrial membrane, but virtually absent from the cell secretory pathway. They are of ancient evolutionary origin supporting respiration, DNA replication, transcription, translation, the biosynthesis of steroids, heme, catabolism of purines, hydroxylation of xenobiotics, and cellular sulfur metabolism. Here, Fe-S cluster and Moco biosynthesis in Drosophila melanogaster is reviewed and the multiple biochemical and physiological functions of known Fe-S and Moco enzymes are described. We show that RNA interference of Mocs3 disrupts Moco biosynthesis and the circadian clock. Fe-S-dependent mitochondrial respiration is discussed in the context of germ line and somatic development, stem cell differentiation and aging. The subcellular compartmentalization of the Fe-S and Moco assembly machinery components and their connections to iron sensing mechanisms and intermediary metabolism are emphasized. A biochemically active Fe-S core complex of heterologously expressed fly Nfs1, Isd11, IscU, and human frataxin is presented. Based on the recent demonstration that copper displaces the Fe-S cluster of yeast and human ferredoxin, an explanation for why high dietary copper leads to cytoplasmic iron deficiency in flies is proposed. Another proposal that exosomes contribute to the transport of xanthine dehydrogenase from peripheral tissues to the eye pigment cells is put forward, where the Vps16a subunit of the HOPS complex may have a specialized role in concentrating this enzyme within pigment granules. Finally, we formulate a hypothesis that (i mitochondrial superoxide mobilizes iron from the Fe-S clusters in aconitase and succinate dehydrogenase; (ii increased iron transiently displaces manganese on superoxide

  11. Solubility of iron in liquid lead

    International Nuclear Information System (INIS)

    Ali-Khan, I.

    1981-01-01

    The use of liquid lead in high temperature chemical and metallurgical processes is well known. The structural materials applied for the containment of these processes are either iron base alloys or possess iron as an alloying element. Besides that, lead itself is alloyed in some steels to achieve some very useful properties. For understanding the effect of liquid lead in such structural materials, it is important to determine the solubility of iron in liquid lead which would also be indicative of the stability of these alloys. At the institute of reactor materials of KFA Juelich, investigations have been conducted to determine the solubility of iron in liquid lead up to a temperature of about 1000 0 C. In this presentation the data concerning the solubility of iron in liquid lead are brought up to date and discussed including the results of our previous investigations. (orig.)

  12. Stabilization of iron and molybdenum amorphous state with interstitials under high rates of cooling

    International Nuclear Information System (INIS)

    Barmin, Yu.V.; Vavilova, V.V.; Verevkin, A.G.; Gertsen, A.T.; Kovneristyj, Yu.K.; Kotyurgin, E.A.; Mirkin, B.V.; Palij, N.A.

    1993-01-01

    Amorphous solidification of iron and molybdenum is investigated in thin films and on surface laser irradiated on air at 10 12 and 10 8 /Ks cooling rates correspondingly. Amorphous solidification occurs during ion plasma spraying in thin films of 50 nm at saturation of carbon and oxygen atoms in the ratio of C:0=2.3, but amorphous state is absent at room temperature. Metastable fcc phase, among bcc, is formed by crystallization

  13. Influence of iron supply on toxic effects of manganese, molybdenum and vanadium on soybean, peas, and flax

    Energy Technology Data Exchange (ETDEWEB)

    Warington, K

    1954-01-01

    The investigations were carried out in nutrient solution with iron as ferric citrate and nitrogen in the form of nitrate. The addition of 2.5 ppm vanadium to plants in which iron chlorosis was already established, either by a lack of iron or by excess manganese, failed to counteract the condition, and caused toxic symptoms. The reduction of the standard iron supply to 1/2 or 1/3 accentuated the toxicity of 2.5 or 5 ppm V to soybean and flax, but a similar reduction in phosphorus had no influence. The toxicity to peas, however, was increased when the phosphorus was reduced to 1/10, provided the iron level was high (20 ppm Fe). Raising the iron supply to 20 or 30 ppm counteracted the toxicity of manganese (10 ppm), molybdenum (40 ppm) and vanadium (2.5 ppm), but the result was less marked when these three elements were combined. Iron supplied in successive, small doses proved less efficient in overcoming molybdenum or vanadium, but not manganese excess, than the same amount of iron supplied in fewer and larger quantities. Varying the iron supply had little effect when the concentration of the three elements was low. When increased iron supply had reduced the chlorosis caused by high manganese or vanadium, it also reduced the manganese and vanadium contents of the shoot (ppm/dm), but the molybdenum content was only lowered by high iron when given in non-toxic concentrations (0.1 ppm Mo) combined with excess manganese. Yield data for soybean and flax indicated an interaction between manganese with both molybdenum and vanadium if the iron supply was low, but none between molybdenum and vanadium. The effect of all three metals was additive in respect to iron.

  14. Bioaccessibility of micron-sized powder particles of molybdenum metal, iron metal, molybdenum oxides and ferromolybdenum--Importance of surface oxides.

    Science.gov (United States)

    Mörsdorf, Alexander; Odnevall Wallinder, Inger; Hedberg, Yolanda

    2015-08-01

    The European chemical framework REACH requires that hazards and risks posed by chemicals, including alloys and metals, that are manufactured, imported or used in different products (substances or articles) are identified and proven safe for humans and the environment. Metals and alloys need hence to be investigated on their extent of released metals (bioaccessibility) in biologically relevant environments. Read-across from available studies may be used for similar materials. This study investigates the release of molybdenum and iron from powder particles of molybdenum metal (Mo), a ferromolybdenum alloy (FeMo), an iron metal powder (Fe), MoO2, and MoO3 in different synthetic body fluids of pH ranging from 1.5 to 7.4 and of different composition. Spectroscopic tools and cyclic voltammetry have been employed to characterize surface oxides, microscopy, light scattering and nitrogen absorption for particle characterization, and atomic absorption spectroscopy to quantify released amounts of metals. The release of molybdenum from the Mo powder generally increased with pH and was influenced by the fluid composition. The mixed iron and molybdenum surface oxide of the FeMo powder acted as a barrier both at acidic and weakly alkaline conditions. These findings underline the importance of the surface oxide characteristics for the bioaccessibility of metal alloys. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  15. molybdenum

    African Journals Online (AJOL)

    A [13]). However, the larger size leads to an enhanced Si-C bond length (1.868 A [13]) relative to that of the C-C bond (1.527 Á [13]). This leads to a net cancellation of effects. Consequently the data suggest that the SiMe, and 'Bu appear of similar size when viewed from the centroid of the substituted cyclopentadienyl ligand ...

  16. Estimation of the effect of molybdenum on chemical and electrochemical stability of iron-based alloys

    International Nuclear Information System (INIS)

    Tyurin, A.G.

    2003-01-01

    The E-pH diagram for Mo-H 2 O system is made more precise. It is shown that a passivating film on molybdenum in weakly acid, neutral and alkali solutions may constitute MoO 2 only. In strongly acid solutions at anodic polarization the film should transform according to the following scheme: MoO 2 → Mo 4 O 11 → Mo 9 O 26 → MoO 3 . Sections of a Fe-Mo-O system phase diagram and a Fe-Mo-H 2 O system E-pH diagram at 25 deg C are plotted. MoO 2 is found to be a product of iron-molybdenum alloy oxidation in the air and in water. For the system of alloy Kh17N13M2-H 2 O the section of a E-pH diagram is plotted at 25 deg C [ru

  17. A chemical approach toward low temperature alloying of immiscible iron and molybdenum metals

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Rabia [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Applied Chemistry Research Centre, Pakistan Council of Scientific and Industrial Research Laboratories Complex, Lahore 54600 (Pakistan); Ahmed, Sohail [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Mazhar, Muhammad, E-mail: mazhar42pk@yahoo.com [Department of Chemistry, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Akhtar, Muhammad Javed; Siddique, Muhammad [Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Khan, Nawazish Ali [Material Science Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Shah, Muhammad Raza [HEJ Research Institute of Chemistry, University of Karachi, Karachi 75270 (Pakistan); Nadeem, Muhammad [Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

    2013-11-15

    Graphical abstract: - Highlights: • Low temperature pyrolysis of [Fe(bipy){sub 3}]Cl{sub 2} and [Mo(bipy)Cl{sub 4}] homogeneous powder. • Easy low temperature alloying of immiscible metals like Fe and Mo. • Uniform sized Fe–Mo nanoalloy with particle size of 48–68 nm. • Characterization by EDXRF, AFM, XRPD, magnetometery, {sup 57}Fe Mössbauer and impedance. • Alloy behaves as almost superparamagnetic obeying simple –R(CPE)– circuit. - Abstract: The present research is based on a low temperature operated feasible method for the synthesis of immiscible iron and molybdenum metals’ nanoalloy for technological applications. The nanoalloy has been synthesized by pyrolysis of homogeneous powder precipitated, from a common solvent, of the two complexes, trisbipyridineiron(II)chloride, [Fe(bipy){sub 3}]Cl{sub 2}, and bipyridinemolybedenum(IV) chloride, [Mo(bipy)Cl{sub 4}], followed by heating at 500 °C in an inert atmosphere of flowing argon gas. The resulting nanoalloy has been characterized by using EDXRF, AFM, XRD, magnetometery, {sup 57}Fe Mössbauer and impedance spectroscopies. These results showed that under provided experimental conditions iron and molybdenum metals, with known miscibility barrier, alloy together to give (1:1) single phase material having particle size in the range of 48–66 nm. The magnetism of iron is considerably reduced after alloy formation and shows its trend toward superparamagnetism. The designed chemical synthetic procedure is equally feasible for the fabrication of other immiscible metals.

  18. A chemical approach toward low temperature alloying of immiscible iron and molybdenum metals

    International Nuclear Information System (INIS)

    Nazir, Rabia; Ahmed, Sohail; Mazhar, Muhammad; Akhtar, Muhammad Javed; Siddique, Muhammad; Khan, Nawazish Ali; Shah, Muhammad Raza; Nadeem, Muhammad

    2013-01-01

    Graphical abstract: - Highlights: • Low temperature pyrolysis of [Fe(bipy) 3 ]Cl 2 and [Mo(bipy)Cl 4 ] homogeneous powder. • Easy low temperature alloying of immiscible metals like Fe and Mo. • Uniform sized Fe–Mo nanoalloy with particle size of 48–68 nm. • Characterization by EDXRF, AFM, XRPD, magnetometery, 57 Fe Mössbauer and impedance. • Alloy behaves as almost superparamagnetic obeying simple –R(CPE)– circuit. - Abstract: The present research is based on a low temperature operated feasible method for the synthesis of immiscible iron and molybdenum metals’ nanoalloy for technological applications. The nanoalloy has been synthesized by pyrolysis of homogeneous powder precipitated, from a common solvent, of the two complexes, trisbipyridineiron(II)chloride, [Fe(bipy) 3 ]Cl 2 , and bipyridinemolybedenum(IV) chloride, [Mo(bipy)Cl 4 ], followed by heating at 500 °C in an inert atmosphere of flowing argon gas. The resulting nanoalloy has been characterized by using EDXRF, AFM, XRD, magnetometery, 57 Fe Mössbauer and impedance spectroscopies. These results showed that under provided experimental conditions iron and molybdenum metals, with known miscibility barrier, alloy together to give (1:1) single phase material having particle size in the range of 48–66 nm. The magnetism of iron is considerably reduced after alloy formation and shows its trend toward superparamagnetism. The designed chemical synthetic procedure is equally feasible for the fabrication of other immiscible metals

  19. Synthesis of carbon nanotubes by CVD method using iron and molybdenum-based catalysts supported on ceramic matrices

    International Nuclear Information System (INIS)

    Teixeira, Ana Paula de Carvalho

    2010-01-01

    , while the MgMo0 4 phase is observed in systems with Mo/Fe ratios greater than 0.2. In spite of the differences between the two methods of preparation, the influence of molybdenum is practically the same in the two series of catalysts studied. In both cases, the reaction yield was directly proportional to the molybdenum concentration. When the Mo concentration, however, was much higher than the Fe concentration, the CN synthesis yield decreased. The highest yields, therefore, were found when the Mo/Fe ratio was equal to 1. We propose that excess molybdenum leads to the formation of Mo metallic agglomerates that do not catalyze the CN synthesis by chemical vapor deposition. We also observed that the presence of molybdenum brought about the formation of multi-walled carbon structures (multi-walled nanotubes - MWNT - and bamboo-like structures), while iron promoted the preferential formation of nanotubes with one - SWNT - or few walls. Besides carbon and MgO nanostructures, iron carbide (Fe 3 C) and molybdenum carbide (Mo 2 C) (catalysts containing Mo) were also formed in all of the samples grown with CVD, and the quantity of Mo 2 C increased with the increase in the Mo content in the catalyst. Based on the results obtained and the literature, two distinct regimes of action of Mo in the studied catalysts on the CVD carbon nanotubes synthesis from ethylene are proposed, when carried out in the conditions used in this work: 1) catalytic systems containing only Fe or small concentrations of Mo (MolFe =O, 0.02, 0.05, and 0.10). In this system, part of the Mo-containing species associate with the Fe phases present in the catalysts. During the decomposition of ethylene, Fe associates in particles with metallic Mo or Mo carbide. This association brings about the formation of MWNTs and carbon nanostructures with a higher degree of defects. The iron particles from the magnesium-ferrite phase or from the Fe solid solution in Mg bring about the formation of SWNTs and CNs with only a

  20. Recovery of molybdenum in froth flotation

    International Nuclear Information System (INIS)

    Parlman, R.M.; Bresson, C.R.

    1981-01-01

    Beta-mercaptoethanol has been found to be an effective suppressant for such minerals as copper, iron and lead in a molybdenum sulfide ore froth flotation operation. The recovery process and a suppressant utilizing said compound are claimed

  1. Influence of iron and beryllium additions on heat resistance of silicide coatings on TsMB-30 molybdenum alloy

    International Nuclear Information System (INIS)

    Zajtseva, A.L.; Fedorchuk, N.M.; Lazarev, Eh.M.; Korotkov, N.A.

    1985-01-01

    Alloying of titanium modified silicide coatings on TsMB-30 molybdenum alloy with iron or beryllium is stated to improve their protective properties. Coatings with low content of alloying elements have the best protective properties. Service life of coatings is determined by the formed oxide film and phase transformations taking place in the coating

  2. Soft Chemistry Preparation of lead Iron Vanadate

    International Nuclear Information System (INIS)

    Melghit, Khaled

    2011-01-01

    In order to prepare the new monoclinic Pb 2 FeV 3 O 11 at low temperature; an acidic solution of vanadium oxide, pH 2, was mixed with a corresponding amount of both lead and iron nitrate at boiling temperature. The yellow precipitate obtained is a mixture of lead pyrovanadate Pb 2 V 2 O 7 and an amorphous phase. At 500deg. C, the new monoclinic Pb 2 FeV 3 O 11 phase appears but mixed with Pb 2 V 2 O 7 . At higher temperature, 570deg. C, the monoclinic phase disappears and a new phase appears. This phase is similar to triclinic Pb 2 Fe 2 V 4 O 15 , recently reported, although the EDAX analysis shows the as-prepared sample with higher amount of vanadium and iron. To understand the mechanism involved, lead and iron nitrate solution were reacted separately with vanadium oxide solution. The phases formed were found to be sensitive to initial concentration and to stirring time

  3. Decomposition of oxidezed lead and aluminium thin films on molybdenum substrates

    International Nuclear Information System (INIS)

    Makarovskij, N.A.

    1981-01-01

    The decomposition of oxidized solid phase lead and aluminium thin films on molybdenum substrates in the process of diffusion annealing in the 5x10 -5 mm Hg vacuum at temperatures from 280 to 320 deg C and from 500 to 560 deg C, respectively, is investigated. The conclusion is made that failure of oxidized lead and aluminium thin film coatings is carried out by the mechanism of volumetric self-diffusion. Experimentally established values of activation energies of the process of lead (Qsub(Mo)sup(Pb)=29 kcal/mol) and aluminium (Qsub(Mo)sup(Al)=35 kcal/mol) film failure are close to corresponding activation energies of lead and aluminium volumetric self-diffusion, which agrees with the conclusions made [ru

  4. Effect of molybdenum, vanadium, boron on mechanical properties of high chromium white cast iron in as-cast condition

    Science.gov (United States)

    Nurjaman, F.; Sumardi, S.; Shofi, A.; Aryati, M.; Suharno, B.

    2016-02-01

    In this experiment, the effect of the addition carbide forming elements on high chromium white cast iron, such as molybdenum, vanadium and boron on its mechanical properties and microstructure was investigated. The high chromium white cast iron was produced by casting process and formed in 50 mm size of grinding balls with several compositions. Characterization of these grinding balls was conducted by using some testing methods, such as: chemical and microstructure analysis, hardness, and impact test. From the results, the addition of molybdenum, vanadium, and boron on high chromium white cast iron provided a significant improvement on its hardness, but reduced its toughness. Molybdenum induced fully austenitic matrix and Mo2C formation among eutectic M7C3 carbide. Vanadium was dissolved in the matrix and carbide. While boron was played a role to form fine eutectic carbide. Grinding balls with 1.89 C-13.1 Cr-1.32 Mo-1.36 V-0.00051 B in as-cast condition had the highest hardness, which was caused by finer structure of eutectic carbide, needle like structure (upper bainite) matrix, and martensite on its carbide boundary.

  5. Iron, lead, and cobalt absorption: similarities and dissimilarities

    International Nuclear Information System (INIS)

    Barton, J.C.; Conrad, M.E.; Holland, R.

    1981-01-01

    Using isolated intestinal segments in rats, the absorption of iron, lead, and cobalt was increased in iron deficiency and decreased in iron loading. Similarly, the absorption of these metals was decreased in transfusional erythocytosis, after intravenous iron injection and after parenteral endotoxin injection. Acute bleeding or abbreviated intervals of dietary iron deprivation resulted in increased iron absorption from isolated intestinal segments and in intact animals, while the absorption of lead and cobalt was unaffected. These results suggest that the specificity of the mucosal metal absorptive mechanism is either selectively enhanced for iron absorption by phlebotomy or brief periods of dietary iron deprivation, or that two or more mucosal pathways for iron absorption may exist

  6. Molybdenum extraction from copper-molybdenum ores

    International Nuclear Information System (INIS)

    Nevaeva, L.M.

    1982-01-01

    Molybdenum extraction from copper-molybdenum ores as practised in different countries is reviewed. In world practice the production process including depression of copper and iron sulfides and flotation of molybdenite is widely spread. At two USA factories the process of a selective flotation with molybdenite depression by dextrin is used

  7. Up-gradation of MoO{sub 3} and separation of copper, iron, zinc from roasted molybdenum ore by a leaching process

    Energy Technology Data Exchange (ETDEWEB)

    Jin-Young, Lee; Jyothi Rajesh, Kumar; Ho-Seok, Jeon; Joon-Soo, Kim, E-mail: rajeshkumarphd@rediffmail.com, E-mail: rkumarphd@kigam.re.kr [Extractive Metallurgy Department, Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM) (Korea, Republic of)

    2013-04-15

    The present research paper deals with the oxidation process of molybdenum ore. The main target of the present study is the up-gradation of MoO{sub 3} from roasted molybdenum ore by a leaching process without waste generation. The most important application of hydrometallurgical processing is the leaching process of the ore and it is the primary process to make pure metal from ore. The present investigations optimize the following experimental parameters to improve the concentration of MoO{sub 3} as well as the separation of copper, iron and zinc in roasted molybdenum ore: effect of acid concentration, temperature, pulp density and leaching time were studied systematically. The temperature study was carried out at 550-595 Degree-Sign C for the oxidation process. The XRD result shows that oxidation process of molybdenum ore and SEM pictures were taken for particles before and after the oxidation process at 585 Degree-Sign C for 360 min. (author)

  8. Arsenic, chromium, copper, iron, manganese, lead, selenium and ...

    African Journals Online (AJOL)

    Arsenic, chromium, copper, iron, manganese, lead, selenium and zinc in the tissues of the largemouth yellowfish, Labeobarbus kimberleyensis (Gilchrist and Thompson, 1913), from the Vaal Dam, South Africa, and associated consumption risks.

  9. Role of lead as modifier on the properties of lead iron phosphate nuclear waste glasses

    International Nuclear Information System (INIS)

    Hazra, G.; Mitra, P.; Das, T.

    2011-01-01

    Lead-iron phosphate glasses are a promising new waste form for the safe immobilization of both high level defence and high level commercial radioactive waste for long term disposal. Lead iron phosphate glasses have several advantages such as lower aqueous corrosion rate, lower processing temperature etc. (author)

  10. Molybdenum from uranium solutions

    International Nuclear Information System (INIS)

    Gardner, H.E.

    1981-01-01

    A method of removing molybdenum from a uranium bearing solution is claimed. It comprises adding sufficient reactive lead compound to supply at least 90 percent of the stoichiometric quantity of lead ion required to fully react with the molybdenum present to form insoluble lead molybdate and continuing the reaction with agitation until the desired percentage of the molybdenum present has reacted with the lead ion

  11. Neutron spectrum in small iron pile surrounded by lead reflector

    International Nuclear Information System (INIS)

    Kimura, Itsuro; Hayashi, S.A.; Kobayashi, Katsuhei; Matsumura, Tetsuo; Nishihara, Hiroshi.

    1978-01-01

    In order to save the quantity of sample material, a possibility to assess group constants of a reactor material through measurement and analysis of neutron spectrum in a small sample pile surrounded by a reflector of heavy moderator, was investigated. As the sample and the reflector, we chose iron and lead, respectively. Although the time dispersion in moderation of neutrons was considerably prolonged by the lead reflector, this hardly interferes with the assessment of group constants. Theoretical calculation revealed that both the neutron flux spectrum and the sensitivity coefficient of group constants in an iron sphere, 35 cm in diameter surrounded by the lead reflector, 25 cm thick, were close to those of the bare iron sphere, 108 cm in diameter. The neutron spectra in a small iron pile surrounded by a lead reflector were experimentally obtained by the time-of-flight method with an electron linear accelerator and the result was compared with the predicted values. It could be confirmed that a small sample pile surrounded by a reflector, such as lead, was as useful as a much larger bulk pile for the assessment of group constants of a reactor material. (auth.)

  12. Potentiometric determination of molybdenum

    International Nuclear Information System (INIS)

    Rusina, O.N.; Gorbatkova, B.Kh.

    1977-01-01

    Potentiometric titration by lead acetate is used to determine molybdenum in the form of molybdate ions. The behaviour of bimetallic electrode couples, i.e. tungsten-lead, platinum-lead, lead-carbon electrode, molybdenum-carbon electrode platinum-molibdenum has been investigated. The greatest jump of the potential in the finite point is observed for platinum-molybdenum electrode couple (150 mV/ml at pH 4.0-5.5). The limiting concentration of molybdenum in potentiometric titration by lead acetate is 2.8x10 -4 M. The measurements are accurate to within +-0.1%

  13. Arsenic, chromium, copper, iron, manganese, lead, selenium and ...

    African Journals Online (AJOL)

    2014-05-20

    May 20, 2014 ... Arsenic, chromium, copper, iron, manganese, lead, selenium and zinc in the ... and sediment were collected and trace element concentrations were measured with an ICP-MS. ..... Clay minerals are known to have high sorption affinities ..... sediment/water quality interaction with particular reference to the.

  14. Synthesis by reactive grinding of molybdenum iron bimetallic nitride; Sintesis por molienda reactiva del nitruro bimetalico Mo-Fe: Mo{sub 3}Fe{sub 3}N

    Energy Technology Data Exchange (ETDEWEB)

    Roldan, M. A.; Ortega, A.; Palencia, I.; Real, C.

    2008-07-01

    The transition metal nitride ternary show similar properties to the binary nitride and some times this behaviour are improved. In the present work, the molybdenum-iron nitride has been prepared by reactive grinding form the two metals under nitrogen atmosphere at a pressure of 11 bar. The characterization of the compounds is presented and it is also shown a study of the stability of the nitride under several atmospheres. (Author) 42 refs.

  15. Elimination of the inter-element interferences of iron, gold, molybdenum, tin and antimony when determined in organic solvents by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Aneva, Zara; Arpadjan, Sonja

    1988-01-01

    The mutual interferences in the flame atomic absorption spectrometric determination of iron, gold, molybdenum, tin and antimony after their extraction - pre-concentration as chloride complexes from platinum solutions into isobutyl methyl ketone are investigated. It is suggested that the interferences are caused by chemical reactions in the flame and are influenced by the flame characteristics. The possibility of eliminating the interferences by addition of long-chain quaternary ammonium salts is discussed. (author)

  16. Nitrogen reduction: Molybdenum does it again

    Science.gov (United States)

    Schrock, Richard R.

    2011-02-01

    Nature reduces dinitrogen under mild conditions using nitrogenases, the most active of which contains molybdenum and iron. The only abiological dinitrogen reduction catalyst that avoids the harsh conditions of the Haber-Bosch process contains just molybdenum.

  17. Formation of a homocitrate-free iron-molybdenum cluster on NifEN: implications for the role of homocitrate in nitrogenase assembly.

    Science.gov (United States)

    Fay, Aaron Wolfe; Blank, Michael Aaron; Yoshizawa, Janice Mariko; Lee, Chi Chung; Wiig, Jared Andrew; Hu, Yilin; Hodgson, Keith Owen; Hedman, Britt; Ribbe, Markus Walter

    2010-03-28

    Molybdenum (Mo)-dependent nitrogenase is a complex metalloprotein that catalyzes the biological reduction of dinitrogen (N(2)) to ammonia (NH(3)) at the molybdenum-iron cofactor (FeMoco) site of its molybdenum-iron (MoFe) protein component. Here we report the formation of a homocitrate-free, iron-molybdenum ("FeMo") cluster on the biosynthetic scaffold of FeMoco, NifEN. Such a NifEN-associated "FeMo" cluster exhibits EPR features similar to those of the NifEN-associated, fully-complemented "FeMoco", which originate from the presence of Mo in both cluster species; however, "FeMo" cluster and "FeMoco" display different temperature-dependent changes in the line shape and the signal intensity of their respective EPR features, which reflect the impact of homocitrate on the redox properties of these clusters. XAS/EXAFS analysis reveals that the Mo centers in both "FeMo" cluster and "FeMoco" are present in a similar coordination environment, although Mo in "FeMo" cluster is more loosely coordinated as compared to that in "FeMoco" with respect to the Mo-O distances in the cluster, likely due to the absence of homocitrate that normally serves as an additional ligand for the Mo in the cluster. Subsequent biochemical investigation of the "FeMo" cluster not only facilitates the determination of the sequence of events in the mobilization of Mo and homocitrate during FeMoco maturation, but also permits the examination of the role of homocitrate in the transfer of FeMoco between NifEN and MoFe protein. Combined outcome of these studies establishes a platform for future structural analysis of the interactions between NifEN and MoFe protein, which will provide useful insights into the mechanism of cluster transfer between the two proteins.

  18. Effects of carbon and molybdenum on the microstructures of high chromium white cast irons

    International Nuclear Information System (INIS)

    Sinatora, Amilton; Ambrosio Filho, Francisco; Goldenstein, Helio; Fuoco, Ricardo; Albertin, Eduardo; Mei, Paulo Roberto

    1992-01-01

    The effects of 3 levels of carbon and 1.5% Mo addition on the solidification structures of a 15% chromium white cast iron were studied. The volume fraction of primary austenite and of eutectic carbides, as well as the number of carbide particles per unit length and the mean secondary dendrite arm spacing were measured. By means of thermal analysis, thermal arrest corresponding to the formation of the primary austenite and of the eutectic were determined. The increase in the carbon content and the addition of Mo led to lowering of the thermal arrests and to coarsening of the particles. (author)

  19. Determination of arsenic, antimony, bismuth, cadmium, copper, lead, molybdenum, silver and zinc in geological materials by atomic-absorption spectrometry

    Science.gov (United States)

    Viets, J.G.; O'Leary, R. M.; Clark, Robert J.

    1984-01-01

    Arsenic, antimony, bismuth, cadmium, copper, lead, molybdenum, silver and zinc are very useful elements in geochemical exploration. In the proposed method, geological samples are fused with potassium pyrosulphate and the fusate is dissolved in a solution of hydrochloric acid, ascorbic acid and potassium iodide. When this solution is shaken with a 10% V/V Aliquat 336 - isobutyl methyl ketone organic phase, the nine elements of interest are selectively partitioned in the organic phase. All nine elements can then be determined in the organic phase using flame atomic-absorption spectrometry. The method is rapid and allows the determination of Ag and Cd at levels down to 0.1 p.p.m., Cu, Mo, and Zn down to 0.5 p.p.m., Pb, Bi and Sb down to 1 p.p.m. and As down to 5 p.p.m. in geological materials.

  20. A kinetic study of the redox reactions of complex cyanides of iron, molybdenum and tungsten with compounds of the group VI A elements

    International Nuclear Information System (INIS)

    Dennis, C.R.

    1981-01-01

    The kinetic study arises out of the fact that few is known about redox kinetics of complex cyanides of molybdenum and tungsten. The redox kinetics of the complex cyanides of iron with organic and inorganic compounds are well known in organic chemistry. This comparitive study is done to obtain more information on redox reactions of complex cyanides of molybdenum and tungsten considering its greater applicability in organic and inorganic chemistry because of the propitious reduction potential of this complex cyanide in acidic and alkaline mediums. Various redox systems are kinetically investigated regarding the influence of the oxidising agent, reducing agent hydrogen ions and alkaline-metal ions on the reaction rate. A reaction mechanism is proposed for every system

  1. Hierarchical assembly of urchin-like alpha-iron oxide hollow microspheres and molybdenum disulphide nanosheets for ethanol gas sensing.

    Science.gov (United States)

    Zhang, Dongzhi; Fan, Xin; Yang, Aijun; Zong, Xiaoqi

    2018-08-01

    In this paper, we fabricated a high-performance ethanol sensor using layer-by-layer self-assembled urchin-like alpha-iron oxide (α-Fe 2 O 3 ) hollow microspheres/molybdenum disulphide (MoS 2 ) nanosheets heterostructure as sensitive materials. The nanostructural, morphological, and compositional properties of the as-prepared α-Fe 2 O 3 /MoS 2 heterostructure were characterized by X-ray diffraction (XRD), energy dispersive spectrometer (EDS), scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS), which confirmed its successful preparation and rationality. The α-Fe 2 O 3 /MoS 2 nanocomposite sensor shows good selectivity, excellent reproducibility, fast response/recovery time and low detection limit towards ethanol gas at room temperature, which is superior to the single component of α-Fe 2 O 3 hollow microspheres and MoS 2 nanosheets. Furthermore, the response of the α-Fe 2 O 3 /MoS 2 nanocomposite sensor as a function of ethanol gas concentration was also demonstrated. The enhanced ethanol sensing properties of the α-Fe 2 O 3 /MoS 2 nanocomposite sensor were ascribed to the synergistic effect and heterojunction between the urchin-Like α-Fe 2 O 3 hollow microspheres and MoS 2 nanosheets. This work verifies that the hierarchical α-Fe 2 O 3 /MoS 2 nanoheterostructure is a potential candidate for fabricating room-temperature ethanol gas sensor. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Synthesis of carbon nanotubes by CVD method using iron and molybdenum-based catalysts supported on ceramic matrices;Sintese de nanotubos de carbono por CVD utilizando catalisadores a base de ferro e molibdenio suportados em matrizes ceramicas

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Ana Paula de Carvalho

    2010-07-01

    all catalytic systems, while the MgMo0{sub 4} phase is observed in systems with Mo/Fe ratios greater than 0.2. In spite of the differences between the two methods of preparation, the influence of molybdenum is practically the same in the two series of catalysts studied. In both cases, the reaction yield was directly proportional to the molybdenum concentration. When the Mo concentration, however, was much higher than the Fe concentration, the CN synthesis yield decreased. The highest yields, therefore, were found when the Mo/Fe ratio was equal to 1. We propose that excess molybdenum leads to the formation of Mo metallic agglomerates that do not catalyze the CN synthesis by chemical vapor deposition. We also observed that the presence of molybdenum brought about the formation of multi-walled carbon structures (multi-walled nanotubes - MWNT - and bamboo-like structures), while iron promoted the preferential formation of nanotubes with one - SWNT - or few walls. Besides carbon and MgO nanostructures, iron carbide (Fe{sub 3}C) and molybdenum carbide (Mo{sub 2}C) (catalysts containing Mo) were also formed in all of the samples grown with CVD, and the quantity of Mo{sub 2}C increased with the increase in the Mo content in the catalyst. Based on the results obtained and the literature, two distinct regimes of action of Mo in the studied catalysts on the CVD carbon nanotubes synthesis from ethylene are proposed, when carried out in the conditions used in this work: 1) catalytic systems containing only Fe or small concentrations of Mo (MolFe =O, 0.02, 0.05, and 0.10). In this system, part of the Mo-containing species associate with the Fe phases present in the catalysts. During the decomposition of ethylene, Fe associates in particles with metallic Mo or Mo carbide. This association brings about the formation of MWNTs and carbon nanostructures with a higher degree of defects. The iron particles from the magnesium-ferrite phase or from the Fe solid solution in Mg bring about

  3. Interaction between sulfur and lead in toxicity, iron plaque formation and lead accumulation in rice plant.

    Science.gov (United States)

    Yang, Junxing; Liu, Zhiyan; Wan, Xiaoming; Zheng, Guodi; Yang, Jun; Zhang, Hanzhi; Guo, Lin; Wang, Xuedong; Zhou, Xiaoyong; Guo, Qingjun; Xu, Ruixiang; Zhou, Guangdong; Peters, Marc; Zhu, Guangxu; Wei, Rongfei; Tian, Liyan; Han, Xiaokun

    2016-06-01

    Human activities have resulted in lead and sulfur accumulation in paddy soils in parts of southern China. A combined soil-sand pot experiment was conducted to investigate the influence of S supply on iron plaque formation and Pb accumulation in rice (Oryza sativa L.) under two Pb levels (0 and 600 mg kg(-1)), combined with four S concentrations (0, 30, 60, and 120 mg kg(-1)). Results showed that S supply significantly decreased Pb accumulation in straw and grains of rice. This result may be attributed to the enhancement of Fe plaque formation, decrease of Pb availability in soil, and increase of reduced glutathione (GSH) in rice leaves. Moderate S supply (30 mg kg(-1)) significantly increased Fe plaque formation on the root surface and in the rhizosphere, whereas excessive S supply (60 and 120 mg kg(-1)) significantly decreased the amounts of iron plaque on the root surface. Sulfur supply significantly enhanced the GSH contents in leaves of rice plants under Pb treatment. With excessive S application, the rice root acted as a more effective barrier to Pb accumulation compared with iron plaque. Excessive S supply may result in a higher monosulfide toxicity and decreased iron plaque formation on the root surface during flooded conditions. However, excessive S supply could effectively decrease Pb availability in soils and reduce Pb accumulation in rice plants. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Investigation of lead-iron-phosphate glass for SRP waste

    International Nuclear Information System (INIS)

    Jantzen, C.M.

    1986-10-01

    The search for a host solid for the immobilization of nuclear waste has focused on various vitreous waste forms. Recently, lead-iron-phosphate (LIP) glasses have been proposed for solidification of all types of HLLW. Investigation of this glass for vitrification of SRP waste demonstrated that the phosphate glass is incompatible with the current borosilicate glass technology. The durability of LIP glasses in deionized water was comparable to current borosilicate waste glass formulations, and the LIP glass has a low melt temperature. However, many of the defense waste constituents have low solubility in the phosphate melt, producing an inhomogeneous product. Also, the LIP melt is highly corrosive which prevents the use of current melter materials, in particular Inconel 690, and thus requires more exotic materials of construction such as platinum

  5. [Reference values of iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols for the Venezuelan population].

    Science.gov (United States)

    García-Casal, Maria Nieves; Landaeta, Maritza; Adrianza de Baptista, Gertrudis; Murillo, Carolain; Rincón, Mariela; Bou Rached, Lizet; Bilbao, Arantza; Anderson, Hazel; García, Doris; Franquiz, Julia; Puche, Rafael; Garcia, Omar; Quintero, Yurimay; Peña-Rosas, Juan Pablo

    2013-12-01

    The review on iron, iodine, zinc, selenium, copper, molybdenum, vitamin C, vitamin E, vitamin K, carotenoids and polyphenols recommendations for Venezuela comprise the definitions adopted worldwide known as Dietary Reference Intakes (DRIs) that include Recommended Dietary Allowance (RDA), Estimated Average Requirement (EAR), Adequate Intake (AI) and Tolerable Upper Intake Levels (UL). The RDA for iron: 11 mg/day for infants Vitamin C: 40-50 mg/day for infants, 15-45 mg/ day for children, 75 mg/day for male adolescents, 65 mg/day for female adolescents, 90 mg/day for adult males, 75 mg/day for adult females, 80-85 mg/day during pregnancy and 115-120 mg/day during lactation. Recommendations for copper, selenium, molybdenum, vitamins E, K, carotenoids and polyphenols are also presented. These recommendations will help to design adequate and efficient policies that could help to avoid or to treat the consequences derived from the deficiency or the excess of these nutrients.

  6. Role of iron and aluminum coagulant metal residuals and lead release from drinking water pipe materials.

    Science.gov (United States)

    Knowles, Alisha D; Nguyen, Caroline K; Edwards, Marc A; Stoddart, Amina; McIlwain, Brad; Gagnon, Graham A

    2015-01-01

    Bench-scale experiments investigated the role of iron and aluminum residuals in lead release in a low alkalinity and high (> 0.5) chloride-to-sulfate mass ratio (CSMR) in water. Lead leaching was examined for two lead-bearing plumbing materials, including harvested lead pipe and new lead: tin solder, after exposure to water with simulated aluminum sulfate, polyaluminum chloride and ferric sulfate coagulation treatments with 1-25-μM levels of iron or aluminum residuals in the water. The release of lead from systems with harvested lead pipe was highly correlated with levels of residual aluminum or iron present in samples (R(2) = 0.66-0.88), consistent with sorption of lead onto the aluminum and iron hydroxides during stagnation. The results indicate that aluminum and iron coagulant residuals, at levels complying with recommended guidelines, can sometimes play a significant role in lead mobilization from premise plumbing.

  7. Electron self-trapped at molybdenum complex in lead molybdate: An EPRand TSL comparative study

    Czech Academy of Sciences Publication Activity Database

    Buryi, Maksym; Laguta, Valentyn; Fasoli, M.; Moretti, F.; Trubitsyn, M.; Volnianskii, M.; Vedda, A.; Nikl, Martin

    2017-01-01

    Roč. 192, Dec (2017), s. 767-774 ISSN 0022-2313 R&D Projects: GA MŠk LO1409; GA MŠk LM2015088; GA ČR GA17-09933S EU Projects: European Commission(XE) 690599 - ASCIMAT Institutional support: RVO:68378271 Keywords : EPR * wavelength resolved TSL * self-trapped electron * lead molybdate * molecular orbitals Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 2.686, year: 2016

  8. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nikel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) seamless pipe and tube

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nikel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) seamless pipe and tube

  9. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045 and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) plate, sheet and strip

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045 and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) plate, sheet and strip

  10. Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) rod, bar, and wire

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nickel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) rod, bar, and wire

  11. Galvanic Corrosion of Lead by Iron (Oxyhydr)Oxides: Potential Impacts on Drinking Water Quality.

    Science.gov (United States)

    Trueman, Benjamin F; Sweet, Gregory A; Harding, Matthew D; Estabrook, Hayden; Bishop, D Paul; Gagnon, Graham A

    2017-06-20

    Lead exposure via drinking water remains a significant public health risk; this study explored the potential effects of upstream iron corrosion on lead mobility in water distribution systems. Specifically, galvanic corrosion of lead by iron (oxyhydr)oxides was investigated. Coupling an iron mineral cathode with metallic lead in a galvanic cell increased lead release by 531 μg L -1 on average-a 9-fold increase over uniform corrosion in the absence of iron. Cathodes were composed of spark plasma sintered Fe 3 O 4 or α-Fe 2 O 3 or field-extracted Fe 3 O 4 and α-FeOOH. Orthophosphate immobilized oxidized lead as insoluble hydroxypyromorphite, while humic acid enhanced lead mobility. Addition of a humic isolate increased lead release due to uniform corrosion by 81 μg L -1 and-upon coupling lead to a mineral cathode-release due to galvanic corrosion by 990 μg L -1 . Elevated lead in the presence of humic acid appeared to be driven by complexation, with 208 Pb and UV 254 size-exclusion chromatograms exhibiting strong correlation under these conditions (R 2 average = 0.87). A significant iron corrosion effect was consistent with field data: lead levels after lead service line replacement were greater by factors of 2.3-4.7 at sites supplied by unlined cast iron distribution mains compared with the alternative, lined ductile iron.

  12. The effect of the hemochromatosis (HFE genotype on lead load and iron metabolism among lead smelter workers.

    Directory of Open Access Journals (Sweden)

    Guangqin Fan

    Full Text Available Both an excess of toxic lead (Pb and an essential iron disorder have been implicated in many diseases and public health problems. Iron metabolism genes, such as the hemochromatosis (HFE gene, have been reported to be modifiers for lead absorption and storage. However, the HFE gene studies among the Asian population with occupationally high lead exposure are lacking.To explore the modifying effects of the HFE genotype (wild-type, H63D variant and C282Y variant on the Pb load and iron metabolism among Asian Pb-workers with high occupational exposure.Seven hundred and seventy-one employees from a lead smelter manufacturing company were tested to determine their Pb intoxication parameters, iron metabolic indexes and identify the HFE genotype. Descriptive and multivariate analyses were conducted.Forty-five H63D variant carriers and no C282Y variant carrier were found among the 771 subjects. Compared with subjects with the wild-type genotype, H63D variant carriers had higher blood lead levels, even after controlling for factors such as age, sex, marriage, education, smoking and lead exposure levels. Multivariate analyses also showed that the H63D genotype modifies the associations between the blood lead levels and the body iron burden/transferrin.No C282Y variant was found in this Asian population. The H63D genotype modified the association between the lead and iron metabolism such that increased blood lead is associated with a higher body iron content or a lower transferrin in the H63D variant. It is indicated that H63D variant carriers may be a potentially highly vulnerable sub-population if they are exposed to high lead levels occupationally.

  13. The effect of the hemochromatosis (HFE) genotype on lead load and iron metabolism among lead smelter workers.

    Science.gov (United States)

    Fan, Guangqin; Du, Guihua; Li, Huijun; Lin, Fen; Sun, Ziyong; Yang, Wei; Feng, Chang; Zhu, Gaochun; Li, Yanshu; Chen, Ying; Jiao, Huan; Zhou, Fankun

    2014-01-01

    Both an excess of toxic lead (Pb) and an essential iron disorder have been implicated in many diseases and public health problems. Iron metabolism genes, such as the hemochromatosis (HFE) gene, have been reported to be modifiers for lead absorption and storage. However, the HFE gene studies among the Asian population with occupationally high lead exposure are lacking. To explore the modifying effects of the HFE genotype (wild-type, H63D variant and C282Y variant) on the Pb load and iron metabolism among Asian Pb-workers with high occupational exposure. Seven hundred and seventy-one employees from a lead smelter manufacturing company were tested to determine their Pb intoxication parameters, iron metabolic indexes and identify the HFE genotype. Descriptive and multivariate analyses were conducted. Forty-five H63D variant carriers and no C282Y variant carrier were found among the 771 subjects. Compared with subjects with the wild-type genotype, H63D variant carriers had higher blood lead levels, even after controlling for factors such as age, sex, marriage, education, smoking and lead exposure levels. Multivariate analyses also showed that the H63D genotype modifies the associations between the blood lead levels and the body iron burden/transferrin. No C282Y variant was found in this Asian population. The H63D genotype modified the association between the lead and iron metabolism such that increased blood lead is associated with a higher body iron content or a lower transferrin in the H63D variant. It is indicated that H63D variant carriers may be a potentially highly vulnerable sub-population if they are exposed to high lead levels occupationally.

  14. Comparison of Heavy-Duty Scuffing Behavior between Chromium-Based Ceramic Composite and Nickel-Chromium-Molybdenum-Coated Ring Sliding against Cast Iron Liner under Starvation

    Directory of Open Access Journals (Sweden)

    Yan Shen

    2017-10-01

    Full Text Available A running-in and starved lubrication experiment is designed to investigate the heavy-duty scuffing behavior of piston ring coatings against cast iron (Fe cylinder liner using the piston ring reciprocating liner test rig. The scuffing resistance of the piston ring with the chromium-based ceramic composite coating (CKS, and that with the thermally sprayed nickel-chromium-molybdenum coating (NCM is compared at different nominal pressures (40~100 MPa and temperatures (180~250 °C. With the failure time as a criterion, the rank order is as follows: NCM/Fe > CKS/Fe. Before the scoring occurs at the interface of the piston ring and cylinder liner (PRCL, the cast iron liner enters into a “polish wear” stage, and iron-based adhesive materials begin to form on the piston ring surface. With the macroscopic adhesion formation, the plastic shearing cycle causes surface damages mainly due to abrasive effects for the CKS/Fe pairs and adhesive effects for the NCM/Fe pairs.

  15. Monitoring of occupational exposure in manufacturing of stainless steel constructions. Part I: Chromium, iron, manganese, molybdenum, nickel and vanadium in the workplace air of stainless steel welders.

    Science.gov (United States)

    Kucera, J; Bencko, V; Pápayová, A; Saligová, D; Tejral, J; Borská, L

    2001-11-01

    Exposure to workplace airborne pollutants was examined in a group of 20 workers dealing mainly with welding, polishing, drilling and assembling of stainless steel constructions. Airborne particulate matter (APM) collected using both personal and stationary samplers was analyzed by instrumental neutron activation analysis (INAA). Quality assurance procedures of both sampling and analytical stages are described. Of the elements determined, results are presented for chromium, iron, manganese, molybdenum, nickel and vanadium. The median values of element concentrations exceeded the maximum admissible limits for workplace pollutants only for chromium, while for nickel the limit was exceeded in several individual cases. Sampling of hair, nails, blood, urine and saliva to be used for biological monitoring of the exposed and control groups is also described.

  16. Experimental investigation and thermodynamic modeling of molybdenum and vanadium-containing carbide hardened iron-based alloys

    International Nuclear Information System (INIS)

    Cabrol, E.; Bellot, C.; Lamesle, P.; Delagnes, D.; Povoden-Karadeniz, E.

    2013-01-01

    Highlights: ► Improvement of a carbide selective extraction method. ► Determination of experimental data on the Fe–C–Cr–Mo–V system for carbides above 900 °C: crystallographic structures and compositions of precipitates, matrix composition. ► High molybdenum solubility in FCC carbides. ► Improvement of thermodynamic databases from experimental results. ► Validation of the optimized database with different compositions steels. -- Abstract: A technique for the microstructural study of steels, based on the use of matrix dissolution to collect the very low number density precipitates formed in martensitic steels, has been considerably improved. This technique was applied to two different grades of alloy, characterized by high nickel and cobalt contents and varying chromium, molybdenum and vanadium contents. The technique was implemented at temperatures ranging between 900 °C and 1000 °C, in order to accurately determine experimental data including the crystallographic structure and chemical composition of the carbides, the carbide solvus temperatures, and variations in the chemical composition of the matrix. These experimental investigations reveal that the solubility of molybdenum in FCC carbides can be very high. These results have been compared with the behavior predicted by computational thermodynamics, and used to evaluate and improve the thermodynamic Matcalc steel database. This upgraded database has been validated on three other steels with different chemical compositions, characterized by the same Fe–Cr–Mo–V–C system

  17. Experimental investigation and thermodynamic modeling of molybdenum and vanadium-containing carbide hardened iron-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Cabrol, E., E-mail: ecabrol@mines-albi.fr [Institut Clément Ader, Mines Albi, Campus Jarlard, F-81013 Albi Cedex 09 (France); Aubert and Duval, BP1 F-63770 Les Ancizes (France); Bellot, C. [Institut Clément Ader, Mines Albi, Campus Jarlard, F-81013 Albi Cedex 09 (France); Aubert and Duval, BP1 F-63770 Les Ancizes (France); Lamesle, P.; Delagnes, D. [Institut Clément Ader, Mines Albi, Campus Jarlard, F-81013 Albi Cedex 09 (France); Povoden-Karadeniz, E. [Christian Doppler Laboratory for Early Stages of Precipitation, Vienna University of Technology, Favoritenstrasse 9-11, A-1040 Vienna (Austria)

    2013-04-15

    Highlights: ► Improvement of a carbide selective extraction method. ► Determination of experimental data on the Fe–C–Cr–Mo–V system for carbides above 900 °C: crystallographic structures and compositions of precipitates, matrix composition. ► High molybdenum solubility in FCC carbides. ► Improvement of thermodynamic databases from experimental results. ► Validation of the optimized database with different compositions steels. -- Abstract: A technique for the microstructural study of steels, based on the use of matrix dissolution to collect the very low number density precipitates formed in martensitic steels, has been considerably improved. This technique was applied to two different grades of alloy, characterized by high nickel and cobalt contents and varying chromium, molybdenum and vanadium contents. The technique was implemented at temperatures ranging between 900 °C and 1000 °C, in order to accurately determine experimental data including the crystallographic structure and chemical composition of the carbides, the carbide solvus temperatures, and variations in the chemical composition of the matrix. These experimental investigations reveal that the solubility of molybdenum in FCC carbides can be very high. These results have been compared with the behavior predicted by computational thermodynamics, and used to evaluate and improve the thermodynamic Matcalc steel database. This upgraded database has been validated on three other steels with different chemical compositions, characterized by the same Fe–Cr–Mo–V–C system.

  18. Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

    International Nuclear Information System (INIS)

    Boatner, L.A.; Sales, B.C.

    1989-01-01

    This patent describes lead-iron phosphate glasses containing a high level of Fe 2 O 3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90 0 C, with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10 2 to 10 3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe 2 O 3 in forming the lead-iron phosphate glass is critical. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms

  19. Effects of iron deficiency on the absorption and distribution of lead and cadmium in rats

    International Nuclear Information System (INIS)

    Ragan, H.A.

    1977-01-01

    In order to evaluate the effects of iron deficiency on the absorption of pollutant metals, an iron-deficient diet was fed to young rats until their tissue-iron stores were depleted. Prior to the development of anemia, the iron-deficient rats and littermate controls were administered an intragastric gavage of lead-210 or cadmium-109 and were killed 48 hr later. The body burden of lead was approximately 6 times greater, and that of cadmium approximately 7 times greater, in iron-deficient rats than in the controls. No consistent effects were observed on concentrations of serum total lipids or serum proteins nor on protein electrophoretic patterns in rats with a deficit in iron stores

  20. Hcl extractable minerals (Iron ,Zinc ,Calcium, Lead,Aluminum and ...

    African Journals Online (AJOL)

    Georgette Koduah

    2012-05-07

    http://www.iom.edu/Activities/Nutrition/SummaryDRIs/DRI-Tables.aspx. National Research Council. National Academy of Sciences, 2011. Accessed. May 7, 2012. 29. Coltman CA Pagophagia and Iron lack. JAMA, 1969; 207: 513- 516. 30. Dreyer MJ, Chaushev PG and RF Gledhill Biochemical investigations in geophagia.

  1. China's emergence as the world's leading iron-ore-consuming country

    Science.gov (United States)

    Kirk, W.S.

    2004-01-01

    China has become the leading iron ore consuming nation, and, based on recent steel production capacity increases and plans for more, its consumption will almost certainly to continue to grow. China's iron ore industry, however, faces a number of problems. China's iron ore is low-grade, expensive to process, and its mines are being depleted. For many Chinese steelmakers, particularly in the coastal regions, the delivered cost of domestic iron ore, is more than the delivered cost of foreign ore. Thus China's iron ore imports are expected to increase. As China's growth continues, it will almost certainly surpass Japan to become the leading iron ore importing country as well. Without China's increasing appetite for iron ore, the world iron ore market would be flat or declining. China's recent imports largely offset the slump in demand in North America and Europe. China is regarded by the iron ore industry as the growth sector for the next decade. Although Chinese imports are expected to continue their rapid increase and imports in other Asian countries are expected to continue growing, there appears to be enough greenfield and expansion projects to meet future demand for iron ore worldwide. Present suppliers of iron ore, Australia, Brazil, India, and South Africa, will probably be the chief beneficiaries of China's increasing consumption of iron ore. How long China can continue its extraordinary growth is the primary issue for the future of the iron ore industry. Based on the number and size of planned blast furnaces it appears that China's growth could continue for several more years. ?? 2004 Taylor and Francis.

  2. Sublethal effects of cadmium, manganese, lead, zinc and iron on the ...

    African Journals Online (AJOL)

    The toxicological evaluations of cadmium, iron, manganese, lead and zinc were carried out against albino mice model, Mus musculus. On the basis of 96 hrLC50 value, cadmium (0.47 mM) was found to be the most toxic followed by zinc (2.40 mM), lead (2.42 mM), iron (4.25 mM) and manganese (5.70 mM) was least toxic.

  3. Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

    Science.gov (United States)

    Boatner, Lynn A.; Sales, Brian C.

    1989-01-01

    Lead-iron phosphate glasses containing a high level of Fe.sub.2 O.sub.3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90.degree. C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10.sup.2 to 10.sup.3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe.sub.2 O.sub.3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800.degree. C., since they exhibit very low melt viscosities in the 800.degree. to 1050.degree. C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550.degree. C. and are not adversely affected by large doses of gamma radiation in H.sub.2 O at 135.degree. C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.

  4. Correlation between blood lead concentration and iron deficiency in ...

    African Journals Online (AJOL)

    Results: We studied 223 cases including 98 control children and 125 patients. All children had lead intoxication. Mean (±SD) blood lead concentration in the control group was 57.1 ± 25.3 (ranged 20-212) μg/dl and in the patient group was 57 ± 20.4 (ranged 10.9-159) μg/dl with no significant difference (P value = 0.713).

  5. A Predictive Framework for Thermomechanical Fatigue Life of High Silicon Molybdenum Ductile Cast Iron Based on Considerations of Strain Energy Dissipation

    Science.gov (United States)

    Avery, Katherine R.

    Isothermal low cycle fatigue (LCF) and anisothermal thermomechanical fatigue (TMF) tests were conducted on a high silicon molybdenum (HiSiMo) cast iron for temperatures up to 1073K. LCF and out-of-phase (OP) TMF lives were significantly reduced when the temperature was near 673K due to an embrittlement phenomenon which decreases the ductility of HiSiMo at this temperature. In this case, intergranular fracture was predominant, and magnesium was observed at the fracture surface. When the thermal cycle did not include 673K, the failure mode was predominantly transgranular, and magnesium was not present on the fracture surface. The in-phase (IP) TMF lives were unaffected when the thermal cycle included 673K, and the predominant failure mode was found to be transgranular fracture, regardless of the temperature. No magnesium was present on the IP TMF fracture surfaces. Thus, the embrittlement phenomenon was found to contribute to fatigue damage only when the temperature was near 673K and a tensile stress was present. To account for the temperature- and stress-dependence of the embrittlement phenomenon on the TMF life of HiSiMo cast iron, an original model based on the cyclic inelastic energy dissipation is proposed which accounts for temperature-dependent differences in the rate of fatigue damage accumulation in tension and compression. The proposed model has few empirical parameters. Despite the simplicity of the model, the predicted fatigue life shows good agreement with more than 130 uniaxial low cycle and thermomechanical fatigue tests, cyclic creep tests, and tests conducted at slow strain rates and with hold times. The proposed model was implemented in a multiaxial formulation and applied to the fatigue life prediction of an exhaust manifold subjected to severe thermal cycles. The simulation results show good agreement with the failure locations and number of cycles to failure observed in a component-level experiment.

  6. Monitoring of occupational exposure in manufacturing of stainless steel constructions. Part I: Chromium, iron, manganese, molybdenum, nickel and vanadium in the workplace air of stainless steel welders

    International Nuclear Information System (INIS)

    Kucera, J.; Hnatowicz, V.; Bencko, V.; Papayova, A.; Saligova, D.; Tejral, J.; Borska, L.

    2000-01-01

    Exposure to workplace airborne pollutants was examined in a group of 20 workers dealing mainly with welding, polishing, drilling and assembling of stainless steel constructions. Monitoring of airborne particulate matter (ARM) was performed using both personal and stationary samplers. For the personal full-shift monitoring, a SKC 224 PCRX-4 constant flow rate pump was used which was connected to a sampling head with mixed cellulose matched-weight filters having a diameter of 32 mm and a 0.8 μm pore size. The constant flow rate amounted to 2 L min -1 . For the stationary sampling, the ''Gent'' stacked filter unit PM10 sampler was used, operating at a flow rate of 16 L min -1 . It collects particles having an equivalent aerodynamic diameter (EAD) of less than 10,um in the separate ''coarse'' (2-10 μm EAD) and ''fine'' (< 2 μm EAD) size fractions on two sequential polycarbonate (Costar, Nuclepore) filters with a 47 mm diameter. The filters of both types were analyzed by instrumental neutron activation analysis (INAA). Of the elements determined, results for chromium, iron, manganese, molybdenum, nickel and vanadium are presented. Procedures for quality assurance of both sampling and analytical stages are described. Sampling of biological material for elemental analysis (hair, nails, urine and blood and/or serum) of exposed and control persons in contamination-free conditions was also performed. In addition, saliva samples were collected for studying immunological and genotoxicity aspects of occupational exposure. (author)

  7. Evaluation of lead-iron-phosphate glass as a high-level waste form

    International Nuclear Information System (INIS)

    Chick, L.A.; Bunnell, L.R.; Strachan, D.M.; Kissinger, H.E.; Hodges, F.N.

    1986-01-01

    The lead-iron-phosphate nuclear waste glass developed at Oak Ridge National Laboratory (ORNL) was evaluated for its potential as an improvement over the current reference waste form, borosilicate glass. Vitreous lead-iron-phosphate glass appears to have substantially better chemical durability than borosilicate glass. However, severe crystallization leading to deteriorated chemical durability would result if this glass were poured into large canisters as is presently done with borosilicate glass. Cesium leach rates from this crystallized material are orders of magnitude greater than those from borosilicate glass. Therefore, in order to realize the performance advantages of the lead-iron-phosphate material in a nuclear waste form, it would be necessary to process it so that it is rapidly cooled, thus retaining its vitreous structure. 22 refs., 4 figs., 4 tabs

  8. Calcium carbonate in the removal of iron and lead from dilute waste water

    Energy Technology Data Exchange (ETDEWEB)

    Hautala, E; Randall, J; Goodban, A; Waiss, A Jr

    1977-01-01

    The utility of powdered CaCO/sub 3/ in the removal of lead and iron from dilute aqueous waste waters has been demonstrated and the results successfully applied to treat industrial waste water from a lead battery plant. The reclaimed water is suitable for recycling to the plant and is now being utilized with consequent economic advantages.

  9. Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element

    International Nuclear Information System (INIS)

    Delaplace, J.

    1960-09-01

    By means of an apparatus which makes possible thermal pre-treatments in vacuo, quenching carried out in a high purity argon atmosphere, and simultaneous recording of time temperature cooling and thermal contraction curves, the author has examined the transformations which occur in uranium-chromium, uranium-iron and uranium-molybdenum alloys during their quenching and subsequent return to room temperature. For uranium-chromium and uranium-iron alloys, the temperature at which the γ → β transformation starts varies very little with the rate of cooling. For uranium-molybdenum alloys containing 2,8 atom per cent of Mo, this temperature is lowered by 120 deg. C for a cooling rate of 500 deg. C/mn. The temperature at which the β → α transformation starts is lowered by 170 deg. C for a cooling rate of 500 deg. C/mn in the case of uranium-chromium alloy containing 0,37 atom per cent of Cr. The temperature is little affected in the case of uranium-iron alloys. The addition of chromium or iron makes it possible to conserve the form β at ordinary temperatures after quenching from the β and γ regions. The β phase is particularly unstable and changes into needles of the α form even at room temperatures according to an autocatalytic transformation law similar to the austenitic-martensitic transformation law in the case of iron. The β phase obtained by quenching from the β phase region is more stable than that obtained by quenching from the γ region. Chromium is a more effective stabiliser of the β phase than is iron. Unfortunately it causes serious surface cracking. The β → α transformation in uranium-chromium alloys has been followed at room temperature by means of micro-cinematography. The author has not observed the direct γ → α transformation in uranium-molybdenum alloys containing 2,8 per cent of molybdenum even for cooling rates of up to 2000 deg. C/s. He has however observed the formation of several martensitic structures. (author) [fr

  10. Blood lead: Its effect on trace element levels and iron structure in hemoglobin

    International Nuclear Information System (INIS)

    Jin, C.; Li, Y.; Li, Y.L.; Zou, Y.; Zhang, G.L.; Normura, M.; Zhu, G.Y.

    2008-01-01

    Lead is a ubiquitous environmental pollutant that induce a broad range of physiological and biochemical dysfunctions. The purpose of this study was to investigate its effects on trace elements and the iron structure in hemoglobin. Blood samples were collected from rats that had been exposed to lead. The concentration of trace elements in whole blood and blood plasma was determined by ICP-MS and the results indicate that lead exists mainly in the red blood cells and only about 1-3% in the blood plasma. Following lead exposure, the concentrations of zinc and iron in blood decrease, as does the hemoglobin level. This indicates that the heme biosynthetic pathway is inhibited by lead toxicity and that lead poisoning-associated anemia occurs. The selenium concentration also decreases after lead exposure, which may lead to an increased rate of free radical production. The effect of lead in the blood on iron structure in hemoglobin was determined by EXAFS. After lead exposure, the Fe-O bond length increases by about 0.07 A and the Fe-Np bond length slightly increases, but the Fe-N ε bond length remains unchanged. This indicates that the blood content of Hb increases, but that the content of HbO 2 decreases

  11. [The intelligence quotient and malnutrition. Iron deficiency and the lead concentration as confusing variables].

    Science.gov (United States)

    Vega-Franco, L; Mejía, A M; Robles, B; Moreno, L; Pérez, Y

    1991-11-01

    This study gave us the opportunity to know the roles iron deficiency and the presence of lead in blood play, as confounding variables, in relation to the state of malnutrition and the intellect of those children. A sample of 169 school children were classified according to their state of nutrition, their condition in reference to serum iron and lead concentrations. In addition, their intelligence was evaluated. The results confirmed that those children with lower weights and heights registered lesser points of intelligence; in fact, iron deficiency cancels out the difference in favor of those taller and weighing more. Lead did not contribute as a confounding variable, but more than half of the children showed possible toxic levels of this metal.

  12. Lead-iron phosphate glass: a stable storage medium for high-level nuclear waste

    International Nuclear Information System (INIS)

    Sales, B.C.; Boatner, L.A.

    1984-01-01

    Results are presented which show that lead-iron phosphate glasses are a promising new waste form for the safe immobilization of both high-level defense and high-level commercial radioactive waste. Relative to the borosilicate nuclear waste glasses that are currently the ''reference'' waste form for the long-term disposal of nuclear waste, lead-iron phosphate glasses have several distinct advantages: (1) an aqueous corrosion rate that is about 1000 times lower, (2) a processing temperature that is 100 0 to 250 0 C lower and, (3) a much lower melt viscosity in the temperature range from 800 0 to 1000 0 C. Most significantly, the lead-iron phosphate waste form can be processed using a technology similar to that developed for borosilicate nuclear waste glasses

  13. A new analytical approach to understanding nanoscale lead-iron interactions in drinking water distribution systems.

    Science.gov (United States)

    Trueman, Benjamin F; Gagnon, Graham A

    2016-07-05

    High levels of iron in distributed drinking water often accompany elevated lead release from lead service lines and other plumbing. Lead-iron interactions in drinking water distribution systems are hypothesized to be the result of adsorption and transport of lead by iron oxide particles. This mechanism was explored using point-of-use drinking water samples characterized by size exclusion chromatography with UV and multi-element (ICP-MS) detection. In separations on two different stationary phases, high apparent molecular weight (>669 kDa) elution profiles for (56)Fe and (208)Pb were strongly correlated (average R(2)=0.96, N=73 samples representing 23 single-unit residences). Moreover, (56)Fe and (208)Pb peak areas exhibited an apparent linear dependence (R(2)=0.82), consistent with mobilization of lead via adsorption to colloidal particles rich in iron. A UV254 absorbance peak, coincident with high molecular weight (56)Fe and (208)Pb, implied that natural organic matter was interacting with the hypothesized colloidal species. High molecular weight UV254 peak areas were correlated with both (56)Fe and (208)Pb peak areas (R(2)=0.87 and 0.58, respectively). On average, 45% (std. dev. 10%) of total lead occurred in the size range 0.05-0.45 μm. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. The determination of aluminum, copper, iron, and lead in glycol formulations by atomic absorption spectroscopy

    Science.gov (United States)

    1977-01-01

    Initial screening tests and the results obtained in developing procedures to determine Al, Cu, Fe, and Pb in glycol formulations are described. Atomic absorption completion was selected for Cu, Fe and Pb, and after comparison with emission spectroscopy, was selected for Al also. Before completion, carbon, iron, and lead are extracted with diethyl dithio carbamate (DDC) into methyl isobutyl ketone (MIBK). Aluminum was also extracted into MIBK using 8-hydroxyquinoline as a chelating agent. As little as 0.02 mg/l carbon and 0.06 mg/l lead or iron may be determined in glycol formulations. As little as 0.3 mg/l aluminum may be determined.

  15. Experimental comparison of gamma attenuations by glasses, lead, iron and concretes

    International Nuclear Information System (INIS)

    Charamathieu, Andre; Papot, Lucien

    1964-08-01

    The authors report the experimental determination, for lead glasses of density 3.3, 4.2, 5.2 and 6.2, of thicknesses equivalent to thicknesses given for lead, iron, ordinary concrete and barite concrete for Cobalt 60 and Caesium 137 radiations. Results are presented under the form of curves. Attenuation measurements made on this opportunity and those made on various hot cells have been compared with theoretical attenuation curves produced in another CEA document [fr

  16. Summary of ENDF/B-V evaluations for carbon, calcium, iron, copper, and lead and ENDF/B-V Revision 2 for calcium and iron

    Energy Technology Data Exchange (ETDEWEB)

    Fu, C Y

    1982-09-01

    This report, together with documents already published, describes the ENDF/B-V evaluations of the neutron and gamma-ray-production cross sections for carbon, calcium, iron, copper, and lead and the ENDF/B-V Revision 2 evaluations for calcium and iron.

  17. Lead-iron phosphate glass as a containment medium for the disposal of high-level nuclear wastes

    Science.gov (United States)

    Boatner, L.A.; Sales, B.C.

    1984-04-11

    Disclosed are lead-iron phosphate glasses containing a high level of Fe/sub 2/O/sub 3/ for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste

  18. Numerical integration of electromagnetic cascade equations, discussion of results for air, copper, iron, and lead

    International Nuclear Information System (INIS)

    Adler, A.; Fuchs, B.; Thielheim, K.O.

    1977-01-01

    The longitudinal development of electromagnetic cascades in air, copper, iron, and lead is studied on the basis of results derived recently by numerical integration of the cascade equations applying rather accurate expressions for the cross-sections involved with the interactions of high energy electrons, positrons, and photons in electromagnetic cascades. Special attention is given to scaling properties of transition curves. It is demonstrated that a good scaling may be achieved by means of the depth of maximum cascade development. (author)

  19. Optical Analysis of Iron-Doped Lead Sulfide Thin Films for Opto-Electronic Applications

    Science.gov (United States)

    Chidambara Kumar, K. N.; Khadeer Pasha, S. K.; Deshmukh, Kalim; Chidambaram, K.; Shakil Muhammad, G.

    Iron-doped lead sulfide thin films were deposited on glass substrates using successive ionic layer adsorption and reaction method (SILAR) at room temperature. The X-ray diffraction pattern of the film shows a well formed crystalline thin film with face-centered cubic structure along the preferential orientation (1 1 1). The lattice constant is determined using Nelson Riley plots. Using X-ray broadening, the crystallite size is determined by Scherrer formula. Morphology of the thin film was studied using a scanning electron microscope. The optical properties of the film were investigated using a UV-vis spectrophotometer. We observed an increase in the optical band gap from 2.45 to 3.03eV after doping iron in the lead sulfide thin film. The cutoff wavelength lies in the visible region, and hence the grown thin films can be used for optoelectronic and sensor applications. The results from the photoluminescence study show the emission at 500-720nm. The vibrating sample magnetometer measurements confirmed that the lead sulfide thin film becomes weakly ferromagnetic material after doping with iron.

  20. Iron

    Science.gov (United States)

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  1. Carbon, chromium and molybdenum contents

    International Nuclear Information System (INIS)

    Sinatora, A; Goldenstein, H.; Mei, P.R.; Albertin, E.; Fuoco, R.; Mariotto, C.L.

    1992-01-01

    This work describes solidification experiments on white cast iron, with 15 and 20% of chromium, 2.3, 3.0 and 3.6 % of carbon and 0.0, 1.5 and 2.5 % of molybdenum in test de samples with 30 mm diameter. Measurements were performed on the austenite and eutectic formation arrests, the number of the eutectic carbide particles relative to the total and the eutectic volumes, and the volume fraction of the primary austenite

  2. Some studies of lead and iron adsorption on the W(100) surface by field emission microscopy

    International Nuclear Information System (INIS)

    Jones, J.P.; Roberts, E.W.

    1978-01-01

    The behaviour of lead and iron adsorbed on the W(100) surface has been studied by probe hole field emission microscopy, field desorption, and by measurement of the total energy distribution (TED) of field-emitted electrons. Lead adsorbed at 300 K which reduces the work function of W(100) can be completely removed at 78 K by field desorption below 3.2 V A -1 and the resulting surface has both the work function and TED, which are characteristic of the clean plane. Condensation at 800 K followed by field desorption, results in a plane surface of work function 4.17 eV and an altered TED. This effect is attributed to the microfacetting, which is observed by LEED. The Swanson peak in the W(100) TED which is removed by submonolayer amounts of lead re-emerges at monolayer coverage when lead adopts the (1 X 1) structure. Such behaviour is consistent with the model proposed by Kar and Soven. A spectral peak observed when lead is adsorbed on the reconstructed W(100) surface is thought to derive for the atomic 1 D state. Adsorption of iron on a W(100) surface reduces phi considerably due to dipole formation and efficiently quenches the Swanson peak. (Auth.)

  3. Does lead use the intestinal absorptive pathways of iron? Impact of iron status on murine 210Pb and 59Fe absorption in duodenum and ileum in vivo

    International Nuclear Information System (INIS)

    Elsenhans, Bernd; Janser, Heinz; Windisch, Wilhelm; Schuemann, Klaus

    2011-01-01

    Highlights: → Absorption of 210 Pb increases much less than that of 59 Fe in murine duodena. → 210 Pb-absorption is almost equally high in murine duodenal and ileal segments. → 59 Fe absorption is much lower in ileal than in duodenal segments. → There must be an additional DMT1-independet pathway for intestinal Pb absorption. -- Abstract: Background: Human isotope studies and epidemiological trials are controversial as to whether lead absorption shares the absorptive pathways of iron and whether body lead content can be reduced by iron supplementation. Aim: To compare the impact of iron-deficiency on 59 Fe- and 210 Pb-absorption rates in duodenal and ileal segments. Methods: 59 Fe- and 210 Pb-absorption was determined in ligated duodenal and ileal segments from juvenile and adult iron-deficient and iron-adequate C57Bl6 wild-type mice (n = 6) in vivo at luminal concentrations corresponding to human exposure (Fe: 1 and 100 μmol/L; Pb: 1 μmol/L). Results and discussion: 59 Fe-absorption increased 10-15-fold in iron-deficient duodena from adult and adolescent mice. Ileal 59 Fe-absorption was 4-6 times lower than in iron-adequate duodena showing no adaptation to iron-deficiency. This in accordance to expectation as the divalent metal transport 1 (DMT1) shows low ileal expression levels. Juvenile 59 Fe-absorption was about twice as high as in adult mice. In contrast, duodenal 210 Pb-absorption was increased only 1.5-1.8-fold in iron-deficiency in juvenile and adult mice and, again in contrast to 59 Fe, ileal 210 Pb-absorption was as high as in iron-adequate duodena. Conclusions: The findings suggest a DMT1-independent pathway to mediate lead absorption along the entire small intestine in addition to DMT1-mediated duodenal uptake. Ileal lead absorption appears substantial, due the much longer residence of ingesta in the distal small intestine. Differences in lead-solubility and -binding to luminal ligands can, thus, explain the conflicting findings regarding the

  4. Induced Phytoextraction of Lead Through Chemical Manipulation of Switchgrass and Corn; Role of Iron Supplement.

    Science.gov (United States)

    Johnson, Deayne M; Deocampo, Daniel M; El-Mayas, Hanan; Greipsson, Sigurdur

    2015-01-01

    The effects of combined chemical application of benomyl, ethylenedianinetetraacetate (EDTA), and iron (Fe) (foliar and root) on lead (Pb) phytoextraction by switchgrass (Panicum virgatum) and corn (Zea mays) was examined. Switchgrass was grown in Pb-contaminated urban topsoil with the following treatments: (C) Control, (B) benomyl, (E) EDTA, (F) foliar-Fe, (BE) benomyl + EDTA, (BF) benomyl + foliar-Fe, (FE) foliar-Fe + EDTA, (BFE) benomyl + foliar-Fe + EDTA. Corn was grown in sand-culture supplemented with Pb (500 mg kg(-1)) with the following treatments: (C) control, (B) benomyl, (E) EDTA, (F) root-Fe, (BE) benomyl + EDTA, (BF) benomyl + root-Fe, (FE) root-iron + EDTA, and, (BFE) benomyl + root-Fe + EDTA. All treatments were replicated three times and pots were arranged in a completely randomized design. Plants were analyzed for element concentration (Fe, Zn, P, and Pb) using either inductively coupled plasma (argon) atomic emission spectroscopy (ICP-AES) or graphite furnace atomic absorption spectrometer. Iron supplementation (foliar and root) affected Pb-translocation in plants. Foliar-Fe treatment increased translocation ratio of Pb (TF-Pb) significantly compared to other treatments with the exception of plants treated with benomyl and BF. Root-Fe treatment in combination with EDTA (FE) increased TF-Pb significantly compared to other treatments. Phytoextraction was improved by the combined chemical application; plants treated with BFE treatment increased Pb-total-phytoextraction by 424% compared to Control plants.

  5. Solubility Measurements and Modeling of Zinc, Lead and Iron Sulfides at High Temperatures and High Pressures

    DEFF Research Database (Denmark)

    Carolina Figueroa Murcia, Diana; Fosbøl, Philip Loldrup; Thomsen, Kaj

    Solubility measurements of sulfides in aqueous solutions are necessary to understand the behaviour of these scaling minerals in geothermal and oil reservoirs. The low solubility levels of Zinc Sulfide (ZnS), Lead Sulfide (PbS) and Iron Sulfide (FeS) make the solubility measurements a challenging...... oxygen atmosphere to avoid the risk of oxidation of sulfide minerals. The solution is kept in an equilibrium cell at constant temperature and pressure with continuous stirring. The concentration of Zn2+, Pb2+, Fe2+ and S2- are measured using Inductively Coupled Plasma Optical Emission spectrometry (ICP...

  6. X-ray target with substrate of molybdenum alloy

    International Nuclear Information System (INIS)

    Hirsch, H.H.

    1980-01-01

    Rotary targets for x-ray tubes are provided comprising a molybdenum base body alloyed with a stabilizing proportion of iron, silicon, cobalt, tantalum, niobium, hafnium, stable metal oxide, or a mixture of the preceding

  7. Tin oxide quantum dots embedded iron oxide composite as efficient lead sensor

    Science.gov (United States)

    Dutta, Dipa; Bahadur, Dhirendra

    2018-04-01

    SnO2 quantum dots (QDs) embedded iron oxide (IO) nanocomposite is fabricated and explored as a capable sensor for lead detection. Square wave anodic stripping voltammetry (SWASV) and amperometry have been used to explore the proposed sensor's response towards lead detection. The modified electrode shows linear current response for concentration of lead ranging from 99 nM to 6.6 µM with limit of detection 0.42 µM (34 ppb). Amperometry shows a detection limit as low as 0.18 nM (0.015 ppb); which is far below the permissible limit of lead in drinking water by World Health Organization. This proposed sensor shows linear current response (R2 = 0.98) for the lead concentration ranging from 133 × 10-9 to 4.4 × 10-6M. It also exhibits rapid response time of 12 sec with an ultra high sensitivity of 5.5 µA/nM. These detection properties promise the use of SnO2 QDs -IO composite for detection of lead in environmental sample with great ease.

  8. Accumulation and distribution of iron, cadmium, lead and nickel in cucumber plants grown in hydroponics containing two different chelated iron supplies.

    Science.gov (United States)

    Csog, Árpád; Mihucz, Victor G; Tatár, Eniko; Fodor, Ferenc; Virág, István; Majdik, Cornelia; Záray, Gyula

    2011-07-01

    Cucumber plants grown in hydroponics containing 10 μM Cd(II), Ni(II) and Pb(II), and iron supplied as Fe(III) EDTA or Fe(III) citrate in identical concentrations, were investigated by total-reflection X-ray fluorescence spectrometry with special emphasis on the determination of iron accumulation and distribution within the different plant compartments (root, stem, cotyledon and leaves). The extent of Cd, Ni and Pb accumulation and distribution were also determined. Generally, iron and heavy-metal contaminant accumulation was higher when Fe(III) citrate was used. The accumulation of nickel and lead was higher by about 20% and 100%, respectively, if the iron supply was Fe(III) citrate. The accumulation of Cd was similar. In the case of Fe(III) citrate, the total amounts of Fe taken up were similar in the control and heavy-metal-treated plants (27-31 μmol/plant). Further, the amounts of iron transported from the root towards the shoot of the control, lead- and nickel-contaminated plants were independent of the iron(III) form. Although Fe mobility could be characterized as being low, its distribution within the shoot was not significantly affected by the heavy metals investigated. Copyright © 2011 Elsevier GmbH. All rights reserved.

  9. Evaluation of lead-iron-phosphate glass as a high-level waste form

    International Nuclear Information System (INIS)

    Chick, L.A.; Bunnell, L.R.; Strachan, D.M.; Kissinger, H.E.; Hodges, F.N.

    1986-01-01

    The lead-iron-phosphate (Pb-Fe-P) nuclear waste glass developed at Oak Ridge National Laboratory (ORNL) was evaluated for its potential as an improvement over the current reference waste form, borosilicate (B-Si) glass. Vitreous Pb-Fe-P glass appears to have substantially better chemical durability than B-Si glass. However, severe crystallization leading to deteriorated chemical durability would result if this glass were poured into large canisters, as is presently done with B-Si glass. Cesium leach rates from this crystallized material are orders of magnitude greater than those from B-Si glass. Therefore, to realize the performance advantages of the Pb-Fe-P material in a nuclear waste form, it would be necessary to process it so that it is cooled rapidly, thus retaining its vitreous structure

  10. Determination of molybdenum by the gravimetric plumbate method (with the molybdenum content from 50 % and above)

    International Nuclear Information System (INIS)

    Stepin, V.V.; Kurbatova, V.I.; Fedorova, N.D.

    1980-01-01

    A gravimetric method of molybdenum determination in ferromolybdenum (Mo content from 50% and higher) after its dissolving in HNO 3 is developed. The method is based on Mo deposition in acetic acid solution in the form of molybdenum oxide lead after separation of Fe and other interfering elements with sodium hydroxide [ru

  11. Evaluation of the effect of divalent metal transporter 1 gene polymorphism on blood iron, lead and cadmium levels

    Energy Technology Data Exchange (ETDEWEB)

    Kayaaltı, Zeliha, E-mail: kayaalti@ankara.edu.tr; Akyüzlü, Dilek Kaya; Söylemezoğlu, Tülin

    2015-02-15

    Divalent metal transporter 1 (DMT1), a member of the proton-coupled metal ion transporter family, mediates transport of ferrous iron from the lumen of the intestine into the enterocyte and export of iron from endocytic vesicles. It has an affinity not only for iron but also for other divalent cations including manganese, cobalt, nickel, cadmium, lead, copper, and zinc. DMT1 is encoded by the SLC11a2 gene that is located on chromosome 12q13 in humans and express four major mammalian isoforms (1A/+IRE, 1A/-IRE, 2/+IRE and 2/-IRE). Mutations or polymorphisms of DMT1 gene may have an impact on human health by disturbing metal trafficking. To study the possible association of DMT1 gene with the blood levels of some divalent cations such as iron, lead and cadmium, a single nucleotide polymorphism (SNP) (IVS4+44C/A) in DMT1 gene was investigated in 486 unrelated and healthy individuals in a Turkish population by method of polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). The genotype frequencies were found as 49.8% homozygote typical (CC), 38.3% heterozygote (CA) and 11.9% homozygote atypical (AA). Metal levels were analyzed by dual atomic absorption spectrometer system and the average levels of iron, lead and cadmium in the blood samples were 446.01±81.87 ppm, 35.59±17.72 ppb and 1.25±0.87 ppb, respectively. Individuals with the CC genotype had higher blood iron, lead and cadmium levels than those with AA and CA genotypes. Highly statistically significant associations were detected between IVS4+44 C/A polymorphism in the DMT1 gene and iron and lead levels (p=0.001 and p=0.036, respectively), but no association was found with cadmium level (p=0.344). This study suggested that DMT1 IVS4+44 C/A polymorphism is associated with inter-individual variations in blood iron, lead and cadmium levels. - Highlights: • DMT1 IVS4+44 C/A polymorphism is associated with inter-individual variations in blood iron, cadmium and lead levels.

  12. Evaluation of the effect of divalent metal transporter 1 gene polymorphism on blood iron, lead and cadmium levels

    International Nuclear Information System (INIS)

    Kayaaltı, Zeliha; Akyüzlü, Dilek Kaya; Söylemezoğlu, Tülin

    2015-01-01

    Divalent metal transporter 1 (DMT1), a member of the proton-coupled metal ion transporter family, mediates transport of ferrous iron from the lumen of the intestine into the enterocyte and export of iron from endocytic vesicles. It has an affinity not only for iron but also for other divalent cations including manganese, cobalt, nickel, cadmium, lead, copper, and zinc. DMT1 is encoded by the SLC11a2 gene that is located on chromosome 12q13 in humans and express four major mammalian isoforms (1A/+IRE, 1A/-IRE, 2/+IRE and 2/-IRE). Mutations or polymorphisms of DMT1 gene may have an impact on human health by disturbing metal trafficking. To study the possible association of DMT1 gene with the blood levels of some divalent cations such as iron, lead and cadmium, a single nucleotide polymorphism (SNP) (IVS4+44C/A) in DMT1 gene was investigated in 486 unrelated and healthy individuals in a Turkish population by method of polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). The genotype frequencies were found as 49.8% homozygote typical (CC), 38.3% heterozygote (CA) and 11.9% homozygote atypical (AA). Metal levels were analyzed by dual atomic absorption spectrometer system and the average levels of iron, lead and cadmium in the blood samples were 446.01±81.87 ppm, 35.59±17.72 ppb and 1.25±0.87 ppb, respectively. Individuals with the CC genotype had higher blood iron, lead and cadmium levels than those with AA and CA genotypes. Highly statistically significant associations were detected between IVS4+44 C/A polymorphism in the DMT1 gene and iron and lead levels (p=0.001 and p=0.036, respectively), but no association was found with cadmium level (p=0.344). This study suggested that DMT1 IVS4+44 C/A polymorphism is associated with inter-individual variations in blood iron, lead and cadmium levels. - Highlights: • DMT1 IVS4+44 C/A polymorphism is associated with inter-individual variations in blood iron, cadmium and lead levels.

  13. The effect of the OSHA lead exposure in construction standard on blood lead levels among iron workers employed in bridge rehabilitation.

    Science.gov (United States)

    Levin, S M; Goldberg, M; Doucette, J T

    1997-03-01

    Over 50,000 workers are at risk of occupational exposure to lead in the course of renovating the nation's deteriorating infrastructure. In mid-1993, to control exposure to lead in the construction setting OSHA promulgated a Lead in Construction Standard. In this study, we assessed the effect of the mandated changes in exposure conditions which followed the introduction of this new standard. We analyzed changes in baseline and maximum blood lead concentrations and in maximum increments in blood lead levels before and after introduction of the standard among iron workers employed in the renovation of a large, lead-painted, steel bridge in New York City. Results indicated that baseline and maximum blood lead levels fell significantly after the implementation of the provisions of the standard, as did maximum increments in blood lead concentrations. Seventy-six percent of the workers maintained blood lead concentrations below 20 micrograms/dl after the OSHA standard, as compared with 66% prior to its implementation. Increments of 20 micrograms/dl or more occurred considerably more frequently before introduction of the standard (13% before vs. 4% after; p = 0.01). Evidence of decreased exposure to lead was observed among iron workers who were present both before and after the introduction of the OSHA standard, as well as among iron workers newly hired after the OSHA provisions were put in place. These findings document the effectiveness of the OSHA construction lead standard in controlling exposure to lead in this complex and variable environment. The data indicate the utility of blood lead determinations in assessing the outcome of industrial hygiene interventions to reduce exposures to lead in the construction setting.

  14. Iron plaque formation on roots of different rice cultivars and the relation with lead uptake.

    Science.gov (United States)

    Liu, Jianguo; Leng, Xuemei; Wang, Mingxin; Zhu, Zhongquan; Dai, Qinghua

    2011-07-01

    The relationships between lead (Pb) uptake and iron/manganese plaque formation on rice roots were investigated with three cultivars. The results showed that the rice cultivars with indica consanguinity were more sensitive to soil Pb stress than the cultivar with japonica consanguinity. Pb concentrations and distribution ratios in root tissues were in the order: Shanyou 63 > Yangdao 6 > Wuyunjing 7, but Pb and Fe concentrations and distribution ratios in the plaques showed a reverse order. Mn concentrations and distribution ratios in the plaques of Wuyunjing 7 were significantly higher (P rice root can provide a barrier to soil Pb stress. The plaque will increase sequestration of Pb on rice root surface and in the rhizosphere, providing a means of external exclusion of soil Pb to some extent. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. In-situ Lead Removal by Iron Nano Particles Coated with Nickel

    Directory of Open Access Journals (Sweden)

    Mohammadreza Fadaei-tehrani

    2016-01-01

    Full Text Available This study investigates the potential of nano-zero-valent iron particles coated with nickel in the removal of lead (Pb2+ from porous media. For this purpose, the nano-particles were initially synthesized and later stablilized using the strach biopolymer prior to conducting batch and continuous experiments. The results of the batch experiments revealed that the reaction kinetics fitted well with the pseudo-first-order adsorption model and that the reaction rate ranged from 0.001 to 0.035 g/mg/min depending on solution pH and the molar ratio of Fe/Pb. Continuous experiments showed that lead remediation was mostly influenced not only by seepage velocity but also by the quantity and freshness of nZVI as well as the grain type of the porous media. Maximum Pb2+ removal rates obtained in the batch and lab models were 95% and 80%, respectively. Based on the present study, S-nZVI may be suggested as an efficient agent for in-situ remediation of groundwater contaminated with lead.

  16. Molybdenum, molybdenum oxides, and their electrochemistry.

    Science.gov (United States)

    Saji, Viswanathan S; Lee, Chi-Woo

    2012-07-01

    The electrochemical behaviors of molybdenum and its oxides, both in bulk and thin film dimensions, are critical because of their widespread applications in steels, electrocatalysts, electrochromic materials, batteries, sensors, and solar cells. An important area of current interest is electrodeposited CIGS-based solar cells where a molybdenum/glass electrode forms the back contact. Surprisingly, the basic electrochemistry of molybdenum and its oxides has not been reviewed with due attention. In this Review, we assess the scattered information. The potential and pH dependent active, passive, and transpassive behaviors of molybdenum in aqueous media are explained. The major surface oxide species observed, reversible redox transitions of the surface oxides, pseudocapacitance and catalytic reduction are discussed along with carefully conducted experimental results on a typical molybdenum glass back contact employed in CIGS-based solar cells. The applications of molybdenum oxides and the electrodeposition of molybdenum are briefly reviewed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Calibration equations for energy-dispersive XRF determination of copper, iron and lead in copper ore slurries

    International Nuclear Information System (INIS)

    Lakosz, M.

    1976-01-01

    Calibration equations for the X-ray fluorescence analysis determination of copper, iron and lead in copper ore slurries have been derived and tested. The measurement of Ksub(α) lines of copper and iron and Lsub(α) line of lead excited by rays from 238 Pu source have been used. Si/Li detector coupled to multichannel analyzer and minicomputer have been applied in measurements. The matrix and density effect have been eliminated by additional measurement of back-scattered primary radiation. (author)

  18. Evaluation of lead-iron-phosphate glass as a high-level waste form

    International Nuclear Information System (INIS)

    Chick, L.A.; Bunnell, L.R.; Strachan, D.M.; Kissinger, H.E.; Hodges, F.N.

    1986-09-01

    The lead-iron-phosphate (Pb-Fe-P) glass developed at Oak Ridge National Laboratory was evaluated for its potential as an improvement over the current reference nuclear waste form, borosilicate (B-Si) glass. The evaluation was conducted as part of the Second Generation HLW Technology Subtask of the Nuclear Waste Treatment Program at Pacific Northwest Laboratory. The purpose of this work was to investigate possible alternatives to B-Si glass as second-generation waste forms. While vitreous Pb-Fe-P glass appears to have substantially better chemical durability than B-Si glass, severe crystallization or devitrification leading to deteriorated chemical durability would result if this glass were poured into large canisters as is the procedure with B-Si glass. Cesium leach rates from this crystallized material are orders of magnitude greater than those from B-Si glass. Therefore, to realize the potential performance advantages of the Pb-Fe-P material in a nuclear waste form, the processing method would have to cool the material rapidly to retain its vitreous structure

  19. High strength tungsten heavy alloys with molybdenum additions

    International Nuclear Information System (INIS)

    Bose, A.; Sims, D.M.; German, R.M.

    1987-01-01

    Tungsten heavy alloys are candidates for numerous applications based on the unique combination of high density, high strength, and high ductility coupled with excellent machinability. Though there has been considerable research on heavy alloys, the primary focus has been on the ductility. These alloys are well suited for ballistic uses due to their high densities and it is expected that for superior ballistic performance, a high hardness, high strength and moderate ductility alloy would be ideal. The major goal of this investigation was to obtain heavy alloys with hardness greater than HRA 72. It is evident from the phase diagrams that molybdenum, which goes into solution in tungsten, nickel and iron, could act as a potential strengthening addition. With this in view, tungsten heavy alloys with molybdenum additions were fabricated from mixed elemental powders. A baseline composition of 90W-7Ni-3Fe was chosen to its good elongation and moderate strength. The molybdenum additions were made by replacing the tungsten. Compared to the baseline properties with no molybdenum addition, the strength and hardness showed a continuous increase with molybdenum addition. The ductility of the alloy continued to decrease with increasing molybdenum content, but even with 16% wt. % molybdenum of the elongation was still around 6%. An interesting facet of these alloying additions is the grain refinement that is brought about by adding to molybdenum to the system. The grain refinement is related to the lower solubility of tunbsten in the matrix due to partial displacement by molybdenum

  20. Iron

    DEFF Research Database (Denmark)

    Hansen, Jakob Bondo; Moen, I W; Mandrup-Poulsen, T

    2014-01-01

    and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced β-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation by activation...... of transcription factors, activation of the mitochondrial apoptotic machinery or of other cell death mechanisms. The pro-inflammatory cytokine IL-1β facilitates divalent metal transporter 1 (DMT1)-induced β-cell iron uptake and consequently ROS formation and apoptosis, and we propose that this mechanism provides...

  1. Activity of molybdenum-containing oxide catalysts in the reaction of ethane oxidation

    International Nuclear Information System (INIS)

    Konovalov, V.I.; Ehpova, T.I.; Shchukin, V.P.; Averbukh, A.Ya.

    1977-01-01

    Investigation results concerning the catalytic activity of molybdenum-containing catalysts in ethane oxidation reaction are presented. It has been found that the greatest activity in the temperature range from 450 to 600 deg C is exhibited by cobalt-molybdenum catalyst; at 600 deg C bismuth-molybdenum catalyst is the most active. Nickel-molybdenum catalyst is selective and active with respect to ethylene. Iron- and manganese-molybdenum catalysts do not show high ethane oxidation rates and their selectivity is insignificant

  2. Iron

    Science.gov (United States)

    ... Share: Search the ODS website Submit Search NIH Office of Dietary Supplements Consumer Datos en español Health ... eating a variety of foods, including the following: Lean meat, seafood, and poultry. Iron-fortified breakfast cereals ...

  3. Photoreduction of Terrigenous Fe-Humic Substances Leads to Bioavailable Iron in Oceans.

    Science.gov (United States)

    Blazevic, Amir; Orlowska, Ewelina; Kandioller, Wolfgang; Jirsa, Franz; Keppler, Bernhard K; Tafili-Kryeziu, Myrvete; Linert, Wolfgang; Krachler, Rudolf F; Krachler, Regina; Rompel, Annette

    2016-05-23

    Humic substances (HS) are important iron chelators responsible for the transport of iron from freshwater systems to the open sea, where iron is essential for marine organisms. Evidence suggests that iron complexed to HS comprises the bulk of the iron ligand pool in near-coastal waters and shelf seas. River-derived HS have been investigated to study their transport to, and dwell in oceanic waters. A library of iron model compounds and river-derived Fe-HS samples were probed in a combined X-ray absorption spectroscopy (XAS) and valence-to-core X-ray emission spectroscopy (VtC-XES) study at the Fe K-edge. The analyses performed revealed that iron complexation in HS samples is only dependent on oxygen-containing HS functional groups, such as carboxyl and phenol. The photoreduction mechanism of Fe III -HS in oceanic conditions into bioavailable aquatic Fe II forms, highlights the importance of river-derived HS as an iron source for marine organisms. Consequently, such mechanisms are a vital component of the upper-ocean iron biogeochemistry cycle.

  4. Analytic chemistry of molybdenum

    International Nuclear Information System (INIS)

    Parker, G.A.

    1983-01-01

    Electrochemical, colorimetric, gravimetric, spectroscopic, and radiochemical methods for the determination of molybdenum are summarized in this book. Some laboratory procedures are described in detail while literature citations are given for others. The reader is also referred to older comprehensive reviews of the analytical chemistry of molybdenum. Contents, abridged: Gravimetric methods. Titrimetric methods. Colorimetric methods. X-ray fluorescence. Voltammetry. Catalytic methods. Molybdenum in non-ferrous alloys. Molydbenum compounds

  5. The potential roles of lime and molybdenum on the growth, nitrogen ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-04-26

    Apr 26, 2010 ... and Molybdenum (Mo) are essential plant nutrients; whose role has been well ... interaction on different photosynthetic activities in P. vulgaris grown ..... concentrations of nickel, cadmium lead and molybdenum. J. Plant. Nutr.

  6. Spectroscopic and thermal properties of Sm3+ doped iron lead bismuthate glasses

    Science.gov (United States)

    Narwal, P.; Yadav, A.; Dahiya, M. S.; Vishal, Rohit, Agarwal, A.; Khasa, S.

    2018-05-01

    The results of the structural, physical, thermal and electrical properties of the glass compositions xFe2O3•(100-x)(3Bi2O3•PbO)• Sm2O3(1 mol%) where x=0, 1, 5, 10, 12, 15 mol% prepared via melt quench technique were studied. The synthesized compositions were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and differential thermal analysis (DTA). The IR study reveals that present system is build up with lead in tetrahedral coordination and bismuth in trigonal as well as octahedral coordination. Density and molar volume have been calculated using Archimedes principle, and the variation in their values has been correlated with structural changes in the glass matrix based on the IR study. The variation in the characteristic temperatures (glass transition temperature Tg, crystallization temperature Tp and melting temperature Tm) with different heating rate and change in the composition of iron oxide were analyzed and reported in the present study.

  7. Effects of nitrate on the treatment of lead contaminated groundwater by nanoscale zerovalent iron.

    Science.gov (United States)

    Su, Yiming; Adeleye, Adeyemi S; Zhou, Xuefei; Dai, Chaomeng; Zhang, Weixian; Keller, Arturo A; Zhang, Yalei

    2014-09-15

    Nanoscale zerovalent iron (nZVI) is efficient for removing Pb(2+) and nitrate from water. However, the influence of nitrate, a common groundwater anion, on Pb(2+) removal by nZVI is not well understood. In this study, we showed that under excess Fe(0) conditions (molar ratio of Fe(0)/nitrate>4), Pb(2+) ions were immobilized more quickly (nitrate-free systems (∼ 15 min) due to increasing pH. With nitrate in excess (molar ratio of Fe(0)/nitratenitrate stimulated the formation of crystal PbxFe3-xO4 (ferrite), which provided additional Pb(2+) removal. However, ∼ 7% of immobilized Pb(2+) ions were released into aqueous phase within 2h due to ferrite deformation. Oxidation-reduction potential (ORP) values below -600 mV correlated with excess Fe(0) conditions (complete Pb(2+) immobilization), while ORP values ≥-475 mV characterized excess nitrate conditions (ferrite process and Pb(2+) release occurrence). This study indicates that ORP monitoring is important for proper management of nZVI-based remediation in the subsurface to avoid lead remobilization in the presence of nitrate. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Iron-Deficiency Anemia Leading to Transient Ischemic Attacks due to Intraluminal Carotid Artery Thrombus

    Directory of Open Access Journals (Sweden)

    H. Z. Batur Caglayan

    2013-01-01

    Full Text Available Reactive thrombocytosis secondary to iron-deficiency anemia (IDA is a rare but recognized cause of stroke. We report the case of a patient with iron-deficiency anemia presenting with multiple transient ischemic attacks (TIA due to intraluminal thrombus of an internal carotid artery. The putative mechanisms underlying anemia and stroke syndromes are not completely understood, and it is believed that iron deficiency may cause ischemic stroke by several potential mechanisms. Thrombocytosis is often associated with iron deficiency, and microcytosis produces a reduction in the red cell deformability and could produce a hypercoagulable state. The platelet count and function observed in iron-deficiency anemia could act synergistically to promote thrombus formation, especially in the setting of an underlying atherosclerotic disease. The presence of floating thrombus in a patient with clinical and MRI evidence of stroke represents a significant therapeutic dilemma and requires immediate decision about treatment.

  9. [Study on the method for the determination of trace boron, molybdenum, silver, tin and lead in geochemical samples by direct current arc full spectrum direct reading atomic emission spectroscopy (DC-Arc-AES)].

    Science.gov (United States)

    Hao, Zhi-hong; Yao, Jian-zhen; Tang, Rui-ling; Zhang, Xue-mei; Li, Wen-ge; Zhang, Qin

    2015-02-01

    The method for the determmation of trace boron, molybdenum, silver, tin and lead in geochemical samples by direct current are full spectrum direct reading atomic emission spectroscopy (DC-Arc-AES) was established. Direct current are full spectrum direct reading atomic emission spectrometer with a large area of solid-state detectors has functions of full spectrum direct reading and real-time background correction. The new electrodes and new buffer recipe were proposed in this paper, and have applied for national patent. Suitable analytical line pairs, back ground correcting points of elements and the internal standard method were selected, and Ge was used as internal standard. Multistage currents were selected in the research on current program, and each current set different holding time to ensure that each element has a good signal to noise ratio. Continuous rising current mode selected can effectively eliminate the splash of the sample. Argon as shielding gas can eliminate CN band generating and reduce spectral background, also plays a role in stabilizing the are, and argon flow 3.5 L x min(-1) was selected. Evaporation curve of each element was made, and it was concluded that the evaporation behavior of each element is consistent, and combined with the effects of different spectrographic times on the intensity and background, the spectrographic time of 35s was selected. In this paper, national standards substances were selected as a standard series, and the standard series includes different nature and different content of standard substances which meet the determination of trace boron, molybdenum, silver, tin and lead in geochemical samples. In the optimum experimental conditions, the detection limits for B, Mo, Ag, Sn and Pb are 1.1, 0.09, 0.01, 0.41, and 0.56 microg x g(-1) respectively, and the precisions (RSD, n=12) for B, Mo, Ag, Sn and Pb are 4.57%-7.63%, 5.14%-7.75%, 5.48%-12.30%, 3.97%-10.46%, and 4.26%-9.21% respectively. The analytical accuracy was

  10. Molybdenum market in transition

    International Nuclear Information System (INIS)

    Sutulov, A.

    1980-01-01

    Since the beginning of 1980 - after seven years of constant unbalance between supply and demand of molybdenum, characterized by a demand overhang and after two years of unprecedented spot market prices - clear signals for a consolidation of the molybdenum market can be recognized. (orig.) [de

  11. Iron-induced nitric oxide leads to an increase in the expression of ferritin during the senescence of Lotus japonicus nodules.

    Science.gov (United States)

    Chungopast, Sirinapa; Duangkhet, Mallika; Tajima, Shigeyuki; Ma, Jian Feng; Nomura, Mika

    2017-01-01

    Iron is an essential nutrient for legume-rhizobium symbiosis and accumulates abundantly in the nodules. However, the concentration of free iron in the cells is strictly controlled to avoid toxicity. It is known that ferritin accumulates in the cells as an iron storage protein. During nodule senescence, the expression of the ferritin gene, Ljfer1, was induced in Lotus japonicus. We investigated a signal transduction pathway leading to the increase of Ljfer1 in the nodule. The Ljfer1 promoter of L. japonicus contains a conserved Iron-Dependent Regulatory Sequence (IDRS). The expression of Ljfer1 was induced by the application of iron or sodium nitroprusside, which is a nitric oxide (NO) donor. The application of iron to the nodule increased the level of NO. These data strongly suggest that iron-induced NO leads to increased expression of Ljfer1 during the senescence of L. japonicus nodules. Copyright © 2016 Elsevier GmbH. All rights reserved.

  12. Iron supplement prevents lead-induced disruption of the blood-brain barrier during rat development

    International Nuclear Information System (INIS)

    Wang Qiang; Luo Wenjing; Zheng Wei; Liu Yiping; Xu Hui; Zheng Gang; Dai Zhongming; Zhang Wenbin; Chen Yaoming; Chen Jingyuan

    2007-01-01

    Children are known to be venerable to lead (Pb) toxicity. The blood-brain barrier (BBB) in immature brain is particularly vulnerable to Pb insults. This study was designed to test the hypothesis that Pb exposure damaged the integrity of the BBB in young animals and iron (Fe) supplement may prevent against Pb-induced BBB disruption. Male weanling Sprague-Dawley rats were divided into four groups. Three groups of rats were exposed to Pb in drinking water containing 342 μg Pb/mL as Pb acetate, among which two groups were concurrently administered by oral gavage once every other day with 7 mg Fe/kg and 14 mg Fe/kg as FeSO 4 solution as the low and high Fe treatment group, respectively, for 6 weeks. The control group received sodium acetate in drinking water. Pb exposure significantly increased Pb concentrations in blood by 6.6-folds (p < 0.05) and brain tissues by 1.5-2.0-folds (p < 0.05) as compared to controls. Under the electron microscope, Pb exposure in young animals caused an extensive extravascular staining of lanthanum nitrate in brain parenchyma, suggesting a leakage of cerebral vasculature. Western blot showed that Pb treatment led to 29-68% reduction (p < 0.05) in the expression of occludin as compared to the controls. Fe supplement among Pb-exposed rats maintained the normal ultra-structure of the BBB and restored the expression of occludin to normal levels. Moreover, the low dose Fe supplement significantly reduced Pb levels in blood and brain tissues. These data suggest that Pb exposure disrupts the structure of the BBB in young animals. The increased BBB permeability may facilitate the accumulation of Pb. Fe supplement appears to protect the integrity of the BBB against Pb insults, a beneficial effect that may have significant clinical implications

  13. Tetrathionate reductase of Salmonella thyphimurium: a molybdenum containing enzyme

    International Nuclear Information System (INIS)

    Hinojosa-Leon, M.; Dubourdieu, M.; Sanchez-Crispin, J.A.; Chippaux, M.

    1986-01-01

    Use of radioactive molybdenum demonstrates that the tetrathionate reductase of Salmonella typhimurium is a molydenum containing enzyme. It is proposed that this enzyme shares with other molybdo-proteins, such as nitrate reductase, a common molybdenum containing cofactor the defect of which leads to the loss of the tetrathionate reductase and nitrate reductase activities

  14. A Triple Iron Triathlon Leads to a Decrease in Total Body Mass but Not to Dehydration

    Science.gov (United States)

    Knechtle, Beat; Knechtle, Patrizia; Rosemann, Thomas; Oliver, Senn

    2010-01-01

    A loss in total body mass during an ultraendurance performance is usually attributed to dehydration. We identified the changes in total body mass, fat mass, skeletal muscle mass, and selected markers of hydration status in 31 male nonprofessional ultratriathletes participating in a Triple Iron triathlon involving 11.4 km swimming, 540 km cycling…

  15. Iron Overload Leading to Torsades de Pointes in β-Thalassemia and Long QT Syndrome

    DEFF Research Database (Denmark)

    Refaat, Marwan M; El Hage, Lea; Steffensen, Annette Buur

    2016-01-01

    The authors present a unique case of torsades de pointes in a β-thalassemia patient with early iron overload in the absence of any structural abnormalities as seen in hemochromatosis. Genetic testing showed a novel KCNQ1 gene mutation 1591C>T [Gln531Ter(X)]. Testing of the gene mutation in Xenopus...

  16. Process for purifying molybdenum

    International Nuclear Information System (INIS)

    Cheresnowsky, J.

    1989-01-01

    This patent describes a process for purifying molybdenum containing arsenic and phosphorus. The process comprising: adding to an acidic slurry of molybdenum trioxide, a source of magnesium ions in a solid form, with the amount of magnesium and the magnesium ion concentration in the subsequently formed ammonium molybdate solution being sufficient to subsequently form insoluble compounds containing greater than about 80% by weight of the arsenic and greater than about 80% by weight of the phosphorus, and ammonia in an amount sufficient to subsequently dissolve the molybdenum and subsequently form the insoluble compounds, with the source of magnesium ions being added prior to the addition of the ammonia; digesting the resulting ammoniated slurry at a temperature sufficient to dissolve the molybdenum and form an ammonium molybdate solution while the pH is maintained at from bout 9 to about 10 to form a solid containing the insoluble compounds; and separating the solid from the ammonium molybdate solution

  17. Influence of molybdenum on hardenability of destabilized high chromium cast irons. Ko kuromu chutetsu no netsushori tokusei ni oyobosu moribuden no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Kuwano, M. (Ube, Collete of Technology, Yamaguchi (Japan)); Ogi, K. (Kyushu University, Fukuoka (Japan). Faculty of Engineering); Sawamoto, A. (Yamaguchi University, Yamaguchi (Japan))

    1991-07-25

    Alloy elements are added to compensate for reduction in hardenability of high chromium cast iron as a result of destabilization heat treatment. With the purpose of investigating the influence of the added elements, this paper describes investigations made on effects of Mo and destabilization heat treatment conditions on martensite transformation , eutectoid transformation and base hardness, using Fe-Cr-C-based alloy containing C at 1.6-3.6%, and Cr at 6.6-26%. The main results obtained are as follows: Mo and Cr had the distribution coefficient for initial crystal austenite is smaller than one and were microscopically segregated in the dendrite base; the solute element distribution in the base is homogenized as a result of the long-time destabilization heat treatment while the Cr and C concentrations reduce largely, and the Mo concentration increases slightly; Mo has little influence on the Ms point, and reduces with the smaller the Cr/C ratio and the higher the retention temperature; and the base hardness corresponds well to a CCT diagram. 14 refs., 11 figs., 1 tab.

  18. U-Pb systematics in iron meteorites: uniformity of primordial lead

    International Nuclear Information System (INIS)

    Goepel, C.; Manhes, G.; Allegre, C.J.

    1985-01-01

    Pb isotopic compositions and U-Pb abundances were determined in the metal phase of six iron meteorites: Canyon Diablo IA, Toluca IA, Odessa IA, Youndegin IA, Deport IA and Mundrabilla An. Prior to complete dissolution, samples were subjected to a series of leachings and partial dissolutions. Isotopic compositions and abundances of the etched Pb indicate a contamination by terrestrial Pb which is attributable to previous cutting of the meteorite. Pb isotopic compositions measured in the decontaminated samples are identical within 0.2% and essentially confirm the primordial Pb value defined by Tatsumoto et al. (1973). These data invalidate more radiogenic Pb isotopic compositions published for iron meteorites, which are the result of terrestrial Pb contamination introduced mainly by analytical procedure. Our results support the idea of a solar nebula which was isotopically homogeneous for Pb 4.55 Ga ago. The new upper limit for U-abundance in iron meteorites, 0.001 ppb, is in agreement with its expected thermodynamic solubility in the metal phase. (author)

  19. Reaction of boron carbide with molybdenum disilicide

    International Nuclear Information System (INIS)

    Novikov, A.V.; Melekhin, V.F.; Pegov, V.S.

    1989-01-01

    The investigation results of interaction in the B 4 C-MoSi 2 system during sintering in vacuum are presented. Sintering of boron carbide with molybdenum disilicide is shown to lead to the formation of MoB 2 , SiC, Mo 5 Si 3 compounds, the presence of carbon-containing covering plays an important role in sintering

  20. Effects of wheat-flour biscuits fortified with iron and EDTA, alone and in combination, on blood lead concentration, iron status, and cognition in children: a double-blind randomized controlled trial.

    Science.gov (United States)

    Bouhouch, Raschida R; El-Fadeli, Sana; Andersson, Maria; Aboussad, Abdelmounaim; Chabaa, Laila; Zeder, Christophe; Kippler, Maria; Baumgartner, Jeannine; Sedki, Azzedine; Zimmermann, Michael B

    2016-11-01

    Lead is a common neurotoxicant and its absorption may be increased in iron deficiency (ID). Thus, iron fortification to prevent ID in populations is a promising lead mitigation strategy. Two common fortificants are ferrous sulfate (FeSO 4 ) and ferric sodium EDTA (NaFeEDTA). EDTA can chelate iron and lead. Our study objective was to determine the effects of iron and EDTA, alone and in combination, on blood lead (BPb) concentration, iron status, and cognition. In this 2 × 2 factorial, double-blind placebo-controlled trial, 457 lead-exposed Moroccan children were stratified by school and grade and randomly assigned to consume biscuits (6 d/wk at school) containing 1) ∼8 mg Fe as FeSO 4 , 2) ∼8 mg Fe as NaFeEDTA that contained ∼41 mg EDTA, 3) ∼41 mg EDTA as sodium EDTA (Na 2 EDTA), or 4) placebo for 28 wk. The primary outcome was BPb concentration; secondary outcomes were iron status and cognitive outcomes from subtests of the Kaufman Assessment Battery for Children and the Hopkins Verbal Learning Test. These outcomes were measured at baseline and endpoint. All data were analyzed by intention-to-treat. The adjusted geometric mean BPb concentration at baseline was 4.3 μg/dL (95% CI: 4.2, 4.3 μg/dL), and at endpoint these values were 3.3 μg/dL (95% CI: 3.1, 3.5 μg/dL) for FeSO 4 , 2.9 μg/dL (95% CI: 2.7, 3.0 μg/dL) for NaFeEDTA, 3.3 μg/dL (95% CI: 3.1, 3.5 μg/dL) for EDTA, and 3.7 μg/dL (95% CI: 3.5, 3.9 μg/dL) for placebo. We found an effect of iron (P = 0.009) and EDTA (P = 0.012) for reduced BPb concentrations at endpoint, but no iron × EDTA interaction. Iron fortification improved iron status, but there were no positive effects of iron or EDTA on cognitive test scores. Food fortification with iron and EDTA additively reduces BPb concentrations. Our findings suggest that NaFeEDTA should be the iron fortificant of choice in lead-exposed populations. This trial was registered at clinicaltrials.gov as NCT01573013. © 2016 American Society for

  1. Determination of molybdenum in flotation concentrates by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Ise, Kazuo

    1978-01-01

    Molybdenum was determined by atomic absorption spectrophotometry in 0.05 N ammoniacal solution after the decomposition of the concentrate with aqua regia. Negros ore from Philippines was used as a flotation feed, which contained chalcopyrites and calcium-magnesium minerals. Among the metals tested copper, iron and the alkaline earths interfered. Less than 50 ppm of copper yielded lower results for molybdenum. Higher results came out with more than 50 ppm of copper. In the presence of iron and citric acid (0.4 g/100 ml) which is a suppressor for hydroxide formation, a lower estimation resulted for molybdenum. Calcium interfered, lower results by 2 and >10% being obtained with respective 2.5 and 20 ppm of calcium. More than 20 ppm of magnesium behaved similarly. Sodium sulfate (0.5 g/100 ml) served as the suppressor for copper, iron and citric acid; 100 ppm each of copper and iron did not interfere in this way. Interferences due to calcium and magnesium (less than 60 ppm) was able to be masked by the addition of sodium silicate (200 ppm as silica). The analysis of flotation products and synthetic samples consisting of molybdenite, chalcopyrite, calcium chloride and magnesium sulfate revealed that the atomic absorption method can be applied to the analysis of the concentrates for molybdenum with an error of about 2%. (auth.)

  2. Bibliographic study on molybdenum biokinetics

    International Nuclear Information System (INIS)

    Erzberger, A.

    1988-05-01

    This bibliographical study compiles and analyzes findings about the metabolism and resorption of molybdenum. Besides including studies on the physiology of molybdenum 99, a general survey is given on molybdenum in the environment and on its physiological behaviour. In particular, information on the dependence of molybdenum resorption on various factors, such as the chemical form, antagonisms etc., are gathered from literature. These factors have to be considered for sensibly carrying out necessary experiments. (orig./MG) [de

  3. Molybdenum solar neutrino experiment

    International Nuclear Information System (INIS)

    Wolfsberg, K.; Cowan, G.A.; Bryant, E.A.

    1984-01-01

    The goal of the molybdenum solar neutrino experiment is to deduce the 8 B solar neutrino flux, averaged over the past several million years, from the concentration of 98 Tc in a deeply buried molybdenum deposit. The experiment is important to an understanding of stellar processes because it will shed light on the reason for the discrepancy between theory and observation of the chlorine solar neutrino experiment. Possible reasons for the discrepancy may lie in the properties of neutrinos (neutrino oscillations or massive neutrinos) or in deficiencies of the standard solar model. The chlorine experiment only measures the 8 B neutrino flux in current times and does not address possible temporal variations in the interior of the sun, which are also not considered in the standard model. In the molybdenum experiment, we plan to measure 98 Tc (4.2 Myr), also produced by 8 B neutrinos, and possibly 97 Tc (2.6 Myr), produced by lower energy neutrinos

  4. Method of producing molybdenum-99

    Science.gov (United States)

    Pitcher, Eric John

    2013-05-28

    Method of producing molybdenum-99, comprising accelerating ions by means of an accelerator; directing the ions onto a metal target so as to generate neutrons having an energy of greater than 10 MeV; directing the neutrons through a converter material comprising techentium-99 to produce a mixture comprising molybdenum-99; and, chemically extracting the molybdenum-99 from the mixture.

  5. Copper Deficiency Leads to Anemia, Duodenal Hypoxia, Upregulation of HIF-2α and Altered Expression of Iron Absorption Genes in Mice

    Science.gov (United States)

    Matak, Pavle; Zumerle, Sara; Mastrogiannaki, Maria; El Balkhi, Souleiman; Delga, Stephanie; Mathieu, Jacques R. R.; Canonne-Hergaux, François; Poupon, Joel; Sharp, Paul A.; Vaulont, Sophie; Peyssonnaux, Carole

    2013-01-01

    Iron and copper are essential trace metals, actively absorbed from the proximal gut in a regulated fashion. Depletion of either metal can lead to anemia. In the gut, copper deficiency can affect iron absorption through modulating the activity of hephaestin - a multi-copper oxidase required for optimal iron export from enterocytes. How systemic copper status regulates iron absorption is unknown. Mice were subjected to a nutritional copper deficiency-induced anemia regime from birth and injected with copper sulphate intraperitoneally to correct the anemia. Copper deficiency resulted in anemia, increased duodenal hypoxia and Hypoxia inducible factor 2α (HIF-2α) levels, a regulator of iron absorption. HIF-2α upregulation in copper deficiency appeared to be independent of duodenal iron or copper levels and correlated with the expression of iron transporters (Ferroportin - Fpn, Divalent Metal transporter – Dmt1) and ferric reductase – Dcytb. Alleviation of copper-dependent anemia with intraperitoneal copper injection resulted in down regulation of HIF-2α-regulated iron absorption genes in the gut. Our work identifies HIF-2α as an important regulator of iron transport machinery in copper deficiency. PMID:23555700

  6. Inhibition of bacterial oxidation of ferrous iron by lead nitrate in sulfate-rich systems.

    Science.gov (United States)

    Wang, Hongmei; Gong, Linfeng; Cravotta, Charles A; Yang, Xiaofen; Tuovinen, Olli H; Dong, Hailiang; Fu, Xiang

    2013-01-15

    Inhibition of bacterial oxidation of ferrous iron (Fe(II)) by Pb(NO(3))(2) was investigated with a mixed culture of Acidithiobacillus ferrooxidans. The culture was incubated at 30 °C in ferrous-sulfate medium amended with 0-24.2 mM Pb(II) added as Pb(NO(3))(2). Anglesite (PbSO(4)) precipitated immediately upon Pb addition and was the only solid phase detected in the abiotic controls. Both anglesite and jarosite (KFe(3)(SO(4))(2)(OH)(6)) were detected in inoculated cultures. Precipitation of anglesite maintained dissolved Pb concentrations at 16.9-17.6 μM regardless of the concentrations of Pb(NO(3))(2) added. Fe(II) oxidation was suppressed by 24.2 mM Pb(NO(3))(2) addition even when anglesite was removed before inoculation. Experiments with 0-48 mM KNO(3) demonstrated that bacterial Fe(II) oxidation decreased as nitrate concentration increased. Therefore, inhibition of Fe(II) oxidation at 24.2 mM Pb(NO(3))(2) addition resulted from nitrate toxicity instead of Pb addition. Geochemical modeling that considered the initial precipitation of anglesite to equilibrium followed by progressive oxidation of Fe(II) and the precipitation of jarosite and an amorphous iron hydroxide phase, without allowing plumbojarosite to precipitate were consistent with the experimental time-series data on Fe(II) oxidation under biotic conditions. Anglesite precipitation in mine tailings and other sulfate-rich systems maintains dissolved Pb concentrations below the toxicity threshold of A. ferrooxidans. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... develop new therapies for conditions that affect the balance of iron in the body and lead to ... Disease Control and Prevention) Iron - Health Professional Fact Sheet (NIH) Iron Dietary Supplement Fact Sheet (NIH) Iron- ...

  8. Blood lead levels, iron metabolism gene polymorphisms and homocysteine: a gene-environment interaction study.

    Science.gov (United States)

    Kim, Kyoung-Nam; Lee, Mee-Ri; Lim, Youn-Hee; Hong, Yun-Chul

    2017-12-01

    Homocysteine has been causally associated with various adverse health outcomes. Evidence supporting the relationship between lead and homocysteine levels has been accumulating, but most prior studies have not focused on the interaction with genetic polymorphisms. From a community-based prospective cohort, we analysed 386 participants (aged 41-71 years) with information regarding blood lead and plasma homocysteine levels. Blood lead levels were measured between 2001 and 2003, and plasma homocysteine levels were measured in 2007. Interactions of lead levels with 42 genotyped single-nucleotide polymorphisms (SNPs) in five genes ( TF , HFE , CBS , BHMT and MTR ) were assessed via a 2-degree of freedom (df) joint test and a 1-df interaction test. In secondary analyses using imputation, we further assessed 58 imputed SNPs in the TF and MTHFR genes. Blood lead concentrations were positively associated with plasma homocysteine levels (p=0.0276). Six SNPs in the TF and MTR genes were screened using the 2-df joint test, and among them, three SNPs in the TF gene showed interactions with lead with respect to homocysteine levels through the 1-df interaction test (plead levels. Blood lead levels were positively associated with plasma homocysteine levels measured 4-6 years later, and three SNPs in the TF gene modified the association. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. Electric field tuning of magnetism in heterostructure of yttrium iron garnet film/lead magnesium niobate-lead zirconate titanate ceramic

    Science.gov (United States)

    Lian, Jianyun; Ponchel, Freddy; Tiercelin, Nicolas; Chen, Ying; Rémiens, Denis; Lasri, Tuami; Wang, Genshui; Pernod, Philippe; Zhang, Wenbin; Dong, Xianlin

    2018-04-01

    In this paper, the converse magnetoelectric (CME) effect by electric field tuning of magnetization in an original heterostructure composed of a polycrystalline yttrium iron garnet (YIG) film and a lead magnesium niobate-lead zirconate titanate (PMN-PZT) ceramic is presented. The magnetic performances of the YIG films with different thicknesses under a DC electric field applied to the PMN-PZT ceramics and a bias magnetic field are investigated. All the magnetization-electric field curves are found to be in good agreement with the butterfly like strain curve of the PMN-PZT ceramic. Both the sharp deformation of about 2.5‰ of PMN-PZT and the easy magnetization switching of YIG are proposed to be the reasons for the strongest CME interaction in the composite at the small electric coercive field of PMN-PZT (4.1 kV/cm) and the small magnetic coercive field of YIG (20 Oe) where the magnetic susceptibility reaches its maximum value. A remarkable CME coefficient of 3.1 × 10-7 s/m is obtained in the system with a 600 nm-thick YIG film. This heterostructure combining multiferroics and partially magnetized ferrite concepts is able to operate under a small or even in the absence of an external bias magnetic field and is more compact and power efficient than the traditional magnetoelectric devices.

  10. A Next-to-Leading Order QCD Analysis of Neutrino - Iron Structure Functions at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Seligman, William Glenn [Nevis Labs, Columbia U.

    1997-01-01

    Nucleon structure functions measured in neutrino-iron and antineutrinoiron charged-current interactions are presented. The data were taken in two high-energy high-statistics runs by the LAB-E detector at the Fermilab Tevatron. Structure functions are extracted from a sample of 950,000 neutrino and 170,000 antineutrino events with neutrino energies from 30 to 360 Ge V. The structure functions $F_2$ and $xF_3$ are compared with the the predictions of perturbative Quantum Chromodynamics (PQCD). The combined non-singlet and singlet evolution in the context of PQCD gives NL0(4) . 2 value of $\\Lambda^{NLO,(4)}_{\\overline MS}$ = 337 ± 28 (exp.) MeV, which corresponds to $\\alpha_s$ ($M^2_z$) = 0.119 ± 0.002 (exp.) ± 0.004 (theory), and with a gluon distribution given by $xG(x,Q^2_0 = 5 GeV^2$ ) = (2.22±0.34) x ($1-x)^{4.65 \\pm 0.68}$

  11. Impact of two iron(III) chelators on the iron, cadmium, lead and nickel accumulation in poplar grown under heavy metal stress in hydroponics.

    Science.gov (United States)

    Mihucz, Victor G; Csog, Árpád; Fodor, Ferenc; Tatár, Enikő; Szoboszlai, Norbert; Silaghi-Dumitrescu, Luminiţa; Záray, Gyula

    2012-04-15

    Poplar (Populus jacquemontiana var. glauca cv. Kopeczkii) was grown in hydroponics containing 10 μM Cd(II), Ni(II) or Pb(II), and Fe as Fe(III) EDTA or Fe(III) citrate in identical concentrations. The present study was designed to compare the accumulation and distribution of Fe, Cd, Ni and Pb within the different plant compartments. Generally, Fe and heavy-metal accumulation were higher by factor 2-7 and 1.6-3.3, respectively, when Fe(III) citrate was used. Iron transport towards the shoot depended on the Fe(III) chelate and, generally, on the heavy metal used. Lead was accumulated only in the root. The amounts of Fe and heavy metals accumulated by poplar were very similar to those of cucumber grown in an identical way, indicating strong Fe uptake regulation of these two Strategy I plants: a cultivar and a woody plant. The Strategy I Fe uptake mechanism (i.e. reducing Fe(III) followed by Fe(II) uptake), together with the Fe(III) chelate form in the nutrient solution had significant effects on Fe and heavy metal uptake. Poplar appears to show phytoremediation potential for Cd and Ni, as their transport towards the shoot was characterized by 51-54% and 26-48% depending on the Fe(III) supply in the nutrient solution. Copyright © 2012 Elsevier GmbH. All rights reserved.

  12. A pre-concentration procedure using coprecipitation for determination of lead and iron in several samples using flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Saracoglu, S.; Soylak, M.; Peker, D.S. Kacar; Elci, L.; Santos, W.N.L. dos; Lemos, V.A.; Ferreira, S.L.C.

    2006-01-01

    The present paper proposes a pre-concentration procedure for determination of lead and iron in several samples by flame atomic absorption spectrometry. In it, lead(II) and iron(III) ions are coprecipitated using the violuric acid-copper(II) system as collector. Afterwards, the precipitate is dissolved with 1 M HNO 3 solution and the metal ions are determined. The optimization step was performed using factorial design involving the variables: pH, violuric acid mass (VA) and copper concentration (Cu). Using the optimized experimental conditions, the proposed procedure allows the determination these metals with detection limits of 0.18 μg L -1 for iron and 0.16 μg L -1 for lead. The effects of foreign ions on the pre-concentration procedure were also evaluated and the results demonstrated that this method could be applied for determination of iron and lead in several real samples. The proposed method was successfully applied to the analysis of seawater, urine, mineral water, soil and physiological solution samples. The concentrations of lead and iron achieved in these samples agree well with others data reported in the literature

  13. Kinetics of molybdenum reduction to molybdenum blue by Bacillus sp. strain A.rzi.

    Science.gov (United States)

    Othman, A R; Bakar, N A; Halmi, M I E; Johari, W L W; Ahmad, S A; Jirangon, H; Syed, M A; Shukor, M Y

    2013-01-01

    Molybdenum is very toxic to agricultural animals. Mo-reducing bacterium can be used to immobilize soluble molybdenum to insoluble forms, reducing its toxicity in the process. In this work the isolation of a novel molybdate-reducing Gram positive bacterium tentatively identified as Bacillus sp. strain A.rzi from a metal-contaminated soil is reported. The cellular reduction of molybdate to molybdenum blue occurred optimally at 4 mM phosphate, using 1% (w/v) glucose, 50 mM molybdate, between 28 and 30 °C and at pH 7.3. The spectrum of the Mo-blue product showed a maximum peak at 865 nm and a shoulder at 700 nm. Inhibitors of bacterial electron transport system (ETS) such as rotenone, sodium azide, antimycin A, and potassium cyanide could not inhibit the molybdenum-reducing activity. At 0.1 mM, mercury, copper, cadmium, arsenic, lead, chromium, cobalt, and zinc showed strong inhibition on molybdate reduction by crude enzyme. The best model that fitted the experimental data well was Luong followed by Haldane and Monod. The calculated value for Luong's constants p max, K(s), S(m), and n was 5.88 μmole Mo-blue hr(-1), 70.36 mM, 108.22 mM, and 0.74, respectively. The characteristics of this bacterium make it an ideal tool for bioremediation of molybdenum pollution.

  14. Geochemistry of manganese, iron, uranium, lead-210 and major ions in the Susquehanna River

    International Nuclear Information System (INIS)

    Lewis, D.M.

    1976-01-01

    The change in water composition accompanying a change in discharge of large streams and the Susquehanna River results from the change in the proportions of the total flow composed of type waters of constant composition. This change in the flow proportions is due to the different hydrologic responses to precipitation inputs of basins underlain by different single rock types. The in-river precipitation of mine-drainage-injected Mn and Fe was studied at a pH of approximately 7. For Mn the removal from solution appears to be first order. The rate constant is 10 3 times greater than the extrapolated autocatalytic rate constant of previous laboratory experiments. The study of the removal of Fe from solution yields a first order rate constant consistent with previous laboratory experiments. Lead-210 was used as a natural tracer to study the fate of trace metals

  15. Molybdenum dioxide-molybdenite roasting

    International Nuclear Information System (INIS)

    Sabacky, B.J.; Hepworth, M.T.

    1984-01-01

    A process is disclosed for roasting molybdenite concentrates directly to molybdenum dioxide. The process comprises establishing a roasting zone having a temperature of about 700 0 C. to about 800 0 C., introducing into the roasting zone particulate molybdenum dioxide and molybdenite in a weight ratio of at least about 2:1 along with an oxygen-containing gas in amount sufficient to oxidize the sulfur content of the molybdenite to molybdenum dioxide

  16. Nano-Structured Magnesium Oxide Coated Iron Ore: Its Application to the Remediation of Wastewater Containing Lead.

    Science.gov (United States)

    Nagarajah, Ranjini; Jang, Min; Pichiah, Saravanan; Cho, Jongman; Snyder, Shane A

    2015-12-01

    Magnetically separable nano-structured magnesium oxide coated iron ore (IO(MgO)) was prepared using environmentally benign chemicals, such as iron ore (IO), magnesium(II) nitrate hexahydrate [Mg(NO3)2 x 6H2O] and urea; via an easy and fast preparation method. The lO(MgO) was characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) and alternating gradient magnetometer (AGM) analyses. The isotherm and kinetic studies indicated that lO(MgO) has a comparably higher Langmuir constant (K(L), 1.69 L mg(-1)) and maximum sorption capacity (33.9 mg g(-1)) for lead (Pb) than other inorganic media. Based on MgO amount, the removal capacity of Pb by IO(MgO) was 2,724 mg Pb (g MgO)(-1), which was higher than that (1,980 mg g(-1)) for flowerlike magnesium oxide nanostructures reported by Cao et al. The kinetics, FE-SEM, elemental mapping and XRD results revealed that the substitution followed by precipitation was identified as the mechanism of Pb removal and plumbophyllite (Pb2Si4O10 x H2O) was the precipitated phase of Pb. A leaching test revealed that IOMgO) had negligible concentrations of leached Fe at pH 4-9. Since the base material, IO, is cheap and easily available, lO(MgO) could be produced in massive amounts and used for remediation of wastewater containing heavy metals, applying simple and fast magnetic separation.

  17. Molybdenum-A Key Component of Metal Alloys

    Science.gov (United States)

    Kropschot, S.J.

    2010-01-01

    Molybdenum, whose chemical symbol is Mo, was first recognized as an element in 1778. Until that time, the mineral molybdenite-the most important source of molybdenum-was believed to be a lead mineral because of its metallic gray color, greasy feel, and softness. In the late 19th century, French metallurgists discovered that molybdenum, when alloyed (mixed) with steel in small quantities, creates a substance that is remarkably tougher than steel alone and is highly resistant to heat. The alloy was found to be ideal for making tools and armor plate. Today, the most common use of molybdenum is as an alloying agent in stainless steel, alloy steels, and superalloys to enhance hardness, strength, and resistance to corrosion.

  18. Effect of high concentration of molybdenum on the structure and properties of niobium

    International Nuclear Information System (INIS)

    Trekina, M.I.; Vasil'eva, E.V.

    1989-01-01

    The effect of alloying of 20,25 and 30 % Mo on the structure and mechanical properties of niobium is studied. It is shown that niobium alloying with molybdenum in the studied concentration leads to grain grinding, which increases with the molybdenum content growth in the alloy. The effective energy values of recrystallization activation of the studied niobium and molybdenum alloys are determined. The high hardness level at some plasticity and deformability of niobium alloy with 20 % Mo is established

  19. Arene activation by a nonheme iron(III)-hydroperoxo complex: pathways leading to phenol and ketone products.

    Science.gov (United States)

    Faponle, Abayomi S; Banse, Frédéric; de Visser, Sam P

    2016-07-01

    Iron(III)-hydroperoxo complexes are found in various nonheme iron enzymes as catalytic cycle intermediates; however, little is known on their catalytic properties. The recent work of Banse and co-workers on a biomimetic nonheme iron(III)-hydroperoxo complex provided evidence of its involvement in reactivity with arenes. This contrasts the behavior of heme iron(III)-hydroperoxo complexes that are known to be sluggish oxidants. To gain insight into the reaction mechanism of the biomimetic iron(III)-hydroperoxo complex with arenes, we performed a computational (density functional theory) study. The calculations show that iron(III)-hydroperoxo reacts with substrates via low free energies of activation that should be accessible at room temperature. Moreover, a dominant ketone reaction product is observed as primary products rather than the thermodynamically more stable phenols. These product distributions are analyzed and the calculations show that charge interaction between the iron(III)-hydroxo group and the substrate in the intermediate state pushes the transferring proton to the meta-carbon atom of the substrate and guides the selectivity of ketone formation. These studies show that the relative ratio of ketone versus phenol as primary products can be affected by external interactions of the oxidant with the substrate. Moreover, iron(III)-hydroperoxo complexes are shown to selectively give ketone products, whereas iron(IV)-oxo complexes will react with arenes to form phenols instead.

  20. Assessment of in situ immobilization of Lead (Pb) and Arsenic (As) in contaminated soils with phosphate and iron: solubility and bioaccessibility

    NARCIS (Netherlands)

    Cui, Y.S.; Du, X.; Weng, L.P.; Riemsdijk, van W.H.

    2010-01-01

    The effect of in situ immobilization of lead (Pb) and arsenic (As) in soil with respectively phosphate and iron is well recognized. However, studies on combined Pb and As-contaminated soil are fewer, and assessment of the effectiveness of the immobilization on mobility and bioaccessibility is also

  1. Predicting molybdenum toxicity to higher plants: Influence of soil properties

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, S.P., E-mail: steve.mcgrath@bbsrc.ac.u [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Mico, C. [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom); Curdy, R. [Laboratory for Environmental Biotechnology (LBE), Swiss Federal Institute of Technology Lausanne (EPFL) Station 6 CH, 1015 Lausanne (Switzerland); Zhao, F.J. [Soil Science Department, Centre for Soils and Ecosystems Functions, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom)

    2010-10-15

    The effect of soil properties on the toxicity of molybdenum (Mo) to four plant species was investigated. Soil organic carbon or ammonium-oxalate extractable Fe oxides were found to be the best predictors of the 50% effective dose (ED{sub 50}) of Mo in different soils, explaining > 65% of the variance in ED{sub 50} for four species except for ryegrass (26-38%). Molybdenum concentrations in soil solution and consequently plant uptake were increased when soil pH was artificially raised because sorption of Mo to amorphous oxides is greatly reduced at high pH. The addition of sulphate significantly decreased Mo uptake by oilseed rape. For risk assessment, we suggest that Mo toxicity values for plants should be normalised using soil amorphous iron oxide concentrations. - Amorphous iron oxides or organic carbon were found to be the best predictors of the toxicity threshold values of Mo to higher plants on different soils.

  2. Predicting molybdenum toxicity to higher plants: Influence of soil properties

    International Nuclear Information System (INIS)

    McGrath, S.P.; Mico, C.; Curdy, R.; Zhao, F.J.

    2010-01-01

    The effect of soil properties on the toxicity of molybdenum (Mo) to four plant species was investigated. Soil organic carbon or ammonium-oxalate extractable Fe oxides were found to be the best predictors of the 50% effective dose (ED 50 ) of Mo in different soils, explaining > 65% of the variance in ED 50 for four species except for ryegrass (26-38%). Molybdenum concentrations in soil solution and consequently plant uptake were increased when soil pH was artificially raised because sorption of Mo to amorphous oxides is greatly reduced at high pH. The addition of sulphate significantly decreased Mo uptake by oilseed rape. For risk assessment, we suggest that Mo toxicity values for plants should be normalised using soil amorphous iron oxide concentrations. - Amorphous iron oxides or organic carbon were found to be the best predictors of the toxicity threshold values of Mo to higher plants on different soils.

  3. Environmental exposure of lead and iron deficit anemia in children age ranged 1-5 years: A cross sectional study

    International Nuclear Information System (INIS)

    Shah, Faheem; Kazi, Tasneem Gul; Afridi, Hassan Imran; Baig, Jameel Ahmed; Khan, Sumaira; Kolachi, Nida Fatima; Wadhwa, Sham Kumar; Shah, Abdul Qadir

    2010-01-01

    Iron (Fe) deficiency is the most common nutritional problem among children and lead (Pb) toxicity is the most common environmental health threat to children all over the world. The objective of this study was to determine blood lead (BPb) levels and prevalence of Fe deficient anemia among 1 to 5 year old children attending day care clinic in pediatric ward of civil hospital Karachi, Pakistan. A total of 340 children of both genders participating in this study, were screened for anemia. Among them 215 were anemic and 125 non-anemic. The anemic group was further divided in two groups on the basis of % hemoglobin (Hb), mild (Hb 10 g/dL). The blood samples were analysed for Pb and Fe, along with hematological parameters. The result indicated that anemic children had a higher mean values of Pb in blood than referent children with Hb > 10 g/dL. The Pb levels 10 μg/dL. The BPb concentration in severe anemic children (53%) was found in the range of 100-200 μg/L, whereas 47% had > 200 μg/L. The significant negative correlations of BPb level with % Hb (r = -0.514 and r = -0.685) and Fe contents (r = -0.522, r = -0.762, p < 0.001) were observed in mild and severe anemic children respectively. While positive correlation was observed between BPb and age of both group and genders (r = 0.69, p < 0.01). The BPb levels were significantly associated with biochemical indices in the blood which have the potential to be used as biomarkers of Pb intoxication and Fe deficient anemia.

  4. Environmental exposure of lead and iron deficit anemia in children age ranged 1-5 years: A cross sectional study

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Faheem; Kazi, Tasneem Gul; Afridi, Hassan Imran; Baig, Jameel Ahmed; Khan, Sumaira, E-mail: skhanzai@gmail.com; Kolachi, Nida Fatima; Wadhwa, Sham Kumar; Shah, Abdul Qadir, E-mail: shah_ceac@yahoo.com, E-mail: tgkazi@yahoo.com, E-mail: hassanimranafridi@yahoo.com, E-mail: jab_mughal@yahoo.com, E-mail: nidafatima6@gmail.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

    2010-10-15

    Iron (Fe) deficiency is the most common nutritional problem among children and lead (Pb) toxicity is the most common environmental health threat to children all over the world. The objective of this study was to determine blood lead (BPb) levels and prevalence of Fe deficient anemia among 1 to 5 year old children attending day care clinic in pediatric ward of civil hospital Karachi, Pakistan. A total of 340 children of both genders participating in this study, were screened for anemia. Among them 215 were anemic and 125 non-anemic. The anemic group was further divided in two groups on the basis of % hemoglobin (Hb), mild (Hb < 10 g/dL) and severe anemic group (Hb < 8 g/dL), while non-anemic as referent children (Hb > 10 g/dL). The blood samples were analysed for Pb and Fe, along with hematological parameters. The result indicated that anemic children had a higher mean values of Pb in blood than referent children with Hb > 10 g/dL. The Pb levels < 100 {mu}g/L were detected in 40% referent children while 60% of them had > 10 {mu}g/dL. The BPb concentration in severe anemic children (53%) was found in the range of 100-200 {mu}g/L, whereas 47% had > 200 {mu}g/L. The significant negative correlations of BPb level with % Hb (r = -0.514 and r = -0.685) and Fe contents (r = -0.522, r = -0.762, p < 0.001) were observed in mild and severe anemic children respectively. While positive correlation was observed between BPb and age of both group and genders (r = 0.69, p < 0.01). The BPb levels were significantly associated with biochemical indices in the blood which have the potential to be used as biomarkers of Pb intoxication and Fe deficient anemia.

  5. Carbon-supported iron and iron-molybdenum sulfide catalysts

    International Nuclear Information System (INIS)

    Ramselaar, W.L.T.M.

    1988-01-01

    The main objective was to describe the relations between the characteristics (composition and dispersion) of the actual sulfide phase and the catalytic activity. Attention was also paid to the influence of preparational aspects on these characteristics. The catalysts were characterized using in-situ Moessbauer spectroscopy down to 2.0 K. 254 refs.; 47 figs.; 22 tabs

  6. Preconcentration and atomic absorption spectrometric determination of cadmium, cobalt, copper, iron, lead, manganese, nickel and zinc in water samples using 6-methyl-2-pyridinecarboxaldehyde-4-phenyl-3-thiosemicarbazone

    International Nuclear Information System (INIS)

    Khuhawar, M.Y.; Das, P.; Dewani, V.K.

    2005-01-01

    The reagent 6-methyl-2-pyridinecarboxaldehyde-4-phenyl-3-thiosemicarbazone (MPAPT) has been examined for the pre-concentration of metal ions and determination using air acetylene flame atomic absorption spectrometer. The method is based on the complexation and extraction of cadmium (II), cobalt(III), copper(II), lead(II), nickel(II), iron(II), iron(II), manganese(II) and zinc(II) in chloroform. The metal iron are back extracted in nitric acid (1:1) or after evaporation of solvent the residue is digested in nitric acid. After necessary adjustment of volume the metal ions were determined in aqueous solution. Pre-concentration is obtained 10-25 times. Metal ions recovery was 95.4-100.8% with coefficient of variation 0.2-7.5%. The method used for the determination of metals in canal and sewerage waters, within 2-6433 mu g/L with C. V 0.-5.2%. (author)

  7. Determination of trace amounts of lead, arsenic, nickel and cobalt in high-purity iron oxide pigment by inductively coupled plasma atomic emission spectrometry after iron matrix removal with extractant-contained resin

    International Nuclear Information System (INIS)

    Xu Yuyu; Zhou Jianfeng; Wang Guoxin; Zhou Jinfan; Tao Guanhong

    2007-01-01

    Inductively coupled plasma atomic emission spectrometry (ICP-AES) was applied to the determination of lead, arsenic, nickel and cobalt in high-purity iron oxide pigment. Samples were dissolved with hydrochloric acid and hydrogen peroxide. The digest was passed through a column, which was packed with a polymer resin containing a neutral organophosphorus extractant, tri-n-butylphosphate. Iron was sorbed selectively on the resin and the analytes of interest passed through the column, allowing the effective separation of them from the iron matrix. Conditions of separation were optimized. The detection limits (3σ) in solution were 10, 40, 7 and 5 μg L -1 , and in pigment were 0.2, 0.8, 0.14 and 0.1 mg kg -1 for lead, arsenic, cobalt and nickel, respectively. The recoveries ranged from 95% to 107% when sample digests were spiked with 5 μg of the analytes of interest, and relative standard deviations (n = 6) were 1.5-17.6% for the determination of the spiked samples. The method was successfully applied to the determination of trace amounts of these elements in high-purity iron oxide pigment samples

  8. Kinetics of Molybdenum Reduction to Molybdenum Blue by Bacillus sp. Strain A.rzi

    Directory of Open Access Journals (Sweden)

    A. R. Othman

    2013-01-01

    Full Text Available Molybdenum is very toxic to agricultural animals. Mo-reducing bacterium can be used to immobilize soluble molybdenum to insoluble forms, reducing its toxicity in the process. In this work the isolation of a novel molybdate-reducing Gram positive bacterium tentatively identified as Bacillus sp. strain A.rzi from a metal-contaminated soil is reported. The cellular reduction of molybdate to molybdenum blue occurred optimally at 4 mM phosphate, using 1% (w/v glucose, 50 mM molybdate, between 28 and 30°C and at pH 7.3. The spectrum of the Mo-blue product showed a maximum peak at 865 nm and a shoulder at 700 nm. Inhibitors of bacterial electron transport system (ETS such as rotenone, sodium azide, antimycin A, and potassium cyanide could not inhibit the molybdenum-reducing activity. At 0.1 mM, mercury, copper, cadmium, arsenic, lead, chromium, cobalt, and zinc showed strong inhibition on molybdate reduction by crude enzyme. The best model that fitted the experimental data well was Luong followed by Haldane and Monod. The calculated value for Luong’s constants pmax, Ks, Sm, and n was 5.88 μmole Mo-blue hr−1, 70.36 mM, 108.22 mM, and 0.74, respectively. The characteristics of this bacterium make it an ideal tool for bioremediation of molybdenum pollution.

  9. Feasibility of preparing patterned molybdenum coatings on bismuth telluride thermoelectric modules.

    Energy Technology Data Exchange (ETDEWEB)

    Sarobol, Pylin; Hall, Aaron Christopher; Miller, Stephen Samuel; Knight, Marlene E.; LePage, William S.; Sobczak, Catherine Elizabeth.; Wesolowski, Daniel Edward

    2013-09-01

    Molybdenum electrical interconnects for thermoelectric modules were produced by air plasma spraying a 30%CE%BCm size molybdenum powder through a laser-cut Kapton tape mask. Initial feasibility demonstrations showed that the molybdenum coating exhibited excellent feature and spacing retention (~170%CE%BCm), adhered to bismuth-telluride, and exhibited electrical conductivity appropriate for use as a thermoelectric module interconnect. A design of experiments approach was used to optimize air plasma spray process conditions to produce a molybdenum coating with low electrical resistivity. Finally, a molybdenum coating was successfully produced on a fullscale thermoelectric module. After the addition of a final titanium/gold layer deposited on top of the molybdenum coating, the full scale module exhibited an electrical resistivity of 128%CE%A9, approaching the theoretical resistivity value for the 6mm module leg of 112%CE%A9. Importantly, air plasma sprayed molybdenum did not show significant chemical reaction with bismuth-telluride substrate at the coating/substrate interface. The molybdenum coating microstructure consisted of lamellar splats containing columnar grains. Air plasma sprayed molybdenum embedded deeply (several microns) into the bismuth-telluride substrate, leading to good adhesion between the coating and the substrate. Clusters of round pores (and cracks radiating from the pores) were found immediately beneath the molybdenum coating. These pores are believed to result from tellurium vaporization during the spray process where the molten molybdenum droplets (2623%C2%B0C) transferred their heat of solidification to the substrate at the moment of impact. Substrate cooling during the molybdenum deposition process was recommended to mitigate tellurium vaporization in future studies.

  10. On molybdenum (6) alcoholates

    International Nuclear Information System (INIS)

    Turova, N.Ya.; Kessler, V.G.

    1990-01-01

    Synthesis techniques for molybdenum (6) alcoholates of MoO(OR) 4 (1) and MoO 2 (OR) 2 (2) series by means of exchange interaction of corresponding oxychloride with MOR (M=Li, Na) are obtained. These techniques have allowed to prepare 1(R=Me, Et, i-Pr) and 2(R=Me, Et) with 70-98 % yield. Methylates are also prepared at ether interchange of ethylates by methyl alcohol. Metal anode oxidation in corresponding alcohol may be used for 1 synthesis. Physicochemical properties of both series alcoholates, solubility in alcohols in particular, depend on their formation conditions coordination polymerism. Alcoholates of 1 are rather unstable and tend to decomposition up to 2 and ether. It is suggested to introduce NaOR microquantities to stabilize those alcoholates

  11. Molybdenum Tube Characterization report

    Energy Technology Data Exchange (ETDEWEB)

    Beaux II, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-07

    Chemical vapor deposition (CVD) techniques have been utilized to produce free-standing molybdenum tubes with the end goal of nuclear fuel clad applications. In order to produce tubes with properties desirable for this application, deposition rates were lowered requiring long deposition durations on the order of 50 hours. Standard CVD methods as well as fluidized-bed CVD (FBCVD) methods were applied towards these objectives. Characterization of the tubes produced in this manner revealed material suitable for fuel clad applications, but lacking necessary uniformity across the length of the tubes. The production of freestanding Mo tubes that possess the desired properties across their entire length represents an engineering challenge that can be overcome in a next iteration of the deposition system.

  12. Diffusion in molybdenum disilicide

    International Nuclear Information System (INIS)

    Salamon, M.; Mehrer, H.

    2005-01-01

    The diffusion behaviour of the high-temperature material molybdenum disilicide (MoSi 2 ) was completely unknown until recently. In this paper we present studies of Mo self-diffusion and compare our present results with our already published studies of Si and Ge diffusion in MoSi 2 . Self-diffusion of molybdenum in monocrystalline MoSi 2 was studied by the radiotracer technique using the radioisotope 99 Mo. Deposition of the radiotracer and serial sectioning after the diffusion anneals to determine the concentration-depth profiles was performed using a sputtering device. Diffusion of Mo is a very slow process. In the entire temperature region investigated (1437 to 2173 K), the 99 Mo diffusivities in both principal directions of the tetragonal MoSi 2 crystals obey Arrhenius laws, where the diffusion perpendicular to the tetragonal axis is faster by two to three orders of magnitude than parallel to it. The activation enthalpies for diffusion perpendicular and parallel to the tetragonal axis are Q perpendicular to = 468 kJ mol -1 (4.85 eV) and Q parallel = 586 kJ mol -1 (6.07 eV), respectively. Diffusion of Si and its homologous element Ge is fast and is mediated by thermal vacancies of the Si sublattice of MoSi 2 . The diffusion of Mo is by several orders of magnitude slower than the diffusion of Si and Ge. This large difference suggests that Si and Mo diffusion are decoupled and that the diffusion of Mo likely takes place via vacancies on the Mo sublattice. (orig.)

  13. Spatial distribution of iron, copper and lead in mangrove sediments in a degradation gradient in Guanabara Bay (Rio de Janeiro State)

    OpenAIRE

    Borges, Anderson C.; Dias, Jailson C.; Machado, Wilson; Patchineelam, Sambasiva R.; Sella, Silvia M.

    2007-01-01

    Iron, copper and lead distribution was evaluated in sediment cores from a disturbed mangrove area in Guanabara Bay: a core from a seaward site where mangrove vegetation was removed ~20 yr before sampling (MD); a core from an intermediate site with dead vegetation, apparently due to insect attack (MP), and a core from a landward site with living vegetation (MV). Metal concentrations showed increasing values seaward while organic matter content showed an inverse trend, displaying a negative cor...

  14. Molecular evidence and physiological characterization of iron absorption in isolated enterocytes of rainbow trout (Oncorhynchus mykiss): Implications for dietary cadmium and lead absorption

    International Nuclear Information System (INIS)

    Kwong, Raymond W.M.; Andres, Jose A.; Niyogi, Som

    2010-01-01

    Recent studies suggested the probable involvement of an apical iron (Fe 2+ ) transporter, the divalent metal transporter-1 (DMT1), in the uptake of several divalent metals in fish. The present study examined the gastrointestinal expression of the DMT1 gene, and investigated the kinetics of Fe 2+ uptake and its interactions with cadmium and lead in isolated enterocytes of freshwater rainbow trout (Oncorhynchus mykiss). The expressions of two DMT1 isoforms (Nramp-β and -γ) were recorded along the entire gastrointestinal tract of fish as well as in the enterocytes. Fe 2+ uptake in isolated enterocytes was saturable and sensitive to the proton gradient and membrane potential, suggesting DMT1-mediated transport. Both cadmium and lead inhibited Fe 2+ uptake in isolated enterocytes in a concentration-dependent manner, and lead appeared to be a stronger inhibitor than cadmium. The kinetic characterization of Fe 2+ uptake revealed that the apparent affinity of uptake was significantly decreased (increased K m ) in the presence of either cadmium or lead, whereas the maximum uptake rate (J max ) remained unchanged-indicating that the interaction between Fe 2+ and cadmium or lead is competitive in nature. Overall, our study suggests that the uptake of dietary cadmium and lead may occur via the iron-transporting pathway in fish.

  15. Molecular evidence and physiological characterization of iron absorption in isolated enterocytes of rainbow trout (Oncorhynchus mykiss): Implications for dietary cadmium and lead absorption

    Energy Technology Data Exchange (ETDEWEB)

    Kwong, Raymond W.M. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK., S7N 5B3 (Canada); Andres, Jose A. [Department of Biology, University of Saskatchewan, Saskatoon, SK., S7N 5E2 (Canada); Niyogi, Som, E-mail: som.niyogi@usask.ca [Department of Biology, University of Saskatchewan, Saskatoon, SK., S7N 5E2 (Canada)

    2010-09-01

    Recent studies suggested the probable involvement of an apical iron (Fe{sup 2+}) transporter, the divalent metal transporter-1 (DMT1), in the uptake of several divalent metals in fish. The present study examined the gastrointestinal expression of the DMT1 gene, and investigated the kinetics of Fe{sup 2+} uptake and its interactions with cadmium and lead in isolated enterocytes of freshwater rainbow trout (Oncorhynchus mykiss). The expressions of two DMT1 isoforms (Nramp-{beta} and -{gamma}) were recorded along the entire gastrointestinal tract of fish as well as in the enterocytes. Fe{sup 2+} uptake in isolated enterocytes was saturable and sensitive to the proton gradient and membrane potential, suggesting DMT1-mediated transport. Both cadmium and lead inhibited Fe{sup 2+} uptake in isolated enterocytes in a concentration-dependent manner, and lead appeared to be a stronger inhibitor than cadmium. The kinetic characterization of Fe{sup 2+} uptake revealed that the apparent affinity of uptake was significantly decreased (increased K{sub m}) in the presence of either cadmium or lead, whereas the maximum uptake rate (J{sub max}) remained unchanged-indicating that the interaction between Fe{sup 2+} and cadmium or lead is competitive in nature. Overall, our study suggests that the uptake of dietary cadmium and lead may occur via the iron-transporting pathway in fish.

  16. Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element; Etude de la trempe et du revenu a la temperature ordinaire d'alliages uranium-chrome, uranium-fer et uranium-molybdene, a faible teneur en element d'alliage

    Energy Technology Data Exchange (ETDEWEB)

    Delaplace, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1960-09-15

    By means of an apparatus which makes possible thermal pre-treatments in vacuo, quenching carried out in a high purity argon atmosphere, and simultaneous recording of time temperature cooling and thermal contraction curves, the author has examined the transformations which occur in uranium-chromium, uranium-iron and uranium-molybdenum alloys during their quenching and subsequent return to room temperature. For uranium-chromium and uranium-iron alloys, the temperature at which the {gamma} {yields} {beta} transformation starts varies very little with the rate of cooling. For uranium-molybdenum alloys containing 2,8 atom per cent of Mo, this temperature is lowered by 120 deg. C for a cooling rate of 500 deg. C/mn. The temperature at which the {beta} {yields} {alpha} transformation starts is lowered by 170 deg. C for a cooling rate of 500 deg. C/mn in the case of uranium-chromium alloy containing 0,37 atom per cent of Cr. The temperature is little affected in the case of uranium-iron alloys. The addition of chromium or iron makes it possible to conserve the form {beta} at ordinary temperatures after quenching from the {beta} and {gamma} regions. The {beta} phase is particularly unstable and changes into needles of the {alpha} form even at room temperatures according to an autocatalytic transformation law similar to the austenitic-martensitic transformation law in the case of iron. The {beta} phase obtained by quenching from the {beta} phase region is more stable than that obtained by quenching from the {gamma} region. Chromium is a more effective stabiliser of the {beta} phase than is iron. Unfortunately it causes serious surface cracking. The {beta} {yields} {alpha} transformation in uranium-chromium alloys has been followed at room temperature by means of micro-cinematography. The author has not observed the direct {gamma} {yields} {alpha} transformation in uranium-molybdenum alloys containing 2,8 per cent of molybdenum even for cooling rates of up to 2000 deg. C

  17. Study of the quenching and subsequent return to room temperature of uranium-chromium, uranium-iron, and uranium-molybdenum alloys containing only small amounts of the alloying element; Etude de la trempe et du revenu a la temperature ordinaire d'alliages uranium-chrome, uranium-fer et uranium-molybdene, a faible teneur en element d'alliage

    Energy Technology Data Exchange (ETDEWEB)

    Delaplace, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1960-09-15

    By means of an apparatus which makes possible thermal pre-treatments in vacuo, quenching carried out in a high purity argon atmosphere, and simultaneous recording of time temperature cooling and thermal contraction curves, the author has examined the transformations which occur in uranium-chromium, uranium-iron and uranium-molybdenum alloys during their quenching and subsequent return to room temperature. For uranium-chromium and uranium-iron alloys, the temperature at which the {gamma} {yields} {beta} transformation starts varies very little with the rate of cooling. For uranium-molybdenum alloys containing 2,8 atom per cent of Mo, this temperature is lowered by 120 deg. C for a cooling rate of 500 deg. C/mn. The temperature at which the {beta} {yields} {alpha} transformation starts is lowered by 170 deg. C for a cooling rate of 500 deg. C/mn in the case of uranium-chromium alloy containing 0,37 atom per cent of Cr. The temperature is little affected in the case of uranium-iron alloys. The addition of chromium or iron makes it possible to conserve the form {beta} at ordinary temperatures after quenching from the {beta} and {gamma} regions. The {beta} phase is particularly unstable and changes into needles of the {alpha} form even at room temperatures according to an autocatalytic transformation law similar to the austenitic-martensitic transformation law in the case of iron. The {beta} phase obtained by quenching from the {beta} phase region is more stable than that obtained by quenching from the {gamma} region. Chromium is a more effective stabiliser of the {beta} phase than is iron. Unfortunately it causes serious surface cracking. The {beta} {yields} {alpha} transformation in uranium-chromium alloys has been followed at room temperature by means of micro-cinematography. The author has not observed the direct {gamma} {yields} {alpha} transformation in uranium-molybdenum alloys containing 2,8 per cent of molybdenum even for cooling rates of up to 2000 deg. C

  18. Simulations of intergranular fracture in nanocrystalline molybdenum

    DEFF Research Database (Denmark)

    Frederiksen, Søren Lund; Jacobsen, Karsten Wedel; Schiøtz, Jakob

    2004-01-01

    Using molecular dynamics simulations we investigate the plastic deformation of nanocrystalline molybdenum with a grain size of 12 nm at high strain rates. The simulations are performed with an interatomic potential which is obtained through matching of atomic forces to a database generated...... with density-functional calculations. The simulations show the plastic deformation to involve both grain boundary processes and dislocation migration which in some cases lead to twin boundary formation. A large component of the strain is accommodated through the formation of cracks in the grain boundaries...

  19. Crystalline silicon films sputtered on molybdenum A study of the silicon-molybdenum interface

    Energy Technology Data Exchange (ETDEWEB)

    Reinig, P.; Fenske, F.; Fuhs, W.; Schoepke, A.; Selle, B

    2003-04-15

    Polycrystalline silicon films were grown on molybdenum (Mo)-coated substrates at high deposition rate using the pulsed magnetron sputtering technique. Our study investigates the silicon-molybdenum interface of these films to elucidate stimulating mechanisms for an ordered crystalline silicon thin film growth. Both Auger electron spectroscopy and Rutherford backscattering reveal that at a substrate temperature as low as T{sub S}=450 deg. C during the deposition process intermixing of Si and Mo at the Si-Mo interface takes place leading to a compositional ratio Mo:Si of about 1:2. By Raman spectroscopy hexagonal {beta}-MoSi{sub 2} could be identified as the dominant phase in this intermixed region. The dependence of the resulting thickness of the reacted interface layer on the deposition conditions is not fully understood yet.

  20. Crystalline silicon films sputtered on molybdenum A study of the silicon-molybdenum interface

    International Nuclear Information System (INIS)

    Reinig, P.; Fenske, F.; Fuhs, W.; Schoepke, A.; Selle, B.

    2003-01-01

    Polycrystalline silicon films were grown on molybdenum (Mo)-coated substrates at high deposition rate using the pulsed magnetron sputtering technique. Our study investigates the silicon-molybdenum interface of these films to elucidate stimulating mechanisms for an ordered crystalline silicon thin film growth. Both Auger electron spectroscopy and Rutherford backscattering reveal that at a substrate temperature as low as T S =450 deg. C during the deposition process intermixing of Si and Mo at the Si-Mo interface takes place leading to a compositional ratio Mo:Si of about 1:2. By Raman spectroscopy hexagonal β-MoSi 2 could be identified as the dominant phase in this intermixed region. The dependence of the resulting thickness of the reacted interface layer on the deposition conditions is not fully understood yet

  1. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... absorb iron and lead to iron-deficiency anemia. These conditions include: Intestinal and digestive conditions, such as ... tract. Inflammation from congestive heart failure or obesity . These chronic conditions can lead to inflammation that may ...

  2. Ion exchange resin fouling of molybdenum in recovery uranium processess

    International Nuclear Information System (INIS)

    Zhang Guowei; Zhao Guirong

    1990-09-01

    The relationship between anion exchange resin fouling and molybdic acid polymerization was studied. By using potentiometer titration and laser-Raman spectroscopy the relationship of molybdic acid polymerization and the pH value of solution or the molybdenum concentration was determined. It was shown that as the concentration of initial molybdenum in solution decreases from 0.2 mol/L to 0.5 mmol/L, the pH value of starting polymerization decreased from 6.5 to 4.5. The experimental results show that the fouling of 201 x 7 resin in the acidic solution is mainly caused by the adsorbing of Mo 3 O 26 4- ion and occupying the exchange radical site of the resin. Under the leaching conditions the molybdenum and phosphate existing in the leaching liquor can form 12-molybdo-phosphate ion. It also leads to resin fouling. The molybdenum on the fouled resin can synergically be desorbed by mixed desorbents containing ammonium hydroxide and ammonium sulfate. The desorbed resin can be used for uranium adsorption and the desorbed molybdenum can be recovered by ion exchange method

  3. Preparation of isotopic molybdenum foils utilizing small quantities of material

    Science.gov (United States)

    Lipski, A. R.; Lee, L. L.; Liang, J. F.; Mahon, J. C.

    1993-09-01

    A simple method utilizing a small amount of isotopic material for production of molybdenum foils is discussed. An e-gun is used in the procedure. The Mo powder undergoes reduction-sintering and melting-solidifying steps leading to the creation of a metallic droplet suitable for further cold rolling or vacuum deposition.

  4. Purification of molybdenum

    International Nuclear Information System (INIS)

    Cheresnowsky, M.J.; Brunelli, T.A.; Kim, T.K.

    1987-01-01

    A method for purifying molybdenum is described comprising: (a) adding to an ammoniacal ammonium molybdate solution which is at a pH of from about 8.5 to about 11 and which contains the impurities of phosphorus and arsenic with the phosphorus concentration being from about 0.01 to about 0.12 g/l, a soluble magnesium salt to form a precipitate comprising magnesium ammonium salts of the phosphorus and the arsenic, and to form a purified ammonium molybdate solution, with the amount of the magnesium salt being added in an amount sufficient to result in a concentration of from about 0.005 to about 0.04 moles Mg/l in the ammoniacal ammonium molybdate solution, and the purified solution containing no greater than about 0.01 g P/l; (b) separating the precipitate from the purified ammonium molybdate solution; and (c) contacting the purified ammonium molybdate solution with a chelating cation exchange resin supplying a sufficient amount of ammonium as the cation to remove the major portion of the magnesium ions from the purified solution and form a further purified ammonium molybdate solution

  5. Mixed graphite cast iron for automotive exhaust component applications

    Directory of Open Access Journals (Sweden)

    De-lin Li

    2017-11-01

    Full Text Available Both spheroidal graphite iron and compacted graphite iron are used in the automotive industry. A recently proposed mixed graphite iron exhibits a microstructure between the conventional spheroidal graphite iron and compacted graphite iron. Evaluation results clearly indicate the suitability and benefits of mixed graphite iron for exhaust component applications with respect to casting, machining, mechanical, thermophysical, oxidation, and thermal fatigue properties. A new ASTM standard specification (A1095 has been created for compacted, mixed, and spheroidal graphite silicon-molybdenum iron castings. This paper attempts to outline the latest progress in mixed graphite iron published.

  6. Method of molybdenum kinetic determination

    International Nuclear Information System (INIS)

    Krejngol'd, S.U.; Dzotsenidze, N.E.; Ruseishviyai, T.G.; Nelen', I.M.

    1980-01-01

    The method molybdenum kinetic determination according to oxidation of pyrogallol with bromate in the medium of 0.05-0.15 M perchloric or sulphuric acids is presented. 1 mg of Ni, Co, Mn, Mg, Zn, Cr(3); 100 μg of Ca, Al, Cu, 10 μg of Cr(4), W; 10 μg of Fe in the presence of 22x10 - 4 M solution of EDTA, as well as 10 - 4 M solutions of chlorides and fluorides, 10 - 5 M solutions of bromides do not interfere with molybdenum determination using the given method. The method is rather simple, it takes 30 min to carry out the analysis. Determination limit of molybdenum constitutes 0.01 μg/ml

  7. Isotope analysis of molybdenum in selected minerals

    International Nuclear Information System (INIS)

    Becker, S.; Dietze, H.J.

    1980-01-01

    An analytical method is described for the mass spectrometric determination of molybdenum abundance values. The results of analyses of three molybdenum mineral samples are presented and compared with the results of other authors. It is shown that the fine variations of molybdenum in natural minerals cannot be analysed with currently available mass spectrometers

  8. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... blocks the intestine from taking up iron. Other medical conditions Other medical conditions that may lead to iron-deficiency anemia ... daily amount of iron. If you have other medical conditions that cause iron-deficiency anemia , such as ...

  9. Nutritional iron deficiency

    NARCIS (Netherlands)

    Zimmermann, M.B.; Hurrell, R.F.

    2007-01-01

    Iron deficiency is one of the leading risk factors for disability and death worldwide, affecting an estimated 2 billion people. Nutritional iron deficiency arises when physiological requirements cannot be met by iron absorption from diet. Dietary iron bioavailability is low in populations consuming

  10. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... also are hoping to determine which iron supplements work best to treat iron-deficiency anemia in children who do not consume the daily recommended amount of iron. Read less Participate in NHLBI Clinical Trials We lead or sponsor many studies related to iron-deficiency anemia. See if you ...

  11. Quantitative determination of iron, copper, lead, chromium and nickel in electronic waste samples using total reflection x-ray fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Elaseer, A. S.; Musbah, A. S; Ammar, M. M. G.; Salah, M. A.; Aisha, E. A.

    2015-01-01

    Total reflection x-ray fluorescence spectroscopy in conjunction with microwave assisted extraction technique was used for the analysis of twenty electronic waste samples. The analysis was limited to the printed circuit boards of electronic devices. Iron, copper, lead, chromium and nickel were quantitatively determined in the samples. The samples were carefully milled to fine powder and 50mg was digested by acid using microwave digestion procedure. The digested samples solution was spread together with gallium as internal standard on the reflection disk and analyzed. The results showed that the cassette recorder boards contain the highest concentration of iron, lead and nickel. The average concentrations of these metals were 78, 73 and 71g/Kg respectively. Computer boards contained the highest copper average concentration 39g/Kg. the highest chromium average concentration 3.6 g/Kg was in mobile phone boards. Measurements were made using PicoTAX portable x-ray device. the instrument was used for quantitative multi-element analysis. An air cooled x-ray tube (40KV, 1 mA) with Mo target and Be window was used as x-ray source. The optics of the device was a multilayer Ni/C, 17.5 keV, 80% reflectivity provides analysis of elements from Si to Zr (K series) and Rh to U (L series). A Si PIN-diode detector (7mm"2, 195eV) was used for the elements detection. In this study heavy metals average concentration in electronic circuit boards in the in the order of iron (35.25g/kg), copper (21.14g/Kg), lead (16.59g/Kg), nickel (16.01g/Kg) and chromium (1.07g/Kg).(author)

  12. Diel cycles in dissolved barium, lead, iron, vanadium, and nitrite in a stream draining a former zinc smelter site near Hegeler, Illinois

    Science.gov (United States)

    Kay, R.T.; Groschen, G.E.; Cygan, G.; Dupre, David H.

    2011-01-01

    Diel variations in the concentrations of a number of constituents have the potential to substantially affect the appropriate sampling regimen in acidic streams. Samples taken once during the course of the day cannot adequately reflect diel variations in water quality and may result in an inaccurate understanding of biogeochemical processes, ecological conditions, and of the threat posed by the water to human health and the associated wildlife. Surface water and groundwater affected by acid drainage were sampled every 60 to 90. min over a 48-hour period at a former zinc smelter known as the Hegeler Zinc Superfund Site, near Hegeler, Illinois. Diel variations related to water quality in the aquifer were not observed in groundwater. Diel variations were observed in the temperature, pH, and concentration of dissolved oxygen, nitrite, barium, iron, lead, vanadium, and possibly uranium in surface water. Temperature, dissolved oxygen, nitrite, barium, lead, and uranium generally attained maximum values during the afternoon and minimum values during the night. Iron, vanadium, and pH generally attained minimum values during the afternoon and maximum values during the night. Concentrations of dissolved oxygen were affected by the intensity of photosynthetic activity and respiration, which are dependent upon insolation. Nitrite, an intermediary in many nitrogen reactions, may have been formed by the oxidation of ammonium by dissolved oxygen and converted to other nitrogen species as part of the decomposition of organic matter. The timing of the pH cycles was distinctly different from the cycles found in Midwestern alkaline streams and likely was the result of the photoreduction of Fe3+ to Fe 2+ and variations in the intensity of precipitation of hydrous ferric oxide minerals. Diel cycles of iron and vanadium also were primarily the result of variations in the intensity of precipitation of hydrous ferric oxide minerals. The diel variation in the concentrations of lead, uranium

  13. The concentration of heavy metals: zinc, cadmium, lead, copper, mercury, iron and calcium in head hair of a randomly selected sample of Kenyan people

    International Nuclear Information System (INIS)

    Wandiga, S.O.; Jumba, I.O.

    1982-01-01

    An intercomparative analysis of the concentration of heavy metals:zinc, cadmium, lead, copper, mercury, iron and calcium in head hair of a randomly selected sample of Kenyan people using the techniques of atomic absorption spectrophotometry (AAS) and differential pulse anodic stripping voltammetry (DPAS) has been undertaken. The percent relative standard deviation for each sample analysed using either of the techniques show good sensitivity and correlation between the techniques. The DPAS was found to be slightly sensitive than the AAs instrument used. The recalculated body burden rations of Cd to Zn, Pb to Fe reveal no unusual health impairement symptoms and suggest a relatively clean environment in Kenya.(author)

  14. Evaluation of molybdenum and its alloys

    International Nuclear Information System (INIS)

    Lundberg, L.B.

    1981-01-01

    The choice of pure molybdenum as the prime candidate material for space reactor core heat pipes is critically examined. Pure molybdenum's high ductile-brittle transition temperature appears to be its major disadvantage. The candidate materials examined in detail for this application include low carbon arc-cast molybdenum, TZM-molybdenum alloy, and molybdenum-rhenium alloys. Published engineering properties are collected and compared, and it appears that Mo-Re alloys with 10 to 15% rhenium offer the best combination. Hardware is presently being made from electron beam melted Mo-13Re to test this conclusion

  15. A next-to-leading-order QCD analysis of neutrino-iron structure functions at the Tevatron

    International Nuclear Information System (INIS)

    Seligman, W.G.

    1997-01-01

    Nucleon structure functions measured in neutrino-iron and antineutrino-iron charged-current interactions are presented. The data were taken in two high-energy high-statistics runs by the LAB-E detector at the Fermilab Tevatron. Structure functions are extracted from a sample of 950,000 neutrino and 170,000 antineutrino events with neutrino energies from 30 to 360 GeV. The structure functions F 2 and xF 3 are compared with the predictions of perturbative Quantum Chromodynamics (PQCD). The combined non-singlet and singlet evolution in the context of PQCD gives value of ΛNLO,(4)/MS = 337 ± 28 (exp.) MeV, which corresponds to α S (M Z 2 ) = 0.119 ± 0.002 (exp.) ± 0.004 (theory), and with a gluon distribution given by xG(x,Q 0 2 = 5GeV 2 ) = (2.22 ± 0.34) x (1 - x) 4.65±0.68

  16. A next-to-leading-order QCD analysis of neutrino-iron structure functions at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Seligman, William Glenn [Columbia Univ., New York, NY (United States)

    1997-01-01

    Nucleon structure functions measured in neutrino-iron and antineutrino-iron charged-current interactions are presented. The data were taken in two high-energy high-statistics runs by the LAB-E detector at the Fermilab Tevatron. Structure functions are extracted from a sample of 950,000 neutrino and 170,000 antineutrino events with neutrino energies from 30 to 360 GeV. The structure functions F2 and xF3 are compared with the predictions of perturbative Quantum Chromodynamics (PQCD). The combined non-singlet and singlet evolution in the context of PQCD gives value of ΛNLO,(4)/MS = 337 ± 28 (exp.) MeV, which corresponds to αS(MZ2) = 0.119 ± 0.002 (exp.) ± 0.004 (theory), and with a gluon distribution given by xG(x,Q02 = 5GeV2) = (2.22 ± 0.34) x (1 - x)4.65±0.68.

  17. Gel Fabrication of Molybdenum “Beads”

    Energy Technology Data Exchange (ETDEWEB)

    Lowden, Richard Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Armstrong, Beth L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Cooley, Kevin M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

    2016-11-01

    Spherical molybdenum particles or “beads” of various diameters are of interest as feedstock materials for the additive manufacture of targets and assemblies used in the production of 99Mo medical isotopes using accelerator technology. Small metallic beads or ball bearings are typically fabricated from wire; however, small molybdenum spheres cannot readily be produced in this manner. Sol-gel processes are often employed to produce small dense microspheres of metal oxides across a broad diameter range that in the case of molybdenum could be reduced and sintered to produce metallic spheres. These Sol-gel type processes were examined for forming molybdenum oxide beads; however, the molybdenum trioxide was chemically incompatible with commonly used gelation materials. As an alternative, an aqueous alginate process being assessed for the fabrication of oxide spheres for catalyst applications was employed to form molybdenum trioxide beads that were successfully reduced and sintered to produce small molybdenum spheres.

  18. HYDROGEN VACANCY INTERACTION IN MOLYBDENUM

    NARCIS (Netherlands)

    Abd El Keriem, M.S.; van der Werf, D.P.; Pleiter, F

    1993-01-01

    Vacancy-hydrogen interaction in molybdenum was investigated by means of the perturbed angular correlation technique, using the isotope In-111 as a probe. The complex InV2 turned out to trap up to two hydrogen atoms: trapping of a single hydrogen atom gives rise to a decrease of the quadrupole

  19. Effects of carbon and molybdenum on the microstructures of high chromium white cast irons; Efeito do carbono e do molibdenio na microestrutura dos ferros fundidos brancos de alto cromo

    Energy Technology Data Exchange (ETDEWEB)

    Sinatora, Amilton; Ambrosio Filho, Francisco; Goldenstein, Helio; Fuoco, Ricardo; Albertin, Eduardo; Mei, Paulo Roberto

    1992-12-31

    The effects of 3 levels of carbon and 1.5% Mo addition on the solidification structures of a 15% chromium white cast iron were studied. The volume fraction of primary austenite and of eutectic carbides, as well as the number of carbide particles per unit length and the mean secondary dendrite arm spacing were measured. By means of thermal analysis, thermal arrest corresponding to the formation of the primary austenite and of the eutectic were determined. The increase in the carbon content and the addition of Mo led to lowering of the thermal arrests and to coarsening of the particles. (author) 15 refs., 6 figs., 5 tabs.

  20. Clean hydrometallurgical route to recover zinc, silver, lead, copper, cadmium and iron from hazardous jarosite residues produced during zinc hydrometallurgy

    International Nuclear Information System (INIS)

    Ju Shaohua; Zhang Yifei; Zhang Yi; Xue Peiyi; Wang Yihui

    2011-01-01

    Highlights: → The extraction fractions of various valuable metals during NH 4 Cl leaching are very high. The sintered residue was leached in 6 mol L -1 aqueous NH 4 Cl solution at 105 o C, followed by filtration. The leaching extraction of Zn, Pb, Cu, Cd and Ag are more than 95%. → The process can detoxified the hazardous elements such as Pb, As, Cd thoroughly. Then the NH 4 Cl leaching residue were leached again in 30 wt% aqueous NaOH solution for 1 h at 160 o C, and about 94% of As and 73% of Si were removed from the residue. → The final residue contains about 55 wt% Fe, and have the potential to be used as iron concentrate. - Abstract: A hydrometallurgical process for treating the hazardous jarosite residue from zinc hydrometallurgy was proposed, for not only detoxifying the residue, but also recovering the contained valuable metal components. The jarosite was initially activated and decomposed by sintering at 650 o C for 1 h. The sintered residue was leached in 6 mol L -1 aqueous NH 4 Cl solution at 105 o C, followed by filtration. The leaching extraction of Zn, Pb, Cu, Cd and Ag are more than 95%. During reduction with Zn powder, more than 93% of Pb, Cu, Ag and Cd can be simultaneously recovered. Then the NH 4 Cl leaching residue were leached again in 30 wt% aqueous NaOH solution for 1 h at 160 o C, and about 94% of As and 73% of Si were removed from the residue. The final residue was almost completely detoxified, and contains about 55 wt% Fe, which can be used as an iron concentration.

  1. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Disorders Lung Diseases Heart and Vascular Diseases Precision Medicine Activities Obesity, Nutrition, and Physical Activity Population and ... lose blood, you lose iron. Certain conditions or medicines can cause blood loss and lead to iron- ...

  2. A study on the alkali leaching of complex compound for molybdenum trioxide and ferric oxide

    International Nuclear Information System (INIS)

    Kim, C.G.; Whang, Y.K.

    1981-01-01

    This study is to determine the alkali-leaching meachanism by which complex compound by the reaction made between molybdenite (MoS 2 ) and ferric oxide (Fe 2 O 3 ) in the roasted are when molybdenum trioxide (MoO 3 ) is formed by the roasting reaction of molybdenite concentrate. The results obtained from this experiment are summarized as follows: The heating reaction analysis shows that the complex compound of iron molybdates (Fe 2 O 3 .3-4 MoO 3 ) is formed by the reaction of molybdenum trioxide and ferric oxide at temperatures of above 500 0 C. It is shown that at various reaction temperature below 400 0 C molybdenum trioxide is almost completely leached by caustic soda irrespective of the mole ratio of two chemical samples used for the experiment, whereas at temperature above 400 0 C the leaching rate of molybdenum trioxide decreases except that it varies from 70.77% at a temperature of 900 0 C at which the mole ratio is 1 to 1 to 84.08% at a temperature of 1000 0 C. The x-ray diffraction analysis has shown that the complex compound reacted at a temperature of 1000 0 C produces a complex compound with the crystal structure of iron molybdates, and the alkali-leached residues even with 19.0% of molybdenum trioxide, however, contain only α-Fe 2 O 3 , without showing iron molybdates. The crystalline compound of iron molybdates obtained as a result of heating reaction was leached by using caustic soda, while MoO 3 and Fe 2 O 3 in the leaching residue was found to contain other compounds unable to be leached by caustic soda. (author)

  3. On the interaction of molybdenum cyanide complexes with hydroperoxide of tertiary butyl

    International Nuclear Information System (INIS)

    Vretsena, N.B.; Nikipanchuk, M.V.; Chernyak, B.I.

    1979-01-01

    Conducted is investigation of interaction of potassium dioxotetracyanomolybdate (4) K 4 [MoO 2 (CN) 4 ], potassium oxotetracyanomolybdate (2) K 4 [MoO(CN) 4 ] and potassium tetracyanomolybdate K 4 [Mo(CN) 4 ] in CCl 4 and hydroperoxide of tertiary butyl medium, (HPTB). Shown is the process complex mechanism which leads to molybdenum oxidation in complexes and also to coordination and HPTB decomposition. Calculated are parameters of complex formation process of molybdenum with HPTB cyanide complexes

  4. Leading research on supermetals. Part 1. Bulky material (iron system); Supermetal no sendo kenkyu. 1. Ogata sozai (tetsukei)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For further improvement of iron system materials, supermetals with ultimate characteristics were researched. Since their strength and toughness have been improved with grain refinement by thermomechanical treatment, improvement of single-phase steel is nearly completed, and the study on ultra-fine multi-phase steel is indispensable. Bulky materials are also restrained from grain refinement because of the capability of existing processing facilities. Making a breakthrough in such restraint requires a challenge to high-speed rolling, repeated shear deformation and ultra-high strain rate process beyond conventional technologies. Further improvement of microstructure and dynamic characteristics requires other energies such as magnetism as well as mechanical energy. {gamma}-{alpha} phase transition important for structure control of steel materials is dependent on magnetism. The study on structure control and characteristics improvement under ferromagnetic field is essential in the future. Material improvement such as reduction of impurities and circulating elements, environmental measures, and mechanical alloying remain as issues to be studied. 224 refs., 176 figs., 18 tabs.

  5. Synthesized chitosan/ iron oxide nanocomposite and shrimp shell in removal of nickel, cadmium and lead from aqueous solution

    Directory of Open Access Journals (Sweden)

    M. Keshvardoostchokami

    2017-09-01

    Full Text Available In this study, an easy synthesized method for preparation of chitosan/iron oxide nanocomposite as a bio-sorbent has been applied. Analytical techniques such as Fourier transform infrared spectroscopy, X-ray diffraction; Field emission scanning electron microscopy and transmission electron microscopy were utilized to survey of morphological structure and the functional groups characterization. The histogram of frequency of particle size confirmed that medium size of the synthesized nanoparticles was 50 nm. Beside the obtained nanocomposite, application of chitosan as the precursor and shrimp shell as natural chitin and a natural polymer were assessed as adsorbents for decontamination of Ni2+, Cd2+ and Pb2+ as examples of heavy metals from drinking water. Batch studies were performed for adsorption experiments by changing variables such as pH, contact time and adsorbent dose. Based on the experimental sorption capacities, 58, 202 and 12 mg of Ni, Cd and Pb per g of Chitosan-Fe2O3 nanocomposite as adsorbent respectively, confirm that combination of Fe2O3 nanoparticles with chitosan makes a more efficient adsorbent than chitosan and chitin. Adsorbents in uptake of the mentioned heavy metals are in the order of Chitosan-Fe2O3 nanocomposite > chitosan> chitin. In addition, the kinetics and isotherm investigations were surveyed. Moreover, it has been shown that the synthesized nanocomposite significantly reduces the amount of the mentioned ions from the real wastewater sample.

  6. Neutron scattering and models: molybdenum

    International Nuclear Information System (INIS)

    Smith, A.B.

    1999-01-01

    A comprehensive interpretation of the fast-neutron interaction with elemental and isotopic molybdenum at energies of le 30 MeV is given. New experimental elemental-scattering information over the incident energy range 4.5 r a rrow 10 MeV is presented. Spherical, vibrational and dispersive models are deduced and discussed, including isospin, energy-dependent and mass effects. The vibrational models are consistent with the ''Lane potential''. The importance of dispersion effects is noted. Dichotomies that exist in the literature are removed. The models are vehicles for fundamental physical investigations and for the provision of data for applied purposes. A ''regional'' molybdenum model is proposed. Finally, recommendations for future work are made

  7. CVD molybdenum films of high infrared reflectance

    Energy Technology Data Exchange (ETDEWEB)

    Carver, G. E.

    1979-01-01

    Molybdenum thin films of high infrared reflectance have been deposited by pyrolytic decomposition of molybdenum carbonyl (Mo(CO)/sub 6/), and by hydrogen reduction of molybdenum pentachloride (MoCl/sub 5/). Reflectance values within 0.7% of the reflectance of supersmooth bulk molybdenum have been attained by annealing films of lower reflectance in both reducing and non-reducing atmospheres. All depositions and anneals proceed at atmospheric pressure, facilitating a continuous, flow-through fabrication. These reflectors combine the high temperature stability of molybdenum thin films with the infrared reflectance of a material such as aluminum. Deposition from Mo(CO)/sub 6/ under oxidizing conditions, and subsequent anneal in a reducing atmosphere, results in films that combine high solar absorptance with low thermal emittance. If anti-reflected, black molybdenum films can serve as highly selective single layer photothermal converters. Structural, compositional, and crystallographic properties have been measured after both deposition and anneal.

  8. The behaviour of molybdenum dialkyldithiocarbamate friction modifier additives

    International Nuclear Information System (INIS)

    Graham, Jocelyn Claire Herries

    2001-01-01

    In recent years there has been growing concern to produce energy-efficient lubricated components and modem engine oil specifications require lubricants to demonstrate fuel efficiency in standardised engine tests. One important method of producing low friction and thus fuel-efficient lubricants is to use oil-soluble, molybdenum-containing, friction modifier additives. In optimal conditions these additives are able to produce very low friction coefficients, in the range 0.045 to 0.075 in boundary lubrication conditions. Very little is known about the chemical and physical mechanisms by which oil soluble molybdenum additives form low friction films in tribological contacts. Information about their activity could lead to optimal use of these additives in lubricants and, therefore, more efficient engine running. The work outlined in this thesis investigated the behaviour of oil-soluble molybdenum additives and showed that these additives were able to effectively reduce friction in the absence of other additives such as ZnDTP. Their activity was shown to be highly concentration and temperature dependent and was also found to be sensitive to the roughness of the contacting surfaces. Raman spectroscopy was used to analyse the chemical nature of molybdenum-containing reaction films and found that friction reduction indubitably arises from the local formation of platelets (diameter 30-50 nm) of MoS 2 . The formation of MoS 2 -rich films was found to occur only during direct asperity-asperity rubbing of the contacting surfaces (this type of contact being especially prevalent in pure sliding contacts). At elevated temperatures and in the presence of oxidising gases the consumption of MoDTC was monitored. MoDTC concentration dropped until the total value fell below a critical level to reduce friction. The study showed that decay rate of molybdenum-containing species was reduced by the addition of peroxide-decomposing antioxidants. (author)

  9. Experimental determination of critical data of liquid molybdenum

    International Nuclear Information System (INIS)

    Seydel, U.; Fucke, W.

    1978-01-01

    The submicrosecond resistive pulse heating of wire-shaped metallic samples in a highly incompressible medium leads to a thermodynamic state very close to the critical point of the liquid metal. The additional application of a static pressure may result in a critical or supercritical transition. First results on the critical data of molybdenum are reported: Tsub(c) = (11 150 +- 550) K, psub(c) = (5460 +- 1160) bar, vsub(c) = (36.5 +- 3.5) cm 3 mol -1 . (author)

  10. Survey of heavy metal pollution (copper, lead, zinc, cadmium, iron and manganese in drinking water resources of Nurabad city, Lorestan, Iran 2013

    Directory of Open Access Journals (Sweden)

    GHodratolah Shams Khorramabadi

    2016-09-01

    Full Text Available Background: Healthy water passes through the pipelines from supply resources to consuming places in which passing from these stages may cause some cases of contamination like heavy metal contamination. Therefore, the aim of this study was to evaluate the contamination of heavy metals (copper, lead, zinc, cadmium, iron, and manganese in water resources of Nurabad city of Lorestan in 2013. Materials and Methods: In this cross-sectional study, samples were collected from 7 wells of drinking water and 2 water storage tanks during 6 months in Nurabad. So that, heavy metal parameters such as copper, lead, zinc, cadmium, iron, and manganese were measured using an atomic absorption device and also electrical conductivity, sulfate, chloride and total dissolved solids were also measured in accordance with standard methods. Results: Results indicated that the concentration of studied metals in water sources was lower than the national standards and World Health Organization standard, and in the water supply system the concentration of some metals was more than standard level. Moreover, the results showed that the concentration of studied heavy metals were more in winter than in autumn. Conclusion: Generally, in the water resources of Nurabad city the concentration of studied heavy metals was lower than the national standards and World Health Organization standard and there are not problems for water consumers. However, due to public health and the presence of a high concentration of these metals in the distribution supply, the heavy metal concentration in drinking water of this region should be monitored regularly by responsible organizations.

  11. Astrocyte dysfunction following molybdenum-associated purine loading could initiate Parkinson's disease with dementia.

    Science.gov (United States)

    Bourke, Christopher A

    2018-01-01

    Sporadic or idiopathic Parkinson's disease is a movement disorder with a worldwide distribution, a long pre-clinical latent period and a frequent association with dementia. The combination of molybdenum deficiency and purine ingestion could explain the movement disorder, the distribution, the latent period and the dementia association. Recent studies in sheep have shown that molybdenum deficiency enables some dietary purines to accumulate in the central nervous system. This causes astrocyte dysfunction, altered neuromodulation and eventually irreversible central nervous system disease. Humans and sheep share the ability to salvage purines and this ability places humans at risk when they ingest xanthosine, inosine, adenosine and guanosine. Adenosine ingestion in molybdenum-deficient humans will lead to adenosine loading and potentially a disturbance to the A2a adenosine receptors in the nigro-striatum. This could result in Parkinson's disease. Guanosine ingestion in molybdenum-deficient humans will lead to guanosine loading and potentially a disturbance to the guanosine receptors in the hippocampus, amygdala and ventral striatum. This could result in dementia. The molybdenum content of the average daily diet in the United States is 0.07 ppm and in the United Kingdom 0.04 ppm. Central nervous system disease occurs in sheep at <0.04 ppm. Consistent with the role proposed for molybdenum deficiency in Parkinson's disease is the observation that affected individuals have elevated sulfur amino acid levels, depressed sulfate levels, and depressed uric acid levels. Likewise the geographical distribution of Parkinson's dementia complex on Guam corresponds with the distribution of molybdenum-deficient soils hence molybdenum-deficient food gardens on that island.

  12. Efficacy and safety of cyclic pyranopterin monophosphate substitution in severe molybdenum cofactor deficiency type A : a prospective cohort study

    NARCIS (Netherlands)

    Schwahn, Bernd C.; Van Spronsen, Francjan J.; Belaidi, Abdel A.; Bowhay, Stephen; Christodoulou, John; Derks, Terry G.; Hennermann, Julia B.; Jameson, Elisabeth; Koenig, Kai; McGregor, Tracy L.; Font-Montgomery, Esperanza; Santamaria-Araujo, Jose A.; Santra, Saikat; Vaidya, Mamta; Vierzig, Anne; Wassmer, Evangeline; Weis, Ilona; Wong, Flora Y.; Veldman, Alex; Schwarz, Guenter

    2015-01-01

    Background Molybdenum cofactor deficiency (MoCD) is characterised by early, rapidly progressive postnatal encephalopathy and intractable seizures, leading to severe disability and early death. Previous treatment attempts have been unsuccessful. After a pioneering single treatment we now report the

  13. Iron and Immunity

    NARCIS (Netherlands)

    Verbon, E.H.|info:eu-repo/dai/nl/413534049; Trapet, P.L.; Stringlis, I.|info:eu-repo/dai/nl/41185206X; Kruijs, Sophie; Bakker, P.A.H.M.|info:eu-repo/dai/nl/074744623; Pieterse, C.M.J.|info:eu-repo/dai/nl/113115113

    2017-01-01

    Iron is an essential nutrient for most life on Earth because it functions as a crucial redox catalyst in many cellular processes. However, when present in excess iron can lead to the formation of harmful hydroxyl radicals. Hence, the cellular iron balance must be tightly controlled. Perturbation of

  14. Iron and Your Child

    Science.gov (United States)

    ... deficiency isn't corrected, it can lead to iron-deficiency anemia (a decrease in the number of red blood ... Parents Kids Teens Anemia Blood Test: Ferritin (Iron) Iron-Deficiency Anemia Vegetarianism Menstrual Problems Pregnant or Breastfeeding? Nutrients You ...

  15. Molybdenum: the element and aqueous solution chemistry

    International Nuclear Information System (INIS)

    Sykes, A.G.

    1987-01-01

    This chapter on the chemistry of the coordination compounds of molybdenum concentrates on the element itself, its recovery from ores and its use in the manufacture of steels. Most of the chapter is devoted to the aqueous solution chemistry of molybdenum in oxidation states II, III and IV. (UK)

  16. Investigation of pressing of molybdenum powder compacts

    International Nuclear Information System (INIS)

    Mymrin, S.A.; Kuznetsov, V.Eh.; Yampol'skij, M.L.; Leonov, S.A.; Mikhridinov, R.M.; Korzukhin, V.A.

    1990-01-01

    Results of an experimental investigation into pressing of compacts of MCh type molybdenum powders using the industrial equipment are presented. To measure the density of powder molybdenum billets a radioisotopic density meter with cesium-137 is used as radioactive gamma radiation source. The dependence of the produced billet density on the specific compacting pressure at different values of the powder bulk density is ascertained

  17. Extraction of molybdenum VI by alpha benzoinoxime

    International Nuclear Information System (INIS)

    Achache, M.; Meklati, M.

    1990-06-01

    The concentration of molybdenum, was studied using alpha benzoinoxime dissolved in chloroform. Several acids and salt at different levels of concentration were investigated as well as other parameters such as (mixing time, extractant to metal ratio, temperature etc.) The molybdenum stippling was also studied in alkaline medium with the subsequent recovery of the extractant and solvent

  18. Molybdenum sealing glass-ceramic composition

    International Nuclear Information System (INIS)

    Eagan, R.J.

    1976-01-01

    A glass-ceramic composition is described having low hydrogen and helium permeability properties, along with high fracture strength, and a thermal coefficient of expansion similar to that of molybdenum. The composition is adaptable for hermetically sealing to molybdenum at temperatures between 900 and about 950 0 C to form a hermetically sealed insulator body

  19. Influence of molybdenum on the high-temperature mechanical resistance especially creep resistance around 7000C of 18-14 type stainless steels

    International Nuclear Information System (INIS)

    Ben Marzouk, M.T.

    1977-06-01

    The influence of molybdenum on the mechanical properties under traction, the creep parameters, sub-structure and diffusion parameters of iron in stainless steels was investigated. Between 20 0 C and 800 0 C molybdenum has no significant effect on the elastic limit, breaking load or consolidation coefficient but increases the distributed elongation between 500 0 C and 800 0 C; its influence is greatest at 700 0 C. Addition of molybdenum reduces the creep rate at high temperature from the start of the test up to breaking point. In the temperature range studied, 600 0 C to 900 0 C, its influence is greatest at 600 0 C, decreases as the temperature rises and disappears at 900 0 C. Addition of 2% molybdenum increases the activation energy from 72 kcal/mole to 88 kcal/mole. At 700 0 C molybdenum hardly affects the precipitation and structure of dislocations but delays healing processes. Between 1000 0 C and 1300 0 C molybdenum has no effect on the iron diffusion coefficient: Q=68.7kcal/mole, D 0 =1.3cm 2 /s. The influence of Mo on the creep resistance of austenitic steels between 600 0 C and 900 0 C does not seem to be due to precipitation but to a solid solution effect, which could be a decrease in the diffusion coefficient of iron below 900 0 C [fr

  20. Effect of molybdenum on the severity of toxicity symptoms in flax induced by an excess of either manganese, zinc, copper, nickel or cobalt in the nutrient solution

    Energy Technology Data Exchange (ETDEWEB)

    Millikan, C R

    1947-01-01

    The addition of molybdenum to solutions containing an excess of either manganese, zinc, copper, nickel or cobalt respectively, resulted in decreases in the severity of iron deficiency symptoms which normally occurred when flax was grown in solutions containing the same concentrations of any of these elements, but without molybdenum. The efficacy of molybdenum in this regard increased with increasing concentration up to 25 parts per million. However, concentrations of 0.5 to 2 parts per million of molybdenum had little effect on the severity of iron deficiency symptoms at the concentrations of heavy metals used. Molybdenum 5, 10 or 25 parts per million also retarded the date of appearance and reduced the severity of lower leaf necrosis which is another characteristic symptom of the presence of excess manganese (25 to 100 parts per million) in the nutrient solution. It is concluded that an essential function of molybdenum is intimately associated with the regulation of the deleterious effect of manganese, zinc, copper, nickel or cobalt on the physiological availability of iron to the plant. 46 references, 3 figures.

  1. Determination of point isotropic buildup factors of gamma rays including incoherent and coherent scattering for aluminum, iron, lead, and water by discrete ordinates method

    International Nuclear Information System (INIS)

    Kitsos, S.; Assad, A.; Diop, C.M.; Nimal, J.C.

    1994-01-01

    Exposure and energy absorption buildup factors for aluminum, iron, lead, and water are calculated by the SNID discrete ordinates code for an isotropic point source in a homogeneous medium. The calculation of the buildup factors takes into account the effects of both bound-electron Compton (incoherent) and coherent (Rayleigh) scattering. A comparison with buildup factors from the literature shows that these two effects greatly increase the buildup factors for energies below a few hundred kilo-electron-volts, and thus the new results are improved relative to the experiment. This greater accuracy is due to the increase in the linear attenuation coefficient, which leads to the calculation of the buildup factors for a mean free path with a smaller shield thickness. On the other hand, for the same shield thickness, exposure increases when only incoherent scattering is included and decreases when only coherent scattering is included, so that the exposure finally decreases when both effects are included. Great care must also be taken when checking the approximations for gamma-ray deep-penetration transport calculations, as well as for the cross-section treatment and origin

  2. Layered ordering of vacancies of lead iron phosphate Pb{sub 3}Fe{sub 2}(PO{sub 4}){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Malakho, A.P. [Moscow State Univ., Dept. of Material Science (Russian Federation); Morozov, V.A.; Pokholok, V.; Lazoryak, B.I. [Moscow State Univ., Dept. of Chemisty (Russian Federation); Morozov, V.A.; Van Tendeloo, G. [Antwerp Univ., EMAT (Belgium)

    2005-07-01

    Lead iron phosphate Pb{sub 3}Fe{sub 2}(PO{sub 4}){sub 4} has been synthesized by solid state method and characterized by X-ray powder and electron diffraction, differential scanning calorimetry, Moessbauer and infrared spectroscopy. A structural model for Pb{sub 3}Fe{sub 2}(PO{sub 4}){sub 4} is proposed and is refined by the Rietveld method. The compound crystallizes in the monoclinic space group P2{sub 1}/c with a=9.0065(6) Angstroms, b=9.0574(6) Angstroms, c=9.3057(6) Angstroms, {beta}=116.880(4) degrees, V=677.10(8) (Angstroms){sup 3}, Z=2, R{sub wp}=3.52%, R{sub p}=2.66%. It exhibits a structure with a three-dimensional open framework. The 3D framework is formed by PO{sub 4} tetrahedra and FeO{sub 6} octahedra connected via common vertices. 3/4 of cavities in the framework are occupied by lead and 1/4 are vacant. (authors)

  3. Materials for Molybdenum 99 purification

    International Nuclear Information System (INIS)

    Wilkinson, M. Victoria; Mondino, Angel V.; Manzini, Alberto C.

    2003-01-01

    The National Atomic Energy Commission (CNEA) produces fission Mo 99, an isotope of wide use in nuclear medicine. In order to simplify the current Mo 99 production process, to shorten its duration and reduce impurities in the final product, alternative methods for purification steps were looked for. In this work a variety of new materials for the purification columns were designed, all of them with carbon. These materials were studied and a material which contribute with the best results for molybdenum retention, was selected. The preparation procedure and the working conditions were determined. (author)

  4. Molybdenum Oxides - From Fundamentals to Functionality.

    Science.gov (United States)

    de Castro, Isabela Alves; Datta, Robi Shankar; Ou, Jian Zhen; Castellanos-Gomez, Andres; Sriram, Sharath; Daeneke, Torben; Kalantar-Zadeh, Kourosh

    2017-10-01

    The properties and applications of molybdenum oxides are reviewed in depth. Molybdenum is found in various oxide stoichiometries, which have been employed for different high-value research and commercial applications. The great chemical and physical characteristics of molybdenum oxides make them versatile and highly tunable for incorporation in optical, electronic, catalytic, bio, and energy systems. Variations in the oxidation states allow manipulation of the crystal structure, morphology, oxygen vacancies, and dopants, to control and engineer electronic states. Despite this overwhelming functionality and potential, a definitive resource on molybdenum oxide is still unavailable. The aim here is to provide such a resource, while presenting an insightful outlook into future prospective applications for molybdenum oxides. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Vapor deposition of molybdenum oxide using bis(ethylbenzene) molybdenum and water

    International Nuclear Information System (INIS)

    Drake, Tasha L.; Stair, Peter C.

    2016-01-01

    Three molybdenum precursors—bis(acetylacetonate) dioxomolybdenum, molybdenum isopropoxide, and bis(ethylbenzene) molybdenum—were tested for molybdenum oxide vapor deposition. Quartz crystal microbalance studies were performed to monitor growth. Molybdenum isopropoxide and bis(ethylbenzene) molybdenum achieved linear growth rates 0.01 and 0.08 Å/cycle, respectively, using atomic layer deposition techniques. Negligible MoO_x growth was observed on alumina powder using molybdenum isopropoxide, as determined by inductively coupled plasma optical emission spectroscopy. Bis(ethylbenzene) molybdenum achieved loadings of 0.5, 1.1, and 1.9 Mo/nm"2 on alumina powder after one, two, and five cycles, respectively, using atomic layer deposition techniques. The growth window for bis(ethylbenzene) molybdenum is 135–150 °C. An alternative pulsing strategy was also developed for bis(ethylbenzene) molybdenum that results in higher growth rates in less time compared to atomic layer deposition techniques. The outlined process serves as a methodology for depositing molybdenum oxide for catalytic applications. All as-deposited materials undergo further calcination prior to characterization and testing.

  6. Mechanical properties of molybdenum alloyed liquid phase-sintered tungsten-based composites

    International Nuclear Information System (INIS)

    Kemp, P.B.; German, R.M.

    1995-01-01

    Tungsten-based composites are fabricated from mixed elemental powders using liquid phase sintering, usually with a nickel-iron matrix. During sintering, the tungsten undergoes grain growth, leading to microstructure coarsening that lowers strength but increases ductility. Often the desire is to increase strength at the sacrifice of ductility, and historically, this has been performed by postsintering deformation. There has been considerable research on alloying to adjust the as-sintered mechanical properties to match those of swaged alloys. Prior reports cover many additions, seemingly including much of the periodic table. Unfortunately, many of the modified alloys proved disappointing, largely due to degraded strength at the tungsten-matrix interface. Of these modified alloys, the molybdenum-containing systems exhibit a promising combination of properties, cost, and processing ease. For example, the 82W-8Mo-7Ni-3Fe alloy gives a yield strength that is 34% higher than the equivalent 90W-7Ni-3Fe alloy (from 535 to 715 MPa) but with a 33% decrease in fracture elongation (from 30 to 20% elongation). This article reports on experiments geared to promoting improved properties in the W-Mo-Ni-Fe alloys. However, unlike the prior research which maintained a constant Ni + Fe content and varied the W:Mo ratio, this study considers the Mo:(Ni + Fe) ratio effect for 82, 90, and 93 wt pct W

  7. Biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin

    International Nuclear Information System (INIS)

    Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Usta, Canan; Soylak, Mustafa

    2007-01-01

    The biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin for preconcentration-separation of them have been investigated. The sorbed analytes on biosorbent were eluted by using 1 mol L -1 HCl and analytes were determined by flame atomic absorption spectrometry. The influences of analytical parameters including amounts of pH, B. sphaericus, sample volume etc. on the quantitative recoveries of analytes were investigated. The effects of alkaline, earth alkaline ions and some metal ions on the retentions of the analytes on the biosorbent were also examined. Separation and preconcentration of Cu, Pb, Fe and Co ions from real samples was achieved quantitatively. The detection limits by 3 sigma for analyte ions were in the range of 0.20-0.75 μg L -1 for aqueous samples and in the range of 2.5-9.4 ng g -1 for solid samples. The validation of the procedure was performed by the analysis of the certified standard reference materials (NRCC-SLRS 4 Riverine Water, SRM 2711 Montana soil and GBW 07605 Tea). The presented method was applied to the determination of analyte ions in green tea, black tea, cultivated mushroom, boiled wheat, rice and soil samples with successfully results

  8. Estrogen-induced disruption of intracellular iron metabolism leads to oxidative stress, membrane damage, and cell cycle arrest in MCF-7 cells.

    Science.gov (United States)

    Bajbouj, Khuloud; Shafarin, Jasmin; Abdalla, Maher Y; Ahmad, Iman M; Hamad, Mawieh

    2017-10-01

    It is well established that several forms of cancer associate with significant iron overload. Recent studies have suggested that estrogen (E2) disrupts intracellular iron homeostasis by reducing hepcidin synthesis and maintaining ferroportin integrity. Here, the ability of E2 to alter intracellular iron status and cell growth potential was investigated in MCF-7 cells treated with increasing concentrations of E2. Treated cells were assessed for intracellular iron status, the expression of key proteins involved in iron metabolism, oxidative stress, cell survival, growth, and apoptosis. E2 treatment resulted in a significant reduction in hepcidin expression and a significant increase in hypoxia-inducible factor 1 alpha, ferroportin, transferrin receptor, and ferritin expression; a transient decrease in labile iron pool; and a significant increase in total intracellular iron content mainly at 20 nM/48 h E2 dose. Treated cells also showed increased total glutathione and oxidized glutathione levels, increased superoxide dismutase activity, and increased hemoxygenase 1 expression. Treatment with E2 at 20 nM for 48 h resulted in a significant reduction in cell growth (0.35/1 migration rate) and decreased cell survival (iron metabolism and precipitates adverse effects concerning cell viability, membrane integrity, and growth potential.

  9. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... loss and lead to iron-deficiency anemia. Common causes of blood loss that lead to iron-deficiency anemia include: Bleeding in your GI tract, from an ulcer, colon cancer, or regular use of medicines such as aspirin ...

  10. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Certain conditions or medicines can decrease your body’s ability to absorb iron and lead to iron-deficiency ... environment or water. Lead interferes with the body’s ability to make hemoglobin. Family history and genetics Von ...

  11. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... lead in their blood from their environment or water. Lead interferes with the body’s ability to make ... iron-deficiency anemia in blood donors affects the quality of donated red blood cells, such as how ...

  12. Mechanistic Studies of the Iron and Molybdenum Nitrogenases

    OpenAIRE

    Harris, Derek

    2017-01-01

    As a basic building block in many biological molecules the element nitrogen (N) is essential for life. Dinitrogen (N2) is abundant in Earth’s atmosphere, but this form is biologically unavailable. To be biologically available N2 must undergo an energy demanding reduction reaction to the fixed form, ammonia (NH3). The industrial Haber-Bosch process, which accounts for approximately 50% of the worlds fixed nitrogen, uses energy from fossil fuels to achieve high pressures and temperatures to fac...

  13. Hexavalent Molybdenum Reduction to Mo-Blue by a Sodium-Dodecyl-Sulfate-Degrading Klebsiella oxytoca Strain DRY14

    Directory of Open Access Journals (Sweden)

    M. I. E. Halmi

    2013-01-01

    Full Text Available Bacteria with the ability to tolerate, remove, and/or degrade several xenobiotics simultaneously are urgently needed for remediation of polluted sites. A previously isolated bacterium with sodium dodecyl sulfate- (SDS- degrading capacity was found to be able to reduce molybdenum to the nontoxic molybdenum blue. The optimal pH, carbon source, molybdate concentration, and temperature supporting molybdate reduction were pH 7.0, glucose at 1.5% (w/v, between 25 and 30 mM, and 25°C, respectively. The optimum phosphate concentration for molybdate reduction was 5 mM. The Mo-blue produced exhibits an absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. None of the respiratory inhibitors tested showed any inhibition to the molybdenum-reducing activity suggesting that the electron transport system of this bacterium is not the site of molybdenum reduction. Chromium, cadmium, silver, copper, mercury, and lead caused approximately 77, 65, 77, 89, 80, and 80% inhibition of the molybdenum-reducing activity, respectively. Ferrous and stannous ions markedly increased the activity of molybdenum-reducing activity in this bacterium. The maximum tolerable concentration of SDS as a cocontaminant was 3 g/L. The characteristics of this bacterium make it a suitable candidate for molybdenum bioremediation of sites cocontaminated with detergent pollutant.

  14. Features of soldering of molybdenum a lols

    International Nuclear Information System (INIS)

    Grishin, V.L.; Rybkin, B.V.; Cherkasov, A.F.

    1980-01-01

    Soldering features of complex-alloy molybdenum alloys were investigated in comparison with alloys based on solid solutions. Soldering features of heterogeneous molybdenum base alloys were investigated using samples of 0.5-1.O mm sheets with the strain of about 95% made of ingots which had been smelted in arc vacuum furnaces. The soldering of samples was carried out in 5x1O -5 mm Hg vacuum using different sources of heating: radiation, electron-ray and contact. It was shown that heat-resisting soldered joints of heterogeneous molybdenum alloys could be produced using zirconium and niobium base solders containing the most effective hardeners of the parent material (titanum, vanadium, tantalum, molybdenum, tungsten). To preserve high mechanical properties of heterogeneous alloys it was expedient to use for welding local heating sources which permitted to decrease considerably temperature- time conditions of the process

  15. Large-Batch Reduction of Molybdenum Trioxide

    Energy Technology Data Exchange (ETDEWEB)

    Kiggans, Jr, James O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lowden, Richard Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Menchhofer, Paul A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nunn, Stephen D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bryan, Chris [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    Unconverted, isotopically-enriched molybdenum metal must be recovered from the spent radiopharmaceutical solution used in NorthStar’s Technetium-99m generator and reused. The recycle process begins by recovering the metal from the aqueous potassium molybdate (K2MoO4) solutions as molybdenum trioxide (MoO3) employing a process developed at Argonne National Laboratory. The MoO3 powder is subsequently reduced to molybdenum metal powder which can be blended with new powder and further processed into a flowable form to be used to produce target disks for irradiation. The molybdenum oxide reduction process has been examined and scaled to produce kilogram quantities of metal powder suitable for processing into a useable form employing spray drying or similar technique and ultimately used for target fabrication.

  16. Spectrophotometric determination of molybdenum with non-ionic surfactant and thiocyanate

    International Nuclear Information System (INIS)

    Hayashi, Kenjiro; Yamamoto, Atsuo; Fujimura, Yasue; Ito, Saburo.

    1980-01-01

    Although the molybdenum (V)-thiocyanate complex is quite stable in non-aqueous solvent such as ether, the complex in dilute acidic solution is unstable. However, this unstable complex was stabilized remarkably by addition of some non-ionic surfactant such as Triton X-100 (alkylphenolpolyoxyethylene ether). The application of this stabilizing effect of the surfactant to the photometric determination of trace amounts of molybdenum with thiocyanate resulted in an increase in the sensitivity. The rate of formation of the Mo(V)-SCN complex was affected by the presence of ferrous ion and its rate constant was proportional to the concentration of Fe(II). The stabilizing effect of the surfactant on the yellowish orange coloration can be understood if we assume that the Mo(V)-SCN complex is incorporated into the micelles of Triton X-100 as [H 2 + , MoO(CNS) 5 2- ]. The optimum condition for the determination of molybdenum is as follows: concentration of sulfuric acid, 0.22 mol dm -3 ; Triton X-100, 0.8%; ascorbic acid, 0.32 mol dm -3 ; thiocyanate, 0.30 mol dm -3 ; iron, 40 mg dm -3 ; standing time for coloration, 10 min and more. Beer's law was obeyed over the range (1 -- 233) μg/50 cm 3 . The molar absorption coefficient at 468 nm was 1.7 2 x 10 4 cm -1 mol -1 dm 3 . The maximum permissible limits of foreign ions (mg/50 cm 3 ) were as follows: Ni(30); Co(12); W(VI) (2); Cu, Zn, V(V) (3); Cr(VI) (5). Large amounts of iron interfered, but this interference was removed by addition of the same amount of iron to the reagent blank. Trace amounts of molybdenum in steel was determined by this method with satisfactory results. (author)

  17. Model Prebiotic Iron-Sulfur Peptides

    Science.gov (United States)

    Bonfio, C.; Scintilla, S.; Shah, S.; Evans, D. J.; Jin, L.; Szostak, J. W.; Sasselov, D. D.; Sutherland, J. D.; Mansy, S. S.

    2017-07-01

    Iron-sulfur clusters form easily in aqueous solution in the presence of thiolates and iron ions. Polymerization of short, iron-sulfur binding tripeptide sequences leads to ferredoxin-like ligand spacing and activity.

  18. Molybdenum solubility in aluminium nitrate solutions

    Energy Technology Data Exchange (ETDEWEB)

    Heres, X.; Sans, D.; Bertrand, M.; Eysseric, C. [CEA, Centre de Marcoule, Nuclear Energy Division, DRCP, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Brackx, E.; Domenger, R.; Excoffier, E. [CEA, Centre de Marcoule, Nuclear Energy Division, DTEC, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Valery, J.F. [AREVA-NC, DOR/RDP, Paris - La Defense (France)

    2016-07-01

    For over 60 years, research reactors (RR or RTR for research testing reactors) have been used as neutron sources for research, radioisotope production ({sup 99}Mo/{sup 99m}Tc), nuclear medicine, materials characterization, etc... Currently, over 240 of these reactors are in operation in 56 countries. They are simpler than power reactors and operate at lower temperature (cooled to below 100 C. degrees). The fuel assemblies are typically plates or cylinders of uranium alloy and aluminium (U-Al) coated with pure aluminium. These fuels can be processed in AREVA La Hague plant after batch dissolution in concentrated nitric acid and mixing with UOX fuel streams. The aim of this study is to accurately measure the solubility of molybdenum in nitric acid solution containing high concentrations of aluminium. The higher the molybdenum solubility is, the more flexible reprocessing operations are, especially when the spent fuels contain high amounts of molybdenum. To be most representative of the dissolution process, uranium-molybdenum alloy and molybdenum metal powder were dissolved in solutions of aluminium nitrate at the nominal dissolution temperature. The experiments showed complete dissolution of metallic elements after 30 minutes long stirring, even if molybdenum metal was added in excess. After an induction period, a slow precipitation of molybdic acid occurs for about 15 hours. The data obtained show the molybdenum solubility decreases with increasing aluminium concentration. The solubility law follows an exponential relation around 40 g/L of aluminium with a high determination coefficient. Molybdenum solubility is not impacted by the presence of gadolinium, or by an increasing concentration of uranium. (authors)

  19. Elimination of excess molybdenum by cattle

    Energy Technology Data Exchange (ETDEWEB)

    Toelgyesi, G.; Elmoty, I.A.

    1967-01-01

    It was found that cattle would ingest spontaneously 5-15 g of molybdenum on one occasion. The uptake of this quantity caused but moderate loss of appetite and mild enteritis, both normalizing in one week. The occurrence of a severe acute molybdenum poisoning can be practically excluded, owing to refusal of the poisoned feed. Spontaneously ingested molybdenum caused on the first day a 30-100 fold rise of ruminal Mo-level, decreasing to the order of the normal value in about one week. But in the urine and faeces, Mo-level was at least 10 fold, in the blood and milk about 4 fold of the normal one, even one or two weeks after ingestion. During this period at least 90% of ingested Mo was eliminated with the faeces, urine and milk. One week after the ingestion of molybdenum, the rumen content showed no evidence on poisoning and no trace of molybdenum. Oral administration of ammonium molybdenate in an amount equivalent to 40 g molybdenum caused no fatality. In fact, cattle would never ingest spontaneously such a large dose.

  20. Measurements of cross-section of charge current inclusive of antineutrino scattering off nucleons using carbon, iron, lead and scintillator at MINER$\

    Energy Technology Data Exchange (ETDEWEB)

    Rakotondravohitra, Laza [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-08-18

    Neutrino physics is one of the most active fields in the domaine of high energy physics during the last century. The need of precise measurement of neutrino-nucleus interactions required by the neutrino oscillation experiments is a an exiting step. These measurements of cross-section are more than essential for neutrino oscillation experiment. Over the year, many measurements from varieties of experiments have been presented. MINERνA is one of the world leaders in measuring cross-section of neutrino and antineutrino -nucleus interactions. MINERνA is a neutrino-nucleus scattering experiment installed in the few-GeV NuMI beam line at Fermilab. In order to study nuclear dependence, MINERνA is endowed with different types of solid nuclear targets as well are liquid targets such as helium and water. This thesis presents measurements of cross-section of antineutrino scattering off nucleons using a variety of solid nuclear targets, carbon, iron, lead and also polystyrene scintillator (CH). The data set of antineutrino used for this analysis was taken between March and July 2010 with a total of 1.60X1020 protons on target. Charged current inclusive interactions were selected by requiring a positive muon and kinematics limitation of acceptance of the muon spectrometer are applied. The analysis requires neutrino energy between 2GeV et 20GeV and the angle of muon θmu < 17degree . The absolute cross-section # as function of neutrino energy and the differential cross-section dσ/ dxbj measured and shown the corresponding systematics for each nuclear targets. Data results are compared with prediction of the models implemented in the neutrino events generators GENIE 2.6.2 used by the experiment.

  1. Method of producing oxidation resistant coatings for molybdenum

    International Nuclear Information System (INIS)

    Timmons, G.A.

    1989-01-01

    A method is described for producing a molybdenum element having adherently bonded thereto a thermally self-healing plasma-sprayed coating consisting essentially of a composite of molybdenum and a refactory oxide material capable of reacting with molybdenum oxide under oxidizing conditions to form a substantially thermally stable refractory compound of molybdenum, the method comprising plasma-spraying a coating formed by the step-wise application of a plurality of interbonded plasma-sprayed layers of a composite of molybdenum/refractory oxide material produced from a particulate mixture thereof. The coating comprises a first layer of molybdenum plasma-sprayed bonded to the substrate of the molybdenum element, a second layer of plasma-sprayed mixture of particulate molybdenum/refactory oxide consisting essentially of predominantly molybdenum bonded to the first layer, and succeeding layers of this mixture. The next step is heating the coated molybdenum element under oxidizing conditions to an elevated temperature sufficient to cause oxygen to diffuse into the surface of the multi-layered coating to react with dispersed molybdenum therein to form molybdenum oxide and effect healing of the coating by reaction of the molybdenum oxide with the contained refractory oxide and thereby protect the substrate of the molybdenum element against oxidation

  2. Determination of molybdenum in natural waters by laser thermal-lens spectrometry

    International Nuclear Information System (INIS)

    Proskurnin, M.A.; Abroskin, A.G.; Artemova, S.I.; Belyaeva, T.V.; Ivanova, E.K.

    1992-01-01

    As before, the determination of nanogram quantities of heavy metals from small sample volumes of natural water represents an acute problem. This task has been solved more or less successfully by the use of different and sufficiently developed physicochemical methods. In most cases the determination requires a 100-fold preconcentration of the component determined (for instance, when using atomic absorption spectrometry). This significant disadvantage can be avoided by the use of thermal-lens laser spectrometry (TLS); some alternatives of the method have already found applications in analytical practice. The objective of the present study has been to investigate the optimum conditions for the determination of molybdenum in natural waters from small sample volumes by TLS. The resulting method based on the reaction with thiocyanate ions in the presence of ascorbic acid, has a detection limit of 19 pg/ml. Masking of iron(III) with a 1000-fold excess of tartrate ions has been proposed and it has been shown that a 10-fold excess of iron does not interfere in the determination of molybdenum. The procedure has been applied to the determination of molybdenum in drinking and natural waters

  3. Selective adsorption of molybdenum(VI) from Mo-Re bearing effluent by chemically modified astringent persimmon

    Energy Technology Data Exchange (ETDEWEB)

    Xiong Ying, E-mail: xiongying_1977@hotmail.com [School of Chemistry, Key Laboratory of Rare-scattered Elements of Liaoning Province, Liaoning University, Shenyang 110036 (China); Wang Haitao; Lou Zhenning; Shan Weijun; Xing Zhiqiang; Deng Guichun [School of Chemistry, Key Laboratory of Rare-scattered Elements of Liaoning Province, Liaoning University, Shenyang 110036 (China); Wu Dongbei [Department of Chemistry, Tongji University, 200092 (China); Fang Dawei [School of Chemistry, Key Laboratory of Rare-scattered Elements of Liaoning Province, Liaoning University, Shenyang 110036 (China); Biswas, Biplob Kumar [Department of Applied Chemistry, Saga University, Honjo 1, Saga 840-8502 (Japan); Department of Applied Chemistry and Chemical Engineering, Jessore Science and Technology University, Jessore (Bangladesh)

    2011-02-28

    Graphical abstract: The use of persimmon for the recovery of Mo(VI) from aqueous chloride medium was investigated. The excellent adsorption characteristics for Mo(VI) were confirmed by adsorption and elution tests using a column packed with the APF gel. Research highlights: {yields} Astringent persimmon was chemically cross-linked by formaldehyde to obtain a novel kind of adsorption gel. By comparing with the adsorption of some other metal ions, especially for Re(VII), this new gel exhibited selectivity only for molybdenum with a remarkably high capacity for Mo(VI) (1.05 mol/kg dry gel). {yields} The adsorption mechanisms of molybdenum on the astringent persimmon gel have been determined for deferent molybdenum species. And, the endothermic adsorption process followed pseudo-second order kinetics, and the adsorption behavior obeys the Langmuir mode. {yields} The excellent adsorption characteristics for Mo(VI) were confirmed by adsorption and elution tests using a column packed with the APF gel, especially from an actual industrial waste effluent. - Abstract: Astringent persimmon was chemically cross-linked by formaldehyde to obtain a novel kind of adsorption gel, which was named as APF gel. The adsorption behaviors of Mo(VI) and Re(VII) along with other coexisting metals onto the APF gel were studied in the present paper. The APF gel was found to be effective for the adsorption of Mo(VI) while the gel is almost completely inert toward rhenium and calcium over the whole hydrochloric acid concentration region. The APF gel has a low affinity for iron, copper, lead, nickel, manganese and zinc ions when the concentration of HCl is higher than 1 mol/L. The gel exhibited selectivity only for Mo(VI) with a remarkably high adsorption capacity 1.05 mol/kg, and the adsorption behavior obeys the Langmuir model. According to the thermodynamic and kinetic studies, the endothermic adsorption process followed pseudo-second order kinetics. Also, its excellent adsorption

  4. Rapid analysis of molybdenum contents in molybdenum master alloys by X-ray fluorescence technique

    International Nuclear Information System (INIS)

    Tongkong, P.

    1985-01-01

    Determination of molybdenum contents in molybdenum master alloy had been performed using energy dispersive x-ray fluorescence (EDX) technique where analysis were made via standard additions and calibration curves. Comparison of EDX technique with other analyzing techniques, i.e., wavelength dispersive x-ray fluorescence, neutron activation analysis and inductive coupled plasma spectrometry, showed consistency in the results. This technique was found to yield reliable results when molybdenum contents in master alloys were in the range of 13 to 50 percent using HPGe detector or proportional counter. When the required error was set at 1%, the minimum analyzing time was found to be 30 and 60 seconds for Fe-Mo master alloys with molybdenum content of 13.54 and 49.09 percent respectively. For Al-Mo master alloys, the minimum times required were 120 and 300 seconds with molybdenum content of 15.22 and 47.26 percent respectively

  5. Intestinal Iron Homeostasis and Colon Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Yatrik M. Shah

    2013-06-01

    Full Text Available Colorectal cancer (CRC is the third most common cause of cancer-related deaths in industrialized countries. Understanding the mechanisms of growth and progression of CRC is essential to improve treatment. Iron is an essential nutrient for cell growth. Iron overload caused by hereditary mutations or excess dietary iron uptake has been identified as a risk factor for CRC. Intestinal iron is tightly controlled by iron transporters that are responsible for iron uptake, distribution, and export. Dysregulation of intestinal iron transporters are observed in CRC and lead to iron accumulation in tumors. Intratumoral iron results in oxidative stress, lipid peroxidation, protein modification and DNA damage with consequent promotion of oncogene activation. In addition, excess iron in intestinal tumors may lead to increase in tumor-elicited inflammation and tumor growth. Limiting intratumoral iron through specifically chelating excess intestinal iron or modulating activities of iron transporter may be an attractive therapeutic target for CRC.

  6. Field experiment for determining lead accumulation in rice grains of different genotypes and correlation with iron oxides deposited on rhizosphere soil.

    Science.gov (United States)

    Lai, Yu-Cheng; Syu, Chien-Hui; Wang, Pin-Jie; Lee, Dar-Yuan; Fan, Chihhao; Juang, Kai-Wei

    2018-01-01

    Paddy rice (Oryza sativa L.) is a major staple crop in Asia. However, heavy metal accumulation in paddy soil poses a health risk for rice consumption. Although plant uptake of Pb is usually low, Pb concentrations in rice plants have been increasing with Pb contamination in paddy fields. It is known that iron oxide deposits in the rhizosphere influence the absorption of soil Pb by rice plants. In this study, 14 rice cultivars bred in Taiwan, including ten japonica cultivars (HL21, KH145, TC192, TK9, TK14, TK16, TN11, TNG71, TNG84, and TY3) and four indica cultivars (TCS10, TCS17, TCSW2, and TNGS22), were used in a field experiment. We investigated the genotypic variation in rice plant Pb in relation to iron oxides deposited in the rhizosphere, as seen in a suspiciously contaminated site in central Taiwan. The results showed that the cultivars TCSW2, TN11, TNG71, and TNG84 accumulated brown rice Pb exceeding the tolerable level of 0.2mgkg -1 . In contrast, the cultivars TNGS22, TK9, TK14, and TY3 accumulated much lower brown rice Pb (iron oxides deposited on the rhizosphere soil show stronger affinity to soil-available Pb than those on the root surface to form iron plaque. The relative tendency of Pb sequestration toward rhizosphere soil was negatively correlated with the Pb concentrations in brown rice. The iron oxides deposited on the rhizosphere soil but not on the root surface to form iron plaque dominate Pb sequestration in the rhizosphere. Therefore, the enhancement of iron oxide deposits on the rhizosphere soil could serve as a barrier preventing soil Pb on the root surface and result in reduced Pb accumulation in brown rice. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Regularly arranged indium islands on glass/molybdenum substrates upon femtosecond laser and physical vapor deposition processing

    Energy Technology Data Exchange (ETDEWEB)

    Ringleb, F.; Eylers, K.; Teubner, Th.; Boeck, T., E-mail: torsten.boeck@ikz-berlin.de [Leibniz-Institute for Crystal Growth, Max-Born-Straße 2, Berlin 12489 (Germany); Symietz, C.; Bonse, J.; Andree, S.; Krüger, J. [Bundesanstalt für Materialforschung und-prüfung (BAM), Unter den Eichen 87, Berlin 12205 (Germany); Heidmann, B.; Schmid, M. [Department of Physics, Freie Universität Berlin, Arnimalle 14, Berlin 14195 (Germany); Nanooptical Concepts for PV, Helmholtz Zentrum Berlin, Hahn-Meitner-Platz 1, Berlin 14109 (Germany); Lux-Steiner, M. [Nanooptical Concepts for PV, Helmholtz Zentrum Berlin, Hahn-Meitner-Platz 1, Berlin 14109 (Germany); Heterogeneous Material Systems, Helmholtz Zentrum Berlin, Hahn-Meitner-Platz 1, Berlin 14109 (Germany)

    2016-03-14

    A bottom-up approach is presented for the production of arrays of indium islands on a molybdenum layer on glass, which can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide used in photovoltaics. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD.

  8. Molybdenum reduction to molybdenum blue in Serratia sp. Strain DRY5 is catalyzed by a novel molybdenum-reducing enzyme.

    Science.gov (United States)

    Shukor, M Y; Halmi, M I E; Rahman, M F A; Shamaan, N A; Syed, M A

    2014-01-01

    The first purification of the Mo-reducing enzyme from Serratia sp. strain DRY5 that is responsible for molybdenum reduction to molybdenum blue in the bacterium is reported. The monomeric enzyme has an apparent molecular weight of 105 kDalton. The isoelectric point of this enzyme was 7.55. The enzyme has an optimum pH of 6.0 and maximum activity between 25 and 35°C. The Mo-reducing enzyme was extremely sensitive to temperatures above 50°C (between 54 and 70°C). A plot of initial rates against substrate concentrations at 15 mM 12-MP registered a V max for NADH at 12.0 nmole Mo blue/min/mg protein. The apparent K m for NADH was 0.79 mM. At 5 mM NADH, the apparent V max and apparent K m values for 12-MP of 12.05 nmole/min/mg protein and 3.87 mM, respectively, were obtained. The catalytic efficiency (k cat/K m ) of the Mo-reducing enzyme was 5.47 M(-1) s(-1). The purification of this enzyme could probably help to solve the phenomenon of molybdenum reduction to molybdenum blue first reported in 1896 and would be useful for the understanding of the underlying mechanism in molybdenum bioremediation involving bioreduction.

  9. Molybdenum Reduction to Molybdenum Blue in Serratia sp. Strain DRY5 Is Catalyzed by a Novel Molybdenum-Reducing Enzyme

    Directory of Open Access Journals (Sweden)

    M. Y. Shukor

    2014-01-01

    Full Text Available The first purification of the Mo-reducing enzyme from Serratia sp. strain DRY5 that is responsible for molybdenum reduction to molybdenum blue in the bacterium is reported. The monomeric enzyme has an apparent molecular weight of 105 kDalton. The isoelectric point of this enzyme was 7.55. The enzyme has an optimum pH of 6.0 and maximum activity between 25 and 35°C. The Mo-reducing enzyme was extremely sensitive to temperatures above 50°C (between 54 and 70°C. A plot of initial rates against substrate concentrations at 15 mM 12-MP registered a Vmax for NADH at 12.0 nmole Mo blue/min/mg protein. The apparent Km for NADH was 0.79 mM. At 5 mM NADH, the apparent Vmax and apparent Km values for 12-MP of 12.05 nmole/min/mg protein and 3.87 mM, respectively, were obtained. The catalytic efficiency (kcat/Km of the Mo-reducing enzyme was 5.47 M-1 s-1. The purification of this enzyme could probably help to solve the phenomenon of molybdenum reduction to molybdenum blue first reported in 1896 and would be useful for the understanding of the underlying mechanism in molybdenum bioremediation involving bioreduction.

  10. Impact of helium implantation and ion-induced damage on reflectivity of molybdenum mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Carrasco, A., E-mail: alvarogc@kth.se [Department of Fusion Plasma Physics, Royal Institute of Technology (KTH), Teknikringen 31, 100 44 Stockholm (Sweden); Petersson, P.; Hallén, A. [Department of Fusion Plasma Physics, Royal Institute of Technology (KTH), Teknikringen 31, 100 44 Stockholm (Sweden); Grzonka, J. [Faculty of Materials Science and Engineering, Warsaw University of Technology, 02-507 Warsaw (Poland); Institute of Electronic Materials Technology, 133 Wolczynska Str., 01-919 Warsaw (Poland); Gilbert, M.R. [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Fortuna-Zalesna, E. [Faculty of Materials Science and Engineering, Warsaw University of Technology, 02-507 Warsaw (Poland); Rubel, M. [Department of Fusion Plasma Physics, Royal Institute of Technology (KTH), Teknikringen 31, 100 44 Stockholm (Sweden)

    2016-09-01

    Molybdenum mirrors were irradiated with Mo and He ions to simulate the effect of neutron irradiation on diagnostic first mirrors in next-generation fusion devices. Up to 30 dpa were produced under molybdenum irradiation leading to a slight decrease of reflectivity in the near infrared range. After 3 × 10{sup 17} cm{sup −2} of helium irradiation, reflectivity decreased by up to 20%. Combined irradiation by helium and molybdenum led to similar effects on reflectivity as irradiation with helium alone. Ion beam analysis showed that only 7% of the implanted helium was retained in the first 40 nm layer of the mirror. The structure of the near-surface layer after irradiation was studied with scanning transmission electron microscopy and the extent and size distribution of helium bubbles was documented. The consequences of ion-induced damage on the performance of diagnostic components are discussed.

  11. Effects of molybdenum and cadmium on the oxidative damage and kidney apoptosis in Duck.

    Science.gov (United States)

    Shi, Lele; Cao, Huabin; Luo, Junrong; Liu, Ping; Wang, Tiancheng; Hu, Guoliang; Zhang, Caiying

    2017-11-01

    Molybdenum (Mo) is an essential element for human beings and animals; however, high dietary intake of Mo can lead to adverse reactions. Cadmium (Cd) is one of the major transitional metals which has toxic effects in animals. To investigate the co-induced toxic effects of Mo and Cd on oxidative damage and kidney apoptosis in duck, 120 ducks were randomly divided into control group and 5 treatment groups which were treated with a commercial diet containing different dosages of Mo and Cd. Kidney samples were collected on the 60th and 120th days to determine the mRNA expression levels of ceruloplasmin (CP), metallothionein (MT), Bak-1, and Caspase-3 by quantitative RT-PCR. Additionally, we also determined the antioxidant activity indexes and contents of Mo, Cd, copper (Cu), iron (Fe), zinc (Zn), and selenium (Se) in serum. Meanwhile, ultrastructural changes of the kidney were observed. The results showed that glutathione reductase (GR) activity and CP level in serum were decreased in combination groups. In addition, the antioxidant indexes were decreased in co-treated groups compared with single treated groups. The mRNA expression levels of Bak-1 and Caspase-3 increased in co-treated groups. The mRNA expression level of CP in high-dose combination group was downregulated, while the mRNA expression of MT was upregulated except for low-dose Mo group. Additionally, in the later period the content of Cu in serum decreased in joint groups while the contents of Mo and Cd increased. In addition, ultrastructural changes showed mitochondrial crest fracture, swelling, deformed nuclei, and karyopyknosis in co-treated groups. Taken together, it was suggested that dietary Mo and Cd might lead to oxidative stress, kidney apoptosis and disturb homeostasis of trace elements in duck, and it showed a possible synergistic relationship between the two elements. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Nitrogenase activity of Herbaspirillum seropedicae grown under low iron levels requires the products of nifXorf1 genes.

    Science.gov (United States)

    Klassen, Giseli; de Oliveira Pedrosa, Fábio; de Souza, Emanuel M; Yates, M Geoffrey; Rigo, Liu Un

    2003-07-29

    Herbaspirillum seropedicae strains mutated in the nifX or orf1 genes showed 90% or 50% reduction in nitrogenase activity under low levels of iron or molybdenum respectively. Mutations in nifX or orf1 genes did not affect nif gene expression since a nifH::lacZ fusion was fully active in both mutants. nifX and the contiguous gene orf1 are essential for maximum nitrogen fixation under iron limitation and are probably involved in synthesis of nitrogenase iron or iron-molybdenum clusters.

  13. Study of the early stages of precipitation of molybdenum in steelwelds

    International Nuclear Information System (INIS)

    Choudhary, H.U.

    2001-01-01

    The addition of molybdenum to steel welds in quite small concentrations leads to a variety of anomalous microstructural and mechanical property effects. In some cases, the effects manifest even there are no obvious changes in microstructure at the resolution of a transmission electron microscope. It has been reported in the published literature, that an increase in the molybdenum concentration leads to a corresponding increase in the proportion of primary microstructure in multipass welds. Another striking anomaly with molybdenum containing welds, identified in the published literature, is that the strength of such welds is much higher than is estimated using normally reliable models for he prediction of mechanical properties. The surprising feature of this anomaly is that it is present even for the as-deposited microstructure, which has not been deliberately or otherwise tempered. The anomaly cannot therefore be attributed to easily observed secondary hardening effects, and indeed precipitates such a molybdenum carbides are not found to occur in the as-deposited state at the resolution of a conventional transmission electron microscope. An investigation has been carried out to study the possible existence of the early stages of precipitation/clustering of molybdenum atoms, using the atomic resolution method know as APFIM (Atom Probe Field Ion Microscopy). The results has given a strong indication that the anomalous strengthening in the as deposited welds is due to sub-microscopic effects, arising from the fine scale clustering of molybdenum atoms. This clustering appears to occur in the ferrite as the weld cools to ambient temperature after solidification. The effect is essentially secondary hardening, but at the very early stages. (author)

  14. Second international round robin for the quantification of serum non-transferrin-bound iron and labile plasma iron in patients with iron-overload disorders

    NARCIS (Netherlands)

    de Swart, Louise; Hendriks, Jan C. M.; van der Vorm, Lisa N.; Cabantchik, Z. Ioav; Evans, Patricia J.; Hod, Eldad A.; Brittenham, Gary M.; Furman, Yael; Wojczyk, Boguslaw; Janssen, Mirian C. H.; Porter, John B.; Mattijssen, Vera E. J. M.; Biemond, Bart J.; MacKenzie, Marius A.; Origa, Raffaella; Galanello, Renzo; Hider, Robert C.; Swinkels, Dorine W.

    2016-01-01

    Non-transferrin-bound iron and its labile (redox active) plasma iron component are thought to be potentially toxic forms of iron originally identified in the serum of patients with iron overload. We compared ten worldwide leading assays (6 for non-transferrin-bound iron and 4 for labile plasma iron)

  15. Preparation of selective molybdenum concentrate from collective coppermolybdenum concentrate

    Directory of Open Access Journals (Sweden)

    N. Tusupbaev

    2016-06-01

    Full Text Available The paper considers possibilities of selective separation of the concentrate of copper and molybdenum from a collective copper-molybdenum concentrate of Aktogay deposit using regrinding and conventional flotation reagents. In the case of conventional flotoreagents, the content of molybdenum in a molybdenum concentrate was 8.0% at extraction effectiveness 83.12%. At 27.96% extraction degree of copper, it’s content in the concentrate equaled to 21.3%. After regrinding, molybdenum content in the concentrate was 24.0% at the extraction effectiveness 59.63%, and copper content in the concentrate was 21.9% at the recovery of 61.23%. Thus, the regrinding of a collective copper-molybdenum concentrate resulted in an increase in the content of molybdenum in molybdenum concentrate by 16%, and the copper concentration increased by 0.6%.

  16. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... exploring about iron-deficiency anemia. Read more New treatments for disorders that lead to iron-deficiency anemia. We are ... and other pathways. This could help develop new therapies for conditions that ... behavior, thinking, and mood during adolescence. Treating anemia in ...

  17. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... during the third trimester of pregnancy. Children between ages 1 and 2, especially if they drink a lot of cow’s milk. Cow’s milk is low in iron. Teens, who have increased need for iron during growth spurts. Older adults, especially those ... environments Children who have lead in ...

  18. Bibliographic study on molybdenum biokinetics. Literaturstudie zur Biokinetik von Molybdaen

    Energy Technology Data Exchange (ETDEWEB)

    Erzberger, A.

    1988-05-01

    This bibliographical study compiles and analyzes findings about the metabolism and resorption of molybdenum. Besides including studies on the physiology of molybdenum 99, a general survey is given on molybdenum in the environment and on its physiological behaviour. In particular, information on the dependence of molybdenum resorption on various factors, such as the chemical form, antagonisms etc., are gathered from literature. These factors have to be considered for sensibly carrying out necessary experiments.

  19. Evaluation of SinoRhizobium meliloti Efficiency and Qualitative Traits of Alfalfa under Application of Molybdenum

    Directory of Open Access Journals (Sweden)

    F Ahmadi Dana

    2017-12-01

    meaningful difference from non-inoculated. Concentration of molybdenum in shoot and root increased, this increase in S. Rhizobium inoculated case was more than non-inoculated cases. Conclusions The use of molybdenum and Rhizobium bacteria increase the production yield and also nitrogen-fixing nodules. The increase in the use of treatments with molybdenum, resulting biological nitrogen fixation leading to conversion of molecular nitrogen (N2 in the atmosphere into ammonium (NH3 in nodules on the roots of plants. Studies have showed that molybdenum important role in nitrogen fixation in legume family of plants, and adding this element increased growth by increasing the efficiency of nitrogen fixation and nitrogenase enzyme in the node structure, which ultimately will lead to increased yield and higher quality in alfalfa. Thus, molybdenum increased the number of branches of the fertile and increase the number of stem and leaf. Molybdenum is essential to plant growth as a component of the enzymes nitrogenase. Legumes need more molybdenum than other crops, such as grass or corn, because the symbiotic bacteria living in the root nodules of legumes require molybdenum for the fixation of atmospheric nitrogen. If sufficient molybdenum is not available, nodulation will be retarded and the amount of nitrogen fixed by the plant will be limited. If other factors are not limiting, the amount of molybdenum will determine the amount of nitrogen fixed by the plant. Increasingly vigorous plant growth, higher protein contents and greater buildup of nitrogen in the plant and soil accompany nodulation and symbiotic microbial activity. Therefore, due to less absorption of molybdenum in the shoot and the highest yield obtained from treated seeds inoculated with the first level of molybdenum, the amount kg ha-1. Molybdenum is suitable for growing of alfalfa. It is important to obtain maximum yield in just one stage (before the first two weeks of growth for the supply of nitrogen for growth

  20. The XUV spectra of highly ionised molybdenum

    International Nuclear Information System (INIS)

    Mansfield, M.W.D.; Peacock, N.J.; Smith, C.C.; Hobby, M.G.; Cowan, R.D.

    1978-01-01

    The spectra of molybdenum ions produced in Tokamaks in the wavelength range 10-200 A have been reproduced in a plasma formed by laser beam irradiation of solid molybdenum targets. Lines from highly ionised stages of molybdenum (Mo XXX to Mo XXXII) have been distinguished by varying the laser beam intensity. Detailed analyses of the simpler ions, Mo XV (Ni-like), Mo XVI (Co-like), Mo XXXII (Na-like), and to a lesser extent Mo XXXI (Mg-like) and Mo XVII (Fe-like), have been achieved by comparison with ab initio calculations. A general interpretation of intermediate ion stages is also given but it is shown that most of these spectra are so complex, as a result of inner-subshell excitation, that detailed term-scheme analyses are nearly impossible. (author)

  1. XUV spectra of highly ionised molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, M W.D.; Peacock, N J; Smith, C C; Hobby, M G [UKAEA, Abingdon. Culham Lab.; Cowan, R D

    1978-05-14

    The spectra of molybdenum ions produced in Tokamaks in the wavelength range 10-200 A have been reproduced in a plasma formed by laser beam irradiation of solid molybdenum targets. Lines from highly ionised stages of molybdenum (Mo XXX to Mo XXXII) have been distinguished by varying the laser beam intensity. Detailed analyses of the simpler ions, Mo XV (Ni-like), Mo XVI (Co-like), Mo XXXII (Na-like), and to a lesser extent Mo XXXI (Mg-like) and Mo XVII (Fe-like), have been achieved by comparison with ab initio calculations. A general interpretation of intermediate ion stages is also given but it is shown that most of these spectra are so complex, as a result of inner-subshell excitation, that detailed term-scheme analyses are nearly impossible.

  2. Molybdenum peroxo complex. Structure and thermal behavior

    Energy Technology Data Exchange (ETDEWEB)

    Segawa, Koichi; Ooga, Katsumi; Kurusu, Yasuhiko

    1984-10-01

    The molybdenum peroxide (Mo-y) prepared by oxidation of molybdenum metal with hydrogen peroxide has been studied to determine its structure and thermal behavior. Temperature programmed decomposition has been used to study the thermal stability of Mo-y. Two distinct peaks, I and II, of decomposition processes are discernible in Mo-y. Peak I corresponds to the elimination of water of crystallization and peak II to the decomposition of a peroxide ion of Mo-y. IR and UV examinations support the results of the thermal analysis. The IR band at 931 cm/sup -1/ and the UV band at 381 nm show the same thermal behavior. Both bands are attributable to the peroxide ion of Mo-y. Spectroscopic studies show that Mo-y has the tetrahedral coordination derived from the single molybdenum complex, which has double bond oxygens attached to Mo atom and has a symmetric type of peroxide ion with one water of crystallization.

  3. Separation and selective determination of molybdenum with sodiumthiosulfate and ethylacetate

    International Nuclear Information System (INIS)

    Hainberger, L.; de Oliveira Andrade, W.

    1982-01-01

    A sensitive and selective method of spectrophotometric determination of molybdenum is described. Molybdenum is extracted to more than 97%. Lambert-Beer's law is obeyed between 0.35 and 30μg/10ml of the used aqueous solution. 43 ions concerning their interference are studied. The method was used to determine the content of molybdenum in black beans. (Author)

  4. Assessment of polyphase sintered iron-cobalt-iron boride cermets

    International Nuclear Information System (INIS)

    Nowacki, J.; Pieczonka, T.

    2004-01-01

    Sintering of iron, cobalt and boron powders has been analysed. As a result iron-iron boride, Fe-Fe 2 B and iron/cobalt boride with a slight admixture of molybdenum, Fe - Co - (FeMoCo) 2 B cermets have been produced. Iron was introduced to the mixture as the Astalloy Mo Hoeganaes grade powder. Elemental amorphous boron powder was used, and formation of borides occurred both during heating and isothermal sintering periods causing dimensional changes of the sintered body. Dilatometry was chosen to control basic phenomena taking place during multiphase sintering of investigated systems. The microstructure and phase constituents of sintered compacts were controlled as well. The cermets produced were substituted to: metallographic tests, X-ray analysis, measurements of hardness and of microhardness, and of wear in the process of sliding dry friction. Cermets are made up of two phases; hard grains of iron - cobalt boride, (FeCo) 2 B (1800 HV) constituting the reinforcement and a relatively soft and plastic eutectic mixture Fe 2 B - Co (400-500 HV) constituting the matrix. (author)

  5. Recovery of uranium and molybdenum from a carbonate type uranium-molybdenum ore

    International Nuclear Information System (INIS)

    Zhou Genmao; Zeng Yijun; Tang Baobin; Meng Shu; Xu Guolong

    2014-01-01

    Based on the results of process mineralogical research of a carbonate type uranium-molybdenum ore, leaching behaviors of the uranium-molybdenum ore were studied by alkali agitation leaching, conventional alkali column leaching and alkali curing column leaching processes. The results showed that using the alkali curing column leaching process, the leaching rate of molybdenum increased to more than 90%, and the leaching rate of uranium was about 85%, Compared with the conventional alkali column leaching process, the leaching time of the alkali curing column leaching process decreased by 60 days. (authors)

  6. Spectrographic analysis of uranium-molybdenum alloys

    International Nuclear Information System (INIS)

    Roca, M.

    1967-01-01

    A spectrographic method of analysis has been developed for uranium-molybdenum alloys containing up to 10 % Mo. The carrier distillation technique, with gallium oxide and graphite as carriers, is used for the semiquantitative determination of Al, Cr, Fe, Ni and Si, involving the conversion of the samples into oxides. As a consequence of the study of the influence of the molybdenum on the line intensities, it is useful to prepare only one set of standards with 0,6 % MoO 3 . Total burning excitation is used for calcium, employing two sets of standards with 0,6 and 7.5 MoO 3 . (Author) 5 refs

  7. Crystallization of nodular cast iron with carbides

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2008-12-01

    Full Text Available In this paper a crystallization process of nodular cast iron with carbides having a different chemical composition have been presented. It have been found, that an increase of molybdenum above 0,30% causes the ledeburutic carbides crystallization after (γ+ graphite eutectic phase crystallization. When Mo content is lower, these carbides crystallize as a pre-eutectic phase. In this article causes of this effect have been given.

  8. Nucleation of microwave plasma CVD diamond on molybdenum (Mo) substrate

    International Nuclear Information System (INIS)

    Inderjeet, K.; Ramesh, S.

    2000-01-01

    Molybdenum is a metal, which is gaining increasing significance in industrial applications. The main use of Mo is as all alloying element added in small amounts to steel, irons and non- ferrous alloys in order to enhance the strength, toughness and wear resistance. Mo is also vastly being employed in the automotive and aircraft industries, mainly due to its low coefficient of friction. Diamond, on be other hand, is a unique material for innumerable applications because of its usual combination of physical and chemical properties. Several potential applications can be anticipated for diamond in many sectors including electronics, optics, as protective corrosion resistant coatings, cutting tools, etc. With the enhancement in science and technology, diamond microcrystals and thin films are now being produced from the vapour phase by a variety of chemical vapour deposition (CVD) techniques; such as microwave plasma CVD. With such technology being made available, it is envisage that diamond-coated molybdenum would further enhance the performance and to open up new avenue for Mo in various industries. Therefore, it is the aim of the present work to study the nucleation and growth of diamond particles on Mo surface by employing microwave plasma CVD (MAPCVD). In the present work, diamond deposition was carried out in several stages by varying the deposition distance. The nucleation and growth rate were studied using scanning electron microscopy (SEM). In addition, the existence of diamond was verified by X-ray diffraction (XRD) analysis. It has been found that the nucleation and growth rate of diamond particles were influenced by the deposition height between the substrate and plasma. Under the optimum condition, well defined diamond crystallites distributed homogeneously throughout the surface, could be obtained. Some of the important parameters controlling the deposition and growth of diamond particles on Mo surface are discussed. (author)

  9. Cellular iron transport.

    Science.gov (United States)

    Garrick, Michael D; Garrick, Laura M

    2009-05-01

    Iron has a split personality as an essential nutrient that also has the potential to generate reactive oxygen species. We discuss how different cell types within specific tissues manage this schizophrenia. The emphasis in enterocytes is on regulating the body's supply of iron by regulating transport into the blood stream. In developing red blood cells, adaptations in transport manage the body's highest flux of iron. Hepatocytes buffer the body's stock of iron. Macrophage recycle the iron from effete red cells among other iron management tasks. Pneumocytes provide a barrier to prevent illicit entry that, when at risk of breaching, leads to a need to handle the dangers in a fashion essentially shared with macrophage. We also discuss or introduce cell types including renal cells, neurons, other brain cells, and more where our ignorance, currently still vast, needs to be removed by future research.

  10. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... blocks the intestine from taking up iron. Other medical conditions Other medical conditions that may lead to ... to advancing science and translating discoveries into clinical practice to promote the prevention and treatment of heart, ...

  11. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... deficiency anemia can cause serious complications, including heart failure and development delays in children. Explore this Health ... lead to iron-deficiency anemia include: End-stage kidney failure, where there is blood loss during dialysis. ...

  12. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... activity. Older adults, who are more likely to fall, should be especially cautious when resuming activities. Reminders ... develop new therapies for conditions that affect the balance of iron in the body and lead to ...

  13. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... interferes with the body’s ability to make hemoglobin. Family history and genetics Von Willebrand disease is an ... develop new therapies for conditions that affect the balance of iron in the body and lead to ...

  14. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... lead to iron-deficiency anemia include: End-stage kidney failure, where there is blood loss during dialysis. People who have chronic kidney disease also often take other medicines—such as ...

  15. Influence of minerals on lead-induced alterations in liver function in rats exposed to long-term lead exposure

    International Nuclear Information System (INIS)

    Herman, D'souza Sunil; Geraldine, Menezes; T, Venkatesh

    2009-01-01

    The objective of this study was to evaluate the role of minerals on lead-induced effect on the liver. Differentiation of minerals and heavy metals pose an inherent problem due to certain common properties shared by them. With this approach to the problem of heavy metal toxicity, in the present study two groups of male Wistar albino rats, one group (well-nourished) fed on mineral rich diet and other group (undernourished) fed on diet without mineral supplements were used. Both the groups of rats were subjected to long-term lead exposure. The diet of well-nourished group was supplemented with calcium (Ca); 1.2%, phosphorous (P); 0.6%, iron (Fe); 90 mg/kg, zinc (Zn); 50 mg/kg, magnesium (Mg); 0.08%, manganese (Mn); 70 mg/kg, selenium (Se); 0.2 mg/kg, copper (Cu); 5 mg/kg, molybdenum (Mo); 0.8 mg/kg, iodine (I); 0.6 mg/kg, cobalt (Co); 3.0 mg/kg. Their blood lead and parameters of liver function were monitored periodically. Results of the study showed a very high statistically significant increase (p < 0.001) in the blood lead (PbB) levels and liver function test parameters in the undernourished subjects compared to the well-nourished subjects. Nutritional management of lead poisoning is of importance since essential elements and toxic heavy metals may interact to minimize the absorption of lead.

  16. Influence of minerals on lead-induced alterations in liver function in rats exposed to long-term lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D' souza Sunil, E-mail: hermansdsouza@rediffmail.com [Department of Biotechnology, Manipal Life Sciences Centre, KMC, Manipal University, Manipal (India); Geraldine, Menezes, E-mail: gere1@rediffmail.com [Department of Biochemistry and Biophysics, St. John' s Medical College, Koramangala, Bangalore 560034, Karnataka (India); T, Venkatesh, E-mail: venky_tv@hotmail.com [Department of Biochemistry and Biophysics, St. John' s Medical College, Koramangala, Bangalore 560034, Karnataka (India)

    2009-07-30

    The objective of this study was to evaluate the role of minerals on lead-induced effect on the liver. Differentiation of minerals and heavy metals pose an inherent problem due to certain common properties shared by them. With this approach to the problem of heavy metal toxicity, in the present study two groups of male Wistar albino rats, one group (well-nourished) fed on mineral rich diet and other group (undernourished) fed on diet without mineral supplements were used. Both the groups of rats were subjected to long-term lead exposure. The diet of well-nourished group was supplemented with calcium (Ca); 1.2%, phosphorous (P); 0.6%, iron (Fe); 90 mg/kg, zinc (Zn); 50 mg/kg, magnesium (Mg); 0.08%, manganese (Mn); 70 mg/kg, selenium (Se); 0.2 mg/kg, copper (Cu); 5 mg/kg, molybdenum (Mo); 0.8 mg/kg, iodine (I); 0.6 mg/kg, cobalt (Co); 3.0 mg/kg. Their blood lead and parameters of liver function were monitored periodically. Results of the study showed a very high statistically significant increase (p < 0.001) in the blood lead (PbB) levels and liver function test parameters in the undernourished subjects compared to the well-nourished subjects. Nutritional management of lead poisoning is of importance since essential elements and toxic heavy metals may interact to minimize the absorption of lead.

  17. Adsorptive Iron Removal from Groundwater

    OpenAIRE

    Sharma, S.K.

    2001-01-01

    Iron is commonly present in groundwater worldwide. The presence of iron in the water supply is not harmful to human health, however it is undesirable. Bad taste, discoloration, staining, deposition in the distribution system leading to aftergrowth, and incidences of high turbidity are some of the aesthetic and operational problems associated with iron in water supplies. Iron removal from groundwater is, therefore, a major concern for water supply companies using groundwater sources....

  18. High-level iron mitigates fusaricidin-induced membrane damage and reduces membrane fluidity leading to enhanced drug resistance in Bacillus subtilis.

    Science.gov (United States)

    Yu, Wen-Bang; Ye, Bang-Ce

    2016-05-01

    Fusaricidins are a class of cyclic lipopeptide antibiotics that have strong antifungal activities against plant pathogenic fungi and excellent bactericidal activities against Gram-positive bacteria. The mechanism through which fusaricidin exerts its action is not yet entirely clear. To investigate the mode of action of fusaricidin, we determined the physiological and transcriptional responses of Bacillus subtilis to fusaricidin treatment by using a systems-level approach. Our data show that fusaricidin rapidly induced the expression of σ(W) regulon and caused membrane damage in B. subtilis. We further demonstrated that ferric ions play multiple roles in the action of fusaricidin on B. subtilis. Iron deprivation blocked the formation of hydroxyl radical in the cells and significantly inhibited the bactericidal activity of fusaricidin. Conversely, high levels of iron (>2 mM) repressed the expression of BkdR regulon, resulting in a smaller cellular pool of branched-chain precursors for iso- and anteiso-branched fatty acids, which in turn led to a decrease in the proportion of branched-chain fatty acids in the membrane of B. subtilis. This change in membrane composition reduced its bilayer fluidity and increased its resistance to antimicrobial agents. In conclusion, our experiments uncovered some novel interactions and a synergism between cellular iron levels and drug resistance in Gram-positive bacteria. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Process for separation of tungsten and molybdenum by extraction

    International Nuclear Information System (INIS)

    Zelikman, A.N.; Voldman, G.M.; Rumyantsev, V.K.; Ziberov, G.N.; Kagermanian, V.S.

    1976-01-01

    A process for the separation of tungsten and molybdenum by extraction involves the addition of HCl or HNO 3 to an aqueous solution containing tungsten and molybdenum to obtain a pH from 0.5 to 4.3, and introduction of a stabilizer comprising water-soluble phosphorus salts and a complexing agent, hydrogen peroxide, in an amount from 1.5 to 2 mole per 1 g-atom of the total content of tungsten and molybdenum. Then molybdenum is selectively extracted from the resulting aqueous solution with tri-n-butylphosphate with equal volumetric proportioning of the aqueous and organic solutions. Re-extraction of molybdenum and partially tungsten is carried out from the organic extracting agent with an alkali or soda solution. The process makes possible the preparation of tungsten solution containing no more than 0.001 g/l of molybdenum, and an increase in the degree of extraction of tungsten and molybdenum

  20. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... lead in their blood from their environment or water. Lead interferes with the body’s ability to make ... also take an iron supplement. Follow your doctor’s recommendations and treatments to control any conditions that lead ...

  1. Recent situation and future of molybdenum mineral resources; Molybdenum shigen no genjo to shorai

    Energy Technology Data Exchange (ETDEWEB)

    Ono, K.; Nishiyama, T. [Kyoto University, Kyoto (Japan)

    1997-05-05

    Molybdenum is produced mainly from molybdenite, and the majority of this ore is exploited from the porphyry deposit. The reserve is estimated at 5.5-million ton. A total of 118-thousand ton was produced across the world in 1995, in the U.S., China, Chile, and Canada, the countries named in the order of quantities they exploited. Molybdenite is first refined by flotation for the production of a sulphide. It is subjected to oxidizing roasting for conversion into crude molybdenum trioxide, which is next subjected to extraction in warmed-up aqueous ammonia and then to evaporation for the crystallization of ammonium paramolybdate. The crystals are baked for conversion into molybdenum trioxide of the ordinary purity, to be further processed into ferromolybdenum, molybdenum compounds, molybdenum powder, etc. In view of the magnitude of demand, the metal is used mostly for the manufacture of special steels and special alloys. The demand for this metal, though small in size, involves important articles, such as line materials for semiconductors in the power industry, catalysts in the chemical industry, and lubricants. Japan`s stockpile includes molybdenum, but the U.S. has been stockpiling none since 1977. 9 refs., 4 figs., 1 tab.

  2. Thermodynamic Properties of Manganese and Molybdenum

    International Nuclear Information System (INIS)

    Desai, P.D.

    1987-01-01

    This work reviews and discusses the data on the various thermodynamic properties of manganese and molybdenum available through March 1985. These include heat capacity, enthalpy, enthalpy of transitions and melting, vapor pressure, and enthalpy of vaporization. The existing data have been critically evaluated and analyzed. The recommended values for the heat capacity, enthalpy, entropy, and Gibbs energy function from 0.5 to 2400 K for manganese and from 0.4 to 5000 K for molybdenum have been generated, as have heat capacity values for supercooled β-Mn and for γ-Mn below 298.15 K. The recommended values for vapor pressure cover the temperature range from 298.15 to 2400 K for manganese and from 298.15 to 5000 K for molybdenum. These values are referred to temperatures based on IPTS-1968. The uncertainties in the recommended values of the heat capacity range from +-3% to +-5% for manganese and from +-1.5% to +-3% for molybdenum

  3. Paraelasticity in electron-irradiated molybdenum

    International Nuclear Information System (INIS)

    Beuneu, Brigitte; Quere, Yves.

    1981-11-01

    The relaxation of a radiation-induced point defect-most probably the rotation of a dumbell-is observed during isothermal anneals of irradiated molybdenum by resistivity measurements. The recovery of close pairs is not affected, in first analysis, by the presence of a uniaxial stress

  4. Exploring atomic defects in molybdenum disulphide monolayers

    KAUST Repository

    Hong, Jinhua; Hu, Zhixin; Probert, Matt; Li, Kun; Lv, Danhui; Yang, Xinan; Gu, Lin; Mao, Nannan; Feng, Qingliang; Xie, Liming; Zhang, Jin; Wu, Dianzhong; Zhang, Zhiyong; Jin, Chuanhong; Ji, Wei; Zhang, Xixiang; Yuan, Jun; Zhang, Ze

    2015-01-01

    Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment-theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy, and also studied by ab-initio calculation. Defect density up to 3.5 × 10 13 cm '2 is found and the dominant category of defects changes from sulphur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high-quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices.

  5. Exploring atomic defects in molybdenum disulphide monolayers

    KAUST Repository

    Hong, Jinhua

    2015-02-19

    Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment-theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy, and also studied by ab-initio calculation. Defect density up to 3.5 × 10 13 cm \\'2 is found and the dominant category of defects changes from sulphur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high-quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices.

  6. Molybdenum silicide based materials and their properties

    International Nuclear Information System (INIS)

    Yao, Z.; Stiglich, J.; Sudarshan, T.S.

    1999-01-01

    Molybdenum disilicide (MoSi 2 ) is a promising candidate material for high temperature structural applications. It is a high melting point (2030 C) material with excellent oxidation resistance and a moderate density (6.24 g/cm 3 ). However, low toughness at low temperatures and high creep rates at elevated temperatures have hindered its commercialization in structural applications. Much effort has been invested in MoSi 2 composites as alternatives to pure molybdenum disilicide for oxidizing and aggressive environments. Molybdenum disilicide-based heating elements have been used extensively in high-temperature furnaces. The low electrical resistance of silicides in combination with high thermal stability, electron-migration resistance, and excellent diffusion-barrier characteristics is important for microelectronic applications. Projected applications of MoSi 2 -based materials include turbine airfoils, combustion chamber components in oxidizing environments, missile nozzles, molten metal lances, industrial gas burners, diesel engine glow plugs, and materials for glass processing. On this paper, synthesis, fabrication, and properties of the monolithic and composite molybdenum silicides are reviewed

  7. Simultaneous spectrophotometric determination of tungsten and molybdenum with dithiol

    International Nuclear Information System (INIS)

    Navale, A.S.

    1987-01-01

    Toluene-3,4-dithiol is a very sensitive reagent for the spectrophotometric determination of tungsten and molybdenum. Since the absorption spectra of the dithiol complexes of these two elements overlap, a separation of the two elements is carried out. This leads to time consuming extraction procedures. Measuring the absorption of the mixed complexes at two wavelengths and solving a set of simultaneous equations is also not favorable because a lot of time and effort is required for solving the simultaneous equations for each sample. A faster and simpler method is described here for the simultaneous determination of the two elements. The method is based on measurement of absorbance of the mixed complexes at three pre-selected wavelengths and simple calculations involving the absorbance differences. The criteria for selecting the three wavelengths and the theory are described. Application of the method for the determination of tungsten and molybdenum in ore samples is presented. The method is applicable to any similar system consisting of two interfering components. 4 figures, 2 tables, 6 refs. (author)

  8. Carbon, chromium and molybdenum contents; Teores de carbono, cromo e molibdenio

    Energy Technology Data Exchange (ETDEWEB)

    Sinatora, A; Goldenstein, H; Mei, P R; Albertin, E; Fuoco, R; Mariotto, C L

    1993-12-31

    This work describes solidification experiments on white cast iron, with 15 and 20% of chromium, 2.3, 3.0 and 3.6 % of carbon and 0.0, 1.5 and 2.5 % of molybdenum in test de samples with 30 mm diameter. Measurements were performed on the austenite and eutectic formation arrests, the number of the eutectic carbide particles relative to the total and the eutectic volumes, and the volume fraction of the primary austenite 9 figs., 3 tabs.

  9. Carbon, chromium and molybdenum contents; Teores de carbono, cromo e molibdenio

    Energy Technology Data Exchange (ETDEWEB)

    Sinatora, A; Goldenstein, H.; Mei, P.R.; Albertin, E.; Fuoco, R.; Mariotto, C.L

    1992-12-31

    This work describes solidification experiments on white cast iron, with 15 and 20% of chromium, 2.3, 3.0 and 3.6 % of carbon and 0.0, 1.5 and 2.5 % of molybdenum in test de samples with 30 mm diameter. Measurements were performed on the austenite and eutectic formation arrests, the number of the eutectic carbide particles relative to the total and the eutectic volumes, and the volume fraction of the primary austenite 9 figs., 3 tabs.

  10. The Development of Molybdenum Speciation as a Paleoredox Tool

    Science.gov (United States)

    Rodley, J.; Peacock, C.; Mosselmans, J. F. W.; Poulton, S.

    2017-12-01

    The redox state of the oceans has changed throughout geological time and an understanding of these changes is essential to elucidate links between ocean chemistry, climate and life. Due to its abundance in seawater and redox-sensitive nature, molybdenum has enormous potential as a paleoredox proxy. Although a significant amount of research has been done on molybdenum in ancient and modern sediments in terms of its concentrations and isotopic ratios there remains a limited understanding of the drawdown mechanisms of molybdenum under different redox conditions restricting its use in identifying a range of redox states. In order to address these uncertainties, we have developed a novel sequential extraction technique to examine molybdenum concentrations in six sediment fractions from modern samples that represent oxic, nitrogenous, ferruginous and euxinic environments. In addition we use µ-XRF and µ-XANES synchrotron spectroscopy to examine the molybdenum speciation within these fractions and environments. To interpret our µ-XANES data we have developed an extensive library of molybdenum XANES standards that represent molybdenum sequestration by the sediment fractions identified from the sequential extraction. To further verify our synchrotron results we developed a series of µ-XANES micro-column experiments to examine preferential uptake pathways of molybdenum to different sediment phases under a euxinic water column. The initial data from both the sequential extraction and µ-XANES methods indicate that molybdenum is not limited to a single burial pathway in any of the redox environments. We find that each of the redox environments can be characterised by a limited set of molybdenum phase associations, with molybdenum adsorption to pyrite likely the dominant burial pathway. These findings agree with existing research for molybdenum speciation in euxinic environments suggesting that both pyrite and sulphidised organic matter act as important molybdenum sinks. Our

  11. Determination of hafnium, molybdenum, and vanadium in niobium and niobium-based alloys by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Ide, Kunikazu; Kobayashi, Takeshi; Sudo, Emiko.

    1985-01-01

    The analytical procedure is as follows: Weigh 1 g of a sample and put it into a 100 cm 3 PTFE beaker. Add 5 ml of distilled water and 5 ml of hydrofluoric acid, and then heat the solution on a hot plate, adding 3 ml of nitric acid dropwise. Dilute the solution to 100 cm 3 with distilled water. When hafnium is determined, add 2 g of diammonium titanium hexafluoride ((NH 4 ) 2 TiF 6 )) before dilution. Working standard solutions are prepared by adding the stock standard solutions of hafnium, molybdenum, and vanadium into niobium solutions. When hafnium is determined, add 2 g of (NH 4 ) 2 TiF 6 and the alloying elements in amounts corresponding to those in sample solutions into the working standard solutions. The tolerable amounts of hydrofluoric acid were 2.9 M, 2.1 M, and 3.1 M and those of nitric acid were 1.0 M, 1.6 M, and 1.6 M for hafnium, molybdenum, and vanadium, respectively. It was found that (NH 4 ) 2 TiF 6 greatly increased the sensitivity for hafnium determination. Niobium showed minus effect for hafnium and plus effect for molybdenum and vanadium. The atomic absorption of molybdenum and vanadium were not influenced by the presence of 20 % of each alloying element, while the atomic absorption of hafnium was given plus effect by 20 % of zirconium, iron, cobalt, nickel, manganese, chromium or vanadium and minus effect by 20 % tungsten. The analytical values of hafnium, molybdenum, and vanadium in niobium-based alloys by this method showed a good agreement with those by X-ray fluorescence analysis. The lower limits of determination (S/N=2) were 0.05, 0.001, and 0.002 % and the relative standard deviation were 3, 1, and 1.5 % for hafnium, molybdenum, and vanadium, respectively. (author)

  12. Iron-based amorphous alloys and methods of synthesizing iron-based amorphous alloys

    Science.gov (United States)

    Saw, Cheng Kiong; Bauer, William A.; Choi, Jor-Shan; Day, Dan; Farmer, Joseph C.

    2016-05-03

    A method according to one embodiment includes combining an amorphous iron-based alloy and at least one metal selected from a group consisting of molybdenum, chromium, tungsten, boron, gadolinium, nickel phosphorous, yttrium, and alloys thereof to form a mixture, wherein the at least one metal is present in the mixture from about 5 atomic percent (at %) to about 55 at %; and ball milling the mixture at least until an amorphous alloy of the iron-based alloy and the at least one metal is formed. Several amorphous iron-based metal alloys are also presented, including corrosion-resistant amorphous iron-based metal alloys and radiation-shielding amorphous iron-based metal alloys.

  13. Finite Element Analysis and Optimization for the Multi-stage Deep Drawing of Molybdenum Sheet

    International Nuclear Information System (INIS)

    Kim, Heung-Kyu; Hong, Seok Kwan; Kang, Jeong Jin; Heo, Young-moo; Lee, Jong-Kil; Jeon, Byung-Hee

    2005-01-01

    Molybdenum, a bcc refractory metal with a melting point of about 2600 deg. C, has a high heat and electrical conductivity. In addition, it remains strong mechanically at high temperatures as well as at low temperatures. Therefore it is a technologically very important material for the applications operating at high temperatures. However, a multi-stage process is required due to the low drawability for making a deep drawn part from the molybdenum sheet. In this study, a multi-stage deep drawing process for a molybdenum circular cup was designed by combining the drawing with the ironing, which was effective for the low drawability materials. A parametric study by FE analysis for the multi-stage deep drawing was conducted for evaluation of the design variables effect. Based on the FE analysis result, the multi-stage deep drawing process was parameterized by the design variables, and an optimum process design was obtained by the process optimization based on the FE simulation at each stage

  14. Transport of trace metals in the Magela Creek system, Northern Territory. I. Concentrations and loads of iron, manganese, cadmium, copper, lead and zinc during flood periods in the 1978-1979 wet season

    International Nuclear Information System (INIS)

    Hart, B.T.; Davies, S.H.R.; Thomas, P.A.

    1981-12-01

    In order that realistic effluent standards may be established for the Ranger uranium operations at Jabiru, Northern Territory, it is necessary that there be a clear and detailed knowledge of the pre-mining levels of trace metals and their behaviour within the Magela Creek system. During the wet season, floodwaters were sampled for conductivity, suspended solids and the trace metals, iron, manganese, cadmium, copper, lead and zinc. All concentrations were found to be very low, as were the denudation rates for the trace metals and suspended materials

  15. The corrosion behavior of molybdenum and Hastelloy B in sulfur and sodium polysulfides at 623 K

    International Nuclear Information System (INIS)

    Brown, A.P.

    1987-01-01

    An experimental study was completed to determine the corrosion behavior of molybdenum and Hastelloy B, a nickel-based alloy with high molybdenum content, in sulfur and sodium polysulfides (Na/sub 2/S/sub 3/,Na/sub 2/S/sub 4/, Na/sub 2/S/sub 5/) at 623 K. In sulfur, molybdenum corrodes very slowly, with a parabolic rate constant of 3.6 x 10/sup -9/ cm s/sup -1/2/. Hastelloy B shows no measurable corrosion after 100h of exposure to sulfur. The corrosion reaction of molybdenum in Na/sub 2/S/sub 3/ is characterized by the formation of a protective film that effectively eliminates further corrosion after the first 100h of exposure. Hastelloy B, however, corrodes rapidly in Na/sub 2/S/sub 3/, with corrosion rates approaching those of pure nickel under the same conditions. After the first 4h of exposure, the kinetics for the corrosion of Hastelloy B in Na/sub 2/S/sub 3/ follows a linear rate law. The scale morphology has multiple spalled layers of NiS/sub 2/, with some crystallites of NiS/sub 2/ appearing on the leading face of the scale and between the individual scale layers. This spalling causes smaller coupons of the Hastelloy B to corrode faster than larger coupons

  16. Molybdenum distribution and sensitivity in tomatoes, sunflowers and beans

    Energy Technology Data Exchange (ETDEWEB)

    Hecht-Buchholz, C

    1973-01-01

    The influence of increasing levels of molybdenum on the growth, molybdenum uptake and distribution in individual plant organs was investigated in tomatoes, beans and sunflowers in a 9 day trial. With tomatoes, which showed marked damage with high molybdenum levels, the molybdenum content of dry matter was highest in the leaf and lowest in the stem. On the other hand, beans, insensitive towards the high molybdenum level, dry matter molybdenum content was appreciably higher in the stem than in the leaf. It is supposed that in plant species, insensitive to high molybdenum levels, molybdenum is held less firmly in this tissue and can attain damaging levels in the cytoplasm of the youngest leaf tissue cells. It is supposed, on the basis of the reactions which were carried out with expressed root juice and on the basis of the yellow coloration attainable in vitro in the tissue caused by the addition of molybdate solution, that the yellow coloration appearing in the cells and plant organs of various plant species, here tomatoes and sunflowers, with high molybdenum levels is due to a reaction between molybdenum and polyvalent phenols in cellsap.

  17. Leading research on supermetal. Part 1. Large-scale materials (iron system); Super metal no sendo kenkyu. 1. Ogata sozai (tetsukei)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Supermetal with critical characteristics is under advanced investigation for further improvement of metal materials. Although iron is most frequently used as structural material among various metals, it should be used more carefully and effectively because of resource limitation and global environmental problem. It is essential to draw various excellent properties much more from iron and to improve recyclability. In particular, the best way to meet these requirements is achievement of more fine structure and higher purity. Since the lowest crystalline grain size is now limited to nearly 10{mu}m, metallic structure composed of grains below 1{mu}m is expected by mesoscopic control. Various methods have been studied to achieve ultra-fine crystalline structure, and study of precise heat treatment control and ultra-strength metallurgy is required. Heat treatment in magnetic field and layered structure by mechanical alloying are also promising. Drastic enhancement of characteristics is expected for heat resistant steel by combining of high purity with fine structure. 299 refs., 166 figs., 18 tabs.

  18. Interactions of iron-bound frataxin with ISCU and ferredoxin on the cysteine desulfurase complex leading to Fe-S cluster assembly.

    Science.gov (United States)

    Cai, Kai; Frederick, Ronnie O; Tonelli, Marco; Markley, John L

    2018-06-01

    Frataxin (FXN) is involved in mitochondrial iron‑sulfur (Fe-S) cluster biogenesis and serves to accelerate Fe-S cluster formation. FXN deficiency is associated with Friedreich ataxia, a neurodegenerative disease. We have used a combination of isothermal titration calorimetry and multinuclear NMR spectroscopy to investigate interactions among the components of the biological machine that carries out the assembly of iron‑sulfur clusters in human mitochondria. Our results show that FXN tightly binds a single Fe 2+ but not Fe 3+ . While FXN (with or without bound Fe 2+ ) does not bind the scaffold protein ISCU directly, the two proteins interact mutually when each is bound to the cysteine desulfurase complex ([NFS1] 2 :[ISD11] 2 :[Acp] 2 ), abbreviated as (NIA) 2 , where "N" represents the cysteine desulfurase (NFS1), "I" represents the accessory protein (ISD11), and "A" represents acyl carrier protein (Acp). FXN binds (NIA) 2 weakly in the absence of ISCU but more strongly in its presence. Fe 2+ -FXN binds to the (NIA) 2 -ISCU 2 complex without release of iron. However, upon the addition of both l-cysteine and a reductant (either reduced FDX2 or DTT), Fe 2+ is released from FXN as consistent with Fe 2+ -FXN being the proximal source of iron for Fe-S cluster assembly. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Evaluation of oxide dispersion strengthened (ODS) molybdenum and molybdenum-rhenium alloys

    International Nuclear Information System (INIS)

    Mueller, A.J.; Bianco, R.; Buckman, R.W. Jr.

    1999-01-01

    Oxide dispersion strengthened (ODS) molybdenum alloys being developed for high temperature applications possess excellent high temperature strength and creep resistance. In addition they exhibit a ductile-to-brittle transition temperature (DBIT) in the worked and stress-relieved condition under longitudinal tensile load well below room temperature. However, in the recrystallized condition, the DBTT maybe near or above room temperature, depending on the volume fraction of oxide dispersion and the amount of prior work. Dilute rhenium additions (7 and 14 wt.%) to ODS molybdenum were evaluated to determine their effect on low temperature ductility. The addition of 7 wt.% rhenium to the ODS molybdenum did not significantly enhance the mechanical properties. However, the addition of 14 wt.% rhenium to the ODS molybdenum resulted in a DBTT well below room temperature in both the stress-relieved and recrystallized condition. Additionally, the tensile strength of ODS Mo-14Re is greater than the base ODS molybdenum at 1,000 to 1,250 C

  20. Development of Solvent Extraction Approach to Recycle Enriched Molybdenum Material

    Energy Technology Data Exchange (ETDEWEB)

    Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Brown, M. Alex [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Sen, Sujat [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Bowers, Delbert L. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Wardle, Kent [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Copple, Jacqueline M. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Pupek, Krzysztof Z. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Dzwiniel, Trevor L. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Krumdick, Gregory K. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2016-06-01

    Argonne National Laboratory, in cooperation with Oak Ridge National Laboratory and NorthStar Medical Technologies, LLC, is developing a recycling process for a solution containing valuable Mo-100 or Mo-98 enriched material. Previously, Argonne had developed a recycle process using a precipitation technique. However, this process is labor intensive and can lead to production of large volumes of highly corrosive waste. This report discusses an alternative process to recover enriched Mo in the form of ammonium heptamolybdate by using solvent extraction. Small-scale experiments determined the optimal conditions for effective extraction of high Mo concentrations. Methods were developed for removal of ammonium chloride from the molybdenum product of the solvent extraction process. In large-scale experiments, very good purification from potassium and other elements was observed with very high recovery yields (~98%).

  1. Cloud point extraction of copper, lead, cadmium, and iron using 2,6-diamino-4-phenyl-1,3,5-triazine and nonionic surfactant, and their flame atomic absorption spectrometric determination in water and canned food samples.

    Science.gov (United States)

    Citak, Demirhan; Tuzen, Mustafa

    2012-01-01

    A cloud point extraction procedure was optimized for the separation and preconcentration of lead(II), cadmium(II), copper(II), and iron(III) ions in various water and canned food samples. The metal ions formed complexes with 2,6-diamino-4-phenyl-1,3,5-triazine that were extracted by surfactant-rich phases in the nonionic surfactant Triton X-114. The surfactant-rich phase was diluted with 1 M HNO3 in methanol prior to its analysis by flame atomic absorption spectrometry. The parameters affecting the extraction efficiency of the proposed method, such as sample pH, complexing agent concentration, surfactant concentration, temperature, and incubation time, were optimized. LOD values based on three times the SD of the blank (3Sb) were 0.38, 0.48, 1.33, and 1.85 microg/L for cadmium(II), copper(II), lead(II), and iron(III) ions, respectively. The precision (RSD) of the method was in the 1.86-3.06% range (n=7). Validation of the procedure was carried out by analysis of National Institute of Standards and Technology Standard Reference Material (NIST-SRM) 1568a Rice Flour and GBW 07605 Tea. The method was applied to water and canned food samples for determination of metal ions.

  2. Study of the molybdenum retention in alumina

    International Nuclear Information System (INIS)

    Wilkinson, Maria V.; Mondino, Angel V.; Manzini, Alberto

    2002-01-01

    The Argentine National Atomic Energy Commission routinely produces 99 Mo by fission of highly enriched uranium contained in targets irradiated in RA-3 reactor. The current process begins with the dissolution of the irradiated target in a basic media, considering the possibility of changing the targets, it could be convenient to dissolve them in acid media. The use of alumina as a first separation step in acid dissolution processes is already known although it is necessary to determine both the type of alumina to be used and the separation conditions. The study of molybdenum retention in alumina was performed at laboratory scale, using Mo-99 as radiotracer. Different kinds of alumina were tried, varying charge solution acidity. Influence of uranium concentration in the loading solution on molybdenum retention was also studied. (author)

  3. Evaluation of a molybdenum assay canister

    International Nuclear Information System (INIS)

    Yoshizumi, T.T.; Keener, S.J.

    1988-01-01

    The performance characteristics of a commercial molybdenum assay canister were evaluated. The geometrical variation of the technetium-99m (/sup 99m/Tc) activity reading was studied as a function of the elution volume for the standard vials. It was found that the /sup 99m/Tc canister activity reading was ∼ 5% lower than that of the standard method. This is due to attenuation by the canister wall. However, the effect of the geometric variation on the clinical dose preparation was found to be insignificant. The molybdenum-99 ( 99 Mo) contamination level was compared by two methods: (1) the commercial canister and (2) the standard assay kit. The 99 Mo contamination measurements with the canister indicated consistently lower readings than those with the standard 99 Mo assay kit. The authors conclude that the canister may be used in the clinical settings. However, the user must be aware of the problems and the limitations associated with this canister

  4. Electrical resistivity of sputtered molybdenum films

    International Nuclear Information System (INIS)

    Nagano, J.

    1980-01-01

    The electrical resistivity of r.f. sputtered molybdenum films of thickness 5-150 nm deposited on oxidized silicon substrates was resolved into the three electron scattering components: isotropic background scattering, scattering at grain boundaries and scattering at surfaces. It was concluded that the isotropic background scattering is almost equal to that of bulk molybdenum and is not influenced by sputtering and annealing conditions. When the film thickness is sufficient that surface scattering can be ignored, the decrease in film resistivity after annealing is caused by the decrease in scattering at the grain boundaries for zero bias sputtered films, and is caused by an increase of the grain diameter for r.f. bias sputtered films. (Auth.)

  5. Investigation of molybdenum pentachloride interaction with chlorine

    International Nuclear Information System (INIS)

    Salyulev, A.B.; Vovkotrub, Eh.G.; Strekalovskij, V.N.

    1993-01-01

    In Raman spectra of molybdenum pentachloride solutions in liquid chlorine lines were recorded in case of 397, 312, 410, 217 and 180 cm - 1 vibrations of ν 1 (A 1 '), ν 2 (A 1 '), ν 5 (E'), ν 6 (E') and ν 8 (E'') monomer (symmetry D 3h ) molecules of MoCl 5 . Interaction of molten molybdenum pentachloride with chlorine at increased (up to 6 MPa) pressures of Cl 2 was studied. In Raman spectra of its vapour distillation in liquid chlorine alongside with MoCl 5 lines appearance of new lines at 363 and 272 cm -1 , similar in their frequency to the ones calculated for the vibrations ν 1 (A 1g ) and ν 2 (E g ) of MoCl 6 molecules (symmetry O h ), was observed

  6. Alternative expression of vacuolar iron transporter and ferritin genes leads to blue/purple coloration of flowers in tulip cv. 'Murasakizuisho'.

    Science.gov (United States)

    Shoji, Kazuaki; Momonoi, Kazumi; Tsuji, Tosiaki

    2010-02-01

    Flowers of tulip cv. 'Murasakizuisho' have a purple perianth except for the bottom region, which is blue in color even though it has the same anthocyanin, delphinidin 3-O-rutinoside, as the entire perianth. The development of the blue coloration in the perianth bottom is due to complexation by anthocyanin, flavonol and iron (Fe), as well as a vacuolar iron transporter, TgVit1. Although transient expression of TgVit1 in the purple cells led to a color change to light blue, the coloration of the transformed cells did not coincide with the dark blue color of the cells of the perianth bottom. We thought that another factor is required for the blue coloration of the cells of perianth bottom. To examine the effect of ferritin (FER), an Fe storage protein, on blue color development, we cloned an FER gene (TgFER1) and performed expression analyses. TgFER1 transcripts were found in the cells located in the upper region of the petals along with purple color development by anthocyanin and were not found in the blue cells of the perianth bottom. This gene expression is in contrast to that of TgVit1, expressed only in the cells of the perianth bottom. Co-expression of TgVIT1 and TgFER-RNAi, constructed for suppressing endogenous TgFER1 by RNA interference (RNAi), changed the purple petal cells to a dark blue color similar to that of the natural perianth bottom. These results strongly suggest that TgVit1 expression and TgFER1 suppression are critical for the development of blue color in the perianth bottom.

  7. Molybdenum-99 supply: a global issue

    International Nuclear Information System (INIS)

    Cote, R.V.

    2011-01-01

    This article discusses the global supply of Molybdenum 99 used in nuclear medicine. Following a disruption in supplies of isotopes in the last few years, a Canadian expert panel assessed the most viable options for securing a sustainable supply of Technitium 99 over the medium to long term. The general recommendations were to strive for diversity and redundancy throughout the supply chain, leverage multi-use infrastructure, continue with international coordination and seek processing standardization within North America.

  8. Reaction between molybdenum hexafluoride and carboxylic acids

    International Nuclear Information System (INIS)

    Shustov, L.D.; Nikolenko, L.N.; Senchenkova, T.M.

    1983-01-01

    Trifluoromethyl derivatives of pyridine, imidazole and difluoromethane are synthesized during interaction of MoF 6 surplUs (190-210 deg) with nicotine-isomicotine-, 2,6-pyridinedicarboxylic-, 4,5-imidazoledicarboxyclic- and diffluoroacetic acids. The yield of trifluoromethyl derivatives attains 84%. Molybdenum hexafluoride offers some advantages in comparisoo with toxic SF 4 . MoF 6 toxicity is low; leakage of MoF 6 vapors is easily detected

  9. Statistics of grain misorientations in molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Rybin, V V; Titovets, Yu F; Teplitskij, D M; Zolotorevskij, N Yu

    1982-03-01

    Sets of misorientations between neighbouring grains for three recrystallized molybdenum polycrystals differing in purity, phase composition and prehistory are experimentally determined. The data obtained are analyzed according to modern representations of intergrain boundary structure. In the two materials among the three mentioned above the share of boundaries close to special boundaries with high density of coinciding points turned to be 1.5 times higher than in the polycrystal with chaotic distribution of grains by orientations.

  10. Biomass as biosorbent for molybdenum ions

    Energy Technology Data Exchange (ETDEWEB)

    Yamaura, Mitiko; Santos, Jacinete L. dos; Damasceno, Marcos O.; Egute, Nayara dos S.; Moraes, Adeniane A.N.; Santos, Bruno Z., E-mail: myamaura@ipen.br, E-mail: jlsantos@ipen.br, E-mail: molidam@ipen.br, E-mail: nayara.egute@usp.br, E-mail: adenianemrs@ig.com.br, E-mail: bzsantos@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Biosorbents have been focused as renewable materials of low cost, and have been used for metal removal from the wastewater by adsorption phenomenon. Biosorbents are prepared of biomass, whose reactive sites in its chemical structure have affinity to bind to metal ions. In this work, performance of corn husk, sugarcane bagasse, coir, banana peel, fish scale, chitin and chitosan as biosorbents of molybdenum (VI) ions in aqueous medium was evaluated. The adsorption experiments were investigated in a batch system varying the pH solution from 0.5 to 12 and the contact time between the phases from 2 min to 70 min. {sup 99}Mo radioisotope was used as radioactive tracer for analysis of molybdenum ions by gamma spectroscopy using a HPGe detector. Results revealed that acidity of the solution favored the adsorption of Mo (VI) ions on the all biosorbents. Adsorption values higher than 85% were found on sugarcane bagasse, coir, corn husk, chitin and chitosan at pH 2.0. Only the chitosan was dissolved at pH 0.5 and a gel was formed. The models of pseudo-second order and external film diffusion described the kinetics of adsorption of Mo ions on the coir. This work showed that the studied biomass has high potential to be used as biosorbent of molybdenum ions from acidic wastewater, and the kinetics of Mo adsorption on the coir suggested high-affinity adsorption governed by chemisorption. (author)

  11. Biomass as biosorbent for molybdenum ions

    International Nuclear Information System (INIS)

    Yamaura, Mitiko; Santos, Jacinete L. dos; Damasceno, Marcos O.; Egute, Nayara dos S.; Moraes, Adeniane A.N.; Santos, Bruno Z.

    2013-01-01

    Biosorbents have been focused as renewable materials of low cost, and have been used for metal removal from the wastewater by adsorption phenomenon. Biosorbents are prepared of biomass, whose reactive sites in its chemical structure have affinity to bind to metal ions. In this work, performance of corn husk, sugarcane bagasse, coir, banana peel, fish scale, chitin and chitosan as biosorbents of molybdenum (VI) ions in aqueous medium was evaluated. The adsorption experiments were investigated in a batch system varying the pH solution from 0.5 to 12 and the contact time between the phases from 2 min to 70 min. 99 Mo radioisotope was used as radioactive tracer for analysis of molybdenum ions by gamma spectroscopy using a HPGe detector. Results revealed that acidity of the solution favored the adsorption of Mo (VI) ions on the all biosorbents. Adsorption values higher than 85% were found on sugarcane bagasse, coir, corn husk, chitin and chitosan at pH 2.0. Only the chitosan was dissolved at pH 0.5 and a gel was formed. The models of pseudo-second order and external film diffusion described the kinetics of adsorption of Mo ions on the coir. This work showed that the studied biomass has high potential to be used as biosorbent of molybdenum ions from acidic wastewater, and the kinetics of Mo adsorption on the coir suggested high-affinity adsorption governed by chemisorption. (author)

  12. Preparation of single phase molybdenum boride

    International Nuclear Information System (INIS)

    Camurlu, Hasan Erdem

    2011-01-01

    Highlights: → Formation of Mo and a mixture of molybdenum boride phases take place in preparation of molybdenum borides. → It is intricate to prepare single phase molybdenum borides. → Formation of single phase MoB from MoO 3 + B 2 O 3 + Mg mixtures has not been reported previously. → Single phase MoB was successfully prepared through a combination of mechanochemical synthesis and annealing process. - Abstract: The formation of MoB through volume combustion synthesis (VCS), and through mechanochemical synthesis (MCS) followed by annealing has been investigated. MoO 3 , B 2 O 3 and Mg were used as reactants while MgO and NaCl were introduced as diluents. Products were leached in dilute HCl solution and were subjected to X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) examinations. Mo was the major phase component in the VCS products under all the experimental conditions. Mo 2 B, MoB, MoB 2 and Mo 2 B 5 were found as minor phases. Products of MCS contained a mixture of Mo 2 B, MoB, MoB 2 and Mo. After annealing the MCS product at 1400 deg. C for 3 h, single phase α-MoB was obtained.

  13. Weldability of powder-metallurgy molybdenum with low oxygen content

    International Nuclear Information System (INIS)

    Hiraoka, Yutaka; Okada, Masatoshi

    1987-01-01

    Relationships between the formation of weld pores and the chemical compositions in powder-metallurgy molybdenum were investigated. It is suggested that almost 100% of Ca and Mg form oxides. In contrast, Fe, Ni, Cr and Al, Si only partly form oxides. A powder-metallurgy molybdenum containing less than 84 at.ppm oxygen did not show any large weld pores. The reduction of the oxygen content was achieved by purifying the molybdenum powder. (orig.) [de

  14. Molybdenum(6) complexing with ethylenediaminedisuccinic acid from PMR spectroscopy data

    International Nuclear Information System (INIS)

    Larchenko, V.E.; Kovaleva, I.B.; Mitrofanova, N.D.; Martynenko, L.I.

    1989-01-01

    Methods of high resolution PMR spectroscopy and pH potentiometry are used to study molybdenum(6) complexing with ethylenediaminedisuccinic acid in aqueous solutions. It is shown that molybdenum(6) interacts with ethylenediaminedisuccinic acid in the narrow range of pH values 4.0-6.5, where MoO 3 H 2 L 2 - and MoO 3 HL 3- complexes with asymmetrical structure are formed. Composition and structure of molybdenum(6) ethylenediaminedisuccinates and ethylenediaminetetraacetates are compared

  15. Deformation localization and cyclic strength in polycrystalline molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Sidorov, O.T.; Rakshin, A.F.; Fenyuk, M.I.

    1983-06-01

    Conditions of deformation localization and its interrelation with cyclic strength in polycrystalline molybdenum were investigated. A fatigue failure of polycrystalline molybdenum after rolling and in an embrittled state reached by recrystallization annealing under cyclic bending at room temperature takes place under nonuniform distribution of microplastic strain resulting in a temperature rise in separate sections of more than 314 K. More intensive structural changes take place in molybdenum after rolling than in recrystallized state.

  16. Matrix composition effects on the tensile properties of tungsten-molybdenum heavy alloys

    International Nuclear Information System (INIS)

    Bose, A.; German, R.N.

    1990-01-01

    Tungsten-base heavy alloys are liquid-phase sintered from mixed tungsten, nickel, and iron powders. The sintered product is a composite consisting of interlaced tungsten and solidified matrix (W-Ni-Fe) phases. These alloys are most useful in applications requiring high density, strength, and toughness. The design of improved tungsten heavy alloys has been the subject of several research investigations. Much success has taken place through improved processing, but parallel compositional studies have resulted in new microstructure-property combinations. As part of these investigations, the Ni/Fe ratio has been varied, with the general conclusion that optimal strength and ductility occur with a ratio between 2 and 4. Brittle intermetallic phases can form outside of this composition range. Historically, a 7/3 Ni/Fe ratio has been selected for processing studies. Recently, others reported higher ductilities and impact energies for 90 and 93 pct W heavy alloys with the 8/2 Ni/Fe ratio. Alternatively, these alloys can be strengthened by both solid solution and grain size refinement through incorporation of molybdenum, tantalum, or rhenium. These additions are soluble in both the tungsten and matrix phases and retard solution-reprecipitation during liquid phase sintering. In this study, the alloy composition was varied in the nickel/iron ratio and molybdenum was partially substituted for tungsten. The sintered tensile properties are assessed vs these compositional variations

  17. Sorption of molybdenum by cellulose polyphosphate from acid solutions

    International Nuclear Information System (INIS)

    Luneva, N.K.; Oputina, A.G.; Ermolenko, I.N.

    1985-01-01

    The sorption of molybdenum on cellulose polyphosphate from acid solutions of ammonium molybdate depending on the phosphorus content in samples, concentration and pH of the solution, sorption time is studied. It is shown that a maximum molybdenum content on the cellulose samples with different phosphorus content is pointed out at an ammonium molybdate concentration 0.02 M. Saturation of the sorption curve is attained at molar ratio of adsrbed molybdenum to phosphorus 1:4. In case of small fillings the compound with molybdenum to phosphorus ratio 1:10 is formed

  18. Separation of uranium from molybdenum by alkyl phosphoric acid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Zhongshi, Li

    1986-08-01

    The regularities of separation of uranium from molybdenum by alkyl phosphoric acid extraction are described. Two parameters, i.e., density ratio of uranium to molybdenum in organic phase at first stage and density of uranium in raffinate at last stage are presented. The relationship between these parameters and purity of molybdenum and uranium products is given. The method of adjusting and controlling these parameters in experiments and production is worked out. The technical key problem in comprehensive utilization of sedimentary type uranium ore containing molybdenum with close concentration of these to elements has been solved.

  19. Iron Oxide Nanoparticles Employed as Seeds for the Induction of Microcrystalline Diamond Synthesis

    Directory of Open Access Journals (Sweden)

    Resto Oscar

    2008-01-01

    Full Text Available AbstractIron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. X-ray diffraction, visible, and ultraviolet Raman Spectroscopy, energy-filtered transmission electron microscopy , electron energy-loss spectroscopy, and X-ray photoelectron spectroscopy (XPS were employed to study the carbon bonding nature of the films and to analyze the carbon clustering around the seed nanoparticles leading to diamond synthesis. The results indicate that iron oxide nanoparticles lose the O atoms, becoming thus active C traps that induce the formation of a dense region of trigonally and tetrahedrally bonded carbon around them with the ensuing precipitation of diamond-type bonds that develop into microcrystalline diamond films under chemical vapor deposition conditions. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

  20. Intense molybdenum accumulation in sediments underneath a nitrogenous water column and implications for the reconstruction of paleo-redox conditions based on molybdenum isotopes

    Science.gov (United States)

    Scholz, Florian; Siebert, Christopher; Dale, Andrew W.; Frank, Martin

    2017-09-01

    The concentration and isotope composition of molybdenum (Mo) in sediments and sedimentary rocks are widely used proxies for anoxic conditions in the water column of paleo-marine systems. While the mechanisms leading to Mo fixation in modern restricted basins with anoxic and sulfidic (euxinic) conditions are reasonably well constrained, few studies have focused on Mo cycling in the context of open-marine anoxia. Here we present Mo data for water column particulate matter, modern surface sediments and a paleo-record covering the last 140,000 years from the Peruvian continental margin. Mo concentrations in late Holocene and Eemian (penultimate interglacial) shelf sediments off Peru range from ∼70 to 100 μg g-1, an extent of Mo enrichment that is thought to be indicative of (and limited to) euxinic systems. To investigate if this putative anomaly could be related to the occasional occurrence of sulfidic conditions in the water column overlying the Peruvian shelf, we compared trace metal (Mo, vanadium, uranium) enrichments in particulate matter from oxic, nitrate-reducing (nitrogenous) and sulfidic water masses. Coincident enrichments of iron (Fe) (oxyhydr)oxides and Mo in the nitrogenous water column as well as co-variation of dissolved Fe and Mo in the sediment pore water suggest that Mo is delivered to the sediment surface by Fe (oxyhydr)oxides. Most of these precipitate in the anoxic-nitrogenous water column due to oxidation of sediment-derived dissolved Fe with nitrate as a terminal electron acceptor. Upon reductive dissolution in the surface sediment, a fraction of the Fe and Mo is re-precipitated through interaction with pore water sulfide. The Fe- and nitrate-dependent mechanism of Mo accumulation proposed here is supported by the sedimentary Mo isotope composition, which is consistent with Mo adsorption onto Fe (oxyhydr)oxides. Trace metal co-variation patterns as well as Mo and nitrogen isotope systematics suggest that the same mechanism of Mo delivery

  1. On the effect of interaction of molybdenum trioxide and magnesium oxide in water

    International Nuclear Information System (INIS)

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

    1992-01-01

    Interaction of molybdenum trioxide and magnesium oxide in water was studied. It is shown that molybdenum trioxide forms consecutively magnesium molybdate, dimolybdate and magnesium polymolybdates with magnesium oxide

  2. Bioaccumulation of Iron and Lead in the soft tissue of some marine molluscs and associated sediment at labor Island,Aden,yemen

    International Nuclear Information System (INIS)

    Ali, Anis Ahmed; Baharoon Aqil Abdulrahman

    2000-01-01

    The aim of this research work is to know the effect of the oil spill from the oil pipes that pass near the Labor Island, in addition the use of the Island as a station for gathering the old ships and boats that been prepared for re-exportation. For this purpose, a number of marine molluscs were used such as, A canthopleura haddoni (chitons), Ostrea cucullata (oysters), Turbo coronatus (sea snails). The were classified to their classes and sizes. Associated surfacial sediments were also used after sieving to <63 μm, in order to be analyzed by using the AAS. The results obtained showed high concentration in Fe and Pb in the soft tissue of the marine animals used and the associated sediment. These results indicate that these two heavy metals were bioaccumulated, and this accumulation may be returned to the oil spill from the oil pipes, or to the spill of drainage from the Iron mountain camp, or all the probabilities together. (author)

  3. The impact of anthropogenic factors on the occurrence of molybdenum in stream and river sediments of central Upper Silesia (Southern Poland

    Directory of Open Access Journals (Sweden)

    Pasieczna Anna

    2017-12-01

    Full Text Available In our study, a detailed survey was conducted with the aim to determine the distribution and possible anthropogenic sources of molybdenum in river and stream sediments in the central Upper Silesian Industrial Region (Southern Poland, where for many years, iron and zinc smelters as well as coking and thermal power plants were operating. At the same time, this has also been a residential area with the highest population density in the country. Sediments (1397 samples in total were collected from rivers and streams, and analysed for the content of molybdenum and 22 other elements. ICP-AES and CV-AAS methods were applied for the determination of the content of elements. The studies revealed molybdenum content in the range of 5 mg·kg−1. The spatial distribution of molybdenum demonstrated by the geochemical map has indicated that the principal factor determining its content in sediments is the discharge of wastewater from steelworks and their slag heaps. Another source of this element in sediments has been the waste of the historical mining of zinc ore and metallurgy of this metal. Additionally, molybdenum migration from landfills of power plants, coal combustion and Mo emission to the atmosphere and dust fall-out have been significant inputs of Mo pollution to the sediments.

  4. Research of the technology of obtaining pure and disperse molybdenum disulfide from molybdenum concentrate

    International Nuclear Information System (INIS)

    Hovsepyan, A.H.; Israyelyan, S.M.

    2009-01-01

    The technology of obtaining pure and disperse molybdenum disulfide is worked out. The processes of refinement from the flotation reagents and deslimation by means of decantation, refinement of molybdenite concentrate from impurities by selective leaching methods are studied. The optimal regime of technological process is chosen

  5. Flame atomic absorption spectrometric determination of zinc, nickel, iron and lead in different matrixes after solid phase extraction on sodium dodecyl sulfate (SDS)-coated alumina as their bis (2-hydroxyacetophenone)-1, 3-propanediimine chelates

    International Nuclear Information System (INIS)

    Ghaedi, M.; Tavallali, H.; Shokrollahi, A.; Zahedi, M.; Montazerozohori, M.; Soylak, M.

    2009-01-01

    A sensitive and simple solid phase extraction method for the simultaneous determination of trace and toxic metals in food samples has been reported. The method is based on the adsorption of zinc, nickel, iron and lead on sodium dodecyl sulfate (SDS)-coated alumina, which is also chelated with bis (2-hydroxyacetophenone)-1, 3-propanediimine (BHAPN). The retained analyte ions on modified solid phase were eluted using 8 mL of 4 mol L -1 HNO 3 . The analyte determinations were carried out by flame atomic absorption spectrometry. The influences of some metal ions and anions on the recoveries of understudy analyte ions were investigated. The proposed method has been successfully applied for the evaluation of these trace and toxic metals in some traditional food samples from Iran.

  6. The Effect of Molybdenum Fertilization on Arachis Glabrata Biomass ...

    African Journals Online (AJOL)

    The effect of molybdenum fertilization on biomass and the number of nodules of Arachis glabrata was assessed at the Teaching and Research Farm of the University of Dschang in 2011 at different periods of mowing. A factorial design comparing four doses of molybdenum as ammonium molybdate (0, 0.75, 1.5 and 2.25 ...

  7. Influence of Soil Solution Salinity on Molybdenum Adsorption by Soils

    Science.gov (United States)

    Molybdenum (Mo) adsorption on five arid-zone soils from California was investigated as a function of equilibrium solution Mo concentration (0-30 mg L-1), solution pH (4-8), and electrical conductivity (EC = 0.3 or 8 dS m-1). Molybdenum adsorption decreased with increasing pH. An adsorption maximum...

  8. Low-temperature heat capacity of molybdenum borides

    International Nuclear Information System (INIS)

    Bolgar, A.S.; Klinder, A.V.; Novoseletskaya, L.M.; Turov, V.P.; Klochkov, L.A.; Lyashchenko, A.B.

    1988-01-01

    Heat capacity of molybdenum borides Mo 2 B, MoB, Mo 2 B 5 is studied for the first time in the 60-300 K range using the adiabatic method. Standard (at 298.15 K) thermodynamic functions (enthalpy, heat capacity, entropy, reduced Gibbs energy) of molybdenum borides are calculated

  9. Behaviour of helium after implantation in molybdenum

    International Nuclear Information System (INIS)

    Viaud, C.; Maillard, S.; Carlot, G.; Valot, C.; Gilabert, E.; Sauvage, T.; Peaucelle, C.; Moncoffre, N.

    2009-01-01

    This study deals with the behaviour of helium in a molybdenum liner dedicated to the retention of fission products. More precisely this work contributes to evaluate the release of implanted helium when the gas has precipitated into nanometric bubbles close to the free surface. A simple model dedicated to calculate the helium release in such a condition is presented. The specificity of this model lays on the assumption that the gas is in equilibrium with a simple distribution of growing bubbles. This effort is encouraging since the calculated helium release fits an experimental dataset with a set of parameters in good agreement with the literature

  10. Spectra from foil-excited molybdenum ions

    International Nuclear Information System (INIS)

    Johnson, B.M.; Jones, K.W.; Cecchi, J.L.; Kruse, T.H.

    1978-01-01

    The extreme-ultraviolet spectra (5 to 55 nm) for foil-excited molybdenum ions have been measured using 22 to 200 MeV beams from the Brookhaven National Laboratory MP tandem Van de Graaff accelerator facility, 20 μg/cm 2 C stripping foils, and a grazing incidence spectrometer. The mean ion charge states (13 to 28) and the narrow distribution widths (about 2 charge states) were accurately predictable from experimental parameters. Where possible, comparisons are given with Mo radiation from tokamaks, vacuum sparks, and laser-excited plasmas

  11. Molybdenum protective coatings adhesion to steel substrate

    Science.gov (United States)

    Blesman, A. I.; Postnikov, D. V.; Polonyankin, D. A.; Teplouhov, A. A.; Tyukin, A. V.; Tkachenko, E. A.

    2017-06-01

    Protection of the critical parts, components and assemblies from corrosion is an urgent engineering problem and many other industries. Protective coatings’ forming on surface of metal products is a promising way of corrosionprevention. The adhesion force is one of the main characteristics of coatings’ durability. The paper presents theoretical and experimental adhesion force assessment for coatings formed by molybdenum magnetron sputtering ontoa steel substrate. Validity and reliability of results obtained by simulation and sclerometry method allow applying the developed model for adhesion force evaluation in binary «steel-coating» systems.

  12. MHD simulations of molybdenum X-pinches

    International Nuclear Information System (INIS)

    Ivanenkov, G.V.; Stepnevski, V.

    2002-01-01

    One investigates into compression of molybdenum X-pinches applying numerical MHD-models with parabolic and conical initial geometry. The second model describing plasma axial motion in greater detail offers a real geometry of a discharge and is applicable to loads characterized by higher masses in contrast to the first one. Both models enabled to describe all basic phases of compression including origination of a minidiode, occurrence of a narrow neck, microexplosion of a hot point and origination of shock waves followed by sausage instability [ru

  13. Hot rolling of thick uranium molybdenum alloys

    Science.gov (United States)

    DeMint, Amy L.; Gooch, Jack G.

    2015-11-17

    Disclosed herein are processes for hot rolling billets of uranium that have been alloyed with about ten weight percent molybdenum to produce cold-rollable sheets that are about one hundred mils thick. In certain embodiments, the billets have a thickness of about 7/8 inch or greater. Disclosed processes typically involve a rolling schedule that includes a light rolling pass and at least one medium rolling pass. Processes may also include reheating the rolling stock and using one or more heavy rolling passes, and may include an annealing step.

  14. Electrochemical ammonia production on molybdenum nitride nanoclusters

    DEFF Research Database (Denmark)

    Howalt, Jakob Geelmuyden; Vegge, Tejs

    2013-01-01

    Theoretical investigations of electrochemical production of ammonia at ambient temperature and pressure on nitrogen covered molybdenum nanoparticles are presented. Density functional theory calculations are used in combination with the computational hydrogen electrode approach to calculate the free...... energy profile for electrochemical protonation of N2 and N adatoms on cuboctahedral Mo13 nanoparticles. Pathways for electrochemical ammonia production via direct protonation of N adatoms and N2 admolecules with an onset potential as low as -0.5 V and generally lower than -0.8 V on both a nitrogen...

  15. Molybdenum Dichalcogenides for Environmental Chemical Sensing

    Directory of Open Access Journals (Sweden)

    Dario Zappa

    2017-12-01

    Full Text Available 2D transition metal dichalcogenides are attracting a strong interest following the popularity of graphene and other carbon-based materials. In the field of chemical sensors, they offer some interesting features that could potentially overcome the limitation of graphene and metal oxides, such as the possibility of operating at room temperature. Molybdenum-based dichalcogenides in particular are among the most studied materials, thanks to their facile preparation techniques and promising performances. The present review summarizes the advances in the exploitation of these MoX2 materials as chemical sensors for the detection of typical environmental pollutants, such as NO2, NH3, CO and volatile organic compounds.

  16. Molybdenum oxide nanocubes: Synthesis and characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Muthamizh, S.; Suresh, R.; Giribabu, K.; Manigandan, R.; Kumar, S. Praveen; Munusamy, S.; Narayanan, V., E-mail: vnnara@yahoo.co.in [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai -600025 (India); Stephen, A. [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai-600025 (India)

    2015-06-24

    Molybdenum oxide nanoparticles were prepared by Solid state synthesis. The MoO{sub 3} nanoparticles were synthesized by using commercially available ammonium heptamolybdate. The XRD pattern reveals that the synthesized MoO{sub 3} has orthorhombic structure. In addition, lattice parameter values were also calculated using XRD data. The Raman analysis confirm the presence of Mo-O in MoO{sub 3} nanoparticles. DRS-UV analysis shows that MoO{sub 3} has a band gap of 2.89 eV. FE-SEM analysis confirms the material morphology in cubes with nano scale.

  17. Solid solutions of hydrogen in niobium, molybdenum and their alloys

    International Nuclear Information System (INIS)

    Ishikawa, T.T.

    1981-01-01

    The solubility of hydrogen in niobium, molybdenum and niobium-molybdenum alloys with varying atomic fraction of molybdenum from 0.15 to 0.75 was measured on the temperature range of 673 0 K to 1273 0 k for one atmosphere hydrogen pressure. The experimental technique involved the saturation of the solvent metal or alloy with hydrogen, followed by quenching and analysis of the solid solution. The results obtained of hydrogen solubility are consistent with the quasi-regular model for the dilute interstitial solid solutions. The partial molar enthalpy and partial molar entropy in excess of the dissolved hydrogen atoms were calculated from data of solubility versus reciprocal doping temperature. The variation of the relative partial molar enthalpy of hydrogen dissolved in niobium-molybdenum alloys, with the increase of molybdenum content of the alloy was analized. (Author) [pt

  18. Thermal cyclic strength of molybdenum monocrystal at high temperatures

    International Nuclear Information System (INIS)

    Strizhalo, V.A.; Uskov, E.I.

    1975-01-01

    The results of the investigation of the thermocyclic creep and low-cycle fatigue of a molybdenum single crystal are discussed. The strength of a molybdenum single crystal under nonisothermal stressing has been investigated by using two different regimes of temperature and load variation. The temperature limits of the cycle were the same for the two testing regimes, the maximum temperature being 1700degC and the minimum 350degC. At higher temperatures (above 1500degC) the short-term strength of single-crystal molybdenum is comparable with that of commercial molybdenum and the refractory alloys, while the ductility is considerably higher. It should be noted that the failure of single-crystal molybdenum under rigid alternating loading is preceded by intensive distortion of the specimen, owing to directional cyclic creep of the metal in zones of bulging and thinning

  19. Synthesis of molybdenum borides and molybdenum silicides in molten salts and their oxidation behavior in an air-water mixture

    NARCIS (Netherlands)

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

    2005-01-01

    The formation of various coatings in molybdenum-boron and molybdenum-silicon systems was investigated. Boronizing and siliciding treatments were conducted in molten salts under inert gas atm. in the 850-1050 DegC temp. range for 7 h. The presence of boride (e.g. Mo2B, MoB, Mo2B5) and silicide

  20. Adsorptive iron removal from groundwater

    NARCIS (Netherlands)

    Sharma, S.K.

    2001-01-01

    Iron is commonly present in groundwater worldwide. The presence of iron in the water supply is not harmful to human health, however it is undesirable. Bad taste, discoloration, staining, deposition in the distribution system leading to aftergrowth, and incidences of high turbidity are some

  1. Crystallization and structure of chromium cast iron with addition of Mo and Ni

    International Nuclear Information System (INIS)

    Pietrowski, S.

    1998-01-01

    The aim of the presented paper is to show the results of examination of the crystallization process using the method of thermal-derivative analysis (ATD) and the structure examination of chromium cast iron, chromium molybdenum c. i. and chromium molybdenum nickel c.i. It was found that molybdenum in amount over 2 wt % causes the crystallization of eutectic carbides M 23 C 6 and M 6 C. The M 23 C 6 carbide crystallizes upon the crystallization of eutectic carbides M 3 C and M 7 C 3 . It is shown that ATD method facilitates both interpretation and control of the crystallization as well as formation of the cast iron structure at the solid state. (author)

  2. Climax-Type Porphyry Molybdenum Deposits

    Science.gov (United States)

    Ludington, Steve; Plumlee, Geoffrey S.

    2009-01-01

    Climax-type porphyry molybdenum deposits, as defined here, are extremely rare; thirteen deposits are known, all in western North America and ranging in age from Late Cretaceous to mainly Tertiary. They are consistently found in a postsubduction, extensional tectonic setting and are invariably associated with A-type granites that formed after peak activity of a magmatic cycle. The deposits consist of ore shells of quartz-molybdenite stockwork veins that lie above and surrounding the apices of cupola-like, highly evolved, calc-alkaline granite and subvolcanic rhyolite-porphyry bodies. These plutons are invariably enriched in fluorine (commonly >1 percent), rubidium (commonly >500 parts per million), and niobium-tantalum (Nb commonly >50 parts per million). The deposits are relatively high grade (typically 0.1-0.3 percent Mo) and may be very large (typically 100-1,000 million tons). Molybdenum, as MoS2, is the primary commodity in all known deposits. The effect on surface-water quality owing to natural influx of water or sediment from a Climax-type mineralized area can extend many kilometers downstream from the mineralized area. Waste piles composed of quartz-silica-pyrite altered rocks will likely produce acidic drainage waters. The potential exists for concentrations of fluorine or rare metals in surface water and groundwater to exceed recommended limits for human consumption near both mined and unmined Climax-type deposits.

  3. High-strength chromium--molybdenum rails

    International Nuclear Information System (INIS)

    Smith, Y.E.; Sawhill, J.M. Jr.; Cias, W.W.; Eldis, G.T.

    1976-01-01

    A laboratory study was conducted with the aim of developing an as-rolled rail of over 100 ksi (689 N/mm 2 ) yield strength. A series of compositions providing both pearlitic and bainitic microstructures was evaluated. A fine pearlitic structure was developed in a 0.73 percent C -- 0.83 percent Mn -- 0.16 percent Si -- 0.75 percent Cr -- 0.21 percent Mo steel by simulating the mill cooling rate of 132-lb/yd (65.5-kg/m) rail. Two 100-ton commercial heats were made of this approximate composition and processed into 132-lb/yd (65.5-kg/m) rail. Samples tested in the laboratory ranged from 109 to 125 ksi (750 to 860 N/mm 2 ) in yield strength. The chromium-molybdenum rails also exhibited excellent fracture toughness and fatigue properties. Sections of the rail were joined by both flash-butt welding and thermite welding. The hardness peaks produced in the flash-butt welds could be reduced by applying either a postweld current or an induction heating cycle. The high-strength chromium-molybdenum rails have been in service for over eight months in curved sections of an ore railway that carries over 55 million gross long tons per year. 7 tables, 18 figs

  4. Neutron activation determination of impurities in molybdenum

    International Nuclear Information System (INIS)

    Usmanova, M.M.; Mukhamedshina, N.M.; Obraztsova, T.V.; Saidakhmedov, K.Kh.

    1984-01-01

    Instrumental neutron-activation techniques of impurity element determination in molybdenum and MoO 3 (solid and powdered samples) have been developed. When determining impurities of Na, K, Mn, Cu, W, Re molybdenum has been irradiated by thermal neutrons in reactor for 20 min, the sample mass constituted 200-300 mg, sample cooling time after irradiation - 2.5-3.5 h. It is shown that in the process of Cr, Fe, Co, Zn determination the samples should be irradiated with thermal neutrons, and in the process of Sb, Ta and Ni determination - with resonance and fast neutrons. Simultaneous determination of the elements during irradiation with neutrons with reactor spectrum is possible. When determining P and S the samples are irradiated with thermal and epithermal neutrons and β-activity of samples and comparison samples are measured using β-spectrometer with anthracene crystal. The techniques developed permit to determine impurities in Mo with a relative standard deviation 0.07-0.15 and lower boundaries of contents determined - 10 -4 - 10 -7 %

  5. Preparation of molybdenum oxide thin films by MOCVD

    International Nuclear Information System (INIS)

    Guerrero, R. Martinez; Garcia, J.R. Vargas; Santes, V.; Gomez, E.

    2007-01-01

    In this study, molybdenum oxide films were prepared in a horizontal hot-wall MOCVD apparatus using molybdenum dioxide acetylacetonate as precursor. The molybdenum precursor was synthesized from acetylacetone and molybdenum oxide powder. Thermal gravimetric (TG) and differential thermal analyses (DTA) of the precursor suggested the formation of molybdenum oxides around 430 o C (703 K). Thus, a range of deposition temperatures varying from 350 to 630 o C (623-903 K) was explored to investigate the effects on the nature of the molybdenum oxide films. X-ray diffraction (XRD) results showed that the films consisted of α-MoO 3 phase at deposition temperatures ranging from 400 to 560 o C (673-833 K). Crystalline α-MoO 3 films can be obtained from molybdenum dioxide acetylacetonate precursor, without need of a post-annealing treatment. The best crystalline quality was found in films having needle-like crystallites grown at deposition temperature of about 560 o C (833 K), which exhibit a strong (0 1 0) preferred orientation and a transparent visual appearance

  6. Preparation of molybdenum oxide thin films by MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, R. Martinez [Depto. de Ingenieria Metalurgica, ESIQIE-IPN, Mexico 07300, D.F. (Mexico); Garcia, J.R. Vargas [Depto. de Ingenieria Metalurgica, ESIQIE-IPN, Mexico 07300, D.F. (Mexico)]. E-mail: rvargasga@ipn.mx; Santes, V. [CIIEMAD-IPN, Miguel Othon de Mendizabal 485, Mexico 07700, D.F. (Mexico); Gomez, E. [Instituto de Quimica-UNAM, Circuito Exterior-Ciudad Universitaria, Mexico 04510, D.F. (Mexico)

    2007-05-31

    In this study, molybdenum oxide films were prepared in a horizontal hot-wall MOCVD apparatus using molybdenum dioxide acetylacetonate as precursor. The molybdenum precursor was synthesized from acetylacetone and molybdenum oxide powder. Thermal gravimetric (TG) and differential thermal analyses (DTA) of the precursor suggested the formation of molybdenum oxides around 430 {sup o}C (703 K). Thus, a range of deposition temperatures varying from 350 to 630 {sup o}C (623-903 K) was explored to investigate the effects on the nature of the molybdenum oxide films. X-ray diffraction (XRD) results showed that the films consisted of {alpha}-MoO{sub 3} phase at deposition temperatures ranging from 400 to 560 {sup o}C (673-833 K). Crystalline {alpha}-MoO{sub 3} films can be obtained from molybdenum dioxide acetylacetonate precursor, without need of a post-annealing treatment. The best crystalline quality was found in films having needle-like crystallites grown at deposition temperature of about 560 {sup o}C (833 K), which exhibit a strong (0 1 0) preferred orientation and a transparent visual appearance.

  7. Behavior of molybdenum in mixed-oxide fuel

    International Nuclear Information System (INIS)

    Giacchetti, G.; Sari, C.

    1976-01-01

    Metallic molybdenum, Mo--Ru--Rh--Pd alloys, barium, zirconium, and tungsten were added to uranium and uranium--plutonium oxides by coprecipitation and mechanical mixture techniques. This material was treated in a thermal gradient similar to that existing in fuel during irradiation to study the behavior of molybdenum in an oxide matrix as a function of the O/(U + Pu) ratio and some added elements. Result of ceramographic and microprobe analysis shows that when the overall O/(U + Pu) ratio is less than 2, molybdenum and Mo--Ru--Rh--Pd alloy inclusions are present in the uranium--plutonium oxide matrix. If the O/(U + Pu) ratio is greater than 2, molybdenum oxidizes to MoO 2 , which is gaseous at a temperature approximately 1000 0 C. Molybdenum oxide vapor reacts with barium oxide and forms a compound that exists as a liquid phase in the columnar grain region. Molybdenum oxide also reacts with tungsten oxide (tungsten is often present as an impurity in the fuel) and forms a compound that contains approximately 40 wt percent of actinide metals. The apparent solubility of molybdenum in uranium and uranium--plutonium oxides, determined by electron microprobe, was found to be less than 250 ppM both for hypo- and hyperstoichiometric fuels

  8. Spheroidization of molybdenum powder by radio frequency thermal plasma

    Science.gov (United States)

    Liu, Xiao-ping; Wang, Kuai-she; Hu, Ping; Chen, Qiang; Volinsky, Alex A.

    2015-11-01

    To control the morphology and particle size of dense spherical molybdenum powder prepared by radio frequency (RF) plasma from irregular molybdenum powder as a precursor, plasma process parameters were optimized in this paper. The effects of the carrier gas flow rate and molybdenum powder feeding rate on the shape and size of the final products were studied. The molybdenum powder morphology was examined using high-resolution scanning electron microscopy. The powder phases were analyzed by X-ray diffraction. The tap density and apparent density of the molybdenum powder were investigated using a Hall flow meter and a Scott volumeter. The optimal process parameters for the spherical molybdenum powder preparation are 50 g/min powder feeding rate and 0.6 m3/h carrier gas rate. In addition, pure spherical molybdenum powder can be obtained from irregular powder, and the tap density is enhanced after plasma processing. The average size is reduced from 72 to 62 µm, and the tap density is increased from 2.7 to 6.2 g/cm3. Therefore, RF plasma is a promising method for the preparation of high-density and high-purity spherical powders.

  9. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... of the body. When your heart has to work harder, this can lead to several conditions: irregular heartbeats called arrhythmias , a heart murmur , an ... chronic conditions, iron-deficiency anemia can make their condition worse or result in treatments not working as well. Look for Diagnosis will discuss any ...

  10. Development of Silicide Coating on Molybdenum Alloy Cladding

    International Nuclear Information System (INIS)

    Lim, Woojin; Ryu, Ho Jin

    2015-01-01

    The molybdenum alloy is considered as one of the accident tolerant fuel (ATF) cladding materials due to its high temperature mechanical properties. However, molybdenum has a weak oxidation resistance at elevated temperatures. To modify the oxidation resistance of molybdenum cladding, silicide coating on the cladding is considered. Molybdenum silicide layers are oxidized to SiO 2 in an oxidation atmosphere. The SiO 2 protective layer isolates the substrate from the oxidizing atmosphere. Pack cementation deposition technique is widely adopted for silicide coating for molybdenum alloys due to its simple procedure, homogeneous coating quality and chemical compatibility. In this study, the pack cementation method was conducted to develop molybdenum silicide layers on molybdenum alloys. It was found that the Mo 3 Si layer was deposited on substrate instead of MoSi 2 because of short holding time. It means that through the extension of holding time, MoSi 2 layer can be formed on molybdenum substrate to enhance the oxidation resistance of molybdenum. The accident tolerant fuel (ATF) concept is to delay the process following an accident by reducing the oxidation rate at high temperatures and to delay swelling and rupture of fuel claddings. The current research for Atf can be categorized into three groups: First, modification of existing zirconium-based alloy cladding by improving the high temperature oxidation resistance and strength. Second, replacing Zirconium based alloys with alternative metallic materials such as refractory elements with high temperature oxidation resistance and strength. Third, designing alternative fuel structures using ceramic and composite systems

  11. Molybdenum plasma spray powder, process for producing said powder, and coating made therefrom

    International Nuclear Information System (INIS)

    Lafferty, W.D.; Cheney, R.F.; Pierce, R.H.

    1979-01-01

    Plasma spray powders of molybdenum particles containing 0.5 to 15 weight percent oxygen and obtained by reacting molybdenum particles with oxygen or oxides in a plasma, form plasma spray coatings exhibiting hardness comparable to flame sprayed coatings formed from molybdenum wire and plasma coatings of molybdenum powders. Such oxygen rich molybdenum powders may be used to form wear resistant coatings, such as for piston rings. (author)

  12. Iron requirements of infants and toddlers

    DEFF Research Database (Denmark)

    Domellöf, Magnus; Braegger, Christian; Campoy, Cristina

    2014-01-01

    Iron deficiency (ID) is the most common micronutrient deficiency worldwide and young children are a special risk group since their rapid growth leads to high iron requirements. Risk factors associated with a higher prevalence of iron deficiency anemia (IDA) include low birth weight, high cow's milk.......There is no evidence that iron supplementation of pregnant women improves iron status in their offspring in a European setting. Delayed cord clamping reduces the risk of iron deficiency. There is insufficient evidence to support general iron supplementation of healthy, European infants and toddlers of normal birth...... intake, low intake of iron-rich complementary foods, low socioeconomic status and immigrant status.The aim of this position paper is to review the field and provide recommendations regarding iron requirements in infants and toddlers, including those of moderately or marginally low birth weight...

  13. The extended family of hexagonal molybdenum oxide

    Energy Technology Data Exchange (ETDEWEB)

    Hartl, Monika [Los Alamos National Laboratory; Daemen, Luke [Los Alamos National Laboratory; Lunk, J H [NON LANL; Hartl, H [NON LANL; Frisk, A T [NON LANL; Shendervich, I [NON LANL; Mauder, D [NON LANL; Feist, M [NON LANL; Eckelt, R [NON LANL

    2009-01-01

    Over the last 40 years, a large number of isostructural compounds in the system MoO{sub 3}-NH{sub 3}-H{sub 2}O have been published. The reported molecular formulae of 'hexagonal molybdenum oxide' (HEMO) varied from MoO{sub 3}, MoO{sub 3} {center_dot} 0.33NH{sub 3}, MoO{sub 3} {center_dot} nH{sub 2}O (0.09 {le} n {le} 0.69) to MoO{sub 3} {center_dot} mNH{sub 3} {center_dot} nH{sub 2}O (0.09 {le} m {le} 0.20; 0.18 {le} n {le} 0.60). Samples, prepared by the acidification route, were investigated using thermal analysis coupled on-line to a mass spectrometer for evolved gas analysis; X-ray powder diffraction; Fourier Transform Infrared, Raman and Magic-Angle-Spinning {sup 1}H-NMR spectroscopy; Incoherent Inelastic Neutron Scattering. The X-ray study of a selected monocrystal confirmed the presence of the well-known framework of edge-sharing MoO{sub 6} octahedra: Space group P6{sub 3}/m, a = 10.527(1), c =3.7245(7) {angstrom}, {gamma} = 120{sup o}. The structure of the synthesized samples can best be described by the structural formula (NH{sub 4})[Mo{sub x}{open_square}{sub 1/2+p/2}(O{sub 3x + 1/2-p/2})(OH){sub p}] {center_dot} yH{sub 2}O (x 5.9-7.1; p {approx} 0.1; y = 1.2-2.6), which is consistent with the existence of one vacancy for 12-15 molybdenum sites. The 'chimie douce' reaction of MoO{sub 3} {center_dot} 0.155NH{sub 3} {center_dot} 0.440H{sub 2}O with a 1:1 mixture of NO/NO{sub 2} at 100 C resulted in the synthesis of MoO{sub 3} {center_dot} 0.539H{sub 2}O. Tailored nano-sized molybdenum powders can be produced using HEMO as precursor.

  14. Low cycle fatigue behavior of titanium carbide coated molybdenum

    International Nuclear Information System (INIS)

    Nishi, Hiroshi; Oku, Tatsuo; Kodaira, Tsuneo; Kikuyama, Toshihiko

    1985-09-01

    Sintered molybdenum coated by TiC is used for the first wall such as a troidal fixed limiter and a magnetic limiter plate in JT-60, that is being operated at JAERI presently. This report describes the low cycle fatigue behavior of sintered molybdenum and the influence of TiC coating on fatigue strength. The low cycle fatigue test was conducted at room temperature and 500 0 C. The test results was also analyzed by fractographic observation, metallography and element analysis using EPMA. The low cycle fatigue strength of the molybdenum coated by TiC at 500 0 C is decreased compared with the one at room temperature. (author)

  15. Cast irons

    CERN Document Server

    1996-01-01

    Cast iron offers the design engineer a low-cost, high-strength material that can be easily melted and poured into a wide variety of useful, and sometimes complex, shapes. This latest handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all engineered materials. The reader will find the basic, but vital, information on metallurgy, solidification characteristics, and properties. Extensive reviews are presented on the low-alloy gray, ductile, compacted graphite, and malleable irons. New and expanded material has been added covering high-alloy white irons used for abrasion resistance and high-alloy graphitic irons for heat and corrosion resistance. Also discussed are melting furnaces and foundry practices such as melting, inoculation, alloying, pouring, gating and rising, and molding. Heat treating practices including stress relieving, annealing, normalizing, hardening and tempering, autempering (of ductile irons), and surface-hardening treatments are covered, too. ASM Spec...

  16. Use of ion exchange during preparation of raw materials for production of molybdenum and tungsten of high purify

    International Nuclear Information System (INIS)

    Blokhin, A.A.; Rumyantsev, V.K.; Taushkanov, V.P.; Maksimkov, S.M.; Majorov, D.Yu.; Pak, V.I.

    1988-01-01

    The data on the application of selective ionites for the steep purification of ammonium molybdate and tungstate solutions, are given. It is shown that to purify molybdenum and ammonium tungstate solutions from the impuerities of alkali earth and two- and threevalent transition metals, iminodiacetate ampholites of the ANKB-35 type are the most effective sorbents. To purify from phosphorus, silicon and arsenic impurities composition ionites on the base of hydrated oxides of multivalent metals introduced in the granules of porous cationites should be used. To extract phosphorus, silicon, arsenic impurities from ammonium molybdate and tungstate solutions and tungsten from ammonium molybdate solutions the method of their coprecipitation with iron (3) hydroxide can also be used. The best results on the purification of ammonium molybdate from tungstate provides for the application of structural organomineral ionites as well as weak-basicity anionites of the AN-31 type and its different modifications containing hydroxyl groups along with aminogroups. To purity ammonium tungstate solutions from molybdate a method is developed which transforms molybdenum in the form of thiocomplexes and the following selective sorption by strong-basicity anionites. The data on the quality of molybdenum monocrystals which are taken from the raw material purified using ionites, are given

  17. Effect of molybdenum and chromium additions on the mechanical properties of Fe3Al-based alloys

    International Nuclear Information System (INIS)

    Sun Yangshan; Xue Feng; Mei Jianping; Yu Xingquan; Zhang Lining

    1995-01-01

    Iron aluminides based on Fe 3 Al offer excellent oxidation and sulfidation resistance, with lower material cost and density than stainless steels. However, their potential use as structural material has been hindered by limited ductility and a sharp drop in strength above 600 C. Recent development efforts have indicated that adequate engineering ductility of 10--20% and tensile yield strength of as high as 500 MPa can be achieved through control of composition and microstructure. These improved tensile properties make Fe 3 Al-based alloys more competitive against conventional austenic and ferritic steels. The improvement of high temperature mechanical properties has been achieved mainly by alloying processes. Molybdenum has been found to be one of the most important alloying elements for strengthening Fe 3 Al-based alloys at high temperatures. However, the RT(room temperature) ductility decreases with the increase of a molybdenum addition. On the other hand, a chromium addition to Fe 3 Al-based alloys is very efficient for improving RT ductility but not beneficial to yield strength at temperatures to 800 C. The purpose of the present paper is to report the effects of combined additions of molybdenum and chromium on mechanical properties at ambient temperature and high temperature of 600 C

  18. Electron emission from molybdenum under ion bombardment

    International Nuclear Information System (INIS)

    Ferron, J.; Alonso, E.V.; Baragiola, R.A.; Oliva-Florio, A.

    1981-01-01

    Measurements are reported of electron emission yields of clean molybdenum surfaces under bombardment with H + , H 2 + , D + , D 2 + , He + , N + , N 2 + , O + , O 2 + , Ne + , Ar + , Kr + and Xe + in the wide energy range 0.7-60.2 keV. The clean surfaces were produced by inert gas sputtering under ultrahigh vacuum. The results are compared with those predicted by a core-level excitation model. The disagreement found when using correct values for the energy levels of Mo is traced to wrong assumptions in the model. A substantially improved agreement with experiment is obtained using a model in which electron emission results from the excitation of valence electrons from the target by the projectiles and fast recoiling target atoms. (author)

  19. Molybdenum-base cermet fuel development

    International Nuclear Information System (INIS)

    Gurwell, W.E.; Moss, R.W.; Pilger, J.P.; White, G.D.

    1987-07-01

    Development of a multimegawatt (MMW) space nuclear power system requires identification and resolution of several technical feasibility issues before selecting one or more promising system concepts. Demonstration of reactor fuel fabrication technology is required for cermet-fueled reactor concepts. MMW reactor fuel development activity at Pacific Northwest Laboratory (PNL) is focused on producing a molybdenum-matrix uranium-nitride (UN) fueled cermet. This cermet is to have a high matrix density (≥95%) for high strength and high thermal conductance coupled with a high particle (UN) porosity (∼25%) for retention of released fission gas at high burnup. Fabrication process development involves the use of porous TiN microspheres as surrogate fuel material until porous UN microspheres become available. Process development has been conducted in the areas of microsphere synthesis, particle sealing/coating, and high-energy-rate forming (HERF) and vacuum hot press consolidation techniques. This paper summarizes the status of these activities

  20. Dithiolato complexes of molybdenum and tungsten

    International Nuclear Information System (INIS)

    Nieuwpoort, A.

    1975-01-01

    The synthesis of eight-coordinated and six-coordinated tungsten and molybdenum complexes with dithioligands is described. Molecular and crystal structures are determined and bond angles, bond lengths and structural parameters tabulated. Infrared spectra of dithiocarbamato complexes are discussed more extensively. Redox reactions are studied by voltammetry and electron transfer properties derived. Properties of the d electrons of the metal ion are interpreted in the ligand field model with data from electronic and e.s.r. spectra and magnetic susceptibilities. The result of molecular orbital calculations with the extended Hueckel-LCAO method are presented for eight-coordinated d 1 and d 2 systems, the six-coordinated complexes, and the free ligands

  1. Scattering of fast neutrons from elemental molybdenum

    International Nuclear Information System (INIS)

    Smith, A.B.; Guenther, P.T.

    1982-11-01

    Differential broad-resolution neutron-scattering cross sections of elemental molybdenum were measured at 10 to 20 scattering angles distributed between 20 and 160 degrees and at incident-neutron energy intervals of approx. = 50 to 200 keV from 1.5 to 4.0 MeV. Elastically-scattered neutrons were fully resolved from inelastic events. Lumped-level inelastic-neutron-scattering cross sections were determined corresponding to observed excitation energies of; 789 +- 23, 195 +- 23, 1500 +- 34, 1617 +- 12, 1787, 1874, 1991, 2063 +- 24, 2296, 2569 and 2802 keV. An optical-statistical model was deduced from the measured elastic-scattering results. The experimental values were compared with the respective quantities given in ENDF/B-V

  2. Thermal ripples in model molybdenum disulfide monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Remsing, Richard C.; Klein, Michael L. [Institute for Computational Molecular Science, Center for the Computational, Design of Functional Layered Materials, and Department of Chemistry, Temple University, 1925 N. 12th St., 19122, Philadelphia, PA (United States); Waghmare, Umesh V. [Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, 560 064, Jakkur, Bangalore (India)

    2017-01-15

    Molybdenum disulfide (MoS{sub 2}) monolayers have the potential to revolutionize nanotechnology. To reach this potential, it will be necessary to understand the behavior of this two-dimensional (2D) material on large length scales and under thermal conditions. Herein, we use molecular dynamics (MD) simulations to investigate the nature of the rippling induced by thermal fluctuations in monolayers of the 2H and 1T phases of MoS{sub 2}. The 1T phase is found to be more rigid than the 2H phase. Both monolayer phases are predicted to follow long wavelength scaling behavior typical of systems with anharmonic coupling between vibrational modes as predicted by classic theories of membrane-like systems. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Ion adsorption properties of molybdenum (II) bromide

    International Nuclear Information System (INIS)

    Ganzerli-Valentini, M.T.; Meloni, S.; Caramella-Crespi, V.; Borroni, P.A.

    1976-01-01

    The adsorption of about 50 ions on molybdenum dibromide, (Mo 6 Br 8 )Br 4 .2H 2 O in nitric acid was investigated. The behaviour of the investigated elements on MDB in nitric acid, in the concentration range 10 -2 -8M is presented, where the distribution coefficients are given against the HNO 3 molarity. In some cases the elements were investigated in different oxidation states. Most of the elements are not adsorbed or poorly adsorbed, among these the stable anions, thus indicating that bromide ions substitution with other anions is not competitive. The preparation of the adsorber and its characterization is presented and discussed. Adsorption mechanism studies were carried out for some noble metals and chromium. Sorption cannot be ascribed to ion exchange mechanism but to formation of insoluble species, and to settlement of few ions into surface sorption sites or into a limited number of cavitites in the cluster crystal structure of the adsorber. (T.G.)

  4. Radio frequency induction plasma spraying of molybdenum

    International Nuclear Information System (INIS)

    Jiang Xianliang

    2003-01-01

    Radio frequency (RF) induction plasma was used to make free-standing deposition of molybdenum (Mo). The phenomena of particle melting, flattening, and stacking were investigated. The effect of process parameters such as plasma power, chamber pressure, and spray distance on the phenomena mentioned above was studied. Scanning electron microscopy (SEM) was used to analyze the plasma-processed powder, splats formed, and deposits obtained. Experimental results show that less Mo particles are spheroidized when compared to the number of spheroidized tungsten (W) particles at the same powder feed rate under the same plasma spray condition. Molten Mo particles can be sufficiently flattened on substrate. The influence of the process parameters on the flattening behavior is not significant. Mo deposit is not as dense as W deposit, due to the splash and low impact of molten Mo particles. Oxidation of the Mo powder with a large particle size is not evident under the low pressure plasma spray

  5. Microplastic relaxations of single and polycrystalline molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Pichl, W.; Weiss, B. [Wien Univ. (Austria). Inst. fuer Materialphysik; Chen, D.L.

    1998-05-01

    The microplasticity of high-purity molybdenum single crystals and of Mo polycrystals of technical purity has been investigated by relaxation step tests in uniaxial compression. A new model for the evaluation of relaxation tests in the microplastic range of b.c.c metals is presented which takes into account the decrease of the mobile dislocation density due to exhaustion of non-screw dislocations. The model allows an independent determination of the activation volume and of the microstructure parameters controlling dislocation exhaustion. The results indicate that in the high-purity single crystals the deformation rate is controlled by interactions of non-screw dislocations with the grown-in network. In the polycrystals additional interactions with impurity atoms seem to occur. In the single crystals the activity and subsequent exhaustion of two different glide systems was observed, followed by a gradual onset of screw dislocation motion. (orig.) 26 refs.

  6. The molybdenum-technetium solar neutrino experiment

    International Nuclear Information System (INIS)

    Schroeder, N.C.; Wolfsberg, K.; Rokop, D.J.

    1991-01-01

    The authors are attempting to measure the time-averaged 8 B solar-neutrino flux over 10 Myr by measuring 98 Tc produced through the 98 Mo( nu ,e - ) reaction in a deeply buried molybdenum deposit. This will test the prediction of periodic mixing of the Sun's core over long time intervals. To separate technetium from 10,000-ton quantities of Henderson ore, the authors have taken advantage of the commercial processing of molybdenite. Technetium, volatilized during roasting of molybdenite to MoO 3 , was scrubbed from the gas stream and collected on anion exchange columns. After sample reduction and chemical separation and purification they measured technetium, as TcO 4 - , using negative thermal ionization mass spectrometry. Measurement of 99 Tc in spiked and 98 Tc in unspiked fractions from one sample gives an apparent solar neutrino production rate of 95.8 SNU. However, roaster memory probably invalidates this result

  7. Measured oscillator strengths in singly ionized molybdenum

    Science.gov (United States)

    Mayo-García, R.; Aragón, C.; Aguilera, J. A.; Ortiz, M.

    2015-11-01

    In this article, 112 oscillator strengths from Mo II have been measured, 79 of which for the first time. The radiative parameters have been obtained by laser-induced breakdown spectroscopy (LIBS). The plasma is produced from a fused glass sample prepared from molybdenum oxide with a Mo atomic concentration of 0.1%. The plasma evolved in air at atmospheric pressure, and measurements were carried out with the following plasma parameters: an electron density of (2.5+/- 0.1)\\cdot {10}17 cm-3 and an electron temperature of 14,400+/- 200 K. In these conditions, a local thermodynamic equilibrium environment and an optically thin plasma were confirmed for the measurements. The relative intensities were placed on an absolute scale by combining branching fractions with the measured lifetimes and by comparing well-known lines using the plasma temperature. Comparisons were made to previously obtained experimental and theoretical values wherever possible.

  8. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... risk for iron-deficiency anemia, including: Vegetarian or vegan eating patterns. Not eating enough iron-rich foods, ... iron-fortified foods that have iron added. Vegetarian diets can provide enough iron if you choose nonmeat ...

  9. Molybdenum isotope fractionation in the mantle

    Science.gov (United States)

    Liang, Yu-Hsuan; Halliday, Alex N.; Siebert, Chris; Fitton, J. Godfrey; Burton, Kevin W.; Wang, Kuo-Lung; Harvey, Jason

    2017-02-01

    We report double-spike molybdenum (Mo) isotope data for forty-two mafic and fifteen ultramafic rocks from diverse locations and compare these with results for five chondrites. The δ98/95Mo values (normalized to NIST SRM 3134) range from -0.59 ± 0.04 to +0.10 ± 0.08‰. The compositions of one carbonaceous (CI) and four ordinary chondrites are relatively uniform (-0.14 ± 0.01‰, 95% ci (confidence interval)) in excellent agreement with previous data. These values are just resolvable from the mean of 10 mid-ocean ridge basalts (MORBs) (0.00 ± 0.02‰, 95% ci). The compositions of 13 mantle-derived ultramafic xenoliths from Kilbourne Hole, Tariat and Vitim are more diverse (-0.39 to -0.07‰) with a mean of -0.22 ± 0.06‰ (95% ci). On this basis, the isotopic composition of the bulk silicate Earth (BSE or Primitive Mantle) is within error identical to chondrites. The mean Mo concentration of the ultramafic xenoliths (0.19 ± 0.07 ppm, 95% ci) is similar in magnitude to that of MORB (0.48 ± 0.13 ppm, 95% ci), providing evidence, either for a more compatible behaviour than previously thought or for selective Mo enrichment of the subcontinental lithospheric mantle. Intraplate and ocean island basalts (OIBs) display significant isotopic variability within a single locality from MORB-like to strongly negative (-0.59 ± 0.04‰). The most extreme values measured are for nephelinites from the Cameroon Line and Trinidade, which also have anomalously high Ce/Pb and low Mo/Ce relative to normal oceanic basalts. δ98/95Mo correlates negatively with Ce/Pb and U/Pb, and positively with Mo/Ce, explicable if a phase such as an oxide or a sulphide liquid selectively retains isotopically heavy Mo in the mantle and fractionates its isotopic composition in low degree partial melts. If residual phases retain Mo during partial melting, it is possible that the [Mo] for the BSE may be misrepresented by values estimated from basalts. This would be consistent with the high Mo

  10. Molybdenum-UO2 cermet irradiation at 1145 K.

    Science.gov (United States)

    Mcdonald, G.

    1971-01-01

    Two molybdenum-uranium dioxide cermet fuel pins with molybdenum clad were fission-heated in a forced-convection helium coolant for sufficient time to achieve 5.3% burnup. The cermet core contained 20 wt % of 93.2% enriched uranium dioxide. The results were as follows: there was no visible change in the appearance of the molybdenum clad during irradiation; the maximum increase in diameter of the fuel pins was 0.8%; there was no migration of uranium dioxide along grain boundaries and no evident interaction between molybdenum and uranium dioxide; and, finally, approximately 12% of the fission gas formed was released from the cermet core into the gas plenum.

  11. Recovering and recycling uranium used for production of molybdenum-99

    Science.gov (United States)

    Reilly, Sean Douglas; May, Iain; Copping, Roy; Dale, Gregory Edward

    2017-12-12

    A processes for recycling uranium that has been used for the production of molybdenum-99 involves irradiating a solution of uranium suitable for forming fission products including molybdenum-99, conditioning the irradiated solution to one suitable for inducing the formation of crystals of uranyl nitrate hydrates, then forming the crystals and a supernatant and then separating the crystals from the supernatant, thus using the crystals as a source of uranium for recycle. Molybdenum-99 is recovered from the supernatant using an adsorbent such as alumina. Another process involves irradiation of a solid target comprising uranium, forming an acidic solution from the irradiated target suitable for inducing the formation of crystals of uranyl nitrate hydrates, then forming the crystals and a supernatant and then separating the crystals from the supernatant, thus using the crystals as a source of uranium for recycle. Molybdenum-99 is recovered from the supernatant using an adsorbent such as alumina.

  12. Sintering of cermets on the base of corundum and molybdenum

    International Nuclear Information System (INIS)

    Fedotov, A.V.

    1987-01-01

    Liquid-phase sintering of cermets has been studied to develop rational technology allowing to produce a dense material at lower temperatures. Molybdenum of the MPCh mark with the specific surface ranged from 1900 to 4000 cm 2 /g and the corundum powder of the VK-94-1 mark with the specific surface of 6000 cm 2 /g containing upto 10% of the glass-phase have been used as initial materials. It is shown that application of the VK-94-1 ceramics powder for molybdenum content cermets allows to decrease the temperature of dense material production (∼ upto 100 deg C). To produce dense materials, it is necessary to restrict the initial porosity of compaction and to correspond it to the sintering conditions. The increase of molybdenum dispersion allows to produce material with the more homogeneous structure, higher density and strength. Molybdenum presence decreases recrystallization of corundum crystals and causes structure production resistant to high-temperature heating

  13. Physical chemical quality control of the molybdenum technetium generator

    International Nuclear Information System (INIS)

    Olive, E.; Cruz, J.; Isaac, M.; Gamboa, R.; D'Alessandro, K.; Desdin, L.F.

    1995-01-01

    Comparative operational procedure imported molybdenum technetium generators have been made. Procedures for determination of chemical, radiochemical and radionuclidic purities that may be applied in Hospital's laboratories and in the quality control of generators production are developed

  14. Electroplating and stripping copper on molybdenum and niobium

    Science.gov (United States)

    Power, J. L.

    1978-01-01

    Molybdenum and niobium are often electroplated and subsequently stripped of copper. Since general standard plating techniques produce poor quality coatings, general procedures have been optimized and specified to give good results.

  15. Alkaline elution of uranium and molybdenum and their recovery

    International Nuclear Information System (INIS)

    Song Wenlan; Wu Peisheng; Zhao Pinzhi; Tao Dening; Xie Chaoyan

    1987-01-01

    The uranium and molybdenum can be simultaneously eluted by using eluant (NH 4 ) 2 CO 3 + (NH 4 ) 2 SO 4 from resin loaded uranium and molybdenum. The ADU is precipitated from eluant by volatilization of ammonia. The molybdenum is extracted by TFA-TBP-kerosene from the filtrate at pH 3.0-3.2 with molybdenum extraction > 98%. Uranium is nearly not extracted. The precipitation of Mo is reached by sulphuric acid after stripping and the ammonium multimolybdate is obtained. This process can give the total recovery more than 99% for U and 90% for Mo. Because of the use of sulphate salt system, the hazard of NO 3 - can be avoided

  16. Mechanical properties of molybdenum coated with titanium carbide film

    International Nuclear Information System (INIS)

    Shikama, T.; Shinno, H.; Fukutomi, M.; Fujitsuka, M.; Okada, M.

    1983-01-01

    TiC-coated molybdenum is mechanically tensile tested. The 6 μm thick TiC-coated molybdenum has a higher 0.2% proof strength with a slight decrease in uniform and rupture elongation than the uncoated one. This strengthening effect of the TiC coating can be explained by the constrained effect of the high strength TiC film. The 1.2 μm thick TiC-coated molybdenum starts its plastic deformation at a lower stress than the uncoated one. Also, the coating makes the stress-strain curve more smooth. These effects are attributed to the surface effect, namely, that the interface between the molybdenum substrate and the strong and brittle TiC film acts as a strong dislocation source. The compressive stress in the TiC film will also help the start of plastic deformation at lower external stresses. (author)

  17. Change of mechanical properties of molybdenum after chemical heat treatment

    International Nuclear Information System (INIS)

    Skuratov, L.P.; Yatsimirskij, V.K.; Kirillova, N.V.

    1987-01-01

    Gaseous media (argon, ammonia, nitrogen-hydrogen-ammonia mixture) are studied for their effect on mechanical characteristics of molybdenum at temperatures up to 1000 deg C. It is established that the highest hardening occurs when molybdenum is esposed in the nitrogen-hydrogen medium, while the highest lost of strength takes place in the ammonia medium. An increase of the ammonia concentration in nitrogen-hydrogen-ammonia mixture promotes regular increasing of the deformation rate. With ammonia concentration of 33.3% the gaseous mixture acts the same as pure ammonia. Change of physical-and-mechanical properties of molybdenum under the action of nitrogen-containing gaseous media is associated with formation of molybdenum compounds with nitrogen. During nitriding in ammonia an internal (volume) nitriding proceeds while in the medium of nitrogen-hydrogen mixture surface nitride layers form

  18. Dinitrogen binding and cleavage by multinuclear iron complexes.

    Science.gov (United States)

    McWilliams, Sean F; Holland, Patrick L

    2015-07-21

    The iron-molybdenum cofactor of nitrogenase has unprecedented coordination chemistry, including a high-spin iron cluster called the iron-molybdenum cofactor (FeMoco). Thus, understanding the mechanism of nitrogenase challenges coordination chemists to understand the fundamental N2 chemistry of high-spin iron sites. This Account summarizes a series of studies in which we have synthesized a number of new compounds with multiple iron atoms, characterized them using crystallography and spectroscopy, and studied their reactions in detail. These studies show that formally iron(I) and iron(0) complexes with three- and four-coordinate metal atoms have the ability to weaken and break the triple bond of N2. These reactions occur at or below room temperature, indicating that they are kinetically facile. This in turn implies that iron sites in the FeMoco are chemically reasonable locations for N2 binding and reduction. The careful evaluation of these compounds and their reaction pathways has taught important lessons about what characteristics make iron more effective for N2 activation. Cooperation of two iron atoms can lengthen and weaken the N-N bond, while three working together enables iron atoms to completely cleave the N-N bond to nitrides. Alkali metals (typically introduced into the reaction as part of the reducing agent) are thermodynamically useful because the alkali metal cations stabilize highly reduced complexes, pull electron density into the N2 unit, and make reduced nitride products more stable. Alkali metals can also play a kinetic role, because cation-π interactions with the supporting ligands can hold iron atoms near enough to one another to facilitate the cooperation of multiple iron atoms. Many of these principles may also be relevant to the iron-catalyzed Haber-Bosch process, at which collections of iron atoms (often promoted by the addition of alkali metals) break the N-N bond of N2. The results of these studies teach more general lessons as well. They

  19. Metallic molybdenum disulfide nanosheet-based electrochemical actuators

    Science.gov (United States)

    Acerce, Muharrem; Akdoğan, E. Koray; Chhowalla, Manish

    2017-09-01

    Actuators that convert electrical energy to mechanical energy are useful in a wide variety of electromechanical systems and in robotics, with applications such as steerable catheters, adaptive wings for aircraft and drag-reducing wind turbines. Actuation systems can be based on various stimuli, such as heat, solvent adsorption/desorption, or electrochemical action (in systems such as carbon nanotube electrodes, graphite electrodes, polymer electrodes and metals). Here we demonstrate that the dynamic expansion and contraction of electrode films formed by restacking chemically exfoliated nanosheets of two-dimensional metallic molybdenum disulfide (MoS2) on thin plastic substrates can generate substantial mechanical forces. These films are capable of lifting masses that are more than 150 times that of the electrode over several millimetres and for hundreds of cycles. Specifically, the MoS2 films are able to generate mechanical stresses of about 17 megapascals—higher than mammalian muscle (about 0.3 megapascals) and comparable to ceramic piezoelectric actuators (about 40 megapascals)—and strains of about 0.6 per cent, operating at frequencies up to 1 hertz. The actuation performance is attributed to the high electrical conductivity of the metallic 1T phase of MoS2 nanosheets, the elastic modulus of restacked MoS2 layers (2 to 4 gigapascals) and fast proton diffusion between the nanosheets. These results could lead to new electrochemical actuators for high-strain and high-frequency applications.

  20. Hydrotreatment activities of supported molybdenum nitrides and carbides

    Energy Technology Data Exchange (ETDEWEB)

    Dolce, G.M.; Savage, P.E.; Thompson, L.T. [University of Michigan, Ann Arbor, MI (United States). Dept. of Chemical Engineering

    1997-05-01

    The growing need for alternative sources of transportation fuels encourages the development of new hydrotreatment catalysts. These catalysts must be active and more hydrogen efficient than the current commercial hydrotreatment catalysts. Molybdenum nitrides and carbides are attractive candidate materials possessing properties that are comparable or superior to those of commercial sulfide catalysts. This research investigated the catalytic properties of {gamma}-Al{sub 2}O{sub 3}-supported molybdenum nitrides and carbides. These catalysts were synthesized via temperature-programmed reaction of supported molybdenum oxides with ammonia or methane/hydrogen mixtures. Phase constituents and compositions were determined by X-ray diffraction, elemental analysis, and neutral activation analysis. Oxygen chemisorption was used to probe the surface properties of the catalysts. Specific activities of the molybdenum nitrides and carbides were competitive with those of a commercial sulfide catalyst for hydrodenitrogenation (HDN), hydrodesulfurization (HDS), and hydrodeoxygenation (HDO). For HDN and HDS, the catalytic activity on a molybdenum basis was a strong inverse function of the molybdenum loading. Product distributions of the HDN, HDO and HDS of a variety of heteroatom compounds indicated that several of the nitrides and carbides were more hydrogen efficient than the sulfide catalyst. 35 refs., 8 figs., 7 tabs.

  1. IRON DOME

    African Journals Online (AJOL)

    6 Israeli Navy 'First Arm of the Sea: The Successful Interception of the Iron Dome Rocket .... sky to destroy them whilst in flight to minimise civilian casualties. ..... Including The Moon and Celestial Bodies.53 Demeyere further emphasises the.

  2. Iron overdose

    Science.gov (United States)

    ... tracing) X-ray to detect and track iron tablets through the stomach and intestines Treatment may include: ... BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016: ...

  3. A cascade of iron-containing proteins governs the genetic iron starvation response to promote iron uptake and inhibit iron storage in fission yeast.

    Directory of Open Access Journals (Sweden)

    Javier Encinar del Dedo

    2015-03-01

    Full Text Available Iron is an essential cofactor, but it is also toxic at high levels. In Schizosaccharomyces pombe, the sensor glutaredoxin Grx4 guides the activity of the repressors Php4 and Fep1 to mediate a complex transcriptional response to iron deprivation: activation of Php4 and inactivation of Fep1 leads to inhibition of iron usage/storage, and to promotion of iron import, respectively. However, the molecular events ruling the activity of this double-branched pathway remained elusive. We show here that Grx4 incorporates a glutathione-containing iron-sulfur cluster, alone or forming a heterodimer with the BolA-like protein Fra2. Our genetic study demonstrates that Grx4-Fra2, but not Fep1 nor Php4, participates not only in iron starvation signaling but also in iron-related aerobic metabolism. Iron-containing Grx4 binds and inactivates the Php4 repressor; upon iron deprivation, the cluster in Grx4 is probably disassembled, the proteins dissociate, and Php4 accumulates at the nucleus and represses iron consumption genes. Fep1 is also an iron-containing protein, and the tightly bound iron is required for transcriptional repression. Our data suggest that the cluster-containing Grx4-Fra2 heterodimer constitutively binds to Fep1, and upon iron deprivation the disassembly of the iron cluster between Grx4 and Fra2 promotes reverse metal transfer from Fep1 to Grx4-Fra2, and de-repression of iron-import genes. Our genetic and biochemical study demonstrates that the glutaredoxin Grx4 independently governs the Php4 and Fep1 repressors through metal transfer. Whereas iron loss from Grx4 seems to be sufficient to release Php4 and allow its nuclear accumulation, total or partial disassembly of the Grx4-Fra2 cluster actively participates in iron-containing Fep1 activation by sequestering its iron and decreasing its interaction with promoters.

  4. Deactivation of iron oxide used in the steam-iron process to produce hydrogen

    NARCIS (Netherlands)

    Bleeker, M.F.; Veringa, H.J.; Kersten, Sascha R.A.

    2009-01-01

    In the steam-iron process pure hydrogen can be produced from any hydrocarbon feedstock by using a redox cycle of iron oxide. One of the main problems connected to the use of the iron oxide is the inherent structural changes that take place during oxygen loading and unloading leading to severe

  5. Electron accelerator-based production of molybdenum-99: Bremsstrahlung and photoneutron generation from molybdenum vs. tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Tsechanski, A. [Ben-Gurion University of the Negev, Department of Nuclear Engineering, P.O. Box 653, Beer-Sheva 84105 (Israel); Bielajew, A.F. [Department of Nuclear Engineering and Radiological Sciences, The University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Archambault, J.P.; Mainegra-Hing, E. [National Research Council of Canada, Ionizing Radiation Standards Laboratory, Ottawa, ON K1A 0R6 (Canada)

    2016-01-01

    A new “one-stage” approach for production of {sup 99}Mo and other radioisotopes by means of an electron linear accelerator is described. It is based on using a molybdenum target both as a bremsstrahlung converter and as a radioisotope producing target for the production of {sup 99}Mo via the photoneutron reaction {sup 100}Mo(γ,n){sup 99}Mo. Bremsstrahlung characteristics, such as bremsstrahlung efficiency, angular distribution, and energy deposition for molybdenum targets were obtained by means of the EGSnrc Monte Carlo simulation code system. As a result of our simulations, it is concluded that a 60 MeV electron beam incident on a thick Mo target will have greater bremsstrahlung efficiency than the same thickness (in units of r{sub 0}) W target, for target thickness z > 1.84r{sub 0}, where r{sub 0} is the electron range. A 50 MeV electron beam incident on a Mo target will result in greater bremsstrahlung efficiency than the same thickness W target (in units of r{sub 0}) for target thickness case: z ⩾ 2.0r{sub 0}. It is shown for the one-stage approach with thicknesses of (1.84–2.0)r{sub 0}, that the {sup 99}Mo-production bremsstrahlung efficiency of a molybdenum target is greater by ∼100% at 30 MeV and by ∼70% at 60 MeV compared to the values for tungsten of the same thickness (in units of the appropriate r{sub 0}) in the traditional two-stage approach (W converter and separate {sup 99}Mo producing target). This advantage of the one-stage approach arises from the fact that the bremsstrahlung produced is attenuated only once from attenuation in the molybdenum converter/target. In the traditional, two-stage approach, the bremsstrahlung generated in the W-converter/target is attenuated both in the converter in the {sup 99}Mo-producing molybdenum target. The photoneutron production yield of molybdenum and tantalum (as a substitute for tungsten) target was calculated by means of the MCNP5 transport code. On the basis of these data, the specific activity

  6. A new molybdenum trioxide hydrate MoO3.1/3H2O and a new monoclinic form of MoO3

    International Nuclear Information System (INIS)

    Harb, F.; Gerand, B.; Nowogrocki, G.; Figlarz, M.

    1986-01-01

    A new hydrate of molybdenum trioxide MoO 3 .1/3H 2 O has been obtained by hydrothermal treatment at 110 0 C of either aqueous suspensions of MoO 3 .2H 2 O or aqueous molybdic acid solutions. The hydrate crystallizes in the orthorhombic system, lattice parameters are given; a structural model is proposed by comparison with the isostructural WO 3 .1/3H 2 O phase. The dehydration of MoO 3 .1/3H 2 O leads to a new anhydrous molybdenum trioxide, monoclinic, the structure of which is of ReO 3 type [fr

  7. Chalcogenhalide cluster rhenium- and molybdenum complexes

    International Nuclear Information System (INIS)

    Fedin, V.P.; Gubin, S.P.; Mishchenko, A.V.; Fedorov, V.E.

    1984-01-01

    The interaction of rhenium- and molybdenum chalcogenhalides with n-donor ligands (L) is studied. At heating Re 3 X 2 Hal 5 complexes up to 100 deg in DMSO in the L presence obtained are the complexes of the 1-6 composition Re 3 X 2 Hal 5 -x Lx DMSO (X=Se, Hal=Cl, L=Et 3 N(1); X=Se, Hal=Cl, L=Bipy(2); X=Se, Hal=Br, L=Et 3 N(3); X=Se, Hal=Br, L=Bipy(4); X=Te, Hal=Br, L=Et 3 N(5); X=Te, Hal=Br, L=(Me 2 NCH 2 ) 2 (6). In the course of boiling of Mo 3 S 7 Hal 4 with PPh 3 in MeCN the Mo 3 S 7 Hal 4 2PPh 3 complexes (Hal=Cl(7); Br(8)) are obtained. For 1 through 8 complexes the chemical analysis data and IR spectra are given. For 4 and 8 complexes the molecular mass is measured. A possible method of obtaining molecular trinuclear clusters from polymer clusters is discussed

  8. Improved processes of molybdenum-99 production

    International Nuclear Information System (INIS)

    Dadachova, K.; La Riviere, K.; Anderon, P.

    1997-01-01

    Two improved processes of Molybdenum-99 production have been developed at ANSTO on laboratory scale. The first one allows to purify Mo of natural isotopic composition from tungsten impurities by using preferential adsorption of tungsten on hydrated tin(IV) oxide SnO 2 x nH 2 O before irradiation in the nuclear reactor. Mo-99 obtained via this route can be used for production of i nstant Tc-99m. As the starting material MoO 3 contains considerable amounts of tungsten impurity (W > 60 ppm), 5-7 days irradiation results in generation of W-188 in amounts sufficient to contaminate the final Tc-99m product with rhenium-188 (Re-188, 16.8 h half-life) - radioactive daughter of W-188. To overcome this problem, a method of MoO 3 purification from W, based on preferential adsorption of W by hydrated tin (IV) oxide has been developed. The contents of W in MoO 3 purified by this technique became 3 and retaining of Mo-99 on a large alumina column. Mo-99 is stripped off the column with 200 mL 1M NH 4 OH followed by loading this solution onto the AG 1x8 column. The next steps are different for each version of separation process

  9. Combustion of environmentally altered molybdenum trioxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Kevin; Pantoya, Michelle L. [Mechanical Engineering Department, Texas Tech University, 2500 Broadway, Lubbock, TX 79409 (United States)

    2006-06-15

    Nanocomposite thermite mixtures are currently under development for many primer applications due to their high energy densities, high ignition sensitivity, and low release of toxins into the environment. However, variability and inconsistencies in combustion performance have not been sufficiently investigated. Environmental interactions with the reactants are thought to be a contributing factor to these variabilities. Combustion velocity experiments were conducted on aluminum (Al) and molybdenum trioxide (MoO{sub 3}) mixtures to investigate the role of environmental interactions such as light exposure and humidity. While the Al particles were maintained in an ambient, constant environment, the MoO{sub 3} particles were exposed to UV or fluorescent light, and highly humid environments. Results show that UV and fluorescent lighting over a period of days does not significantly contribute to performance deterioration. However, a humid environment severely decreases combustion performance if the oxidizer particles are not heat-treated. Heat treatment of the MoO{sub 3} greatly increases the material's ability to resist water absorption, yielding more repeatable combustion performance. This work further quantifies the role of the environment in the decrease of combustion performance of nanocomposites over time. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  10. Groundwater Molybdenum from Emerging Industries in Taiwan.

    Science.gov (United States)

    Tsai, Kuo-Sheng; Chang, Yu-Min; Kao, Jimmy C M; Lin, Kae-Long

    2016-01-01

    This study determined the influence of emerging industries development on molybdenum (Mo) groundwater contamination. A total of 537 groundwater samples were collected for Mo determination, including 295 samples from potentially contaminated areas of 3 industrial parks in Taiwan and 242 samples from non-potentially contaminated areas during 2008-2014. Most of the high Mo samples are located downstream from a thin film transistor-liquid crystal display (TFT-LCD) panel factory. Mean groundwater Mo concentrations from potentially contaminated areas (0.0058 mg/L) were significantly higher (p industry and following wastewater batch treatment were 0.788 and 0.0326 mg/L, respectively. This indicates that wastewater containing Mo is a possible source of both groundwater and surface water contamination. Nine samples of groundwater exceed the World Health Organization's suggested drinking water guideline of 0.07 mg/L. A non-carcinogenic risk assessment for Mo in adults and children using the Mo concentration of 0.07 mg/L yielded risks of 0.546 and 0.215, respectively. These results indicate the importance of the development of a national drinking water quality standard for Mo in Taiwan to ensure safe groundwater for use. According to the human health risk calculation, the groundwater Mo standard is suggested as 0.07 mg/L. Reduction the discharge of Mo-contaminated wastewater from factories in the industrial parks is also the important task in the future.

  11. Raman Signatures of Polytypism in Molybdenum Disulfide.

    Science.gov (United States)

    Lee, Jae-Ung; Kim, Kangwon; Han, Songhee; Ryu, Gyeong Hee; Lee, Zonghoon; Cheong, Hyeonsik

    2016-02-23

    Since the stacking order sensitively affects various physical properties of layered materials, accurate determination of the stacking order is important for studying the basic properties of these materials as well as for device applications. Because 2H-molybdenum disulfide (MoS2) is most common in nature, most studies so far have focused on 2H-MoS2. However, we found that the 2H, 3R, and mixed stacking sequences exist in few-layer MoS2 exfoliated from natural molybdenite crystals. The crystal structures are confirmed by HR-TEM measurements. The Raman signatures of different polytypes are investigated by using three different excitation energies that are nonresonant and resonant with A and C excitons, respectively. The low-frequency breathing and shear modes show distinct differences for each polytype, whereas the high-frequency intralayer modes show little difference. For resonant excitations at 1.96 and 2.81 eV, distinct features are observed that enable determination of the stacking order.

  12. Molybdenum disilicide composites produced by plasma spraying

    International Nuclear Information System (INIS)

    Castro, R.G.; Hollis, K.J.; Kung, H.H.; Bartlett, A.H.

    1998-01-01

    The intermetallic compound, molybdenum disilicide (MoSi 2 ) is being considered for high temperature structural applications because of its high melting point and superior oxidation resistance at elevated temperatures. The lack of high temperature strength, creep resistance and low temperature ductility has hindered its progress for structural applications. Plasma spraying of coatings and structural components of MoSi 2 -based composites offers an exciting processing alternative to conventional powder processing methods due to superior flexibility and the ability to tailor properties. Laminate, discontinuous and in situ reinforced composites have been produced with secondary reinforcements of Ta, Al 2 O 3 , SiC, Si 3 N 4 and Mo 5 Si 3 . Laminate composites, in particular, have been shown to improve the damage tolerance of MoSi 2 during high temperature melting operations. A review of research which as been performed at Los Alamos National Laboratory on plasma spraying of MoSi 2 -based composites to improve low temperature fracture toughness, thermal shock resistance, high temperature strength and creep resistance will be discussed

  13. The Role of Oxygen in the Evolution of Molybdenum Nitrogenase

    Science.gov (United States)

    Peters, J.; Boyd, E. S.; Hamilton, T. L.

    2012-12-01

    Since early in Earth's history, the supply of nitrogen (N) into the biosphere has been controlled by the activity of nitrogenase, an oxygen sensitive enzyme that catalyzes the reduction of dinitrogen gas (N2) to bioavailable ammonia. The most common form of nitrogenase harbors a complex molybdenum (Mo) cofactor at its active site [Mo-nitrogenase (Nif)], although other phylogenetically related (alternative) forms of nitrogenase that differ in their active-site metal composition also likely contribute NH3 in environments that are limiting in Mo. The solubility of Mo is significantly influenced by redox and this fact has been used to argue that that the iron (Fe)-dependent nitrogenase (Anf) was predominant prior to ~ 2.5 Ga because oceans were depleted in Mo and rich in Fe. This hypothesis, however, is inconsistent with recent phylogenetic data which strongly suggest that Anf is derived from Nif. Here, we examine the evolutionary history of the Nif enzyme complex in reference to the physiological, biochemical, and morphological strategies for reducing damage by molecular oxygen. A total of 189 nif operons were characterized and quantitatively mapped on a NifHDK concatenated phylogenetic tree. An overlay of the primary mode of metabolism, as defined as either anaerobic (AN) or aerobic/facultative aerobic (AFA), on the NifHDK tree indicates that Nif originated in an anoxic environment and was first acquired in an AFA lineage within the actinobacteria. The complexity of nif operons increased during the evolutionary history of Nif, with a pronounced increase observed during the transition from AN to AFA modes of metabolism. This increase in operon complexity is accompanied by a number of gene loss (nifI1 and nifI2) and gene acquisition (nifW, nifT, nifZ, nifQ) events, with variation in the overall composition of nif operons attributable to adaptations that mediated the toxicity of O2. Collectively, these results underscore the role of O2 in shaping the evolutionary

  14. Adsorption of heavy metal ions on molybdenum and molybdenum trioxide from dilute aqueous solution

    International Nuclear Information System (INIS)

    Utsunomiya, Taizo; Hoshino, Yoshio; Sakabe, Ken-ichi

    1984-01-01

    The adsorption of heavy metal ions such as Co(II), Cu(II) and Pb(II) on molybdenum powder has been investigated by the batch technique as a function of soaking time, concentration of heavy metal ions and coexisting salts, pH etc. Molybdenum trioxide was also used as an adsorbent for a comparison to discuss the adsorption mechanism. The amount of these heavy metal ions adsorbed was highly pH and coexisting salts dependent. These adsorbents have features of selective adsorption for Pb(II) and large adsorption rate. The adsorption of heavy metal ions on these adsorbents proceeds independently or concurrently by following complex mechanism; (1) cation exchange reaction by hydroxyl radical on the surface of Mo and MoO 3 is predominant for most of heavy metal ions except Pb(II) [Co(II), Mn(II), Fe(III), Ni(II), Zn(II), Cd(II) and Sr(II)], (2) reduction (electron exchange reaction) to low ionic or metallic state after cation exchange reaction [Cu(II) and Ag(I) on Mo] and (3) formation of a compound [Pb(II) on both Mo and MoO 3 ]. (author)

  15. Uranium and Molybdenum extraction from a Cerro Solo deposit ore

    International Nuclear Information System (INIS)

    Becquart, Elena T.; Arias, Maria J.; Fuente, Juan C. de la; Misischia, Yamila A.; Santa Cruz, Daniel E.; Tomellini, Guido C.

    2009-01-01

    Cerro Solo, located in Chubut, Argentina, is a sandstone type uranium-molybdenum deposit. Good recovery of both elements can be achieved by acid leaching of the ore but the presence of molybdenum in pregnant liquors is an inconvenient to uranium separation and purification. A two steps process is developed. A selective alkaline leaching of the ore with sodium hydroxide allows separating and recovering of molybdenum and after solid-liquid separation, the ore is acid leached to recover uranium. Several samples averaging 0,2% uranium and 0,1% molybdenum with variable U/Mo ratio have been used and in both steps, leaching and oxidant reagents concentration, temperature and residence time in a stirred tank leaching have been studied. In alkaline leaching molybdenum recoveries greater than 96% are achieved, with 1% uranium extraction. In acid leaching up to 93% of the uranium is extracted and Mo/U ratio in solvent extraction feed is between 0,013 and 0,025. (author)

  16. Reduction and immobilization of molybdenum by Desulfovibrio desulfuricans

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, M.D.; Barton, L.L.; Thomson, B.M. [Sandia National Laboratories, Albuquerque, NM (United States)

    1997-07-01

    Molybdenum contamination of groundwater occurs through activities such as molybdenum and copper mining and processing, shale oil production and power generation from coal-fired power plants. The mobility of Mo in the environment is strongly dependent on its chemical oxidation state. Under oxidizing conditions, Mo occurs as highly soluble and mobile Mo(VI) and Mo(V) compounds. However, under reducing conditions Mo usually forms insoluble Mo(IV) phases. The objective of this study was to demonstrate the ability of the sulfate-reducing bacterium, Desulfovibrio desulfuricans, to reduce Mo(IV) to Mo(IV) in anaerobic environments. Molybdenum-VI was reduced to Mo(IV) by washed cells of D. desulfuricans suspended in bicarbonate buffer solution with either lactate or H{sub 2} as the electron donor and Mo(VI) as the electron acceptor. Molybdenum-VIi reduction by D. desulfuricans in the presence of sulfide resulted in the extracelluar precipitation of the mineral molybdenite. Molybdenum-VI reduction did not occur in the absence of an electron donor or in the presence of heat-killed cells of D. desulfuricans. The results indicate that enzymatic reduction of Mo(VI) by sulfate-reducing bacteria may contribute to the accumulation of Mo(IV) in anaerobic environments and that there organisms may be useful for removing soluble Mo from contaminated water. 20 refs., 6 figs., 4 tabs.

  17. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... iron-rich foods, especially during certain stages of life when more iron is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and iron- ...

  18. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... that are good sources of iron include dried beans, dried fruits, eggs, lean red meat, salmon, iron- ... of iron, including iron-fortified breads and cereals, beans, tofu, dried fruits, and spinach and other dark ...

  19. Iron in diet

    Science.gov (United States)

    ... Reasonable amounts of iron are also found in lamb, pork, and shellfish. Iron from vegetables, fruits, grains, ... strawberries, tomatoes, and potatoes) also increase iron absorption. Cooking foods in a cast-iron skillet can also ...

  20. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... from developing iron-deficiency anemia. Foods that are good sources of iron include dried beans, dried fruits, ... iron is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and ...

  1. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... you are diagnosed with iron-deficiency anemia. Risk Factors You may have an increased risk for iron- ... iron-deficiency anemia if you have certain risk factors , including pregnancy. To prevent iron-deficiency anemia, your ...

  2. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... for your body to absorb iron from the gastrointestinal tract (GI tract). Blood loss When you lose blood, ... iron deficiency. Endurance athletes lose iron through their gastrointestinal tracts. They also lose iron through the breakdown of ...

  3. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... iron in your body is low. For this reason, other iron tests are also done. Ferritin measure ... iron is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and ...

  4. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... to moderate iron-deficiency anemia, or red blood cell transfusion for severe iron-deficiency anemia. You may ... body needs iron to make healthy red blood cells. Iron-deficiency anemia usually develops over time because ...

  5. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... enough iron-rich foods, such as meat and fish, may result in you getting less than the ... pregnancy. Good sources of iron are meat, poultry, fish, and iron-fortified foods that have iron added. ...

  6. Iron Dextran Injection

    Science.gov (United States)

    Iron dextran injection is used to treat iron-deficiency anemia (a lower than normal number of red blood cells ... treated with iron supplements taken by mouth. Iron dextran injection is in a class of medications called ...

  7. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... and severity. Treatments may include iron supplements, procedures, surgery, and dietary ... iron supplements, also called iron pills or oral iron, by mouth once or several times a ...

  8. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... developing iron-deficiency anemia. Foods that are good sources of iron include dried beans, dried fruits, eggs, ... is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and iron- ...

  9. Iron deficiency

    DEFF Research Database (Denmark)

    Schou, Morten; Bosselmann, Helle; Gaborit, Freja

    2015-01-01

    BACKGROUND: Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked. OBJECTIVES.......043). CONCLUSION: ID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF...

  10. Potentiometric titration of molybdenum (6) with a cathode-polarized solid electrode

    International Nuclear Information System (INIS)

    Boeva, L.V.; Kimstach, V.A.; Bagdasarov, K.N.

    1980-01-01

    The possibility has been studied of using solid electrodes for potentiometric precipitation titration of molybdenum (6). A cathode-polarized electrode, electrochemically covered with a molybdenum blue layer, can be used as indicator electrode. The best results were obtained during deposition of molybdenum blue on a tungsten electrode. The mechanism of electrode work during titration has been investigated. A procedure has been developed of titration of molybdenum (6) in acid solutions using hydroxylamine N-aryl derivatives as titrants

  11. Molybdenum Cycling During Crust Formation and Destruction

    Science.gov (United States)

    Greaney, A. T.; Rudnick, R. L.

    2016-12-01

    Molybdenum geochemistry has become an important tool for tracking the redox state of the early atmosphere and oceans as well as the emergence and sustainability of Mo-cofactored enzymes. However, in order for Mo to be enriched in the oceans, it must first be weathered out of the crust. Sulfides that weather in the presence of atmospheric O2have historically been deemed the predominant crustal source of Mo. Here, we test this assumption by determining the mineralogical hosts of Mo in Archean, Proterozoic, and Phanerozoic upper crustal rocks, using LA-ICP-MS. We also investigate Mo behavior during igneous differentiation and continental crust formation. We find that molybdenite, MoS2, is a weatherable sulfide source of Mo, but common igneous sulfides are not because their Mo concentrations are too low. However, molybdenite is uncommon in the upper continental crust. By contrast, volcanic glass is much more abundant and is a significant weatherable source of Mo that readily breaks down to release oxidized, soluble Mo whether or not atmospheric O2is present. Other common crustal mineral hosts of Mo are Ti-bearing phases like titanite, ilmenite, magnetite, and rutile that are resistant to weathering. Significant Mo depletion (relative to Ce and Pr) is observed in nearly every granitic rock analyzed in our study, but is not observed in OIB or MORB (Jenner and O'Neill, 2012). There are two possible reasons for this: 1) Mo is removed from cooling plutons during fluid expulsion, or 2) Mo is fractionated during igneous differentiation. The first scenario is a likely explanation given the solubility of oxidized Mo. However, correlations between Mo/Ce and Nb/La in several plutonic suites suggest a fractionating phase like rutile may sequester Mo in the lower crust. Additionally, a correlation between Mo/Ce and inferred tectonic setting (enrichments observed in rift-related plutons) suggest an overall tectonic influence on the availability of Mo in the upper crust.

  12. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Research Home / < Back To Health Topics / Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency ... iron-deficiency anemia. Blood tests to screen for iron-deficiency anemia To screen for iron-deficiency anemia, your doctor ...

  13. Study of defects near molybdenum surface using thermal desorption spectrometer

    International Nuclear Information System (INIS)

    Naik, P.K.

    1980-01-01

    Thermal desorption spectrometry is utilized to study the migration of atoms and defects near molybdenum surface. The thermal desorption spectra of inert gas ions (neon, argon and krypton) injected with various energies (430-1950 eV) into a polycrystalline molybdenum target with various dosages (6.4 x 10sup(12) - 3.9 x 10sup(14) ions/cmsup(2)) are investigated. Four different states of binding of the trapped atoms corresponding to the activation energies for desorption have been revealed from the spectra. The activation energies are found to be relatively insensitive to the species of the bombarding ion, incident ion energy and the dosage. The patterns of the spectra are strongly influenced by the mean projected range of the ions into the solid. The activation energies deduced are in good agreement with those reported for the migration of atoms and defects in molybdenum. (auth.)

  14. Targets for the production of neutron activated molybdenum-99

    International Nuclear Information System (INIS)

    Hetherington, E.L.R.; Boyd, R.E.

    1999-01-01

    Neutron activation of natural molybdenum is, ostensibly, the least complex route to 99m Tc. However in most commercial generators the severe limitation in 99 Mo specific activity that the route imposes has caused manufacturers to choose the alternative fission process despite its disadvantages of being more expensive and requiring a more complex waste management strategy. The development of a newer generator technology is capable of reviving the demand for neutron activated 99 Mo and might encourage the production of 99m Tc by countries possessing less developed nuclear infrastructures. The targets used in the (n,γ) production route consist of analytical grade molybdenum trioxide which has been further refined to remove both rhenium and tungsten trace impurities. The basic methods used by ANSTO to produce a molybdenum target capable of yielding 99m Tc of high radionuclidic purity are described. (author)

  15. Microstructures define melting of molybdenum at high pressures

    Science.gov (United States)

    Hrubiak, Rostislav; Meng, Yue; Shen, Guoyin

    2017-03-01

    High-pressure melting anchors the phase diagram of a material, revealing the effect of pressure on the breakdown of the ordering of atoms in the solid. An important case is molybdenum, which has long been speculated to undergo an exceptionally steep increase in melting temperature when compressed. On the other hand, previous experiments showed nearly constant melting temperature as a function of pressure, in large discrepancy with theoretical expectations. Here we report a high-slope melting curve in molybdenum by synchrotron X-ray diffraction analysis of crystalline microstructures, generated by heating and subsequently rapidly quenching samples in a laser-heated diamond anvil cell. Distinct microstructural changes, observed at pressures up to 130 gigapascals, appear exclusively after melting, thus offering a reliable melting criterion. In addition, our study reveals a previously unsuspected transition in molybdenum at high pressure and high temperature, which yields highly textured body-centred cubic nanograins above a transition temperature.

  16. Molybdenum erosion measurements in Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    Wampler, W.R. [Sandia National Labs., Albuquerque, NM (United States); LaBombard, B.; Lipshultz, B.; Pappas, D.; Pitcher, C.S. [Massachusetts Inst. of Tech., Cambridge, MA (United States); McCracken, G.M. [JET Joint Undertaking, Abingdon (United Kingdom)

    1998-05-01

    Erosion of molybdenum was measured on a set of 21 tiles after a run campaign of 1,090 shots in the Alcator C-Mod tokamak. The net erosion of molybdenum, was determined from changes in the depth of a thin chromium marker layer measured by Rutherford backscattering. Net Mo erosion was found to be approximately 150 nm near the outer divertor strike point, and much less everywhere else. Gross erosion rates by sputtering were estimated using ion energies and fluxes obtained from Langmuir probe measurements of edge-plasma conditions. Predicted net erosion using calculated gross erosion with prompt redeposition and measured net erosion agree within a factor of 3. Sputtering by boron and molybdenum impurities dominates erosion.

  17. A molybdenum disulfide/carbon nanotube heterogeneous complementary inverter.

    Science.gov (United States)

    Huang, Jun; Somu, Sivasubramanian; Busnaina, Ahmed

    2012-08-24

    We report a simple, bottom-up/top-down approach for integrating drastically different nanoscale building blocks to form a heterogeneous complementary inverter circuit based on layered molybdenum disulfide and carbon nanotube (CNT) bundles. The fabricated CNT/MoS(2) inverter is composed of n-type molybdenum disulfide (MOS(2)) and p-type CNT transistors, with a high voltage gain of 1.3. The CNT channels are fabricated using directed assembly while the layered molybdenum disulfide channels are fabricated by mechanical exfoliation. This bottom-up fabrication approach for integrating various nanoscale elements with unique characteristics provides an alternative cost-effective methodology to complementary metal-oxide-semiconductors, laying the foundation for the realization of high performance logic circuits.

  18. Effect of thermal treatment conditions on properties of vanadium molybdenum oxide catalyst in acrolein oxidation reaction to acrylic acid

    International Nuclear Information System (INIS)

    Gorshkova, T.P.; Tarasova, D.V.; Olen'kova, I.P.; Andrushkevich, T.V.; Nikoro, T.A.

    1984-01-01

    The effect of thermal treatment conditions (temperature and gas medium) on properties of vanadium molybdenum oxide catalyst in acrolein oxidation reaction to acrylic acid is investigated. It is shown that active and selective catalysts are formed in the course of thermal decomposition of the drying product of ammonium metavanadate and paramolybdate under the conditions ensuring the vanadium ion reduction up to tetravalent state with conservation of molybdenum oxidation degree equal to 6. It is possible to realize it either by treatment of the catalyst calcinated in the air flow at 300 deg by the reaction mixture at the activation stage or by gas-reducer flow treatment at 280 deg. Thermal treatment in the reducing medium of the oxidized catalyst does not lead to complete regeneration of its properties

  19. Experiment on bio-leaching of associated molybdenum and uranium ore

    International Nuclear Information System (INIS)

    Zheng Ying; Fan Baotuan; Liu Jian; Meng Yunsheng; Liu Chao

    2007-01-01

    Column leaching experiment results on associated molybdenum uranium ore by bacteria (T. f) are introduced. The ore are leached for 210 days using bacteria domesticated to tolerate molybdenum, the leaching of uranium is of 98% and leaching of molybdenum is of 41%. Sulphuric acid produced by bio-oxidation of sulfides in ore can meet the demand of ore leaching. (authors)

  20. Iron monoxide photodissociation

    Science.gov (United States)

    Chestakov, D. A.; Parker, D. H.; Baklanov, A. V.

    2005-02-01

    The photodissociation of Fe56O was studied by means of the velocity map imaging technique. A molecular beam of iron atoms and iron monoxide molecules was created using an electrical discharge with an iron electrode in a supersonic expansion of molecular oxygen. The ground state iron atom Fe(D45) and FeO concentrations in the molecular beam have been estimated. The dissociation energy of the FeO XΔ5 ground electronic state was found to be D00(FeO )=4.18±0.01eV. The effective absorption cross section of FeO at 252.39nm (vac), leading to the Fe(D45)+O(P3) dissociation channel, is ˜1.2×10-18cm2. A (1+1) resonantly enhanced multiphoton ionization spectrum of Fe56O in the region 39550-39580 cm-1 with rotational structure has been observed, but not assigned. Angular distributions of Fe(D45) and Fe(D35) products for the channel FeO →Fe(D4,35)+O(P3) have been measured at several points in the 210-260nm laser light wavelength region. The anisotropy parameter varies strongly with wavelength for both channels.

  1. Spectrophotometric determination of molybdenum(VI) with sodium 2-bromo-4, 5-dihydroxyazobenzene-4'-sulfonate in the presence of cetyltrimethylammonium chloride

    International Nuclear Information System (INIS)

    Wakamatsu, Yoshinobu

    1977-01-01

    Sodium 2-bromo-4,5-dihydroxyazobenzene-4'-sulfonate (abbreviated as BDAS) reacts with molybdenum(VI) in the presence of excessive cetyltrimethylammonium chloride(CTMAC) to form a water-soluble ternary complex. The combining ratio of molybdenum(VI) and BDAS in the ternary complex was shown to be 1 : 2. The ternary complex having its absorption maximum at 525 nm is quantitatively formed between pH 1.0 and 2.0. A constant absorbance was obtained when the concentrations of BDAS and CTMAC were more than 1.8 x 10 -4 M and (1.2 -- 1.6) x 10 -3 M, respectively. The procedure for the determination of molybdenum(VI) is as follows: Transfer the sample solution containing up to 28 μg of molybdenum(VI) to a 25 ml volumetric flask. Add 3 ml of 2.0 x 10 -3 M BDAS solution and an appropriate amount of a masking agent such as ascorbic acid, EDTA or sodium fluoride. Adjust the pH to about 1.6 with hydrochloric acid and sodium acetate. Add 3.5 ml of 0.01 M CTMAC solution and dilute the solution to the mark with water. Measure the absorbance at 525 nm against the reagent blank. A linear calibration curve was obtained over the concentration range 0 -- 28 μg of molybdenum(VI). The apparent molar absorptivity is 6.1 x 10 4 l cm -1 mol -1 at 525 nm, and the sensitivity of the reaction is 1.5 x 10 -3 μg cm -2 . The interference from metal ions such as iron(III), titanium(IV), zirconium(IV) and vanadium(V) could be eliminated by the addition of ascorbic acid, EDTA, sodium fluoride, or a mixture of these reagents. Tungsten(VI), however, interfered with the determination of molybdenum(VI) even when present at microgram levels. The present method was applied to the determination of molybdenum in three standard steel samples. Analytical results were satisfactory. (auth.)

  2. Iron and iron derived radicals

    International Nuclear Information System (INIS)

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fast! Think small! In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab

  3. Composite sheet made of molybdenum and dispersion-strengthened copper

    International Nuclear Information System (INIS)

    Nicholson, R.D.; Fusco, R.S.

    1990-01-01

    This patent describes a roll-bonded composite sheet product having at least one layer of dispersion-strengthened copper and at least one layer of molybdenum. The composite is characterized by a sharply defined, cleavage-resistant interface between the copper and the molybdenum with substantially no detectable diffusion of one metal into the other across the interface. The composite is resistant to delamination and being capable of maintaining structural integrity upon repeated high temperature firings at temperatures up to 900 degrees C

  4. Recovery of uranium from sulphate solutions containing molybdenum

    International Nuclear Information System (INIS)

    Weir, D.R.; Genik-Sas-Berezowsky, R.M.

    1983-01-01

    A process for recovering uranium from a sulphate solution containing dissolved uranium and molybdenum includes reacting the solution with ammonia (pH 8 to 10), the pH of the original solution must not exceed 5.5 and after the addition of ammonia the pH must not be in the vicinity of 7 for a significant time. The resultant uranium precipitate is relatively uncontaminated by molybdenum. The precipitate is then separated from the remaining solution while the pH is maintained within the stated range

  5. Electrochemistry and biochemistry of molybdenum. Ehlektrokhimiya i biokhimiya molibdena

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhov, A M; Zajtsev, P M; Mambetkaziev, E A; Zhdanov, S I

    1992-07-01

    Using the review of data on polarographic behaviour of double and ternary systems molybdenum(6)-oxidant-organic ligand (oxy- and aminoacids of protein composition) by way of example, the possibility to use the metal ferments for the study of peculiarities in behaviour of the metal ions manifested in reactions was considered. The content of molybdenum in organism is noticeably different for healthy people and patients with malignant neoplasms and diabetes mellitus. There is a certain relation between catalytic activity of the metal ions and multiplicity of their accumulation in human organism.

  6. Nitrogen incorporation in sputter deposited molybdenum nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Stöber, Laura, E-mail: laura.stoeber@tuwien.ac.at; Patocka, Florian, E-mail: florian.patocka@tuwien.ac.at; Schneider, Michael, E-mail: michael.schneider@tuwien.ac.at; Schmid, Ulrich, E-mail: ulrich.e366.schmid@tuwien.ac.at [Institute of Sensor and Actuator Systems, TU Wien, Gußhausstraße 27-29, A-1040 Vienna (Austria); Konrath, Jens Peter, E-mail: jenspeter.konrath@infineon.com; Haberl, Verena, E-mail: verena.haberl@infineon.com [Infineon Technologies Austria AG, Siemensstraße 2, 9500 Villach (Austria)

    2016-03-15

    In this paper, the authors report on the high temperature performance of sputter deposited molybdenum (Mo) and molybdenum nitride (Mo{sub 2}N) thin films. Various argon and nitrogen gas compositions are applied for thin film synthetization, and the amount of nitrogen incorporation is determined by Auger measurements. Furthermore, effusion measurements identifying the binding conditions of the nitrogen in the thin film are performed up to 1000 °C. These results are in excellent agreement with film stress and scanning electron microscope analyses, both indicating stable film properties up to annealing temperatures of 500 °C.

  7. A review of chromium, molybdenum, and tungsten alloys

    International Nuclear Information System (INIS)

    Klopp, W.D.

    1975-01-01

    The mechanical properties of chromium, molybdenum, and tungsten alloys are reviewed, with particular emphasis on high-temperature strength and low-temperature ductility. Precipitate strengthening is highly effective at 0.4-0.8 Tsub(m) in these metals, with HfC being most effective in tungsten and molybdenum, and Ta(B,C) most effective in chromium. Low-temperature ductility can be improved by alloying to promote rhenium ductilizing or solution softening. The low-temperature mechanical properties of these alloys appear related to electronic interactions rather than to the usual metallurgical considerations. (Auth.)

  8. Selective emission multilayer coatings for a molybdenum thermophotovoltaic radiator

    Science.gov (United States)

    Cockeram, Brian Vern

    2004-01-27

    Multilayer coating designs have been developed to provide selective emission for a molybdenum thermophotovoltaic (TPV) radiator surface. These coatings increase the surface emissivity of a molybdenum TPV radiator substrate in the wavelength range that matches the bandgap of the TPV cells to increase the power density of the TPV system. Radiator emission at wavelengths greater than the bandgap energy of the TPV cells is greatly reduced through the use of these coatings, which significantly increases the efficiency of the TPV system. The use of this coating greatly improves the performance of a TPV system, and the coating can be tailored to match the bandgap of any practical TPV system.

  9. LEADING WITH LEADING INDICATORS

    International Nuclear Information System (INIS)

    PREVETTE, S.S.

    2005-01-01

    This paper documents Fluor Hanford's use of Leading Indicators, management leadership, and statistical methodology in order to improve safe performance of work. By applying these methods, Fluor Hanford achieved a significant reduction in injury rates in 2003 and 2004, and the improvement continues today. The integration of data, leadership, and teamwork pays off with improved safety performance and credibility with the customer. The use of Statistical Process Control, Pareto Charts, and Systems Thinking and their effect on management decisions and employee involvement are discussed. Included are practical examples of choosing leading indicators. A statistically based color coded dashboard presentation system methodology is provided. These tools, management theories and methods, coupled with involved leadership and employee efforts, directly led to significant improvements in worker safety and health, and environmental protection and restoration at one of the nation's largest nuclear cleanup sites

  10. Preparation and characterization of molybdenum disilicide coating on molybdenum substrate by air plasma spraying

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yi [Key Laboratory of Ministry of Education for Non-ferrous Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Central South University, Changsha 410083 (China); School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Wang, Dezhi, E-mail: dzwang68@163.com [Key Laboratory of Ministry of Education for Non-ferrous Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Central South University, Changsha 410083 (China); School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Yan, Jianhui [Advanced Materials Synthesis and Application Technology Laboratory, Hunan University of Science and Technology, Xiangtan 411201 (China); Sun, Aokui [Key Laboratory of Ministry of Education for Non-ferrous Materials Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals, Central South University, Changsha 410083 (China); School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

    2013-11-01

    MoSi{sub 2} oxidation protective coatings on molybdenum substrate were prepared by air plasma spraying technique (APS). Microstructure, phase composition, porosity, microhardness and bonding strength of the coatings were investigated and determined. Oxidation behavior of the coating at high temperature was also examined. Results show that composition of the coatings is constituted with MoSi{sub 2} and Mo{sub 5}Si{sub 3}, the surface morphology is described as flattened lamellar features, insufficiently flattened protuberance with some degree of surface roughness, a certain quantity of spherical particles, microcracks and pores. Testing results reveal that microhardness and bonding strength of the coatings increase, and porosity decreases with increasing power or decreasing Ar gas flow rate. Moreover, with decreasing the porosity, the microhardness of the coatings increases. The bonding strength of the coatings also increases with increasing spray distance. The MoSi{sub 2} coated Mo substrate exhibited a good oxidation resistance at 1200 °C.

  11. Preparation and characterization of molybdenum disilicide coating on molybdenum substrate by air plasma spraying

    International Nuclear Information System (INIS)

    Wang, Yi; Wang, Dezhi; Yan, Jianhui; Sun, Aokui

    2013-01-01

    MoSi 2 oxidation protective coatings on molybdenum substrate were prepared by air plasma spraying technique (APS). Microstructure, phase composition, porosity, microhardness and bonding strength of the coatings were investigated and determined. Oxidation behavior of the coating at high temperature was also examined. Results show that composition of the coatings is constituted with MoSi 2 and Mo 5 Si 3 , the surface morphology is described as flattened lamellar features, insufficiently flattened protuberance with some degree of surface roughness, a certain quantity of spherical particles, microcracks and pores. Testing results reveal that microhardness and bonding strength of the coatings increase, and porosity decreases with increasing power or decreasing Ar gas flow rate. Moreover, with decreasing the porosity, the microhardness of the coatings increases. The bonding strength of the coatings also increases with increasing spray distance. The MoSi 2 coated Mo substrate exhibited a good oxidation resistance at 1200 °C.

  12. Catalytic hydrotreatment of Illinois No. 6 coal-derived naphtha: comparison of molybdenum nitride and molybdenum sulfide for heteroatom removal

    Energy Technology Data Exchange (ETDEWEB)

    Raje, A.; Liaw, S.J.; Chary, K.V.R.; Davis, B.H. [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

    1995-03-16

    The hydrotreatment of naphtha derived from Illinois No. 6 coal was investigated using molybdenum sulfide and nitride catalysts. The two catalysts are compared on the basis of total catalyst weight. Molybdenum sulfide is more active than molybdenum nitride for hydrodesulfurization (HDS) of a coal-derived naphtha. The rate of hydrodeoxygenation (HDO) of the naphtha over both catalysts are comparable. For hydrodenitrogenation (HDN), the sulfide is more active than the nitride only at higher temperatures ({gt}325{degree}C). Based upon conversion data, the naphtha can be lumped into a reactive and a less reactive fraction with each following first-order kinetics for heteroatom removal. The HDS and HDN rates and activation energies of the less reactive lump are smaller for the nitride than for the sulfide catalyst.

  13. Cleavage and formation of molecular dinitrogen in a single system assisted by molybdenum complexes bearing ferrocenyldiphosphine.

    Science.gov (United States)

    Miyazaki, Takamasa; Tanaka, Hiromasa; Tanabe, Yoshiaki; Yuki, Masahiro; Nakajima, Kazunari; Yoshizawa, Kazunari; Nishibayashi, Yoshiaki

    2014-10-20

    The N≡N bond of molecular dinitrogen bridging two molybdenum atoms in the pentamethylcyclopentadienyl molybdenum complexes that bear ferrocenyldiphosphine as an auxiliary ligand is homolytically cleaved under visible light irradiation at room temperature to afford two molar molybdenum nitride complexes. Conversely, the bridging molecular dinitrogen is reformed by the oxidation of the molybdenum nitride complex at room temperature. This result provides a successful example of the cleavage and formation of molecular dinitrogen induced by a pair of two different external stimuli using a single system assisted by molybdenum complexes bearing ferrocenyldiphosphine under ambient conditions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Iron and stony-iron meteorites

    DEFF Research Database (Denmark)

    Ruzicka, Alex M.; Haack, Henning; Chabot, Nancy L.

    2017-01-01

    By far most of the melted and differentiated planetesimals that have been sampled as meteorites are metal-rich iron meteorites or stony iron meteorites. The parent asteroids of these meteorites accreted early and differentiated shortly after the solar system formed, producing some of the oldest...... and interpretations for iron and stony iron meteorites (Plate 13.1). Such meteorites provide important constraints on the nature of metal-silicate separation and mixing in planetesimals undergoing partial to complete differentiation. They include iron meteorites that formed by the solidification of cores...... (fractionally crystallized irons), irons in which partly molten metal and silicates of diverse types were mixed together (silicate-bearing irons), stony irons in which partly molten metal and olivine from cores and mantles were mixed together (pallasites), and stony irons in which partly molten metal...

  15. Molybdenum (6) determination by the method of high-frequency and pH titration

    International Nuclear Information System (INIS)

    Lukianets, I.G.; Kulish, N.G.

    1981-01-01

    A possibility to determine Mo(6) using the method of high frequency and pH-metric titration is investigated. By means of the high frequency contact R-cell Mo(6) titration is performed using different precipitators: 8-oxiquinoline, lead nitrate and acetate and silver nitrate. It is established that the best conditions are achieved during titration of 67.2-1343 mg/10 ml Mo(6) with lead acetate (pH 4.5-6.5). Relative standard deviation Ssub(r) constitutes 0.005 pH-metric titration of Mo(6) with complexone 3 is studied. The range of Mo(6) concentrations determined constitutes 13.43-134.3 mg at pH initial value of 3.5-5.5. Relative standard deviation Ssub(r) constitutes 0.003. Techniques of molybdenum determination in ferromolybdenum using the method of high frequency and pH-metric titration are developed [ru

  16. Recovery of uranium and molybdenum elements from gebel gattar raw material, eastern desert, Egypt. Vol. 3

    International Nuclear Information System (INIS)

    El-Hazek, N.T.; Mahdy, M.A.; Mahmoud, H.M.K.

    1996-01-01

    G. Gatter uranium mineralizations are located along the faults and fracture zones crossing G.Gattar granitic pluton and long the contact of the pluton with the hammamat sediments. Also, molybdenum id presented in more than one mode of occurrence. The molybdenum mineralization treated in this work is the dessimenated type. The uranium and molybdenum raw material was subjected to series of leaching experiments including acid and alkaline agitation, alkaline percolation, and acid heap leaching techniques. Recovery of uranium and molybdenum was achieved by anion-exchange method followed by their elution by acidified sodium chloride. Uranium precipitation was performed in the form of ammonium diuranate (Yellow Cake). On the other hand molybdenum was precipitated in the form of molybdenum oxide. A tentative flowsheet for the extraction of both uranium and molybdenum is proposed and discussed. 13 figs., 3 tabs

  17. Recovery of uranium and molybdenum elements from gebel gattar raw material, eastern desert, Egypt. Vol. 3

    Energy Technology Data Exchange (ETDEWEB)

    El-Hazek, N T; Mahdy, M A; Mahmoud, H M.K. [Nuclear Materials Authority, Cairo, (Egypt)

    1996-03-01

    G. Gatter uranium mineralizations are located along the faults and fracture zones crossing G.Gattar granitic pluton and long the contact of the pluton with the hammamat sediments. Also, molybdenum id presented in more than one mode of occurrence. The molybdenum mineralization treated in this work is the dessimenated type. The uranium and molybdenum raw material was subjected to series of leaching experiments including acid and alkaline agitation, alkaline percolation, and acid heap leaching techniques. Recovery of uranium and molybdenum was achieved by anion-exchange method followed by their elution by acidified sodium chloride. Uranium precipitation was performed in the form of ammonium diuranate (Yellow Cake). On the other hand molybdenum was precipitated in the form of molybdenum oxide. A tentative flowsheet for the extraction of both uranium and molybdenum is proposed and discussed. 13 figs., 3 tabs.

  18. Activity and selectivity of three molybdenum catalysts for coal liquefaction reactions

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, C.W.; Pellegrino, J.L.

    The activity and selectivity of three different molybdenum catalysts for reactions occurring in coal liquefaction, specifically for hydrogenation (HYD), hydrodeoxygenation (HDO), hydrodenitrogenation (HDN), hydrodesulfurization (HDS), and hydrocracking (HYC), have been examined. The three molybdenum catalysts used were molybdenum napthenate, molybdenum on ..gamma..-alumina, and a precipitated, disordered MoS/sub 2/. Molybdenum naphthenate was most selective for HYD and HDN. All three catalysts exhibited approximately equal activity for HDS and HDO and little selectivity for HYC of alkyl bridge structures. The activity and selectivity of the three molybdenum catalysts for producing hydrocarbons and removing heteroatoms from coal during liquefaction were determined and compared. Molybdenum naphthenate was the most active catalyst for hydrocarbon production and removal of nitrogen- and oxygen-containing species during coal liquefaction. 31 refs., 4 figs., 7 tabs.

  19. Microstructure and mechanical properties of multi-components rare earth oxide-doped molybdenum alloys

    International Nuclear Information System (INIS)

    Zhang Guojun; Sun Yuanjun; Zuo Chao; Wei Jianfeng; Sun Jun

    2008-01-01

    Pure molybdenum and molybdenum alloys doped with two- or three-components rare earth oxide particles were prepared by powder metallurgy. Both the tensile property and fracture toughness of the pure molybdenum and multi-components rare earth oxide-doped molybdenum alloys were determined at room temperature. The multi-components rare earth oxide-doped molybdenum alloys are fine grained and contain a homogeneous distribution of fine particles in the submicron and nanometer size ranges, which is why the molybdenum alloys have higher strength and fracture toughness than pure molybdenum. Quantitative analysis is used to explain the increase in yield strength with respect to grain size and second phase strengthening. Furthermore, the relationship between the tensile properties and microstructural parameters is quantitatively established

  20. Response of soybean plants to phosphorus, boron and molybdenum fertilization

    International Nuclear Information System (INIS)

    Abdel-Aziz, H. A.; Aly, M. E.

    2012-12-01

    A pot experiment was carried out to study the effect of added phosphorus levels (30. 60 kg p/fed) with the addition of boron at (2, 6 ppm) and molybdenum at (5, 10.ppm) and without addition beside the control the control on growth and mineral content and root nodules in soybean plants. The results indicated that the effect of phosphorus on the formation of nodules had a clear effect when added with boron, molybdenum and when boron added at a rate of 2 ppm in the absence of phosphorus led to increase in root nodules in each of the 5, 10 ppm led to increased formation of, naldetuss in of the alluvial and calcareous soil. The molybdenum, nitrogen and phosphorus uptake increased directly proportional to the result of increased rate of addition of phosphorus and molybdenum. While the uptake born may be added with the rate of increased concentration of 2 ppm, while when added at 6 ppm led tp increased absorption of boron in the calcareous soil, but led to a decrease in the alluvial soils. (Author)

  1. Technology of niobium and molybdenum refining by electron beam

    International Nuclear Information System (INIS)

    Conti, R.A.; Pinatti, D.G.; Sandim, H.R.Z.

    1988-01-01

    The uses of metals and alloys in superconductors (Nb46%Ti), aerospatial industry (Ti6Al4V), electroeletronic industry (Nb, Mo, W) and in surgical implants (Ti, Nb) are increasing nowadays. A refining process of niobium and molybdenum by electron beam technique, since the oxides reduction till the obtention of a high purity ingot is presented. (C.G.C.) [pt

  2. Radiation damage in molybdenum and tungsten in high neutron fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Veljkovic, S; Milasin, N [Institute of Nuclear Sciences Boris Kidric, Department of Reactor Materials, Vinca, Beograd (Serbia and Montenegro)

    1964-04-15

    The effects of radiation on molybdenum and tungsten in high neutron fluxes are presented. The changes induced, particularly defects with a high migration activation energy, are analyzed. The correlation of these changes with the basic concepts of radiation damage in solids is considered. An attempt is made to relate the defects studied with the changes in macroscopic properties (author)

  3. Electrical Transport Properties of Polycrystalline Monolayer Molybdenum Disulfide

    Science.gov (United States)

    2014-07-14

    Lou, Sina Najmaei, Matin Amani, Matthew L. Chin, Zheng Se. TASK NUMBER Liu Sf. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAMES AND ADDRESSES 8...Transport Properties of Polycrystalline Monolayer Molybdenum Disulfide Sina Najmaei,t.§ Matin Ama ni,M Matthew L. Chin,* Zhe ng liu/ ·"·v: A. Gle n

  4. Flexible Molybdenum Electrodes towards Designing Affinity Based Protein Biosensors.

    Science.gov (United States)

    Kamakoti, Vikramshankar; Panneer Selvam, Anjan; Radha Shanmugam, Nandhinee; Muthukumar, Sriram; Prasad, Shalini

    2016-07-18

    Molybdenum electrode based flexible biosensor on porous polyamide substrates has been fabricated and tested for its functionality as a protein affinity based biosensor. The biosensor performance was evaluated using a key cardiac biomarker; cardiac Troponin-I (cTnI). Molybdenum is a transition metal and demonstrates electrochemical behavior upon interaction with an electrolyte. We have leveraged this property of molybdenum for designing an affinity based biosensor using electrochemical impedance spectroscopy. We have evaluated the feasibility of detection of cTnI in phosphate-buffered saline (PBS) and human serum (HS) by measuring impedance changes over a frequency window from 100 mHz to 1 MHz. Increasing changes to the measured impedance was correlated to the increased dose of cTnI molecules binding to the cTnI antibody functionalized molybdenum surface. We achieved cTnI detection limit of 10 pg/mL in PBS and 1 ng/mL in HS medium. The use of flexible substrates for designing the biosensor demonstrates promise for integration with a large-scale batch manufacturing process.

  5. Brazing molybdenum and tungsten for high temperature service

    International Nuclear Information System (INIS)

    Lundberg, L.B.; Turner, W.C.; Hoffman, C.G.

    1978-01-01

    Investigations were conducted to develop vacuum brazes for molybdenum and tungsten which can be used in seal joint applications up to 1870 K (1597 C, 2907 F). Joints were attempted in molybdenum, tungsten and tungsten--molybdenum. The braze materials included: Ti--10Cr powder, Ti--30V wire, Ti--65V wire, V wire, Ni electroplate, MoB--50MoC powder mixture, V--50Mo powder mixture, Mo--15MoB 2 powder mixture and Mo--49V--15MoB 2 powder mixture. Braze temperature ranged from 1900 K (1627 C, 2961 F) to 2530 K, (2257 C, 4095 F), and leak-tight joints were made with all braze materials except Ti--10Cr. After heat treatments up to 1870 K (1597 C, 2907 F) Kirkendall voiding was found to cause leakage of some of the joints made with only substitutional alloying elements. However, adding base metal powders to the braze or narrowing the root opening eliminated this problem. Kirkendall voiding was not a problem when interstitial elements were a major ingredient in the braze material. Shear testing of Ti--65V, V, MoB--50MoC and V--50Mo brazed molybdenum at 1670 K (1397 C, 2547 F) indicated strengths equal to or better than the base metal. Ti--65V, V--50Mo and MoB--50MoC brazed joints were exposed to basalt at 1670 K (1397 C, 2547 F) for 3 h without developing leaks

  6. Radiation damage in molybdenum and tungsten in high neutron fluxes

    International Nuclear Information System (INIS)

    Veljkovic, S.; Milasin, N.

    1964-01-01

    The effects of radiation on molybdenum and tungsten in high neutron fluxes are presented. The changes induced, particularly defects with a high migration activation energy, are analyzed. The correlation of these changes with the basic concepts of radiation damage in solids is considered. An attempt is made to relate the defects studied with the changes in macroscopic properties (author)

  7. Femtosecond laser surface structuring of molybdenum thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kotsedi, L., E-mail: Kotsedi@tlabs.ac.za [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); Mthunzi, P. [Council for Scientific and Industrial Research (CSIR), Biophotonics Lab: National Laser Centre Pretoria, 0001 (South Africa); Nuru, Z.Y. [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); Eaton, S.M. [Physics Department, Politecnico di Milano, Piazza Leonardo Da Vinci, 32, 20133 Milano (Italy); Center for Nano Science and Technology, Istituto Italiano di Tecnologia, Via Pascoli 70/3, 20133 Milano, Itala (Italy); Sechoghela, P.; Mongwaketsi, N. [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape Province (South Africa); Ramponi, R. [Institute for Photonics and Nanotechnologies (IFN)–CNR, Piazza Leanardo Da Vinci, 32, 20133 Milano (Italy); Maaza, M. [UNESCO-UNISA Africa Chair in Nanosciences-Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, PO Box 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure Road, Somerset West 7129, PO Box 722, Somerset West, Western Cape Province (South Africa)

    2015-10-30

    Highlights: • Color change of the molybdenum thin film from shinny to violet–yellowish color after laser irradiation at various laser powers. • Formation of the molybdenum dioxide coating after laser exposure, as confirmed by the X-ray diffraction spectrometry. • Selective solar absorbing nature of the laser exposed films. • Study of the binding energies is presented in this contribution using the XPS spectrometry. - Abstract: This contribution reports on the femtosecond surface structuring of molybdenum thin coatings deposited by electron beam evaporation onto Corning glass substrates. The 1-D type periodic grating lines created by such an ablation showed that the widths of the shallow grooves followed a logarithmic dependence with the laser energy incident on the molybdenum film. The electronic valence “x” of the created oxide surface layer MoO{sub x} was found to be incident laser power dependent via Rutherford backscattering spectrometry, X-ray photoelectron spectroscopy and X-ray diffraction investigations. Such a photo-induced MoO{sub x}–Mo nanocomposite exhibited effective selective solar absorption in the UV–vis–IR spectral range.

  8. Chromium and molybdenum diffusion in tungsten single crystals

    International Nuclear Information System (INIS)

    Klotsman, S.M.; Koloskov, V.M.; Osetrov, S.V.; Polikarpova, I.P.; Tatarinova, G.N.; Timofeev, A.N.

    1989-01-01

    Consideration is given to results of measuring temperature dependences of diffusion coefficients of homovalent impurities of chromium and molybdenum in tungsten single crystals. It is concluded that the difference of activation energies of selfdiffusion and impurity diffusion in the system 'tungsten-homovalent impurity' is conditioned by interaction of screened potentials of impurity and vacancy with Lazarus-Le Claire model

  9. Process for producing molybdenum foil and collapsible tubing

    Science.gov (United States)

    Bretts, G. R.; Gavert, R. B.; Groschke, G. F.

    1971-01-01

    Manufacturing process produces molybdenum foil 0.002 cm thick and 305 m long, and forms foil into high-strength, thin-walled tubing which can be flattened for storage on a spool. Desirable metal properties include high thermal conductivity stiffness, yield and tensile stress, and low thermal expansion coeffecient.

  10. Chemical effects of nuclear transformations in molybdenum complexes

    International Nuclear Information System (INIS)

    Millan S, S.A.

    1977-01-01

    The Szilard-Chalmers effect was studied in the complexes: tetraacetatedimolybdenum(II), tetrabenzoatedimolybdenum(II), benzenetricarbonylmolybdenym(0). The results we obtained in the measurement of the Szilard-Chalmers effect on the studied complexes imply some influence of the structure in the molecular fragmentation, or the conservation of the links molybdenum-ligands. (author)

  11. Recovery of Tungsten and Molybdenum from Low-Grade Scheelite

    Science.gov (United States)

    Li, Yongli; Yang, Jinhong; Zhao, Zhongwei

    2017-10-01

    With most high-quality tungsten ores being exhausted, the enhancement of low-grade scheelite concentrates processing has attracted a great deal of attention. The objective of this study is to develop a method to maximize the recovery tungsten and molybdenum from a low-grade scheelite via a new acid leaching process followed by solvent extraction. Under optimal conditions (350 g/L H2SO4, 95°C, and 2 h), approximately 99.8% of tungsten and 98% of molybdenum were leached out. In the subsequent solvent extraction process, more than 99% of the tungsten and molybdenum were extracted with a co-extraction system (50% TBP, 30% HDEHP, and 10% 2-octanol in kerosene) using a three-stage cross-flow extraction. The raffinate can be recycled for the next leaching process after replenishing the H2SO4 to the initial value (approximately 350 g/L). Based on these results, a conceptual flowsheet is presented to recover tungsten and molybdenum from the low-grade scheelite.

  12. Characterization of the uranium--2 weight percent molybdenum alloy

    International Nuclear Information System (INIS)

    Hemperly, V.C.

    1976-01-01

    The uranium-2 wt percent molybdenum alloy was prepared, processed, and age hardened to meet a minimum 930-MPa yield strength (0.2 percent) with a minimum of 10 percent elongation. These mechanical properties were obtained with a carbon level up to 300 ppM in the alloy. The tensile-test ductility is lowered by the humidity of the laboratory atmosphere

  13. GEMAS: Molybdenum Spatial Distribution Patterns in European Soil

    Science.gov (United States)

    Cicchella, Domenico; Zuzolo, Daniela; Demetriades, Alecos; De Vivo, Benedetto; Eklund, Mikael; Ladenberger, Anna; Negrel, Philippe; O'Connor, Patrick

    2017-04-01

    Molybdenum is an essential trace element for both plants and animals as well as for human being. It is one such trace element for which potential health concerns have been raised but for which few data exist and little investigation or interpretation of distributions in soils has been made. The main goal of this study was to fill this gap. Molybdenum (Mo) concentrations are reported for the similar spatial distribution patterns mainly governed by geology (parent material and mineralisation), as well as weathering, soil formation and climate since the last glaciations period. The dominant feature is represented by low Mo concentrations over the coarse-grained sandy deposits of the last glaciations in central northern Europe while the most extensive anomalies occur in Scandinavian soils. The highest Mo concentration value occurs to the North of Oslo close to one of the largest porphyry Mo deposit of the World. Some interesting anomalous patterns occur also in Italy in correspondence with alkaline volcanics, in Spain and Greece associated with sulfides mineralizations and in Slovenia and Croatia where are probably related to the long weathering history of karstic residual soils. Anomalous concentrations in some areas of Ireland represent a clear example of how an excess of molybdenum has produced potentially toxic pastures. In fact, these give rise to problems particularly in young cattle when excess molybdenum in the herbage acts as an antagonist, which militates against efficient copper absorption by the animal.

  14. MOLYBDENUM CATALYZED ACID PEROXIDE BLEACHING OF EUCALYPTUS KRAFT PULP

    Directory of Open Access Journals (Sweden)

    Marcos S. Rabelo

    2008-08-01

    Full Text Available Molybdenum catalyzed peroxide bleaching (PMo Stage consists of pulp treatment with hydrogen peroxide under acidic conditions in the presence of a molybdenum catalyst. Molybdenum is applied in catalytic doses (50-200 mg/kg pulp and may originate from various sources, including (NH46Mo7O24.4H2O, Na2MoO4.2H2O, siliconmolybdate, etc. This work is aimed at optimizing the PMo stage and evaluating its industrial application in the OAZDP sequence. Optimum PMo stage conditions for bleaching eucalyptus pulp were 90 ºC, pH 3.5, 2 h, 0.1 kg/adt Mo and 5 kg/adt H2O2. The PMo stage was more efficient to remove pulp hexenuronic acids than lignin. Its efficiency decreased with increasing pH in the range of 1.5-5.5, while it increased with increasing temperature and peroxide and molybdenum doses. The application of the PMo stage as replacement for the A-stage of the AZDP sequence significantly decreased chlorine dioxide demand. The PMo stage caused a decrease of 20-30% in the generation of organically bound chlorine. The quality parameters of the pulp produced during the PMo stage mill trial were comparable to those obtained with the reference A-stage.

  15. Growth of molybdenum disulphide using iodine as transport material

    Indian Academy of Sciences (India)

    In the present paper an attempt has been made to describe the chemical vapor transport (CVT) technique used for the growth of molybdenum disulphide (MoS2) single crystals. Iodine (I2) is used as transporting material for this purpose. The energy dispersive analysis by X-ray (EDAX) confirmed the stoichiometry of the ...

  16. A Supply and Demand Update of the Molybdenum-99 Market

    International Nuclear Information System (INIS)

    2012-08-01

    Medical diagnostic imaging techniques using technetium-99m account for roughly 80% of all nuclear medicine procedures, representing over 30 million examinations worldwide every year. Disruptions in the supply chain of these medical isotopes - which have half-lives of 66 hours for molybdenum-99 ( 99 Mo) and 6 hours for its daughter isotope, technetium-99m (' 99m Tc), and thus must be produced continually - can lead to cancellations or delays in important medical testing services. Unfortunately, supply reliability has declined over the past decade due to unexpected or extended shutdowns at the few ageing 99 Mo-producing research reactor and processing facilities. These shutdowns have created global supply shortages. In 2011, the OECD Nuclear Energy Agency (NEA), along with its High-level Group on the Security of Supply of Medical Radioisotopes (HLG-MR), released a report that presents the reasons behind the lack of infrastructure that led to global supply shortages and a policy approach to encourage long-term medical isotope supply security. In that report, The Supply of Medical Radioisotopes: The Path to Reliability, the NEA also provides potential futures of supply and demand out to 2030. Since the release of The Path there have been a number of changes in the market and therefore this document provides an update on the 2011 supply and demand situation. This update is based on information provided to the NEA by members of the HLG-MR and other key stakeholders. This presentation of supply and demand future scenarios for the 99 Mo market revises previous NEA future scenarios based on new data and target conversion commitments from the supply chain. The update, unfortunately, does not present a more optimistic future scenario than previous presentations - the concern around the uneconomic situation of the supply chain continues to dominate the potential for new projects. This results in the potential for long-term shortages within the decade. However, there are a

  17. Magnetic and Structural Properties of Electrodeposited Iron on Copper and Silver

    International Nuclear Information System (INIS)

    Koempe, K.; Kuehl, E.; Nagorny, K.

    2002-01-01

    Electrodeposition of iron on copper or silver leads to the formation of bcc-iron or amorphous iron. Thermal annealing usually results in soluted iron (also γ-iron and clusters) in copper. On silver the insolubility of iron never causes the formation of bcc-iron. Instead on copper as well as on silver fcc-iron states are formed, especially at relatively low temperatures with short times of annealing. Moessbauer spectroscopy accompanied by X-ray diffraction (XRD) and vibrating sample magnetometry (VSM) are applied for characterisation of the iron states.

  18. Geochemistry, Mineralogy and Microbiology of Molybdenum in Mining-Affected Environments

    Directory of Open Access Journals (Sweden)

    Francesca Frascoli

    2018-01-01

    Full Text Available Molybdenum is an essential element for life, with growing production due to a constantly expanding variety of industrial applications. The potentially harmful effects of Mo on the environment, and on human and ecosystem health, require knowledge of Mo behavior in mining-affected environments. Mo is usually present in trace amounts in ore deposits, but mining exploitation can lead to wastes with very high Mo concentrations (up to 4000 mg/kg Mo for tailings, as well as soil, sediments and water contamination in surrounding areas. In mine wastes, molybdenum is liberated from sulfide mineral oxidation and can be sorbed onto secondary Fe(III-minerals surfaces (jarosite, schwertmannite, ferrihydrite at moderately acidic waters, or taken up in secondary minerals such as powellite and wulfenite at neutral to alkaline pH. To date, no Mo-metabolising bacteria have been isolated from mine wastes. However, laboratory and in-situ experiments in other types of contaminated land have suggested that several Mo-reducing and -oxidising bacteria may be involved in the cycling of Mo in and from mine wastes, with good potential for bioremediation. Overall, a general lack of data is highlighted, emphasizing the need for further research on the contamination, geochemistry, bio-availability and microbial cycling of Mo in mining-affected environments to improve environmental management and remediation actions.

  19. Static recrystallisation and precipitation after hot deformation of austenitic stainless steels containing molybdenum and niobium

    International Nuclear Information System (INIS)

    Lombry, R.; Rossard, C.; Thomas, B.J.

    1981-01-01

    In general the hot workability of austenite depends on the work hardening during deformation and the kinetics of the dynamic and static restoration processes. Static recrystallisation is a very important factor in the case of hot rolling. The present work was undertaken to determine the effect of additions of molybdenum or niobium on the kinetics of static recrystallisation. The results show that the rate of static recrystallisation of type 304, 316 and 347 stainless steels decreases in this order for a given amount of prior deformation (epsilon=0,44). The differences in the rates of recrystallisation increases as the temperature is lowered towards 900 deg C. The effect of molybdenum appears to be attribuable to a solute drag effect on the mobility of dislocations, subgrain boundaries or grain boundaries whereas niobium additions lead to the formation of NbC precipitates on the dislocation cell walls and sub boundaries. It is also shown that in the case of type 316 and type 347 steels the dynamic recrystallisation process (observed in type 304 steels at all temperatures above 900 deg C) is replaced by dynamic recovery at temperatures egal to or below about 1000 deg C [fr

  20. Tunneling measurements in amorphous layers of superconducting transition metals: molybdenum, vanadium, and niobium

    International Nuclear Information System (INIS)

    Roll, U.

    1981-01-01

    Tunneling experiments with amorphous Molybdenum and Vanadium layers are presented, showing no significant increase of the reduced energy gap 2δ(O)/kTsub(c)(δ) compared with the BCS-value, in contrast to all previous measurement on amorphous superconducting materials of simple s-p-metals, showing on enhanced electron-phonon-interaction. This fact may lead to the conclusion that the strong electron-phonon coupling is caused by the amorphous structure of the superconductor. The present results, however, indicate that the strong electron-phonon interaction cannot be explained only ba the amorphous structure of the superconductor. In the measurements of the second derivative d 2 U/dI 2 no phonon-induced structures have been observed for amorphous molybdenum, vanadium and niobium films. Apparently the phonon density of states F(#betta#) of amorphous transition metals has no structure, thus the longitudinal and transverse phonons cannot be identified in the measured (d 2 U/dI 2 )-curves. This particular behaviour of the amorphous transition metals in contrast to the simple s-p-metals may be interpreted by the strongly localized d-electrons. (orig./GG) [de

  1. 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

  2. Crystallization and structure of chromium cast iron with addition of Mo and Ni; Krystalizacja i struktura zeliwa chromowego z dodatkami Mo i Ni

    Energy Technology Data Exchange (ETDEWEB)

    Pietrowski, S. [Instytut Inzynierii Materialowej i Technik Bezwiorowych, Politechnika Lodzka, Lodz (Poland)

    1998-12-31

    The aim of the presented paper is to show the results of examination of the crystallization process using the method of thermal-derivative analysis (ATD) and the structure examination of chromium cast iron, chromium molybdenum c. i. and chromium molybdenum nickel c.i. It was found that molybdenum in amount over 2 wt % causes the crystallization of eutectic carbides M{sub 23}C{sub 6} and M{sub 6}C. The M{sub 23}C{sub 6} carbide crystallizes upon the crystallization of eutectic carbides M{sub 3}C and M{sub 7}C{sub 3}. It is shown that ATD method facilitates both interpretation and control of the crystallization as well as formation of the cast iron structure at the solid state. (author) 14 refs, 16 figs, 5 tabs

  3. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency anemia is a ... address the cause of your iron deficiency, such as any underlying bleeding. If undiagnosed or untreated, iron- ...

  4. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... To Health Topics / Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency ... anemia. Blood tests to screen for iron-deficiency anemia To screen for iron-deficiency anemia, your doctor ...

  5. Iron-Deficiency Anemia

    Science.gov (United States)

    ... To Health Topics / Iron-Deficiency Anemia Iron-Deficiency Anemia Also known as Leer en español Iron-deficiency ... anemia. Blood tests to screen for iron-deficiency anemia To screen for iron-deficiency anemia, your doctor ...

  6. The structure and function of supported molybdenum nitride and molybdenum carbide hydrotreating catalysts

    Science.gov (United States)

    Dolce, Gregory Martin

    1997-11-01

    A series of gamma-Alsb2Osb3 supported molybdenum nitrides and carbides were prepared by the temperature programmed reaction of supported molybdates with ammonia and methane/hydrogen mixtures, respectively. In the first part of this research, the effects of synthesis heating rates and molybdenum loading on the catalytic properties of the materials were examined. A significant amount of excess carbon was deposited on the surface of the carbides during synthesis. The materials consisted of small particles which were very highly dispersed. Oxygen chemisorption indicated that the nitride particles may have been two-dimensional. The dispersion of the carbides, however, appeared to decrease as the loading increased. The catalysts were evaluated for hydrodenitrogenation (HDN), hydrodesulfurization (HDS), and hydrodeoxygenation (HDO). The molybdenum loading had the largest effect on the activity of the materials. For the nitrides, the HDN and HDS activities were inverse functions of the loading. This suggested that the most active HDN and HDS sites were located at the perimeter of the two-dimensional particles. The HDN and HDS activities of the carbides followed the same trend as the oxygen uptake. This result suggested that oxygen titrated the active sites on the supported carbides. Selected catalysts were evaluated for methylcarbazole HDN, dibenzothiophene HDS, and dibenzofuran HDO. The activity and selectivity of the nitrides and carbides were competitive with a presulfided commercial catalyst. In the second part of this work, a series of supported nitrides and carbides were prepared using a wider range of loadings (5-30 wt% Mo). Thermogravimetric analysis was used to determine the temperature at which excess carbon was deposited on the carbides. By modifying the synthesis parameters, the deposition of excess carbon was effectively inhibited. The dispersions of the supported nitrides and carbides were constant and suggested that the materials consisted of two

  7. Combined Therapy of Iron Chelator and Antioxidant Completely Restores Brain Dysfunction Induced by Iron Toxicity

    Science.gov (United States)

    Sripetchwandee, Jirapas; Pipatpiboon, Noppamas; Chattipakorn, Nipon; Chattipakorn, Siriporn

    2014-01-01

    Background Excessive iron accumulation leads to iron toxicity in the brain; however the underlying mechanism is unclear. We investigated the effects of iron overload induced by high iron-diet consumption on brain mitochondrial function, brain synaptic plasticity and learning and memory. Iron chelator (deferiprone) and antioxidant (n-acetyl cysteine) effects on iron-overload brains were also studied. Methodology Male Wistar rats were fed either normal diet or high iron-diet consumption for 12 weeks, after which rats in each diet group were treated with vehicle or deferiprone (50 mg/kg) or n-acetyl cysteine (100 mg/kg) or both for another 4 weeks. High iron-diet consumption caused brain iron accumulation, brain mitochondrial dysfunction, impaired brain synaptic plasticity and cognition, blood-brain-barrier breakdown, and brain apoptosis. Although both iron chelator and antioxidant attenuated these deleterious effects, combined therapy provided more robust results. Conclusion In conclusion, this is the first study demonstrating that combined iron chelator and anti-oxidant therapy completely restored brain function impaired by iron overload. PMID:24400127

  8. Delamination wear mechanism in gray cast irons

    International Nuclear Information System (INIS)

    Salehi, M.

    2000-01-01

    An investigation of the friction and sliding wear of gray cast iron against chromium plated cast irons was carried out on a newly constructed reciprocating friction and wear tester. The tests were the first to be done on the test rig under dry conditions and at the speed of 170 cm/min, and variable loads of 20-260 N for a duration of 15 min. to 3 hours. The gray cast iron surfaces worn by a process of plastic deformation at the subsurface, crack nucleation, and crack growth leading to formation of plate like debris and therefore the delamination theory applies. No evidence of adhesion was observed. This could be due to formation of oxides on the wear surface which prevent adhesion. channel type chromium plating ''picked'' up cast iron from the counter-body surfaces by mechanically trapping cast iron debris on and within the cracks. The removal of the plated chromium left a pitted surface on the cast iron

  9. Phase composition and catalytic properties of oxide multicomponent molybdenum-containing catalysts for partial oxidation of propylene

    International Nuclear Information System (INIS)

    Malakhov, V.V.; Vlasov, A.A.; Boldyreva, N.N.; Dovlitova, L.S.; Plyasova, L.M.; Andrushkevich, T.V.; Kuznetsova, T.G.

    1996-01-01

    The catalytic properties and phase composition of multicomponent molybdenum-containing catalyst treated under various redox conditions have been studied. The phase composition has been considered by the methods of X-ray phase analysis and noncalibrated methods of differentiating dissolution (DD). Using the DD method the data on element composition, stoichiometry and quantitative content of phases of complex molybdates have been obtained for the first time. Data on modification of basic phases of the catalyst-cobalt and iron molybdates - by other cations from its composition suggest that the mechanism of action of the multicomponent catalyst is defined by the properties of one or several formed modified phases combining all the functions of an effective catalyst. 18 refs., 7 figs., 2 tabs

  10. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... making new blood cells. Visit our Aplastic Anemia Health Topic to learn more. ... recommend that you take iron supplements, also called iron pills or oral iron, by mouth once or several times a ...

  11. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... red meat, salmon, iron-fortified breads and cereals, peas, tofu, dried fruits, and dark green leafy vegetables. ... stored iron has been used. Ferritin is a protein that helps store iron in your body. Reticulocyte ...

  12. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... drinking black tea, which reduces iron absorption. Other treatments If you have chronic kidney disease and iron- ... and lifestyle changes to avoid complications. Follow your treatment plan Do not stop taking your prescribed iron ...

  13. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... diagnoses you with iron-deficiency anemia, your treatment will depend on the cause and severity of the ... of iron. The recommended daily amounts of iron will depend on your age, sex, and whether you ...

  14. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... heart failure . Increased risk of infections Motor or cognitive development delays in children Pregnancy complications, such as ... iron-deficiency anemia may require intravenous (IV) iron therapy or a blood transfusion . Iron supplements Your doctor ...

  15. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... for iron-deficiency anemia. Lifestyle habits Certain lifestyle habits may increase your risk for iron-deficiency anemia, including: Vegetarian or vegan eating patterns. Not eating enough iron-rich foods, such ...

  16. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... because your body’s intake of iron is too low. Low intake of iron can happen because of blood ... delivery or giving birth to a baby with low birth weight In people with chronic conditions, iron- ...

  17. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... breastfeeding. Recommended daily iron intake for children and adults. The table lists the recommended amounts of iron, ... increased need for iron during growth spurts. Older adults, especially those over age 65. Unhealthy environments Children ...

  18. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... girls. From birth to 6 months, babies need 0.27 mg of iron. This number goes up ... screen blood donors for low iron stores. Reliable point-of-care testing may help identify iron deficiency ...

  19. Iron metabolism and toxicity

    International Nuclear Information System (INIS)

    Papanikolaou, G.; Pantopoulos, K.

    2005-01-01

    Iron is an essential nutrient with limited bioavailability. When present in excess, iron poses a threat to cells and tissues, and therefore iron homeostasis has to be tightly controlled. Iron's toxicity is largely based on its ability to catalyze the generation of radicals, which attack and damage cellular macromolecules and promote cell death and tissue injury. This is lucidly illustrated in diseases of iron overload, such as hereditary hemochromatosis or transfusional siderosis, where excessive iron accumulation results in tissue damage and organ failure. Pathological iron accumulation in the liver has also been linked to the development of hepatocellular cancer. Here we provide a background on the biology and toxicity of iron and the basic concepts of iron homeostasis at the cellular and systemic level. In addition, we provide an overview of the various disorders of iron overload, which are directly linked to iron's toxicity. Finally, we discuss the potential role of iron in malignant transformation and cancer

  20. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... amount of iron, and medical conditions that make it hard for your body to absorb iron from ... hepcidin. Hepcidin prevents iron from leaving cells where it is stored or from being absorbed in the ...

  1. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... bleeding. If undiagnosed or untreated, iron-deficiency anemia can cause serious complications, including heart failure and development ... iron is too low. Low intake of iron can happen because of blood loss, consuming less than ...

  2. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... iron-fortified foods that have iron added. Vegetarian diets can provide enough iron if you choose nonmeat ... Anemia in Chronic Kidney Disease (National Institute of Diabetes and Digestive and Kidney Diseases) Avoiding Anemia (National ...

  3. Iron-Deficiency Anemia

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    Full Text Available ... lean red meat, salmon, iron-fortified breads and cereals, peas, tofu, dried fruits, and dark green leafy ... sources of iron, including iron-fortified breads and cereals, beans, tofu, dried fruits, and spinach and other ...

  4. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... starch. Restless legs syndrome Shortness of breath Weakness Complications Undiagnosed or untreated iron-deficiency anemia may cause ... as complete blood count and iron studies. Prevent complications over your lifetime To prevent complications from iron- ...

  5. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... you do not have enough iron in your body. People with mild or moderate iron-deficiency anemia ... and where to find more information. Causes Your body needs iron to make healthy red blood cells. ...

  6. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... from developing iron-deficiency anemia. Foods that are good sources of iron include dried beans, dried fruits, eggs, lean red meat, ... signs of iron-deficiency anemia include: Brittle nails ...

  7. Taking iron supplements

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007478.htm Taking iron supplements To use the sharing features on this page, ... levels. You may also need to take iron supplements as well to rebuild iron stores in your ...

  8. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... fruits, eggs, lean red meat, salmon, iron-fortified breads and cereals, peas, tofu, dried fruits, and dark ... choose nonmeat sources of iron, including iron-fortified breads and cereals, beans, tofu, dried fruits, and spinach ...

  9. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... ESAs are usually used with iron therapy or IV iron, or when iron therapy alone is not enough. Look for Living With will discuss what your doctor may recommend, including lifelong lifestyle changes ...

  10. Iron-Deficiency Anemia

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    Full Text Available ... and pregnancy. Good sources of iron are meat, poultry, fish, and iron-fortified foods that have iron ... Anemia Restless Legs Syndrome Von Willebrand Disease Other Resources NHLBI resources Your Guide to Anemia [PDF, 1. ...

  11. Uranium-molybdenum alloys containing 0,5 to 3 per cent by weight of molybdenum

    International Nuclear Information System (INIS)

    Lehmann, J.

    1959-01-01

    The following properties have been determined in the new cast state of uranium alloys containing 0.5-1-1.8-2 and 3.5 per cent of molybdenum: micro-graphical aspect, crystalline structure, thermal expansion, the mechanical characteristics, behaviour when subjected to cyclic temperature variations, and heat treatment. The transformation curves have been established for continuous cooling at rates varying between 2.5 and 200 deg. C per minute, using a dilatation method for the alloys containing 1.0, 2.0 and 3.0 per cent Mo. T.T.T. curves have been traced for 0.5 and 1.0 per cent Mo alloys and the Ms points determined for alloys containing 2.0 and 3.0 par cent Mo. In this way it has been possible to show the different results of transformation, brought about either by nucleation and diffusion or by shear - the alloy containing 1 per cent Mo, give two martensites α' and α'' and the alloys containing 2 and 3 per cent Mo give one martensite with a band structure. (author) [fr

  12. Iron Status of Vegetarian Children: A Review of Literature.

    Science.gov (United States)

    Pawlak, Roman; Bell, Kami

    2017-01-01

    Iron is considered a nutrient of concern for vegetarians. In children, inadequate iron status may lead to anemia and poor growth. Thirteen original manuscripts met the inclusion criteria. Various biochemical markers of iron status, such as hemoglobin (Hb) and serum ferritin, were used. Seven of the 13 studies reported the prevalence of iron deficiency separately for vegetarians and non-vegetarians. Five out of 7 showed a higher prevalence of iron deficiency among the vegetarian participants, while the other 2 showed a higher prevalence of iron deficiency among non-vegetarians. A wide range of iron deficiency prevalence, from 4.3% of vegetarian participants in one study to 73% having ferritin vegetarian children varies considerably from one study to another. The wide variation in the prevalence of inadequate iron status was consistent for studies from industrial and developing countries. The physiological significance of low iron status among vegetarians reported in some studies is unknown. © 2017 S. Karger AG, Basel.

  13. Genetics Home Reference: iron-refractory iron deficiency anemia

    Science.gov (United States)

    ... refractory iron deficiency anemia Iron-refractory iron deficiency anemia Printable PDF Open All Close All Enable Javascript ... expand/collapse boxes. Description Iron-refractory iron deficiency anemia is one of many types of anemia , which ...

  14. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... increased need for iron during growth spurts. Older adults, especially those over age ... athletes. Athletes, especially young females, are at risk for iron deficiency. Endurance ...

  15. Iron and stony-iron meteorites

    DEFF Research Database (Denmark)

    Benedix, Gretchen K.; Haack, Henning; McCoy, T. J.

    2014-01-01

    Without iron and stony-iron meteorites, our chances of ever sampling the deep interior of a differentiated planetary object would be next to nil. Although we live on a planet with a very substantial core, we will never be able to sample it. Fortunately, asteroid collisions provide us with a rich...... sampling of the deep interiors of differentiated asteroids. Iron and stony-iron meteorites are fragments of a large number of asteroids that underwent significant geological processing in the early solar system. Parent bodies of iron and some stony-iron meteorites completed a geological evolution similar...... to that continuing on Earth – although on much smaller length- and timescales – with melting of the metal and silicates; differentiation into core, mantle, and crust; and probably extensive volcanism. Iron and stony-iron meteorites are our only available analogues to materials found in the deep interiors of Earth...

  16. Adverse health effects in Canada geese (Branta canadensis) associated with waste from zinc and lead mines in the Tri-State Mining District (Kansas, Oklahoma, and Missouri, USA).

    Science.gov (United States)

    van der Merwe, Deon; Carpenter, James W; Nietfeld, Jerome C; Miesner, John F

    2011-07-01

    Lead and zinc poisoning have been recorded in a variety of bird species, including migrating waterfowl such as Canada Geese (Branta canadensis), at sites contaminated with mine waste from lead and zinc mines in the Tri-State Mining District, Kansas, Oklahoma, and Missouri, USA. The adverse health impacts from mine waste on these birds may, however, be more extensive than is apparent from incidental reports of clinical disease. To characterize health impacts from mine waste on Canada Geese that do not have observable signs of poisoning, four to eight apparently healthy birds per site were collected from four contaminated sites and an uncontaminated reference site, and examined for physical and physiologic evidence of metals poisoning. Tissue concentrations of silver, aluminum, arsenic, barium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, nickel, lead, selenium, thallium, vanadium, and zinc were determined by inductively coupled plasma mass spectroscopy. Adverse health effects due to lead were characterized by assessing blood δ-aminolevulinic acid dehydratase (ALAD) enzyme activity. Adverse effects associated with zinc poisoning were determined from histologic examination of pancreas tissues. Elevated tissue lead concentrations and inhibited blood ALAD enzyme activities were consistently found in birds at all contaminated sites. Histopathologic signs of zinc poisoning, including fibrosis and vacuolization, were associated with elevated pancreatic zinc concentrations at one of the study sites. Adverse health effects associated with other analyzed elements, or tissue concentrations indicating potentially toxic exposure levels to these elements, were not observed.

  17. Extending hydraulic lifetime of iron walls

    International Nuclear Information System (INIS)

    Mackenzie, P.D.; Sivavec, T.M.; Horney, D.P.

    1997-01-01

    Iron walls for control of groundwaters contaminated with chlorinated solvents and reducible metals are becoming much more widely used and field studies of this technology have proven successful to date. However, there is still much uncertainty in predicting long-term performance. This work focuses on two factors affecting the lifetime of the iron media: plugging at the treatment zone entrance and precipitation in the bulk iron media. Plugging at the system entrance is due principally to dissolved oxygen in the incoming water and is an issue in aerobic aquifers or in ex-situ canister tests. In an in-situ treatment system, plugging would result in a dramatic reduction in flow through the iron zone. Designs to minimize plugging in field applications include use of larger iron particles and admixing sand of comparable size with the iron particles. Mineral precipitation in the bulk iron media can lead to porosity losses in the media, again reducing flow through the treatment zone. Decreases in reactivity of the iron media may also occur. The nature of the mineral precipitation and the factors that affect extent of mineral precipitation are examined by a variety of tools, including tracer tests, aqueous inorganic profiles, and surface analysis techniques. At short treatment times, measured porosity losses are due mainly to entrapment of a film of H 2 gas on the iron surfaces and also to Fe(OH) 2 precipitation. Over longer treatment times precipitation of Fe(OH) 2 and FeCO 3 in low carbonate waters and of Fe(OH) 2 , FeCO 3 and CaCO 3 in higher carbonate waters will begin to dominate porosity losses. Preliminary results of an on-going study to control pH in an iron zone by admixing iron sulfide with iron show no difference in extent of carbonate precipitation versus a 100% iron system, suggesting that these systems are supersaturated with respect to carbonate precipitation

  18. Whole-body iron-59 retention measurements for estimating the iron status of piglets

    International Nuclear Information System (INIS)

    Pfau, A.; Rudolphi, K.; Heinrich, H.C.; Gabbe, E.E.

    1976-01-01

    A large-volume, 4π whole-body liquid scintillation detector was used to determine 59 Fe absorption in 173 one-to-six-weeks-old piglets with normal and depleted iron stores. Values of intestinal absorption from a 10 μmole (corresponds to 0.558 mg) 59 Fe 2+ test dose were compared with levels of haemoglobin, haematocrit, and serum iron as well as with stainable diffuse iron of bone marrow reticuloendothelial cells, and the dose relationship of intestinal iron absorption from 59 Fe-labelled FeSO 4 and methaemoglobin was measured. The investigations indicated that neither blood parameters, cytochemical gradings nor absorption levels from the 59 Fe test dose alone were sufficient to describe quantitatively the various stages of iron deficiency in piglets. A synopsis of all parameters appeared to be necessary for defining normal iron status and prelatent, latent and manifest iron deficiency. Piglets fed on sows' milk only developed manifest iron deficiency within the first three weeks of age. After an access to soil and/or creep feed from the eighth day of age, or intramuscular injections of 200 mg Fe as iron-dextran at three days of age, or injections of 200 or 400 mg Fe combined with access to creep feed, stages of manifest, latent or prelatent iron deficiency could be observed. For an iron-dextran dose of 800 mg Fe injected in amounts of 400 mg Fe at 3 and 10 days of age, a normal iron status was obtained in three-week-old piglets. The iron dose relationship indicated that 20 mg Fe administered orally as FeSO 4 or 40 mg Fe as methaemoglobin-Fe daily should cover the iron requirement of piglets for the first three weeks of life, whereas a three-week total of iron given orally in a single dose would lead to unphysiological or fatal conditions in nursing pigs. (author)

  19. Radiation shielding lead shield

    International Nuclear Information System (INIS)

    Dei, Shoichi.

    1991-01-01

    The present invention concerns lead shields for radiation shielding. Shield boxes are disposed so as to surround a pipeline through which radioactive liquids, mists or like other objects are passed. Flanges are formed to each of the end edges of the shield boxes and the shield boxes are connected to each other by the flanges. Upon installation, empty shield boxes not charged with lead particles and iron plate shields are secured at first at the periphery of the pipeline. Then, lead particles are charged into the shield boxes. This attains a state as if lead plate corresponding to the depth of the box is disposed. Accordingly, operations for installation, dismantling and restoration can be conducted in an empty state with reduced weight to facilitate the operations. (I.S.)

  20. Iron from Zealandic bog iron ore -

    DEFF Research Database (Denmark)

    Lyngstrøm, Henriette Syrach

    2011-01-01

    og geologiske materiale, metallurgiske analyser og eksperimentel arkæologiske forsøg - konturerne af en jernproduktion med udgangspunkt i den sjællandske myremalm. The frequent application by archaeologists of Werner Christensen’s distribution map for the occurrence of bog iron ore in Denmark (1966...... are sketched of iron production based on bog iron ore from Zealand....

  1. Formation of quinones, indanones and furans by the reaction of molybdenum carbene complexes with alkynes

    International Nuclear Information System (INIS)

    Doetz, K.H.; Larbig, H.

    1992-01-01

    (Alkoxy)carbene complexes of molybdenum react with terminal alkynes to give carbene annulation of cycloaddition products, the skeleton of which depends on the carbene substitution pattern and the alkyne used. (CO) 5 Mo=C(OMe)-p-tol undergoes carbene annulation upon reaction with trimethylsilylacetylene leading to naphthoquinone after oxidative work-up. Similar products are obtained from (CO) 5 Mo=C(OMe)2-furyl and hex-1-yne or oct-1-yne. The reaction of these alkynes results in the formation of indanones as five-membered annulation products. In the presence of 3.3-dimethylbut-1-yne the (phenyl) carbene ligands act as a C 1 -synthon, which is incorporated into the furan cycloaddition products

  2. Template removal via Boudouard equilibrium allows for synthesis of mesostructured molybdenum compounds

    Energy Technology Data Exchange (ETDEWEB)

    Schieder, Martin; Bojer, Carina; Koch, Sebastian; Martin, Thomas; Breu, Josef [Lehrstuhl fuer Anorganische Chemie I, Universitaet Bayreuth (Germany); Stein, Julia vom [Abteilung fuer Heterogene Katalyse, Max-Planck-Institut fuer Kohlenforschung, Muelheim a.d. Ruhr (Germany); Schmalz, Holger [Lehrstuhl fuer Makromolekulare Chemie II, Universitaet Bayreuth (Germany); Lunkenbein, Thomas [Abteilung fuer Anorganische Chemie, Fritz-Haber-Institut, Max-Planck-Gesellschaft, Berlin (Germany)

    2017-11-06

    Oxidative thermal removal of the polymeric templates is not trivial for molybdenum oxides and hampers mesostructuring of this material. At ambient oxygen fugacity, Mo{sup VI} is the thermodynamically stable oxidation state and sublimation of MoO{sub 3} leads to a quick loss of the mesostructure through Oswald ripening. Taking advantage of the Boudouard equilibrium allows to fix the oxygen fugacity at a level where non-volatile MoO{sub 2-x} is stable while carbonaceous material may be oxidized by CO{sub 2}. Mesostructured MoO{sub 2-x} can be chemically converted into MoO{sub 3} or MoN under retention of the mesostructure. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Production of Molybdenum-99 using Neutron Capture Methods

    Energy Technology Data Exchange (ETDEWEB)

    Toth, James J; Greenwood, Lawrence R; Soderquist, Chuck Z; Wittman, Richard S; Pierson, Bruce D; Burns, Kimberly A; Lavender, Curt A; Painter, Chad L; Love, Edward F; Wall, Donald E

    2011-01-01

    Pacific Northwest National Laboratory (PNNL), operated by Battelle, has identified a reference process for the production of molybdenum-99 (99Mo) for use in a chromatographic generator to separate the daughter product, technetium-99m (99mTc). The reference process uses the neutron capture reaction of natural or enriched molybdenum oxide via the reaction 98Mo(n,γ)99Mo. The irradiated molybdenum is dissolved in an alkaline solution, whereby the molybdenum, dissolved as the molybdate anion, is loaded on a proprietary ion exchange material in the chromatographic generator. The approach of this investigation is to provide a systematic collection of technologies to make the neutron capture method for Mo-99 production economically viable. This approach would result in the development of a technetium Tc99m generator and a new type of target. The target is comprised of molybdenum, either natural or enriched, and is tailored to the design of currently operating U.S. research reactors. The systematic collection of technologies requires evaluation of new metallurgical methods to produce the target, evaluation of target geometries tailored to research reactors, and chemical methods to dissolve the irradiated target materials for use in a chromatographic generator. A Technical specification for testing the target and neutron capture method in a research reactor is also required. This report includes identification of research and demonstration activities needed to enable deployment of neutron capture production method, including irradiations of prototypic targets, chemical processing of irradiated targets, and loading and extraction tests of Mo99 and Tc99m on the sorbent material in a prototypic generator design. The prototypical generator design is based on the proprietary method and systems for isotope product generation. The proprietary methods and systems described in this report are clearly delineated with footnotes. Ultimately, the Tc-99m generator solution provided by

  4. Molybdenum-UO2 cerment irradiation at 1145 K

    Science.gov (United States)

    Mcdonald, G.

    1971-01-01

    Two molybdenum-UO2 cermet fuel pins were fission heated in a helium-cooled loop at a temperature of 1145 K and to a total burnup of 5.3 % of the U-235. After irradiation the fuel pins were measured to check dimensional stability, punctured at the plenums to determine fission gas release, and examined metallographically to determine the effect of irradiation. Burnup was determined in several sections of the fuel pin. The results of the postirradiation examination indicated: (1) There was no visible change in the fuel pins on irradiation under the above conditions. (2) The maximum swelling of the fuel pins was less than 1%. (3) There was no migration of UO2 and no visible interaction between the molybdenum and the UO2. (4) Approximately 12% of the fission gas formed was released from the cermet cone into the gas plenum.

  5. The Structure and Stability of Molybdenum Ditelluride Thin Films

    Directory of Open Access Journals (Sweden)

    Zhouling Wang

    2014-01-01

    Full Text Available Molybdenum-tellurium alloy thin films were fabricated by electron beam evaporation and the films were annealed in different conditions in N2 ambient. The hexagonal molybdenum ditelluride thin films with well crystallization annealed at 470°C or higher were obtained by solid state reactions. Thermal stability measurements indicate the formation of MoTe2 took place at about 350°C, and a subtle weight-loss was in the range between 30°C and 500°C. The evolution of the chemistry for Mo-Te thin films was performed to investigate the growth of the MoTe2 thin films free of any secondary phase. And the effect of other postdeposition treatments on the film characteristics was also investigated.

  6. Crystallochemical transformations at low temperature reduction of molybdenum trioxide

    International Nuclear Information System (INIS)

    Solonin, Yu.M.

    1979-01-01

    Results are given of studying development of reaction products morphology at different stages of reduction of molybdenum trioxide separate crystals. It is determined that character of MoO 3 macrocrystals destruction at the first stage (MoO 3 -MoO 2 ) is determined by anisotropy of the chemical bond at the original crystal. MoO 2 nuclei are formed as intensively branched dendrite-like single crystals regularly oriented with respect to MoO 3 crystal. The degree of branching is determined by the reduction temperature and increases with its decrease. Formation of MoO 2 nuclei is proceeded by appearance of crystallographic shear planes in MoO 3 crystal. At the stage of MoO 2 -Mo transition no additional development of the reduction products surface takes place. The forming molybdenum crystals are strongly textured

  7. Novel target configurations for selective ionization state studies in molybdenum

    International Nuclear Information System (INIS)

    Ilcisin, K.J.; Feldman, U.; Schwob, J.L.; Wouters, A.; Suckewer, S.; Princeton Univ., NJ

    1990-03-01

    Details of experiments aimed at achieving low ionization state selectivity in molybdenum are presented. Targets are excited with a 10 J CO 2 laser and the resultant VUV spectrum (300--700 Angstrom) has been studied. Combinations of focal spot size, target depth, and target geometries are compared. Simple attenuation of energy is shown not to vary ionization stage composition significantly. Experiments conducted with grazing incidence targets result only in a hot plasma. Modular targets with cooling cylinders of various radii demonstrated good selectivity of the ionization states, but with low absolute signals. Finally, results from combinations of focal spot adjustment and radiative cooling illustrate increased control over desired plasma temperature and density for spectroscopic studies of molybdenum. 7 refs., 14 figs

  8. Preparation and properties of molybdenum-tungsten-carbonitrides

    International Nuclear Information System (INIS)

    Schreiner, M.; Ettmayer, P.; Kieffer, R.

    1982-01-01

    Molybdenum-tungsten-carbonitrides can be prepared by reacting prealloyed powders of Mo and W with carbon in the presence of nitrogen or ammonia. Single phase carbonitrides (Mo,W) (C,N) with the WC-type structure can be obtained. The nitrogen content of these carbonitrides increases with increasing molybdenum content. Flowing ammonia has a decarburizing effect, which has to be counterbalanced by an addition of a carbonaceous gas such as methane. Nitrogen instead of ammonia is equally effective and gives carbonitrides which have a nitrogen content only insignificantly lower than the carbonitrides obtained in flowing ammonia. The lattice parameters of the carbonitrides are found to slightly smaller than the lattice parameters of the corresponding carbides. (Author)

  9. In situ hydrogenation of molybdenum oxide nanowires for enhanced supercapacitors

    KAUST Repository

    Shakir, Imran

    2014-01-01

    In situ hydrogenation of orthorhombic molybdenum trioxide (α-MoO 3) nanowires has been achieved on a large scale by introducing alcohol during the hydrothermal synthesis for electrochemical energy storage supercapacitor devices. The hydrogenated molybdenum trioxide (H xMoO3) nanowires yield a specific capacitance of 168 F g-1 at 0.5 A g-1 and maintain 108 F g-1 at 10 A g-1, which is 36-fold higher than the capacitance obtained from pristine MoO3 nanowires at the same conditions. The electrochemical devices made with HxMoO3 nanowires exhibit excellent cycling stability by retaining 97% of their capacitance after 3000 cycles due to an enhanced electronic conductivity and increased density of hydroxyl groups on the surface of the MoO3 nanowires. This journal is © The Royal Society of Chemistry.

  10. Native iron

    DEFF Research Database (Denmark)

    Brooks, Charles Kent

    2015-01-01

    System, was reduced. The oxidized outer layers of the Earth have formed by two processes. Firstly, water is decomposed to oxygen and hydrogen by solar radiation in the upper parts of the atmosphere, the light hydrogen diffusing to space, leaving oxygen behind. Secondly, plants, over the course......, hematite, or FeO.Fe2O3, magnetite), with carbon in the form of coke. This is carried out in a blast furnace. Although the Earth's core consists of metallic iron, which may also be present in parts of the mantle, this is inaccessible to us, so we must make our own. In West Greenland, however, some almost......We live in an oxidized world: oxygen makes up 22 percent of the atmosphere and by reacting with organic matter produces most of our energy, including the energy our bodies use to function: breathe, think, move, etc. It has not always been thus. Originally the Earth, in common with most of the Solar...

  11. Critical evaluation of molybdenum and its alloys for use in space reactor core heat pipes

    International Nuclear Information System (INIS)

    Lundberg, L.B.

    1981-01-01

    The choice of pure molybdenum as the prime candidate material for space reactor core heat pipes is examined, and the advantages and disadvantages of this material are brought into focus. Even though pure molybdenum heat pipes have been built and tested, this metal's high ductile-brittle transition temperature and modest creep strength place significant design restrictions on a core heat pipe made from it. Molybdenum alloys are examined with regard to their promise as potential replacements for pure molybdenum. The properties of TZM and molybdenum-rhenium alloys are examined, and it appears that Mo-Re alloys with 10 to 15 wt % rhenium offer the most advantage as an alternative to pure molybdenum in space reactor core heat pipes

  12. Friction and corrosion resistance of sputter deposited supersaturated metastable aluminium-molybdenum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Zeid, O.A. [Univ. of the United Arab Emirates, Al-Ain (United Arab Emirates). Dept. of Mech. Eng.; Bates, R.I. [Design, Mfg. and Marketing Research Inst., Univ. of Salford (United Kingdom)

    1996-12-15

    Two closed field unbalanced magnetrons with targets of aluminium and molybdenum have been used for the co-deposition of aluminium-molybdenum coatings with different compositions. A pin on disk machine and a computer controlled potentiostat have been used to evaluate respectively, the tribological and corrosion properties of the deposited alloys. Results have shown that introducing molybdenum into aluminium coatings improves their poor tribological properties. Aluminium-molybdenum coatings with different compositions have shown low wear behaviour and for coatings with high molybdenum contents (> 80%) friction coefficients against steel, as low as 0.18 have been obtained. The addition of molybdenum into aluminium coatings has reduced their corrosion tendency and corrosion current density in a marine environment. (orig.)

  13. Lead poisoning

    Science.gov (United States)

    ... drinking water in homes containing pipes that were connected with lead solder . Although new building codes require ... lead in their bodies when they put lead objects in their mouths, especially if they swallow those ...

  14. Lead Poisoning

    Science.gov (United States)

    Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

  15. Suitability of the hydrocarbon-hydroxylating molybdenum-enzyme ethylbenzene dehydrogenase for industrial chiral alcohol production.

    Science.gov (United States)

    Tataruch, M; Heider, J; Bryjak, J; Nowak, P; Knack, D; Czerniak, A; Liesiene, J; Szaleniec, M

    2014-12-20

    The molybdenum/iron-sulfur/heme protein ethylbenzene dehydrogenase (EbDH) was successfully applied to catalyze enantiospecific hydroxylation of alkylaromatic and alkylheterocyclic compounds. The optimization of the synthetic procedure involves use of the enzyme in a crude purification state that saves significant preparation effort and is more stable than purified EbDH without exhibiting unwanted side reactions. Moreover, immobilization of the enzyme on a crystalline cellulose support and changes in reaction conditions were introduced in order to increase the amounts of product formed (anaerobic atmosphere, electrochemical electron acceptor recycling or utilization of ferricyanide as alternative electron acceptor in high concentrations). We report here on an extension of effective enzyme activity from 4h to more than 10 days and final product yields of up to 0.4-0.5g/l, which represent a decent starting point for further optimization. Therefore, we expect that the hydrocarbon-hydroxylation capabilities of EbDH may be developed into a new process of industrial production of chiral alcohols. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Weldability of molybdenum and its alloy sheet, 1

    International Nuclear Information System (INIS)

    Matsuda, Fukuhisa; Ushio, Masao; Nakata, Kazuhiro; Edo, Yoshiaki

    1979-01-01

    Basic weldability of electron-beam melted pure molybdenum has been examined in electron-beam welding in high vacuum and GTA welding in pure and air mixed argon atmospheres by paying attention to weld defects such as hot cracking and porosity in weld metal and also mechanical properties of welded joint in comparison with conventional TZM alloys. The main conclusions obtained were as follows; (1) The weld metals of electron-beam melted pure molybdenum with electron-beam and GTA weldings in pure and air mixed argon atmosphere up to about 1% were almost porosity free. However, large amount of oxygen content of 200 ppm in powder-metallurgy TZM alloy made very porous weld bead in electron-beam welding in high vacuum. Therefore, oxygen content in base metal should be lowered to the minimum, that is, less than 10 ppm, especially in electron-beam welding in high vacuum. (2) Hot cracking occurred in the weld metal of GTA welding when air content in argon atmosphere exceeded about 0.6% for electron-beam melted pure molybdenum and powder metallurgy TZM alloy. In less than 0.26% air, no hot cracking were observed in this experiment. Moreover, in electron-beam welding, no hot cracking was observed in weld metals for both materials. In order to prevent the formation of hot cracking, the purity of welding atmosphere should be kept as high as possible. (3) Joint efficiency of the welded joint of electron-beam melted pure molybdenum with electron-beam welding was 50 to 60% to base metal at room temperature and 500 0 C and almost 100% at 1000 0 C. Those of GTA welds in pure and 0.13% air mixed argon atmospheres were fairly lower than those in electron-beam welding for each testing temperature. (author)

  17. Ternary cobalt-molybdenum-zirconium coatings for alternative energies

    Science.gov (United States)

    Yar-Mukhamedova, Gulmira; Ved', Maryna; Sakhnenko, Nikolay; Koziar, Maryna

    2017-11-01

    Consistent patterns for electrodeposition of Co-Mo-Zr coatings from polyligand citrate-pyrophosphate bath were investigated. The effect of both current density amplitude and pulse on/off time on the quality, composition and surface morphology of the galvanic alloys were determined. It was established the coating Co-Mo-Zr enrichment by molybdenum with current density increasing up to 8 A dm-2 as well as the rising of pulse time and pause duration promotes the content of molybdenum because of subsequent chemical reduction of its intermediate oxides by hydrogen ad-atoms. It was found that the content of the alloying metals in the coating Co-Mo-Zr depends on the current density and on/off times extremely and maximum Mo and Zr content corresponds to the current density interval 4-6 A dm-2, on-/off-time 2-10 ms. Chemical resistance of binary and ternary coatings based on cobalt is caused by the increased tendency to passivity and high resistance to pitting corrosion in the presence of molybdenum and zirconium, as well as the acid nature of their oxides. Binary coating with molybdenum content not less than 20 at.% and ternary ones with zirconium content in terms of corrosion deep index are in a group ;very proof;. It was shown that Co-Mo-Zr alloys exhibits the greatest level of catalytic properties as cathode material for hydrogen electrolytic production from acidic media which is not inferior a platinum electrode. The deposits Co-Mo-Zr with zirconium content 2-4 at.% demonstrate high catalytic properties in the carbon(II) oxide conversion. This confirms the efficiency of materials as catalysts for the gaseous wastes purification and gives the reason to recommend them as catalysts for red-ox processes activating by oxygen as well as electrode materials for red-ox batteries.

  18. Determination of U (Ⅵ) content in uranium molybdenum ores

    International Nuclear Information System (INIS)

    Wang Haisheng; Ding Hongfang

    2014-01-01

    Potentionmetric titration is established to determine U (Ⅵ) in uranium molybdenum ores. In the closed condition, U (Ⅵ) is leached by carbonate solution. U (Ⅵ) is reduced to U (Ⅳ) by ferrous sulfate in phosphoric acid. The exess ferrous sulfate is oxidized by sodium nitrite. urea decompose the exess sodium nitrite. U (Ⅳ) is titrated by ammonium metavanadate standard solution with potentionmetric titration. The precision is better than 5%, The recovery rate is 97.2%∼101.9%. (authors)

  19. Deposit of molybdenum associated with uranium in Pena Blanca, Mexico

    International Nuclear Information System (INIS)

    Reyes-Cortes, M.

    1985-01-01

    The uranium-molybdenum deposits are in the Sierra Pena Blanca, 45 km north of the city of Chihuahua. The largest amounts of uranium-molybdenum ore are found in the area of Las Margaritas-Puerto III. The ratio of molybdenum mineralization to uranium is 2:1 in this area and the deposits are distributed at depths of 55-100 m in ignimbritic rocks of the so called Escuadra Formation. This volcanic unit consists of an altered crystalline-lithic ash-flow tuff of Oligocene age. The molybdenum mineral occurs as powellite (CaMoO 4 ) and is found predominantly in two size ranges: phenocrysts 0.1-20 mm in diameter are abundant in the upper part of the deposit, while a material which varies between cryptocrystalline and amorphous predominates in the lower part. This latter material can easily be identified inside the mine by its strong orange fluorescence; it is also easy to recover by leaching. In contrast, the metallurgical process of recovery by leaching of the phenocrystalline portion of the powellite has so far presented problems. Powellite is generally found in association with carnotite, margaritasite and uranophane, and its mineralization consists of disseminated lumps, druses, crustifications and veins; frequently, it partially replaces the phenocrysts of argillized feldspars of the Escuadra Formation. Fractured and brecciated zones with intense oxidation of jarosite, haematite, limonite and goethite sometimes show high U-Mo concentrations; on other occasions the concentration is found with alunite at the contact between the ignimbrite and the layers of argillized vitrophyre. The mineralizations of fluorite, pyrite, jarosite, alunite and opal are indicative of hydrothermal deposition, possibly at low temperature with supergene or geothermal alterations. (author)

  20. Concentrations of boron, molybdenum, and selenium in chinook salmon

    Science.gov (United States)

    Hamilton, Steven J.; Wiedmeyer, Raymond H.

    1990-01-01

    The concentrations of boron, molybdenum, and selenium in young chinook salmon Oncorhynchus tshawytscha were determined in three partial life cycle chronic toxicity studies. In each study, fish were exposed to a mixture of boron, molybdenum, selenate, and selenite in the proportions found in subsurface agricultural drainage water in the basin of the San Joaquin Valley, California. Tests were conducted in well water and in site-specific fresh and brackish waters. No boron or molybdenum was detected in fish exposed to concentrations as high as 6,046 μg boron/L and 193 μg molybdenum/L for 90 d in well water or fresh water; however, whole-body concentrations of selenium increased with increasing exposure concentrations in well water and fresh water, but not in brackish water. Concentrations of selenium in chinook salmon were strongly correlated with reduced survival and growth of fish in well water and with reduced survival in a 15-d seawater challenge test of fish from fresh water. Concentrations of selenium in fish seemed to reach a steady state after 60 d of exposure in well water or fresh water. Fish in brackish water had only background concentrations of selenium after 60 d of exposure, and no effects on survival and growth in brackish water or on survival in a 10-d seawater challenge test were exhibited. This lack of effect in brackish water was attributed to initiation of the study with advanced fry, which were apparently better able to metabolize the trace element mixture than were the younger fish used in studies with well water and fresh water. In all three experimental waters, concentration factors (whole-body concentration/waterborne concentration) for selenium decreased with increasing exposure concentrations, suggesting decreased uptake or increased excretion, or both, of selenium at the higher concentrations.