Health & Environmental Research Online (HERO)


Molybdenum (7439-98-7 )


21,129 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Constructing sphere-like cobalt-molybdenum-nickel ternary hydroxide and calcined ternary oxide nanocomposites for efficient removal of U(VI) from aqueous solutions

Authors: Yu, S; Yin, L; Pang, H; Wu, Y; Wang, X; Zhang, Pan; Hu, B; Chen, Z; Wang, X (2018) HERO ID: 4842369

[Less] Uranium is considered to be a strategic means for the nuclear power as well as a worldwide highly toxic . . . [More] Uranium is considered to be a strategic means for the nuclear power as well as a worldwide highly toxic pollutant. For the enhanced U(VI) elimination from wastewater, novel Co-Mo-Ni ternary hydroxide (CMN) and calcined CMN (CCMN) nanocomposites were prepared via a simplistic single-step hydrothermal technique and calcination process. The elimination process and adsorption property of U(VI) on CMN and CCMN were analysed by batch experiment as well as spectroscopy analysis, and the researches showed that U(VI) was formed stable and strong complexes with the surface groups of CMN and CCMN. The maximal removal capacities of U(VI) on CMN and CCMN amounted to be 585.6 and 973.7 mg/g at pH = 5.0 and T = 298 K, correspondingly, that exhibited competitiveness with the majority of the reported adsorbents. The U(VI) uptake was substantially impacted by the tested solution pH and not affected by the ionic strength, which revealed that the interaction mechanism was primarily inner-sphere surface complexation, which received further confirmation by the XPS analysis. Based on the above analyses, the facile synthesis process and excellent U(VI) elimination performance denoted that the ternary (hydr)oxide materials were applicable as an attractive adsorbent for the radionuclides preconcentration and removal from aqueous solutions in natural environmental management.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Efficient Technology for Combined Processing of Silicate and Carbonate Uranium Ores

Authors: Smirnov, KM; Molchanova, TV; Akimova, ID; Krylova, OK (2018) HERO ID: 4695456

[Less] The results of studies on the processing of carbonate ores with extraction of uranium and molybdenum . . . [More] The results of studies on the processing of carbonate ores with extraction of uranium and molybdenum by means of autoclave and atmospheric leaching and sorption extraction of valuable components using carboxyl cationionites and strongly basic anionites are presented. The most stable and highest indices for the extraction of uranium and molybdenum into solution were obtained for autoclave leaching with the following process parameters: pressure 12-14 psig, temperature similar to 140A degrees C, pulp processing time 4-6 h, and initial sodium carbonate concentration 40-50 g/dm(3). The degree of extraction of uranium and molybdenum into solution was 96%. Almost complete separation of uranium from molybdenum was obtained on carboxyl cationites without bicarbonate solutions in the pH range 6.5-7.5. An efficient technology is proposed for combined processing of silicate and carbonate ores using a unified sorption scheme making it possible to extract uranium and molybdenum separately while obtaining ammonium uranyl tricarbonate and ammonium paramolybdate.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Uranium isotope geochemistry in modern coastal sediments: Insights from Toulon Bay, France

Authors: Duc Huy Dang; Evans, RD; Wang, Wei; Omanovic, D; El Houssainy, A; Lenoble, V; Mullot, JU; Mounier, S; Garnier, C (2018) HERO ID: 4695914

[Less] By assessing U geochemistry in marine sediments of Toulon Bay (NW Mediterranean Sea), authigenic U accumulation . . . [More] By assessing U geochemistry in marine sediments of Toulon Bay (NW Mediterranean Sea), authigenic U accumulation was found to be tightly linked to that of Mo and V with slight differences in accumulation rate depending on sediment redox conditions. In sediments collected on a transect along a river plume, the authigenic accumulation of these redox-sensitive elements appears to be linked to sediment grain size which probably drives the redox status of the sediments. A typical U loss in re-oxidized sediments was observed in sediments that had been previously disturbed. However, the dissolved U profiles do not show a simple and typical depletion trend but rather a depletion in the top 10 cm followed by release in deeper pore waters that could be linked to a potential reoxidation/mobilization of authigenic U(IV). The released U could be further scavenged as a U-P precipitate.

The U isotopic data (delta U-238), which are the first reported for the coastal hypoxic sediments of Toulon Bay, average -0.12 +/- 0.12% in surface sediments. However, sediments situated in front of river mouths show higher values of delta U-238 (up to +0.75%); these high values are reported for the first time in sediments below an oxic water column.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Uranium assay and trace element analysis of the fourth collaborative material exercise samples by the modified Davies-Gray method and the ICP-MS/OES techniques

Authors: Nelwamondo, AN; Colletti, LP; Lindvall, RE; Vesterlund, A; Xu, N; Tan, AHJun; Eppich, GR; Genetti, VD; Kokwane, BL; Lagerkvist, P; Pong, BKin; Rameback, H; Tandon, Lav; Rasmussen, G; Varga, Z; Wallenius, M (2018) HERO ID: 4697720

[Less] An international group of laboratories participating in CMX-4 subjected three samples to comparative . . . [More] An international group of laboratories participating in CMX-4 subjected three samples to comparative nuclear forensic analysis using uranium assay and trace element analysis techniques to determine if the samples had similar or different origins. Uranium assay indicated that two pellet samples (ES-2 and ES-3) were nearly pure UO2 while the black powder sample ES-1 was primarily UO2 with UO3 and/or U3O8 forms present as impurities. Trace element analysis by five of the six participating laboratories reported molybdenum concentrations below 10 A mu g/g U in all of the exercise samples, suggesting the same likely facility of origin for all three samples.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Uranium adsorption from sulfuric acid media using silica materials functionalised with amide and phosphorous ligands

Authors: Le Nedelec, Tom; Charlot, A; Calard, F; Cuer, F; Leydier, A; Grandjean, A (2018) HERO ID: 4843675

[Less] Various functionalised silica materials have been investigated as uranium extractants from sulfuric . . . [More] Various functionalised silica materials have been investigated as uranium extractants from sulfuric acid solutions. Silica was grafted with zero, one or two amido and phosphonate groups either directly or by peptide coupling. The role of the residual functions (silanol, amine and amide) was evaluated. Our results show that the uranium extraction efficiency of materials bearing residual silanol or amide groups may be affected by the presence of molybdenum. Comparing the performance of materials with different numbers of phosphonic acids on the phosphonate group revealed that only those with a monoacid function extract uranium efficiently. Among these materials, those with a diamido phosphonate ligand demonstrated the highest selectivity for uranium versus iron. Adjusting the length and steric hindrance of the alkyl chains of the amido and the phosphonate group, the best extraction capacity and selectivity versus iron were achieved with a butyl group on the phosphonate and an ethyl group on the ternary amide of the diamido phosphonate ligand. Finally, the [ligand]/[U] ratio was found not to vary with the alkyl chain at the end of the amido group or with the bridge length between the carbamoyl monophosphonate extracting group and the amidopropyl anchor to the silica, suggesting that the extraction mechanism remains unchanged.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Calculation of the displacement energy of alpha and gamma uranium

Authors: Beeler, B; Zhang, Y; Okuniewski, M; Deo, C (2018) HERO ID: 4836954

[Less] Uranium (U) is alloyed with molybdenum (Mo) or zirconium (Zr) in order to stabilize the high-temperature . . . [More] Uranium (U) is alloyed with molybdenum (Mo) or zirconium (Zr) in order to stabilize the high-temperature body-centered cubic gamma phase of uranium for use in nuclear reactors. Although these two alloy systems possess different mechanical, chemical and thermodynamic properties, they exhibit a similarity in that there exists alpha variable degree of phase decomposition from the cubic gamma phase of uranium to the orthorhombic a phase of uranium, depending on both the Mo/Zr content and fabrication conditions. These two alpha phases of uranium are believed to exhibit distinct swelling and radiation damage behavior. Understanding the differences in behavior under irradiation between the alpha and gamma phases can provide valuable information to guide the manufacturing process of U alloys and can inform multiphysics, continuum-level fuel performance codes. The threshold displacement energy (TDE) is the minimum amount of kinetic energy required to displace an atom from its lattice site. It is critically important to determine an accurate value of the TDE in order to calculate the total number of displacements due to a given irradiation condition, and thus to understand the materials response to irradiation. In this study, molecular dynamics simulations have been performed to calculate the threshold displacement energy for both the alpha and gamma phases of uranium as a function of temperature. This study utilizes three different interatomic potentials that have been previously developed: U MEAM, U-Zr MEAM and U-Mo ADP. The threshold displacement energy in gamma U at 800 K is 73.2 eV, 47.1 eV and 35.6 eV for the U MEAM, U-Zr MEAM and U-Mo ADP potentials. respectively. The threshold displacement energy for alpha U at 600 K is 66.3 eV for the U-Mo ADP. Published by Elsevier B.V.

Journal Article
Journal Article

Mo-98/Mo-95 and U-238/U-235 in lamproites, shoshonites, and high-K calc-alkaline rocks from Western Alps: inferences on their genesis

Author: Casalini, M (2018) HERO ID: 4839069

[Less] Oligocene ultrapotassic and associated potassic rocks from Western Alps derived from the crystallisation . . . [More] Oligocene ultrapotassic and associated potassic rocks from Western Alps derived from the crystallisation of magmas originated from partial melting of mantle sources extremely enriched in recycled crustal components. These rocks are well suited for studying the effects of subduction-related, sediment-derived metasomatism on Molybdenum and Uranium isotopes. This paper reports the first Mo-98/Mo-95 and U-238/U-235 data on potassic and ultrapotassic rocks at destructive plate margins. Both Mo-98/Mo-95 and U-238/U-235 ratios show large variations in the samples from Western Alps. U isotope compositions are consistent with an increasing role of metasomatising melts from recycled sediments, which explains the variable enrichment in potassium and incompatible trace elements passing from high-K calc-alkaline to lamproitic magmas through shoshonitic ones. The variation of Mo isotope compositions is more complex due to the extreme depletion in Mo observed and since their values exceed the range observed for volcanic arcs. These features were investigated considering several possible processes such as secondary weathering, hosting of Mo related to residual mineral phases during sediment melting or physical removal during subduction. The results were also discussed in the framework of the complex processes responsible for the genesis and geochemical characteristics of the Tethyan Realm Lamproites, particularly in relationship with the exotic SALATHO geochemical component.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Minerals and Trace Elements in Milk, Milk Products, Infant Formula, and Adult/Pediatric Nutritional Formula, ICP-MS Method: Collaborative Study, AOAC Final Action 2015.06, ISO/DIS 21424, IDF 243

Authors: Pacquette, LH; Thompson, JJ; Malaviole, I; Zywicki, R; Woltjes, F; Ding, Y; Mittal, A; Ikeuchi, Y; Sadipiralla, B; Kimura, S; Veltman, H; Miura, A (2018) Journal of AOAC International 101:536-561. HERO ID: 4266386

[Less] AOAC Final Action Official MethodSM 2015.06 "Minerals and Trace Elements in Milk, Milk Products, . . . [More] AOAC Final Action Official MethodSM 2015.06 "Minerals and Trace Elements in Milk, Milk Products, Infant Formula and Adult/Pediatric Nutritional Formula, ICP-MS Method" was collaboratively studied. Note that "milk, milk products" has now been added to the title of the Final Action method because whole milk and several dairy ingredients were successfully incorporated into the collaborative study for the purpose of developing an International Organization for Standardization/International Dairy Federation standard (ISO/DIS 21424; in progress). The method determines sodium, magnesium, phosphorus, potassium, calcium, iron, manganese, zinc, copper, chromium, molybdenum, and selenium by inductively coupled plasma (ICP)-MS after microwave digestion. Ten laboratories participated in the study, and data from five different model ICP-MS units were represented. Thirteen products, five placebo products, and six dairy samples were tested as blind duplicates in this study, along with a standard reference material, for a total 50 samples. The overall repeatability and reproducibility for all samples met Standard Method Performance Requirements put forth by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals, with a few exceptions. Comparisons are made to ICP-atomic emission data from a collaborative study of AOAC Official Method 2011.14 carried out concurrently on these same samples.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Redox evolution during Eemian and Holocene sapropel formation in the Black Sea

Authors: Wegwerth, A; Eckert, S; Dellwig, O; Schnetger, B; Severmann, S; Weyer, S; Brueske, A; Kaiser, J; Koester, J; Arz, HW; Brumsack, HJ (2018) HERO ID: 4270240

[Less] The Black Sea repeatedly experienced major hydrographic changes during glacial-interglacial transitions, . . . [More] The Black Sea repeatedly experienced major hydrographic changes during glacial-interglacial transitions, with alternating limnic and brackish stages. While the redox conditions during the present Holocene brackish period (since similar to 9,000 yr BP) have been intensively studied, the redox evolution during the last interglacial, the Eemian (similar to 128,000-120,000 yr BP), remains largely unexplored. With its at least 3 degrees C warmer climate and an up to 10 m higher global sea level, the Eemian could open a window into the future development of the Black Sea. This study provides a detailed comparison of the Black Sea redox evolution during Eemian and Holocene sapropel formation. We show that the redox conditions and associated geochemical processes in the Black Sea water column can strongly deviate from the Holocene when sea level and climate conditions are different. Mo/Al and Re/Mo as well as Mo and Fe isotope proxies record a comparatively uniform rise of the Eemian redoxcline culminating in pronounced euxinia. This scenario strongly contrasts with weaker euxinic conditions during the Holocene Unit II sapropel (similar to 8,000-2,500 yr BP). Higher Mo/TOC ratios during the Eemian and Mo inventory considerations suggest a higher Eemian Mo availability, possibly due to an improved connection to the Mediterranean Sea. We conclude that higher temperatures, productivity, sea level -associated salinity changes, and corresponding higher sulphide levels were ultimately responsible for enhanced trace metal enrichment during the Eemian Black Sea sapropel stage.

Journal Article
Journal Article

INFLUENCE OF CARBIDE-PROMOTING ELEMENTS ON THE PEARLITE CONTENT AND THE TENSILE PROPERTIES OF HIGH SILICON SSDI DUCTILE IRON

Authors: Riebisch, M; Soenke, HG; Pustal, B; Buehrig-Polaczek, A (2018) HERO ID: 4260064

[Less] Steel scrap is one of the most important raw materials for the production of ductile iron (DI) because . . . [More] Steel scrap is one of the most important raw materials for the production of ductile iron (DI) because of its low cost. Most low alloyed steels contain carbide-promoting elements such as chromium, manganese, molybdenum and niobium and are currently not used for the production of DI because of their negative impact on the mechanical properties. The solid solution strengthened DI grades (SSDI) exhibit an increased tolerance toward carbide-promoting elements and thus allow the production of ferritic DI using low alloyed steel scrap. Therefore, the tolerance limits of these elements need to be identified. The following article shows the influence of low contents of Cr, Mn, Mo and Nb on the microstructure and the tensile properties of the SSDI grade EN-GJS-500-14. The results indicate that even low levels of chromium and molybdenum have a negative impact on tensile properties, whereas manganese and niobium are tolerable up to much higher levels.