43,287 results on '"molybdenum"'
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152. Molybdenum powder induced Fe2+/Fe3+ cycling enhanced activation peroxydisulfate for degradation of AO7: cost analysis, degradation mechanism, and toxicity evaluation.
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Lin, Yingzi, Chen, Jing, Chen, Junjie, Chen, Lei, Yang, Hong, Sun, ShengBo, Sun, Ningning, Weng, Qixuan, and Tian, Shiqi
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FRONTIER orbitals , *COST analysis , *TOXICITY testing , *X-ray photoelectron spectroscopy , *MOLYBDENUM - Abstract
To address the disadvantage of poor degradation effect of Fe2+/peroxydisulfate (PDS) system, a co-catalyst was introduced in this study to construct a molybdenum (Mo)/Fe2+/PDS system for the degradation of Acid Orange 7 (AO7), and the degradation rate could reach 95.67%. The effects of different parameters (initial pH, Fe2+ concentration, etc.) on the degradation effect of AO7 in this system were investigated, and the optimal degradation conditions were obtained by combining cost analysis. Cycling experiments showed that Mo had good stability. The co-catalytic mechanism of Mo powder was determined using X-Ray Diffraction, Scanning Electron Microscope, and X-ray Photoelectron Spectroscopy. The effects of different inorganic anions on AO7 were discussed: Cl− and NO3− had little effect on degradation, while SO42− and HCO3− both inhibited the removal of AO7 from the system to different degrees, with HCO3− showing a greater inhibition than SO42−. The main active radicals were identified as sulfate radical (SO4·−) and hydroxyl radical (·OH). In addition, intermediates were identified, and the attack sites were determined by combining the highest occupied molecular orbital/lowest unoccupied molecular orbital energy levels and the Fukui index to hypothesize the degradation pathways. Toxicity indicators such as the mutagenicity of AO7 and intermediates were evaluated, and the overall trend of toxicity was decreasing. This study is expected to provide an efficient treatment process for dye wastewater. [ABSTRACT FROM AUTHOR]
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- 2024
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153. Structural and electronic properties of Mo‐decorated graphene, reduced graphene and reduced graphene oxide: a DFT calculation.
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Mohseninia, Nazanin, Rezagholipour Dizaji, Hamid, Memarian, Nafiseh, and Hajiabadi, Hossein
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GRAPHENE oxide , *GRAPHENE , *MOLYBDENUM , *FRONTIER orbitals , *DENSITY functional theory , *BAND gaps - Abstract
The structural and electronic properties of pure graphene, graphene with a vacancy, graphene with two vacancies and molybdenum‐doped graphene were investigated. In addition, the adsorption of Mo atoms on graphene (G), reduced graphene (rG) and reduced graphene oxide (rGO) was examined. The possible energies of different active adsorption sites of nanostructured Mo‐decorated G, rG and rGO have been calculated using density functional theory (DFT). Mo atoms are predicted to create bonds with six C atoms in G, three C atoms in rG, and both C and O atoms in rGO sheets after geometry optimizations. The study focused on changing the electronic structure of G, including opening the zero band gap and controlling the band structure, which was done by creating defects and adding impurities. The present study revealed a significant correlation between the adsorption of the Mo atom and the characteristics exhibited by frontier orbitals. The results indicated that the adsorption characteristics of Mo atoms in pure G, rG and rGO are different, despite chemisorption being the common mechanism. Specifically, Mo‐decorated rG exhibited higher adsorption energy, while Mo‐decorated G demonstrated a lower adsorption energy. According to these findings, it is reasonable to anticipate that Mo‐decorated rG could be applied as a novel adsorbent for the removal of pollutants. [ABSTRACT FROM AUTHOR]
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- 2024
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154. Theoretical Study of Carbon K‐Edge Energy‐Loss Near‐Edge Structure Spectra in the Ordered Mo2TiAlC2 MAX and Mo2TiC2 MXene.
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Derikvandi, Zahra and Dadsetani, Mehrdad
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QUANTUM confinement effects , *DENSITY functional theory , *CHARGE exchange , *MOLYBDENUM , *CHEMICAL bond lengths , *TRANSITION metals , *X-ray absorption near edge structure , *CHEMICAL shift (Nuclear magnetic resonance) - Abstract
By means of density functional theory, the energy‐loss near‐edge structure (ELNES) of carbon K‐edge of Mo2TiAlC2 and corresponding MoTiC2 Mxene at orientational‐independent condition is dealt with. Compared to the MAX (M is transition metal, A is an elment from group 13–16, X is C or N) phase, the energy separations increase between the main spectral features at the C K edge of Mo2TiC2 MXene owing to the structural change and decreased bond length. The dispersions of the C K edge in both systems are similar to p‐symmetry densities of states. It is indicated that the source of the first fine structure at the C 1s edge in both phases mainly comes from the electron transfer to px + py‐like character. The other fine structures result from the transition to hybridization of pz and px + py states with the prominent contribution of px + py‐like character. Moreover, the comparison of C K‐edge ELNES spectra in three Mo‐based compounds reveals that, ongoing from Mo2TiAlC2 to Mo2TiC2 and then to Mo2C, the energy position of the fine structures is shifted to higher energies (blueshifted), due to the quantum confinement effects and the change of the chemical environment around the excited carbon. [ABSTRACT FROM AUTHOR]
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- 2024
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155. Late-Onset Molybdenum Cofactor Deficiency Type A: A Treatable Cause of Developmental Delay.
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Lund, Allan M., Berland, Siren, Tangeraas, Trine, Christensen, Mette, Confer, Nils, Squires, Liza, and Brannsether, Bente
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HETEROCYCLIC compounds , *METALS in the body , *GENOME-wide association studies , *MOLYBDENUM , *INBORN errors of metabolism , *BRAIN , *VITAMIN B12 , *MAGNETIC resonance imaging , *CHILD development deviations , *URINALYSIS , *SEQUENCE analysis , *GENETIC testing , *COENZYMES , *BIOMARKERS , *DISEASE complications ,INBORN errors of metabolism diagnosis ,DIAGNOSIS of child development deviations - Abstract
Molybdenum cofactor deficiency classically presents in neonates with intractable seizures; however, milder cases generally present before age 2 years with developmental delays and may go undiagnosed. Early diagnosis, and safe, US Food and Drug Administration-approved substrate replacement are critical to preserve neurologic function. This article discusses 2 children who presented with late-onset molybdenum cofactor deficiency type A. [ABSTRACT FROM AUTHOR]
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- 2024
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156. The Effect of Cr Addition on the Strength and High Temperature Oxidation Resistance of Y 2 O 3 Dispersion Strengthened Mo Composites.
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Guan, Haochen, Lv, Chongshan, Ding, Qingming, Wang, Guangda, Xiong, Ning, and Zhou, Zhangjian
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DISPERSION strengthening , *MOLYBDENUM , *MECHANICAL alloying , *POWDERS , *SOLUTION strengthening , *ALLOY powders , *HIGH temperatures , *OXIDATION , *GRAIN refinement - Abstract
Y2O3 dispersion-strengthened Molybdenum (Mo) composites were prepared by the mechanical alloying of Mo and Y powders then consolidation by spark plasma sintering. The effects of Chromium (Cr) addition (0 wt. %, 5 wt. %, 10 wt. % and 15 wt. %, respectively) on the mechanical performance and high-temperature oxidation resistance of Mo-Y2O3 were investigated. The introduction of Cr had a significant influence on the mechanical property and oxidation resistance of the Mo-Y2O3 composite. The highest bending strength reached 932 MPa when the addition of Cr content was 5 wt. % (Mo–5Cr–1Y sample). This improvement is likely attributable to the dual mechanism of grain refinement and solid solution strengthening. Moreover, the Mo–5Cr–1Y sample showed the thinnest oxide layer thickness after high-temperature oxidation tests, and exhibited the best oxidation resistance performance compared with the other samples. First principle calculation reveals that Cr could improve the Mo–MoO3 interface bonding to prevent rapid spalling of the oxide layer. Meanwhile, Cr also facilitates the formation of the dense Cr2(MoO4)3 layer on the surface, which can inhibit further oxidation. [ABSTRACT FROM AUTHOR]
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- 2024
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157. Timing and Tectonic Setting of the Gaoaobei Tungsten-Molybdenum Deposit in Nanling Range, South China.
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Li, Jianfeng, Ma, Kemeng, Lu, Youyue, Fu, Jianming, Cheng, Shunbo, Li, Yuan, and Li, Chuanbiao
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RARE earth metals , *MOLYBDENUM , *OSMIUM , *GRANITE - Abstract
The Gaoaobei tungsten-molybdenum deposit is a newly discovered large-scale quartz-vein-type deposit in the Nanling metallogenic belt in South China. The ore bodies are hosted in the Indosinian granites and the Cambrian Xiangnan Group slates and are controlled by NWW-oriented faults, which are obviously different from the "five-story building" model in southern Jiangxi Province. The magmatic rocks in the study area are dominated by medium- to coarse-grained biotite monzogranite, with a few NW-oriented fine-grained granite dykes. The medium- to coarse-grained biotite monzogranite and fine-grained granite dykes have zircon U-Pb ages of 229.4 ± 1. 9 Ma (MSWD = 1.5) and 164.9 ± 3.3 Ma (MSWD = 0.75), respectively, corresponding to the Indosinian and Yanshanian magmatism. The monzogranites have higher contents of FeO, CaO, K2O, P2O5, and TiO2, while the granite dykes have slightly higher contents of SiO2, Al2O3, MnO, and Na2O. Their A/CNK values are 1.11–1.75 and 1.19–2.25, and the contents of CIPW normative corundum are 1.71%–6.66% and 2.41%–9.50%, suggesting both the monzogranites and granite dykes are S-type granite. The total amount of rare earth elements in the monzogranites (from 84.7 ppm to 129 ppm) is slightly lower than that in the granite dykes (from 128 ppm to 133 ppm). The Eu/Eu* values range from 0.12 to 0.30 in monzogranites and from 0.001 1 to 0.001 3 in granite dykes, indicating the fine-grained granites underwent more intense fractional crystallization. The monzogranite and granite dykes have high 87Sr/86Sri values of 0.716 9–0.719 3 and 0.728 25–0.728 80, low εNd(t) values ranging from −10.2 to −9.6 and from −11.5 to −11.4, and TDM2 ages of 1 835–1 785 and 1 957–1 946 Ma, respectively. These isotope data indicate their origin from the remelting of the Paleoproterozoic crustal materials. Combined with regional geology, it is concluded that the medium- to coarse-grained biotite monzogranite was formed in a post-collisional extensional environment. In addition, 40Ar-39Ar dating of the greisen type tungsten-molybdenum ore gave consistent plateau age of 164.0 ± 1.2 Ma, isochronal age of 162.0 ± 2.4 Ma and anti-isochronal age of 161.4 ± 1.8 Ma. Combined with the published molybdenite Re-Os age, the Gaoaobei tungsten-molybdenum deposit was formed at ∼164 Ma, which is inferred to be genetically related to the contemporaneous finegrained granite dykes (165 Ma). The deposit was likely formed during the large-scale magmatism and mineralization event in the early Yanshanian of the Nanling Range in an intra-continental extensional environment caused by the subduction of the paleo-Pacific plate. The late and small granite dykes within the large granite plutons thus require further attention during mineral prospecting in the regions. [ABSTRACT FROM AUTHOR]
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- 2024
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158. The critical role of a conserved lysine residue in periplasmic nitrate reductase catalyzed reactions.
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Giri, Nitai C., Mintmier, Breeanna, Radhakrishnan, Manohar, Mielke, Jonathan W., Wilcoxen, Jarett, and Basu, Partha
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NITRATE reductase , *CAMPYLOBACTER jejuni , *LYSINE , *CATALYTIC activity , *CHARGE exchange , *NITRITES - Abstract
Periplasmic nitrate reductase NapA from Campylobacter jejuni (C. jejuni) contains a molybdenum cofactor (Moco) and a 4Fe–4S cluster and catalyzes the reduction of nitrate to nitrite. The reducing equivalent required for the catalysis is transferred from NapC → NapB → NapA. The electron transfer from NapB to NapA occurs through the 4Fe–4S cluster in NapA. C. jejuni NapA has a conserved lysine (K79) between the Mo-cofactor and the 4Fe–4S cluster. K79 forms H-bonding interactions with the 4Fe–4S cluster and connects the latter with the Moco via an H-bonding network. Thus, it is conceivable that K79 could play an important role in the intramolecular electron transfer and the catalytic activity of NapA. In the present study, we show that the mutation of K79 to Ala leads to an almost complete loss of activity, suggesting its role in catalytic activity. The inhibition of C. jejuni NapA by cyanide, thiocyanate, and azide has also been investigated. The inhibition studies indicate that cyanide inhibits NapA in a non-competitive manner, while thiocyanate and azide inhibit NapA in an uncompetitive manner. Neither inhibition mechanism involves direct binding of the inhibitor to the Mo-center. These results have been discussed in the context of the loss of catalytic activity of NapA K79A variant and a possible anion binding site in NapA has been proposed. [ABSTRACT FROM AUTHOR]
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- 2024
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159. Fabrication of a Molybdenum Dioxide/Multi-Walled Carbon Nanotubes Nanocomposite as an Anodic Modification Material for High-Performance Microbial Fuel Cells.
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Ma, Jianchun, Wang, Lifang, Zhang, Yezhen, and Jia, Jianfeng
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CARBON nanotubes , *MULTIWALLED carbon nanotubes , *MOLYBDENUM , *ENERGY harvesting , *NANOCOMPOSITE materials , *TRANSITION metal oxides , *MICROBIAL fuel cells , *ANODIC oxidation of metals - Abstract
A nanocomposite of multi-walled carbon nanotubes (MWCNTs) decorated with molybdenum dioxide (MoO2) nanoparticles is fabricated through the reduction of phosphomolybdic acid hydrate on functionalized MWCNTs in a hydrogen–argon (10%) atmosphere in a tube furnace. The MoO2/MWCNTs composite is proposed as an anodic modification material for microbial fuel cells (MFCs). MWCNTs have outstanding physical and chemical peculiarities, with functionalized MWCNTs having substantially large electroactive areas. In addition, combined with the exceptional properties of MoO2 nanoparticles, the synergistic advantages of functionalized MWCNTs and MoO2 nanoparticles give a MoO2/MWCNTs anode a large electroactive area, excellent electronic conductivity, enhanced extracellular electron transfer capacity, and improved nutrient transfer capability. Finally, the power harvesting of an MFC with the MoO2/MWCNTs anode is improved, with the MFC showing long-term repeatability of voltage and current density outputs. This exploratory research advances the fundamental application of anodic modification to MFCs, simultaneously providing valuable guidance for the use of carbon-based transition metal oxide nanomaterials in high-performance MFCs. [ABSTRACT FROM AUTHOR]
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- 2024
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160. Influence of Molybdenum Tailings Powder on the Hydration Characteristics of Cement Paste.
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Meng, Weiqi, Ma, Kunlin, Long, Guangcheng, Meng, Qingyin, Chen, Rongjian, and Fan, Jiazhi
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MOLYBDENUM , *HEAT of hydration , *CEMENT , *PORTLAND cement , *PASTE , *HYDRATION , *POWDERS - Abstract
Molybdenum tailings are accumulated in large quantities, occupying the land and polluting the environment. Therefore, the resource utilization of molybdenum tailings is imperative. In this paper, the influence of molybdenum tailings powder (MTs) as admixture on hydration characteristics, including hydration heat, hydration products, phase composition, and mechanical properties evolution of cement paste were investigated. Results showed that the early hydration of cement paste can be promoted when the content of MTs is not more than 15%. The compressive strength of cement paste with 15% MTs at 3, 28, and 120 days was 89.37%, 96.14%, and 91.68% of that of the portland cement (PC) group, respectively. When the content of MTs does not exceed 15%, the second exothermic peak of hydration heat of cement paste appears ahead of time and the peak value increases. With the increase of MTs content, the cumulative heat release of 72 h gradually decreased. The addition of MTs does not produce new hydration products, but introduces the mineral phase of MTs itself, and leads to the early transformation of ettringite (AFt) into monosulfoaluminate (AFm) in paste. There is still a close linear relationship between the compressive strength and cumulative heat release and chemically bound water content after addition of MTs into cement paste. It was also discovered that the pozzolanic activity of MTs in cement paste mainly occurred from 3 to 28 days. After 28 days, the particle-filling effect of MTs was dominant mainly. The research results are expected to provide basic research for the resource utilization of MTs. [ABSTRACT FROM AUTHOR]
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- 2024
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161. Effect of the Foliar Application with Seaweed, Moringa Extracts, Molybdenum and Boron on The Vegetative Growth and Yield of Plum Trees.
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Harhash, Mohamed M. M., A. M., Aly M., Abdo, Mostafa A., and Mosa, Walid F. A.
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PLUM , *MORINGA , *MOLYBDENUM , *MARINE algae , *MICROIRRIGATION , *MARINE plants - Abstract
The current study was conducted during 2022 and 2023 seasons on plum (Prunus salicina Lindl.) cv. Kelsy was planted in sandy soil under a drip irrigation system in a private Farm located at Salah Al-Abd Village, Bostan Region, Nubaria, Behaira Governorate, Egypt to study the effect of foliar application of molybdenum 0.5 g/L, boron at 0.5 g/L, seaweed extract at 2000 ppm, moringa leaf extract at 4000 ppm, molybdenum 0.5g/L + boron 0.5g/L, molybdenum 0.5g/L + seaweed extract 2000ppm, molybedem0.5g/L + moringa extract 4000ppm, boron 0.5g/L + seaweed extract 2000ppm, boron 0.5 g/L + moringa extract 4000 ppm, seaweed extract 2000 ppm + moringa extract 4000 ppm and molybdenum 0.5g/L + boron 0.5g/L + moringa extract4000ppm + seaweed extract 2000 ppm as compared to the control treatments on vegetative growth and yield characteristics. The trees were planted at 3 x 3.5 m in sandy soil under a drip irrigation system. Sixty uniform trees of the same age, growth and size were randomly chosen. The foliar application of the twelve treatments was arranged in a randomized complete block design (RCBD) in five replicates during the two seasons. The trees were sprayed three times; before flowering, after fruit set and after one month after the second spraying. The obtained results showed that the application of the seaweed extract, moringa extract, boron and molybdenum individually or in combination effectively increased the vegetative growth attributes and fruit yield. The best results were obtained by the application of 0.5 g/L boron + 0.5 g/L molybdenum + seaweed extract + moringa extract in both seasons. [ABSTRACT FROM AUTHOR]
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- 2024
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162. Ligand‐promoted dehydrogenative coupling of γ‐/β‐amino alcohols with ketones to N‐heterocycles via molybdenum catalysts.
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Wang, Yuanyuan, Ma, Ning, Yan, Xiuli, Li, Libin, Lin, Qing, Han, Peng, Zhao, Bin, Mahmood, Qaiser, Liu, Qingbin, and Wang, Zheng
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MOLYBDENUM catalysts , *IRIDIUM catalysts , *METAL catalysts , *KETONES , *CATALYTIC activity , *AMINO alcohols , *RUTHENIUM catalysts , *QUINOLINE - Abstract
Molybdenum‐based efficient and broadly applicable catalytic system is presented for the dehydrogenative coupling of γ‐/β‐amino alcohols with ketones. In particular, complex Mo(CO)6 in combination with Xantphos and t‐BuOK as base provides direct synthesis of structurally diverse quinoline, pyridine, and pyrrole compounds (total 55 examples) with isolated yields up to 92%. Low catalyst loading, cost‐effective, and high catalytic activities with high tolerance to stand with diverse functional groups are additional features of these molybdenum catalysts exhibiting high efficacy to replace the precious metal catalysts such as ruthenium and iridium. Furthermore, the DFT and experimental studies were explored for the reaction mechanism which can assist in broadening the scope of the molybdenum catalysts for different transformation reactions. [ABSTRACT FROM AUTHOR]
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- 2024
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163. Nickel and Molybdenum Composites Decorated Nitrogen‐Doped Carbon Catalysts from Spent Coffee Grounds for Alkaline Hydrogen Evolution.
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Ge, Xianlong, Zhang, Chuan, Meng, Minfeng, Song, Yankai, Hu, Shaohua, and Gu, Yingying
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COFFEE grounds , *MOLYBDENUM , *HYDROGEN evolution reactions , *ALKALINE batteries , *DOPING agents (Chemistry) , *CATALYSTS , *HYDROGEN production , *CATALYTIC activity - Abstract
Biomass‐derived materials can help develop efficient, environmentally friendly and cost‐effective catalysts, thereby improving the sustainability of hydrogen production. Herein, we propose a simple method to produce nickel and molybdenum composites decorated spent coffee grounds (SCG) as an efficient catalyst, SCG(200)@NiMo, for electrocatalytic hydrogen production. The porous carbon supporter derived form SCG provided a larger surface, prevented aggregation during the high temperature pyrolysis, optimized the electronic structure by N and provided a reducing atmosphere for the oxides reduction to form heterojunctions. The sieved SCG showed obvious improvement of HER performance and enhanced conductivity and long‐term durability. The obtained SCG(200)@NiMo exhibits the highest electrochemical performance for the hydrogen evolution reaction process, as evidenced by the overpotential of only 127 mV at a current density of ɳ10 and 97.7 % catalytic activity retention even after 12 h of operation. This work may stimulate further exploration of efficient electrocatalysts derived from biomass. [ABSTRACT FROM AUTHOR]
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- 2024
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164. A Mini Review: Phase Regulation for Molybdenum Dichalcogenide Nanomaterials.
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Han, Xiaosong, Zhang, Zhihong, and Wang, Rongming
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ELECTRONIC band structure , *MOLYBDENUM , *NANOSTRUCTURED materials , *TRANSITION metals , *ELECTRONIC structure , *CHEMICAL properties - Abstract
Atomically thin two-dimensional transition metal dichalcogenides (TMDCs) have been regarded as ideal and promising nanomaterials that bring broad application prospects in extensive fields due to their ultrathin layered structure, unique electronic band structure, and multiple spatial phase configurations. TMDCs with different phase structures exhibit great diversities in physical and chemical properties. By regulating the phase structure, their properties would be modified to broaden the application fields. In this mini review, focusing on the most widely concerned molybdenum dichalcogenides (MoX2: X = S, Se, Te), we summarized their phase structures and corresponding electronic properties. Particularly, the mechanisms of phase transformation are explained, and the common methods of phase regulation or phase stabilization strategies are systematically reviewed and discussed. We hope the review could provide guidance for the phase regulation of molybdenum dichalcogenides nanomaterials, and further promote their real industrial applications. [ABSTRACT FROM AUTHOR]
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- 2024
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165. Effect of High Molybdenum Diet on Copper Status, Growth Performance, Blood Metabolites, Select Liver and Kidney Minerals, and Immune Responses of Boer Crosses.
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Solaiman, Sandra G., Beguesse, Kyla A., and Min, Byeng R.
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MOLYBDENUM , *IMMUNE response , *AFRIKANERS , *TRACE elements , *COPPER , *KIDNEYS , *LIVER - Abstract
Simple Summary: Trace minerals like copper and molybdenum are essential for overall animal health and play crucial roles in metabolic reactions involving tissues and organs. A major factor affecting the absorption and utilization of trace minerals is the interactions that occur between them. A copper deficiency induced by a high molybdenum concentration in the diet (when a sheep trace mineral mix high in Mo is fed to goats) is detrimental, resulting in tremendous economic losses for the goat production industry. An experiment was conducted to determine the effect of an induced copper deficiency by increasing molybdenum on the growth performance, feed efficiency, carcass characteristics, blood metabolites, and immune responses in goats. Eighteen Boer crosses goat kids housed individually were randomly assigned to three treatment groups; (1) control, (2) 5 ppm Mo, and (3) 10 ppm Mo, with 0, 5, and 10 mg/kg of molybdenum added to the grain mix, respectively. The results indicate that low-copper diets with increasing molybdenum did not negatively affect the feed efficiency, animal performance, blood metabolites, or carcass characteristics; however, it did alter the liver's copper and iron concentration as well as immune responses. These results suggest that additional Mo reduced the copper and iron in the liver for the duration of this experiment, and negatively impacted the immune response. This study examined the effects of elevated molybdenum (Mo) in goat diets on the growth, blood parameters, and immune responses in goats. Eighteen Boer crosses goats (BW = 25.6 ± 1.03 kg) were randomly assigned to three treatment groups: (1) control (no additional Mo), (2) 5 ppm Mo, and (3) 10 ppm Mo as ammonium molybdate was added to the grain mix. Animals were fed a 50:50 hay:grain diet ad libitum twice daily. Daily feed refusals were monitored, and intake was adjusted weekly. Body weights were recorded every 14 days and blood samples were collected on the second week of every month to determine Cu, Mo, Fe, Zn, and other blood metabolites. After 85 days, animals were humanely euthanized and carcass traits were measured. Liver, longissimus muscle area, and kidney samples were collected postmortem. Liver Cu (p < 0.003), blood triacylglycerides (p < 0.03), and serum total protein (p < 0.03) levels were reduced; the liver (p = 0.07) and kidney (p < 0.001) Mo concentrations were increased; and the immune response was decreased linearly (p < 0.01) with additional Mo. Low levels of Cu with increasing Mo levels in the diet did not negatively impact animal performance or blood metabolites, in the duration of this study (85 days); however, it lowered the liver Cu, Fe, and immune responses in goats. [ABSTRACT FROM AUTHOR]
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- 2024
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166. Synthesis of molybdenite reference materials for in situ molybdenum and sulfur isotope measurement using laser ablation MC-ICP-MS.
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Jing Tian, Zhian Bao, Kaiyun Chen, Nan Lv, Wenqiang Yang, Xiaojuan Nie, and Honglin Yuan
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MOLYBDENUM isotopes , *SULFUR isotopes , *REFERENCE sources , *MOLYBDENUM , *LASER ablation , *MOLYBDENITE , *SULFUR cycle - Abstract
Analyzing sulfur (S) and molybdenum (Mo) isotope ratios in molybdenite, the most common sulfide mineral, is crucial for studying the genesis of ore deposits. However, it is necessary to prepare matrix-matched reference materials for molybdenite. In this study, we employed two different techniques, the high-temperature-high-pressure (HTHP) technique and the rapid hot-pressing technique, to synthesize molybdenites and assessed their suitability as reference materials for in situ Mo and S isotope analysis in molybdenite. The molybdenites synthesized through HTHP and rapid hot-pressing exhibit smooth surfaces and dense structures, making them suitable as reference materials for in situ Mo and S isotope analysis, respectively. These synthesized molybdenites exhibit homogeneous Mo and S isotope compositions based on a large number of LA-MC-ICP-MS measurements. The mean δ98MoNIST SRM 3134 values of 0.70 ± 0.06‰ (n = 4, 2SD) and 0.70 ± 0.05‰ (n = 4, 2SD) determined by solution nebulization MC-ICP-MS are suggested as recommended δ98Mo/95Mo values for Mo-H8 and Mo-P. The mean δ34SV-CDT value of −0.22 ± 0.10‰ (n = 9, 2SD) determined by elemental analyzer isotope ratio mass spectrometry (EA-IRMS) is suggested as a recommended δ34S/32S value for Mo-H8 and Mo-P. Therefore, we recommend combining ultrafine powders with a high-temperature–high-pressure technique and/or a rapid hot-pressing technique to synthesize reference materials for isotopic analysis of other minerals. [ABSTRACT FROM AUTHOR]
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- 2024
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167. Studying the role of Bombyx mori molybdenum cofactor sulfurase in Bombyx mori nucleopolyhedrovirus infection.
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Lv, Jun‐li, Lai, Wen‐qing, Gong, Yu‐quan, Zheng, Kai‐yi, Zhang, Xiao‐ying, Wang, Xue‐yang, Dai, Li‐shang, and Li, Mu‐wang
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NUCLEOPOLYHEDROVIRUSES , *URIC acid , *MOLYBDENUM , *EMBRYOLOGY , *VIRUS diseases , *SILKWORMS - Abstract
Molybdenum cofactor sulfurase (MoCoS) is a key gene involved in the uric acid metabolic pathway that activates xanthine dehydrogenase to synthesise uric acid. Uric acid is harmful to mammals but plays crucial roles in insects, one of which is the immune responses. However, the function of Bombyx mori MoCoS in response to BmNPV remains unclear. In this study, BmMoCoS was found to be relatively highly expressed in embryonic development, gonads and the Malpighian tubules. In addition, the expression levels of BmMoCoS were significantly upregulated in three silkworm strains with different levels of resistance after virus infection, suggesting a close link between them. Furthermore, RNAi and overexpression studies showed that BmMoCoS was involved in resistance to BmNPV infection, and its antivirus effects were found to be related to the regulation of uric acid metabolism, which was uncovered by inosine‐ and febuxostat‐coupled RNAi and overexpression. Finally, the BmMoCoS‐mediated uric acid pathway was preliminarily confirmed to be a potential target to protect silkworms from BmNPV infection. Overall, this study provides new evidence for elucidating the molecular mechanism of silkworms in response to BmNPV infection and new strategies for the prevention of viral infections in sericulture. [ABSTRACT FROM AUTHOR]
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- 2024
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168. Bayesian batch optimization for molybdenum versus tungsten inertial confinement fusion double shell target design.
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Vazirani, Nomita N., Sacks, Ryan, Haines, Brian M., Grosskopf, Michael J., Stark, David J., and Bradley, Paul A.
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INERTIAL confinement fusion , *NUCLEAR fusion , *FUSION reactors , *TUNGSTEN , *CONTROLLED fusion , *MOLYBDENUM , *GAUSSIAN processes - Abstract
Access to reliable, clean energy sources is a major concern for national security. Much research is focused on the "grand challenge" of producing energy via controlled fusion reactions in a laboratory setting. For fusion experiments, specifically inertial confinement fusion (ICF), to produce sufficient energy, the fusion reactions in the ICF fuel need to become self‐sustaining and burn deuterium‐tritium (DT) fuel efficiently. The recent record‐breaking NIF ignition shot was able to achieve this goal as well as produce more energy than used to drive the experiment. This achievement brings self‐sustaining fusion‐based power systems closer than ever before, capable of providing humans with access to secure, renewable energy. In order to further progress toward the actualization of such power systems, more ICF experiments need to be conducted at large laser facilities such as the United States's National Ignition Facility (NIF) or France's Laser Mega‐Joule. The high cost per shot and limited number of shots that are possible per year make it prohibitive to perform large numbers of experiments. As such, experimental design relies heavily on complex predictive physics simulations for high‐fidelity "preshot" analysis. These multidimensional, multi‐physics, high‐fidelity simulations have to account for a variety of input parameters as well as modeling the extreme conditions (pressures and densities) present at ignition. Such simulations (especially in 3D) can become computationally prohibitive to turn around for each ICF experiment. In this work, we explore using Bayesian optimization with Gaussian processes (GPs) to find optimal designs for ICF double shell targets, while keeping computational costs to manageable levels. These double shell targets have an inner shell that grades from beryllium on the outer surface to the higher Z material molybdenum, as opposed to the nominally used tungsten, on the inside in order to trade off between the high performance associated with high density inner shells and capsule stability. We describe our results for "capsule‐only" xRAGE simulations to study the physics between different capsule designs, inner shell materials, and potential for future experiments. [ABSTRACT FROM AUTHOR]
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- 2024
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169. High-efficiency electrocatalytic nitrite-to-ammonia conversion on molybdenum doped cobalt oxide nanoarray at ambient conditions.
- Author
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Li, Ye, Ouyang, Ling, Chen, Jie, Fan, Xiaoya, Sun, Hang, He, Xun, Zheng, Dongdong, Sun, Shengjun, Luo, Yongsong, Liu, Qian, Li, Luming, Chu, Wei, Du, Juan, Kong, Qingquan, Zheng, Baozhan, and Sun, Xuping
- Subjects
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COBALT oxides , *NITRITES , *MOLYBDENUM , *DENSITY functional theory , *NITROGEN cycle , *POWER density , *OXYGEN reduction - Abstract
As a high-efficiency electrocatalyst for NH 3 production via NO 2 − reduction, Mo-doped Co 3 O 4 nanoarray exhibits an extremely high Faradaic efficiency of 96.9 % and a corresponding NH 3 yield of up to 651.5 μmol/h cm−2 at −0.5 V. [Display omitted] • Mo-doped Co 3 O 4 nanoarray on titanium mesh is synthesized as an effective catalyst for NO 2 −-to-NH 3 conversion. • Mo-Co 3 O 4 /TM exhibits a high NH 3 Faradaic efficiency of 96.9 % and a related yield of 651.5 μmol h−1 cm−2 with strong stability. • DFT calculations reveal the catalytic mechanism of NO 2 −RR on Mo-Co 3 O 4. • The fabricated Zn-NO 2 − battery achieves a peak power density of 3.6 mW cm−2 and a satisfactory NH 3 yield of 108.4 μmol h−1 cm−2. Electrochemical conversion of nitrite (NO 2 −) contaminant to green ammonia (NH 3) is a promising approach to achieve the nitrogen cycle. The slow kinetics of the complex multi-reaction process remains a serious issue, and there is still a need to design highly effective and selective catalysts. Herein, we report that molybdenum doped cobalt oxide nanoarray on titanium mesh (Mo-Co 3 O 4 /TM) acts as a catalyst to facilitate electroreduction of NO 2 − to NH 3. Such a catalyst delivers an extremely high Faradaic efficiency of 96.9 % and a corresponding NH 3 yield of 651.5 μmol h−1 cm−2 at −0.5 V with strong stability. Density functional theory calculations reveal that the introduction of Mo can induce the redistribution of electrons around Co atoms and further strengthen the adsorption of NO 2 −, which is the key to facilitating the catalytic performance. Furthermore, the assembled battery based on Mo-Co 3 O 4 /TM suggests its practical application value. [ABSTRACT FROM AUTHOR]
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- 2024
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170. Effect of Calcium, Magnesium Fertigation and Molybdenum Foliar Sprays on Yield and Fruit Quality of Flame Seedless Table Grape Cultivar.
- Author
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El-Katawy, Mohammed FMA, Abdel Ghany, Nazmy A., Ibrahim, Mohamed FM, Ghobrial, Ghobrial F., and Nasser, Mohamed A.
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FERTIGATION , *MOLYBDENUM , *FRUIT quality , *MAGNESIUM , *CALCIUM - Abstract
This investigation was performed during the 2018 and 2019 seasons in a private vineyard to study the effect of calcium, magnesium fertigation and molybdenum foliar sprays on the yield and fruit quality of Flame seedless table grape cultivar. The experimental layout was arranged in a split-plot design. All treatments were applied on three dates: after the bud burst stage, at the fruit set stage and veraison stage. The results showed that the combined application of 30 Kg calcium with 20 Kg magnesium fertigation and foliar spraying of 30 ppm molybdenum was the most effective among all treatments in terms of enhancing vegetative growth characteristics, increasing leaf content of total chlorophylls and mineral elements as well as improving yield and fruit quality attributes. [ABSTRACT FROM AUTHOR]
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- 2024
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171. Simple separation of technetium from molybdenum for tracer isotope production.
- Author
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Kmak, Kelly N., Despotopulos, John D., and Kerlin, William M.
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MOLYBDENUM isotopes , *MOLYBDENUM , *TECHNETIUM , *ION exchange resins , *ION exchange chromatography , *LABORATORY equipment & supplies - Abstract
A procedure for the separation of technetium isotopes from bulk molybdenum was developed in nitric acid media. After irradiation of natMo foils, and dissolution in H2O2, the solution is acidified to 2 M HNO3, and anion exchange resin is used to separate technetium from molybdenum. The procedure is simple, requiring only basic laboratory equipment and, with a two-column separation, the technetium yield is high (~ 85%) with extremely high purity (< 0.1 ppm natMo). This is ideally suited for laboratory production of technetium tracer isotopes, particularly 95mTc. [ABSTRACT FROM AUTHOR]
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- 2024
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172. Extraction of Molybdenum and Uranium from Low-Grade Molybdenum Bearing Ore Containing Uranium through Mechanical Activation Following Acid Leaching.
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Wang, Yongliang, Wang, Congying, Liu, Hui, and Meng, YunSheng
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URANIUM , *MOLYBDENUM , *LEACHING , *URANIUM ores , *SULFURIC acid , *SOLVENT extraction , *SURFACE area , *OXIDIZING agents - Abstract
Extraction of molybdenum (Mo) from jordisite is difficult due to the amorphous state of MoS2. In this study, mechanical activation was employed to pretreat this type of ore with a low Mo content of 0.26%, and then molybdenum and uranium were both extracted from the milled ore using sulfuric acid. The effects of milling time, oxidant, and optimal leaching conditions were investigated in the laboratory. The results show that the mechanical activation will reduce the particle size and increase the specific surface area of the ore under certain milling conditions. Mechanical activation without oxidants in a hypoxia environment is not conductive to the recovery of molybdenum. When the oxidant of MnO2 is added during the milling process, the Mo recovery will increase greatly. The effect of mechanical activation on U recovery is not so obvious. The phenomenon of agglomerate will occur during the milling process, which will reduce Mo recovery seriously, especially when the milling time is more than 120 min. The Mo and U recovery can reach 84.52% and 61.39%, respectively, after optimization of sulfuric acid leaching process conditions. [ABSTRACT FROM AUTHOR]
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- 2024
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173. Design and analysis of polarization-insensitive molybdenum-based ultra-wideband solar energy absorber with wide-incident-angle.
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Abouelez, Ahmed Elsayed and Eldiwany, Essam A.
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MOLYBDENUM , *ENERGY harvesting , *POLARITONS , *REFRACTORY materials , *OPTICAL polarization - Abstract
We introduce an ultra-wideband absorber with a molybdenum and Al2O3 multilayer structure for solar energy harvesting. The proposed structure could maintain its structural integrity at high temperatures thanks to the refractory materials used in its construction. Under normal incidence of optical waves, absorption of more than 90% is achieved throughout a broad range of wavelengths from 300 nm to approximately 3177 nm with a bandwidth of 2877 nm which covers ultraviolet, visible, and near-infrared spectral bands. The average absorption in that band is calculated to be 96.46%. The proposed design's symmetrical characteristic makes the absorber insensitive to the polarization of the incident optical wave. Furthermore, throughout a broad range of optical wave angles of incidence for both transverse electric and transverse magnetic polarizations, the absorber supports absorptivity greater than 80%. [ABSTRACT FROM AUTHOR]
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- 2024
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174. Iodide clusters of molybdenum and tungsten as promising agents for photodynamic inactivation and therapy.
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Mikhailov, M. A. and Sokolov, M. N.
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PHOTODYNAMIC therapy , *REACTIVE oxygen species , *TUNGSTEN , *MOLYBDENUM , *BACTERICIDAL action , *CYTOTOXINS - Abstract
Octahedral iodide clusters of molybdenum and tungsten [M6I8L6] are considered as promising components of new classes of luminescent materials. When excited with the light at a wavelength of ≤450 nm, the clusters form long-lived triplet states emitting red phosphorescence. This phosphorescence is deactivated in the presence of molecular oxygen to form singlet oxygen in a high yield. Due to the capability of photogenerating singlet oxygen, the [M6I8L6] clusters and related materials exhibit photoinduced cytotoxicity and bactericidal action. Universal methods developed to date make it possible to prepare cluster compounds with specified compositions and properties depending on ligand L. This review considers the prospects for developing drugs for antimicrobial photodynamic inactivation and photodynamic cancer therapy based on the [M6I8L6] clusters. [ABSTRACT FROM AUTHOR]
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- 2024
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175. Solution NMR chemical shift assignment of apo and molybdate-bound ModA at two pHs.
- Author
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Nguyen, Hiep LD and Crowhurst, Karin A.
- Abstract
ModA is a soluble periplasmic molybdate-binding protein found in most gram-negative bacteria. It is part of the ABC transporter complex ModABC that moves molybdenum into the cytoplasm, to be used by enzymes that carry out various redox reactions. Since there is no clear analog for ModA in humans, this protein could be a good target for antibacterial drug design. Backbone
1 H,13 C and15 N chemical shifts of apo and molybdate-bound ModA from E. coli were assigned at pHs 6.0 and 4.5. In addition, side chain atoms were assigned for apo ModA at pH 6.0. When comparing apo and molybdate-bound ModA at pH 6.0, large chemical shift perturbations are observed, not only in areas near the bound metal, but also in regions that are distant from the metal-binding site. Given the significant conformational change between apo and holo ModA, we might expect the large chemical shift changes to be more widespread; however, since they are limited to specific regions, the residues with large perturbations may reveal allosteric sites that could ultimately be important for the design of antibiotics that target ModA. [ABSTRACT FROM AUTHOR]- Published
- 2024
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176. Influence of the Studied Factors on the Yield, Structure and Quality Indicators of Vegetable Peas under the Conditions the South of Ukraine.
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Almashova, Viktoria, Breus, Denys, and Olifirenko, Vitalii
- Abstract
The article considered the elements of the resource-saving technology for the production of vegetable peas with the use of low doses of synthetic fertilizers by stimulating the action of nitrogen-fixing nodule bacteria. They are symbionts of vegetable peas, with the help of bacteria and microfertilizers. They are much cheaper than mineral fertilizers and are not harmful for the environment and, thanks to microdoses, are absolutely safe for people. During the research, it was established that, in addition to increasing the yield of agricultural crops, such agro-techniques contribute to increasing soil fertility (due to the accumulation of a greater amount of biologically pure nitrogen in it after harvesting vegetable peas, compared to existing technologies) and make it possible to extend the period of technical maturity of seeds and the period of their processing. This is a very important and urgent problem in southern Ukraine. It was also determined that the treatment of seeds with boron, molybdenum and Rizotorfin affects the timing of the onset of the main phases of development and the duration of the growing season of vegetable peas, extending it by several days, and this, in turn, allows farmers to harvest on time without economic losses. For the first time, for the conditions of the south of Ukraine, an opportunity was found to significantly extend the term of receipt of raw materials for processing without deterioration of quality indicators and dietary properties. The proposed techniques allow, in addition to the existing technology, to accumulate up to 40-60 kg/ha of biological nitrogen in the soil. It was recorded that the highest yield of the vegetable pea crop was formed during the first sowing period, when the seeds were treated with boron and molybdenum and amounted to 9.21 t/ha, which is 2.32 t/ha higher than the control. Based on the generalization of research results, a mathematical model of vegetable pea crop programming was built based on the principle of relationships between individual factors that affect the culture and the formation of its plant productivity. [ABSTRACT FROM AUTHOR]
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- 2024
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177. Trace mineral concentrations in Canadian beef calves at weaning.
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Waldner, Cheryl and Campbell, John
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ANIMAL weaning ,TRACE elements ,MOLYBDENUM ,COPPER ,AGE differences ,PREGNANCY tests ,COWS ,HEIFERS - Abstract
Copyright of Canadian Veterinary Journal / Revue Vétérinaire Canadienne is the property of Canadian Veterinary Medical Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
178. Investigating Material Performance in Artificial Ankle Joints: A Biomechanical Study.
- Author
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Nazha, Hasan Mhd, Adrah, Muhsen, Osman, Thaer, Issa, Mohammad, Imran, Ahmed, Zhang, Yicha, and Juhre, Daniel
- Subjects
BIOMECHANICS ,MATERIALS testing ,VANADIUM compounds ,BENCHMARKING (Management) ,TITANIUM ,CHROMIUM compounds ,MOLYBDENUM ,FINITE element method ,COBALT ,JOINT dislocations ,ALUMINUM compounds ,ALLOYS ,ARTIFICIAL joints ,PHYSIOLOGIC strain ,ANKLE joint ,COMPARATIVE studies ,POLYETHYLENE ,PROSTHESIS design & construction ,STAINLESS steel ,EVALUATION - Abstract
This study delves into an in-depth examination of the biomechanical characteristics of various materials commonly utilized in the fabrication of artificial ankle joints. Specifically, this research focuses on the design of an ankle joint resembling the salto-talaris type, aiming to comprehensively understand its performance under different loading conditions. Employing advanced finite element analysis techniques, this investigation rigorously evaluates the stresses and displacements experienced by the designed ankle joint when subjected to varying loads. Furthermore, this study endeavors to identify the vibrating frequencies associated with these displacements, offering valuable insights into the dynamic behavior of the ankle joint. Notably, the analysis extends to studying random frequencies across three axes of motion, enabling a comprehensive assessment of directional deformities that may arise during joint function. To validate the effectiveness of the proposed design, a comparative analysis is conducted against the star ankle design, a widely recognized benchmark in ankle joint prosthetics. This comparative approach serves dual purposes: confirming the accuracy of the findings derived from the salto-talaris design and elucidating the relative efficacy of the proposed design in practical application scenarios. [ABSTRACT FROM AUTHOR]
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- 2024
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179. Physical, optical, and radiation shielding features of molybdenum-reinforced LZS glasses.
- Author
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Abdel Wahab, E. A., Aloraini, Dalal Abdullah, and Shaaban, Kh. S.
- Subjects
MOLYBDENUM ,OPTICAL susceptibility ,RADIATION shielding ,REFRACTIVE index ,BAND gaps ,PERMITTIVITY ,GLASS - Abstract
Five glass samples of the composition (5 − x)ZnO − xMoO
3 –35Pb3 O4 –60SiO2 have been investigated and x takes the values between 0 and 5 mol%. The XRD technique was utilized to confirm the amorphous status. The density of the glasses was measured and varied between 5.91 g/cm3 for LZSM0 and 6.249 g/cm3 for LZSM5 . The field strength, cohesive energy, bond density, and electronegativity were examined. According to the findings, these criteria are dependent on the ratio of molybdenum concentration in the present specimen. The optical properties of nonlinear and linear characteristics were also investigated. The absorption and transmittance of glasses were measured, and the edge of the spectrum was found to be affected by MoO3 content. The Eg energy gap and n the refraction index susceptibilities and dielectric constant are enhanced by supplying molybdenum in the glass network. The Eg and n take values between 2.68 and 2.56 eV and 2.52 and 2.56, respectively. The radiation attenuation capacity with the addition of MoO3 has been addressed here. The mass and linear attenuation factor enhanced between 4.35 to 4.31 cm2 /g and 25.71 to 26.97 cm−1 at 0.1 MeV for the specimens LZSM0 and LZSM5, respectively. The half-value layer HVL and MFP the mean free path also improved by adding MoO3 to the fabricated glasses samples. The present study suggests that adding MoO3 to lead zinc silicate glass can modify the glass network and enhance the ability to safeguard against radiation, especially LZSM5 with higher molybdenum content. [ABSTRACT FROM AUTHOR]- Published
- 2024
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180. Ni-Mo-P coatings on thrust plate of a gear pump to enhance its mechanical, tribological, and corrosion resistance properties.
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Sharma, Anubhav Kumar, Kumar, Niranjan, Das, Alok Kumar, and Kumar, Monty
- Abstract
Thrust plate in an external gear pump is one of the most important element which aligns the rotating gears and prevents the leakage through lateral clearances between rotating and non-rotating surfaces. It acts as a sacrificing element and fails frequently under fluctuating load pressure condition. The present research aims at enhancing the relative mechanical and tribological properties of the sacrificial thrust plate through electroless Ni-Mo-P coatings. Molybdenum (Mo) concentration in the electroless bath were tested for their effects on surface morphology, hardness, phase formation, wear rate, and wettability. A hard and self-lubricating layer (Al, Ni, Si, and Mo phases) on the coated surface was indicated by the compositional analysis performed using EDS and XRD. Results show that the microhardness of the coated surfaces has increased significantly by 149.5% (maximum hardness ~ 183.45 HV
0.2 ) for 32 g L−1 Mo concentration. With 32 g L−1 Mo, the maximum coating thickness and water contact angle were 58 µm and 111°, respectively. The base material's coefficient of friction was 0.5, whereas it was 0.25, 0.10, 0.06, and 0.03 for the samples made with 8, 16, 24, and 32 g L−1 Mo concentration, respectively. Compared to the uncoated sample, the maximum decrement in corrosion rate was found to be about six to seven times in the coated sample (with 32 g L−1 Mo). As a result, the developed coating surfaces provide hardness, lubricity, hydrophobicity, corrosion, and wear resistance simultaneously. The methodology of surface treatment can be used to modify the surface of critical hydraulic components having significant wear like in case of hydraulic cylinders. [ABSTRACT FROM AUTHOR]- Published
- 2024
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181. HAXPES reference spectra of bulk Mo and MoSe2 with Cr Kα excitation.
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Deleuze, Pierre-Marie, Gauthier, Nicolas, Artyushkova, Kateryna, Martinez, Eugénie, and Renault, Olivier
- Subjects
PHOTOELECTRON spectroscopy ,MOLYBDENUM compounds ,MOLYBDENUM ,BINDING energy ,RADIATION - Abstract
Monochromatic Cr K
α radiation (5414.8 eV) was used to acquire high-energy photoelectron spectroscopy (HAXPES) data on pure Mo and bulk MoSe2 compound with special attention paid to binding energy scale correction and quantification. The reported spectra include a survey scan and high-resolution Mo 2s, Mo 2p1/2 , Mo 2p3/2 , Mo 3d, Mo 3p1/2 , Mo 3p3/2 , Mo 3s, Mo 4s, Mo4p, Se2s, Se 2p1/2 , Se 2p3/2 , Se 3s, Se 3p1/2 , Se 3p3/2 , and Se 3d core-levels. The data will be useful as reference core-level spectra for HAXPES studies on molybdenum and its compounds. [ABSTRACT FROM AUTHOR]- Published
- 2024
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182. Cluster Mo2C deposited on graphene nanowalls by x-ray photoelectron spectroscopy.
- Author
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Chaitoglou, Stefanos, Ospina, Rogelio, and Bertran-Serra, Enric
- Subjects
X-ray photoelectron spectroscopy ,MOLYBDENUM ,GRAPHENE ,ADHESIVE tape ,COPPER - Abstract
Molybdenum deposited on carbon graphene nanowalls was characterized by x-ray photoelectron spectroscopy with an Al K
α (1486.6 eV) excitation source. The sample was fixed to a stainless-steel sample holder with copper double-sided adhesive tape. Survey spectrum, C 1s, O 1s, Si 2p, and Mo 3d core levels spectra were acquired. [ABSTRACT FROM AUTHOR]- Published
- 2024
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183. Molybdenum single-atoms decorated multi-channel carbon nanofibers for advanced lithium-selenium batteries.
- Author
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Zheng, Yang, Khan, Mustafa, Yan, Suxia, Yang, Dahai, Chen, Ying, Zhang, Li, Song, Xiaohui, Li, Guochun, Liu, Junfeng, Wang, Yong, Ding, Ning, and Wu, Xiang
- Subjects
- *
MOLYBDENUM , *ELECTROSPINNING , *ENERGY storage , *RENEWABLE energy standards , *LITHIUM-ion batteries - Abstract
The cathode in lithium-selenium (Li-Se) batteries has garnered extensive attention owing to its superior specific capacity and enhanced conductivity compared to sulfur. Nonetheless, the adoption and advancement of Li-Se batteries face significant challenges due to selenium's low reactivity, substantial volume fluctuations, and the shuttle effect associated with polyselenides. Single-atom catalysts (SACs) are under the spotlight for their outstanding catalytic efficiency and optimal atomic utilization. To address the challenges of selenium's low chemical activity and volume expansion in Li-Se batteries, through electrospun, we have developed a lotus root-inspired carbon nanofiber (CNF) material, featured internal multi-channels and anchored with molybdenum (Mo) single atoms (Mo@CNFs). Mo single atoms significantly enhance the conversion kinetics of selenium (Se), facilitating rapid formation of Li2Se. The internally structured multi-channel CNF serves as an effective host matrix for Se, mitigating its volume expansion during the electrochemical process. The resulting cathode, Se/Mo@CNF composite, exhibits a high discharge specific capacity, superior rate performance, and impressive cycle stability in Li-Se batteries. After 500 cycles at a current density of 1 C, it maintains a capacity retention rate of 82% and nearly 100% coulombic efficiency (CE). This research offers a new avenue for the application of single-atom materials in enhancing advanced Li-Se battery performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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184. Two-dimensional flake Co/Co2N0.67 modified by molybdenum oxides achieves enhancement of bifunctional hydrogen electrocatalysis.
- Author
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Li, Zhixin, Zhou, Menyan, Zhu, Lijie, Xie, Fangyan, Chen, Jian, Wang, Nan, Jin, Yanshuo, Yu, Xiang, and Meng, Hui
- Subjects
- *
MOLYBDENUM oxides , *ION-permeable membranes , *HYDROGEN evolution reactions , *ELECTROCATALYSIS , *MOLYBDENUM , *HYDROGEN as fuel - Abstract
To address the urgent need for non-precious metal-based catalysts in the industrial preparation and application of hydrogen energy, we present a secondary hydrothermal strategy to prepare a Mo-modified cobalt carbonate precursor, resulting in the Mo–Co/Co 2 N 0.67 catalyst. The cobalt-based materials exhibit a layered flake structure due to molybdenum modification, exposing more active sites, while molybdenum oxide modification enhances hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR). In alkaline HER measurements, Mo–Co/Co 2 N 0.67 achieves a remarkable current density of 10 mA cm−2 at only 27 mV. The overall water splitting of Mo–Co/Co 2 N 0.67 + RuO 2 can reach 10 mA cm−2 at 1.52 V voltage. In alkaline HOR measurements, it exhibits the current density of 2.92 mA cm−2@0.1 V vs. RHE and an exchange current density (J 0) of 2.96 mA cm−2. This work highlights the effective regulation of non-noble metal-based electrocatalysts through Mo modification, providing valuable insights for the development of efficient non-precious metal-based hydrogen electrocatalysis within the context of anion exchange membrane unitized reversible fuel cells (AEM-URFC). [Display omitted] • The surface modification by molybdenum optimizes the hydrogen reaction. • Flake Mo–Co/Co 2 N 0.67 provides more reaction channels and electrochemical active area. • Mo–Co/Co 2 N 0.67 exhibits −10 mA cm−2 at −27 mV and Tafel slope of 58.63 mV dec−1. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
- View/download PDF
185. Two-dimensional molybdenum ditelluride waveguide-integrated near-infrared photodetector.
- Author
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Wang, Xinxue, Zeng, Guang, Shen, Lei, Chen, Wei, Du, Fanyu, Chen, Yu-Chang, Ding, Si-Tong, Shi, Cai-Yu, Zhang, David Wei, Chen, Liao, and Lu, Hong-Liang
- Subjects
- *
PHOTODETECTORS , *MOLYBDENUM , *SILICON nitride , *QUANTUM efficiency , *INTEGRATED circuits - Abstract
Low-cost, small-sized, and easy integrated high-performance photodetectors for photonics are still the bottleneck of photonic integrated circuits applications and have attracted increasing attention. The tunable narrow bandgap of two-dimensional (2D) layered molybdenum ditelluride (MoTe2) from ∼0.83 to ∼1.1 eV makes it one of the ideal candidates for near-infrared (NIR) photodetectors. Herein, we demonstrate an excellent waveguide-integrated NIR photodetector by transferring mechanically exfoliated 2D MoTe2 onto a silicon nitride (Si3N4) waveguide. The photoconductive photodetector exhibits excellent responsivity (R), detectivity (D *), and external quantum efficiency at 1550 nm and 50 mV, which are 41.9 A W−1, 16.2 × 1010 Jones, and 3360%, respectively. These optoelectronic performances are 10.2 times higher than those of the free-space device, revealing that the photoresponse of photodetectors can be enhanced due to the presence of waveguide. Moreover, the photodetector also exhibits competitive performances over a broad wavelength range from 800 to 1000 nm with a high R of 15.4 A W−1 and a large D * of 59.6 × 109 Jones. Overall, these results provide an alternative and prospective strategy for high-performance on-chip broadband NIR photodetectors. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
186. Intercalating a potassium–aqua complex cation into an α-MoO3 layer without reducing molybdenum: a potential storage system.
- Author
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Jana, Debu, Mishra, Shalini Sanjay, and Das, Samar K.
- Subjects
- *
ALKALI metal ions , *MOLYBDENUM , *CATIONS , *ION exchange (Chemistry) , *ACETATES , *AQUEOUS solutions - Abstract
We have demonstrated a green aqueous synthesis of rod-shaped MoO3 material, [MoVI3O9{K(H2O)4}(CH3COO)]·H2O (2) intercalating potassium–aqua-complex acetate into its lamellar space, simply by ion-exchange of Co(II)–aqua-complex in compound [MoVI4O12(CH3COO)2{CoII(H2O)6}]·2H2O (1) by {K(H2O)4}+ in an aqueous solution of 1 and KCl. Compound 2 acts as a potential storage system of alkali metal ions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
187. Bimetallic nickel molybdenum nitride catalyst with low pressure and reduced hydrogen consumption for hydrogenation of dimethyl oxalate to ethanol: the impact of reduction temperature on catalytic performance.
- Author
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Gong, Jiang, Zhang, Hanqing, Shu, Weihan, Zheng, Fengling, Zhang, Chuancai, Wang, Hao, Zhang, Ni, and Dai, Bin
- Subjects
- *
MOLYBDENUM nitrides , *ETHANOL , *OXALATES , *MOLYBDENUM catalysts , *MOLYBDENUM , *HYDROGENATION , *CATALYTIC reduction , *ETHANES - Abstract
Herein, a novel bimetallic nickel molybdenum nitride (Ni3Mo3N) catalyst is reported for the first time for the hydrogenation of dimethyl oxalate (DMO) to ethanol (EtOH). Remarkably, the Ni3Mo3N-600 catalyst realizes a remarkable 97.5% EtOH yield at a low pressure of 0.5 MPa and a low H2/DMO molar ratio of 10. Moreover, it exhibits exceptional catalytic stability for at least 300 h, marking the first instance of achieving such high EtOH yield under mild reaction conditions. The present study investigates the impact of different reduction temperatures on the catalyst, and various characterization analyses reveal the formation of Ni3Mo3N. The electron-rich structure of the Ni3Mo3N-600 catalyst facilitates the activation of C=O and enhances the adsorption and dissociation of H2. Specifically, the low-valence Mo promotes the activation of carbonyl oxygen, while Ni0 facilitates the adsorption and dissociation of H2, considerably enhancing the deep hydrogenation ability of the Ni3Mo3N-600 catalyst. Furthermore, the well-defined crystallinity of the Ni3Mo3N-600 catalyst coupled with Lewis acid sites that promote C=O adsorption and activation, Brønsted acid sites that facilitate C–O adsorption and activation, and hydrogenation sites collectively contribute to the efficient conversion of DMO to EtOH. This study presents new insights into designing high-performance catalysts for the hydrogenation of DMO toward EtOH. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
188. Effect of humic substances on the fraction of heavy metal and microbial response.
- Author
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Wang, Mengmeng, Song, Gangfu, Zheng, Zhihong, Song, Zhixin, Mi, Xiao, Hua, Jiajun, and Wang, Zihang
- Subjects
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HUMUS , *HEAVY metals , *SOIL amendments , *HUMIC acid , *FULVIC acids , *MOLYBDENUM - Abstract
Contamination of soils by Molybdenum (Mo) has raised increasing concern worldwide. Both fulvic acid (FA) and humic acid (HA) possess numerous positive properties, such as large specific surface areas and microporous structure that facilitates the immobilization of the heavy metal in soils. Despite these characteristics, there have been few studies on the microbiology effects of FA and HA. Therefore, this study aimed to assess the Mo immobilization effects of FA and HA, as well as the associated changes in microbial community in Mo-contaminated soils (with application rates of 0%, 0.5% and 1.0%). The result of the incubation demonstrated a decrease in soil pH (from 8.23 ~ 8.94 to 8.05 ~ 8.77). Importantly, both FA and HA reduced the exchangeable fraction and reducible fraction of Mo in the soil, thereby transforming Mo into a more stable form. Furthermore, the application of FA and HA led to an increase in the relative abundance of Actinobacteriota and Firmicutes, resulting in alterations to the microbial community structure. However, it is worth noting that due to the differing structures and properties of FA and HA, these outcomes were not entirely consistent. In summary, the aging of FA and HA in soil enhanced their capacity to immobilization Mo as a soil amendment. This suggests that they have the potential to serve as effective amendments for the remediation of Mo-contaminated soils. [ABSTRACT FROM AUTHOR]
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- 2024
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189. Enhanced Catalytic Hydrogenation of Olefins in Sulfur-Rich Naphtha Using Molybdenum Carbide Supported on γ-Al 2 O 3 Spheres under Steam Conditions: Simulating the Hot Separator Stream Process.
- Author
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Abbas, Hadj Abbas, Pour, Zahra Asgar, Alnafisah, Mohammed S., Cortes, Pablo Gonzalez, El Hariri El Nokab, Mustapha, Elshewy, Ahmed, and Sebakhy, Khaled O.
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CATALYTIC hydrogenation , *NAPHTHA , *ALKENES , *SUPERCRITICAL fluid chromatography , *MOLYBDENUM , *SPHERES - Abstract
Spheres comprising 10 wt.% Mo2C/γ-Al2O3, synthesized through the sucrose route, exhibited unprecedented catalytic activity for olefin hydrogenation within an industrial naphtha feedstock that contained 23 wt.% olefins, as determined by supercritical fluid chromatography (SFC). The catalyst demonstrated resilience to sulfur, exhibiting no discernible deactivation signs over a tested 96 h operational period. The resultant hydrogenated naphtha from the catalytic process contained only 2.5 wt.% olefins when the reaction was conducted at 280 °C and 3.44 × 106 Pa H2, subsequently blended with Athabasca bitumen to meet pipeline specifications for oil transportation. Additionally, the carbide catalyst spheres effectively hydrogenated olefins under steam conditions without experiencing any notable hydrogenation in the aromatics. We propose the supported carbide catalyst as a viable alternative to noble metals, serving as a selective agent for olefin elimination from light petroleum distillates in the presence of steam and sulfur, mitigating the formation of gums and deposits during the transportation of diluted bitumen (dilbit) through pipelines. [ABSTRACT FROM AUTHOR]
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- 2024
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190. Uncovering the effect of Mo addition on the precipitation kinetics of the γ′ phase in Ni–Al–Mo model superalloys using CALPHAD-assisted phase-field simulations.
- Author
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Wang, Zexin, Liang, Chuanxin, Wang, Dong, and Ding, Xiangdong
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PRECIPITATION (Chemistry) kinetics , *SOLUTION strengthening , *TERNARY alloys , *PHASE partition , *MOLYBDENUM - Abstract
Mo is a key solid solution strengthening element that improves the mechanical properties of Ni-based superalloys, but the partitioning behavior of Mo remains controversial. Herein, we uncover the effect of Mo addition on the precipitation kinetics of the γ′ phase in Ni–(17−x) Al–x Mo at.% (x = 2, 3, 4, and 5) alloys by directly coupling accurate thermodynamic and kinetic descriptions with a phase-field model. Our simulations show that the addition of Mo would decrease the γ′ coarsening rate due to the decrease in the diffusion rate and the γ/γ′ lattice misfit. Besides, the partitioning behavior of Mo is reversed from the γ′ phase ( K Mo γ ′ / γ > 1 ) into the γ matrix ( K Mo γ ′ / γ < 1 ) with increasing Mo concentration, which is attributed to the solubility limit of Mo in the γ′ phase as well as a decrease in the γ/γ′ lattice misfit. Meanwhile, Al and Mo preferentially occupy the Al sublattice site of the γ′–Ni3Al and form the Ni3(Al, Mo) phase in Ni–Al–Mo ternary model alloys. Furthermore, the solid solution strengthening effect increases with increasing Mo concentration because of an increase in the Mo concentration in the γ matrix. Our results provide valuable insights into understanding the effect of Mo addition to Ni-based superalloys on the coarsening kinetics of γ′ phase and elemental partitioning behavior. [ABSTRACT FROM AUTHOR]
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- 2024
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191. Isotope evidence for the enrichment mechanism of molybdenum in methane-seep sediments: Implications for past seepage intensity.
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Jin, Meng, Chen, Fang, Li, Niu, Peckmann, Jörn, Mathur, Ryan, Godfrey, Linda, and Chen, Duofu
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ISOTOPE separation , *MARINE sediments , *SEDIMENTS , *COLD seeps , *MOLYBDENUM , *SEQUESTRATION (Chemistry) - Abstract
Methane release from marine sediments strongly influences the local seafloor environment and ecosystems, and may impact Earth's climate system. Recent studies revealed anomalous molybdenum (Mo) enrichment in seep sediments, which was linked to methane release events. Marine seep sediments are a potential sink of Mo for the global ocean, while the mechanisms leading to local Mo enrichment are not fully understood. The sediments from a gas hydrate-bearing area of the South China Sea analyzed herein reveal authigenic Mo (Mo auth) contents ranging from 0 and 31.4 µg/g and δ98Mo auth values ranging from 0.18 ‰ to 3.31 ‰. The range of δ98Mo auth values of seep sediments is therefore similar to values of modern iron-rich sediments with low concentrations of dissolved porewater hydrogen sulfide and sediments deposited under weakly euxinic sediments. Among the obtained South China Sea data, the more positive δ98Mo auth values (>ca. 1.5 ‰) are interpreted to reflect diffusion of seawater Mo into the sediment at moderate seepage rates and Mo isotope fractionation during the formation of thiomolybdates in the sulfidic seep environment. The lower δ98Mo auth values (
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- 2024
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192. Higher Concentrations of Essential Trace Elements in Women Undergoing IVF May Be Associated with Poor Reproductive Outcomes Following Single Euploid Embryo Transfer.
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Gonzalez-Martin, Roberto, Palomar, Andrea, Perez-Deben, Silvia, Salsano, Stefania, Quiñonero, Alicia, Caracena, Laura, Fernandez-Saavedra, Rocio, Fernandez-Martinez, Rodolfo, Conde-Vilda, Estefania, Quejido, Alberto J., Giles, Juan, Vidal, Carmen, Bellver, Jose, and Dominguez, Francisco
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EMBRYO transfer , *INTRACYTOPLASMIC sperm injection , *FERTILIZATION in vitro , *TRACE elements , *HUMAN in vitro fertilization , *MOLYBDENUM , *REPRODUCTIVE health - Abstract
Essential trace elements are micronutrients whose deficiency has been associated with altered fertility and/or adverse pregnancy outcomes, while surplus may be toxic. The concentrations of eight essential trace elements were measured using inductively coupled mass spectrometry (ICP-MS) and assessed with respect to clinical in vitro fertilization (IVF) outcomes in a population of 51 women undergoing IVF with intracytoplasmic sperm injection (ICSI), pre-implantation genetic screening for aneuploidy (PGT-A), and single frozen euploid embryo transfer (SET/FET). Specifically, copper (Cu), zinc (Zn), molybdenum, selenium, lithium, iron, chromium, and manganese were quantified in follicular fluid and whole blood collected the day of vaginal oocyte retrieval (VOR) and in urine collected the day of VOR and embryo transfer. We found that the whole blood Cu/Zn ratio was significantly associated with superior responses to ovarian stimulation. Conversely, the whole blood zinc and selenium concentrations were significantly associated with poor ovarian response outcomes. Higher levels of whole blood zinc and selenium, urinary selenium, lithium, and iron had significant negative associations with embryologic outcomes following IVF. Regarding clinical IVF outcomes, higher urinary molybdenum concentrations the day of VOR were associated with significantly lower odds of implantation and live birth, while higher urinary Cu/Mo ratios on the day of VOR were associated with significantly higher odds of implantation, clinical pregnancy, and live birth. Our results suggest that essential trace element levels may directly influence the IVF outcomes of Spanish patients, with selenium and molybdenum exerting negative effects and copper-related ratios exerting positive effects. Additional studies are warranted to confirm these relationships in other human populations. [ABSTRACT FROM AUTHOR]
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- 2024
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193. Synergistic effect of dual phase cocatalysts: MoC-Mo2C quantum dots anchored on g-C3N4 for high-stability photocatalytic hydrogen evolution.
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Tan, Xin-Quan, Zhang, Peipei, Chen, Binghui, Mohamed, Abdul Rahman, and Ong, Wee-Jun
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QUANTUM dots , *IRRADIATION , *HYDROGEN , *HYDROGEN evolution reactions , *MOLYBDENUM , *PHOTOCATALYSTS - Abstract
[Display omitted] The extensive examination of hexagonal molybdenum carbide (β-Mo 2 C) as a non-noble cocatalyst in the realm of photocatalytic H 2 evolution is predominantly motivated by its exceptional capacity to adsorb H+ ions akin to Pt and its advantageous conductivity characteristics. However, the H 2 evolution rate of photocatalysts modified with β-Mo 2 C is limited as a result of their comparatively low ability to release H through desorption. Therefore, a facile method was employed to synthesize carbon intercalated dual phase molybdenum carbide (MC@C) quantum dots (ca. 3.13 nm) containing both α-MoC and β-Mo 2 C decorated on g-C 3 N 4 (gCN). The synthesis process involved a simple and efficient combination of sonication-assisted self-assembly and calcination techniques. 3-MC@C/gCN exhibited the highest efficiency in generating H 2 , with a rate of 4078 µmol g−1h−1 under 4 h simulated sunlight irradiation, which is 13 times higher than pristine gCN. Furthermore, from the cycle test, 3-MC@C/gCN showcased exceptional photochemical stability of 65 h, as it maintained a H 2 evolution rate of 40 mmol g−1h−1. The heightened level of activity observed in the 3-MC@C/gCN system can be ascribed to the synergistic effects of MoC-Mo 2 C that arise due to the existence of a carbon layer. The presence of a carbon layer enhanced the transmission of photoinduced electrons, while the MoC-Mo 2 C@C composite served as active sites, thereby facilitating the H 2 production reaction of gCN. The present study introduces a potentially paradigm-shifting concept pertaining to the exploration of novel Mo-based cocatalysts with the aim of augmenting the efficacy of photocatalytic H 2 production. [ABSTRACT FROM AUTHOR]
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- 2024
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194. Computational design of cooperatively acting molecular catalyst systems: carbene based tungsten- or molybdenum-catalysts with rhodium- or iridium-complexes for the ionic hydrogenation of N2 to NH3.
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Mondal, Totan, Leitner, Walter, and Hölscher, Markus
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MOLYBDENUM , *NITROGEN , *METALWORK , *CATALYST poisoning , *DENSITY functional theory , *HYDROGENATION , *CATALYSTS , *CARBENE synthesis - Abstract
This density functional theory (DFT) study explores the efficacy of cooperative catalytic systems in enabling the ionic hydrogenation of N2 with H2, leading to NH3 formation. A set of N-heterocyclic carbene-based pincer tungsten/molybdenum metal complexes of the form [(PCP)M1(H)2] (M1 = W/Mo) were chosen to bind N2 at the respective metal centres. Simultaneously, cationic rhodium/iridium complexes of type [Cp*M2{2-(2-pyridyl)phenyl}(CH3CN)]+ (Cp* = C5(CH3)5 and M2 = Rh/Ir), are employed as cooperative coordination partners for heterolytic H2 splitting. The stepwise transfer of protons and hydrides to the bound N2 and intermediate NxHy units results in the formation of NH3. Interestingly, the calculated results reveal an encouraging low range of energy spans ranging from ∼30 to 42 kcal mol−1 depending on different combinations of ligands and metal complexes. The optimal combination of pincer ligand and metal center allowed for an energy span of unprecedented 29.7 kcal mol−1 demonstrating significant potential for molecular catalysts for the N2/H2 reaction system. While exploring obvious potential off-cycle reactions leading to catalyst deactivation, the computed results indicate that no increase in energy span would need to be expected. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
195. Computational design of cooperatively acting molecular catalyst systems: carbene based tungsten- or molybdenum-catalysts with rhodium- or iridium-complexes for the ionic hydrogenation of N2 to NH3.
- Author
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Mondal, Totan, Leitner, Walter, and Hölscher, Markus
- Subjects
MOLYBDENUM ,NITROGEN ,METALWORK ,CATALYST poisoning ,DENSITY functional theory ,HYDROGENATION ,CATALYSTS ,CARBENE synthesis - Abstract
This density functional theory (DFT) study explores the efficacy of cooperative catalytic systems in enabling the ionic hydrogenation of N
2 with H2 , leading to NH3 formation. A set of N-heterocyclic carbene-based pincer tungsten/molybdenum metal complexes of the form [(PCP)M1 (H)2 ] (M1 = W/Mo) were chosen to bind N2 at the respective metal centres. Simultaneously, cationic rhodium/iridium complexes of type [Cp*M2 {2-(2-pyridyl)phenyl}(CH3 CN)]+ (Cp* = C5 (CH3 )5 and M2 = Rh/Ir), are employed as cooperative coordination partners for heterolytic H2 splitting. The stepwise transfer of protons and hydrides to the bound N2 and intermediate Nx Hy units results in the formation of NH3 . Interestingly, the calculated results reveal an encouraging low range of energy spans ranging from ∼30 to 42 kcal mol−1 depending on different combinations of ligands and metal complexes. The optimal combination of pincer ligand and metal center allowed for an energy span of unprecedented 29.7 kcal mol−1 demonstrating significant potential for molecular catalysts for the N2 /H2 reaction system. While exploring obvious potential off-cycle reactions leading to catalyst deactivation, the computed results indicate that no increase in energy span would need to be expected. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
196. Comparative mathematical modeling of causal association between metal exposure and development of chronic kidney disease.
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Miaoling Wu, Weiming Hou, Ruonan Qin, Gang Wang, Da Sun, Ye Geng, and Yinke Du
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CHRONIC kidney failure ,DISEASE risk factors ,INDUCTIVELY coupled plasma mass spectrometry ,KIDNEY development ,CAUSAL models ,MOLYBDENUM ,POTASSIUM - Abstract
Background: Previous studies have identified several genetic and environmental risk factors for chronic kidney disease (CKD). However, little is known about the relationship between serum metals and CKD risk. Methods: We investigated associations between serum metals levels and CKD risk among 100 medical examiners and 443 CKD patients in the medical center of the First Hospital Affiliated to China Medical University. Serum metal concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS). We analyzed factors influencing CKD, including abnormalities in Creatine and Cystatin C, using univariate and multiple analysis such as Lasso and Logistic regression. Metal levels among CKD patients at different stages were also explored. The study utilized machine learning and Bayesian Kernel Machine Regression (BKMR) to assess associations and predict CKD risk based on serum metals. A chained mediation model was applied to investigate how interventions with different heavy metals influence renal function indicators (creatinine and cystatin C) and their impact on diagnosing and treating renal impairment. Results: Serum potassium (K), sodium (Na), and calcium (Ca) showed positive trends with CKD, while selenium (Se) and molybdenum (Mo) showed negative trends. Metal mixtures had a significant negative effect on CKD when concentrations were all from 30
th to 45th percentiles compared to the median, but the opposite was observed for the 55th to 60th percentiles. For example, a change in serum K concentration from the 25th to the 75th percentile was associated with a significant increase in CKD risk of 5.15(1.77,8.53), 13.62 (8.91,18.33) and 31.81(14.03,49.58) when other metals were fixed at the 25th , 50th and 75th percentiles, respectively. Conclusions: Cumulative metal exposures, especially double-exposure to serum K and Se may impact CKD risk. Machine learning methods validated the external relevance of the metal factors. Our study highlights the importance of employing diverse methodologies to evaluate health effects of metal mixtures. [ABSTRACT FROM AUTHOR]- Published
- 2024
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197. Comparative Analysis of Thermal Properties in Molybdenum Substrate to Silicon and Glass for a System-on-Foil Integration.
- Author
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Huang, Tzu-Jung, Kiebala, Tobias, Suflita, Paul, Moore, Chad, Housser, Graeme, McMahon, Shane, and Puchades, Ivan
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THERMAL properties ,MOLYBDENUM ,THERMAL analysis ,FUSED silica ,ORGANIC semiconductors ,FINITE element method - Abstract
Advanced electronics technology is moving towards smaller footprints and higher computational power. In order to achieve this, advanced packaging techniques are currently being considered, including organic, glass, and semiconductor-based substrates that allow for 2.5D or 3D integration of chips and devices. Metal-core substrates are a new alternative with similar properties to those of semiconductor-based substrates but with the added benefits of higher flexibility and metal ductility. This work comprehensively compares the thermal properties of a novel metal-based substrate, molybdenum, and silicon and fused silica glass substrates in the context of system-on-foil (SoF) integration. A simple electronic technique is used to simulate the heat generated by a typical CPU and to measure the heat dissipation properties of the substrates. The results indicate that molybdenum and silicon are able to effectively dissipate a continuous power density of 2.3 W/mm
2 as the surface temperature only increases by ~15 °C. In contrast, the surface temperature of fused silica glass substrates increases by >140 °C for the same applied power. These simple techniques and measurements were validated with infrared camera measurements as well as through finite element analysis via COMSOL simulation. The results validate the use of molybdenum as an advanced packaging substrate and can be used to characterize new substrates and approaches for advanced packaging. [ABSTRACT FROM AUTHOR]- Published
- 2024
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198. A New Molybdenum Blue Structure Type: How Uranium Expands this Family of Polyoxometalates.
- Author
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Felton, Daniel E., Smith, Kyson R., Poole, Nicholas A., Cronberger, Karl, and Burns, Peter C.
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MOLYBDENUM , *URANIUM , *POLYOXOMETALATES , *RACEMIC mixtures , *DIMERS , *PHASE transitions - Abstract
The assembly of molybdenum polyoxometalates (POMs) has afforded large discrete nanoclusters with varied degrees of reduction such as the ~20 % reduced molybdenum blues. While many heterometals have been incorporated into these clusters to afford new properties, uranium has yet to be reported. Here we report the first uranium containing molybdenum blue clusters and the unique properties exhibited by this incorporation. The uranyl ion (UO22+) directs formation of Mo72U8, a square POM comprised of two faces connected by eight edge‐sharing molybdenum dimers. Mo72U8, a chiral cluster, crystallizes as a racemic mixture and, in the solid state, has a 'negative' charge localized on one face of the cluster opposite the 'positively' charged face of another cluster. Using U(IV) as both heterometal and molybdenum reductant afforded crystals of Mo97U10, a wheel cluster with a heptamolybdate cap on one face. Mo97U10 dissociates in solution, losing the heptamolybdate, to form Mo90U10. Using more solvent during synthesis afforded crystals of Mo90U10S4 which, instead of heptamolybdate, contains four sulfate ions. Crystals of Mo90U10S4 undergo a dehydration induced phase change where clusters form a sheet through oxide bridges. Half of the bridges are cation‐cation interactions between the uranyl oxygen atom and molybdenum, the first reported of this kind. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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199. Preparation of MOF-derived molybdenum-carbide-modified PtCu nano-alloy catalysts and their methanol oxidation performance.
- Author
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Zhang, Xuanhua, Wang, Chao, Luan, Chao, Liao, Mengyin, and Xu, Wenyuan
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OXIDATION of methanol , *HYDROGEN evolution reactions , *DIRECT methanol fuel cells , *MOLYBDENUM , *CATALYSTS , *CATALYTIC activity , *CARBON-based materials , *METHANOL , *METHANOL as fuel - Abstract
Direct methanol fuel cells (DMFC) are a promising new energy source. However, the lack of high-performance and low-cost methanol oxidation electrocatalysts hinders their commercial application. Firstly, we successfully prepared NENU-5-derived molybdenum carbide material (Cu-MoC) via a co-precipitation and high-temperature carbonization method using a material composed of a copper-based metal–organic skeleton and a molybdenum-based carbide as the main body. Secondly, PtCu nano-alloy catalysts (Pt/Cu-MoC) were prepared using a unique, spontaneous single replacement reaction after metal–organic skeleton (MOF) carbonization. Through the synergistic effect between Pt and Cu and the strong interaction between Mo2C and PtCu, the electronic structure of the Pt is modified, the energy of the d-band center is reduced, electron exchange is accelerated, and catalytic activity is enhanced. Compared with a commercial Pt/C catalyst in alkaline environments, the Pt0.10/Cu-MoC catalyst has a better MOR catalytic activity (563.25 mA mgPt−1), which is 1.5 times higher than that of commercial Pt/C (376.67 mA mgPt−1). The Pt0.10/Cu-MoC catalyst has an onset potential for CO oxidation that is 16 mV lower than that of commercial Pt/C, indicating better resistance to CO poisoning. Exploring carbon materials derived from MOFs with excellent junction support and using them as carriers to prepare Pt-based catalysts is a practical and feasible approach. It provides a way to develop new Pt-based catalysts that perform efficient MOR. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
200. Corrosion behavior of electrodeposited nickel-based coatings with W, Mo, and TiOx.
- Author
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Arnaudova, Marina, Lefterova, Elefteria, and Rashkov, Rashko
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- *
HYDROGEN evolution reactions , *X-ray photoelectron spectroscopy , *MOLYBDENUM , *COMPOSITE coating , *OPEN-circuit voltage , *SURFACE coatings - Abstract
The corrosion behavior of electrodeposited nickel-based coatings with W, Mo, and TiOx as potential catalytic material for hydrogen evolution reaction (HER) in highly aggressive media, 0.5 M H2SO4 and 6 M KOH, is presented. A wide range of electrochemical and spectroscopic methods have been used, such as linear sweep voltammetry, open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) to characterize the coatings before and after a residence time of 336 h in the model corrosion environment. The NiW alloy and the NiWTiOx composite coating demonstrate the best corrosion resistance in an acidic environment due to the stable tungstate phase formation (H0.33O3W and H2O4W) on the surface. In alkaline environments, all the systems studied show enviable resistance, but the alloys containing molybdenum stand out. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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