398,372 research outputs found
Studies on Bis(imido) molybdenum complexes containing unsaturated hydrocarbon ligands
No full textThis thesis describes the synthesis and characterisation of molybdenum bis(imido) complexes containing unsaturated hydrocarbon ligands. A principal objective of the work was to examine the effect of various imido substituents on the coordination number of the complex and the orientations adopted by olefin and acetylene ligands. Chapter One highlights areas of transition metal chemistry relevant to the thesis, with particular emphasis on the psuedo-isolobal analogy between cyclopentadienyl and imido ligands, A convenient one-pot synthesis of molybdenum bis(imido) complexes of the type Mo(NR)(NR')Cl(_2).DME (R=R'=l-adamantyl, 2-t- BUC(_6)H(_4); R=2,6-i-Pr(_2)C(_6)H(_3), R'=t-Bu) is described in Chapter Two. Mo(N-l- adamantyl)(O)Cl(_2).DME has been synthesised, and its structure determined by single crystal X-ray diffraction.- The preparation of olefin complexes Mo(NR)(NR')(C(_2)H(_4))(PMe(_3))n (R=R'=l-adamantyl, n=l; R=R'=2-t-BuC(_6)H(_4), n=2; R=2,6-i-Pr(_2)C(_6)H(_3), R'=t- Bu, n=l) is outlined in Chapter Three. Structural information derived from NMR data has allowed comparison with metallocene-like olefin adducts. Chapter Four describes the synthesis of complexes containing σ-bound phenyl ligands (Mo(NR)(NR')(σ-C(_6)H(_5))(PMe(_3)) (R=R'=l-adamantyl, 2-t-BuC(_6)H(_4); R=2,6-i-Pr(_2)C(_6)H(_3), R'=t-Bu)) as potential precursors to benzyne complexes. Chapter Five describes the preparation of diphenylacetylene complexes Mo(NR)(NR')(PhC=CPh)(PMe(_3)), structural information derived from NMR data allows comparison with previously known metallocene-like acetylene complexes. Full experimental details for Chapters Two to Five are given in Chapter Six
Efficacy and safety of the RTS,S/AS01 malaria vaccine during 18 months after vaccination : a phase 3 randomized, controlled trial in children and young infants at 11 African sites
No full textA malaria vaccine could be an important addition to current control strategies. We report the safety and vaccine efficacy (VE) of the RTS,S/AS01 vaccine during 18 mo following vaccination at 11 African sites with varying malaria transmission.; 6,537 infants aged 6-12 wk and 8,923 children aged 5-17 mo were randomized to receive three doses of RTS,S/AS01 or comparator vaccine. VE against clinical malaria in children during the 18 mo after vaccine dose 3 (per protocol) was 46% (95% CI 42% to 50%) (range 40% to 77%; VE, p>0.01 across all sites). VE during the 20 mo after vaccine dose 1 (intention to treat [ITT]) was 45% (95% CI 41% to 49%). VE against severe malaria, malaria hospitalization, and all-cause hospitalization was 34% (95% CI 15% to 48%), 41% (95% CI 30% to 50%), and 19% (95% CI 11% to 27%), respectively (ITT). VE against clinical malaria in infants was 27% (95% CI 20% to 32%, per protocol; 27% [95% CI 21% to 33%], ITT), with no significant protection against severe malaria, malaria hospitalization, or all-cause hospitalization. Post-vaccination anti-circumsporozoite antibody geometric mean titer varied from 348 to 787 EU/ml across sites in children and from 117 to 335 EU/ml in infants (per protocol). VE waned over time in both age categories (Schoenfeld residuals p>0.001). The number of clinical and severe malaria cases averted per 1,000 children vaccinated ranged across sites from 37 to 2,365 and from -1 to 49, respectively; corresponding ranges among infants were -10 to 1,402 and -13 to 37, respectively (ITT). Meningitis was reported as a serious adverse event in 16/5,949 and 1/2,974 children and in 9/4,358 and 3/2,179 infants in the RTS,S/AS01 and control groups, respectively.; RTS,S/AS01 prevented many cases of clinical and severe malaria over the 18 mo after vaccine dose 3, with the highest impact in areas with the greatest malaria incidence. VE was higher in children than in infants, but even at modest levels of VE, the number of malaria cases averted was substantial. RTS,S/AS01 could be an important addition to current malaria control in Africa
Electrical, morphological and structural properties of RF magnetron sputtered Mo thin films for application in thin film photovoltaic solar cells
No full textMolybdenum (Mo) thin films were deposited using radio frequency magnetron sputtering, for application as a metal back contact material in ‘‘substrate configuration’’ thin film solar cells. The variations of the electrical, morphological, and structural properties of the deposited films with sputtering pressure, sputtering power and post-deposition annealing were determined. The electrical conductivity of the Mo films was found to increase with decreasing sputtering pressure and increasing sputtering power. X-ray diffraction data showed that all the films had a (110) preferred orientation that became less pronounced at higher sputtering power while being relatively insensitive to process pressure. The lattice stress within the films changed from tensile to compressive with increasing sputtering power and the tensile stress increased with increasing sputtering pressure. The surface morphology of the films changed from pyramids to cigar-shaped grains for a sputtering power between 100 and 200 W, remaining largely unchanged at higher power. These grains were also observed to decrease in size with increasing sputtering pressure. Annealing the films was found to affect the resistivity and stress of the films. The resistivity increased due to the presence of residual oxygen and the stress changed from tensile to compressive. The annealing step was not found to affect the crystallisation and grain growth of the Mo films
Comparison between calculations of shortwave radiation with different aerosol datasets and measured data at the MSU MO (Russia)
No full textThe radiation block of the COSMO non-hydrostatic mesoscale model of the atmosphere and soil active layer was tested against a relatively new effective CLIRAD(FC05)-SW radiation model and radiative measurements at the Moscow State University Meteorological Observatory (MSU MO, 55.7N, 37.5E) using different aerosol datasets in cloudless conditions. We used the data of shortwave radiation components from the Kippamp;Zonen net radiometer CNR4. The model simulations were performed with the application of various aerosol climatologies including the new MACv2 climatology and the aerosol and water vapor dataset from CIMEL (AERONET) sun photometer measurements. The application of the new MACv2 climatology in the CLIRAD(FC05)-SW radiation model provides the annual average relative error of the total global radiation of -3 varying from 0.5 in May to -7.7 in December. The uncertainty of radiative calculations in the COSMO model according to preliminary estimates changes from 1.4 to 8.4. against CLIRAD(FC05)-SW radiation model with the same parameters. We showed that in clear sky conditions the sensitivity of air temperature at 2 meters to shortwave net radiation changes is about 0.7-0.9°C per100 W/m2 due to the application of aerosol climatologies over Moscow. © 2017 Author(s)
Photochemical reactions of M(CO)6 (M = Cr, Mo, W) with Ph2P(S)P(S)Ph2
No full textNew complexes {M(CO)4[Ph2P(S)P(S)Ph2]} (M = Cr, Mo and W), (1a) - (3a), [(1a), M = Cr; (2a), M = Mo; (3a), M = W] and {M2(CO)10[µ-Ph2P(S)P(S)Ph2]} (M = Cr, Mo, W), [(1b) - (3b) [(1b), M = Cr; (2b), M = Mo; (3b), M = W] have been prepared by the photochemical reaction of M(CO)6 with Ph2P(S)P(S)Ph2 and characterized by elemental analyses, f.t.-i.r. and 31P-(1H)-n.m.r. spectroscopy and by FAB-mass spectrometry. The spectra suggest cis-chelate bidentate coordination of the ligand in {M(CO)4[Ph2P(S)P(S)Ph2]} and cis-bridging bidentate coordination of the ligand between two metals in (M = Cr, Mo and W).We thank BP (Turkey) for the provision of photochemical apparatus and the Research Foundation of Ege University for funds. We are grateful to Dr G. Hogarth for obtaining the mass spectra and n.m.r. data at the University College, London. -
Revealing the influence of Mo addition on interphase precipitation in Ti-bearing low carbon steels
No full textMo is widely used as an effective microalloying element to improve mechanical performance of interphase precipitation steels, but the precise role of Mo in interphase precipitation behavior is not fully understood. In this contribution, interphase precipitation behavior in a series of Ti-Mo-bearing low carbon steels is systematically studied, and the role of Mo in interphase precipitates and its coarsening behavior is revisited. It is found that (Ti, Mo)C precipitates instead of TiC are formed in the Mo-containing alloys, and the average site fraction of Mo in (Ti, Mo)C is almost independent of the bulk Mo content. Moreover, the number density of interphase precipitates can be substantially enhanced by a minor addition of Mo, albeit it does not further rise with increasing the bulk Mo content. This is because the Mo fraction in (Ti, Mo)C rather than the bulk Mo content governs the driving force for precipitation nucleation and the interfacial energy of the (Ti, Mo)C/α and (Ti, Mo)C/γ interfaces. In addition to the reduced interfacial energy, decrease of Ti trans-interface diffusivity has been identified as another key reason for the enhanced carbide coarsening resistance in Mo-containing alloys.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Novel Aerospace Material
Упругое рассеяние атомных пар Mo-Mo, Mo-S и S-S в диапазоне относительных кинетических энергий 2-200 eV
No full text
AbstractThe interatomic binary potentials of Mo-Mo, Mo-S and S-S, approved by Molecular Dynamics, were used to calculate elastic phase shifts and cross sections of the atomic pairs in the relative kinetic energy range of 2–200 eV. It is expected the obtained differential and integral cross sections to be of help to describe sputtering of MoS_2 nanometer layers in design of perspective devices of nanoelectronics and photonics.
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Especificação semântica de QoS: a ontologia QoS-MO
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da ComputaçãoEste trabalho apresenta a ontologia QoS-MO que permite a especificação de características e requisitos de QoS para Web Services Semânticos ou Componentes de Software e pode ser facilmente utilizada para estender a OWL-S ou outras ontologias de descrição funcional de Componentes. As especificações de QoS modeladas a partir da ontologia QoS-MO podem ser utilizadas no projeto, desenvolvimento, publicação e descoberta de Web Services ou Componentes de Software. Um mecanismo de busca semântica de Web Services ou Componentes de Software foi especificado, voltado para a descoberta de Componentes que atendam a um conjunto definido de restrições de QoS, utilizando a ontologia QoS-MO e a linguagem de consulta SPARQL. Um protótipo deste mecanismo foi desenvolvido, contando tanto com uma interface de programação como uma interface Web. Os testes realizados demonstraram que o mecanismo proposto é viável e apresenta um desempenho aceitável e que a ontologia definida é capaz de expressar características de QoS complexas. A comparação com mecanismos de descoberta de Web Services de propostas similares demonstrou que a abordagem QoS-MO é mais simples e eficiente, pois não depende de nenhum algoritmo complexo para sua execução, apenas de um mecanismo de inferência simples e da linguagem SPARQL
Mo-Doped Ni<sub>3</sub>S<sub>2</sub> Nanosheet Arrays for Overall Water Splitting
No full textDesigning effective and low-cost bifunctional electrocatalysts
for the alkaline hydrogen evolution reaction (HER) and oxygen evolution
reaction (OER) is essential to achieve green development of the hydrogen
economy. Herein, we have developed Mo-doped Ni3S2 nanosheet array catalysts with excellent electrochemical properties.
Only 85 mV (HER) and 230 mV (OER) overpotentials are required under
alkaline conditions at 10 mA cm–2 and remain undegraded
for 100 h. In addition, it only required 1.52 V at 10 mA cm–2 in an alkaline electrolyzer, and it remained unchanged for more
than 100 h in stability tests, outperforming most reported electrocatalysts.
Experiments and density functional theory (DFT) calculations confirmed
that the doping of Mo could expose more active sites of Ni3S2 and optimize the adsorption free energy of the intermediate,
which in turn improves its intrinsic activity. This work reveals the
key role of Mo in Ni3S2 electrocatalytic performance
enhancement at the atomic scale
Monte-Carlo simulation with FLUKA for solid Mo-100 target
No full textThe influence of proton beam profile and beam angle impinging a solid Mo-100 target at 24 MeV has been studied with the Monte-Carlo code FLUKA. The yield of Tc-99m is dependent on both the profile and the angle, with the extreme case of a reduction of the yield by about 50% when a more realistic Gaussian beam was used and a beam angle of 60° to the normal of the target plate
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