1,515 research outputs found

    Sensing properties of gas sensor based on adsorption of NO2 with defect, pristine, Fe and Si-MoS2 layer

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    Two-dimensional (2D) layered materials are currently being considered as entrant for future electronic devices. Molybdenum disulphide (MoS2) belongs to a family of layered transitional metal dichalcogenides(TMDS),has a unique characteristics of showing intrinsic semiconducting nature is being considered a major advantageous over graphene (which has no intrinsic band gap) as a two-dimensional (2D) channel material in field effect transistors(FET). In the paper, the results of investigations are presented concerning the affects of adsorption of NO2 gas on the surface of MoS2, defect-MoS2, Si-MoS2 and Fe-MoS2 layer. The changes density of states (DOS) and electrostatic difference potential of Si-MoS2 by applying different gate voltage were studied. We proposed that, NO2 might play an important role on MoS2 layer that can be used as gas sensor. In the research, it has been shown that in the case of gas sensor, the adsorption of NO2 with MoS2, Fe-MoS2, Si-MoS2 and defect-MoS2 play an important rule for sensing behavior

    Sensing properties of gas sensor based on adsorption of NO2 with defect, pristine, Fe and Si-MoS2 layer

    Get PDF
    Two-dimensional (2D) layered materials are currently being considered as entrant for future electronic devices. Molybdenum disulphide (MoS2) belongs to a family of layered transitional metal dichalcogenides(TMDS),has a unique characteristics of showing intrinsic semiconducting nature is being considered a major advantageous over graphene (which has no intrinsic band gap) as a two-dimensional (2D) channel material in field effect transistors(FET). In the paper, the results of investigations are presented concerning the affects of adsorption of NO2 gas on the surface of MoS2, defect-MoS2, Si-MoS2 and Fe-MoS2 layer. The changes density of states (DOS) and electrostatic difference potential of Si-MoS2 by applying different gate voltage were studied. We proposed that, NO2 might play an important role on MoS2 layer that can be used as gas sensor. In the research, it has been shown that in the case of gas sensor, the adsorption of NO2 with MoS2, Fe-MoS2, Si-MoS2 and defect-MoS2 play an important rule for sensing behavior

    Security Issues in a SOA-based Provenance System

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    Recent work has begun exploring the characterization and utilization of provenance in systems based on the Service Oriented Architecture (such as Web Services and Grid based environments). One of the salient issues related to provenance use within any given system is its security. Provenance presents some unique security requirements of its own, which are additionally dependent on the architectural and environmental context that a provenance system operates in. We discuss the security considerations pertaining to a Service Oriented Architecture based provenance system. Concurrently, we outline possible approaches to address them

    Nucleon Structure from Lattice QCD

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    Recent advances in lattice field theory, in computer technology and in chiral perturbation theory have enabled lattice QCD to emerge as a powerful quantitative tool in understanding hadron structure. I describe recent progress in the computation of the nucleon form factors and moments of parton distribution functions, before proceeding to describe lattice studies of the Generalized Parton Distributions (GPDs). In particular, I show how lattice studies of GPDs contribute to building a three-dimensional picture of the proton. I conclude by describing the prospects for studying the structure of resonances from lattice QCD.Comment: 6 pages, invited plenary talk at NSTAR 2007, 5-8 September 2007, Bonn, German

    Risk factors for coronary heart disease in the Indians of Durban

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    Coronary heart disease (CHD) is a major problem in migrant Indians throughout the world. In South Africa it has reached 'epidemic' proportions. A field survey was conducted among Indians in the metropolitan area of Durban to determine the prevalence and known risk factors for CHD. In a study of 778 subjects aged 15 - 69 years (408 men), 15,3% (sex and age adjusted 13,4%) had a history of CHD. The important risk factors in men were hypercholesterolaemia, hypertriglyceridaemia, diabetes, and smoking, and in women diabetes, hypercholesterolaemia, and hypertriglyceridaemia. The minor risk factors were hyperuricaemia, sedentary occupation, obesity in women and a positive family history of CHD. A study of the major risk factors leading to CHD showed that 52% (sex and age adjusted 45,5%) had at least one major risk factor at the higher (level A) and 68% (sex and age adjusted 61,9%) at the lower (level B) risk levels. Diabetes mellitus was strongly associated with a positive history of CHD. In 47,6% (sex and age adjusted 48,2%) of the total group resting ECG abnormalities were found that could be coded. Because of the severe nature of CHD in the migrant Indian, an immediate and intensive programme of primary prevention of CHD risk factors should be instituted

    Chiral perturbation theory with Wilson-type fermions including a2a^2 effects: Nf=2N_f=2 degenerate case

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    We have derived the quark mass dependence of mπ2m_{\pi}^2, mAWIm_{\rm AWI} and fπf_{\pi}, using the chiral perturbation theory which includes the a2a^2 effect associated with the explicit chiral symmetry breaking of the Wilson-type fermions, in the case of the Nf=2N_f=2 degenerate quarks. Distinct features of the results are (1) the additive renormalization for the mass parameter mqm_q in the Lagrangian, (2) O(a)O(a) corrections to the chiral log (mqlogmqm_q\log m_q) term, (3) the existence of more singular term, logmq\log m_q, generated by a2a^2 contributions, and (4) the existence of both mqlogmqm_q\log m_q and logmq\log m_q terms in the quark mass from the axial Ward-Takahashi identity, mAWIm_{\rm AWI}. By fitting the mass dependence of mπ2m_\pi^2 and mAWIm_{\rm AWI}, obtained by the CP-PACS collaboration for Nf=2N_f=2 full QCD simulations, we have found that the data are consistently described by the derived formulae. Resumming the most singular terms logmq\log m_q, we have also derived the modified formulae, which show a better control over the next-to-leading order correction.Comment: 21 pages, 4 figures (10 eps files), Revtex4, some discussions and references added, the final version to appear in PR

    Initiatives of Tropical Agroforestry to Sustainable Agriculture: A Case Study of Capasia Village, Northern Bangladesh

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    A relatively large percentage of the population in Bangladesh lives under the poverty line and is affected by the country's degrading natural resources. Agroforestry has been seen as one of the few options to lift people out of poverty. Research into the costs and benefits of agroforestry was undertaken in Capasia Village in Northern Bangladesh. Initial results indicate that agroforestry may not only be an optimal livelihood solution for poor farmers, biodiversity conservation and environmental sustainability but agroforestry systems also provide good economic rates of return. Thus the farmers who engage in agroforestry are benefited in different ways

    Global modeling of the nitrate radical (NO3) for present and pre-industrial scenarios

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    AbstractIncreasing the complexity of the chemistry scheme in the global chemistry transport model STOCHEM to STOCHEM-CRI (Utembe et al., 2010) leads to an increase in NOx as well as ozone resulting in higher NO3 production over forested regions and regions impacted by anthropogenic emission. Peak NO3 is located over the continents near NOx emission sources. NO3 is formed in the main by the reaction of NO2 with O3, and the significant losses of NO3 are due to the photolysis and the reactions with NO and VOCs. Isoprene is an important biogenic VOC, and the possibility of HOx recycling via isoprene chemistry and other mechanisms such as the reaction of RO2 with HO2 has been investigated previously (Archibald et al., 2010a). The importance of including HOx recycling processes on the global budget of NO3 for present and pre-industrial scenarios has been studied using STOCHEM-CRI, and the results are compared. The large increase (up to 60% for present and up to 80% for pre-industrial) in NO3 is driven by the reduced lifetime of emitted VOCs because of the increase in the HOx concentration. The maximum concentration changes (up to 15ppt) for NO3 from pre-industrial to present day are found at the surface between 30oN and 60oN because of the increase in NOx concentrations in the present day integrations

    Group sex event participation: A link to STI risk among African-American heterosexual men incarcerated in North Carolina

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    Group sex events (GSEs) among heterosexuals and other groups may facilitate STI transmission by contributing to rapid partner exchange and links to high-risk partners
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