2,131 research outputs found

    Epitaxial growth of Cu (001) on Si (001): Mechanisms of orientation development and defect morphology

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    We describe the evolution of microstructure during ultrahigh vacuum ion beam sputter deposition of Cu (001) at room temperature on hydrogen-terminated Si (001). In situ reflection high energy electron diffraction indicates growth of an epitaxial Cu (001) film on Si (001) with the intensity of the Bragg rods sharpening during 5–20 nm of Cu film growth. Post-growth x-ray diffraction indicates the Cu film has a mosaic spread of (001) textures of about ±2° and that a small fraction (0.001–0.01) is of (111) textures. High-resolution transmission electron microscopy shows an abrupt Cu/Si interface with no interfacial silicide, and reveals an evolution in texture with Cu thickness so as to reduce the mosaic spread about (001). Moiré contrast suggests a nearly periodic elastic strain field extending into the Cu and Si at the interface. Other aspects of film growth which are critical to epitaxy are also discussed

    An algorithm for general quadratic programming

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    Resistivity network and structural model of the oxide cathode for CRT application

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    In this paper, the electrical properties of oxide cathode and oxide cathode plus, supplied by LG Philips Displays, have been investigated in relation to different cathode activation regimes and methods. Oxide cathode activation treatment for different durations has been investigated. The formations of the compounds associated to the diffusion of reducing elements (Mg, Al, and W) to the Ni cap surface of oxide cathode were studied by a new suggestion method. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX) was used as analytical techniques. Al, W, and Mg doping elements take place during heating to 1080 K (Ni-Brightness) under a rich controlled Ba–SrO atmosphere through an acceleration life test. The chemical transport of these elements was occurred mainly by the Ni cap grain boundary mechanism with significant pile-up of Mg compounds. Al and W show a superficial concentrations and distribution. A new structural and resistivity network model of oxide cathode plus are suggested. The new structural model shows a number of metallic and metallic oxide pathways are exist at the interface or extended through the oxide coating. The effective values of the resistances and the type of the equivalent circuit in the resistivity network model are temperature and activation time dependent.</p

    Evolution of structural and magnetic properties in Ta/Ni_81Fe_(19) multilayer thin films

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    The interdiffusion kinetics in short period (12.8 nm) Ta/Ni81Fe19 polycrystalline multilayer films has been investigated and related to the evolution of soft magnetic properties upon thermal annealing in the temperature range 300-600-degrees-C. Small angle x-ray diffraction and transmission electron microscopy were used to estimate the multilayer period. Interdiffusion in the multilayers was directly computed from the decay of the satellites near (000) in a small angle x-ray diffraction spectrum. A kinetic analysis of interdiffusion suggests that grain growth is concurrent with grain boundary diffusion of Ta in Ni81Fe19. The evolution of soft magnetic properties of Ni81Fe19, i.e., lowering of 4piM(s) and increase in coercivity H(c), also lend support to the above analysis

    Reduced graphene oxide-multiwalled carbon nanotubes hybrid film with low Pt loading as counter electrode for improved photovoltaic performance of dye-sensitised solar cells

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    In this work, the role of reduced graphene oxide (rGO) with hyperbranched surfactant and its hybridisation with multiwalled carbon nanotubes (MWCNTs) and platinum (Pt) nanoparticles (NPs) as counter electrode (CE) were investigated to determine the photovoltaic performance of dye-sensitised solar cells (DSSCs). Sodium 1,4-is(neopentyloxy)-3-(neopentyloxycarbonyl)- 1,4-dioxobutane-2-sulphonate (TC14) surfactant was utilised as dispersing and stabilising agent in electrochemical exfoliation to synthesise graphene oxide (GO) as initial solution for rGO production prior to its further hybridisation and fabrication as thin film. A chemical reduction process utilising hydrazine hydrate was conducted to produce rGO due to the low temperature process and water-based GO solution. Subsequently, hybrid solution was prepared by mixing 1 wt% MWCNTs into the produced rGO solution. TC14-rGO and TC14-rGO_MWCNTs hybrid solution were transferred into fluorine-doped tin oxide substrate to fabricate thin film by spraying deposition method. Finally, the CE films were prepared by coating with thin Pt NPs. Photoanode film was prepared by a two-step process: hydrothermal growth method to synthesise titanium dioxide nanowires (TiO2 NWs) and subsequent squeegee method to apply TiO2 NPs. According to solar simulator measurement, the highest energy conversion efficiency (η) was achieved by using CE-based TC14-rGO_MWCNTs/Pt (1.553%), with the highest short current density of 4.424 mA/cm2. The highest η was due to the high conductivity of CE hybrid film and the morphology of fabricated TiO2 NWs/TiO2 NPs. Consequently, the dye adsorption was high, and the photovoltaic performance of DSSCs was increased. This result also showed that rGO and rGO_MWCNTs hybrid can be used as considerable potential candidate materials to replace Pt gradually

    Prioritizing implementation factors of electronic document management system (EDMS) using topsis method: a case study in Iraqi government organizations

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    Taking into consideration a complexity of EDMS implementation process which involves a combination of technological, organizational and users factors, this study explores how EDMS implementation factors can be ranked through these dimensions. This paper begins with an examination of the literature on EDMS implementation studies where a conceptual framework has been derived. The study then adopts the TOPSIS method as the analytical tool that tackles the issue in prioritizing the most desirable factors influencing EDMS implementation project. From the results, the top management support, budgetary, strategic planning, staff training, awareness, resistance to change, IT implementation team, ICT infrastructure, security and privacy/trust, and collaboration are the top-ten important factors for Iraqi government organizations to implement EDMS applications. This paper draws on the research results for implications of IT managerial practice, and then suggests some empirical tactics in order to enhance in managing the EDMS implementation process in government

    Occupational Safety and Health Risk Management: A Practical Approach

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    Occupational safety and health (OSH) strive to reduce (or ideally eliminate) any form of injury, illness or damages to human capital and assets.Low rates of injury, illness and damage can improve organization’s reputation and worker’s morale, increase productivity,money stays where it should be or spent at areas needed most.OSH is increasingly a best practice at best companies/organization, simply a mark of civilized community. Risk assessment is a major component in managing occupational safety and health. The lecture focuses on how risk assessment is done in a practical way

    Inappropriate use of antibiotics in the treatment of pharyngo-tonsilitis in children in Khartoum, Sudan

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    Background: Pharyngo-tonsillitis represents a major public health problem all over the world. Recent studies in Sudan have revealed alarming results reporting antibiotics over prescription in the management of acute tonsillitis.Objectives: The aim of this study was to estimate the prevalence of Group A Beta hemolytic streptococci and document the appropriateness of using antibiotics in the treatment of acute tonsillo-pharyngitis in Jaafar Ibn Auf Pediatrics Hospital.Materials and Methods: A cross sectional hospital based study was conducted in the period January to August 2012 in Jaafar Ibn Auf Hospital, the largest tertiary pediatrics hospital in Sudan. The sample size was 100 including children aged 2-17 years and got antibiotics treatment for their current sore throat. A pharyngeal swab was collected at presentation from tonsils and posterior pharynx. Gram staining was done first, and then Group A Beta hemolytic streptococci were isolated and identified in the laboratory by their growth characteristics. All children included in the study were assessed clinically and subjected to a structural questionnaire. Data were analyzed by SPSS version 19.Results: The estimated prevalence of Group A Beta hemolytic streptococci tonsillitis and/or pharyngitis was 22%, nevertheless the proportion of antibiotic prescription was 100%.Conclusion: Most children were treated inappropriately regarding the need for using antibiotics, the type of antibiotics used and the duration of management. As many studies suggested that increased using of antibiotics may be due to uncertainty of diagnosis, requesting scoring system or rapid diagnostic test can contribute to the reduction of the rate of antibiotics prescription.Keyword: Pharyngo-tonsillitis, inappropriate, children, antibiotics, Suda
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