2,428 research outputs found

    X-ray emission spectroscopic study of chloride solid compounds using synchrotron radiation

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    An x-ray emission spectrometer, developed at beamline 9.3.1 of the Advance Light Source (ALS), Lawrence Berkeley National Laboratory (LBNL), will allow performing measurements of x-ray emission from molecules and materials in gas, liquid and solid phases with energy, angle and polarization dependence. A two-dimensional position-sensitive detector system with data acquisition software is developed for the spectrometer that allows collecting a complete x-ray emission spectrum simultaneously. Mechanical supports for detector mounting and a holder for solid samples are designed and manufactured. Energy calibration, resolution, and performance of the detector system and the spectrometer are tested by studying a solid potassium chloride (KCl) sample with photon energies in the vicinity of Cl K edge. A detectable energy range of 55--60 eV with a resolution of 0.2 eV are obtained and reported. The detector system and data acquisition software are suitable for x-ray emission measurements

    Microscopic and spectroscopic studies of metal deposition on carbon-based materials

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    This dissertation is focused on studying the atomic and electronic structure of carbon-based materials, namely highly-ordered pyrolytic graphite (HOPG), single-walled carbon nanotubes (SWNT), and C60 fullerenes, with and without metal (Ti and Li) deposition. The work is motivated by ongoing efforts to understand and improve the hydrogen storage capability of carbon-based nanomaterials as well as their potential applications for developing novel electronic devices; Ti and Li deposition on the surface of SWNT, C60, and HOPG samples have been performed in ultra-high vacuum. The morphology and local geometric and electronic structure of the samples was investigated by scanning tunneling microscopy and spectroscopy (STM and STS). The chemical and electronic structure of the samples was studied by X-ray and UV photoelectron spectroscopy (PES). Changes in the carbon core- and valence-electronic levels upon metal deposition were observed and correlated with detailed morphological and electronic characteristics. The results give detailed information about the interaction between metal adatoms and carbon-based materials. In addition, several important aspects related to the deposited metals, such as the formation of oxides, were studied. The results provide fundamental insight into metal-carbon interactions and help to develop approaches to improve the performance of carbon-based materials for hydrogen storage and novel electronic devices

    Modelling and thermal analysis of a seismic borehole sensor: diploma 2015

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    Analysis and adaptation of an acquisition system for a seismometer to enable operation at high temperatures (up to 180 [°C]). The simulation software and thermal measurements are used to validate theoretical results

    Pengaruh Persepsi Teknologi dan Persepsi Risiko Terhadap Kepercayaan Pengguna M-banking BRI Konvensional (Studi Pada Mahasiswa FEB UM Metro)

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    This study aims to determine the effect of technology perceptions and risk perceptions on the trust of M-Banking users. This type of research is quantitative research with the data used is field data (field research). Data collection was obtained from the results of questionnaires to 85 students of the Department of Management, Faculty of Economics and Business, UM Metro, which were taken using the formula from Slovin. Research data analysis was carried out using quantitative data analysis by testing instrument requirements, requirements analysis and hypotheses.                The results showed that the technology perception variable obtained a t-count value of 1.428 <t-table (0.165) and a significance value of 0.006 <0.05, then H1 was accepted, which means technology perception had a greater and more significant effect on user trust, while the risk perception variable obtained t-value of 1.328 <t-table (0.165) and a significance value of 0.009 <0.05, then H2 is accepted, which means that risk perception has a significant effect on user trust. So that technology perceptions and risk perceptions have a simultaneous effect on trust in the use of m-banking   Keywords: Perception of Technology, Perception of Risk, User Trust

    Entropic insertion of a big sphere into a cylindrical vessel

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    We calculate the spatial distribution of the entropic potential between a big sphere and an even bigger vessel with cylindrical shape, which are immersed in small spheres, using the three-dimensional integral equation theory. The distribution is strongly dependent on relative magnitudes of the big-sphere diameter and the inner diameter of the vessel unless the latter is much larger than the former. For a fixed value of the inner diameter, a big sphere whose diameter lies in a specific range is spontaneously inserted into the vessel and strongly confined within a small space almost in the center of the vessel cavity

    Hearing Loss in Children with Congenital Cytomegalovirus Infection

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    SOUND TRANSMISSION ACROSS A FINITE SIMPLY SUPPORTED DOUBLE-LAMINATED COMPOSITE PLATE WITH ENCLOSED AIR CAVITY

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    ABSTRACTSound transmission across a finite orthotropic laminated double-composite plate with enclosed air cavity on an infinite acoustic rigid baffle is investigated analytically. Sound velocity potential method combined with simply supported boundary conditions is used instead of traditional methods, has good scalability and is important for studies of acoustic vibration of structures. The sound transmission loss is calculated from the ratio of incident to transmitted acoustic powers. Specifically, the focus is placed on the effects of several key system parameters on sound transmission including the plate dimensions, the laminate configurations, the boundary conditions, and the composite materials are systematically examined

    Cell Tropism and Pathogenesis of Measles Virus in Monkeys

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    Measles virus (MV) is an enveloped negative strand RNA virus belonging to the family of Paramyxoviridae, genus Morbillivirus, and causes one of the most contagious diseases in humans. Experimentally infected non-human primates are used as animal models for studies of the pathogenesis of human measles. We established a reverse genetics system based on a highly pathogenic wild-type MV. Infection of monkeys with recombinant MV strains generated by reverse genetics enabled analysis of the molecular basis of MV pathogenesis. The essential in vivo function of accessory genes was indicated by infecting monkeys with recombinant MV strains deficient in the expression of accessory genes. Furthermore, recombinant wild-type MV strains expressing enhanced green fluorescent protein enabled visual tracking of MV-infected cells in vitro and in vivo. To date, three different molecules have been identified as receptors for MV. Signaling lymphocyte activation molecule (SLAM, also called CD150), expressed on immune cells, is a major receptor for MV. CD46, ubiquitously expressed in all nucleated cells in humans and monkeys, is a receptor for vaccine and laboratory-adapted strains of MV. The newly identified nectin-4 (also called poliovirus-receptor-like-4) is an epithelial cell receptor for MV. However, recent findings have indicated that CD46 acts as an MV receptor in vitro but not in vivo. The impact of the receptor usage of MV in vivo on the disease outcome is now under investigation

    Capacity to make health care decisions: its importance in clinical practice

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    Background. Assessment of capacity plays a pivotal role in determining when decisions need to be made on behalf of an individual. It therefore has major clinical management implications for health care professionals and civil liberties implications for the person concerned. In many countries, there is a presumption that adults have the capacity to make health care decisions. However, in persons with a mental disability, capacity may be temporarily or permanently impaired. Methods. A selective review is presented which considers: (i) the broad approaches taken to determining capacity; (ii) the abilities commonly assessed in determining capacity; and (iii) the principles underlying health care decision-making for adults who are without capacity. Results. Capacity is a functional concept, determined by the person's ability to understand, retain, and weigh up information relevant to the decision in order to arrive at a choice, and then to communicate that choice. We have reviewed the studies that examined decision-making abilities in people with dementia, chronic mental illness or intellectual disabilities. Approaches to decision-making in adults who lack capacity include: anticipatory decisions made through advance health care statements or decisions by proxy based on ‘best interests’ or ‘substituted judgement’. Conclusions. The understanding of clinical and legal aspects of capacity is still developing. This paper examines current concepts of capacity and decision-making on behalf of those without capacity. We propose a framework, in line with current ethical and legal guidelines, as an aid to clinicians when they are seeking consent for a health care intervention.published_or_final_versio
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