7,622,123 research outputs found

    Analyses of long-term measurements (2005-2012) of 7Be concentrations in surface air aerosols

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    Studies of radionuclide activities in aerosol particles provide a mean for evaluating the integrated effects of transport and meteorology on the atmospheric loadings of substances with different sources. The aim of the present study is to explain the behaviour of aerosols associated with 7Be (T1/2=53.3 days) in the surface atmosphere using exploratory data analysis to obtain information on their possible mechanisms of transport and deposition. This naturally occurring radionuclide is an important isotope in studying atmospheric processes because of its convenient half-life and sufficiently detectable -radiation (E = 0.477 MeV), which has served for studying precipitation scavenging, vertical and horizontal removal of air masses, aerosol transit and residence times in the troposphere [1]

    Historical Analyses of Disordered Handwriting

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    Handwritten texts carry significant information, extending beyond the meaning of their words. Modern neurology, for example, benefits from the interpretation of the graphic features of writing and drawing for the diagnosis and monitoring of diseases and disorders. This article examines how handwriting analysis can be used, and has been used historically, as a methodological tool for the assessment of medical conditions and how this enhances our understanding of historical contexts of writing. We analyze handwritten material, writing tests and letters, from patients in an early 20th-century psychiatric hospital in southern Germany (Irsee/Kaufbeuren). In this institution, early psychiatrists assessed handwriting features, providing us novel insights into the earliest practices of psychiatric handwriting analysis, which can be connected to Berkenkotter’s research on medical admission records. We finally consider the degree to which historical handwriting bears semiotic potential to explain the psychological state and personality of a writer, and how future research in written communication should approach these sources

    Perspective on gravitational self-force analyses

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    A point particle of mass μ\mu moving on a geodesic creates a perturbation habh_{ab}, of the spacetime metric gabg_{ab}, that diverges at the particle. Simple expressions are given for the singular μ/r\mu/r part of habh_{ab} and its distortion caused by the spacetime. This singular part h^\SS_{ab} is described in different coordinate systems and in different gauges. Subtracting h^\SS_{ab} from habh_{ab} leaves a regular remainder habRh^\R_{ab}. The self-force on the particle from its own gravitational field adjusts the world line at \Or(\mu) to be a geodesic of gab+habRg_{ab}+h^\R_{ab}; this adjustment includes all of the effects of radiation reaction. For the case that the particle is a small non-rotating black hole, we give a uniformly valid approximation to a solution of the Einstein equations, with a remainder of \Or(\mu^2) as μ0\mu\to0. An example presents the actual steps involved in a self-force calculation. Gauge freedom introduces ambiguity in perturbation analysis. However, physically interesting problems avoid this ambiguity.Comment: 40 pages, to appear in a special issue of CQG on radiation reaction, contains additional references, improved notation for tensor harmonic

    XAFS analyses of molten metal fluorides

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    X-ray absorption fine structure studies of molten metal fluorides containing the materials related to nuclear engineering are intensively summarized. By using XAFS spectra data of divalent and trivalent cation metal fluorides in molten state which have been collected by authors’ group for a few years, local structure have been extracted and discussed systematically in conjunction with other spectroscopic studies and numerical calculations. In molten divalent fluorides, tetrahedral coordination of fluorides around a cation is predominant. In the case of pure molten trivalent fluorides, structure with more than 6-coordination has been suggested in some cases, but octahedral coordination structure is much stabilized at heavier rare earth metal fluorides. By mixing with alkali metal fluorides, it is a general trend that inter-ionic distances keep constant, but coordination number of fluorides decreases. In experimental chapter, all the details of sample preparation, furnace installation, X-ray optics setups and data analyses procedures are explained. Finally, future expectations of XAFS technique are also suggested
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