24,719 research outputs found

    Combined Release and Radiation Effects Satellite (CRRES) experiments data collection, analysis, and publication

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    The Combined Release and Radiation Effects Satellite (CRRES) program experiments data collection, analysis, and publication activities are described. These activities were associated with both the satellite chemical release and a planned Puerto Rico sounding rocket campaign. To coordinate these activities, a working group meeting was organized and conducted

    On Atkin and Swinnerton-Dyer Congruence Relations (2)

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    In this paper we give an example of a noncongruence subgroup whose three-dimensional space of cusp forms of weight 3 has the following properties. For each of the four residue classes of odd primes modulo 8 there is a basis whose Fourier coefficients at infinity satisfy a three-term Atkin and Swinnerton-Dyer congruence relation, which is the pp-adic analogue of the three-term recursion satisfied by the coefficients of classical Hecke eigen forms. We also show that there is an automorphic LL-function over Q\mathbb Q whose local factors agree with those of the ll-adic Scholl representations attached to the space of noncongruence cusp forms.Comment: Last version, to appear on Math Annale

    Accuracy Assessment of the 2006 National Land Cover Database Percent Impervious Dataset

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    An impervious surface is any surface that prevents water from infiltrating the ground. As impervious surface area increases within watersheds, stream networks and water quality are negatively impacted. The Multi-Resolution Land Characteristic Consortium developed a percent impervious dataset using Landsat imagery as part of the 2006 National Land Cover Database. This percent impervious dataset estimates imperviousness for each 30-meter cell in the land cover database. The percent impervious dataset permits study of impervious surfaces, can be used to identify impacted or critical areas, and allows for development of impact mitigation plans; however, the accuracy of this dataset is unknown. To determine the accuracy of the 2006 percent impervious dataset, reference data were digitized from one-foot digital aerial imagery for three study areas in Arkansas, USA. Digitized reference data were compared to percent impervious dataset estimates of imperviousness at multiple 900m2 , 8,100m2 , and 22,500m2 sample grids to determine if accuracy varied by ground area. Analyses showed percent impervious estimates and digitized reference data differ modestly; however, as ground area increases, percent impervious estimates and reference data match more closely. These findings suggest that the percent impervious dataset is useful for planning purposes for ground areas of at least 2.25ha

    Family, Time, and Meaning toward the End of Life in Japan

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    In contrast to media images of lonely deaths, stereotypes of the Japanese calm acceptance of dying, and the “naturalness” of dependency in old age or illness, this paper explores the complex ways in which changing perceptions of time refocus people towards the question of how to live. Time both narrows to the level of medication schedules and bodily functions, and expands to more immediate engagement with others in the past and future. The idea of a moral timeline of such changes builds upon recent work in the anthropology of morality by recognizing shifting ideas and actions people take to retain agency through suffering. People near the end of life in Japan commonly employ cultural idioms of effort, reciprocity, and gratitude to express their continual striving to be moral persons in a social world. Ultimately, such efforts determine not only how they see themselves and are seen by others through their final days, but whether theirs will be judged to be a “good death,” and thus the nature of the person’s continued social existence in spirit and memories after death. The moral timeline expressed by many of the people I met reflected intensified concern with becoming a burden and with reciprocity as the end of life came close. For many, that deepened their sense of engagement, sometimes transforming their relationships with others who would survive them or who had preceded them in death. The ethnographic data in this article come from a participant-observation study of adults of all ages with life-threatening illnesses, and from an interview study of frail elderly and their family caregivers in the early 21st century in urban and rural settings

    Emerging applications of high temperature superconductors for space communications

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    Proposed space missions require longevity of communications system components, high input power levels, and high speed digital logic devices. The complexity of these missions calls for a high data bandwidth capacity. Incorporation of high temperature superconducting (HTS) thin films into some of these communications system components may provide a means of meeting these requirements. Space applications of superconducting technology has previously been limited by the requirement of cooling to near liquid helium temperatures. Development of HTS materials with transition temperatures above 77 K along with the natural cooling ability of space suggest that space applications may lead the way in the applications of high temperature superconductivity. In order for HTS materials to be incorporated into microwave and millimeter wave devices, the material properties such as electrical conductivity, current density, surface resistivity and others as a function of temperature and frequency must be well characterized and understood. The millimeter wave conductivity and surface resistivity were well characterized, and at 77 K are better than copper. Basic microwave circuits such as ring resonators were used to determine transmission line losses. Higher Q values than those of gold resonator circuits were observed below the transition temperature. Several key HTS circuits including filters, oscillators, phase shifters and phased array antenna feeds are feasible in the near future. For technology to improve further, good quality, large area films must be reproducibly grown on low dielectric constant, low loss microwave substrates
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