6,492 research outputs found

    Thermal stress cycling of GaAs solar cells

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    A thermal cycling experiment was performed on GaAs solar cells to establish the electrical and structural integrity of these cells under the temperature conditions of a simulated low-Earth orbit of 3-year duration. Thirty single junction GaAs cells were obtained and tests were performed to establish the beginning-of-life characteristics of these cells. The tests consisted of cell I-V power output curves, from which were obtained short-circuit current, open circuit voltage, fill factor, and cell efficiency, and optical micrographs, spectral response, and ion microprobe mass analysis (IMMA) depth profiles on both the front surfaces and the front metallic contacts of the cells. Following 5,000 thermal cycles, the performance of the cells was reexamined in addition to any factors which might contribute to performance degradation. It is established that, after 5,000 thermal cycles, the cells retain their power output with no loss of structural integrity or change in physical appearance

    High Resolution BPM Upgrade for the ATF Damping Ring at KEK

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    A beam position monitor (BPM) upgrade at the KEK Accelerator Test Facility (ATF) damping ring has been accomplished, carried out by a KEK/FNAL/SLAC collaboration under the umbrella of the global ILC R&D effort. The upgrade consists of a high resolution, high reproducibility read-out system, based on analog and processing, and also implements a new automatic gain error correction schema. The technical concept and realization as well as results of beam studies are presented.Comment: 3 pp. 10th European Workshop on Beam Diagnostics and Instrumentation for Particle Accelerators DIPAC 2011, 16-18 May 2011. Hamburg, German

    The future of sovereignty in multilevel governance Europe: a constructivist reading

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    Multilevel governance presents a depiction of contemporary structures in EU Europe as consisting of overlapping authorities and competing competencies. By focusing on emerging non-anarchical structures in the international system, hence moving beyond the conventional hierarchy/anarchy dichotomy to distinguish domestic and international arenas, this seems a radical transformation of the familiar Westphalian system and to undermine state sovereignty. Paradoxically, however, the principle of sovereignty proves to be resilient despite its alleged empirical decline. This article argues that social constructivism can explain the paradox, by considering sovereign statehood as a process-dependent institutional fact, and by showing that multilevel governance can feed into this process

    A Wire Position Monitor System for the 1.3 GHZ Tesla-Style Cryomodule at the Fermilab New-Muon-Lab Accelerator

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    The first cryomodule for the beam test facility at the Fermilab New-Muon-Lab building is currently under RF commissioning. Among other diagnostics systems, the transverse position of the helium gas return pipe with the connected 1.3 GHz SRF accelerating cavities is measured along the ~15 m long module using a stretched-wire position monitoring system. An overview of the wire position monitor system technology is given, along with preliminary results taken at the initial module cool down, and during further testing. As the measurement system offers a high resolution, we also discuss options for use as a vibration detector.Comment: 4 pp. 15th International Conference on RF Superconductivity (SRF2011). 25-29 Jul 2011. Chicago, Illinois, US

    Der Zusammenhang von Umweltbewusstsein und Umweltverhalten:Eine explorative Studie zu einem Kernproblem der Umweltsoziologie am Beispiel von Wissensarbeiter*innen

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    Die Umweltsoziologie befasst sich seit ihrer Entstehung mit dem Zusammenhang von Umweltbewusstsein und Umweltverhalten. Sind sich die Menschen der Krise des gesellschaftlichen Naturverhältnisses bewusst? Und vor allem: Gelingt es ihnen, ihr Umweltbewusstsein und ihren Veränderungswillen in ein anderes Umweltverhalten zu übersetzen? Im vorliegenden Buch werden diese klassischen Fragen der Umweltbewusstseins-Umweltverhaltens-Forschung aufgegriffen und die theoretischen Modelle des Problemfeldes anhand der empirischen Ergebnisse einer Untersuchung zum Umweltbewusstsein und Umweltverhalten von Wissensarbeiter*innen diskutiert und weiterentwickelt. <br

    Estrategias de formulación de los mercados de abasto y su influencia en la sociedad y cultura

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    Los mercados de abasto es una de las infraestructuras más antiguas de comercialización que convive con el retail moderno, manteniendo su posicionamiento, gracias no solo a la ventaja competitiva del producto fresco sino a los impactos sociales y culturales que generan. Por otro lado los supermercados y su gran desarrollo logístico operacional y fuerte crecimiento, han modificado los hábitos de compra del consumidor, con la creación de distintos formatos de venta, posicionándose cada vez más en la preferencia de compra, pudiéndose perder ese potencial beneficio sociocultural, por lo que los mercados de abasto tradicionales necesitan implementar nuevas estrategias que les permita seguir desarrollando esos aspectos relevantes de la sociedad, recuperando sus orígenes de ser edificaciones potencialmente influyentes de su entorno, a través de intervenciones que generan vinculaciones sociales y culturales, encontrándose en la investigación soluciones como: Beneficios sociales a través de la integración estratégica de comerciantes y vecinos, Beneficios urbanos a través de la integración con su entorno, Beneficios culturales a través de nuevos servicios con valor agregado, mejoras de los servicios internos implementando el diseño emocional y merchandising en la exhibición

    Selenium-Binding Protein 1 Indicates Myocardial Stress and Risk for Adverse Outcome in Cardiac Surgery

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    Selenium-binding protein 1 (SELENBP1) is an intracellular protein that has been detected in the circulation in response to myocardial infarction. Hypoxia and cardiac surgery affect selenoprotein expression and selenium (Se) status. For this reason, we decided to analyze circulating SELENBP1 concentrations in patients (n = 75) necessitating cardioplegia and a cardiopulmonary bypass (CPB) during the course of the cardiac surgery. Serum samples were collected at seven time-points spanning the full surgical process. SELENBP1 was quantified by a highly sensitive newly developed immunological assay. Serum concentrations of SELENBP1 increased markedly during the intervention and showed a positive association with the duration of ischemia (ρ = 0.6, p < 0.0001). Elevated serum SELENBP1 concentrations at 1 h after arrival at the intensive care unit (post-surgery) were predictive to identify patients at risk of adverse outcome (death, bradycardia or cerebral ischemia, "endpoint 1"; OR 29.9, CI 3.3-268.8, p = 0.00027). Circulating SELENBP1 during intervention (2 min after reperfusion or 15 min after weaning from the CPB) correlated positively with an established marker of myocardial infarction (CK-MB) measured after the intervention (each with ρ = 0.5, p < 0.0001). We concluded that serum concentrations of SELENBP1 were strongly associated with cardiac arrest and the duration of myocardial ischemia already early during surgery, thereby constituting a novel and promising quantitative marker for myocardial hypoxia, with a high potential to improve diagnostics and prediction in combination with the established clinical parameters

    Multifractal detrending moving average cross-correlation analysis

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    There are a number of situations in which several signals are simultaneously recorded in complex systems, which exhibit long-term power-law cross-correlations. The multifractal detrended cross-correlation analysis (MF-DCCA) approaches can be used to quantify such cross-correlations, such as the MF-DCCA based on detrended fluctuation analysis (MF-X-DFA) method. We develop in this work a class of MF-DCCA algorithms based on the detrending moving average analysis, called MF-X-DMA. The performances of the MF-X-DMA algorithms are compared with the MF-X-DFA method by extensive numerical experiments on pairs of time series generated from bivariate fractional Brownian motions, two-component autoregressive fractionally integrated moving average processes and binomial measures, which have theoretical expressions of the multifractal nature. In all cases, the scaling exponents hxyh_{xy} extracted from the MF-X-DMA and MF-X-DFA algorithms are very close to the theoretical values. For bivariate fractional Brownian motions, the scaling exponent of the cross-correlation is independent of the cross-correlation coefficient between two time series and the MF-X-DFA and centered MF-X-DMA algorithms have comparative performance, which outperform the forward and backward MF-X-DMA algorithms. We apply these algorithms to the return time series of two stock market indexes and to their volatilities. For the returns, the centered MF-X-DMA algorithm gives the best estimates of hxy(q)h_{xy}(q) since its hxy(2)h_{xy}(2) is closest to 0.5 as expected, and the MF-X-DFA algorithm has the second best performance. For the volatilities, the forward and backward MF-X-DMA algorithms give similar results, while the centered MF-X-DMA and the MF-X-DFA algorithms fails to extract rational multifractal nature.Comment: 15 pages, 4 figures, 2 matlab codes for MF-X-DMA and MF-X-DF

    Modus Vivendi Beyond the Social Contract: Peace, Justice, and Survival in Realist Political Theory

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    This essay examines the promise of the notion of modus vivendi for realist political theory. I interpret recent theories of modus vivendi as affirming the priority of peace over justice, and explore several ways of making sense of this idea. I proceed to identify two key problems for modus vivendi theory, so conceived. Normatively speaking, it remains unclear how this approach can sustain a realist critique of Rawlsian theorizing about justice while avoiding a Hobbesian endorsement of absolutism. And conceptually, the theory remains wedded to a key feature of social contract theory: political order is conceived as based on agreement. This construes the horizontal tensions among individual or group agents in society as prior to the vertical, authoritative relations between authorities and their subjects. Political authority thereby appears from the start as a solution to societal conflict, rather than a problem in itself. I argue that this way of framing the issue abstracts from political experience. Instead I attempt to rethink the notion of modus vivendi from within the lived experience of political conflict, as oriented not primarily toward peace, but political survival. With this shift of perspective, the idea of modus vivendi shows us, pace Bernard Williams, that the “first political question” is not how to achieve order and stability, but rather: what can I live with
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