519 research outputs found

    A Model for Study Table Designed for Freshmen Athletes

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    A study table program was designed and evaluated, including having a student proctor class checking freshmen athletes and meeting with them to review class material. Students who met a benchmark at mid-semester had reduced study table hours as an incentive. The program showed an increase in student GPA above the previous year's freshmen athletes and non-athletes as well

    Dynamics of open quantum systems

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    The coupling between the states of a system and the continuum into which it is embedded, induces correlations that are especially large in the short time scale. These correlations cannot be calculated by using a statistical or perturbational approach. They are, however, involved in an approach describing structure and reaction aspects in a unified manner. Such a model is the SMEC (shell model embedded in the continuum). Some characteristic results obtained from SMEC as well as some aspects of the correlations induced by the coupling to the continuum are discussed.Comment: 16 pages, 5 figure

    Molecular dynamics approach: from chaotic to statistical properties of compound nuclei

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    Statistical aspects of the dynamics of chaotic scattering in the classical model of α\alpha-cluster nuclei are studied. It is found that the dynamics governed by hyperbolic instabilities which results in an exponential decay of the survival probability evolves to a limiting energy distribution whose density develops the Boltzmann form. The angular distribution of the corresponding decay products shows symmetry with respect to π/2\pi/2 angle. Time estimated for the compound nucleus formation ranges within the order of 10−2110^{-21}s.Comment: 11 pages, LaTeX, non

    Styrene-Associated Health Outcomes at a Windblade Manufacturing Plant

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    Background: Health risks of using styrene to manufacture windblades for the green energy sector are unknown. Methods: Using data collected from 355 (73%) current windblade workers and regression analysis, we investigated associations between health outcomes and styrene exposure estimates derived from urinary styrene metabolites. Results: The median current styrene exposure was 53.6 mg/g creatinine (interquartile range: 19.5–94.4). Color blindness in men and women (standardized morbidity ratios 2.3 and 16.6, respectively) was not associated with exposure estimates, but was the type previously reported with styrene. Visual contrast sensitivity decreased and chest tightness increased (odds ratio 2.9) with increasing current exposure. Decreases in spirometric parameters and FeNO, and increases in the odds of wheeze and asthma-like symptoms (odds ratios 1.3 and 1.2, respectively) occurred with increasing cumulative exposure. Conclusions: Despite styrene exposures below the recommended 400 mg/g creatinine, visual and respiratory effects indicate the need for additional preventative measures in this industry

    Quantum relaxation in open chaotic systems

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    Using the supersymmetry technique, we analytically derive the recent result of Casati, Maspero and Shepelyansky [cond-mat/9706103] according to which the quantum dynamics of open chaotic systems follows the classical decay up to a new quantum relaxation time scale tq∌tctHt_q\sim\sqrt{t_c t_H}. This scale is larger than the classical escape time tct_c but still much smaller than the Heisenberg time tHt_H. For systems with orthogonal or unitary symmetry the quantum decay is slower than the classical one while for the symplectic case there is an intermediate regime in which the quantum decay is slightly faster.Comment: 4 pages Rev-Tex, one figure, important modifications in introduction and conlusion, four references added or modifie

    Towards an analytical framework of science communication models

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    This chapter reviews the discussion in science communication circles of models for public communication of science and technology (PCST). It questions the claim that there has been a large-scale shift from a ‘deficit model’ of communication to a ‘dialogue model’, and it demonstrates the survival of the deficit model along with the ambiguities of that model. Similar discussions in related fields of communication, including the critique of dialogue, are briefly sketched. Outlining the complex circumstances governing approaches to PCST, the author argues that communications models often perceived to be opposed can, in fact, coexist when the choices are made explicit. To aid this process, the author proposes an analytical framework of communication models based on deficit, dialogue and participation, including variations on each

    Quantum mechanical time-delay matrix in chaotic scattering

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    We calculate the probability distribution of the matrix Q = -i \hbar S^{-1} dS/dE for a chaotic system with scattering matrix S at energy E. The eigenvalues \tau_j of Q are the so-called proper delay times, introduced by E. P. Wigner and F. T. Smith to describe the time-dependence of a scattering process. The distribution of the inverse delay times turns out to be given by the Laguerre ensemble from random-matrix theory.Comment: 4 pages, RevTeX; to appear in Phys. Rev. Let
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