3,643 research outputs found

    Application of second-order turbulent modeling to the prediction of radiated aerodynamic sound

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    The Ribner formulation of the generation of aerodynamic sound is coupled with predictions of second-order velocity correlations and integral scale to estimate the sound radiated from several complicated jet flows. In particular, it is shown that the sound radiated from a cold swirling jet is greater than from its nonswirling equal thrust counterpart. The noise radiated from the flow field of a multitube suppressor was estimated and compared with an equal thrust diameter Gaussian jet. It is shown that the multitube concept is indeed quieter

    To what extent do the Classical Equations of Motion Determine the Quantization Scheme?

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    A simple example of one particle moving in a (1+1) space-time is considered. As an example we take the harmonic oscillator. We confirm the statement that the classical Equations of Motion do not determine at all the quantization scheme. To this aim we use two inequivalent Lagrange functions, yielding Euler-Lagrange Equations, having the same set of solutions. We present in detail the calculations of both cases to emphasize the differences occuring between them.Comment: LaTeX 20 page

    Like Mark Twain: The Death of Academic Law Libraries Is an Exaggeration

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    At the 2013 CALI Conference on Law School Computing, Professor James Milles, professor and former library director of the SUNY Buffalo Law School, presented his draft paper positing that academic law libraries are doomed. The author presented his contrasting viewpoints in the same session. This paper is based on his presentation and has been updated to account for adoption of the revised law school accreditation standards approved by the ABA Council on Legal Education and Admissions to the Bar in 2014. While the author agrees with the underlying observations set out by Professor Milles, he envisions a scenario where law libraries, and more importantly librarians, remain an essential part of law school life

    Atmospheric-wake vortex interactions

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    The interactions of a vortex wake with a turbulent stratified atmosphere are investigated with the computer code WAKE. It is shown that atmospheric shear, turbulence, and stratification can provide the dominant mechanisms by which vortex wakes decay. Computations included the interaction of a vortex wake with a viscous ground plane. The observed phenomenon of vortex bounce is explained in terms of secondary vorticity produced on the ground. This vorticity is swept off the ground and advected about the vortex pair, thereby altering the classic hyperbolic trajectory. The phenomenon of the solitary vortex is explained as an interaction of a vortex with crosswind shear. Here, the vortex having the sign opposite that of the sign of the vorticity in the shear is dispersed by a convective instability. This instability results in the rapid production of turbulence which in turn disperses the smoke marking the vortex

    Law School Education in the 21st Century: Adding Information Technology Instruction to the Curriculum

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    For the past 120 years, legal education in the United States has been fundamentally unchanged, even while the practice of law has been revolutionized by information technology. The ideal of the Socratic Method is still dominant in first year and many upperclass courses. Clinical and practice courses have expanded since the early-1980s; however, although state-of-the-art technology is now commonplace in law offices, most federal courthouses, and some state courtrooms, until now, there has been little effort to contextualize the importance of technology for law students. The authors review the availability of courses covering use of technology in law practice at American law schools and set out their own proposal for such a course at Duke University School of Law

    More, More, More: Reducing Thrombosis in Acute Coronary Syndromes Beyond Dual Antiplatelet Therapy-Current Data and Future Directions.

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    © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.Common to the pathogenesis of acute coronary syndromes (ACS) is the formation of arterial thrombus, which results from platelet activation and triggering of the coagulation cascade.1 To attenuate the risk of future thrombotic events, patients with ACS are treated with dual antiplatelet therapy (DAPT), namely, the combination of aspirin with a P2Y12 inhibitor, such as clopidogrel, ticagrelor, or prasugrel. Despite DAPT, some ≈10% of ACS patients experience recurrent major adverse cardiovascular events over the subsequent 30 days,2 driving the quest for more effective inhibition of thrombotic pathways. In this review, we provide an overview of studies to date and those ongoing that aim to deliver more effective combinations of antithrombotic agents to patients with recent ACS. We have chosen to confine the review to ACS patients without atrial fibrillation because those with atrial fibrillation have a clear indication for combination therapy that includes oral anticoagulation and should, we feel, be treated as a separate cohort. In this article, we discuss the limitations of the currently available clinical trial data and future directions, with suggestions for how practice might change to reduce the risk of coronary thrombosis in those at greatest risk, with minimal impact on bleeding.Peer reviewedFinal Published versio

    Magnon-Paramagnon Effective Theory of Itinerant Ferromagnets

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    The present work is devoted to the derivation of an effective magnon-paramagnon theory starting from a microscopic lattice model of ferromagnetic metals. For some values of the microscopic parameters it reproduces the Heisenberg theory of localized spins. For small magnetization the effective model describes the physics of weak ferromagnets in accordance with the experimental results. It is written in a way which keeps O(3) symmetry manifest,and describes both the order and disordered phases of the system. Analytical expression for the Curie temperature,which takes the magnon fluctuations into account exactly, is obtained. For weak ferromagnets TcT_c is well below the Stoner's critical temperature and the critical temperature obtained within Moriya's theory.Comment: 14 pages, changed content,new result

    Development of a Short Trauma Screening Tool (STST) to Measure Child Trauma Symptoms: Establishing Content Validity

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    Purpose: The purpose of the study was to identify major symptom domain variables common to child trauma and create a prototype short trauma symptom screening tool (STST) intended for use in pediatric medical settings. Methods: This manuscript describes the first two phases of an on-going prospective mixed-method instrument development study. Phase 1 exploratory factor analysis was conducted with an archived LONGSCAN CBCL dataset to: (1) identify behavioral symptoms endorsed by children with known trauma exposure; and (2) generate a preliminary STST item pool. During Phase 2, researchers convened an expert panel (N = 10) and conducted Content Validity Index (CVI) procedures with the 20-item preliminary STST item pool, to further inform item retention, elimination and modification for an updated prototype STST. Findings: Expert quantitative scores yielded a CVI of 0.90 for the overall preliminary STST. The first two phases of this study assisted researchers with identifying 12 items that represent nine child trauma symptom domain variables, which include: (1) aggression/anger; (2) anxiety/fear; (3) sexual concerns; (4) elimination concerns; (5) somatic concerns; (6) depression; (7) dissociation; (8) physical acting out; and (9) dysregulation. Conclusions: The first two phases of STST development resulted in development of a brief, empirically-derived prototype screening tool that features 12 items operationalizing nine domains of child trauma symptoms. Developers can now advance to the next phase of STST development; feasibility assessment and psychometric testing

    Gender Differences in Personality across the Ten Aspects of the Big Five

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    This paper investigates gender differences in personality traits, both at the level of the Big Five and at the sublevel of two aspects within each Big Five domain. Replicating previous findings, women reported higher Big Five Extraversion, Agreeableness, and Neuroticism scores than men. However, more extensive gender differences were found at the level of the aspects, with significant gender differences appearing in both aspects of every Big Five trait. For Extraversion, Openness, and Conscientiousness, the gender differences were found to diverge at the aspect level, rendering them either small or undetectable at the Big Five level. These findings clarify the nature of gender differences in personality and highlight the utility of measuring personality at the aspect level

    C-axis Optical Sum Rule in Josephson Coupled Vortex State

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    Observed violations of the cc-axis optical sum rule can give important information on deviations from in-plane Fermi liquid behavior and on the nature of interlayer coupling between adjacent copper oxide planes. Application of a magnetic field perpendicular to these planes is another way to probe in-plane dynamics. We find that the optical sum rule is considerably modified in the presence of the cc-axis magnetic field. Interlayer correlation of pancake vortices is involved in the sum rule modification; however, details of the vortex distribution in the plane are less important.Comment: one figure. To be published in PRB (Sep. 20001
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