48 research outputs found

    High-precision Studies of the 3^{\bf{3}}He(e,eâ€Č^{\bf{\prime}}p) Reaction at the Quasielastic Peak

    Full text link
    Precision studies of the reaction 3^{3}He(e,eâ€Č^\primep) using the three-spectrometer facility at the Mainz microtron MAMI are presented. All data are for quasielastic kinematics at ∣q⃗∣=685|\vec{q} | =685 MeV/c. Absolute cross sections were measured at three electron kinematics. For the measured missing momenta range from 10 to 165 MeV/c, no strength is observed for missing energies higher than 20 MeV. Distorted momentum distributions were extracted for the two-body breakup and the continuum. The longitudinal and transverse behavior was studied by measuring the cross section for three photon polarizations. The longitudinal and transverse nature of the cross sections is well described by a currently accepted and widely used prescription of the off-shell electron-nucleon cross-section. The results are compared to modern three-body calculations and to previous data.Comment: 4 pages, 3 figures. Submitted for publication in Phys. Rev. Let

    Single-shot divergence measurements of a laser-generated relativistic electron beam

    Full text link
    Copyright 2010 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas, 17(11), 113106_1-113106_7, 2010 and may be found at http://dx.doi.org/10.1063/1.351459

    Regulating E-Cigarettes: Why Policies Diverge

    Get PDF
    This paper, part of a festschrift in honor of Professor Malcolm Feeley, explores the landscape of e-cigarette policy globally by looking at three jurisdictions that have taken starkly different approaches to regulating e-cigarettes—the US, Japan, and China. Each of those countries has a robust tobacco industry, government agencies entrusted with protecting public health, an active and sophisticated scientific and medical community, and a regulatory structure for managing new pharmaceutical, tobacco, and consumer products. All three are signatories of the World Health Organization’s Framework Convention on Tobacco Control, all are signatories of the Agreement on Trade-Related Aspects of Intellectual Property Rights, and all are members of the World Trade Organization. Which legal, economic, social and political differences between the three countries explain their diverse approaches to regulating e-cigarettes? Why have they embraced such dramatically different postures toward e-cigarettes? In seeking to answer those questions, the paper builds on Feeley\u27s legacy of comparative scholarship, policy analysis, and focus on law in action

    Phase Transition Lowering in Dynamically Compressed Silicon

    Get PDF
    Silicon, being one of the most abundant elements in nature, attracts wide-ranging scientific and technological interest. Specifically, in its elemental form, crystals of remarkable purity can be produced. One may assume that this would lead to silicon being well understood, and indeed, this is the case for many ambient properties, as well as for higher-pressure behaviour under quasi-static loading. However, despite many decades of study, a detailed understanding of the response of silicon to rapid compression—such as that experienced under shock impact—remains elusive. Here, we combine a novel free-electron laser-based X-ray diffraction geometry with laser-driven compression to elucidate the importance of shear generated during shock compression on the occurrence of phase transitions. We observe lowering of the hydrostatic phase boundary in elemental silicon, an ideal model system for investigating high-strength materials, analogous to planetary constituents. Moreover, we unambiguously determine the onset of melting above 14 GPa, previously ascribed to a solid–solid phase transition, undetectable in the now conventional shocked diffraction geometry; transitions to the liquid state are expected to be ubiquitous in all systems at sufficiently high pressures and temperatures

    Differentiating attention styles and regulatory aspects of self-reported interoceptive sensibility

    No full text
    Based on prior research, multiple discriminable dimensions of interoception have been defined: awareness, accuracy and sensibility. Some investigators defined interoceptive awareness as metacognitive awareness of interoceptive accuracy, assessed as correspondence between subjective confidence in and objective accuracy of one's heartbeat detection. However, metacognitive awareness has been understood quite differently: ‘a cognitive set in which negative thoughts/feelings are experienced as mental events, rather than as the self’ or as ‘error awareness’. Interoceptive sensibility, defined as self-reported interoception, distinguishes self-reported interoception from objective interoceptive accuracy, but does not differentiate between anxiety-driven and mindful attention styles towards interoceptive cues, a distinction of key clinical importance: one attention style is associated with somatization and anxiety disorders; the other has been viewed as healthy, adaptive, resilience-enhancing. The self-report Multidimensional Assessment of Interoceptive Awareness was developed to differentiate these attention styles. It has been translated into 16 languages and applied in cross-sectional and longitudinal studies. Findings from these applications suggest that differentiating interoceptive sensibility according to attention style and regulatory aspects (i) provides insights into the psychology of interoceptive awareness, (ii) differentiates between clinically maladaptive and beneficial interoceptive attention, and (iii) helps elucidate therapeutic approaches that claim to provide health benefits by training mindful styles of bodily awareness. This article is part of the themed issue ‘Interoception beyond homeostasis: affect, cognition and mental health’
    corecore