5,465 research outputs found

    Strangeness contribution to the vector and axial form factors of the nucleon

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    The strangeness contribution to the vector and axial form factors of the nucleon is presented for momentum transfers in the range 0.45<Q2<1.00.45<Q^2<1.0 GeV2^2. The results are obtained via a combined analysis of forward-scattering parity-violating elastic e⃗p\vec{e}p asymmetry data from the G0G^0 and HAPPEx experiments at Jefferson Lab, and elastic Îœp\nu p and Μˉp\bar{\nu} p scattering data from Experiment 734 at Brookhaven National Laboratory. The parity-violating asymmetries measured in elastic e⃗p\vec{e}p scattering at forward angles establish a relationship between the strange vector form factors GEsG_E^s and GMsG_M^s, with little sensitivity to the strange axial form factor GAsG_A^s. On the other hand, elastic neutrino scattering at low Q2Q^2 is dominated by the axial form factor, with still some significant sensitivity to the vector form factors as well. The combination of the two data sets allows the simultaneous extraction of GEsG_E^s, GMsG_M^s, and GAsG_A^s over a significant range of Q2Q^2 for the very first time.Comment: 3 pages, 1 figure, will appear in AIP Conference Proceedings for PANIC 200

    Vibrational Stability of NLC Linac accelerating structure

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    The vibration of components of the NLC linac, such as accelerating structures and girders, is being studied both experimentally and analytically. Various effects are being considered including structural resonances and vibration caused by cooling water in the accelerating structure. This paper reports the status of ongoing work.Comment: 3 pages 8 figures Presented at EPAC 2002 Paris Franc

    Post-Foucauldian governmentality: what does it offer critical social policy analysis?

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    This article considers the theoretical perspective of post-Foucauldian governmentality, especially the insights and challenges it poses for applied researchers within the critical social policy tradition. The article firstly examines the analytical strengths of this approach to understanding power and rule in contemporary society, before moving on to consider its limitations for social policy. It concludes by arguing that these insights can be retained, and some of the weaknesses overcome, by adopting a ‘realist governmentality’ approach (Stenson 2005, 2008). This advocates combining traditional discursive analysis with more ethnographic methods in order to render visible the concrete activity of governing, and unravel the messiness, complexity and unintended consequences involved in the struggles around subjectivity

    The Direct Sensing of Damage to Ion Implanted Materials

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    Material damage caused by the implantation of a high concentration of hydrogenic ions requires regular remote monitoring in order to study the atomic and nuclear reaction processes taking place within each sample. Real time continuous measurements of acoustic emission, X-ray production and emitted particle flux enable processes such as bubble or crack formation, changes in crystalline order, and nuclear fusion reactions can be studied in detail through examination of secondary or associated emission products. Fracturing of a material may generate a unique signature which, when taken in conjunction with time-averaged quantities such as changes in resistivity, surface strain, and induced radioactivity, enable an overall picture of the onset and nature of crack formation to be acquired. The overall usefulness of the remote sensing of damage processes and nuclear reactions is discussed. Surface studies involving inelastic Raman scattering and atomic force spectroscopy can contribute substantially to the overall picture, and identify clustering and cluster processes

    Vibrational Stability of NLC Linac and Final Focus Components

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    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.Comment: 3 pages, 8 figures presented at the LINAC 2002 conference, Gyeongju Kore

    Effect of Cooling Water on Stability of NLC Linac Components

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    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.Comment: 6 Pages 13 Figures Presented at The Nanobeam 2002 Workshop (Lausanne Switzerland

    Turbulence Measurements in Shear Flow Liquid Systems

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    The paper is a composite of a number of years of work on turbulence measurements in a variety of liquid flow systems. The trials and tribulations of such measurements are emphasized. Pipe flow Is considered in some detail, and the consistency between results of various investigators is analyzed. Other systems discussed are a stirred tank unit and a multi-jet reactor configuration. Statistical turbulence measurements such as autocorrelation, spectrum, probability density, flatness factor, and skewness factor are considered in terms of obtaining these from digital signals obtained by conversion of the normal analog signals. Descriptive parameters of statistical turbulence, such as microscale, macroscale, and kinetic energy dissipation, are discussed, as well as various attempts at the estimation of these without using statistical turbulence measurements
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