81 research outputs found

    Precision neutron interferometric measurements of the n-p, n-d, and n-3He zero-energy coherent neutron scattering amplitudes

    Full text link
    We have performed high precision measurements of the zero-energy neutron scattering amplitudes of gas phase molecular hydrogen, deuterium, and 3^{3}He using neutron interferometry. We find bnp=(3.7384±0.0020)b_{\mathit{np}}=(-3.7384 \pm 0.0020) fm\cite{Schoen03}, bnd=(6.6649±0.0040)b_{\mathit{nd}}=(6.6649 \pm 0.0040) fm\cite{Black03,Schoen03}, and bn3He=(5.8572±0.0072)b_{n^{3}\textrm{He}} = (5.8572 \pm 0.0072) fm\cite{Huffman04}. When combined with the previous world data, properly corrected for small multiple scattering, radiative corrections, and local field effects from the theory of neutron optics and combined by the prescriptions of the Particle Data Group, the zero-energy scattering amplitudes are: bnp=(3.7389±0.0010)b_{\mathit{np}}=(-3.7389 \pm 0.0010) fm, bnd=(6.6683±0.0030)b_{\mathit{nd}}=(6.6683 \pm 0.0030) fm, and bn3He=(5.853±.007)b_{n^{3}\textrm{He}} = (5.853 \pm .007) fm. The precision of these measurements is now high enough to severely constrain NN few-body models. The n-d and n-3^{3}He coherent neutron scattering amplitudes are both now in disagreement with the best current theories. The new values can be used as input for precision calculations of few body processes. This precision data is sensitive to small effects such as nuclear three-body forces, charge-symmetry breaking in the strong interaction, and residual electromagnetic effects not yet fully included in current models.Comment: 6 pages, 4 figures, submitted to Physica B as part of the Festschrift honouring Samuel A. Werner at the International Conference on Neutron Scattering 200

    Association between hourly wages and dietary intake after the first phase of implementation of the Minneapolis minimum wage ordinance

    Get PDF
    Objective: In 2018, Minneapolis began phased implementation of an ordinance to increase the local minimum wage to 15/h. We sought to determine whether the first phase of implementation was associated with changes in frequency of consumption of fruits and vegetables (F&V), whole-grain-rich foods, and foods high in added sugars among low-wage workers. Design: Natural experiment. Setting: The Wages Study is a prospective cohort study of 974 low-wage workers followed throughout the phased implementation of the ordinance (2018-2022). We used difference-in-difference analysis to compare outcomes among workers in Minneapolis, Minnesota, to those in a comparison city (Raleigh, North Carolina). We assessed wages using participants' pay stubs and dietary intake using the National Cancer Institute Dietary Screener Questionnaire. Participants: Analyses use the first two waves of Wages data (2018 (baseline), 2019) and includes 267 and 336 low-wage workers in Minneapolis and Raleigh, respectively. Results: After the first phase of implementation, wages increased in both cities, but the increase was 0·84 greater in Minneapolis (P = 0·02). However, the first phase of the policy's implementation was not associated with changes in daily frequency of consumption of F&V (IRR = 1·03, 95 % CI: 0·86, 1·24, P = 0·73), whole-grain-rich foods (IRR = 1·23, 95 % CI: 0·89, 1·70, P = 0·20), or foods high in added sugars (IRR = 1·13, 95 % CI: 0·86, 1·47, P = 0·38) among workers in Minneapolis compared to Raleigh. Conclusions: The first phase of implementation of the Minneapolis minimum wage policy was associated with increased wages, but not with changes in dietary intake. Future research should examine whether full implementation is associated dietary changes

    DER OKONOMISCHE EFFEKT EINER ERHOHUNG DER ARBEITSLOSENLEISTUNGEN : NEUBETRACHT UNTER VERWENDUNG DES ATKINSON MODELLS

    Get PDF
    In der zweiten Halfte der 1970er begannen sich wirtschaftliche Kennziffern industrialisierter Staaten rapide zu verschlechtern. Gleichzeitig ruckte der Wohlfahrtsstaat als Ursache in das Zentrum der Kritik. Einige Wirtschaftswissenschaftler, insbesondere die deutschen Neo- Liberalisten, hatten bereits seit den 1950ern eine kritische Haltung zum wohlfahrtsstaatlichen Konzept eingenommen. Seit den 1970ern gesellten sich zu diesen Liberalisten auch viele Wirtschaftswissenschaftler, die zuvor den Wohlfahrtsstaat unterstutzt hatten. A.B. Atkinson wies jedoch daraufhin, daB viele der verwandten okonomischen Analysen auf un- fundierten theoretischen Modellen basierten, die die eigentlichen Merkmale des sozialen Wohlfahrtsprogramms auBer Acht lieBen. In der vorliegenden Arbeit gehen wir daher, den wirtschaftlichen Auswirkungen der Arbeitslosenversicherung in Einklang mit Atkinsons Kritik nach. Es gelang ihm gegenteilige Ergebnisse zu dem popularen Shapiro und Stiglitz Shirking Modell, durch Einfuhrung zweier Annahmen, d.h. Arbeitslosenleistungen werden identifizierten Shirkern vorenthalten und Arbeitslosenleistungen werden generell nur fur einen bestimmten Zeitraum angeboten, nachzuweisen. In der vorliegenden Arbeit zeigen wir, daB Gehalt basierende Arbeitslosenleistungen sich positiv auf Produktivitat und Beschaftigung auswirken. Zeitliche Begrenzung und eine ansteigende Sockelleistung alleine haben nicht die gleichen Ergebnisse im Shapiro und Stiglitz Modell

    A Pre-Landing Assessment of Regolith Properties at the InSight Landing Site

    Get PDF
    This article discusses relevant physical properties of the regolith at the Mars InSight landing site as understood prior to landing of the spacecraft. InSight will land in the northern lowland plains of Mars, close to the equator, where the regolith is estimated to be ≥3--5 m thick. These investigations of physical properties have relied on data collected from Mars orbital measurements, previously collected lander and rover data, results of studies of data and samples from Apollo lunar missions, laboratory measurements on regolith simulants, and theoretical studies. The investigations include changes in properties with depth and temperature. Mechanical properties investigated include density, grain-size distribution, cohesion, and angle of internal friction. Thermophysical properties include thermal inertia, surface emissivity and albedo, thermal conductivity and diffusivity, and specific heat. Regolith elastic properties not only include parameters that control seismic wave velocities in the immediate vicinity of the Insight lander but also coupling of the lander and other potential noise sources to the InSight broadband seismometer. The related properties include Poisson’s ratio, P- and S-wave velocities, Young’s modulus, and seismic attenuation. Finally, mass diffusivity was investigated to estimate gas movements in the regolith driven by atmospheric pressure changes. Physical properties presented here are all to some degree speculative. However, they form a basis for interpretation of the early data to be returned from the InSight mission.Additional co-authors: Nick Teanby and Sharon Keda

    Evaluation of the sustainability of contrasted pig farming systems: the procedure, the evaluated systems and the evaluation tools

    Get PDF
    Although a few studies consider the sustainability of animal farming systems along the three classical main pillars (economy, environment and society), most studies on pig farming systems address only one of these pillars. The present paper is the introduction to a series of companion papers presenting the results of a study undertaken within the EU-supported project Q-PorkChains, aiming at building a comprehensive tool for the evaluation of pig farming systems, which is robust to accommodate the large variability of systems existing in Europe. The tool is mostly based on questions to farmers and comprises a total of 37 dimensions distributed along eight themes: Animal Welfare, Animal Health, Breeding Programmes, Environmental Sustainability, Meat Safety, Market Conformity, Economy and Working Conditions. The paper describes the procedure that was used for building the tool, using it on 15 contrasted pig farming systems and analysing the results. The evaluated systems are briefly described and a short overview of the dimensions is provided. Detailed descriptions of the theme-wise tools and results, as well as the results of an integrated evaluation, are available in the companion paper

    Feint Lines: Notes on the Creation of a Skateboard Choreography

    Get PDF
    Magnetic fields on a range of scales play a large role in the ecosystems of galaxies, both in the galactic disk and in the extended layers of gas away from the plane. Observing magnetic field strength, structure and orientation is complex, and necessarily indirect. Observational data of magnetic fields in the halo of the Milky Way are scarce, and non-conclusive about the large-scale structure of the field. In external galaxies, various large-scale configurations of magnetic fields are measured, but many uncertainties about exact configurations and their origin remain. There is a strong interaction between magnetic fields and other components in the interstellar medium such as ionized and neutral gas and cosmic rays. The energy densities of these components are comparable on large scales, indicating that magnetic fields are not passive tracers but that magnetic field feedback on the other interstellar medium components needs to be taken into account.Comment: 13 pages, 7 figures. Accepted in Space Science Review

    Overview of physics results from NSTX

    Full text link
    corecore