110,954 research outputs found

    Aspects of Neutrino Interactions (Scattering at small Q2Q^2- Region)

    Full text link
    The article begins with a description of chiral symmetry and its application to neutrino induced reactions. For small Q2Q^2 (forward direction) the process is dominated by the amplitute with helicity zero where the pion pole disappears when multiplied with the polarization vector. The remaining part of the amplitude is determined by PCAC. For Eν>2E_\nu > 2 GeV the computed cross sections are in good agreement with data. In coherent pion production we expect equal yields for neutrinos and antineutrinos a relation which for Eν>2E_\nu > 2 GeV is fulfilled. We discuss specific features of the data and suggest methods for improving them by presenting new estimates for the incoherent background.Comment: Presented at the CETUP-Workshop on Neutrino Interactions, July 22-31, 2014 at Lead/Dead Wood, South Dakota, USA. The resubmission contains minor correction

    Comparing Heterogeneous Consumption in US and Japanese Meat and Fish Demand

    Get PDF
    This article uses national, quarterly data to conduct an empirical analysis of pre-committed meat and fish demand by US and Japanese households using the Generalized Almost Ideal Demand System (GAIDS). US consumers are found to hold pre-committed demand for beef and pork, while Japanese consumers appear to possess significant pre-committed demand for beef and fish. This provides evidence to partly explain observed differences in Japanese and US consumer reactions to non-price and non-income effects in beef, pork, poultry, and fish. In addition, the first known empirical comparison of how the GAIDS and more traditional AIDS models assess meat and fish demand is offered with both in- and out-of-sample evaluations.US/Japanese meat demand, demand forecasting, food safety, Generalized Almost Ideal Demand System, pre-committed consumption, Demand and Price Analysis,

    Studies of low-energy ionic collisions Final report, 1 Oct. 1965 - 30 Sep. 1967

    Get PDF
    Ionic-molecular collisions, and collision induced dissociation of ion

    A consistent spatial differencing scheme for the transonic full-potential equation in three dimensions

    Get PDF
    A full-potential steady transonic wing flow solver has been modified so that freestream density and residual are captured in regions of constant velocity. This numerically precise freestream consistency is obtained by slightly altering the differencing scheme without affecting the implicit solution algorithm. The changes chiefly affect the fifteen metrics per grid point, which are computed once and stored. With this new method, the outer boundary condition is captured accurately, and the smoothness of the solution is especially improved near regions of grid discontinuity

    Gamma-ray spectrometry in the field: Radioactive heat production in the Central Slovakian Volcanic Zone

    Get PDF
    We report 62 sets of measurements from central-southern Slovakia, obtained using a modern portable gamma-ray spectrometer, which reveal the radioactive heat production in intrusive and extrusive igneous rocks of the Late Cenozoic Central Slovakian Volcanic Zone. Sites in granodiorite of the Štiavnica pluton are thus shown to have heat production in the range ~ 2.2–4.9 μW m− 3, this variability being primarily a reflection of variations in content of the trace element uranium. Sites in dioritic parts of this pluton have a lower, but overlapping, range of values, ~ 2.1–4.4 μW m− 3. Sites that have been interpreted in adjoining minor dioritic intrusions of similar age have heat production in the range ~ 1.4–3.3 μW m− 3. The main Štiavnica pluton has zoned composition, with potassium and uranium content and radioactive heat production typically increasing inward from its margins, reflecting variations observed in other granodioritic plutons elsewhere. It is indeed possible that the adjoining dioritic rocks, hitherto assigned to other minor intrusions of similar age, located around the periphery of the Štiavnica pluton, in reality provide further evidence for zonation of the same pluton. The vicinity of this pluton is associated with surface heat flow ~ 40 mW m− 2 above the regional background. On the basis of our heat production measurements, we thus infer that the pluton has a substantial vertical extent, our preferred estimate for the scale depth for its downward decrease in radioactive heat production being ~ 8 km. Nonetheless, this pluton lacks any significant negative Bouguer gravity anomaly. We attribute this to the effect of the surrounding volcanic caldera, filled with relatively low-density lavas, ‘masking’ the pluton's own gravity anomaly. We envisage that emplacement occurred when the pluton was much hotter, and thus of lower density, than at present, its continued uplift, evident from the local geomorphology, being the isostatic consequence of localized erosion. The heat production in this intrusion evidently plays a significant role, hitherto unrecognized, in the regional geothermics

    Spatial control of irreversible protein aggregation

    Get PDF
    Liquid cellular compartments spatially segregate from the cytoplasm and can regulate aberrant protein aggregation, a process linked to several medical conditions, including Alzheimer's and Parkinson's diseases. Yet the mechanisms by which these droplet-like compartments affect protein aggregation remain unknown. Here, we combine kinetic theory of protein aggregation and liquid-liquid phase separation to study the spatial control of irreversible protein aggregation in the presence of liquid compartments. We find that, even for weak interactions between the compartment constituents and the aggregating monomers, aggregates are strongly enriched inside the liquid compartment relative to the surrounding cytoplasm. We show that this enrichment is caused by a positive feedback mechanism of aggregate nucleation and growth which is mediated by a flux maintaining the phase equilibrium between the compartment and the cytoplasm. Our model predicts that the compartment volume that maximizes aggregate enrichment in the compartment is determined by the reaction orders of aggregate nucleation. The underlying mechanism of aggregate enrichment could be used to confine cytotoxic protein aggregates inside droplet-like compartments suggesting potential new avenues against aberrant protein aggregation. Our findings could also represent a common mechanism for the spatial control of irreversible chemical reactions in general

    Three-dimensional analytical magnetohydrostatic equilibria of rigidly rotating magnetospheres in cylindrical geometry

    Full text link
    We present three-dimensional solutions of the magnetohydrostatic equations in the co-rotating frame of reference outside a magnetized rigidly rotating cylinder. We make no symmetry assumption for the magnetic field, but to be able to make analytical progress we neglect outflows and specify a particular form for the current density. The magnetohydrostatic equations can then be reduced to a single linear partial differential equation for a pseudo-potential UU, from which the magnetic field can be calculated by differentiation. The equation for UU can be solved by standard methods. The solutions can also be used to determine the plasma pressure, density and temperature as functions of all three spatial coordinates. Despite the obvious limitations of this approach, it can for example be used as a simple tool to create three-dimensional models for the closed field line regions of rotating magnetospheres without rotational symmetry.Comment: 13 pages, 2 figures, accepted for publication by Geophysical and Astrophysical Fluid Dynamic

    Transport Anomalies and Marginal Fermi-Liquid Effects at a Quantum Critical Point

    Full text link
    The behavior of the conductivity and the density of states, as well as the phase relaxation time, of disordered itinerant electrons across a quantum ferromagnetic transition is discussed. It is shown that critical fluctuations lead to anomalies in the temperature and energy dependence of the conductivity and the tunneling density of states, respectively, that are stronger than the usual weak-localization anomalies in a disordered Fermi liquid. This can be used as an experimental probe of the quantum critical behavior. The energy dependence of the phase relaxation time at criticality is shown to be that of a marginal Fermi liquid.Comment: 4 pp., LaTeX, no figs., requires World Scientific style files (included), Contribution to MB1

    Radiation of Angular Momentum by Neutrinos from Merged Binary Neutron Stars

    Get PDF
    We study neutrino emission from the remnant of an inspiraling binary neutron star following coalescence. The mass of the merged remnant is likely to exceed the stability limit of a cold, rotating neutron star. However, the angular momentum of the remnant may also approach or even exceed the Kerr limit, J/M^2 = 1, so that total collapse may not be possible unless some angular momentum is dissipated. We find that neutrino emission is very inefficient in decreasing the angular momentum of these merged objects and may even lead to a small increase in J/M^2. We illustrate these findings with a post-Newtonian, ellipsoidal model calculation. Simple arguments suggest that the remnant may form a bar mode instability on a timescale similar to or shorter than the neutrino emission timescale, in which case the evolution of the remnant will be dominated by the emission of gravitational waves.Comment: 12 pages AASTeX, 2 figures, to appear in Ap
    • …
    corecore