822 research outputs found

    Home country effects of offshoring. A critical survey on empirical literature.

    Get PDF
    The International fragmentation of production processes is of rising importance. One part of this fragmentation involves the relocation of a production process from a home- to a new host country. This literature survey deals with the effects of such relocations on the home country. First of all, we try to conceptualize the terms and definitions most frequently used in this context which are "outsourcing", "offshore outsourcing" and "offshoring". Despite the fact that there is little textual documentation dealing directly with the phenomena of offshoring and offshore outsourcing we try to give an overview of possible empirical literature to which one can regard to. Including FDI literature we try to cover empirical literature which can provide helpful insight on the effects of a relocation to foreign countries on the home country in connection with wages, skill upgrading, prices, profits, taxes and unions. (author's abstract)Series: Discussion Papers SFB International Tax Coordinatio

    Instanton Effects in QCD at High Baryon Density

    Get PDF
    We study instanton effects in QCD at very high baryon density. In this regime instantons are suppressed by a large power of (ΛQCD/ÎŒ)(\Lambda_{QCD}/\mu), where ΛQCD\Lambda_{QCD} is the QCD scale parameter and ÎŒ\mu is the baryon chemical potential. Instantons are nevertheless important because they contribute to several physical observables that vanish to all orders in perturbative QCD. We study, in particular, the chiral condensate and its contribution mGB2∌mm_{GB}^2\sim m to the masses of Goldstone bosons in the CFL phase of QCD with Nf=3N_f=3 flavors. We find that at densities ρ∌(5−10)ρ0\rho\sim (5-10) \rho_0, where ρ0\rho_0 is the density of nuclear matter, the result is dominated by large instantons and subject to considerable uncertainties. We suggest that these uncertainties can be addressed using lattice calculations of the instanton density and the pseudoscalar diquark mass in QCD with two colors. We study the topological susceptibility and Witten-Veneziano type mass relations in both Nc=2N_c=2 and Nc=3N_c=3 QCD.Comment: 27 pages, 8 figures, minor revision

    Instanton interactions in dense-matter QCD

    Full text link
    A Coulomb gas representation of dense-matter QCD is derived from a dual transformation of the low-energy effective Lagrangian. The point-like charges Q=+1,-1 of the gas are identified with the instantons and anti-instantons of such topological charges. An instanton repels another instanton with the same force as it attracts an anti-instanton, in contrast to the semiclassical interaction.Comment: 8 pages, Revtex (a typo fixed

    Impact of speciation on behaviour of uranium in a solar powered membrane system for treatment of brackish groundwater

    Get PDF
    Factors affecting uranium removal from brackish groundwater using a direct solar powered ultrafiltration-nanofiltration/reverse osmosis membrane system were investigated during a field trial in the Australian outback. The key variables were uranium speciation (as a function of pH), groundwater type as well as energy variation over the course of a day. It was found that uranium was retained by the membranes over the pH range 3-11, but strongly adsorbed to membranes at pH 4-7. The speciation of uranium pH 4-7 explained the adsorption to the membrane. The presence of other inorganic species, in particular calcium, was a likely cause of uranium co-precipitation at pH 10-11. During solar energy experiments, it was found that the specific energy consumption increased over the course of the day. This indicated fouling through precipitation on the membranes which caused reduced retention of uranium towards the end of the solar day

    Impact of organic matter and speciation on the behaviour of uranium in submerged ultrafiltration

    Get PDF
    Influence of organic matter (OM) on uranium removal mechanisms by ultrafiltration (UF) over a pH range of 3–11 was investigated. Humic, alginic and tannic acid were used as OM. It was found that uranium adsorbed strongly to the membrane while retention by size exclusion did not occur. Adsorption was dependent on pH and type of OM used. Speciation predictions performed using Visual Minteq explain some of these results. In the absence of OM, uranium primarily adsorbed to the membrane at pH 5 and 7 where UO2OH+ and UO2CO3 were the dominant species. In the presence of humic acid (HA), uranium adsorption increased in the acidic range, especially at pH 3 (from 11% to 74%) due to the complexation. The structure of alginic acid (AA) did not favour complexation with uranium and therefore did not have a significant influence on its behaviour in UF. The exception was at pH 3 where adsorption increased from 11% to 52%. At this pH no charge repulsion between the uranium species and the AA occurs and complexation is favoured. The highest effect on uranium adsorption was obtained in the presence of tannic acid (TA) at pH 10 and 11 where adsorption increased from 20% up to 100%. Uranium is most likely forming complexes with the gallic acid fraction of the dissociated TA

    Neutrino Emission from Goldstone Modes in Dense Quark Matter

    Get PDF
    We calculate neutrino emissivities from the decay and scattering of Goldstone bosons in the color-flavor-locked (CFL) phase of quarks at high baryon density. Interactions in the CFL phase are described by an effective low-energy theory. For temperatures in the tens of keV range, relevant to the long-term cooling of neutron stars, the emissivities involving Goldstone bosons dominate over those involving quarks, because gaps in the CFL phase are ∌100\sim 100 MeV while the masses of Goldstone modes are on the order of 10 MeV. For the same reason, the specific heat of the CFL phase is also dominated by the Goldstone modes. Notwithstanding this, both the emissivity and the specific heat from the massive modes remain rather small, because of their extremely small number densities. The values of the emissivity and the specific heat imply that the timescale for the cooling of the CFL core in isolation is ∌1026\sim 10^{26} y, which makes the CFL phase invisible as the exterior layers of normal matter surrounding the core will continue to cool through significantly more rapid processes. If the CFL phase appears during the evolution of a proto-neutron star, neutrino interactions with Goldstone bosons are expected to be significantly more important since temperatures are high enough (∌20−40\sim 20-40 MeV) to admit large number densities of Goldstone modes.Comment: 29 pages, no figures. slightly modified text, one new eqn. and new refs. adde

    The QCD Phase Diagram at Nonzero Temperature, Baryon and Isospin Chemical Potentials in Random Matrix Theory

    Get PDF
    We introduce a random matrix model with the symmetries of QCD at finite temperature and chemical potentials for baryon number and isospin. We analyze the phase diagram of this model in the chemical potential plane for different temperatures and quark masses. We find a rich phase structure with five different phases separated by both first and second order lines. The phases are characterized by the pion condensate and the chiral condensate for each of the flavors. In agreement with lattice simulations, we find that in the phase with zero pion condensate the critical temperature depends in the same way on the baryon number chemical potential and on the isospin chemical potential. At nonzero quark mass, we remarkably find that the critical end point at nonzero temperature and baryon chemical potential is split in two by an arbitrarily small isospin chemical potential. As a consequence, there are two crossovers that separate the hadronic phase from the quark-gluon plasma phase at high temperature. Detailed analytical results are obtained at zero temperature and in the chiral limit.Comment: 13 pages, 5 figures, REVTeX

    The intrinsic charm contribution to the proton spin

    Full text link
    The charm quark contribution to the first moment of g1(x,Q2)g_1(x,Q^2) is calculated using a heavy mass expansion of the divergence of the singlet axial current. It is shown to be small.Comment: LATEX, 6 page

    The Crystallography of Color Superconductivity

    Get PDF
    We develop the Ginzburg-Landau approach to comparing different possible crystal structures for the crystalline color superconducting phase of QCD, the QCD incarnation of the Larkin-Ovchinnikov-Fulde-Ferrell phase. In this phase, quarks of different flavor with differing Fermi momenta form Cooper pairs with nonzero total momentum, yielding a condensate that varies in space like a sum of plane waves. We work at zero temperature, as is relevant for compact star physics. The Ginzburg-Landau approach predicts a strong first-order phase transition (as a function of the chemical potential difference between quarks) and for this reason is not under quantitative control. Nevertheless, by organizing the comparison between different possible arrangements of plane waves (i.e. different crystal structures) it provides considerable qualitative insight into what makes a crystal structure favorable. Together, the qualitative insights and the quantitative, but not controlled, calculations make a compelling case that the favored pairing pattern yields a condensate which is a sum of eight plane waves forming a face-centered cubic structure. They also predict that the phase is quite robust, with gaps comparable in magnitude to the BCS gap that would form if the Fermi momenta were degenerate. These predictions may be tested in ultracold gases made of fermionic atoms. In a QCD context, our results lay the foundation for a calculation of vortex pinning in a crystalline color superconductor, and thus for the analysis of pulsar glitches that may originate within the core of a compact star.Comment: 41 pages, 13 figures, 1 tabl

    Spectrum of the SU(3) Dirac operator on the lattice: Transition from random matrix theory to chiral perturbation theory

    Get PDF
    We calculate complete spectra of the Kogut-Susskind Dirac operator on the lattice in quenched SU(3) gauge theory for various values of coupling constant and lattice size. From these spectra we compute the connected and disconnected scalar susceptibilities and find agreement with chiral random matrix theory up to a certain energy scale, the Thouless energy. The dependence of this scale on the lattice volume is analyzed. In the case of the connected susceptibility this dependence is anomalous, and we explain the reason for this. We present a model of chiral perturbation theory that is capable of describing the data beyond the Thouless energy and that has a common range of applicability with chiral random matrix theory.Comment: 8 pages, RevTeX, 15 .eps figure
    • 

    corecore