2,494 research outputs found

    Isotope sourcing of prehistoric willow and tule textiles recovered from western Great Basin rock shelters and caves e proof of concept

    Get PDF
    Isotope and trace-metal analyses were used to determine the origin of plants used to manufacture prehistoric textiles (basketry and matting) from archaeological sites in the western Great Basin. Research focused on strontium (87Sr/86Sr) and oxygen (18O/16O) isotope ratios of willow (Salix sp.) and tule (Schoenoplectus sp.), the dominant raw materials in Great Basin textiles. The oxygen-isotope data indicated that the willow and tule used to produce the textiles were harvested from the banks of rivers or in marshes characterized by flowing water and not from lakes or sinks. The strontium-isotope data were useful in showing which plants came from the Humboldt River and which came from rivers headed in the Sierra Nevada

    Tachyon Kink on non-BPS Dp-brane in the General Background

    Full text link
    This paper is devoted to the study of the tachyon kink on the worldvolume of a non-BPS Dp-brane that is embedded in general background, including NS-NS two form B and also general Ramond-Ramond field. We will explicitly show that the dynamics of the kink is described by the equations of motion that arrise from the DBI and WZ action for D(p-1)-brane.Comment: 28 page

    Deforming tachyon kinks and tachyon potentials

    Full text link
    In this paper we investigate deformation of tachyon potentials and tachyon kink solutions. We consider the deformation of a DBI type action with gauge and tachyon fields living on D1-brane and D3-brane world-volume. We deform tachyon potentials to get other consistent tachyon potentials by using properly a deformation function depending on the gauge field components. Resolutions of singular tachyon kinks via deformation and applications of deformed tachyon potentials to scalar cosmology scenario are discussed.Comment: To appear in JHEP, 19 pages, 5 eps figures, minor changes and one reference adde

    Dynamics of D1-brane in I-brane Background

    Full text link
    This paper is devoted to the study of the effective field theory description of the probe D1-brane in the background of the system of two stacks of fivebranes in type IIB theory that intersect on R1,1R^{1,1}. We study the properties of the Dirac-Born-Infeld action for D1-brane moving in this background. We will argue that this action is invariant under an additional symmetry in the near horizon limit and that this new symmetry is closely related to the enhanced symmetry of the I-brane background considered recently in [hep-th/0508025]. We also solve explicitly the equation of motion of D1-brane in the near horizon limit.Comment: 21 pages, references adde

    Complete N=4 Structure of Low-Energy Effective Action in N=4 Super Yang-Mills Theories

    Get PDF
    Using the N=2{\cal N}=2 superfield approach, we construct full N=4{\cal N}=4 supersymmetric low-energy effective actions for N=4{\cal N}=4 SYM models, with both N=2{\cal N}=2 gauge superfield strengths and hypermultiplet superfields included. The basic idea is to complete the known non-holomorphic effective potentials which depend only on N=2{\cal N}=2 superfield strengths WW and Wˉ{\bar W} to the full on-shell N=4{\cal N}=4 invariants by adding the appropriate superfield hypermultiplet terms. We prove that the effective potentials of the form lnWlnWˉ{ln} W {ln} \bar W can be N=4{\cal N} = 4 completed in this way and present the precise structure of the corresponding completions. However, the effective potentials of the non-logarithmic form suggested in hep-th/9811017 and hep-th/9909020 do not admit the N=4{\cal N}=4 completion. Therefore, such potentials cannot come out as (perturbative or non-perturbative) quantum corrections in N=4{\cal N}=4 SYM models.Comment: 14 pages, Latex, no figures, slight corrections, refs adde

    Warner-Bratzler shear force values and ranges of steaks from cattle of known sires

    Get PDF
    Carcass data and Warner-Bratzler shear force (WBSF) data on strip loin steaks were collected from nearly 8,500 cattle in contemporary groups of progeny from the more popular sires in 14 different beef cattle breeds in the Carcass Merit Traits project funded by Beef Checkoff dollars, the breed associations, and MMI Genomics. In addition, trained sensory panel evaluations were conducted on over 2,500 strip loin steaks from contemporary groups of progeny from five sires included in the DNA marker validation component of the project. The correlation between WBSF and tenderness scored by the trained sensory panel was -0.82, indicating that as WBSF increased, tenderness scored by the sensory panel decreased. Our results showed that a WBSF value of ≥ 11.0 lb generally results in a sensory score of slightly tough or tougher. In this study, 22.8% of the cattle had WBSF values ≥ 11.0 lb and 26.3% had sensory scores of slightly tough or tougher. The phenotypic range of WBSF means for sires within breeds ranged from 1.9 to 6.6 lb. The phenotypic range of WBSF means across breeds was 8.9 lb, whereas the range among sires across breeds was a dramatic 14.4 lb. The phenotypic range for flavor intensity scores among sires within and across breeds was much smaller than for tenderness, with juiciness scores being intermediate. The 40 widely used sires that produced progeny with steaks that were unacceptable in tenderness in this study might be expected to be sires of several thousand bulls used in commercial herds. This demonstrates that seedstock producers should aggressively utilize sires that have genetics for tender meat

    Time Evolution in Superstring Field Theory on non-BPS brane.I. Rolling Tachyon and Energy-Momentum Conservation

    Full text link
    We derive equations of motion for the tachyon field living on an unstable non-BPS D-brane in the level truncated open cubic superstring field theory in the first non-trivial approximation. We construct a special time dependent solution to this equation which describes the rolling tachyon. It starts from the perturbative vacuum and approaches one of stable vacua in infinite time. We investigate conserved energy functional and show that its different parts dominate in different stages of the evolution. We show that the pressure for this solution has its minimum at zero time and goes to minus energy at infinite time.Comment: 16 pages, 5 figures; minor correction

    Bosonic D-brane Effective Action in Linear Dilaton Background

    Full text link
    In this paper we will study tachyon effective action for Dp-brane in bosonic string theory in the linear dilaton background. We obtain the tachyon effective Lagrangian from boundary state coeficient of Dp-brane in the linear dilaton background and compare it with tachyon effective Lagrangians that were proposed in previous papers.Comment: 16 pages, Typos correcte

    Entangled Quantum Clocks for Measuring Proper-Time Difference

    Full text link
    We report that entangled pairs of quantum clocks (non-degenerate quantum bits) can be used as a specialized detector for precisely measuring difference of proper-times that each constituent quantum clock experiences. We describe why the proposed scheme would be more precise in the measurement of proper-time difference than a scheme of two-separate-quantum-clocks. We consider possibilities that the proposed scheme can be used in precision test of the relativity theory.Comment: no correction, 4 pages, RevTe
    corecore