13,989 research outputs found

    Detecting D-Wave Pairing and Collective Modes in Fermionic Condensates with Bragg Scattering

    Full text link
    We show how the appearance of d-wave pairing in fermionic condensates manifests itself in inelastic light scattering. Specifically, we calculate the Bragg scattering intensity from the dynamic structure factor and the spin susceptibility, which can be inferred from spin flip Raman transitions. This information provides a precise tool with which we can identify nontrivial correlations in the state of the system beyond the information contained in the density profile imaging alone. Due to the lack of Coulomb effects in neutral superfluids, this is also an opportunity to observe the Anderson-Bogoliubov collective mode

    Auger electron spectroscopy study of oxidation of a PdCr alloy used for high-temperature sensors

    Get PDF
    A Pd-13 wt. percent Cr solid solution is a promising high-temperature strain gage alloy. In bulk form it has a number of properties that are desirable in a resistance strain gage material, such as a linear electrical resistance versus temperature curve to 1000 C and stable electrical resistance in air at 1000 C. However, unprotected fine wire gages fabricated from this alloy perform well only to 600 C. At higher temperatures severe oxidation degrades their electrical performance. In this work Auger electron spectroscopy was used to study the oxidation chemistry of the alloy wires and ribbons. Results indicate that the oxidation is caused by a complex mechanism that is not yet fully understood. As expected, during oxidation, a layer of chromium oxide is formed. This layer, however, forms beneath a layer of metallic palladium. The results of this study have increased the understanding of the oxidation mechanism of Pd-13 wt. percent Cr

    Slow light with integrated gain and large pulse delay

    Full text link
    We demonstrate slow and stored light in Rb vapor with a combination of desirable features: minimal loss and distortion of the pulse shape, and large fractional delay (> 10). This behavior is enabled by: (i) a group index that can be controllably varied during light pulse propagation; and (ii) controllable gain integrated into the medium to compensate for pulse loss. Any medium with the above two characteristics should be able to realize similarly high-performance slow light.Comment: 5 pages, 4 figures; abstract is shortened, some typo correcte

    Undergraduate Curriculum In Supply Chain Management

    Get PDF
    A proposal is presented for an undergraduate curriculum in Supply Chain Management(SCM) in a typical BBA program in an AACSB accredited Business School

    Analytical model of brittle destruction based on hypothesis of scale similarity

    Full text link
    The size distribution of dust particles in nuclear fusion devices is close to the power function. A function of this kind can be the result of brittle destruction. From the similarity assumption it follows that the size distribution obeys the power law with the exponent between -4 and -1. The model of destruction has much in common with the fractal theory. The power exponent can be expressed in terms of the fractal dimension. Reasonable assumptions on the shape of fragments concretize the power exponent, and vice versa possible destruction laws can be inferred on the basis of measured size distributions.Comment: 10 pages, 3 figure

    Effect of Inhomogeneous Heat Flow on the Enhancement of Heat Capacity in Helium-II by Counterflow near Tλ

    Get PDF
    In 2000 Harter et al. reported the first measurements of the enhancement of the heat capacity ΔCQ[equivalent]C(Q)-C(Q=0) of helium-II transporting a heat flux density Q near Tλ. Surprisingly, their measured ΔCQ was ~7–12 times larger than predicted, depending on which theory was assumed. In this report we present a candidate explanation for this discrepancy: unintended heat flux inhomogeneity. Because C(Q) should diverge at a critical heat flux density Qc, homogeneous heat flow is required for an accurate measurement. We present results from numerical analysis of the heat flow in the Harter et al. cell indicating that substantial inhomogeneity occurred. We determine the effect of the inhomogeneity on ΔCQ and find rough agreement with the observed disparity between prediction and measurement

    Submarine landslides on the upper southeast Australian passive continental margin – preliminary findings

    Get PDF
    The southeast Australian passive continental margin is narrow, steep and sediment-deficient, and characterized by relatively low rates of modern sedimentation. Upper slope (\u3c1200m) sediments comprise mixtures of calcareous and terrigenous sand and mud. Three of twelve sediment cores recovered from geologically-recent, submarine landslides located offshore New South Wales/Queensland (NSW/QLD) are interpreted to have sampled failure surfaces at depths of between 85 cm and 220 cm below the present-day seabed. Differences in sediment physical properties are recorded above and below the three slide-plane boundaries. Sediment taken directly above the inferred submarine landslide failure surfaces and presumed to be post-landslide, returned radiocarbon ages of 15.8 ka, 20.7 ka and 20.1 ka. The last two ages correspond to adjacent slide features, which are inferred to be consistent with their being triggered by a single event such as an earthquake. Slope stability models based on classical soil mechanics and measured sediment shearstrengths indicate that the upper slope sediments should be stable. However, multibeam sonar data reveal that many upper slope landslides occur across the margin and that submarine landsliding is a common process. We infer from these results that: a) an unidentified mechanism regularly acts to reduce the shear resistance of these sediments to the very low values required to enable slope failure, and/or b) the margin experiences seismic events that act to destabilise the slope sediments

    Masters Degree In Management Information Systems With A Supply Chain Management Focus

    Get PDF
    A graduate curriculum in Management Information Systems with a Supply Chain Management focus is presented. The motivation for this endeavor stems from the fact that the global scope of modern business organizations and the competitive environment in which they operate, requires an information system leveraged supply chain management system (SCM) to ensure the efficient delivery of the right product, at the right place, at the right time, in the right quantity, and at a competitive price to the customer

    Control System Analysis and Synthesis via Linear Matrix Inequalities

    Get PDF
    A wide variety of problems in systems and control theory can be cast or recast as convex problems that involve linear matrix inequalities (LMIs). For a few very special cases there are "analytical solutions" to these problems, but in general they can be solved numerically very efficiently. In many cases the inequalities have the form of simultaneous Lyapunov or algebraic Riccati inequalities; such problems can be solved in a time that is comparable to the time required to solve the same number of Lyapunov or Algebraic Riccati equations. Therefore the computational cost of extending current control theory that is based on the solution of algebraic Riccati equations to a theory based on the solution of (multiple, simultaneous) Lyapunov or Riccati inequalities is modest. Examples include: multicriterion LQG, synthesis of linear state feedback for multiple or nonlinear plants ("multi-model control"), optimal transfer matrix realization, norm scaling, synthesis of multipliers for Popov-like analysis of systems with unknown gains, and many others. Full details can be found in the references cited

    Introducing Big Sagebrush into a Crested Wheatgrass Monoculture

    Get PDF
    Crested wheatgrass (Agropyron desertorum or A. cristatum) has been effectively used to stabilize arid and semi-arid range sites for decades. Reestablishing native plant materials into these areas is often desirable to increase wildlife habitat and ecological diversity. Due to its competitive nature, efforts to reestablish native plants into crested wheatgrass monocultures have had limited success. Tillage will control the grass but leaves the soil vulnerable to erosion and weed invasion. This publication will report on a trial conducted near Nephi, Utah to find a method of introducing native plants into a crested wheatgrass monoculture without subjecting the resource base to degradation in the conversion process. In this trial, the effect of chemically controlling crested wheatgrass before transplanting big sagebrush (Artemisia tridentata) was studied. Small container grown plants of sagebrush were transplanted either directly into a 60 year-old stand of crested wheatgrass or after chemically controlling the grass. Three different subspecies of big sagebrush; Basin big sagebrush (Artemisia tridentata Nutt. ssp. tridentata), Mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana (Rydb.) Beetle) and Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young); were planted to see if there would be differences among subspecies. Four years of data indicate that controlling crested wheatgrass prior to transplanting resulted in higher sagebrush survival and faster establishment. There were some differences among sagebrush subspecies. Basin big sagebrush survived equally well with or without grass control but grew faster with grass control. Chemical control of the grass was important for both the survival and growth of Mountain big sage and Wyoming big sage
    • …
    corecore