11,404 research outputs found
Microwave dichroic plate
A dichroic plate for microwave energy includes an array of interlaced crossed slots or dipole elements. Each of the elements includes first and second crossed arms that are at approximately right angles to each other and aligned with X and Y axes. The elements are arranged so that the centers thereof are aligned parallel to the X and Y axes to form columns and rows, and the interlacing is such that a line between the centers of all adjacent elements has nonzero, differing components relative to the X and Y axes. In one embodiment, the spacing between adjacent arms of different, adjacent elements is the same along the X and Y axes, while in a second embodiment, the spacing between similarly directed arms of adjacent elements differs from the spacing between oppositely directed arms of adjacent elements
Reverse Triangle Inequalities for Riesz Potentials and Connections with Polarization
We study reverse triangle inequalities for Riesz potentials and their
connection with polarization. This work generalizes inequalities for sup norms
of products of polynomials, and reverse triangle inequalities for logarithmic
potentials. The main tool used in the proofs is the representation for a power
of the farthest distance function as a Riesz potential of a unit Borel measure
Start/stop switches for testing detonation velocity of explosives
Printed-circuit process produces ordnance-initiated start/stop switches. Method is faster and less costly than fabriction by hand, and produces switches of uniform quality
10-04 "Buyer Power in U.S. Hog Markets: A Critical Review of the Literature"
The U.S. Departments of Justice and Agriculture have focused attention recently on rising levels of corporate concentration in agricultural markets and the challenges that may pose to U.S. anti-trust enforcement and agricultural policies. Both agencies have raised particular concerns about dominant firmsâ exercise of buyer power over farmers, especially in livestock markets controlled by a shrinking number of large multinational meat packers. U.S. hog markets have undergone rapid concentration in the last 25 years, with the top four packers now controlling two-thirds of the market and Smithfield Foods, the industry leader, commanding 31 percent. Despite the rapid structural changes in the U.S. hog industry, the literature on buyer power in hog markets is quite limited. In this paper, we review the available literature, which has been generally presented as demonstrating that buyer power is not a significant problem. We find that interpretation to be poorly justified. Researchers have found well-documented evidence of market power on both the seller and the buyer sides of the market, though the studies have been less clear on the specific causes. Mirroring prevailing practices in Justice Department merger reviews, researchers have often discounted buyer power using methodologies more appropriate to seller power, then dismissed findings of seller power by pointing to offsetting âefficiency gainsâ from concentration. Yet such apparent efficiency gains in seller markets can include reductions in the prices concentrated firms pay for animals through their exercise of buyer power. We also raise the question of how buyer power in concentrated retail markets may compound the exercise of buyer power by packers. The paper concludes with a set of recommendations for further research, including the refinement of methodologies for the study of buyer power, and an assessment of proposed new USDA regulations on packer buying practices.
Convergence Analysis and Error Estimates for a Second Order Accurate Finite Element Method for the Cahn-Hilliard-Navier-Stokes System
In this paper, we present a novel second order in time mixed finite element
scheme for the Cahn-Hilliard-Navier-Stokes equations with matched densities.
The scheme combines a standard second order Crank-Nicholson method for the
Navier-Stokes equations and a modification to the Crank-Nicholson method for
the Cahn-Hilliard equation. In particular, a second order Adams-Bashforth
extrapolation and a trapezoidal rule are included to help preserve the energy
stability natural to the Cahn-Hilliard equation. We show that our scheme is
unconditionally energy stable with respect to a modification of the continuous
free energy of the PDE system. Specifically, the discrete phase variable is
shown to be bounded in and the discrete
chemical potential bounded in , for any time
and space step sizes, in two and three dimensions, and for any finite final
time . We subsequently prove that these variables along with the fluid
velocity converge with optimal rates in the appropriate energy norms in both
two and three dimensions.Comment: 33 pages. arXiv admin note: text overlap with arXiv:1411.524
Saturated hydrocarbon polymeric binder for advanced solid propellant and hybrid solid grains Quarterly report no. 3, 1 May - 31 Jul. 1966
Saturated hydrocarbon polymeric binder for advanced solid propellant and hybrid solid grain
Social death and the loss of a âworldâ: an anatomy of genocidal harm in Sudan
This article explores Claudia Cardâs hypothesis that social death is the distinctive harm of genocide. Drawing on original in-depth interviews with individuals from the genocide-affected regions of Darfur and the Nuba Mountains in Sudan (now living in, and interviewed in, the US and the UK), I illustrate the value and validity of the concept of social death as a phenomenological lens for understanding the depth, extent and character of genocideâs harms for its victims and survivors. Aided by the work of a number of authors (including Elias and Jean-Luc Nancy), I outline a relational interpretation of Cardâs important scholarship in order to show that understanding the distinctiveness of genocide requires that we also consider, in ontological terms, what it means to be human. I seek to do this in a way that may form the basis of a flexible definitional approach to genocide, and which overcomes oppositions between individualist and collectivist approaches to conceptualising harm. Often falling through the gaps of technical legal discourse and conventional frameworks of understanding, the profound, existential harm of genocide can be challenging to grasp. By centring the concept of social death, this article aims to contribute to our ability to do
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