ENERGY PROBLEMS AND ALTERNATIVES: IMPLICATIONS FOR THE SOUTH

Resource /Energy Economics and Policy,

RCS reduction of a microstrip patch using lumped loads

In this report we consider the radar cross section (RCS) of a single rectangular patch antenna in a recessed cavity. Using a previously developed finite element-boundary integral method code, a study is performed on the patch's RCS as a function of frequency. To reduce the RCS of the patch at the resonant frequency, lumped (resistive) loads are placed at the edges of the patch. The effects of the lumped loads on the patch's RCS and gain are examined and it is observed that the RCS and gain are reduced as the as the load value decreases, whereas the antenna's bandwidth is increased. At resonance, the usual relations between the RCS and gain is observed, but it is shown that this relation no longer holds at frequencies away from resonance

OPTIMAL MANAGEMENT STRATEGIES FOR ALFALFA PRODUCTION WITHIN A TOTAL FARM PLAN

This paper examines the impacts of alternative management strategies for the production of alfalfa within the context of a total farm plan. A linear programming model is used to represent a 600-acre farm which can grow either grain crops or alfalfa. Alfalfa production competes with the grain crops for available land, labor, machinery, and field time over a calendar of tillage, plating, cutting, spraying, and harvesting activities. The profitability of an acre of alfalfa and the contribution of alfalfa to net returns for the farm varies quite widely depending on the particular alfalfa management strategy selected.Farm Management,

EFFECTS OF EEC AGRICULTURAL POLICY ON EUROPEAN IMPORTS OF MEAT, DAIRY PRODUCTS, AND EGGS

International Relations/Trade,

GOVERNMENT PRICE POLICIES AND THE AVAILABILITY OF CRUDE OIL

This study examines the effects of price incentives on the availability of petroleum. Expected sustained higher crude oil prices to domestic producers constitute an incentive to increase both exploratory drilling and secondary and tertiary recovery of oil as well as production out of reserves. Reserve-production ratios tend to fall under high prices. Equalization of the domestic price to the real world price would make the U.S. self sufficient within a six year period. Constant prices result in no new additions to reserves after a five year period and very low production levels. Imports reach sixty-five percent of domestic consumption.Resource /Energy Economics and Policy,

One Health in food safety and security education: Subject matter outline for a curricular framework.

Educating students in the range of subjects encompassing food safety and security as approached from a One Health perspective requires consideration of a variety of different disciplines and the interrelationships among disciplines. The Western Institute for Food Safety and Security developed a subject matter outline to accompany a previously published One Health in food safety and security curricular framework. The subject matter covered in this outline encompasses a variety of topics and disciplines related to food safety and security including effects of food production on the environment. This subject matter outline should help guide curriculum development and education in One Health in food safety and security and provides useful information for educators, researchers, students, and public policy-makers facing the inherent challenges of maintaining and/or developing safe and secure food supplies without destroying Earth's natural resources

Insight into the description of van der Waals forces for benzene adsorption on transition metal (111) surfaces

Exploring the role of van der Waals (vdW) forces on the adsorption of molecules on extended metal surfaces has become possible in recent years thanks to exciting developments in density functional theory (DFT). Among these newly developed vdW-inclusive methods, interatomic vdW approaches that account for the nonlocal screening within the bulk [V. G. Ruiz, W. Liu, E. Zojer, M. Scheffler, and A. Tkatchenko, Phys. Rev. Lett. 108, 146103 (2012)] and improved nonlocal functionals [J. Klimes, D. R. Bowler, and A. Michaelides, J. Phys.: Condens. Matter 22, 022201(2010)] have emerged as promising candidates to account efficiently and accurately for the lack of long-range vdW forces in most popular DFT exchange-correlation functionals. Here we have used these two approaches to compute benzene adsorption on a range of close-packed (111) surfaces upon which it either physisorbs (Cu, Ag, and Au) or chemisorbs (Rh, Pd, Ir, and Pt). We have thoroughly compared the performance between the two classes of vdW-inclusive methods and when available compared the results obtained with experimental data. By examining the computed adsorption energies, equilibrium distances, and binding curves we conclude that both methods allow for an accurate treatment of adsorption at equilibrium adsorbate-substrate distances. To this end, explicit inclusion of electrodynamic screening in the interatomic vdW scheme and optimized exchange functionals in the case of nonlocal vdW density functionals is mandatory. Nevertheless, some discrepancies are found between these two classes of methods at large adsorbate-substrate separations

Conversion Functions for Symmetric Key Ciphers

As a general design criterion, a symmetric key cipher should not be closed under functional composition due to the implications on the security of the cipher. However, there are scenarios in which this property is desirable and can be obtained without reducing the security of a cipher by increasing the computational workload of the cipher. We expand the idea of a symmetric key cipher being closed under functional composition to a more general scenario where there exists a function that converts the ciphertext resulting from encryption under a specific key to the ciphertext corresponding to encryption with another key. We show how to perform such a conversion without exposing the plaintext. We discuss the tradeoff between the computational workload and security, and the relationship between such conversions and proxy cryptography. We conclude with a discussion of some practical applications of our results

Conversion Functions for Symmetric Key Ciphers

As a general design criterion, a symmetric key cipher should not be closed under functional composition due to the implications on the security of the cipher. However, there are scenarios in which this property is desirable and can be obtained without reducing the security of a cipher by increasing the computational workload of the cipher. We expand the idea of a symmetric key cipher being closed under functional composition to a more general scenario where there exists a function that converts the ciphertext resulting from encryption under a specific key to the ciphertext corresponding to encryption with another key. We show how to perform such a conversion without exposing the plaintext. We discuss the tradeoff between the computational workload and security, and the relationship between such conversions and proxy cryptography. We conclude with a discussion of some practical applications of our results

Constructing the Cubic Interaction Vertex of Higher Spin Gauge Fields

We propose a method of construction of a cubic interaction in massless Higher Spin gauge theory both in flat and in AdS space-times of arbitrary dimensions. We consider a triplet formulation of the Higher Spin gauge theory and generalize the Higher Spin symmetry algebra of the free model to the corresponding algebra for the case of cubic interaction. The generators of this new algebra carry indexes which label the three Higher Spin fields involved into the cubic interaction. The method is based on the use of oscillator formalism and on the Becchi-Rouet-Stora-Tyutin (BRST) technique. We derive general conditions on the form of cubic interaction vertex and discuss the ambiguities of the vertex which result from field redefinitions. This method can in principle be applied for constructing the Higher Spin interaction vertex at any order. Our results are a first step towards the construction of a Lagrangian for interacting Higher Spin gauge fields that can be holographically studied.Comment: Published Version; comments added in introduction; minor typos and references correcte