Neutron matter on the lattice with pionless effective field theory

We study neutron matter by combining pionless effective field theory with non-perturbative lattice methods. The neutron contact interaction is determined by zero temperature scattering data. We simulate neutron matter on the lattice at temperatures 4 and 8 MeV and densities below one-fifth normal nuclear matter density. Our results at different lattice spacings agree with one another and match bubble chain calculations at low densities. The equation of state of pure neutron matter obtained from our simulations agrees quantitatively with variational calculations based on realistic potentials.Comment: 28 pages, 13 figure

The Ohio Grain Marketing Legislation of 1982 and 1983

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Inequalities for Light Nuclei in the Wigner Symmetry Limit

Using effective field theory we derive inequalities for light nuclei in the Wigner symmetry limit. This is the limit where isospin and spin degrees of freedom can be interchanged. We prove that the energy of any three-nucleon state is bounded below by the average energy of the lowest two-nucleon and four-nucleon states. We show how this is modified by lowest-order terms breaking Wigner symmetry and prove general energy convexity results for SU(N). We also discuss the inclusion of Wigner-symmetric three and four-nucleon force terms.Comment: 10 page

Modelling Functional Behavior of Event-based Systems: A Practical Knowledge-based Approach

AbstractFunctional behavior is considered to be the most basic, yet a critical notion in order to determine the characteristics of a system. However, how to reason about the functional behavior of a system in a systematic manner, is mostly limited by our cognitive processing abilities. While the UML-based behavior models can support a visual conceptualization of the functional behavior, they lack the rigorous, machine-processable reasoning capabilities. In this paper, we present a practical, knowledge-based approach to model the functional behavior that incorporates the notions of Commonsense Reasoning and Functional Reasoning over its core defining aspects. We demonstrate our approach with a detailed example, along with a set of use case scenarios. The main motivation behind this work was to develop a rigorous, logic-based approach to verify the levels of functional consistencies between cross-platform event-based systems. The focus of this paper, however, is to present the representational facility that can be utilized for the consistency validation system. While we provide a brief overview of the consistency validation system in this paper, a separate article will be dedicated for the comprehensive overview of the validation system itself

Bifurcated polarization rotation in bismuth-based piezoelectrics

ABO3 perovskite-type solid solutions display a large variety of structural and physical properties, which can be tuned by chemical composition or external parameters such as temperature, pressure, strain, electric, or magnetic fields. Some solid solutions show remarkably enhanced physical properties including colossal magnetoresistance or giant piezoelectricity. It has been recognized that structural distortions, competing on the local level, are key to understanding and tuning these remarkable properties, yet, it remains a challenge to experimentally observe such local structural details. Here, from neutron pair-distribution analysis, a temperature-dependent 3D atomic-level model of the lead-free piezoelectric perovskite Na0.5Bi0.5TiO3 (NBT) is reported. The statistical analysis of this model shows how local distortions compete, how this competition develops with temperature, and, in particular, how different polar displacements of Bi3+ cations coexist as a bifurcated polarization, highlighting the interest of Bi-based materials in the search for new lead-free piezoelectrics

Soybean Shipping Patterns in the United States for 1985

Information about soybean shipping patterns that enables the soybean industry participants to improve market performance through better decision making will contribute to a more efficient flow of soybeans. Such information may improve the investment decisions in port facilities, rail, truck and barge services, elevator and processor facilities, and farm production. The objectives of this paper are to determine regional soybean flows by mode of transportation for 1985 and compare these flows with similar data for 1977. Soybean flow data were collected for the 1985 calendar year through personal interviews, mail surveys and telephone calls with representatives of the soybean handling, storage and processing firms in 36 states. The volume of soybean exports for 1985 is slightly less than for 1977, and the distribution of these exports by region reveals significant changes. The Gulf exports more than any other region and has become relatively more important from 1977 to 1985. Soybean exports from the Great Lakes have declined significantly and the Atlantic region exports have declined slightly in this period. The biggest relative increase in soybean exports occurred in the Pacific region. Changes in international markets, unit train shipment rates and increased size of ocean shipping vessels are the major factors explaining the changes in export shares among regions. This trend may continue into the 1990s affecting production, transportation and shipping patterns by export ports. Barge shipments continue to be the dominant mode of transportation for export soybeans, accounting for 73 percent of all movements in 1985 compared to 61 percent in 1977. Truck and rail shipments declined from 16 to 8 percent and 23 to 19 percent, respectively, in this same period. Transportation deregulation does not appear to have helped the railroad compete for export bound soybeans. Strong competition among modes of transportation due to excess capacity in rail and barge transportation facilities in 1985 may explain this failure of railroads to gain market share relative to barge shipments. The elimination of the excess capacity since 1985 may change the rail-barge competitive structure during the 1990s