High speed binary to decimal conversion system Patent

Design and operation of high speed binary to decimal conversion syste

Spins coupled to a Z2Z_2-Regge lattice in 4d

We study an Ising spin system coupled to a fluctuating four-dimensional $Z_2$-Regge lattice and compare with the results of the four-dimensional Ising model on a regular lattice. Particular emphasis is placed on the phase transition of the spin system and the associated critical exponents. We present results from finite-size scaling analyses of extensive Monte Carlo simulations which are consistent with mean-field predictions.Comment: Lattice2001(surfaces), 3 pages, 2 figure

Surface properties of ocean fronts

Background information on oceanic fronts is presented and the results of several models which were developed to study the dynamics of oceanic fronts and their effects on various surface properties are described. The details of the four numerical models used in these studies are given in separate appendices which contain all of the physical equations, program documentation and running instructions for the models

Reflection absorption infrared spectroscopy and temperature programmed desorption investigations of the interaction of methanol with a graphite surface

Reflection absorption infrared spectroscopy (RAIRS) and temperature programmed desorption (TPD) have been used to investigate the adsorption of methanol (CH3OH) on the highly oriented pyrolytic graphite (HOPG) surface. RAIRS shows that CH3OH is physisorbed at all exposures and that crystalline CH3OH can be formed, provided that the surface temperature and coverage are high enough. It is not possible to distinguish CH3OH that is closely associated with the HOPG surface from CH3OH adsorbed in multilayers using RAIRS. In contrast, TPD data show three peaks for the desorption of CH3OH. Initial adsorption leads to the observation of a peak assigned to the desorption of a monolayer. Subsequent adsorption leads to the formation of multilayers on the surface and two TPD peaks are observed which can be assigned to the desorption of multilayer CH3OH. The first of these shows a fractional order desorption, assigned to the presence of hydrogen bonding in the overlayer. The higher temperature multilayer desorption peak is only observed following very high exposures of CH3OH to the surface and can be assigned to the desorption of crystalline CH3OH. (C) 2005 American Institute of Physics

Control considerations for high frequency, resonant, power processing equipment used in large systems

Addressed is a class of resonant power processing equipment designed to be used in an integrated high frequency (20 KHz domain), utility power system for large, multi-user spacecraft and other aerospace vehicles. It describes a hardware approach, which has been the basis for parametric and physical data used to justify the selection of high frequency ac as the PMAD baseline for the space station. This paper is part of a larger effort undertaken by NASA and General Dynamics to be sure that all potential space station contractors and other aerospace power system designers understand and can comfortably use this technology, which is now widely used in the commercial sector. In this paper, we will examine control requirements, stability, and operational modes; and their hardware impacts from an integrated system point of view. The current space station PMAD system will provide the overall requirements model to develop an understanding of the performance of this type of system with regard to: (1) regulation; (2) power bus stability and voltage control; (3) source impedance; (4) transient response; (5) power factor effects, and (6) limits and overloads

Critical exponents of a three dimensional O(4) spin model

By Monte Carlo simulation we study the critical exponents governing the transition of the three-dimensional classical O(4) Heisenberg model, which is considered to be in the same universality class as the finite-temperature QCD with massless two flavors. We use the single cluster algorithm and the histogram reweighting technique to obtain observables at the critical temperature. After estimating an accurate value of the inverse critical temperature \Kc=0.9360(1), we make non-perturbative estimates for various critical exponents by finite-size scaling analysis. They are in excellent agreement with those obtained with the $4-\epsilon$ expansion method with errors reduced to about halves of them.Comment: 25 pages with 8 PS figures, LaTeX, UTHEP-28

Ice Sheets and the Anthropocene

Ice could play a role in identifying and defining the Anthropocene. The recurrence of northern hemisphere glaciation and the stability of the Greenland Ice Sheet are both potentially vulnerable to human impact on the environment. However, only a very long hiatus in either would be unusual in the context of the Quaternary Period, requiring the definition of a geological boundary. Human influence can clearly be discerned in several ice-core measurements. These include a sharp boundary in radioactivity due to atmospheric nuclear testing; increases, unprecedented at least in the Holocene, in Greenland concentrations of sulphate, nitrate and metals such as lead; the appearance in ice-core air bubbles of previously undetectable compounds such as SF6; and the rise, unprecedented in the last 800 ka, in concentrations of carbon dioxide and methane. Some combination of these changes could be used by future generations to clearly identify the onset of a new epoch defined at a particular calendar date. However, it is not yet clear what the character of the fully developed Anthropocene will be, and it might be wise to let future generations decide, with hindsight, when the Anthropocene started, acknowledging only that we are in the transition towards it

An Economic Analysis of Selected Irrigation Systems Applicable to the Eastern Missouri Slope Area of South Dakota

For many years the prospect of irrigation development has captured the minds of farmers, agribusinessmen, and residents of the Eastern Missouri Slope area of South Dakota. The area has shared in the over-all technological advance in agriculture, but agricultural production and incomes have remained highly variable. This variability is generated by inconsistent yields caused by extreme annual fluctuations in the quantity and seasonal distribution of rainfall. Irrigation is the logical solution for stabilizing production and income. In the last decade there has been a major transition from gravity to sprinkler irrigation systems. Economic and physical factors have caused the trend toward sprinkler irrigation. Rising labor costs and more efficient power sources have led farmers to substitute mechanical power and capital investment for farm labor and thus convert to sprinkler irrigation. The current technology in sprinkler irrigation permits the farmer to irrigate shallow topsoil without disturbing it by land leveling. He can sprinkler-irrigate sloping and sandy lands without problems of excessive runoff and soil erosion. Also, the farmer can apply a rather exact, uniform quantity of water where and when needed. As a result of these advantages, land which would have otherwise been considered non-irrigable under gravity irrigation can often be adapted to sprinkler systems. The objectives of the study were: 1.To determine the optimum enterprise combinations and farm organization necessary to maximize returns from the adoption of irrigation in Eastern Missouri Slope area of South Dakota. 2.To determine how the optimum combination of enterprises vary between different systems