1,207 research outputs found

    Chapter 9: Aquatic Macroinvertebrates, Section A: Aquatic Macroinvertebrates (Exclusive of Mosquitoes)

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    Final Report. Excerpt (Chapter 9, Section A) from The Des Plaines River Wetlands Demonstration Project, Volume II, Baseline Survey, edited by Donald L. Hey and Nancy S. PhilippiReport issued on: October 1985INHS Technical Report prepared for Wetlands Research, Inc

    Drivers of Arctic shipping & marine operation

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    Geothermal reservoir engineering research

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    The Stanford University research program on the study of stimulation and reservoir engineering of geothermal resources commenced as an interdisciplinary program in September, 1972. The broad objectives of this program have been: (1) the development of experimental and computational data to evaluate the optimum performance of fracture-stimulated geothermal reservoirs; (2) the development of a geothermal reservoir model to evaluate important thermophysical, hydrodynamic, and chemical parameters based on fluid-energy-volume balances as part of standard reservoir engineering practice; and (3) the construction of a laboratory model of an explosion-produced chimney to obtain experimental data on the processes of in-place boiling, moving flash fronts, and two-phase flow in porous and fractured hydrothermal reservoirs

    Using New Selection Tools

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    The goal of most beef production systems is to increase or at least maintain profitability. Producers can attempt to increase profitability in a variety of ways that might include reducing feed costs, changing their marketing program, or perhaps by changing the performance of their herd through genetic improvement. Focusing on this latter option, there are two primary genetic tools available: selection and mating where selection refers to the selection of breeding animals and mating includes which females are mated to which bulls, for example, crossbreeding systems. This paper focuses on the former, the selection of the appropriate animals for a production system with the goal to improve profitability. The best tool available for making selection decisions is expected progeny differences (EPD). Over the years the number of EPD available to guide producers in making selection decisions has grown from 5 to over 15 in most cases. Simply put, the amount of information that the breeder must sift through to try to make a good selection decision has become overwhelming. The producer must determine which EPD have the greatest influence on their income and their expenses, and by how muchā€”a daunting task. Historically this task has depended on the ā€œintuitionā€ and experience of the breeder. For instance, they know that selection for heavier weaning weight will increase the weight of calves sold at weaning, but that blind selection for weaning weight will also increase calving difficulty and if replacements are kept, likely increase cow size and feed costs. Breeders have been performing a balancing act with little concrete information on how important each of those traits is to their profitability. Fortunately, there are several tools that have recently become available to ease the process of combining the costs and the revenues of beef production with EPD to make selection decisions that will produce progeny which are more profitable

    Use of Electroshock for Euthanizing and Immobilizing Adult Spring Chinook Salmon in a Hatchery

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    This study evaluated the use of electroshock as in alternative to traditional techniques for immobilizing and euthanizing hatchery fish. We used a commercially available electroanesthesia unit at the U.S. Fish and Wildlife Service\u27s Carson National Fish Hatchery (Carson, Washington) to euthanize adult spring Chinook salmon Oncorhynchus tshawytscha and to son and collect gametes of fish at maturation. During euthanization by electroshock, the response of each fish was observed, Muscular and vertebral hemorrhaging wits quantified, and electrical settings were optimized accordingly. During gamete collection, fish were either electroshocked or exposed to tricaine methanesulfortate (MS-222); hemorrhaging, egg viability. egg size and quantity, and resultant fry quality were examined for each treatment group. Electroshocked fish had a higher likelihood Of injury during gamete collection than did fish exposed to MS-222. On average, each electroshocked fish had less than two hemorrhages oil both fillets examined. The size of each hemorrhage was less than 0.10% of the fillet surface. Fecundity and egg and fry quality were not affected by either immobilization method. Electroshock was a viable and efficient means of euthanizing adult spring Chinook salmon or sorting the fish and collecting their gametes. However, equipment settings must be optimized based on site-specific (e.g., water conductivity) and species-specific (e.g., fish size and seasonal state of maturation) factors

    A TPD and RAIRS comparison of the low temperature behavior of benzene, toluene, and xylene on graphite

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    The first comparative study of the surface behavior of four small aromatic molecules, benzene, toluene, p-xylene, and o-xylene, adsorbed on graphite at temperatures ā‰¤30 K, is presented. Intermolecular interactions are shown to be important in determining the growth of the molecules on the graphite surface at low (monolayer) exposures. Repulsive intermolecular interactions dominate the behavior of benzene and toluene. By contrast, stronger interactions with the graphite surface are observed for the xylene isomers, with islanding observed for o-xylene. Multilayer desorption temperatures and energies increase with the size of the molecule, ranging from 45.5 to 59.5 kJ molāˆ’1 for benzene and p-xylene, respectively. Reflection absorption infrared spectroscopy gives insight into the effects of thermal processing on the ordering of the molecules. Multilayer benzene, p-xylene, and o-xylene form crystalline structures following annealing of the ice. However, we do not observe an ordered structure for toluene in this study. The ordering of p-xylene shows a complex relationship dependent on both the annealing temperature and exposure

    Powerful alliances in graphs

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    AbstractFor a graph G=(V,E), a non-empty set SāŠ†V is a defensive alliance if for every vertex v in S, v has at most one more neighbor in Vāˆ’S than it has in S, and S is an offensive alliance if for every vāˆˆVāˆ’S that has a neighbor in S, v has more neighbors in S than in Vāˆ’S. A powerful alliance is both defensive and offensive. We initiate the study of powerful alliances in graphs

    Optimized energy calculation in lattice systems with long-range interactions

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    We discuss an efficient approach to the calculation of the internal energy in numerical simulations of spin systems with long-range interactions. Although, since the introduction of the Luijten-Bl\"ote algorithm, Monte Carlo simulations of these systems no longer pose a fundamental problem, the energy calculation is still an O(N^2) problem for systems of size N. We show how this can be reduced to an O(N logN) problem, with a break-even point that is already reached for very small systems. This allows the study of a variety of, until now hardly accessible, physical aspects of these systems. In particular, we combine the optimized energy calculation with histogram interpolation methods to investigate the specific heat of the Ising model and the first-order regime of the three-state Potts model with long-range interactions.Comment: 10 pages, including 8 EPS figures. To appear in Phys. Rev. E. Also available as PDF file at http://www.cond-mat.physik.uni-mainz.de/~luijten/erikpubs.htm

    The Soviet maritime Arctic : proceedings of a workshop held May 10-13, 1987 by the Marine Policy Center of the Woods Hole Oceanographic Institution

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    This report is a summary of an international workshop on the Soviet Maritime Arctic held May 10-13, 1987 by the Marine Policy Center of the Woods Hole Oceanographic Institution. Twenty-eight scholars from Canada, Great Britain, Norway and the United States participated. The workshop provided a forum for Western scholars to examine and discuss Soviet domestic and international policies regarding the Arctic Ocean. Interdisciplinary workshop sessions addressed the following concerns: strategic, geographic, historical, legal, scientific, technological, transportation, geopolitical and resource development. This report includes an overview of the workshop, 15 abstracts of contributed papers (8 with figures or tables), and an edited transcript of the concluding discussion session. Appendices include the final program, a list of participants and a list of discussion questions contributed by the participants prior to the workshop. Several key findings of the workshop include: more than 500 years of Russian involvement in the Arctic Ocean; USSR operation of the world's largest polar fleet primarily for transportation and resource development; Russian nationalism as a possible driving force in Soviet activity in the Arctic; Soviet concerns for the Arctic representing an amalgamation of interests (economic, security, environmental, resource, others), none of which alone is predominant; probable Soviet participation in international Arctic regimes based on past actions; and, Soviet legislative enactments which indicate that the balance of interests embodied in the Law of the Sea Convention are largely acceptable to the Soviet Union and that extreme doctrinal views on the legal status of polar seas do not enjoy support in law or State practice.Funding was provided by the John D. and Catherine T. MacArthur Foundatio

    Universal and Non-Universal First-Passage Properties of Planar Multipole Flows

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    The dynamics of passive Brownian tracer particles in steady two-dimensional potential flows between sources and sinks is investigated. The first-passage probability, p(t)p(t), exhibits power-law decay with a velocity-dependent exponent in radial flow and an order-dependent exponent in multipolar flows. For the latter, there also occur diffusive ``echo'' shoulders and exponential decays associated with stagnation points in the flow. For spatially extended dipole sinks, the spatial distribution of the collected tracer is independent of the overall magnitude of the flow field.Comment: 7 pages, LaTe
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