101,602 research outputs found

    Ontogeny of the Tibial Spur in \u3ci\u3eMegamelus Davisi\u3c/i\u3e (Homoptera: Delphacidae) and its Bearing on Delphacid Classification

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    The forms of the nymphal tibial spur in Megamelus davisi Van Duzee, and their relation to Muir\u27s classification of delphacid subfamilies and tribes, are discussed

    Notes on the Biology of \u3ci\u3eNersia Florens\u3c/i\u3e (Homoptera: Fulgoroidea: Dictyopharidae) with Descriptions of Eggs, and First, Second, and Fifth Instars

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    Information on food plants and laboratory rearing of Nersia florens Stal is provided, and the eggs and Ist, 2nd, and 5th instars are described

    Universal scaling behavior at the upper critical dimension of non-equilibrium continuous phase transitions

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    In this work we analyze the universal scaling functions and the critical exponents at the upper critical dimension of a continuous phase transition. The consideration of the universal scaling behavior yields a decisive check of the value of the upper critical dimension. We apply our method to a non-equilibrium continuous phase transition. But focusing on the equation of state of the phase transition it is easy to extend our analysis to all equilibrium and non-equilibrium phase transitions observed numerically or experimentally.Comment: 4 pages, 3 figure

    Dynamic modeling of spacecraft in a collisionless plasma

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    A new computational model is described which can simulate the charging of complex geometrical objects in three dimensions. Two sample calculations are presented. In the first problem, the capacitance to infinity of a complex object similar to a satellite with solar array paddles is calculated. The second problem concerns the dynamical charging of a conducting cube partially covered with a thin dielectric film. In this calculation, the photoemission results in differential charging of the object

    A methodology for the decomposition of discrete event models for parallel simulation

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    Parallel simulation has presented the possibility of performing high-speed simulation. However, when attempting to make a link between the requirements of parallel simulation and discrete event simulation used in commercial areas such as manufacturing, a major problem arises. This lies in the decomposition of the simulation into a series of concurrently executing objects. Using the activity cycle diagram simulation technique as an illustrative example, this paper suggests a solution to this decomposition problem. This is discussed within the context of providing a conceptually seamless methodology for translating simulation models into a form which can exploit the benefits of parallel computing

    Satellite Precipitation and Cloud Experiment (SPACE)

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    An experiment plan was formulated to support an investigation of the precipitation processes associated with mesoscale systems and the interaction of rain producing cloud complexes with the meso and macro-scale environment. The field program necessary to accomplish the scientific goals is designed to incorporate satellite information (VIS and IR as well as VAS data), special radiosonde and surface observing capabilities, radar observations of storms development, special observations from aircraft and ground based lightning measurements. The observing network comprises rawinsonde stations located in northern Alabama and eastern Tennessee. A high density raingauge network and the MSFC lightning location network also cover the area. Coordination with NASA U2 and ER2 aircraft programs and with the operational requirements of the microburst severe thunderstorm program can assure the most efficient utilization of the observing resources

    Atmospheric observations for STS-1 landing

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    A summary of synoptic weather conditions existing over the western United States is given for the time of shuttle descent into Edwards Air Force Base, California. The techniques and methods used to furnish synoptic atmospheric data at the surface and aloft for flight verification of the STS-1 orbiter during its descent into Edwards Air Force Base are specified. Examples of the upper level data set are given

    Quantifying the impact of technical barriers to trade : a framework for analysis

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    There has been increasing use of technical regulations as instruments of commercial policy in the context of multilateral, regional, and global trade. These nontariff barriers are of special concern to developing countries, which may bear additional costs in meeting mandatory standards. Many industrial and developing countries express frustration with regulations that vary across their export markets, require duplicative conformity procedures, and are continually revised to exclude imports. The authors provide a comprehensive overview of the policy debate and methodological issues surrounding product standards and technical barriers to trade. They begin with a review of the policy context driving demand for empirical analysis of standards in trade, then provide an analytical overview of the role of standards and their relationship to trade. They then review methodological approaches that have been used to analyze standards and theirimpact on trade. Their main interest lies in advancing techniques that are practical and may be fruitfully extended to the empirical analysis of regulations and trade. They discuss concrete steps that could be taken to move forward a practical, policy-relevant program of empirical research. Such steps would include: a) administering firm-level surveys in developing countries; b) devising methods for assessing how much standards restrict trade; and c) establishing econometric approaches that could be applied to survey and microeconomic data, to improve understanding of the role of standards in exports.Environmental Economics&Policies,Economic Theory&Research,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Trade and Services,Trade and Regional Integration

    The cost of compliance with product standards for firms in developing countries: an econometric study

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    Standards and technical regulations exist to protect consumer safety or to achieve other goals, such as ensuring the interoperability of telecommunications systems, for example. Standards and technical regulations can, however, raise substantially both start-up and production costs for firms. Maskus, Otsuki, and Wilson develop econometric models to provide the first estimates of the incremental production costs for firms in developing nations in conforming to standards imposed by major importing countries. They use firm-level data generated from 16 developing countries in the World Bank Technical Barriers to Trade (TBT) Survey Database. Their findings indicate that standards do increase short-run production costs by requiring additional inputs of labor and capital. A 1 percent increase in investment to meet compliance costs in importing countries raises variable production costs by between 0.06 and 0.13 percent, a statistically significant increase. The authors also find that the fixed costs of compliance are nontrivial-approximately $425,000 per firm, or about 4.7 percent of value added on average. The results may be interpreted as one indication of the extent to which standards and technical regulations might constitute barriers to trade. While the relative impact on costs of compliance is relatively small, these costs can be decisive factors driving export success for companies. In this context, there is scope for considering that the costs associated with more limited exports to countries with import regulations may not conform to World Trade Organization rules encouraging harmonization of regulations to international standards, for example. Policy solutions then might be sought by identifying the extent to which subsidies or public support programs are needed to offset the cost disadvantage that arises from nonharmonized technical regulations.Environmental Economics&Policies,Economic Theory&Research,Health Economics&Finance,Administrative&Regulatory Law,Science Education
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