1,708 research outputs found

    The Pilot Land Data System (PLDS) at the Ames Research Center manages aircraft data in collaboration with an ecosystem research project

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    The Pilot Land Data System (PLDS) is a data and information system serving NASA-supported investigators in the land science community. The three nodes of the PLDS, one each at the Ames Research Center (ARC), the Goddard Space Flight Center (GSFC) and the Jet Propulsion Laboratory (JPL), cooperate in providing consistent information describing the various data holding in the hardware and software (accessible via network and modem) that provide information about and access to PLDS-held data, which is available for distribution. A major new activity of the PLDS node at the Ames Research Center involves the interaction of the PLDS with an active NASA ecosystem science project, the Oregon Transect Ecosystems Research involves the management of, access to, and distribution of the large volume of widely-varying aircraft data collected by OTTER. The OTTER project, is managed by researchers at the Ames Research Center and Oregon State University. Its principal objective is to estimate major fluxes of carbon, nitrogen, and water of forest ecosystems using an ecosystem process model driven by remote sensing data. Ten researchers at NASA centers and universities are analyzing data for six sites along a temperature-moisture gradient across the western half of central Oregon (called the Oregon Transect). Sensors mounted on six different aircraft have acquired data over the Oregon Transect in support of the OTTER project

    New Associate Editor

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    Francesco M. Angelici, Ph.D., currently works in the areas of behavioral ecology, wildlife management, zoogeography, and mammal systematic and conservation studies, particularly concerning carnivores, lagomorphs, and ungulates. His other fields of research are ornithology (Falconiformes, Passeriformes, and Strigiformes) and herpetology (ecology of snakes). He studies Mediterranean and tropical fauna, with particular reference to the conservation of vertebrates. He also works in the areas of planning and environmental conservation. He has planned 3 international congresses on “Problematic Wildlife,” and he is editor of 2 books published by Springer (one in press) on the same topic. He currently works also as a zoologist conservationist with hunting management agencies. He is also a specialist in African savannah environments as well as desert and tropical rain forests. He was a lecturer in courses in zoology (Vertebrate Zoology, Wildlife Management, Animal Ecology, and Zoogeography) from 1990 to 2009 in Italian universities. He is an associate professor in the Italian (and European) academic system

    Experimental and numerical investigation of silicon carbide and refractory materials under extreme conditions

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    The chemical and mechanical aspects related to the use of refractory materials at high-temperatures and under oxidizing conditions were investigated. The behavior of silicon carbide and tantalum were studied with an emphasis on their performance as fuel cladding in nuclear power plants

    Computer-aided boundary delineation of agricultural lands

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    The National Agricultural Statistics Service of the United States Department of Agriculture (USDA) presently uses labor-intensive aerial photographic interpretation techniques to divide large geographical areas into manageable-sized units for estimating domestic crop and livestock production. Prototype software, the computer-aided stratification (CAS) system, was developed to automate the procedure, and currently runs on a Sun-based image processing system. With a background display of LANDSAT Thematic Mapper and United States Geological Survey Digital Line Graph data, the operator uses a cursor to delineate agricultural areas, called sampling units, which are assigned to strata of land-use and land-cover types. The resultant stratified sampling units are used as input into subsequent USDA sampling procedures. As a test, three counties in Missouri were chosen for application of the CAS procedures. Subsequent analysis indicates that CAS was five times faster in creating sampling units than the manual techniques were

    Catalyst system comprising a first catalyst system tethered to a supported catalyst

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    The present invention provides new catalyst formats which comprise a supportedcatalyst tethered to a second and different catalyst by a suitable tethering ligand.A preferred system comprises a heterogeneous supported metal catalyst tethered to a homogeneous catalyst. This combination of homogeneous and heterogeneous catalysts has a sufficient lifetime and unusually high catalytic activity in arene hydrogenations, and potentially many other reactions as well, including, but not limited to hydroformylation, hydrosilation, olefin oxidation, isomerization, hydrocyanation, olefin metathesis, olefin polymerization, carbonylation, enantioselective catalysis and photoduplication. These catalysts are easily separated from the products, and can be reused repeatedly, making these systems very economical

    Urban solar photovoltaics potential: An inventory and modelling study applied to the San Fernando Valley region of Los Angeles

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    Procedures for analyzing the potential of solar photovoltaic collectors to meet energy requirements in a metropolitan region are described and a modeling effort is applied to the San Fernando Valley region of Los Angeles. The procedure involves a series of steps designed to produce maps and tabulations revealing the amount of rooftop area available for establishing solar collectors and the proportion of energy requirement that could be potentially supplied by solar photovoltaics within each of the 533 mainline feeder service areas in the study area. For the sixty five square mile study area, the results showed that, with half the available flat and south facing roofs used and assuming the availability of energy storage, 52.7 percent of the actual kWh energy requirements could have been met in 1978 using photovoltaic collectors. Hourly, daily, weekly, and monthly fluctuations in potential supply and actual loads and recommendations of avenues for further research are discussed. Some further potential applications of the modeling technique are suggested

    A Land Use Change Monitoring System Based on LANDSAT

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    A procedure for economically determining statistics on acreages of change in the use of land between two dates has been developed to support a Department of Housing and Urban Development program on neighborhood change modeling. The application of image processing techniques to LANDSAT imagery in four stages (registration, differencing, classification, and tabulation) provides one of the basic data sets needed to model future land use in one of six typical urban areas. After appropriate LANDSAT imagery for two desired dates is obtained, date-to-date registration of the study area is performed. Once the two images are adequately registered, the procedures of determining the geographic areas of change are initiated. The ratio of two raw bands for the early date is computed and then subtracted from the same ratio for the late date. This difference is allowed to conform to a gaussian distribution, and those pixels whose values lie beyond two standard deviations from the mean are designated as areas of change. The first step in the creation of a late date classification map is to extract and classify only those areas that show change. Then the early date classified data for unchanged areas is digitally summed with the late date classified data in changed areas. Using polygon overlay routines individually for both the early and late date classifications and then combining the results, a tabulation revealing general land use changes (e.g., the number of acres of residential in the early date versus the number in the late date) can be generated. To determine the manner of the change (e.g., the number of acres changed from rural to urban), the land use classes are first aggregated into rural/urban dicotomies and then a routine which permits comparison of individual pixel values is executed. Finally, a tabulation can display the manner of the land use change aggregated by the administrative district desired (e.g., census tracts)

    The lion in Ghana: its historical and current status

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    El león en Ghana: su situación pasada y presenteHistóricamente, la población de león (Panthera leo) en Ghana ha sido poco estudiada y su situación actual está poco documentada. Tras los últimos intentos infructuosos de encontrar indicios de la presencia de la especie, son numerosos los autores que opinan que la población de león en Ghana está prácticamente extinguida. En un intento por recabar más datos, desde 2005 hemos venido realizando estudios sobre esta especie en los parques más importantes de Ghana y otras zonas protegidas del país, que se han centrado principalmente en el Parque Nacional de Mole (MNP). Asimismo, hemos examinado los datos publicados con el fin de reconstruir la historia de la presencia del león en el país. Si bien nuestra investigación no aportó datos inequívocos, se recabó información circunstancial que sugiere que aún podría existir una pequeña población de león en el MNP y sus zonas circundantes.Historically, the lion (Panthera leo) population in Ghana has been little studied and its status is poorly documented. Currently, after recent unsuccessful attempts to find signs of the presence of the species, many authors believe that the Ghanaian lion population is most likely extinct. In an attempt to gather more data, since 2005 we have been carrying out lion surveys in the most important parks and other protected areas of Ghana, mainly focusing on Mole National Park (MNP). We have also been extensively reviewing the literature in an attempt to reconstruct the history of the presence of the lion in the country. Although our research has not provided unequivocal evidence of the presence of the lion, we have collected circumstantial evidence that suggests that a small lion population might still be present in MNP and its surrounding areas.El león en Ghana: su situación pasada y presenteHistóricamente, la población de león (Panthera leo) en Ghana ha sido poco estudiada y su situación actual está poco documentada. Tras los últimos intentos infructuosos de encontrar indicios de la presencia de la especie, son numerosos los autores que opinan que la población de león en Ghana está prácticamente extinguida. En un intento por recabar más datos, desde 2005 hemos venido realizando estudios sobre esta especie en los parques más importantes de Ghana y otras zonas protegidas del país, que se han centrado principalmente en el Parque Nacional de Mole (MNP). Asimismo, hemos examinado los datos publicados con el fin de reconstruir la historia de la presencia del león en el país. Si bien nuestra investigación no aportó datos inequívocos, se recabó información circunstancial que sugiere que aún podría existir una pequeña población de león en el MNP y sus zonas circundantes
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