1,019 research outputs found

    Satellite monitoring of sea surface pollution

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    The author has identified the following significant results. Image processing techniques developed are well adapted to the exploration and isolation of local areas which exhibit small temperature differences between themselves and their surroundings. In the worst case of imagery of small areal extent of sea surface having no coastal boundary in the area, there is yet no method of distinguishing unambiguously an oil spill from fog, cloud, the effect produced by shallow sediments, or the effects of naturally occuring thermal fronts. In the case of uniform slicks of liquid North Sea oil in still air, laboratory simulation experiments show that, for oil thicknesses in excess of 1 or 2 mm, there is, under equilibrium conditions, little dependence of oil surface temperature on the thickness of the oil layer. The surface temperature of oil is consistently higher than that of water, the difference being about 1 K at low values of relative humidity, but tending to increase as the relative humidity increases

    Solubility, stability, and electrochemical studies of sulfur-sulfide solutions in organic solvents

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    A preliminary study of the sulfur electrode in organic solvents suggests that the system warrants further investigation for use in a low temperature (100 deg to 120 C) Na-S secondary battery. A qualitative screening was undertaken at 120 C to determine the solubilities and stabilities of Na2S and Na2S2 in representatives of many classes of organic solvents. From the screening and quantitative studies, two classes of solvents were selected for work; amides and cyclic polyalcohols. Voltammetric and Na-S cell charge discharge studies of sulfide solutions in organic solvents (e.g., N, N-dimethylformamide) at 120 C suggested that the reversibilities of the reactions on Pt or high density graphite were moderately poor. However, the sulfur electrode was indeed reducible (and oxidizable) through the range of elemental sulfur to Na2S. Reactions and mechanisms are proposed for the oxidation reduction processes occurring at the sulfur electrode

    Status, Dispersal, and Breeding Biology of the Exotic Eurasian Collared-Dove (Streptopelia decaocto) in Arkansas

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    The exotic Eurasian Collared-Dove (Streptopelia decaocto) was first sighted in Arkansas at Harrison (Boone Co.) on 25 June 1989. Since this initial sighting the species has grown in numbers and is now present in 42 of 75 counties across the state. In the spring and summer of 2009 and 2010, 20 nests were observed in the urban areas of Fort Smith (Sebastian County). Fifteen of the 20 nests (75%) were located on human-made structures of which 13 (65%) were on an electrical substation and two (10%) were on utility poles. The remaining 5 nests (25%) were in trees. Mean nest height was 7.62 m (n = 20 nests), and the mean width of the nest site support was 40 cm (n = 6 nests). Thirteen of the 20 nests (65%) yielded fledgling(s). Three focal nests were chosen for intense observation. Nest building lasted 1 to 3 days (mean = 2 days); incubation period was 15 days; and fledging occurred 17-18 days after hatching (n = 3 nests). A total of 6 young fledged from these 3 nests

    Search for solid conductors of Na(+) and K(+) ions: Five new conductors

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    Five conductors of three structure types were discovered which, as solids, can transport Na(+) or K(+) ions with conductivities of approximately .00001/(omega cm) at 300 K. These compounds are: (1) the pyrochlores NaTaWO6 and NaTa2O5F, both with an activation energy for conduction delta E of 21 kJ/mole; (2) the bodycentered cubic form of NaSbO3, with delta E = 42 kJ/mole; and (3) the niobates 2Na2O with 3Nb2O5 and 2K2O with 3Nb2O5, with the alkali ions probably in open layers of the incompletely determined structure; delta E = 17 kJ/mole. On the basis of approximately 40 structure types, some generalizations were made regarding the relation between structure and ionic transport

    Low cost home ownership in Glasgow: an analysis of recent housing policy

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    `Low Cost Home Ownership' represents a package of policy measures which are part of government housing policy to extend home ownership. The package was outlined by the Department of the Environment in a publicity brochure entitled `A First Home' (1981) aimed at local authorities and housing associations. The different Low Cost Home Ownership measures have been pioneered and implemented at a local level as part of the government's wider strategy of privatising housing provision and consumption. This thesis is directly concerned with exploring the structure, substance and impact of Low Cost Home Ownership policy, in the context of Glasgow. The thesis is based on three levels of analysis, linked through a focus on policy and the role of the state at national and local levels. First, a preliminary level of analysis evaluates the success of Low Cost Home Owernship policy in its own terms. It is suggested, for example, that the term `low cost' home ownership is a misnomer in many cases. At a second level of analysis, the thesis examines the structure of policy, including the division between central and local levels of government, and the categorisation of policy as, for instance, housing or planning. A third level of analysis incorporates the substance of Low Cost Home Ownership policy. The underlying assumptions of the policy are analysed, particularly the tenure bias of Low Cost Home Ownership. Urban policy encompasses Low Cost Home Ownership policy measures in several cities, including Glasgow, and the thesis examines the functionalist objectives of population and socio economic stability in the city. In addition, Low Cost Home Ownership policy in Glasgow is aimed at widening tenure choice and meeting housing needs. An analysis of these policy objectives requires the conceptualisation of `choice' and `need' in housing policy and housing studies

    A modified copper hot water system

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    A good supply of hot and boiling water for cleansing and sterilising utensils is essential for hygienic milk production. Dairy Instructor F. Fielder, M.D.D., describes an efficient and economical modification of a copper hot water system for this purpose. SINGLE copper units of 14 or 16 gallon capacity to supply hot and boiling water for the dairy are no longer good enough for most dairy farms

    Distribution of Fish Within Headwater Riffles of the Illinois River System, Washington County, Arkansas

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    Quantitative sampling of fish was performed in five headwater riffles of the Illinois River System, Washington County, Arkansas during low flow conditions. This study revealed differing fish species composition, biomass and feeding guild segregation between head and tail riffle reaches in 1st through 3rd order. Thirty species representing 10 families were identified. Of this number, darters (Percidae), sculpins (Cottidae), madtoms (Ictaluridae), and central stonerollers (Campostoma anomalum) (Cyprinidae) comprised 67 to 98 percent of riffle head populations. Fish biomass was greater for riffle head areas (0.58-6.6/0.28-2.0 g/m2 ) within sectivores and herbivores dominating. Total fish numbers decreased from riffleheads to tails, while number of species increased. Dominant fish groups in tail areas were minnows (Cyprinidae), darters (Percidae), and sunfishes (Centrarchidae). Feeding guild fish groups in tail areas were predominately insectivore and insectivore-piscivore. Stomach analysis of Cottus carolinae, the dominant headwater riffle predator, indicated selective feeding of macrobenthic invertebrates and fish based on size class. Abundance of herbivore and insectivore fishes in riffles, particularly head reaches, suggests a correlation with positive rheotaxic behavior, microhabitat preference or abundance of macrobenthic invertebrate populations

    Reactions of NaCl with Gaseous SO3, SO2, and O2

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    Hot corrosion of gas turbine engine components involves deposits of Na2SO4 which are produced by reactions between NaCl and oxides of sulfur. For the present investigation, NaCl single crystals were exposed at 100 to 850 C to gaseous mixtures of SO3, SO2, and O2. The products formed during this exposure depend, primarily, on the temperatures. The four product films were: NaCl-SO3; Na2S2O7; Na2SO4; and NaCl-Na2SO4. The kinetics of the reactions were measured

    Conductivity of boules of single crystal sodium beta-alumina

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    The ionic and electrochemical polarization characteristics of two boules of single crystal sodium beta-alumina (Na2O.8Al2O3), 2 cm in diameter, were investigated over the range of 25 to 300 C using 2- and 4-probe ac and dc techniques with reversible and ion-blocking electrodes. Textural (or internal) polarization at 27 C was present only in boule 1 which cleaved easily. Interfacial polarization, using solid sodium electrodes, was present at 27 C in the 2-probe conductivities for both boules. Cleaning with liquid sodium at 300 C reduced its magnitude, but some interfacial polarization was still present in the 2-probe conductivities for boule 2 below about 140 C. Above 140 C, with liquid sodium electrodes, the 2-probe conductivities, essentially polarization-free, were given by KT = 3300 exp(-3650/RT). The conductivity of boule 2 at 180 C remained essentially constant with increasing current density up to about 140 milliamps per square centimeter

    Production-line calf feeding

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    MANY cream-producing dairy farmers have found that it can be profitable to increase the number of calves they rear. In fact, it is big business for those who can rear up to 200 calves a year, and a few have already achieved this number
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