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  • 1995-1999  (2)
  • 1990-1994  (3)
  • 1975-1979  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture research 28 (1997), S. 0 
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Growth performances of advanced fry of Indian major carps. Labeo rohita (Hamilton). Catla catla (Hamilton) and Cirrhinus mrigala (Hamilton), were examined in simulated pond systems using monthly application of the following fertilizers in six treatments: Mussoorie rockphosphate (MPR) in low (100 kg P2O5 ha−1) and high doses (200 kg P2O5 ha−1), single superphosphate (SSP) (50 kg P2O5 ha−1), single superphosphate mixed with rockphosphate (1:1 by weight: 50 kg P2O5), compost (C) (water hyacinth and cattle manure) and composted rockphosphate (MPR-C). The amount of available P in surface sediment of MPR-C did not differ from that in either the SSP or the MPR + SSP treatment, whereas the total and available N contents differed greatly. There was an inverse relationship between the time to reach phosphate peak of water and the retention time of fertilizer in surface sediments. It is evident that total P of surface sediment was the most significant contributor to fish growth in exclusively MPR treatments, whereas total P and total N of surface sediments are involved in the MPR treatments in combination with compost or SSP.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of applied ichthyology 8 (1992), S. 0 
    ISSN: 1439-0426
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Thirty-two glass jars (3 L each) in the laboratory and outdoor tanks (300 L) were used to examine the influence of common carp (Cyprinus carpio L.) in increasing the fertilizer value of phoshate rock in eight treatment combinations in quadruplicate. Input of water soluble hosphate was determined to quantify the effects of bioturbation, fish excrements and soil. The level of orthophosphate in water was always lowest in the control series. Introduction of common carp fry resulted in a net increase of 0.1 to 0.114 mg. L-1 of orthophosphate attributable to the effect of fish excrement. Bioturbation caused by common carp resulted in as high as a 72 to 100 % influx of phosphate from bottom soil in the presence of phosphate rock but only about 7 to 8 % in the absence of phosphate rock.〈section xml:id="abs1-2"〉〈title type="main"〉Zusammenfassung Die Bedeutung eingesetzter Karpfen (Cyprinus carpio L.) zur Steigerung des Düngerwertes von Phosphatgestein32 Glasgefäße (3 L Volumen) wurden im Labor und 4 Behälter (300 L) im Freien aufgestellt urn den Einfluß zunehmender Düngung durch Phosphatgestein auf Karpfen (Cyprinus carpio L.) in 8 unterschiedlichen Applikationen mit jeweils 4 Replikaten zu testen. Der Eintrag wasserloslichen Phosphats wurde bestimmt, urn die Wirkung von Bioturbation, Fischexkrementen und Bodensubstrat zu prüfen. Die Konzentration an Orthophosphat war in den Kontrollen am niedrigsten. Das Einsetzen von Karpfen-Jungfischen erhöhte die Nertozunahme des Orrhophosphats auf 0,1 bis 0,114 mg. -1 und diese Zunahme muß den Ausscheidungen der Fische zugeschrieben werden. Die durch die Karpfen verursachte Bioturbation resultiene in einer 72 bis 100% igen Zunahme des Influx des Phosphats aus dem Bodensubstrat wenn Phosphatgestein dem Boden zugegeben wurde, wahrend dieser Wert nur 7–8%) ohne Phosphatgestein betrug.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Catalysis letters 22 (1993), S. 179-187 
    ISSN: 1572-879X
    Keywords: Cu-Zn-Al catalyst ; hybrid catalyst ; hydrotalcite ; methanol synthesis ; synthesis of C2-C4 hydrocarbons ; zeolites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A copper-zinc-aluminum methanol synthesis catalyst has been prepared using a precipitated hydrotalcite-type precursor that decomposes to a mixture of the corresponding amorphous oxides at a low temperature. TPR studies show that such a mixture is easy to reduce giving a highly dispersed catalyst. When this is mixed with a zeolite, the resulting hybrid catalyst gives C2-C4 hydrocarbons with very high selectivity. This may be useful in obtaining LPG from synthesis gas.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 26 (1991), S. 3004-3008 
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Crystallization and ageing of pure ammonium nitrate crystals was studied by scanning electron microscopy. Ageing the crystals beyond 1 h led to the growth of secondary grains along the grain boundaries of primary grains (140–200 μm). After 6 h ageing secondary growth along grain boundaries was not observed; instead, distinct clusters with morphologies similar to the secondary grains were formed. The ancillary growth obeys approximately the parabolic relation L=(Kt)1/n+1 where n=1 justifies grain growth in the pure crystals, and its formation is ascribed to the dissolution of dendrites, edges and corners. The high interfacial activity and interparticle voids can affect the storage and mechanical properties of the material.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Reaction kinetics and catalysis letters 11 (1979), S. 63-69 
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Были приготовлены образцы окиси никеля, насышенные литием и индием, с содержанием допанта до 3 ат.%-ов. Были исследованы электрические свойства этих образцов. Для всех образцов была обнаружена проводимость типа р, которая возрастает с литиевым насыщением и уменышается с индиевым насыщением. Дегидрирование 2-пропанола на этих катаизаторах уменьшается с увеличением концетрации дырок в твердом веществе. Ступенью, лимитирующей скорость процесса, является десорбция ацетона. Предлагается вероятный менанизм протекания процесса.
    Notes: Abstract Lithium and indium doped nickel oxide samples have been prepared with up to 3 at. % of dopant. The electrical properties of these samples have been studied. All the samples exhibit p-type conductivity which increases with lithium doping and decreases upon doping with indium. Dehydrogenation of 2-propanol on these catalysts increases with the hole concentration in the solid. Desorption of acetone appears to be the rate-determining step. A possible mechanism for the reaction is proposed.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Reaction kinetics and catalysis letters 6 (1977), S. 307-314 
    ISSN: 1588-2837
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract Разложение изопропанола на V2O5 и бронзах: Li0,02V2O5, Na0,02V2O5, Na0,06V2O5, Li0,33V2O5 и Na0,33V2O5 было исследовано в области температур 186–300°C. Для первых четырех катализаторов основной реакцией оказалась дегидратация до пропена с незначительной дегидрогенизацией до ацетона. Дегидратация на этих катализаторах увеличивается с содержанием щелочного металла, а энергия активации остается неизменной. На последних двух катализаторах дегидратация и дегидрогенизация протекают при сравнимых скоростях. Исходя из влияния продуктов на начальную скорость, данных электропроводимости катализаторов и их ЭПР спектров, предлагается механизм дегидратации изопропанола.
    Notes: Abstract Decomposition of isopropanol on V2O5 and the bonzes Li0.02V2O5, Na0.02V2O5, Na0.06V2O5, Li0.33V2O5, and Na0.33V2O5 has been studied in the temperature range 168–300°C. The main reaction was found to be dehydration to propene with negligible dehydrogenation to acetone on the first four catalysts. Dehydration on these catalysts increased with the alkali metal content, but the energy of activation remained unchanged. On the last two catalysts, dehydration and dehydrogenation proceeded at comparable rates. A tentative mechanism for the dehydration of isopropanol is proposed, based on the effect of the product on the initial rate, the electric conductivity of the catalysts and their ESR spectra.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 11 (1976), S. 1347-1353 
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The electrical conductivity and Seebeck coefficients have been measured from room temperature to 500° C for polycrystalline V2O5 and V2O5 doped with lithium and sodium in the α-phase range. The conductivity increases with doping and the energy of activation decreases. The Seebeck coefficient indicates that electrons are the majority carriers. The results have been discussed in terms of the two-level hopping model.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 60 (1996), S. 2125-2132 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Semi- and full interpenetrating polymer networks (IPNs) of epoxy resin and poly(butyl methacrylate) (PBMA) were prepared by the sequential mode of synthesis. These were characterized with respect to their mechanical properties, such as ultimate tensile strength, percent elongation at break, and modulus. The densities of these samples were evaluated and compared. Differential scanning calorimetry (DSC) and thermogravimetric analysis were undertaken for thermal characterization of the IPNs. Phase morphology was studied by polarized light microscopy of the undeformed specimens and by scanning electron microscopy of the fractured surfaces of samples undergoing tensile failure. The effects of variations of the blend ratios on the above-mentioned properties were examined. A gradual decrease in modulus and tensile strength was observed for both the semi- and full IPNs with consequent increases in elongation at break and toughness as the proportion of PBMA increased. The densities also followed the same pattern. Semi-IPNs, however, were characterized by higher densities, tensile strengths, and moduli than the corresponding full IPNs. The DSC tracings displayed broadening of transitions, indicating some phase blending. The percent weight retentions in the thermal decomposition of the IPNs and pseudo-IPNs were higher than that observed during the thermal degradation of the epoxy resin homopolymer network. Phase-separated PBMA domains of various sizes were presumed to be responsible for the increased toughness of PBMA-modified epoxy. © 1996 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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