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  • 2015-2019
  • 1995-1999  (4)
  • 1965-1969
  • epoxy resin  (2)
  • eutrophication  (2)
  • 1
    Electronic Resource
    Electronic Resource
    A reference system for continental running waters: plant communities as bioindicators of increasing eutrophication in alkaline and acidic waters in north-east France (1996)
    Springer
    Hydrobiologia 340 (1996), S. 67-76 
    Details
    ISSN: 1573-5117
    Keywords: acidic water ; alkaline water ; autoecology ; bioindication ; macrophyte community ; eutrophication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two bioindication scales of the degree of eutrophication based on aquatic macrophyte communities were established in two types of running waters free of organic matter, the one in acidic “soft” waters (pH 5.5–7.0, conductivity 40–110 μS.cm−1), the other in alkaline hard waters (pH 7–8, conductivity 500–900 μS.cm−1). We show that the main determining factor of the macrophyte distribution is the nutrient level (trophy), especially the level of phosphate and ammonia. The acidic scale, with increasing pH, includes four stages ranging from oligotrophic to eutrophic level (traces to 300 μg.l−1 N-NHinf4p+ and P-PO4 3−), while the alkaline scale at constant pH comprises six stages of a trophic gradient. For the most part, the floristic composition found in the two sequences is different and depends on conductivity and alkalinity variation. However, some species occur in the two scales and may reflect differences in the trophic level, depending on whether the waters are alkaline or acidic. This change of trophic level for these species is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00012736
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    A macrophyte communities sequence as an indicator of eutrophication and acidification levels in weakly mineralised streams in north-eastern France (1999)
    Springer
    Hydrobiologia 410 (1999), S. 17-24 
    Details
    ISSN: 1573-5117
    Keywords: eutrophication ; acidification ; macrophyte communities ; weakly mineralized streams ; France
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Northern Vosges streams are subjected to acidification upstream and to eutrophication downstream. A bio-indicator scale of the degree of eutrophication and of the level of acidification, based on four aquatic macrophyte communities, was established in these weakly mineralized streams. Aquatic plant communities therefore begin as Group A, develop into Group B and become Group C or D downstream. The A community was characterized by bryophytes (Scapania undulata, Sphagnum sp.) and Potamogeton polygonifolius in oligotrophic, acidified to weakly acidified, and poorly buffered streams. The B community, defined by P. polygonifolius and the appearance of Ranunculus peltatus and Callitriche species (C. platycarpa, C. hamulata) was found in oligotrophic waters with a higher buffer capacity than the A community. The C community was determined by the disappearance of P. polygonifolius and the appearance of Elodea species (E. canadensis, E. nuttallii) and rare species in mesotrophic and neutral streams. The D community, with very high nutrient loading, was characterized by the abundance of Callitriche obtusangula, by the presence of Amblystegium riparium, Fissidens crassipes and the development of filamentous algae. This macrophyte sequence corresponded to an upstream to downstream zonation, which was characterized by an increase in buffer capacity and in nutrient levels and a decrease in protons and aluminium load.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003829921752
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Mechanistic study of thermal behavior and combustion performance of epoxy resins: I homopolymerized TGDDM (1995)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 6 (1995), S. 53-62 
    Details
    ISSN: 1042-7147
    Keywords: epoxy resin ; homopolymerization ; thermal decomposition ; combustion ; 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
    Notes: Tetraglycidyl 4,4′-diaminodiphenylmethane (TGDDM) undergoes homopolymerization on heating. Intramolecular reactions which compete with crosslinking favor the formation of cyclic structures with increasing thermal and fire resistance of the resin, whereas physical mechanical properties tend to decrease.The mechanism of thermal decomposition of TGDDM is studied by thermogravimetry, differential scanning calorimetry and thermal volatilization analysis with characterization of volatiles evolved and residue left. Thermal degradation of poly-(TGDDM) starts at 260°C with elimination of water from secondary alcoholic groups which is a typical pathway for epoxy resin degradation. Resulting unsaturations weaken bonds in the β-position and provoke the first chain breaking at allyl-amine and allyl-either bonds. With increasing temperature, saturated alkyl-ether bonds and alkyl carbon-carbon bonds are broken first, followed by the most stable alkyl-aryl bonds at T〉365°C. The combustion performance of TGDDM is discussed on the basis of the thermal degradation behavior.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pat.1995.220060201
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Epoxy resins cured with aminophenylmethylphosphine oxide 1: Combustion performance (1996)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 7 (1996), S. 823-830 
    Details
    ISSN: 1042-7147
    Keywords: epoxy resin ; phosphorylated hardener ; combusion ; fire retardancy ; 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
    Notes: The kinetics of curing tetraglycidyl 4,4′-diaminodiphenyl methane (TGDDM) or of the mixture TGDDM/diglycidylether of bisphenol A (DGEBA) by bis(m-aminophenyl)methylphosphine oxide (BAMPO) was studied using differential scanning calorimetry. At low advancement of curing (〈50%), the low activation energy interaction between epoxy and amino groups seems to be controlled by diffusion, whereas above 50% the role of homopolymerization tends to increase and the process becomes chemically controlled.BAMPO shows a higher fire-retardant effectiveness in the mixture TGDDM/DGEBA than in TGDDM or DGEBA alone, for which the oxygen and nitrous oxide index tests suggest a condensed phase or a gas phase fire-retardant action depending on phosphorus content. An intumescent char is formed on the surface of burning fire-retarded specimens which tends, however, to be oxidized, thus reducing the fire-proofing effect at high BAMPO content.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
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