Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1995-1999  (4)
  • 1995  (4)
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 99 (1995), S. 13569-13570 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 30 (1995), S. 6209-6217 
    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 process of removing a multicomponent binder from a metal powder compact has been investigated. Model experiments of debinding were performed on compounds consisting of less than 40 vol% binders (low molecular weight polyethylene, paraffin and Carnauba waxes) and more than 60 vol% metal content. As typical representatives for injection moulding morphology and meeting all other requirements for optimal powder characteristics, elemental powders of the Fe-Al system were used. Viscosity results over a wide range of shear rates for various plastisols are presented as functions of binder system composition and metal powder content. Based on the rheological response, an optimization of plastisol formulation was performed. Results are reported on three series of debinding modes using heat and fluid wicking in air and in nitrogen. The time dependence of fractional debinding, x(t), during wicking has been estimated using a model. Direct observation by SEM of binder distribution and pore structure evolution at different stages of the debinding process was made. Wick-assisted thermal debinding in nitrogen proved to be an effective debinding method in terms of shape preservation and the absence of defects in the studied material.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 165 (1995), S. 46-55 
    ISSN: 1432-136X
    Keywords: Citrate synthase ; Enzyme characteristics ; Temperature adaptation ; Isopod crustacea ; Euphausiid crustacea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The characteristics and properties chromatographically purified citrate synthase from the euphausiids Euphausia superba (Antarctica) and Meganyctiphanes norvegica (Scandinavian Kattegat and Mediterranean Sea) and from the isopods Serolis polita (Antarctica) and Idotea baltica (Baltic Sea) were used to elucidate biochemical mechanisms of temperature adaptation. Additionally, maintenance experiments were carried out on the euphausiids to determine mechanisms of short term acclimation. Temperature optima (between 37 and 45°C) were unrelated to genotypic cold adaptation, but the activation energy of the Antarctic krill E. superba (10.9 kJ · mol-1) was only a quarter of that in other species (41.8–45.1 kJ · mol-1). The minima of apparent Michaelis constants (total range: 4–20 μmol · 1-1 oxaloacetate; 7–45 μmol · 1-1 acetyl-coenzyme A) showed no relation to natural conditions, and no distinct pH optimum occurred at ambient temperatures. In contrast, apparent Michaelis constants and specific enzyme activities were related to maintenance temperatures in M. norvegica, but not in E. superba. The differences between M. norvegica and E. superba can be interpreted as adaptations to the changes in ambient temperature with regard to the respective steno- and eurythermic tolerances of these crustaceans.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of comparative physiology 165 (1995), S. 56-61 
    ISSN: 1432-136X
    Keywords: Citrate synthase ; Enzyme regulation ; Temperature adaptation ; ATP inhibition ; Crustacea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Citrate synthase is a regulatory enzyme of the energy metabolism pathway controlling the citric acid cycle. It was studied in order to determine modes of enzyme regulation with regard to the life-style of the investigated species. Citrate synthase from crustaceans with different life-styles were compared: the pelagic euphausiids Euphausia superba from the Antarctic and Meganyctiphanes norvegica from the Scandinavian Kattegat and the Mediterranean were compared to the benthic isopods Serolis polita from the Antarctic and Idotea baltica from the Baltic. Citrate synthase was partly purified chromatographically and the influence of adenosine 5′-triphosphate on enzyme activity was examined. Mechanisms of inhibition and inhibitor constants were determined. Two different mechanisms of enzyme regulation by ATP were found. Citrate synthase from isopods was only competitively inhibited, while citrate synthase from euphausiids showed not only competitive inhibition but also activation by low concentrations of ATP. This activation is equivalent to the reversed methanism of uncompetitive inhibition. The ecophysiological relevances of the coupling of these mechanisms are discussed. The degree of competitive inhibition was different in the two groups of investigated crustaceans. Inhibitor constants were similar within the euphausiids but not in isopods, which showed higher or lower inhibition depending on the climatic zone: the colder the ambient temperature the lower the ATP inhibition. A possible mechanism of temperature adaptation through effects of varying inhibition constants is concluded.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...