Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Rheological and drag reduction characteristics of xanthan gum solutions (1988)
    Springer
    Rheologica acta 27 (1988), S. 617-627 
    Details
    ISSN: 1435-1528
    Keywords: Shearviscosity ; firstnormal-stress difference ; drag reduction ; semi-flexibility ; self-association ; xanthan gum solution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Abstract The rheological and turbulent drag reducing characteristics of commercial and purified xanthan gum solutions of concentrations 50–500 ppm have been studied with and without addition of 100 ppm NaCl. The purification by soxlet extraction of xanthan gum using 95% ethanol is effective in removing low-molecular-weight impurities from xanthan. The increased content of higher molecular-weight xanthan in purified xanthan is evident from rheological and drag reduction behavior. The addition of 100 ppm salt to dilute solutions introduces semi-flexibility in xanthan gum solution without occurrence of self-association. The change in molecular behavior in the presence of salt is evident from rheological normal-stress and turbulent drag reduction behaviors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01337457
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Symbiotic algal nitrogenase activity and heterocyst frequency in sevenAzolla species after phosphorus fertilization (1988)
    Springer
    Hydrobiologia 169 (1988), S. 313-318 
    Details
    ISSN: 1573-5117
    Keywords: Azolla ; symbiont ; Anabaena azollae ; heterocyst ; acetylene reducing activity ; phosphorus ; fertilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Seven species ofAzolla (A. caroliniana, A. microphylla, A. nilotica, A. filiculoides, A. mexicana, A. rubra, A. pinnata the last from both Malaysia and India) grown in pots of flooded soil were subjected to three different treatments with respect to P: none, single application, split application. The experiments were carried out under greenhouse conditions. Heterocyst frequency inAnabaena azollae and acetylene reducing activity (ARA) were studied in successiveAzolla leaves. Both variables increased from the first leaf (shoot apex) to the last one (before branch) in all species in the presence or absence of P. However, heterocyst frequency, ARA andAzolla biomass were all less in the treatment lacking P. Heterocyst frequency inA. azollae, ARA and biomass ofAzolla were higher when P was applied in split doses than in the other treatments.Azolla plants exhibited more ARA than the isolated leaves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00007554
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Drag reduction by polymer-polymer mixtures (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 36 (1988), S. 837-858 
    Details
    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: An extensive study on the turbulent drag reduction caused by the various mixtures of polyacrylamide, purified guargum, xanthangum, and their graft copolymers has been conducted at low concentrations and Re = 14,000 using a turbulent flow rheometer. It has been found in most of the cases that the drag reduction caused by mixtures shows a positive deviation from the linearly additive straight line. This effect is more prominent when the drag reduction caused by both the constituents differ appreciably. In most of the cases, the drag reduction caused by the mixtures is higher than the DR caused by either of the constituent polymers; however, the drag reduction caused by the mixture is less than the sum of the drag reduction caused by both the constituents at their respective concentration in the mixture. It has also been noticed that there is no evidence of synergism in these mixtures at low concentrations.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1988.070360409
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Comparative detection of mild strains of potato spindle tuber viroid from the dormant potato tubers by Return-polyacrylamiee gel electrophoresis and nucleic acid hybridization (1988)
    Springer
    Potato research 31 (1988), S. 159-166 
    Details
    ISSN: 1871-4528
    Keywords: sensitivity ; routine testing ; silver staining ; dot-blot ; severe strain ; separation of strains
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Using a modified procedure of Return-polyacrylamide gel electrophoresis (R-PAGE) mild strains of potato spindle tuber viroid (M-PSTV) were detected reliably from dormant tubers. The sensitivity of R-PAGE detection of M-PSTV was equivalent to that of nucleic acid hybridization. Both methods detected M-PSTV when infected tissue was mixed with healthy tissue in a ratio of 1 to 100. When extracted nucleic acid was diluted with buffer, R-PAGE detected PSTV at a dilution of 1:256 and nucleic hybridization only up to 1:64 PSTV was readily detected from 18 potato cultivars. In addition, mild, ‘intermediate’ and severe strains were separated by R-PAGE, on the basis of their mobility on the electrophorogram.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02360033
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...