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
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Biology and fertility of soils 29 (1999), S. 262-269 
    ISSN: 1432-0789
    Keywords: Keywords Axial pressure ; Earthworms ; Ecological groups ; Radial pressure ; Burrowing activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  The aim of this study was to measure the pressures exerted by earthworms during burrowing. For this purpose we developed two methods with which to quantify the axial and radial pressure. The data were recorded with an electronic balance that was connected to a PC. Artificial earthworm burrows were used to standardize the measurements. Plexiglas tubes with diameters ranging from 2 to 6.3 mm which corresponded to the diameter of the earthworms were used. A pin was placed inside the tubes, on which the earthworms exerted a pressure by peristaltic locomotion. Only the maximum values of the pressure measurement were taken into account for evaluation, and the arithmetic mean was calculated. The measurements were conducted with Aporrectodea longa, Lumbricus terrestris, Aporrectodea caliginosa, Octolasion cyaneum, Allolobophora chlorotica, Aporrectodea rosea, Lumbricus rubellus and Dendrobaena octaedra. The species examined were classified into ecological groups. The mean axial pressures exerted by each group were in the order: epigeic (14–25 kPa), endogeic (27–39 kPa) and anecic (46–65 kPa). For the mean radial pressure the order was: epigeic (39–63 kPa), anecic (72–93 kPa) and endogeic (59–195 kPa). It was apparent from the results that radial pressure is the most important pressure with respect to the burrowing activity of earthworms.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Advanced Materials for Optics and Electronics 6 (1996), S. 330-334 
    ISSN: 1057-9257
    Keywords: conductive composites ; organic metals ; BEDO-TTF ; nanocrystals ; polymer composites ; optical properties ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: The possibilities of increasing the transparency of conductive organic polymeric composites obtained by growing crystalline conductive networks in situ are discussed and new methods of preparation of practically colourless conductive polymer films are presented. We show that in most cases the colour which appears during the preparation of a conducting composite by reticulate doping is not directly related to the conducting network, which usually consist of relatively well-formed microcrystals, but results instead from the additive molecules present in the polymer matrix as less organised aggregates or a molecularly dispersed phase. By an appropriate choice of preparation conditions or electrochemically one can get rid of the strongly absorbing part of the complex so that the absorption in the visible range can be substantially reduced without losing conductivity and without deterioration of the conductive network.These phenomena are demonstrated on polycarbonate with fine networks of BEDO-TTF iodine and bromine salts obtained by casting or spin coating in order to obtain thin homogeneous films, e.g. to prepare electrodes for electro-optical investigations. Transparent, colourless conductive films 20-2 μm thick (surface resistivity of the order of 103-104 Ω/□) have been obtained and the structure of the conductive networks in these materials, their optical properties in the visible and near-infrared range as well as their electrical properties are discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 41 (1990), S. 273-279 
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: By transmission electron microscopy, globular structures were observed on the fracture surface of the phenolic resin matrix. From water diffusion experiments the existence of a layer between the globules with a lower network density can be deduced. When the resin is modified by NBR or by tung oil combined with tricresyl phosphate, two separated phases are indicated by dynamic mechanical analysis, by thermally stimulated depolarization measurements, and by TEM.
    Notes: Auf Matrixbruchflächen werden mittels Transmissionselektronenmikroskopie globulare Strukturen beobachtet. Aus Untersuchungen zur Wasserdiffusion kann auf eine Zwischenschicht mit geringerer Vernetzungsdichte geschlossen werden. Ist die Harzmatrix mit NBR-Kautschuk oder mit Holzöl in Kombination mit Tricresylphosphat modifiziert, so weisen die dynamisch-mechanische Analyse, Messungen der thermisch stimulierten Depolarisation und TEM-Untersuchungen auf zwei separierte Phasen hin.
    Additional Material: 11 Ill.
    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...