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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 254 (1976), S. 267-278 
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Summary Microtome cuts of partially crystalline injection mouldings (PE, PP, POM) were taken out of different cross-section layers and analysed with the polarization microscope, the DTA/DSC-analysis and by density measurements. The crystallinity and morphological structure are strongly inhomogeneous according to the different cooling and flow conditions across the cross-section. With linear polyethylene the zone of the highest crystallinity lies closely under the moulding's surface. In differential thermal analysis a typical double melting peak appears with samples of this range. In the tensile test these zones show a small elongation at fracture, whereas the marginal and core layers behave ductily.
    Notes: Zusammenfassung Es wurden Mikrotomschnitte von teilkristallinen Spritzgußteilen (PE, PP, POM) aus verschiedenen Querschnittstiefen entnommen und mit dem Polarisationsmikroskop, der DTA/DSC-Analyse sowie durch Dichtemessungen untersucht. Die Kristallinität und Gefügestruktur sind entsprechend den unterschiedlichen Abkühl- und Fließbedingungen über dem Querschnitt stark inhomogen. Bei linearem Polyäthylen liegt die Zone höchster Kristallinität dicht unterhalb der Formteiloberfläche. Bei der Differential-thermoanalyse tritt bei Proben aus diesem Bereich ein typischer Doppelschmelzpeak auf. Im Zugversuch weisen diese Zonen eine geringe Bruchdehnung auf, während sich die Rand- und Kernschichten duktil verhalten.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Entomologia experimentalis et applicata 18 (1975), S. 451-456 
    ISSN: 1570-7458
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Im Labor gezogene Männchen von P. gossypiella wurden mit 32P gefüttert, um Ausbreitung und Paarung im Baumwollfeld zu studieren. Freigelassene Falter, teils bestrahlt mit 20 Krad, teils unbestrahlt, wurden vorwiegend innerhalb von 100 m von der Freilassungsstelle gefunden. Vor Bildung eines geschlossenen Bestandes waren die Tagesruheplätze der Falter Bodenspalten and der Basis der Pflanzen. Später, wenn ein schützender, dichter Pflanzenbestand gebildet war, hatten die Falter ihre Ruheplätze etwa zur Hälfte in dem unteren Bereich des Pflanzenbestandes, davon viele in verwelkten Blüten. Zwischen freigelassenen Männchen und Freilandweibchen kam es nur zu wenig Paarungen, wahrscheinlich wegen des zahlenmässigen Übergewichts der Freilandmännchen im Gebiet. Die Technik der Autoradiographie von Freilandweibchen zur Erkennung einer Paarung mit freigelassenen, markierten Männchen war einfach und wirkungsvoll.
    Notes: Abstract Radioactive phosphorus was fed to laboratory-reared male pink bolloworms, Pectinophora gossypiella (Saunders), for studies of dispersal and mating in the field. Released moths either irradiated with 20 Krad or unirradiated, were found predominantly within a few hundred meters of the release points. Prior to formation of a plant canopy, daytime-resting places of moths were soil crevices at the bases of the plants. Later, when a protective plant canopy had formed, about half of the moths took resting places in the lower canopy, many in withered blooms. Little mating occurred between released males and native females, probably due to the great preponderance of native males in the test area. The technique of autoradiography of native females to determine mating with released labeled males was simple and effective.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Antonie van Leeuwenhoek 53 (1987), S. 147-158 
    ISSN: 1572-9699
    Keywords: Aspergillus ; aflatoxin ; DNA relatedness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Aspergillus nomius is described and represents a new aflatoxigenic species phenotypically similar to A. flavus. Strains examined were isolated from insects and agricultural commodities. Separation from A. flavus is based on the presence of indeterminate sclerotia and a lower growth temperature. Comparisons of DNA relatedness show A. nomius to have only relatively recently evolved from A. flavus and A. tamarii.
    Type of Medium: Electronic Resource
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  • 14
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The depolarization of atomic alkali beams (6Li,7Li,23Na) during ionization on oxygen covered hot metal surfaces (Ir, Mo, Re, W) has been investigated. The polarization of the ionized beams was detected by a beam foil experiment. The temperature dependence of the observed depolarization is interpreted as due to a relaxation process caused by the interaction of the nuclear moments with fluctuating fields on the surface.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Journal of engineering mathematics 22 (1988), S. 253-265 
    ISSN: 1573-2703
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Technology
    Notes: Abstract The flexible high-pressure hose we consider in this paper, is a rubber tube reinforced by two steel braids. Each of the latter consists of two families of thin steel wires which are wound helicoidally around the cylinder. In order to achieve an optimal strength of the tube, the stresses in the wires of the two braids must be much the same. We investigate whether this can be accomplished by a proper choice of the braid angles of the two braids. Throughout this paper we apply a linear theory.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Flow, turbulence and combustion 45 (1988), S. 251-281 
    ISSN: 1573-1987
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Flexible hoses, consisting of a rubber tube reinforced by one or more cylindrical braids composed of thin steel wires, are frequently used in hydraulics. They need to be both capable of withstanding high pressures, and rather flexible, two more or less contradictory requirements. In this paper we consider a straight tube with only one steel braid. We calculate stresses and strains resulting from an internal pressure using three models of a tube. Two of these are membrane models, one with elastic steel fibres and the other with inextensible wires. The third one is a thick-walled tube model. In particular, we pay attention to the effect of the so-called neutral angle of the wires. Part of the analysis is non-linear. However, the ultimate numerical evaluation pertains to a linearized theory, i.e. the deformations are small.
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Hyperfine interactions 30 (1986), S. 73-108 
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Recent experiments using thermal beams of nuclear-spin-polarized alkali atoms adsorbed on hot metal surfaces show that polarized nuclei are sensitive probes of surface electromagnetic field distributions. The high polarization of the probe beams, when coupled with the efficiency of atomic physics techniques used for monitoring the polarization of desorbed particles, makes possible a variety of interesting spinrelaxation experiments on single-crystal surfaces, including nuclear magnetic resonance. Extension of the current experimental method to semiconductor and insulator surfaces at arbitrary temperatures appears to be straightforward. The information from spin-polarized nuclear surface spectroscopy (SPNSS) will allow detailed tests of charge-density profiles now available in self-consistent surface structure calculations. Moreover, the variety of presently available polarized nuclear species suggests that the chemistry of many interesting adsorbate-surface systems could also be profitably investigated by this technique. The use of spin-polarized hydrogen nuclei in particular offers enticing prospects for fundamental studies in catalysis, surface structure and basic two-dimensional physics.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 343 (1992), S. 53-53 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Hyperfine interactions 16 (1983), S. 987-991 
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Nuclear spin polarized alkali atom beams are used to investigate metal surfaces. The surface diffusion of the alkali atoms on the surface results in a randomly fluctuating electric field gradient. The relaxation is measured in dependence of the surface temperature. Using an additional external RF field, also NMR measurement can be performed. Besides some fluctuating components of the EFG which cause the relaxation process, there is also a static part of the EFG. This results in an energy splitting of the nuclear spin states and can be detected by the NMR experiments.
    Type of Medium: Electronic Resource
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