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  • 61.80  (2)
  • corona discharges  (2)
  • Economy in design  (1)
  • Springer  (5)
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  • Springer  (5)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Oecologia 90 (1992), S. 518-526 
    ISSN: 1432-1939
    Keywords: Leaf orientation ; Biomechanics ; Light interception ; Economy in design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Computer simulations were used to assess the influence of palmate leaf morphology, decussate phyllotaxy, and the elastic moduli of petioles on the capacity of turgid and wilted twigs ofAesculus hippocastanum to intercept direct solar radiation. Leaf size, morphology, orientation, and the Young's and shear moduli (E and G) of petioles were measured and related to leaf position on 8 twigs whose cut ends were placed in water (“turgid” twigs) and 8 twigs dried for 8 h at room temperature (“wilted” twigs). Petioles mechanically behaved as elastic cantilevered beams; the loads required to shear petioles at their base from twigs were correlated with the cross-sectional areas of phyllopodia but not with petiole length or tissue volume. Empirically determined morphometric and biomechanical data were used to construct “average” turgid and wilted twigs. The diurnal capacity to intercept direct sunlight for each was simulated for vertically oriented twigs for 15 h of daylight, 40° N latitude. The daily integrated irradiance (DII) of the wilted twig was roughly 3% less than that of the otherwise comparable twig bearing turgid leaves. Simulations indicated that the orientation of turgid leaves did not maximize DII. More decumbent (wilted) petioles increased DII by as much as 4%. Reduction in the girth, E, or G of petioles, or an increase in petiole length or the surface area of laminae (with attending increase in laminae weight), increased petiolar deflections and DII. Thus, the mechanical design of petioles ofA. hippocastanum was found not to be “economical” in terms of investing biomass for maximum light interception.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 35 (1984), S. 249-253 
    ISSN: 1432-0630
    Keywords: 61.70 ; 61.80 ; 71.35 ; 78.55
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The topograms revealing the anisotropic distribution of defects in the volume of monocrystalline YAG samples have been obtained by the thermoluminescence (TL) technique. It has also been shown that the anisotropic distribution of the lattice defects affects strongly the shape of the TL curves. The greatest changes in the TL intensity were observed in the areas of the samples distributed symmetrically every 120°. It was noted that the selective distribution of the TL intensity is caused mainly by the presence of the (211) facets as well as growth striations formed during the growth process. The groups of lines observed in the TL spectrum have been ascribed to the Tb3+ ions, excited owing to the radiationless energy transfer from the bound exciton states (BES).
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 34 (1984), S. 87-92 
    ISSN: 1432-0649
    Keywords: 61.70 ; 61.80 ; 71.35 ; 78.55
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The spectral distribution of the thermoluminescence (TL) of YAG:Nd crystals coloured by x-ray irradiation at room temperature (RT) and at 80 K has been investigated. The spectral distribution of TL in the uv-, visible and near ir ranges shows that the energy transfer by bound exciton states (BES) to the RE3+ ions (Nd3+ and Tb3+) decreases with increasing temperature. The TL spectrum in the uv range is ascribed to the hole defect centers. Diminution of the energy transferred by the BES to the Nd3+ and Tb3+ ions is the direct cause for the occurrence of the group of lines ascribed to the Nd3+ ions in TL observed at LT, whereas at RT and higher only the groups of Tb lines are observed.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1572-8978
    Keywords: dielectric barrier discharges ; corona discharges ; atmospheric pressure plasma ; plasma cleaning ; metal sheet ; degreasing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract The plasma-activated removal of oil from contaminated silicon substrates and galvanized steel sheets has been performed using dielectric barrier discharges (DBD) at atmospheric pressure. Removal rates were determined by ellipsometric measurement of the oil film thickness, using polished silicon as substrates. With galvanized steel sheets, qualitative and quantitative investigations were done using fluorescence microscopic characterization of theplasma-treated surfaces. Both the ellipsometric and the fluorescence microscopic measurements yield the dependence of the removal rate on treatment parameterssuch as plasma–gas composition and gas flow. The film thickness measurements were calibrated using quantitative IR spectroscopic measurements. It could be shown that the removal rate increases with increasing oxygen content in the process gas, static removal rates of 0.6 nm/s and 7 nm/s being obtainedin pure nitrogen and in pure oxygen, respectively. Fluorescence microscopic investigations showed that oil can be removed even from grooves in the galvanized steel sheets.
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  • 5
    ISSN: 1572-8978
    Keywords: dielectric barrier discharges ; corona discharges ; atmospheric pressure plasma deposition ; plasma polymerization ; surface functionalization ; functional groups
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract Dielectric barrier discharge (DBD)-based plasma deposition at atmospheric pressure, using glycidyl methacrylate (GMA, methacrylic acid-[2,3-epoxy-propyl ester]) as a prototype precursor was investigated in order to evaluate the applicability of dielectric barrier discharges to obtain plasma polymers with a high degree of structural retention of the starting precursor. Using pulsed excitation of the discharge, up to about 90% of the epoxy groups of GMA can be retained in plasma polymers obtainableat deposition rates in the order of 3–5nm/s. Preliminary investigations of the mechanism of film formation under pulsed plasma conditions indicate that the reaction of intact monomer molecules withsurface radicals generated during the pulses play a prominent role.
    Type of Medium: Electronic Resource
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