Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 1990-1994  (5)
  • 1985-1989  (5)
  • 1955-1959  (1)
  • 1
    Digitale Medien
    Digitale Medien
    Sonic Energy in Granular Solid Fluidization (1955)
    s.l. : American Chemical Society
    Industrial & engineering chemistry 47 (1955), S. 1170-1175 
    Details
    ISSN: 1520-5045
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/ie50546a023
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Theoretical and experimental studies of CO2 laser evaporation of clouds (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 4601-4616 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A study of the effects of laser radiation on cloud drops and of the possibility of producing a clear optical channel in a cloud is presented. In order to produce a model that is appropriate to a realistic cloud with a distribution of drop sizes it is first necessary to study what happens to a single water drop subjected to laser radiation of different intensities. Various heating regimes are mapped out as a function of laser flux and fluence at the 10.6 μm wavelength. It is found that typical cloud drops can superheat until they become unstable and explode from the center. For a long laser pulse the boundary for this to occur is found to be 50(5/r)2 kW/cm2, where r is the drop radius in microns. Using these results a model that is spatially one-dimensional through the cloud is constructed for a distribution of drop sizes. Laser beam intensity as the light penetrates a cloud is calculated from Mie scattering and absorption cross sections for a beam diameter that is small in the sense that light scattered once is assumed lost. The internal temperature distribution of the drops is calculated and a phenomenological drop explosion model is given for drops that reach the unstable 305 °C spinodal temperature at their center. Energy and water mass content are conserved as the cloud background is modified in an average sense by drop evaporation or recondensation. Recondensation is treated in the diffusion regime according to the Kohler model, with vapor pressure over a drop modified by surface tension and dissolved nonwater content. Comparison with experimental data for a laboratory produced cloud is given and good agreement, particularly with respect to the predicted onset of drop explosion, is found. Results are also presented for hypothetical cloud conditions and laser intensities. The possibility of clearing a thin cloud with low fluence to the 3.8 μm is considered, as well as the passive evaporation of melted ice crystal clouds.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.349097
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Fluid model treatment of surface plasma structures (1992)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 4 (1992), S. 784-795 
    Details
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A fluid model is presented for the purpose of calculating numerically the structures of surface plasmas with neutrals returning from the surface, in collision-dominated parameter regimes. Limiting corrections to thermal conduction and viscous pressure are obtained through comparisons with previous Fokker–Planck transport calculations. The model includes removal by pumping, as well as by ionization, of some of the returning neutrals, and solutions are obtained for different relative strengths of pumping. Increasing velocities of plasma flow toward the surface and increasing plasma temperatures near the surface are seen with increased pumping. In the asymptotic region, far from the surface, agreement is found between these families of numerical model solutions and two classes of analytic solutions. Applications to other fundamental and applied problems are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.860233
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Collisional transport treatment of surface plasma structures (1989)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 1 (1989), S. 1911-1925 
    Details
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Calculations are shown of the structure of plasmas in equilibrium with solid surfaces that reemit incident plasma ions as relatively cold neutral gas. A numerical transport model that includes a Fokker–Planck treatment of ion–ion collisions obtains the distribution function for ions in a phase space of one spatial coordinate and two velocities. This is done self-consistently with an electrostatic potential, a Maxwell–Boltzmann description of electrons, and electron impact ionization of the reemited neutrals. Solutions are obtained from a higher temperature kinetic regime where Coulomb collisions are nearly negligible to a lower temperature regime where plasma behavior is approximately fluidlike. A result of these calculations is the resolution of an ambiguity posed by previous kinetic regime calculations that omitted ion–ion collisions and obtained a family of solutions for each set of physical parameters [Phys. Rev. Lett. 49, 650 (1982); Phys. Fluids B 1, 448 (1989)]. The physically correct solution for semi-infinite surface plasmas is shown to be the member of each family that maximizes the ion thermal conduction to the surface and the magnitude of a maximum in the electrostatic potential that is found in these and the previous calculations. Further results are in agreement at lower temperatures with solutions obtained from a fluid model and the identification of the correct boundary condition on normal flow velocity to be used in fluid models.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.858923
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Self-consistent growth rate of the Rayleigh–Taylor instability in an ablatively accelerating plasma (1985)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 28 (1985), S. 3676-3682 
    Details
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The linear stability of an ablating plasma is investigated as an eigenvalue problem by assuming the plasma to be at the stationary state. For various structures of the ablating plasma, the growth rate is found to be expressed well in the form γ=α(kg)1/2 −βkVa, where α=0.9, β(approximately-equal-to)3–4, and Va is the flow velocity across the ablation front, and is found to agree well with recent two-dimensional simulations in a classical transport regime. Short-wavelength lasers inducing enhanced mass ablation are suggested to be advantageous to stable implosion because of the ablative stabilization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.865099
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Stationary flow model of ablatively imploded spherical shells (1990)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 2 (1990), S. 353-370 
    Details
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The stationary flow model of spherical ablation is extended to shells, solutions with a density discontinuity at the critical surface, and charged-particle-beam-driven ablation. Parameter studies of the shell solutions show the relationship between shell aspect ratio, relative ablative mass removal or burnthrough, laser power, and shell material type. The discontinuous solutions are shown to occur when the critical surface and sonic surface coalesce. The relationship of these discontinuous solutions to particular physical situations is shown to be ambiguous in a way that must be resolved by microscopic transport calculations. Charged-particle-driven ablative implosion processes are shown to resemble laser-driven ablation. However, qualitatively different ablation processes occur in different regimes of the power and particle range of the incident beam. Procedures are described by which stationary solutions can be used to predict and interpret the results of experiments and numerical simulations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.859324
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Surface plasma structures in the kinetic regime (1989)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 1 (1989), S. 448-467 
    Details
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A numerical study is done of a plasma in contact with a solid surface that reemits some fraction of the incident plasma as neutral gas. The calculation uses a steady-state, kinetic treatment of the transport equations in one space dimension and one or two velocity dimensions to determine self-consistently the distribution functions of the interacting species and the electrostatic potential. The dominant phenomena are the ionization of the neutral gas and the acceleration of the resulting ions away from a potential maximum that is predicted to form in the ionization region. Other effects involved are a Debye sheath structure between the solid surface and the potential maximum, and collisional trapping and untrapping of electrons in the well represented by the potential maximum. Results are presented from a nondimensional model with a monatomic returning neutral species, and for diatomic molecular deuterium returning from the surface. For each set of physical parameters chosen, a one parameter family of solutions is obtained. A hypothesis is presented for the choice from this family of solutions that would be found experimentally.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.859160
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Observation of muons using the polar ice cap as a Cerenkov detector (1991)
    [s.l.] : Nature Publishing Group
    Nature 353 (1991), S. 331-333 
    Details
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] Neutrinos would be detected by the standard technique of observing the Cerenkov light emitted by upward-moving muons, produced by neutrinos interacting in or below the detector. At these high energies, the direction of the muon produced is within 1° of the direction of the parent neutrino, so ...
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1038/353331a0
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Honey bees choosing a home prefer previously occupied cavities (1985)
    Springer
    Insectes sociaux 32 (1985), S. 217-220 
    Details
    ISSN: 1420-9098
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Honigbienen (Apis mellifera) bevorzugen ehemals bewohnte Brutkästen bei der Wahl zwischen noch nie benutzten und vormals von Bienen bewohnten Brutkästen mit Wabe (p=0.032). Dieses Verhalten ist möglicherweise adaptiv in Bezug auf Energieersparnis, verglichen mit einer neuen Kolonie. Die Wahl eines vormals bewohnten Brutkästens könnte jedoch den einfachen Grund haben, daß bereits benutzte Brükästen mit Wabe für die Bienen auffälliger und leichter zu finden sind.
    Notizen: Summary Given a choice between nesting in boxes which had been previously occupied by bees, containing comb, and boxes never occupied, honey bees (Apis mellifera) show a significant (p=0.032) preference for the previously occupied cavities. This behavior may be adaptive in terms of energetic savings to a new colony, or cavities with comb may simply be more conspicous.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02224236
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Field evaluation of starter N and delayed inoculation ofLespedeza cuneata grown in minesoil (1988)
    Springer
    Plant and soil 109 (1988), S. 109-113 
    Details
    ISSN: 1573-5036
    Schlagwort(e): inoculation method ; nitrogen fixation ; reclamation ; Rhizobium ; sericea lespedeza ; surface mining
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A field study was conducted on freshly reclaimed surface-mined area to determine response of sericea lespedeza (Lespedeza cuneata [Dumont] G. Don.) to delayed rhizobial inoculation. Soybeans (Glycine max L.) were used as a control legume. Plots were inoculated with spray applications of rhizobial suspensions at seeding, cotyledon stage or second trifoliate leaf stage, or not inoculated. Starter N at 0, 10 or 20 kg ha−1 was applied preplant in a factorial arrangement with inoculation timings.G. max. was grown for 92 days andL. cuneata for 121 days. Starter N increased plant growth and total shoot N in both species. However, % shoot N was found to increase only inL. cuneata. Delaying inoculation had no significant effect upon total shoot N or % shoot N accumulation inL. cuneata. Inoculation ofG. max at planting produced greater plant growth and N accumulation than delayed inoculation treatments. Application of inoculum as a surface spray appeared to be an effective method for delayed inoculation as evidenced by nodule formation. Lack of increased plant growth, regardless of time of inoculation, suggests that delayed inoculation does not improve establishment and growth ofL. cuneata in minesoil.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02197587
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...