ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
Filter
  • SOLAR PHYSICS  (3)
  • Chemistry  (1)
  • FLUID MECHANICS AND HEAT TRANSFER  (1)
  • Modelling  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Modelling the response of terrestrial ecosystems to acidification and desiccation scenarios (1995)
    Springer
    Water, air & soil pollution 85 (1995), S. 1101-1106 
    Details
    ISSN: 1573-2932
    Keywords: Modelling ; Soil Acidification ; Vegetation Changes ; National Assessment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Changes in vegetation are often caused by changes in abiotic site factors, such as pH, nitrogen availability and soil moisture. It has been recognized that abiotic site factors are affected by atmospheric deposition and groundwater-table changes. In order to evaluate the effects of eutrophication, acidification and desiccation on site factors, the model SMART2 has been developed. For the Netherlands combinations of two acidification and two seepage scenarios (1990–2050) were evaluated with SMART2. The results are focused on pH, nitrogen availability and base saturation. Calculations were made for combinations of five vegetation structures on seven soil types and the five groundwater-table classes, using a 1 km2 grid. Results showed that deposition reductions lead to a relatively fast improvement of the site factors, increase in pH and base saturation and decrease in N availability. Whereas a reduction in groundwater abstractions of 25% has little or no effect on the pH and N availability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00477128
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Application of two-dimensional NMR to the structure determination of an unsymmetrical monosubstituted bisporphyrin (1993)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 31 (1993), S. 878-880 
    Details
    ISSN: 0749-1581
    Keywords: 1H NMR ; 13C NMR 2D NMR ; Chemical shift assignments ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The complete assignment of 1H and 13C data of an unsymmetrical monosubstitute bisporphyrin based on an extensive application of two-dimensional 1H—1H, 1H—13C and 13C-13C shift spectroscopy is described. The 1H—1H shift correlation through dipolar interaction (2D NOESY) was essential to prove the connection of the alkyl fragments and to distinguish protons spatially close but belonging to different units. The additive structural increments method allowed the assignment of the quatenary carbons of tolyl residues.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260310917
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    facet.materialart.
    Unknown
    On the identification of normal modes of oscillation from observations of the solar periphery (1984)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The decomposition of solar oscillations into their constituent normal modes requires a knowledge of both the spatial and temporal variation of the perturbation to the Sun's surface. The task is especially difficult when only limited spatial information is available. Observations of the limb darkening function, for example, are probably sensitive to too large a number of modes to permit most of the modes to be identified in a power spectrum of measurements at only a few points on the limb, unless the results are combined with other data. A procedure was considered by which the contributions from quite small groups of modes to spatially well resolved data obtained at any instant can be extracted from the remaining modes. Combining these results with frequency information then permits the modes to be identified, at least if their frequencies are low enough to ensure that modes of high degree do not contribute substantially to the signal.
    Keywords: SOLAR PHYSICS
    Type: NASA-CR-173667 , NAS 1.26:173667
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Nonlinear anelastic modal theory for solar convection (1983)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Solar envelope models are developed using single-mode anelastic equations as a description of turbulent convection which provide estimates for the variation with depth of the largest convective cellular flows, with horizontal sizes comparable to the total depth of the convection zone. These models can be used to describe compressible motions occurring over many density scale heights. Single-mode anelastic solutions are obtained for a solar envelope whose mean stratification is nearly adiabatic over most of its vertical extent because of the enthalpy flux explicitly carried by the big cell, while a subgrid scale representation of turbulent heat transport is incorporated into the treatment near the surface. It is shown that the single-mode equations allow two solutions for the same horizontal wavelength which are distinguished by the sense of the vertical velocity at the center of the three-dimensional cell. It is found that the upward directed flow experiences large pressure effects which can modify the density fluctuations so that the sense of the buoyancy force is changed, with buoyancy braking actually achieved near the top of the convection zone. It is suggested that such dynamical processes may explain why the amplitudes of flows related to the largest scales of convection are so weak in the solar atmosphere.
    Keywords: SOLAR PHYSICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Nonlinear modal analysis of penetrative convection (1982)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: It is pointed out that thermal convection in many astrophysical and geophysical settings occurs in an unstable layer bounded above and below by regions which are stably stratified. The convective motions may extend a substantial distance into the adjacent stable zones. If the motions have little direct effect upon the mean stratification of the stable zone, then they are usually referred to as convective overshooting. The primary objective of the present investigation is to study the dynamics of overshooting at very large Rayleigh numbers, mainly with stellar applications in mind. Numerically this is only feasible if severe simplifications are made in the description of what are likely to be turbulent motions. The approach employed in the investigation utilizes nonlinear modal equations in which the vertical and temporal structure of the convection is described accurately at the expense of the horizontal structure. A summary of the salient properties of penetrative convection is provided on the basis of the results of the conducted studies.
    Keywords: FLUID MECHANICS AND HEAT TRANSFER
    Type: Geophysical and Astrophysical Fluid Dynamics; 22; 1-2,; 1982
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    On the identification of normal modes of oscillation from observations of the solar periphery (1984)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The decomposition of solar oscillations into their constituent normal modes requires a knowledge of both the spatial and temporal variation of the perturbation to the sun's surface. The task can be especially difficult when only limited spatial information is available. Observations of the limb-darkening function, for example, are probably sensitive to too large a number of modes to permit most of the modes to be identified in a power spectrum of measurements at only a few points on the limb, unless the results are combined with other data. In this paper a procedure is considered by which the contributions from quite small groups of modes to spatially well resolved data obtained at any instant can be extracted from the remaining modes. Combining these results with frequency information then permits the modes to be identified, at least if their frequencies are low enough to ensure that modes of high degree do not contribute substantially to the signal.
    Keywords: SOLAR PHYSICS
    Type: Astronomy Express (ISSN 0265-5365); 1; 9-24
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...