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
  • 1
    Electronic Resource
    Electronic Resource
    Nitrogen dynamics in a eutrophic lake sediment (1988)
    Springer
    Hydrobiologia 159 (1988), S. 177-188 
    Details
    ISSN: 1573-5117
    Keywords: eutrophic lake water ; nitrogen flux ; anaerobic sediment ; simulation model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Nitrogen flux from sediment of a shallow lake and subsequent utilization by water hyacinth (Eichhornia crassipes [Mart] Solms) present in the water column were evaluated using an outdoor microcosm sediment-water column. Sediment N was enriched with 15N to quantitatively determine the movement of NH4-N from the sediment to the overlying water column. During the first 30 days. 48% of the total N uptake by water hyacinth was derived from sediment 15NH4-N. This had decreased to 14% after 183 days. Mass balance of N indicates that about 25% sediment NH4-N was released into the overlying water, but only 17% was assimilated by water hyacinth. NH4-N levels in the water column were very low, with very little or no concentration gradients. NH4-N levels in the interstitial water of the sediment were in the range of 30–35 mg L−1 for the lower depths (〉 35 cm), while in the surface 5 cm of depth NH4-N levels decreased to 3.2 mg L−1. Simulated results also showed similar trends for the interstitial NH4-N concentration of the sediment. The overall estimated NH4-N flux from the sediment to the overlying water was 4.8 µg cm−2 day−1, and the soluble organic N flux was 5.8 µg N cm−2 day−1. Total N flux was 10.6 µg N cm−2 day−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00014726
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Energetics of hydrophobic solute retention on reversed-phase chromatography supports: Effects of solute, solvent, and sorbent properties (1992)
    Springer
    Chromatographia 33 (1992), S. 403-412 
    Details
    ISSN: 1612-1112
    Keywords: Column liquid chromatography ; Hydrophobic solutes ; Enthalpy and entropy changes ; Eluent composition effects ; Surface area effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Chromatographic retention of several nonpolar solutes by three reversed-phase liquid chromatography (RPLC) supports was measured at several temperatures with binary mixtures of methanol/water and acetonitrile/water as the mobile phase. These data were used to estimate enthalpy and entropy changes (ΔH sorp o and ΔS sorp o ) associated with solute retention. The dependence of these two thermodynamic parameters on organic solvent content (θ) in the mobile phase, solute hydrophobic surface area (HSA), and bonded n-alkyl chain length (Nc) of the RPLC support was evaluated. The differences noted in the two solvent mixtures were attributed to: (1) the manner in which solvent surface tension changes with increasing θ, and (2) the differences in the interaction of methanol and acetonitrile with the bonded alkyl chains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02262319
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...