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Nitrous oxide emissions from a wheat field in response to elevated carbon dioxide concentration and open-top chamber enclosure
1998
Pleijel, H. | Sild, J. | Danielsson, H. | Klemedtsson, L. (IVL, P.O. Box 470 86, SE-402 58 Goteborg (Sweden))
Evaluation of SO2 and NO2 concentration levels in vilnius (Lithuania) using passive diffusion samplers
1998
Perkauskas, D. | Mikelinskiene, A. (Institute of Physics, Savanoriu 231, 2028 Vilnius (Lithuania))
The influence of drought and natural rewetting on nitrogen dynamics in a coniferous ecosystem in Ireland
1998
Dise, N.B. | Matzner, E. | Forsius, M. (Department of Earth Sciences, The Open University, Milton Keynes, MK76AA (United Kingdom))
The Henry's Law Constant of Trichloroacetic Acid
1998
Bowden, Derek J. | Clegg, Simon L. | Brimblecombe, Peter
The Henry's law constant of trichloroacetic acid [K′H (mol kg⁻¹ atm⁻¹) for the equilibrium CCl₃COOH₍g₎ ⇌ CCl₃COOH₍ₐq₎] has been determined from measured partial pressures over aqueous solutions at 298.15 K and 308.15 K. Its value is given by: ln(K′H) = (11.21 ± 0.5) – 8.66 × 10³ (l/Tᵣ – l/T) where T (K) is temperature and Tᵣ is equal to 298.15 K, for an aqueous phase dissociation constant (Kₐ) of 0.55 mol kg⁻¹ determined from literature osmotic coefficient and electromotive force data. Accuracy is estimated to be 4–30% in the product K′HKₐ. Trichloroacetic acid is highly soluble and will partition strongly into aqueous atmospheric aerosols, and completely into fog and cloud water. Its occurrence and transport in the environment are therefore to be associated primarily with liquid phases.
Показать больше [+] Меньше [-]Comparison of soil thermal regimes in a deforested area with various grass cover in the Beskids Mts. [Czech Republic]
1998
Tuma, I. (Akademie Ved, Brno (Czech Republic). Ustav Ekologie Krajiny)
The studies of grass communities, which spread in deforested areas, also involved observations of soil thermal regimes. Three sites were chosen in order to determine differences in diurnal and seasonal variations of soil temperatures: (1) open site (barren) without plant cover, (2) site covered by a young, lower and thinner stand of Avenella flexuosa, and (3) old, dense stand of Calamagrostis villosa with a layer of plant litter on the soil surface. Soil temperatures were measured at the soil surface and in the soil depth of 5 and 10 cm. In summer months, the greatest differences in maximal temperatures recorded at the soil surface and at the 5, 10 cm depth between the bare site and the old stand of C. villosa represented 21.6, 15.9, 12.4 deg C, respectively. Soil temperatures measured in the bare plot in autumn months were lower than those in grass stands.
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