137Cs in the fungal compartment of Swedish forest soils

The (137)Cs activities in soil profiles and in the mycelia of four ectomycorrhizal fungi were studied in a Swedish forest in an attempt to understand the mechanisms governing the transfer and retention of (137)Cs in forest soil. The biomass of four species of fungi was determined and estimated to be 16 g m(-2) in a peat soil and 47-189 g m(-2) in non-peat soil to the depth of 10 cm. The vertical distribution was rather homogeneous for two species (Tylospora spp. and Piloderma fallax) and very superficial for Hydnellum peckii. Most of the (137)Cs activity in mycelium of non-peat soils was found in the upper 5 cm. Transfer factors were quite high even for those species producing resupinate sporocarps. In the peat soil only approximately 0.3% of the total (137)Cs inventory in soil was found in the fungal mycelium. The corresponding values for non-peat soil were 1.3, 1.8 and 1.9%.     

The gas flux distribution in the XHV chamber of the vacuum primary standard developed by PTB

The ultimate pressure in the XHV calibration chamber of the PTB primary standard CE3, whose operation is based on the continuous expansion of gas, has been reduced by the use of a relatively large orifice area. Thus, the gas density and flux distributions cannot be taken as uniform in the calibration chamber. To eliminate this drawback we examined the gas flux distribution by Direct Simulation using the Monte Carlo method. This paper describes the gas flux distribution over the chamber walls, which was simulated, recorded and related to the idealized conditions. This allows determining the gauge position correction factor K_gi for each of the gauge ports. Using these factors, it is possible to eliminate the systematic deviation of the gas flow parameters from those under the idealized Maxwellian conditions and to improve the uncertainty budget.     

Status of coal gasification processes

The current status of a number of processes which have been or are being developed to produce high-Btu, medium-Btu, and low-Btu gas from coal is given.     

Die Berechnung der Temperaturverteilung und des übertragenen Wärmestroms bei Rohren mit Rechteckrippen mittels eines Differenzenverfahrens

Zusammenfassung Bei der Berechnung des von einem Rippenrohr übertragenen W?rmestroms wird meistens mit einem Rippenwirkungsgrad operiert, der die ver?nderliche Temperaturdifferenz zwischen Rippenoberfl?che und Umgebungsmedium berücksichtigt. In dieser Arbeit wird ein anderer Weg beschritten, und zwar wird versucht, die W?rmedurchgangszahl eines Rippenrohrs auf die eines Glattrohrs zurückzführen, um so eine leichte Bestimmung des zu übertragenden W?rmestroms zu erm?glichen. Dazu ist zun?chst die Kenntnis der Temperaturverteilung im Rippenrohr notwendig. Zwar werden in verschiedenen Arbeiten [1 bis 8] Verfahren zur L?sung dieses Problems angegeben, jedoch werden oft sehr weitgehende vereinfachungen vorgenommen bzw. L?sungen durch komplizierte Ans?tze gesucht. Deshalb wird hier ein Differenzenverfahren beschrieben, das die Berechnung der Temperaturverteilung und des W?rmestroms auf einfache Weise und ohne viele der sonst üblichen N?herungen gestattet. VDI     

Average variability of the radiation reflected by vegetated surfaces due to differing irradiations

The average variability of the reflected radiation field due to differing distributions of the irradiation in case of a savannah was given in a previous paper. In this paper, equivalent results are given for three more surfaces: bog, pasture land, and coniferous forest. Because the results are rather similar, mean values for vegetated surfaces can be derived. They indicate a change of the reflected radiance by $\text{± 1\%}$ per degree change of the solar zenith angle and per 10% change of the optical depth of the atmosphere.     

Primary processes of the thermal degradation of HET acid containing unsaturated polyester cured with styrene

The primary processes of thermal degradation of 1,4,5,6,7,7-hexachloro-5-norbornene-2,3-dicarboxylic (HET) group containing unsturated polyesters cured with styrene were investigated. DTA traces in nitrogen atmosphere showed a much more pronounced endothermic reaction as the chlorine content in the unsaturated polyester resin decreased. This could be associated to the unzipping of the polystyrene units which is interfered by hexachlorocyclopentadiene ejected during degradation. Actually the styrene formation is prevented in a certain range of temperature due to the interaction with hexachlorocyclopentadiene. This was proved by on-line mass spectroscopic analysis of the degrading polymer.     

MUNICIPAL USE OF CITIZEN SURVEYS

The use of citizen surveys by cities in the United States has been increasing in the past decade. In 1982, almost 62 percent of 274 cities with over 50,000 population reported using some form of survey in the past 10 years. Survey data are used to supplement other forms of internal data and external political feedback. Two problems recognized by city officials in using surveys are: (1) difficulties in interpreting data; and (2) asking questions on which the citizen is uninformed. Nevertheless, survey data provide better information about citizen opinions than is available from any other source.     

Solid-state and multidimensional solution-state NMR of solid phase extracted and ultrafiltered riverine dissolved organic matter

In this study we used multidimensional solution-state NMR to elucidate the differences in the chemical composition of solid phase extracted and ultrafiltered DOM isolates. DOM was isolated from water sampled from an oligotrophic river, the River Tagliamento (Italy). The recovery of total DOM was up to 42% with both isolation techniques. In addition to 1- and 2-D solution-state NMR, we also applied 1-D solid-state 13C NMR spectroscopy for DOM characterization. 13C NMR spectroscopy only produced broad overlapping resonances, thus allowing a bulk characterization of DOM composition. However, it demonstrated that the bulk chemical composition of the two DOM fractions exhibited minor spatial-temporal changes. The 2-D experiments (TOCSY, HMQC) showed that the solid phase extracted hydrophobic DOM contained predominantly aliphatic esters, ethers, and hydroxyl groups, whereas the ultrafiltered DOM was comprised partially of peptides/protein, with further evidence for a small amount of aliphatic/fatty acid material. Sugars were present in both DOM fractions. The results show the two isolation techniques selected for different suites of compounds within the bulk DOM pool.