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331.
Sensory irritations and pulmonary effects in human volunteers following short-term exposure to pinewood emissions 总被引:1,自引:0,他引:1
Richard Gminski Rainer Marutzky Sebastian Kevekordes Frank Fuhrmann Werner Bürger Dieter Hauschke Winfried Ebner Volker Mersch-Sundermann 《Journal of Wood Science》2011,57(5):436-445
Pinewood (Pinus ssp.) is widely used for furniture and building purposes. However, despite its widespread use, information on possible human
sensory irritations and pulmonary effects caused by exposure to volatile organic compounds (VOC) emitted from pinewood is
sparse. For this purpose, (1) sensory irritation of eyes, nose and throat, (2) lung function parameters (FVC, FEV1), (3) exhaled nitrogen oxide (NO) concentration, (4) eye blink frequency, and (5) sensory evaluation (using the SD method)
were investigated before, after, and partly during exposure of human volunteers to emissions from pinewood panels. Fifteen
healthy nonsmokers were exposed for 2 h under controlled conditions to VOCs emitted from pinewood panels in a 48 m3 test chamber. VOC concentrations were about 5 mg/ m3 (loading rate, 1 m2/m3), 8 mg/m3 (loading rate, 2 m2/m3), and 13 mg/m3 (loading rate, 3 m2/m3), respectively. Terpene and aldehyde exposure concentrations ranged from about 3.50 ± 0.51 mg/m3 and 0.07 ± 0.008 mg/m3, 5.00 ± 0.95 mg/ m3, and 0.20 ± 0.02 mg/m3 or 9.51 ± 1.10 mg/m3 and 0.21 ± 0.04 mg/m3 for loading rates of 1, 2, and 3 m2/m3, respectively. The emissions consisted predominantly of α-pinene and δ3-carene. No concentration-dependent effects before or after exposure to the emissions were measured with respect to sensory
irritation, pulmonary function, exhaled NO, and eye blink frequency. Only the odor of the emissions was perceived by the study
subjects, rated as being closer to “pleasant” than to “unpleasant.” In conclusion, the results of our study suggest that short-term
exposure to high VOC concentrations, even up to 13 mg/m3, released from pinewood does not elicit sensory irritation or pulmonary effects in healthy humans under controlled conditions. 相似文献
332.
333.
Baggenstoss J Poisson L Kaegi R Perren R Escher F 《Journal of agricultural and food chemistry》2008,56(14):5836-5846
The impact of time-temperature combinations of roasting processes on the kinetics of aroma formation in coffee was investigated. The development of 16 aroma compounds and the physical properties of coffee beans was followed in a commercial horizontal drum roasting process and in laboratory scale fluidizing-bed roasting processes at high temperature-short time and low temperature-long time conditions. All trials were run to an equal roast end point as defined by the lightness of coffee beans. In addition, the effect of excessive roasting on aroma composition was studied. Compared to low temperature-long time roasting, high temperature-short time roasting resulted in considerable differences in the physical properties and kinetics of aroma formation. Excessive roasting generally led to decreasing or stable amounts of volatile substances, except for hexanal, pyridine, and dimethyl trisulfide, whose concentrations continued to increase during over-roasting. When the drum roaster and the fluidizing bed roaster were operated in the so-called temperature profile mode, that is, along the identical development of coffee bean temperature over roasting time, the kinetics of aroma generation were similar in both processes. 相似文献
334.
Estimating soil water and air capacity from physical properties in anthropogenic substrate horizons Up to now there is no appropriate method available to estimate soil water and air capacity in anthropogenic substrate horizons. The “Bodenkundliche Kartieranleitung” (German soil classification key) was developed for natural soils and can be applied to anthropogenic soils only with limited validity. For developing an estimation system, a data base of 197 anthropogenic substrate horizons was established, consisting of soil characterizations gained from own investigations and from literature. By using multiple linear regression analysis, estimating models were developed to calculate soil water and air capacity derived from values of soil bulk density, texture, amount of skeleton and content of organic matter. Though every regression model proved to be highly significant, some gained coefficients of determination less than 50%. Absolute mean standard errors of estimate vary between 3.4 and 9.1 Vol%. 相似文献
335.
Soil air permeability is an important parameter which governs the aeration in soils that significantly promotes the root growth of field and grassland species and leads, in turn, to higher levels of evapotranspiration. The German Landfill Directive (2009) requires a rigid or a minimal shrinking capping system that ensures a high evapotranspiration rate to decrease the infiltration rate through the underlying waste body and therefore the leachate generation. This research is focussed on the questions if compacted glacial till can ensure the required rigidity and if and how air permeability is affected by soil compaction. The objective was to compare air‐filled porosity and the direction‐dependency of air permeability of a capping soil when assuming rigid and non‐rigid conditions considering a shrinkage factor. Intact soil cores were sampled in vertical and horizontal direction in 0.05, 0.2, 0.5, and 0.8 m depths at two profiles of a mineral landfill capping system at the Rastorf landfill in Northern Germany. Desiccation experiments were carried out on differently‐compacted soils and soil shrinkage was measured with a 3D laser triangulation device, while the air permeability was estimated with an air flow meter. The results indicate that the “engineered” soil structure which was predominately platy due to a layered installation, led to a more anisotropic behaviour and therefore to higher air permeability in horizontal than in vertical direction. The compacted installation of the capping system seems to be effective and observes the statutory required more‐or‐less rigid system, otherwise, soil shrinkage would lead to vertical cracks and a more pronounced isotropic behaviour. 相似文献
336.
337.
Reiner Pospischil Klaus Szomm Michael Londershausen Iris Schrder Andreas Turberg Rainer Fuchs 《Pest management science》1996,48(4):333-341
Populations of the housefly Musca domestica isolated from farms in different German districts with strong resistance problems were compared to laboratory strains with varying resistance spectra. Resistance against pyrethroids, organophosphates and carbamates was tested using impregnated filter papers, and by topical application using a susceptible housefly strain (origin WHO) for comparison. The multi-resistant fly strains tested had a strong resistance against these insecticide groups, ranging from 37- to >10000-fold for organophosphates and 150- to >6600-fold for pyrethroids. The constituent enantiomer pairs of the α-cyano-pyrethroid cyfluthrin were tested, as was beta-cyfluthrin. With respect to multi-resistant fly strains, the isomers II and IV had the best activity, with LD50 values of 0·012 and 0·014 μg per fly, respectively. In addition, different groups of insect growth regulators (juvenile hormone analogues, chitin synthesis inhibitors and one triazine derivative) were tested in a special larvicidal test. The chitin synthesis inhibitors were quite effective against multi-resistant M. domestica strains except for one strain with strong resistance against chitin synthesis inhibitors, developed after extensive treatments with benzoylphenylureas for several years. The fly strains tested were not resistant against cyromazine. Additionally, the insecticides were combined with the synergists piperonyl butoxide, tributylphosphorotrithioate (DEF) and Cibacron blue and tested against the fly strain with the strongest resistance spectrum (‘Grimm’) in comparison to the susceptible strain (‘WHO-N’). Piperonyl butoxide had the greatest effect on the efficacy of cyfluthrin followed by Cibacron blue and DEF. In a parallel investigation with susceptible and resistant house fly strains, different enzyme activities related with resistance mechanisms were tested, e.g. glutathione S-transferase (3·5-fold) and mixed-function oxidase (2·3-fold). Implications of these results for management of insecticide resistance in M. domestica are discussed. 相似文献
338.
The interlaboratory variations in the fumigation extraction method and the analytical procedures for measuring C and N in the soil microbial biomass were tested with one soil sample, and two soil extracts (non-fumigated and fumigated) sent to 25 different laboratories. Four groups of analytical procedures for organic C, i.e. (1) oven oxidation/ IR detection, (2) UV-persulfate oxidation/lR detection, (3) UV-persulfate oxidation/colorimetric detection and (4) dichromate oxidation/ titration, and three groups for total N, i.e. (1) Kjedahl reduction to NH4+, (2) UV-persulfate and (3) persulfate-borate oxidation to NO3? were used by the different laboratories. The coefficient of variation for C and N measurements between different laboratories and analytical procedures varied between 15 and 34% in non-fumigated samples, between 13 and 20% in fumigated samples, and between 12 and 24% in the differences Ec and EN. The average coefficients of variation between the replicate measurements within one laboratory were much smaller, i.e. they varied between 3.0 and 9.2% in non-fumigated samples, between 2.4 and 5.5% in fumigated samples, and between 4.5 and 12.8% in the differences Ec and En. Extraction and fumigation were not the major source of the variations observed. They were mainly a result of differences in the analytical procedures used to measure the low concentrations of C and N in the extracts. However, all of these analytical procedures should be able to measure correct values if they are properly calibrated and performed. 相似文献
339.
340.
Size matters: How single-species management can contribute to ecosystem-based fisheries management 总被引:1,自引:0,他引:1
Rainer Froese Amanda Stern-Pirlot Henning Winker Didier Gascuel 《Fisheries Research》2008,92(2-3):231-241
In this study we show how substantial gains towards the goals of ecosystem-based fisheries management (EBFM) can be achieved by different single-species management. We show that fishing has much less impact on stocks if fish are caught after they have reached the size (Lopt) where growth rate and cohort biomass are maximum. To demonstrate our point we compare the impact of three fishing scenarios on 9 stocks from the North Sea and the Baltic. Scenario (1) is the current fishing regime, scenario (2) is a new management regime proposed by the European Commission, aiming for maximum sustainable yield obtained from all stocks, and scenario (3) is set so that it achieves the same yield as scenario (2), albeit with fishing on sizes beyond Lopt. Results show that scenarios (2) and (3) are significant improvements compared to current fishing practice. However, scenario (3) consistently shows least impact on the stocks, with seven-fold higher biomass of demersal fishes and an age structure similar to an unfished stock. This allows juveniles and adults to better fulfil their ecological roles, a major step towards the goals of ecosystem-based fisheries management. We give examples where scenario (3) is practiced in successful fisheries. We present a new interpretation of the relative yield per recruit isopleth diagram with indication of a new target area for fisheries operating within the context of EBFM. We present a new expression of the relative biomass per recruit isopleth diagram, which supports our analysis. We conclude that size matters for precautionary and ecosystem-based fisheries management and present a list of additional advantages associated with fishing at Lopt. 相似文献