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981.
982.
Heidelore Fiedler Gerd Rippen Susanne Sievers Peter Friesel Birgit Gras Christoph Lau Thomas Reich Uwe Schacht Roland Schwörer Hansjörg F. Wesp Otto Hutzinger Fritz Vahrenholt 《Environmental Sciences Europe》1997,9(3):131-135
The sources and reservoirs of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) in the city of Hamburg, Germany, in the year 1992 were identified and quantified combining analytical data of PCDD/PCDF with statistical data on annual fluxes of materials and products. Fluxes and amounts of PCDD/PCDF were estimated for the environmental compartments water, air, and soil. Dioxin emissions originating from industrial, commercial or private activities were also calculated. Together with the analysis of the specific regional nutrition data, the human exposurevia the various pathways could be determined. It could be shown that the total PCDD/PCDF intake of individuals in Hamburg was about the same as the national average. High annual fluxes of PCDD/PCDF connected with the trade of industrial products and the waste management and disposal: system in Hamburg obviously had no influence on the human intake of PCDD/PCDF. 相似文献
983.
984.
Elizabeth Otto 《The Environmentalist》2012,32(3):318-325
While modern architecture and design have often been seen as harsh and impersonal, this essay reassesses this association through a closer look at the influence of mysticism and the occult on the Bauhaus, an interwar German reform movement and school for art, craft, design, and architecture. Even as they developed their famous streamlined designs, members of the school also produced images based on alternative religions, spiritism, and other experimental and occult practices. Such images participated in a broader context of research into the otherworldly and a rediscovery of nature and the environment. Reintegrating this other history into what we know of the Bauhaus allows us to understand modernism anew, not as cold and soulless but as part of larger attempts to perceive and shape a new world that was quickly unfolding around its subjects. 相似文献
985.
986.
Andrea M. Hofmaier Siegfried M. G. Schwirzer Friedrich J. Wiebel Karl-Werner Schramm Martin Wegenke Antonius A. F. Kettrup 《Environmental Sciences Europe》1999,11(1):2-8
Polychlorinated aromatic hydrocarbons (HAH) like 2,3,7,8-tetrachloro-p-dioxin (TCDD) elicit a multitude of toxic and biological effects. A common trait of these substances is their affinity for a cytosolic receptor protein and the subsequent induction of the synthesis of several gene products, including cytochrome P450 1A1 (CYP 1A1). In this publication we present a bioassay to determine the induction of CYP 1A1 as a sum parameter for the total toxic potential of critical halogenated compounds in complex environmental matrices. In order to eliminate compounds like polycyclic aromatic hydrocarbons (PAH) and naturally occurring substances which might interfere with the bioassay we developed a simple cleanup procedure. TEQ values derived from bioassay are in good agreement with those obtained from chemical analysis. This bioassay in combination with the simplified “single column” clean up represents a cost and time effective alternative to chemical analysis for the screening of large numbers of environmental matrices. 相似文献
987.
988.
Hilmar Möhlmann Anja Hansen Michael Flake Otto Richter 《Environmental Sciences Europe》2000,12(5):294-305
When discussing strategies for realising an environmental friendly agricultural production, there are methods for quantifying environmental effects which do not originate in agricultural contexts. For instance, the methodology of Life Cycle Assessment is mainly developed from analyses of industrial production lines and products. Substance flow analyses in agriculture contain a complete analysis of agriculturally caused substance and energy flows, to which certain environmental effects are assigned, and also an assessment of these effects. For the provision of production means, balancing agricultural production procedures includes the extraction of energy sources and mineral resources from their reservoirs. The growth phase of the crops regarded (cereals, sugar beet, rape) is described depending on the nutrients nitrogen, phophor, potassium and calcium. The nitrogen flux within the system plant-soil-atmosphere is recorded referring to its temporal dynamic. In the framework of this study, selected environmental effects of agricultural production procedures of winter wheat are calculated regarding different conditions of locations and are supplemented by declining scenario simulations. Essential features of the structure of the substance flow net, which is implemented for the calculation and which can be used completely or as for single modules for further studies, are explained. Basing on selected categories of effectiveness, ecological optimisation potentials of varying agricultural provision of production means and procedures are estimated within the whole context of provision. Thereby, the effects of a reduced employment of fertilisers, of a change as for the kind of fertiliser and of the region of origin of the N-fertiliser, as well as variations concerning mechanical work in the fields are outlined for the cultivation of winter wheat. 相似文献
989.
Quantitative analysis of environmental factors in differential weighing of blank Teflon filters 总被引:1,自引:0,他引:1
Hänninen OO Koistinen KJ Kousa A Keski-Karhu J Jantunen MJ 《Journal of the Air & Waste Management Association (1995)》2002,52(2):134-139
Mass differences less than 100 microg must be correctly measured in gravimetric analysis of particles collected on filters. Even small variations in mass measurement may contribute significant errors to calculated concentrations. In addition to the collected particles, a number of other factors affect the observed mass difference between the measurements before and after sampling. The most often controlled of these factors are static charge, temperature, and humidity. Using 951 laboratory blank filter weights, we have statistically analyzed these and other factors that affect the observed filter weight. Some of these are controllable or correctable; others are not and enter into the final results as errors. The standard deviation of differential blank filter weighing after applying all corrections was 2.7 microg. The most important correctable factors are air buoyancy variation and filter storage time. When weighing blank Teflon filters at relative humidity < 50%, these are an order of magnitude more important than weighing-room humidity. Using field blank filters in each weighing batch could control these three factors but also doubles the errors caused by balance random variation and filter handling contamination, because four weighing measurements and the handling of two filters are needed to obtain one corrected differential mass result. 相似文献
990.
Studies on the effects of various salinities on the uptake and catabolism of glucose in Vibrio marinus MP-1 revealed several significant shifts in total uptake and respiration as the cells were subjected to increasingly greater concentrations of NaCl. As the salinity increased from 0.30 to 1.0 M NaCl, there was a decrease in the C6/C1 (CO2) ratio. The resulting patterns suggests that the relative participation of the hexose monophosphate pathway in glucose catabolism was altered. This pathway is apparently shut down in the region of the minimum-growth salinity, and may be related to growth limitation at rower salinities. The shift in C6/C1 ratio was not affected by changing the incubation temperature, nor was it dependent specifically on the presence of Na+ or Cl-. As the salinity increased from 0.15 to 0.30 M NaCl, there was a shift in the total uptake patterns which suggests the formation and loss of metabolic by-products derived from the first, second, sixth, and presumably fifth carbons of glucose.This paper was taken in part from a dissertation by the senior author, submitted in partial fulfillment of the requirement for the Ph.D. degree, Oregon State University, Corvallis. Published as technical paper No. 3647, Oregon Agricultural Experiment Station. 相似文献