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91.
On June 18, 19, and 20, 1970, two aircraft, a rawinsonde, two pibal stations, and four ground stations provided simultaneous samples of total oxidant, temperature, and winds up to 8000 ft in an area extending from Santa Monica, Calif., east to Redlands and north across the San Bernardino Mountains. It was shown that photochemical oxidant formed in the marine layer is vented up the slopes and over the crest of the San Bernardino Mountains during the day. Layers of high oxidant concentrations were detected above the inversion base, suggesting that some pollution is vented up the slopes and subsequently advected back to the south. The diurnal changes in the temperature inversion also contribute to the high concentration found above the inversion base. These processes result in multi-layers of pollution. The study suggests that oxidant air pollution is transported up to 80 mi to forested mountains, where severe damage to conifer species has been documented.  相似文献   
92.
Oxyfuel combustion is a promising technology that may greatly facilitate carbon capture and sequestration by increasing the relative CO2 content of the combustion emission stream. However, the potential effect of enhanced oxygen combustion conditions on emissions of criteria and hazardous air pollutants (e.g., acid gases, particulates, metals and organics) is not well studied. It is possible that combustion under oxyfuel conditions could produce emissions posing different risks than those currently being managed by the power industry (e.g., by changing the valence state of metals). The data available for addressing these concerns are quite limited and are typically derived from laboratory-scale or pilot-scale tests. A review of the available data does suggest that oxyfuel combustion may decrease the air emissions of some pollutants (e.g., SO2, NOx, particulates) whereas data for other pollutants are too limited to draw any conclusions. The oxy-combustion systems that have been proposed to date do not have a conventional “stack” and combustion flue gas is treated in such a way that solid or liquid waste streams are the major outputs. Use of this technology will therefore shift emissions from air to solid or liquid waste streams, but the risk management implications of this potential change have yet to be assessed. Truly useful studies of the potential effects of oxyfuel combustion on power plant emissions will require construction of integrated systems containing a combustion system coupled to a CO2 processing unit. Sampling and analysis to assess potential emission effects should be an essential part of integrated system tests.

Implications: Oxyfuel combustion may facilitate carbon capture and sequestration by increasing the relative CO2 content of the combustion emission stream. However, the potential effect of enhanced oxygen combustion conditions on emissions of criteria and hazardous air pollutants has not been well studied. Combustion under oxyfuel conditions could produce emissions posing different risks than those currently being managed by the power industry. Therefore, before moving further with oxyfuel combustion as a new technology, it is appropriate to summarize the current understanding of potential emissions risk and to identify data gaps as priorities for future research.  相似文献   
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The chemical and physical properties of raw biooils prevent their direct use in combustion engines. We processed raw pyrolytic biooil derived from chicken manure to yield a colorless refined biooil with diesel qualities. Chemical characterization of the refined biooil involved elemental and several spectroscopic analyses. The physical measurements employed were viscosity, density and heat of combustion. The elemental composition (% wt/wt) of the refined biooil was 82.7 % C, 15.3 % H, 0.2 % N and 1.8 % O, no S. Its viscosity was 0.006 Pa.s and a heat of combustion of 43 MJ kg?1. The refined biooil fraction contains n-alkanes, ranging from n-C14 to n-C27, alkenes varying from C10:1 to C22:1, and long-chain alcohols. The refined biooil makes a good diesel fuel due to its chemical and physical properties.  相似文献   
95.
Slices from the hepatopancreas of various oceanic curstaceans incorporated radioactivity into wax esters from 14C glucose and 14C aspartic acid to a lesser extent and from 14C palmitic acid to a much greater extent. Radioactivity was incorporated from 14C palmitic acid into both fatty acid and fatty alcohol moieties of wax esters, the percentage of total radioactivity present in alcohol moieties being greater in deep-living than in shallow-living species. Cell-free preparations from the hepatopancreas but not from muscle, supplemented with ATP and reduced pyridine nucleotides, incorporated radioactivity from 1-14C palmitoyl Coenzyme A into both fatty alcohol and fatty acid moieties of wax esters. Incorporation into fatty alcohol was NADPH- rather than NADH-specific. Preparations from deep-living species had a greater percentage of total radioactivity in the fatty alcohol moieties of wax esters than preparations from shallow-living species. We conclude that the level of wax esters in a given species is correlated with the rate at which the species biosynthesises these lipids de novo; deep-living species have higher rates of wax ester biosynthesis and higher levels of wax esters than shallow-living species. The results support the thesis that wax esters in oceanic crustaceans are derived largely from the animals' internal biosynthetic activities, presumably in response to particular biochemical and/or physiological requirements, rather than from their diets.  相似文献   
96.
The FloodProBE project started as a FP7 research project in November 2009.Floods, together with wind related storms, are considered the major natural hazard in the EU in terms of risk to people and assets. In order to adapt urban areas (in river and coastal zones) to prevent flooding or to be better prepared for floods, decision makers need to determine how to upgrade flood defences and increasing flood resilience of protected buildings and critical infrastructure (power supplies, communications, water, transport, etc.) and assess the expected risk reduction from these measures.The aim of the FloodProBE-project is to improve knowledge on flood resilience and flood protection performance for balancing investments in flood risk management in urban areas. To this end, technologies, methods and tools for assessment purposes and for the adaptation of new and existing buildings and critical infrastructure are developed, tested and disseminated.Three priority areas are addressed by FloodProBE. These are: (i) vulnerability of critical infrastructure and high-density value assets including direct and indirect damage, (ii) the assessment and reliability of urban flood defences including the use of geophysical methods and remote sensing techniques and (iii) concepts and technologies for upgrading weak links in flood defences as well as construction technologies for flood proofing buildings and infrastructure networks to increase the flood resilience of the urban system.The primary impact of FloodProBE in advancing knowledge in these areas is an increase in the cost-effectiveness (i.e. performance) of new and existing flood protection structures and flood resilience measures.  相似文献   
97.
222Rn and 220Rn in geothermal steam at Wairakei, NZ, range from 11 to 19, 500 Bq kg-1, and 25 to 16, 700 Bq kg-1, respectively, but do not cause toxic concentrations in air. The wide ranges are mainly due to differences in different physical conditions underground (e.g. thin silica diffusion barriers), not geochemical differences. Groundwater Rn from outside the area probably plays only a minor role. 210Po was found present in non-toxic levels in the steam. Historical records showed little change in Rn concentration over several decades, therefore potentially hazardous concentrations might be predicted from early exploration. 220Rn concentrations at Wairakei should decrease as the field becomes steam-dominated. Rock surfaces were variably leached or enriched with U, Th, Ra and 210Pb, providing a possible model for deposition in cooler regions near the field. Estimates of 222Rn permeability ranged from 2 to 77% of the maximum possible, with a median of 13%.  相似文献   
98.
Whole animal concentrations of Pb, Zn and Cd were measured in herbivorous (1 snail species; 1 dipteran larva species), herbivorous + detritivorous (2 slug species), detritivorous (3 woodlouse species; 3 earthworm species), and carnivorous (1 carabid beetle species; 1 lithobiid centipede species) terrestrial macroinvertebrates collected at a disused Pb/Zn mine site. No evidence was found for an accretion of any metal during transference from herbivores to carnivores; the highest metal concentrations were, in fact, generally found in detritivores. The lack of metal bio-amplification during food chain transference is probably due to the sequestration of metals (notably Pb and Zn) in insoluble inorganic-rich granules within certain target organs and cells.

Earthworms and woodlice, respectively, showed major differences in metal concentrations. These differences between closely related species frequently exceeded differences between unrelated species occupying different trophic levels, and may be attributable to a combination of ill-defined ecological and physiological differences that ensure habitat and resource partitioning.  相似文献   
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