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111.
Environmental Science and Pollution Research - Water contamination is a common problem, especially considering dyes and drugs disposal. A possible and effective treatment method to remove these...  相似文献   
112.
    
A mathematical programming model was formulated to determine the optimal atmospheric emission control alternatives for the pulp industry. Generalized multi-path diagrams were developed showing the emission sources, the unit emissions from these sources, and the available control alternatives. Using these diagrams it is possible to depict a given mill by selecting the appropriate flow paths. The formulation of the optimization model as a mixed integer-linear programming problem is presented. Then the results of a sample analysis using the model are described. A procedure is presented for determining the net cost of particulate emission standards as well as a sensitivity analysis of the impact on the optimal solution of varying the value of recovered chemicals.  相似文献   
113.
/ A methodology to estimate the number of pump-out facilities and dump stations required to service human waste disposal for recreational power boating activities in Pennsylvania during the 1994 boating season is described. Study results suggest that a total of 39 additional pump-out stations and 13 dump stations may be required on seven major waterbodies: The Three Rivers Area, Lake Erie/Presque Isle Bay, Raystown Lake, the Susquehanna River, the Delaware River, Lake Wallenpaupack, and the Kinzua Reservoir. Suggestions for improving the methodology are provided. KEY WORDS: Human waste; Recreation; Power boating; Waste facilities; Waste disposal; Pennsylvania  相似文献   
114.
Temperature was found to have a dramatic effect on secondary organic aerosol formation from two ozonolysis systems, cyclohexene and α-pinene. Isothermal experiments were conducted for both systems where the lowest temperature, 278 K, formed approximately 2.5–3 times and 5–6 times the SOA formed at 300 K and 318 K, respectively. Changing the cyclohexene system temperature to a different isothermal experimental set point after completion of SOA formation did not lead to sufficient condensation/evaporation to reproduce the SOA formation at other temperature set points. When the system temperature was cycled between two set points at the end of an experiment, the α-pinene system showed reversibility between the initial temperature 318 K and 300 K. For temperature cycles between the initial temperature of 300 K–318 K, an irreversible loss of mass is observed after the first heating cycle with reversibility observed between subsequent temperature cycles. The SOA formed at 278 K was reversible over a 22 K range but was unable to evaporate sufficiently to match the SOA mass formed at 300 K. Hygroscopicity measurements, taken after the completion of SOA formation, indicate that hygroscopicity of the aerosol is also a function of temperature and that the aerosol does not continue to be oxidized after initial growth is complete. The differing hygroscopicity of the semi-volatile component of the aerosol is evident during system temperature changes after completion of the experiment.  相似文献   
115.
116.
The seasonal cycle of sexual reproduction in the corallimorpharian sea anemone Corynactis californica (Calgren, 1936) was studied for 18 consecutive months (July 1987 to December 1988) at a subtidal area in the Hopkins Marine Refuge (HMLR), Pacific Grove, Monterey Bay, California. Samples were collected, histological sections were prepared, and gametocytes were examined and measured. C. californica grows by multiple or longitudianl fission to form single-sexed clones of various color and size. In female clones, oocytes appeared in late August and early September; they increased in size steadily in fall, and peaked in early December in both years. In male clones, spermatogenesis was synchronous with the female oogenic cycle, and motile sperm were observed in most testes in early December. Spawned gonads were found in both sexes from late November to early December. Spawning was induced in the laboratory in early December, and external fertilization was followed by development of free-swimming larvae. Gametogenesis and spawning are correlated with seasonal increases in seawater temperature and phytoplankton abundance, and we discuss and compare timing of sexual reproduction in this corallimorpharian to those in several actiniarian and scleractinian species.  相似文献   
117.
Climate change effects on river flow to the Baltic Sea   总被引:1,自引:0,他引:1  
Graham LP 《Ambio》2004,33(4-5):235-241
River flow to the Baltic Sea originates under a range of different climate regimes in a drainage basin covering some 1,600,000 km2. Changes to the climate in the Baltic Basin will not only affect the total amount of freshwater flowing into the sea, but also the distribution of the origin of these flows. Using hydrological modeling, the effects of future climate change on river runoff to the Baltic Sea have been analyzed. Four different climate change scenarios from the Swedish Regional Climate Modelling Programme (SWECLIM) were used. The resulting change to total mean annual river flow to the Baltic Sea ranges from -2% to +15% of present-day flow according to the different climate scenarios. The magnitude of changes within different subregions of the basin varies considerably, with the most severe mean annual changes ranging from -30% to +40%. However, common to all of the scenarios evaluated is a general trend of reduced river flow from the south of the Baltic Basin together with increased river flow from the north.  相似文献   
118.
119.
The amount of catechin and 4-hydroxyacetophenone in the methanolic extract of the Norway spruce needles at the locality Bíly Kríz (Moravian-Silesian Beskydy Mts.) was found in the range 2.8-12.1 mg g(-1) (dry weight) and 0.2-17.7 mg g(-1) (dry weight), respectively. Total amount of catechin (sum of the last three needle year-classes) is statistically higher (p<0.01) in the sparse areas compared to the dense ones and similar trends were recorded for catechin content in current and one-year-old needles. These results may support an idea about primary control of phenolic production by the incident solar radiation, which depends on the social position of the tree and canopy closure degree.  相似文献   
120.
The Do?ana National Park (Spain), one of the most important wildlife sites in the West of Europe, was affected (25 April 1998) by the spill of acidic waste rich in toxic metals (mainly zinc, lead, copper, etc.), arsenic and aromatic amines from the Aznalcollar mine accident. Micronuclei test with May Grunwald-Giemsa and with CREST-antikinetocore staining using DAPI as counter-staining were performed on peripheral blood erythrocytes from Algerian mice to evaluate genotoxic damage. Animals were collected in four locations each differently affected by the disaster. Higher frequencies of micronuclei and CREST-positive micronuclei were observed in the sites, which were reached by toxic sludge and contaminated water in comparison with those located within the park. The results obtained applying the two methods indicate that DAPI staining is more sensitive in detecting micronuclei. Genotoxic biomonitoring should be further carried out in the area to control the mutagenetic level in natural populations.  相似文献   
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