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51.
The concentration of total suspended particulate (TSP) matter was determined at commercial, residential, rural and industrial sites in metropolitan Jacksonville during the summers of 1989 and 1990. These data were compared to samples taken at the Mathews Bridge Toll Plaza in 1989 and at a similar location one year later, after removal of the toll facility. All samples were analyzed by reflectance analysis and the approximate elemental carbon content used to estimate the contribution of vehicular traffic at the roadway. The results indicate a significant improvement in air quality at the location of the previous toll facility, but did not show that a widespread improvement resulted from the removal of tolls in Jacksonville, Florida.  相似文献   
52.
Elemental carbon (EC) particles have been found in the lungs of dolphins. The question arose as to whether these particles originated over land or water. This project determined the amount of EC particulate found in terrestrial air. Portions of paniculate filters and associated data collected during the period from January 1990 through December 1991 were provided by the Florida Department of Environmental Regulation. Using reflectance spectroscopy and laboratory-generated standards, atmospheric concentrations of EC and TSP were determined. This paper addresses the data from those counties which surround Tampa Bay.

In the spring of 1992, a television news station reported that researchers at Mote Marine Institute had found black carbon particulates in the lungs of dolphins (reported as “...dolphins with Black Lung Disease..."). The dolphins were found in the Gulf of Mexico off the coast of Florida.1 In discussions with a principal investigator of the dolphin study, the question arose as to whether these particulates came from urban or marine sources. No comprehensive investigation of soot concentrations in the air over Florida had been made. This study reports the elemental carbon (EC) content of urban particulate matter in the Tampa Bay region, where the affected dolphins were discovered between 1988 and 1990 (Sarasota County). This is the first step toward answering whether urban concentrations of EC were sufficient to contribute measurably to the EC found in the marine environment. Future efforts will address marine concentrations and sources of EC.

Elemental carbon, commonly termed “soot,” is a product of incomplete combustion. Common urban sources of EC in particulate matter include both mobile sources (diesel-powered buses, cars, and trucks) and point sources (incinerators, power plants and home heating units). The State of Florida operates environmental monitoring stations in selected municipalities around the state. At these stations, which were sited according to EPA requirements2, Total Suspended Particulate (TSP) samples were collected using the accepted methods.3 These samples were suitable for EC analysis. Samples collected in the Tampa Bay region in 199b and 1991 were analyzed for EC content using reflectance spectroscopy. EC concentrations were calculated in micrograms per cubic meter (μg/m3).  相似文献   
53.
针对某钼矿选矿厂浮选废水,以PAC、PFS和FeCl3为凝聚剂,以APAM-A和APAM-N为絮凝剂,以H2SO4和NaOH为pH调整剂,研究了不同混凝剂、不同pH值和不同水力条件下废水处理后的浊度和COD.实验结果表明,在最佳水力条件下,原水pH不调整,以APAM-A为絮凝剂,以PAC为凝聚剂,其用量分别为15 g/t,750g/t时,处理后上清液浊度为25 NTU,COD小于30 mg/L.浮选废水经处理后回用于选矿浮选流程,大大改善了选矿指标.  相似文献   
54.
Many of the new particle sizing instruments utilize light scattering principles to detect and size aerosolparticles. The sensitivity of such nstruments is quite good, although extensive light shielding and focusingmethods must be used. A visible He-Ne gas laser cavity with its low gain is very sensitive to disturbances in its optical cavity and so may provide a new particle sizing approach.  相似文献   
55.
To evidence a possible mechanism of defense toward oxidative stress induced by herbicides in plants, an investigation was carried on the activity of glutathione peroxidase (GPX) in Italian ryegrass (Lolium multiflorum) and in Festuca (Festuca arundinacea) in response to atrazine (6-chloro-N-ethyl-N′-isopropyl-1,3,5-triazine-2,4-diamine) and fluorodifen (4-nitrophenyl α,α,α-trifluoro-2-nitro-p-tolyl ether). In general, the herbicide treatments significantly induced GPX activity in the shoots of Italian ryegrass, whereas inhibited it in Festuca. These opposite behaviors are examined, taking into account the accumulation and persistence of the two herbicides in the plants, and they are discussed in terms of GPX counteraction to oxidative stress in the first case, and of a lower detoxification rate unable to prevent a deleterious effect on the GPX activity in the second case. Further information on the properties of Italian ryegrass and Festuca GPX were achieved by purification and isolation of the enzymes, performed by protein liquid chromatography and by electrophoretic analyses. GPX of both the plants were found to be heterodimer with multiple function in showing also glutathione S-transferase (GST) activity.  相似文献   
56.
57.
The Mar Piccolo of Taranto, classified as a ‘Site of National Interest’ (SIN), is a semi-enclosed basin divided into two inlets with lagoon features and sea influences, seriously affected by anthropic activities. In the framework of the RITMARE project, a study has been carried out to evaluate the functionality of this ecosystem. As part of this work, measurements of the water abiotic parameters were performed in order to assess the physical–chemical features of this area after the activation, in the last decade, of treatment plants for various urban and industrial dumping. Seawater intrusions and continental inputs, as well as several submarine freshwater springs, clearly affect physical–chemical characteristics of the water column in the two inlets. This finding suggests that small-scale patterns in water circulation have the potential to influence the chemical properties of the seawater. The comparison with a 20-year dataset reveals a drastic decrease in nutrient concentrations after the year 2000, validating the functionality of the treatment plants. The reduction of nutrient inputs into the basin (up to ?90 % in the first inlet characterized by lower hydraulic residence time) has changed the biogeochemical characteristics of the Mar Piccolo from being relatively eutrophic to moderately oligotrophic.  相似文献   
58.
59.
The Patos Lagoon Estuary, southern Brazil, is an area of environmental interest not only because of tourism, but also because of the presence of the second major port of Brazil, with the related industrial and shipping activities. Thus, potential hydrocarbon pollution was examined in this study. Sediment samples were collected at 10 sites in the estuary, extracted, and analyzed by GC-FID and GC-MS for composition and concentration of the following organic geochemical markers: normal and isoprenoid alkanes, petroleum biomarkers, linear alkylbenzenes (LABs), and polycyclic aromatic hydrocarbons (PAHs). The total concentrations varied from 1.1 to 129.6 microg g(-1) for aliphatic hydrocarbons, from 17.8 to 4510.6 ng g(-1) for petroleum biomarkers, from 3.2 to 1601.9 ng g(-1) for LABs, and from 37.7 to 11,779.9 ng g(-1) for PAHs. Natural hydrocarbons were mainly derived from planktonic inputs due to a usual development of blooms in the estuary. Terrestrial plant wax compounds prevailed at sites located far from Rio Grande City and subject to stronger currents. Anthropogenic hydrocarbons are related to combustion/pyrolysis processes of fossil fuel, release of unburned oil products and domestic/industrial waste outfalls. Anthropogenic hydrocarbon inputs were more apparent at sites associated with industrial discharges (petroleum distributor and refinery), shipping activities (dry docking), and sewage outfalls (sewage). The overall concentrations of anthropogenic hydrocarbons revealed moderate to high hydrocarbon pollution in the study area.  相似文献   
60.
Summary Mongolian gerbils were observed over seasonal changes in day length and temperature in an outdoor enclosure containing an extensive burrow system. Animals could choose between the stable environment of their burrow and the daily and seasonal flunctuations aboveground. Surgically implanted radio transmitters provided body temperature and location of animals.Gerbils avoided temperature extremes by emerging from their burrow when ambient temperature fell below burrow temperature in hot weather and rose above burrow temperature in cold weather. They delayed emergence in the winter until several hours after sunrise and emerged before or after sunset in summer (Fig. 1).Circadian changes in core-body temperature corresponded to increases and decreases in behavioral activity. Emergence from the burrow was predictable by an increase in body temperature, as a warm-up period preceded emergence (Fig. 3).We conclude that gerbils, when subjected to extreme temperatures in the wild, probably time their activity to correspond to preferred ambient temperatures and thus shift from diurnal activity in the winter to nocrurnal activity in the summer (Fig. 2). This desert rodent's exceptional thermoregulatory capacity adapts it for synchronizing its daily activity to temperature.  相似文献   
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