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991.
992.
Surface and near-surface soil arsenic levels were measured at a former crude oil storage facility within the greater Los Angeles area of Southern California. Arsenic was present in soil within some portions of the site at concentrations defined as being hazardous by both the State of California and the United States Environmental Protection Agency. The elevated soil total arsenic concentrations ranged from about 30 to 2300?mg/kg and generally occurred in, and adjacent to, the former washing and storage tank locations and along piping runs. In contrast, background concentrations of arsenic in soil at the site ranged from less than the analytical method detection limits (0.5?mg/kg) to approximately 8.0?mg/kg. The elevated soil arsenic concentrations are believed to be the result of the use of arsenical corrosion inhibitors within production wells and possibly the use of arsenical biocides in washing and skimmer tanks. Flow lines from production wells within the oil field to the crude oil storage facility contained crude oil and produced (formation) water. Arsenical corrosion inhibitors placed into the oil wells may have flowed with the crude oil/produced-water streams into the washing and skimmer tanks. Over the course of approximately 55 years of operation, tankage and piping leaks at the facility may have contributed to the elevated soil arsenic concentrations encountered at the site. A site-specific cleanup goal of 22?mg/kg total arsenic was established by the regulatory agency with oversight for the site. Remediation of the arsenic-impacted soil was accomplished by excavation and on site treatment using a chemical fixation process. Confirmatory samples collected after the fixation process was completed verified that the treatment reduced the concentrations of arsenic that could by leached from the soil to nonhazardous levels. The treated soil was subsequently transported offsite to an asphalt recycling facility for incorporation into asphalt paving products.  相似文献   
993.
Based on meteorological observations at Nouadhibou Airport, Mauritania, over the period 1953–1990 frequency distributions and averages are computed for wind speed and direction. Average wind speed reaches a maximum in May–June (9 m s–1) and a minimum in November–December (6 m s–1). About 85% of the time winds blow from northerly directions. Based on a data set collected since 1952 maps of surface water temperatures are constructed. Based on these maps and on observations on salinity an hypothetical current pattern for the shallow area between Nouadhibou and Cap Timiris, Mauritania, is proposed.  相似文献   
994.
995.
Abstract

The phylogenetic history, paleontological implications, and ecology of larger New Zealand Recent species of Neilo (sensu stricto) are discussed. N. wairoana delli, N. blacki, and N. (Pseudomalletia) aoteana are described as new. The following taxa are reduced to chronosubspecies: N. jugifera Marwick - of N. australis (Quoy & Gaimard); N. annectens Powell and N. rugata Dell - of N. sublaevis Marwick; N. sinangula Finlay - of N. awamoana Finlay.  相似文献   
996.
Abstract

The Louisiana and Texas Rigs-to-Reefs programs enjoy widespread public, industry, and government support and have become models for similar programs around the world. Louisiana’s Rigs-to-Reefs program is the largest in the world, and since its inception in 1986 about 363 oil and gas platforms have been donated, or on average about 12 structures per year. Texas’s Rigs-to-Reefs program started in 1990, and since this time about 154 structures have been donated, or about six structures per year. A summary update of the Louisiana and Texas reef programs is provided, along with recent changes in legislative activity. Donation trends and statistics are reviewed. The Rigs-to-Reefs programs are unlikely to see donation activity above historic levels, and both programs should start planning for a future where the income generated from future projects diminishes.  相似文献   
997.
A sandy soil from the Vesuvian volcanic area, low in organic matter, was treated in pot experiments with raw farm-yard manure, green horse bean and wheat straw in order to study the effects of organic amendments on physical, chemical and biological properties. Farm-yard manure, rawly composted, caused a significant decrease of bulk density and improved water retention and the content of available phospate and potassium. It also showed the higher conversion co-efficient to stable humus during two years of the incubation period. It depressed the wheat seed germination and cotyledon growth for a one-year incubation period. Horse bean green manure was rapidly mineralized and did not remarkably improve the physical properties of the soil. Furthermore, it produced the lowest humus content and negatively affected seed development for eight months, but remarkably increased nutrient elements' contents (P and K). Wheat straw, added with N (2% urea form), improved humus formation and soil structure compared to horse bean; it increased K and P content and negatively affected seedling development for two months only.  相似文献   
998.
Abstract. Walking alate virginoparae of Brevicoryne brassicae (L.) and Aphis fabae Scopoli were presented with odours of steam-distilled extracts of the non-host plants summer savoury ( Satureja hortensis L.) and tansy ( Tanacetum vulgare L.) in an olfactometer. No effects of the extracts were observed on B. brassicae. However, A.fabae were repelled by summer savoury and tansy odour; both extracts also masked an attractant response to bean (host plant) odour. In a flight chamber, air permeated with odour from host or non-host plants was blown over flying alates of both species, with a green, plant-mimicking target presented once a minute. The incidence of targeted (host-responsive) flight of B.brassicae was not affected by odour from a growing host plant ( Brassica oleoracea ) or a non-host plant tansy. Host plant ( Vicia faba ) odour did not affect the initial rate of climb or the incidence of targeted flight of A.fabae , but when the bean odour was alternated with odour from non-host tansy plants a greater number of targeted flights occurred in the host plant odour. The volatile extracts of tansy and summer savoury were also presented to flying A.fabae. Aphids flying in air permeated with tansy odour at 450g plant equivalents initiated fewer targeted flights than when flying in clean air. However, no differences in flight behaviour were observed with summer savoury extract. In a horizontal wind tunnel the tansy extract at 90 g plant equivalents blown across the surface of yellow targets reduced the numbers of alate A.fabae landing. The results indicate that plant odours can affect flight and landing of aphids.  相似文献   
999.
The responses of male and female Glossina pallidipes Austen to a visual target were recorded in a slow-speed wind tunnel, using a video system. Addition of ox odour or carbon dioxide at an equivalent concentration to the airstream resulted in an increase in flight activity and a marked increase in flies alighting on the visual target. In the absence of ox odour flights were characterised by a number of collisions with the walls and ceiling of the cage used to retain the flies, whereas in the presence of ox odour the flies circled around the centre of the cage avoiding the edges. Removal of the visual target did not alter this response. The results are discussed in the light of field observations on the behaviour of G. pallidipes around baited targets. When flies were observed in groups, mutual disturbance increased the activity during control periods thus masking the activating effect of ox odour. The activity of individual flies occurred in bursts (22.1 s mean duration) consisting of a number of flights (3.3 s mean duration) and longer periods of inactivity (85.8 s mean duration). The burst lenght did not change when ox odour was added to the airstream but the number of flights per burst increased. These results are discussed in relation to the random dispersal theory of tsetse populations.
Résumé Les réactions de G. pallidipes mâles et femelles, à l'odeur de vache, au gaz carbonique et à des stimulations visuelles ont été enregittrées sur un système vidéo, lors d'expériences dans un tunnel à vent à faible vitesse. Les adultes ont été mis à jeûner pendant 3 jours après leur premier repas, avant d'être introduits à l'intérieur du tunnel à vent dans une cage en fil nylon, conçue pour maintenir les mouches dans le champ de la caméra. Dans les premières expériences, 10 mouches ont été observées simultanément. L'introduction d'odeur de vache ou de CO2 n'a augmenté l'activité d'aucun des deux sexes, mais a brutalement accru le nombre de vols s'achevant sur une cible mate noire. Une étude plus précise et continue pendant 60 minutes, de groupes de 5 mâles et de 5 femelles, a révélé que les envols n'étaient pas indépendants et que les perturbations mutuelles avaient masqué l'action stimulante de l'odeur de vache et du CO2. Pour surmonter le problème des perturbations mutuelles, les mouches ont été observées individuellement. Mâles et femelles ont répondu par une augmentation de l'activité de vol à l'introduction d'odeur de vache dans le courant d'air. Les mâles ne se sont posés sur les cibles que dans les minutes ayant suivi l'addition d'odeur de vache, tandis que les femelles se sont posées tout le long de l'expérience, le nombre d'atterrissages s'étant accru significativement avec l'addition d'odeur de vache. L'odeur de vache a modifié le type de vol, passant du vol au hasard entraînant de nombreuses collisions avec les parois et le plafond de la cage, à un vol plus direct provoquant le tournoiement des mouches dans la cage. Par ailleurs, ce comportement a subsisté après le retrait des cibles mates noires de la cage. On peut en conclure que l'odeur de vache active les femelles et augmente la perception visuelle du paysage. L'activité de G. pallidipes avait lieu avec de brêves poussées (durée moyenne 22,1 secondes) de nombreux vols, suivies de périodes d'inactivité plus longues (durée moyenne 85,8 secondes). La durée moyenne d'un vol était de 3,3 s. Partant de ces données et d'une vitesse de vol estimée à 5,0 m/s, la longeur d'un vol élémentaire pour une dispersion théoriquement au hasard, est 16,5 m. La durée de la poussée d'activité n'a pas changé avec l'introduction d'odeur de vache, mais le nombre de vols par poussée a augmenté, et bien qu'il ait été impossible de comparer la durée des périodes de repos avec et sans odeur, des expériences précédentes suggèrent qu'elles devraient diminuer en présence d'odeur.
  相似文献   
1000.
Collisions with wind turbines are an increasing conservation concern for migratory birds that already face many threats. Existing collision‐risk models take into account parameters of wind turbines and bird flight behavior to estimate collision probability and mortality rates. Two behavioral characteristics these models require are the proportion of birds flying at the height of the rotor swept‐zone and the flight speed of birds passing through the rotor swept‐zone. In recent studies, investigators have measured flight height and flight speed of migrating birds using fixed‐beam radar and thermal imaging. These techniques work well for fixed areas where migrants commonly pass over, but they cannot readily provide species‐specific information. We measured flight heights of a nesting shorebird, the federally threatened Piping Plover (Charadrius melodus), using optical range finding and measured flight speed using videography. Several single‐turbine wind projects have been proposed for the Atlantic coast of the United States where they may pose a potential threat to these plovers. We studied Piping Plovers in New Jersey and Massachusetts during the breeding seasons of 2012 and 2013. Measured flight heights ranged from 0.7 to 10.5 m with a mean of 2.6 m (N = 19). Concurrent visually estimated flight heights were all within 2 m of measured heights and most within 1 m. In separate surveys, average visually estimated flight height was 2.6 m (N = 1674) and ranged from 0.25 m to 40 m. Average calculated flight speed was 9.30 m/s (N = 17). Optical range finding was challenging, but provided a useful way to calibrate visual estimates where frames of reference were lacking in the environment. Our techniques provide comparatively inexpensive, replicable procedures for estimating turbine collision‐risk parameters where the focus is on discrete nesting areas of specific species where birds follow predictable flight paths.  相似文献   
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