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131.
The effectiveness of presettling basins as component of stormwater best management practice (BMP) technologies was investigated. Storm event monitoring and sediment collection were conducted from May 2009 to November 2012 on the presettling basins of the three BMP technologies designed to capture and treat stormwater runoff from highly impervious roads and parking lots. Data on captured runoff and sediment, total suspended solids (TSS) loadings, rainfall and runoff rate, sediment accumulation rate, as well as particle distribution and pollutant concentrations of sediment were gathered and analyzed along with the physical design characteristics of the presettling basins such as surface area and storage volume. Regression models were generated to determine significant relationships between design parameters. Results revealed that the storage volume ratio (ratio of storage volume of presettling basin to BMP) was an important parameter in designing the presettling basin of the BMP. For practicality, optimizing the design of the presetfling basin means that the storage volume ratio should be determined based on the desired captured amount of runoff and sediment from runoff to limit the frequency of maintenance caused by the accumulation of sediment. It was recommended that pretreatment of runoff should be employed when the site in which the BMP is to be sited has high TSS loading and runoff rate, and is subjected to high intensity rainfall.  相似文献   
132.
The Northern wheatear (Oenanthe oenanthe) is a small long-distance migratory songbird that breeds throughout the Northern hemisphere and winters in sub-Saharan Africa. The main components of its migratory behaviour, i.e. seasonal migratory restlessness and body mass changes, have been shown to be under endogenous control. However, it is still unknown whether the disposition to accumulate fuel reserves is an inherited trait. We cross-bred Northern wheatears from two populations known to accumulate different amounts of fuel in a common-garden setup, and measured their maximum fuelling as the difference between the lightest and heaviest body mass recorded over each year for 4 years or longer. We used the largest value as a measure of maximum voluntary fuelling potential. F1-generation “hybrids” showed intermediate values to those of the parent populations. It was previously shown that in the wheatear the amount of fuel accumulated is closely linked to the presence of large ecological barriers to cross. This study shows that this adaptation has been fixed at the genetic level, and that intermediate traits are transferred to the next generation, with possible implications on the viability of such individuals in nature.  相似文献   
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Marine protected areas (MPAs) are attaining increasing importance in the management of marine ecosystems. They are effective for conservation in tropical and subtropical areas (mainly coral and rocky reefs), but it is debated whether they are useful in the management of migratory fish stocks in open temperate regions. World War II created a large marine area within which commercial fishing was prevented for 6 years. Here we analyse scientific trawl data for three important North Sea gadoids, collected between 1928 and 1958. Using statistical models to summarise the data, we demonstrate the potential of MPAs for expediting the recovery of over-exploited fisheries in open temperate regions. Our age-structured data and population models suggest that wild fish stocks will respond rapidly and positively to reductions in harvesting rates and that the numbers of older fish in a population will react before, and in much greater proportion, than their younger counterparts in a kind of Mexican wave. Our analyses demonstrate both the overall increase in survival due to the lack of harvesting in the War and the form of the age-dependent wave in numbers. We conclude that large closed areas can be very useful in the conservation of migratory species from temperate areas and that older fish benefit fastest and in greater proportion. Importantly, any rise in spawning stock biomass may also not immediately result in better recruitment, which can respond more slowly and hence take longer to contribute to higher future harvestable biomass levels.  相似文献   
134.
Mit impr?gnierten Filtermaterialien ist es m?glich, die Schwermetalle Blei, Kupfer und Nickel sowie Arsen durch Sorption bzw. chemische Bindung aus Wasser zu entfernen. Bei 24stündiger Einwirkungszeit wurden Reduktionsraten von 97% bis>99,9% erreicht.  相似文献   
135.
Tiny light sources made of semiconducting material and thin glass fibers begin to revolutionize signal transmission. While the first systems are already performing well in the field, scientists are working on further miniaturizing and integrating components for communication systems of the future.  相似文献   
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Gleichzeitig mit der Forcierung der Energiegewinnung aus Biomasse (Hackgut, Rinde, S?gesp?ne) steigen auch die Mengen an Verbrennungsrückst?nden, den Holzaschen, stark an. Für eine umweltvertr?gliche und ?kologisch effektive Kreislaufwirtschaft mit der anfallenden Asche ist die genaue Kenntnis ihrer Zusammensetzung eine Voraussetzung. Bereits durchgeführte Analysen zeigten, da? in der komplexen Matrix Holzasche aufgrund der gro?en Bandbreite der zu bestimmenden Komponenten, die in sehr unterschiedlichen Konzentrationen vorliegen, korrekte Analysenergebnisse nur mit Schwierigkeiten erzielt werden k?nnen. Es ist daher norwendig, eine kostengünstige Kombination von Analysenverfahren zu finden, die einen vollst?ndigen Nachweis der in der Asche enthaltenen N?hrstoffe und Schwermetalle erm?glicht. In dieser Arbeit wurden Holzascheproben unterschiedlicher Zusammensetzung und Herkunft sowohl mittels na?chemischer (S?ureaufschlüsse und atomspektrometrische Detektion) als auch mittelstrockener Methoden (R?ntgenanalysen) untersucht. Die Ergebnisse wurden verglichen und mittels statistischer Methoden sowie mittels Stoffbilanzen für die anorganischen Elemente vom Brennstoff zur Asche auf ihre Plausibilit?t geprüft. Aufgrund der Ergebnisse dieser Bewertung wird eine für die Analyse von Aschen aus Biomassefeuerungen geeigneteStandardmethode vorgeschlagen die einen vollst?ndigen Elementnachweis gew?hrleistet. Es handelt sich dabei um eine Kombination aus R?ntgenuntersuchungen (für die Elemente Si, Ca, Mag, K. P, Al, Fe, Mn) und Na?analytik (für den exakten Schwermetallnachweis).  相似文献   
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