6 research outputs found

    Pelagic distribution of Gould’s Petrel (Pterodroma leucoptera): linking shipboard and onshore observations with remote-tracking data

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    This study describes and compares the pelagic distribution and migratory patterns of the two subspecies of Gould’s Petrel (Pterodroma leucoptera), and contrasts data obtained from tracking birds at sea using geolocators with observational data (shipboard sightings, by-catch records and beachcast specimens). While breeding, tracked individuals of both subspecies (P. l. leucoptera and P. l. caledonica) foraged within the Tasman Sea and south of the Australian continent, with forays west into the Indian Ocean before laying. After breeding, both subspecies migrated to distinct non-breeding ranges within the eastern tropical Pacific Ocean. Observational data identified the general pattern of migration and foraging areas of the species, whereas data from geolocators provided details of routes and timing of migration, core foraging ranges, and marked spatial and temporal segregation between the two subspecies. However, by attaching geolocators only to established breeders, as is typical of studies of small and medium-sized seabirds, these devices failed to identify that non-breeding birds (pre-breeders and adults that are deferring breeding) may not follow the same migratory schedules or have the same at-sea distribution. We conclude that integrating data from electronic tracking with observational data substantially improves our understanding of the pelagic distribution of seabird populations

    Přípravek pro měření součinitele smykového tření při tažení plechů

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    Počítačová simulace procesů tažení plechů vyžaduje zadání podmínek tažení, mezi které patří i součinitel smykového tření. V úvodu příspěvku jsou rozebrány vlivy působící na hodnotu součinitele tření. Skutečné podmínky při tažení napodobuje metoda protahování proužku plechu sevřeného mezi plochými čelistmi. Jsou popsány poměry ve skutečném nástroji a možnosti jejich napodobení touto metodou. Byl navržen nový přípravek pro měření tření, který umožňuje zkvalitnění dřívější metody měření, jsou rovněž uvedeny potřebné výpočtové vztahy.Computer simulation of sheet-metal drawing process requires setting of drawing conditions. Friction coefficient is also among these conditions. Introduction of the article deals with influences impacting on coeficient of friction value. Real conditions at drawing are simulated by a method - drawing of sheet-metal strip clamped between flat jaws. There are described situations inside tools and possibilities simulation these situations by the method. Possibilities improved the quality of the method are indicated by designing of apparatus for measurement of friction coefficient with necessary computational patterns

    A Global Map of Costal Recreation Values: Results from a Spatially Explicit Based Meta-Analysis

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    The welfare dimension of the recreational services provided by global coastal ecosystems is examined through a meta-analytical regression-based valuation approach. First, we construct a global, state-of-the-art database of stated and revealed preference estimates on coastal recreation, which includes also the grey literature and with the latest entry updated to February 2010. Second, the profile of each of the 253 observations of our dataset, which correspond to individual value estimates, was further enriched with characteristics of the built coastal environment (site accessibility, anthropogenic pressure, level of human development), characteristics of the natural coastal environment (presence of protected area, type of ecosystem, and marine biodiversity richness), geo-climatic factors (temperature and precipitation), as well as sociopolitical characteristics, such as the political stability index. In this context, the proposed meta-analytical valuation exercise explores the spatially explicit dimension of the values building upon Geographic Information System (GIS) tools. GIS are relied upon for the spatial characterization of the valued ecosystems, the determination of the role of spatially explicit variables in the meta analytical value transfer model, as well as for the value transfer exercise. The GIS characterization is observed to be extremely significant in explaining the spatial diversity of the estimates values and underlying explanatory factors. The resulting integrated valuation framework constitutes a worldwide première and it results in the first global map of the recreational value of coastal ecosystems. We argue that the presented global map may play an important role in studying the prioritization for the conservation of coastal areas from a social perspective
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