Winners and losers over 35 years of dragonfly and damselfly distributional change in Germany

Aim: Recent studies suggest insect declines in parts of Europe; however, the generality of these trends across different taxa and regions remains unclear. Standardized data are not available to assess large-scale, long-term changes for most insect groups but opportunistic citizen science data are widespread for some. Here, we took advantage of citizen science data to investigate distributional changes of Odonata. Location: Germany. Methods: We compiled over 1 million occurrence records from different regional databases. We used occupancy-detection models to account for imperfect detection and estimate annual distributions for each species during 1980–2016 within 5 × 5 km quadrants. We also compiled data on species attributes that were hypothesized to affect species’ sensitivity to different drivers and related them to the changes in species’ distributions. We further developed a novel approach to cluster groups of species with similar patterns of distributional change to represent multispecies indicators. Results: More species increased (45%) than decreased (29%) or remained stable (26%) in their distribution (i.e. number of occupied quadrants). Species showing increases were generally warm-adapted species and/or running water species, while species showing decreases were cold-adapted species using standing water habitats such as bogs. Time series clustering defined five main patterns of change—each associated with a specific combination of species attributes, and confirming the key roles of species’ temperature and habitat preferences. Overall, our analysis predicted that mean quadrant-level species richness has increased over most of the time period. Main conclusions: Trends in Odonata provide mixed news—improved water quality, coupled with positive impacts of climate change, could explain the positive trends of many species. At the same time, declining species point to conservation challenges associated with habitat loss and degradation. Our study demonstrates the great value of citizen science and the work of natural history societies for assessing large-scale distributional change

Possible threats related to airbag activation in case of out-of-position configuration at driver side

Poduszki powietrzne stosowane w samochodach osobowych mają na celu zredukowanie przeciążeń działających na ludzki organizm w czasie zderzenia a przez to zwiększenie szans na minimalizację obrażeń czy - w krańcowym przypadku - przeżycie. Stosowane niezgodnie z założeniami projektantów mogą jednak stanowić zagrożenie dla użytkownika. Niestandardowa pozycja w samochodzie, nietypowy ze względu na charakterystyki antropometryczne pasażer, mogą spowodować nieprzewidziane przez konstruktora zadziałanie poduszki. Konstruktorzy starają się uwzględnić możliwe źródła zagrożeń, rozbudowując zakres testów o konfiguracje nietypowe (OoP - Out of Position) oraz próbując zminimalizować negatywny ich wpływ na działanie poduszki.Air bags are meant to reduce excessive loads acting on occupant's body during the crash, decreasing injury risk. Used in configuration other than designed they may not provide its proper functionality to the occupant. Untypical position in car (called Out-of-Position) or non-standard occupant (away from a 50-percentile occupant) may cause abnormal operation of the air bag. The developers try to take possible sources of risk into account, adding Out-of-Position to the standard testing procedure and focusing on minimizing its negative influence on airbag functionality

Wpływ podwyższonej temperatury na właściwości niskocyklowe stali WCLV/1.2344

In this paper the results of low cycle fatigue tests of hot-work tool WCLV (1.2344) steel carried out at the temperatures of 20ºC and 600°C were presented. These results are used for numerical modelling of the wearing course of forging tools. This analysis was performed by means of hysteresis loop parameters recorded during tests. It was stated that the elevated temperature influences fatigue life and changes of hysteresis loop parameters in the function of loading cycles. At the temperature of 600°C, changes in the parameters were significantly higher than at 20°C. It make mare difficult to calculate the fatigue life of objects operating at elevated temperatures, because materiał data determined during tests reflects only the momentary properties of steel.W pracy zamieszczono wyniki niskocyklowych badań zmęczeniowych stali WCL V 1.2344 w temperaturze 20°C oraz 600°C. Analizę wyników prowadzono przy wykorzystaniu parametrów pętli histerezy rejestrowanych w trakcie badań. W pracy stwierdzono, że podwyższona temperatura ma wpływ na trwałość zmęczeniową oraz zmiany parametrów pętli w funkcji liczby cykli obciążenia. W temperaturze 600°C zmiany parametrów są zdecydowanie większe niż w temperaturze 20°C. Utrudnia to prowadzenie obliczeń trwałości obiektów poddanych eksploatacji w temperaturze podwyższonej. Wyznaczone podczas badań dane materiałowe odzwierciedlają bowiem jedynie chwilowe właściwości stali