Search results for "EED"
showing 10 items of 5952 documents
Food Caching By Willow and Crested Tits: A Test of Scatterhoarding Models
1995
In coniferous forests of Central Finland, Willow (Parus montanus) and Crest- ed Tits (P. cristatus) store seeds in a scattered distribution within their territory during the autumn. Individuals cache and recover food items while moving together as members of mixed-species flocks. The purpose of this study was to test certain predictions of scatter- hoarding models (Stapanian and Smith 1978, Clarkson et al. 1986), which predict how the animal should hoard food items from a superabundant source to maximize the number of caches recovered. Our field experiments gave support to most of the predictions of the models. Individual tits stored seeds closer to the food source when food had been availa…
Amerykańscy Polacy na frontach Wielkiej Wojny: współczesny symbol i treść
2023
Założeniem niniejszego artykułu jest zebranie w sposób systematyczny dotychczasowych ustaleń badawczych związanych z dokumentowaniem działań Polaków i Amerykanów polskiego pochodzenia walczących w szeregach Amerykańskiego Korpusu Ekspedycyjnego (American Expeditionary Forces, AEF). Celem artykułu jest wskazanie przede wszystkim wymiaru historycznego, militarnego i politycznego owego zaangażowania. Artykuł stanowi studium z polityki historycznej, mające przełożenie na współczesne realia i koncepcje politycznych rozwiązań. Za narzędzia badawcze posłużyły m.in. metody: historyczna, porównawcza, statystyczna, analizy zawartości prasy, w tym szczególnie prasy polonijnej. Tematyka wymagała w spos…
A methodology for evaluation of operational zones for distributed generation based on DFIG
2017
This study developed a methodology to determine zones of acceptable voltage profiles for wind power generation connected to distribution systems. Three load profiles (residential, commercial and industrial) connected to the distribution network were analyzed considering the impact on voltage levels and steady-state stability for different wind speeds and wind generator control strategies. The wind generator model is based on doubly fed induction generator (DFIG) and were developed using Matlab/Simulink. The presented methodology can be used to map the impact on operation of different types of control, the time of day and the available wind speed and it is not limited only for DFIG. The resu…
Applying Numerical Weather Prediction Models to the Production of New European Wind Atlas : Sensitivity studies of the wind climate to the planetary …
2018
Reliable and precise information about the wind speed climate is crucial for the development of wind energy. Meteorological processes in the mesoscale (2 – 200 km) can be represented using Numerical Weather Prediction (NWP) models such as the Weather Research and Forecast model (WRF), but before their application for creating wind energy atlases, their results and sensitivity to modelling parameters should be investigated. Here the WRF model wind speed results for the year 2015 for the Baltic Sea region are investigated, and the effect of the planetary boundary layer parametrization scheme is analyzed.
Numerical and analytical analysis of a monopile-supported offshore wind turbine under ship impacts
2021
Abstract Offshore wind turbines in the vicinity of ship traffic are exposed to increased risks of ship collisions. To better understand the impact mechanism, this paper evaluates the dynamic responses of a monopile-supported wind turbine under ship impacts, using both numerical and analytical methods. The nonlinear finite element method is applied during the numerical simulations, and the wind load effects, soil conditions, and rigid and deformable ship bows are considered. The analytical approach, originally developed based on the energy method, is extended here to address the damping effects of monopile-supported wind turbines. In the case study, the impacts are studied between a 4600-ton…
Verification of Numerical Weather Prediction Model Results for Energy Applications in Latvia
2014
Abstract Wind power forecasting greatly relies on wind speed forecasts. Numerical Weather Prediction (NWP) models are a reliable source of meteorological forecasts and they can also be used in wind resource assessment. In this work we carry out the verification of wind speed results from the NWP model Weather Research and Forecast (WRF), grid resolution - 3 km. Results from 172 model runs in May and November 2013 are compared with meteorological observations in 24 stations in Latvia. The model usually predicts wind speed values that are larger than the observed and the diurnal cycle has a large impact on verification results. Verification results obtained by interpolating model results betw…
Wind speed spatial estimation for energy planning in Sicily: introduction and statistical analysis
2008
Abstract The exploitation of the renewable energy sources plays a key role for achieving the CO 2 emissions reduction targets established by the Kyoto Protocol, as well as for facing the shortage of world fossil fuels reserves. In countries like Italy, with an high potential in terms of wind power generation, an efficient energy planning based on renewables is a very complex task. It encompasses many aspects: the resource availability assessment, the compliance with environmental and legislative constraints and last, but not least, the technical aspects linked to the safe integration to the grid of the intermittent power generated by the wind farms. This paper is the first part of a study a…
The formation of feed-in tariffs and the emergence of wind power in Finnish routine corporatism: favoring the economics of large-scale energy product…
2021
We explore the role and influence of the Finnish energy elite’s inner circle in the process of transition to renewable energy. Finland is a corporatist country where economic interest groups have p...
Joint probability distributions for wind speed and direction. A case study in Sicily
2015
In this study we analyze data of hourly average wind speed and direction measured at three different sampling stations located in Sicily (Italy) and provide a statistical model for their joint probability density function. Singly truncated from below Normal Weibull mixture distribution and a linear combination of von Mises distributions are used to model wind speed and direction. Sites with heterogeneous local conditions (prevailing wind direction and/or elevation) have been considered in order to investigate the reliability of the model here taken into consideration.
New colony of little egrets egretta garzetta at trapani saltpans
2016
Breeding on man made structures has never been cited in literature for this species. First records of breeding in windmill in the saltpans of Trapani are here reported.