Spectroscopy of the infrared He I (λ10830) line with KECK/NIRSPEC and IRTF/CSHELL and of the ultraviolet C III (λ977) and O VI (λ1032) emission with FUSE reveals that the classical T Tauri star TW Hydrae exhibits P Cygni profiles, line asymmetries, and absorption indicative of a continuous, fast (∼400 km/s), hot (∼300,000 K) accelerating outflow with a mass loss rate ∼10–10 M⊙ yr −1 or larger. ...

In this paper, we propose a novel technique to determine the optimal placement of wind farms, thereby taking into account wind characteristics and electrical grid constraints. We model the long-term variability of wind speed using a Weibull distribution according to wind direction intervals, and formulate the metrics that capture wind speed characteristics at a specific location, namely the ari...

Offshore wind turbines have been installed in increasing water depths over the last years. Support structures with monopile or gravity based foundation could successfully be used for all realized offshore-projects, but the trend of increasing water depths reached a level that makes application of those relatively simple types of support structures inappropriate. New concepts like tripods or lat...

This article presents a review of the state of the art of the Wind Farm Design and Optimization (WFDO) problem. The WFDO problem refers to a set of advanced planning actions needed to extremize the performance of wind farms, which may be composed of a few individual Wind Turbines (WTs) up to thousands of WTs. The WFDO problem has been investigated in different scenarios, with substantial differ...

Nowadays the position of the renewable energy is so important because of the environment pollution and the limitation of fossil fuels in the world. Energy can be generated more and more by the renewable sources, but the fossil fuels are non-renewable. One of the most important renewable sources is the wind energy. The wind energy is an appropriate alternative source of fossil fuel. The replacem...

one of the main problems in wind energy conversion system (wecs) is how to achieve maxim­u­m output power in different wind speeds. maximum methods for maximum power point tracking in wind energy conversion syst­e­ms require the knowledge of system characteristics and mechanic sensors. so, using these methods practically will follow with high price and an abundant difficulties. in this paper, n...

In a steam power plant, the temperature of the cooling water leaving the condenser for recyclingshould decrease. This is achieved in a cooling tower. The Heller cooling tower does not require waterfor operation, thus, it is a suitable system for use in thermal power plants throughout Iran. Wind is anenvironmental factor that unfavorably affects the performance of a cooling tower. Previous studi...

according to this fact that wind is now a part of global energy portfolio and due to unreliable and discontinuous production of wind energy; prediction of wind power value is proposed as a main necessity. in recent years, various methods have been proposed for wind power prediction. in this paper the prediction structure involves feature selection and use of artificial neural network (ann). in ...