Ducted wind turbines are a kind of small wind turbine having a diffuser or any other shape around the rotor which increases the air flow through the blades and absorbs more power. In the present study, a small wind turbine was ducted with a relatively simple ring and its performance was investigated in a wind tunnel. The duct is shaped using rolling steel sheets on a sloping surface and finally...

BACKGROUND Windscapes affect energy costs for flying animals, but animals can adjust their behavior to accommodate wind-induced energy costs. Theory predicts that flying animals should decrease air speed to compensate for increased tailwind speed and increase air speed to compensate for increased crosswind speed. In addition, animals are expected to vary their foraging effort in time and space ...

"This paper attempts to describe the nature of Zambia's demographic situation, which eventually led to the formulation of a national population policy; the policy instrument; and some of the measures necessary for the effective implementation of the policy....[The] situation is characterised by three dominant features: a high rate of natural increase, massive urbanisation, and wide variations ...

The renewable energy sources such as wind energy maintain to increase in popularity since they are inexhaustible and pollution-free. The horizontalaxis wind turbine has been the most common type of wind turbines but due to recent increase in popularity of personal green energy solutions, Vertical-Axis Wind Turbines (VAWT) are becoming more common. Besides two mayor rotor types of VAWTs the Darr...

sensitivity analysis to determine variations in evapotranspiration is much important considering a known variation in one of climatic variables. in this study, sensitivity of evapotranspiration from penmann-mantith, penmann-kimberly (1996), penman-kimberly (1972) and penmann (1984)  and hargrivs (1985) approaches to three climatic variations (maximum temperature, wind speed, solar radiation) wa...

Wind-energy production may be expanded beyond regions with high-average wind speeds (such as the Midwest U.S.A.) to sites with lower-average speeds (such as the Southeast U.S.A.) by locating favorable regional matches between natural wind-speed and energy-demand patterns. A critical component of wind-power evaluation is to incorporate wind-speed dynamics reflecting documented diurnal and season...

As the scale of wind power bases rises, it becomes significant in power system planning and operation to provide detailed correlation characteristic of wind speed in different geographical hierarchies, that is among wind turbines, within a wind farm and its regional wind turbines, and among different wind farms. A new approach to analyze the correlation characteristics of wind speed in differen...

In this paper, a missing wind speed data temporal interpolation and extrapolation method in the wind energy industry was investigated. Given that traditional methods have previously ignored part of mixed uncertainty of wind speed, a concrete granular computing method is constructed and a new Measure–Correlate–Predict (MCP) method of wind speed data temporal interpolation and extrapolation consi...