Not exist
Saleh R. Abdussalam Gashoot, A.K.Misra(7-2003)

Abstract Wind turbines are the means of converting wind energy into electrical energy. It is not unexpected that certain brands of horizontal wind turbines are optimally designed for certain wind speed regimes prevailing at certain sites. It has been the objective of this study to find out whether it is possible to design a wind turbine that is more suitable for a site of lower annual mean wind speed such as the western coast of Libya. In achieving this objective, use was made of a typical wind turbine aerodynamic design and performance analysis procedure together with actual wind speed data recorded at the city of Misurata.Based on the annual wind energy yield obtained from different designs of wind turbines having different rated wind speeds and different blade design tip speed ratios, this study indicates that the decrease of the rated wind speed leads to a continuous increase of annual energy yield as well as an increase of the cost of the wind turbine. Therefore the optimum value of rated wind speed for this site may only be determined as a compromise between added wind energy yield and added cost. Moreover, for any given rated wind speed this study indicates that a blade design tip speed ratio equal to six seems to be the optimum value for the given site.
محمد على نايلي (2015)

Abstract The objective of this study is to formulate a drilling cost model which incorporates the drilling parameters, encountered during drilling operation of the petroleum well. This model is coupled with the selected drilling rate model proposed by Bourgoyne & Young, in order to predict the bit rotating time utilized in this model. The new drilling cost model was formulated using actual drilling data collected from thirteen wells selected in three oil fields in Sirte Basin (Ghani, Zenad, and Ed Dib).The drilling engineer can use drilling correlations in the planning stages of a well to help evaluate various drilling parameters encountered during drilling operations in order to update the proposal drilling plan and to evaluate any deviations from original projections. The gathered information will help selecting the best completion strategies as well as gaining experiences in the drilled area which will be the basis for the planning of future drilling activities in the area.
عزالدين أحمد أحمد (2009)