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Vertical Axis Wind Turbines (VAWTs) are steadily continued to gain more attention from both academia and governments as they can provide promising solutions for harnessing wind energy in locations with modest wind speeds as well as varying wind directions. In spite of all of the flexibility in working conditions as well as low installation costs and ease of maintenance associated with the VAWTs, their lower efficiency levels significantly obstruct their competiveness in the wind energy field. Therefore, enhancing the performance of such turbines is very critical in exploiting their full potential. Accordingly, this paper proposed a mechanical mechanism which is mainly consists of gears and timing belt that are specially designed to effectively enable the turbine blades to instantaneously reorient themselves to face the wind direction. Also, the proposed turbine is enclosed in a specially designed cage with a rear blade attached to it. This rear blade, as affected by the wind, is responsible for making the cage redirect itself such that its inlet is facing the wind direction. To test the validity of the introduced concept, a VAWT prototype with the proposed mechanism has been manufactured and tested using wind tunnel. The test results demonstrated the self-oriented capability of new design that guaranteed maintaining a continuous perpendicular position between the affecting wind direction and the blade surface. The experimental results also confirmed the expected efficiency improvements and the assessed natural theoretically frequencies ensured that the developed turbine can safely rotate with considerably high angular speeds with no resonance risks.

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rapid depletion of fossil fuels is the major concern of the industrial countries' over the last decades. Fortunately, the rapid depletion problem can be resolved using clean and cheap renewable resources like wind and solar energy. These renewable energy sources can compensate for the shortage between the growing demand and the available traditional types of energies in countries that are suffering from insufficient traditional energies. Apparently, renewable energy sources can be used in many applications which include generating cheap electricity for the deprived communities in the desert areas in addition to powering the desalination plants for producing the

Research progress in the automotive industry sector is highly motivated by scarcity and rapid depletion of the fossil fuels. Hence, designing automotive components that could support decreasing power losses is critical to efficient use of fuel. Clutches are basic elements in automotive industries for controlling motion transmission. Furthermore, loss of power related to the "spin loss" phenomenon in clutches significantly affects the motion transmission efficiency. egtmtrjmt , automotive industry wtotejbtm/ rmt ejjsejh rjmd rmw .j wtotejb rworjetw ee..egt/ that yield to low losses associated with quick response. The friction in clutches' disks is a main source of power losses. Also, the friction affects the clutches life time which causes sudden troubles. This paper presents a conceptual design of low friction clutch using permanent magnet cylinders, planetary gears and cams mechanisms for reducing loss of power in order to improve system efficiency. This clutch uses the magnetic forces effect of magnetic cylinders instead of the direct contact effect of the regular clutch's friction disks. Also, this clutch is provided with cams mechanism for assuring that motion is completely stopped. Moreover, planetary gears of this clutch decrease rotation speed and increase torque as an initial reduction gear box. Finally, a prototype of this clutch is presented for testing the conceptual design validity.