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The need for electricity in Indonesia becoming increasingly part of people's needs. Fossil fuels suchas oil and coal used as the main material for producing electrical energy the more limitedavailability, especially in its use of fossil fuels that pollute the environment. Wind energy is arenewable energy source that could potentially be developed. Wind energy is clean and does notpollute the environment in utilization into mechanical or electrical energy. The conversion of windenergy into electrical energy by converting this energy into mechanical rotation. In the wind energyutilization process made a tool to convert wind energy into electrical energy, that is windturbines.Wind turbine or windmill is a tool for converting wind energy. Wind turbines transformkinetic energy into mechanical energy in the form of a round shaft. Shaft speed is then used to rotatethe dynamo or a generator which produces electricity. The research was carried out on a horizontalaxis wind turbine NACA 4412, diameter 1 m, the number of blades 3 pieces and variations in windspeed 2-8 m / s. Results showed the greatest lift (CL) at 14o angle of attack with a value of 1.583.The driving force of the smallest (CD) at an angle of attack -4o to 2o with a value of 0.008. Value CL/ CD was found in the angle of attack of 6o with a value of 93.057. The maximum power generatedby 484.63 Watt. Wind speed, the number of blades, angle of attack and the election of the airfoileffect on the generated power.Keywords : wind energy, wind turbines, airfoil NACA 4412.

Cardiovascular disease is the leading cause of death worldwide. Arterial stenting as a transluminal angioplasty procedure allows re-opening of narrowed vessels and restoring normal blood flow with stent placement. The development of stents ed at the end of 19 century with bare-metal stents (BMS). Now, it has been based on the application of biodegradable or natural decomposed and coated stents. The coated stent has been found to improve BMS properties in terms of biocompatibility, cytotoxicity, and better mechanical and biophysical properties. Also, a biodegradable stent may support the blood micro-vessel during the estimated period of time before downgraded constituents. The biodegradable stent also allows a reinsertion for several months to improve the vessel wall's quality. This paper describes the possible materials for stents and their properties such as design criteria, degradation behavior, disadvantages, and advantages with clinical and preclinical trials to date. Stent degradation allows reinsertion of the stent after several months and improves the vessel wall quality. This paper focuses on developing materials for stents, which describe the possible materials for stents and their properties. Furthermore, the current clinical trial of the new proposed stent will also be highlighted.