Savonius turbine is a type of vertical-axis wind turbines. The turbine has a potential to be developed as it has a simple construction and is suitable for low wind speeds. However, the turbine is still rarely used because of the low efficiency of the turbine compared to other turbines. The low efficiency of the turbine is due to the negative moment. Some efforts have been done to reduce the negative moment such as by adding a wind concentrator. The wind concentrator can steer the incoming wind toward the turbine blades that generate positive moments, consequently, the generated power increases. The aim of this research is to determine the effect of the number and diameter of the Savonius blade wind turbine with an additional concentrator. The concentrator had a concentration ratio of 6:1 and it was tested at the lower wind speeds of 2-5 m/s. The result shows that adding a wind concentrator can increase the rotational speed of the rotor, power coefficient, and the turbine power. The Savonius turbine with two blades has the best performance compared to the three and four blades. The Savonius blade wind turbine with the rotor diameter of 12 cm is the best Savonius turbine for the concentration ratio of 6:1.
Indonesia is one of the countries which has a largest pineaple plantation in Asia, that is more than 165.690 hektare besides Thailand, Filipina, and Malaysia. Pineaple is one of the plants which contains karbohidrat and sugar as well as corn, cassava, sugar palm, etc. Thus in this occasion the pineaple will be used as material for producing bioetanol cause besides its quantity is large, it’s potential to make bioetanol. This research head for identify the efect of fermentation periode and distilation temperature as independent variable to the specific gravity and heating value as dependent variable. In this research the fermentation periode used are 5, 7, and 9 days while distilation temperature are 60, 75, and 800C. Producing of this pineaple bioetanol is doing by fermentation proses. In producing this pineaple bioetanol each sample which mass is 1750 gr added with 75 gr crushed yeast or equal with 4,3 % mass of sample. From the research it’s found that the alcohol content is increase with fermentation periode and decresing of distilation temperature. Specific gravity decrease with increasing of fermentation periode and decreasing of distilation temperature. Heating value is increase with increasing of fermentation periode and deacreasing of distilation temperature.
In the present research preparation and characterization of polyester composite reinforced hybrid fiber Hibiscus tiliaceust bark fiber (HTBF) and palm fibers (PF). PF is obtained from palm plantation in Kekait village. HTBF has gained from the beach Krandangan, West Lombok, Indonesia. The fibers were treated with alkali by soaking it in 5% NaOH solution for 2 days Composites were made using the vacuum infusion method. The matrix used is polyester resin BTQN 157. The volume fractions between palm fibers (PF) and Hibiscus tiliaceust bark fiber (HTBF) are, 5% : 25%, 10% : 20%, 15% : 15%, and 20% : 10 %. Specimens for tensile testing using the ASTM D638-03 Type I standard and impact testing using the Izod method, specimens using the ASTM D256-03 standard, and further Observation of the specimen fracture was carried out using Canon EOS 700D Kit (EF S18-55 IS STM) camera. The results of this study indicate the addition of the volume fraction of palm fiber (PF), affects the tensile strength, modulus of elasticity, impact toughness and the extent of the fracture shape of the specimen. As the volume fraction of PF increases, the tensile strength, modulus of elasticity, fracture area increases, but the impact toughness of the specimen decreases. The specimen is suitable to be used as a leveler, mainly crushing and destroying paddy fields
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