Judul: Pemanfaatan gas karbon tungku sekam untuk pengembangan kompor dengan bahan bakar campuran air dan bahan bakar nabati/bahan bakar fosil dengan metode kavitasi
Abstrak: The world's population continuously grows at a quarter million people per day. This fast growing population has raised the world energy consumption up to 474x1018 J per year with 80 to 90 percent derived from the combustion of fossil fuels. It is estimated that the fossil energy will be lasted in 42 years. Rice husk is an alternative of non-fossil energy that may be utilized in traditional way of cooking (burning it in a traditional stove). One of the renewable energy has great potential to overcome the energy crisis was utilization of rice husk to husk stove. However, the utilization of rice husks to generate carbon gas stove that quite a lot. Excessive concentration of carbon in the air is not a good for the environment, because the excees carbon released into the air can make climate change will complicate things even further. So, we need a new alternative to utilize carbon gases from burning the husk. The purpose of the utilization of carbon gases from burning rice husk is to create alternative energy that can reduce the release of carbon into the air as part of efforts to reduce global warming impact method used in the manufacture of alternative energy is the method by cavitation. In order to reduce the gas pollution the gas may be mixed with kerosene and water using sonochemical technique to produce dry steam, so the dry steam from cavitation process can be used as fuel. The process result can be done to boil 1 liter water with energy efficiency between 11.44% - 18.16%. The stove with fuel of waterbio ethanol using cavitation method can be used to boil 1 liter water with energy efficiency between 13.25% - 17.50%. Carbon flown on stove interfered toward energy efficiency and can accelerate boiling time of 1 liter water.
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Judul: Uji keragaan biopelet dari biomassa limbah sekam padi (Oryza sativa sp.) sebagai bahan bakar alternatif terbarukan
Abstrak: The abundance of rice husks in Indonesia is a potential source of biomass that can be converted into biomass pellet (biopellets). Pelletization can improve the quality and burning characteristic of the biomass. The purpose of this study is to improve the quality of rice husks biopellets by combining the rice husks powders and the rice husks charcoal. Carbonization process was done by using kiln drum whose height is 30 cm and diameter is 19 cm for ±5 hours at a temperature of 400 0C. The percentage of rice husks charcoal used was 0%, 10%, and 20%. Densification process was done by pellet mill whose capacity is 300 kg/h with a dies diameter of 8 mm. Used cooking oil was added to the raw material for 4.77% w/w. Biopellets was sun-dried for 4 hours. Then, the physico-chemical properties and the combustion characteristics were tested. Mass and energy flows were measured by using method of input-output analysis for the biopellets production process. The results of this research showed that the addition of rice husk charcoal into the rice husk biopellet generated a different effect significantly to the moisture content, ash content, volatile matter, bulk density, and the heating value of rice husks biopellet, but there was no significant effect to the level of fixed carbon, firmness, consumption rate, and the efficiency of combustion. Based on the physico-chemical properties and the combustion characteristics, rice husk biopellets that contained 10% of husk charcoal has the best quality. It has 3.60 % of moisture content, 17.47% of ash content, 72.86% of volatile matter, 9.68% of fixed carbon, and 728.43 kg/m3 of bulk density. The heating value of the biopellets was 4329.63 kcal/kg, while the firmness was 10.54 kg/cm2. In addition, the consumption rate of the biopellets was 1.84 kg/h while the efficiency of combustion was 8.34%. The production of rice husk biopellets on a laboratory scale produced yield of 18.67%. Biopellets increased the heating value of ricu husk for 25.49%.
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Judul: Profil Antibodi IgM dan IgG pada Beruk (Macaca nemestrina) setelah Diinfeksi Virus Dengue Serotipe-3 (DEN-3) melalui Rute Intravena
Abstrak: The aim of this study was to detect IgM and IgG in pig-tailed macaques (Macaca nemestrina) primarily innoculated by Dengue virus serotype-3 (DEN-3) by intravenous route. A total of 84 plasma samples were examined in the study. Plasma samples were taken on day 0 before infection, followed by plasma collections on day 1 through day 13 post infection. The obtained plasma samples were analyzed using indirect ELISA test. The results showed the increasing titer of IgM started on day-3 post infection with its peak occurred on day 11 post infection and started to decline afterward; while the IgG titer started to increase on day 6 or day 7 post infection and continue to increase until the day 13 post infection. These results showed that in a primary infection of DEN-3 byintravenous route, the tendency of IgM titer increase was higher than the IgG titer increase; also shown that the IgM titer increase was occured earlier than IgG. The profile of IgM and IgG antibodies is outlined in this study.
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