Judul: Proses Co-Composting Abu Ketel dengan Bagas menggunakan Kotoran Sapi dengan Perlakuan Laju Aerasi dan Nilai C/N Awal
Abstrak: Boiler ash and bagasse contain high organic carbon and have a good characteristic, so it facilitate the circulation and air flow went into co-composting. The objective of this research were to utilize solid waste of sugar cane industry, in the form of boiler ash and bagasse by composting (co-composting) with addition of cow dung, to understand the influence of aeration rate to the compossing process of bagasse and boiler ash, as well as the cow dung, to understand the influence of first C/N to the compossing process of bagasse and boiler ash from sugarcane industry and also the cow dung. In this research, to increase nitrogen value, it was added with the cow dung. The cow dung contained high N, P, and K as compost. Co-composting was done by aerated pile method and a passive aerated treatment defines as a control. The treatment was done with different composition of bagasse, boiler ash, and cow dung and the different aeration. The aeration was conducted in the rate 0.8 l/minute kg ingredient, 1.2 1/minute kg ingredients, and C/N formulation 30, 40, 50. Composting process was done in 42 days with active aeration in the first week. The analysis showed that aeration technique had no significant effect to change the C/N value. Generally, aeration factor had no different interaction, while the first C/N formulation had different results.
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Judul: Pengaruh Perbedaan Nilai C/N Dan Laju Aerasi Pada Proses Co-Composting Bagasse Dengan Blotong Pada Limbah Industri Gula
Abstrak: The sugarcane industry in Indonesia produce the waste from bagasse and filter cake that until recently is still not optimum in processing. One of alternatives handling is co-composting bagasse and filter cake that will produce compost and can reduce the amount of sugarcane industry wastes. This research aims to utilize bagasse and filter cake of sugarcane industrial waste for composting and aeration as well as differing effect of giving the C/N of the process. Composting methods used were aerated static pile technique and uses two factors of aeration and C/N ratio. Aeration was provided via active aeration (0,4 L/Kg of material and 1,2 L/kg material) and passive aeration with C/N respectively 30, 40, and 50. The composting process was running for a month with active aeration at first week. Analysis results show that aeration technique proved didn’t have significant effect in changing C/N value. After analysis, result shows that the most decrease C/N value is compost with starting condition 50 of C/N value. Generally, aeration factor are not related yet and do not have any significant interaction to co-composting C/N value.
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Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model