Judul: Estimasi Kerugian Ekonomi Akibat Pencemaran Limbah Ternak dan Evaluasi Proyek Biogas di Desa Suntenjaya, Lembang, Jawa Barat
Abstrak: Suntenjaya Village which is located in headwaters of Cikapundung River. Most of its population as cow farmer, from 632 cow farmers in Suntenjaya Village just 100 cow farmers who use biogas, rest of them still waste their poultry’s waste to Cikapundung River. The research was aimed to estimate the economic losses caused by poultry’s waste in Suntenjaya Village, to evaluate the feasibility of biogas project in Suntenjaya Village and identify factors that affect revenue from biogas project, also to identify environmental and economic impacts from biogas. The total losses economic value was analyzed by replacement cost methods. The Result shows that biogas project is feasible to be developed. Variables that have significant influence of the biogas project are number of cattle and education. Economic impact of biogas from employment was 1.96%, furthermore fuel cost savings of biogas was Rp 1 406 160. Environmental impact show that mostly of cow farmer agree that biogas development project give positive impacts to enviroment
Keyword: financial feasibility evaluation, replacement cost, biogas

Judul: Dampak ekonomi sosial dan Lingkungan pemanfaatan limbah ternak sapi perah di Kampung Areng Desa Cibodas Kecamatan Lembang Kabupaten Bandung Barat
Abstrak: Indonesia has great beef cattle population potentially cause pollution from livestock waste. Utilization of livestock waste into biogas as an alternative energy is a solution. This study analyzed the perception of the respondents about the use of livestock waste into biogas, analyzed the factors that influence the decision of breeders in use livestock waste into biogas, to analyze the changes of energy consumption before and after the use of biogas and energy consumption cost difference between the farmers types I and II, and analyzed the impact of social and environment from the use livestock waste into biogas. The research results show that the majority of respondents have that utilization of livestock waste into biogas have direct and indirect benefit for breeders and community around location. Significant factors that influence th breeders decision to use biogas is long of cattle business, the number of livestock, the level of education , and the participation of the group of cattle. The results showed that the rate of dairy cattle business income type I is higher than type II with the the total value income of Rp 200.970 /month . The difference in the cost of energy consumption between the two types of cattle business Rp 22.050. The social and environment impact from the utilization of livestock waste into biogas are improve cultural cooperation communities, improve the performance of the group of cattle, changes in environmental conditions around the cage cleaner, and reduced air pollution due to a heap of livestock waste.
Keyword: Bogor Agricultural University, the impact of economicsocial and environment, logistic regression, livestock waste, biogas

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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