Judul: Persepsi peternak tentang inovasi teknologi biogas hasil fermentasi kotoran sapi (kasus kelompok peternak sapi perah "Maju Terus" kelurahan Kebon Pedes, Bogor)
Abstrak: The aim of this research were : (1) to know the characteristic of the cattle farmer at Kebon Pedes Village, (2) to know the communication activities of the cattle farmers, (3) to know the perception of the cattle farmers and decision to adopt the biogas technology innovation, (4) to analyze the correlation between the perception and communication.
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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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