Judul: Pemanfaatan Hijauan di Pematang Sawah di Desa Cihideung Udik, Cibitung Tengah, dan Situ Udik, Kabupaten Bogor, Jawa Barat
Abstrak: Dike in is considerable as forage potency. Forage growing around the dike in has been used by farmers, depend on people who sickling in the dike in. This study aimed to evaluate the potential of forage in dike in as forage source and potency local forage mapping also to evaluate the dike in changes. This study used botanical composition analysis, vegetation analysis, capacity improvement of ruminant livestock population, and area mapping. The results of botanical composition showed that Eleusine indica (L.) Gaertn., Ageratum conyzoides L., and Axonopus compressus (Sw.) P. Beauv. were the top three. The conclusion of the research conducted in the dike in at Cihideung Udik, Cibitung Tengah, and Situ Udik village are Brachiaria mutica (Forsk.) Stapf., Pennisetum purpureum Schumaker., and Eleusine indica (L.) Gaertn. are potential as forages source.
Keyword: dike in, forage potential, geographic information system, botanical composition

Judul: Pemanfaatan Hijauan di Lahan Irigasi di Desa Cihideung Udik, Cibitung Tengah, dan Situ Udik, Kabupaten Bogor, Jawa Barat
Abstrak: Irrigation dike which overgrow with a variety of vegetation potentially as forage source, but still underutilized by farmers. The aim of this research was to evaluate how much irrigation area that is potential for forage source and mapping potential forage source at Cihideung Udik, Cibitung Tengah, and Situ Udik village. This research used geographic information system mapping, botanical composition, vegetation analysis, and capacity improvement of ruminant livestock population. The result of botanical composition showed that Wedelia montana var pilosa H., Brachiaria mutica (Forsk.) Stapf., and Panicum repens L. occupies the main peringkat. The vegetation analysis showed that Wedelia montana is the dominant plant. The conclusion of this research was irrigation area at Cihideung Udik, Cibitung Tengah, and Situ Udik village have forage potential to be used by farmers. The two forages that dominate these villages are Panicum repens L. and Brachiaria mutica (Forsk.) Stapf..
Keyword: irrigation, geographic information system, forage potential, botanical composition

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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