Judul: Proses Adopsi Agroforestri Sengon Petani Teh (Studi Kasus di Desa Sukaresmi, Kecamatan Kadupandak, Kabupaten Cianjur, Provinsi Jawa Barat)
Abstrak: Adoption of sengon agroforestry in tea crops of smallholder will influence private forest development and changeover of tea (Camellia sinensis) commodity in Sukaresmi Village. The research aims to know the characteristics and sengon agroforestry management system in tea crops smallholder Sukaresmi Village and how tea smallholder to adopt it. Data were colected from interview, observation, dan literature. Tea leaf productivity at sengon agroforestry is 2861.25 kg/ha/year and tea crops smallholder is 5133.33 kg/ha/year. It caused tea smallholder applied sengon agroforestry in their low productivity tea crops. Sengon agroforestry management system in tea crops smallholder Sukaresmi Village is similar with common private forest. Sengon agroforestry is innovation which diffused through the timber market channel or interactions between community members. The tea smallholder decision adopts sengon agroforestry is optional and generally based on economic consideration.
Keyword: sengon agroforestry, adoption

Judul: Kajian Pengelolaan Hutan Rakyat Sengon (Paraserianthes falcataria (L) Nielsen): Kasus Desa Kesenet, Kecamatan Banjarmangu Kabupaten Banjarnegara
Abstrak: This research aims to study the management and cultivation of sengon community forest, to presume its potential, and also to calculate the contribution of sengon and other agroforestry plants toward the farmer’s total income in Kesenet Village, Banjarmagu District, Banjarnegara Residence of Central Java. The methods of the data collection used were quantitative and qualitative method. The quantitative method was used to measure the dimension of sengon and other agroforestry plants with sixty sampling plots in 0,1 hectare of circle shape which were determined by using purposive sampling with 3,10% sampling intensity. The qualitative method was used to analyze the forest management by interviewing through questionnaires to the sixty chosen farmers who own sampling plots and by studying literature. In general, the forest management in Kesenet Village applied the land preparation and management, seeding, planting, cultivation, harvesting and marketing. The stages of the management activities have not been completely achieved because of the traditional hereditary system which was still used. The potency of sengon per hectare in Kesenet Village was estimated on the average of 79,27 m3/ha or between 50,99 m3/ha to 107,55 m3/ha. The total area of sengon in Kesenet village was 193,86 ha and then the total wood of sengon was achieved 15.368,24 m3 or between 9.863,66 m3 to 20.872,83 m3. The income contribution of sengon 4,37% and 84,68 % of salak pondoh of total income forest farmer was illustrated that the sengon cultivation still becomes a secondary business for Kesenet villagers. The efforts that should be done to develop the management of sengon community forest are both by intensifying counseling and training the sengon management technique gradually. Besides that, the market information in warranting the stability of a certain cost can make the farmers easier in bargaining position. The countermeasure of the insects, pests, and karat puru disease which have been attacking 80% sengon plants up until now needs to get a serious attention, especially to warrant the developmental continuation of society business in community forest of sengon.
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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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