Judul: Penyebaran Spasial Keanekaragaman Tumbuhan Pangan dan Obat di Kampung Nyungcung, Desa Malasari, Kecamatan Nanggung, Bogor.
Abstrak: Nyungcung Kampong is situated near to the forest, in which very rich in term of plant biodiversity. The plant potentially can be utilized by the community to fulfill their need of food and medicine. The objective of the research was to identify the diversity, potency, and spatial distribution of food and medicinal plants in Nyungcung Kampong. The research was conducted by vegetation inventory and eksploration during March 2015. Result showed there was different diversity value and evenness index among every growth strata. In total, there were 318 specieses or 98 families that consist of 56 species of food plants, 112 species of food functional plants, and 150 spesies of medicinal plants. With regard to land cover/land use class, home garden had the highest number of food and medicinal plants. The plants distributed mostly on elevation of about 600--800 mdpl (308 species) or at gentle slope of about 0-8% (168 species). In addition to slope and elevation, biotic (factor caused by human) have a considerable effect in the distribution of plants. In short, the community need of necessity food and medicine can be provided by the forest and its surrounding areas.
Keyword: food and medicinal plants, Nyungcung kampong, plants potency, spatial distribution

Judul: Sebaran Spasial Tumbuhan Pangan yang Dimanfaatkan Masyarakat Kampung Nyungcung, Desa Malasari, Kecamatan Nanggung, Kabupaten Bogor.
Abstrak: Nyungcung Kampong is one of the kampong which has variety local food. The purposes of this research are to identify character of food and its utilization type. In addition, character biophysical condition and its accessibility in Nyungcung Kampong community are recorded. Data were collected by literature study, interview, and observation. The result showed that there are 155 crops species from 61 families that are utilized by the local people and most of them are from Fabaceae families. The most widely used was the fruits and tree. In comparisn with wild species, cultivated plants mostly utilized. In term of spatial distribution, the plants were found at eleveation of about 700-800 mdpl. The nearest plant distribution area was located 22.12 meters and the farest was 413.43 meter from their house.
Keyword: crops, nyungcung kampong, spatial distribution

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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