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 Obat yang Dimanfaatkan Masyarakat Kampung Nyungcung, Desa Malasari, Kecamatan Nanggung, Kabupaten Bogor.
Abstrak: Nyungcung kampoong is least developed village, situated in Nanggung sub-district. The community of the kampoong utilized medicinal plant from its sorrounding location included forest area. For the purposes of management, spatial distribution mapping is very important. The purpose of the study is to identify the diversity and forms of utilzation as well as biophysical characteristics and accessibility. Data collection, interview and field observation were conducted in March 2015 in Nyungcung kampoong, Village Malasari, Nanggung subdistrict, Bogor. Result showed that there were 140 species of medicinal plants utilized by the community. Among the medicinal plants species family Zingiberaceae was the most predominantly utilized located in home garden and upland field. The average distance medicinal plants from the house was about 214 meters from the house situated on 600–800 meters above sea level, with gentle slope. Community utilized medicinal plants that located at its surrounding house. This is due to the fact that they have conducted domestication of the wild species from the forest. This showed that community contribute to forests conservaton.
Keyword: distribution, medicinal plant, utilization

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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