Judul: Studi Keanekaragaman Jenis Tumbuhan Pakan Bekantan (Nasalis Larvatus) Di Taman Nasional Tanjung Puting Kalimantan Tengah (Studi Kasus Di Areal Research Pondok Ambung )
Abstrak: Bekantan (Nasalis larvatus) is one of an endemic primate in Indonesia, especially in Kalimantan and this species protected by the law. Bekantan had a priority to be an object in food ecology research because of this species is rare and also endemic. Their habitat limited in forest around the rivers, mangrove and peat swamp forests and nowadays some of that threatened by human activities. On February, 22nd 2008 fire attack Pondok Ambung Areal Research part of Tanjung Puting National Park which burned around 5,6 ha. This damage decrease the number of bekantan population along the year. Because of that, conservation action needed into population of bekantan, ecosystem of peat swamp forest and swamp forest around the rivers. Study about food variety in bekantan especially at Tanjung Puting National Park, Province of Center Kalimantan really important as an a conservation action in population of bekantan. Direct and indirect identification of feed variety was used as method to collect the data. Direct observation was conducted for 12 days on 4 groups of bekantan. Vegetation analyze was conducted by using line transect method. This study found 11 species that consumed by bekantan in 12 observation days. From 12 time monitoring, most after consumed vegetation is Genua motleyana, but they just consumed the leaves. Crudia teysmanii and Eugenia zeylanica are another choice often Genua motleyana. In Eugenia zeylanica, bekantan just consumed the flowers and leaves. Comparison between leaves : flowers : fruit is 79% : 18 % : 3%. Result from vegetation analysis in swamp forest and lowland forest found 22 food variety of bekantan. Result from species diversity indexs (Shannon- Wieners index) showed foods variety level in swamp forest is more diverse than in lowland forest. This difference may influenced by difference of seasons that related to tree phenology. If was found 22 foods species of bekantan in swamp forest and lowland forest, among them Genua motleyana, Syzygium leucoxylon, Neoscortechinia sp., Eugenia zeylanica and Crudia teysmanii. Bekantan prefer to consumed leaves than flowers and fruits.
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Judul: Karakteristik Habitat dan Populasi Bekantan (Nasalis larvatus Wurmb. 1787) di Kebun Karet Dusun Pararawen Kalimantan Tengah
Abstrak: Bekantan merupakan salah satu satwa endemik Borneo yang dilindungi di Indonesia. Populasinya semakin menurun akibat banyaknya sebaran populasi yang kecil dan sebagian besar berada di luar kawasan konservasi. Penelitian ini bertujuan untuk melakukan kajian mengenai karakteristik habitat, populasi, serta ancaman bekantan di kebun karet Dusun Pararawen. Data ini penting digunakan sebagai upaya dalam konservasi bekantan. Pengambilan data dilakukan pada Bulan Maret 2014. Metode yang digunakan untuk memperoleh data habitat adalah dengan observasi lapang (data aspek fisik habitat dan pakan) dan metode analisis vegetasi (data vegetasi), serta data populasi diperoleh dengan menggunakan metode konsentrasi. Hasil penelitian menunjukkan bahwa bekantan dijumpai pada ketinggian antara 66 – 256 m dpl. Terdapat 41 jenis tumbuhan dari 21 Famili yang diperoleh dari hasil analisis vegetasi dan 15 jenis tumbuhan dimanfaatkan sebagai sumber pakan bekantan serta 1 jenis invertebrata (rayap). Populasi bekantan yang diperoleh adalah sebanyak 34 ekor yang terdiri dari 5 jantan dewasa, 10 betina dewasa, 10 remaja, dan 9 anakan yang terbagi kedalam 4 sub kelompok.
Keyword: bekantan, habitat, populasi

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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