Judul: Daily Behavior and Space Utilization of Timor Deer, Sambar Deer and Bawean Deer in Captive Breeding
Abstrak: Penangkaran rusa timor (Rusa timorensis), rusa sambar (Rusa unicolor), dan rusa bawean (Axis kuhlii) dilakukan secara bersama di dalam satu areal kandang yang sama, seperti yang dilakukan di Penangkaran Rusa, Hutan Penelitian Dramaga, Bogor. Ketiga jenis rusa ditangkarkan bersama-sama di dalam satu areal kandang pedok terbuka berukuran 38 x 38 meter. Data perilaku harian dan penggunaan ruang dikumpulkan dengan metode focal animal sampling. Untuk mengidentifikasi penggunaan ruang, maka ruang kandang dibagi menjadi tiga zona yang berbeda (Zona Depan 1, Zona Tengah 2, Zona Belakang 3). Rusa timor menunjukkan perilaku makan (ingestif) lebih sering (37,32% hari kerja dan 36,06% pada akhir pekan) dibanding rusa sambar (25,35% akhir pekan dan 26,63% hari kerja) dan rusa bawean (17,68% akhir pekan dan 18,89% hari kerja). Terkait penggunaan ruang, ketiga jenis rusa lebih sering menggunakan zona 1 dibanding dengan kedua zona lainnya, berturut-turut yang paling sering adalah rusa bawean (73,50%), rusa timor (71,34%) dan rusa sambar (62,46%)., The captivity of timor deer (Rusa timorensis), Sambar deer (Rusa unicolor) and Bawean deer (Axis kuhlii) is carried out together in the same enclosure area, as was done in Deer Captivity, Dramaga Research Forest, Bogor. The breeding of timor deer (Rusa timorensis), sambar deer (Rusa unicolor), and Bawean deer (Axis kuhlii) is carried out together in the same enclosure area, as was done in Deer Breeding, Dramaga Research Forest, Bogor. The three types of deer are bred together in an open pedok cage measuring 38 x 38 meters. Daily behavior and space use data were collected using the focal animal sampling method. To identify space usage, the cage space is divided into three distinct zones (Front Zone 1, Middle Zone 2, Rear Zone 3). Timor deer show eating behavior (ingestive) more often (37,32% on weekdays and 36,06% on weekends) than Sambar deer (25,35% on weekends and 26,63% on weekdays) and Bawean deer (17, 68% weekends and 18,89% weekdays). Regarding the use of space, the three species of deer use zone 1 more often than the other two zones, respectively Bawean deer (73,50%), Timor deer (71,34%) and sambar deer (62,46%) are the most frequent.
Keyword: captive breeding, daily behavior, deer, space utilization

Judul: Perilaku dan Aspek Pakan Rusa Timor (Rusa timorensis Blainville 1822) Remaja Pada Kandang dan Jenis Pakan yang Berbeda
Abstrak: Efforts to improve the productivity of java deer (Rusa timorensis) can be done through improvements in the feed management and maintenance customized with deer behavior. This research aims to study the aspects of feed and daily behavior of java deer in adolescent age group (12-24 months) in captive breeding of Hutan Penelitian Dramaga, Bogor. In this study, deer were fed selective forage (Coix lacryma-jobi Lour, Pennisetum purpureum Schum, Hierochloe horsfieldii Maxim, and Commelina benghalensis L) and field grass. Result show on individual cages, the highest feed preference value was Pennisetum purpureum Schum and the highest feed palatability value was Hierochloe horsfieldii Maxim. The opposite result occured in the collective cage. On feeding selective forage, the average daily consumption of fresh and dry matter of feed, daily gain and feed efficiency deer were 4.87± 0.51 kg/head/day, 0.73±0.07 kg/head/day, 0.15±0.05 kg/head/day and 22.59%. Averaged digestibility coefficients of feed of java deer was 52.95±6.90% of dry matter, 30.87±26.00% of crude fat, 49.68±2.76%of crude protein, 56.49±6.48% of crude fiber, and 59.21±8.40% of N-free extractive. Daily behavior of java deer in individual cages were dominated by eating, rumination, movement and resting. In conclusion, to increase production that deers is better to be raised on individual cages.
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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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