Judul: Aktivitas Makan dan Status Gizi Owa Jawa (Hylobates moloch) di Pusat Primata Schmutzer Taman Margasatwa Ragunan Jakarta
Abstrak: Hylobates moloch is endemic Indonesian primate which live in Java. The population of javan gibbon is declining because of the loss of feeds due to the degradation of habitats. This research aims to identify feeding activities, type of feeds, and nutrient status of javan gibbon (Hylobates moloch) in Schmutzer Primate Centre Ragunan Zoo Jakarta. Feeding activities observation was performed using focal animal sampling method which done in the same time with feed palatability. Feeds were given once a day which consist of fruits, vegetables, eggs, and bread. Highest feeding activities was recorded in the feeding given by zoo keeper. Biting and swallowing are the highest was shown Kecil (juvenile) feeding activities of first cage (22.00%). Highest feeding activity in second cage made by Rano (male) was chewing (21.43%) and in the third cage was carried out by Eneng (female) which were biting, chewing, and swallowing each 23.31%. Based on the palatability rank in the three cages, kumak (Lactuca indica) and banana (Musa paradisiaca) was categorized as the most favored feed. Based on the nutrient status, it was obtained that dry materials were consumed 683,83 to 1099,03 g/cage/day, protein consumption 13,13 to 19,37 g/cage/day, fat consumption 4,58 to 8,51 g/cage/day, and energy consumption from 594,64 to 1154,50 kal/cage/day.
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Judul: Jenis Pakan dan Pola Pemanfaatan Tajuk berdasarkan Aktivitas Makan Owa Jawa (Hylobates moloch Audebert, 1798) di Taman Nasional Gunung Halimun Salak Provinsi Jawa Barat.
Abstrak: Javan gibbon (Hylobates moloch) is one of Javan endemic primates. Gunung Halimun Salak National Park is one of its suitable habitat that supports significant number of population of the gibbon in Java. One of the habitat usage by Javan Gibbon is for foraging at tree canopies. Canopy is part of cover area for Javan gibbon which can be used to do some activity such as feeding and hiding from intruders. This study aimed to reveal food plants and and canopy usage pattern of Javan gibbon based on feeding activity. This study was conducted from June to August 2011 at Cikaniki Research Station, Citalahab village and the surrounding habitats. The equipments used in this study included binocular, range finder, camera, stop watch, ribbon, compass, tally sheet, rope, work map, and stationary. This study was focussed on two groups of Javan gibbon consisting 4 and 3 individuals respectively. The data collected were plant species and their coordinates of the trees that used by the Javan gibbon for their feeding activities, duration of feeding activities at the trees, and different spaces used of the animal at the trees’ canopy. The data collected using focal animal sampling with continous recording and scan sampling methods. The observations were carried out from 06.00 am to 05.00 pm or when Javan gibbon started doing their activities until they went to the sleeping trees. Javan gibbon consumed 47 kind of feeds covering 46 species of plants and one species of insect. Parts of the plants eaten by the Javan gibbon were fruits, leaves, and flowers representing 77,8% , 21,02% , 1,18% respectively. The Javan gibbon was also observed eating insects which was 0,002% of the total consumption. The usage of the tree canopy based on feeding activity can be catagorized into two types, trees as food sources and trees as place to eat. For feeding activity at trees used as food source, the Javan gibbon preferred the edges of canopies, that was CII canopy part. The canopy space selection at the edge of the canopy, aften found at ki dage tree (Bruinsmia styracoides) that used for hanging. Whereas trees that used as a place to eat, Javan gibbon were mainly found at the lower middle of canopy (AIII) which were mostly observed at rasamala trees (Altingia excelsa) which were also used for hanging. Javan gibbon used four models of tree architecture including attims, massart, rauh, and scarrone. Of the four models, attims was the most used by Javan gibbon when doing their feeding activities.
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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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