Judul: Penyelesaian Persamaan Korteweg-De Vries Orde Tinggi Dengan Metode Ekspansi
Abstrak: Gelombang internal merupakan gelombang yang terjadi di bawah permukaan laut. Jenis gelombang internal yang sering diamati adalah gelombang soliter. Gelombang soliter internal adalah suatu gelombang berjalan yang dalam perambatannya mempertahankan bentuk dan kecepatannya. Salah satu model matematika yang dapat menjelaskan gelombang soliter internal adalah persamaan Korteweg-de Vries (KdV). Persamaan KdV diturunkan dari persamaan dasar fluida ideal, yaitu fluida yang taktermampatkan dan takkental. Persamaan KdV orde tinggi diselesaikan dengan metode ekspansi dan diperoleh penyelesaian dalam bentuk gelombang berjalan. Penggunaan metode ekspansi ini dilakukan dengan cara yang sederhana karena hanya melibatkan persamaan diferensial orde dua. Penyelesaian yang diperoleh diilustrasikan dalam grafik menggunakan software Mathematica 10.1.
Keyword: gelombang internal, metode ekspansi, persamaan KdV orde tinggi

Judul: Persamaan Korteweg-de Vries Orde Tinggi untuk Menggambarkan Gerak Gelombang Internal
Abstrak: The ocean can be considered of layers of fluid that each layer has a constant density. Internal waves are waves occur in the interface of every'two layers with different density. Because it occures underneath the surface of the ocean, it is invisible. One of internal waves is internal solitary waves. One of formulation that can describe intemal waves movement is KdV equation. KdV equation is derived from governing equations of ideal fluid in Lagrange formulation using asymptotic method. On this thesis, KdV equation is derived in higher order and then its solution is derived by using internal solitary waves assumption. An example of a two-layer fluid is a case will be used. By using Mathematica6 software, for this case will be obtained the coefficients in lower and higher order explicitly and the corresponding between coefficients and relative lower layer depths and fluid depths, the corresponding between coefficients and relative densities, and also observed the different between solitary waves in lower and higher order.
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Judul: Aktivitas Makan dan Status Gizi Lutung Perak (Trachypithecus cristatus) di Pusat Primata Schmutzer, Taman Margasatwa Ragunan, Jakarta
Abstrak: Silvered leaf monkeys (Trachypithecus cristatus) are primate that live in groups on trees and consume leaves. The feeding activities of silvered leaf monkey relates to the fulfillment of their dialy energy. The energy is needed for the continuity of the group existence. The feeding activities of silvered leaf monkeys have several activities. They are observing, taking, sorting, processing, biting, chewing, ingesting, pulling out their mouth, and disposing the feed. The study aimed to identify the feeding activities, kind and composition of feed, nutrient consumption and energy of silvered leaf monkeys (Trachypithecus cristatus) in Schmutzer Primate Center (PPS), Ragunan Zoo, Jakarta. Data is collected from June to September 2011 with total of 480 hours observations. The data collection for the feeding activities was performed using ad libitum and focal animal sampling methods. Based on the observations, there were three types of activities with the highest frequency. Such as resting, locomotion, and feeding activity at 44.87%, 40.89%, and 38.70%. Respectively the chewing feed activities on infants were the higest of the feeding activities (36.90%). Silvered leaf monkeys in Schmutzer Primate Center (PPS) have good palatability in type of lamtoro leaves (Leucaena glauca). The result of the study revealed that adult and infants monkeys have sufficient dry matter and protein consumption (40,5 g/BW/d, 8 g/BW/d and 63 g/BW/d, 12,5 g/BW/d), but less for fat and energy (2,37 g/BW/d, 23,87 kcal/BW/d and 3,75 g/BW/d, 37 kcal/BW/d), while nutrient recommendation
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