Judul: Characteristics of Cattle Forage Supply in Buffer Hamlet of Mount Merapi National Park
Abstrak: Peternakan sapi yang dikelola masyarakat dukuh penyangga Taman Nasional Gunung Merapi (TNGM) menerapkan sistem pemeliharaan intensif secara tradisional dengan perkandangan sederhana, ketersediaan pakan bergantung pada alam, dan pola penyediaan hijauan pakan dengan sistem cut and carry. Tujuan penelitian ini mengukur karakteristik penyediaan hijauan pakan ternak sapi di dukuh penyangga TNGM. Data yang digunakan adalah data primer yang dikumpulkan melalui survei dan observasi dan data sekunder yang diperoleh dari Badan Pusat Statistik (BPS), kantor kepala desa, dan sitasi dari sumber literatur yang relevan. Data yang diperoleh dianalisis secara deskriptif. Hasil penelitian menunjukkan penyediaan hijauan pakan ternak sapi di dukuh penyangga Taman TNGM dilakukan dengan metode cut and carry. Karakteristik penyediaan hijauan pakan dipengaruhi oleh umur peternak, jenis kelamin peternak, pengalaman beternak, jumlah ternak, jenis moda yang digunakan, dan kapasitas mengarit. Terdapat 24 jenis tumbuhan pakan yang ditemukan di kandang yang didominasi Pennisetum purpureum, Anadenanthera peregrina, dan Galingsoga parviflora., Cattle farms managed by community of buffer hamlet in Mount Merapi National Park (TNGM) applies a traditional intensive rearing system with simple caging, feed availability depending on nature, and a pattern of forage supply using cut and carry system. The aim of this research is to measure the characteristics of the supply of forage for cattle in Mount Merapi National Park buffer hamlet. The data used is primary data which collected through survey and observation activities and secondary data were obtained from the Central Statistics Agency (BPS), village head's office, and relevant literature. The data obtained was analyzed descriptively. The research results showed that the supply of forage for cattle in buffer hamlets of TNGM Park was carried out using the cut and carry method. The characteristics of forage supply are influenced by the farmer's age, farmer's gender, farming experience, number of livestock, type of mode used, and grazing capacity. There were 24 types of forage plants found in the cages which were dominated by Pennisetum purpureum, Anadenanthera peregrina, and Galingsoga parviflora.
Keyword: sapi, Taman Nasional Gunung Merapi, dukuh penyangga, hijauan pakan

Judul: Produktivitas Tenaga Pengarit dan Komposisi Hijauan Pakan Domestik di Peternakan Sapi Perah Pondok Ranggon, Kecamatan Cipayung, Jakarta Timur
Abstrak: Pondok Ranggon farm is one of the dairy farms in Jakarta where the pattern of availability forage depending on natural pastures. The aim of this experiment were to analyze labor productivity of grass seekers and to identify the composition of domestic forage in the dairy farm of Pondok Ranggon. This experiment used descriptive analysis, composition of botany and Nell and Rollinson method. The result showed that the capacity of grass seekers influenced by body weight, age and experience of cutting. The result showed, the highest capacity of cutting obtained by grass seekers in the age of 40 years old. Composition of forage consist of 52.63% grasses, 15.79% legumes and 31.58% rumbah. The most frequent type of grass that used were Imperata cylindrica (LINN.) P.Beauv., Pennisetum polystachyon (L.) Schult., and Panicum maximum Jacq. Type of legumes that often used was Calopogonium mucunoides Desv. and the types of rumbah that most commonly used were Asystasia coromodeliana Ness., Biden pilosa L. and Lantana camara L.
Keyword: legume, leaves, grass, cutting, composition of forage

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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