Judul: Kualitas Fermentasi Dan Kandungan Nutrien Silase Beberapa Jenis Rumput Yang Dipanen Pada Waktu Berbeda
Abstrak: The aims of the research were to analyze fermentation quality. The research used randomized factorial design (5x3) with factor A was grass sources (Pennisetum purpureum, Pennisetum purputhypoides, Panicum maximum, Brachiaria humidicola, and Paspalum notatum) and factor B was the harvest time (morning, noon, and night). The results showed that grass sources and harvest time significantly (P<0.05) influenced pH, solubility and Water Soluble Carbohydrate (WSC). Solubility, those of pH and WSC from Pennisetum purputhypoides were higher than those of the others, and pH and WSC lost from grass harvested at night were higher than the others silage. There were interaction between grass Pennisetum purputhypoides and time of harvesting. It is concluded that kind and harvesting time of the grass influenced pH, WSC and silage solubility but it did not affect sillage dry matter lost and number of lactic acid bacteria.
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Judul: Kualitas Silase Daun Singkong, Daun Ubi Jalar, dan Daun Lamtoro yang Dipanen pada Waktu Berbeda
Abstrak: dijadikan bahan pakan. Pemberian pakan hijauan pada ternak dapat berupa hijauan segar atau berupa hijauan yang diawetkan seperti hay dan silase. Silase merupakan pakan ternak yang dihasilkan melalui proses fermentasi an aerob dengan kandungan air yang tinggi. Keberhasilan dalam proses silase salah satunya ditentukan oleh kandungan Water Soluble Carbohydrate (WSC) yang ada pada bahan baku silase. Kandungan WSC pada hijauan berkaitan dengan penerimaan cahaya matahari. Tanaman merubah energi dari matahari menjadi gula sehingga konsentrasi gula secara umum lebih tinggi pada sore atau menjelang malam hari. Konsentrasi gula mulai menurun pada malam hari melalui proses respirasi dalam tanaman dan lebih rendah lagi pada pagi hari. Sehingga kajian kualitas silase hijauan yang dipanen pada waktu berbeda sangat diperlukan. Penelitian ini bertujuan untuk mengetahui dan membandingkan kualitas silase dari daun lamtoro, daun singkong, dan daun ubi jalar yang dipanen pada waktu berbeda. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) berpola faktorial (3x3). Faktor A adalah jenis hijauan (daun singkong, daun ubi jalar, dan daun lamtoro); faktor B adalah waktu panen (pagi, siang, dan sore hari).
Keyword: cassava leaves silage, sweet potato leaves silage, leucaena leaves silage, organoleptic characteristic, lactic acid bacteria (LAB) population, water Soluble Carbohydrate, WSC lost

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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