Judul: Pengaruh Penambahan Beberapa Aditif terhadap Kualitas Silase Daun Rami (Boehmeria nivea, L. GAUD)
Abstrak: Tingginya permintaan akan daging membuat industri peternakan semakin meningkat sehingga dibutuhkan pakan dalam jumlah yang tinggi pula terutama sumber serat untuk ternak ruminansia. Sumber serat di Indonesia umumnya diperoleh dari rumput dan limbah partanian. Pada musim hujan produksi rumput tinggi sehingga pakan untuk ternak akan tersedia tetapi pakan musim kemarau produksi hijauan akan menurun yang mengakibatkan pakan untuk ternak berkurang. Daun rami dapat digunakan sebagai alternatif pakan terutama pada musim kemarau. Hasil penelitian terdahulu menunjukkan bahwa daun rami mengandung semua nutrien utama yang diperlukan oleh ternak (Duarte, 1997), daun rami juga merupakan sumber protein daun terbaik untuk ternak (Pirie, 2005). Kandungan protein daun rami sekitar 20% dengan kandungan serat kasar sekitar 16%. Tiap tahunnya tanaman rami menghasilkan limbah hijauan berupa daun dan pucuk sekitar 300 ton bahan segar/ha (FAO, 2005). Daun rami dapat diperoleh dari sisa pemanenan batang yang dilakukan secara periodik dengan interval 25 – 40 hari. Oleh karena itu perlu dilakukan teknik pengawetan yang tepat agar daun rami dapat digunakan sebagai pakan harian.
Keyword: fiber source, agricultural waste, grass, animal feed, hemp leaf, preservation techniques, daily feed

Judul: Optimalisasi kualitas silase daun  rami (Boehmeria nivea, L. GAUD) melalui penambahan beberapa zat additif
Abstrak: A research to study the influence of additives and ensiling times on ramie leaves silage qualities for ruminant have been studied in vitro using completely and block factorial 3 x 3 designs. Three types of water soluble carbohydrate (WSC) and dry matter sources as additives (A1 = cassava meal, A2 = pollard and A3 = corn meal) and three ensiling times (B1 = 28, B2 = 35, and B3 = 42 days) have been investigated. The degradability of organic matter to form VFA and protein to form NH3 were measured according to General Laboratory Procedure (1966), while the rate organic matter fermentation was measured follow the procedure of Menke et al., (1979). Value of pH and protein degradability were measured follow procedure of Naumann dan Bassler (1997) and Carro dan Miller (1999). The variable of this research consist of physical characteristic and fermentation parameters, fermentability and digestibility of the silages by ruminant have been determined in vitro. In generally, physical characteristic of ramie leaf silage are green brown, lactic acid odor and softer texture. Ramie leaf silage with additive corn meal (A3) have breakage. pH parameters showed that A1 acidified the silages faster than the A2 ones (3,62 vs 5,13). High pH of A3 (7,35) treatment was caused by the rought texture of corn meal used in this experiment. The silages were categorized as fermentable and high digestible feeds for ruminants (NH3 > 8,89 mM, VFA > 94.88 mM). Production gas for 24 hours incubation rumen liquor and estimation of organic matter digestibility (OMD) after 6 weeks ensiling time were around 72% and 50%.
Keyword: 

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.
Keyword: