Judul: Pengaruh penambahan probiotik Leuconostoc citreum TSD-10 pada substrat yang berbeda terhadap kecernaan serat, aktivitas fermentasi, dan populasi bakteri rumen (in vitro)
Abstrak: Telah banyak usaha yang dilakukan untuk memanipulasi lingkungan rumen dengan tujuan memperbaiki efisiensi fermentasi yang menyeluruh dalam rumen, sehingga dapat memperbaiki produktivitas temak. Salah satunya adalah dengan penggunaan pakan tambahan yang mampu mempengaruhi beberapa komponen dari metabolisme rumen.
Keyword: Invitro, Fermentation, Bacteria

Judul: Evaluasi Penambahan Probiotik dan Enzim pada Pakan Ruminansia terhadap Fermentabilitas dan Kecernaan secara In Vitro.
Abstrak: Penelitian ini bertujuan mengevaluasi penambahan probiotik L. plantarum (P), combination enzymes (CE), dan enzyme stimulation secretion (ESS40) pada pakan secara in vitro. Penelitian dilakukan dua tahap, yaitu pengujian taraf probiotik menggunakan rancangan acak lengkap dengan 3 perlakuan (P1: 2%; P2:5%; P3:10%), pengujian fermentatif menggunakan rancangan acak kelompok dengan 12 perlakuan (X0 = ransum basal; X1 = X0 + 1% ESS40; X2 = X0 + 0.5% CE; X3 = X0 + 1% CE; X4 = X0 + 1% P; X5 = X1 + 0.5% CE; X6 = X1+ 1% CE; X7 = X1 + 1% P; X8 = X2 + 1% P; X9 = X3 + 1% P; X10 = X5 + 1% P; X11 = X6 + 1% P). Data dianalisis menggunakan analysis of variance (ANOVA) dan hasil yang signifikan (P<0,05) diuji lanjut menggunakan uji Duncan dan kontras ortogonal. Parameter yang diukur yaitu mikrobiologi probiotik, pH, konsentrasi NH3, KcBK, KcBO, VFA, total gas, dan gas metana. Penggunaan taraf inokulan berpengaruh nyata terhadap pH dan total asam laktat. Penambahan probiotik, CE dan ESS40 berpengaruh nyata terhadap VFA, total gas dan gas metana. Simpulan penelitian ini adalah penggunaan probiotik, CE, dan ESS40 belum optimal memengaruhi produk fermentasi rumen, namun menurunkan produksi metana., This study aims to evaluate the addition of probiotics L. plantarum (P), combination enzymes (CE), and enzyme stimulation secretion (ESS40) to feed in vitro. The study was conducted in two stages, probiotic level testing using a completely randomized design with 3 treatments (P1: 2%; P2: 5%; P3: 10%), fermentative testing using a randomized block design with 12 treatments (X0 = basal ration; X1 = X0 + 1% ESS40; X2 = X0 + 0.5% CE; X3 = X0 + 1% CE; X4 = X0 + 1% P; X5 = X1 + 0. 5% CE; X6 = X1+ 1% CE; X7 = X1 + 1% P; X8 = X2 + 1% P; X9 = X3 + 1% P; X10 = X5 + 1% P; X11 = X6 + 1% P). Data was analyzed using analysis of variance (ANOVA) and significant results (P<,05) were tested using Duncan's test and orthogonal contrast. Parameters was probiotics microbiology, pH, concentration of NH3, KcBK, KcBO, VFA, total gas, and methane gas. The use of inoculant levels had a significant effect on pH and total lactic acid. The addition of probiotics, CE and ESS40 had a significant effect on VFA, total gas and methane gas. The conclusion of this study is that the use of probiotics, CE, and ESS40 had not optimally affected rumen fermentation products, but reduced methane production.
Keyword: fermentative, gas, inoculant, digestibility, methane

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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