Judul: Daun  Sambiloto (Andrographis paniculata Nees) dalam Ransum Ternak Perah: Suatu  Analisis In Vitro Keamanan Dan Aktivitas Mikroba Rumen
Abstrak: Penelitian ini bertujuan menganalisis keamanan penggunaan daun sambiloto (andrographis paniculata Nees) di dalam ransum terhadap populasi mikroba rumen dan kecernaannya di dalam rumen in vitro. Rancangan percobaan yang digunakan pada tahap awal adalah RAK dengan 4 kelompok dan 5 perlakuan menggunakan metode infusa dengan level 0, 5, 10, 15 dan 20% ekstrak daun sambiloto. Pada penelitian in vitro digunakan RAK dengan 3 kelompok dan 7 jenis ransum sebagai perlakuan. Perlakuan terdiri dari: R0: 60% Hijauan + 40% Konsentrat (Kontrol), R1: R0 + 2,5% daun sambiloto (DS), R2: R0 + 5% DS, R3: R0 + 7,5% DS, R4: R0 + 10% DS, R5: R0 + 12,5% DS, dan R6: R0 + 15% DS. Analisis data dan uji lanjut menggunakan analisis sidik ragam (ANOVA), polinomial ortogonal, kontras orthogonal, dan regresi. Parameter tahap awal yang diukur meliputi daya hidup bakteri dan protozoa rumen, sedangkan in vitro mengukur pH, fermentabilitas, dan kecernaan in vitro. Hasil penelitian menunjukkan bahwa peningkatan penggunaan ekstrak daun sambiloto mengakibatkan penurunan secara linier populasi bakteri total, namun masih dalam rentang normal. Penggunaan daun sambiloto sampai 10% di dalam ransum ternak perah tidak mengganggu pertumbuhan mikroba rumen dan aktivitas fermentasi di dalam rumen secara invitro., This study aimed to analyze the safety of the use of bitter leaf (Andrographis paniculata Nees) in the diet on the rumen microbial population and its digestibility in the rumen in vitro. The experimental design used in the early stages used randomized blok disign with 4 group and 5 treatments the infusion method with levels 0, 5, 10, 15 and 20% bitter leaf extrack. In in vitro, testing used randomized blok disign with 3 group and 7 treatments. The treatments were: R0: 60% Forage + 40% Concentrate (Control), R1: R0 + 2.5% bitter leaf (DS), R2: R0 + 5% DS, R3: R0 + 7.5% DS, R4 : R0 + 10% DS, R5: R0 + 12.5% DS, and R6: R0 + 15% DS. Data analysis and further testing used analysis of variance (ANOVA), polynomial orthogonal, orthogonal contrast, and regression. The results showed that the increase in the use of bitter leaf extract resulted in a linear decrease in the total bacterial and protozoan population, but was still within the normal range. Bitter leaf up to 10% in dairy cattle rations does not interfere with rumen microbial growth and fermentation activity in the rumen in vitro.
Keyword: Andrographis paniculata Nees, digestibility, fermentability, in vitro, rumen microbes

Judul: Binahong Leaf (Anredera Cordifolia (Ten.) Stennis) in Dairy Cattle Ration: An In Vitro Analysis of Microbial Safety and Activity in the Rumen
Abstrak: Penelitian ini bertujuan mengkaji keamanan penggunaan daun binahong (Anredera cordifolia (Ten.) Stennis) dan imbuhannya dalam ransum ternak perah melalui pengamatan daya hidup mikroba, fermentabilitas dan kecernaan in vitro. Pengujian daya hidup mikroba rumen menggunakan ekstrak daun binahong dengan level 0%, 5%, 10%, 15% dan 20%. Data dianalisis dengan analisis regresi. Pengujian in vitro, digunakan rancangan acak kelompok (RAK) dengan 7 perlakuan dan 3 waktu pengambilan rumen sebagai kelompok. Perlakuan terdiri dari: R0: 60% hijauan + 40% konsentrat (kontrol), R1: R0 + 2.5% daun binahong (DB), R2: R0 + 5% DB, R3: R0 + 7,5% DB, R4: R0 + 10% DB, R5: R0 + 12,5% DB, R6: R0 + 15% DB. Data dianalisis menggunakan analisis sidik ragam (ANOVA), pengujian lanjut menggunakan kontras orthogonal. Penggunaan daun binahong (Anredera cordifolia (Ten.) Stennis) sampai 10% di dalam ransum ternak perah laktasi masih dinilai aman jika dianalisis dari dinamika populasi mikroba dan aktivitas fermentasinya di dalam rumen secara in vitro., This study aimed to assess the safety of using binahong (Anredera cordifolia (Ten.) Stennis) leaves and their supplementation in dairy cattle rations by observing in vitro microbial viability, fermentability and digestibility. Rumen microbial viability test used binahong leaf extract with levels of 0%, 5%, 10%, 15% and 20%. Data were analyzed by regression analysis. In in vitro testing used randomized block design with 7 treatments and 3 rumen collection times as a group. The treatments were: R0: 60% forage + 40% concentrate (control), R1: R0 + 2.5% binahong leaves (DB), R2: R0 + 5% DB, R3: R0 + 7.5% DB, R4: R0 + 10 %DB, R5: R0 + 12.5% DB, R6: R0 + 15% DB. Data were analyzed by analysis of variance (ANOVA), further tested orthogonal contrast. The use of binahong leaves (Anredera cordifolia (Ten.) Stennis) up to 10% in the ration of lactating dairy cattle is still considered safe when analyzed from the dynamics of the microbial population and its fermentation activity in the rumen in vitro.
Keyword: binahong (Anredera cordifolia (Ten.) Stennis), fermentabilitas, in vitro, kecernaan, mikroba rumen

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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