Judul: Carob as Alternatif Energy Source Dairy Concentrates on Fermentability and Digestibility In Vitro
Abstrak: Tujuan penelitian ini untuk mengevaluasi penggunaan carob sebagai sumber energi alternatif menggantikan molases dan onggok terhadap fermentabilitas dan kecernaan konsentrat sapi perah. Penelitian ini menggunakan Rancangan Acak Kelompok (RAK) yang terdiri atas lima perlakuan yang terdiri dari konsentrat dengan onggok 10% (K1), konsentrat dengan molases 10% (K2), konsentrat dengan onggok 5% + carob 5% (K3), konsentrat dengan molases 5% + carob 5% (K4), serta konsentrat dengan carob 10% (K5) dengan empat kelompok berdasarkan pengambilan cairan rumen. Analisis data menggunakan metode ANOVA dengan SAS ODA dan jika berpengaruh nyata diuji lanjut Tukey. Hasil analisis menunjukan substitusi carob tidak berpengaruh nyata (P>0,05) terhadap pH rumen, populasi bakteri, populasi protozoa, kecernaan bahan kering dan bahan organik, namun berpengaruh nyata (P<0,05) terhadap konsentrasi NH3 dan VFA. Penggunaan carob sebagai kombinasi sumber energi sebanyak 10% dapat meningkatkan konsentrasi VFA yang dihasilkan serta mempertahankan pH, konsentrasi NH3, populasi mikroba, dan kecernaan., The objective of this study was to evaluate the use of carob as an alternative energy source replacing molasses and tapioca waste on the fermentability and digestibility of dairy cattle concentrate. This study used a Randomized Block Design (RDB) consist of five treatments including concentrate with 10% tapioca waste (K1), concentrate with 10% molasses (K2), concentrate with 5% tapioca waste + 5% carob (K3), concentrate with 5% molasses + 5% carob (K4), and concentrate with 10% carob (K5) with four groups based on rumen fluid sampling. Data analysis was performed using ANOVA method with SAS ODA and if significant effect, further tested with tukey. The results of the analysis showed that substitution of carob did not significantly affect (P>0.05) rumen pH, bacterial population, protozoal population, dry matter digestibility and organic matter digestibility, however, substitution significantly affected (P<0.05) NH3 concentration and VFA. The use of 10% carob as combination of energy sources can increase VFA produced also maintain pH, NH3, microbial population and digestibility.
Keyword: carob, Energi, molases, onggok

Judul: Evaluation of Carob Powder as an Energy Source on Fermentability and Digestibility of Dairy Cow Rations In Vitro
Abstrak: Carob (Ceratonia siliqua L.) merupakan sumber energi potensial yang mengandung karbohidrat tinggi (64%), namun penggunaan untuk ransum sapi perah masih terbatas. Penelitian ini bertujuan untuk mengevaluasi penambahan bubuk carob terhadap fermentabilitas dan kecernaan secara in vitro menggunakan rancangan acak kelompok (RAK) dengan 5 perlakuan dan 4 kelompok pengambilan cairan rumen. Perlakuan yang diberikan meliputi ransum + 6% onggok (R1), ransum + molases 6% (R2), ransum + 3% carob + 3% onggok (R3), ransum + 3% carob + 3% molases (R4), ransum + 6% carob (R5). Peubah yang diuji meliputi pH, konsentrasi NH3, VFA total, populasi bakteri dan protozoa rumen, serta kecernaan bahan kering dan kecernaan bahan organik (KCBK dan KCBO). Data dianalisis menggunakan ANOVA, dengan signifikansi pada P<0,05, kemudian dilakukan uji lanjut Duncan. Hasil penelitian menunjukkan bahwa pemberian bubuk carob hingga 6% (R5) signifikan meningkatkan VFA total dan populasi bakteri. Simpulan penelitian ini adalah pemberian bubuk carob memberikan respon yang sama dengan molases dan onggok pada sebagian besar parameter kecuali VFA, namun kombinasi carob dan molases menurunkan populasi bakteri., Carob (Ceratonia siliqua L.) is a potential energy source that contains high carbohydrate (64%), but its use for dairy cow rations is still limited. This study aimed to evaluate the addition of carob powder on fermentability and digestibility in vitro using a randomized block design (RBD) consisted of 5 treatments and 4 groups of rumen fluid collection. The treatments included rations with 6% cassava waste (R1), rations with 6% molasses (R2), rations + 3% carob powder + 3% cassava waste (R3), ration 3% carob powder + 3% molasses (R4), rations with 6% carob powder (R5). The parameters tested include pH, NH3 levels, total VFA, rumen bacteria and protozoan populations, and dry matter digestibility and organic matter digestibility (DMD and OMD). Data were analysed using ANOVA, with significance at P<0.05, followed by Duncan’s test. The results showed that carob inclusion up to 6% (R5) significantly increased total VFA and bacterial populations. The conclusion of this study is carob inclusion produced similar results to molasses and cassava waste across most parameters except VFA, but combining carob with molasses and cassava waste tended to decrease total bacterial.
Keyword: carob powder, digestibility, energy source, fermentability

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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