Judul: Tingkat Retensi Karoten Total dan Protein serta Aktivitas Antioksidan Masakan Torbangun (Coleus amboinicus Lour)
Abstrak: Bataknese Simalungun women in North Sumatra who consume Torbangun soup believe that it can stimulate the breast milk production. Until now information and use of Torbangun is still very limit. People need to know more about Torbangun apart from its benefit but also on the effect of cooking towards nutrients especially those sensitive to the total carotenoids and proteins as well as antioxidant activity. The purpose of this research was to study the effects of Cuisine types on the retention of carotenoids, protein, and antioxidant activity of Torbangun cuisine. There are three types of Torbangun cuisine used in this study namely lodeh, pecel, and stir-fry. Chemical analysis conducted in this study include the analysis of water, fat, protein, ash, carbohydrate cntents, total carotene, and antioxidant activity. The study used Complete Randomized Design (CRD). Data were analyzed using Analysis of Variance, Duncan, and independent T-Test. Cuisine types significantly effected the nutrient content of water, ash, carbohydrates, and carotene, while there were no significant effect of the nutrient content of fat, and protein then antioxidant activity. The contribution of vitamin A in the torbangun cuisine (per serving) was more than 20% of the recommended reference Label Nutrition (ALG), so that these products can be categorized as high provitamin A. Independent T-Test results showed that the levels of crude carotene lodeh before and after cooking were significantly different (p <0.05), whereas carotene levels of pecel and stir-fry were not significantly different, as well as protein content and antioxidant activity before and after cooking (p > 0.05).
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Judul: Evaluasi Kandungan Nutrisi Daun Torbangun (Coleus amboinicus Lour) terhadap Daya Hidup Mikroba Rumen dan Kecernaan In vitro
Abstrak: This research was conducted to examine the effect of torbangun (Coleus amboinicus Lour) in the diet on the viability of rumen microbes (bacteria and protozoa populations) and in vitro digestibility, using randomized block design with rumen liquid collecting time as a group with 5 treatments and 3 replicates. The treatments were: R0 (kontrol): 60% H + 40% K, R1: RO + 2.5% T, R2: RO + 5% T, R3: RO + 7.5% T, R4: RO + 10% T. Data were analyzed by Analysis of Variance. Further tested Contrast Ortogonal and Polynomial, if there was significant differences. Parameters that measured include: viability rumen of microorganisms (bacteria and protozoa populations), fermentability (the concentration of TVFA and N-NH3), and digestibility (dry and organic matter) in the rumen. The experiment showed that treatments significantly (P<0.05) affected dry matter digestibility and VFA concentration on additional treatment torbangun leaves as much as 2.5% in the ration (R1).
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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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