Judul: Pengaruh Propolis Trigona spp Asal Pandeglang Terhadap Beberapa Isolat Bakteri Usus Sapi dan Penelusuran Komponen Aktifnya
Abstrak: Propolis has been shown to have antimicrobial activity.This research dealts with analysis of effect of Trigona spp propolis on some bacterial isolated from cattle intestine and analysis of propolis active components. In the first step, propolis was extracted from bee hives by maceration technique using ethanol 70 percent. In the second step, propolis was subjected to antibacterial activity tests against pathogenic and nonpathogenic bacteria isolated from cattle intestine using agar diffusion method. The third step was phytochemycal analysis to test the presence of terpenoid, alkaloid, and flavonoid using Harborne method. The fourth step was analysis of active compounds of propolis through fractination using the Thin Layer Chromatography (TLC) and column chromatography methods. The fifth step, examination of antibacterial activity from factions to E. coli bacteria. And the last step was determination of active agents from the fraction of propolis which had higher antibacterial activity, by GC-MS technique. The results showed that yield of propolis was 17.23%. Antibacterial activity tests showed that propolis inhibited growth of pathogenic bacteria was 64.102 %, and non pathogen bacteria was 35.89%. The results of phytochemical analysis showed that propolis contained tanin, flavonoid and steroid. Determination of active agents showed the presence of eight fractions. Test on antibacterial activity of fractions to E. coli bacteria, showed that fraction C has the highest antibacterial activity. GC-MS analysis showed that fraction C contained 24 compounds. The biggest compound from fraction C was similar to 9,19-cyclolanost-24-en-3-ol, ( 3.beta). This compound had retention time of 40.25 minute and wide area of 49.91%. This compound can inhibit the growth of bacteria.
Keyword: Trigona spp, Propolis, Cattle intestine bacteria, Antibacterial agent, Active compounds

Judul: Antibacterial Activity of Microencapsulation of Trigona spp. Propolis Pandeglang after Following Exposure to Cattle Rumen Fluid.
Abstrak: The use of antibiotics to overcome diarrhea in cattle causes some problems related to microbe resistence and antibiotic residue. The alternative solution is using natural antibiotic like propolis. Aim of this research is study the effect of propolis microencapsulation on release time of propolis following exposure to cattle rumen fluid. Trigona spp. Propolis used on this research collected from Pandeglang, West Java. Propolis was extracted with maseration method. Then, condensed extract propolis was microencapsulated using maltodextrin as filler. Concentration of propolis were 2% and 4%. The mixture was dried using vaccum drying method. Then, propolis microcapsule was put into hard gelatine capsule size 00 and 1. Capsules were then tested with endurance test to cattle rumen. After that, antibacterial activity of propolis was tested using well diffusion method. Rendement of propolis extract produced is 8.81%. Propolis microcapsule has brown-yellow colour. Antibacterial activity of propolis was still detected until 24 hour after cattle rumen fluid treatment. Microencapsulation of propolis has a potency to slow down release of propolis active compounds in cattle rumen. The effective value of the highest inhibition compared to propolis X-brand on 227 mg of capsule size and propolis 4% is 160.69%.
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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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