Judul: Antibacterial Activity of Trigona spp. Bee Propolis From Pandeglang Against Enterobacter sakazakii.
Abstrak: Propolis has many advantages and specific potencies, due to its properties as antibacterial, antivirus, and anticancer. The characteristics and properties of E. sakazakii has been studied well due to its physiological properties and resistances in the environment. The research aim is to determine the propolis potency of Trigona spp as antibacterial agent against E. sakazakii. Propolis was extracted from bee hives of Trigona spp using maceration method with ethanol 70% (propolis extract) yielded 17,76% extract. The antibacterial activity test was performed by a modified agar well diffusion against three isolates of bacteria E. sakazakii IB-19b, IB-29a, and ATCC 35217. Through the initiation test, propolis activity was higher than commercial propolis, and lower than ampicillin. The effectivities of propolis extract to commercial propolis for each isolate IB-19b, IB-29a, and ATCC 35217 were 143,99%, 169,65%, and 155,76% respectively. The effectivities of propolis extract to ampicillin for each isolate IB-19b, IB-29a, and ATCC 35217 were 39,37%, 38,94%, and 47,37% respectively. The minimum inhibition concentration differed for each isolate, the minimum inhibition concentration for IB-19b, IB-29a, and ATCC 35217 were 12,50%, 25,00%, and 50,00% respectively. The propolis activity to each isolate showed the concentration dependent activity, the antibacterial activity decrease as the propolis concentration decrease.
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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: 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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