Judul: Ciri kimiawi asam resin kopal  Agathis loranthifolia
Abstrak: Copal is originated from exudate of Agathis loranthifolia trees, which flows out from the tapping. Indonesian copal includes manila copal, is divided into four groups among others: bua, loba, melengket and Pontianak copal. Research of resin acid from copal has not been widely studied. Therefore, purpose of this study is to identify resin acids of copal from Sukabumi and Ternate area. Extraction was done using acetone:MeOH (9:1) solvent, followed by fractionation using some solvents, i.e. n-hexane, ethylacetate, H2 O, and acetone:MeOH (9:1). Identification was done using gas chromatography-mass spectrometer (GCMS). The quality of copal was evaluated based on SNI 7634-2011. Resin acids copal from Sukabumi identified by GCMS are 44% limonene, ethylene oxide hexamer, cis-limonene oxide, toluene, trans-carveol, 2-siclohexane-1-one, trans-limonene oxide, and alpha pinene. Copal from Ternate are 37% limonene, ethylene oxide hexamer, preludin, toluene, carveol 1, 2-siclohexane-1-one, acetat acid, hexaethylen glycol, champhen, and trans-limonene oxide. However, fractionation of the copal converted resin acids to 100% carvone. These results suggest that limonene are easily oxidized to carvone. Properties of manila copal from Sukabumi and Ternate fall to the first class, and are possible to be improved to the premium class by removing some dirt compount.
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Judul: Eksplorasi dan identifikasi senyawa anti jamur dari beberapa jenis kayu tropis
Abstrak: Widely used wood preservation is made from synthetic chemistry, where the raw material is non-renewable and environmental unfriendly. One solution is to look for alternative preservations using certain extractive substances from a durable tropical wood as a wood preservative. The main objectives of this study were to determine the potential extractive substances in woods of kupa (Syzygium polycephalum (Mig)), pelawan (Tristaniopsis whiteana (Griff)), palepek baringin (Shorea laevis Ridl), and mahalilis (Palaquium sp.), to evaluate the use of extractive substances as anti-fungal wood decay Schizophyllum commune Fries and Pleurotus ostreatus, and to identify the structure of anti-fungal compound. The maceration extraction method used methanol solvent, and multilevel fractionation used n-hexane, chloroform, ethyl acetate and butanol solvents. The extracts, subsequently, were carried out fungus S. commune and P. ostreatus the tests, and CCB preservative was used as negative control. The result showed that the highest extractive content was in S. laevis, followed by Palaquium sp., T. whiteana and S. polycephalum. Moreover, the results of column chromatography showed that ethyl acetate fraction of S. polycephalum was obtained 8 (G.1-G.8) compounds, the fraction of chloroform of T. whiteana was obtained 8 (PL.1-PL.8) compounds, the fraction of butanol of S. laevis was obtained 16 (PB.1-PB.16) compounds and the fractions of chloroform of Palaquium sp. was obtained 5 (M.1-M.5). Based on the maceration extract, fractionation and column chromatography, all the wood types were capable of inhibiting the growth of the fungus S. commune and P. ostreatus. Structure identifications with LC-MS, 1H and 13C NMR anti-fungal compound for G.2, Pl.3, PB.1.1, and M.2 were 3-O-glucosyl-3’,4’,5-trihydroxyflavonol, Heptanoic acid, 2,3-dihydroxyoctadecanoic acid and 2,3-dihydroxypropylpentadecanoate, respectively .
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Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model