Judul: Studi pemanfaatan gambir (Uncaria gambir Roxb) dalam proses pewarnaan kain mori
Abstrak: Gambier is an extract of leaves and branches of gambier plant (Uncaria gambier Roxb). Gambier is one of Indonesia export commodities mostly produced in Sumatera island. Indonesia plays role as the world’s largest gambier exporter. In Indonesia, gambier utilized traditionally as leather tanning material, ingredient of traditional medicine, rust omission, etc. Chemical components of gambier mostly utilized are catechin and tannin. Technology of gambier processing that existed in Indonesia is still low in capacity, so the processing of gambier is mostly done traditionally. This kind of processing resulted on low quality and lack of economical value products of gambier. Therefore, development of processing method and wide utilization of Gambier in industry are needed to increase gambier added value. Tannin and catechin on gambier also can be utilized as colouring agent in textile industry to gain reddish brown colour on batik clothes that will be endure on intense sunlight exposure. Textile industries in Indonesia, especially batik industries, are now developing rapidly where the trend of batik clothes on every occasion is becoming common interest. On technological side, in general the batik industrialists have not done any development on their production sytem and method, so they could be more productive and produce uniformity of product quality. Utilization of natural colouring agent is also not becoming a consideration of most batik industrialists in the environmental issue that is now being widely concerned.
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Judul: Penggunaan Gambir Sebagai Pewama Pada Pencelupan Kain Kapas
Abstrak: Gambir adalah sari kental yang diperoleh dari pengolahan daun dan tangkai tanaman gambir (Uncaria gambir Roxb.) yang diendapkan dalam berbagai bentuk yang sudab dikeringkan (SNI 0 1-3391-2000). Gambir yang digunakan dalam penelitian ini menghasilkan warna coklat. Penelitian ini berdasarkan fenomena yang terjadi pada petani pengolah gambir. Mereka sulit menghilangkan noda gambir yang terdapat pada pakaiannya. Volume ekspor gambir Indonesia yang selalu mengalami peningkatan dari tahun ke tahun, menjadikannya potensial sebagai komoditas industri. Gambir mengandung katekin yang dapat digunakan sebagai bahan pewarna tekstil.
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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