Judul: Sifat anatomi the least known wood species suku Magnoliaceae: Talauma gigantifolia Miq., T. liliifera O. K., T. rubra Miq., dan T. singapurensis Ridl.
Abstrak: INTRODUCTION: Indonesia has 4000 species of trees, but only 400 species of them have been known as commercial timbers. Magnoliaceae is a family which its member has not been much studied yet, except of Aromadendron elegans. Therefore, the objective of this study was to asses the wood properties of Talauma gigantifolia, T. liliifera, T. rubra and T. singapurensis, macroscopicand microscopically, and then compared them to the property of A. elegans’ wood. These four species of Talauma spp. were expected to be a better substitution of A. elegans which has been commonly used for construction and furniture manufacturing. In this study, the authentic wood samples collection of Xylarium Bogoriensis 1915 of Research and Development Center of Forest Engineering and Forest Products Processing, Bogor were used as the sample. Each species was represented by small portion of their heartwood. METHODS: Macroscopic characteristic namely wood color, figure, texture and grain orientation were observed following the method of Martawijaya et al. (1981) stated in Atlas Kayu Indonesia, while its microscopic namely vessel elements, axial and ray parenchyma as well as their fibers were observed by maceration and microtome specimens. Maceration was made following Forest Products Laboratory method, while microtome specimens were produced following Sass’ method (1961)
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Judul: Struktur Anatomi dan Sifat Fisis serta Alternatif Tujuan Penggunaan Tiga Jenis Kayu Asal Kalimantan
Abstrak: Wood is a product of living organism that has special characteristic and appearance. Every single species has its own character. Indonesia has about 4000 species of woody plants, but only 95 species have been studied comprehensively. Therefore, study on wood properties is very important not only for determining their proper utilization, but also for better processing and further treatments. Among thousands of existing wood species in Kalimantan, utilization of Belangeran (Shorea Balangeran (Korth.) Buck), Bungur (Lagerstroemia speciosa Pers.) and Medang (Cinnamomum spp.) woods is still limited and has not optimize yet. Through well understanding of their wood characteristics and properties, utilization of these three wood species become more optimize. It was hope that these three woods could be utilized as the alternative to replace the conventional species which tended to decrease year by year. The main material used is a small piece of wood (a disc 5 cm thick) extracted from tree stem at 1.3 meters above the ground from each species. From each disc, wood sample for every measurement was taken representatively following procedural standard. Macroscopic characteristics consist of wood color, figure, texture, grain, lustre, odor and hardness, while microscopic characteristics consist of pore (its arrangement and distribution, perforation plate, pitting structure on the cell wall and contain); ray parenchym (its size, composition and contain); type of axial parenchym and fiber morphology. Microscopic observation was conducted through the maceration specimens of Schlutze and the microtome specimens of Sass. Physical properties of wood consist of moisture content as well as density and specific gravity. The result showed that wood color of three species studied varied: reddish brown in Belangeran, pale brown to reddish in Bungur and yellowish brown in Medang. Heartwood and sapwood demarcation is clearly distinguished only in Belangeran wood, while growth ring is clearly only in Bungur wood. Diffuse pattern of pore was found in Belangeran and Medang woods, while ring porous pattern in Bungur wood. Generally, their vessels are solitary and radially multiple 2-4 cells. Vestured pit, tilosis and axial intercellular channels are the specific characters of Belangeran wood, while Bungur wood are vestured pit and prismatic crystal. Specific characters of Medang wood is yellowish white of amorphous material and oil cell (laticifer). Regarding to pulp and paper raw material, fiber quality of three wood species studied belong to Class III. In term of strengthness, these three wood species are suitable for structural purposes: Belangeran is for Strength Class II, while Medang and Bungur Strength Class III. Belangeran and Bungur woods are also potential as raw material of meubel and furniture.
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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