Judul: Kajian Struktur Anatomi dan Sifat Fisis Kayu Terap (Artocarpus odoratissimus), A Lesser Known Species Asal Kalimantan Selatan
Abstrak: Wood properties are correlated to proper utilization as well as processing. The objective of this research was to assess anatomical characteristics and physical properties of terap wood from South Kalimantan to promote its better utilization. Wood disk of 5 cm thick from a single tree at 1.3 m from the ground was utilized as sample unit. Radial variation of fiber length, microfibril angle (MFA), wood density, specific gravity (SG) and moisture content was measured from pith towards the bark represented by heartwood portion, sap- and heartwood region as well as sap wood region. Fiber dimension was measured through maceration specimens, while the MFA by microtome specimens. Wood density, SG and moisture content were measured by using gravimetric method. It was showed that wood properties were not affected by sample location within the wood disk. Wood density and SG tended to increase from pith towards the bark, while MFA tended to decrease. Average values of moisture content, wood density, SG, fiber length and MFA are 14.34%, 0.35g/cm3, 0.31, 1198.30±201.54 μm, 20.16±2.74o, respectively. With the 2-nd rank for fiber quality and 4-th rank for the strength, it determined wood could be used as raw materials for pulp and paper production and for lightweight construction.
Keyword: terap wood, microfibril angle, physical properties, anatomical structure

Judul: Struktur Anatomi dan Sifat Fisis Kayu Reaksi pada Kayu Terap (Artocarpus odoratissiumus) Asal Kalimantan Selatan
Abstrak: Wood is a product of tree metabolism. It varies among species, between trees of similar species and also within a single stem. Besides genetic factor, another factor that affecting these variabilities is growing condition and maturation level of the cells. Wood variation within a single stem of the tree will be increased dues to the existence of natural defect such as reaction wood, which can affect the entire characteristics and quality of the wood. Since study of reaction wood in tropical plantation wood species is very limited, this research aims to determine anatomical structure, fiber morphology and some physical properties of tension wood of terap (A. odoratissimus). The results are then compared to those of the opposite wood. The result shows that only MFA and wood density are varied between tension- and opposite woods. MFA of the tension wood are 14.83% greater than that of opposite wood, while wood density is 10.42% greater than that of the opposite wood. Compared to those of normal wood, fiber length of tension wood is shorther, but their MFA, specific gravity and wood density are bigger.
Keyword: fiber length, Artocarpus odoratissimus, tension wood, MFA, opposite wood

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