Judul: Karakteristik dan Aplikasi Papan Partikel “coco fiber” sebagai Kotak Penyimpanan Talas (Colocasia esculenta L.).
Abstrak: Coconuts production in Indonesia reach 3.21 million ton per year. The largest waste product of coconuts are coco fibers, which 35% weight of coconut. Nowadays, coco fibers are only used to produce doormat, broom etc. Therefore a research to increase the additional value of coco fiber is required. This research was aimed to utilize coco fiber as the raw material of particle board, and studied the physical, mechanical, and thermal properties of the particle board. The products were reached out the standard of SNI 03-2105-2006, except the thickness swelling and modulus of elasticity. Specific heat test of particle board is 843.42 J/kg K and thermal conductivity of particle board is 0.1960 W/m °C.
Keyword: physical-mechanical-thermal properties, particle board, coco fiber

Judul: Karakteristik Fisik, Mekanik dan Termal Papan Partikel Sabut Kelapa (Cocos nucifera L.) Berlapis Bambu Betung (Dendrocalamus asper sp.) Sebagai Material Bangunan
Abstrak: Demand of woods as raw materials in the industry are more than the availability, therefore research is needed to develop the other alternatives to substitute the woods as the primarily raw material. In this case, the aim of this research are to construct particle boards made of coco fiber and betung bamboo and to research their physical, mechanical and thermal characteristics. Physical characteristics of particle board have qualified the particle board standards, that are: density 0.79 cm3/g, moisture content 13.88 %, and water absorption 40.1%, except the thickness swelling percentage reached 15.18%. The mechanical characteristics of particle board have qualified the JIS A 5908-2003 and SNI 03-2105-2006 standards, that are: tensile strength 137.57 kgf /cm2, compressive strength 87.44 kgf/cm2, Modulus of Elasticity (MOE) 24970.46 kg/cm2, screw-withdrawal strength 105.81 kgf, and internal bond 2.54 kgf/cm2, except the Modulus of Rupture (MOR) value that only reached 21.10 kg/cm2. This study also reveals that using particle boards made of coco fiber and bamboo betung as storage walls are less capable to prevent the oven heats which is proven by the increasing of temperature of taro inside the storage box along the increasing of temperature of the oven.
Keyword: betung bamboo, coco fiber, mechanical characteristics, particle boards, physical characteristics

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