Judul: Karakteristik Bambu Lapis Menggunakan Anyaman Kajang dari Bambu Andong (Gigantochloa pseudoarundinaceae)
Abstrak: Wood production from forests is decreasing. In other side, the needs on wood as raw material for wood processing industries indicate an inclination to increase. As a consequence, wood supply is getting lower and the price of raw material is increasing. Hence, an effort is needed to produce alternative materials as wood substitution to ensure the sustainability of wood-based industries. The objective of this research was to analyze the influence of adhesive types, composition of width and thickness of bamboo’s strip to the physical and mechanical properties of ply bamboo. Bamboo was used in kajang bamboo mate type with different thickness of 0.5 mm and 1 mm, and different width of 1 cm and 2 cm. The internal bonding and modulus of elasticity (MOE) were not in accordance with SNI 01-5008.2-2000 with the values of less than 7 kg/cm2 dan 80 000 kg/cm2, respectively. Modulus of Rupture (MOR) and physical properties including moisture content and density fulfilled the SNI 01-5008.2-2000 standard which were less than 320 kg/cm2 for MOR and 14% for moisture content. Plybamboos in all combinations of width and thickness using epoxy were better than plybamboo which used PVAc as adhesive. The damage testing of ply bamboo using epoxy was 20.10%-35.58%. Plybamboo using thickness of 8 mm, width of 2 cm, and glued together with epoxy had better physical and mechanical properties compared with other plybamboos.
Keyword: PVAc, plybamboo, epoxy, andong bamboo

Judul: Karakteristik Bambu Lapis dari Anyaman Bambu Betung (Dendrocalamus asper) yang Direkat Menggunakan Perekat MDI dan PVAc dengan Metode Pencelupan
Abstrak: Plybamboo is an innovative product that should be improved strength and appearance to produce high quality products. The purpose of this research was to analyze the influence of adhesive type, and woven pattern toward the physical and mechanical characteristics of woven plybamboo. Water content, bonding strength, and MOR of plybamboo made using MDI adhesive is suitable with SNI 01-5008.2-2000 standard. Its water content value is under 14%, its bonding strength is more than 7 kg/cm2, and its MOR is more than 320 kg/cm2. Moreover, the water content, bonding strength, and MOR of woven bamboo made using PVAc did not suitable with SNI 01-5008.2-2000 standard. The density of plybamboo was ranged between 0.41-0.68 g/cm3. Based on shrinkage and swelling test of plybamboo, swelling phase was larger than shrinkage phase. The MOE of all samples did not suitable with SNI 01-5008.2-2000 standard. Plybamboo bonded using MDI with Tindih 2 pattern has better physical and mechanical characteristics than other plybamboos.
Keyword: PVAc, plybamboo, MDI, betung bamboo, bamboo woven

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