Judul: Karakterisasi kulit buah jarak (Jatropa curcas L) dan pemanfaatannya sebagai bahan baku papan pertikel berkualitas
Abstrak: Jatropha fruit hulls (JFH) is a waste resulted from biodiesel process and its used only as compos materials. According to fiber proportion and chemical composition, JFH had a potency for using as raw materials of particleboard manufacturing. However, the acidity properties of JFH caused problem in UF resin curing, so that resulting inferior bonding strength of board. Adjusting of acidity and controlling of pressing temperature and time were expected to solve those problem. The objective of this research was to obtain the best condition to produce high quality particleboard made of JFH and UF resin. This research consist of five steps. The first step was to analyse of materials characteristic of JFH and UF resin included of pH, buffering capacity, chemical component, chemical compound, wettability, solid content, viscosity, and gelatine time. Suitability indicator between of JFH and UF was determined by extractive content, pH, and wettability. Second step was to analyse of particle immersing treatment (immersing in cold water for 24 hours, hot water for 1 hours, and 1% acetic acid solution) to physical and mechanical properties of particleboard. Third step was to analyse of pressing temperature and time to obtain optimum pressing condition in particleboard manufacturing. The fourth step was to analyse of wood shaving (mangium wood) and wood veneer (sengon and jabon wood) to reinforce of mechanical properties of particleboard. The last step was to analyse of non wood particle (bamboo and sorghum stalk) to reinforce of mechanical properties of particleboard. The result showed that JFH had alkali properties, it was caused by alkaline from several chemical compound that composed of JFH i.e ammonium bicarbonate, mercaptomethane, guaiacol, 2,6-dimethoxyphenol dan cyclopropyl carbinol. Immersing treatment was reducing of extractive content, pH and increased of JFH wettability. Furthermore, those parameter used as indicator to determine of lignocellulosic materials compatibility with UF resin to result the best quality of particleboard. Based on technical and efficiency considering, immering treatment in cold water for 24 hours, hot water for 1 hour, and 1% acetic acid solution were selected for particleboard manufacturing. The best properties of particleboard was resulted by JFH immersing treatment in acetic acid solution. The exploration of pressing temperature and time to obtain of the best pressing condition was expected for optimizing of UF resin polymerization. Hot pressing in 130 0C temperature for 10 minute resulting the best properties of particleboard, but the thickness swelling and modulus of elasticity value were not fulfill of JIS A 5908 (2003). The reinforcement method by strong materials were expected of resulting the improvement of mechanical properties. JFH and wood shaving mixture, overlaid with wood veneer, JFH and non wood particle mixture resulted to improve of physical and mechanical properties especially of MOE and MOR value. The overlaid with sengon and jabon veneer, and JFH and bamboo acid treated mixture was increasing of MOE and MOR value. The overlay technique by veneer and JFH and bamboo acid treated mixture resulting MOE value that fulfill of JIS A 5908 (2003). Based on this reseach had resulted of recomendations included of immersing in 1% acetic acid solution, hot pressing at
Keyword: Extractive, particle acidity, jatropha fruit hulls, particleboard, urea formaldehyde resin

Judul: Pemanfaatan Ampas Biji Jarak Pagar (Jatropha curcas L.) Hasil Samping Pengepresan Minyak Sebagai Bahan Baku Pembuatan Papan Partikel
Abstrak: Jatropha press cake (Jatropha curcas L) has high crude fiber which is potential to be utilized as raw material for particle board production. This study aims to assess the physical and mechanical properties of jatropha press cake particle board and effect of addition of paraffin and sago starch to improve the quality of particle board. The parafin were added at 0, 1, 3%, and the sago starch were at 6, 8, and 10%, respectively. The physical and mechanical properties of particle board product were evaluated. The density of particle board ranged at 0,84 - 0,95 g/cm3, moisture content 4,56 - 6,19%, the thickness-swelling for 2 and 24 hours water soaking were 11,6 7- 20,12% and 16,22-25,70%, respectively. The water absorption of particle board for 2 and 24 hours water soaking were 48,74-62,20% and 63,10-72,75%. The Modulus of Rufture (MoR) and Modulus of Elasticity (MoE) of particleboard were 19,70 - 97,44 kgf/cm2 and 1552,26-7234,66 kgf/cm2. The addition of paraffin and sago starch have positive effect for physical and mechanical properties of particle board. The particle board with addition of 3% paraffin and 10% sago starch achieves to pass of MoR that accordance with JIS A 5908:2003 standard.
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Judul: Pengaruh vaksinasi terhadap dinamika populasi pada model SIR (Susceptible-Infected-Recovered)
Abstrak: SIR model can be used to model the spread of diseases in a closed population based on certain assumptions. In this research, the SIR model is formulated by including the factor of vaccination. As the result, the model has been shown to have two equilibrium points, i.e. disease free and endemic equilibrium. A simulation study is carried out to illustrate the model. The results show that some equilibrium points are asymptotically stable. Moreover, a minimum level of vaccination has been defined. For the vaccination level less than the minimum level, increase in the vaccination level results in decrease of the proportion of infected individuals in the corresponding equilibrium point. On the other hand, for the vaccination level greater than the minimum level, increase in the vaccination level results in decrease the proportion of susceptible individuals in the corresponding equilibrium point. Furthermore, when vaccination level is greater than the minimum level, it is found that the time needed for the disease to extinct is shorter.
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