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: Eco-Friendly Particle Board from Coco Fiber with Starch-Based Adhesives
Abstrak: Serat sabut kelapa merupakan serat alami yang memiliki potensi untuk dimanfaatkan sebagai bahan baku pembuatan papan partikel, karena mengandung lignoselulosa dan memiliki sifat ramah lingkungan. Penggunaan perekat maltodekstrin dengan asam sitrat sebagai perekat ramah lingkungan cukup baik dalam mengikat serat kayu sehingga pada penelitian ini mencoba menggunakan maltodekstrin-asam sitrat. Penelitian ini bertujuan untuk mengetahui ukuran partikel yang optimum untuk menghasilkan produk papan partikel. Penelitian ini menggunakan ukuran partikel sebesar 40-50 mesh, 50-60 mesh, dan lolos 60 mesh. Sifat fisis yang diuji dalam penelitian ini antara lain kerapatan, kadar air, daya serap air dan pengembangan tebal. Sifat mekanis yang diuji yaitu Modulus of Elasticity (MOE) dan Modulus of Rupture (MOR). Hasil penelitian menunjukkan ukuran partikel ukuran partikel tidak memberikan pengaruh yang nyata pada kerapatan, kadar air, daya serap air, pengembangan tebal, MOE dan MOR. Nilai sifat fisis yang diuji telah mencapai standar JIS A 5908-2003. Ukuran partikel optimum seratsabut kelapa untuk menghasilkan papan partikel cukup baik yaitu lolos 60 mesh., Coconut fiber is a natural fiber that has the potential to be used as a raw material for making particleboard, because it contains lignocellulose and has environmentally friendly properties. The use of maltodextrin adhesive with citric acid as an environmentally friendly adhesive is quite good in binding woodfibers, so in this study we tried to use maltodextrin-citric acid. This study aims to determine the optimum particle size to produce particleboard products. This study used a particle size of 40-50 mesh, 50-60 mesh, and passed 60 mesh. The physical properties tested in this study include density, moisture content, water absorption and thickness expansion. The mechanical properties tested were the Modulus of Elasticity and the Modulus of Rupture. The results showed that the particle size didn’t have a significant effect on density, moisture content, water absorption, thickness swelling, MOE and MOR. The value of the tested physical properties has reached the JIS A 5908-2003 standard.The optimum particle size of coco fiber to produce particleboard is quite good, which is passed 60 mesh.
Keyword: Coco fiber, Mechanical properties, Particle board, Particle size, Physical properties

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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