Judul: Pengaruh Kombinasi Tebal dan Orientasi Sudut Lamina Terhadap Karakteristik Cross Laminated Timber Kayu Nangka Menggunakan Perekat Isosianat
Abstrak: Cross Laminated Timber is a multi-layer wooden panel made of lumber. Each layer of boards is placed cross-wise to the adjacent layers for increased rigidity and stability. The objectives of this research are to determine the effect of lamination board thickness combination and angle orientation to characteristic of Cross Laminated Timber from nangka wood (Arthocarpus heterophyllus) using isosianat adhesive. The average of density, moisture content, volumetric swelling , volumetric shrinkage, delamination of cold water, and delamination of hot water are 0.60 g/cm3, 14.59% , 3,63%, 2,84%, 0,50%, 16,00% , respectively. And then for MOE, MOR, Shear Strength, and Compression Strength are 59156 kg/cm2, 274 kg/cm2, 263 kg/cm2, 22,2 kg/cm2 , respectively.
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Judul: Pengaruh Kombinasi Tebal dan Orientasi Sudut Lamina Terhadap Karakteristik Cross Laminated Timber Kayu Jabon Menggunakan Paku
Abstrak: Cross Laminated Timber is a multi-layer wooden panel made of boards. Each layer of boards is placed cross-wise to the adjacent layers for increased rigidity and stability. The objectives of this research are to determine the effect of lamination board thickness combination and angle orientation to characteristic of Cross Laminated Timber from jabon wood using nails. Value of density, moisture content, and swelling volume Cross Laminated Timber from jabon wood affected by interaction of laminated board thickness combination and angle orientation. While shrinkage volume just affected by thickness combination and angle orientation. Value of density Cross Laminated Timber range from 0,33 g/cm³ to 0,51 g/cm³ and value of moisture content range from 12,88% to 18,25%. Combination of 1,67-1,67-1,67 cm thickness combination and 90° angle orientation had lower value for volume swelling and shrinkage volume, respectively 2,82% and 3,31%. Modulus of elasticity, modulus of rupture, lateral resistance, and shear strength of nails Cross Laminated Timber from jabon wood affected by interaction of laminated board thickness combination and angle orientation. Higher value of Modulus of elasticity present in combination of 2-1-2 cm thickness combination and 0° angle orientation, it was 12121 kg/cm². Modulus of rupture of combination A3B1 had highest value, it was 255 kg/cm². Combination of 1,67-1,67-1,67 cm thickness combination and 60° angle orientation had higher value of lateral resistance and shear strength of nail. Results of dimensional stability, MOE, and MOR, panel of 1,67-1,67-1,67 cm thickness combination and 45° angle orientation are best CLT panel.
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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