Judul: Karakteristik cross laminated timber kayu kecapi (Sandoricum koetjape Merr) berdasarkan orientasi sudut lamina
Abstrak: Cross Laminated Timber (CLT) is a multi-layer wooden panel made from lumber. Each layer of boards are placed cross-wise to the adjacent layers for increased rigidity and stability. The objectives of this research is used to determine the magnitude of the influence of orientation angle of the lamina of the mechanical and physical properties of cross laminated timber panels from kecapi wood (Sandoricum koetjape Merr) by using isosianat adhesive. The CLT panel was made from kecapi wood with 15 cm in thickness (five layers) from the board with 3 cm x 18 cm x 150 cm in size and orientation angle 450 and 900. The adhesive was used isosianat with surface weight 280 g/m³. Testing of the physical properties of CLT consist of moisture content, density, shrink/swelling and delamination test. Otherwise testing of mechanical properties of CLT include bonding strength and racking test. Result of racking test show that CLT’s stiffness at 450 angle larger than 900 angle; likewise, the strength of CLT show that at 450 angle stronger than 900 angle.
Keyword: Bogor Agricultural University (IPB), angle orientation., isosianat, kecapi wood, cross laminated timber

Judul: Analisis kekuatan tekan tegak lurus serat pada permukaan panel cross laminated timber kayu Kecapi (Sandoricum koetjapi Merr)
Abstrak: Cross Laminated Timber (CLT) merupakan panel yang dihasilkan dari perekatan lamina-lamina yang disusun secara bersilangan satu dengan yang lainnya. Tujuan penelitian ini adalah untuk menentukan pengaruh orientasi sudut lamina dan tipe pembebanan terhadap kekuatan tekan tegak lurus serat cross laminated timber kayu Kecapi (Sandoricum koetjape Merr). Pengujian yang dilakukan meliputi pengujian sifat fisik (kadar air, kerapatan, pengembangan penyusutan, dan delaminasi) dan sifat mekanis (keteguhan rekat dan kekuatan tekan). Hasil penelitian menunjukkan bahwa sifat fisik berpengaruh terhadap kekuatan tekan. Hasil penelitian kekuatan tekan serat menunjukkan berdasarkan posisi pembebanan maka posisi plat beban di pinggir menghasilkan kekuatan tekan yang lebih rendah dibandingkan posisi plat di tengah. Hasil kekuatan tekan memperlihatkan bahwa tipe pembebanan T﬩ (plat beban diletakkan di tengah tegak lurus permukaan) memiliki nilai kekuatan tertinggi.
Keyword: angle orientation, compression strength perpendicular to grain, cross laminated timber, kecapi wood

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