Judul: Kekuatan Tekan Tegak Lurus Serat Cross Laminated Timber Kayu Mindi (Melia Azedarach Linn ) Dan Sengon (Falcataria Moluccana (Miq.) Barneby & J.W Grimes)
Abstrak: Cross Laminated Timber (CLT) adalah salah satu produk rekayasa kayu yang berkembang beberapa tahun terakhir. Dibuat dengan cara menyusun lamina secara bersilangan dan direkatkan dengan perekat atau paku. Tujuan penelitian ini adalah untuk menguraikan karakteristik sifat fisis dan kekuatan tekan tegak lurus serat pada permukaan cross laminated timber kayu mindi (Melia azedarach Linn ) dan sengon (Falcataria moluccana (Miq.) Barneby & J.W Grimes ). Hasil penelitian menunjukkan panel CLT mindi lebih kuat dibandingkan dengan panel CLT sengon. Sifat fisis panel CLT mindi diantaranya kerapatan, kadar air, susutkembang volume, delaminasi air dingin dan air panas lebih tinggi dibandingkan dengan panel CLT sengon. Kekuatan tekan tegak lurus serat pada permukaan panel CLT diuji dengan empat tipe pembebanan yaitu pinggir-sejajar serat, pinggir-tegak lurus serat, tengah-sejajar serat, dan tengah-tegak lurus serat. Kekuatan tekan tertinggi dari kedua jenis CLT dihasilkan pada posisi plat beban diletakkan di tengah dengan permukaan plat tegak lurus serat kayu pada permukaan CLT. Kekuatan tekan tegak lurus panel CLT mindi lebih tinggi dibandingkan dengan panel CLT sengon.
Keyword: CLT, sengon, mindi, kekuatan tekan tegak lurus serat

Judul: Karakteristik Cross Laminated Timber dari Kayu Sengon (Falcataria moluccana (Miq.) Barneby & J.W. Grimes) dan Mindi (Melia azedarach L) menggunakan Perekat Isosianat
Abstrak: Wood needs as raw material construction has been increased. The advance of wood engineering technology can develop product by the raw material from the fast growing species. CLT (Cross Laminated Timber) is wood engineered product manufactured by lumber panel layer was placed perpendicular to raise a rigidity and stability. The aim of this research is to determined wood influence to characteristic of mechanical and physical properties of CLT products of fast growing species especially mindi (Melia azedarach L) and sengon (Falcataria moluccana (Miq.) Barneby & J.W. Grimes). This research was conducted by the manufacturing of panel CLT and testing of physical properties (density, moisture contents, swelling, hot water delamination, and cold water delamination) and mechanical properties (bonding, racking stiffness, and racking strength). The results showed CLT-450 mindi panel was relative more forceful than CLT-450 sengon panel. Physical properties testing carried out density, moisture content, soaking cold water delamination, and hot water delamination of CLT-450 mindi panel is higher than the CLT-450 sengon panel. Shrinkage CLT-450 mindi panel lower than CLT-450 sengon panel, but swelling volume (CLT mindi) higher than CLT-450 sengon panel. The applications of isocyanate relative more resistant to soaking cold water delamination than soaking hot water delamination. Beside of the influence of density, the bonding strength value of CLT-450 mindi panel higher than CLT-450 sengon panel which was contribute to racking strength test. However, the influence of water content to stiffness of CLT-450 sengon panel inverse to higher than CLT- 450 mindi panels. TR 1 correction and TR 5 carried out CLT-450 sengon and mindi panel had greatest point on water displacement.
Keyword: Bogor Agricultural University (IPB), racking strength, racking stiffness, mindi, sengon, CLT

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