Judul: Ketahanan Papan Komposit Plastik Berkerapatan Tinggi dari Limbah Serbuk Jati dan Plastik Polietilena terhadap Serangan Rayap Tanah Coptotermes curvignathus Holmgreen
Abstrak: Penggunaan kayu komposit plastik telah berkembang dari 50.000 ton pada tahun 1995 menjadi hampir 600.000 ton pada tahun 2002. Kayu komposit tersebut dapat digunakan sebagai bahan kontruksi bangunan gedung, pertamanan, otomotif mebel, pagar, dermaga, pelapis dinding, badan kapal, serta beragam infrastruktur lainnya. Namun demikian ketahanannya terhadap rayap tanah belum banyak ditaporkan. Suatu penelitian telah dilakukan untuk mengetahui ketahanan komposit serbuk kayu plastik polietilena berkerapatan tinggi (high density polyethylene) terhadap serangan rayap tanah Coptotermes curvignathus Holmgren berdasarkan standar JIS K 1571:2004. Hasil penelitian menunjukan bahwa papan komposit plastik berkerapatan tinggi memiliki ketahanan yang sangat tinggi terhadap serangan rayap tanah C. curvignathus Berdasarkan klasifikasi Standar Nasional Indonesia (SNI) 01. 7202 2007 ketahanan kayu komposit tersebut tergolongoke dalam Kelas I (sangat tahan)…
Keyword: Composite, Durability, Mortality, Polyethylene, Termite, SNI, Wood plastic composities, Kayu komposit, Kayu plastik, Ketahanan kayu, Forestry

Judul: Ketahanan Papan Komposit dari Limbah Kayu dan Karton Gelombang terhadap Serangan Rayap Tanah (Coptotermes curvignathus Holmgren)
Abstrak: This research was designed to determine the level of composite boards resistance against subterranean termites C. curvignathus. The composition of the adhesive between the water-based polymer isocyanate (WBPI) and melamine-formaldehyde (MF) were 1:0, 1:4, 0:1, and paraffin content of 0, 4, 8% based on oven dry particle and corrugated carton. The produced composite boards consisting of three layers. The face and back layers made of corrugated carton waste and the core layer was made of wafer wood waste. The board target density was 0.7 g cm-3. The board was hot pressed at 170 ºC with specific pressure of 25 kgf cm-2, for 12 minutes. The composite boards resistance were tested according to Japanese Standard JIS K 1571:2004. Research results show that B8 type composite board (WBPI-MF were 1:4 and paraffin content of 8%) performed the best result compared to the other types. B8 type composite boards can be determined as the optimum conditions for the composite board production made of wood waste and corrugated carton.
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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