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: Uji Laboratoris Daya Tahan Komposit Serbuk Kayu Plastik Polietilena Berkerapatan Tinggi Setelah Pelunturan Terhadap Serangan Rayap Tanah (Coptotermes Gestroi)
Abstrak: In 1999, economic lost caused by termite attack in Indonesia’s building reached 300 billion and in 2000 was predicted reached Rp 3 trilyun (Nandika et al. 2003). In general, damage in this building caused by soil termite attack of Coptotermes genus. To over take this problem, many efforts has been implemented such as development of composite wood technology by combining wood powder with plastic. It is hoped that this combination can decrease termite attack case. Generally, plastic wood composite is made from wood powder and polyethylene mixture. Implementing leaching procedure, testing endurance to soil termite attack by calculating weight decline and termite mortality after baiting was conducted to know the endurance of high density polyethylene plastic wood powder composite from soil termite (Coptotermes gestroi). The smallest leaching percentage was in mixture of HDPE and acetylated wood powder mixture amount of 0,13 %, acetylation treatment increase weight addition percentage and produce wood with higher hydrofobisity (Hadi et al. 1993), while the highest leaching percentage was in control test sample amount of 2,07 %. This is happened because it is easier for wood component to be dissolve in water. Leaching effect was not significant to the sample weight, which means that HDPE and wood powder is resistance to C. gestroi attack. Plastic became the physical blocker for termites to use wood cellulosa. Termite mortality was increase since the first week until observation to all test sample. Research results showed that the resistance of high density polyethylene plastic wood powder composite to C. gestroi attack was not significantly effected by leaching process. Plastic wood powder composite with of HDPE could increase Pinus ponderosa resistance to C. gestroi attack. Wood powder acetylation treatment to plastic wood powder composite produce better resistance to soil termite attack than the others treatment. Coupling agent treatment gave a very small effect increasing plastic wood powder composite resistance to C. gestroi attack. Treatment by adding 1 % zinc borate to P. ponderosa wood powder produce a good plastic wood powder composite resistance to C. gestroi attack.
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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