Judul: Pengaruh Berat Labur terhadap Sifat Fisis dan Mekanis Papan Com-ply dari Kayu Karet dan Oriented Strand Board Bambu Andong
Abstrak: Alternatif memenuhi kebutuhan industri perkayuan yaitu papan com-ply. Penggunaan venir karet (Hevea brasiliensis Muel. Arg) pada lapisan permukaan dan oriented strand board bambu andong (Gigantochla pseudoarundinacea (Steudel) Widjaja) pada lapisan inti dapat menghasilkan papan com-ply yang memiliki sifat fisis dan mekanis yang unggul. Strand bambu andong diberi perlakuan steam bilas NaOH 1%. OSB dibuat dengan kadar perekat (PF) 8% dan target kerapatan 0,7 g/cm3. Analisis papan com-ply perlakuan berat labur dengan tiga taraf, yaitu 200 g/m2, 225 g/m2, dan 250 g/m2 untuk mengetahui pengaruh yang dihasilkan terhadap kualitas papan com-ply dan taraf yang optimal untuk diaplikasikan pada pembuatan papan com-ply. Nilai sifat fisis dan mekanis cenderung lebih baik pada berat labur 250 g/m2, selain MOE dan MOR sejajar seratserta IB. Secara keseluruhan, karakeristik com-ply pada setiap varian berat labur tidak memenuhi standar JIS 5908:2003 dan JAS 003:2014, terkecuali kerapatan, kadar air, serta IB., An alternative to meet the needs of the woodworking industry is com-ply boards. The use of rubber veneer (Hevea brasiliensis Muel. Arg) on the surface layer and oriented strand board of andong bamboo (Gigantochla pseudoarundinacea (Steudel) Widjaja) on the core layer can produce composite boards that have superior physical and mechanical properties. Andong bamboo strands were treated with 1% NaOH steam rinse. OSB was made with an adhesive content (PF) of 8% and a target density of 0.7 g/cm3. Analysis of com-ply boards with treatment of glue spread, namely 200 g/m2, 225 g/m2, and 250 g/m2 to determine the resulted effect of the com-ply boards quality and the optimal level to be applied to the manufacture of com-ply boards. The value of physical and mechanical properties tends to be better at 250 g/m2 glue spread, in addition to MOE and MOR parallel to fiber and IB. Overall, the com- ply characteristics of each hull weight variant did not meet the standards of JIS 5908:2003 and JAS 003:2014, with the exception of density, moisture content, and IB.
Keyword: adhesive, bamboo, com-ply, glue spread, oriented strand board

Judul: Pengaruh kadar perekat MDI dan kombinasi strand terhadap sifat fisis mekanis Oriented Strand Board dari tiga jenis bambu dengan perlakuan pendahuluan perendaman air dingin
Abstrak: Forestry industry is currently experiencing a high slump. This evidenced by the number of industries that shortages supply of raw materials to meet production. Demands of solid wood raw material has been very difficult to find. Therefore, Many of the forestry industry ultimately close out of business. Nowadays, introduced a new innovation of materials and technology of composite product, OSB (Oriented Strand Board). OSB is a structural composite board product produced from the strand-shaped particles and waterproof thermosetting adhesive. OSB is very effective in overcoming the problems of the forestry industry because the raw material criteria is acquired easely, that is using low density wood and small diameter logs. However, the context of natural resources fin efficiency of wood, bamboo have lignoselulosa compound is one of the potential resources that can be used as a raw material substitute for wood in the manufacture of OSB. The variables this study consisted of combination three types of bamboo and levels MDI adhesive. Bamboo that used are Andong, Betung, and Ampel which the code of each row are A, B, and C. OSB board combination consist of two types of bamboo which one kind bamboo as face and back layers, and another one kind as core layer the racio of face, core and back raw is 1:2:1. OSB board made by nine combinations of AAA, ABA, ACA, BBB, BAB, BCB, CCC, CAC and CBC with adhesive consists of concentration levels of 3%, 4% and 5%. Physical properties and mechanical parameters observed included density, moisture content, water absorption, thickness swelling, Modulus Of Elasticity (MOE), Modulus Of Rupture (MOR), adhesion strength (internal bond) and screw holding power. After the OSB boards are sorted in the importance of value, the results of a combination of CBC (Ampel, Betung, Ampel) at 5% adhesive content is the lowest OSB value that is recommended as OSB board with the best quality when compared with the characteristic of OSB properties to other combination of strands and adhesive concentration. But in the efficiency of production cost, the right alternative combination is the combination of CAC (Ampel, Andong, Ampel) with adhesive levels of 3%.
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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