Judul: Characteristics of Particleboard from Corn Stalk and Corn Cob on Various Types Adhesives
Abstrak: Produksi jagung yang meningkat setiap tahunnya menyebabkan hasil ikutan jagung turut meningkat. Hasil ikutan yang dihasilkan berupa batang, tongkol, daun, dan kulit. Batang dan tongkol jagung dapat dimanfaatkan sebagai bahan baku papan partikel karena mengandung lignoselulosa. Penelitian ini bertujuan mengetahui karakteristik papan partikel batang dan tongkol jagung menggunakan berbagai jenis perekat. Metode yang dilakukan yaitu studi pustaka. Papan partikel batang jagung menggunakan perekat sintetis dari polyurethane menghasilkan sifat fisis yang lebih baik dibandingkan UF, PF, dan isosianat. Sementara itu, papan partikel batang jagung menggunakan perekat isosianat menghasilkan sifat mekanis yang lebih baik dibandingkan polyurethane, UF, dan PF. Karakteristik papan partikel batang jagung menggunakan perekat alami dari pati lebih baik dibanding perekat asam sitrat. Papan partikel tongkol jagung menggunakan perekat sintetis MF menghasilkan karakteristik yang lebih baik dibanding perekat UF. Karakteristik papan partikel batang dan tongkol jagung menggunakan perekat alami lebih baik dibanding perekat sintetis., Corn production which keeps increasing every year causes production of corn by-products to also increase. The resulting by-products are in the form of corn stalk, corn cob, corn leaves, and corn skin. Corn stalk and cobs can be used as raw material for particleboards as they contains lignocellulose. This literature research aims to determine the characteristic of particleboard from corn stalk and corn cob on various adhesives. The method used was literature study. Corn stalk particleboards that use synthetic adhesives from polyurethane produces better physical properties than UF, PF, and isocyanate. Meanwhile, corn stalk particleboards that use isocyanate produces better mechanical properties than polyurethane, UF, and PF. The characteristics of corn stalk particleboard that use natural adhesives from starch was better than citric acid adhesive. Particleboard from corn cob that use synthetic adhesives on MF provides better characteristics than those of UF adhesive. The characteristics of particleboard from corn stalk and corn cob that use natural adhesives are better than those that use synthetic adhesives.
Keyword: adhesive, by-products, corn cob, corn stalk, particleboards

Judul: Properties of Particle Board Made from Corn Husk: The Effect of Various Board Density and Water Chitosan Soluble Chitosan Adhesive Concentration
Abstrak: Kelobot jagung merupakan biomassa dari jagung yang potensial sebagai bahan baku untuk pembuatan papan partikel. Tujuan penelitian ini adalah mengetahui pengaruh variasi kerapatan papan dan kadar perekat kitosan larut air terhadap karakteristik papan partikel dari kelobot jagung. Papan partikel dibuat dalam tiga target kerapatan: 0,6 g/cm3, 0,8 g/cm3 & g/cm3 dengan kadar perekat kitosan larut air: 6%, 8%, & 10%. Papan partikel diproduksi menggunakan kempa panas dengan suhu kempa 180C dan tekanan kempa 25 kgf/cm2 selama 15 menit. Hasil penelitian menunjukkan bahwa nilai koefisien absorpsi suara (α) berkisar antara -0,064 hingga 0,112 untuk seluruh frekuensi (500-3000 Hz), kerapatan papan 0,51-1,02 g/cm3, kadar air 6,11-9,89%, pengembangan tebal 121,99-152,99%, daya serap air 261,44-364,95%, MOE 171,33-9045 kgf/cm2, MOR 7,95-112,59 kgf/cm2, IB 0,05-0,98 kgf/cm2, dan SHP 2,63-12,49 kgf. Secara keseluruhan, parameter koefisien absorpsi suara (α) papan belum memenuhi standar ISO 11654. Parameter kerapatan, kadar air dan MOR memenuhi standar JIS A 5908: 2003 untuk kerapatan papan 1 g/cm3. Secara keseluruhan, papan partikel dengan kerapatan papan 0,8 g/cm3 dan kadar perekat kitosan larut air 8% memberikan karakteristik papan partikel terbaik., Corn husk extracted from maize was considered as the potential material for manufactured particleboard. The purpose of this study was to evaluate the influence of variations in board density and water-soluble chitosan concentration on the properties of corn husks particleboard. Particleboards were made in three different density targets of 0.6 g/cm3, 0.8 g/cm3 & 1 g/cm3 with water-soluble chitosan adhesive concentration of 6%, 8%, & 10%. The particleboard was manufactured using a hydraulic hot press with a pressing temperature of 180°C and a pressing pressure of 25 kgf/cm2 for 15 minutes. The results showed that sound absorption coefficient (α) value ranges from -0.064 to 0.112 for all frequencies (500-3000 Hz), density 0.51-1.02 g/cm3, moisture content 6.11-9.89%, thickness swelling 121.99-152.99%, water absorption 261.44-364.95%, MOE 171.33-9045 kgf/cm2, MOR 7.95-112.59 kgf/cm2, IB 0.05-0, 98 kgf/cm2, and SHP 2.63-12.49 kgf. The sound absorption coefficient of the particleboard didn’t fulfil the requirement of ISO 11654. Density, moisture content, and MOR of the particleboard with density 1 g/cm3 fulfilled requirement JIS A 5908: 2003. Overall, the particleboard with a board density of 0,8 g/cm3 and an adhesive content of 8% water-soluble chitosan gave the best particleboard properties.
Keyword: kelobot jagung, kitosan larut air, koefisien absorpsi suara, papan partikel

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