Judul: Pengaruh Suhu Kempa Terhadap Karakteristik Papan Partikel Kelobot Jagung Dengan Perekat Kitosan Larut Air
Abstrak: Kelobot jagung atau kulit jagung merupakan hasil sampingan dari pemanenan jagung. Papan partikel tanpa perekat sintetis merupakan salah satu produk papan komposit yang ramah lingkungan, karena bahan bakunya berasal dari berbagai produk samping. Penelitian ini bertujuan untuk mengetahui pengaruh suhu kempa terhadap karakteristik papan partikel dari kelobot jagung (Zea mays saccharata L.) dengan menggunakan perekat kitosan larut air. Pengujian sifat fisis dan mekanis dilakukan berdasarkan standar JIS A 5908:2003. Hasil penelitian didapatkan nilai kerapatan 0,64-0,81 g/cm3 , kadar air 6,74-9,46%, pengembangan tebal 135,80-299,61%, daya serap air 227,7-398,03%, keteguhan lentur 123982,96-601899,74 kPa, keteguhan patah 2275,20-10517,23 kPa, keteguhan rekat internal 9,17-46,82 kPa, kuat pegang sekrup 482,42-1095,71 kPa. Nilai koefisien serap bunyi tertinggi terdapat pada papan partikel dengan suhu kempa 200oC dan konsentrasi perekat 10%. Papan partikel dengan suhu kempa 180oC dan konsentrasi perekat 6% adalah yang paling baik untuk pembuatan papan partikel.
Keyword: corn husks, hotpress, particle board, Water soluble chitosan

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: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
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