Judul: Karakteristik Wood Pellet Campuran Cangkang Sawit dan Kayu Bakau (Rhizhophora spp.)
Abstrak: Wood pellet adalah bahan bakar padat berbentuk silinder yang dapat menjadi alternatif energi. Penelitian ini bertujuan untuk menguji karakteristik wood pellet cangkang sawit dan kayu bakau. Kosentrasi serbuk cangkang sawit dan kayu bakau (100%:0%, 75%:25%, 50%:50%, 25%:75%, 0%:100%) dikempa pada wood pellet hidrolik dengan suhu 200°C selama 15 menit. Hasil penelitian menunjukkan bahwa, penambahan setiap 25% kayu bakau terhadap cangkang sawit meningkatkan nilai kadar air, kerapatan, keteguhan tekan, zat terbang tetapi dapat menurunkan nilai karbon terikat, kadar abu dan nilai kalor. Karakteristik wood pellet seperti kerapatan, keteguhan tekan, kadar air, zat terbang, kadar abu, karbon terikat dan nilai kalor secara berturut-turut memiliki nilai 1.1204-1.1564 g/cm3, 32–700 kgf/cm2, 4.35-5.78%, 72.44-74.70%, 1.09-1.36%, 18.43-21.85%, 4448-4859 kal/g.
Keyword: wood pellet, kayu bakau, cangkang sawit

Judul: Karakteristik Biopelet dari Campuran Cangkang Sawit dan Kayu Sengon sebagai Bahan Bakar Alternatif Terbarukan
Abstrak: yang digunakan pada pembuatan biopelet ini berasal dari cangkang sawit dan limbah gergajian kayu sengon. Biopelet memiliki ukuran diameter biopelet antara 3–12 mm dengan panjang yang bervariasi yaitu antara 6–25 mm. Metode yang digunakan adalah penambahan persentase campuran serbuk gergajian sengon dari 0%, 25%, 50%, 75% dan 100%. Pengujian terhadap biopelet ini meliputi kadar air, kerapatan, kadar abu, kadar zat terbang, kadar karbon terikat, nilai kalor dan keteguhan tekan. Penambahan serbuk gergajian sengon mengakibatkan terjadi peningkatan pada nilai kadar air, kadar abu, kadar karbon terikat dan keteguhan tekan. Peningkatkan kadar air mencapai 4.94%, kadar abu 2.14%, karbon terikat 22.50% dan keteguhan tekan mencapai 21.25 kg/cm3 sedangkan pada nilai kadar zat terbang dan nilai kalor mengalami penurunan. Penambahan cangkang sawit dapat meningkatkan nilai kalor hingga 5452.30 kkal/kg.
Keyword: Biopelet, cangkang kelapa sawit, serbuk sengon

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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