Judul: Torrified Biopellet of Coconut Husk
Abstrak: Kepadatan energi sabut kelapa dapat ditingkatkan melalui proses torefaksi. Penelitian ini bertujuan untuk mengetahui mutu biopelet sabut kelapa yang ditorefaksi pada suhu dan waktu torefaksi yang beragam. Mutu biopelet ditentukan berdasarkan kadar air, kadar abu, zat terbang, karbon terikat, kerapatan, ketahanan dan nilai kalor yang mengacu pada standar DIN EN 14961-2 dan SNI 8021-2014. Secara umum biopelet yang dihasilkan telah memenuhi standar SNI 8021-2014. Hasil penelitian menunjukkan bahwa biopelet memiliki kadar air sebesar 5,41-5,54%, zat terbang sebesar 31,88-32,25%, kadar abu sebesar 2,95-3,26%, karbon terikat sebesar 59,26-59,45%, kerapatan sebesar 0,91- 1,02 g/cm3, ketahanan sebesar 93,57-93,81%, dan nilai kalor sebesar 4.454-4.923 kkal/kg. Torefaksi biopelet sabut kelapa pada suhu 300oC selama 15 menit mampu meningkatkan nilai kalor sampai dengan 4.923 kkal/kg, The energy density of coconut husk can be increased through torefaction process. This research was intended to determine the quality of coconut husk biopelet torefied at various temperatures and retention times. Biopelet quality parameter was determined based on moisture content, volatile matter, ash content, fix carbon, density, durability, and heating value refered to the standards of DIN EN 14961-2 and SNI 8021-2014. In general, the biopellet produced have met the SNI 8021-2014 requirements. The results showed that the biopellets had a moisture content of 5,41-5,54%, a volatile matter of 31,88-32,25%, an ash content of 2,95-3,26%, a fix carbon of 59,26-59,45%, a density of 0,91-1,02 g/cm3, a durability of 93,57-93,81%, and a heating value of 4.454-4.923 kcal/kg. Torefaction of the biopelet at 300oC for 15 minutes increased the heating value up to 4.923 kcal/kg.
Keyword: Biopelet, coconut husk, torrefaction, bioenergy

Judul: Biopelet Arang Torefaksi Batang Kelapa Sawit.
Abstrak: Limbah batang kelapa sawit berpotensi tinggi sebagai bahan baku energi. Penelitian ini bertujuan untuk menentukan mutu biopelet yang dibuat dari bagian bawah dan tengah batang kelapa sawit dengan menggunakan lindi pengarangan sebagai perekat. Sebelum biopeletisasi, bahan baku ditorefaksi suhu 200 oC. Mutu biopelet ditentukan berdasarkan kadar air, zat terbang, kadar abu, karbon terikat, ketahanan dan nilai kalor biopelet yang ditentukan mengacu pada standar DIN EN 14961-2 dan SNI 01-6235-2000. Hasil penelitian menunjukkan bahwa biopelet memiliki kadar air, kadar zat terbang, kadar abu, karbon terikat, ketahanan dan nilai kalor berturut-turut 1.95-17.58%, 59.16-68.60%, 3.33-5.72%, 17.54-27.39%, 73.89-99.15%, dan 5304-5864 kkal/kg. Perlakuan torefaksi pada bahan baku dapat meningkatkan nilai kalor biopelet secara signifikan.
Keyword: batang kelapa sawit, biopelet, torefaksi

Judul: Penjadwalan dokter kamar darurat di RSCM menggunakan pemrograman linear integer
Abstrak: At an emergency unit of a hospital are generally posted several physicians for 24 hours for each and every day. The management unit of an emergency room usually has to deal with schedulling problem of physicians with time constraint of availability. This scheduling problem can be modeled as an integer linear programming (ILP) problem. ILP is an optimization problem with linear objective function, linear constraints, and integer variables. Scheduling problem is formulated in an optimization model, where the objective function is to minimize the operational cost of emergency room with the following constraints: (i) the time availability of physicians, (ii) the balanced work load for every physicians, (iii) holiday and dayoff determination of each physician. This paper discusses the schedulling of an emergency room’s physicians problem in the form of ILP, with a case study at Emergency Unit of Cipto Mangunkusumo Hospital (RSCM), Jakarta. The model is solved using Lingo 8.0 software. The solution obtained using ILP scheduling method is found to be more balanced than the corresponding solution using conventional method.
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