Judul: Karakteristik Pelet Campuran Tandan Kosong Kelapa Sawit :(Elaeis guineensis jacq.) dan Arang
Abstrak: Oil palm empty fruit bunches (EFB) is very abundant in Indonesia. It has huge potential to be used as renewable energy. This study tries to assess the use of EFB as biopellet to be used as alternative renewable fuel. Pellets are made from mixing oil palm empty fruit bunch powder and oil palm empty fruit bunch char at a ratio of 0, 10, and 20% respectively. Biopellet is molded using pellet mill machine that produces cylindrical shaped pellets with a diameter of 0.4 cm and a length of + 4 cm. The result of the study indicates that adding char could increase the calorific value of pellets. The calorific value of pellets to which 10 and 20% of char has been added will produce pellets that have a calorific value of 17,21 MJ/kg and 17,38 MJ/kg respectively. Meanwhile the calorific value of dry empty palm oil bunch feedstock and its pellets are 16,21 MJ/kg and 17,38 MJ/kg respectively. In addition to calorific value, adding char to pellets made from oil palm empty fruit bunched will reduce the moisture and ash contents and improve the bulk density of pellets. In general, the quality of biopellets that have been mixed with 20% of char is capable of meeting the French standard as regard to diameter size, length size, moisture content, and calorific value parameters, on the other hand as regard to ash content, and bulk density, all biopellet types still hasn’t been able to fulfill the requirements.
Keyword: alternative renewable energy, charcoal, calorific value, biopellet, oil palm empty fruit bunch

Judul: Pemanfaatan Limbah Kelapa Sawit (Elaeis guineensis Jacq.) dan Serbuk Kayu Mahoni sebagai Bahan Baku Biopelet
Abstrak: Despite widely known for its use as food, palm’s wastes produced by the plantation aren’t optimally used yet. Palm waste has potential to be made into fuel, one of which is biopellet. This research aims to find out the biopellet’s characteristic made from palm waste and examine the effect of augmenting mahoni sawdust toward biopellet’s quality. Materials used are exterior part of palm plant’s trunks, interior part of palm’s trunks, palm’s midrib, leaves, and mixed materials such as mahoni sawdust (0%, 15%, 30%, 50%). Biopellet was made using 40-60 mesh particle and compressed in 200 oC temperature for 15 minutes. Biopellet characteristics were examined using SNI 06-4369-1996 and SNI 01-2891-1992 standard. Research results show that biopellet’s water content is 0.14% - 2.34%, with volatile matter 62.34% - 76.29%, 1.12% - 13.32% ash content, 0.65 g/cm3 – 0.94 g/cm3 density, calor value as much as 4269.27 cal/g – 4729.99 cal/g, sulphur content 0.012% - 0.038%, nitrogen 0.290% - 1.95%, and chlorine content < 0.01%.
Keyword: calor value, biopellet, sawdust, oil palm

Judul: Tinjauan Matematis pada Model Makroskopik dan Mikroskopik Arus Lalu-lintas
Abstrak: Traffic flow phenomenon can be described through mathematical model such as continuous dynamic model with an ordinary differential equation so that it can be solved with integral factors. In this paper three simple models of traffic flow are discussed, i.e, two macroscopic and one microscopic models. Macroscopic model formulates dynamics of the traffic flow that occurs on a large number of vehicles on a road. While the microscopic model explains drivers’ behavior in their interaction with other vehicles ahead, i.e, car-following model. This paper shows the existence of ordinary differential equation found in the traffic flow model and indicates some different representations in the context of the same model. It also reviews a simple model of traffic flow along a single link, which leads to some unexpected results, i.e, it can express the solution model in term of link outflows as well as trip time. In the microscopic model, simulation is done to illustrate the behavior of the drivers with a sensitivity coefficient as a benchmark parameter.
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