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: Pembuatan Biopelet dari Cangkang Kelapa Sawit dengan Penambahan Arang Cangkang Sawit dan Serabut Sawit sebagai Bahan Bakar Alternatif Terbarukan
Abstrak: Biopellet is one of an alternative energy for rural community. The abundance of palm shell and palm fiber is a potential source of biomass that can be converted into biomass pellet (biopellet). Pelletization can improve the quality and burning characteristic of the biomass. The purpose of this Fesearch was to learn the utilization of palm shell and fiber into biopellet production and to know the affectation of addition the palm shell charcoal and palm fiber. The research begun with an analysis of physic-chemical properties contained in the raw material. Then the result continued by analysis of tombustion characteristic. Based on the physic-chemical properties and the combustion Characteristics; biopellet of palm shell that contained 80% of palm shell and 20% of palm shell charcoal has the best quality. It has 0.47% of moisture content; 9.83% of ash content; 55.34% of Polatile matter; 34.84% of fixed carbon content; 5,265.92 kcal/kg of the heating value; 1,260.30 kg/m² f bulk density; and 82.09 kg/cm of strength pressure. The consumption rate of the best formulation biopellet was 1.39 kg/jam and the combustion efficient was 11.59%. The production of palm shell biopellet on a laboratory scale produced yield of 11.54%. Energy input for this process is 101,751.86 cal and energy output is 9,794.61 kcal. Biopellet increased the heating value of palm shell for 25.55% or 7,008.84 kcal/kg.
Keyword: Palm shell, Palm fiber, Biopellet, Charcoal, Carbonization

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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