Judul: Biopelet: Energi Terbarukan dari Batang Kelapa Sawit
Abstrak: Oil palm trunk (OPT) is a potentional source of biomass for the production of biopellet. In the present research, biopellets were prepared from 25 years old OPT. It was prepared by mixing the meristem part with various percentages of its bark (0, 10, dan 30% bark content). The properties of the resulting biopellet were statistical examined. The durability of biopellet was measured according to ASABE standard procedures and its combustion behavior was examined by thermogravimetry and differential thermal analysis (TG–DTA). The highest biopellet durability was found for biopellet produced at 130 oC pressing temperature with 30% bark content. Scanning electron microscopy (SEM) of pellet of OPT showed the weak of particle bonding due to low of pelletizing pressure. The moisture content, unit density, ash content, and caloric value of pellets were 3.55–5.35%, 525.56–855.23 kg/m3, 2.76–3.44%, dan 17.89–19.14 MJ/kg, respectively. The combustion profiles of biopellet seemed to be unaffected by the bark content on TGA curve. Thermogravimetric analysis on DTA curve indicated that hemicellulose, cellulose, and lignin retained a different pyrolysis characteristic
Keyword: Bogor Agricultural University (IPB), pyrolysis, durability, pellet, Oil palm trunk

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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