Judul: Briket Arang Serbuk Kayu Sengon Berperekat Limbah Pengolahan Resin Pinus
Abstrak: Sengon wood sawdust is a potential resource of renewable energy. Its calorific value can be increased through charcoal briquetting. Unclassified Pine Rosin from the waste of pine resin processing was used as the briquette binder. The binder was expected to increase briquette durability and calorific value. In this study, the briquettes were prepared by mixing sawdust charcoal sengon and waste processing pine resin with various composition (G20, G25, and G30%). Briquetting performed by hot compression method with variation of temperature (120, 140, and 160oC) and time (15 and 20 min). Moisture content, density, volatile matter, ash content, fixed carbon and calorific value of briquettes determined according to ASTM D 5142-02. The durability of briquettes determined according to ASABE standard procedures and its combustion behaviour was examined by Thermogravimetry and Differential Thermal Analysis (TG-DTA). Data were analyzed using completely randomized design. The results showed that the density, moisture content, durability, volatile matter, ash content, fixed carbon, and calorific value of the resulting briquette was of 0.69- 0.86 g/cm3, 4.63-7.35%, 36.64-83.73%, 32.26-41.59 %, 4.11-6.02%, 46.63- 54.53%, 6014-6312 kcal/kg, respectively. Thermal analysis showed that during briquette combustion, the water loss occurred at 39-100oC, materials decomposition at 100-480oC with the weight loss of 15.8-65.4%, and no further weight loss occurred above the temperature of 428 oC. An acceptable charcoal briquette quality can be resulted with the addition of 30% rosin briquetting at 160oC C for 15 minutes
Keyword: Bogor Agricultural University (IPB), durability, thermal behaviour, resin, sengon, charcoal briquette

Judul: Pemanfaatan Limbah Tebu sebagai Bahan Briket Arang
Abstrak: The potentially biomass waste of sugarcane as an alternative energy is abundance but has not fully processed. This research propose on the processing of sugarcane waste as an alternative energy such as carbon briquettes. Carbonazation is done by using a modified drum furnace. The obtained carbon was then milled into a powder form, filtered using a 80 mesh sieve and the carbon that passes from the filter is mixed with tapioca adhesive levels of 2.5% and 5%. The raw materials manually compressed using a hydraulic system at a pressure of 20 tons, then dried in an oven at 70 C for 48 hours. Carbon briquettes produced in general result in physical properties are better than the raw one. Water content ranges from 0.475, ash content of 9.164 %, levels of substance evaporates 15.440 %, bonded carbon content 75.395 %, density, firmness press 82.04 kg/ and calorific value 6219 cal / gram. The addition of starch adhesives will affects the quality of carbon briquettes in physical and chemical properties. Carbon briquette with good quality found on the additional adhesive with a concentration of 5%.
Keyword: Bogor Agricultural University (IPB), sugarcane waste., heat value, compressive strength, Carbon briquettes

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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