Judul: Sago Waste Briquettes as an Alternative Fuel
Abstrak: Briket biomassa dari ampas sagu dapat digunakan sebagai bahan bakar alternatif. Briket biomassa dibuat melalui beberapa tahapan, yaitu pengarangan, pencampuran dengan perekat, pengempaan, dan pengeringan. Pada pembuatan briket ampas sagu digunakan perekat kanji dengan ragam 3%, 5%, dan 7%. Pencirian mutu briket meliputi kadar air, kadar abu, bagian yang hilang pada suhu 950 °C, dan nilai kalor. Berdasarkan nilai kalor yang memenuhi standar arang kayu Indonesia (SNI 06-3730-1995) diperoleh bahwa briket ampas sagu dapat dijadikan sebagai salah satu bahan bakar alternatif.
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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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