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: Pemanfaatan limbah Tebu menjadi briket dan biopelet
Abstrak: Sugarcane (Saccharum officinarum) is one of Indonesia's main commodities that provide benefits for life. Sugarcane bagasse and leaves are major waste of sugar mills. Both of waste have not been optimally used. This research conduct a briquette procesing used bagasse and biopellet processing used sugarcane leaves. The aims of this study was to determine concentration of adhesive of briquette and to optimize biopellet process at compression temperature and time. Briquette was made by the addition of tapioca adhesive with concentration of 5, 10 and 15%. Biopellet made used compression temperature and compression time with compression temperature were varied iii from 130 - 270oC and compression time consisted of 8 - 22 minutes. The best briquettes treatment obtained at a concentration of 5% adhesive, with value of 3.87% moisture content, 3.35% ash content, 76.35% volatile matter, 20.29 fixed carbon and heat level 4155 kcal/kg. Sugarcane leaves biopellet has optimal at compression temperature of 250oC for 20 minutes. Compression with these conditions produced moisture content of 3.41%, ash content of 12.19%, compressive strength of 119.22 kgf/cm2 and heat level of 4490 kcal/kg.
Keyword: Bogor Agricultural University (IPB), bagasse, sugarcane waste, bioenergy, briquette, biopellet

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model