Judul: Kajian Idenfikasi Bahan Tambahan Pangan Hasil Fraksinasi Asap Cair dari Tongkol Jagung
Abstrak: Corn cob is one type of agricultural waste that can be processed into useful products such as food additives through pyrolysis and fractionation. In pyrolisis, degradation of components contained in the corn cob as cellulose, hemicelluloses, and lignin into various organic compound was occurred. Range of temperature and pressure treatment based on the boiling point of every individual chemical compounds contained in the liquid smoke 550oC with the addition of 1.5 % atapulgite catalyst. Fractionation of liquid smoke was done by using vacuum distillation method that make compound which has high boiling point will more quickly evaporated. Furthermore, components of chemical compounds in the liquid smoke fractions identified by GC-MS ((Gas Mass Chromatography Spectrometry). Fraction of liquid smoke can be produced at a pressure of 100 mbar at all points of temperature, but at a pressure of 90 mbar with a temperature of 70oC and pressure of 80 mbar with a temperature of 67.5oC and 70oC, the liquid can’t be fractionationed again, because temperature and pressure was too high. The result of GC-MS showed that some component contained in the liquid smoke were phenol, ketons, furans, aldehydes, hydrocarbons, and acids. The largest component is phenol, which produced at all temperatures in all pressure points.These compound can be used in the manufactured of food additives such as preservatives, antioxidant, and flavor.
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Judul: Kajian Optimasi Proses Pirolisis Tongkol Jagung untuk Produksi Asap Cair
Abstrak: Corn is usually used as food, feed, and also raw materials for industries. The increasing of annual corn consumption’s impact on the increasing of its biomass, especially the corn cobs. These corn cobs, as raw materials, are still not used optimally yet. Corn cobs can be used as main raw materials for smoke liquid through pyrolysis. But, optimal temperature condition and catalyst concentration added are still unknown to create maximal liquids. The aim of this research is to understand the influence of temperature and catalyst concentration in pyrolysis process to its yield. Getting its surface response from factors of temperature and catalyst concentration and its optimum condition of pyrolysis process become the other objective of this research. Setting up the temperature and catalyst added treatment is based on Response Surface Methods (RSM). Center point is set based on previous research done by Choiriyah (2010). Temperature that used is of 4500C-6500C (-1, +1 point) and atapulgit that added is 1-2% (-1, +1 point). The result then be analyzed by SAS 9.1 to get optimal yield treatment. The liquid components are identified by GC MS and the raw material decomposition are fixed by fiber and silica proportion test. Optimum result is shown on center point, 10.01, that 22. 225 gram liquids and 32.93 gram ashes are resulted on 5500C and 1.5% catalyst added. As high the temperature, as low ashes would be resulted, as high the weigh loss value, and as low lignocelluloses value. Silica value increase together with catalyst adding. GC MS analysis shows the component of aldehydes, phenol, ketones, hydrocarbon, and furan as the result. That compounds can be used as food additives, such as preservatives, antioxidant, and flavor. The most component variation set on 5500C with the adding of 0.79% catalyst, which resulted in phenol, aldehydes, acids, alcohols, ketones, and hydrocarbons.
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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