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 Pirolisis Batang dan Daun Jagung Untuk Bahan Tambahan Makanan
Abstrak: The development in agricultural activity will produce an overflow of the waste. In the future, it will cause an environment issue thus it need a convertion technology to modify the waste useful product. Corn, for example, is one of agricultural plants which produces much waste such as leaf, husk, cob, stalk, stover, etc. These by product, off course, will be valuable if it could be used for food, feed or others. The purpose of this research was to investigate the effect of temperature and catalyst percentage toward pyrolysis of corn stalk and leaves. Furthermore, the research was to know the contents liquid resulting form the pyrolysis of the corn leaves and stalk material whether it can be use for food additive. The best treatment was fixed by yield and the content of pyrolysis liquid. The first stage of this research was to determine the temperature of the operational pyrolysis using TGA. The process of the pyrolysis was conducted in the temperature range of 150-650ºC. There are two kind of process, with 1,5% catalyst and without catalyst. Furthermore, the amount of component which contained in liquid resulted from the pyrolysis was determined by using GC-MS. The last stage, it determined group and function from the components containing in that liquid. The best result was achieved at temperature of 350ºC, without catalyst and produced 17,035 g of liquid and 37,18 g of char. So far the pyrolysis without catalyst produced more liquid and char but less gass. In the meanwhile addition of 1,5% catalyst increased the amount of gass and decreased of liquid and char. GCMS identifed the component in the liquid as its group and function. Liquid resulted from the pyrolysis without catalyst contained more fenol group while the process with catalyst had more acid and fenol group. From the GC-MS analysist, it was comfirmed that the pirolysis without catalyst at temperature of 350ºC produced more components wich functioned as food additive, i.e. : p-cresol, pyrocatechol, vanillin, palmitic acid, and syringaldehide.
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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