Judul: Analisis keprasan optimal per tanaman tebu untuk produksi gula studi kasus di PG Kremboong-Sidoarjo
Abstrak: Kebijaksanaan pemerintah untuk melestarikan swasembada gula merupakan tantangan berat bagi industri gula di ; Indonesia. Beberapa langkah pemikiran yang perlu dilakukan dalam upaya meningkatkan produksi gula adalah pemilihan varietas yang tepat, perbaikan faktor lingkungan dan memacu proses pertumbuhan tanaman tebu. Mengusahakan tanaman tebu sampai beberapa kali keprasan merupakan salah satu ciri budidaya teSu dilahan kering. Tujuar. penelitian ini dalah menentukan tingkat keprasan ymq paling optimal untuk di proses di pabrik gula serta menentukan biaya keprasan, biaya produksi dan hasil produksi yanq diperoleh.
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Judul: Analisis efisiensi proses produksi untuk peningkatan kinerja industri gula tebu (Cane Sugar) (Studi kasus di PG. Jatiluhur Majalengka, Jawa Barat)
Abstrak: Sugar is one of the most important commodities in Indonesia. Most of sugar manufacturing in Indonesia was owned or sun by Indonesian government. Sugar consumption rate cannot be fulfilled by local sugar manufacturer, that's why importing sugar became an option. The insignificant rate of increasing of sugar production every year make import rate is keep increasing Efficiency in sugar production process is one thing that need some attention. This time, most of sugar factory that owned by government are decreasing in productivity. PG Jatitujuh is sugar processing factory that processing cane into white crystal sugar (SHS) and one of sugar factory in Java that still runs well. Efficiency in sugar production process can be analyzed by using PG Jatitujuh production data. Analysis result shows that efficiency in sugar production process can be rendered, by optimalised increasing of imbibitions water. The optimum value of imbibitions water is 25-30 percent of processed cane. The decline of pol value in the amount of 0,01 percent is equal with 1,729 ton or equal with Rp. 8.297.865,- recovery sugar £rom bagasse. The decline of HK value in the amount of 0,01 percent is equal with 0,273 ton or equal with Rp. 1.3 12.524,- recovery sugar from molasses.
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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