Judul: Kualitas Filamen Sutera Liar (Attacus atlas) Pada Suhu Dan Waktu Perebusan Kokon Yang Berbeda
Abstrak: Attacus atlas is known as wild silkworm that produces cocoon and the cocoon produces silk which has a great economic potential. By procedure, the process for producing silk went through several steps: firstly, cocoon was boiled for obtaining silk filament which will determine the quality of silktread produced. The aim of this research was to assess the quality of silk filament on the different temperature and time of cocoon boiling treatments. Factorial randomized completely design was used in this study, using two treatments, i.e. boiling temperature 70, 80, and 90 oC and boiling time 30 and 60 minutes with seven replications. Parameter measured were length of filament, weight of filament, filament thickness, filament percentage, reelability of cocoon and visual observation using SEM (Scanning Electron Microscope). The results indicates that the treatment had no significant difference (P>0,05) on the length of filament, weight of filament, filament thickness, and its percentage including the reelability of cocoon. Based on the visual observation, each treatment showed different morphological characteristics of filament.
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Judul: Effect of Concentration of Medium and Boiling Time in Processing of Attacus atlas Cocoon and The Effects on Filamen Quality.
Abstrak: Attacus atlas was one of wild silkworm species that spreads around Indonesia. In pupa stage, A. atlas formed brown color cocoon that was the last product in silkworm sericulture. Cocoon of A. atlas has different characteristic with cocoon of the domestic silkworm Bombyx mori. It caused cocoon of A. atlas can not be proceed by the boiling process that commonly used in processing cocoon of B. mori. Therefore, special treatment and chemical compound addition are needed to process cocoon of A. atlas. The research aims to find the best chemical compound concentration and optimal boiling time to process cocoon of A. atlas and observe the treatment effect on the quality of filament. The research used two factors such as concentration of NaOH and boiling time. Concentration of NaOH that were used are 0.5 g/l (N1), 1g/l (N2), 2g/l (N3), and 3g/l (N4), while the boiling time that were used are 1 hour (T1) and 2 hours (T2). Based on ANNOVA testing, each treatment produced no significant difference (P>0.05) on the length and weight of filament also the number of filament broken. Meanwhile, based on the mean value of the length and weight of filament, N3T2 treatment showed the highest value than other treatment. The visual observation showed each treatment produced different characteristics of filament. The good quality of filament was produced by N3T1 treatment that was shown by the good color and strength of filament also the ease of cocoon processing. Key word: Attacus atlas, cocoon, fibroin, sericin
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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