Judul: Kemurnian Selulosa Serabut Ampas Sagu pada Berbagai Perlakuan Isolasi
Abstrak: Sago waste fibers is wasted by sago starch industry and contain 42% cellulose. The cellulose was isolated to obtain the best isolate through various processes and treatments, including preparation with and without grinding, pulping in NaOH with and without heating in HCl, as well as delignification. Grinding and heating in HCl treatment were found to increase the alpha cellulose content. Heating treatment in HCl with and without grinding produced 79.96% and 74.70%, of alpha cellulose, respectively, higher than without heating in HCl that was 72.98% and 63.20%, respectively. Fourier transform infrared spectra of the isolates were not significantly different from a commercial cellulose showing characteristic by β-glycoside absorption at 894 cm-1. Heating in HCl with and without grinding also increased the crystallinity index by removing part of the amorphous region. The differential thermogram showed that the isolates started to lose the mass at around 98–102 °C and lost the maximum weight lost at around 352–377 oC.
Keyword: cellulose, isolation, sago

Judul: Cellulose Benzoate Stationary Phase from Non-Fiber Sago Waste for Separation of Java Turmeric Active Components.
Abstrak: Pengolahan sagu di Indonesia menghasilkan pati sebagai produk utama dan juga limbah ampas sagu. Limbah ampas sagu terdiri atas fraksi serabut dan non-serabut. Penelitian ini memanfaatkan ampas sagu non-serabut untuk diisolasi selulosanya kemudian dimodifikasi menjadi barang yang lebih ekonomis. Selulosa diisolasi dengan menghilangkan kandungan senyawa lain seperti pati dan lignin. Penghilangan pati dilakukan dengan HCl 3% dan lignin dengan pulping menggunakan NaOH 20% dilanjutkan dengan pemucatan (bleaching) dengan H2O2 5%. Selulosa hasil bleaching ditambahkan HCl 2.5 N lalu diesterifikasi menggunakan benzoil klorida dalam piridina pada suhu 60 °C dengan variasi waktu 4, 6, dan 8 jam. Produk esterifikasi ialah selulosa benzoat. Pembentukan selulosa benzoat dipantau dengan analisis gugus fungsi menggunakan spektrofotometer inframerah transformasi Fourier. Derajat substitusi tertinggi sebesar 1.8807 diperoleh dari esterifikasi selama 8 jam. Selanjutnya selulosa benzoat diuji ketahanannya terhadap pelarut organik, dan ketahanan paling baik terlihat pada pelarut metanol. Elusi ekstrak temu lawak dengan eluen metanol dalam kromatografi kolom berbasis selulosa benzoat menunjukkan peningkatan kadar xantorizol dan kurkuminoid dibandingkan dengan ekstrak awal.
Keyword: 

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