Judul: Production of Cellulose Acetate Films from Non-Wood Source in Indonesia: Theoretical Study
Abstrak: Lignocellulose is a type of polysaccharide consists of cellulose, hemicellulose, and lignin that forming in plants. Wood consumption in the world always increasing but areal planting is decreasing. Material from non-wood is required because it’s very abundant and renewable natural resource. Cellulose acetate is derivative product from cellulose is very important in industry. This study aims to determine the potential production of cellulose acetate films from non-wood materials in Indonesia and to identify raw materials that have the potential to produce cellulose acetate films. The methodology for this study using collection of data needed to conduct an analysis of the potential production of cellulose acetate films was carried out in the territory of Indonesia. Cellulose acetate and each production from cotton stalk, sorghum straw, sugarcane bagasse, rice husk, and Oil Palm Empty Fruit Brunch (OPEFB) have different methods. Every cellulose acetate has different each production from different journals to get best result. The data for cellulose acetate films was analyzed by several characteristics such as the production process, yield and Degree of Substitution (DS), Fourier Transform Infrared (FTIR), and mechanical properties. This study explains utilization from non-wood resources which is abundant in Indonesia can be an alternative besides using wood., Lignoselulosa merupakan salah satu jenis polisakarida yang terdiri dari selulosa, hemiselulosa, dan lignin yang terbentuk pada tumbuhan. Konsumsi kayu di dunia selalu meningkat namun areal tanam semakin berkurang. Bahan dari non kayu dibutuhkan karena sumber daya alamnya yang sangat melimpah dan terbarukan. Selulosa asetat merupakan produk turunan dari selulosa yang sangat penting dalam industri. Penelitian ini bertujuan untuk mengetahui potensi produksi film selulosa asetat dari bahan non kayu di Indonesia dan mengidentifikasi bahan baku yang berpotensi menghasilkan film selulosa asetat. Metodologi penelitian ini menggunakan pengumpulan data yang diperlukan untuk melakukan analisis potensi produksi film selulosa asetat yang dilakukan di wilayah Indonesia. Selulosa asetat dan setiap produksi dari kapas, jerami sorgum, ampas tebu, sekam padi, dan Tandan Kosong Kelapa Sawit (TKKS) memiliki metode yang berbeda. Setiap selulosa asetat memiliki produksi yang berbeda dari jurnal yang berbeda untuk mendapatkan hasil yang terbaik. Data film selulosa asetat dianalisis dengan beberapa karakteristik seperti proses produksi, rendemen dan Derajat Substitusi (DS), Fourier Transform Infrared (FTIR), dan sifat mekanik. Studi ini menjelaskan pemanfaatan sumber bukan kayu yang melimpah di Indonesia dapat menjadi salah satu alternatif selain pemanfaatan kayu.
Keyword: cellulose acetate films, non-wood materials, characteristics of cellulose acetate

Judul: Penggunaan Selulosa TandanKosong Kelapa Sawit dan Selulosa Mikrobial dari Nata de Cassavasebagai Pensubstitusi Selulosa Kayu dalam Pembuatan Kertas
Abstrak: Nowadays, forest-extracted wood cellulose still predominantly serves as raw material for pulp and paper manufacture in Indonesia. Consequently, the deforestation rate has alarmingly increased 2% per year. Attempts are necessary to seek alternative cellulose sources that sound potentially available, among which are empty oil-palm fruit bunches (EOPFB) and microbial-cellulose, as synthesizedwith the aid of microorganisms from substrate containing glucose, fructose, sucrose, or other simple carbohydrates, such as juicy waste from tapioca processing (e.g. nata de cassava). In this research, pulp of nata de cassava‟s microbial cellulose was mixed with EOPFB pulp at various proportions (w/w), i.e. 100%+0%, 75%+25%, 50%+50%, 25%+75%, 0%+100%to be processed into pulp and paper. Grammage target made was 60 gr/m2 and 120 gr/m2. Prior to paper-sheet forming, additives were added to such mixture (i.e. 2% alum, 2.5% tapioca starch, and 5% kaolin). Sheet forming also made without additives (as control). The forming of each combination between mixture proportion, grammage target and additive/control-use was replicated 2 times, and the data examined comprised pulp/paper physical and strength properties. The data were analyzed using a completely randomized design with factorial pattern. The yields of microbial-cellulose pulp and of EOPFB pulp were consecutively (wet basis) 60,09% and 61,619%. Physical and strength properties of paper with grammage 60 gr/m2and 120gr/m2consecutively, i.e. water content (4,04-8,95% & 3,83- 9,01%), grammage (59,8-78,92gr/m2& 107,64-145,32 gr/m2), tensile index 0,0056-0,0424 & 0,01002-0.06499 kNm/g), tear index (4,04-8,22 & 4,55-7,72 mN m2/gr),folding endurance (3,5-108,5 & 4-397,5), Cobb60 (56,86-211,32 & 75,03- 398,12 g/m2 for the smooth surface; and 51,07-218,91 & 57,65-404,46 g/m2for the rough/lower surface), brightness (15,64-38,03% & 13,1-26,26%) and printing opacity (62,81-97,55% & 42,99-99,38%). Analysis on biomass conversion revealed that the manufacture of paper from the mixture (w/w) of nata de cassava‟s microbial cellulose (50%) and empty oil palm fruit bunch pulp (50%) through the expansion of each cultivating areas, both totaling 200 ha can substitute for 4.247.156forest-tree stands per year. With this tree-saving figure, it can afford the CO2absorption (uptake) from the air equal to approximately 594.601,85 tons of CO2 per year.
Keyword: carbon uptake, biomass conversion analysis, pulp/paper, empty oil-palm fruit bunch, nata de cassava, microbial cellulose

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