Judul: Pembuatan Biofilm Selulosa Asetat dari Selulosa Mikrobial Nata de Cassava
Abstrak: Cellulose acetate is one of cellulose derivative produced by acetylation in acetate anhydride reactant. The objectives of this research are to produce cellulose acetate biofilm from microbial cellulose nata de cassava. Nata de cassava as fermentation product of tapioca liquid waste assisted by Acetobacter xylinum for 8 days dried and crushed into powder. Microbial cellulose powder was activated by glacial acetate acid, acetyled in acetate anhydride using ratio 1:3, 1:4, and 1:5 for 1, 2, and 3 hours then hydrolyzed by weak acetate acid. The suspension deposited in aquades, dried then crushed into powder form. Cellulose acetate powder diluted in acetone and added by glycerin then poured into glasses plate. Cellulose acetate has acetyl number between 30,60-44,51%. Biofilm has average tensile strength 320,50 kgf/cm2, elongation 3,06%, WVTR 461,97 g/m2/24 jam, and water absorbing power 10,52%.
Keyword: biofilm, cellulose acetate, microbial cellulose, nata de cassava

Judul: Pembuatan Karboksimetil Selulosa dari Selulosa Mikrobial (Nata de cassava)
Abstrak: Utilization of microbial cellulose from nata de cassava as carboxymethyl cellulose (CMC) provide an alternative raw material of cellulose in manufacturing CMC. The purpose of this study is to investigate carboxymethyl cellulose manufacturing process using nata de cassava and to determine the best concentration of natrium hydroxide solution in alkalization to produce the CMC with the characteristics that qualified, characterized from the parameter degree of substitution (ds), purity, acidity, concentration of sodium chloride (NaCl), moisture and viscosity of CMC solution. The methods of manufacturing CMC are alkalization and etherification process. Alkalization produces alkali cellulose which has a higher reactivity than cellulose. Etherification is an exchange process of hydroxyl group with carboxyl group. In this research, natrium hydroxide with concentration 30%, 35%, and 40% were used in alkalization. Based on this research, the best product was made using natrium hydroxide concentration 35% with the characteristics of the degree of substitution is 0.9613, moisture 6.4228%, acidity 7.97, viscosity 148.52 cP, NaCl content 0.0291%, and purity 93.58%.
Keyword: Bogor Agricultural University (IPB), viscosity, nata de cassava, microbial cellulose, carboxymethyl cellulose, alkalization

Judul: Integration of Islamic Stock Markets of OIC Countries Before and During the Russia-Ukraine War Crisis
Abstrak: Pasar saham yang terintegrasi memberikan dampak negatif seperti percepatan co-movement (pergerakan bersama) yang rentan terhadap guncangan ekonomi, maupun krisis pasar global ke pasar domestik. Salah satu krisis yang terjadi pada tahun 2022 adalah perang Rusia-Ukraina yang berdampak pada pasar saham, termasuk pada saham syariah yang dipercaya lebih tahan terhadap guncangan krisis global. Penelitian ini bertujuan untuk meneliti perkembangan, integrasi dan respon lima pasar saham syariah negara OKI pada perang Rusia-Ukraina. Metode yang digunakan adalah VAR/VECM pada indeks DJIMMT25, SPSADS, SPSUAEDS, JII, DJIMT, SPBMIR, dan SPBMIU. Hasil penelitian menunjukkan pergerakan yang sama pada pasar saham UAE dan Arab Saudi, sedangkan Turki mengalami tren positif selama perang. Pasar saham syariah negara OKI selama periode perang Rusia-Ukraina terkointegrasi, sementara pasar saham Malaysia memengaruhi pasar saham syariah empat negara OKI lainnya. Hasil IRF menunjukkan terdapat efek permanen pada volatilitas pasar saham syariah negara OKI akibat guncangan yang diberikan. Namun, respon volatilitas relatif kecil karena kontribusi guncangan lebih didominasi oleh pasar saham itu sendiri, An integrated stock market has negative impacts, such as accelerating co-movement, which is vulnerable to economic shocks and global market crises on the domestic market. One of the crises in 2022 was the Russia-Ukraine war which impacted the stock market, including Sharia stocks which were believed to be more resistant to the shocks of the global crisis. This study examines the development, integration, and response of OIC countries five Islamic stock markets in the Russia-Ukraine war. The method used is VAR/VECM on the DJIMMT25, SPSADS, SPSUUAEDS, JII, DJIMT, SPBMIR, and SPBMIU indices. The results show the same movement in the UAE and Saudi Arabia stock markets, while Turkey experienced a positive trend during the war. The Islamic stock market of the OIC countries during the Russia-Ukraine war was cointegrated. In contrast, the Malaysian stock market influenced the Islamic stock markets of the other four OIC countries. The IRF results show a permanent effect on the volatility of the Islamic stock market in OKI countries due to the shocks given. However, the volatility response is relatively small because the stock market itself dominates the contribution of shocks.
Keyword: co-movement, OIC, Rusia-Ukraine war, sharia stock market integration