Judul: Hidrolisis Polisakarida Rumput Laut Caulerpa racemosa dengan Fermentasi Lactobacillus plantarum SK (5)
Abstrak: Hidrolisis polisakarida diketahui dapat meningkatkan aktivitas biologis dengan merubah struktur gugus fungsi polisakarida dan menurunkan bobot molekul. Hidrolisis enzim merupakan metode hidrolisis yang ramah lingkungan karena tidak membentuk produk sampingan yang beracun. Lactobacillus plantarum dapat menghasilkan enzim amilase dan selulase yang dapat digunakan untuk menghidrolisis polisakarida C. racemosa. Penelitian ini bertujuan menentukan waktu fermentasi dan konsentrasi starter terbaik dalam proses hidrolisis polisakarida C. racemosa, serta menentukan konsentrasi glukosa C. racemosa sebelum dan setelah fermentasi. Penelitian dibagi menjadi dua tahap, yaitu tahap I dan tahap II. Lama fermentasi pada tahap I adalah 6 hari, sedangkan pada tahap II adalah 48 jam. Konsentrasi starter yang digunakan adalah 0%, 5%, dan 10%. Hasil analisis menunjukkan bahwa perbedaan konsentrasi starter dan lama fermentasi menyebabkan perubahan nilai total BAL, TAT, gula pereduksi, dan konsentrasi glukosa, serta menurunkan nilai pH. Perlakuan terbaik ditunjukkan pada penambahan starter 5% dengan lama fermentasi 24 jam., Hydrolysis of polysaccharides is known to increase biological activity by changing the structure of polysaccharide functional groups and reducing molecular weight. Enzyme hydrolysis is an environmentally friendly hydrolysis method because it does not form toxic by-products. Lactobacillus plantarum can produce amylase and cellulase enzymes which can be used to hydrolyse C. racemosa polysaccharides. This research aims to determine the best fermentation time and starter concentration in the C. racemosa polysaccharide hydrolysis process, as well as determine the C. racemosa glucose concentration before and after fermentation. The research was divided into two stages, namely stage I and stage II. The fermentation time in stage I is 6 days, while in stage II it is 48 hours. The starter concentrations used are 0%, 5%, and 10%. The analysis results showed that differences in starter concentration and fermentation time caused changes in the total values of LAB, TAT, reducing sugar and glucose concentration, as well as reducing the pH value. The best treatment was shown by adding 5% starter with a fermentation time of 24 hours.
Keyword: Caulerpa racemosa, fermentasi, hidrolisis, Lactobacillus plantarum

Judul: Pretreatment Basa NaOH Makroalga Caulerpa racemosa untuk Produksi Bioetanol
Abstrak: Makroalga, termasuk Caulerpa racemosa, merupakan bahan baku yang potensial untuk pembuatan bioetanol, yaitu bahan bakar alternatif yang diolah dari bahan alami (tanaman), yang digunakan sebagai bahan substitusi untuk bensin. Penelitian ini bertujuan untuk mengetahui pengaruh perendaman basa pada makroalga Caulerpa racemosa dalam menghasilkan kadar gula pereduksi pada produksi bioetanol. Rumput laut kering yang telah dibersihkan direndam dalam air, NaOH 0.05 N, dan NaOH 0.1 N selama 3 hari, dan kembali dijemur di bawah sinar matahari. Hasil analisis proksimat menunjukkan sebagian besar komposisi kimia Caulerpa racemosa adalah karbohidrat dan serat kasar. Sampel perendaman air memiliki karbohidrat sebesar 36.69% dan serat kasar sebesar 40.87%. Sampel perendaman NaOH 0.05 N memiliki karbohidrat sebesar 36.12% dan serat kasar sebesar 44.50%. Sampel perendaman NaOH 0.1 N karbohidrat sebesar 38.97% dan serat kasar sebesar 46.73%. Hidrolisat sampel perendaman air memiliki kadar gula pereduksi sebesar 7.67% (b/v). Gula sederhana, yang diperoleh dari hasil hidrolisis rumput laut menggunakan asam, dikonversi menjadi bioetanol melalui proses fermentasi. Kadar etanol pada bioetanol dari sampel dengan perendaman air yaitu 0.70% (v/v) dengan efisiensi fermentasi 17.26.%.
Keyword: bioetanol, Caulerpa racemosa, perendaman basa

Judul: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite