Judul: Pengaruh Konsentrasi Pemlastis Dietil Glikol Terhadap Karakteristik Bioplastik dari Polyhydroxyalkanoates (PHA) yang dihasilkan Ralstonia eutropha pada Substrat Hidrolisat Minyak Sawit
Abstrak: PHA (Poli-B-hydroksialkanoates) merupakan salah satu alternatif komponen plastik yang dapat didegradasi secara biologis. PHA terbentuk secara alamiah, merupakan sumber karbon intraseluler dan cadangan energi yang terakumulasi dalam sejumlah strain bakteri. Selain itu, PHA sebagai suatu polimer memiliki kekuatan dan kekerasan yang baik, resisten terhadap kelembaban dan memiliki permeabilitas O2 yang sangat rendah. Berdasarkan sifat PHA tersebut, maka PHA merupakan komponen penting dalam pembuatan bioplastik. Adapun tujuan penelitian ini adalah untuk mengetahui pengaruh konsentrasi pemlastis dietil glikol (DEG) yang ditambahkan pada saat pembuatan bioplastik dari PHA yang dihasilkan oleh Ralstonia eutropha dengan menggunakan hidrolisat minyak sawit sebagai sumber karbon. Selain itu juga untuk mengetahui karakteristik bioplastik yang dihasilkan akibat variasi konsentrasi pemlastis yang digunakan.
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Judul: Pengaruh Konsentrasi Tributil Fosfat terhadap Karakteristik Bioplastik dari Poli-B-Hidroksialkanoat (PHA) yang dihasilkan oleh Ralstonia eutropha dengan Substrat Hidrolisat Minyak Sawit
Abstrak: Plastik yang berbasis petrokimia merupakan bahan yang paling banyak digunakan dalam kehidupan sehari-hari. Kelemahan plastik yang berbasis petrokimia ini adalah tidak dapat diurai oleh mikroorganisme sehingga menimbulkan masalah lingkungan. Salah satu alternatif solusi terhadap masalah ini adalah menggunakan plastik alami/bioplastik, misalnya PHA. PHA merupakan cadangan makanan bakteri yang diperoleh dari proses kultivasi. Bakteri yang digunakan dalam penelitian ini adalah Ralstonia eutropha dengan substrat hidrolisat minyak sawit.
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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