Judul: Potensi Bioplastik Berbasis Pati Biji Nangka dengan Selulosa Sabut Kelapa sebagai Material Pengisi
Abstrak: Bioplastik berbasis pati biji nangka dengan material pengisi selulosa sabut kelapa merupakan salah satu upaya pengendalian dan pemanfaatan limbah untuk mengatasi masalah plastik. Penelitian ini bertujuan membuat bioplastik dari pati biji nangka dengan material pengisi selulosa sabut kelapa, serta memprediksikan sifat bioplastik yang dihasilkan dan potensi pengembangannya. Kadar pati pada biji nangka adalah 30.23% dengan kadar air sebesar 2.09%, sedangkan rendemen selulosa dari sabut kelapa sebesar 31.14% dengan kadar air sebesar 1.97%. Bioplastik secara kasat mata berwarna putih dengan komponen selulosa yang tersebar merata, permukaan sedikit kasar, dan relatif kaku. Kajian terhadap hasil penelitian terdahulu menunjukan bahwa, bioplastik dengan bahan-bahan yang digunakan pada penelitian ini berpotensi untuk dikembangkan menjadi bioplastik kemasan dengan densitas tinggi. Penambahan selulosa pada bioplastik ini diprediksi meningkatkan kuat tarik, memperbaiki permukaan penampang, mampu menurunkan nilai pemanjangan, dan menurunkan daya serap air. Bioplastik yang dihasilkan dihubungkan dengan interaksi fisik.
Keyword: bioplastik, pati biji nangka, selulosa sabut kelapa

Judul: Bioplastic Based on Jackfruit Seed Starch with Coconut Husks Cellulose Nanocrystal as Filling Material
Abstrak: Plastik yang banyak digunakan sampai saat ini adalah plastik berbasis minyak bumi yang tidak bisa terdegradasi secara alami sehingga menyebabkan pencemaran lingkungan. Pengembangan plastik yang dapat terdegradasi oleh alam atau bioplastik menjadi salah satu alternatif untuk menyelesaikan masalah tersebut. Oleh karena itu, penelitian ini bertujuan mengembangkan bioplastik berbasis pati biji nangka dengan penambahan nanokristal selulosa sabut kelapa untuk meningkatkan sifat fisiknya. Bioplastik dibuat dengan penambahan 0%; 5%; 10%; dan 15% nanokristal selulosa dari total bobot pati. Bioplastik diuji densitas, daya serap air, Laju transmisi uap air, kuat tarik, elongais, dan spektroskopi fourier transform infrared (FTIR). Secara umum, penambahan nanokristal selulosa menghasilkan sifat fisik yang lebih baik dibandingkan bioplastik berbasis pati tanpa nanokristal selulosa. Bioplastik pati-nanokristal selulosa memiliki nilai densitas, daya serap air, dan laju transmisi uap air yang semakin rendah dengan meningkatnya nanokristal selulosa. Nilai kuat tarik dan elongasi menurun seiiring dengan bertambahnya konsentrasi nanokristal selulosa. Hasil spektrum FTIR bioplastik menunjukkan adanya gugus -OH, -CH, dan -C-O-C-.
Keyword: bioplastik, nanokristal selulosa, pati, sabut kelapa, bioplastic, cellulose nanocrystal, coconut husks, starch

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