Judul: Peningkatan Sifat Fisik dan Mekanis Edible Film Karagenan melalui Penambahan Penaut Silang Kation Ca2+ dan Nanopartikel Karbon.
Abstrak: Edible film dari karagenan merupakan lapisan tipis yang terbuat dari bahan yang dapat dikonsumsi. Aplikasi edible film pada penyalut makanan bermanfaat untuk menambah masa simpan makanan dan melindungi makanan dari mikroorganisme berbahaya. Penambahan nanopartikel karbon dan penaut silang kation Ca2+ pada edible film berbahan dasar karagenan bertujuan meningkatkan kuat tarik dan menurunkan laju permeabilitas uap air. Nanopartikel karbon dan Ca2+ ditambahkan pada setiap film dengan konsentrasi 5%, 10%, 15%, dan 20% b/v. Kuat tarik edible film meningkat seiring peningkatan konsentrasi nanopartikel karbon dan Ca2+, sedangkan nilai permeabilitas uap air menurun seiring dengan meningkatnya nanopartikel karbon dan Ca2+. Ca2+ dapat berperan sebagai panaut silang yang ditandai dengan pergeseran bilangan gelombang ke arah yang lebih rendah pada spektrum inframerah yang dihasilkan. Pencirian menggunakan SEM (scanning electron microscope) menunjukkan bahwa terdapat aglomerasi nanopartikel karbon pada permukaan edible film.
Keyword: karagenan, nanopartikel karbon, penaut silang Ca2+, permeabilitas air, sifat mekanik

Judul: Edible film based on carrageenan, bacterial cellulose, and nanocarbon with additional crosslinker Fe2+
Abstrak: Edible film dari karaginan merupakan lapisan tipis yang terbuat dari bahan yang dapat dikonsumsi. Aplikasi edible film pada pelapisan makanan bermanfaat untuk menambah masa simpan makanan dan melindungi makanan dari mikroorganisme berbahaya. Penambahan selulosa, gliserol, nanokarbon, dan penaut silang Fe2+ bertujuan memperbaiki sifat mekanik dan permeabilitas uap air. Nanokarbon pada edible film akan memancarkan warna saat disinari ultraviolet pada panjang gelombang 366 nm. Konsentrasi nanokarbon yang digunakan berturut-turut 0.5%, 1%, 1.5%, dan 2% b/v. Nilai kuat tarik dan permeabilitas uap air meningkat seiring meningkatnya konsentrasi nanokarbon yang diberikan. Penaut silang Fe2+ yang digunakan berturut-turut 1.5%, 3%, dan 5% b/v dengan nilai kuat tarik optimum pada konsentrasi 5%. Keberadaan karaginan dalam film ini ditunjukkan oleh spektrum inframerah pada bilangan gelombang 1234.44 cm-1 yang merupakan ciri khas karaginan, yaitu gugus fungsi fungsi ester sulfat. Kata kunci: karaginan, nanokarbon, penaut silang Fe2+, permeabilitas air, sifat mekanik., Edible film from carrageenan is a thin layer made of food grade materials. Application of edible coating films could increase food product shelflife and protect food from microorganisms. The addition of cellulose, glycerol, nanocarbon, and crosslinker Fe2+ aims to improve the mechanical properties and permeability. Nanocarbon on edible film will flouresence when exposed to UV at a wavelength of 366 nm. The added nanocarbonwere 0.5, 1, 1.5, and 2% w/v. Tensile strength and permeability increased with increasing concentration of nanocarbon. The added cross-linker was 1.5%, 3%, and 5% w/v with the optimum value of tensile strength at 5%. The presence of carrageenan in this film was showed by Fourier transform infra-red in wave number 1234.44 cm-1 which is the characteristic of functional group in carrageenan, namely sulfate esters. Keywords: carrageenan, crosslinker Fe2+, mechanical properties, nanocarbon, permeability.
Keyword: karaginan, nanokarbon, penaut silang Fe2+, permeabilitas air, sifat mekanik

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