Judul: Lapisan dan fraksinasi senyawa antibakteri dari rumput laut bulu ayam (Caulerpa sertularioides)
Abstrak: Rumput laut bulu ayam (Caulerpa sertulariodes) merupakan salah satu jenis Caulerpa sp. yang belum banyak dimanfaatkan sehingga perlu dilakukan penelitian kandungan senyawa antibakteri dari Caulerpa sertularioides. Metode penelitian terdiri dari ekstraksi bahan aktif, uji aktifitas antibakteri ekstrak kasar, fraksinasi ekstrak metanol Caulerpa sertularioides dengan kromatografi Lapis Tipis (KLT) dan Kromatografi Kolom (KK) serta uji antibakteri fraksi yang dihasilkan.
Keyword: 

Judul: Isolasi dan identifikasi senyawa bioaktif bahan anestetik dari makro alga hijau jenis caulerpa racemosa
Abstrak: Caulerpa racemosa telah dimanfaatkan oleh masyarakat pesisir pantai selain sebagai bahan pangan, juga digunakan dalam bidang farmasi sebagai obat luka luar. Jenis ini dikenal memiliki toksin yang disebut "toksin marin", karena dapat mengakibatkan matirasa (paraestesia) pada mulut dan lidah bila mengkonsumsinya. Oleh sebab itu diduga Caulerpa racemosa mengandung komponen bioaktif berupa bahan anestetik ringan. Dalam bidang perikanan, bahan anestetik alami ini diperkirakan dapat dipakai untuk keperluan transportasi ikan hidup dengan teknik pembiusan. Penelitian ini bertujuan untuk mengisolasi makro alga hijau jenis Caulerpa racemosa menjadi ekstrak kasar dan mengidentifikasi komponen bioaktifnya yang diduga berfungsi sebagai bahan anestetik ringan. Penelitian ini meliputi tahap isolasi komponen bioaktif dengan cara ekstraksi; tahap pemisahan dan pemurnian dengan khromatografi lapis tipis (TLC), khromatografi cairan kinerja tinggi (HPLC), dan khromatografi kolom; serta tahap identifikasi dengan spektrofotometer infra merah dan GC-MS. Juga dilakukan bioessai terhadap nauplius Artemia salina untuk menguji daya pembiusan. ...
Keyword: 

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