Judul: Kinerja Microbial Fuel Cell pada Limbah Cair Pemindangan dengan Membran Separator Alginat-PVA.
Abstrak: Microbial fuel cell (MFC) merupakan teknologi yang menggunakan mikroba untuk mengubah bahan organik pada substrat menjadi listrik. Sistem MFC biasanya menggunakan membran sebagai sel bahan bakar yaitu nafion yang sangat mahal. Mahalnya harga nafion dapat diatasi dengan menggunakan membran alternatif, salah satu membran alternatif yaitu alginat dan polyvinyl alcohol (PVA). Penelitian ini bertujuan menentukan pengaruh rasio alginat dan PVA terhadap karakteristik membran separator dan terhadap kinerja MFC dalam menghasilkan elektrisitas, serta menentukan kinerja penurunan beban polutan limbah cair. Penelitian menggunakan rancangan acak lengkap (RAL) dengan uji lanjut Duncan. Rasio perbandingan alginat dan PVA yang digunakan yaitu 1:1, 2:1, dan 3:1. Rasio terbaik terdapat pada perbandingan 3:1 dengan nilai konduktivitas proton sebesar 1,28 x 10-5 S/cm, tegangan listrik sebesar 0,42±0,03V, kuat arus sebesar 1,11±0,16 mA, dan daya sebesar 473,39±86,99 mW. Nilai COD, BOD, dan TAN mengalami penurunan secara berturut-turut yaitu 75,05%, 58,15%, dan 90,07%, sedangkan pH mengalami kenaikan. Microbial fuel cell berpotensi menghasilkan elektrisitas dan menurunkan beban polutan pada limbah cair.
Keyword: alginate, electricity, microbial fuel cell, PVA, separator

Judul: Kinerja Microbial Fuel Cells pada Pengolahan Limbah Cair Pemindangan dengan Membran Separator Campuran Polimer Kitosan/PVA
Abstrak: Separator pada MFC dapat mengurangi jarak antara katoda dan anoda serta menghambat oksigen untuk masuk ke dalam ruang anoda. Penggunaan polimer campuran kitosan/polyvinil alcohol (PVA) diharapkan dapat memiliki kemampuan dari kitosan dan PVA utuk meningkatkan recovery elektron dari substrat. Penelitian ini bertujuan untuk mengeksplorasi kinerja teknologi MFC. penggunaan separator dilakukan untuk mengetahui pengaruhnya dalam mengurai limbah cair perikanan serta hasil samping dalam produksi elektrisitas. Polimer separator dibuat dengan mencampurkan 2% kitosan dengan 5% PVA dalam perbandingan yang berbeda yaitu, 2:3 (K2P3), 1:1 (K1P1), 3:2 (K3P2), dan perlakuan tanpa separator. Nilai COD dan TAN tidak memberikan perbedaan yang signifikan. Nilai BOD menunjukan penurunan yang signifikan dengan nilai 45,33±1,53 mg/L atau 56,54 %. Perlakuan nilai elektrisitas tertinggi diperoleh pada perlakuan K2P3 dengan rata-rata tegangan 0,615±0,056 V. Membran separator dari bahan campuran kitosan/PVA memberikan pengaruh terhadap elektrisitas MFC. Perlakuan K2P3 memiliki kenaikan nilai rapat daya tertinggi seiring peningkatan rapat arus.
Keyword: kitosan microbial fuel cells, polyvinil alkohol, separator

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