Judul: Kinerja Baterai Kimia Menggunakan Nitrobenzena sebagai Elektro-Organik pada Reaktor Katode
Abstrak: Prinsip baterai kimia melibatkan reaksi reduksi dan oksidasi pada suatu sel. Penambahan elektron yang terjadi pada reduksi nitrobenzena mentransfer proton melewati membran nafion lebih banyak dibandingkan asam oksalat sehingga menghasilkan kerapatan arus dan daya yang tinggi. Tujuan penelitian ini adalah menentukan logam terbaik untuk kinerja baterai mengggunakan pelarut nitrobenzena pada reaktor katode. Reduksi nitrobenzena sebagai elektro-organik menjadi anilina dievaluasi dari nilai tegangan dan arus yang dihasilkan, serta diuji secara kualitatif menggunakan β-naftol. Kinerja baterai yang baik didasarkan pada 7 parameter, yaitu arus rangkaian pendek, tegangan rangkaian terbuka, arus maksimal, tegangan maksimal, kerapatan daya, kerapatan arus, dan faktor pengisi yang tinggi. Peningkatan konsentrasi nitrobenzena menghasilkan kerapatan arus dan daya yang lebih tinggi. Kinerja baterai terbaik berturut-turut menggunakan logam Zn, Cu, dan yang terkecil Fe.
Keyword: baterai, katode, nafion, nitrobenzena, sel bahan bakar

Judul: Kinerja Baterai Berbasis Asam Oksalat dan Membran Nafion
Abstrak: Baterai adalah sel elektrokimia yang dapat mengubah energi kimia menjadi energi listrik melalui reaksi kimia. Baterai berbasis asam oksalat dan membran nafion menggunakan prinsip redoks dalam aplikasinya. Reduksi pada katode dari asam oksalat akan menghasilkan asam glikolat yang dapat dideteksi perbedaannya menggunakan Fourier-Transform Infrared. Parameter kinerja baterai yang diukur diantaranya arus rangkaian pendek, tegangan rangkaian terbuka, kerapatan arus maksimum, tegangan maksimum, faktor pengisian, dan kerapatan daya pada logam Zn, Cu, dan Fe sebagai anode. Kinerja baterai terbaik dimiliki logam Zn karena memiliki nilai tertinggi pada semua parameter.
Keyword: asam oksalat, asam glikolat, baterai, nafion, PME

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