Judul: Studi Biodegradasi Implan Logam Fe Berpori pada Tulang Tikus
Abstrak: Penelitian ini bertujuan melihat biodegradasi suatu implan berbahan dasar Fe berpori pada tikus. Sebanyak 60 ekor tikus Sprague Dawley jantan dengan rataan berat 175 gram dibagi menjadi empat kelompok perlakukan berdasarkan ukuran pori yaitu implan 450 μm, 580 μm, dan 800 μm serta kontrol. Tikus diimplan di bagian os femur yang telah dikikis menggunakan bor tulang. Pengambilan sampel otot dan implan dilakukan pada hari ke-7, 14, dan 30 pascaimplantasi. Parameter yang diamati meliputi intensitas warna karat material implan, intensitas warna karat pada otot sekitar implantasi dan berat material. Intensitas warna karat pada otot sekitar implantasi dan material implan dianalisis dengan menggunakan perangkat lunak ImageJ®. Hasil analisis menunjukkan nilai intensitas warna karat material implan Fe berpori pada tiap pengamatan tidak berbeda nyata untuk semua kelompok perlakuan (p>0.05). Nilai intensitas warna karat pada otot yang diimplan Fe berpori berbeda nyata (p<0.05). Kenaikan berat implan tidak berbeda nyata untuk semua kelompok perlakuan dan hari pengamatan (p>0.05). Adanya karat pada Fe berpori dan perubahan warna pada jaringan otot menandakan implan Fe mengalami proses degradasi yang dipengaruhi oleh ukuran pori implan dan waktu implantasi.
Keyword: biodegradasi, biomaterial, Fe berpori, intensitas warna karat

Judul: Kadar Ion Fe pada Jaringan Otot Peri-implan Tikus dengan Implan Biodegradasi Fe Berpori
Abstrak: Tujuan dari penelitian ini adalah untuk mengukur kadar ion Fe yang berasal dari proses degradasi implan logam Fe berpori pada jaringan otot paha peri-implan tikus. Penelitian ini menggunakan 60 ekor tikus putih Sprague Dawley dengan rataan berat 175 gram. Tikus dibagi menjadi empat kelompok berdasarkan ukuran pori implan 450 μm, 580 μm, dan 800 μm serta kontrol. Hewan diimplan di bagian os femur kemudian dilakukan pengambilan sampel otot peri-implan pada hari ke-7, 14, dan 30 pascaoperasi. Kadar ion Fe pada sampel otot peri-implan diukur menggunakan atomic absorption spectrophotometer (AAS). Pada semua jaringan otot peri-implan dari keempat kelompok perlakuan terdeteksi adanya ion Fe. Kadar ion Fe di jaringan otot paha peri-implan tikus mengalami peningkatan terutama otot yang dekat dari implan dibandingkan otot yang jauh dari implan (p<0.05). Peningkatan kadar ion Fe paling tinggi ditunjukkan oleh jaringan otot yang diimplan dengan implan Fe berpori 450 μm pada hari pengamatan ke-7 dibandingkan dengan implan yang lain (p<0.05). Secara umum, kadar ion Fe mengalami penurunan selama 30 hari pengamatan. Berdasarkan hasil tersebut disimpulkan bahwa kadar ion Fe lebih tinggi pada jaringan otot paha peri-implan tikus yang dekat dari implan dan secara umum mengalami penurunan konsentrasi sepanjang waktu pengamatan.
Keyword: Implan Fe berpori, jaringan otot peri-implan, kadar ion Fe

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