Judul: Kemampuan pembentikan enzim reduktase oleh beberapa bakteri dalam susu melalui uji reduktsi
Abstrak: Uji reduktasi merupakan uji tidak langsung untuk mengetahui populasi bakteri dalam susu. Perhitungan jumlah bakteri dibuat berdasarkan korelasi antara waktu reduktasi dengan populasi bakteri dalam sampel. Semakin banyak bakteri dalam susu semakin cepat waktu reduktasinya. Beberapa bakteri dalam susu mempunyai kemampuan berbeda dalam pembentukan enzim reduktase. Bakteri dalam susu segar mampu mereduktasi biru metilen lebih cepat dibandingkan masing-masing bakteri dalam populasi. Bakteri Micrococcus sp (11.0±3,5 jam) mempunyai kemampuan reduktasi yang paling rendah dibandingkan dengan bakteri yang lainnya. Streptococcus sp (8,9-2,6 jam) mempunyai kemampuan reduktasi yang lebih rendah dibandingkan dengan bakteri dalam susu segar (6,6+1,5 jam), Bacillus sp (7,5±1,4 jam), coli (8.62 1,1 jam) dan Staphylococcus sp (8,010,7 Jam). Uji reduktasi digunakan untuk menganalisis jumlah bakteri secara kualitatif Penggunaan uji ini menjadi tidak efektif pada susu yang mengandung jumlah bakteri yang sedikit. Sesuai dengan ketentuan SNI 01-2782-1998 yang menyatakan angka reduktasi yang melampaui 5 dicurigai mendapatkan perlakuan (pemanasan, mengandung residu antibiotika dan desinfektan).
Keyword: reductase enzyme, reduction test, milk bacteria

Judul: Kemampuan uji katalase sebagai uji penentuan kualitas susu segar
Abstrak: Uji katalase merupakan salah satu uji untuk menentukan kualitas susu segar secara tidak langsung. Enzim katalase mampu merombak Hidrogen Peroksida (H₂O₂) menjadi air (H₂O) dan Oksigen (O2). Volume gas oksigen yang dibebaskan kemudian diukur. Enzim katalase dihasilkan oleh sel bakteri, sel somatis, dan sel organis. Angka katalase yang tinggi mengindikasikan bahwa susu mengandung sel penghasil enzim katalase dalam jumlah banyak. Penelitian ini bertujuan untuk mengetahui kemampuan uji katalase dalam menentukan kualitas susu segar dan memberikan masukan kepada pemerintah (pihak yang berwenang) dalam menentukan standar kualitas susu di Indonesia Pada susu yang telah mengalami pemanasan, angka katalase nol, sedangkan pada susu segar dan susu yang telah dipanaskan kemudian ditambahkan bakteri Micrococcus sp., secara statistik tidak berbeda nyata. Peningkatan angka katalase terjadi pula pada susu yang telah dipanaskan kemudian ditambahkan santan. Perbandingan volume susu dan santan yang digunakan pada penelitian ini adalah 8 bagian 2 bagian dan 9 bagian: I bagian. Keduanya menunjukkan perbedaan yang nyata dan keduanya secara statistik berbeda nyata pula dengan susu segar maupun susu yang telah dipanaskan,
Keyword: catalase enzyme, Hydrogen Peroxide, bacterial cells, somatic cells

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