Judul: Effect of Chitosan Coating on Urea for Amonia Concentration In Vitro
Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh pemberian coating urea berlapis kitosan dengan taraf 1%, 2%, dan 3% dalam menurunkan konsentrasi amonia dalam rumen secara in vitro. Penelitian ini menggunakan Rancangan Acak Kelompok (RAK) faktorial untuk menguji parameter amonia dan Rancangan Acak Lengkap (RAK) untuk parameter pH, Sintesis Protein Mikroba (SPM), Kecernaan Bahan Kering (KCBK), Kecernaan Bahan Organik (KCBO), dan Volatile Fatty Acid (VFA) serta uji lanjut Tukey HSD. Data yang diperoleh dianalisis dengan menggunakan General Linear Model (GLM) dengan software SPSS versi 25. Hasil penelitian tersebut menunjukkan bahwa pemberian coating urea berlapis kitosan tidak berpengaruh nyata terhadap pH, KCBK, KCBO, SPM, dan konsentrasi amonia di dalam rumen. Akan tetapi berpengaruh nyata (P<0,05) dalam menurunkan konsentrasi VFA. Dapat disimpulkan bahwa pemberian coating urea berlapis kitosan tidak berpengaruh pada degradasi urea di dalam rumen
Keyword: ammonia, chitosan, coating urea, Non Protein Nitrogen

Judul: Slow Release Urea Nitrate with Acetaldehyde and Formaldehyde Coating Techniques against Fermentability and In Vitro Digestibility
Abstrak: Penelitian ini bertujuan mengevaluasi pengaruh pemberian coating asetaldehid dan formladehid terhadap fermentabilitas, kecernaan, serta produksi gas dalam rumen secara in vitro. Penelitian ini menggunakan rancangan acak lengkap (RAL) untuk menguji parameter pH, kecernaan bahan kering (KcBK), kecernaan bahan organik (KcBO), konsentrasi amonia, produksi gas, gas metan dan volatile fatty acid (VFA) total serta uji lanjut Tukey HSD. Data yang diperoleh dianalisis dengan menggunakan software SPSS versi 25. Hasil penelitian tersebut menunjukkan bahwa pemberian coating urea nitrat berlapis asetaldehid dan formladehid tidak berpengaruh nyata terhadap pH, KCBK, KCBO, VFA, gas metan dan konsentrasi amonia di dalam rumen. Akan tetapi berpengaruh nyata (P <0,05) dalam menurunkanproduksi gas. Dapat disimpulkan bahwa Penggunaan slow release urea nitrat (SRUN) dengan bahan coating asetaldehid lebih efektif memperlambat laju degradasi amonia dari pada bahan coating formaldehid, namun bahan coating asetaldehid dan formaldehid tidak berdampak terhadap fermentasi rumen, kecernaan, dan produksi metana., This study aimed evaluate the effect of coating acetaldehyde and formaldehyde on fermentability, digestibility, and gas production in the rumen in vitro. This study used a completely randomized design (CRD) to test the parameters of pH, dry matter digestibility (DMD), organic matter digestibility (OMD), ammonia concentration, gas production, methane gas and volatile fatty acid (VFA) ) and differences among mean values were examined using Tukey HSD test. The data obtained were analyzed using SPSS software version 25. The results showed that the coating of urea nitrate coated with acetaldehyde and formaldehyde had no significant effect on pH, DMD, OMD, VFA, methane gas and ammonia concentration in the rumen. However, it had a significant effect (P <0.05) in reducing gas production. The use of slow release urea nitrate (SRUN) with acetaldehyde coating materials is more effective in slowing the rate of ammonia degradation than formaldehyde coating materials, but acetaldehyde and formaldehyde coating materials have no impact on rumen fermentation, digestibility, and methane production.
Keyword: ammonia, acetaldehyde, formaldehyde, urea nitrate coatings

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