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 Zeolite Using Coating Method: In Vitro Study
Abstrak: Penelitian ini bertujuan untuk mengevaluasi pengaruh penyalut zeolit yang dilakukan secara in vitro pada urea-nitrat. Penelitian ini menggunakan rancangan acak kelompok (RAK) dengan 5 perlakuan dan 4 kelompok. Perlakuan terdiri dari P0 = ransum kontrol; P1 = P0 + urea tanpa coating; P2 = P0 + urea-nitrat tanpa coating; P3 = P0 + urea-nitrat dengan coating zeolit tanpa aktivasi; P4 = P0 + urea-nitrat dengan coating zeolit teraktivasi. Parameter yang diamati yaitu kecernaan bahan kering (KcBK), kecernaan bahan organik (KcBO), pH, volatile fatty acid (VFA), konsentrasi amonia (NH3), sintesis protein mikroba, dan produksi metana. Hasil penelitian menunjukkan bahwa pemberian ransum perlakuan tidak berpengaruh nyata (P>0,05) terhadap KcBK, KcBO, pH, VFA, sintesis protein mikroba, produksi gas total, dan produksi metana, tetapi berpengaruh nyata terhadap konsentrasi amonia. Pemberian coating zeolit pada urea-nitrat dapat menurunkan konsentrasi amonia dan tidak berdampak terhadap fermentasi rumen, kecernaan, sintesis protein mikroba, produksi gas, dan produksi metana., The research aimed to evaluate the effect of in vitro zeolite coating on urea-nitrate. This study used a randomized block design (RBD) with 5 treatments and 4 groups. The treatment consisted of P0 = control ration; P1 = P0 + uncoated urea; P2 = P0 + uncoated urea-nitrate; P3 = P0 + urea-nitrate with unactivated zeolite coating; P4 = P0 + urea-nitrate with activated zeolite coating. Parameters observed were dry matter digestibility (DMD), organic matter digestibility (OMD), pH, volatile fatty acid (VFA), ammonia concentration ( NH3), microbial protein synthesis, and methane production. The results showed that the application of urea-nitrate coating with zeolite had no significant effect (P>0,05) on DMD, OMD, pH, VFA, microbial protein synthesis, gas and methane production, but had a significant effect on ammonia concentrations. Applying a zeolite coating to urea-nitrate reduced ammonia concentrations and had no impact on rumen fermentation, digestibility, microbial protein synthesis, gas and methane production.
Keyword: ammonia, coating urea-nitrate, in vitro, methane, zeolite

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