Judul: Uji Kecernaan In vitro Silase Campuran Rumput Gajah (Pennisetum purpureum) dan Lamtoro Merah (Acacia villosa)
Abstrak: The aim of this experiment was to study in vitro digestibility of mixed Pennisetum purpureum and Acacia villosa silage in different proportion. The experiment used factorial block randomized design 3x6 with three replicates. Factor A was the ratio between P. purpureum and A. villosa i.e. A1 = 60% P. purpureum : 40% A. villosa, A2 = 50% P. purpureum : 50% A. villosa, and A3 = 40% P. purpureum and 60% A. villosa. Factor B was incubation times i.e. B1-B6 for 4, 8, 12, 24, 48, and 72 hours. Data were analyzed using analysis of variance (ANOVA), the difference between treatments were tested with polynomial and Duncan test. The result showed that bacterial population, and organic digestibility were influenced by treatments (P<0.05). Ammonia concentrations, and dry matter digestibility were influenced by incubation time (P<0.05). Protozoa populations was influenced by treatments and incubation time (P<0.05). Interaction between two factors was detected (P<0.05) on total VFA concentrations. Methane was reduced by the increased of A. villosa. It is concluded that the addition of 40% of A. villosa cause the highest digestibility and total VFA production but produce the highest methane.
Keyword: P. purpureum, methane, digestibility, A. villosa

Judul: Utilisasi Silase Jerami Jagung dengan Suplementasi Kulit Matoa terhadap Penurunan Produksi Gas Metan secara In Vitro
Abstrak: Penelitian ini bertujuan untuk menganalisis pengaruh jerami jagung dengan suplementasi kulit matoa terhadap fermentabilitas dan kecernaan rumen secara in vitro. Penelitian menggunakan rancangan acak lengkap (RAL) dengan 4 perlakuan dan 4 ulangan. Perlakuan meliputi P0 = 1 kg jerami jagung; P1 = 1 kg jerami jagung + 20% kulit matoa; P2 = 1 kg jerami jagung + 30% kulit matoa; P3 = 1 kg jerami jagung + 40% kulit matoa. Parameter yang diamati yaitu analisis proksimat, gas total, gas metana, pH rumen, volatile fatty acid (VFA), NH3, sintesis protein mikrobial (SPM), kecernaan bahan kering (KcBK), kecernaan bahan organik (KcBO), total bakteri, dan populasi protozoa. Data dianalisis menggunakan analysis of variance (ANOVA) dan diuji lanjut dengan Uji Duncan menggunakan program SPSS 25. Perlakuan tidak berpengaruh nyata terhadap pH rumen, kadar NH3, SPM, KcBK, dan KcBO. Namun, berpengaruh nyata pada total produksi gas total, penurunan gas metan, dan konsentrasi VFA. Silase jerami jagung dengan suplementasi kulit matoa efektif menurunkan gas metan, tetapi tidak mempengaruhi fermentabilitas dan kecernaan rumen., This study aimed to analyze the effect of corn straw silage with matoa peel supplementation on fermentability and rumen digestibility in vitro. This study used a completely randomized design (CRD) with 4 treatments and 4 replications. The treatments consisted of P0 = 1 kg corn straw; P1 = 1 kg corn straw + 20% matoa peel; P2 = 1 kg corn straw + 30% matoa peel; P3 = 1 kg corn straw + 40% matoa peel. Parameters observed were proximate analysis, gas production, methane gas, rumen pH, volatile fatty acid (VFA), NH3, microbial protein synthesis (MPS), dry matter digestibility (DMD), organic matter digestibility (OMD), total bacteria, and protozoa population. Data were analyzed using analysis of variance (ANOVA) and further tested with Duncan's test using the SPSS 25 program. The treatment had no significant effect on rumen pH, NH3 levels, MPS, DMD, and OMD. However, the treatment had a significant effect on total gas production, methane gas reduction, and VFA concentration. Corn straw silage with matoa peel reduced methane gas but it did not affect on rumen fermentability and digestibility.
Keyword: fermentabilitas, in vitro, jerami jagung, kulit matoa, Metan

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