Judul: Proses Co-composting Bagas dan Sludge dari Industri Gula dengan Pengaruh Perbedaan Nilai C/N Awal dan Aerasi
Abstrak: Bagasse and sludge are solid waste of sugar industry which contained high organic material and have not been used optimally. The purpose of this research was to utilize bagas and sludge of the sugar industry through co-composting technology for making organic fertilizer and determine the influence of aeration and materials concentration on the value of C/N. Bagas and sludge combination were composted at C/N value of 30, 40, and 50. In composting process, aeration rate set on 0.4 l/minute.kg and 1.2 L/Kg of dry basis materials. The research was carried out two stages, that was preliminary research, it was determined composition of raw materials mixture, and primary research for determining C/N value during composting. Parameters monitored during composting were temperature done every day, pH and C/N determined every week. The result showed that aeration treatment did not give noticeable effect on C/N value and compost with initial C/N value of 30 gave the fastest decomposition process in co-composting stages
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Judul: Pengaruh Perbedaan Nilai C/N Dan Laju Aerasi Pada Proses Co-Composting Bagasse Dengan Blotong Pada Limbah Industri Gula
Abstrak: The sugarcane industry in Indonesia produce the waste from bagasse and filter cake that until recently is still not optimum in processing. One of alternatives handling is co-composting bagasse and filter cake that will produce compost and can reduce the amount of sugarcane industry wastes. This research aims to utilize bagasse and filter cake of sugarcane industrial waste for composting and aeration as well as differing effect of giving the C/N of the process. Composting methods used were aerated static pile technique and uses two factors of aeration and C/N ratio. Aeration was provided via active aeration (0,4 L/Kg of material and 1,2 L/kg material) and passive aeration with C/N respectively 30, 40, and 50. The composting process was running for a month with active aeration at first week. Analysis results show that aeration technique proved didn’t have significant effect in changing C/N value. After analysis, result shows that the most decrease C/N value is compost with starting condition 50 of C/N value. Generally, aeration factor are not related yet and do not have any significant interaction to co-composting C/N value.
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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