Judul: Pengaruh Pemakaian Bahan Kimia dalam Pelunakan Serpih terhadap Sifat Pulp Semikimia Acacia mangium Willd
Abstrak: Pengolahan pulp pada umumnya harus menggunakan pengolahan konvensional berteknologi tinggi sehingga memerlukan permodalan yang besar. Hal ini disebabkan penggunaan bahan kimia yang relatif mahal dan konsumsi energi yang tinggi sehingga memerlukan biaya produksi dan investasi yang tinggi, Langkah yang diperlukan adalah menemukan suatu modifikasi proses pengolahan pulp yang dapat diaplikasikan ke industri menengah dan kecil dan menghasilkan mutu yang baik. Penelitian ini mempakan penelitian pendahuluan yang bertujuan untuk mengetahui pengaruh beberapa jenis dan konsentrasi bahan kimia serta konsentrasinya dalam pelunakan serpih terhadap rendemen dan sifat fisik pulp semikimia,
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Judul: Pengaruh suhu pemasakan dan perlakuan mekanis terhadap rendemen dan sifat pul[p semi kimia sulfit netral (NSSC) dari kayu Acacia mangium Willd
Abstrak: Dewasa ini kebutuhan pulp dan kertas semakin meningkat. Sesuai dengan usaha industri pulp dan kertas yang mengarah pada penggunaan bahan baku seefisien mungkin, penelitian ini mencoba menerapkan proses pembuatan pulp rendemen ting- gi semi kimia sulfit netral, dengan Acacia mangium sebagai bahan baku. Tujuan penelitian ini adalah untuk mengetahui dan mem- bandingkan pengaruh suhu pemasakan serta perlakuan mekanis terhadap rendemen dan sifat pulp yang dihasilkan, sehingga diketahui kondisi pengolahan yang paling optimal. Penelitian ini terdiri atas 2 tahap, tahap pertama dilakukan pengukuran bobot jenis dan dimensi serat kayu, dilanjutkan dengan pembuatan pulp dan analisa sifat-sifat pulp yang dihasilkan pada tahap selanjutnya. Perlakuan yang dicobakan adalah suhu pemasakan (A) yang terdiri atas 2 taraf (160 dan 170°C), skala refiner (B) yang terdiri atas 3 taraf (15, 20, dan 25 mm), dan tingkat penggilingan/jumlah putaran pisau PFI mill (C) yang terdi- ri atas 5 taraf (0, 1500, 3000, 4500 dan 6000 rpm). Ran- cangan yang digunakan adalah rancangan split-split plot de- ngan 2 kali ulangan. ...
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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