Judul: Characterization of Biopellet from Corncob Waste Biopellet with Sengon Wood Sawdust Mixture as Renewable Alternative Fuel
Abstrak: Limbah pertanian berpotensi sebagai sumber energi berkelanjutan untuk memenuhi kebutuhan energi yang kian meningkat. Penelitian ini bertujuan untuk menganalisis karakteristik dan menentukan komposisi biopelet limbah tongkol jagung, serbuk kayu sengon dan kombinasi campuran keduanya sebagai bahan bakar alternatif terbarukan skala rumah tangga. Pembuatan biopelet tongkol jagung dan serbuk kayu sengon dibuat dengan beberapa perbandingan komposisi bahan baku yaitu A1 (100% tongkol jagung), A2 (100% serbuk kayu sengon), A3 (80% tongkol jagung : 20% serbuk kayu sengon), A4 (70% tongkol jagung : 30% serbuk kayu sengon), A5 (60% tongkol jagung : 40% serbuk kayu sengon), A6 (50% tongkol jagung : 50% serbuk kayu sengon). Hasil penelitian menunjukkan untuk bahan tunggal pada perlakuan A2 dengan bahan 100% serbuk kayu sengon dan untuk bahan campuran pada perlakuan A3 dengan campuran komposisi 80% tongkol jagung dan 20% serbuk kayu sengon menjadi perlakuan dengan komposisi terbaik berdasarkan nilai parameter yang telah memenuhi standar mutu SNI 8675-2018 serta memiliki nilai bobot tertinggi dalam metode uji pembobotan. Pada perlakuan A2 diperoleh nilai kerapatan sebesar 0,47 g/cm3, kadar air sebesar 7,25%, nilai ketahanan sebesar 93,35%, kadar abu sebesar 1,83%, kadar karbon terikat sebesar 9,3%, dan nilai kalor sebesar 17,17 MJ/kg, sedangkan perlakuan A3 diperoleh nilai kerapatan sebesar 0,59 g/cm3, kadar air sebesar 8,87%, nilai ketahanan sebesar 97,99%, kadar abu sebesar 3,5%, kadar karbon terikat sebesar 12%, dan nilai kalor sebesar 17,13 MJ/kg. Analisis rasio energi dalam proses pembuatan biopelet menunjukkan nilai positif pada kisaran 1,1-2,2, dimana energi hasil produk biopelet lebih tinggi dari energi yang diperlukan. Limbah tongkol jagung dan limbah serbuk kayu sengon dapat ditingkatkan manfaatnya sebagai bahan bakar pembuatan biopelet.
Keyword: Biopellet, Corn cob, Sengon sawdust, Biomass, Alternative fuel, Renewable

Judul: Karakteristik Biopelet Limbah Ampas Tebu dan Batang Singkong
Abstrak: Limbah ampas tebu (bagasse) dan batang singkong merupakan biomassa yang berpotensi menjadi alternatif bahan bakar terbarukan untuk memenuhi kebutuhan energi yang kian meningkat. Penelitian ini bertujuan untuk menganalisis karakteristik biopelet dan menentukan formulasi biopelet terbaik dari campuran limbah ampas tebu dan batang singkong. Pembuatan biopelet menggunakan pelletizer tipe rotary dies dengan perbandingan komposisi bahan baku yaitu A1 (100% serbuk batang singkong), A2 (100% limbah ampas tebu), A3 (20% limbah ampas tebu : 80% serbuk batang singkong), A4 (80% limbah ampas tebu : 20% serbuk batang singkong), A5 (50% limbah ampas tebu : 50% serbuk batang singkong), A6 (65% limbah ampas tebu : 35% serbuk batang singkong), A7 (35% limbah ampas tebu: 65% serbuk batang singkong). Penentuan biopelet terbaik berdasarkan pembobotan dengan tingkat kepentingan parameter dengan bobot tertinggi hingga terendah yaitu nilai kalor, kadar abu, kadar zat terbang, kerapatan, kadar air, dan laju pembakaran. Formulasi terbaik dari campuran kedua bahan baku berdasarkan SNI 8675-2018 didapatkan dari perlakuan A5 dengan rata-rata hasil uji kerapatan sebesar 0,60 g/cm³, kadar air 8,29%, kadar zat terbang 77,63%, kadar abu 4,10%, kadar karbon terikat 9,98%, nilai kalor 17,40 MJ/kg, keteguhan 96,55%, laju pembakaran 3,57 kg/jam, serta suhu pembakaran 761°C., Sugarcane bagasse and cassava stems are biomass waste which have potential as alternative renewable fuels by converting it into biopellets. This research aims to analyze the characteristics of biopellets made from a mixture of sugarcane bagasse and cassava stems waste, and determine the best formulation based on SNI no 8765-2018. A rotary dies type pelletizer has been used to produce the pellets. Pellets formulation was represented by the ratio of raw material composition, they were A1 (100% cassava stem powder), A2 (100% sugarcane bagasse waste), A3 (20% sugarcane bagasse waste : 80% cassava stem powder), A4 (80% bagasse waste : 20% cassava stem powder), A5 (50% sugarcane bagasse waste : 50% cassava stem powder), A6 (65% sugarcane bagasse waste : 35% cassava stem powder), A7 (35% sugarcane bagasse waste : 65 % cassava stem powder). Determination of the best biopellets is based on the scoring with the level of lightness of the parameters with the highest to lowest score is calorific value, ash content, volatile matter content, density, moisture content, and combustion rate. The best formulation obtained from A5 composition (50% bagasse and 50% cassava stem) with average density of 0,60 g/cm³, water content of 8,29%, volatile matter content of 77,63%, ash content of 4,10%, bound carbon content of 9,98%, calorific value 17,40 MJ/kg, durability 96,55%, and combustion rate 3,67 kg/hour, combustion temperature 761°C.
Keyword: biomassa, biopelet, bagasse, batang singkong, pelletizer

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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