Judul: Biopellet Characterization of Arabica Coffee Grounds and Teak Sawdust as A Result of Torrefaction
Abstrak: Limbah ampas kopi arabika dan serbuk gergaji kayu jati memiliki potensi untuk dijadikan substitusi energi yang bersifat keberlanjutan. Salah satu pemanfaatannya adalah dengan menjadikan biopelet yang ditingkatkan mutunya melalui proses torefaksi. Penelitian ini bertujuan untuk menganalisis karakterisasi biopelet hasil torefaksi pre-treatment (A) dan post-treatment (B). Biopelet dibuat dengan menggunakan pelletizer tipe flat dies dengan formulasi bahan baku 1:1 (perekat 5%), dan pemrosesan torefaksi menggunakan suhu 220 oC (A1 dan B1), 250 oC (A2 dan B2), dan 280 oC (A3 dan B3). Kondisi pre-treatment merupakan torefaksi bahan baku mentah, sementara post-treatment merupakan torefaksi biopelet. Pengujian fisiokimia biopelet mengacu pada SNI 8675-2018 yang mencakup kerapatan, kadar air, kadar zat terbang, kadar abu, kadar karbon terikat, nilai kalor. Pengujian fisik mencakup dimensi, ketahanan, dan hidrofobisitas. Formulasi terbaik pada tiap parameter dicapai oleh perlakuan A3 dengan nilai kerapatan 0,46 g/cm3 , kadar air 3,32%, kadar zat terbang 44,7%, kadar abu 4,75%, kadar karbon terikat 50,55%, dan nilai kalor 25,96 MJ/kg dan perlakuan B3 dengan nilai kerapatan 0,34 g/cm3 , kadar air 3,11%, kadar zat terbang 39,04%, kadar abu 6,97%, kadar karbon terikat 53,98%, dan nilai kalor 25,12 MJ/kg., The potential of Arabica coffee grounds and teak sawdust waste as sustainable energy substitutes by converting them into bio-pellets enhanced through torrefaction. The research focuses on characterizing bio-pellets from pre-treatment (raw material torrefaction) and post-treatment (bio-pellet torrefaction). Using a flat die pelletizer, the bio-pellets were produced with a 1:1 raw material ratio (5% adhesive) and torrefied at 220°C, 250°C, and 280°C. The bio-pellets' physicochemical properties, including density, moisture content, volatile matter content, ash content, fixed carbon content, and calorific value, were evaluated according to SNI 8675:2018 standards. Physical properties such as dimensions, durability, and hydrophobicity were also assessed. The optimal formulations were A3, with a density of 0,46 g/cm³, moisture content of 3,32%, volatile matter content of 44,7%, ash content of 4,75%, fixed carbon content of 50,55%, and a calorific value of 25,96 MJ/kg, and B3, with a density of 0,34 g/cm³, moisture content of 3,11%, volatile matter content of 39,04%, ash content of 6,97%, fixed carbon content of 53,98%, and a calorific value of 25,12 MJ/kg
Keyword: biopelet, Ampas kopi arabika, serbuk gergaji kayu jati, torefaksi pre-treatment dan post-treatment

Judul: Biopellet Characterization of Arabica Coffee  Grounds and Teak Sawdust as A Result of Torrefaction
Abstrak: Limbah ampas kopi arabika dan serbuk gergaji kayu jati memiliki potensi untuk dijadikan substitusi energi yang bersifat keberlanjutan. Salah satu pemanfaatannya adalah dengan menjadikan biopelet yang ditingkatkan mutunya melalui proses torefaksi. Penelitian ini bertujuan untuk menganalisis karakterisasi biopelet hasil torefaksi pre-treatment (A) dan post-treatment (B). Biopelet dibuat dengan menggunakan pelletizer tipe flat dies dengan formulasi bahan baku 1:1 (perekat 5%), dan pemrosesan torefaksi menggunakan suhu 220 oC (A1 dan B1), 250 oC (A2 dan B2), dan 280 oC (A3 dan B3). Kondisi pre-treatment merupakan torefaksi bahan baku mentah, sementara post-treatment merupakan torefaksi biopelet. Pengujian fisiokimia biopelet mengacu pada SNI 8675-2018 yang mencakup kerapatan, kadar air, kadar zat terbang, kadar abu, kadar karbon terikat, nilai kalor. Pengujian fisik mencakup dimensi, ketahanan, dan hidrofobisitas. Formulasi terbaik pada tiap parameter dicapai oleh perlakuan A3 dengan nilai kerapatan 0,46 g/cm3 , kadar air 3,32%, kadar zat terbang 44,7%, kadar abu 4,75%, kadar karbon terikat 50,55%, dan nilai kalor 25,96 MJ/kg dan perlakuan B3 dengan nilai kerapatan 0,34 g/cm3 , kadar air 3,11%, kadar zat terbang 39,04%, kadar abu 6,97%, kadar karbon terikat 53,98%, dan nilai kalor 25,12 MJ/kg., The potential of Arabica coffee grounds and teak sawdust waste as sustainable energy substitutes by converting them into bio-pellets enhanced through torrefaction. The research focuses on characterizing bio-pellets from pre-treatment (raw material torrefaction) and post-treatment (bio-pellet torrefaction). Using a flat die pelletizer, the bio-pellets were produced with a 1:1 raw material ratio (5% adhesive) and torrefied at 220°C, 250°C, and 280°C. The bio-pellets' physicochemical properties, including density, moisture content, volatile matter content, ash content, fixed carbon content, and calorific value, were evaluated according to SNI 8675:2018 standards. Physical properties such as dimensions, durability, and hydrophobicity were also assessed. The optimal formulations were A3, with a density of 0,46 g/cm³, moisture content of 3,32%, volatile matter content of 44,7%, ash content of 4,75%, fixed carbon content of 50,55%, and a calorific value of 25,96 MJ/kg, and B3, with a density of 0,34 g/cm³, moisture content of 3,11%, volatile matter content of 39,04%, ash content of 6,97%, fixed carbon content of 53,98%, and a calorific value of 25,12 MJ/kg.
Keyword: Biopelet, Ampas kopi arabika, serbuk gergaji kayu jati, torefaksi pre-treatment dan post-treatment, bio-pellets, arabica coffee grounds, teak sawdust waste, pre-treatment  and post-treatment torrefaction

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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