Judul: Characteristics of Polyester-Coconut Fiber Composite Board with the Addition of Sorghum Bagasse Powder
Abstrak: Produktivitas hutan Indonesia semakin menurun, sedangkan kebutuhan manusia akan bahan baku kayu semakin meningkat seiring dengan bertambahnya jumlah penduduk. Salah satu solusi untuk mengatasi masalah ini antara lain dengan mengembangkan pambuatan metrial papan komposit. Penelitian ini bertujuan untuk membuat papan komposit polyester berpenguat serat kelapa dengan penambahan serbuk bagas sorgum terhadap kualitas papan komposit polyester. Penelitian ini menggunakan metode dengan 2 faktor yaitu presentase kadar partikel (20%, 30%, dan 40%) dan variasi ukuran mesh sorgum (40-60 mesh dan lolos 60 mesh) dengan kadar matrik resin polyester 70% dan penambahan hardener 3%. Kerapatan target papan komposit polyester 1 g cm-3 . Secara keseluruhan kerapatan papan berkisar antara 1,10-1,15 g cm-3 . Campuran papan komposit polyester-serat kelapa dengan serbuk bagas sorgum dapat meningkatkan sifat fisis, mekanis, dan impak. Kadar partikel hanya berpengaruh nyata pada kekuatan impak papan sehingga dapat meningkatkan nilai kekuatan papan komposit. Ukuran partikel tidak berpengaruh nyata terhadap sifat fisis, mekanis dan impak papan komposit. Papan komposit dengan presentase kadar partikel yang tinggi dapat meningkatkan nilai kuat tarik dan impak pada papan., The productivity of Indonesia's forests is declining gradually everyday, while the human needs for the raw materials such as wood is increasing along with the increasing population. One possible solution for this problem is to develop composite materials manufacturing. The purpose of this study is to make polyester composite boards reinforced with coconut fiber with the addition of sorghum bagasse powder to increase the quality of polyester composite boards. This method uses 2 factors, namely the percentage of particle content (20%, 30%, and 40%) and variations in the size of the sorghum mesh (40-60 mesh and 60 mesh) with a matrix content of 70% polyester resin and the addition of 3% hardener. The target density of polyester composite board is 1 g cm-3 . Overall board density ranges from 1,10- 1,15 g cm-3 . A mixture of polyester-coconut fiber composite board with sorghum bagasse powder can increase the value of physical, mechanical and impact properties. The particle content has significant effect on the impact strength of the board, therefore it can increase the strength value of the board. Particle size has no significant effect on the physical, mechanical and impact properties of the board. Composite boards with a high percentage of particle content can increase the tensile and impact strength values of the boards.
Keyword: olyester, sorghum, coconut fiber, composite board

Judul: Eco-Friendly Particle Board from Coco Fiber with Starch-Based Adhesives
Abstrak: Serat sabut kelapa merupakan serat alami yang memiliki potensi untuk dimanfaatkan sebagai bahan baku pembuatan papan partikel, karena mengandung lignoselulosa dan memiliki sifat ramah lingkungan. Penggunaan perekat maltodekstrin dengan asam sitrat sebagai perekat ramah lingkungan cukup baik dalam mengikat serat kayu sehingga pada penelitian ini mencoba menggunakan maltodekstrin-asam sitrat. Penelitian ini bertujuan untuk mengetahui ukuran partikel yang optimum untuk menghasilkan produk papan partikel. Penelitian ini menggunakan ukuran partikel sebesar 40-50 mesh, 50-60 mesh, dan lolos 60 mesh. Sifat fisis yang diuji dalam penelitian ini antara lain kerapatan, kadar air, daya serap air dan pengembangan tebal. Sifat mekanis yang diuji yaitu Modulus of Elasticity (MOE) dan Modulus of Rupture (MOR). Hasil penelitian menunjukkan ukuran partikel ukuran partikel tidak memberikan pengaruh yang nyata pada kerapatan, kadar air, daya serap air, pengembangan tebal, MOE dan MOR. Nilai sifat fisis yang diuji telah mencapai standar JIS A 5908-2003. Ukuran partikel optimum seratsabut kelapa untuk menghasilkan papan partikel cukup baik yaitu lolos 60 mesh., Coconut fiber is a natural fiber that has the potential to be used as a raw material for making particleboard, because it contains lignocellulose and has environmentally friendly properties. The use of maltodextrin adhesive with citric acid as an environmentally friendly adhesive is quite good in binding woodfibers, so in this study we tried to use maltodextrin-citric acid. This study aims to determine the optimum particle size to produce particleboard products. This study used a particle size of 40-50 mesh, 50-60 mesh, and passed 60 mesh. The physical properties tested in this study include density, moisture content, water absorption and thickness expansion. The mechanical properties tested were the Modulus of Elasticity and the Modulus of Rupture. The results showed that the particle size didn’t have a significant effect on density, moisture content, water absorption, thickness swelling, MOE and MOR. The value of the tested physical properties has reached the JIS A 5908-2003 standard.The optimum particle size of coco fiber to produce particleboard is quite good, which is passed 60 mesh.
Keyword: Coco fiber, Mechanical properties, Particle board, Particle size, Physical properties

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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