Judul: Coffee Grounds Composite as an Environmentally Friendly Heat-Resistant Material
Abstrak: Poli asam laktat (Polylactic Acid/PLA) merupakan polimer ramah lingkungan, namun penggunaan PLA sebagai material tahan panas masih kurang diminati karena lebih mahal dibandingkan polyolefin. Pencampuran PLA dengan Thermoplastic Starch (TPS) mampu mengurangi harga PLA namun sifat fisis, mekanis dan thermal komposit menurun. Pencampuran dengan sukrosa dan ampas kopi bertujuan untuk memperbaiki karakteristik dari komposit PLA-TPS (PT). Penelitian ini bertujuan untuk mengembangkan dan mengevaluasi sukrosa dan ampas kopi sebagai material komposit tahan panas yang dicampurkan dengan PLA dan TPS. Komposit dibuat dengan berbagai variasi kadar penambahan sukrosa (1,2,3 % b⁄b) dan ampas kopi (5,10,15 % b⁄b). Hasil penelitian menemukan bahwa karakteristik terbaik dihasilkan oleh ampas kopi pada kadar 5% dengan hasil: Water Vapor Transmission Rate (1276 g/m2.d), Water Vapor Permeable (1.86256×10-7 g/m.s Pa), modulus young (420 MPa), elongasi (2.59%) dan kuat tarik (5 MPa). Penambahan sukrosa dapat meningkatkan sifat fisis, mekanis dan thermal komposit PT sedangkan penambahan kopi dapat meningkatkan sifat thermal dan kristalinitas dari PT.
Keyword: Composite, Environmentally Friendly Composite, Polylactic Acid, Spent Coffee Ground, Thermoplastic Starch

Judul: The Effect of Lignin Consentration on Physical and Mechanical Properties of Bioplastic with Polylactic acid (PLA) based
Abstrak: Plastik dengan sifat biodegradable mudah dihancurkan dan ramah lingkungan. Bioplastik dapat menjadi solusi pengganti plastik karena dapat terurai oleh aktivitas mikroorganisme tanpa menyisakan residu beracun, terbuat dari bahan yang dapat diperbarui, dan dapat menjaga kualitas produk. PLA merupakan polimer alami yang mempunyai sifat biodegradable dalam pembuatan bioplastik. Penambahan lignin dalam pembuatan bioplastik dapat menjadi agen penguat yang baik dalam polimer matriks PLA dan merupakan kandidat yang potensial untuk bahan pembuatan bioplastik. Salah satu sumber lignin adalah tandan kosong kelapa sawit (TKKS). Tujuan dari penelitian ini adalah mengisolasi lignin dari TKKS dan menganalisis sifat fisik dan mekanik bioplastik PLA-lignin. Lignin diperoleh dari proses isolasi lignin dan ultrasonikasi. Bioplastik PLA-lignin dihasilkan dari campuran PLA sebagai matriks dengan penambahan konsentrasi lignin yang berbeda (0%, 2.5%, 5%, 7.5%, 10%). Pembuatan bioplastik dilakukan dengan metode solvent casting. Komposisi lignin dalam TKKS diperoleh dengan uji proksimat. Karakterisasi morfologi lignin dan film bioplastik dianalisis menggunakan scanning electron microcopy (SEM), komponen gugus fungsi dianalisis dengan fourier transform infrared (FTIR), sifat mekanik dianalisis dengan uji mekanik tensile strength, dan laju transmisi uap air pada film bioplastik dianalisis dengan uji WVTR. Bioplastik PLA-lignin menghasilkan adhesi permukaan dan kompatibilitas yang baik ketika ukuran lignin diperkecil. Lignin dengan konsentrasi 5% pada pembuatan bioplastik dapat menghasilkan adhesi permukaan dan kompatibilitas yang lebih baik dibandingkan dengan konsentrasi diatas 5%. Pencampuran PLA dan lignin dapat meningkatkan sifat fisik dan mekanik dari film bioplastik PLA-lignin seperti meningkatkan kuat tarik, elongasi, dan modulus Young dibandingkan dengan bioplastik dari PLA murni., The properties of biodegradable plastic are easily decomposed and ecofriendly. Bioplastics can be a plastic replacement solution because they can be decomposed by microorganism activity without leaving toxic residues, made from renewable materials, and maintaining the product quality. PLA is a natural polymer that has biodegradable properties in bioplastics manufacturing. The addition of lignin can be a good reinforcement agent in PLA matrix polymers and potential candidates in bioplastic manufacturing materials. One of the lignin sources is oil palm empty fruit bunches (OPEFB). The research aims to isolate the lignin from OPEFB and analyze the physical and mechanical properties of PLA-lignin. Lignin from OPEFB is obtained from isolation and ultrasonication process. PLA-lignin-based bioplastics are produced from a mixture of PLA as matrix and lignin in different concentrations (0%, 2.5%, 5%, 7.5%, 10%). The casting method was applied to produce the bioplastics. The composition of lignin in OPEFB was obtained by proximate test. Morphological structure of lignin, bioplastic films and functional group components were analyzed by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR), respectively. Mechanical properties and water transmission rate of bioplastic films were analyzed by mechanical tensile strentgh and WVTR test, respectively. PLA-lignin-based bioplastics produce a good compatibility and surface adhesion when the size of lignin is reduced. The 5% of lignin concentration in bioplastics showed that the better compatibility and surface adhesion compared to the higher concentration. Compared to PLA-based bioplastics, PLA-lignin-based bioplastics can increase the mechanical and physical properties, such as tensile strength, elongation, and Young’s modulus.
Keyword: bioplastic, lignin, Polylactic acid (PLA), TKKS, physical and mechanical properties

Judul: Mitochondrial DNA Gene Organization and Phylogenetic Relationship of Naja siamensis
Abstrak: Naja siamensis is one of Asiatic cobra in the Family of Elapidae, known as a cryptic snake. It has many morphological variations that lead to misidentification. Misidentification can cause the wrong concept in developing antivenom types due to high snakebite cases occur in Thailand. Thus, an accurate species identification using a molecular approach is crucially required. Mitochondrial DNA has been used widely in snake molecular studies. These studies were aimed to determine the arrangement of the N. siamensis partial mitochondrial genes using reptile-oriented primers and to reveal the phylogenetic relationship among other species of Asian cobra. DNA extraction was carried out based on the standard DNA salting-out protocol and was conducted by bioinformatics analysis using BLASTn and MEGA 6 software. Gene annotation was performed against N. kaouthia complete genome. A total of 3121 bp of N. siamensis mtDNA genes were sequenced consisting of partial of six regions: 16S rRNA, ND1, tRNA-Ile, CRII region, tRNA-Leu, tRNA-Gln, and COI genes. The mtDNA gene organization of N. siamensis was predicted to has a similar pattern with the common Elapidae mtDNA gene organization. This study showed that there is a monophyletic form in Naja genus and N. kaouthia is the closest species with N. siamensis based on partial 16S rRNA and ND1 gene.
Keyword: 16S rRNA, Elapidae, ND1, phylogenetic relationship