Judul: Tambahan Kulit Batang Kelor (Moringa oleifera) sebagai Antibakteri pada Bioplastik Pati Onggok Singkong dan Kitosan
Abstrak: Antibakteri diperlukan pada bioplastik berbasis pati untuk memperpanjang daya simpan. Kulit batang kelor (Moringa oleifera) menjadi salah satu solusi sebagai bahan antibakteri karena kandungan metabolit sekunder, seperti fenolat dan tanin. Penelitian ini bertujuan mengukur kemampuan kulit batang kelor (Moringa oleifera) sebagai antibakteri pada bioplastik berbasis pati onggok singkong dan kitosan. Bioplastik dibuat tanpa ekstrak kulit batang kelor dan dengan ekstrak kulit batang kelor sebanyak 4, 8, dan 12 mL. Berdasarkan uji t terdapat perbedaan yang nyata antara bioplastik tanpa tambahan ekstrak dan dengan ekstrak etanol kulit batang kelor. Bioplastik yang ditambah 8 mL ekstrak dapat menghambat bakteri Staphylococcus aureus dengan diameter zona hambat tertinggi. Tambahan gliserol memengaruhi sifat mekanik bioplastik. Sifat kuat tarik menurun dan elongasi bioplastik meningkat jika tambahan gliserol semakin banyak. Daya serap air dan ketebalan bioplastik semakin meningkat saat ditambahkan gliserol. Ekstrak etanol kulit batang kelor memengaruhi elongasi bioplastik., Antibacterial is required in starch-based bioplastics to extend shelf life. Moringa bark (Moringa oleifera) is one of the solutions as antibacterial agents due to its secondary metabolites, such as phenolics and tannins. This experiment aims to determine the ability of Moringa bark as an antibacterial in bioplastics based on cassava starch and chitosan. Bioplastics were prepared without and with bark extract of 4, 8, and 12 mL. The t-test showed a significant difference between the bioplastics without and that with ethanol extract of Moringa bark. Bioplastics added with 8 mL extracts can inhibit Staphylococcus aureus with the highest inhibition zone diameter. The addition of glycerol affects the mechanical properties of the bioplastics. The tensile strength decreased, and the elongation of the bioplastic increased as the addition of glycerol increased. In addition, the water absorption and thickness of the bioplastics increased when glycerol was added. The ethanol extract of Moringa stem bark affects bioplastic elongation.
Keyword: antibacterial, bark of Moringa oleifera, bioplastics, cassava starch, chitosan

Judul: Bioplastic characterization of cassava starch with addition of sodium alginate, cellulose, and limonene
Abstrak: Penggunaan plastik sintetik meningkat setiap tahunnya, namun plastik yang beredar menghasilkan limbah yang sulit terurai sehingga dibuat plastik yang ramah lingkungan. Dalam penelitian ini, bioplastik dibuat dengan paduan tepung singkong dan gliserol dengan nisbah komposisi 75:5 serta beragam konsentrasi natrium alginat, limonena dan selulosa. Bioplastik yang dihasilkan dianalisis bobot jenis, sifat mekanik, permeabilitas uap air, sifat termal, dan morfologi permukaannya. Penggunaan natrium alginat dan selulosa meningkatkan kuat tarik dan bobot jenis. Limonena hasil ekstraksi kulit jeruk meningkatkan elongasi bioplastik dan menurunkan permeabilitas uap air. Analisis termal dengan kalorimeter pemayaran diferensial menghasilkan nilai titik leleh yang meningkat dengan tambahan natrium alginat. Bioplastik yang dihasilkan memiliki morfologi permukaan yang homogen., There is high demand of sintetic plastic production each year, but the use of plastic produces non biodegradable wastes. Therefore, biodegradable plastics can be an alternative solution to overcome the problem in relating with the need of environmentally friendly plastics. Theaim of this study was to characterized bioplastics made of cassava starch with addition of sodium alginate, cellulose, and limonene. Bioplastics were made of composit of cassava starch and gliserol (75:5) and various concentrations of sodium alginate: limonen:celullose. The analysis of density, mechanical properties, thermal analysis, water vapour permeability and morfology were conducted for the biodegradable plastics. The results showed that sodium alginate and celullose increased the tensile strength and density. Limonene extracted from orange peels increased percentage of elongation and the thickness, also decrease the water vapour permeability. Thermal analysis using differential scanning calorimeter showed that sodium alginate addition increased the melting point and it indicated interaction among constituents. The surface morfology of bioplastics composite in thies study showed homogenous character. Keyword: bioplastic, cellulose, limonene, sodium alginate
Keyword: bioplastik, limonena, natrium alginat, selulosa

Judul: Asymptotic Distribution of Estimator for the Intensity Function of a Doubly Periodic Poisson Process
Abstrak: In this manuscript, estimation of the intensity function of a doubly periodic Poisson process is discussed. It is assumed that only a single realization of the Poisson process is observed in a bounded window [0,n]. It is also assumed that the period of the intensity function is known. The rate of consistency and asymptotic normality of the estimator are formulated. Finally, a confidence interval for the local intensity function is also formulated.
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