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: Synthesis of Coconut Pulp-Based Bioplastics with the  Addition of Sorbitol and Chitosan
Abstrak: Bioplastik merupakan plastik biopolimer yang mudah terurai oleh mikroorganisme sehingga dapat menjadi alternatif pengganti plastik komersial. Salah satu polimer alam yang banyak digunakan sebagai bahan bioplastik adalah polisakarida. Ampas kelapa berpotensi sebagai bahan baku pembuatan bioplastik dengan penambahan kitosan dan sorbitol sebagai plasticizer. Penelitian bertujuan untuk membuat bioplastik sebagai pengemas makanan berbasis ampas kelapa dengan metode solution casting, serta melihat pengaruh variasi kitosan dan sorbitol terhadap karakteristik bioplastik. Karakterisasi meliputi uji ketebalan, uji mekanik, uji water vapor transmission rate (WVTR), uji biodegradabilitas, uji masa simpan produk, dan analisa scanning electron microscope (SEM). Penambahan kitosan dan sorbitol berpengaruh pada ketebalan film bioplastik. Nilai tensile strength 3 MPa - 18,16 MPa. Nilai elongation 0,52%-24,10%. Nilai WVTR 2,13 g/m2.jam - 2,87 g/m2.jam. Waktu bioplastik terdegradasi sempurna yaitu 3-6 hari. Morfologi permukaan film bioplastik terdapat spot spot putih, berpori dan kurang homogen., Bioplastics is a biopolymer plastic that is easily decomposed by microorganisms so that it can be an alternative to commercial plastics. Polysaccharides are one of the natural polymers that are widely used as bioplastic materials. Coconut pulp has the potential as raw material for making bioplastics with the addition of chitosan and sorbitol as plasticizers. The research aims to make bioplastics as food packaging based on coconut pulp with the solution casting method and to see the effect of variations of chitosan and sorbitol on the characteristics of bioplastics. Characteristic includes the thickness, mechanical property test, water vapor transmission rate (WVTR), biodegradability, product shelf life test, and surface morphology analysis with SEM. The addition of chitosan and sorbitol affects the thickness of the bioplastic film. The tensile strength value is 3 MPa-18,16 MPa. The elongation value is 0,52%-24,10%. The WVTR Value is 2,13 g/m2.hour - 2,87 g/m2.hour. The entire degradability time for films is 3-6 days. The surface morphology of the bioplastic film has white spots, is porous, and is less homogeneous.
Keyword: bioplastic, coconut pulp, chitosan, sorbitol

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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