Judul: Manufacture and Characterization of Nonwood Paper from Dry Sugarcane Leaves and Rice Straw Waste as Paper Bags
Abstrak: Bahan nonkayu menjadi alternatif untuk mengatasi kebergantungan akan kayu dalam industri kertas. Daun kering tebu dan jerami padi merupakan dua contoh limbah pertanian pascapanen yang belum banyak dimanfaatkan. Penelitian ini bertujuan membuat kertas yang dapat digunakan sebagai kantong kertas dengan memanfaatkan limbah daun kering tebu dan jerami padi. Daun kering tebu dan jerami padi dicampurkan dalam tiga perlakuan (%b/b), T1 (50:50), T2 (75:25), dan T3 (25:75). Pulp dibuat secara kimiawi menggunakan NaOH 10% pada suhu ±100 °C selama 120 menit. Pulp lalu dicampurkan dengan perekat PVAc 5% sebelum dicetak menjadi lembaran berukuran A4. Hasil uji ANOVA menunjukkan pengaruh yang nyata (P<0,05) antara perbedaan nisbah bahan baku dengan nilai gramatur, ketahanan tarik, dan ketahanan sobek kertas. Perlakuan T3 menghasilkan kertas terbaik, memenuhi standar mutu kertas, dan dapat digunakan sebagai kantong kertas., Nonwood materials are an alternative to overcome dependence on wood in the paper industry. Dried leaves of sugarcane and rice straw are two examples of postharvest agricultural waste that has not been widely utilized. This research aims to prepare a paper that can be used as paper bags by utilizing dry leaf waste of sugarcane and rice straw. Dried leaves of sugarcane and rice straw were mixed in three treatments (%w/w), T1 (50:50), T2 (75:25), and T3 (25:75). The pulp was chemically prepared using 10% NaOH at ±100°C for 120 min. The pulp was mixed with 5% PVAc adhesive before molding into A4-sized sheets. The ANOVA test results showed a significant effect (P<0.05) between the various ratios of raw materials to grammage, tensile strength, and tear resistance of the paper. T3 treatment produced the best paper, complies with paper quality standards, and can be used as paper bags.
Keyword: agricultural waste, dry sugarcane leaves, paper, paper bags, rice straw

Judul: Manufacture and Characterization of Physical Properties of Non-Wood Paper from Palm Oil Solid Waste as Packaging Paper
Abstrak: Penelitian ini bertujuan membuat kertas dari bahan non-kayu, yaitu limbah padat kelapa sawit, yang bernilai ekonomis serta menganalisis sifat fisiknya. Proses yang digunakan untuk membuat pulp serat mesokarp dan tandan kosong kelapa sawit (TKKS) adalah metode kimia menggunakan NaOH 10% selama 60 menit, pada suhu 100 ℃. Kertas dibuat dengan nisbah pulp limbah kelapa sawit dan kertas bekas 60:40 dan 70:30 dengan tambahan perekat 2−5%. Kertas dengan kualitas terbaik dihasilkan dari nisbah serat mesokarp dan TKKS 60% dan kertas bekas 40% dengan tambahan perekat 5%. Kertas dari campuran serat mesokarp dan kertas bekas menghasilkan gramatur sebesar 157,0 g/m2, kekuatan tarik 0,94 kN/m, dan ketahanan sobek 511,8 mN. Kertas dari TKKS menghasilkan nilai gramatur sebesar 134,7 g/m2, kekuatan tarik 0,87 kN/m, dan ketahanan sobek 441,1 mN. Hasil penelitian menunjukkan bahwa gramatur dan ketahanan sobek kertas dari serat mesokarp dan TKKS sudah sesuai SNI 8218:2015, sedangkan kekuatan tarik belum memenuhi standar. Spektrum inframerah menunjukkan bahwa kedua kertas mengandung selulosa dan lignin., This research aimed to prepare low-cost non-wood paper and analyze the properties of non-wood paper produced from palm oil solid waste. The method used to make mesocarp fiber pulp and empty fruit bunch (EFB) pulp was a chemical method using 10% NaOH for 60 minutes at a temperature of 100 ℃. The paper was prepared with a 60:40 and 70:30 ratios of palm oil waste pulp and waste paper with the addition of 2-5% adhesive. The best-quality paper was produced from 60% palm oil waste pulp and 40% waste paper with 5% adhesive added. Mesocarp fiber paper has grammage of 157.0 g/m2, a tensile strength of 0.94 kN/m, and a tear resistance of 511.8 mN. The EFB paper has a grammage of 134.7 g/m2, a tensile strength of 0.87 kN/m, and a tear resistance of 441.1 mN. As result, the grammage and tear resistance of paper from mesocarp fibers and EFB met the requirements of SNI 8218:2015, while the tensile strength did not meet the standard. The infrared spectrum showed that both papers contained cellulose and lignin.
Keyword: EFB, mesocarp fiber, packaging paper, palm oil waste

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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