Judul: Effect of storage time, packaging type, and antioxidant addition of physical and chemical quality of rice bran
Abstrak: Lama penyimpanan cenderung meningkatkan kadar air bahan yang akan menunjang pertumbuhan jamur. Penelitian ini bertujuan mengevaluasi kualitas fisik dan kimia dedak padi dengan penambahan antioksidan pada lama penyimpanan dan jenis kemasan berbeda. Rancangan penelitian yang digunakan adalah rancangan acak lengkap faktorial 3x4 dengan 4 ulangan. Faktor W yaitu lama penyimpanan (W0: 0 minggu, W4: 4 minggu, dan W8: 8 minggu) dan faktor P yaitu jenis kemasan (P1: karung goni + 0 ppm antioksidan, P2: karung goni + 125 ppm antioksidan, P3: hermetik + 0 ppm antioksidan, dan P4: hermetik + 125 ppm antioksidan). Hasil penelitian didapatkan bahwa lama penyimpanan dan jenis kemasan dapat mempengaruhi populasi serangga, kadar air, dan kadar protein kasar dedak padi. Hasil penelitian juga didapatkan bahwa lama penyimpanan dan jenis kemasan berpengaruh nyata (P<0,05) terhadap kerapatan tumpukan, kerapatan pemadatan tumpukan, dan berat jenis dedak padi. Dapat disimpulkan bahwa jenis kemasan hermetik dapat mempertahankan kualitas fisik dan kimia dedak padi hingga penyimpanan 8 minggu. Penambahan 125 ppm antioksidan belum efektif dalam mempertahankan kualitas fisik dan kimia dedak padi., Long storage tends to increase moisture content of the material which will support the growth of mold. This research was conducted to evaluate physical and chemical quality of rice bran with antioxidant addition at different storage time and packaging type. The experiment using completely randomized design factorial 3x4 with 4 replications. Factor W was storage time (W0: 0 week, W4: 4 weeks, and W8: 8 weeks) and factor P was packaging type (P1: jute sac + 0 ppm antioxidant, P2: jute sac + 125 ppm antioxidant, P3: hermetic + 0 ppm antioxidant, and P4: hermetic + 125 ppm antioxidant). The result found that storage time and packaging type can affected insect population, moisture content, and crude protein. The result also found that storage time and packaging type significantly (P<0.05) affected bulk density, tapped density, and true density. Based on result can be concluded that hermetic packaging can maintaining physical and chemical quality of rice bran for up to 8 weeks of storage. 125 ppm antioxidant addition have not been effective in mainting physical and chemical quality of rice bran.
Keyword: antioxidant, hermetic, jute sac, rice bran, storage

Judul: Impact of Storage Time, Packaging Type and Calcium Propionate Application on Moisture Content and Quality of Physical Properties of Rice Bran
Abstrak: Dedak padi merupakan salah satu bahan pakan yang dapat digunakan pada berbagai jenis ternak dengan ketersediaan cukup tinggi di Indonesia. Selain ketersediaannya melimpah namun dedak padi memiliki daya simpan rendah. Berdasarkan latar belakang tersebut penelitian ini bertujuan untuk mempertahankan kualitas dedak padi selama penyimpanan dengan penggunaan kemasan hermetik (kedap udara) dan pemberian bahan pengawet (kalsium propionat). Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) faktorial (3 x 4) dengan 4 ulangan, yang terdiri dari faktor waktu penyimpanan (0, 30, dan 60) hari dan faktor jenis kemasan + penambahan bahan pengawet (karung goni + 0 ppm kalsium propionat (P1), karung goni + 160 ppm kalsium propionat (P2), karung hermetik + 0 ppm kalsium propionat (P3) dan karung hermetik + 160 ppm kalsium propionat (P4)). Peubah yang diamati yaitu kadar air, kerapatan tumpukan, kerapatan pemadatan tumpukan dan berat jenis. Data yang diperoleh dari hasil penelitian dianalisis menggunakan analisis ragam ANOVA (Analysis of Variance) dan bila terjadi perbedaan yang signifikan dilanjutkan dengan uji Duncan menggunakan software SPSS Hasil penelitian menunjukan bahwa perbedaan waktu penyimpanan, jenis kemasan dan interaksi nyata (p<0.05) mempengaruhi kadar air dan nilai sifat fisik dedak padi. selama penyimpanan kadar air meningkat dan terjadi penurunan nilai kerapatan tumpukan, kerapatan pemadatan tumpukan dan berat jenis serta terjadi peningkatan pada jumlah serangan serangga. Jenis kemasan karung goni dengan dan tidak ditambah kalsium propionat nyata (p<0.05) lebih kecil nilai sifat fisiknya dan kandungan kadar air lebih tinggi dibanding karung hermetik selama penyimpanan (0, 30 dan 60) hari. Dapat disimpulkan bahwa penggunaan karung hermetik dan penambahan kalsium propionat pada dedak padi dapat mempertahankan kualitas dedak padi selama penyimpanan kurang dari 60 hari., Rice bran is a feed ingredient that is commonly used in animal husbandry and is widely available in Indonesia. In addition to the plentiful availability, rice bran has a low shelf life. Based on this background, this study aims to maintain the quality of rice bran during storage by using hermetic packaging (anti air) and adding preservatives (calcium propionate). This study used a Factorial Completely Randomized Design (CRD) (3 x 4) with 4 replications, that consisted of factor storage time (0, 30, and 60) days and factor type packaging + addition of preservatives (burlap sacks + 0 ppm calcium propionate (P1), burlap sack + 160 ppm calcium propionate (P2), hermetic bag + 0 ppm calcium propionate (P3) and hermetic bag + 160 ppm calcium propionate (P4)). The variables observed were moisture content, bulk density, tapped density and true density. The data obtained from the research results were analyzed using ANOVA (Analysis of Variance) and if there was a significant difference followed by the Duncan used software SPSS. The results showed that differences in storage time, type of packaging and treatment interaction had a significant effect (p<0,05) on moisture content and physical properties of rice bran. During storage the moisture content increased and there was a decrease of bulk density, tapped compaction density and true density and increase of insect attaction. The packaging type of burlap sack with and without added calcium propionate (p<0,05) had lower physical properties and contained higher moisture content than hermetic sacks during
Keyword: dedak, hermetik, kalsium propionat, karung goni, sifat fisik, calcium propionate, rice bran, burlap sack, hermetic, phisycal propeties

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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