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: The Effect of Storage and Packaging on Physical Quality and Moisture Content of Rice Brain
Abstrak: Dedak padi merupakan bahan pakan yang biasa digunakan dalam ransum ternak karena cukup banyak tersedia dan disukai ternak. Kelemahan dedak padi selain mengandung zat anti nutrisi juga daya simpannya yang rendah sehingga mudah menurun kualitasnya. Masalah daya simpan dapat diatasi secara teknologi dengan menambahkan bahan pengawet (aditif asam organik) dan penggunaan kemasan kedap udara (hermetik). Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) faktorial (3 x 4) dengan 4 ulangan, yang terdiri dari faktor lama penyimpanan (0, 30, 60 hari) dan faktor jenis kemasan (karung plastik polipropena, karung goni, kantong plastik polietilena, dan kantong hermetik). Peubah yang diamati yaitu kerapatan tumpukan, kerapatan pemadatan tumpukan, berat jenis, dan kadar air. Data yang diperoleh dari hasil penelitian dianalisis menggunakan analisis ragam ANOVA (Analyses of Variance) dan bila terjadi perbedaan yang signifikan dilanjutkan dengan uji Tukey menggunakan software minitab. Hasil penelitian menunjukkan bahwa perbedaan waktu penyimpanan, jenis kemasan dan interaksi nyata (p<0,05) mempengaruhi nilai kerapatan tumpukan, kerapatan pemadatan tumpukan, berat jenis dan kadar air dedak padi. Selama penyimpanan terjadi penurunan nilai kerapatan tumpukan, kerapatan pemadatan tumpukan, dan berat jenis serta terjadi peningkatan pada nilai kadar air dan jumlah serangan serangga. Perlakuan kantong plastik polietilena dan kantong hermetik seiring dengan penyimpanan (0, 30, dan 60 hari) nyata (p<0,05) lebih tinggi dalam mempertahankan kualitas dedak padi dibanding kemasan karung plastik polipropena dan karung goni. Dapat disimpulkan bahwa penggunaan kantong plastik polietilena dan kantong hermetik lebih baik dalam mempertahankan kualitas dedak padi dibandingkan karung plastik polipropena dan karung goni dengan waktu optimal penyimpanan antara 30 hari sampai kurang dari 60 hari., Rice bran is a feed ingredient commonly used in livestock rations because it is widely available and favored by livestock. The weakness of rice bran in addition to containing anti-nutritional substances is also a low storability so that it is easy to decrease its quality. This problem may be overcome technologically by adding preservatives (organic acid additives) and the use of anti air packaging (hermetic). This research used a factorial completely randomized design (CRD) (3 x 4) with 4 replications, that consist of factor storage time (0, 30, 60 days) and factor type of packaging (polypropyline plastic sacks, burlap sacks, polyethylene bag, and hermetic bag). The variables observed were bulk density, tapped density, true density and moisture content. The data obtained from the results of the research were analyzed using analyses of variance (ANOVA) and if there was a significant difference followed by the tukey test using minitab software. The results of the research showed that the differences in storage, type of packaging and treatment interaction had a significant effect (p<0.05) on bulk density, tapped density, true density and moisture content. During the storage there was a decrease in the value of bulk density, tapped density and true density and increase in the value of moisture content and insect attaction. The treatment of polyethylene bag and hermetic bag during the storage (0, 30, 60 days) was significantly (p<0.05) higher in maintaining the quality of rice bran than polypropyline plastic sacks and burlap sacks. The conclusion is the use of polyethylene bag and hermetic bag is better in maintaining
Keyword: packaging, physical properties, rice bran, storage

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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