Judul: Purification of Traditional Salt to SNI Standard Iodized Salt Raw Material Through Hydroextraction Method in Alkaline
Abstrak: Kebutuhan garam dari tahun ke tahun semakin meningkat, tetapi belum diikuti dengan kualitas garam rakyat sesuai standar bahan baku garam konsumsi beryodium. Hingga saat ini berbagai metode purifikasi terus dikembangkan untuk meningkatkan kualitas garam rakyat. Dalam penelitian ini purifikasi menggunakan metode hidroekstraksi dengan tambahan CaO dan NaOH sebagai bahan pengikat pengotor. Garam yang digunakan ialah garam krosok dari media tanah dan plastik geomembran. Metode hidroekstraksi berhasil menurunkan kadar pengotor dan meningkatkan kadar NaCl. Kadar pengotor Ca, Mg, dan SO4 dari kedua jenis garam setelah purifikasi menurun, berturut-turut 8,42%; 24,62%; 11,90% dan 61,24%; 0,26%; 0,43%. Kadar NaCl garam dari media plastik dan media geomembran berturut-turut meningkat 1,49% dan 1,38%. Kadar NaCl yang dihasilkan memenuhi standar sebagai bahan baku untuk garam konsumsi beryodium kualitas garam K1 dan K2., The need for salt from year to year is increasing, but the quality of traditional salt has not followed it according to standards as raw material for iodized consumption salt. Until now, various purification methods have continued to be developed to improve the quality of traditional salt. Purification was carried out in this research using the hydroextraction method by adding CaO and NaOH as binders for impurities. The salt used was krosok salt from soil media and geomembrane plastic. The hydroextraction method succeeded in reducing the level of impurities and increasing the level of NaCl. The impurity levels of Ca, Mg, and SO4 of the two types of salt used after purification decreased by 8,42%; 24,62%; 11,90% and 61,24%; 0,26%; 0,43%. NaCl salt content from the plastic media and the geomembrane media increased by 1,49% and 1,38%, respectively. The level of NaCl produced complies with the standard as a raw material for iodized consumption salt with the quality of K1 and K2 salts.
Keyword: hydroextraction, impurity binders, NaCl, purification, traditional salt

Judul: Characterization of Seaweed Salt Based on Grateloupia angusta
Abstrak: Garam dengan kandungan natrium yang tinggi dapat menyebabkan masalah kesehatan, khususnya hipertensi. Alternatif dari hal tersebut, Grateloupia angusta dapat digunakan sebagai sediaan bahan baku garam diet. Penelitian ini bertujuan menentukan karakteristik rumput laut G. angusta, mendapatkan garam rumput laut dengan perbandingan pelarut dan tepung rumput laut yang optimum yang memiliki kadar NaCl <60%, rasio Na:K yang rendah, dan hasil rendemen dan aktivitas antioksidan yang tinggi. Konsentrasi bahan baku terhadap pelarut yang digunakan yaitu 1:5, 1:10, dan 1:15 (b/v). Penambahan konsentrasi pelarut berpengaruh nyata (p<0,05) terhadap nilai rendemen, mineral, %NaCl, total fenol dan aktivitas antioksidan antioksidan garam. Konsentrasi pelarut terbaik yaitu garam 1:15 yang menghasilkan nilai rendemen 20,9 ± 2,30%, rasio Na:K 0,90, %NaCl 60,36 ± 0,15%, total fenol 1.543,37 ± 2,35 mg/GAE/g, aktivitas antioksidan CUPRAC 37,30 ± 1,43 μg/mL asam askorbat/g sampel, dan ABTS dengan nilai IC50 150,6 ± 8,81 μg/mL., Salt with a high concentration of sodium content can cause health problems, particularly hypertension. As an alternative to this matter, G. angusta can be used as a raw material for dietary salt. This study aims to determine the characteristics of G. angusta seaweed, to obtain seaweed salt with the optimum ratio of seaweed flour and solvent containing NaCl < 60%, a low ratio of Na: K, and a high result in yield and antioxidant activity. The concentration of raw material on the solvent used is 1:5, 1:10, and 1:15 (b/v). The addition of solvent concentration increased the value of yield, minerals, NaCl, total phenol, and antioxidant activity significantly (p 0,05). The best solvent concentration is 1:15, which produces a yield value of 20.9 ± 2.30%, Na:K ratio of 0.90, % NaCl 60.36 ± 0.15%, total phenol 1.543,37 ± 2.35 mg/GAE/g, CUPRAC antioxidant activity 37.30 ± 1.43 μg/mL ascorbic acid/g sample, and ABTS with an IC50 of 150.6 ± 8.81 μg /mL.
Keyword: antioxidant, Grateloupia angusta, seaweed salt

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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