Judul: Conformity Analysis of Quality Parameters for Sargassum sp. Seaweed Salt Residue Body Scrub Products against the Quality Standards of National Agency of Drug and Food Control
Abstrak: Krim lulur diperlukan sebagai perawatan kulit yang membantu mengangkat sel-sel kulit mati, menyegarkan serta menghaluskan kulit yang kasar dan kering. Pemanfaatan residu garam rumput laut (RGRL) Sargassum sp. dari hasil samping proses pembuatan garam rumput laut memiliki bentuk butiran kasar yang berfungsi sebagai exfoliator dan pengganti bahan silika sintetik pada krim lulur. Penambahan kolagen ikan berfungsi sebagai bahan tambahan dalam produk perawatan anti penuaan dini. Penelitian ini bertujuan menentukan konsentrasi residu garam rumput laut Sargassum sp. dengan kombinasi kolagen ikan terpilih berdasarkan uji kadar pH, ALT, logam berat merkuri, AKK, dan uji sensori. Pembuatan sediaan krim lulur yaitu pencampuran dari fase air dan fase minyak dengan penambahan kolagen ikan 0,5% dan RGRL Sargassum sp 0%, 2%, 4%, dan 8%. Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan dua kali ulangan. Hasil penelitian menunjukkan bahwa rasio RGRL Sargassum sp. dan kolagen ikan terbaik didapatkan pada perlakuan SK 4:0,5%. Karakteristik produk dengan nilai pH 5,64, negatif mengandung logam berat merkuri (Hg), kapang khamir <10 koloni/g, dan ALT 4,0 x 106 koloni/g., Body scrub is needed as a skin care to remove dead skin cells, refreshes and smoothes rough and dry skin. Utilization of seaweed salt residue (SSR) of Sargassum sp. as a by-product of seaweed salt production , seaweed has a coarse grained form that functions as an exfoliator and a substitute for synthetic silica in commonly used body scrub. The addition of fish collagen serves as an additional ingredient in anti-aging care products. This study aimed to determine the seaweed salt residual concentration of Sargassum sp. selected combination with fish collagen based on pH, total plate number, heavy metal mercury, yeast mold, and sensory tests. The preparation of scrub cream preparations was a mixture of water phase and oil phase with the addition of 0.5% fish collagen and SSR Sargassum sp 0%, 2%, 4%, and 8%. This study used a one way anova method with two replications. The results showed that the best ratio of SSR and fish collagen was obtained at 4:0,5%. Product characteristics with a pH value of 5.64, negative containing heavy metal mercury (Hg), yeast <10 colonies/g, and total plate number 4.0 x 106 colonies/g.
Keyword: garam rumput laut, krim lulur, Sargassum sp., Sargassum sp., seaweed salt residue, body scrub

Judul: Effect of Seaweed Salt Residue (Sargassum sp.) Concentration on the Characteristics of a Body Scrub Made from Black Tea Dregs
Abstrak: Produk kecantikan ramah lingkungan mulai diminati konsumen karena keamanan produk dan dampak positif bagi lingkungan. Residu garam rumput laut Sargassum sp. dapat digunakan sebagai pengamplas kulit alami pengganti microbeads. Penambahan ampas teh dapat meningkatkan nilai fungsionalitas produk terhadap kesehatan kulit. Penelitian ini bertujuan menentukan karakteristik produk body scrub dari residu garam rumput laut Sargassum sp. dan ampas teh hitam. Body scrub diformulasikan residu garam Sargassum sp. konsentrasi 6%, 7% dan 8% dengan penambahan ampas teh 2% di semua perlakuan. Konsentrasi terbaik body scrub yaitu formula 1 atau penambahan residu garam Sargassum sp. 6%. Body scrub mengandung senyawa aktif alkaloid, flavonoid, saponin, steroid, dan tanin. Formulasi terbaik body scrub yaitu nilai pH 6,9, viskositas 11.498 cp, daya sebar 3,25 cm, sediaan homogen, tipe emulsi minyak dalam air (m/a), stabil, meningkatkan kelembapan 9%, tidak mengiritasi kulit, nilai total fenol 5,17 mg GAE/g dan aktivitas antioksidan DPPH 51,98 ppm., Consumers are beginning to be more interested in green beauty products because of the product's safety and positive impact on the environment. Salt residue from the seaweed Sargassum sp. can be used as a natural skin scrubber to replace microbeads. The addition of tea leaves can increase the functional value of the product for skin health. The aim of this research is to determine the properties of a body scrub made from seaweed Sargassum sp. and black tea dregs. The body scrub is formulated with Sargassum sp. salt residue at concentrations of 6%, 7% and 8% with the addition of 2% tea dregs in all treatments. The best concentration of body scrub is formula 1 with the addition of 6% Sargassum sp. salt residue. Body scrubs contain active compounds such as alkaloids, flavonoids, saponins, steroids and tannins. The best body scrub formulation has pH 6.9, viscosity 11,498 cp, spreadability 3.25 cm, homogeneous preparation, oil-in-water (o/w) emulsion type, stable, increases moisture 9%, does not irritate the skin, total phenolic value 5,17 mg GAE/g and DPPH antioxidant activity 51.98 ppm.
Keyword: antioxidant, back tea dreg, green cosmetics, scrub preparation

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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