Judul: Characteristics of Body Scrub Sargassum sp. Seaweed Salt Residue with the Addition of Turmeric Rhizome Powder
Abstrak: Residu garam rumput laut Sargassum sp. dapat berperan sebagai scrub alami yang diharapkan mampu menggantikan mikroplastik polyethylene. Penambahan bubuk rimpang kunyit berfungsi untuk meningkatkan nilai fungsi sediaan body srub, seperti aktivitas antioksidannya. Penelitian ini bertujuan menentukan penambahan konsentrasi bubuk rimpang kunyit (Curcuma longa) terbaik pada sediaan body scrub residu garam rumput laut Sargassum sp. 7% dengan karakteristik yang sesuai. Sediaan body scrub terbuat dari campuran bahan fase minyak dan bahan fase air dengan penambahan residu garam rumput laut Sargassum sp. 7% dan bubuk rimpang kunyit 0,5%, 1%, dan 1,5%. Produk sediaan body scrub terpilih yaitu SK 7:0,5 (kombinasi residu garam rumput laut Sargassum sp. 7% dan bubuk rimpang kunyit 0,5%) dan telah sesuai dengan acuan yang ditetapkan, kecuali uji daya sebar. Sediaan body scrub SK 7:0,5 memiliki nilai pH 6,52, waktu lekat 1,54 detik, diameter sebar 3,33 cm, emulsi yang stabil, homogen, mampu meningkatkan kelembaban kulit, total fenol 464,52 ± 12,67 mg GAE/g, aktivitas antioksidan CUPRAC 1,20 ± 0,003 μg/mL asam askorbat/g sampel dan ABTS dengan nilai IC50 195,99 ± 1,30 μg/mL., Sargassum sp. seaweed salt residue acts as a natrual scrub that is expected to replace polyethylene microplastics. The addition of turmeric rhizome powder serves to increase the functional value of body scrub, such as antioxidant activity. The aim of this research was to determine the best concentration of addition turmeric rhizome powder (Curcuma longa) to body scrub Sargassum sp. 7% with the best characteristics. The body scrub was producted from mixing oil and water phase material with the addition of Sargassum sp. seaweed salt residue 7% and turmeric rhizome powder 0.5%, 1%, and 1.5%. The body scrub product selected was SK 7:0.5 (a combination of Sargassum sp. seaweed salt residue 7% and turmeric rhizome powder 0.5%) and was in accordance with the established standards, except for spreadability test. The body scrub SK 7:0.5 had pH value 6.52, adhesion time 1.54 seconds, spread diameter 3.33 cm, stable emulsion, homogeneous, able to increase skin moisture, total phenol 464.52 ± 12.67 mg GAE /g, antioxidant activity of CUPRAC 1.20 ± 0.003 g/mL ascorbic acid/g sample and ABTS with IC50 value of 195.99 ± 1.30 g/mL.
Keyword: Antioxidant, microplastic, moisture, 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: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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