Judul: Characteristics of Seaweed Salt Residue Sargassum polycystum and Coffee Dregs as Raw Materials for Body Scrubs
Abstrak: Kosmetik tersedia dalam berbagai sediaan, salah satunya yaitu dalam sediaan body scrub yang mengandung butiran kasar yang bersifat sebagai pengampelas (obrasiver). Pembuatan body scrub dari residu rumput laut Sargassum polycystum dapat ditambahkan dengan ampas kopi. Penelitian ini bertujuan untuk menentukan karakteristik residu garam rumput laut cokelat Sargassum polycystum dan ampas kopi serta menentukan pengaruh penambahan ampas kopi terhadap karakteristik body scrub berbahan baku residu garam rumput laut Sargassum polycystum 7%. Penambahan ampas kopi dengan konsentrasi (0; 1; 2; 3%) pada body scrub. Produk terpilih yaitu body scrub yang ditambah residu garam rumput Sargassum polycystum 7% dan ampas kopi 3% (SA 7:3). Nilai pH dari produk terpilih adalah 6,76 dan daya sebar pada 3,57 cm. Uji stabilitas emulsi menunjukkan bahwa krim dalam keadaan stabil. Aktivitas antioksidan dari produk terpilih dengan metode 1.1-diphenyl-2-picryl-hydrazyl (DPPH) adalah 55,54 ppm dan Cupric Ion Reducing Antioxidant Capacity (CUPRAC) 78,84 (µM/g). Hasil penelitian menunjukkan pada body scrub mempunyai kelembaban yang baik untuk kulit., Cosmetics are available in various preparations, one of which is a body scrub that contains coarse grains which act as a sandpaper (obrasiver). Make a body scrub from the residue of Sargassum polycystum seaweed can be added with coffee grounds. This study aims to determine the characteristics of the salt residue of Sargassum polycystum brown seaweed and coffee grounds and to determine the effect of the addition of coffee grounds on the characteristics of a body scrub made from 7% Sargassum polycystum seaweed salt residue. Addition of coffee grounds with a concentration (0; 1; 2; 3%) to the body scrub. The selected product was a body scrub with 7% Sargassum polycystum grass salt residue and 3% coffee grounds (SA 7:3). The pH value of the selected product was 6.76 and the dispersion was 3.57 cm. The emulsion stability test showed that the cream was in a stable state. The antioxidant activity of the selected product using the 1.1-diphenyl-2-picryl-hydrazyl (DPPH) method was 55.54 ppm and the Cupric Ion Reducing Antioxidant Capacity (CUPRAC) was 78.84 (µM/g). The results showed that body scrubs have good moisture for the skin.
Keyword: body scrub, coffee grounds, Sargassum polycystum

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: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model