Judul: Determinan dan Invers Matriks Left Circulant dengan Entri Barisan Bilangan Jacobsthal-Lucas Menggunakan Metode OBD dan OKD.
Abstrak: Matriks persegi merupakan susunan bilangan dalam baris dan kolom membentuk persegi panjang yang pada umumnya digunakan dalam menyelesaikan persoalan matematis di kehidupan sehari-hari, terutama terkait dengan sistem persamaan linear. Metode untuk menentukan determinan dan invers matriks persegi dapat disederhanakan dalam bentuk suatu formulasi ketika struktur dan entrinya didefinisikan secara khusus. Maka dari itu, banyak penelitian dilakukan dalam mencari rumus sederhana dari determinan dan invers dengan beragam struktur dan entri khusus. Pada karya ilmiah ini, dicari rumus sederhana dari determinan dan invers matriks left circulant dengan entri barisan bilangan Jacobsthal-Lucas menggunakan metode operasi baris dan kolom dasar. Hasil penelitian menunjukkan bahwa terdapat sebuah formula umum yang dapat digunakan dalam mencari determinan dan invers matriks left circulant dengan entri barisan bilangan Jacobsthal-Lucas., A square matrix is an arrangement of numbers in rows and columns to form a square which is generally used in solving mathematical problems in daily life, especially those related to systems of linear equations. The method that is used to determine the determinant and inverse of a square matrix can be simplified in the form of a formulation when the structure and entries are specifically defined. Therefore, much research has been done to determine simple formulas of the determinant and inverse of square matrices with various special structure and entry. In this scientific work, we obtain simple formulas for the determinants and inverses of left circulant matrices with Jacobsthal-Lucas number entries using the elementary row and column operations method. The results showed that there is a general formula that can be used to find the determinant and inverse of left circulant matrices with the Jacobsthal-Lucas number entries.
Keyword: Jacobathal-Lucas, Matriks left circulant, Operasi baris dan kolom dasar, Jacobsthal-Lucas, left circulant matrix, elementary row and column operation

Judul: Perhitungan Determinan dan Invers Matriks Circulant dengan Entri Jacobsthal Numbers Menggunakan Operasi Baris atau Kolom Dasar
Abstrak: Matriks circulant merupakan matriks segi berukuran n × n dengan setiap diagonal mempunyai elemen yang sama serta elemen matriks pada baris sebelumnya digeser satu posisi ke kanan pada baris berikutnya. Salah satu sifat yang dimiliki matriks circulant, yaitu inversnya juga berupa circulant. Entri-entri dari matriks circulant dapat menggunakan entri dengan berbagai bilangan, salah satunya adalah Jacobsthal Number. Pada karya ilmiah ini ditentukan perhitungan determinan dan invers matriks circulant dengan entri Jacobsthal Numbers. Pembuktian formulasi determinan matriks circulant dengan entri Jacobsthal Numbers didapatkan dari serangkaian operasi baris dasar sehingga terbentuk matriks segitiga atas, sedangkan formulasi invers matriks didapatkan berdasarkan sifat-sifat ekuivalensi matriks dari hasil serangkaian operasi baris dan kolom dasar sehingga terbentuk matriks diagonal. Matrix circulant is a n × n triangular matrix with the identical elements on each diagonal and the elements from the previous row relocated one place to the right in the next row. The circulant's entries can contain a variety of numbers, one of which is the Jacobsthal numbers. In this scientific work, it is determined the calculation of the determinant and the inverse of the circulant with the entry of Jacobsthal Numbers. The determinant formulation is obtained from a series of elementary row operations to get an upper triangular matrix, and the inverse formulation is based on the matrix equivalence properties of a series of elementary row and column operations to get a diagonal matrix.
Keyword: elementary row or column operation, circulant matrices, determinant, invers, jacobsthal numbers

Judul: Durability of Specific Immunoglobulin (Ig) Y Againts Influenza and Covid-19 in Sunscreen
Abstrak: The benefit of specific immunoglobulin Y (Ig Y) as an active ingredient in personal care products such as sunscreen has not been properly studied. Our study aims to evaluate the reliability of specific IgY against influenza and the COVID-19 virus in a sample sunscreen product. Specific IgY influenza and COVID-19 viruses were inserted in the sample sunscreen at two concentrations of 0.1% and 0.25%. Three treatments were observed: control (C) sunscreen without IgY, treatment 1 (T1) sunscreen with 0.1% IgY, and treatment 2 (T2) sunscreen with 0.25% IgY. Organoleptic observations were carried out to monitor changes in aroma, color, and texture, and sunscreen sampling was done every week for 6 weeks. The durability of IgY was evaluated using an enzyme-linked immunosorbent assay (ELISA) and a neutralization assay. Organoleptic observation from weeks 1 to 6 showed consistency in its aroma, color, and texture. Enzyme-linked immunosorbent assay and neutralization assay (NA) results of the T1 and T2 groups showed negative results except for sample T1 at week 5, which showed a positive result in the Influenza A ELISA. Based on the results, it seems that IgY concentrations of 0.1% or 0.25% were not optimal. However, this negative result might be due to low concentration of the IgY and the presence of beeswax, which inhibits IgY and causes it to dissolve in distilled water, thus preventing it from being detected in the assay.
Keyword: Immunoglobulin Y, Sunscreen, Influenza, COVID-19, Biological Activity