Judul: Model Pertumbuhan Ekonomi Dua Daerah Berdasarkan Modal dan Knowledge
Abstrak: Model pertumbuhan Domar menyatakan produksi secara eksplisit sebagai fungsi dari modal/kapital saja (Chiang & Wainwright 2005). Model ini disempurnakan oleh Solow (1956) dengan memasukkan variabel tenaga kerja dalam fungsi produksi secara eksplisit, dengan demikian modal dan tenaga kerja dapat dikombinasikan dalam berbagai proporsi. Pada periode tahun 1927 sampai tahun 1952, produksi perusahaan besi Horndal di Swedia meningkat rata-rata 2% per tahun padahal tidak ada investasi baru (Genberg 1992). Peningkatan produksi dengan investasi tetap ini menimbulkan satu pertanyaan, yakni faktor apakah yang membuat peningkatan produksi tersebut terjadi? Permasalahan ini tidak dapat dijelaskan oleh model pertumbuhan Domar dan Solow, karena model pertumbuhan Domar hanya mencantumkan modal secara eksplisit dalam fungsi produksinya, sedangkan model pertumbuhan Solow secara eksplisit hanya mencantumkan modal dan tenaga kerja dalam fungsi produksinya. Verdoorn (1956) menghubungkan output sekarang (current output) dengan output kumulatif untuk menjelaskan adanya learning by doing yang bisa dijadikan jawaban untuk menjelaskan kasus Horndal. Analisis formal terhadap perubahan knowledge pertama kali dikemukakan oleh Arrow (1962).
Keyword: Economic growth model, Capital accumulation, Knowledge accumulation, Equilibrium

Judul: Two Sector Economic Growth Model in Discrete Time
Abstrak: Economic growth is a condition in the economy that is reflected in the increase of goods and services produced within the community. The purpose of this thesis is to study two sectors economic growth model in discrete time proposed by Zhang (2007). The model involves an economic society with two commodities produced, i.e. capital goods and consumption goods. Both goods are produced with capital and labor as independent variables. The production function is the Cobb-Douglas function. This model shows that the dynamic system has a unique equilibrium solution. Based on some simulations, it has been shown that an increased propensity to save will increase per capita capital and output.
Keyword: 

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