Judul: The Effect Of The Addition Of Sodium Biborate On The Characteristics Of Fish Glue Made From The Skin Of Catfish (Pangasius sp.)
Abstrak: Lem ikan merupakan perekat alami yang berbahan dasar tulang, kulit, dan sisik ikan dengan penambahan bahan aditif maupun tidak. Lem ikan memiliki kelemahan, yaitu kontaminasi kapang selama masa penyimpanan. Natrium biborat memperpanjang masa simpan lem ikan. Penelitian ini bertujuan untuk mengevaluasi pengaruh penambahan natrium biborat dengan konsentrasi yang berbeda terhadap karakteristik lem ikan berbahan kulit ikan patin dan efektivitasnya terhadap pertumbuhan kapang. Natrium biborat ditambahkan ke dalam lem ikan dengan konsentrasi 0,5%; 1% dan 1,5% (perbandingan natrium biborat dan lem ikan serta kontrol). Prosedur penelitian terdiri dari preparasi kulit ikan patin, ekstraksi, produksi lem ikan, pengujian karakteristik kimia dan fisik lem ikan, kemampuan pertumbuhan kapang selama 14 hari dan pengamatan mikroskop. Hasil penelitian menunjukkan penambahan natrium biborat berpengaruh terhadap karakteristik fisik dan kimianya. Kemunculan kapang tercepat yaitu pada hari ke-5 dengan perlakuan kontrol dan kemunculan kapang terlama yaitu hingga hari ke-14 tidak ada tanda kemunculannya pada perlakuan 1,5% natrium biborat.
Keyword: fish glue, histology, mold, natrium biborat

Judul: Effect of NaOH Comparison on Patin Skin Pretreatment (Pangasius hypophthalamus) on Gelatin and Its Application on Hard Capsule Shells
Abstrak: Kulit ikan patin sangat potensial menjadi sumber gelatin, namun proses pretreatment yang dilakukan belum maksimal. Penelitian ini bertujuan menentukan perbandingan NaOH dan sampel dalam proses preatreatment, serta karakteristik fisik-kimia gelatin kulit ikan patin. Metode yang dilakukan yaitu Rancangan Acak Lengkap dan uji lanjut Duncan. Karakteristik gelatin yang telah sesuai dengan standar GMIA 2019 dan SNI 8622-2018. Perlakuan terbaik didapatkan pada perlakuan perbandingan 1:8 (b/v). Perlakuan tersebut menghasilkan rendemen 22,66 ± 1,07%; pH 6,43 ± 0,14; viskositas 67,5 ± 1,50 mps; dan kekuatan gel 244,143 ± 1,69 bloom. Perlakuan tersebut diaplikasikan dalam pembuatan cangkang kapsul keras. Karakteristik cangkang kapsul keras yang dihasilkan telah sesuai dengan standar Departemen Kesehatan RI (2020). Analisis histologi menunjukkan bahwa perlakuan yang digunakan belum mampu menghancurkan lapisan stratum compactum, sehingga perlu dilakukan treatment dengan cara lain agar rendemen gelatin yang dihasilkan maksimal., Pangasius skin has the potential to be a source of gelatin, but the process of pretreatment is not optimal. The purpose of this research was to determine the ratio of NaOH and samples in the process of the pre-treatment, as well as physicochemical characteristics of gelatin from catfish skin. The method used was Completely Randomized Design and Duncan's further test. Gelatin characteristics that are in accordance with the GMIA 2019 standard and SNI 8622-2018. The best treatment was obtained at a 1:8 (w/v) comparison treatment. This treatment resulted in a yield of 22.66 ± 1.07%; pH 6.43 ± 0.14; viscosity 67.5 ± 1.50 mps; and gel strength 244.143 ± 1.69 bloom. This treatment was applied in the manufacture of hard capsule shells. The characteristics of the hard capsule shell produced meet the standards of the Indonesian Ministry of Health (2020). Histological analysis showed that the treatment used had not been able to destroy the layer stratum compactum, so it was necessary to do other treatments in order to maximize the yield of gelatin.
Keyword: catfish, gelatin, hard capsule, NaOH, pretreatment

Judul: Analysis of Unequal Income Distribution with Cobb-Douglas Production Function
Abstrak: This paper studies the economic growth model by Moav (2002). Moav model shows the existence of unequal income distribution between low-income with high-income community. That kind of unequal income distribution is caused by uneven distribution of income. On this Moav model, there is one area called the threshold. Threshold becomes a benchmark to determining whether a society is categorized into low- or high- income community. The production function used in this paper is the Cobb-Douglas function. The dynamics of this model is described as difference equation of low-income, threshold, and high-income community. Simulation study on the model is carried out using Maple 13 and Mathematica 7.0 software. Overall, from the observed case, high-income community will reach a stable condition earlier, followed by the threshold, and then the low-income community.
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