Judul: The Chitin Production Process from Shell of Crab Legs at CV. Bio Chitosan Indonesia
Abstrak: CV. Bio Chitosan Indonesia merupakan perusahaan yang mengolah cangkang udang dan kepiting salju (snow crab) menjadi kitin dan kitosan yang berkualitas tinggi. Penelitian ini dilakukan untuk menganalisis pengaruh konsentrasi HCl, waktu proses, dan suhu proses demineralisasi pada produksi kitin dari cangkang kaki rajungan di CV. Bio Chitosan Indonesia. Percobaan dilakukan melalui dua tahapan proses produksi kitin pada skala laboratorium menggunakan Rancangan Acak Lengkap Faktorial (RALF) dan Rancangan Acak Lengkap Single Factor (RALSF). Analisis ragam menunjukkan konsentrasi HCl, waktu proses demineralisasi, dan interaksi keduanya tidak berpengaruh nyata terhadap rendemen dan mutu kitin dari cangkang kaki rajungan, namun suhu proses demineralisasi berpengaruh nyata terhadap rendemen dan mutu kitin dari cangkang kaki rajungan. Perlakuan terbaik diperoleh dari kondisi proses produksi kitin dari cangkang kaki rajungan menggunakan larutan HCl 8%, waktu proses 3 jam, dan suhu ruang (30oC) dengan rendemen, kadar air, dan kadar abu masing – masing sebesar 20,44%, 3,36%, 0,33%. Kitin yang diperoleh sudah memenuhi standar mutu yang ditetapkan pembeli CV. Bio Chitosan Indonesia dan SNI., CV. Bio Chitosan Indonesia is a company engaged in processing shrimp and snow crab shells into high-quality chitin and chitosan. This research was conducted to analyze the influence of HCl concentration, process time, and demineralization process temperature on chitin production from shell of crab legs at CV. Bio Chitosan Indonesia. The experiment was carried out in two stages of chitin production at the laboratory scale using a Full Factorial Randomized Complete Design (FFRCD) and a Single Factor Randomized Complete Design (SFRCD). Analysis of variance showed that the concentration of HCl, demineralization process time, and their interaction did not significantly affect the yield and quality of chitin from the shell of crab legs. However, the demineralization process temperature significantly affected the yield and quality of chitin from the shell of crab legs. The best treatment was obtained from the chitin production process conditions from shell of crab legs using an 8% HCl solution, a process time of 3 hours, and room temperature (30°C), resulting in yields, moisture content, and ash content of 20.44%, 3.36%, and 0.33%, respectively. The obtained chitin meets the quality standards set by the buyers of CV. Bio Chitosan Indonesia and SNI.
Keyword: crab leg shell, demineralization, chitin

Judul: Optimization of Chitin Production Process from Blue  Crab Legs Sheel at CV. Bio Chitosan Indonesia
Abstrak: CV. Bio Chitosan Indonesia merupakan perusahaan yang mengolah cangkang udang dan cangkang kaki kepiting salju (snow crab) menjadi kitin dan kitosan. Keterbatasan bahan baku kepiting salju mendorong perusahaan untuk melakukan substitusi penggunaan bahan baku potensial seperti cangkang kaki rajungan. Penelitian ini bertujuan untuk melakukan optimasi proses produksi kitin dari cangkang kaki rajungan. Penelitian dilakukan untuk mengetahui jumlah penggunaan ulang larutan HCl pada proses demineralisasi dan optimasi kondisi proses deproteinasi menggunakan metode Response Surface Methodology (RSM) dengan faktor suhu dan waktu proses. Penggunaan ulang larutan HCl pada proses demineralisasi hanya dapat dilakukan sebanyak 2 kali. Optimasi proses dengan faktor suhu dan waktu mendapatkan respon mean sehingga kondisi optimum didapatkan pada suhu 70? dan waktu 4 jam. Penggunaan ulang larutan HCl sebanyak 2 kali ulangan dan optimasi kondisi proses deproteinasi dengan suhu 70? dan waktu 4 jam menurunkan harga pokok produksi (HPP) sebesar 43,07 %.
Keyword: cangkang kaki rajungan, demineraliasi, deproteinasi, kitin

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology