Judul: Oxygen Consumption Rate and Feed Preferences of Freshwater Crab (Parathelphusa convexa De Man, 1879)
Abstrak: Ancaman terhadap sumberdaya kepiting air tawar yang diakibatkan oleh pencemaran di perairan dan kerusakan habitat dapat mengancam kepunahan pada kepiting air tawar (Parathelphusa convexa). Permasalahan tersebut diperlukan upaya berupa domestikasi pada kepiting air tawar. Kegiatan domestikasi membutuhkan informasi terkait tingkat konsumsi oksigen dan kebutuhan makanan. Penelitian ini bertujuan menghitung tingkat konsumsi oksigen dan menentukan jenis pakan dalam kegiatan domestikasi untuk menunjang pertumbuhan kepiting air tawar. Rancangan yang digunakan pada penelitian tingkat konsumsi osigen dan preferensi makanan kepiting air tawar menggunakan Rancangan Acak Faktorial (RAF). Hasil penelitian diolah dan dianalisis secara statistik menggunakan uji Analisis Ragam (ANOVA) dengan menggunakan software Microsoft Excel, dan dilakukan uji lanjut yaitu uji BNt menggunakan software IBM SPSS. Hasil penelitian menunjukkan bahwa tingkat konsumsi oksigen kepiting air tawar jantan maupun kepiting air tawar betina di luar media air memiliki nilai yang lebih lebih tinggi dari pada di media air. Pakan terbaik untuk kepiting air tawar jantan adalah cacing tanah, dan pakan terbaik untuk kepiting air tawar betina adalah pakan buatan., Threats to freshwater crab resources caused by water pollution and habitat destruction can threaten the extinction of freshwater crabs (Parathelphusa convexa). This problem requires efforts in the form of domestication of freshwater crabs. Domestication activities require information on oxygen consumption levels and food requirements. This research aims to calculate the oxygen consumption rate and determine the types of feed in domestication activities to support the growth of freshwater crabs. The design used in research on oxygen consumption levels and feed preferences for freshwater crabs used a Factorial Randomized Design (FRD). The research results were processed and statistically analyzed using Analysis of Variance (ANOVA) test with Microsoft Excel software, and further analysis was conducted with the BNt test using IBM SPSS software. The research results indicate that the oxygen consumption rate of both male and female freshwater crabs outside the water media is higher than in the water media. The best food for male freshwater crabs is earthworms and the best food for female freshwater crabs is artificial feeding.
Keyword: earthworms, freshwater crab, feed, FRD, oxygen

Judul: Assessment of Wastewater Quality from Mud Crab (Scylla  sp.) Rearing
Abstrak: Limbah kegiatan pemeliharaan kepiting dapat meningkatkan jumlah nutrien di perairan, sehingga menyebabkan terjadinya eutrofikasi. Penelitian ini bertujuan menganalisis limbah hasil pemeliharaan kepiting bakau (Scylla sp.) dengan sistem kolam terpal. Penelitian dilaksanakan pada bulan September hingga November 2023. Rancangan penelitian menggunakan rancangan acak lengkap (RAL) dengan dua perlakuan (rucah dan pelet) dan 20 ulangan. Parameter yang dikaji dan dianalisis meliputi kualitas air, limbah hasil pemeliharaan, dan kondisi biologis. Hasil penelitian menunjukkan, kondisi kualitas air pada kedua media pemeliharaan sesuai dengan baku mutu pemeliharaan kepiting. Persentase limbah sisa pakan perlakuan pelet lebih sedikit yaitu 12% dari jumlah makanan total yang diberikan. Kondisi kualitas perairan dan sisa pakan mempengaruhi kondisi biologis kepiting. Kondisi biologis kepiting dengan perlakuan pelet memiliki nilai yang lebih baik dibanding rucah dengan nilai survival rate 95.50±1.54%, specific growth rate 1.39±0.63%, molting rate 5.5±5.10%. Perlakuan makanan berupa pelet memiliki kualitas air yang baik, jumlah sisa pakan lebih sedikit, dan lebih mendukung pertumbuhan kepiting bakau, namun kandungan amonia dan nitrat pada media pemeliharaannya tinggi., Waste from crab rearing activities can increase the amount of nutrients in the water, causing eutrophication. This study aims to analyze the waste from rearing mud crabs (Scylla sp.) with a tarpaulin pond system. The research was conducted from September to November 2023. The research design used a complete randomized design (CRD) with two treatments (crabs and pellets) and 20 replicates. Parameters studied and analyzed included water quality, waste from rearing, and biological conditions The results showed that the water quality conditions in both rearing media were in accordance with the quality standards for crab rearing. The percentage of waste left over from the pellet treatment was less at 12% of the total amount of food given. Water quality conditions and residual feed affect the biological condition of the crabs. The biological condition of crabs with pellet treatment has a better value than rucah with a survival rate value of 95.50 ± 1.54%, specific growth rate 1.39 ± 0.63%, molting rate 5.5 ± 5.10%. The pellet food treatment had good water quality, less feed residue, and was more suitable of mud crab growth, but the amonia and nitrate content of the rearing medium was high.
Keyword: mud crab, water quality, waste, rearing, crab food

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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