Judul: Ability of ORP Enhancer as an ORP  Enhancer of Sangkuriang Catfish (Clarias gariepinus) Aquaculture Waste Water
Abstrak: Ikan lele (Clarias sp.) merupakan salah satu jenis ikan yang memiliki nilai ekonomis, dapat tumbuh dengan cepat dan dapat dibudidayakan pada sistem intensif. Kegiatan budidaya menghasilkan limbah padat dan limbah cair yang berasal dari feses dan sisa pakan ikan. Akumulasi limbah tersebut dapat menyebabkan penurunan kualitas air yang berpengaruh terhadap proses fisiologis, tingkah laku, pertumbuhan, dan mortalitas ikan. Salah satu upaya pengelolaan untuk meningkatkan kualitas air dan mengoptimalkan pemanfaatan air budidaya adalah dengan penggunaan bahan aktif berupa Oxidation Reduction Potensial (ORP) Enhancer untuk mendegradasi limbah terlarut di dalam air yang berupa nitrit, Total Ammonia Nitrogen (TAN), dan Total Organic Matter (TOM). ORP Enhancer adalah suatu bahan yang berfungsi sebagai agen peningkat kadar ORP di dalam suatu perairan. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian ORP Enhancer dengan dosis yang berbeda untuk meningkatkan nilai potensial redoks pada limbah budidaya lele. Penelitian ini terdiri atas empat perlakuan dengan empat ulangan yang meliputi perlakuan kontrol (tanpa pemberian ORP Enhancer), Perlakuan A (dosis 0,2 mg/L), Perlakuan B (dosis 0,4 mg/L) dan Perlakuan C (dosis 0,6 mg/L). Hasil penelitian menunjukkan kinerja ORP Enhancer secara umum mampu meningkatkan kadar redoks serta menurunkan kadar nitrit, TAN, dan TOM pada air limbah ikan lele. Berdasarkan data penelitian dosis ORP Enhancer yang paling optimal dalam meningkatkan ORP pada air limbah sebesar 0,4 mg/L., Catfish (Clarias sp.) is one type of fish that has economic value, can grow quickly and can be cultivated in intensive systems. Cultivation activities produce solid waste and liquid waste derived from feces and fish feed residues. The accumulation of these wastes can cause a decrease in water quality which affects the physiological processes, behavior, growth, and mortality of fish. One of the management efforts to improve water quality and optimize the utilization of aquaculture water is the use of active ingredients in the form of (Oxidation Reduction Potensial) ORP Enhancer to degrade marine wastes in the form of nitrite, (Total Ammonia Nitrogen) TAN, and (Total Organic Matter) TOM. ORP Enhancer is a material that functions as an agent to increase ORP levels in a water body. This study aims to determine the effect of giving ORP Enhancer with different doses to increase the redox potential value of catfish farming waste. This study consists of four treatments with four replicates which include control treatment (without ORP Enhancer), Treatment A (0,2 mg/L dose), Treatment B (0,4 mg/L dose) and Treatment C (0,6 mg/L dose). The results showed the performance of ORP Enhancer in general was able to increase redox levels and reduce nitrite, TAN, and TOM levels in catfish wastewater. Based on the research data, the most optimal ORP Enhancer dose in increasing ORP in wastewater is 0,4 mg/L.
Keyword: catfish, ORP enhancer, oxidation reduction potential, wastewater

Judul: Effect of Addition of Probiotic Bacillus NP5 in  Biofloc System on Growth and Health Status of Catfish Juvenile Clarias sp.
Abstrak: Teknologi bioflok telah diketahui dapat menurunkan kadar amonia pada media pemeliharaan budidaya sistem intensif dan probiotik Bacillus NP5R telah diketahui dapat meningkatkan pertumbuhan dan tingkat kelangsungan hidup melalui peningkatan efisiensi pencernaan dan kesehatan ikan. Penelitian bertujuan mengevaluasi penambahan probiotik Bacillus NP5R pada sistem bioflok dalam meningkatkan kinerja pertumbuhan dan status kesehatan benih lele Clarias sp.. Penelitian menggunakan rancangan acak lengkap (RAL) dengan tiga perlakuan dan tiga ulangan, yaitu ikan dipelihara tanpa aplikasi bioflok dan penambahan probiotik Bacillus NP5R (K), ikan dipelihara dengan sistem bioflok (BF), dan ikan dipelihara dalam sistem bioflok dengan penambahan probiotik Bacillus NP5R (BFP). Larva lele dengan panjang rata-rata 0,83±0,00 cm dan bobot rata-rata 0,02±0,01 g dipelihara dengan padat tebar 300 ekor/akuarium selama 30 hari. Parameter yang diamati meliputi pertumbuhan panjang mutlak, laju pertumbuhan harian, rasio konversi pakan, koefisien keragaman, kelimpahan bakteri Bacillus NP5R , total eritrosit, total leukosit, kadar hemoglobin, kadar hematokrit, dan tingkat kelangsungan hidup. Hasil penelitian menunjukkan bahwa penambahan probiotik Bacillus NP5R dalam sistem bioflok dapat meningkatkan laju pertumbuhan 5%, tingkat kelangsungan hidup 15%, dan status kesehatan benih lele yang menunjukkan hasil terbaik dibandingkan perlakuan lainnya. Penerapan sistem bioflok dengan penambahan Bacillus NP5R diharapkan menjadi alternatif solusi untuk mengurangi limbah amonia pada budidaya ikan lele., Biofloc technology has been known to reduce ammonia levels in aquaculture’s intensive system maintenance media and the probiotic Bacillus NP5R has been known to increase growth and survival rates through improved digestive efficiency and fish health. This study aimed to evaluate the addition of probiotic Bacillus NP5R in the biofloc system in improving growth and health status of catfish juvenile Clarias sp.. This study used a complete randomized design (RAL) of three treatments and three replications, namely fish reared without biofloc system and without addition of probiotic Bacillus NP5R (K), fish reared in a biofloc system (BF), and fish reared in a biofloc system with the addition of probiotic Bacillus NP5R (BFP) within 30 days of treatment. The larvae that used had an average length of 0,83±0,00 cm and an average weight of 0,02±0,01 g with a stocking density of 300 individuals per aquarium. Parameters observed during the study included absolute length growth, daily growth rate, feed conversion ratio, coefficient of diversity, abundance of Bacillus NP5R bacteria, total erythrocytes, total leukocytes, hemoglobin levels, hematocrit levels, and survival rates. The results showed that the addition of the probiotic Bacillus NP5R in the biofloc system can increase the growth rate by 5%, survival rate by 15%, and the health status of catfish juvenile which showed the best results compared to other treatments. The application of the biofloc system with the addition of Bacillus NP5R is expected to be an alternative solution to reduce ammonia waste in catfish farming.
Keyword: Bacillus NP5R, biofloc, Clarias sp., growth, health status

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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