Judul: Peningkatan Laju Redoks Sedimen TambakUdang Vannamei (Litopenaeus vannamei) Berbasis Penggunaan Bahan Oksidator Kimia
Abstrak: Budidaya udang vannamei (Litopenaeus vannamei) dihadapkan pada permasalah yaitu belum mampunya memenuhi permintaan yang tinggi sehingga kegiatan budidaya yang berjalan dilakukan dengan padat tebar yang tinggi, padat tebar yang tinggi ini menyebabkan banyaknya limbah yang dihasilkan. Tingginya limbah yang dihasilkan menyebabkan buruknya kualitas air dan sedimen sehiingga perlu dicarikan solusi untuk menangani masalah ini. Salah satu solusi untuk mengurangi limbah yang terendap di sedimen tambak adalah dengan menambahkan bahan kimia oksidator seperti KMnO₄ dan H₂O₂. Penambahan bahan oksidator dapat merubah bahan organik yang berbahaya menjadi aman untuk udang dengan cara pertukaran elektron. Tujuan penelitian ini adalah mengetahui pengaruh pemberian bahan oksidator KMnO₄ dan H₂O₂ dengan dosis yang berbeda terhadap laju redoks, total bahan organik, konsumsi oksigen, dan tekstur sedimen tambak. Penelitian ini dilakukan di Laboratorium Lingkungan Akuakultur, Departemen Budidaya Perairan, Fakultas Perikanan dan Ilmu Kelautan, Institut Pertanian Bogor. Sampel sedimen yang berasal dari Tambak Pinang Gading dimasukkan kedalam botol sampel dengan ukuran diameter 4 cm dan tinggi 6 cm sebanyak 300 gram. Sampel diberi perlakuan Kontrol, penambahan KMnO₄ 0,15 mg, KMnO₄ 0,3 mg, H₂O₂ 11 ml, dan H₂O₂ 22 ml. Selama 40 hari sampel diinkubasi dan diukur nilai potensial redoks pagi sebelum dan sesudah aduk, potensial redoks siang sebelum dan sesudah aduk, konsumsi oksigen sedimen, total karbon organik, dan tekstur tanah. Hasil penelitian menunjukkan hasil terbaik terdapat pada perlakuan KMnO₄ 0,3 mg dengan peningkatan nilai redoks sekitar 60 mV., Vannamei shrimp cultivation is faced with a problem, namely the inability to meet high demand so that ongoing cultivation activities are carried out with high stocking densities, this high stocking density causes a lot of waste to be produced. The high amount of waste generated causes poor water and sediment quality, so it is necessary to find a solution to deal with this problem. One solution to reduce waste that settles in pond sediments is to add oxidizing chemicals such as KMnO₄ and H₂O₂. The addition of oxidizing agents can change harmful organic matter to be safe for shrimp by exchanging electrons. The purpose of this study was to determine the effect of the oxidizing agent KMnO₄ and H₂O₂ at different doses on the redox rate, total organic matter, oxygen consumption, and pond sediment texture. This research was conducted at the Aquaculture Environmental Laboratory, Department of Aquaculture, Faculty of Fisheries and Marine Sciences, Bogor Agricultural University. Sediment samples from Tambak Pinang Gading were put into a sample bottle with a diameter of 4 cm and a height of 6 cm as much as 300 grams. Samples were given control treatment, adding 0.15 mg KMnO₄, 0.3 mg KMnO₄, 11 ml H₂O₂, and 22 ml H₂O₂. For 40 days the samples were incubated and the redoks potential values were measured in the morning before and after shaking, redoks potential in the afternoon before and after shaking, sediment oxygen consumption, total organic carbon, and soil texture. The results showed that the best results were found in the H₂O₂ treatment with an increase in the redoks value of about 40 mV.
Keyword: KMnO₄, H₂O₂, organic matter.

Judul: Kinerja Produksi Pendederan Udang Vaname (Litopenaeus vannamei) dalam Sistem Resirkulasi dengan kombinasi Zeolit dan Bioball
Abstrak: Pendederan udang vaname dengan sistem resirkulasi menjadi salah satu alternatif yang dapat diterapkan untuk meningkatkan produksi, sehingga budidaya dapat dilakukan baik di daerah dekat pantai hingga pekarangan rumah. Media filter pada sistem resirkulasi sangat mempengaruhi kualitas air, biaya produksi, serta keberhasilan budidaya. Penelitian ini bertujuan untuk mengetahui peran kombinasi zeolit dan bioball sebagai filter dalam sistem resirkulasi terhadap kinerja produksi pendederan udang vaname (Litopenaeus vannamei). Desain penelitian yang digunakan adalah rancangan acak lengkap (RAL) yang terdiri dari 4 perlakuan dan 3 ulangan. Perlakuan tersebut terdiri dari 100% zeolit, 75% zeolit dan 25% bioball, 25% zeolit dan 75% bioball, dan 100% bioball. Udang dengan bobot awal 0,004±0,000 g dipelihara dalam akuarium 60 x 40 x 40 cm dengan kepadatan 100 ekor akuarium-1 selama 28 hari dan diberi pakan komersil (protein 41%) sebanyak empat kali sehari dengan feeding rate 8,5–9,0%. Kombinasi 75% zeolit dan 25% bioball (p<0,05) memberikan kinerja produksi terbaik dengan kelangsungan hidup 86,67±1,53%, pertumbuhan bobot spesifik 8,88±0,02%, rasio konversi pakan 1,17±0,06 dan produktivitas 0,66±0,01 kg m-2., Intermediate rearing of vannamei shrimp with a recirculation system is an alternative that can be applied to increase production, so that shrimp farming be carried out both in areas near the coast and in the yard. Filter media in the recirculation system greatly affects water quality, cost production, and the success of farming.This research aims to determine the role of the zeolite and bioball combination as a filter in the recirculation system on the production performance of the vaname shrimp (Litopenaeus vannamei) nursery. The research design used a completely randomized design (CRD) consisting of 4 treatments and 3 replications. The treatments consisted of 100% zeolite, 75% zeolite and 25% bioball, 25% zeolite and 75% bioball, and 100% bioball. Shrimp with initial weights of 0.004±0.000 g are kept in an aquarium 60 x 40 x 40 cm with a density of 100 fish aquarium-1 for 28 days and are given commercial (41% protein) feed 4 times a day with a feeding rate of 8,5–9,0%. The best production performance was obtained in the combination of 75% zeolite and 25% bioball (p<0.05) with 86,67±1,53% survival, growth specific weight was 8,88±0,02%, feed conversion ratio was 1,17±0,06, and productivity was 0,66±0,01 kg m-2.
Keyword: Amonia, bakteri total, nitrat, nitrit

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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