Judul: Effect of Turmeric Powder (Curcuma longa) Supplemented feed on Indonesian shortfin eel (Anguilla bicolor bicolor) gonadal development
Abstrak: Anguilla bicolor bicolor merupakan komoditas dengan nilai ekonomis tinggi. Namun, budidaya sidat masih bergantung pada benih hasil tangkapan alam, serta menggunakan pakan yang tidak sesuai dengan kebutuhan sidat. Tujuan penelitian ini adalah menganalisa pengaruh suplementasi serbuk kunyit pada pakan formulasi terhadap kematangan gonad ikan sidat. Sidat dipelihara dalam bak beton berukuran 3 x 1,5 x 1,3 m. Padat tebar dari tiap kolam uji yang digunakan adalah 12 ekor per kolam. Sidat dipelihara selama 56 hari dengan diberikan perlakuan K, NS, dan S. Parameter yang diamati adalah pertumbuhan biomassa mutlak, rasio konversi pakan, indeks pencernaan, indeks hepatosomatik, indeks gonadosomatik, dan gambaran mikroskopis gonad. Hasil menunjukkan perlakuan pakan suplementasi memberikan hasil yang terbaik dalam meningkatkan perkembangan gonad sidat. Pakan formulasi yang disuplementasi kunyit mampu meningkatkan perkembangan gonad sidat ditunjukkan dengan adanya peningkatan pada indeks pencernaan yang lebih baik jika dibandingkan dengan perlakuan pakan komersial, yakni meningkat hingga 31%. Dalam penelitian ini, perlakuan pakan suplementasi merupakan perlakuan terbaik., Indonesian shortfin eel (Anguilla bicolor bicolor) is a commodity with high economical value. Unfortunately, its culture still depends on wild catch seeds, and using improper feeds with its requirement. The objective of this research is to analyze the effect of turmeric powder supplementation on European eel’s gonadal development. The aim of this research was to analyze the effect of turmeric powder supplementation on feed to improve Eruopean eel gonadal development. Eels was reared on 3 x 1.5 x 1.3 pond. Each pond was filled with 12 eels. Eels was reared for 56 days with K, NS, and S treatments. Parameters observed were absolute biomass growth, feed convertion ratio, digestive tract somatic index, hepatosomatic index, gonadosomatic index, and gonad microscopical image. Results showed that supplemented feed treatment gave the best result on increasing eels gonadal development. Supplemented feed was able to increase DTSI better than commercial feed, up to 31%. On this research, supplemented feed treatment was the best treatment.
Keyword: Indonesian Shortfin Eel, Feed, Gonad, Growth, Trumeric

Judul: Evaluation of Gonad Development of Eels (Anguilla bicolor bicolor) Fed with Formulated Feed with Turmeric Supplementation (Curcuma longa)
Abstrak: Permasalahan dalam kegiatan pembenihan sidat salah satunya adalah sulit didapatkan induk matang gonad dalam wadah budidaya dan pertumbuhannya yang lambat. Kunyit yang mengandung kukurmin diketahui bersifat estrogenik, dapat menginduksi vitellogenesis pada ikan. Penelitian ini bertujuan untuk menganalisis pengaruh suplementasi kunyit dalam pakan formulasi IPB terhadap perkembangan gonad ikan sidat. Ikan sidat berukuran 455±245 g/ekor (60.8±44.5 cm) diberi perlakuan pakan komersial (K), pakan formulasi non suplementasi (NS), dan pakan disuplementasi kunyit (S). Setiap perlakuan terdiri dari 10 ekor sidat dengan individu sebagai ulangan. Ikan dipelihara dalam kolam beton berukuran 3 x 1.5 x 1.3 m dan diberi pakan 1% bobot tubuh per hari, pagi dan sore. Variabel yang dianalisis adalah pertumbuhan bobot mutlak (PBM), pertumbuhan panjang mutlak (PPM), digestive track somatic index (DTSI), indeks hepatosomatik (HIS), dan indeks gonadosomatik (IGS). Hasil penelitian menunjukkan bahwa pakan formulasi IPB disuplementasi kunyit mengindikasikan peningkatan PBM, PPM, DTSI, dan GSI dibandingkan dengan pakan komersial. Suplementasi kunyit dapat digunakan untuk mempercepat pematangan gonad sidat., One of the problems in eel hatchery activities is that it is difficult to obtain mature gonads in cultivation containers and their growth is slow. Turmeric containing curcurmin is known to be estrogenic and can induce vitellogenesis in fish. This study aims to analyze the effect of turmeric supplementation in IPB formulated feed on the development of eel fish gonads. Eel fish measuring 455 ± 245 g/fish (60.8 ± 44.5 cm) were treated with commercial feed (K), nonsupplemented formulated feed (NS), and turmeric supplemented feed (S). Each treatment consisted of 10 eels with individuals as replicates. Fish are kept in concrete ponds measuring 3 x 1.5 x 1.3 m and fed 1% of body weight per day, morning and evening. The variables analyzed were absolute weight growth (PBM), absolute length growth (PPM), digestive track somatic index (DTSI), hepatosomatic index (HIS), and gonadosomatic index (IGS). The research results showed that IPB formulated feed supplemented with turmeric indicated an increase in PBM, PPM, DTSI, and GSI compared to commercial feed. Turmeric supplementation can be used to accelerate eel gonad maturation.
Keyword: pakan, pertumbuhan, sidat, kunyit, gonad

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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