Judul: Evaluasi Atribut Produktivitas Ikan Sidat (Anguilla bicolor bicolor) di Sungai Cimandiri, Pelabuhanratu, Kabupaten Sukabumi, Jawa Barat
Abstrak: Purpose the research is to evaluate NOAA methods and attribute productivity of anguillid eel needed to suppose sustainable potention anguillid eel. All arrested the anguillid eel pigmented in Cimandiri Rivers observed growth parameters, reproduction, and mortality rate. Sample anguillid eel in gather for research in Juni to December totaled 209 tail. An abundance of anguillid eel increase the same time as the rainy season. Evaluation the attribute of productivity indicate that score made by NOAA not comforming if adapted to anguillid eel and the result 3 score krom NOAA and 1,375-2,5 to be score modification. Based on the result obtained, which made The score NOAA can not be adapted to the anguillid eel. Fish difference and environment can to affect productivity.
Keyword: Cimandiri River, Anguillid eel, Evaluate attribute productivity

Judul: Kondisi perairan di beberapa sungai yang bermuara di Teluk Palabuhan Ratu, Jawa Barat sebagai habitat Ikan Sidat (Anguilla Spp.)
Abstrak: Ikan sidat (Anguilla spp.) merupakan salah satu sumber daya perikanan yang dapat pulih, namun rentan kepunahan. Penelitian ini bertujuan untuk mengetahui status kondisi perairan di beberapa sungai yang bermuara di Teluk Palabuhan Ratu sebagai habitat ikan sidat (Anguilla spp.). Kegiatan penelitian meliputi kegiatan lapang dan analisis laboratorium. Lokasi sampling terbagi menjadi dua bagian badan sungai yakni hulu dan hilir sungai, meliputi Sungai Cibareno, Sungai Citiis, Sungai Cimaja, Sungai Cisukawayana, Sungai Citepus, Sungai Cipalabuhan, dan Sungai Cimandiri. Hasil analisis menunjukkan bahwa Sungai Cimaja bagian hulu dan hilir memiliki status sangat baik, Sungai Citiis, Sungai Cibareno, dan Sungai Cisukawayana bagian hulu memiliki status baik dan hilir memiliki status sangat baik, Sungai Cimandiri bagian hulu dan hilir memiliki status baik, Sungai Citepus bagian hulu memiliki status baik dan hilir memiliki status sedang, dan Sungai Cipalabuhan bagian hulu dan hilir memiliki status sedang. Upaya pengelolaan meliputi membatasi limbah dari kegiatan antropogenik, membuat IPAL, pembuatan kawasan hijau di pinggiran sungai, dan membatasi penggunaan bahan berbahaya (mengandung logam berat)., Eels (Anguilla spp.) is one of the fisheries resources can be recovered but are susceptible to extinction. The purpose of the research was to determine the water quality status for eels in rivers that end in Palabuhan Ratu Bay, West Java as habitat for eels (Anguilla spp.). This research included field activity and laboratory analysis. Sampling location was divided into two parts on the body of the river that is upstream and downstream of the river which includes Cibareno, Citiis, Cimaja, Cisukawayana, Citepus, Cipalabuhan, and Cimandiri River. Result showed are Cimaja River upstream and downstream was a very good status, Citiis, Cibareno, and Cisukawayana River upstream was a good status and downstream was a very good status, Cimandiri River upstream and downstream was a good status, Citepus River upstream was a good status and downstream was a average status, and Cipalabuhan River upstream and downstream was a average status. Management efforts that are restricting waste input of anthropogenic activities, making WWTP, making green belt in beside the river, and restricting the use of hazardous materials (containing heavy metals).
Keyword: ikan sidat, pengelolaan, sungai

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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