Judul: Jenis dan kelimpahan bakteri pada Belut Sawah Monopterus albus kondisi sakit dan sehat di wilayah Jawa Barat
Abstrak: Bakteri adalah salah satu agensia yang mempengaruhi kesehatan pada belut sawah Monopterus albus. Kelimpahan dan diversitas jenis bakteri perlu diketahui untuk mendukung pengembangan teknologi budidaya belut sawah. Penelitian ini bertujuan untuk mengidentifikasi dan menginventarisasi isolat bakteri pada belut sawah Monopterus albus kondisi sakit dan sehat serta membandingkan kelimpahan bakteri berdasarkan 3 stasiun pengambilan sampel di wilayah Jawa Barat yang diwakili oleh Kabupaten Cianjur, Karawang, dan Sukabumi. Bakteri diisolasi kemudian diidentifikasi dengan uji karakterisasi sifat biokimia dan fisiologis serta uji morfologi. Sebanyak 20 jenis bakteri berhasil diidentifikasi dari keseluruhan sampel. Jenis bakteri yang memiliki kelimpahan tertinggi pada belut kondisi sakit asal Cianjur adalah Nocardia sp., jenis bakteri Aeromonas sp. pada belut asal Karawang, dan jenis bakteri Staphylococcus sp. pada belut asal Sukabumi. Jenis bakteri pada belut kondisi sehat yang memiliki kelimpahan tertinggi yaitu Bacillus sp. pada belut asal Cianjur dan Sukabumi, serta Staphylococcus sp. pada belut asal Karawang…
Keyword: Monopterus albus, Rice-field eel, Bacterial species, Bacterial abundance, Belut sawah, Aeromonas Sp., Eels

Judul: Bakteri dan Cacing Parasitik pada Hati dan Saluran Pencernaan Ikan Belut (Monopterus albus
Abstrak: This study aims to identified the bacterial and parasitic worms in the liver and gastrointestinal tract of eels. The identification of isolated bacteria was done by using Gram staining, triple sugar iron agar, citrate, indole and fermentation of sugar. Parasitic worms stained with KOH clove oil for semi-permanent coloring and Semichon's Acetocarmine for permanent staining. Pseudomonas maltophilia, Proteus mirabilis, Pseudomonas aeroginosa, Salmonella sp, and Vibrio cholerae was found in the liver, and Pseudomonas aeroginosa, Salmonella sp., Chromobacterium sp., Enterobacter aerogenes and Vibrio cholerae from the gastrointestinal tract. The results showed that there are two types of parasitic worms in the digestive tract, ie Procamallanus sp., And Acanthocephala sp ..
Keyword: digestive tract, liver, parasitic worms, bacteria, Monopterus albus

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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