Judul: Pengelompokan beberapa isolat jamur tiram putih (Pleurotus spp.) berdasarkan sifat pertumbuhan dan perkembangan
Abstrak: Jamur tiram putih (Pleurotus spp.) merupakan jamur pangan yang berprospek ekonomi tinggi. Penelitian ini bertujuan mempelajari pengelompokan delapan isolat jamur tiram putih berdasarkan sifat pertumbuhan dan perkembangannya untuk koleksi sumberdaya genetik yang dapat dimanfaatkan pada program pemuliaan jamur tiram putih. Penelitian ini menggunakan delapan isolat jamur tiram putih yang berasal dari berbagai sumber. Masing-masing isolat ditumbuhkan pada 30 kantong plastik (17x35cm) yang berisi masing-masing 1000 g substrat produksi dengan bahan utama serbuk gergajian kayu sengon (Paraserianthes falcataria). Berdasarkan parameter pertumbuhan dan perkembangan, maka kedelapan isolat terbagi menjadi empat kelompok, yaitu kelompok kesatu beranggotakan isolat MTR, kelompok kedua beranggotakan isolat AMD, TBN, dan BNK, kelompok ketiga beranggotakan isolat USX dan BBR, serta kelompok keempat beranggotakan isolat CSR dan PGN. Analisis korelasi menunjukkan bahwa diameter terbesar pileus berkorelasi negatif terhadap jumlah pileus. Jumlah pileus dan jumlah panen berkorelasi positif terhadap bobot basah. Bobot basah berkorelasi positif terhadap efisiensi biologi. Masing-masing fase vegetatif dan fase reproduktif berkorelasi positif terhadap masa pertumbuhan dan perkembangan. Jumlah panen berkorelasi positif terhadap efisiensi biologi.
Keyword: Kelompok Pleurotus spp., Pertumbuhan dan perkembangan, Korelasi, Bogor Agricultural University

Judul: Seleksi Isolat Jamur Tiram Putih (Pleurotus spp.) Berdasarkan Sifat Pertumbuhan dan Perkembangan
Abstrak: The research objective is a selection of isolates of white oyster mushrooms (Pleurotus spp.) based on characters of growth and development for obtaining excellent isolate and they can be used for breeding program. The materials were consisted of seven isolates of white oyster mushrooms from several source is AMD, MTR, BBR, PGN, USX, BNK, TBN, and CSR isolates. The works consisted of isolate maintenance, seed production, planting, harvesting, observation, data collection, and data analysis using SPSS 10.01 application program. Based on research results, USX isolate had the highest biological efficiency, MTR isolate had the fastest reproduction phase, BBR isolate had the highest weight of fruit body, BNK isolate had the highest number of fruit body and AMD isolate had the shortest vegetative phase and the shortest period of growth and development. The isolate which accomplished the criterias of selection was AMD isolate because it had a short period of growth and development, high biological efficiency value, produced the highest number of fruit bodies, also had diameter of fruit body suitable to criterias of consumer.
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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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