Judul: Keragaan galur harapan padi sawah tipe baru di Sukabumi dalam rangka uji multi lokasi
Abstrak: Agronomy and Horticultural Departement, Bogor Agricultural University, has been researched for several rice promising lines to release high yielding variety. This experiment is a part of multilocation yield trial. The experiment was conducted at Sukabumi Regency, West Java on January until May 2010. The research was arranged by Randomized Compately Block Design with 3 replications. The result showed that the highest yield (7,7 t/ ha) obtained from IPB102-F-92-1-1 whereas the lowest yield obtained from IPB102-F-91-2-1 (5,2 t/ha). The productivity of IPB102-F-92-1-1 is only significantly higher than Ciherang and IR64. The other productivity were as same as Ciherang and IR64. The performances of IPB97-F-13-1-1, IPB97-F-15-1-1, IPB97-F-20-2-1, IPB97- F-31-1-1, IPB102-F-92-1-1, and IPB107-F-16-5-1 are representing new plant ideotype.
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Judul: Pengujian 10 Galur Harapan Padi (Oryza sativa L.) Tipe Baru IPB di Dramaga, Bogor dalam Rangka Uji Multilokasi
Abstrak: The experiment was conduted to evaluate production variability and agronomic traits of ten new plant type rice held at Sawah Baru Experimental Field, Dramaga, Bogor in April−August 2014. Experiment using Randomized Completely Block Design, single factor and three replications. The factor was lines which selected from advanced yield trial that have been conducted before (IPB160-F-36-2-1, IPB160-F-36-5-1, IPB160-F-36-25-1, IPB160-F-46-6-1, IPB160-F-54-2-1, IPB160-F-54-3-1, IPB160-F-54-21-1, IPB162-F-10-2-1, IPB162-F-17-1-1, IPB168-F-8-1-1), and two national varieties (Ciherang and Mekongga) as a check. The result showed that line IPB160-F-36-2-1 which productivity is 7.95 ton ha-1 have significantly higher productivity than Ciherang (6.62 ton ha-1) and Mekongga (6.86 ton ha-1). There are lines that have equal productivity from check with good yield components which potential for further development, that lines are IPB160-F-54-2-1 (7.37 ton ha-1) and IPB160-F-54-21- 1 (7.51 ton ha-1)
Keyword: Bogor Agricultural University (IPB), rice, new type, multilocation, line, high yield

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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