Judul: Evaluasi Produktivitas Beberapa Varietas Padi
Abstrak: The research was conducted during February to June 2014 in Muara Rice Research Institute, Bogor. The purpose of this study was to determine the factors that affect the productivity of some rices varieties The design used was a randomized complete design group with one factor consists of 6 varieties. The varieties used were high yielding varieties (Inpari 13, Ciherang, Mekongga), a new plant type of rice (IPB 4S), local variety (Mentik Wangi), and hybrid variety (Hipa Jatim 2). Each variety was replicated of three. The results showed that in general, high yielding varieties (VUB) Inpari 13, Ciherang and Mekongga have higher productivity than other varieties (local, PTB, hybrid). VUB Productivity ranged from 4.59 to 5.62 tons per hectare. The results of the three VUB productivity was influenced by yield components such as number of productive tillers, 1000 grain weight, percentage of filled grain and resistance to pests and diseases.
Keyword: Bogor Agricultural University (IPB), productivity, yield component, rice varieties

Judul: Analisis Produktivitas Beberapa Tipe Padi
Abstrak: This research was carried out in November 2012 until April 2013. The objective of this research was to study the productivity of some types of rice and some factors that influence it. Four varieties of rice were used. The varieties are Mentik Wangi as a local variety, IPB 3S as a new plant type of rice, Inpari 13 as a new variety of rice and Hipa 8 as a hybrid type. A Randomized Complete Blocked Design with three replications using for this experiment. This research was conducted at Muara Experiment station. The result showed that Inpari 13 had a high productivity, 6 ton ha-1. The variety may use the assimilates in stems and alocate the dry matter during grain filling effectively. In addition, the resistance of Inpari 13 against bacterial leaf blight attack is one of the factors that cause the high productivity
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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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