Judul: Evaluasi daya gabung dan heterosis jagung manis (Zea mays L. var. saccharata)
Abstrak: The aims of this research were to estimate the values of general combining ability, specific combining ability and heterosis in sweet corn using a half dialel mating design. There were 7 inbreds, 21 hybrids, and 2 checks varieties (Bonanza and SG 75) used in this research. This research was conducted in Leuwikopo experimental station Dramaga Bogor, from November 2014 to January 2015. The experimental design was a randomized complete block design with 3 replicates. General combining ability values were estimated by Griffing II method. Heterosis were calculated based on mid-parent and high-parent values. Inbred JM8-4-3-1- 15-14 has the highest general combining ability in sugar content and yield. Inbred JM14-4-10-10-13-15 has the high general combining ability in ear length and days to harvest. Inbred JM17-6-13-1-12 has highest general combining ability for ear height. Hybrid 17 X 14 has the highest specific combining ability for yield and ear length. High heterosis values for yield and ear length were found in hybrid 17X6 hybrid.
Keyword: Bogor Agricultural University, combining ability, Griffing method, half diale, hybrid

Judul: Evaluasi Daya Hasil Jagung Manis (Zea mays L. var. saccarata)
Abstrak: Research has been done is the yield evaluation of hybrid sweet corn (Zea mays L. var. saccharata) with the aim of testing the results of seven sweet corn. Hybrids in order to support the needs of hybrid corn seed. The research began in Cibeurem, Darmaga, Bogor in October 2011 to January 2012. Genotypes used were: 3 x 4B, 6 x 8, 6 x 4A, 6 x 3, 3 x 8, 3 x 4A, and 6 x 4B and four commercial varieties were Mutiara, Sweet Boy, Super Sweet Corn, and Talenta. The hypothesis of this research is the evaluation of sweet corn hybrids can be superior or equal to the commercial varieties that can be continued into the new varieties. Experimental design used was Randomized Complete Block Design with three replications. Data were analyzed using the F test and if significantly different be followed by Dunnet (α = 5%). The result of this research showed that skin cobs weight, skin cobs weight/plot, productivity, and harvest index from 6 x 3, 6 x 4A and 6 x 4B hybrids were not significantly different with the best commercial variety, Talenta. Hybrid of 3 x 4A, 3 x 4B, and 3 x 8 have skin cobs weight and harvest index which not significantly different with the best commercial variety, Talenta. Total soluble solids(°brix) of seven hybrid was not significantly with the best commercial variety, Talenta.
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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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