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: Penampilan hibrida, pendugaan nilai heterosis dan daya gabung galur-galur jagung (Zea mays L.)
Abstrak: The research was conducted to select superior maize inbred lines and their hybrids based on combining ability and heterosis value. The F1’s of 8x8 diallel crosses, their reciprocals and parents were evaluated at two locations, in Bogor, West Java and Metro, Central Lampung from December 2007 – May 2008. The experimental design was randomized complete block design with three replications. Analysis of variance showed that genotypes, General Combining Ability (GCA) and Specific Combining Ability (SCA) were significantly different in ear length, number of kernel per ear and 1000 grain weight in both locations. Reciprocal effect gave significant difference for ear length and 1000 grain weight characters in Lampung, also for ear diameter, ear weight and yield in both locations. Inbreds 276-4, 425-3 and 969 had the highest GCA value for characters ear length, number of kernels per ear and 1000 grain weight observed in both locations. Inbred 605 had the highest GCA value for ear diameter character, for ear weight and yield character, inbred 969 had the highest GCA value in both locations. Meanwhile, the best SCA values in Bogor were from the crosses between 426/612 for ear length and numbers of kernel per ear characters, 261-2/425-3 for 1000 grain weight character. In Lampung, hybrids 261-2/425-3, 276-4/786 and 276-4/261-2 showed the best SCA value for ear length, numbers of kernel per ear and 1000 grain weight. Hybrid 786/969 had the highest SCA value for ear diameter character and hybrid 261-2/425-3 for ear weight and yield in both locations. Crosses between 261-2/425-3 in Bogor and 276-4/261-2 in Lampung had the best heterosis and heterobeltiosis for ear weight and yield characters.
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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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