Judul: Karakterisasi Morfologi Anggrek Phalaenopsis spp. Spesies Asli Indonesia
Abstrak: Crossing artificial propagation is an attempt to produce a better hibrid, but it often fails because of incompatibity of the parent. This could be minimized by performing characterization to determine the relationship between parental crosses. The purpose of this research was to study the morphological characters of 14 accessions of the Phalaenopsis orchid species i.e, Ph. gigantea A, Ph. bellina, Ph. amabilis ‘Halong’, Ph. violacea, Ph. doritis, Ph. schilleriana, Ph. modesta, Ph. cornu-cervi, Ph. pantherina, Ph. tetraspis, Ph. pulchra, Ph. amabilis ‘Cidaun’, Ph. amabilis ‘Treanggalek’ and Ph. gigantea B. The results showed that each member of each accession in Phalaenopsis species have a very close genetic relationship that is 100%, except Ph. tetraspis 87% relation due to the different tip shape of the leaves, Ph. gigantea A with Ph. bellina (87%), Ph. amabilis with Ph. gigantea B (87%), Ph. violacea with Ph. pulchra (87%) and Ph. amabilis Halong with Ph. pantherina (87% ). Based on the flower classification, Ph. violacea and Ph. modesta (78%) has close genetic relationship. While the classification based on leaf and flower, showed that Ph. violacea and Ph. modesta had close genetic relationship of 70%
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Judul: Karakterisasi Morfologi Anggrek Phalaenopsis Hibrid
Abstrak: Orchid is one of ornamental plants that have a high aesthetic value and Phalaenopsis hybrid is one type of orchid that was famous in Indonesia. Characterization of Phalaenopsis hybrid should be made to determine the similarity between hybrids and as a basic information on plant breeding activities. The purpose of this study was to study the morphological character and similarity of 5 gentype of Phalaenopsis hybrid i.e, four genotype white flowering hybrid, one genotype yellow flowering hybrids and Phalaenopsis amabilis ‘Cidaun’ ecotype. Based on the morphology of leaves and flowers, two of the four genotype white flowering hybrid have similarity coefficient 1.00, without observation on flower color. Every Phalaenopsis hybrid clustered together on the similarity coefficient 0.729, but one of three replications yellow flowering hybrids have similarity coefficient 0.47 with main differences in leaf shape and flowering types. Phalaenopsis amabilis ‘Cidaun’ ecotype have similarity coefficient 0.528 with main differences with Phalaenopsis hybrid in flowers shape and flowering types.
Keyword: Phalaenopsis hybrid, morphological character, leaves, flowers, Coefficient similarity

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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