Judul: Analisis keragaman morfologi tanaman manggis (Garcinia Mangostana L.) dari empat sentra produksi di Bali
Abstrak: Mangosteen population has been reported performed apomixis reproduction, lead to assumption genetically homogen. Early studies showed that there were variation among mangosteen population. However the variation could be originated from environment variation. To elucidate genetic variability among mongosteen population in more detail seedling from Purworejo, Purwakarta, Leuwiliang and Trenggalek where grew at same environment in Bogor. The objective of this study is to analysis variability among mangosteen population from Purworejo, Purwakarta, Leuwiliang and Trenggalek. The studies was carried out in the origin of population for morphological character and at Bogor for seedling performance since February 2003 to July 2003. The plant material for this study were ten parent trees from each production centre and ten fruits from each trees, subsequently their seed used for seedling at Bogor. Obtained data analyzed by using homogenity of variance test (Bartlet test) and was continued with Tukey's Studentized Range Test. The plants in seedling were arranged in Completely Randomized Design consisted of four treatment with 10 replications. The result of this study was showed the homogenity variance in leaf weight, leaf area indeks, leaf length, leaf width, fruit weight, seed weight, number of seed. In seedling all character that observed had homogen variance. The analysis of mean morphological character showed that Trenggalek might had the best condition for mangosteen growth. Plant from Trenggalek showed the highest mean in leaf length, leaf width, plant height and number of leaf. All character that observed in seedling had high heritability. Comparison with other study in 2002 and 2001 showed that population had the same result in homogenity variance, was performed that leaf area index, leaf length, leaf width, plant height and number of leaf had homogen variance. It showed that mangosteen population probably had a stable response to enviromental influence
Keyword: apomixis reproduction, Completely Randomized Design, mangosteen population

Judul: Studi Keragaman Morfologi Tanaman Dan Semaian Populasi Manggis (Garcinia Mangostana L.) Dari Tiga Sentra Produksi Di Pulau Jawa
Abstrak: The studies was aimed to evaluate genetic variability of mangosteen population from three production center of Java island, Wanayasa (West Java). Watulimo (East Java) and Gunung Walat (West Java) base on morphological characters of parent trees (leaf area index, leaf weight, canopy shape, stem ring), fruit characters (seed weight, fruit weight) and seedling performance (flush colour, plant height, number of leaves, flush rate, leaf area index, germination rate). The studies was carried out in the location of population for morphological character and at Tajur Bogor for seedling perfurmance since March to September 2002.
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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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