Judul: Pengaruh Umur Pohon Tetua dan Jumlah Buku Stek Cabang terhadap Pertumbuhan Bibit Jarak Pagar (Jatropha curcas L.).
Abstrak: The research was conducted in February-July 2010 in the greenhouse and in the seed science and technology laboratory of agronomy and horticulture department, leuwikopo, Bogor Agriculture University,. The aim of this research to know the effect of mother plant age, internode numbers of stem cutting, and interaction on growth of seedling-stem cutting of Jatropha curcas Linn. Research method applied Randomize Complete Block Design with two factors, namely mother plant age (U) (U1=2 year, U2=3 year, and U3=4 year) and internode numbers (B) (B1= 10 internode, B2= 15 internode, and B3= 20 internode) with three replicates. The result showed that there are effects of mother plant age, internode numbers, and their interaction on growth of seedling-stem cutting of Jatropha curcas Linn. The mother plant age for the best sprout length, leaf length, and leaf width are 4 year and 2 year. The best internode numbers for the best sprout number are the 20 and 15 internode. Interaction between mother plant age and the best internode numbers according to the plant height parameter is mother plant age 4 year with 20 internode.
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Judul: Pengaruh Frekuensi Penyiraman pada Fase Bibit terhadap Pertumbuhan Bibit dan Dampaknya pada Pertumbuhan Tanaman Jarak Pagar (Jatropha curcas L.).
Abstrak: The objective of the research was to determine the effect of watering frequency on the growth of seedlings in the three genotypes of Jatropha (Jatropha curcas L.), and the effects of watering frequency on seedling phase to the plants growth in the field. This research was conducted in the greenhouse, in the soil physics laboratory, and in the experimental field of Cikabayan, IPB Dramaga, Bogor, from March to December 2010. First experiment was used Randomized Complete Block Design (RKLT) with 2 factors, namely the frequencies of watering (5, 8, and 11 watering days) and genotypes of Jatropha (Biak, Bengkulu, and Bogor). Second experiment was used Randomized Complete Block Design with 1 factor, namely genotypes of Jatropha from the first experiment. The result of green house experiment showed that the watering frequency were affected plant height at 2 - 12 weeks after treatment (WAT), the number of leaves at 2 WAT, and the diameter of stem at 4 - 12 WAT. The genotypes only affected on the diameter of stem at 4 - 12 WAT and the number of leaves at 2 WAT. The interactions between watering frequency and genotype treatments was no effect on all variables. The three genotypes of Jatropha were observed (Biak, Bengkulu, and Bogor) had almost the same resistance to frequency of watering treatment. The best watering intervals at three genotypes of Jatropha in this research was the frequency of 8 watering days. The result of field experiment showed that the genotype treatment only affected on the diamater of stem at 2 WAT. The impact of watering frequency on all three genotypes of jatropha were not visible on plant growth in the field, both of vegetative and generative phases.
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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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