Judul: Ragam Cendawan Mikoriza Arbuskula pada Areca di Kebun Raya Bogor
Abstrak: Areca known as the pinang tree and have benefit as a powerful medicine on men. Arbuscular mycorrhizal fungi (AMF) are symbiotic on almost every root plants, but the diversity of AMF on rizosfer Areca is unknown. Therefore research on variety and colonies AMF on rizosfer Areca is needed. Soil samples of Areca were isolated and processed by wet sieving and decauting method. Root samples of Areca were stained by using trypan blue in lactoglycerol. There were 3 genera of AMF collected from Bogor Botanical Garden (4 species Acaulospora, 3 species Glomus, and 2 species Scutellospora) which is associated with 3 species of Areca. Percentage colonies of AMF rizosfer on roots Areca was counted. Areca has an intermediate type of arbuscular
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Judul: Cendawan Mikoriza Arbuskula pada Pohon Bisbul (Diospyros blancoi) di Bogor
Abstrak: Bisbul (Diospyros blancoi) fruit is edible and could be potent inhibitors of the ageing process in the skin. Study on arbuscular mycorrhizal fungi (AMF) of bisbul has never been reported, while most of root plants associated with AMF. The general objective of this study was to observe the AMF colony and AMF spore in the rhizophere of bisbul tree and attempt to pot culture with Pueraria javanica as the host plant. Root and soil samples from rhizosphere of bisbul were taken from three locations, i.e Kampus IPB Darmaga, Cibinong, dan Ciampea. Roots were stained by using of trypan blue 0.05%. Soil samples were air dried, then part of it used for spore isolation and other part for pot culture. Spores were separated by using wet sieving and decanting method and continued with centrifugation. The result showed that bisbul roots have arbuscules, vesicles, coiled hypha, and internal hypha of AM. AMF spores isolated from bisbul rhizosphere were Acaulospora scrobiculata, Acaulospora tuberculata, Gigaspora spp., Glomus spp., and Scutellospora sp
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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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