Judul: Pemanfaatan Pupuk Kandang Ayam dan Fungi Mikoriza Arbuskula untuk Memperbaiki Pertumbuhan Bibit Jeruk Siam
Abstrak: The experiment was conducted to study the effects of manure, vasicular arbuscular michorizae (VAM) and their interaction on the growth of siam citrus seedling. The experiment was conducted at Kacinambun village, Karo, North Sumatera in Maret-Juli 2012. Experiment using Randomized Completely Block Design two factors. First factor was manure: 0 g, 250 g, and 500 g manure plant-1 and the second factor was VAM: 0 g, 5 g, 10 g, and 15 g VAM plant-1. The results showed that the manure at 500 g plant-1 showed better for number of branch, number of leaf, shoot dry weight, and leaf P concentration. VAM increase the percentage of root colonizations and leaf P concentration. Interaction of 250 g manure plant-1 and 15 g VAM plant-1 showed better result for the leaf P concentration.
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Judul: Pemanfaatan Fungi Mikoriza Arbuskula dan Arang Tempurung Kelapa Untuk Meningkatkan Pertumbuhan Semai Gmelina dan Balsa
Abstrak: Latosol has spread quite widely in Indonesia, but this soil was very old so that have low soil fertility. The success rate of planting in latosol can be support by species selection and high quality seedling. The one way to improve seedlings quality is the application of arbuscular mycorrhizal fungi (AMF) and coconut shell charcoal. The research was conducted in a greenhouse used split plot design with a completely randomized design. The combination of the best interactions on seedling quality index on G. arborea seedling shown by AMF type was Gigaspora sp. without the addition of charcoal was 14.87. While the combination of the best interactions on seedling quality index on O. bicolor seedling shown by AMF type was Glomus sp. with the addition of charcoal 20% dose was 0.04. In general, inoculation of Gigaspora sp. provided better response than inoculation of Glomus sp. and was not inoculated (control)
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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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