Judul: Aplikasi Bakteri Probiotik untuk Meningkatkan Vigor Bibit Cabai (Capsicum annuum L.)
Abstrak: Chilli (Capsicum annuum L.) is an important horticultural commodities in Indonesia and has high economic value. This research aims to study the effects of spraying with Serratia marcescens, Pseudomonas group of fluorescens, and Bacillus subtilis to improve vigor of chilli seedling. The seed that use is coated seed with the same bacteria and have been storaged for 6, 9, 12, 15 and 18 weeks. Spray application with bacteria and Luria-Bertani media is done when the seedling was 2 and 4 weeks. Coating seed using Serratia marcescens produce the best vigor seed in the period of 6, 12, and 15th weeks. The best application to increase growth of chilli seedling derived from seeds that have been storaged is using Pseudomonas group of fluorescens with application on seed coating and spraying chilli seedling.
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Judul: Aplikasi Bakteri dalam Perlakuan Seed Coating untuk Mempertahankan Viabilitas dari Benih Cabai (Capsicum annuum L.) yang Sehat
Abstrak: This research was conducted to study the effect of seed coating using Bacillus subtilis, Pseudomonas group fluorescens and Serratia marcescens toward the viability of undiseased chilli seed (Capsicum annuum L.) during storage. This study used nested design with three replications. The main plot is storage period (0, 3, 6, 9, 12, 15, 18, 21 and 24 weeks) and the subplot is seed coating treatment with bacteria (Bacillus subtilis, Pseudomonas group fluorescens, Serratia marcescens and control). Chilli seed IPB C5 still have a good viability until 24 weeks, showed from the percentage of germination that is 77.3%. Control and coating used bacteria treatment showed unsignificant difference on germination, vigour index, growth rate and normal seedling dry weight. The bacteria as coater were still alive until 24 weeks of storage periode with population 5.89 x 104 cfu g-1 for Pseudomonas group fluorescens, 4.79 x 104 cfu g-1 for Bacillus subtilis and 1.70 x 104 cfu g-1 for Serratia marcescens.
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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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