Judul: Viabilitas Benih Cabai (Capsicum annuum L.) pada Beberapa Tingkat Kemasakan Buah dan Genotipe
Abstrak: This research used six open pollinated chilli genotypes, namely Anies 1, Anies 2, Seloka 1, Seloka 2, Seloka 3, and SSP were tested in 5 different fruit maturity levels, namely 32, 35, 38, 41, and 44 days after anthesis (DAA). This research used 3 different group of branches, namely the first branches (branches 2-5), second branches (branches 6-7), and third branches (branches 8-9). Physiological maturity is determined by seed viability, vigor and dry seed weight. This study showed the highest values of viability and vigor occured at the level of maturity 44 DAA. The highest viability had germination (DB) on average 84.17% and the highest vigor had vigor index value (IV) on average 20.83%. Germination value was high, and the value of the vigor index was low. Seeds dry weight had started to increase at 38 DAA for all genotypes and remained stable until 44 DAA. The highest seed dry weight indicated that seeds were physiologically mature. Quantitative characters of fruits and seeds were not significantly correlated to the value of IV and DB. The value of IV and DB in first branches was not different with second branches, but most of the quantitative characters of fruits and seeds at first branches were different with second branches.
Keyword: vigor index, seeds, germination, correlation, Branches

Judul: Vigor daya simpan dan vigor kekuatan tumbuh benih pada beberapa genotipe cabai (Capsicum annuum L.)
Abstrak: Chili peppers (Capsicum annuum L.) is one of commercial vegetables which has high economic value in Indonesia. The research was aimed to study the storability period and vigor of nine genotypes of chili pepper seeds through salinity stress and drought stress. The experiment of accelarated aging was using chemical method through methanol (20%) soak period i.e 1, 2 and 3 hour. The genotype number 307 (Bhaskara F1) has highest storability (VDS) based on dry weight of normal seedlings (BKKN) 3.99 mg, 2.77 mg and 1.29 mg, germination percentage (DB) 7.45%, 4.67% and 2.08%, speed of germination (KCT) 3.17% etmal-1, 1.93% etmal-1 and 1.14% etmal-1, and seedling growth rate (LPK) 1.32 mg, 1.54 mg and 1.20 mg. The experiment of sub optimum condition through salinity stress was using NaCl concentration treatment that is 2500, 3750 and 5000 ppm. The genotype number 293 (SKB 27) was elucidated as the most tolerant genotypes to salinity stress through dry weight of normal seedlings 5.15 mg, 5.06 mg and 4.67 mg, germination percentage 68.52%, 57.58% and 53.94%, speed of germination 16.60% etmal-1, 14.30% etmal-1 and 14.00% etmal-1, and seedling growth rate 1.48 mg, 1.54 mg and 1.47 mg. Experiments vigor chilli pepper seeds to drought stress was using PEG 6000 at -1.0, -1.5 and -2.0 bar. The genotype number 307 (Bhaskara F1) was elucidated as the most resistance genotypes to drought stress through dry weight of normal seedlings 5.07 mg, 5.02 mg and 4.69 mg, germination percentage 60.84%, 60.81% and 56.59%, speed of germination 16.04% etmal-1, 15.13% etmal-1 and 13.88% etmal-1, seedling growth rate 1.52 mg, 1.51 mg and 1.49 mg and the length of radicle (PR) 2.20 cm, 1.46 cm and 1.81 cm.
Keyword: vigor, salinity, rapid, drought, chili, Bogor Agricultural University (IPB)

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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