Judul: The indication of seed deterioration due to shock impact on kenaf (Hibiscus cannabinus L.)
Abstrak: Penelitian dilaksanakan dalam tiga tahapan percobaan. Percobaan I menggunakan kendaraan truk sebagai alat transportasi benih kenaf. Percobaan dilaksanakan secara Faktorial 23 dalam Rancangan Acak Lengkap dengan ulangan tiga kali. Percobaan I1 menggunakan alat mesin pengguncang, dilaksanakan secara Faktorial 23 dalam Rancangan Acak Kelompok dengan ulangan tiga kali. Percobaan III masih menggunakan alat mesin pengguncang, dilaksanakan secara Faktorial 2x5~3 dalam Rancangan Acak Kelompok dan diulang tiga kali.
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Judul: Controlled Deterioration Test untuk Menguji Ketahanan Benih Kacang Hijau (Phaseolus radiatus L.) terhadap Kondisi Cekaman Kekeringan.
Abstrak: The research was conducted from February to April 2012 at the Seed Science and Technology Laboratory, Agronomy and Horticulture Department, Bogor Agricultural University. This research consist of three experiment. The first experiment was to determine the tolerance of five varieties of mungbean seeds to drought using PEG 6000 with different levels of osmotic pressure ( 0, -0.5, -1, -2, and -3 bar). The second experiment, determining the seed vigor of five mungbean seed lots using controlled deterioration test (CDT) with condition of temperature was 45°C, the seed moisture content were 20%, 22%, 24%, 26% and the deterioration time were 0 h, 24 h, 48h, 72h. The experimental design that used was randomized complete block design with two factor. The third experiment was to determine the relationship between the results of first experiment with the second experiment results. The third experiment also could show the effectiveness of the CDT method in testing the resistance of mungbean seeds against drought stress. Based on the observations of the variable results, it was obtained that the -1 bar PEG 6000 had capability of selecting seeds that were resistant and not resistant to drought. The result of the second experiment was CDT conditions that can be used to test for seed vigor were 20%/48 hours and 22%/24 hours. Correlation analysis between the variables in the -1 bar PEG 6000 with CDT on two conditions CDT (20%/48 hours and 22%/24 hours) showed significant correlation to the normal germination percent(r= 0.61 and 0.58) and speed germination(r= 0.62 and 0.59 ).
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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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