Judul: Peranan fotoperiode dan GA3 pada pembungaan dan produksi benih sejati bawang merah (allium cepa var aggregatum) (true shallot seed).
Abstrak: Effect of Photoperiod and GA3 on Flowering and True Shallot Seed Production (Allium cepa var aggregatum).
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Judul: Peran Vernalisasi dan Zat Pengatur Tumbuh dalam Peningkatan Pembungaan dan Produksi Biji Bawang Merah di Dataran Rendah dan Dataran Tinggi
Abstrak: The aim of this research was to observe the effect of vernalization and growth regulator in increasing flowers and true shallot seed yield in lowland and highland. This reaserch was conducted at lowland, Dramaga (250 masl, t=25- 260C, rainfall: 105-548 mm/month, RH:71-87%), and highland, Cipanas (1250 masl, t=20-210C, rainfall 204-479 mm/month, RH:80-87%). Shallot bulb 5-7 g was used as planting material. This research was conducted in two experiments. In the first experimental completely Randomized Block Design with two factors was used. The first factor was vernalisation, i.e.without vernalisation (V0) and vernalisation at 10 0C for thirty five days (V1) s, and the second factor was GA3 concentration, i.e. 0 ppm (G1), 100 ppm (G2), and 200 ppm (G3). In the second experiment, NAA at concentration of 0 (A1), 50 (A2), 100 (A3) and 200 ppm(A4) was used. Before planting, the bulbs was vernalized and submerged in 200 ppm GA3 solution for one hour. NAA is given by spraying to the plants aged 3 and 5 weeks after planting. The result showed that vernalization and GA3 affected flowering and TSS production. In lowland, combination of vernalization and 200 ppm GA3 increased flowering 233 times compared to the control and increased one-half times compared to the vernalization treatment without GA3 and in highland it increased four times compared to the control and one-half times compared to the vernalization without GA3. Combination of vernalization and 200 ppm GA3 resulted in the TSS production 3.93 g/m2 (39.3 kg/ha) in lowland and 4:41 g/m2 (44.1 kg/ha) in highland. Aplication of 200 ppm GA3 without vernalization and combination of vernalization until 200 ppm GA3 produced > 80% germination in lowland and highland. Aplication of 50 ppm NAA increase 24% flowering, 4.80 g or equal to 48.00 kg/ha TSS production with 87% germination. The result also show that vernalization can be substituted by GA3 aplication to enhance flowering and TSS production in highland however in lowland as well as high land area a combination of vernalization and GA3 was the best treatment.
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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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