Judul: Kajian Resistensi Lima Jenis Beras Varietas Lokal Terhadap Serangan Sitophilus zeamais Motsch.
Abstrak: The present study was conducted to evaluate resistance of local rice varieties i.e. Batutegi, Silugonggo, Ciherang, Mamberamo and Indragiri from the attack of post harvest pest Sitophilus zeamais Motsch. The research was divided into two stages, the preparation and the experiments. In the preparation, S. zeamais culture was cultured to get adult S. zeamais aged 7-14 days. In the first experiment, 10 adult insects aged 7-14 days were infested for 7 days. The adults were then removed and discarded. The infested grains were incubated to allow the emergence of progenies. The emerged progenies were counted daily till there was no emergence for 5 days consecutively. From this experiment, the parameters were number of progenies (Nt), development period (D), development index (ID), intrinsic rate of increase (Rm) and weekly multiplication capacity (λ). In the second experiment, 100 gram of rice was infested with 25 adults of S. zeamais for 5 weeks. From this experiment, the parameters used were percentage of weight loss and percentage of holed grain. Based on number of progenies (Nt), development index (ID), intrinsic rate of increase (Rm), weekly multiplication capacity (λ), percentage of weight loss and percentage of holed grain, showed that Silugonggo variety was the most resistance among other tested rice varieties. The values are 57, 12.5239, 0.3781, 1.4596, 10.94%, and 12.45% respectively.
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Judul: The relative resistance of brown rice and milled rice from five rice varieties of superior paddy  from the attack of rice weevil sitophilus oryzae (l.)
Abstrak: In the storage stage, weight loss of grains such as paddy and rice was caused by storage pests such asSitophilusoryzae. This reseacrh was conducted to evaluate theresistance of rice of the so called superior paddy from the attack of post harvest pest, Sitophilusoryzae. The five varieties evaluated were Sintanur, Mamberamo, Inpari 13, Inpari 10, and Ciherang. In the present study both brown rice and milled rice are subjected to S. oryzae infestation. In the first experiment,10 adults insect aged 7 – 15 days were infested to 200 grains for 7 days. At the end of the infestation period the insects are removed and discarded. The infested grains are incubated for 14 days before observation of the emergence of progenies was conducted. The emerged progenies were counted daily until there is no emergence for 5 days consecutively. The parameters from this experiment are total population (Nt), development period (D), development index (ID), interinsic rate of increase (Rm) and weekly multiplication capacity (λ). In the second experiment, 100 gram of rice of both type was infested with 25 adults of S.oryzae The result of the research show that variety affect significantly (p<0.01) all of the parameters in first experiment and second experiment. The experiment showed that inform of brown rice, Inpari 13 with the values of Nt, D, ID, Rm, λ, percentage of weight loss, and percentage of holed grains of 43.67, 28.11, 13.09, 0.34, 1.42, 4.05, and 9.05 respectively was among the most resistance variety. On the other hand, in the form of milled rice, Mamberamo with the values of Nt, D, ID, Rm, λ, percentage of weight loss, and percentage of holed grains of 22.0, 39.0, 7.95, 0.14, 1.15, 7.2, and 7.37 respectively was among the most resistance variety. However based on the statistical analysis, the parameters of Inpari 13 variety in the form of milled rice were not significantly different from that of parameters of Mamberamo variety.The Inpari 13 variety was found to be the most promising variety to be establish as “unggul variety” as between the five varieties tested it is among the most resistance to the attack of Sitophilus poryzae both in the form of brown rice as well as milled rice. for 4 weeks. The parameters used in this experiment are total population (Nt), percentage of weight loss and percentage of holed grain.Parameters in first experiment and second experiment were subjected to correlation test with each paddy varieties intrinsic factor i.e. water content, protein content, and fat content.
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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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