• Korean journal of applied entomology
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• v.14 no.4 s.25
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• pp.193-198
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• 1975

This experiment was performed to clarify the concentration of rice stripe virus in the rice Plant leaves by serological test, and was attempted to inspect the virus carrier among small brown planthopper by antibody-sensitized hemagglutination test. The antiserum was prepared by injecting intervenously into the external marginal vein of the ear of a rabbit. The precipitin titer of it was 1 : 16. The rough virus fluid prepared from diseased leaves was centrifuged at 10.000 rpm, and then the supernatant solution was treated at $55^{\circ}C$ for 5 minutes and the solution clarified by removing the agglutinate was used as the antigen solution. Antibody-sensitized erythrocyte solution was prepared from sheep erythrocytes sensitized by rice stripe virus with tannic acid, and its agglutination titer was 1 : 512. The virus concentrations in flag leaves or first leaves just below them showing different symptoms was high with progressing the severity of symptoms. And the concentrations of the virus in leaves of varieties of the rice plant showing same degree symptom were lower in suscetible varieties, Sadominori, Palgoeng, Mangyong and Nihonbare, than in the resistant one, Tongil, but in Yooshin which was known as the resistant, lower rather than in Tongil. The reacton of antibody-sensitized hemagglutination test to inspect the virus carrier, was so highly sensitive that this reaction was recognized as a method which is able to Identify the carrier accurately in short time.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.756-762
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• 2013

The economical feasibility was conducted to find the adequate method to treat the dredged sediments from agricultural reservoirs in a pilot project that had been operated to improve the quality of water and benthic environments by dredging of contaminated sediments. For benefit/cost (B/C) analysis, the net expenses were considered as the costs of project, and the benefits were calculated from the saving of waste-treatment cost through reuse of dredged sediment, the saving of construction cost of settling pond, and the values of retained water by dredging. Although the economic feasibility depended on the sites of operation, the average B/C value of the pilot project was estimated as 1.32, indicating this project is economically feasible. Depending on the treatment methods, the B/C values were in the order of the methods of coagulating sedimentation, machinery dewatering, stabilization through exothermic reaction, and soil improvement and stabilization. The machinery dewatering method is estimated as the most adequate one to treat the dredged sediments because of the minimum riskiness of secondary pollution, the recyclability, and its economic feasibility.

• Journal of Korea Water Resources Association
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• v.57 no.5
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• pp.347-357
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• 2024

Numerous prior studies have delineated the size distribution of noncohesive sediment in suspension, focusing on mean size and standard deviation. However, suspensions comprise a heterogeneous mixture of sediment particles of varying sizes. The transport dynamics of suspended sediment in turbulent flow are intimately tied to settling velocities calculated based on size and density. Consequently, understanding the grain size distribution becomes paramount in comprehending sediment transport phenomena for noncohesive sediment. This study aims to introduce a straightforward modeling approach for simulating the grain size distribution of suspended sediment amidst turbulence. Leveraging insights into the contrast between cohesive and noncohesive sediment, we have meticulously revised a stochastic flocculation model originally designed for cohesive sediment to aptly simulate the grain size distribution of noncohesive sediment in suspension. The efficacy of our approach is corroborated through a meticulous comparison between experimental data and the grain size distribution simulated by our newly proposed model. Through numerical simulations, we unveil that the modulation of grain size distribution of suspended sediment is contingent upon the sediment transport capacity of the carrier fluid. Hence, we deduce that our simplified approach to simulating the grain size distribution of suspended sediment, integrated with a sediment transport model, serves as a robust framework for elucidating the pivotal bulk properties of sediment transport.

• Journal of agricultural medicine and community health
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• v.13 no.1
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• pp.41-59
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• 1988

In many of the helminthic infections, diagnosis is accomplished by the demonstration of the eggs or, occasionally the adult worms or their parts. Diagnosis can be made by the identification of larval stage obtained from stool or surgically extracted materials too. However some kinds of parasitic disease can not be diagnosed by above mentioned procedure alone. Brain cysticercosis, ectopic paragonimiasis, Capillaria hepatica infection in liver is a good example. In such a case, immunologic method would be helpful for the decision of physician. In this paper, immunologic tools such as indirect hemagglutination test, indirect fluorescent antibody test, circumoval precipitation test, ELISA, western blot were applied for the diagnosis of Clonorchis sinenisis, Cysticercosis and C. hepatica a infection and their efficacy was evaluated. The results obtained were as follows ; 1) In the diagnosis of clonorchiasis, ELISA revealed sensitiveity of 83.3%, but cross reaction against antibody of Paragonimus westermani and Taenia species were observed. For the identification of cross reaction and species specific band of Ag-Ab reaction, western blot was applied. 59Kd relative molecular weight and 21Kd band were identified as a Clonorchis sinensis specific band. OD values of ELISA performed with sera of 18 months after praziquantel treatment decreased to half level compared to that of before treatment. Negative conversion rate of ELISA after 18 months of treatment was 60%. 2) In the diagnosis of cysticercosis, IFAT disclosed 95.8%(23/24) of sensitivity and reaction was most strongly occurred in inner membrane. ELISA revealed 90.0% (36/40) of sensitivity, but cross reaction was observed in both technique. In western blot, 91, 63 and 21Kd Mw bands were identified as a strongly positive band. Among them 63Kd band showed positive reaction against almost all sera of cysticercosis patient. 3) Circumoval precipitation, ELISA, IFAT, showed 85.0% of sensitivity in the diagnosis of C. hepatica infection in rat. The antigenic localities were inner membrane of sectioned egg antigen on the prectipitates around the mucoid plugs which were induced by circumoval precipitation reaction. Sera from rats infected with 2000eggs were collected periodically to observe the changing patterns of antibody titers by IFAT and ELISA, which showed that high titers were detected at weeks 3 and 5, then gradually declined through weeks 9until to negatively converted at weeks 13.