This study aims to test the feasibility of combined use of EFDC (Environmental Fluid Dynamics Code) hydrodynamic model and WASP7.3 (Water Quality Analysis Program) model to improve accuracy of water quality predictions of the Yongdam Lake, Korea. The orthogonal curvilinear grid system was used for EFDC model to represent riverine shape of the study area. Relationship between volume, surface and elevation results were checked to verify if the grid system represents morphology of the lake properly. Monthly average boundary water quality conditions were estimated using the monthly monitored water quality data from Korean Ministry of Environment DB system. Monthly tributary flow rates were back-routed using dam discharge data and allocated in proportion to each basin area as direct measurements were not available. The optimum number of grid system was determined to be 372 horizontal cells and 10 vertical layers of the site for 1 year simulation of hydrodynamics and water quality out of iterative trials. Monthly observed BOD, TN, TP and Chl-a concentrations inside the lake were used for calibration of WASP7.3 model. This study shows that EFDC and WASP can be used in series successfully to improve accuracy in water quality modeling. However, it was observed that the amount of data to develop inflow water quality and flow rate boundary conditions and water quality data inside lake for calibration were not enough for accurate modeling. It is suggested that object-oriented data collection systems would be necessary to ensure accuracy of EFDC-WASP model application and thus for efficient lake water quality management strategy development.
This research aims at examining the amount of scattered radiation generated during irradiation by adhering structures with different sizes of aluminum prominence and depression to the inside of a radiotherapy room. The irregular aluminum structures were stuck to the wall of a radiotherapy room, and the scattered radiation generated during irradiation was measured. The sizes of the aluminum prominence and depression were 1.5×1.5, 3×3, and 5×5 cm 2 with the width of 60 cm and the height of 60 cm. The distance between TLD and the wall of the radiotherapy room to measure scattered radiation was 310 cm, and the used radiation energy was 6 MV and 15 MV generated from a linear accelerator. The research result showed that the irradiation amount at 6 MV was 100, and at 300 cGy the scattered radiation decreased by the installation of the structure with aluminum prominence and depression, but at 200 cGy, only the scattered radiation of the uneven structure of 5×5 cm 2 decreased. At 15 MV, the irradiation amount was 200 cGy, and at 300 cGy, the scattered radiation was reduced when the rugged aluminum structure was set up, but at 100 cGy, similar result values were produced regardless of the uneven structure. Consequently, installation of an additional structure with aluminum prominence and depression in the present interior structure can decreased the stochastic effect of the scattered radiation generated from the wall of a radiotherapy room and patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.