[en] The Ulchin 364 nuclear units, which are the lead units of the standard design in Korea and scheduled for operation in 1998 and 1999, will lead to self-reliance of the Korean nuclear industry. The authors discuss the background, design, plant safety, and future prospects of the standardized plant design

[en] Our previous studies showed that the promyelocytic leukemia, PML, protein functions as a cellular and growth suppressor. Transient expression of PML was also found to repress the activity of the epidermal growth factor receptor gene promoter. In this study we have examined the effects of PML on A431 cells, which express a high level of + protein. The PML gene was introduced into the cells using the adenovirus-mediated gene transfer system. Western blot analysis on the extracts from the cells expressing PML showed a significant repression in the expression of the epidermal growth factor receptor protein. The cells were examined for growth and DNA synthesis. The data showed a marked reduction in both growth and DNA synthesis rate in the cells expressing PML compared with the control cells. Furthermore, in comparison with the controls, the cells expressing PML were found to be more in G1 phase, fewer in S and about the same number in the G2/M phase. This data clearly demonstrated that the repression of epidermal growth factor receptor expression in A 431 cells by PML was associated with inhibition of cell growth and alteration of the cell cycle distribution, suggesting a novel mechanism for the known growth inhibitory effects of PML

[en] The dynamic behaviour of continuous AUC (Ammonium Uranyl Carbonate) precipitation in a circulation mixing MSMPR (Mixed Suspension Mixed Product Removal) crystallizer was studied. Simulating the dynamic crystallization models by the method of moment transformation, the growth and nucleation models of AUC particles were proposed and those reaction constants were determined experimentally. Particularly, nucleation model was in good agreement with experimental result when secondary nucleation caused by mixing energy or else was considered and crystal size distribution of transient state was also calculated semianalytically. For the future practical operation, the properties of the products were investigated by changing the mean residence time which is one of the operating variables

[en] Graphical Abstract: Display Omitted -- Highlights: • Higher short-circuit photo current density can be obtained using TiO_2 compact layers. • Investigation of the effects of AZO annealing temperature on cell efficiency. • Comparison of TiO_2 porous sintered at different temperatures. • Grey Taguchi analysis offers an efficient way to increase experimental efficiency. -- Abstract: This work presents the optimal deposition parameters for TiO_2 compact layers and low cost Al_2O_3-doped zinc oxide (ZnO:Al_2O_3 = 97wt%:3wt%, AZO) transparent conducting films, using radio frequency (rf) magnetron sputtering to improve the performance of dye-sensitized solar cells (DSSCs). The structure, morphology and photocatalytic performance of the TiO_2 compact layer (blocking layer) and the effect of AZO films on the DSSC’s conversion efficiency are studied. The grey-based Taguchi method is used to determine the processing parameters for the deposition of the TiO_2 compact layer (rf power, substrate temperature, O_2/(Ar+O_2) flow ratios and sputtering pressure) by considering multiple performance characteristics. These films are analyzed using scanning electron microscopy, X-ray diffraction and UV-vis-NIR spectroscopy. The results show that the TiO_2 compact layer prevents charge recombination, which results in a greater short-circuit photocurrent density. The intensity of the X-ray peaks for the AZO films also increases with annealing treatment, which gives improved crystallinity for the films. This study further determines the effect of the AZO annealing temperature on cell conversion efficiency. If the AZO is annealed at 500 °C and the TiO_2 porous layer is sintered at 450 °C with a holding time of 30 min, the experimental results demonstrate that the efficiency of the DSSCs with TiO_2 compact layer are increased from 2.24 to 5.69%

[en] KSNP - the Korean Standard Nuclear Power Plant - represents the culmination of Korea's efforts to achieve self-reliance in nuclear technology. It is a 1000 MWe class, two loop Pressurized Water Reactor and is intended to help the country secure a stable electric power supply for the future. Its designers also hope that it will enable the nuclear industry to continue to expand with a consensus of support from the general public. The lead KSNP units, Ulchin 3 and 4, are currently under construction. (Author)

[en] An experimental study on the air entrainment phenomena during mid-loop operation has been performed for Ulchin 3 and 4 nuclear power plant (UCN 3 and 4). The UCN 3 and 4 is the standard Combustion Engineering (CE) System 80, two-loop, 2825 MWt pressurized water reactor which is currently under construction in Korea. This study was undertaken by Korea Atomic Energy Research Institute to provide a basis for modification of CE system 80 design which has relatively small mid-loop operating range, and to investigate the impact of the air entrainment on the shutdown cooling pump. A 1/4 scale model test was performed for two shutdown cooling suction nozzle configurations, with and without bellmouth entry, to obtain data relative to air ingestion and vortex formation at the shutdown cooling suction nozzle during mid-loop operation. The test model size was determined based on Froude number corresponding to that which occurs in plants by considering that the Weber number and Reynolds number are large enough to ensure that liquid surface tension and viscosity would not significantly affect the vortex formation. An empirical correlation between the flow rate and the critical submergence was obtained with respect to the Froude number. The impact of the air entrainment of the pump was also investigated to select parameters for plant operators to monitor the onset of air entrainment into shutdown cooling system (SCS). Effects of the bellmouth entry on the critical submergence were also investigated. (author)

[en] Rheological properties of gamma-irradiated arrowroot starch was examined to utilize as fundamental research data for processing. Irradiated arrowroot starch solutions (3, 4, 5, 6%) were gelatinized at 95℃ for 40 min, and its flow properties measured using rheometer at 30℃ and 10 to 200 rpm rotation rate. Rheological parameters of irradiated arrowroot starch gelatinized solution were calculated using Herschel-Bulkley equation

[en] Effects of α-adrenergic antagonists have been studied during environmental heating but not during microwave-induced heating. Tolazoline may exert some of its effects via α-adrenergic blockade. In the present study, ketamine-anesthetized Sprague-Dawley rats were exposed to 2450-MHz microwaves at an average power density of 60 mW/cm² (whole-body specific absorption rate of approximately 14 W/kg) until lethal temperatures were attained. The effects of tolazoline (10 mg/kg body weight) on physiological responses (including changes in body temperature, heart rate, blood pressure, and respiratory rate) were examined. Survival time was significantly shorter in the tolazoline group than in saline-treated animals. In general, heart rate and blood pressure responses were similar to those that occur during environmental heat stress. Heart rate, however, was significantly elevated in animals that received tolazoline, both before and during terminal microwave exposure. It is possible that changes associated with the elevated heart rate (e.g., less cardiac filling) in tolazoline-treated animals resulted in greater susceptibility to microwave-induced heating and the lower survival time. 47 refs., 3 figs., 2 tabs

No abstract available

[en] A numerical result of the flow and mixing characteristics is presented for the flow field created by water injected into a cylindrical tank with an initially stationary fluid. The flow is relevant to the operation of the chemical addition system in the chemical and volume control system (CVCS) of nuclear power plants. This study was undertaken to provide a basis for modification of the previous design which gave a number of difficulties in installation and operation of the chemical addition system because it needs a special reciprocating pump with a high actual head. For the tank of length-to-diameter ratios (L/D) of 1, 2 and 3, each with and without a baffle inside, calculation results were obtained by solving the unsteady laminar two-dimensional elliptic forms of governing equations for the mass, momentum and species concentration. Finite-difference method was used to obtain discretization equations, and the SIMPLER solution algorithm was employed for the calculation procedure. Results showed that the baffle was very effective in enhancing the mixing in the tank, and that a baffle should be installed near the tank entrance in order to inject chemicals into the reactor coolant system (RCS) within the operating time required. (orig.)