• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.1
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• pp.18-30
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• 2017

The East Sea is almost entirely composed of sandy facies, and the facies type is the major factor influencing benthic polychaete communities. There have been few studies of the effects of environmental factors on benthic polychaetes in thermal discharge areas consisting of different sediment types. This study identified the spatial distribution patterns based on the species composition and distribution of benthic polychaete communities, and the environmental factors influencing benthic polychaetes near power plants were investigated. The polychaete communities in the Uljin, Hupo, and Gori coastal areas near the power plants in the East Sea were seasonally investigated from August 2006 to February 2013. As a result, 283 species were collected. The dominant species were Spiophanes bombyx, Magelona japonica, Lumbrineris longifolia, and Sternaspis scutata. Spiophanes bombyx was the dominant species at Uljin and Hupo, but M. japonica was the dominant species at Gori. Two dominant species from the coastal waters of the East Sea, Lumbrineris longifolia and M. japonica, were rare in the power plant water intake or drainage areas. Cluster analysis was performed to divide the study area into groups by the total organic carbon content, sediment grain size and facies patterns. This study suggests that the community structures of polychaetes are more affected by the total organic carbon, grain size of sediment and facies than by disturbance from thermal discharge, which only affected the polychaete community near power plant drainage areas.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.136-140
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• 1992

The purpose of this research is to develop the lithium secondary battery. This paper describes the preparation, electrochemical properties of nontstoichiometric(NS)-$V_6O_{13}$ and characteristics of Li/$V_6O_{13}$ secondary battery. NS-$V_6O_{13}$ was prepared by thermal decomposition of $NH_4VO_3$ under Ar stream of 140ml/min~180ml/min flow rate. And then, this NS-$V_6O_{13}$ was used for cathode active material. Cathode sheet was prepared by compressing the composite of NS-$V_6O_{13}$, acetylene black(A.B) and teflon emulsion (T.E). Characteristics of the test cell are summarised as follows. Oxidation capacity of NS-$V_6O_{13}$ was about 20% less than its reduction capacity. A part of NS-$V_6O_{13}$ cathode active material showed irreversible reaction in early charge-discharge cycle. This phenomena seems to be caused by irreversible incoporation/discoporation of lithium cation to/from NS-$V_6O_{13}$ host. Discharge characteristics curve of Li/$V_6O_{13}$ cell showed 4 potential plateaus. Charge-discharge capacity was declined in the beginning of cycling and slowly increased in company with increasing of coulombic efficiency. Energy density per weight of $V_6O_{13}$ cathode material was as high as 522Wh/kg~765Wh/kg.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.338-347
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• 2006

A small hydro-power plant using the seawater used as the cooling (circulated) water and discharged is under construction. The bigger size of the small hydro-power plant, the better in order to maximize the efficiency and the electric power. The optimal size, however, should be determined in the constraints of the channel un-disturbed range. The water level change should be checked in detail based on the hydraulic behaviour. In this study, the FLOW3D model, three-dimensional flow model, is setup using the flow measurement data in the effluent discharge channel and the flow pattern changes due to the small hydro-power plant construction are predicted by the model. The plant construction makes the increasing of the water level, and the water level in the upstream of the channel weir is increased 65 cm from 4.32 m to 4.97 m, in the condition of the design discharge $156m^3/s$ and the movable weir height of the hydro-power plant 3.8 m.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.3
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• pp.3-12
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• 2000

The field surveys and the measurements of seawater temperatures were conducted every month from 1997 to 1999, and the distributions of seawater temperature were simulated and reproduced by a three dimensional hydrodynamic numerical model over the southern waters of Cheju island. In order to estimate the marine environmental capacity for the reception of the heat loads of cooling water discharged from Hwasoon Thermal Power Plant(HTPP) in the study area, the simulations for predicting the situation of unfavorable environment in which marine organisms might not be satisfied with change in seawater temperature were peformed using a three dimensional hydrodynamic numerical model by controlling quantitatively the heat loads of cooling water from HTPP Currently, HTPP discharges cooling water of 35.9℃ into the sea as much as 112,800m³/day in summer. As the results of simulations, the more the heat loads from the power plant increase, the more increase the seawater temperatures around the water areas adjacent to the power plant. In case the heat loads of cooling water from HTPP become about 5 times as high as the present loads, seawater temperatures at near-shore waters adjacent to HTPP appear to be increased to the extent of 0.5℃ above the existing seawater temperature in summer. The marine environmental capacity for the reception of thermal discharge from HTPP is estimated to be about 530×10/sup 6/kcal/day which is equivalent to the increase of a factor of 2 in the temperature of cooling water without any change in the discharge rate of cooling water or which is equivalent to the increase of a factor of 4.6 in the discharge rate of cooling water without any change in the temperature of cooling water. Comparing the case of the increase in the discharge rate of cooling water with the case of the increase in the temperature of cooling water on the basis of the same heat loads of 530×10/sup 6/kal/day, the former case is expected to increase seawater temperature a little higher and to extend the area affected by heat loads a little broader.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.429-434
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• 1996

K-REM［1］, which is under development as a realistic evaluation model of large break LOCA, is applied to the analysis of cold leg guillotine break of Ulchin 3&4. Fuel parameters on which statistical analysis of their effects on the peak cladding temperature (PCT) are made and system parameters on which the concept of limiting value approach (LVA) are applied, are determined from the single parameter sensitivity study. 3 parameters of fuel gap conductance, fuel thermal conductivity and power peaking factor are selected as fuel related ones and 4 parameters of axial power shape, reactor power, decay heat and the gas pressure of safety injection tank (SIT) are selected as plant system related ones. Response surface of PCT is generated from the plant calculation results and on which Monte Carlo sampling is made to get plant application uncertainty which is statistically combined with code uncertainty to produce the 95th percentile PCT. From the break spectrum analysis, blowdown PCT of 1350.23 K and reflood PCT of 1195.56 K are obtained for break discharge coefficients of 0.8 and 0.5, respectively.

• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.379-387
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• 1999

During the past several decades, electricity generating plant increased with remarkable rapidity in Korea. Recently the increase has been much more rapid as the rate of industrialization has accelerated. Construction of nuclear power plants in coastal areas inevitably caused the perturbation of critical coastal habitats and thus influenced marine algal species composition. Particularly, an increase in the building of nuclear power plants led the amounts of heat discharged to increase exponentially. As far as the effects of cooling water and thermal discharges are concerned, benthic marine algae are likely to be vulnerable to a discharge. Heated effluents from nuclear power plants, with the temperature rises of 7~12$^{\circ}C$ under normal operating and design conditions, are discharged through the discharge canal and into natural water bodies. It is clear that the characteristic marine algal community is developed in the area affected by the thermal discharges; i.e. low species richness and low species diversity. Nevertheless, it is worthwhile to note that elevated temperatures exert differential effects depending on the algal populations. Benthic marine algae grown at the discharge canal can be regarded as warm tolerant species. 35 species (4 blue-green, 9 green, 8 brown and 14 red algae) of marine algae occurred more than 20eye frequency at discharge canal of three nuclear power plants in the east coast during 1992 ~ 1998 and thus can be categorized as warm tolerant species in Korea. To minimize the ecological impacts of waste heat on benthic marine algae, it is recommended that, in the future, nuclear power plants will have to employ some form of closed-cycle cooling for the condensers.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.329-337
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• 2006

A small hydro-power plant operated by cooling water discharged from the power plant is under construction. In this study, the flow characteristics of the effluent channel and the outfall coastal zone in which the facilities are constructed have been measured and analysed. The flow pattern is highly dependent on the effluent discharge and clearly classified as these typical areas; the upstream and downstream areas of the weir, and the outfall coastal zone. The discharge and the width of the channel in the upstream area of the weir are increased step by step, so the water level fluctuation is small. The flow overtopping the weir is rapidly changing and has highly vertical fluctuation patterns after hydraulic jump just below the weir. The flow pattern in the outfall zone is directed toward the seaward direction and the velocity is dominated by the tidal level fluctuation. The mean tidal range in this area is about 10% greater than that of the Tongyeong tidal gauging station and the wave effects are negligible because of the sheltering effects of this area.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.74-79
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• 2019

Specially designed test material was used for workpiece temperature measurement in the commercial reheating furnace and a linearized thermal model was applied for real time temperature prediction. The applied furnace is a walking beam type and specification of the workpiece is a STS302 which is 160mm in width, 160mm in height and 8100mm in length. Also six thermocouples were installed in width, height and length direction for temperature measurement. Ambient temperature in the furnace was raised to 1265 Celsius degrees and it took about 2.5 hours from loading to discharging of the workpiece. As a result of the experiment, temperature of the workpiece at discharge was 1257 Celsius degrees on the average in the range of 1256 to 1259 Celsius degrees, and predicted average temperature through the thermal model was 1251 Celsius degrees. Therefore, the deviation of the analysis and test results is about 6 degrees, which is within the range of 10 degrees required by the industry.

• Journal of Ocean Engineering and Technology
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• v.20 no.4 s.71
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• pp.50-57
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• 2006

The effect of discharges from the Seomjin River on the dispersion of thermal effluent from the Hadong Power Plant, located along the south coast of Korea, was investigatedusing intensive field observation and three-dimensinal Princeton Ocean Model simulations. A POM and observed CTD data was used to predict the mixing behaviour of the Summer freshet, during the July 2005 intensive observing period. The dispersal of the river discharge anomaly, associated with the Seomjin River plume, was seen to be highly responsive to tidal currents and river flows during the spring tide.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.1
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• pp.81-86
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• 2003

For the simultaneous removal of $SO_2$/NOx from an iron-ore sintering plant, industrial plasma experiments have been conducted with a flue gas flow rate of $5,000Nm^3/hr$. The maximum 40kW power using the magnetic pulse compression (MPC) system generates a peak value of 100-150kV pulse voltage with its risetime of 200nsec and full width at half maximum (FWHM) of 500nsec, and with a frequency <300Hz. The plasma reactor module adopts a wire-plate structure with a gap of 200-400mm ID between plates. Initial concentrations of $SO_2$ and NOx were around 100-150ppm, respectively in the presence of 15% $O_2$ and <10% $H_2O$. Various reaction parameters such as specific energy ($Whr/Nm^3$), $NH_3$ injection with corona discharge, flow rate and injection of hydrocarbons were investigated for $SO_2$/NOx removal characteristics. About 90/65% of $SO_2$/NOx were simultaneously removed with a specific energy of $3.0Whr/Nm^3$ when both $NH_3$ and hydrocarbons were injected. Practical implications that the pilot-scale plasma results provide are further discussed.