• Journal of Environmental Health Sciences
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• v.28 no.2
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• pp.131-139
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• 2002

초기생애단계의 일본송사리를 실험어류로 사용하여 TCDD와 PCB 126의 생물농축정도를 비교 측정하였고, TCDD와 PCB 126의 체외 배설에 대한 동태학적 특성을 비교 분석하였다. 생물농축실험은 초기생애단계의 새끼치어 및 어린 물고기에 TCDD와 PCB 126을 여러 농도로 물에 용해시켜 96시간 동안 정체된 상태로 폭로시킨 후 생물농축계수(BCF)와 지방-표준화한 생물농축계수(BCF$_{L}$)를 측정하였다. TCDD와 PCB 126의 일본송사리 초기생애단계의 새끼치어 및 어린 물고기에서 측정된 96-h BCF값 및 96-h BCF$_{L}$값은 폭로된 농도와 상관없이 비슷하게 나타나 반면, 생체크기가 클수록 그 값은 작게 나타났다. 일본송사리 새끼치어, 어린 물고기, 성어의 생체 내 총 지방함량은 각각 5.7, 4.2, 4.6%로 측정되었다. 체외배설 동태실험은 어린 물고기에 TCDD와 PCB 126을 3가지 농도롤 물에 용해시켜 96시간 동안 정체된 상태로 폭로시킨 후, flow-through장치로 공급되는 맑은 물로 옮겨 42일간 사양하면서 0, 7, 14, 21, 28, 42일에 생체 내 TCDD와 PCB 126 잔류량을 측정하여 분석하였다. 배설은 1차 반응속도론적으로 이루어졌으며 한 구획모형보다 두 구획모형이 더 적합한 것으로 분석되었다. 두 구획모형을 사용한 분석에서 TCDD와 PCB 126의 체외배설 반감기(t$\frac{1}{2}$) 및 배설속도상수($\beta$)는 각각 27.2일과 32.3일 및 0.025/d와 0.021/d로 측정되었다.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.219-224
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• 1996

노심설계에서 현재 사용되는 일체형 가연성 흡수봉인 Gd, ZrB$_2$ 그리고 Er의 한국표준형 원전 노심 설계에의 타당성을 노심 F$\Delta$H 제어, 저누출 장전모형 설계, 농축도/주기길이 그리고 주기말의 잔존 페널티 등의 측면에서 분석하였다. 초기노심의 경우는 영광 3호기 1주기 장전모형에 동일 연료집합체를 사용한 Gd/ZrB$_2$/Er의 경우와 ZrB$_2$/Er 최적장전모형에 동일 연료집합체를 사용한 경우에 대하여 분석하였다. 평형노심은 Gd/ZrB$_2$/Er 모두 동일한 장전모형을 사용한 18개월 주기길이의 노심에 대하여 동일한 농축도에서의 주기길이차이와 동등 주기길이를 내는데 필요한 농축도 요구량에 대하여 분석하였다. 초기노심 평형노심 모두 F$\Delta$H 제어에는 ZrB$_2$/Er가 Gd보다 유리하였으며, 저누출 장전모형의 설계에도 ZrB$_2$와 Er가 Gd보다 유리하였다. 평형노심에서 동일한 주기길이를 내는데 요구되는 농축도는 ZrB$_2$에 비하여 Er는 0.182 w/o Gd는 0.063 w/o 높게 나타났으며 동일 농축도를 사용할 경우 주기길이는 ZrB$_2$에 비하여 Gd는 165 MWD/MTU 그리고 Er은 575 MWD/MTU가 짧게 나타났다. 따라서, F$\Delta$H 제어와 저누출 장전모형은 설계에는 ZrB$_2$와 Er가 Gd보다 유리하였으나 Er의 경우 주기말에서의 잔존 페널티가 매우 크다는 단점이 있다.

• KSBB Journal
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• v.14 no.6
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• pp.655-660
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• 1999

Supercritical fractional extraction of DHA and EPA from the mixture of fatty acids composing the fish oil was performed. The compositions, extracted quantities, and cumulative extracted quantities of fatty acids in the extract and the raffinate were investigated according to the fractional steps. The temperature and pressure for the miximum concentration of DHA and EPA in the extract or the raffinate were 60$^{\circ}C$ and 101 bar respectively among the extraction conditions considered in this study. In this case, the weight percent of EPA in the extract was 50% and that of DHA in the raffinate was 40%. These values were two times higher than those in fish oil. THe same temperature and pressure were used to extract DHA and EPA from the mixture of fatty acids whose the initial weight percent of DHA was 34%. The weight percent of DHA in the raffinate after the fourth fractionation was 7-%. And the remaining weight of DHA in the raffinate was 80% of DHA initially loaded in the extraction vessel.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.458-463
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• 1998

고준위방사성페기물의 기준 처분시스템 (Reference Geological Disposal System)의 개념설정을 위하여 현재 국내 원전에서 발생되고 있거나 향후 2010까지 건설될 원전으로부터 발생될 모든 사용 후 핵연료연료의 특성(크기, 무게, 초기농축도, 연소도, 냉각기간 등)을 대표할 수 있는 기준 사용 후 핵연료를 선정하였다.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.10a
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• pp.312-312
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• 1998

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.226-231
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• 1996

A serum-pulp method was applied to concentrate peach pulp with aroma recovery. The serum portion was concentrated to five-fold at $50{\sim}55^{\circ}C$ and $30{\sim}50$ mmHg with aroma recovery. The concentrated serum, insoluble pulp and aroma fraction were recombined to make a two-fold concentrated peach pulp. The results of GC and GC/MS analysis for volatile compounds and sensory evaluation of concentrated peach pulp indicated that flavor quality was significantly improved by addition of aroma fractions. A 10% aroma recovery appeared to be appropriate for peach pulp.

• Membrane Journal
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• v.13 no.4
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• pp.268-282
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• 2003

Pervaporation-facilitated esterification with slow reaction regime was characterized by using a practical model based on non-perfect separation through membrane. A non-perfect separation in which the membrane is not perfectly permselective to water was applied to the model. Thus, membrane selectivity and membrane capability to remove water were included in the simulation model to explain how they influence the membrane-facilitated reaction process and improve the reactor performance. It was shown by simulation that in the reaction systems with non-perfect separation, reaction completion can hardly be achievable when any reactant at initial molar ratio=1 or the less abundant reactant at initial molar ratio>1 permeates through membrane, and the permeation of ester accelerates the forward reaction md increase reaction conversion at any instant through removal of product species like water. The volume change causes concentrating both reactants and products that affect the reaction with time in opposite ways; reactant-concentrating effect is dominant during the initial stage of reaction, increasing the reaction rate, and then concentrating product influences more reaction by decreasing the reaction rate.

• Journal of Navigation and Port Research
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• v.37 no.2
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• pp.129-135
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• 2013

Recently, waste water treatment system is developed in small and middle size to get more economic advantage. Freeze concentration system has high thermodynamic efficiency and low energy consumption, can re-use purified water and cold energy obtained from ice. This study was experimentally performed to investigate pollution containment in frozen layer by cooling wall temperature, air-bubble flow methods, initial ice-lining thickness of frozen layer in NaCl aqueous solution and the representative heavy metals, Pb and Cr aqueous solution. As the result, a decrease in the cooling wall temperature bring a higher growth rate of ice front and the more solute was involved in frozen layer. The method to inject directly air-bubble into ice-liquid interface through ring shape nozzle gave high purity of ice compared to indirect method. Ice lining in 5mm thickness resulted in frozen layer with higher purity than 1mm thickness.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.411-422
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• 2016

Recently, because the wet pool storage facilities of NPPs in Korea has become saturated, there has been much active R&D on an interim dry storage system using a transportation and storage cask. Generally, the shielding evaluation for the design of a spent fuel transportation and storage cask is performed by the design basis fuel, which selects the most conservative fuel among the fuels to be loaded into the cask. However, the loading of actual spent fuel into the transportation metal cask is not limited to the design basis fuel used in the shielding evaluation; the loading feasibility of actual spent fuel is determined by the shielding evaluation that considers the characteristics of the initial enrichment, the maximum burnup and the minimum cooling period. This study describes a shielding analysis method for determining the minimum cooling period of spent fuel that meets the domestic transportation standard of the dual purpose metal cask. In particular, the spent fuel of 3.0~4.5wt% initial enrichment, which has a large amount of release, was evaluated by segmented shielding calculations for efficient improvement of the results. The shielding evaluation revealed that about 81% of generated spent fuel from the domestic nuclear power plants until 2008 could be transported by the dual purpose metal cask. The results of this study will be helpful in establishing a technical basis for developing operating procedures for transportation of the dual purpose metal cask.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.51-52
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• 2006

This study was progressed on the freezing behavior of waste water in relation to freeze concentration method useful to waste water treatment system of small and middle size and which can re-use purified water. The object of this experiment is comparing a pollutant contain of the frozen layer and of an aqueous solution by cooling wall temperature, a flow field effect and a initial thickness of frozen layer.