• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.3
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• pp.217-224
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• 2008

In deep geological disposal system, the integrity of a disposal canister having spent fuels is very important factor to assure the safety of the repository system. This disposal canister is one element of the engineered barriers to isolate and to delay the radioactivity release from human beings and the environment for a long time so that the toxicity does not affect the environment. The main requirement in designing the deep geological disposal system is to keep the buffer temperature below 100$^{\circ}C$ by the decay heat from the spent fuels in the canister in order to maintain the integrity of the buffer material. Also, the disposal canister can endure the hydraulic pressure in the depth of 500 m and the swelling pressure of the bentonite as a buffer. In this study, new concept of the disposal canister for the CANDU spent fuels which were considered to be disposed without any treatment was developed and the thermal stability and the structural integrity of the canister were analysed. The result of the thermal analysis showed that the temperature of the buffer was 88.9$^{\circ}C$ when 37 years have passed after emplacement of the canister and the spacings of the disposal tunnel and the deposition holes were 40 m and 3 m, respectively. In the case of structural analysis, the result showed that the safety factors of the normal and the extreme environment were 2.9 and 1.33, respectively. So, these results reveal that the canister meets the thermal and the structural requirements in the deep geological disposal system.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.269-277
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• 2010

Selenium is an essential micronutrient for normal body function and functions as an essential constituent of selenoproteins. This study was carried out to investigate effect of selenium on the formation of colonic aberrant crypt foci (ACF) and tumor formation in a mouse model. Five-week old ICR mice were acclimated for one week and fed different selenium diet (0.02, 0.1, and 0.5 ppm) for 12 weeks. Animals received three intraperitoneal injections of azoxymethane (10 mg/kg B.W. in saline for 3 weeks), followed by 2% dextran sodium sulfate in the drinking water for a week. There were four experimental groups, including a normal control group and three different selenium levels groups. After sacrifice, the total numbers of aberrant crypt (AC) and ACF were measured in the colonic mucosa after methylene blue staining. The number of tumors was noted for tumor incidence. Liver selenium concentration was measured using ICP-AES method. Gutathione peroxidase (GPx) activity was determined using a GPx assay kit in the liver and colon. TUNEL assay and proliferating cell nuclear antigen (PCNA) staining were performed to examine the cell apoptosis and cell proliferation, respectively. Immunohistochemistry of $\beta$-catenin was also performed on the mucous membrane tissue of colon. The activity of GPx in the liver and colon was decreased in the selenium-deficient diet group while it was increased in the selenium-overloaded diet group. Apoptotic positive cells were increased in the selenium-overloaded diet group but decreased in the selenium-deficient diet group. PCNA staining area was decreased in the selenium-overloaded diet group. In addition, the $\beta$-catenin protein level in the selenium-deficient diet group was increased but decreased in the selenium-overloaded diet group. These results indicate that dietary selenium might exert a modulating effect on colon cancer by inhibiting the development of ACF and colon tumor formation in this mouse model.

• Progress in Medical Physics
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• v.22 no.4
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• pp.190-197
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• 2011

Currently, the dose distribution calculation used by commercial treatment planning systems (TPSs) for high-dose rate (HDR) brachytherapy is derived from point and line source approximation method recommended by AAPM Task Group 43 (TG-43). However, the study of Monte Carlo (MC) simulation is required in order to assess the accuracy of dose calculation around three-dimensional Ir-192 source. In this study, geometry factor was calculated using segmented sources integration method by dividing microSelectron HDR Ir-192 source into smaller parts. The Monte Carlo code (MCNPX 2.5.0) was used to calculate the dose rate $\dot{D}(r,\theta)$ at a point ($r,\theta$) away from a HDR Ir-192 source in spherical water phantom with 30 cm diameter. Finally, anisotropy function and radial dose function were calculated from obtained results. The obtained geometry factor was compared with that calculated from line source approximation. Similarly, obtained anisotropy function and radial dose function were compared with those derived from MCPT results by Williamson. The geometry factor calculated from segmented sources integration method and line source approximation was within 0.2% for $r{\geq}0.5$ cm and 1.33% for r=0.1 cm, respectively. The relative-root mean square error (R-RMSE) of anisotropy function obtained by this study and Williamson was 2.33% for r=0.25 cm and within 1% for r>0.5 cm, respectively. The R-RMSE of radial dose function was 0.46% at radial distance from 0.1 to 14.0 cm. The geometry factor acquired from segmented sources integration method and line source approximation was in good agreement for $r{\geq}0.1$ cm. However, application of segmented sources integration method seems to be valid, since this method using three-dimensional Ir-192 source provides more realistic geometry factor. The anisotropy function and radial dose function estimated from MCNPX in this study and MCPT by Williamson are in good agreement within uncertainty of Monte Carlo codes except at radial distance of r=0.25 cm. It is expected that Monte Carlo code used in this study could be applied to other sources utilized for brachytherapy.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.257-258
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• 2004

The dose from radionuclides released from high-level radioactive waste (HLW) glasses as they corrode must be taken into account when assessing the performance of a disposal system. In the performance assessment (PA) calculations conducted for the proposed Yucca Mountain, Nevada, disposal system, the release of radionuclides is conservatively assumed to occur at the same rate the glass matrix dissolves. A simple model was developed to calculate the glass dissolution rate of HLW glasses in these PA calculations [1]. For the PA calculations that were conducted for Site Recommendation, it was necessary to identify ranges of parameter values that bounded the dissolution rates of the wide range of HLW glass compositions that will be disposed. The values and ranges of the model parameters for the pH and temperature dependencies were extracted from the results of SPFT, static leach tests, and Soxhlet tests available in the literature. Static leach tests were conducted with a range of glass compositions to measure values for the glass composition parameter. The glass dissolution rate depends on temperature, pH, and the compositions of the glass and solution, The dissolution rate is calculated using Eq. 1: $rate{\;}={\;}k_{o}10^{(ph){\eta})}{\cdot}e^{(-Ea/RT)}{\cdot}(1-Q/K){\;}+{\;}k_{long}$ where $k_{0},\;{\eta}$ and Eaare the parameters for glass composition, pH, $\eta$ and temperature dependence, respectively, and R is the gas constant. The term (1-Q/K) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_{0},\;{\eta}\;and\;E_{a}$ are the parameters for glass composition, pH, and temperature dependence, respectively, and R is the gas constant. The term (1-Q/C) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_0$, and Ea are determined under test conditions where the value of Q is maintained near zero, so that the value of the affinity term remains near 1. The dissolution rate under conditions in which the value of the affinity term is near 1 is referred to as the forward rate. This is the highest dissolution rate that can occur at a particular pH and temperature. The value of the parameter K is determined from experiments in which the value of the ion activity product approaches the value of K. This results in a decrease in the value of the affinity term and the dissolution rate. The highly dilute solutions required to measure the forward rate and extract values for $k_0$, $\eta$, and Ea can be maintained by conducting dynamic tests in which the test solution is removed from the reaction cell and replaced with fresh solution. In the single-pass flow-through (PFT) test method, this is done by continuously pumping the test solution through the reaction cell. Alternatively, static tests can be conducted with sufficient solution volume that the solution concentrations of dissolved glass components do not increase significantly during the test. Both the SPFT and static tests can ve conducted for a wide range of pH values and temperatures. Both static and SPFt tests have short-comings. the SPFT test requires analysis of several solutions (typically 6-10) at each of several flow rates to determine the glass dissolution rate at each pH and temperature. As will be shown, the rate measured in an SPFt test depends on the solution flow rate. The solutions in static tests will eventually become concentrated enough to affect the dissolution rate. In both the SPFt and static test methods. a compromise is required between the need to minimize the effects of dissolved components on the dissolution rate and the need to attain solution concentrations that are high enough to analyze. In the paper, we compare the results of static leach tests and SPFT tests conducted with simple 5-component glass to confirm the equivalence of SPFT tests and static tests conducted with pH buffer solutions. Tests were conducted over the range pH values that are most relevant for waste glass disssolution in a disposal system. The glass and temperature used in the tests were selected to allow direct comparison with SPFT tests conducted previously. The ability to measure parameter values with more than one test method and an understanding of how the rate measured in each test is affected by various test parameters provides added confidence to the measured values. The dissolution rate of a simple 5-component glass was measured at pH values of 6.2, 8.3, and 9.6 and $70^{\circ}C$ using static tests and single-pass flow-through (SPFT) tests. Similar rates were measured with the two methods. However, the measured rates are about 10X higher than the rates measured previously for a glass having the same composition using an SPFT test method. Differences are attributed to effects of the solution flow rate on the glass dissolution reate and how the specific surface area of crushed glass is estimated. This comparison indicates the need to standardize the SPFT test procedure.

• Women's Health Nursing
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• v.5 no.3
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• pp.389-409
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• 1999

This study was carried out to identify the differences between nursing needs and levels of satisfaction of postpartum women during the early postpartum period. The goal of this study was to obtain needed to develope the nursing quality for postpartum women. The subjects were 87 postpartum women who had vaginal delivery at 2 general hospital and 2 maternity hospital in the Ulsan City. The period for the data collection was from June 1 to 29, 1999. The data was gathered using an 98 items questionnaire which was a modified version of a questionnaire the developed by Y. J. Chun. Results found are as follows : 1. The general characteristics of the subjects : The majority of subjects were 25-29 yrs. (57.5%), high school and college graduates(96.5%), unemployed(75.9%), middle ranged economics(93.1%), had no religion(43.7%), male baby(52.9%), birth weight 3-3.5Kg(49.4%), wanted pregnancy(96.6%), no abortion history(50.6%), had antenatal care(89.7%), had prenatal education(32.2%), postnatal education(42.5%), intended breast feeding (46.0%), had resonable self confidence about self(20.7%), infant care(36.8%) and nuclear family pattern(82.3%). 2. The level of nursing needs of overall nursing care(3.93) and the levels of satisfaction(3.86) was relatively high. The nursing needs by category of nursing care, the highest need was in the emotional and psychological care(4.09), and the lowest need was in physical need(3.73). The satisfactions by category of nursing care, the highest satisfaction was in emotional and psychological care(4.11) and the lowest satisfaction was in education in self care(3.64). The significant differences between nursing needs and satisfactions were found on education in infant care(p=.005), and education in self care(p=.020). 3. Among items of physical care, 'accurate medication and treatment(4.21)', 'control of postpartum hemorrhage(4.13)', 'pain control and care of episiotomy wound (4.12)' and 'regular observation of postpartum conditions(4.09)' showed high nursing needs. 'Accurate medication and treatment(4.31)', 'regular observation of postpartum condition(4.24)', 'control of postpartum hemorrhage(4.22)' and 'pain control and care of episiotomy wound(4.12)' showed high satisfaction levels. 4. Among items of emotional and psychological care, 'personal treatment(4.32)', kind and faithful care(4.30)', 'detailed explanation on the treatment or nursing care(4.25)', 'adequate draping during the care and treatment(4.23)' and detailed explanation on a doubt(4.13)', showed high nursing needs, 'personal treatment(4.52)', 'kind and faithful care(4.45)', 'detailed explanation on a doubt(4.24)', 'detailed explanation on the treatment or nursing care(4.21)' and 'adequate draping during the care and treatment(4.18)' showed high satisfaction of nursing care. Difference between the level of nursing needs and satisfaction was significant except item of 'early contacts with their baby and breast feeding'. 5. Among items of environmental care, the highest level of need and satisfaction were on the items of 'neat bedding and clothes(4.05, 4.21)' and 'room cleansing or care of room(4.01, 4.28)'. Differences between the level of nursing care and satisfaction were 'room cleansing of care of room'. 6. Among items of educational needs on self care, 'sitz bath method(4.22)', 'high risk symptoms to immediate clinic visits(4.13)', 'the timing of tub bath(4.05)' and 'good secretion of breast milk(4.03)', showed high nursing needs, 'sitz bath method(4.22)' showed high satisfaction of nursing care. Differences between the level of nursing care and satisfaction were 'the timing of hair shampoo', 'the timing of tub bath', ' the method of pad change', 'postpartum exercise', 'good secretion of breast milk', 'maintenance of breast figure', 'contraindicated drugs in postpartum women', 'kegel exercise' and 'breast self examination'. 7. Among items of educational needs on infant care, 'immunization of infants(4.36)', 'symptoms of sickness to immediate clinic visits(4.28)'. 'safety and emergency care(4.28)', 'umbilical care(4.26)', 'feeding times and intervals(4.24)', 'normal growth and development of infant(4.24)' and 'infection control(4.22)', showed high level of nursing care, 'immunization of infants(4.21)', 'feeding times and intervals(4.17)', were high satisfaction items showed significant differences between the level of nursing care and satisfaction. 8. Relationship between nursing needs and levels of satisfaction among postpartum women were as follows : 1) Physical area : There were no significant differences in the level of nursing needs, but satisfaction levels were significantly different among 'working mothers', 'baby's weights', 'baby's sex', 'planning of feeding' and 'routes of receiving postpartum informations'. 2) Emotional and psychological area : The level of nursing needs were significantly different in the area of 'confidence in self care'. Satisfaction levels were significantly different among 'baby's sex', 'baby's weights', 'the confidence of infant care' and 'working mother'. 3) Environment area : There were on significant differences in the level of nursing needs, but satisfaction levels were significantly different among 'maternal age' and 'baby's weights'. 4) Education in self care : The level of nursing needs were significantly different among 'parity history' and 'type of family formation'. Satisfaction levels were significantly different among 'working mother', 'baby's sex', 'antenatal care', 'postpartum education', 'planning of feeding', 'routes of receiving postpartum informations'. 5) Education in infant care area : The level of nursing needs were significantly different among 'parity history'. Satisfaction levels were significantly different among 'baby's sex', 'receiving postpartum education or not' and 'working mother'.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.432-438
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• 1996

This study was carried out to prepare information for the establishment of countermeasures for an area contaminated with minewaste from an old zinc mine at Kahak-long in Kwangmyong. Minewaste and bottom sediments from the streams in this area were sampled and were analyzed for Cd, Cu, Pb, and Zn extracted with different solution. Total heavy metal contents in both minewaste and bottom sediments were fairly high. Cadmium and Zn contents in the minewaste and Cd, Cu, Pb, and Zn contents in the bottom sediments extracted with 0.1 N HCl showed a much higher level than those in the background level of paddy soils and in the soils around the other metal mines regardless of the distance from the mine. Sulfide/residue forms of Cd, Cu, Pb, and Zn covered the highest portions for the minewaste. For bottom sediments, sulfide/residue forms of Cu and Zn formed the highest portions, whereas the contents of both carbonate and sulfide/residue forms of Cd and Pb were significant. The lower the pH of the extracting solutions, the more heavy metals extracted from both minewaste and bottom sediments.

• Journal of the Korea Concrete Institute
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• v.25 no.3
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• pp.321-329
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• 2013

Recently, the medium-low level radioactive waste from nuclear power plant must be transported from temporary storage to the final repository. Medium-low level radioactive waste, which is composed mainly of the liquid ion exchange resin, has been consolidated with cementitious material in the plastic or iron container. Since cementitious material is brittle, it would generate cracks by impact load during transportation, signifying leakage of radioactive ray. In order to design the safety transporting equipment, there is a need to check the compressive strength of the current waste. However, because it is impossible to measure strength by direct method due to leakage of radioactive ray, we will estimate the strength indirectly by the dynamic modulus of elasticity. Therefore, it must be identified the relationship between of strength and dynamic modulus of elasticity. According to the waste acceptance criteria, the compressive strength of cement based solid is defined as more than 3.44 MPa (500 psi). Compressive strength of the present solid is likely to be significantly higher than this baseline because of continuous hydration of cement during long period. On this background, we have tried to produce the specimens of the 28 day's compressive strength of 3 to 30 MPa having the same material composition as the solid product for the medium-low level radioactive waste, and analyze the relationship between the strength and the dynamic modulus of elasticity. By controling the addition rates of AE agent, we made the mixture containing the ion exchange resin and showing the target compressive strength (3~30 MPa). The dynamic modulus of elasticity of this mixtures is 4.1~10.2 GPa, about 20 GPa lower in the equivalent compressive strength level than that of ordinary concrete, and increasing the discrepancy according to increase strength. The compressive strength and the dynamic modulus of elasticity show the liner relationship.

• Journal of the Korean Society of Radiology
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• v.14 no.3
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• pp.279-287
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• 2020

Recently, interest in radiation protection is increasing because of the occurrence of accidents related to exposure dose. So, the nuclear safety act provides to install the shields to avoid exceeding the dose limit. In particular, when the worker conducts the non-destructive testing (NDT) without the fixed shielding structure, we should monitor the access to the workplace based on a constant dose rate. However, when we apply for permits for NDT work in these work environments, the consideration factors to the estimation of the distance and exposure dose are not legally specified. Therefore, we developed the excel model that automatically calculates the distance, exposure dose, and cost if we input the factors. We applied the assumption data to this model. As a result of the application, the distance change rate was low when the thickness of the lead blanket and collimator is above 25 mm, 21.5 mm, respectively. However, we didn't consider the scattering and build-up factor. And, we assumed the shape of the lead blanket and collimator. Therefore, if we make up for these limitations and use the actual data, we expect that we can build a database on the distance and exposure dose.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1090-1098
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• 2016

The anti-inflammatory effects of ethanol extract from Grateloupia crispata (GCEE) were investigated in lipopolysaccharide (LPS)-stimulated murine macrophages. Anti-inflammatory effects were detected by enzyme-linked immunosorbent assay, Western blotting, and immunohistochemistry. There was no cytotoxic effect on proliferation of macrophages treated with GCEE compared to the control. GCEE significantly inhibited production of pro-inflammatory cytokines [interleukin (IL)-6, tumor necrosis $factor-{\alpha}$, and $IL-1{\beta}$] as well as nitric oxide in LPS-stimulated RAW 264.7 cells. In addition, GCEE suppressed expression of inducible nitric oxide synthase, cyclooxygenase-2, and nuclear $factor-{\kappa}B$ in a dose-dependent manner. GCEE significantly reduced activation of mitogen-activated protein kinases. In the in vivo test, evaluation of anti-inflammatory activity of GCEE was performed using croton oil-induced ear edema in ICR mice. Oral administration of 10 mg/kg to 250 mg/kg of GCEE significantly reduced ear edema in a dose-dependent manner compared to croton oil-induced mice. Moreover, GCEE reduced ear thickness and the number of mast cells compared to croton oil-induced mice in the histological analysis. These data suggest that GCEE could be used as a potential source for anti-inflammatory agents.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.4
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• pp.271-278
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• 2004

This paper shows our experiment is performed to understand the exposure tendency of $^{137}Cs$ according to the height of area and also, to supplement it by considering chemical characters of $^{137}Cs$ exposed to the soil. The samples we use for this experiment are from the general flat area of Yeonggwang county where it has NPPs, the high places of Keumjung & Bulgap mountains, and Naejan mountain where it is quite far from the NPPs. The data from this experiment show that the exposure of $^{137}Cs$ is not harmful since its range is around 252 Bq/kg-dry in most of sampled soils such as from the general flat area, the high place of Keumjung mountain where is 2 km away from the NPPs, the other high place of Bulgap mountain where is about 20 km away from the NPPs, and Naejan mountain where it is far from the NPPs. Not like the general flat area, however, the data show that the higher the area is the more $^{137}Cs$ is exposed. That is, at the top of mountains, the more $^{137}Cs$ is exposed compared to at the bottom area. It is almost $2{\~}6$ times more than the general flat area of Yeonggwang county where it has NPPs. The data also show that the spread of $^{137}Cs$ is deeply related to the geographical(the height of area, rainfall, etc..) factors and chemical factors of soils. As the geographical factors, there are far more chances to be exposed of $^{137}Cs$ at the high area of mountains through the air compared to at lower area and therefore, we can get more high-leveled readings of $^{137}Cs$ at the high area while it is low-leveled ones at the general flat area even if both of them have the same soil conditions. Regarding the chemical factors of soil, it is clarified that the CEC is the key factor. The CEC means the capability of sticking $^{137}Cs$ accumulated into the soil. Hence, the more CEC it has the more high-leveled readings of $^{137}Cs$ we get under the same geographical condition.