• Nuclear Engineering and Technology
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• v.16 no.3
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• pp.169-179
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• 1984

An efficient procedure of evaluating the fuel cladding failures occurring in the normal operations of typical PWR's has been investigated through the analysis of fission product(FP) activities in the reactor coolant using an analytical model, FIPREL code. Performed by this code is an extensive study on the sensivities of FP activities to such physical parameters as enrichment, turnup, and operation temperature of failed fuel rod as well as the effective failure size quantified in terms of the magnitude of gap release coefficient. The results of study are generally in agreement with those by PROFIP method. In the presence of tramp uranium the portion of activities released from failed rod is separated by an iterative calculation based on the activity ratios of fission nuclides chemically more stable than iodines. Obtained are the linear power density and the number of failed rods, the effective failure size, and the mass of tramp uranium. The operation experiences of 4 cycles of Kori Unit 1 are analyzed and the results show that the model is highly reliable for the survey and evaluation of fuel rod conditions during reactor operations.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.59-69
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• 1998

To increase the solubility of quercetin, which is a practically insoluble flavonoid of Ginkgo biloba leaf, the effects of nonaqueous vehicles. Their cosolvents, water-sol uble polymers and modified cyclodextrins (CDs) were observed. Polyethylene glycols, diethyleneglycol monoethyl ether, and their cosolvents with water showed a good solvency toward quercetin. Also the aqueous solutions of povidone, copolyvidone and Cremophor RH 40 was effective in solubilizing quercetin. Complex formation of quercetin with ${\beta}$-cyclodextrin (${\beta}$-CD), dimethyl-${\beta}$-cyclodextiin (DMCD), 2-hydroxypropyl-${\beta}$-cyclodextrin (HPCD) and ${\beta}$-cyclodextrin sulfobutyl ether (SBCD) in water was investigated by solubility method at $37^{\circ}C$. The addition of CDs in water markedly increased the solubility of quercetin with increasing the concentration. AL type phase solubility diagrams were obtained with CDs studied. Solubilizaton efficiency by CDs was in the order of SBCD >> DMCD > HPCD > ${\beta}$-CD. The dissolution rates of quercetin from solid dispersions with copolyvidone, povidone and HPCD were much faster than those of drug alone and corresponding physical mixtures, and exceeded the equilibrium solubility (3.03${\pm}1.72{\mu}$g/ml). The permeation of quercetin through duodenal mucosa did not occur even in the presence of enhancers such as bile salts, but the permeation was observed when the mucus layer was scraped off. This was due to the fact that quercetin had a strong binding to mucin ($58.5{\mu}$g/mg mucin). However rutin was permeable to the duodenal mucosa. The addition of enhancer significantly increased the permeation of rutin in the order of sodium glycocholate.

• Journal of Soil and Groundwater Environment
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• v.25 no.2_spc
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• pp.86-100
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• 2020

Analyzing and monitoring environmental contaminants based on geophysical exploration techniques have become important and it is now widely applied to delineate spatial distribution geophysical characteristics in wide area. Among the techniques, induced polarization (IP) method, which measures polarization effects on electrical potential distribution, has drawn much attention as an effective tool for environmental monitoring since IP is sensitive to changes in biochemical reactions. However, various reactions stemming from the presence of multiple contaminants have greatly enhanced heterogeneity of polluted sites to result in highly variable electrical characteristics of the site. Those contaminants influence chemical and physical state of soil and groundwater to alter electrical double layer, which in turn influences polarization of the media. Since biochemical reactions between microbes and contaminants result in various IP effects, IP laboratory experiments were conducted to investigate IP responses of the contaminated soil samples under various conditions. Field IP surveys can delineate the spatial distribution of contamination, while providing additional information about electrical properties of a target medium, together with DC resistivity. Reviewing IP effects of contaminants as well as IP surveys can serve as a good starting point for the application of IP survey in site assessment for environmental remediation.

• Journal of dental hygiene science
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• v.21 no.4
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• pp.213-218
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• 2021

Background: The purpose of this study is to identify the gender sensitivity and gender role stereotypes of students in dental hygiene and to provide basic data to expand social awareness of equal gender sensitivity and gender role in dental hygiene and students by identifying the degree of correlation. Methods: The purpose of this study was to study dental hygiene students at colleges in Gyeonggi and Chungcheong areas. The survey was conducted from April 1 to April 30, 2021. The final sample was analyzed on 157 subjects. T-test and ANOVA analysis were performed to compare gender sensitivity and gender role stereotypes according to general characteristics. Equal variances were tested using the Levene statistic, and significant differences between groups were identified through Scheffe's post hoc analysis. Pearson's correlation analysis was performed to confirm the correlation between gender sensitivity and gender role stereotypes. Results: Gender sensitivity was 2.69 and gender role stereotypes were 1.83. Among the sub-areas of gender sensitivity, gender role openness was the highest at 2.86, and non-violence was the lowest at 2.50. As for gender role stereotypes, social stereotypes were the highest among sub-areas at 1.71. Among the general characteristics, there was a statistically significant difference in gender sensitivity according to the presence or absence of opposite sex friends (p=0.011). The gender identity openness of gender sensitivity and the physical sub-areas of gender role stereotypes showed the highest positive correlation(r=0.955). Among the sub-areas of gender sensitivity, gender role openness and domestic stereotypes showed the lowest negative correlation (r=-0.404) among the sub-areas of gender role stereotypes. Conclusion: Dental hygiene students should be able to critically analyze and solve problems of not only sexual violence but also gender discrimination and imbalance in social life. For this, environmental factors such as school education and professor guidance must be strengthened.

• Elastomers and Composites
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• v.56 no.4
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• pp.234-242
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• 2021

The demand for truck bus radial (TBR) tires with enhanced fuel efficiency and wear resistance have grown in recent years. In addition, as the issue of particulate matter and air pollution increases, efforts are being made to reduce the generation of particulate matter. In this study, the properties of epoxidized natural rubber (ENR) containing a silica-friendly functional group were evaluated by considering it as a base rubber and varying the silica ratio in this binary filler system. The results showed that the wear resistance of the NR/BR blend compound decreased as the silica ratio increased. In contrast, the ENR/BR blend compound exhibited an increase in wear resistance as the silica ratio was increased. In particular, the ENR-50/BR blend compound showed the best wear resistance due to the presence of several epoxide groups. Furthermore, we observed that for tan 𝛿 at 60℃, higher epoxide content resulted in the higher T_g of the rubber, indicating a higher tan 𝛿 at 60℃. On the other hand, it was confirmed that increasing the silica ratio decreased the value of tan 𝛿 at 60℃ in all compounds. In addition, we measured the amount of wear particulate matters generated from the compound wear. These measurements confirmed that in the binary filler system, regardless of the filler type, the quantity of the generated wear particulate matters as the filler-rubber interaction increased. In conclusion, the silica filled ENR/BR blend compound exhibited the lowest generation of wear particulate matters.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.97-97
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• 2019

Chaga mushroom and Cheonggukjang have been used in alternative medicine. In this study, we determined the anti-obesity effects of fermented Chaga-Cheonggukjang (FCC), an extract prepared by secondary fermentation of a mixture of Cheonggukjang and Chaga by Lactobacillus acidophilus on highfat diet (HFD)-induced mice. Male ICR mice were fed a normal diet or HFD in the presence or absence of 3% and 5% FCC (FCC3 and FCC5). After 3 months, the mice were sacrificed, and serum and tissue samples were examined. Body weight and epididymal fat pad (EFP) weight were significantly lowered in FCC3 and FCC5 groups compared to those in the HFD control group. FCC supplementation suppressed serum triglyceride (TG) and increased serum HDL levels. Serum GOT, GPT, leptin levels and hepatic COX-2 mRNA expression were significantly higher in the HFD groups, and these increases were significantly attenuated by FCC supplementation. FCC suppressed body weight and EFP weight gain, as well as inflammatory responses in the liver in HFD-fed mice. Thus, FCC supplementation may have protective effects for obesity-related disease.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.282-289
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• 2019

Objective: This study aimed to elucidate whether innovative sous vide treatment has a significant influence on the beef semitendinosus muscle as compared to common sous vide treatment and traditional cooking. Methods: The innovative sous vide treatments were cooked at $45^{\circ}C$ and $65^{\circ}C$ for 6 h (SV45-65), common sous vide treatment at $45^{\circ}C$ and $65^{\circ}C$ for 3 h (SV45 and SV65) and traditional cooking at $75^{\circ}C$ for 30 min (CON75). Water loss and cooking loss, as well as the physical properties (color and shear force) and chemical properties (protein and collagen solubility) of the treated meat, were investigated. Results: The results obtained indicated that the innovative sous vide with double thermal treatment (SV45-65) and cooked with air presence (CON75) resulted to lower $a^*$ and higher $b^*$ values, respectively. The water loss and cooking loss increased when temperature increased from $45^{\circ}C$ to $65^{\circ}C$, and lower water loss was recorded in SV45 and CON75. These samples presented higher water content and revealed strong correlation to protein solubility. Warner-Bratzler shear force (SF) analysis showed the marked interaction between cooking temperature and time. Sample cooked at a high temperature (CON75) and a long period (SV45-65) showed a significantly lower value of SF than sample SV65 (p<0.05). Interestingly, there was no difference in SF values between SV45-65 and CON75. Conclusion: The innovative sous vide treatment with double thermal effect appears an attractive cooking method as compared to common sous vide and traditional cooking method, as it has a potential for improving tenderness values of cooked beef semitendinosus muscle.

• Safety and Health at Work
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• v.10 no.1
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• pp.39-46
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• 2019

Background: As of now, the impact of low back pain (LBP) and its chronic state, chronic low back pain (CLBP), on mental health-related quality of life (HRQOL) has never been investigated among police officers. The present investigation aims at studying this relationship using a biopsychosocial model. Methods: Between May and October 2014, a Web-based cross-sectional study was conducted among Quebec police officers (Quebec, Canada). Mental HRQOL was measured using the role emotional (RE) and the mental health (MH) domains of the SF-12v2 Health Survey. The impact of CLBP on mental HRQOL (as opposed to acute/subacute LBP or no LBP) was studied with a multivariate linear regression model. Results: Of the 3,589 police officers who participated in the study, 1,013 (28.4%) reported CLBP. The mean age of respondents was $38.5{\pm}8.7years$, and 32.0% were females. The RE (44.1/100) and MH (49.0/100) mean scores of the CLBP group were comparable with the scores found in populations suffering from cancer or heart diseases. Compared to officers without LBP, the presence of CLBP was significantly associated with lower RE (${\beta}$: -0.068; p = 0.003) and MH (${\beta}$: -0.062; p = 0.002) scores. These relationships were not found in the acute/subacute LBP group. Conclusion: Our results underscore how frequent CLBP is among police officers and how burdensome it is. Considering the importance of good physical and mental health for this occupational population, police organizations should be aware of this issue and contribute to the efforts toward CLBP prevention and management in the workplace.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.4
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• pp.558-564
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• 2021

With the recent introduction of 5G, electromagnetic radiation sources are spreading throughout life, so it is necessary to establish a citizen-centered electromagnetic safety management system. In particular, the beamforming method of the 5G antenna increases the power density measurement of electromagnetic waves by more than 10 times when the wireless base station is installed, so it is unreasonable to determine the safety by physical measurement. Therefore, it is necessary to determine the presence or absence of electromagnetic wave safety in daily life through a predictive method by calculation through systematic model analysis. In this paper, in order to check the possibility of a 5G wireless base station using an electromagnetic wave numerical analysis tool as a way to solve this problem, we compared the measured values of the actual base stations and the predicted values through the prediction model to compare the reliability. A method of constructing a real-time base station electromagnetic wave strength prediction evaluation system combined with software was also proposed.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.1
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• pp.71-89
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• 2011

This study was carried out to get the exact information of the physical structures and humanistic landscapes to restore the prototype of the rear garden at Changkyung Palace. In this study, various drawings and historical documents such as Donggwoldo(東闕圖) and Joseonwangzosilok(朝鮮王朝實錄) were analysed. The innate characteristics and identity being inherent of rear garden of Changkyung Palace were tried to match the presence of acting to the specific places. The rear garden at Changkyung Palace was not only the secret garden for the rest of royal family and private life for king and queens but also used as public space for the various ceremonies. At the beginning of building, the rear garden at Changkyung Palace was built for the farming and sericulture of royal family. Since then, various events were held in this place such as archery, military drill and royal plowing and meeting with vassals which were political activities. At the rear garden of Changkyung Palace, Chundangdae(春塘臺), Kwanfunggak(觀豊閣) and Kwandukjung(觀德亭) were the base of specific activities. Also function, use, form, structure, planting and water elements were related organically in these areas.