• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.32-37
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• 2005

The soil properties of the royal tombs (managed by cultural properties administration) located in Seoul and suburban Gyonggi area were investigated to see the influence of the change in soil environment on the royal tomb s이I. To compare the soil chemical properties of four royal tombs soil of Changdeokgung, Jongmyo, Seooneung, and Dongguneung, pH, organic content, available phosphate, extractable calcium, extractable potassium, extractable magnesium, cation exchange capacity, degree of base saturation, and total nitrogen content were measured. The concentrations of Cd, Pb, and Cu measured as the degree of heavy metal contamination can be an indication of atmospheric pollution in the soil environment. To estimate the degree of soil compaction, soil hardness, pore space, porosity, bulk density, and soil atmosphere were analyzed. Through these studies, following conclusions were made: 1. The soil hardness and pore space which can be used as indexes of soil compaction, were worse in the soil of Seooneung than in those of Changdeokgung and Dongguneury. These phenomena seem to be the result of increase in visitors in Seooneung and Dongguneung better and soil management in Changdeokgung and Dongguneung. When three different regions of forest area, prohibited area, and soil compaction area in Seooneung soil were compared, the degree of compaction in the forest area was less than compaction area, indicating the need for the employment of soil resting period in the compaction area. 2. The pH measurements of all four royal tombs soil were higher in top soil than sub soil. The higher soil pH values in Jongmyo and Seooneung seem to result from the application of soil conditioner. In the case of Seooneung, the values for soil pH and organic content were higher in the forest area than those in compaction area. It is thought that active soil management was employed in the forest area through application of organic matters and soil conditioners. 3. The heavy metal contents from soil of Changdeokgung and Jongmyo were higher than that from soil of Dongguneung. Since Changdeokgung and Jongmyo are located inside Seoul, it is thought that the high level of heavy metal concentrations in these royal tomb soil is the result of accumulation of pollutants from the city.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.655-665
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• 2014

The effect of modified atmosphere packaging (MAP) on kohlrabi (Brassica olerace L. gongulodes group)'s quality and antioxidant molecule during storage was examined to determine the optimal film package for maintaining freshness. To extend shelf life, MAP was tested using PE $50{\mu}m$ and oriented polypropylene (OPP) films with oxygen transmission rate (OTR) at 3,000, 10,000, $15,000mL/m^2/day/atm$. The OPP film packaging with modified oxygen transmission rate showed a delay in a weight loss and extended storage period. The package with OTR 3000 attained the desired gas composition of $O_2$ 3.2-6.7 kPa and $CO_2$ 13.1-19.8 kPa, in storage at room temperature. Kohlrabi stored in this package showed the lowest weight loss and the highest visual quality. Deterioration and off-odor were developed more rapidly in PE $50{\mu}m$ towards the end of the storage at room temperature. However, there are no differences among OTR films in visual quality and off-odor until 60 days at cold storage. Vitamin C content of kohlrabi was reduced rapidly in OTR 15000 with high transmission rate and showed less loss in PE $50{\mu}m$ and OTR 3000 in both room temperatures and cold storage. Results revealed that an OPP film with OTR 3000 extended the shelf life of kohlrabi in storage with maintained quality and vitamin C.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.135-140
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• 2014

Pre-storage ultra-violet (UV) light treatment on fresh produce is known to inactivate the contaminated microorganisms, activate the defense system, and delay ripening extending the shelf life. As UV light emitting diode (LED) becomes available at a relatively low price, continuous or intermittent UV treatment during chilled storage is possible in a container or package. This study attempted an in situ UV LED treatment on fresh produce stored under a refrigerated container in order to see its potential in the fresh produce storage and further optimize its application conditions. The effect of in-container UV LED irradiation on the quality preservation of shredded carrots was investigated in the air and modified atmosphere (MA) conditions. Two sets of experiment with Escherichia coli inoculation and with natural microbial flora in the air (two 30 minute on-off cycles of 1 $diode/dm^2$ per day at a location above 2 cm) showed a clear and significant effect of the UV LED irradiation on the suppression of microbial growth: 280 nm was the most effective by maintaining a lower microbial count by at least 0.5 log (CFU/g) throughout the 6 day storage period. The carotenoids content of shredded carrots subjected to UV LED treatment at 365 and 405 nm in the air was higher than that of the control shredded carrots. In MA condition of $O_2$ of 1.2~4.3% and $CO_2$ of 8.4~10.6% being indifferent with LED wavelengths, 280 nm UV LED irradiation was also effective in inhibiting the microbial growth. While there was no observed difference in the carotenoids content between untreated and UV LED-treated shredded carrots in MA, UV LED irradiation at 365 and 405 nm was slightly better in DPPH radical scavenging activity. The use of UV LED in storage container or package seems to give the benefits of preserving the microbial and nutritional qualities of minimally processed fruits and vegetables.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.3
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• pp.60-70
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• 2019

Today, Deoksugung Doldam-gil, which is a well-known area in Seoul, has become a mixed place as many places reaching a critical age have been converted into parks. However, the previous research on the Deoksugung Doldam-gil was deficient in that the user, an essential variable, was not considered when assessing the place. Based on that, this study aims to analyze and interpret the perception of the places in Deoksugung Doldam-gil and to analyze factors to further enrich the place to visitors. According to the research, the representative idea of Deoksugung Doldam-gil is "the distance you want to go" and that has influencing factors, such as vehicle restrictions and the improvement of the walking environment. The analysis of classifying the variables that make up the perception of the place, physical environments, activities and meanings showed high awareness in, "streets of green (3.95)" and "stone walls of curves (3.88)." In the category of activities, "walking activities in the inner city (4.01)" and "love and romance (3.57)" were high. These results seem to reflect the spatial characteristics of the streets and the familiar image of the place were important. Five factors were extracted from the factor analysis to provide a more detailed understanding of the place perception, the correlation between each factor, and the place atmosphere of Deoksugung Doldam-gil. These factors confirmed a high correlation between 'green landscape' and 'historicity.' This can be attributed to the fact that the analysis reflects vital space, visual experience, and free walking conditions to be important, and these variables are present in urban parks. It also indicates the long-accumulated image and behavior near the site of Deoksugung Palace, including the historical and cultural heritage. It was confirmed that the factors related to the cognitive perception of Deoksugung Doldam-gil and the formation of the atmosphere of the place were strongly recognized. It found that there was a need to reflect the value and importance of 'green' in the future as culture or in the use of preservation and management related to heritage. This study presented a direction to be noted from the perspective of a user's place awareness, but considered only a fraction of the variables that affect the multidimensional sense of place and location recognition, and thus must be supplemented in the future.

• Food Science and Preservation
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• v.30 no.5
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• pp.822-832
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• 2023

This study investigates the effectiveness of CA (controlled atmosphere) containers in maintaining the freshness of exported melons. The melons were harvested on June 5, 2023, in the Yeongam area of Jeollanam-do, Korea. The CA container was loaded with melon samples packed in an export box. The temperature inside the container was set at 4℃, while the gas composition was set at 5% oxygen, 12% carbon dioxide, and 83% nintrogen. Following two weeks of simulated transportation, quality analysis was conducted at 10℃. The melons were inoculated with spore suspensions, and the decay rate was determined to investigate the effect of the gas composition inside the CA container on suppressing the occurrence of Penicillium oxalicum in melons. The results were compared with a Reefer container set at the same temperature. The samples transported in the CA container exhibited lower weight loss. The melon pulp softening, respiration rate, and ethylene production were slower using the CA container. Moreover, the decay rate during the distribution period in the CA container was lower than in the Reefer container. In contrast, the firmness of melons transported in the Reefer container decreased significantly (from 9.03N to 5.18N) immediately after transportation. The soluble solid content (SSC) of melons transported in the Reefer container also decreased rapidly. The results suggested that the CA container is the optimal export container for maintaining the freshness of melons.

• Journal of Embryo Transfer
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• v.24 no.3
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• pp.199-205
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• 2009

This study was carried out to investigate the effective genetic resources preservation system using the frozen boar semen. The porcine oocytes were matured for 44 hours in NCSU-23 medium with or without 10% Porcine Follicle Fluid (PFF), 0.5 ${\mu}g/ml$ porcine FSH, 0.5 ${\mu}g/ml$ equine LH, 1.0 ${\mu}g/ml$ 17 $\beta$-estradiol ($E_2$) and 10 ng/ml Epidermal Growth Factor (EGF) under mineral oil at $38.5^{\circ}C$ in humidified atmosphere of 5% $CO_2$ in air. After 44 h of culture, the oocytes were inseminated with frozen-thawed semen and fresh semen prepared with mTBM medium for 6 h. Later, set of 50 presumptive zygotes were transferred into 4-well dish (500 ${\mu}l$) of IVC medium. for embryos freezing, slow-freezing and vitrification methods were used as a cryopreservation. Differences among treatments were analyzed using General Linear Model Procedure by SAS Package (version 6.12) differences were considered significant when p<0.05. Following IVF and IVC, the rates of cleavage and blastocysts formation were significantly higher (p<0.05) in hormone supplemented group than that of hormone-free group (25.7 vs, 12.1). The development rates to cleavage and blastocysts were significantly higher in PZM-5 group than NCSU-23 group (60.3%, 46.6% vs 27.4%, 11.1%). Further improvement was achieved when PZM-5 was supplemented with FBS. Cleavage rates was significantly higher in fresh semen source group than frozen semen (66.7% vs 43.7%). However in blastocysts rates was similar two groups. Post-thaw survival rates of embryos were 1.2% and 2.2% in slow-frezing and vitrification groups, respectively. The results of our study suggest that it is still possible to improve the culture conditions and boar semen cryopreservation for enhance reproductive technology and animal genetic resources conservation.

• Journal of Korean society of Dental Hygiene
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• v.11 no.6
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• pp.951-959
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• 2011

Objectives : The author has studied the effects of behavior of preventive treatment on job satisfaction in dental hygienist. Methods : The hygienists who had worked from June 27th to August 1st in 2011 were explained about this research objectives and only the hygienists who agreed with this research participation were conducted a self-administered Questionnaire survey and the results were collected immediately. The collected questionnaire was 297, but the final 250 questionnaire were decided as a target except for the trustless ones. This analysis was extracted using SPSS(SPSS 12.0 for windows, SPSS Inc, Chicago, USA). Results : 1. Preventive treatment of dental hygienist was shown as this order - Educational needs 4.25, Importance 4.12, Usefulness 4.09, Perform 3.42. Job satisfaction was reached the moderate level. 2. Analysis of preventive treatment of hygienist was shown as this order - Basic brushing education 4.72 was ranked the highest, Taking patient history and Incremental dental health care 4.58 was held the second place. Dental caries activity tests 3.30 was shown the lowest figures. Response of preventive treatment conducting was like this order - Taking patient history 4.30, Dental prophylaxis 4.28, Basic brushing education 4.11, Incremental dental health care 4.04. Dental caries activity tests 2.05 was shown the lowest figures. 3. General characteristics in behavior of preventive treatment was resulted in this case that the respondents who have worked for less one year in current job than the ones who have worked for more than five years was shown such a low level, this was taken as a meaningful difference.(p=0.008) 4. It was shown that the higher fulfillment of preventive treatment(${\beta}$=0.340, p<0.001) and the greater earnings(${\beta}$=0.194, p=0.001) and usefulness of preventive treatment(${\beta}$=0.130, p=0.042), the higher job satisfaction. Conclusions : Considering these results, environment where the hygienists can concentrate on preventive treatment which is their proper job should be built up as soon as possible. And through this environment, the atmosphere where hygienists, as oral health professionals, can play a role to improve the oral health of the people by boosting job satisfaction should be created. Also It is thought that an institutional, actual improvement-changing the social awareness towards hygienists and dentists, the recognition of scope of the hygienists' work - should be established urgently.

• Korean Journal of Materials Research
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• v.24 no.9
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• pp.443-450
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• 2014

Amorphous (a-Si) films were epitaxially crystallized on a very thin large-grained poly-Si seed layer by a silicide-enhanced rapid thermal annealing (SERTA) process. The poly-Si seed layer contained a small amount of nickel silicide which can enhance crystallization of the upper layer of the a-Si film at lower temperature. A 5-nm thick poly-Si seed layer was then prepared by the crystallization of an a-Si film using the vapor-induced crystallization process in a $NiCl_2$ environment. After removing surface oxide on the seed layer, a 45-nm thick a-Si film was deposited on the poly-Si seed layer by hot-wire chemical vapor deposition at $200^{\circ}C$. The epitaxial crystallization of the top a-Si layer was performed by the rapid thermal annealing (RTA) process at $730^{\circ}C$ for 5 min in Ar as an ambient atmosphere. Considering the needle-like grains as well as the crystallization temperature of the top layer as produced by the SERTA process, it was thought that the top a-Si layer was epitaxially crystallized with the help of $NiSi_2$ precipitates that originated from the poly-Si seed layer. The crystallinity of the SERTA processed poly-Si thin films was better than the other crystallization process, due to the high-temperature RTA process. The Ni concentration in the poly-Si film fabricated by the SERTA process was reduced to $1{\times}10^{18}cm^{-3}$. The maximum field-effect mobility and substrate swing of the p-channel poly-Si thin-film transistors (TFTs) using the poly-Si film prepared by the SERTA process were $85cm^2/V{\cdot}s$ and 1.23 V/decade at $V_{ds}=-3V$, respectively. The off current was little increased under reverse bias from $1.0{\times}10^{-11}$ A. Our results showed that the SERTA process is a promising technology for high quality poly-Si film, which enables the fabrication of high mobility TFTs. In addition, it is expected that poly-Si TFTs with low leakage current can be fabricated with more precise experiments.

• Bulletin of the Korean Chemical Society
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• v.27 no.9
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• pp.1310-1314
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• 2006

Sulfur-substituted $LiMn_{0.9}Cr_{0.1}O_{2-x}S_x$ $(0\;\leq\;x\;\leq\;0.1)$ layered oxides have been prepared by solid state reaction under inert atmosphere. From powder X-ray diffraction analyses, all the present lithium manganates were found to be crystallized with monoclinic-layered structure. Electrochemical measurements clearly demonstrated that, in comparison with the pristine $LiMn_{0.9}Cr_{0.1}O_2$, the sulfur-substituted derivatives exhibit smaller discharge capacities for the entire cycle range but the recovery of discharge capacity after the initial several cycles becomes faster upon sulfur substitution. The effect of the sulfur substitution on the chemical bonding nature of $LiMn_{0.9}Cr_{0.1}O_{2-x}S_x$has been investigated using X-ray absorption spectroscopic (XAS) analyses at Mn and Cr K-edges. According to Mn K-edge XAS results, the trivalent oxidation state of manganese ion remains unchanged before and after the substitution whereas the local structure around manganese ions becomes more distorted with increasing the substitution rate of sulfur. On the other hand, the replacement of oxygen with sulfur has negligible influence on the local atomic arrangement around chromium ions, which is surely due to the high octahedral stabilization energy of $Cr^{+III} $ ions. Based on the present experimental findings, we have suggested that the decrease of discharge capacity upon sulfur substitution is ascribable to the enhanced structural distortion of $MnO_6$ octahedra and/or to the formation of covalent Li-S bonds, and the accompanying improvement of cyclability would be related to the depression of Mn migration and/or to the pillaring effect of larger sulfur anion.

• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.463-476
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• 2017

Climate change is considered as the greatest threat to our future and descendants. The Korean government has set a target for 2030 to reduce emission of greenhouse gases (GHGs) by 37% from the business-as-usual levels which are projected to reach 851 million metric tons of $CO_2eq$ (Carbon dioxide equivalent). In Korea, GHGs emission from agriculture account for almost 3.1% of the total of anthropogenic GHGs. The GHGs emitted from agricultural land are largely classified into three types: carbon dioxide ($CO_2$), methane ($CH_4$), and nitrous oxide ($N_2O$). In Korea, rice paddies are one of the largest agricultural $CH_4$ sources. In order to analyze domestic research trends related to $CH_4$ emission from rice paddies, 93 academic publications including peer reviewed journals, books, working papers, reports, etc., published from 1995 to September 2017, were critically reviewed. The results were classified according to the research purposes. $CH_4$ characteristics and assessment were found to account for approximately 65.9% of the research trends, development of $CH_4$ emission factors for 9.5%, $CH_4$ emission reduction technology for 14.8%, and $CH_4$ emission modeling for 6.3%, etc. A number of research related to $CH_4$ emission characteristics and assessment have been studied in recent years, whereas further study on $CH_4$ emission factors are required to determine an accurate country-specific GHG emission from rice paddies. Future research should be directed toward both studies for reducing the release of $CH_4$ from rice paddies to the atmosphere and the understanding of the major controlling factors affecting $CH_4$ emission.