• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.255-264
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• 2019

In this study, we conducted the hot box tests to compare the changes in thermal insulation for the four types of multi-layer thermal screens by the used period after collecting them from the greenhouses in the field when they were replaced at the end of their usage. The main materials for these four types of multi-layer thermal screens were matt georgette, non-woven fabrics, polyethylene (PE) foam, chemical cotton, etc. These materials were differently combined for each multi-layer thermal screen. We built specimens ($70{\times}70cm$) for each of these multi-layer thermal screens and measured the temperature descending rate, heat transmission coefficient, and thermal resistance for each specimen through the hot box tests. With regard to the material combinations of multi-layer thermal screens, thermal insulation can be increased by applying a multi-layered PE foam. However, it is considered that the multi-layered PE foam significantly less contributes to heat-retaining than chemical wool that forms an air-insulating layer inside multi-layer thermal screens. For the suitable heat-retaining performance of multi-layer thermal screens, basically, materials with the function of forming an air-insulating layer such as chemical cotton should be contained in multi-layer thermal screens. The temperature descending rate, heat transmission coefficient, and thermal resistance of multi-layer thermal screens were appropriately measured through the hot box tests designed in this study. However, in this study, we took into consideration only the four kinds of multi-layer thermal screens due to difficulties in collecting used multi-layer thermal screens. This is the results obtained with relatively few examples and it is the limit of this study. In the future, more cases should be investigated and supplemented through related research.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.243-254
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• 2019

With the recent accelerated policy-making and interests in new renewable energy, plans to develop and supply the new renewable energy have been devised across multiple regions in Korea. Solar energy, in particular, is being applied to small-scale power supply in provincial areas, as solar cells are used to convert solar energy into electric energy to produce electric power. Nonetheless, in the case of solar power plants, the need for a large stretch of land and considerable sum of financial support implies that the planning step should take into consideration the most suitable meteorological and geographical factors. In this study, the proxy variables of meteorological and geographical factors associated with solar energy were considered in analyzing the vulnerable areas regarding the photovoltaic power generation facility across the nation. GIS was used in the spatial analysis to develop a map for assessing the optimal location for photovoltaic power generation facility. The final vulnerability map developed in this study did not reveal any areas that exhibit vulnerability level 5 (very high) or 1 (very low). Jeollanam-do showed the largest value of vulnerability level 4 (high), while a large value of vulnerability level 3 (moderate) was shown by several administrative districts including Gwangju metropolitan city, Jeollabuk-do, Chungcheongbuk-do, and Gangwon-do. A value of vulnerability level 2 (low) was shown by the metropolitan cities including Daegu, Ulsan, and Incheon. When the 30 currently operating solar power plants were compared and reviewed, most were found to be in an area of vulnerability level 2 or 3, indicating that the locations were relatively suitable for solar energy. However, the limited data quantity for solar power plants, which is the limitation of this study, prevents the accuracy of the findings to be clearly established. Nevertheless, the significance of this study lies in that an attempt has been made to assess the vulnerability map for photovoltaic power generation facility targeting various regions across the nation, through the use of the GIS-based spatial analysis technique that takes into account the diverse meteorological and geographical factors. Furthermore, by presenting the data obtained for all regions across the nation, the findings of this study are likely to prove useful as the basic data in fields related to the photovoltaic power generation.

• Korean Journal of Heritage: History & Science
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• v.50 no.1
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• pp.18-41
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• 2017

The Gangjin WolnamSaji(月南寺址) is a small site where three-story pagodas and a destroyed tombstone remained. In 1973, it was discovered that the destroyed tombstone was that of the second master of Susunsa, Hye shim(慧諶), who had a special relationship with the military regime in Goryeo, and it once again attracted attention as a result of the recent excavation of the Rooftile of Yeonhwamun(蓮花文). In particular, the Windchime excavated in 2012 is a large-sized one group with a length of 23cm, and a relatively large Sanskrit character was decorated on four sides of the body. In addition, it was also confirmed in preservation process that the word 'gaecheon(盖天)' was engraved. The Sanskrit characters(梵字) om( , oṃ), a( , a), hum( , hūṃ), brum( , bhrūṃ) were decorated on the body of the Wind-chime excavated in WolnamSaji. Om( , oṃ), a( , a), hum( , hūṃ) are known as the Sammiljineon(三密眞言) and brum( , bhrūṃ) has the meaning of having the highest honor. In addition, the Sammiljineon(三密眞言) allows us to understand the truth by responding to the principle of universe, which is the Vairocana Buddha(毘盧遮那佛), and brum( , bhrūṃ) has the meaning of unity. In the end, the meaning of the Sanskrit decorating the four sides of the Wind-chime, of WolnamSaji(月南寺址), can be interpreted as the expression of the Buddha's doctrine, or the willingness to be combined with Buddha, the highest existence in itself. It is possible that the word 'gaecheon(盖天)' carved on the body can be regarded as the name of the master craftsman related to the making of the Wind-chime, but it is unlikely that it is the name of the master craftsman, considering that it is a place where the location is not easily seen. If so, you can think of the original function that the Wind-chime has. In other words, it can be interpreted symbolically and implicitly that the wish of the sound of the airwaves symbolized by the words of the Buddha covers the sky and spreads all over the place. It is thought that the Wind-chime excavated in WolnamSaji(月南寺址) was made in the mid to late 13th century considering the comparisons with another wind-chime excavated from the temple site, the historical situation in the late Goryeo, the publication date of the scriptures(經典) of Esoteric Buddhism(密敎).

• Journal of Life Science
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• v.29 no.6
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• pp.679-687
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• 2019

Litsea populifolia, a plant species of the Lauraceae family, is widely distributed in the tropical and subtropical areas of Asia. The phylogenetic relationships and botanical characteristics of L. populifolia have been reported; however, its anti-oxidative and anti-cancer activities remain unclear. In this study, we evaluated the anti-oxidative and anti-cancer effects of ethanol extracts of L. populifolia (EELP) together with the molecular mechanism of its anti-cancer activity in human lung adenocarcinoma A549 cells. EELP showed significant anti-oxidative effects with a 50% inhibitory concentration at $11.71{\mu}g/ml$, which was measured by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. EELP exhibited cytotoxic activity and induced cell cycle arrest at the G1 phase in A549 cells in a dose-dependent manner, whereas EELP did not have the cytotoxic effect on the normal human lung cell line IMR90. Treatment with EELP also resulted in a decreased expression of G1/S transition-related molecules-including cyclin-dependent kinase (CDK) 2, CDK6, cyclin D1, and cyclin E-both for the transcription and translation levels. EELP-induced G1 arrest was associated with the phosphorylation of checkpoint kinase 2 (CHK2), p53, cell division cycle 25 homolog A (CDC25A), and the reduction of CDC25A expression in A549 cells. Collectively, these results suggest that EELP may exert an anti-cancer effect by cell cycle arrest at the G1 phase through both p53-dependent and p53-independent (ATM/CHK2/CDC25A/CDK2) pathways in A549 cells.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.2
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• pp.105-113
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• 2019

A two-year study was conducted from 2017 to 2018 by the establishment of a test field at Chungju-si and Cheongyang-gun. Plant height, number of leaves, insects and diseases, and fresh and dry matter yields for corn hybrid('Kwangpyeongok') were investigated. Daily average, maximum, and minimum temperature, monthly average temperature, daily precipitation, and sunshine duration during the growing season were investigated. We selected climate-critical factors to corn productivity and conducted an evaluation of vulnerability to climate change from 1999 to 2018 for both regions. In 2018, the dry matter yield of forage corn was 6,475 and 7,511 kg/ha in Chungju and Cheongyang, respectively, which was half of that in 2017. The high temperature and drought phenomenon in the 2018 summer caused the corn yield to be low. As well as temperature, precipitation is an important climatic factor in corn production. As a result of climate impact vulnerability assessment, the vulnerability has increased recently compared to the past. It is anticipated that if the high temperature phenomenon and drought caused by climate change continues, a damage in corn production will occur.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.2
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• pp.199-208
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• 2019

This study reports water-resistant oil-in-water (O/W) emulsion-based sunscreening formulations prepared using a poly(ethylene glycol)-poly(${\varepsilon}$-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG) triblock polymeric surfactant. As a result of a variety of outdoor recreational activities such as swimming and hiking, consumer needs for development of advanced water-resistant sunscreen formulations are increasing. Water-resistant sunscreens are mostly based on water-in-oil (W/O) emulsions, because they should not be wiped off by water or sweat. However, the W/O emulsion formulations have a disadvantage in that the feeling of use is oily and difficult to remove. On the other hand, the O/W emulsion formulations are excellent in achieving the better skin feel as well as the easier removal. However, it is difficult to provide the O/W emulsion formulations with the water-repelling performance, since re-emulsification likely occurs upon getting touch with water. To solve this problem, this study proposes a O/W emulsion-based sunscreen formulation, a triblock polymeric surfactant having relatively high interfacial tension HLB value (~ 10). This allows the sunscreen formulations to exhibit the improved water repellence function by preventing their re-emulsification. The sunscreen formation system prepared in this study would be useful for diversification of functional sunscreen products, taking advantages of its excellent emulsion stability, UV protection performance, long lasting water-resistant function and selective cleansing effect with only foam cleanser.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.2
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• pp.152-158
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• 2019

This study was conducted to develop and prove the effects of an agronomical pest control measure on ginseng cultivated by direct seeding in paddy field, and the results obtained are as follows. Decomposition of ginseng in field during overwintering was due to gray mold rot caused by Botrytis cinerea, which occurred in October or November of 2016 and intensified in February and March the following year. The occurrence rate of gray mold rot based on shading materials was 6.5%, 16.8%, and 29.5% with light-proof paper, PE shade net, and rice straw shade, respectively. The initial infection occurred in the leaves prior to wintering and secondary infection occurred in the stems after wintering. The rate of screrotium formation by gray mold in the above-ground parts of ginseng tended to increase: 26.6% on October 20, 33.7% in November 20, and 41.8% on December 20. The force needed to remove the leaves and stems from withered ginseng was 0.2, 0.94, 2.5, and 5 kg for 1-, 2-, 3-, and 4- and 5-year holds; the force required was 1 kg after wintering, making it relatively easy to remove. The disease incidence rate after the removal of leaves and stems was 2.5%, 1.2%, and 2.2% in 4-, 5-, and 6-year-old plants, respectively, and a disease high incidence rate of 8.8%, 13.0%, and 18.2%, respectively, was seen when the leaves and stems were not removed. In both transplanting and direct seeding, the miss-planted rate decreased and the germination rate increased when shading material was removed and the surface of ridge was covered with soil or vinyl.

• Journal of The Korean Astronomical Society
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• v.52 no.1
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• pp.11-21
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• 2019

Intensive Monitoring Survey of Nearby Galaxies (IMSNG) is a high cadence observation program monitoring nearby galaxies with high probabilities of hosting supernovae (SNe). IMSNG aims to constrain the SN explosion mechanism by inferring sizes of SN progenitor systems through the detection of the shock-heated emission that lasts less than a few days after the SN explosion. To catch the signal, IMSNG utilizes a network of 0.5-m to 1-m class telescopes around the world and monitors the images of 60 nearby galaxies at distances D < 50 Mpc to a cadence as short as a few hours. The target galaxies are bright in near-ultraviolet (NUV) with $M_{NUV}$ < -18.4 AB mag and have high probabilities of hosting SNe ($0.06SN\;yr^{-1}$ per galaxy). With this strategy, we expect to detect the early light curves of 3.4 SNe per year to a depth of R ~ 19.5 mag, enabling us to detect the shock-heated emission from a progenitor star with a radius as small as $0.1R_{\odot}$. The accumulated data will be also useful for studying faint features around the target galaxies and other science projects. So far, 18 SNe have occurred in our target fields (16 in IMSNG galaxies) over 5 years, confirming our SN rate estimate of $0.06SN\;yr^{-1}$ per galaxy.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.114-121
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• 2019

In this study, antioxidative, antibacterial and cytoprotective effects of the ethanol extract and ethylacetate fraction of Lycopus lucidus (L. lucidus) were compared and analyzed. Free radical scavenging activities ($FSC_{50}$) of the L. lucidus extract and fraction were found to be 65.1 and $64.9{\mu}g/mL$ respectively. In the $Fe^{3+}-EDTA/H_2O_2$ system, the reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) for the extract and fraction were 6.6 and $6.3{\mu}g/mL$, respectively which showed excellent total antioxidant abilities. The extract showed antibacterial activity against S. aureus, while the fraction showed in all the bacteria except for A. niger. The cytoprotective effect of L. lucidus extract was compared to that of the fraction and the effect against $^1O_2$-induced cellular damage of human erythrocytes (${\tau}_{50}$) was 51.3 and 73.7 min at $50{\mu}g/mL$, respectively. For the cytoprotective effect of keratinocytes damaged by $H_2O_2$ and UVB, the extracts did not show any efficacy but showed efficacy at $1-2{\mu}g/mL$, respectively. The fraction increased the cell viability up to 85.8 and 81.9%, respectively. As a result of intracellular ROS scavenging activity, the scavenging activity was observed at $1-2{\mu}g/mL$ of the fraction. From the results comparing the physiological activities of L. lucidus extract and the fraction, the ethylacetate fraction of L. lucidus has antioxidative effect similar to that of the extract whereas superior antimicrobial and cytoprotective effects than that of the extract. Overall, the ethylacetate fraction of L. lucidus protects cells from an external stress which can be used as a potential cosmetic material.

• Journal of Food Hygiene and Safety
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• v.34 no.1
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• pp.65-72
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• 2019

This study was aimed at investigating the levels of the natural preservatives of benzoic, sorbic and propionic acids in cereal grains, nuts and seeds. Benzoic and sorbic acid were analyzed by high-performance liquid chromatography with a diode-array detector (HPLC-DAD) and further confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), whereas propionic acid was analyzed using a gas chromatography-flame ionization detector (GC-FID) and further confirmed by gas chromatography-mass spectrometry (GC-MS). Benzoic, sorbic and propionic acids were found in 44, 22, and 550 samples out of 702 samples, respectively. From the total of 702 samples. The concentrations of benzoic, sorbic and propionic acid were ranged from not detected (ND) to 23.74 mg/L, from ND to 7.90 mg/L, and from ND to 37.39 mg/L in cereal grains, nuts and seeds, respectively. The concentration ranges determined in this study could be used as standard criteria in the process of inspecting cereal grains, nuts and seeds for preservatives as well as to address consumer complaints or trade disputes.