• Journal of Mushroom
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• v.12 no.4
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• pp.330-340
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• 2014

Coprinellus micaceus, belongs to family Psathyrellaceae of Agaricales, Basidiomycota, has been used for edible purposes in the world. This study was initiated to evaluate the antioxidant, anti-diabetic, anti-cholinesterase, anti-tyrosinase, and nitric oxide inhibitory activities of fruiting bodies from C. micaceus extracted with methanol and hot water. The HPLC analysis of phenolic compounds from the mushroom extracts identified 4 phenolic compounds including procatechuic acid, chlorogenic acid, (-)-epicatechin, and naringin. In 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging assay, the scavenging activities of methanol and hot water extracts were lower than that of positive control, BHT. The chelating effects of methanol and hot water extracts were significantly higher than that of BHT, the positive control at the all concentrations tested. In the reducing power assay, methanol and hot water extracts exhibited the lower activities compared with positive control at the 0.125-0.2 mg/ml. The methanol and hot water extracts of the mushroom inhibited the ${\alpha}$-glucosidase activity by 62.26% and 67.59%, respectively at the 2.0 mg/ml, while acarbose, the positive control, inhibited the ${\alpha}$-glucosidase activity by 81.81% at the same concentration. In the acetylcholinesterase(AChE) inhibitory activity assay, methanol and hot water extracts of the mushroom inhibited the AChE by 94.64% and 74.19%, respectively at 1.0 mg/ml, whereas the galanthamine, standard drug, inhibited the AChE activity by 97.80% at the same concentration. The tyrosinase inhibitory activities of methanol and hot water extracts were 91.33% and 91.99% at 2.0 mg/ml, while the inhibitory activity of kojic acid, the positive control, was 99.61% at the same concentration. Nitric oxide(NO) production in lipopolysaccahride (LPS) activated RAW 264.7 cells were inhibited by the methanol and hot water extracts in a concentration dependent manner. Therefore, it is concluded that fruiting bodies of C. micaceus contained natural antioxidant, anti-acetylcholinesterase and ${\alpha}$-glucosidase inhibitory, anti-inflammatory, anti-tyrosinase substances which might be used for promoting human health.

• The Journal of Engineering Geology
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• v.28 no.3
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• pp.475-488
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• 2018

This study evaluates geothermal system efficiency in terms of input power and heat exchange volume on the heat-source and load sides, by applying a combined open-closed type loop system comprising a geothermal system and a groundwater well to a cultivation site. In addition, this study analyzes the effects of heating and cooling for a complex geothermal system, by evaluating the temperatures of an external site and a cultivation site during operation. During cooling operations the heat exchange volume on the heat source side, average 90.0kW/h for an open type system with an input of 235L/minute groundwater, and 40.1kW/h for a closed type system with an input of 85L/minute circulating water, for a total average heat exchange volume of 130.1kW/h. The actual heat exchange volume delivered on the load side averages 110.4kW/h. The average EER by analysis of the geothermal system's cooling efficiency is 5.63. During heating operation analysis, the heat exchange volume on the heat source side, average 60.4kW/h in an open type system with an input of 266L/minute groundwater, and 22.4kW/h in closed type system with an input of 86L/minute circulating water, for a total average heat exchange volume of 82.9kW/h. The actual heat exchange volume delivered on the load side averages 112.0kW/h in our analysis. The average COP determined by analysis of the geothermal system's heating efficiency is 3.92. Aa a result of the tradeoff between the outside temperature and the inside temperature of the production facility and comparing the facility design with a combined well and open-closed loops geothermal(CWG) system, we determine that the 30RT-volume CWG system temperature are lower by $3.4^{\circ}C$, $6.8^{\circ}C$, $10.1^{\circ}C$ and $13.4^{\circ}C$ for ouside temperature is of $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$ and $35^{\circ}C$, respectively. Based on these results, a summer cooling effect of about $10^{\circ}C$ is expected relative to a facility without a CWG system as the outside temperature is generally ${\geq}30^{\circ}C$. Our results suggest that a complex geothermal system provides improvement under a variety of conditions even when heating conditions in winter are considered. Thus It is expected that the heating-cooling tradeoffs of complex geothermal system are improved by using water screen.

• Microbiology and Biotechnology Letters
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• v.41 no.2
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• pp.228-235
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• 2013

Radish (Raphanus sativus) is a common cruciferous vegetable, and its aerial parts, called Mu-chung in Korean, have plentiful nutritional components such as vitamins, minerals and dietary fibers. Mu-chung has been used as a kimchi, a traditional Korean fermented dish, and dried Mu-chung is an important component of soups commonly consumed during winter in Korea. Since the advent of the mass production of radish in Korea, with the segregation of farm areas and towns and changing diets, Mu-chung has mostly been discarded instead of utilized. In addition, studies concerning the efficient utilization and useful bioactivities of Mu-chung are still lacking worldwide. In this study, we prepared the ethanol extract of Mu-chung and its subsequent solvent fractions. Antimicrobial, antioxidation, and anticoagulation activities were then evaluated in the hopes of developing a functional biomaterial from Korean radishes' aerial parts. The ethanol extraction yield for hot-air dried Mu-chung was 5.6%, and the fraction yields of n-hexane (H), ethylacetate (EA), butanol (B) and water residue were 25.3, 3.6, 19.4, and 51.7%, respectively. Analysis of total polyphenol and total flavonoid contents showed that the EA fraction had the highest content (97.57 and 152.91 mg/g) amongst the fractions. In antimicrobial activity assays, the H and EA fractions were effective against gram positive bacteria (Staphylococcus aureus, Listeria monocytogenes, and Bacillus subtilis), but not effective against gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The B fraction also exhibited moderate antibacterial activity, suggesting that the extract of Mu-chung has various antibacterial components. In antioxidation activity assays, the EA fraction showed strong DPPH, ABTS and nitrite scavenging activities ($69-222{\mu}g/ml$ of $IC_{50}$), including reducing power. In anticoagulation activity assays, the EA fraction demonstrated strong inhibition activity against human thrombin and prothrombin. Prominent anticoagulation activity was found in aPTT assays; the aPTT of the EA fraction was extended 15-fold compared than that of the solvent control. Our results suggest that Mu-chung is an attractive nutritional food material possessing useful bioactivities, and the EA fraction of Mu-chung could be developed as a functional food ingredient.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.267-273
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• 1977

Rainbow trout were reared in a small indoor aquarium which was equipped with a simple recirculating biofilter combined with a small amount of inflowing water for 199 days from April 25 to November 10, 1977 in Busan where very hot summer air temperature is encountered, and results obtained were promissing as following; 1. The aquarium has dimensions of $1m\;\times\;1m\;\times\;67cm(depth)$, and a bottom center sedimentation chamber of conical type through which out-flowing water is pushing fecal matter and other detritus outward. The conical sedimentation chamber measures 20 cm depth and 20 cm diameter at its upper mouth and tapers to the bottom end which is connected to 4 cm diameter draining pipe. The draining pipe goes through under the tank and then is elevated on the side. The water depth was maintained at about 40 cm depth by adjusting the heigh of draining pipe. The filter bed contained 16 l of $3\~5\;mm$ zeolite gravels, and water circulation rate was about 1030 l/hr. 2. Continuous inflowing water resulted in a good elimination of waste materials through its outflowing water thus reducing waste loading in the filter. 3. Mean temperature of water in the rearing aquarium containing about 400 l water volume was maintained at around 20 to $22^{\circ}C$ by 0.59 l/min of the inflowing well water which usually maintained the temperature of $17^{\circ}C$ during the hot summer season from the first of July to the first of October when the 10-days-mean air temperature ranged from $20^{\circ}\;to\;27.3^{\circ}C$ $(total\;mean\;24.6^{\circ}C) $ and under this condition the fish continued normal growth. 4. The production per 1 l/min of inflowing water with this simple biofilteration reached 30 hg. 5. The total cost including all feed and power during this experimental rearing period fell well within the economic establishment and if the feed and filteration system are improved the benefit-cost ratio will be much increased.

• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.153-161
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• 2020

Arthrospira platensis is the oldest marine microalgae on the planet, is said to contain most of the nutrients needed by the human body. It's components are reported to contain a large amount of various substances such as phycocyanin, chlorophyll and β-carotene, and are known to have an aging and whitening effect. In this study, UVB-induced reactive oxygen species reduction efficacy and antioxidant activity of spirulina purified water extract were investigated. effect was confirmed by measuring DPPH radical scavenging activity, FRAP reducing power and ABTS⁺ radical scavenging activity of 0.05, 0.10, 0.50 1.0 mg/mL of spirulina purified water extract. The coagulation rate, hatching rate and heart rate toxicity were measured by treating spirulina purified water extract with 0.05, 0.10, 0.50 mg/mL concentration using Zebrafish, an alternative experimental animal model. UVB-induced ROS measurement was treated with spirulina extract at 0.05, 0.10, 0.50 mg/mL concentration, and then stained with DCFH-DA to confirm the inhibitory effect of ROS. As a result of measuring antioxidant effect, DPPH, FRAP and ABTS⁺ showed concentration-dependent antioxidant effects in comparison with ascorbic acid. and measuring the coagulation rate, hatching rate, and heart rate using Zebrafish, an alternative experimental animal, it was confirmed that there was no toxicity in 0.05 and 0.10 mg/mL except 0.5 mg/mL compared to the control group. The ROS scavenging activity of UVB-induced zebrafish showed higher ROS reduction than the positive control. The results of this study suggest that spirulina and purified water extracts are valuable for UV and skin protection cosmetics.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.48-59
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• 2018

This study was conducted to suggest the effective management and recycling processes of coffee waste, which can be easily obtained from coffee shops and coffee-related products industries. Prior to the fabrication of pellets, the potential of coffee waste as a raw material of pellet was investigated through the examination of its chemical compositions and fuel characteristics. Major gradient included in coffee waste was holocellulose, followed by fat/oil and protein. Coffee waste contained a small quantity of ash (0.7%), such as calcium, sodium, potassium and magnesium. Interestingly, coffee waste was easily dried probably due to its porous structure. Pellets fabricated with coffee waste and larch sawdust showed good fuel characteristics, such as moisture content, ash content, density and durability. The pellets exceed greatly the minimum requirements of $1^{st}$-grade wood pellet standard designated by National Institute of Forest Science (NIFOS). Particularly, the high calorific value of coffee waste showed the potential as a raw material of pellet. However, owing to high nitrogen and sulfur contents, coffee waste is like to be used as a raw material of wood pellet for combined heat and power plants equipped with a reduction system of $NO_x$ and $SO_x$ gases. On the other hand, 91 wt% larch sawdust and 9 wt% coffee waste are required to fabricate the $1^{st}$-grade wood pellets designated by NIFOS. Pellets fabricated with the conditions are estimated to have nitrogen content of 0.298% and sulfur content of 0.03%. Lastly, if amounts of coffee waste and sawdust in the production of wood pellets are adequately adjusted according to its purchasing price, the manufacturing cost of pellet can effectively be reduced. In addition, it is expected tp prepare the effective recycling process of waste and to relieve the environmental burden with the reduction of waste from the commercialization of coffee waste/larch pellets.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.423-429
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• 2008

Currently, Ash-free clean coal producing process by solvent extraction is under development. The produced ash-free clean coal can be directly combusted in a gas turbine which results in substantial improvement of power generation efficiency. However, the clean coal produced by the solvent extraction still contain trace amount of alkali metal which may cause corrosion on turbine blades during the direct combustion. In present work ${\alpha},{\beta}$-metal (Zr and Ti) phosphates and H-Y zeolite were synthesized and their ion exchange characterizations were investigated for the application on alkali metal removal for clean coal production. $Na^+$ ion removal capacities of the metal phosphates and H-Y zeolite were measured and compared in both aqueous solution (100 ppmw, $Na^+$) and coal dissolved N-methyl-2-pyrrolidone (NMP, 12 ppmw $Na^+$) at elevated temperature. In aqueous solution, the ${\beta}$ form metal phosphates showed very high ion exchange capacities compared to ${\alpha}$ form. ${\beta}$ form metal phosphates also showed higher $Na^+$ removal capacities than H-Y zeolite. In ion exchange medium of NMP, all the ${\alpha}$ form metal phosphates showed over 90% of $Na^+$ ion removal efficiency in the temperature range of 200 to 400 while that of H-Y zeolite decreased as a half when the temperature was over 350. In addition, the regenerated metal phosphates by acid treatment showed no sign of degradation in $Na^+$ removal efficiency. Among the metal phosphates used, $Zr_{0.75}Ti_{0.25}(HPO_4)_2$ showed the best performance in $Na^+$ removal and is expected to be the most suitable inorganic ion exchanger for the alkali metal removal process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.375-375
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• 2010

CdTe as an absorber material is widely used in thin film solar cells with the heterostructure due to its almost ideal band gap energy of 1.45 eV, high photovoltaic conversion efficiency, low cost and stable performance. The deposition methods and preparation conditions for the fabrication of CdTe are very important for the achievement of high solar cell conversion efficiency. There are some rearranged reports about the deposition methods available for the preparation of CdTe thin films such as close spaced sublimation (CSS), physical vapor deposition (PVD), vacuum evaporation, vapor transport deposition (VTD), closed space vapor transport, electrodeposition, screen printing, spray pyrolysis, metalorganic chemical vapor deposition (MOCVD), and RF sputtering. The RF sputtering method for the preparation of CdTe thin films has important advantages in that the thin films can be prepared at low growth temperatures with large-area deposition suitable for mass-production. The authors reported that the optical and electrical properties of CdTe thin film were closely connected by the thickness-uniformity of the film in the previous study [1], which means that the better optical absorbance and the higher carrier concentration could be obtained in the better condition of thickness-uniformity for CdTe thin film. The thickness-uniformity could be controlled and improved by the some process parameters such as vacuum level and RF power in the sputtering process of CdTe thin films. However, there is a limitation to improve the thickness-uniformity only in the preparation process [1]. So it is necessary to introduce the external or additional method for improving the thickness-uniformity of CdTe thin film because the cell size of thin film solar cell will be enlarged. Therefore, the authors firstly applied the chemical mechanical polishing (CMP) process to improving the thickness-uniformity of CdTe thin films with a G&P POLI-450 CMP polisher [2]. CMP process is the most important process in semiconductor manufacturing processes in order to planarize the surface of the wafer even over 300 mm and to form the copper interconnects with damascene process. Some important CMP characteristics for CdTe were obtained including removal rate (RR), WIWNU%, RMS roughness, and peak-to-valley roughness [2]. With these important results, the CMP process for CdTe thin films was performed to improve the thickness-uniformity of the sputtering-deposited CdTe thin film which had the worst two thickness-uniformities of them. Some optical properties including optical transmittance and absorbance of the CdTe thin films were measured by using a UV-Visible spectrophotometer (Varian Techtron, Cary500scan) in the range of 400 - 800 nm. After CMP process, the thickness-uniformities became better than that of the best condition in the previous sputtering process of CdTe thin films. Consequently, the optical properties were directly affected by the thickness-uniformity of CdTe thin film. The absorbance of CdTe thin films was improved although the thickness of CdTe thin film was not changed.

• Journal of Mushroom
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• v.15 no.1
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• pp.45-53
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• 2017

Profitability of farmers has decreased mainly owing to low price while the gross amount of mushroom production has increased continuously in South Korea. In this regard, analyzing patterns of mushroom consumption is believed to be meaningful. We used a panel data set consisting of 667 families, from 2010 to 2015. Based on the panel data, mushroom consumption patterns of people living in city areas were examined. Multiple descriptive analysis methods and frequency analysis approaches were adopted in this study in terms of time and space dimensions, demographic properties, and purchase behaviors. The findings of this studyshow that mushroom purchase is highly dependent on seasonal events, which implies that the product consumption timing is predictable. In addition, yearly purchase amount patterns reflect that superstores have become the major mushroomtrading venues. This directly supports the need to establish supply chain capabilities for mushroom farmers so that they gain more bargaining power against enterprise-type groceries. Finally, functional features of mushroom can be linked with marketing promotion because purchase patterns demonstrate potential needs for healthcare food in mushroom categories. Based on the analyzed patterns, this paper provides insightful implications for policy makers who want to promote mushroom consumption.

• Korean Journal of Heritage: History & Science
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• v.53 no.3
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• pp.224-243
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• 2020

The rock-cut relief of two Buddhas seated side-by-side in Wonpungri is a large Buddha sculpture in relief on the side of a cliff in Wonpung-ri, Goesan. This Buddha sculpture is from the Buddhist scripture Sutra of the Lotus. <法華經> Two seated Buddhas statues were prevalent in the Balhae Kingdom, but this was not popular in Silla and Goryeo. In the main text, the time that the two seated Buddhas in Wonpung-ri was created is identified as being during the 10th century. King Gwangjong created a Buddha statue for political purposes. The relief of two seated Buddha image carved on a cliff is located on an important traffic route over the Sobaek Mountain Range. After King Gwangjong took the throne, he paid close attention to the reigning powers of Jincheon and Cheongju because the people of Jincheon and Cheongju were engaged in a power struggle against Gwangjong. The huge relief of two seated Buddhas statue shows the authority of King Gwangjong. In particular, the people of Jincheon and Cheongju had to see this Buddha statue when crossing the Sobaek Mountain Range. The image contained in the relief of the two seated Buddhas features many characteristics of the sculpture style of the Balhae Kingdom. After the fall of Balhae, many of the Balhae people settled in Mungyeong. Balhae people from Mungyeong participated in the production of the relief of the two seated Buddhas. Through the relief of the two seated Buddhas, King Gwangjong wanted to show the people of Jincheon and Cheongju that the Balhae people were supporting him. The relief of two seated Buddhas reflects the historical situation of the King Gwangjong era in the late 10^th century and the style of sculpture.