• Spatial Information Research
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• v.18 no.4
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• pp.1-11
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• 2010

Unlike the previous studies which have focused on 2-dimensional urban characteristics, this paper presents statistical models explaining urban heat island(UHI) effect by 3-dimensional urban morphologic information and addresses its policy implications. 3~dimensional informations of Columbus, Ohio arc captured from LiDAR data and building boundary informations are extracted from a building digital map, Finally NDV[ and temperature data are calculated by manipulating band 3, band 4, and thermal hand of LandSat images. Through complicated data processing, 6 independent variables(building surface area, building volume, height to width ratio, porosity, plan surface area) are introduced in simple and multiple linear regression models. The regression models are specified by Box-Tidwell method, finding the power to which the independent variable needs to raised to be in a linearity. Porosity, NDVI, and building surface area are carefully chosen as explanatory variables in the final multiple regression model, which explaining about 57% of the variability in temperatures. On reducing UHI, various implications of the results give guidelines to policy-making in open space, roof garden, and vertical garden management.

• Resources Recycling
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• v.21 no.6
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• pp.12-22
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• 2012

This study investigated a utilization technology of light burned dolomite. light burned dolomite ($CaMg(CO_3)_2$) generated in furnace (steel manufacturer) is an alternative to quick lime. Using light burned dolomite has an effect on reducing the consumption of fluorite slag MgO concentration in supersaturated solution by prolonging the life of softening effect. Armophous MgO, not containing periclase is formed by firing dolomite under $800^{\circ}C$. It has larger surface area and higher reactivity than periclase, and also shows better expansion effect than quicklime. Due to those effects, therefore, armophous MgO produced from light burned dolomite is used as an alternative expansion agent in mortar. In the experiment, characteristics of light burned dolomite were compared to those of existing expansion agents such as anhydrite and quicklime. Then, each expansion and shrinkage rates were measured over a period of about 3 months in both of 1m Jis mold at labscale and apartment mortar flooring at field scale. In the result, it was observed that light burned dolomite in mortar flooring more compensates for the expansion and shrinkage rates than the existing expansion agents, showing low expansion rate of below 0.05% and also decreases the crack.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.1
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• pp.77-84
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• 1998

In order to investigate microbiological control of malodors, particularly including ammonia, the effect of three thermophilic ammonium tolerant bacteria strains. TAT112. TAT117 and TAT119, were tested during composting of pig manure in the laboratory scale composters. The total weight, volatile solids and BOD of the pig manure compost were decreased during composting process in all treatments. The temperature in all treatments rose in first 3 days dramatically, but that in control without inoculation reached its maximum most lately among the treatments. The nitrogen content of drain water accumulated inside and outside composter, and trapped in 6N $H_2SO_4$ was lower in TAT112 inoculated composter than in control. However, it was not lower in the treatment of TAT117 and TAT119 inoculated. Ammonia concentration in the exhaust gas monitored everyday during composting also demonstrated that it was lowest at TAT112 inoculated among all treatments. It was appeared to have an effect on reducing ammonia emission at the treatment of TAT112 inoculated than the control.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.135-148
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• 2019

King oyster mushroom(Pleurotus eryngii) is one of the most commercially important mushrooms in Korea. Development of fruit body and disease occurrence are sensitive to environmental conditions such as temperature, humidity, carbon dioxide(CO₂) concentration. The purpose of this study was to investigate the changes in the growth environment of king oyster mushroom by installing Airocide, an air purifier for the purpose of improving mushroom cultivation environment. The results of the environment conditions, identification of pathogenic organisms and pathogenesis during the cultivation were as follows. Airocide operation increased the CO₂ concentration of the cultivation room by more than 400 ppm on average, but the increase of CO₂ concentration at this level had little effect on the quality and growth of fruit body. Operation of the Airocide tended to reduce the air humidity of the cultivation room and required more humidification. In humidifying conditions, the Airocide has the effect of lowering the species and density of bacteria and reducing bacterial symptoms and abnormal fruiting body of mushroom. Pseudomonas sp., the mushroom pathogen, was isolated from the cultivation room without Airocide, resulting in serious disease and loss of yields, so that only about 83% of substrate could harvest normal fruiting bodies. No disease symptom caused by bacteria and fungi in the cultivation room with Airocide. Trichoderma sp., Penicillium sp. and Cladosporium sp. were isolated from all experimental conditions, but did not inhibit fruit growth or caused diseased.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.578-586
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• 2009

This study was conducted to determine the effects of alkaline electrolyzed water (AIEW), acidic electrolyzed water (AcEW), 1% citric acid, and 100 ppm sodium hypochlorite, either alone or in combination with citric acid, in reducing the populations of spoilage bacteria and foodborne pathogens (Listeria monocytogenes and Escherichia coli O157:H7) on lettuce at various exposure times (3, 5, and 10 min) with different dipping temperatures (1, 20, 40, and $50^{\circ}C$). In addition, the inhibitory effect of alkaline electrolyzed water combined with citric acid on the browning reaction during storage at $4^{\circ}C$ for 15 days was investigated. Compared to the untreated control, electrolyzed water more effectively reduced the number of total bacteria, mold, and yeast than 100 ppm sodium hypochlorite under the same treatment conditions. All treatments exposed for 5 min significantly reduced the numbers of total bacteria, yeast, and mold on head lettuce. The inactivation effect of each treatment on head lettuce was enhanced as the dipping temperature increased from 1 to $50^{\circ}C$, but there was no significantly difference at temperatures greater than $40^{\circ}C$ (p<0.05). The total counts of yeast and mold in head lettuce were completely eliminated when a combination of 1% citric acid and AlEW treatment was used at temperatures greater than $40^{\circ}C$. However, decreased reduction in L. monocytogenes (2.81 log CFU/g), and E. coli O157:H7 (2.93 log CFU/g) on head lettuce was observed under these treatment conditions. In addition, enhanced anti-browning effect was observed when the samples were subjected to both 1% citric acid and AlEW treatment at temperatures greater than $40^{\circ}C$ compared to when single treatments alone were used. Thus, this combined treatment might be considered a potentially beneficial sanitizing method for improving the quality and safety of head lettuce.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.2
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• pp.68-81
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• 2023

This study aims to establish a scenario based on the spacing and arrangement of the roadside trees to reduce heat waves and fine dust in cities that occurred during the urbanization process and to quantitatively analyze the degree of reduction. The ENVI-met 5.0.2v model, a micro-climate simulation program, was used to analyze the degree of improvement in the thermal environment and fine dust according to the roadside tree scenario. As a result of temperature analysis according to street tree spacing, the narrower the distance between roadside trees, the lower the temperature during the day as the number of planted trees increased, and a similar pattern was shown regardless of the distance between roadside trees in the morning and evening. In the case of fine dust emitted from the road, the concentration of fine dust increased slightly due to the increase in roadside trees, but the concentration of sidewalks where people walk increased slightly or there was no difference because of blocking fine dust on trees. The temperature according to the arrangement of street trees tended to decrease as the number of planted trees increased as the arrangement increased. However, not only the amount of trees but also the crown projected area was judged to have a significant impact on the temperature reduction because the temperature reduction was greater in the scenario of planting the same amount of trees and widening the interval of arrangement. In terms of the arrangement, the fine dust concentration showed a difference from the results according to the interval, suggesting that the fine dust concentration may change depending on the relationship between the main wind direction and the tree planting direction. By quantitatively analyzing the degree of thermal environment and fine dust improvement caused by roadside trees, this study is expected to promote policies and projects to improve the roadside environment efficiently, such as a basic plan for roadside trees and a project for wind corridor forests.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.195-195
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• 2016

Titanium and its alloys are widely used as implants in orthopedics, dentistry and cardiology due to their outstanding properties, such as high strength, high level of hemocompatibility and enhanced biocompatibility. Hence, recent works showed that the synthesis of new Ti-based alloys for implant application involves more biocompatible metallic alloying element, such as, Nb, Hf, Zr and Mo. In particular, Nb and Hf are one of the most effective Ti ${\beta}-stabilizer$ and reducing the elastic modulus. Plasma electrolyte oxidation (PEO) is known as excellent method in the biocompatibility of biomaterial due to quickly coating time and controlled coating condition. The anodized oxide layer and diameter modulation of Ti alloys can be obtained function of improvement of cell adhesion. Silicon (Si) and magnesium (Mg) has a beneficial effect on bone. Si in particular has been found to be essential for normal bone and cartilage growth and development. In vitro studies have shown that Mg plays very important roles in essential for normal growth and metabolism of skeletal tissue in vertebrates and can be detected as minor constituents in teeth and bone. The aim of this study is to research Si and Mg doped hydroxyapatite film formation by plasma electrolytic oxidation. Ti-29Nb-xHf (x= 0, 3, 7 and 15wt%, mass fraction) alloys were prepared Ti-29Nb-xHf alloys of containing Hf up from 0 wt% to 15 wt% were melted by using a vacuum furnace. Ti-29Nb-xHf alloys were homogenized for 2 hr at $1050^{\circ}C$. Each alloy was anodized in solution containing typically 0.15 M calcium acetate monohydrate + 0.02 M calcium glycerophosphate at room temperature. A direct current power source was used for the process of anodization. Anodized alloys was prepared using 270V~300V anodization voltage at room. A Si and Mg coating was produced by RF-magnetron sputtering system. RF power of 100W was applied to the target for 1h at room temperature. The microstructure, phase and composition of Si and Mg coated oxide surface of Ti-29Nb-xHf alloys were examined by FE-SEM, EDS, and XRD.

• International Journal of Highway Engineering
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• v.12 no.3
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• pp.93-101
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• 2010

As the number of indispensable needs of clean energy increases due to the green new deal revolution, the possibility of heat energy harvesting from the surrounding infrastructures such as a railroad or highway was verified. In order to find more efficient usage of a heat source, the possibility of transforming heat into electricity were confirmed using Bi-Te type thermoelectric element, and electrical quality were tested with experiments of different heat source and environmental change in the surrounding infrastructures. After careful experiments, the possibility of collecting thermal energy and findings of the heat temperature change in infrastructrue are verified with a result of obtaining almost 20.82W in 70 celcius($^{\circ}C$) temperature differences and $1m^2$ surface area. Consequently, the ratio of heat temperatiure change and transforming surface area is the most crucial factor in the harvesting heat energy, and reducing thermal loss and improving thermal convection as well as transformation efficiency of thermoelectric element is required to get more efficient and durable generation.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.1
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• pp.1-6
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• 2006

Biological nutrient removal(BNR) process used in this study, which was packed with EPS(expanded polystylene) media, has more many advantages in aspect of reducing hydraulic retention time(HRT) of the process and having less effect of temperature in the winter season than commercial process in the present. Bench-scale study was performed using domestic wastewater. In the results, it was observed that the T-N removal efficiencies in HRT 6 hr and HRT 4 hr were 55% and 51%, respectively, showing the small reduction (about 4%) of T-N removal efficiency according to shortening of HRT. In comparison of T-N removal characteristic in summer and winter seasons, it showed that T-N removal efficiencies in summer and winter seasons were 65% and 54%, respectively, showing the 11% lower T-N removal efficiency in winter season than in summer season due to deterioration of nitrification in winter season. In the studies of influent loading rate and C/N ratio, the process showed stable effluent quality under the condition of broad influent loading rate and C/N ratio. Therefore, it is anticipated that the developed process in this study could be applicable to small wastewater treatment plant in nutrient removal.

• Food Science and Preservation
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• v.23 no.2
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• pp.233-238
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• 2016

A effect of extraction methods, including stirrer extraction method (SE), ultrasonification extraction method (USE), reflux extraction method (RE), autoclave extraction (AE) and low temperature high pressure extraction (LE) method on the antioxidative and antimicrobial activities of ethanol extracts of Oenothera biennis was investigated. The extraction yield (46.33%), total polyphenol (463.05 mg GAE/g) and flavonoid (71.71 mg RHE/g) content of Oenothera biennis extract obtained by RE were higher than those from other extraction methods. The antimicrobial activity of Oenothera biennis extract was only observed against Bacillus cereus among other tested organisms (Bacillus cereus, Staphylococcus aureus, Escherichia coli and Salmonella Typhimurium). Oenothera biennis obtained by RE showed the best DPPH radical scavenging ability (74.40%), ABTS radical scavenging ability (65.29%), reducing power (1.370 ($OD_{700}$)) and ferrous ion chelating ability (90.14%) compared with other tested extraction methods tested. The RE method was the most efficient method for extracting crude antioxidant and antimicrobial substances from Oenothera biennis. These results suggested that Oenothera biennis obtained by RE could be used as a bioactive and functional material in the food industry.