• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1565-1572
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• 2010

Onion (Allium cepa L.) production in Korea has increased gradually over the past 15 years, placing second in food consumption survey with 20.6 g daily intake in 2006. Onions, used as an ingredient in many dishes and accepted by almost all traditions and cultures, have been reported to have a range of health benefits which include anticarcinogenic, antiasthmatic, antibiotic, and antioxidative effects. These effects may be attributable to a powerful flavonoid pigment-containing compounds, such as quercetin and alk(en)yl cysteine sulphoxides (ACSOs). Although antiplatelet and antithrombotic activities of onion have been confirmed by many of in vitro or animal studies, only a few human intervention studies have been examined. The majority of human studies identified that onion improves some cardiovascular markers such as lipid profile and platelet coagulant. With regard to antioxidative effects, somewhat positive effects are confirmed through strengthening the resistance of oxidative DNA damage in lymphocyte and urine, while most studies failed to find inhibitory effects on LDL oxidation. The discrepancies among studies might be ascribed to producing area, processing methods of onion, dosage, subject characteristics, study duration, and measurement methods. In this review, we focused on the preventive effect of cardiovascular disease through onion consumption in human intervention studies.

• Journal of the Korean GEO-environmental Society
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• v.21 no.7
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• pp.5-16
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• 2020

Currently, the seismic design standards have been strengthened due to the occurrence of the Gyeongju and Pohang earthquake, and seismic performance evaluation of existing facilities is being conducted. It aims to secure a seismic performance effect during earthquakes by improving the micro-pile method, which can be constructed in limited confined places while minimizing damage to existing facilities. The improvement method is to construct all the piles in the square-tray-type plate on the top of the pile by constructing the slope pile in the form of an umbrella around the vertical pile, the main pillar. In this paper, the numerical analysis was performed to analyze the horizontal displacement behavior of an umbrella-type micropile for various real-measurement seismic waves in sandy soil. As a result of numerical analysis, the softer the ground, the better the effect of horizontal resistance of umbrella-type micropile. The horizontal displacement reduction effect was pronounced when the embedded depth was 15 m or more at the same ground strength, and it was found to be effective in earthquakes if it was settled on the ground with an N value of 30 or more. The embedded depth and horizontal displacement suppression effect of the micropile was proportional. Generally, the weaker the ground, the greater the displacement suppression effect. Umbrella-type micropile had a composite resistance effect in which the vertical pile resists the moment and inclined pile resists the axial force.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.112-119
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• 2011

Sheaths are arranged in the web and lower part of prestressed-concrete girder bridges, and prestressing wires and concrete are indirectly bonded together by filling interior parts of the sheaths. However, when the filling is not sufficient, water can penetrate the interior parts of the sheaths and, thereby, prestressing wires can be corroded or transverse cracks would occur around sheaths by the freezing and thawing action of the penetrated water. Therefore, it is an important element in maintenance management of structures to find out the sheaths unfilled with grout early after construction. In this paper, in order not to damage bridge members, the impact-echo method with a new approach in application is used to probe sheaths unfilled with grout for real structures. The location of sheaths is first estimated with reinforcing bar probing instrument of radar type and the measurement locations of sheaths are determined. By sending elastic wave to the side of girders and receiving the response, the location of the unfilled part of a sheath was estimated from the difference between high frequency peak and twice the resonance frequency indicating thickness. To verify the location of void estimated by the impact-echo method, pictures were taken by an industrial fiber scope after drilling a hole.

• Journal of Conservation Science
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• v.28 no.4
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• pp.305-319
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• 2012

The Myeongdongseongdang Cathedral, which was designated as Historic Site No. 258 in Korea, is a representative cathedral of Korean Catholic church designed by a French priest Eugene-Jean Georges Coste and completed in 1898. It is a Gothic-styled architecture constructed with bricks and stones. Lithological and mineralogical analyses determined that holy stone relics were made of marble and granite, and foundation stones are of pink feldspar granite. Deterioration mapping and ultrasonic measurement revealed main weathering and damage were exfoliation (40%) and black discoloration (37%) in the holy water basin, and exfoliation (6%) and discoloration (46%) in the exterior foundation stones. Ultrasonic velocity of the stones were calculated as 3,525m/s in the holy water basin and 2,795m/s in the exterior stones that indicated these stones were sorted into moderately to highly weathered rock. This was resulted from moisture and atmospheric pollutants around the cathedral.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1134-1139
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• 2007

This study was conducted to investigate the effects of four kinds of tea (Camellia sinensis) extracts on the antioxidant defense systems as well as the activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in ethanol administered ICR mice. According to the results, treatment with puerh tea significantly increased the superoxide dismutase activity and glutathion reductase activity in liver. In addition, the group treated with oolong tea exhibited higher superoxide dismutase activity and glutathion reductase activity in serum than those of puerh tea, green tea and black tea treated groups. The oolong tea and puerh tea also reduced malondealdehyde contents in both liver and serum. These results suggested that puerh tea and oolong tea were the most effective against alcohol-induced oxidative damage among the Camellia sinensis teas. On the other hand, in the measurement of alcohol break-down enzyme activities, the group treated with green tea exhibited the highest hepatic ADH and ALDH activities, suggesting that the group treated with green tea might be useful for alcohol down-regulation.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.5
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• pp.35-42
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• 2014

Thermal analysis properties and adhesive properties of self-healing agents were evaluated through differential scanning calorimetry, reaction heat measurement, and adhesive shear test. D1E0, D3E1, D1E1, D1E3, and D0E1, depending on the mixing ratio of DCPD and ENB, were considered as self-healing agents. The amount of Grubbs' catalyst, depending on the type of self-healing agents, was varied from 0.1 wt% to 1.5 wt%. In the case of DCPD, the polymerization reaction occurred faster and the stabilized adhesive strength increased as the amount of catalyst increased; however, a large amount of catalyst was required. ENB had excellent reactivity with a small amount of the catalyst; however, high reaction heat was observed at the early stage of polymerization. Thermal analysis properties and adhesive properties of self-healing agents can be controlled by varying a mixing ratio of DCPD and ENB. Among the self-healing agents used for this study, the D3E1 would be one of the most preferable candidates with regard to maximum adhesive strength, reaching time to maximum adhesive strength, stabilized adhesive strength, and reaction heat.

• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.684-693
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• 2021

Purpose: The purpose is to establish a safe facility environment from abnormal voltages such as lightning by developing a smart land resistance measuring device that can acquire real-time land resistance data using Arduino. Method: This paper studied design models and application cases by developing a land resistance acquisition and analysis system with Arduino and a power line communication (PLC) system. Some sites in the wind power generation complex in Gyeongsangnam-do were selected as test beds, and real-time land resistance data applied with new technologies were obtained. The electrode arrangement adopted a smart electrode arrangement using a combination of a Wenner four electrode arrangement and a Schlumberger electrode arrangement. Result: First, the characteristic of this technology is that the depth of smart multi-electrodes is organized differently to reduce the error range of the acquired data even in the stratigraphic structure with specificity between floors. Second, IT convergence technology was applied to enable real-time transmission and reception of information on land resistance data acquired from smart ground electrodes through the Internet of Things. Finally, it is possible to establish a regular management system and analyze big data accumulated in the server to check the trend of changes in various elements, and to model the optimal ground algorithm and ground system design for the IT convergence environment. Conclusion: This technology will reduce surge damage caused by lightning on urban infrastructure underlying the 4th industrial era and design an optimized ground system model to protect the safety and life of users. It is also expected to secure intellectual property rights of pure domestic technology to create jobs and revitalize our industry, which has been stagnant as a pandemic in the post-COVID-19 era.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.4
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• pp.28-36
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• 2021

It is known that buried rebars inside concrete structures are protected from corrosion due to passive layer. It is very important to delay the timing of corrosion or evaluate a detection of corrosion initiation for the purpose of cost-beneficiary service life of a structure. In this study, corrosion monitoring was performed on concrete specimens considering 3 levels of cover depth(60 mm, 45 mm, and 30 mm), W/C(water to cement) ratio(40.0%, 50.0%, and 60.0%) and chloride concentration(0.0%, 3.5%, and 7.0%). OCP(Open Circuit Potential) was measured using agar-based socket type sensors. The OCP measurement showed the consistent behavior where the potential was reduced in wet conditions and it was partially recovered in dry conditions. In the case of 30 mm of cover depth for most W/C ratio cases, the lowest OCP value was measured and rapid OCP recovery was evaluated in increasing cover depth from 30 mm to 45 mm, since cover depth was an effective protection against chloride ion ingress. As the chloride concentration increased, the effect on the cover depth tended to be more dominant than the that of W/C ratio. After additional monitoring and physical evaluation of chloride concentration after specimen dismantling, the proposed system can be improved with increasing reliability of the corrosion monitoring.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.1-9
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• 2019

Large-scale industrial boilers operating at high temperature and high pressure, have a large amount of water, and a large amount of energy is released at the time of explosion. Currently, most industrial boilers use gas fuel such as LNG and LPG, etc. and fuel exists in the same space as equipment, so there is a high possibility of secondary damage such as fire or explosion in the event of a boiler accident. Both special care and management are required to operate the very dangerous equipment that causes casualty 2.51 per accident. For boilers of a certain size or more, the Korea Energy Agency conducts inspections in accordance with the Energy Usage Rationalization Act, KS, and public notice of the Ministry of Industry, Trade and Resources. In this research, based on the results of the inspection, the hazard factorss are configured, and a questionnaire is conducted to the inspector, the equipment manager, the maintenance person, and the person in charge of the manufacturer. We analyzed the results by using AHP (Analytic Hierarchy Process). As a result of analysis, generally recognized hazard factorss are not good management, measurement failure, specification failure, water leak, leak analysis, but connection, welding, scale, and corrosion, etc. are relatively less important. It is judged that the adverse factors that are recognized to be highly important among all groups and careers are already well managed, but less important and adverse factors should be well managed to ensure that the safe usage of the boiler.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.359-365
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• 2019

This paper is a basic study for the performance evaluation, durability improvement and optimal design of tractor transmission. The engine torque of the 78 kW agricultural tractor during rotary tillage was measured using CAN communication. It was calculated with equivalent torque and then analyzed. In order to develop a reliable tractor, it is important to convert measured torque in various agricultural operations into equivalent torque and analyze it. The equivalent torque was calculated using Palmgren-Miner's rule, which is a representative cumulative damage law. The equivalent torque of rotary tillage period and steering period are 229.2 and 136.7 Nm, respectively. The maximum and average torque during rotary tillage period are 336.0 and 234.4 Nm, respectively. The maximum and average torque of the steering period are 288.0 and 134.6 Nm, respectively. The engine torque in rotary tillage period is higher than in the steering period because of cultivation of soil through PTO. The maximum and rated torque of engine are 387.0 and 323.0 Nm, respectively, which are 183% and 136% higher than the equivalent torque during rotary tillage and of steering section. Because transmission of agricultural tractor in Korea companies is generally designed by the rated torque of engine, there is a difference from measured torque during agricultural operations. Therefore, it is necessary to consider it for optimal design.