• Journal of Life Science
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• v.28 no.11
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• pp.1369-1378
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• 2018

Prunus mume Siebold & Zucc., a member of the Rosaceae family (called Maesil in Korea), has been widely distributed in East Asia, e.g. Korea, Japan and China, and its fruit has been used as a traditional drug and health food. In this study, we evaluated physicochemical properties and physiological activities of condensed Prunus mume juice treated with pectinase (PJ). The values of total acidity, pH, sugar contents, turbidity moisture content of the PJ were 35.81%, 2.73, $54.36^{\circ}Brix$, 2.75 and 51.32%, respectively. The PJ had effective DPPH radical scavenging activity, reducing power effect, $H_2O_2$ scavenging activity and ${\beta}$-carotene bleaching effect. DPPH radical scavenging activities of PJ was 46.31%; their reducing power ($OD_{700}$) was 1.80; $H_2O_2$ scavenging activity of PJ was 91.62%; and ${\beta}$-carotene bleaching effect of PJ was 73.02%. Also, PJ showed effective levels of ${\alpha}$-glucosidase inhibition activity. The cell viability was measured by SRB assay. The PJ significantly decreased the cell viability of mouse melanoma cells (B16) and human melanoma cells (SK-MEL-2 and SK-MEL-28) in a dose-dependent manner, however, there was no effect on human keratinocyte HaCaT. In morphological study, PJ-treated SK-MEL-2 cells showed distorted and shrunken cell masses. Total polyphenol contents and total flavonoid contents of PJ were 588.31 mg% (gallic acid equivalent) and 860.45 mg% (rutin equivalent). The antiproliferative effect of PJ seems to be associated with the antioxidant activity of its flavonoid and polyphenol contents. In conclusion, PJ may be beneficial in development of a functional food material.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1189-1194
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• 2011

The Maglev train is operated by levitating from a power of a large number of magnets and moving without direct contact to railway track so that reduces noise and vibration due to mechanical friction. Also, the Maglev passes sharp curves and steep hill without any difficulties. The Maglev has a potential to be an alternative transport system urban areas. For successful commercializing of Maglev, the organization of interface for safety and reliability of third rail system are one of the key considerations. Especially, the components of the third rail system, such as power rail, expansion joints, FRP section insulator, and supporter with epoxy insulator, should be durable, convenient for construction, and easy to maintenance. This paper analyzes the characteristics of the third rail system components and proposes organization of interface for system engineering. The operating tests of KIMM for the proposed third rail system verify the safety. Also, this paper analyzes the life cycle of the system components to improve the system reliability and evaluation.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.3
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• pp.228-234
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• 2016

As a college dormitory has the features of high dwelling density and a floating population that becomes crowded during particular times, when a disaster such as a fire occurs, it has the risk of causing much loss of life. In this study, the fire simulation program Fire Dynamics Simulator (FDS), is used to predict the risk when a fire occurs, to analyze the problem, and to suggest an improvement plan for a new cadet dormitory at an university in Korea. The research results are as follows. When a fire occurred in the ironing room inside the cadet dormitory, a smoke detector operated after 65 seconds. Thirteen seconds later, a sprinkler started to operate. The temperature and carbon monoxide density reached the limit value at 241 and 248 seconds, respectively. Because the limit visibility value was reached within 66 seconds after the occurrence of a fire, it is predicted that preparation must be finished and evacuation should begin within 1 minute after the fire occurs, in order to have no casualties. Synthesizing this dormitory fire risk prediction result, the visibility value is considered to be the most dangerous factor for personal safety. Because of this, installing a smoke extraction system is suggested to secure visibility. After the installation of a smoke extraction system, the problem of smoke diffusion in the corridors improved.

• Current Research on Agriculture and Life Sciences
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• v.24
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• pp.1-8
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• 2006

When tea trees were introduced to Korea peninsular from China? Historically, Mr. Taeryum, an envoy of Shilla dynasty brought tea seeds from China during Tang dynasty and the seeds were planted at Jiri Mt. by the order of King Heungduk at AD828. During Koryo Dynasty(918 1392), Buddhism spread rapidly all over the country and the tea culture reached its highest stage of prosperity. At the Chosun Dynasty, however, the ceremonial drinking of tea vanished almost completely due to the flourishing Confucian tradition, a kind of substitution of Buddhism. But a few people have supported the traditional tea culture by themselves. Since the independence of Korea soon after the World War II at 1945, Korean War have been exploded at 1950. After economic evolution have been succeeded at 1980, the cultivation area of tea trees has been increased about 2,000ha and the cultural tradition of tea drinking has become popular again at a tea consume quantities amounted to 100g per capita at 2004. The northern limited area of tea plant is lined on the southern part of Korea peninsular. It is very small region compared to China about one million ha and to Japan over 60 thousand ha. It is problem not only the area of tea fields but also the methodology of tea cultivation, for examples without clonal cultivars and mechanical systems. WTO treatments was discussing with Korea, China and Japan government at 2005. Green tea custom is very high at 514% in Korea. If three countries will be agreed the imported tax will be cut off, the Korean tea farmers will be confused because of unstable situation of tea markets. All most of tea farmers should be made the tea fields by seeding not clonal propagation. Because of clonal cultivars have not developed in Korea, there have not been the research institutes for tea plants and manufactures before 1992. Now there are three research institute of tea in Korea; Tea Experiment Station at Bosung of Jeonnam Agricultural Research & Extension Services, Mokpo Experimental Station of National Institute of Crop Science, and Green Tea Cluster Institute of Hadong. Mokpo and Hadong Research Station were established at 2004 and at 2005 but Bosung Station was established at 1992. Seven clonal tea cultivers were selected at Bosung Station; Bohyang, Myngsun, Chanlok, Sunhyang, Mihyang, Jinhyang and Ohsun until 2004. Mokpo Experimental Institute was started the tea provenance testing about 4 provenances: Kangwon-do, Jeonlabuk-do, Jeonlanam-do, and Kyungsangnam-do. Korean new tea cultivers should be selected because Koran wild tea population have been high genetic variation. If tea breeding research will be successful to select new clonal cultivers, the tea farmers of Korea will be stable after WTO treatment with each country.

• Korean Journal of Agricultural Science
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• v.31 no.2
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• pp.105-114
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• 2004

This study was performed to examine the physical and mechanical properties of eco-concrete using soil, natural coarse aggregate, soil compound and polypropylen fiber. The mass loss ratio was decreased with increasing the content of coarse aggregate and soil compound. The compressive strength, flexural strength, ultrasonic pulse velocity and dynamic modulus of elasticity were increased with increasing the content of coarse aggregate, soil compound and polypropylene fiber. The compressive and flexural strengths were showed in 8.07 MPa and 2.641 MPa at the curing age 28 days, respectively. The coefficient of permeability was decreased with increasing the content of coarse aggregate and soil compound, but it was increased with increasing the content of polypropylene fiber. The lowest coefficent of permeability was showed in $5.066{\times}10^{-9}cm/s$.

• Current Research on Agriculture and Life Sciences
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• v.33 no.2
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• pp.41-47
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• 2015

This study calculated the overall heat transfer coefficient (U-value) of greenhouse covering materials with thermal screens using a simulation model and then estimated the validity of the calculated results by comparison with measured values. The U-value decreased gradually as the thickness of the air space between the double glazing increased, and then remained essentially constant at thicknesses exceeding 25 mm. The U-value also increased with the difference in temperature between the inside and outside of the hot box. The vigorous convective heat transfer between two plastic films caused unsteady heat flow and then created a nonlinear temperature distribution in the air space. The distance did not affect the U-value at distances of 50~200 mm between the plastic covering and thermal curtain. The numerical calculation results, with and without sky radiation, were in accord with the experimental results for a $30^{\circ}C$ temperature difference between the inside and outside of the hot box. In conclusion, a reliable U-value can be calculated for a temperature difference of $30^{\circ}C$ or more between the inside and outside of the hot box.

• Archives of design research
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• v.11 no.2
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• pp.215-226
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• 1998

As late as middle of 1980s, what was referred to as new model cars consisted, on the premise of a standardized packaging layout, principally of the endeavor to transform their style images by changing little by little the form of layouts almosts similar to or with larger bodies than those of the old model ones. Afterwards even in the period of competition of engeineering and mechanical body styles for reducing fuel cost and improving comfortability in riding, the standardized packaging layout did not change visibly, simply trying to ameliorating commercialism through high output and high efficacy on the engineering part. Today the sudden prevalent motorization in every walk of life has brought about the development of the car industry, thus producing surplus supply and technical standardization. This phenomenon of technical standardization leads the concept of the renovation of car design to a way quite different from that of the past and so may be said to be confronted with an era that requires genuine-sense car design in a way. It seems that interior design plans are of much more importance than external shapes. This is because the effort for enhancing comfortability to keep car passengers' needs of transportation is one of the essences of car design. The objective of this study consists in inquiring into how to plan motorcar interior design, an essential prerequisite in determining the external or of a car, obtaining data needed via analysis of interior design plans of the car models that have won favorable criticism from consumers, thus contributing to the use of the data obtained for reference in car design activities in a genuine sense.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.3
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• pp.41-47
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• 2009

Post-tensioned concrete pavement(PTCP) was developed to built long-span concrete pavement(120 m span) and to maintain long-term service life(over 40 years) of concrete pavement. In the present study, research for high-durable concrete was conducted to utilize the advantage of PTCP construction method efficiently. First of all, 20% of fly ash(by binder weight) was replaced to control alkali silica reaction. Second, silica fume was applied to improve the water-permeability and early-age strength. Results of tests for mechanical properties, water-permeability resistance, and surface-scaling resistance of ternary blended cement concrete showed that the early-age strength was improved significantly with addition of silica fume. The water-permeability resistance was improved from "Low" to "Very Low"(ASTM C 1202). However, surface-scaling resistance was decreased with an increase of silica fume, therefore, content of silica fume should be kept in less than 5%(by binder weight) to assure field application considering durability. The results of air-void analysis showed that durability factors were improved since spacing factors were estimated as 250$\pm$15 micron in adjusted mixtures.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.2
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• pp.170-176
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• 2012

In the nuclear industry, wall thinning defect of straight pipe occur the enormous loss in life evaluation and safety evaluation. To use non-destructive technique, we measure deformation, vibration, defect evaluation. But, this techniques are a weak that is the measurement of the wide area is difficult and the time is caught long. In the secondary side of nuclear power plants mostly used steel pipe, artificiality wall thinning defect make in the side and different thickness make to the each other, wall thinning defect part of deformation measure by using shearography. In addition, optical measurement through deformation, vibration, defect evaluation evaluate pipe and thickness defects of pressure vessel is to evaluate quantitatively. By shearography interferometry to measure the pipe's internal wall thinning defect and the variation of pressure use the proposed technique, the quantitative defect is to evaluate the thickness of the surplus. The amount of deformation use thickness of surplus prediction of the actual thickness defect and approximately 7 percent error by ensure reliability. According to pressure the amount of deformation and the thickness of the surplus through DB construction, nuclear power plant pipe use wall thinning part soundness evaluation. In this study, pressure vessel of thickness defect measure proposed nuclear pipe of wall thinning defect prediction and integrity assessment technology development. As a basic research defected theory and experiment, pressure vessel of advanced stability and soundness and maintainability is expected to contribute foundation establishment.

• Journal of radiological science and technology
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• v.26 no.3
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• pp.51-57
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• 2003

Mitigation of fast neutron irradiation damage on reactor vessel and improvement of mechanical integrity are desired for the successful plant life-time extension. In this study, the performance of metallic hydride for this application is reviewed and compared. First, selected prospective metallic hydrides are evaluated by MCNP code and put into the attenuation test using Cf-252 neutron source. Since for the reactor application high moderation and reflection with no absorption are favored, Z factor is introduced for the evaluation. According to the Z value estimation $ZrD_2$ and $TiD_2$ are turned out to be the most favorable fast neutron shielding materials. More thorough evaluation by computer simulation and experimentally, will be followed.