• Journal of Ginseng Research
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• v.42 no.4
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• pp.540-548
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• 2018

Background: Acute hepatic failure is a life-threatening critical condition associated with rapid deterioration of liver function and liver transplantation. Several studies have shown that Panax ginseng Mayer has antidiabetic and hepatoprotective effects. However, the hepatoprotective effect of ginseng berry is still unveiled. In this study, we evaluated the hepatoprotective effects of ultrasonication-processed ginseng berry extract (UGBE) on acute hepatic failure model in rats. Methods: Ginseng berry extract (GBE) was ultrasonically processed. The GBE, silymarin, and UGBE were orally administered to male Sprague-Dawley rats for 4 wk. Twenty-four h after the last administration, rats were challenged with D-galactosamine (D-GalN)/lipopolysaccharide (LPS). Results: After ultrasonication, the component ratio of ginsenosides Rg2, Rg3, Rh1, Rh4, Rk1, Rk3, and F4 in GBE had been elevated. Administration of UGBE significantly increased the survival rate of D-GalN/LPS-challenged rats. Pretreatment with UGBE significantly decreased serum alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels in D-GalN/LPS-challenged rats in a dose-dependent manner. The levels of enzymatic markers for oxidative stress (superoxide dismutase, glutathione peroxidase, catalase, and glutathione) were increased by UGBE treatment in a dose-dependent manner. Tumor necrosis factor alphalevel, inducible nitric oxide synthase activities, and nitric oxide productions were reduced by UGBE treatment. In addition, hemeoxygenase-1 levels in liver were also significantly increased in the UGBE-treated group. The protein expression of toll-like receptor 4 was decreased by UGBE administration. Hematoxylin and eosin staining results also supported the results of this study showing normal appearance of liver histopathology in the UGBE-treated group. Conclusion: UGBE showed a great hepatoprotective effect on D-GalN/LPS-challenged rats via the toll-like receptor 4 signaling pathway.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.101-104
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• 2008

The cost of repairing the deterioration of concrete structures due to corrosion of the reinforcement steel has been the prominent figure in the maintenacne of the reinforced-concrete infrastructures. As an alternative material to steel reinforcement, the use of Fiber Reinforced Polymer (FRP) bar in concrete is being actively studied for the high resistance of chemical environment and high strength to weight ratio properties of FRP. However, there remain various aspects of FRP properties that still need to be studied before the standard design criteria can be established. One of the imminent issues is the bond between FRP and concrete. In this study, the bond-behavior of FRP bars in concrete is investigated via the pullout test with three varying parameters: surface condition of FRP bars, concrete compression strength, and cyclic loading patterns. As a result of experiment, the bond strength of GFRP increased with the concrete compression strength increasing and decreased with applying cyclic load.

• Journal of Korean Association for Spatial Structures
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• v.9 no.3
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• pp.93-100
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• 2009

As interest in latest cultural heritance is increased, an importance about conservation of dilapidated cultural building asset is risen. Most of cultural building asset used wood by main material and conservation repair about corrosion and damage by deterioration of these cultural building asset considers cultural value of member and the basis principle is the archetype maintenance. Accordingly, conservation processing method that use synthetic is embossed. This paper experimented with reinforcement sectional area ratio, direction of section, length, strength of synthetic resins as variable and manufactures total 14 specimens as experimental study about compression reinforcement performance of circular section wood that strengthen by synthetic resins. The result of this paper has shown that adequate strengthen is more efficient than new member and the most important authenticity in strengthen and repair of cultural heritance can be ensured.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.2
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• pp.9-17
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• 2020

The ratio of the deterioration housing in rural area was 29.6%, but it was 18.3% in urban area based on a 2018 survey. In consideration of the point, this study aims to analyze the actual condition of indoor air quality in rural houses to provide basic data for improving the indoor air environment. It was investigated 15housings of Hongseong-gun, Chungchengnam-do. To investigate the correlation between indoor air quality and housing type, both the field survey of housing type and precision diagnosis of concentration of indoor air pollutants such as HCHO, TVOC, Fine dust(PM-10, PM-2.5), CO₂, Radon. The results of this study are as follows. First, according to the average value of each element of rural old housing, the construction year was distributed in 1939~2004, and 12households(80%) living in houses older than 30years have passed for about 46years. As for the housing area, more than 12houses(80%) of 60㎡ or more and 3 houses (20%) of less than 60㎡ were often living in relatively small-scale housing. Second, as a result of measuring indoor air pollutants in rural houses, substances exceeding the standard values were found in HCHO, TVOC, CO₂. Third, in the case of Fine dust and Radon, none of such factors were exceeded the standard. Fourth, there was no significant difference in indoor air quality depending on housing type in rural houses. This paper is expected to contribute to the regional development projects and effective implementation of rural policies.

• Elastomers and Composites
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• v.47 no.2
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• pp.162-167
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• 2012

Surface modification of macromolecules renders a progressive and favorable method to enhance the properties of polymeric materials and improves conductivity, wettability, stability, adhesion, antibacterial properties, etc. of polymeric surfaces without deterioration of the polymer bulk properties. Polyolefins such as polyethylene and polypropylene were grafted with maleic anhydride(MAH) as a functional monomer in solution. Evidence for grafting was shown with FTIR measurement. The grafting ratio was determined from chemical titration. The higher MAH loading, the lower contact angle(${\theta}$) was obtained. With the increasing content of MAH, melting temperature($T_m$) of maleic anhydride grafted polymer decreased while decomposition temperature($T_d$) of maleic anhydride grafted polymer increased.

• Korean Journal of Plant Resources
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• v.28 no.1
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• pp.135-144
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• 2015

The Korean daily intake of vegetable oils has increased about 2.5-fold from 17 g/day to 46 g/day for the last several decades. Perilla (Perilla frutescens var. frutescens) has been cultivated in Korea for a long time as a dietary oil seed which has the highest content of ${\alpha}$-linolenic acid, accounting for nearly 60%. It is known that the main role of ALA is as a precursor to the longer-chain ${\omega}-3$, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), the metabolic products of ${\alpha}$-linolenic acid (ALA, ${\omega}-3$). Dietary ${\omega}-3$ fatty acids reduce inflammation and the risk of chronic diseases such as heart disease, cancer, and arthritis, but they also may act as functional components for cognitive and behavioral function. Thus, ${\alpha}$-linolenic acid is one of the essential nutrients in modern dietary patterns in which much linoleic acid is consumed. Nevertheless, perilla oil, rich in ${\alpha}$-linolenic acid, can be easily oxidized, giving rise to controversies with respect to shelf life, the deterioration of the product's commercial value, and further related toxicity. Recent research using genetic modifications has tried to develop new plant oil seeds that balance the ratio of ${\omega}-6/{\omega}-3$ fatty acids. Such trials could be a strategy for improving an easily oxidizable property of perilla oil due to high ${\alpha}$-linolenic acid. Alternatively, appropriate application of antioxidant to the oil can be considerable.

• Structural Engineering and Mechanics
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• v.54 no.6
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• pp.1135-1152
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• 2015

Most of current bridge decks are made of reinforced concrete and often deteriorate at a relatively rapid rate in operational environments. The quick deterioration of the deck often impacts other critical components of the bridge. Another disadvantage of the concrete deck is its high weight in long-span bridges. Therefore, it is essential to examine new materials and innovative designs using hybrid system consisting conventional materials such as concrete and steel with FRP plates which is also known as composite deck. Since these decks are relatively new, so it would be useful to evaluate their performances in more details. The present study is dedicated to Hat-Shape composite girder with concrete slab. The structural performance of girder was evaluated with nonlinear finite element method by using ABAQUS and numerical results have been compared with experimental results of other researches. After ensuring the validity of numerical modeling of composite deck, parametric studies have been conducted; such as investigating the effects of constituent properties by changing the compressive strength of concrete slab and Elasticity modulus of GFRP materials. The efficacy of the GFRP box girders has been studied by changing GFRP material to steel and aluminum. In addition, the effect of Cross-Sectional Configuration has been evaluated. It was found that the behavior of this type of composite girders can be studied with numerical methods without carrying out costly experiments. The material properties can be modified to improve ultimate load capacity of the composite girder. strength-to-weight ratio of the girder increased by changing the GFRP material to aluminum and ultimate load capacity enhanced by deformation of composite girder cross-section.

• Journal of the Korea Concrete Institute
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• v.13 no.2
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• pp.175-183
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• 2001

Immersion tests with artificial seawater were carried out to investigate the resistance to seawater attack of 5 types of cement matrices. From the results of compressive strength and length change, it was found that blended cement mortars due to mineral admixtures, were superior to portland cement mortars with respect to the resistance to seawater attack. Moreover, XRD analysis indicated that the peak intensity ratio of low heat portland cement(LHC) paste, in portland cement pastes, had better results, and so did that of blended cement Paste. Pore volume of pastes by mercury intrusion porosimetry method demonstrated that total pore volume of ordinary portland cement(OPC) paste had a remarkable increase comparing with that of other pastes. In case of immersion of artificial seawater, the use of ground granulated blast-furnace slag and fly ash, however, showed the beneficial effects of 56% and 32% in reduction of total pore volume, respectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.263-270
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• 2011

In this study, the performance of Poly-Naphthalene Sulfonate (PNS) type-admixture used widely in South Korea and Polycarboxilic type-admixture(i.e., WF2000) developed in the J company of the domestic, for precast concrete products produced in the factories, was evaluated. With the 20% reduced usage of WF2000 compared to PNS type-admixture, workability was considerably improved due to high water-reducing ratio, accelerating effect of concrete setting and accelerant dispersant action, which the product has, under the high temperature. In addition, the development of initial and long-term strengths of PHC plies was predominant. For WF2000, it is also possible to correspond with the change of original materials and environmental conditions since the control of water-reducing and supporting forces is feasible. Accordingly, it was noted that WF2000 is superior for deterioration of production & workability and bad casting problems in summer and the solution of initial strength reduction problem due to the delay of setting in winter.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.3
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• pp.1-8
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• 2017

An experimental study is needed a reinforcing method for seismic load to apply for RC structures because a lot of earthquakes have frequently happened in the world and those also collapsed infrastructures or damaged human lives. The reinforcing effect of PolyUrea (PU) appeared to be excellent under blast and impact about RC structures. In this study, Stiff Type PolyUrea (STPU) had developed by manipulating the ratio of the components of prepolymer and hardener of PU. And the durability performance evaluation of STPU for deterioration and chemical resistance has been performed. Acid environmental exposure test and ultraviolet (UV) exposure test have been performed as the durability performance evaluation for STPU. Concrete carbonation exposure test and freezing and thawing test for concrete coated with STPU have been performed. The experimental result showed that STPU has high resisting capacity and durability in all tests. Therefore, STPU would be used as seismic reinforcement materials.