• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.931-938
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• 2005

When concrete structures are exposed under marine condition for a long time, the steel in concrete is corroded due to the ingression of chlorides in the seawater. Because the damages of corrosion resulting from the chloride ion are very serious, many researches have been performed. Silver nitrate colormetric method that can measure easily penetration depth of chloride ion has been executed, recent)y. However, characteristics of silver nitrate colormetric method were not fully examined. Therefore, the objective of this paper Is to study the applicability of colormetric method. For the purpose of this, effect factors and reaction mechanism of colormetric method were investigated, and the colormetric method is applied for marine concrete structures. According to the results of silver nitrate colored method, two reactions such as white reaction of AgCl and brown reaction of AgOH were shown when $AgNO_3$ was sprayed in splited section. And velocity constant ratio(K) of two reactions appeared that white reaction, AgCl reacts with the fast speed by 3240. When the colormetric method was applied in concrete, it is reasonable that $AgNO_3$ solution more than 0.05N concentration was sprayed. It is confirmed that the colormetric method is useful tool for estimating the chloride of concrete structures in situ. The average chloride amount of colored parts indicates $0.9kg/m^3$ per concrete unit weight.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.513-521
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• 2019

With rapid climate change and increasing global warming, the distribution of evergreen broad-leaved trees (EBLTs) is gradually expanding to the inland regions of Korea. The aim of the present study was to analyze the survival rate of 148 EBLT plantations measuring 180 ha and to determine the optimal plantation size that would help in coping with climate change in the warm, temperate climate zone of the Korean peninsula. For enhancing the reliability of our estimated survival model, we selected a set of 11 control variables that may have also influenced the survival rates of the EBLTs in the 148 plantations. The results of partial correlation analysis showed that the survival rate of 67.0±26.9 of the EBLTs in the initial plantation year was primarily correlated with plantation type by the crown closure of the upper story of the forest, wind exposure, and precipitation. For predicting the probability of survival by quantification theory, 148 plots were surveyed and analyzed with 11 environmental site factors. Survival rate was in the order of plantation type by the crown closure of upper story of the forest, wind exposure, total cumulative precipitation for two weeks prior to planting, and slope stiffness in the descending order of score range in the estimated survival model for the EBLTs with the fact that survival rate increased with shade rate of upper story to some extent.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.469-477
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• 2002

One of the major deficiencies of composite restorative resins is their insufficient resistance to wear. Of the multitude of factors that have been associated with wear, subsurface degradation within the restoration is considered to be one. The aim of this study was to evaluate the resistance to degradation of four commercial composite resins in an alkaline solution. The brands studied were Z100(3M), Clearfil AP-X(Kuraray), Tetric Ceram(Vivadent), Aelit flo(Bisco). Resistance to degradation was evaluated on the basis of the following parameters: (a) mass loss(%) - determined from pre-and post-exposure specimen weights: (b) Si loss(ppm) - obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation depth(${\mu}m$) - measured microscopically (SEM) from polished circular sections of exposed specimens. The results were as follows: 1. The sequence of the mass loss was in ascending order by AE, EL, TC, Z100. There was statistically significant difference of mass loss between AE, CL group and TC, Z100 group(p<0.05). 2. The sequence of the degree of degradation layer depth was in ascending order by AE, CL, TC, Z100. But there was no statistically significant difference of degree of degradation layer depth between AE and CL(p<0.05). 3. For the Si concentration, Z100 was the highest of all. 4. The correlation coefficient between mass loss and degradation depth was relatively high(r=0.71 p<0.05).

• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.121-134
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• 2012

This study was conducted to investigate the acceptance of vegetable menus by high school students and the factors that influence the acceptability. Second-grade high school students (n=389) in Seoul were asked to assess their acceptability of vegetable menus and plate waste, and answered survey questions concerning their demographic characteristics, health-related attitudes, dietary attitudes, dietary habits, and nutritional knowledge. Overall, the menus containing items that were sweet or familiar to the subjects were preferred. Acceptability was significantly associated with the amount of consumption. The acceptability was correlated with dietary habits, dietary attitudes, nutritional knowledge, and several health-related variables. The vegetable-liking groups showed significantly higher scores concerning dietary habits, dietary attitudes, and nutritional knowledge, but did not exhibit a specific pattern of association with the health-related variables. This result implies that intervention strategies focusing on changes in cognitive and/or hedonic factors, such as nutritional education or flavor-flavor learning, would be beneficial for increasing students' acceptance of vegetable menus.

• Journal of Life Science
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• v.21 no.1
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• pp.36-43
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• 2011

Diabetes mellitus is associated with vascular complications. Diabetic patients exhibit high levels of glycated adducts in serum compared to non-diabetic individuals. The aim of this study was to investigate whether extracellular glycated albumin (GA) predisposes vascular smooth muscle cells (VSMCs) to pro-inflammatory phenotype. Exposure of rat aortic smooth muscle cells (AoSMCs) to GA not only enhanced interleukin-6 (IL-6) release but also activated promoter activity of the IL-6 gene. GA-induced IL-6 promoter activation was suppressed by dominant-negative forms of Toll-like receptor (TLR)-4 and myeloid differentiation factor 88 (MyD88), but not by dominant-negative-forms of TLR-2 and TIR-domain-containing adapter-inducing interferon-$\beta$ (TRIF). Extracellular signal-regulated kinase (ERK) inhibition and diphenyleneiodium (DPI) also attenuated IL-6 induction by GA. Mutation at the nuclear factor-${\kappa}B$ (NF-${\kappa}B$)-binding site in the IL-6 promoter region suppressed promoter activation in response to GA. The present study proposes that GA would contribute to inflammatory reaction in the stressed vasculature by inducing IL-6 in VSMCs, and that TLR-4, EKR, and NF-${\kappa}B$ play active roles in the process.

• Journal of Conservation Science
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• v.25 no.1
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• pp.49-60
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• 2009

Outdoor iron artefacts are easily corroded by salts, especially $Cl^-$ion, from environmental pollutants and acid rain because of their location, so that they need conservational treatments such as stabilization. However the conservation of outdoor iron artefacts are limited to be consolidated for the present and there are a few the studies for the desalinization. The general desalinization method is that objects are immersed in reagent such as alkaline corrosion inhibiting solutions targeting on buried iron artefacts, thus they are not available for outdoor iron artefacts. In this study, concerning those difficulties, the different desalting method is experimented that materials soaked in alkaline solutions attach to objects and they are packed by waterproof to avoid evaporation. This paper experiment burial iron artefacts at first in order to fine out an adaptable method for outdoor iron artefacts. The soaking materials are Korean traditional paper, gauze, cotton wipers, spill pads and the desalting regent is NaOH 0.1M. Additionally the exiting desalinization method which is to immerse objects in solution is performed to compare. The analyses are microscopes, SEM-EDS, X-ray diffraction, pH meter and Ion chromatography. The result is that spill pads show the best desalting effect out of other materials similar to immersing desalting method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.83-91
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• 2015

With varying conditions of concrete surface, induced chloride contents are changed and this is a key parameter for steel corrosion and service life in RC (Reinforced Concrete) structures. Many surface enhancement techniques using impregnation have been developed, however the evaluation techniques for chloride behavior through doubly layered media and time-dependent diffusion are rarely proposed. This paper presents an analysis technique considering double-layer concrete and time-dependent diffusion behavior, and the results are compared with those from the previous test results through reverse analysis. The chloride profiles from the surface-impregnated concrete exposed to atmospheric, tidal, submerged zone for 2 years are adopted. Furthermore surface chloride contents and diffusion coefficients are obtained, and are compared with those from Life365. Through consideration of time effect, the relative error decreases from 0.28 to 0.20 in atmospheric, 0.29 to 0.11 in tidal, and 0.54 to 0.40 in submerged zone, respectively, which shows more reasonable results. Utilizing the diffusion coefficients from Life365, relative errors increases and it needs deeper penetration depth (e) and lower diffusion coefficient ratio ($D_1/D_2$) due to higher diffusion coefficient.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.4 no.2
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• pp.77-87
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• 1986

As for the deformation measurement of structure, there are many controversial points in using the methods by the strain guage, inclinometer, bial guage, and geodetic method because of the difficulty of instrument setting and the problem in the degree of accuracy of the results as well as in the economical aspect. Therefore, to verify the superiority of the Close- Range Photogrammetry method for the structural deformation measurement, the result of load deformation on the model structure, which was made using the Close-Range Photogrammetry method was compard with the results which was made using the methods of dial guage, precision level, and triangulation. In addition to that, to consider the general problem which would happen when C. R. P method was applied to the practical structure. The elements of C. R. P method like camera rotation angle ($\psi$,$\omega$), exposure elevation (Z$_{L}$), and angle of inclined base line ($\theta$) were experimented, and their specificities were reconsidered. As a result, the application of C. R. P method to the general structure is expected to be increased not only in the aspect of accuracy but in the economical aspect.t.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.4
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• pp.351-359
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• 2015

Acute and chronic ultraviolet (UV) irradiation triggers severe skin photoaging processes, which directly disrupt the normal three-dimensional integrity of skin. UV light stimulates the expression of matrix metalloproteinases (MMPs) which degrade constituents of extracellular matrix (ECM) proteins. These MMPs reduce collagen synthesis and decrease skin elasticity and integrity, resulting in wrinkle formation. In this study, we identified Rosa multiflora hip extract (RME) as an effective anti-photoaging ingredient. First, cell proliferation activity of RME was verified using Hs68 human dermal fibroblast cell line. RME downregulated MMPs expression through the inhibition of activator protein (AP)-1. In addition, type I and IV collagen expressions were increased with RME treatment and UVB-induced inflammatory responses were also reduced after RME treatment. In conclusion, R. multiflora hip extract may effectively improve UVB-induced skin aging and wrinkle formation which may provide as an anti-aging, anti-wrinkle, and anti-inflammation ingredient in cosmetic industry.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.1
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• pp.79-87
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• 2010

Ultraviolet is the one of the main environmental factors promoting aging process via increased intracellular generation of reactive oxygen species (ROS) and decreased expression of endogenous antioxidant enzymes and molecules. Therefore, in this study, we tried to search for natural skin-protective antioxidant materials from marine origins (Porphyra Thalli, Laminariae japonicae thallus, Ostreae Concha, Sargassum Thallus, Undaria thallus, Haliotidis Concha, Codium thalli, Syngnathoides biaculeatus, Hippocampus, Stichopus Stichopus, Thalli, Hizikia fusiforme thalli) which exhibit free radical scavenging activity and protect against UVB-induced cytotoxicity and oxidative cell death. Free radical scavenging activity was shown in order of Undaria thallus. Sargassum Thallus, Laminariae japonicae thallus, Hippocampus, Haliotidis Concha, Ostreae Concha, Syngnathoides biacuJeatus. In another experiment, UVB-induced cytotoxicity and cell death were effectively suppressed by treatment of Sargassum Thallus, Haliotidis Concha, Codium thalli, or Hippocampus water extract. Furthermore, UVB-induced cell death was mediated by intracellular accumulation or ROS, which was significantly inhibited by treatment with aforementioned extracts. The protective effect of these marine natural products seemed to be mediated by increased expression of antioxidant enzymes such as catalase, superoxide dismutase, and heme oxygenase-1. These results suggest that Sargassum Thallus, Haliotidis Concha, Codium thalli, and Hippocampus may have preventive and protective potentials as new functional cosmetics against oxidative stress-mediated skin damages and aging with antioxidant properties.