• Proceedings of the Korea Water Resources Association Conference
• /
• 2016.05a
• /
• pp.193-193
• /
• 2016

In past decades beach erosion has been remarkably severe along coasts of different parts of the world, so that distinct types of coastal protective measures have been implemented; seawalls, wave-dissipating breakwaters, groins, artificial headlands or detached breakwaters have been constructed. In recent years, at Bongpeong beach, South Korea, an artificial headland was constructed to stop the beach erosion. The structure resulted in severe beach erosion of the adjoining places. In order to stop the consequences, another headland was constructed at some distance, but the construction of double headland did not prevent the erosion significantly. This paper focuses on the accurate design of the artificial double headland construction. The study presents the application of equilibrium shoreline empirical formula of parabolic type to estimate the equilibrium stages of the artificial double headland beaches and an analytic solution is presented in the present study. The research has solved the empirical formula of parabolic type to find the optimum result by considering the essential parameters that influence the erosion after the construction of double headland.

• Applied Chemistry for Engineering
• /
• v.26 no.4
• /
• pp.470-476
• /
• 2015

In this study, three dicaffeoylquinic acids (DCQAs) isolated from Gnaphalium affine D. DON. extracts were structurally identified and evaluated for their antioxidant activities, cellular protective effects, and tyrosinase inhibitory activities. The ethyl acetate fraction of G. affine was chromatographed, which yielded 3 DCQA derivatives of 1-3 : 3,5-dicaffoylquinic acid (3,5-DCQA, 1), 4,5-dicaffeoylquinic acid (4,5-DCQA, 2), 1,5-dicaffoylquinic acid (1,5-DCQA, 3). The structure of each compounds was determined using $^1H$ NMR and MS analyses. Compounds of 1-3 showed strong free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities ($FSC_{50}=3.70$, 5.80, and $5.50{\mu}M$, respectively) compared to those of a commonly used lipophilic antioxidant, (+)-${\alpha}$-tocopherol ($21.90{\mu}M$). Cellular protective effects of 1-3 compounds on the $^1O_2$ sensitized photohemolysis of human erythrocytes were similar to (+)-${\alpha}$-tocopherol. 1-3 compounds also exhibited higher tyrosinase inhibitory effects ($IC_{50}=0.15$, 0.16, and 0.13 mM) compared to arbutin (0.33 mM), known as a skin-whitening agent. These results indicate that three DCQA derivatives may be applied as an antioxidant and a skin whitening agent in food or cosmetic industries.

• Journal of the Korean Society of School Health
• /
• v.11 no.1
• /
• pp.111-121
• /
• 1998

This is the study to the effect that the problems of the protective institution where the whole health of school is performed should be solved for the purpose of much more effective school business after investigating the situations of the management about health system in the elementary school of seoul city The subjects of the research are five students of the school which practices health class in the protective institution, five students of the school which puts health class to practice in each classroom and five nursing teachers who work for each elementary school Its data resulted from that from July to September 1997, I visited five schools in person at Kang nam ku, Dong chak ku, Yong san ku, Kwan ak ku, Kang dong ku and then I met and talked with the nursing teacher and the children Through this inspection and interpretation, I could figure out such things as follows. 1 The structure of the nursing room is so small that it has quite a few things inconvenient for the children and the nursing teacher to use together So for the sake of the health in school, first of all, Its size has to be larger 2. The name as the protective institution has to be changed into the health room. And the room for rest cure, dressing room, counselling room and the room for the health education should be equipped with the inside of health room 3 The nursing teacher as a health teacher has to carry out the health class at a health room. 4 It was required that the principal and the Ministry of Education should be highly interested in the health of school In particular, the advice for instructing expert agents about the health and the cooperation of the principal was urgently demanded. Through the result above, the health of school will be accomplished not only in first-aid treat and injection but also in the education about health as a main duty And the nursing teacher also can play a role as a teacher for health fully The programming, practice and estimation of the health room of the business for health in school will be feedback.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.48 no.2
• /
• pp.123-134
• /
• 2022

In this study, the whitening and antioxidant effects of the extracts from Hydrangea petiolaris (H. petiolaris) leaves was confirmed, and the chemical structure was identified by separating the active ingredients. In the whitening tests using α-MSH stimulated B16F10 melanoma cells, the n-hexane (Hex) fraction inhibited the cellular melanogenesis and intracellular tyrosinase activities without causing cell toxicity. In addition, the Hex fraction reduced expression of tyrosinase and TRP-2 protein. Upon the anti-oxidative studies by DPPH and ABTS⁺ radicals, potent radical scavenging activities were observed in the ethyl acetate (EtOAc) fraction. Also, for the cellular protective effects on HaCat keratinocytes damaged by H₂O₂, the EtOAc fraction indicated protective effects against oxidative stress. Eight phytochemicals were isolated from the extract of H. petiolaris leaves; ethyl linoleate (1), ethyl linolenate (2), 1-linoleoyl glycerol (3), 1-linolenoyl glycerol (4), epi-catechin (5), afzelin (6), quercitrin (7), hyperin (8). Among the isolates, the compounds 5 - 8 showed DPPH and ABTS⁺ radical scavenging activities. The contents of quercitirin, a major isolated in this extract, determined by HPLC analysis were confirmed to be about 31.3 mg/g for the 70% ethanol extract and 169.8 mg/g for the EtOAc fraction. Based on these results, it was suggested that the extract from H. petiolaris leaves could be potentially applicable as whitening and anti-oxidative ingredients in cosmetic formulations.

• Journal of the Korean institute of surface engineering
• /
• v.42 no.6
• /
• pp.287-293
• /
• 2009

The passivation films with epoxy layer on LiF, $SiN_x$ and LiF/$SiN_x$ inorganic layer were fabricated on OLED to protect device from the direct damage of $O_2$ and $H_2O$ and to apply for a buffer layer between OLED device and passivation multi-layer with organic/inorganic hybrid structure as to diminish the thermal stress and expansion. Red OLED doped with 1 vol.% Rubrene in $Alq_3$ was used as a basic device. The device structure was multi-layer of ITO(150 nm) / ELM200_HIL(50 nm) / ELM002_HTL(30 nm) / $Alq_3$: 1 vol.% Rubrene(30 nm) / $Alq_3$(30 nm) / LiF(0.7 nm) / Al(100 nm). LiF/epoxy applied as a protective layer didn't contribute to the improvement of life time. While in case of $SiN_x$/epoxy, damage was done in the passivation process because of difference in heat expansion between films which could occur during the formation of epoxy film. Using LiF/$SiN_x$/epoxy improved lifetime significantly without suffering damage in the process of forming films, therefore, the best structure of passivation film with inorganic/epoxy layers was LiF/$SiN_x$/E1.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.480-480
• /
• 2010

In the present work, we studied effect of the deposition parameters on the structure and properties of ZnO films deposited by DC arc plasmatron. The varied parameters were gas flow rates, precursor composition, substrate temperature and post-deposition annealing temperature. Vapor of Zinc acetylacetone was used as source materials, oxygen was used as working gas and argon was used as the cathode protective gas and a transport gas for the vapor. The plasmatron power was varied in the range of 700-1,500 watts. Flow rate of the gases and substrate temperature rate were varied in the wide range to optimize the properties of the deposited coatings. After deposition films were annealed in the hydrogen atmosphere in the wide range of temperatures. Structure of coatings was investigated using XRD and SEM. Chemical composition was analyzed using x-ray photo-electron spectroscopy. Sheet conductivity was measured by 4-point probe method. Optical properties of the transparent ZnO-based coatings were studied by the spectroscopy. It was shown that deposition by a DC Arc plasmatron can be used for low-cost production of zinc oxide films with good optical and electrical properties. Sheet resistance of 4 Ohms cm was achieved after the deposition and 30 min annealing in the hydrogen at $350^{\circ}C$. Elevation of the substrate temperature during the deposition process up to $350^{\circ}C$ leads to decreasing of the film's resistance due to rearrangement of the crystalline structure.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.9
• /
• pp.1143-1150
• /
• 2017

The aim of this study was to determine the chemical and intracellular antioxidant activities of ${\beta}$-carotene and lycopene and to compare their quantitative structure-activity relationship (QSAR). In our previous study, the second ionization energy of lycopene was higher than that of ${\beta}$-carotene, as calculated by QSAR. Chemical antioxidant activities of ${\beta}$-carotene, lycopene, and Trolox were examined by measuring ferric reducing antioxidant power (FRAP) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Intracellular antioxidant activities were evaluated by intracellular reactive oxygen species (ROS) and DNA fragmentation. The FRAP of lycopene was higher than that of ${\beta}$-carotene (P<0.05), and the two carotenoids had similar antioxidant activities in DPPH radical scavenging activity assay. Trolox had the greatest chemical antioxidant activities (P<0.05). When RAW264.7 cells were treated with lipopolysaccharide (LPS) (100 ng/mL) for 20 h, intracellular ROS and DNA fragmentation significantly increased (P<0.05). RAW 264.7 cells pretreated with ${\beta}$-carotene ($4{\mu}M$) and lycopene ($0.4{\sim}2{\mu}M$) for 4 h formed significantly less intracellular ROS than LPS-treated control cells (P<0.05), whereas cells with Trolox did not reduce production of intracellular ROS. In addition, cells pretreated with $2{\mu}M$ lycopene produced less intracellular ROS than those treated with ${\beta}$-carotene (P<0.05). DNA fragmentation of cells with ${\beta}$-carotene and lycopene was similar to that of LPS-treated control cells as measured by Hoechst staining. The antioxidant ability of lycopene was greater than that of ${\beta}$-carotene in the QSAR, FRAP, and intracellular ROS assays (P<0.05). ${\beta}$-Carotene and lycopene had lower antioxidant activities as measured by FRAP (P<0.05) but higher intracellular protective effects against LPS-induced oxidative stress in comparison with Trolox.

• KSBB Journal
• /
• v.19 no.2
• /
• pp.138-142
• /
• 2004

Cigarette smoke causes atypical structure of pulmonary (cell structural) and oxidative damage. Therefore, we carried out to determine if exposure to cigarette smoke alters pulmonary structure and anti-oxidant related enzyme in a ICR mice model, when natural product extracts using by manual sprayer. The mice were divided into five groups, control group, sham-treated group (Sham), natural product extracts-treated group (NPE), natural product extracts-treated with smoke-exposed group (NPE-SM) and smoke-exposed (SM) group. All groups are similar to control group in weight, but SM group is lower than the other groups. Microscopic image of the pulmonary structure in SM group showed deleterious alterations in the morphology, but the other groups are maintained in original structure. In anti-oxidant related enzyme, SOD (superoxide dismutase) and catalase, SM group represents the lowest enzyme activity among all groups. These results indicate that the natural product extracts is an efficient tissue protective agent against smoke-induced lung injury.

• Journal of the Korea Institute of Building Construction
• /
• v.3 no.1
• /
• pp.93-105
• /
• 2003

The Precast Concrete(PC) method was developed for a large production of a structure in Europe. Afterwards, this PC method has been applied to a structure and an outside Coating of buildings extensively. The outside Coating of the building applied this PC method is a method to put tiles or stones to base concrete. And there is a method to use paints for, so the expression of various patterns is possible. The Multi-Layer Coating is one of the methods to use paints. This Multi-Layer Coating method can show various designs of external appearance with Foam when it is made with the PC panel. Also, the paint film of the PC panel enables a splendid appearance, and a protective function of concrete is possible, too. Therefore, it makes good durability of the PC. Besides, maintenance is easy to manage because it is free from pollution when it uses metallic materials, stones, or any other materials. You might have no trouble in applying the Multi-Layer Coating method in order to save a merit of an outside Coating on the PC panel. However, the Multi-Layer Coating method used as a current outside Coating method has pollution and bad working environment because Oil Epoxy Resins have toxicity and flammability. Therefore, a lot of warnings are required for coating work in order to have appropriate quality because working hours are short, and production efficiency is low too. These reasons make the cost of construction of the Multi-Layer Coating method increase. And employers or designers may have problems in selecting this Multi-Layer Coating method. Therefore, the purpose of this study is to get activation of the Multi-Layer Coating method by offering improvement measures about the problems of the existing Multi-Layer Coating method.

• Journal of the Korean Institute of Gas
• /
• v.17 no.6
• /
• pp.52-57
• /
• 2013

In this study, the strain energy density, stress and deformation behaviors have been analyzed as functions of a thickness and a force area of protective helmets with and without an extruder on the top of the shell structure using the finite element method. The strain energy density in which is related to the absorption capacity of an impact energy transfer is one of a key element of the helmet safety. The FEM analyzed results show that when the impulsive force of 4,540N is applied on the top surface of the helmets, the maximum stress is linearly reduced for an increased area of impact forces. But, the maximum strain energy density has been reduced for the increased force area. The reduced strain energy density may increase the impulsive forces transferred to the head and neck of helmet wearers, which may decrease the impact energy absorption safety of the helmets. In thus, it is safer design of the helmet in which has an extruded structure on the summit surface, but the modified helmet may decrease the impact energy absorption capacity.