• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.4
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• pp.323-327
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• 2013

Various indicators representing skin characteristics such as skin hydration, sebum excretion rate, lightness, and pH are different depending on environmental and genetic factors. However, they are absolute skin indicators and are different from skin characteristics that a person recognizes. Based on this fact, many recent studies have been mainly conducting researches on perspective changes according to changes of absolute skin. This study was proposed not only to find out differences on skin colors of asian by nations, but also to find out whether there was any difference in skin brightness they perceive depending on actual skin color changing. As many as 410 subjects of three Asia nations were participated in this study, and investigated their responses on skin brightness using questionnaire, which was answered their skin color in three different levels. It was also were analyzed how actual skin brightness were changed depending on their perceived skin color changes of subjects. There was a trend showing that the brightness of the actual skin color was increased when participants felt their skin color got brighter regardless of their nationalities. However, there were some differences in color between perceived color and actual color. In addition, there was a different aspect by nations in changes of skin redness and skin yellowness. In conclusion, it was revealed that factors which help people to perceive their own skin brightness were not based on absolute skin brightness, but on different criteria depending on where they are from.

• Journal of Korean Clinical Nursing Research
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• v.23 no.1
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• pp.83-90
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• 2017

Purpose: This study was to develop evidence-based clinical practice guideline in order to prevent contrastinduced nephropathy (CIN) for patients undergoing percutaneous coronary intervention (PCI). Methods: The guideline was developed based on the "Scottish Intercollegiate Guidelines Network (SIGN)". The first draft of guideline was developed through 5 stages and evaluated by 10 experts.(1) Clinical questions were ensured in PICO format.(2) Two researchers conducted a systematic search through electronic database, identifying 170 studies. We selected 27 full text articles including 16 randomized clinical trials, 7 systematic reviews, and 4 guidelines. Quality of each studies were evaluated by the Cochran's Risk of Bias, AMSTAR, K-AGREEII. Among the studies, 11 studies were excluded.(3) The strength of recommendations were classified and quality of recommendations were ranked.(4) Guideline draft was finalized.(5) Content-validation was conducted by an expert group. All contents were ranked above 0.8 in CVI. Results: Evidence-based clinical practice guideline to prevent CIN was dveloped.(1) The guideline for preventing CIN recommends using 0.9% saline.(2) Standardized rate of fluid therapy is 1 to 1.5ml/kg/hr.(3) Execute hydration for 6~12hrs before PCI and after PCI. Conclusion: This study suggests evidence-based clinical practice guideline for preventing CIN which can be more efficiently used in clinical practice.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.255-262
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• 2020

Blended cement with fly ash and bottom ash from Circulating Fluidized Bed Combustor boiler(CFBC) burned at a low temperature, can be high heat of hydration and abnormal setting caused by higher volumn contents of Fe₂O₃, free-CaO, SO₃. In this study, the ground CFBC bottom ash powder mixed with blast furnace slag was used as substitute activator of gypsum and recycled iron slag was produced from mix and pulverized by ball mill to increase the recycling rate. The effect on compressive strength of cements with the mixture of original and hydrated bottom ash mixtures with BFS with small water, respectively, was analyzed, and it was found that the hydrated bottom ash activator was more effective in initial strength development. To improve the initial strength of blended cement, an activator mixed with a blast furnace slag and bottom ash mixing ratio of 5:95 and 10:90, respectively, the slag cement by about 6%, and it was analyzed to develop an initial strength similar to gypsum as a conventional activator.

• Journal of the Korea Concrete Institute
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• v.29 no.1
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• pp.11-21
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• 2017

The paper presents experimental results of self-healing effects of OPC-GGBFS paste with cracked and uncracked specimens. The self-healing of cracked specimens is processes of crack closing with re-hydration of unhydrated in crack surface. The OPC paste with GGBFS replacement ratios of 0%, 10%, 20% and 30% were prepared having a constant water-binder ratios of 0.5. The OPC-GGBFS paste specimens immersed in tap-water and sea-water. The temperature of tap and sea-water was $5^{\circ}C$, $15^{\circ}C$ and $25^{\circ}C$. The cracked specimens after deterioration were immersed for 60 days. The relationship between self-healing effect and age-effect was calculate based upon the experimental results. The self-healing effect was measured in ultrasonic pulse velocity (UPV) before and after loading. When the relative change rate of UPV is increases with the increase in GGBFS replacement ratios. Moreover, the self-healing effect is increased with the temperature of tap-water is increase. But the cracked specimens immersed in sea-water was unclear effects of different temperature. Furemore, most of the healing for OPC-GGBFS specimens immersed in tap-water and sea-water occurred during the first 30 days. The self-healing effect until 30 days is higher than that the age-effect. After 30 days, self-effect and age-effect was largely decreases. SEM/EDS analysis of crack on the surface of the specimens in tap-water were covered with aragonite, and sea-water were covered with brucite.

• Journal of the Korea Institute of Building Construction
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• v.18 no.1
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• pp.25-31
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• 2018

In this study, the Controlled Low Strength Material (CLSM) was investigated to utilize the bottom ash and fly ash generated in the Circulating Fluidized Bed Combustor (CFBC). It was confirmed that the CFBC fly ash (CFBC-F) and CFBC bottom ash (CFBC-B) had an irregular particle shape through SEM measurement. According to the results of the hazard analysis, it was also confirmed that they were environmentally safe. In the case of mixing with CFBC-F, the unit quantity was increased. Regarding the rate of change of length, shrinkage in the range of -0.05~0.50% occurred in the air dry curing condition and expansion in the range of 0.1~0.6% in the sealed curing condition. Compressive strength was increased in the sealed curing condition compared to the air dry curing condition because there was enough moisture for hydration reaction in the long term. Therefore, the results of this study are likely be used as basic research data of mine filler materials.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.4
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• pp.44-50
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• 2016

A study to apply phase change material(PCM) to rapid hardening cement paste forming semi-rigid pavement was carried out. The characteristics fresh and hardened paste were evaluated through the experiment for a total of 6 mixtures according to the cement type and the substitution of phase change material for acrylate. The fluidity by substituting phase change material for acrylate satisfied the target flow time of 10 to 13 seconds. In case of setting time, it was possible to secure the performance of rapid hardening cement by substituting phase change material, and if the substitution ratio over 60%, the initial set occurred 1 to 2 minutes faster than other mixtures. In case of compressive strength and bond strength, it showed similar strength characteristics with the plain mixture, and it satisfied both the target compressive and bonding strength of 36MPa and 2MPa. The mixture substituting phase change material showed higher resistance to chloride ion penetration than the mixture only using acrylate and the OPC level was insufficient. From the results of physical and mechanical performances of semi-rigid pavement cement paste, the phase change material substitution rate of 20% was effective in the range of this study.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.251-255
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• 2019

The effect of soaking temperature on the moisture uptake and the protein loss of soybeans during soaking process investigated. As the soaking temperature increased, the soaking rate significantly increased and Peleg model was suitable for describing the soaking characteristics of the soybean with high $R^2$ values (>0.991). The soaking time to achieve the target moisture content of soybean (130%) was estimated to be 12.6, 3.11 and 2.31 h at 25, 35 and $45^{\circ}C$, respectively. Peleg model well described the protein loss kinetics of soybean during soaking with high $R^2$ values (>0.941). The results showed that the protein loss of soybean at the target moisture content were 35.2, 93.1 and 103.0 mg/g at 25, 35 and $45^{\circ}C$, respectively. In this study, the optimum soaking condition for quality of soybean was 12.6 h of soaking time at $25^{\circ}C$.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.404-414
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• 2021

This study was to investigate the differences of functional health status and medical service experience and needs between general and vulnerable older people in community. This study is a cross-sectional descriptive research. The data obtained through direct visit surveys from November to December 2016. The target population of the study was older people over 65 years old, the final study subjects were 444 older people residing in one district of Seoul. The chi-square test was conducted to confirm the difference in their functional health areas and medical service experiences, and the necessity of medical service utilization in accordance to the social class. In the experience of abnormality in functional health, the vulnerable older people had higher experience in cognitive function, nutrition, hydration, pain, and falling than the general older people. The rate of experience of using medical service to solve the cognitive function problem for general older people was 31.9%, higher than that of the vulnerable older people. In contrast, the medical service utilization needs of the vulnerable older people in the pain management category was significantly higher than that of the general older people. In setting policy of public medical service programs for general and vulnerable older people in community may be differentially developed based on this study. In order to improve the medical accessibility of the vulnerable older people, public medical institutions should be actively supported to overcome obstacles to medical use due to economic barriers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6C
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• pp.303-311
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• 2009

In this study, weakly cemented sand was cured at air dry condition with different periods (3, 7, 14, 21, 28 days) and its unconfined compressive strength was evaluated. As a result, the strength of specimens with low cement ratios such as 4 and 8% increases until 7 days curing but, after 7 days, their strength continuously decreases. The strength of specimens with relatively high cement ratios such as 12 and 16% increases up to 7 days curing and then stays almost constant until 21 days. After 21 days curing, their strength suddenly dropped down, which is much lower than the strength of 3 days curing specimen. A cemented sand and gravel called CSG, which is highly permeable, could be exposed to repetitive drying and wetting conditions due to rainfall or groundwater table change during curing. In this study, the weakly cemented sand is exposed to repetitive drying and wetting and then its unconfined compressive strength was evaluated. As a result, the strength of a specimen with 27 days drying condition following 1 day wetting was at maximum 35% lower than the one cured under 28 days drying. The strength degradation due to wetting decreases as a cement ratio increases. However, the strength of a specimen with repetitive drying and wetting increases as the number of wetting increases until 3 cycles. After 3 cycles of drying and wetting, the rate of strength increase decreases due to an insufficient water for hydration or stays constant. If the sufficient water supply is provided to cemented sand during curing, the target or design strength increase can be achieved. Otherwise, the strength degradation due to wetting should be considered at the design stage.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.263-278
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• 2004

Ursolic acid (UA) and Oleanolic acid (ONA), known as urson, micromerol and malol, are pentacyclic triterpenoid compounds which naturally occur in a large number of vegetarian foods, medicinal herbs, and plants. They may occur in their free acid form or as aglycones for triterpenoid saponins, which are comprised of a triterpenoid aglycone, linked to one or more sugar moieties. Therefore UA and ONA are similar in pharmacological activity. Lately scientific research, which led to the identification of UA and ONA, revealed that several pharmacological effects, such as antitumor, hepato-protective, anti-inflammatory, anticarcinogenic, antimicrobial, and anti-hyperlipidemic could be attributed to UA and ONA. Here, we introduced the effect of UA and ONA on acutely barrier disrupted and normal hairless mouse skin. To evaluate the effects of UA and ONA on epidermal permeability barrier recovery, both flanks of 8-12 week-old hairless mice were topically treated with either 0.01-0.1mg/mL UA or 0.1-1mg/mL ONA after tape stripping, and TEWL (transepidermal water loss) was measured. The recovery rate increased in those UA or ONA treated groups (0.1mg/mL UA and 0.5mg/mL ONA) at 6h more than 20% compared to vehicle treated group (p < 0.05). Here, we introduced the effects of UA and ONA on acute barrier disruption and normal epidermal permeability barrier function. For verifying the effects of UA and ONA on normal epidermal barrier, hydration and TEWL were measured for 1 and 3 weeks after UA and ONA applications (2mg/mL per day). We also investigated the features of epidermis and dermis using electron microscopy (EM) and light microscopy (LM). Both samples increased hydration compared to vehicle group from 1 week without TEWL alteration (p < 0.005). EM examination using RuO4 and OsO4 fixation revealed that secretion and numbers of lamellar bodies and complete formation of lipid bilayers were most prominent (ONA=UA > vehicle). LM finding showed that thickness of stratum corneum (SC) was slightly increased and especially epidermal thickening and flattening was observed (UA > ONA > vehicle). We also observed that UA and ONA stimulate epidermal keratinocyte differentiation via PPAR Protein expression of involucrin, loricrin, and filaggrin increased at least 2 and 3 fold in HaCaT cells treated with either ONA (10${\mu}$M) or UA (10${\mu}$M) for 24 h respectively. This result suggested that the UA and ONA can improve epidermal permeability barrier function and induce the epidermal keratinocyte differentiation via PPAR Using Masson-trichrome and elastic fiber staining, we observed collagen thickening and elastic fiber elongation by UA and ONA treatments. In vitro results of collagen and elastin synthesis and elastase inhibitory activity measurements were also confirmed in vivo findings. These data suggested that the effects of UA and ONA related to not only epidermal permeability barrier functions but also dermal collagen and elastic fiber synthesis. Taken together, UA and ONA can be relevant candidates to improve epidermal and dermal functions and pertinent agents for cosmeseutical applications.