• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.3
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• pp.223-230
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• 2017

In this study, we evaluated the skin moisturizing effect of Brasenia schreberi (B. schreberi) mucilage polysaccharide on human skin and in vitro and the potent cosmetic ingredient for skin. To protect skin from various environmental stresses and aging, we should increase moisture content of skin and prevent water loss. We have found that polysaccharides extracted from mucilage of B. schreberi improved the roughness of skin with its lubricating behavior. In vitro, the expression of transglutaminase 1 (TGM1) gene, which plays a role in cross-linking the skin barrier, was increased when the keratinocytes were treated with B. schreberi polysaccharides. In addition, the expression of hyaluronan synthase 3 (HAS3) gene, an enzyme that synthesizes water-binding matrix hyaluronic acid, aquaporin 3 (AQP3), which regulates the movement of water and glycerol were also increased. In addition, an experiment to evaluate its potential as a cosmetic ingredient has shown anti-inflammatory and collagen synthesis-promoting effects. As a result, the mucilaginous polysaccharide from natural products which has not existed before, showed moisturizing effect, anti-inflammation and collagen synthesis-promoting effects for skin protection and hydration.

• Journal of the Korea Concrete Institute
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• v.26 no.6
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• pp.723-730
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• 2014

The usage of Ground Granulated Blast Furnance Slag (GGBFS) has been increased recently. Studies on the cement hydration model incorporating GGBFS as well as the properties of cement paste done with GGBFS such as compressive strength, hydration products and hydration heat have been the subjects of many researches. However, studies on the reaction degree of GGBFS that affect the properties of cement paste incorporating GGBFS are lacking globally and specially in Korea. Thus, in this study, the reaction degree of GGBFS using the method if selective dissolution, compressive strength, the amount of chemical bound water and $Ca(OH)_2$ were measured and analysed in accordance with water-binder ratio, replacement ratio of GGBFS, and curing temperature. The results show that the reaction degree of GGBFS, the amount of chemical bound water and $Ca(OH)_2$ in cement paste with GGBFS were higher in conditions where the replacement ratio of GGBFS was low and both water-binder ratio and curing temperature were high. Finally, the reaction degree of GGBFS was achieved at a value between 0.3~0.4.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.35-41
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• 2005

We investigated the effects of skin hydration and anti-irritation of exopolysaceharide (GF-glucan) produced from submerged culture of Grifola frondosa. The moisturizing effects and trans-epidermal water loss (TEWL) of GF-glucan in cosmetic products (O/W emulsion) were clinically studied. GF-glucan showed good skin hydration effects when compared with sodium hyaluronate which is a commonly using moisturizer. The skin protective effects of GF-glucan against sodium lauryl sulfate (SLS) were also found. Twice a day application of the CF-glucan to skin reduced local inflammation remarkably. Irritant reactions were assessed by various aspects of skin function, erythema (skin color reflectance), hydration (electrical capacitance) and TEWL. In the human skin test, 5-day treatment of the GF-glucan was found to reduce SLS-induced skin erythema and Improve bier regeneration. Taken all together, GF-glucan should be a very useful cosmetic ingredient, as a moisturizer, and a protecting agent for various skin irritations.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.204-210
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• 2022

Cement is pointed out as the main cause of carbon dioxide emission in the construction industry. Many researchs are underway to use blast furnace slag, an industrial by-product, as a substitute for cement to reduce carbon dioxide emitted during the manufacturing the cement. When blast furnace slag is used as a substitute for cement, it has advantages such as long-term strength and chemical resistance improvement. However, blast furnace slag has a problem that makes initial strength low. This is due to the impermeable film on the surface created during the production of blast furnace slag. The created film is known to be destroyed in an alkaline environment, and based on this, previous studies have suggested a solution using various alkali activators. But, alkali activator is dangerous product since it is a strong alkaline material. And it has the disadvantage in price competitiveness. In this study, an experiment was conducted to improve the initial hydration reactivity of the blast furnace slag to secure the initial strength of the mortar substituted with the blast furnace slag and to check whether the carbonation resistance was increased. As a result of the experiment, it was confirmed that the mortar using alkaline water showed higher strength than the mortar using tap water, and there were more hydration products generated inside. In addition, it was confirmed that the mortar using alkaline water as a compounding water had high carbonation resistance.

• Journal of the Korea Institute of Building Construction
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• v.23 no.6
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• pp.703-714
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• 2023

This research conducts a series of tests to investigate the setting retarding properties and strength development in cement pastes incorporating various types and dosages of sugar-based super retarding agents. Six such agents, including Sucrose, Sugar powder, Saccharin, Aspartame, Stevioside, and Mogroside, commercially available, were selected for evaluation. The study also examines the micro-structural properties of these cement pastes. The test mixtures were prepared using a 27.5% water-to-cement ratio and ordinary Portland cement. Micro-structural analyses were conducted using Scanning Electron Microscopy(SEM), X-Ray Diffraction(XRD), and Energy Dispersive Spectroscopy(EDS). The findings reveal that the incorporation of sucrose, sugar powder, and stevioside significantly retards the setting time. Particularly, adding 0.1% sucrose extended the setting time by approximately two-fold compared to the control(Plain) mixture. Most mixtures, barring those with sugar powder and stevioside, exhibited compressive strength comparable to the Plain mixture. Notably, with 0.2% sucrose, strength measurements were not feasible at 1 day, but at 3 days, the strength gains aligned with the Plain mixture. XRD, SEM, and EDS analyses confirmed the hydration delay(set retarding) of C3S due to sucrose, with further quantitative corroboration provided by EDS. SEM was used to verify the presence or absence of hydration products. The study concludes that sucrose, as a sugar-based retarder, offers effective set retarding capabilities and compressive strength development in concrete.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.24 no.3
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• pp.84-107
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• 2011

Purposes : The purpose of present study is to detect the effects of ointment contained Takrisodok-Eum on the skin barrier's recovery of the Atopic dermatitis. Methods : A total of 44 patients who visited Semyung Oriental Medical Center from April 27th, 2011 to September 20th, 2011 were included in the study. In this study, the patients were treated with Takrisodok-Eum (experimental group) and positive control group. For 8 weeks of gross examination, hematological examination and instrumental asessment were made before and after the study to examine how well the products for experimental group with those for control group in recovering the damaged skin barriers by Atopic dermatitis. Results : 1. In the primary endpoint, SCORAD Index showed a statistically significant decline in experimental group. 2. In the secondary endpoint index of skin hydration, both the experimental group and the control group showed statistical significance. 3. In the secondary endpoint index of TEWL, the experimental group showed greater statistical significance than the control group. 4. In the secondary endpoint index of skin pH, skin pH showed a statistically significant decline in both the control group and the experimental group within the normal range. 5. In the secondary endpoint index of Total IgE, Eosinophil count, IL-10, IL-13, both the experimental group and the control group showed no statistical significance. 6. To evaluate the safety of the products for the human body, hematological examination and hematological biochemical examination, vital sign check were conducted; both control group and experimental group showed no abnormal level. And There were no severe adverse events during this study. Therefore, it is suggested that the safety of the products, if used for certain period, should be safe for the human body. Conclusions : According to the above experiments, it is suggested that Takrisodok-Eum should be effective for the Atopic dermatitis.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.276-281
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• 2023

Water pipes manufactured using existing Portland cement suffer from the problem of rapid deterioration and reduced durability due to the hydration product of cement being vulnerable to acids. Therefore, in this study, water pipes were manufactured using slag and fly ash, which are industrial by-products from various industries, and their characteristics were analyzed. As a result of the experiment, slump in unhardened concrete tended to increase due to the ball bearing action of fly ash, and the amount of air was reduced due to unburned coal, indicating that measures for frost resistance were needed. In addition, the initial strength of the compressive strength was increased through steam curing, and the results were equal to or better than OPC when mixing more than 50 % of slag. The acid resistance results showed that the mass reduction rate was less than 5 %, showing excellent durability performance, and the bending failure load of the water pipe also exceeded the KS standards, so it is judged to be commercializable.

• Journal of the Korea Institute of Building Construction
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• v.14 no.4
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• pp.308-313
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• 2014

Recently, for longevity of resident building, the main trend is that the change of the inside space organization of resident building from wall construction to rhamen construction, which resulted in increase in use of lightweight composite panel. Thus, in this study, authors analyzed the engineering property of oxide of magnesium depending on the magnesium chloride addition ratio. The results of this research is expected to contribute on providing a fundamental material for the surface materials of lightweight composite panel. As the result of the experiment, as fluidity increased, air content decreased and initial set and final set as the magnesium chloride addition ratio increase. In the aspect of flexural strength and compressive strength, the test specimen showed the highest strength at 40% of the magnesium chloride addition ratio. At 20% of the magnesium chloride addition ratio, the test specimen showed the lowest water absorption rate. As the magnesium chloride addition ratio increases, the expansibility tends to increase as well in the aspect of shrinkage strain. After observing microstructure, we can see hydration products in the form of needle. It appeared high flexural strength because the hydration products have mineral fibrous tissue shape, which also contribute to the cause of the expansibility.

• Journal of the Korea Concrete Institute
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• v.27 no.1
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• pp.85-92
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• 2015

The chloride ions, responsible for the initiation of the corrosion mechanism, intrude from the external medium into the concrete. A part of the intruding chloride ions will be retained by the hydration products of the binder in concrete, either through chemical adsorption or by physical adsorption. Since the hydration products of cement are responsible for the chloride binding in concrete, this study focused on the chloride binding in individual hydrate. The purpose of this study is to explore the time dependant behaviors of chloride ions adsorption with cement hydrates, focused on its mechanism. AFt phase and CH phase were not able to absorb chloride ion, however, C-S-H phase and AFm phase had a significant chloride adsorption capacity. In particular, AFm phase showed a chemical adsorption with slow rate in 40 days, while C-S-H phase showed binding behaviors with 3 stages including momentary physical adsorption, physico-chemical adsorption, and chemical adsorption. Based on the results, this study suggested theoretical approach to depict chloride adsorption behavior with elapsed time of C-S-H phase and AFm phase effectively. It is believed that the approach suggested in this study can provide us with a good solution to understand the mechanism on chloride adsorption with hydrates and to calculate a rate of chloride penetration with original source of chloride ions, for example, marine sand at initial time or sea water penetration later on.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.219-228
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• 2010

It has been well known that concrete structures exposed to acid and sulfate environments such as sewer, sewage and wastewater, soil, groundwater, and seawater etc. show significant decrease in their durability due to chemical attack. Such deleterious acid and sulfate attacks lead to expansion and cracking in concrete, and thus, eventually result in damage to concrete matrix by forming expansive hydration products due to the reaction between portland cement hydration products and acid and sulfate ions. Objectives of this experimental research are to investigate the effect of mineral admixtures on the resistance to acid and sulfate attack in concrete and to suggest high-resistance concrete mix against acid and sulfate attack. For this purpose, concretes specimens with three types of cement (ordinary portland cement (OPC), binary blended cement (BBC), and ternary blended cement (TBC) composed of different types and proportions of admixtures) were prepared at water-biner ratios of 32% and 43%. The concrete specimens were immersed in fresh water, 5% sulfuric acid, 10% sodium sulfate, and 10% magnesium sulfate solutions for 28, 56, 91, 182, and 365 days, respectively. To evaluate the resistance to acid and sulfate for concrete specimens, visual appearance changes were observed and compressive strength ratios and mass change ratios were measured. It was observed from the test results that the resistance against sulfuric acid and sodium sulfate solutions of the concretes containing mineral admixtures were much better than that of OPC concrete, but in the case of magnesium sulfate solution the concretes containing mineral admixtures was less resistant than OPC concrete due to formation of magnesium silicate hydrate (M-S-H) which is non-cementitious.