• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.3
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• pp.1-12
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• 2019

A bridge is a structure constructed on water or in the air for convenient passage. Compared to other buildings, the building materials and structures of bridge required unique functions to cross the space. It depends on the productivity of the building, the level of science and technology, and the ecological environment of the building site. Also, it has important relationship with functions such as politics, military, economy, and life. Most of the academic research on bridges is focused on research in the field of bridge-building technology, so the study on the landscape aesthetics and history of bridges is lacking. Against this backdrop, the study will be valuable as a accumulation of both countries' understanding of bridge types, history and culture, as well as technical and aesthetic data, by analyzing the bridges located within the palaces of Korea and China. The research method is to analyze the bridge through field survey and literature analysis.. First, the bridges of royal palace of Korea and China are to be classified quantitatively as physical shapes, landscapes, and decorations by comparing the materials, forms, landscapes, and decorative culture of bridges. Second, characteristics, common points, and differences are extracted by classifying bridges of both countries. Also, the results are discussed based on the physical environment or cultural background. This would be worth cross-referencing in the building technology and aesthetics of the two countries. For the first important characteristics of result, main materials of Korean and Chinese palaces are stone. However, the bridge in China's royal palaces is also focused on wood. Second, in terms of form, the bridges in the royal gardens of Korea and China are all based on the beam bridge. However, the specific form, ratio, style of the beam bridge, and airspace of arched bridge are very different. Third, most of the connection methods are focused on the over bridge. It values the convergence with the surrounding landscape. Due to the difference in the area and location of water, the bridge in the Korean palace is more focused on the convergence of the surrounding buildings and plants, while the bridge in the Chinese palace is more concerned about the harmony of hydration. Fourth, the decoration places importance on the artistry and aesthetics of both the bridges in Korea and China. There is a difference in style in the same type of decoration due to culture.

• Journal of Life Science
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• v.27 no.9
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• pp.975-985
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• 2017

To investigate the beneficial effects of an agar gel mask (AGM) on UV-induced photoaging, SKH-1 hairless mice were treated with a topical application of AGM and an AGM dipped in essence (AGMdE). The mice were divided into an no radiation group, UV + AGM, UV + AGMdE, and UV + vehicle (PBS) treatment groups. Alterations in skin wrinkles, skin phenotype, histological structures, oxidative status, and toxicity were then evaluated during 4 weeks of exposure. The topical application of AGM and AGMdE inhibited wrinkle formation, suppressed the erythema index, prevented transepidermal water loss, and enhanced skin hydration. In addition, epidermal thickness recovered to a similar level as that in the no irradiation group in the UV + AGM and UV + AGMdE treatment groups compared with the UV + vehicle (distilled water) group. Furthermore, the expression levels of matrix metalloproteinase-1 (MMP-1) and tyrosinase were reduced in the UV + AGM and UV + AGMdE treatment groups, although the highest level varied. Moreover, superoxide dismutase (SOD) activity was significantly lower in the UV + AGM and UV + AGMdE treatment groups as compared with the UV + vehicle group. No significant alterations induced by most toxic compounds were measured in serum biochemical markers and liver and kidney histological features of the UV + AGM and UV + AGMdE treatment groups. These results suggest that AGM may protect against skin aging by regulating skin morphology, histopathological structures, and oxidative conditions.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.104-111
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• 2015

This study shows the mechanical properties of alkali-activated slag cement (AASC) synthesized using sulfate with NaOH solution. The used sulfates were calcium sulfate ($CaSO_4$, denoted CS) and sodium sulfate ($Na_2SO_4$, denoted SS). The replacement ratio of sulfates was 2.5, 5.0, 7.5 and 10.0% by weight of slag. NaOH solution of 2M and 4M concentration was used. A sample was activated with sulfate and activated with blended activator (blending NaOH solution with sulfate) respectively. 24 mix ratios were used and the water-binder weight ratio for the test was set 0.5. This research carried out the compressive strength, flexural strength, ultrasonic pulse velocity (UPV), absorption and X-ray diffraction (XRD). In the case of samples with CS, sample with 7.5% CS, sample with 2M NaOH+5.0% CS and sample with 4M NaOH+5.0% CS showed the good performance in the strength development. In the case of samples with SS, sample with 10.0% SS, sample with 2M NaOH+7.5% SS and sample with 4M NaOH+2.5% SS obtained good performance in strength. The results of UPV and water absorption showed a similar tendency to the strength properties. The XRD analysis of samples indicated that the hydration products formed in samples were ettringite, CSH and silicate phases. In this study, it is indicated that when compared to the use of sulfate only, the use of both sulfate and NaOH solution makes mechanical properties of AASC better.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.97-102
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• 2005

One of the key molecules involved in skin moisture is hyaluronan (hyaluronic acid, HA) with its associated water of hydration. The predominant component of the ECM (extracellular matrix) of skin is HA. It Is the primordial and the simplest of the GAGs (glycosaminoglycans), a water-sorbed macromolecule In extracellular matrix, Included between the vital cells of epidermis. In the skin, HA was previously thought to derive extlusively from dermis. But, recent studies revealed that HA could be synthesized in epidermis. Flavonoids are polyphenolic compounds that is found mainly in foods of plant origin. Kaempferol was known to increase glutathione synthesis in human keratinocyte. And quercetin blocked PPAR-meidated keratinocyte differentiation as lipoxygenase inhibitors. In this study, we sought to evaluate the effect of flavonid, kaempferol and quercetin on production HA in keratinocyte. We examined the changes of three human hyaluronan synthase genes (HASI, HAS2, HAS3) expression by semi-quantitative RT-PCR when kaempferol or quercetin was added to cultured human keratinocytes. We found that these flavonoids slightly upregulated HAS2, HAS3 mRNA after 24 h. And we investigated the effect on HA production by ELISA. When we evaluated the level of HA in culture medium after 24 h incubation. We found enhanced accumulation of HA in the culture medium. Although the effects of above flavonoids are less than retinoic acid, the data indicate that kaempferol, quercetin can dose-dependently increase the level of HA in epidermis cell line. It suggested that flavonoid, kaempferol, and quercetin increased production of HA in skin and it helped to elevate skin moisture and improve facial wrinkle.

• International Journal of Highway Engineering
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• v.6 no.3 s.21
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• pp.1-7
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• 2004

Roads, like bikeways, parkways and walks, are to be just capable of supporting light traffic and traveling public, but they are required to be human friendly and environmental-oriented. Lately soil-solidifier mixture, a kind of soil-cement, has developed and has been applied to the recycling and environment-oriented pavement as the surfacing material. Soil-solidifier pavement structure has been designed by only experience. To design this pavement mechanically, it is necessary to find out basic engineering properties of soil-solidifier mixture. This study focuses on finding out mechanical characteristics of the mixture according to mixture proportions and aging. Test molds with various mixture proportions are made, and then unconfined strength tests are performed for test molds with aging of the mixture. As the result of this study, it is found that the strength of the mixture increases with amount of cement and that maximum strength is achieved at 6%$\sim$8% of the ratio of solidifier and water. The strength increase rapidly until 14 days, after then slowly. After 28 days the strength of the mixture approaches to the constant value. The heat of hydration during curing of the mixture is measured no significantly. It also shows that temperature characteristics of the mixture is similar to that of soil. Since this mixture is mixed with soil and is able to improve engineering problems in pavement due to temperature, this mixture is expected to use effectively in the environment-oriented pavement for light traffic.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.2
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• pp.111-118
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• 2016

Acne vulgaris is a chronic inflammatory condition characterized by comedo, papule, cyst, nodule and postinflammatory hyperpigmentation. Meanwhile, it is also induced by adverse event of drugs. Among them, acneiform folliculitis is a side effect of epidermal growth factor receptor (EGFR) inhibitor, which is an anticancer agent, and its incidence may occur in upward of 75 ~ 100% of cases. The main method of acne vulgaris treatment is oral antibiotics, retinoids, topical medication and so on. However, it is limitation that teratogenicity caused by retinoids and antibiotic resistance increased by using antibiotics. In this study, we aimed to evaluate the clinical efficacy and safety of topical recombinant human (rh) EGF in treating facial acne vulgaris. Twenty three Koreans (age: 10 ~ 29 years) with mild to moderate acne vulgar participated in the study and applied topical rhEGF cream (trouble control EGF) with 3 products (trouble control clarifying cleansing foam, trouble control all-clear filling toner, redroll calming moisture) on their face twice daily for four weeks. Several assessment methods were applied: Acne lesion counts score by investigator's global assessment, efficacy and satisfaction score by subjects. Skin sebum output level, hydration level and redness level were also measured at each visit. At the final visit, skin sebum level, transepidermal water loss, skin redness statistically decreased and acne lesions (comedone, papule) were statistically reduced. No severe side effects were observed during the study. In conclusion, topical rhEGF seems to be an effective and safe adjuvant treatment option for mild acne vulgaris.

• Food Engineering Progress
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• v.15 no.4
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• pp.404-412
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• 2011

The purpose of this study is to prepare extruded rice flours suitable for baking rice cookies. The extruded rice flours were prepared at 100 and 130$^{\circ}C$ temperature and 25 and 27% moisture content in a co-rotating twin screw extruder. The rice extrudates were dried at 100$^{\circ}C$ for 18 hr and subsequently ground into the fine flour. Characteristics of the extruded rice flours were examined by rapid visco analysis, hydration property analysis, differential scanning calorimetry (DSC), and in vitro digestion test. Water absorption, solubility, and swelling power of all extruded rice flours were higher than those of native rice flour. DSC analysis showed that native rice flour had a peak at about 65$^{\circ}C$ while all extruded rice flours did not show any peaks since they were already gelatinized during the extrusion proess. Viscosity of the extruded rice flours decreased with increasing temperature and lowering moisture content in the extrusion proess. The extruded rice flours prepared at 130$^{\circ}C$ exhibited lower viscosity than those prepared at 100$^{\circ}C$. The operating temperature of the extrusion proess was critical for the starch digestion in vitro. The extruded rice flours prepared at 130$^{\circ}C$ showed a rapid decrease in digestible starch content while an increased level of slowly digestible starch content was observed compared to those treated at 100$^{\circ}C$ in the extruder. Cookies were prepared with a mixture of wheat flour and extruded rice flours at the ratio of 7 to 3. The cookies made with the extruded rice flours had lower spread factor and darker yellow color than those prepared with wheat flour only. Hardness of the extruded rice flour-added cookies was similar to that of the wheat flour cookie whereas their overall acceptance was better. Therefore the rice cookies partially supplemented with extruded rice flours may have a potential as early childhood foods which require soft texture and allergy reduction.

• Journal of the Mineralogical Society of Korea
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• v.31 no.4
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• pp.267-275
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• 2018

The purposes of this study were to analyze the mineralogical characteristics of slaked lime used for wall repair of traditional buildings in Bagan, Myanmar and to evaluate the physical properties of lime plaster produced by the same method as Bagan region. In the X-ray diffraction and thermal analysis of the Myanmar slaked lime, portlandite ($Ca(OH)_2$) and brucite ($Mg(OH)_2$) were detected as main constituent minerals, and a carbonate rock mainly composed of dolomite ($CaMg(CO_3)_2$) minerals may be used as a raw material to make slaked lime. The field-emission scanning electron microscope analysis showed that the Myanmar slaked lime was composed of irregularly shaped crystals of $0.5{\mu}m$ or larger and a small amount of $0.1{\mu}m$ of plate - like crystals. The size and uniformity of crystals in Myanmar lime is different from that of Korea slaked lime. This may be attributed to the effect of the mineral composition and the lime hydration method of Myanmar, which produces slurry by immersing the burnt lime in excess water for a long period of time. The compressive strength of the lime plaster in Myanmar resulted in a mean value of $1.13N/mm^2$ for the specimens cured for 28 days. The strength of the specimens with Bale juice was $1.03N/mm^2$, respectively. The lime is an air setting material that exhibits strength through long carbonation process. Therefore, it is necessary to evaluate physical properties according to curing period through long-term curing over 28 days in the future.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.4
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• pp.303-312
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• 2023

The determination of the oxidation states of metal elements in manganese nodules sheds light on the understanding of the formation mechanism of nodules, providing insights into the paleo-environmental conditions such as the redox potential of the aqueous system. This study aims to reveal the oxidation states and chemical bonding of manganese in the natural polymetallic nodules, utilizing conventional X-ray photoelectron spectroscopy (XPS). Specifically, shallow manganese nodules from the Siberian Arctic Sea, effectively recording mineralogical variations, were used in this study. Detailed analysis of XPS Mn 2p spectra showed changes in the manganese oxidation state from the center to the outer parts of the nodules. The central part of the nodules showed a higher Mn⁴⁺ content, approximately 67.9%, while the outermost part showed about 63% of Mn⁴⁺ due to an increase in the Mn³⁺+Mn²⁺. The decrease in the Mn oxidation state with the growth is consistent with the previously reported mineralogical variations from todorokite to birnessite with growth. Additionally, the O 1s spectra presented a predominance of Mn-O-H bonds in the outer layers compared to the center, suggesting hydration by water in the layered manganates of outer layers. The results of this study demonstrate that XPS can be directly applied to understand changes in paleo-environmental conditions such as the redox states during the growth of manganese nodules. Finally, future studies using high-resolution synchrotron-based XPS experiments could achieve details in oxidation states of manganese and trace metal elements.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.3
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• pp.103-134
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• 1977

The physiological and biochemical role of potassium for upland crops according to recent research reports and the nutritional status of potassium in Korea were reviewed. Since physical and chemical characteristics of potassium ion are different from those of sodium, potassium can not completely be replaced by sodium and replacement must be limited to minimum possible functional area. Specific roles of potassium seem to keep fine structure of biological membranes such as thylacoid membrane of chloroplast in the most efficient form and to be allosteric effector and conformation controller of various enzymes principally in carbohydrate and protein metabolism. Potassium is essential to improve the efficiency of phoro- and oxidative- phosphorylation and involve deeply in all energy required metabolisms especially synthesis of organic matter and their translocation. Potassium has many important, physiological functions such as maintenance of osmotic pressure and optimum hydration of cell colloids, consequently uptake and translocation of water resulting in higher water use efficiency and of better subcellular environment for various physiological and biochemical activities. Potassium affects uptake and translocation of mineral nutrients and quality of products. potassium itself in products may become a quality criteria due to potassium essentiality for human beings. Potassium uptake is greatly decreased by low temperature and controlled by unknown feed back mechanism of potassium in plants. Thus the luxury absorption should be reconsidered. Total potassium content of upland soil in Korea is about 3% but the exchangeable one is about 0.3 me/100g soil. All upland crops require much potassium probably due to freezing and cold weather and also due to wet damage and drought caused by uneven rainfall pattern. In barley, potassium should be high at just before freezing and just after thawing and move into grain from heading for higher yield. Use efficiency of potassium was 27% for barley and 58% in old uplands, 46% in newly opened hilly lands for soybean. Soybean plant showed potassium deficiency symptom in various fields especially in newly opened hilly lands. Potassium criteria for normal growth appear 2% $K_2O$ and 1.0 K/(Ca+Mg) (content ratio) at flower bud initiation stage for soybean. Potassium requirement in plant was high in carrot, egg plant, chinese cabbage, red pepper, raddish and tomato. Potassium content in leaves was significantly correlated with yield in chinese cabbage. Sweet potato. greatly absorbed potassium subsequently affected potassium nutrition of the following crop. In the case of potassium deficiency, root showed the greatest difference in potassium content from that of normal indicating that deficiency damages root first. Potatoes and corn showed much higher potassium content in comparison with calcium and magnesium. Forage crops from ranges showed relatively high potassium content which was significantly and positively correlated with nitrogen, phosphorus and calcium content. Percentage of orchards (apple, pear, peach, grape, and orange) insufficient in potassium ranged from 16 to 25. The leaves and soils from the good apple and pear orchards showed higher potassium content than those from the poor ones. Critical ratio of $K_2O/(CaO+MgO)$ in mulberry leaves to escape from winter death of branch tip was 0.95. In the multiple croping system, exchangeable potassium in soils after one crop was affected by the previous crops and potassium uptake seemed to be related with soil organic matter providing soil moisture and aeration. Thus, the long term and quantitative investigation of various forms of potassium including total one are needed in relation to soil, weather and croping system. Potassium uptake and efficiency may be increased by topdressing, deep placement, slow-releasing or granular fertilizer application with the consideration of rainfall pattern. In all researches for nutritional explanation including potassium of crop yield reasonable and practicable nutritional indices will most easily be obtained through multifactor analysis.