• Journal of the Korea Concrete Institute
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• v.22 no.3
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• pp.297-303
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• 2010

The current encased-concrete deep corrugated steel plate has an arch type plate structure, which is a compressive strength-dominant structure that has a small moment due to its arch shape. Therefore, it increases the strength against compression by adding reinforcements to make concrete-filling spaces for increasing the compressive strength and forming cross sections that contain reinforced concrete. In this study, the safety factor of the new-concept encased-concrete bridge plate member was evaluated by comparing the compressive strength obtained from the compressive tests, flexural tests and the design compressive strength determined by using the Canadian Highway Bridge Design Code (CHBDC, 2003), which is a design standard for the encased-concrete bridge plate structures. The results of the safety factor evaluation using the design compressive strength and the test results showed that the safety factor was well above the appropriate value 2.0, which could be adjudged very conservative. If the safety factor based on this study results is considered and applied to the design, economical construction will be possible due to the reduced cross section and construction cost.

• Journal of the Korea Concrete Institute
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• v.27 no.4
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• pp.451-458
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• 2015

The infill-wall strengthening method has been widely used for the seismic performance enhancement of the conventional reinforced concrete (RC) frame structures with non-seismic detail, which is one of the promising techniques to secure the high resisting capacity against lateral forces induced by earthquake. During the application of the infill-wall strengthening method, however, it often restricts the use of the structure. In addition, it is difficult to cast the connection part between the wall and the frame, and also difficult to ensure the shear resistance performances along the connection. In this study, an advanced strengthening method using the externally-anchored precast wall-panel (EPCW) was proposed to overcome the disadvantages of the conventional infill-wall strengthening method. The one-third scaled four RC frame specimens were fabricated, and the cyclic loading tests were conducted to verify the EPCW strengthening method. The test results showed that the strength, lateral stiffness, energy dissipation capacity of the RC frame structures strengthened by the proposed EPCW method were significantly improved compared to the control test specimen.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1635-1641
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• 2014

Diospyros lotus has been cultivated for its edible fruits, which are considered to have medicinal importance. The aim of this study was to evaluate the antioxidant and antipruritic activities of water-soluble, methanol extract, and ethyl acetate (EA) fractions from D. lotus leaves. The EA fraction showed the lowest $IC_{50}$ vale (DPPH: $5.3{\mu}g/mL$, ABTS: $53.8{\mu}g/mL$). Therefore, we further investigated anti-inflammatory and antipruritic effects of the EA fraction. TNF-${\alpha}$ production increased by PMA plus A23187 treatment was significantly inhibited by the EA fraction in a dose-dependent manner. The EA fraction also inhibited histamine release from rat peritoneal mast cells stimulated by compound 48/80, which promotes histamine release. Furthermore, EA fraction had inhibitory effects on scratching behavior induced by compound 48/80 in Balb/c mice. These results suggest that the EA fraction from D. lotus leaves has potential as ameliorative agent against oxidative stress and pruritus-related disease.

• Journal of Life Science
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• v.20 no.12
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• pp.1838-1843
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• 2010

Skin aging is related to genetic and environmental factors (e.g., gene mutation and UV radiation respectively). To develop a new anti-wrinkle cosmetic or functional food by using Korean rice wine cake, we examined the effects of Korean rice wine cake, a brewery byproduct, on antioxidant effect, collagen synthesis and expression of MMP-1. Interestingly, we found that Korean rice wine cake has the ability to promote scavenging activity of DPPH radical. We also found that the cell proliferation and synthesis of collagen in HS27 cells was increased by Korean rice wine cake in a concentration-dependent manner. However, elastase inhibitory activity was not changed. In addition, the expression of MMP-1 was inhibited by Korean rice wine cake in a concentration-dependent manner. All these results suggest that Korean rice wine cake can be effectively used for the prevention of wrinkles in human skin.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.799-804
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• 2006

Antioxidative and antimicrobial activities were measured for the Pleurotus eryngii (P. eryngii) solvent extracts in order to discover new functional activities. In P. eryngii, the powder moisture was 9.0%, and the carbohydrate, crude protein, crude ash and crude fat contents were 63.06, 20.70, 5.20 and 2.0%, respectively. Among the detected minerals, potassium (K) had the highest levels and manganese (Mn) the lowest. The amount of polyphenol in EtEx (Ethanol Extract) was 387 mg% for the whole body, 158 mg% for the stipe, and 593 mg% for the pileus. Higher levels of polyphenol in the entire body were found in the BuEx (Butanol Extract) (594 mg%) and WaEx (Water extract) (404 mg%) of the P. eryngii powder. BuEx had the highest level in the pileus, and EtEx and BuEx were higher than the other extracts in the stipe. The electron donating ability (EDA) of EtEx of the P. eryngii powder was the highest, at 91.12%, for the whole body, while it was the lowest, at 62.90%, in the stipe. In addition, the EDA of WaEx was 90.39% for the whole body. These EDA values were similar to those for tocopherol (93.93%) and BHT (96.72%), supporting the potential of these extracts to act as antioxidants. A number of the extracts were certified to have antimicrobial activities for small number of microorganisms, especially for gram-negative microorganisms. In other words, BuEx and EAEx in the pileus and WaEx in the stipe were found to inhibit the growth of Pseudomonas aeruginosa (gram negative). Additionally, EtEx and WaEx in all parts were shown to act as antimicrobial agents for Escherichia coli of gram negative.

• Korean Journal of Food Science and Technology
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• v.14 no.3
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• pp.236-243
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• 1982

In order to remove the high content of malic acid (0.48%) in freshly fermented apple wine by applying malo-alcoholic fermentation(MAF) using malate-decomposing yeasts, Schizosaccharomyces japonicus var. japonicus or Schizosaccharomyces pombe, some factors which influenced malic acid decomposition in apple wine by malate-decomposing yeasts were investigated. By incubating the apple wine with these yeasts, 80% of initial malic acid was decomposed in 13 days at $20^{\circ}C$, whereas only 32% reduction in malic acid was observed in 40 days when MAF was not induced. For malic acid decomposition, Schizosaccharomyces pombe was superior to Schizosaccharomyces japonicus var. japonicus in natural medium such as apple wine, whereas Schizosaccharomyces japonicus var. japonicus was superior to Schizosaccharomyces pombe in synthetic medium. The optimum temperature for the MAF using these yeasts was between $20\;to\;30^{\circ}C$ and no adverse effect was detected by the addition of $SO_2$ up to 200ppm. Additions of $Mg^{2+}$ or certain amino acids such as alanine, aspartic acid to the wine could enhance the composition of malic acid.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.29-29
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• 2011

아라미드 섬유는 열에 강한 튼튼한 방향족 폴리아마이드 섬유이다. 아마이드는 "85%이상의 아미드(CO-NH)기가 두 개의 방향족 고리에 직접 연결된 합성 폴리아미드로부터 제조된 섬유"로 정의된다. 아라미드 섬유는 크게 파라계와 메타계로 대별되는데 본 연구에서 사용한 파라계 아라미드는 인장강도, 강인성, 내열성이 뛰어나며 고강력 고탄성률을 지니고 있다. 일반적인 유기 섬유와는 다른 우수한 성질을 바탕으로 부직포, UD laminatig, staple 등의 형태로 크게 섬유보강 고무 복합재료 등의 각종 복합재료, 로프, 케이블, 방탄방호용과 같은 산업자재의 용도로 자동차, 우주항공, 정보통신, 국방, 등 다양한 관련 산업분야에서 사용이 확대되고 있는 고부가 소재이며 가격대비 성능비가 우수하기 때문에 세계적으로 산업용 섬유 및 초고성능 섬유시장에서 비중이 증가될 것으로 예상되고 있다. 본 연구에서는 Para-Aramid 필라멘트를 이용하여 ATY를 생산할 때 제조공정조건에 따른 ATY 물성을 알아보고 고강도를 요구하는 방화복, 고무 보강용 섬유 등의 소재에 맞는 ATY 사가공 최적공정조건을 도출하여 체계화된 data-base를 구축하여 생산성 향상 및 품질개선과 함께 산업자재용 직물개발에 응용하고자 한다. 아라미드를 ATY로 제조할 경우, 표면에 생기는 loop로 인하여 타소재와 접착시, 접착제 담지 성능이 향상되어 접착력이 상승되는 반면, 아라미드 ATY가 기존의 아라미드의 물성보다 저하되는 약점을 가지고 있으므로 이를 보완하기 위해 본 연구에서는 ATY 제조공정에서 중요 공정인자인 사속, heater 온도, over feed ratio를 변화시켜 시료를 제조하여 이들의 물성을 분석하여 최적의 물성을 갖는 ATY 사가공 공정을 도출함으로써 물성이 저하되는 문제를 보완 가능할 것으로 기대된다. 물성분석은 강신도, 초기탄성률을 각각 측정하여 인장특성을 확인하였으며, 습열수축률과 건열수축률을 측정하여 시료의 열수축률에 대해 측정을 하였다. 표면의 루프 발현 정도를 보기 위하여 Crimp Rigidity(CR%), 형태 불안정성(instability)등을 측정하였으며, 영상 현미경 시스템을 사용하여 ${\times}40$ 배율로 표면특성을 측정하였다.

• Development and Reproduction
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• v.9 no.2
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• pp.135-142
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• 2005

Vitellogenins(VTGs) are the precursor of egg-yolk proteins in most oviparous species from invertebrates to vertebrates. In oviparose vertebrates, VTGs are synthesized in the liver and transported through the blood to oocytes. In female fish, concentrations of plasma VTG increase rapidly at onset of vitellogenesis in the normal reproductive cycle. Male fishes also possess the gene for VTG, but plasma concentrations of the protein typically remain small, presumably due to low levels of endogenous estrogens. However, exposure of males to exogenous estrogenic mimics can result elevated. Therefore, the VTG in fish can be used as a useful biomarker for appropriate tools of endocrine disrupting compounds effects. In this studies, we prepared the test methods that can measure the plasma VTG level in the gobies that live in polluted area with mimic estrogen. For the purpose, we purified VTG of floating goby(Chaenogobius annularis) and prepared specific monoclonal and polyclonal antisera to yolk protein, then developed a sandwich competitive ELISA system for measurement of plasma VTG levels. Validation for the ELISA system using monoclonal and polyclonal antibodies against VTG was tested. The absorbance curve of serial dilutions of serum from vitellogenic female was paralleled to the standard curve of VTG, but normal male was not paralleled. The developed sandwich ELISA system was measured for VTG levels in plasma of common goby(Acanthogobius flaviman) and javeline goby(A. hasta) as well as in plasma of floating goby(C. annularis).

• Journal of Energy Engineering
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• v.24 no.3
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• pp.150-163
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• 2015

Gasification technology is one of the representative next-generation fossil fuel utilization technologies, converting low grade fossil fuels such as coal, heavy residue oil, pet-coke into highly clean and efficient energy sources. Accordingly, related market demand for gasification technology is ever increasing steadily and rapidly. A few years ago, conventional pulverized coal utilization technology had an edge over the gasification technology but the most significant technical barrier of limited capacity and availability has been largely overcome nowadays. Futhermore, it will be more competitive in the future with the advancement of related technologies such as gas turbine, ion transfer membrane and so on. China has recently completed a commercialization-capable large-scale coal gasification technology for its domestic market expansion and foreign export, rapidly becoming a newcomer in the field and competing with existing US and EU technical leadership at comparable terms. Techno-economic aspect deserves intensive attention and steady R&D efforts need to continue in organized, considering that gasification technology is quite attractive combined with $CO_2$ capture process and coal to SNG plant is economically viable in Korea where natural gas is very expensive. In the present paper, recent technology development and commercialization trend of many leading companies with coal gasification expertise have been reviewed with significant portion of literature cited from the recently held '2014 Gasification Technology Conference'.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.12
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• pp.1337-1344
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• 2007

In this research, we synthesized potassium ferrate(VI) acting as an oxidant, disinfectant, and coagulant, and used it to treat natural organic matter(NOM, HA and FA) in river water. The removal efficiencies obtained by $UV_{254}$ ranged from 20.7 to 73.6% for 10 mg/L HA and from 52.6 to 77.5% for 10 mg/L FA in Nakdong river sample as the ferrate dose varied from 2 to 46 mg/L(as Fe). However, the removal efficiencies by TOC analysis ranged from 0 to 20.3% for HA and from 0 to 26.6% for FA at the same ferrate doses. The removal efficiencies of NOM increased either with decreasing pH or with increasing temperature. The removal efficiency of HA by ferrate was comparable to those by traditional coagulants such as $Al_2(SO_4)_3{\cdot}18H_2O$, $FeSO_4{\cdot}7H_2O$, and FeO(OH). The reaction between ferrate and HA reached a steady state within 60 seconds, showing first-order with respect to the reaction time. The removal efficiencies of HA by traditional coagulants were improved by pretreatment of HA using a small amount of ferrate.