• Title/Summary/Keyword: 강화재

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A Study on Countermeasures for Technical Barriers of Trade in Korea-China FTA (한.중 FTA의 무역기술장벽 대응방안에 관한 연구)

  • Seo, Min-Kyo;Kim, Hee-Jun
    • International Commerce and Information Review
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    • v.14 no.4
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    • pp.491-516
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    • 2012
  • The purpose of this study is to research the situation of Technical Barriers of Trade(TBT) between Korea and China and analyze a pending issue such as a regular TBT notifications and specific trade concerns informed to WTO/TBT committee by Korea and China and seek the Countermeasures for Technical Barriers of Trade in Korea-China FTA. Generally, in case of a regular TBT notifications, "a protection of human health or safety" and "protection of the environment" are drawn a main articles from TBT committee data. And in case of a specific trade concerns, "international standard" and "transparency" are drawn a important factor from the said data. Henceforth those kinds of articles shall be an issuable matters for negotiation of Technical Barriers of Trade in Korea-China FTA. The results of the study indicate mainly that as Countermeasures of Korea for Technical Barriers of Trade in Korea-China FTA, Korean government level requires to withdraw an exclusive technical regulation of China and supports to improve Chinese technology for safety of products. Korean enterprises should develop products to meet an environment regulation and Korean government should support finance incentive, tax incentive to enterprises. Besides, regarding new international standard it is necessary for Korean side to dominate a relative regulation. First of all, it is important to secure a strength of capability and human resource for international standard activity. For improving a conveyance of notification information and transparency between Korea and China, it is efficient to establish a mutual direct network of notification.

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Supercritical Dyeing Technology (초임계 염색 기술)

  • Kim, Taewan;Park, Geonhwan;Kong, Wonbae;Lee, Youn-Woo
    • Clean Technology
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    • v.24 no.1
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    • pp.1-8
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    • 2018
  • As the social demands for environmental pollution increase and regulations on the dyeing process wastewater are strengthened, supercritical dyeing process has been attracting attention as an alternative technology to reduce wastewater and energy consumption. In the supercritical dyeing process where carbon dioxide is used as a solvent instead of water as a solvent, there is no wastewater generated. The unfixed dyes can be reused later which makes the process environment-friendly. Also, after dyeing process, dried textiles can be obtained without additional drying process, which makes the process energy efficient. In this article, we have summarized the development of the supercritical dyeing process along with the research in Korea today and compared the principle of supercritical dyeing process with conventional dyeing process. To further explain the principle, studies of the distribution factor and mass transfer of dyes in supercritical carbon dioxide and fibers, as well as solubility between supercritical $CO_2$ and dyes are discussed. The dynamic behavior of dyes in supercritical dyeing apparatus and summary of the supercritical dyeing facilities developed around the world are also discussed. Finally, we suggest the direction of research and development for optimization of supercritical dyeing process and application to synthetic fibers and natural fibers except for polyester.

Effect of aging on expression of nitric oxide and inducible nitric oxide synthase in human gingival fibroblasts (노화가 사람 치은섬유아세포의 nitric oxide와 inducible nitric oxide synthase 발현에 끼치는 영향)

  • Ji, Suk;Kook, Jung-Ki;Park, Joo-Cheol;Kim, Heung-Joong;Jang, Hyun-Seon;Kim, Chong-Kwan;Kim, Byung-Ock
    • Journal of Periodontal and Implant Science
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    • v.36 no.2
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    • pp.361-373
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    • 2006
  • 치주질환의 진행이 나이에 의해 영향을 받는다는 사실은 알려져 있으나 노화에 따른 치주조직 세포의 기능적인 변화에 관한 사실은 많이 알려져 있지 않다. 노화에 따른 세포의 노화가 치주질환의 진행에 어떠한 여향을 끼치는가를 아는 것은 중요하다. 염증 상태에서 nitric oxide (NO)는 조직 파괴에 관여하는 인자로 작용하여 치주질환의 진행에 관여하는 것으로 알려져 있다. 따라서 이 연구는 사람의 치은에서 배양된 치은섬유아세포를 이용하여 세포의 노화에 따른 NO와 이의 합성효소인 inducible nitric oxide synthase (iNOS)의 발현을 알아봄으로써 세포의 노화가 치주질환의 진행에 끼치는 영향에 대해 알아보고자 하였다. 10세의 환자와 55세의 환자에서 각각 채취한 치은에서 배양된 세포와 10세의 환자에서 채취한 세포를 계속적인 계대배양을 통해 얻은 실험실 상 노화된 세포를 포함하여 총 3 종류의 치은섬유세포를 실험에 이용하였다. Hot phenol-water extraction을 통해 추출된 Porphyromonas, gingivalis ATCC 33277 lipopolysaccharide (LPS)와 재조합 $IFN-{\gamma}$ 를 세포에 적용시켜 Griess assay를 통해 조건화된 배지에서 NO를 측정하였다. 20세와 55세의 환자에서 채취된 치은 조직과 총 3 종류의 배양된 세포에 NOS-II 항체를 적용시켜 iNOS 단백질 발현을 관찰하였다. Total RNA를 추출하여 RT-PCR를 통해 iNOS mRNA의 발현을 분석하였다. 치은섬유아세포에서 NO는 자발적으로 발생되었고, 이러한 발현은 젊은 세포보다 노화된 세포에서 강하였다. P, gingivalis LPS와 제조합 $IFN-{\gamma}$는 치은섬유아세포에서 NO의 발현을 증가시켰고, 이러한 발현은 젊은 세포보다 노화된 세포에서 강하였다. 면역조직화학 염색에서 iNOS 단백질은 젊은 사람과 노화된 사람의 치은 조직 모두에서 치은섬유아세포와 상피의 기저층 세포와 염증세포에서 발현되었으나 노화에 따른 발현의 차이를 구별할 수는 없었다. 세포의 면역염색에서 iNOS 단백질은 노화된 세포에서 강하게 발현되었고 이러한 발현은 LPS와 $IFN-{\gamma}$ 에 의해 강화되었다. LPS와 $INF-{\gamma}$ 의 조건이 주어지지 않은 상태에서 iNOS mRNA는 젊은 세포에서보다 노화된 세포에서 강하게 발현되었다. 이러한 결과를 통해 세포의 노화가 NO와 iNOS 발현을 증가시킴으로서 치주질환의 진행에 영향을 끼칠 수 있음을 시사하였다.

CHARACTERISTICS OF FLUORIDE RELEASING RESTORATIVE MATERIALS AFTER TOOTHBRUSH-DENTIFRICE ABRASION (잇솔질 마모 처리한 불소방출성 수복재의 특성)

  • Park, Jong-Ha;Baik, Byeong-Ju;Yang, Yeon-Mi;Kim, Jae-Gon
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.4
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    • pp.705-713
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    • 2004
  • The objectives of this study were to evaluate the fluoride release and the change of surface roughness of fluoride releasing restorative materials after toothbrush-dentifrice abrasion. Seven commercially available fluoride releasing restorative materials (Fuji II LC Improved: FL, Compoglass F: CG, Dyract AP: DR, F2000: FT, Ariston: AT, Tetric: TR, and Gradia: GD) were selected as experimental materials. The results obtained were summarized as follows: 1. The AT, FL, and CF groups produce an initially large burst of fluoride release and comparatively low but continuous release of fluoride. But other groups produce no initial burst of fluoride and levels of release remain relatively constant. 2. The rate of fluoride release remains steady state after 40 days. The results of Tukey's test (P<.05), the fluoride release showed the order of decreasing rank as follows: AT > FL > compomers > TC and GD. 3. The surface roughness indicated that the highest value was observed in the FT group and the lowest value was observed in the CF group. The surface roughness of Tukey's test showed the significant differences between groups of FT, AT and FL and groups of CF, DR, GD and TC (P<0.05).

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Enhanced Lycopene Production in Recombinant Escherichia coli by Random Transposon and NTG Mutagenesis (Transposon 및 NTG 돌연변이를 이용한 재조합 대장균의 라이코펜 생산성 증진)

  • Yoon, Sang-Hwal;Ko, Min-Su;Park, Kyoung-Ae;Jung, Kyung-Hwa;Shin, Yong-Chul;Lee, Young-Mi;Lee, Sook-Hee;Kim, Seon-Won
    • KSBB Journal
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    • v.21 no.2
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    • pp.90-95
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    • 2006
  • Escherichia coli harboring pAC-LYCO4 and pDdxs was used for lycopene production. Three wild type strains of E. coli OW1, MG1655, and W3110 were compared with DH5${\alpha}$ used before for lycopene production. Lycopene productivity of E. coli MG1655 was similar to DH5${\alpha}$ and the highest among those wild type strain. Therefore, MG1655 strain was used for random transposon and NTG mutagenesis to increase lycopene productivity. Through transposon mutation, five transposon mutants with increased lycopene productivity were obtained. It was found that genes knocked out by transposon insertion were treB in Tn1 mutant, B2436 in Tn2 mutant, and rfaH in Tn3, 4, and 5 mutants. Lycopene productivity was the highest in Tn4 mutant among the Tn mutants, which was 6-fold and 8-fold higher in lycopene concentration and content, respectively, in comparison with those obtained with wild type strain. NTG4 mutant was acquired with NTG mutation. The highest lycopene productivity of 6 mg/L and 4 mg/g DCW was obtained from the NTG4 mutant when arabinose of 0.013 mM was added for induction of dxs, rate-limiting gene of MEP pathway. The lycopene productivity of NTG4 mutant was increased 18-fold and 12-fold in lycopene concentration and content, respectively when comparing with the wild type strain.

Development for Penetrative Performance Improving Agent to In Prevent Deterioration of Concrete Structures (콘크리트 구조물의 내구성능 저하를 방지하는 침투형 성능개선제 개발)

  • Ryu Gum-Sung;Koh Kyoung-Taek;Kim Sung-Wook;Kim Do-Gyeum
    • Journal of the Korea Concrete Institute
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    • v.17 no.4 s.88
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    • pp.489-498
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    • 2005
  • Recently, the deterioration of concrete structures have been increased by the damage from salt, carbonization, freezing & thawing and the others. Therefore, the measures for the deterioration of concretes have been taken. Among them, it has been often used that surface treatment which cut off the deterioration factors of durability by protecting the surface of concrete. The water proof and repair materials for concrete mainly use organic materials such as epoxy, these materials excel in intial bonding force and resistance to chemical agents. But they cause difference in the modulus of elasticity and the rate of shrinkage and expansion of concrete, and thus result in such problems as scaling and spatting in the progress of time. Therefore in this study it develop the performance Improving agent of concrete surface that can block a deterioration cause such as $CO_2$ gas, chloride ion and water from the outside and enhance waterproofing ability by reinforcing the concrete surface when applying it to concrete structures.

Study on Market Prospects, Financing Challenges and Alternative Solutions in New Nuclear Power Projects (신규 원전의 시장전망 및 금융조달의 과제와 대안)

  • Lee, Jang-pyo
    • KEPCO Journal on Electric Power and Energy
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    • v.2 no.1
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    • pp.133-141
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    • 2016
  • Although construction of any new nuclear power projects had not been launched since mid-1970s until recently in the USA, many new nuclear power plants have been constructed in many countries with the support of their governments mainly as part of their national energy security and electric source diversification policies. For many reasons, the nuclear power industry seemed to reclaim their renaissance from the beginning of this century and the investment in the nuclear power projects draw positive concern from the private financial sector. But the global financial crisis in 2008 and subsequent economic slow-down together with tighter bank credit regulations caused commercial banks, the main source of financing, to lose appetite for investing in new nuclear power projects. But the nuclear power economics shows that the nuclear power is viable in terms of the environmental benefit and long-term average cost compared to other power generation sources. Also doubt about nuclear power safety was much mitigated due to technology development and reinforced safety-related tests and monitoring. Therefore, the prospect for nuclear power market expansion remains positive although there are comparatively big differences among different scenarios. After Korea Electric Power Corp. won the UAE nuclear power project in December of 2009, the competition in nuclear power markets is undergoing huge changes. Competitors backed by the support of their own governments are now entering the market with many aggressive and innovative financing packages to win bids of new nuclear power projects. This report analyzed the nuclear power market prospects, competitive edges of nuclear power, risk management measures, and financing challenges and recommends alternative solutions to promote competitive edges in winning bids of new nuclear power projects.

A Study on the Characteristic of Conversion Efficiency for Three-way Catalyst in Hydrogen-Natural Gas Blend Fueled Engine (수소-천연가스 혼합연료 엔진의 삼원촉매 전환효율 특성 연구)

  • Park, Cheol-Woong;Yi, Ui-Hyung;Kim, Chang-Gi;Lee, Janghee
    • Journal of the Korean Institute of Gas
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    • v.20 no.6
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    • pp.23-30
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    • 2016
  • The conventional natural gas engine realized lean combustion for the improved efficiency. However, in order to cope with exhaust gas regulations enforced gradually, the interest has shifted at the stoichiometric mixture combustion system. The stoichiometric mixture combustion method has the advantage of a three-way catalyst utilization whose purification efficiency is high, but the problem of thermal durability and the fuel economy remains as a challenge. Hydrogen-natural gas blend fuel (HCNG) can increase the rate of exhaust gas recirculation (EGR) because the hydrogen increases burning speed and lean flammability limit. The increase in the EGR rate can have a positive impact on heat resistance of the engine due to the decreased combustion temperature, and further can increase the compression ratio for efficient combustion. In this study, to minimize the exhaust emission developed HCNG engine with stoichiometric combustion method, developed three-way catalyst was applied to evaluate the conversion characteristics. The tests were carried out during the steady state and transient operating conditions, and the results were compared for both the conventional and proto-three-way catalyst of HCNG engine for city buses.

The Effect of Perceived Value, Satisfaction and Self-Congruity on the Revisit Intention and the Word-of-Mouth Intention (스키장 방문자들의 가치, 만족, 자아일치성이 재방문의도와 구전의도에 미치는 영향)

  • Hong, Sung-Kwon;Kim, Jae-Hyun;Jang, Ho-Chan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.2
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    • pp.74-85
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    • 2012
  • As competition increases, ski resort managers need to search for ways to attract previous visitors or to gain new visitors through word-of-mouth. This study examined the impact of skiers' perceived value, satisfaction and self-congruity on the revisit intention and the positive word-af-mouth intention. Total respondents were also segmented into a promotion-focus and prevention-focus individuals then later examined the differences in the effect of independent variables between groups in order to suggest a managerial direction that will enhance business competency of ski resorts. Results from regression analysis showed that all independent variables utilized in this study were good predictors of two dependent variables. Specially, satisfaction was a highly significant predictor. Promotion and prevention-focused individuals were also differed in evaluating the importance of independent variables for their revisit and word-of-mouth intention. It means that self-regulatory focus is an effective variable for segmentation. More specifically, satisfaction was the only variable influencing the revisit intention for promotion-focused individuals; whereas both satisfaction and self-congruity had significant effects on the revisit intention for prevention-focused individuals. All independent variables had significant effects on the word-of-mouth intention, except self-congruity for promotion-focused individuals. This research suggests several managerial implications on the findings based on the analysis and the characteristics of the visitors.

Analysis on the Damage Status by Diagnostical Methodology for the Improvement Landscape on the Supyo-bridge at Chunggae-stream (청계천 수표교(水標橋)의 경관 향상을 위한 진단학적(診斷學的) 훼손상태 분석)

  • An, Jin-Sung;Choi, Ah-Hyun;Kim, Yu-Il
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.3
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    • pp.105-113
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    • 2010
  • This study is for the preservation plan of the tradition space which is performed by the damage status analysis through performing the value assessment. Especially, it is an experimental study for finding the process and methods by analyzing the major element for the value assessment of the selected object's damage status through the expert group who are systematized in their interest to conserve the traditional structure in traditional space. For that purpose, this study should be performed by the fundamental understanding of the physical property of the Supyo-bridge and the condition of the selected site's environment. Meanwhile, this study has been done that 'map of the damage status distribution' for making records of damage status of the Supyo-bridge on the property utilized field measurement adapted by photogrammetry and assessment guidelines, which are for investigation on damage status of objects that are standardized 'Raccomandazioni Normal' which could be said construction culture assets management guidelines of Italian government. As the result of investigation, damage status of each part in the Supyo-bridge was mostly composed of damage by sediment and corrosion and in case of 9 damage types including corrosion, in consideration of physical and chemical properties and distribution status of those elements, it is made an judgement that is not working as a threatened factor regarding security of the Supyo-bridge. On the contrary, for the improvement landscape, in case of 'Thermoclastism' phenomenon observed in 'upper floor', 'Myungae stone' and 'bridge pier' is that when taking it into consideration that is widely distributed concentrated on the bridge pier, surface reinforcement job along with elimination of damage part will be judged to be requested for earliest treatment.