VES-LMC 덧씌우기를 이용한 콘크리트 포장 보수

정원경,김용곤,김기헌,윤경구 강원대학교 산업기술연구소 2005 産業技術硏究 Vol.25 No.B

Since in 1970, the length of concrete pavements(JCP, JRCP and CRCP) are growing rapidly at both of main highways and local roads. Many of them are deteriorated and old enough to be repaired or replaced. The pavement is more important than the other infrastructures and it is very difficult to go around or block the traffic during the rehabilitation. The very-early strength latex-modified concrete(VES-LMC)may offer the advantages of high-early-strength, higher flexural strength, higher bond strength, and improved durability. The VES-LMC could be used at a kind of fast track ofr early opening to the traffic after 3 hours of concrete placement. The installation of VES-LMC overlay at Jung-Boo highway was successfully done from April 28 to 29, 2005. The traffic was closed at 07:00 PM and opened to traffic at 08:30 AM. The compressive and flexural strength of VES-MC were more than 28MPa, 6.2MPa after 4 hours, respectively.

대유행 인플루엔자(H1N1 2009) 급성호흡곤란증후군에 대한 체외막 산소화 장치의 조기적용 1예

이경학,이길수,오원섭,유숙원,천성빈,이승준 대한감염학회 2010 감염과 화학요법 Vol.42 No.2

Despite advanced technologies in intensive care, pandemic influenza (H1N1 2009) can rapidly progress to acute respiratory distress syndrome (ARDS) and cause death in a small subset of patients. Extracorporeal membrane oxygenation (ECMO) is expected to provide adequate gas exchange, to reduce ventilator-induced lung injury and, eventually, to improve outcome in these patients. A previously healthy, young female received mechanically ventilatory support because of rapidly progressive respiratory failure caused by 2009 H1N1 influenza. As she failed to respond to high ventilatory support, ECMO was instituted at 6 hours after admission. We describe detailed course of case and literature review on ECMO, helping physicians make a decision to initiate ECMO in patients with influenza-related ARDS.

국립 디지털도서관 조경설계

김도경,최원만,박지순 경희대학교 디자인연구원 2005 예술· 디자인학연구 Vol.9 No.2

This winning landscape design was presented to a national design competition for the master plan of new Digital Library on the existing National Library of Korea. The site is located at San 60-1, Banpo-Bong, Seocho-Gu, Seoul and has an area of 142,233㎡. The judging criteria for landscape design set by the client could be articulated as follows: an environment friendly design and a landscape design harmonizing existing facilities with new digital library. In this design, we first tried to respect its existing setting and context, a library in a city park environment, Also the design required an interpretation of the meaning of 'digital library' and its relationship with 'old' library.

콘크리트 鋪裝의 初期計測을 통한 初期擧動 特性分析

정원경,김동호,권혁찬,윤경구 강원대학교 산업기술연구소 2003 産業技術硏究 Vol.23 No.A

The purpose of this paper is to analysis of initial behavior of concrete pavement with initial measurement strain gauge for concrete pavement at field, and to investigate the field test results for field applicability testing. The early-age behaviors of concrete pavement slabs were measured using the strain gauges. From the slab depths and positions, the outputs from each gauges were recorded at initial curing period The initial measurement of concrete pavement and check of crack at the joint were performed. the results could be summarized as follows. From the results of concrete strength, compressive strength and flexural strength were showed 271kgf/㎝', 43kgf/㎝' respectively. From the tests of early-age strain measurement, it was found that the strain varied at the maximum value of 150μ ε and early1 behavior of concrete slab was showed a tensile strain However. for long-term was showed a compressive strain due to dry-shrinkage.

소포제를 이용한 초속경 LMC의 특성 개선연구

윤경구,김성환,정원경,권혁찬 강원대학교 부설 석재복합신소재 제품연구센터 2003 석재연 논문집 Vol.8 No.-

본 논문은 콘크리트 배합시 발생하는 과도한 기포 발생 문제점을 해결하기 위하여 최적의 소포제 종류 및 혼입률 범위를 산정하여 초속경 라텍스개질 콘크리트 성능을 개선하는 것이다. 초속경 라텍스개질 콘크리트 실험은 2종류의 소포제 A, C와 혼입률 0, 1, 2, 3%을 주요 변수로 하여 공기량 시험, 압축강도 및 휨강도 시험을 수행하였다. 또한, 내구성 평가를 위하여 염소이온 투과실험도 수행하였다. 초속경 라텍스 개질 콘크리트의 공기량시험 결과 소포제 종류에 상관없이 소포제 혼입률 1%이상 첨가시 공기량은 50%이상 감소하였다. 또한, 소포제 첨가에 의한 기포 발생량 감소에 의해서 압축강도의 증진을 이루었다. 초속경 라텍스개질 콘크리트 실험은 A, C 소포제로 선정하여 실험을 수행하였다. 초속경 라텍스개질 콘크리트의 강도 특성에서는 A 소포제 혼입률 1%에서 압축강도 235kgf/㎠ , 휨강도는 조기 교통개방에 요구되는 휨강도 기준 45kgf/㎠를 초과하는 49kgf/㎠를 나타내었다. The purpose of this study was to remove the excessive air foaming which was produced in mixing the RSLMC(latex-modified concrete with rapid-setting cement) by choosing the best antifoam agent type and the optimized quantity for performance improved RSLMC. The main experimental variables such as antifiamer types(A, C), antifoamer contents(0, 1, 2, 3%), and latex contents(15%). Air content test and compressive, flexural tests were carried out to measure the improved properties of RSLMC. the rapid chloride permeability was carried out to estimate a durability of RSLMC. The results of RSLMC showed that the decrease of 50% air content was obtained by admixturing a antifoam agent by 1%. Two kinds and the optimized quantities of antifoam agent were selected for using in RSLMC. The results of RSLMC were obtained at a latex content of 15% and a antifoam agent quantity of 1% with antifoamer A type. The compressive strength and flexural strength at 3 hours after RSLMC placement were 235kgf/㎠ and 49kgf/㎠, respectively, which exceeded the flexural strength criterion of 45kgf/㎠ in order to open the RSLMC placed to traffic.

라텍스개질 콘크리트의 물-시멘트비에 따른 건조수축 특성

정원경,김성환,김동호,이주형,이봉학 江原大學校 産業技術硏究所 2002 産業技術硏究 Vol.22 No.A

Drying shrinkage cracking which may be caused by the relatively large specific suface is a matter of grave concern for latex modified concrete(LMC) overlay and rapid-setting cement latex modified concrete(RSLMC) overlay. LMC and RSLMC were studied for field applications very actively in terms of strength and durability in Korea. However, there were no considerations in drying shrinkage. Therefore, the purpose of this dissertation was to study the drying shrinkage properties of LMC and RSLMC with the main experimental variables such as cement types(ordinary portland cement, rapid setting cement), water-cement ratios and curing days at a same controlled environment of 60% of relative humidity and 20℃ of temperature. The drying shrinkage for specimens was measured with a digital dial gauge of Demec. The test results showed that the drying shrinkage of LMC and RSLMC were considerably lower with low water-cement ratio, respectively. This might be attributed to the interlocking of hydrated cement and aggregates by a film of latex particles, water retention due to hydrophobic, and colloidal properties of the latexes resulting in reduced water evaporation.

라덱스 혼입률에 따른 철근콘크리트의 휨파괴 거동특성

정원경,김동호,이주형,임홍범,윤경구 江原大學校 産業技術硏究所 2002 産業技術硏究 Vol.22 No.A

Reinforced concrete(R/C) is commonly used to structures because they have many merits that compressive strength, economy and so on. However, reinforced concrete has a crack at the tensile section which is due to the relatively lower tensile strength than its compressive strength. Latex modified concrete(LMC) has higher tensile and flexural strength than the ordinary portland cement, due to the interconnections of hydrated cement and aggregates by a film of latex particles. The purpose of this study was to investigate the flexural behavior of reinforced concrete beam with latex modified concrete, having the main experimental variables such as concrete types(ordinary portland cement concrete, latex modified concrete), latex contents(0%, 15%), flexural steel ratios(0.012, 0.0235), and with/without shear reinforcement. The beam of LMC showed considerably higher initial cracking loads and ductility than that of OPC, but, similar to ultimate strength and deflection. This might be attributed to the interlocking of hydrated cement and aggregates by a film of latex particles, water retention due to hydrophobic, and colloidal properties of the latexes resulting in reduced water evaporation. The beam with latex modified concrete could be adopted at field for controlling and reducing the tensile crack due to its higher tensile strength.

한국산 나비 目(Lepidoptera)의 발향린(Androconia)에 관한 주사전자현기경적 연구 III. 네발나비科

박원학,류성만,서경인,이종욱 嶺南大學校 基礎科學硏究所 1992 基礎科學硏究 Vol.12 No.-

한국산 네발나비과에 보고된 77종 중 북한산 12종과 채집하지 못한 21종을 제외한 44종, 670여 개체를 재료로 광학현미경으로 발향린의 유무 및 분포를 확인하였다. 이중 발향린이 관찰된 10종을 대상으로 주사전자현미경으로 그 형태를 비교 연구하였다. 1. 발향린이 관찰된 종은 Brentis ino(R.), Argyronome laodice (P.). A. ruslana (M.). Damora sagana (D.), argynnis paphia (L.), Childrena zenobia (L.), Speyeria aglaja (L.), Fabriciana pallescens (B.), F. adippe (L.), F. nerippe(c.et R. F.) 10종이다. 2. 발향린은 암컷에서는 관찰되지 않았고, 수컷이 앞날개 표면에서만 관찰되었으며, 시맥위에서만 분포한다. 3. 확인, 관찰된 10종의 발향린은 나발막(fimbriae), 경부(neck), 잎새(laminar), 자루병반(foot stalk) 등 발향린의 전형적인 모양을 나타내었으며, 동종내 개체간 변이는 관찰되지 않았다. 4. Argyronome laodice, A. ruslana, Damora sagana, argynnis paphia, Childrena zenobia, Fabriciana pallescens 등 6종에서는 2가지 형태의 발향린이 관찰되었다. 5. 본 연구에서 관찰한 10종은 Subfamily Argynninae아과의 Argynnini족에서만 관찰되었으며, 관찰된 발향린중 Type ⅠⅠ의 형태는 종간에 큰 차이점이 없었고, Type Ⅰ은 많은 형태적 차이를 보이므로 분류학적으로 중요한 형질이라 사료된다. this paper observed through microscope the existance and the distribution of the androconia of the 44 species Nymphalidae among 77 ones that have been reported in Korea, excluding 12 species in North Korea and 21 one's not collected ten species that were observed the androconia among those were chifely compared and studied through Scanning Electron Microscope. 1. The 10 species that observed androconia is Brentis ino(R.), Argyronome laodice (P.). A. ruslana (M.). Damora sagana (D.), Argynnis paphia (L.), Childrena zenobia (L.), Speyeria aglaja (L.), Fabriciana pallescens (B.), F. adippe (L.), F. nerippe(C. et R. F.) 2. The androconia was not found at the female, but only on the dorsal surface of male's fore wings. 3. The androconia of 10 species was not observed intraspecific seasonal variation and individual variation. It was appeared the androconia as general type of fimbriae, neck, laminar and foot stalk. 4. Two types(typeⅠ and Ⅱ) of androconia were observed at the species of Argyronome laodice, A. ruslana, Damora sagana, Argynnis paphia, Childrena zenobia, Fabriciana pallescens. 5. According to this study, the androconia of 10 species observed only Argynnini, subfamily Argynniae. The type Ⅱ of the androconia similar to between species but type Ⅰ was observed multitudes of morphological difference. These difference of type Ⅰ was very important taxonomical characters.

초속경 LMC의 시험시공을 위한 시방배합 및 현장배합 연구

윤경구,김성환,정원경,최성욱 강원대학교 부설 석재복합신소재 제품연구센터 2002 석재연 논문집 Vol.7 No.-

본 논문은 콘크리트 배합시 발생하는 과도한 기포 발생 문제점을 해결하기 위하여 최적의 소포제 종류 및 혼입률 범위를 산정하여 초속경 라텍스 개질 콘크리트 성능을 개선하는 것이다. 초속경 라텍스 개질 모르타르 실험은 4종류의 소포제 A, B, C, D와 혼입률 0, 1, 2, 3%을 주요 변수로 하여 실험을 수행하였으며, 초속경 라텍스 개질 모르타르 및 콘크리트의 특성을 분석하기 위하여 공기량 시험, 압축강도 및 휨강도 시험을 수행하였으며, 투수특성을 분석하기 위해서 염화이온 투과시험을 수행하였다. 초속경 라텍스 개질 모르타르의 공기량시험 결과 소포제 종류에 상관없이 소포제 혼입률 1%이상 첨가시 공기량은 50%이상 감소하였다. 또한, 소포제 첨가에 의한 기포발생량 감소에 의해서 압축강도의 증진을 이루었다. 초속경 라텍스 개질 콘크리트 실험은 모르타르 실험에서 우수한 특성을 나타낸 A, C 소포제로 선정하여 실험을 수행하였다. 초속경 라텍스 개질 콘크리트의 강도 특성에서는 A 소포제 혼입률 1%에서 압축강도 235 kgf/㎠, 휨강도는 조기 교통개방에 요구되는 휨강도 기준 45kgf/㎠를 초과하는 49kgf/㎠를 나타내었다. 초속경 라텍스 개질 콘크리트의 투수성을 분석하기 위한 염화이온투과시험에서 A 소포제는 각각 혼입률 1%, 2%에서 가장 우수한 투수저항성을 나타내어 재령 28일에서는 통과전하량이 100쿨롱 이하를 나타내어 불투수성을 나타내었다. The purpose of this study was to remove the excessive air foaming which was produced in mixing the RSLMC(latex-modified concrete with rapid-setting cement) by choosing the best antifoam agent type and the optimized quantity for performance improved RSLMC. A series of RSLMM(latex-modified mortar with rapid-setting cement) experiments were carried out as the basic for RSLMC with the main experimental variables such as antifiamer types (A, B, C, D), antifoamer contents (0, 1, 2, 3%), and latex contents (15%). A series of RSLMC experiments, also, were carried out with the similar main experimental variables but with the selected antifoamer types (A, C). Air content test and compressive, flexural tests were carried out to measure the improved properties of RSLMM and RSLMC. Chloride ion permeability test was carried out to estimate water permeability resistance. The results of RSLMM showed that the decrease of 50% air content was obtained by admixturing a antifoam agent by 1%. Two kinds and the optimized quantities of antifoam agent were selected for using in RSLMC. The results of RELMC were obtained at a latex content of 15% and an antifoam agent quantity of 1% with antifoamer A type. The compressive strength and flexural strength at 3 hours after RSLMC placement were 235 kgf/㎠ and 49kgf/㎠, respectively, which exceeded the flexural strength criterion of 45 kgf/㎠ in order to open the RSLMC placed to traffic. The rapid chloride permeability test was used to evaluate the permeability of RSLMC. The optimited quantity of antifoamer A and C type were 1% and 2% for the permeability test, respectively. The chloride permeability using A and C antifoamer at 28 days were below 100 coulombs, which was the permeability rating of negligible according to ASTM.

근관 세척법이 Resilon/Epiphany sealer와 Gutta-percha/AH 26 sealer의 근관 상아질과의 접착에 미치는 영향

김서경,황윤찬,황인남,오원만 大韓齒科保存學會 2008 Restorative Dentistry & Endodontics Vol.33 No.2

본 연구에서는 근관 세척법이 두 가지 근관 충전재 (Gutta-percha/AH 26 sealer, Resilon/Epiphany sealer)의 근관 상아질과의 접착메 미치는 영향을 평가하였다. 총 30개의 발거된 상악 전치를 각자 5개씩 6개의 군으로 분류하여 근관 성형을 하고 마지막 세척을 다음과 같이 시행 한 후 Gl, G2, G3군은 Gutta-percha/AH 26 sealer로, Rl, R2, R3군은 Resilon/Epiphany sealer로 근관 충전하였다. Gl, Rl군 : 5.25% NaOCl세척 G2, R2군 : 5.25% NaOCl세척 후 sterile saline 세척 G3, R3군 : 5.25% NaOCl세척 후 17% EDTA, sterile saline 순으로 세척 각 군의 충전된 치아를 아크릴 레진에 매몰하고 약 1 mm 두께로 절단한 후 만능 물성 시험기상에서 push-out bond strength를 측정하였고 실험 후 파절 양상을 Image-analyzing microscope으로 관찰하여 다음과 같을 결과를 얻었다. 1. Gutta-percha/AH 26 sealer 충전군에서 Resilon/Epiphany sealer 충전군보다 push-out bond strength가 높게 나타났다 (p < 0.05). 2. Resilon/Epiphany sealer 충전군 중 17% EDTA, sterile saline순으로 세척시 5.25% NaOCl 세척에 비해 push-out bond strength가 높게 나타났다 (p<0.05). 3.파절 양상을 분석시 모든 군은 접착성과 혼합성 파절 양상을 나타내었고, Gl, G2, Rl 군은 응집성 파절 양상이 나타나지 않았으며, Resilon/Epiphany sealer 충전군은 Gutta-percha/AH 26 sealer 충전군에 비해 응집성과 혼합성 파절 망상이 더 높은 비율로 나타났다. The purpose of this study was to evaluate whether intracanal irrigation method could affect the adhesion between intracanal dentin and root canal filling materials (Gutta-percha/AH 26 sealer and Resilon/Epiphany sealer). Thirty extracted human incisor teeth were prepared. Canals were irrigated with three different irrigation methods as a final rinse and obturated with two different canal filling materials (G groups : Gutta-percha/AH 26 sealer, R groups : Resilon/Epiphany sealer) respectively. Group Gl, Rl - irrigated with 5.25% NaOCl Group G2, R2 - irrigated with 5.25% NaOCl, sterile saline Group G3, R3 - irrigated with 5.25% NaOCl, 17% EDTA, stehle saline Thirty obturated roots were horizontally sliced and push-out bond strength test was performed in the universal testing machine. After test, the failure patterns of the specimens were observed using Image-analyzing microscope. The results were as follows. 1. Gutta-percha/AH 26 sealer groups had significantly higher push-out bond strength compared with the Resilon/Epiphany sealer groups (p < 0.05). 2. Push-out bond strength was higher when using 17% EDTA followed by sterile saline than using NaOCl as a final irrigation solution in the Resilon/Epiphany sealer groups (p < 0.05). 3. In the failure pattern analysis, there was no cohesive failure in Group Gl, G2, and Rl. Gutta-percha/AH 26 sealer groups appeared to exhibit predominantly adhesive and mixed failure patterns, whereas Resilon/Epiphany sealer groups exhibited mixed failures with the cohesive failure occurred within the Resilon substrate.