유ㆍ무기계 제품이 함께하는 기업, 콘스타(주)

이준철(Jun-Cheol Lee) 한국콘크리트학회 2009 콘크리트학회지 Vol.21 No.6

Ru 코팅량에 따른 RuO₂/Ti 전극의 염소 발생

이준철(Jun Cheol Lee),박대원(Dae Won Pak) 大韓環境工學會 2012 대한환경공학회지 Vol.34 No.11

단위면적당(cm2) 루테늄의 코팅량이 1.5 mg, 2.5 mg, 3.5 mg, 5.5 mg, 8.5 mg의 RuO₂/Ti 전극을 제조하여 코팅량에 따른 전기화학적 특성 차이와 염소 발생에 미치는 영향을 조사하였다. 순환전압 실험 결과 루테늄이 코팅된 전극의 염소 발생 과전압은 약 1.15 V (vs. Ag/AgCl)로 거의 일정하였다. 그러나 교류 임피던스 분광법, 동전위분극실험 결과 단위면적당(cm2) 루테늄의 코팅량이 2.5 mg, 3.5 mg RuO₂/Ti 전극의 저항은 각각 0.4582 Ω, 0.5267 Ω, 부식속도는 각각 0.082 mm/yr, 0.058 mm/yr로 내구성이 가장 우수하였다. 염소 발생량은 단위면적당(cm2) 루테늄의 코팅량 3.5 mg 전극이 15.2 mg/L로 가장 높게 측정되었다. We investigated the effects of electrochemical characteristics and generation of chlorine by the different amount of Ru coating which was prepared for RuO₂/Ti electrode coated with 1.5 mg, 2.5 mg, 5.5 mg, 8.5 mg Ru per unit area (cm2). As a Result of the cycle voltammetry experiments, chlorine overvoltage of Ru-coated electrodes showed to be the nearly sustained value of approximately 1.15V (vs. Ag/AgCl). By contrary, According to the results of the AC impedance spectroscopy and potentiodynamic polarization tests, the amount of Ru per unit area (cm2) included 2.5 mg, 3.5 mg as RuO₂/Ti offered the highest levels of durability which was electrode resistance and corrosion rate appeared to be 0.4582 Ω, 0.5267 Ω and 0.082 mm/yr, 0.058 mm/yr, respectively. It was also observed that generation of chlorine coated with 3.5 mg per unit area (cm2) was the highest value of 15.2 mg/L.

우포늪 저서성 대형무척추동물의 계절별 군집구조 변화

이준철 ( Jun Cheol Lee ),구본윤 ( Bon Yoon Koo ),윤춘식 ( Chun Sik Yoon ),이동준 ( Dong Jun Lee ),정선우 ( Seon Woo Cheong ) 한국환경과학회 2011 한국환경과학회지 Vol.20 No.2

The studies on community structure of benthic macroinvertebrates and environmental survey in selected four sites were performed on wetland Upo from 2008 to 2009. The lowest water temperature was measured at Upo and Mokpo showing 7℃ in February of 2008 and 2009 respectively. The highest water temperature was measured at Upo showing 32℃ in August of 2009. The lowest pH was measured at Topyeong with 5.3 in August of 2009, and the highest pH was measured at Mokpo with 10.1 in August of 2008. Generally the levels pH of 2008 were higher than those of 2009. The range of electric conductivity to the sites was big. Overall, the higher electric conductivity was seen at Sajipo and the lower one was seen at Mokpo. The level of Dissolved oxygen was lowest at Upo with 5.53㎎/ℓ in August 2008, and it was highest at Upo with 14.76㎎/ℓ in February of 2008. The investigation was performed with both quantitative and qualitative collecting methods from four surveying sites, Upo, Mokpo, Sajipo and Topyeong. Through the eight times of seasonal survey, 6 classes, 17 orders, 59 families, 131 species and 5460 individuals of benthic macroinvertebrates were collected. 6 classes, 17 orders, 53 families 106 species and 2439 individuals were identified in 2008, and 6 classes, 16 orders, 44 families, 93 species and 3021 individuals were collected in 2009. The number of species was decreased in 2009 comparing that of 2008, however, the number of individuals were increased in 2009. The dominant species and the subdominant species was Plea (Paraplea) indistinguenda and Diplonychus esakii with 20.16% and 11.90% of dominant indices respectively. From the community analysis, both the species diversity index and the species richness index were highest in Topyeong showing 4.743 and 9.054 respectively. The similarity evaluation to the investigation sites with the species in there showed very high similarity among Upo, Mokpo and Sajipo showing 5 or lower levels of distance cluster combine.

압전센서를 이용한 플라이애시 치환 시멘트 페이스트의 응결 시점 평가

이준철(Jun-Cheol Lee),고태용(Tae-Yong Go),이창용(Chang-Yong Yi) 한국건설순환자원학회 2024 한국건설순환자원학회 논문집 Vol.12 No.2

본 연구에서는 전기역학적 임피던스(electro-mechanical impedance, EMI) 센싱기법을 통해 플라이애시를 치환한 시멘트 페이스트의 응결시점을 평가하였다. 시멘트 중량대비 10 %, 20 %, 30 %를 플라이애시로 치환하여 물-바인더비 40 %의 시멘트 페이스트를 제조하였다. 제조된 시멘트 페이스트에 압전 센서를 매립하여 압전 센서의 EMI 신호변화를 연속적으로 모니터링하였다. EMI 센싱기법의 유효성을 검증하기 위해 비카트침 시험과 간이단열 온도시험을 동시에 수행하였다. 실험결과, 시멘트 페이스트의 응결구간에서 압전센서의 EMI 공진피크와 공진주파수에서 주목할 만한 변화가 나타났다. EMI 센싱기법에서 측정된 응결시간은 비카트침 시험과 간이단열 온도시험에서 측정된 응결시간과 상관관계가 있음을 확인하였다. This study investigated the setting characteristics of cement paste with varying proportions of fly ash replacement using the electro-mechanical impedance (EMI) sensing technique. Cement paste samples were prepared with a water-to-binder ratio of 40 %, substituting fly ash for 10 %, 20 %, and 30 % of the cement weight. Piezoelectric (PZT) sensors were embedded in the center of each cement paste sample to continuously monitor the EMI signals. Vicat needle test and semi-adiabatic calorimetry test were conducted to validate the reliability of the EMI sensing technique in monitoring the setting of cement paste. Experimental results revealed notable changes in the magnitude and resonant frequency of the EMI resonant peaks during the setting time. It was confirmed that the setting times measured through the EMI sensing technique were correlated with those determined by the Vicat needle test and semi-adiabatic calorimetry test.

가시광선 반응형 광촉매를 이용한 점토 도료의 개발과 대기정화성능에 관한 특성 연구

이준철(Lee, Jun-cheol),김화중(Kim, Wha-Jung) 한국콘크리트학회 2006 한국콘크리트학회 학술대회 논문집 Vol.2006 No.5

그래핀-이산화티탄 복합 나노와이어를 혼입한 모르타르의 물성 평가

이준철 ( Lee Jun-cheol ) 한국건축시공학회 2021 한국건축시공학회 학술발표대회 논문집 Vol.21 No.1

The properties of cement mortar with graphene-titanium dioxide composite nanowires (TiO2(G)NW) were investigated in this study. The following tests were conducted with the cement mortar : (1) setting times (2) Flow test of fresh cement mortar, (3) compressive strength and (4) acetaldehyde removal efficiency under visible light. As the increase of TiO2(G) NW, the flow value of cement mortar was decreased and the setting times of cement mortar were faster. The compressive strength and the acetaldehyde removal efficiency were increased by the increase of TiO2(G) NW.

시멘트 페이스트의 압축강도에 있어서 미생물의 영향

이준철(Lee, Jun-Cheol),김화중(Kim, Wha-Jung),천우영(Chun, Woo-Yong),이창준(Lee, Chang-Joon) 대한건축학회 2013 大韓建築學會論文集 : 構造系 Vol.29 No.7

This study investigated the effect of microorganisms on compressive strength development of cement paste. The Sporosarcina pasteurii used in this study was capable of microbial induced calcite precipitation(MICP). Four different cell concentrations were selected ranging from 10 to 10? per ml. distilled water as mixing water. From experimental results, cement paste with microorganisms showed higher strength gain compared with reference cement paste at earlier ages. From TG/DSC analysis, more calcium hydroxide was observed in the cement paste with microorganisms. The degree of hydration of the cement paste with microorganisms, evaluated by measuring non-evaporable water contents in cement paste, was also higher than that of reference cement paste. It is very likely that the strength improvement of cement paste is due to acceleration of hydration process caused by the metabolism of microorganisms. Further investigation is in progress to identify the specific mechanisms which is responsible for the improvement of compressive strength in early ages.

동영상 재생의 시점 전환기술에 관한 연구

이준철(Lee, Jun-Cheol),류상률(Ryu, Sang-Ryul) 한국산학기술학회 2008 한국산학기술학회 학술대회 Vol.- No.-

본 논문에서는 MPEG-4 기반으로 다시점 동영상 재생을 위한 전송방법을 제안한다. 그리고 MP4 파 일포맷을 분석하여 OSMO₄에서 제공하는 MP4BOX를 이용해서 동영상을 MP4 파일로 변환한다. 기존 의 MPEG4 플레이어는 다시점 동영상을 전송하기 위한 정보들이 부족하여 활용하지 못하지만, 새로운 객체 기술자와 BIFS 구조를 추가하여 OSMO₄ 플레이어에 입력되는 MP4 파일이 다시점 동영상임을 알 수 있게 하여 OSMO₄에서 다시점 동영상 시점 전환이 가능하도록 한다. 실험은 여러 개의 영상에 대한 시점의 스위칭을 수행했으며, N개의 다시점 동영상으로도 확장이 가능함을 보여준다.

긴급 상황 시나리오 해석을 위한 독립 객체의 규칙 기반 및 확률적 이벤트 인식

이준철(Jun-Cheol Lee),최창규(Chang-Gyu Choi) 한국멀티미디어학회 2008 멀티미디어학회논문지 Vol.11 No.3

바이오 수소를 이용한 이산화탄소의 메탄 전환 연구

이준철(Jun Cheol Lee),김재형(Jae Hyung Kim),최광근(Kwang Keun Choi),박대원(Dae Won Pak) 大韓環境工學會 2008 대한환경공학회지 Vol.30 No.9

유기성 폐기물을 이용하여 생산된 수소를 환원제로 활용하여 이산화탄소를 유용한 에너지원인 메탄으로 전환시키고자 하였다. 3개월 동안 혐기성 미생물을 이산화탄소와 수소만을 이용하여 배양하였으며, 그 결과 acetogenotrophs의 영향에 의한 메탄의 생성은 없었고, 이산화탄소를 8 mL/min으로 주입하였을 때 이산화탄소와 수소의 주입비가 1:5에서 메탄의 생성량이 2.2 m3/m3day로 가장 많았으며, 이때의 이산환탄소 저감률 또한 92%로 가장 우수하였다. 회분형태로 수소 생산과 메탄발효조와의 연계실험을 통하여, 연속적으로 수소를 생산하면서 이산화탄소를 같이 메탄발효조에 주입하여, 이산화탄소의 메탄으로의 전환을 확인하였다. In the present study, carbon dioxide was converted to methane, using bio-hydrogen. Here, the bio-hydrogen was produced from organic waste. The anaerobic microorganism was cultured using only carbon dioxide and hydrogen for duration of 3 months. Therefore methane was not produced with acetogenotrophs. During methane production, carbon dioxide and hydrogen are taken in different ratios; among which 1:5 ratio has shown the highest methane yield. Carbon dioxide and hydrogen were introduced into the reactor at the rate of 8 mL/min and 40 mL/min, respectively. In this case, 92% of carbon dioxide was reduced and 2.2 m3/m3 day amount of methane was produced. Thus, the process has been successful in conversion of carbon dioxide into methane by purging it into methane fermentation reactor with bio-hydrogen using batch process.