소석회와 CO₂를 이용한 상수관로의 부식제어(II) - 관종별 부식특성 평가

이두진,김영일,송영일,박현아,Lee, Doo-Jin,Kim, Young-Il,Song, Young-Il,Park, Hyun-A 대한상하수도학회 2008 상하수도학회지 Vol.22 No.3

The pH & alkalinity adjustment method by lime and carbon dioxide($CO_2$) for corrosion control in water distribution system was investigated to evaluate the corrosion characteristics of metal pipes, such as galvanized iron, copper, stainless steel, and carbon steel. When the pH in sand filtered and ozone+GAC treated water was increased with lime and $CO_2$ from 7.5 to 8.0, the concentration of residual chlorine decreased at higher pH and longer reaction time; the concentration of trihalomethane increased. The corrosion rate of coupons with corrosion control using lime and carbon dioxide was showed much smaller than those without corrosion control using pilot-scale simulated distribution system. The galvanized iron was corroded much faster than carbon steel, copper, and stainless steel. Especially, copper and stainless steel coupons were hardly corroded. The galvanized iron and carbon steel coupons with corrosion control were produced the corrosion products less than those without corrosion control by the results of environmental scanning electron microscope(ESEM) and energy dispersive x-ray spectroscopy(EDS) analyses. The galvanized iron coupon with pH and alkalinity adjustment by lime and carbon dioxide was detected about 30 percent of zinc, when the carbon steel was detected about 30 percent of calcium by calcium carbonate products formation. For the results of X-ray diffraction(XRD) analyses, the goethite(${\alpha}$-FeOOH) was identified as primary corrosion product of galvanized iron without corrosion control, while the Zinc oxide(ZnO) was found on corrosion products of galvanized iron coupon with corrosion control as the results of EDS analyses. However, the carbon steel corrosion products regardless of corrosion control were composed predominantly of maghemite(${\gamma}-Fe_2O_3$) and hematite(${\alpha}-Fe_2O_3$).

산화 스트레스에 대한 신선초 녹즙과 돌미나리 녹즙의 보호효과

이두진(Doo-Jin Lee),이진하(Jin-Ha Lee),이옥환(Ok-Hwan Lee),김보경(Boh-Kyung Kim),박건영(Kun-Young Park),김종대(Jong-Dai Kim) 한국식품과학회 2015 한국식품과학회지 Vol.47 No.4

본 연구에서는 신선초 녹즙과 돌미나리 녹즙을 다양한 실험을 통하여 산화방지 활성을 측정하였다. DPPH 라디칼, NO, O₂?, ·OH 라디칼 소거능 실험을 이용하여 유기농 및 일반농 신선초 녹즙과 돌미나리 녹즙의 산화방지 활성을 측정해 본 결과, 모든 시료군에서 높은 라디칼 소거 활성이 나타났다. 또한, 산화적 스트레스에 민감한 LLC-PK₁ 세포를 이용하여 유기농 및 일반농 신선초 녹즙과 돌미나리 녹즙의 산화적 스트레스 개선 효과를 살펴본 결과, 신선초 녹즙과 돌미나리 녹즙은 AAPH, SNP, 파이로갈롤과 SIN-1에 의해 유발된 산화적 스트레스(NO, O₂?와 ONOO?)에 대한 세포 생존율을 증가시키고, 지질과산화를 억제시켜 라디칼에 의한 산화적 스트레스에 대한 개선 효과가 뛰어난 것으로 사료된다. 이상의 결과로부터 신선초 녹즙과 돌미나리 녹즙은 우수한 산화방지 활성과 지질과산화 개선 효과를 나타내어 신선초 녹즙과 돌미나리 녹즙으로부터 산화방지 영양소를 충분히 섭취하는 것이 산화적 손상과 관련된 질병을 예방하는 좋은 방법이 될 수 있을 것이라 사료된다. The objectives of the present study were to investigate the protective effects of Angelica keiskei juice and Oenanthe javanica juice against oxidative damage in LLC-PK1 renal epithelial cells and to evaluate their free radicalscavenging activities. Both A. keiskei juice and O. javanica juice showed a strong in vitro antioxidant activities such as α, α-diphenyl-β-picrylhydrazyl (DPPH), nitric oxide (NO), O₂?, and ·OH radical-scavenging activities. The LLC-PK₁ cells showed significant lipid peroxidation and cell death due to oxidative stress when it was induced by 2, 2’-azobis (2-amidinopropane) dihydrochloride (AAPH), sodium nitroprusside (SNP), pyrogallol, and 3-morpholinosydnonimine (SIN-1). Treatment with both A. keiskei juice and O. javanica juice significantly increased cell viability and inhibited lipid peroxidation. These results suggest that A. keiskei juice and O. javanica juice are potential natural antioxidants.

인적자본투자 관점에서의 직업훈련 내실화에 관한 연구

이두진(Doo-Jin Lee) 산업기술교육훈련학회 2008 산업기술연구논문지 (JITR) Vol.12 No.4

Looking at them from a view of labor economics, there are varieties of ranges, target groups and goals in human capital investment. This study defines the theoretical concepts of general training for which is invested by individuals as labor suppliers with direct influence to the production fields and specific training for which the investors are the industrial companies in demand of labor force, and also suggests the points to be considered when operating practical training subjects for initial training and developing advanced training programs (specific training programs) in a public training institute which operates vocational training courses (general training and specific training) for a duration of up one year, based on the research findings and statistics. This study aims at informing the government and training institutions, that they should consider the points of improvement and of consideration and apply them, so that each of the investment target groups can increase the rate of return on investment. This study was carried out to provide a help for changing the identity of vocational training, by reexamining the vocational training from a viewpoint of changed labor market and labor economics, and by increasing investor satisfaction rate.

관로,관망 : 장대관로의 적정 소독능 유지를 위한 재염소 운영방안

이두진 ( Doo Jin Lee ),이종민 ( Jong Min Lee ),임재림 ( Jae Lim Lim ),이경혁 ( Kyung Hyuk Lee ),손진식 ( Jin Sik Sohn ) 대한상하수도학회 2005 공동추계 학술발표회 논문집 Vol.2005 No.-

논문 : 관로 내 적정소독능 확보를 위한 재염소 기법의 적용

이두진 ( Doo Jin Lee ),김영일 ( Young Il Kim ),이종민 ( Jong Min Lee ),정남정 ( Nam Jung Jung ),김용운 ( Yong Woon Kim ) 대한상하수도학회 2006 상하수도학회지 Vol.20 No.5

L-Probe 원형 패치 안테나를 이용한 ISO 11452-2 근거리 내성 시험 모사에 대한 연구

이두진(Doo-Jin Lee),한준희(Jun-hee Han),나완수(Wan-Soo Nah) 한국전자파학회 2020 한국전자파학회논문지 Vol.31 No.9

본 논문에서는 근거리 내성 시험을 모사하기 위해 필요한 L-probe 원형 패치 안테나의 설계, 제작 및 성능시험 결과에 대해 기술하였다. 전장품 복사 내성 시험 규격인 ISO 11452-2를 수행하기 위해서는 대형 안테나와 고출력 증폭기 등이 필요하다. 또한, 강한 전계가 인가되는 상태에서 발생된 문제를 분석하고, 대책을 검증하는 것은 시험 규격이 요구하는 환경 이외에도 추가 장비를 구축해야 하며, 이는 많은 비용과 시간을 요구한다. 본 논문에서 제안된 안테나를 근거리 내성 시험에 사용할 경우, 낮은 출력 증폭기를 이용하여 800 V/m 이상의 전계를 발생시킬 수 있다. 이를 활용하면, 복사내성 시험 시 발생된 문제를 저비용 환경에서 효율적으로 분석하고, 상대적으로 간편하게 재현할 수 있으며, 해결 방법의 유효성을 사전에 검증할 수 있음을 보였다. ISO 11452-2 is a well-known standard that tests the electromagnetic immunity of a device under test(DUT) in an anechoic chamber. ISO 11452-2 needs a large antenna and high-power amplifier to provide a high electric field in the chamber. In this test setup, finding the root cause and debugging issues is not easy because of varied limitation conditions. In this paper, we suggest two L-probe-fed circular patch antennas that emit a high electric field(over 800 V/m in the radar pulse ranges) on DUTs in the near field. Because the DUT is located 50 mm away from the antenna, the power amplifier consumes a small amount of power for the same electric field in ISO 11452-2. The proposed procedure has the advantage of industry usefulness with fast, handy, and cost-effective radiated immunity debugging of the DUT without considering the environment required by ISO 11452-2 and certain types of monitoring equipment with high immunity.

고도처리공정이 관로 내 잔류염소 감소 및 THM 생성에 미치는 영향

이두진(Doo Jin Lee),김영일(Young Il Kim),김성수(Sung Su Kim),이경혁(Kyung Hyuk Lee),박현아(Hyun A Park) 大韓環境工學會 2007 대한환경공학회지 Vol.29 No.4

깨끗하고 안전한 수돗물에 대한 소비자들의 욕구가 커짐에 따라 막, 오존, 활성탄 등 다양한 고도처리공정이 정수장에 도입되고 있다. 본 연구에서는 고도처리공정의 도입으로 인한 관로 내 잔류염소 감소 및 THM 생성특성에 대하여 살펴보았다. 오존, 활성탄, 오존/GAC 공정별 DOC 제거특성과 bottle test를 이용한 잔류염소 감소 및 THM 생성특성을 평가하였다. 모든 처리공정에서 DOC 제거율보다 UV₂54 유발물질의 제거율이 우수한 것으로 나타났다. 특히, 오존공정에 의한 DOC 제거율은 기존 모래여과수 대비 약 4%에 불과하였으나, UV₂₅₄는 약 17%로 DOC 제거율보다 훨씬 더 큰 차이를 보였는데, 이는 오존에 의해 소수성 유기물이 친수성 유기물로 변환되었기 때문이다. 오존/GAC 공정이 유기물 제거에 가장 효과적이었으며, 모래여과, 오존, GAC, 그리고 오존/GAC공정을 거친 처리수의 잔류염소 감소계수는 각각 0.0230, 0.0307, 0.0117 그리고 0.0098 hr^-1로 나타났으며, 190시간 반응 이후 모래여과수는 THM이 81.8 μg/L 생성된 반면, 오존, GAC, 그리고 오존/GAC의 처리수는 모래여과수에 비해 각각 6.0, 26.2, 30.3% 적게 생성되었다. 결론적으로 고도처리공정에 의해 관로 내 잔류염소의 지속성이 증대되었으며, THM 생성 또한 감소하는 것으로 나타났다. According to increase of consumer`s desire for clean tap water, advanced treatment processes include with membrane, ozone, and granular activated carbon(GAC) were introduced. In order to evaluate the effect of advanced treatment processes for residual chlorine decay and trihalomethane(THM) formation in water distribution system, dissolved organic matter(DOC) removal of each advanced treatment process was investigated. The residual chlorine decay and THM formation using bottle tests were also evaluated. UV₂54 removal in all advanced treatment was better than DOC removal. Especially, DOC by ozone treated was removed as 4% in contrast with sand filtered water, but UV₂₅₄ was removed about 17%. This result might be due to convert from hydrophobic DOC to hydrophilic DOC by ozonation. Ozone/GAC process was most effective process for DOC removal. The residual chlorine decay constants in treated water by sand filtration, ozonation, GAC adsorption, and ozone/GAC processes were 0.0230, 0.0307, 0.0117 and 0.0098 hr^-1, respectively. The sand filtered water was produced 81.8 μg/L of THM after 190 hours of reaction time, as the treated water by ozone, GAC, and Ozone/GAC was less produced 6.0, 26.2, 30.3% in contrast with sand filtered water, respectively. Consequently, the durability of residual chlorine and reduction of THM formation were improved by advanced treatment processes.

소형 코먼레일 디젤 엔진에서의 조기 분사가 연소 및 배기특성에 미치는 영향

이두진(Doo Jin Lee),김명윤(Myung Yoon Kim),윤승현(Seung Hyun Yoon),노현구(Hyun Gu Roh),이제형(Je Hyung Lee),이창식(Chang Sik Lee) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

An experimental investigation of early injection were conducted on a small single cylinder common-rail diesel engine to reduce NOx emission. The main objectives of the study were to investigate the emissions, performance ad combustion characteristics of partially homogeneous charge compression ignition combustion. The two stage injection was conducted to reduce wall-wetting of early injected spray on the cylinder wall and to promote the ignition of premixed charge. The engine test was performed at conditions of 1500rpm, injection timing ranging from TDC to BTDC 80˚. The experimental results show that NOx emissions of early injection and two stage injection decreased than conventional diesel injection combustion (near TDC injection), but soot, incomplete products (i.e. HC ad CO) are slightly increased. Also, the second injection near TDC promoted the ignition of premixed fuel, therefore, IMEP was increased.

관로, 관망 : 오염부하 물질수지분석을 통한 합류식하수관거 적정 차집용량 결정에 관한 연구

이두진 ( Doo Jin Lee ),안효원 ( Hyo Won Hyo ),김주환 ( Ju Hwan Kim ),우형민 ( Hyung Min Woo ) 대한상하수도학회 2004 공동추계 학술발표회 논문집 Vol.2004 No.-

균일 예혼합 연소를 적용한 코먼레일 엔진의 연소 및 배기특성

이두진(Doo Jin Lee),김명윤(Myung Yoon Kim),노현구(Hyun Gu Roh),김대식(Dae Sik Kim),이제형(Je Hyung Lee),이창식(Chang Sik Lee) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

An experimental study on homogeneous charge compression ignition combustion in combination with direct fuel injection was conducted using a single cylinder common-rail diesel engine. To improve the homogeneity of fuel-air mixture, the premixed fuel (gasoline) was injected into premixing chamber with high pressure and the combustion of directly injected diesel fuel was promoted ignition of the gasoline mixture in the combustion chamber. The experimental results show that soot emissions dramatically were decreased with the increase in fuel premixing ratio, however incomplete products (i.e. HC and CO) of combustion increased as the premixed ratio was increased. Earlier injection of diesel fuel promoted the stability of combustion with decreased NO and soot.