유향-가중 그래프 이론의 상수도관망에 적용

이승엽,정동휘,Lee, Seung-Yeop,Jeong, Dong-Hwi 한국수자원학회 2018 물과 미래(한국수자원학회지) Vol.51 No.6

한국원자력연구소 지하처분연구시설(KURT)의 암석 풍화 및 지화학적 특성

이승엽,백민훈,조원진,한필수,Lee, Seung-Yeop,Baik, Min-Hoon,Cho, Won-Jin,Hahn, Pil-Soo 한국방사성폐기물학회 2006 방사성폐기물학회지 Vol.4 No.4

A basic research was conducted on the mineral weathering and geochemical characteristics in the KURT (KAERI Underground Research Tunnel), which was recently constructed at a site in KAERI. Some rock samples exposed during the KURT construction were examined using a microscope and chemical analysis for some micro-changes of the rocks caused by the chemical weathering. The weathered granite has some small and fine cracks around the rock-forming minerals. In particular, there are a characteristic weathering of feldspar mineral and a preferential leaching of Ca component from the mineral dissolution. In addition, by the dissolution of biotite containing $Fe^{2+}$ component there were iron-oxides precipitates as secondary products into the microcracks of around minerals. The results also show that the micro-cracks initiated from the mineral interior are extended and connected into the larger cracks along the grain boundary with the progress of the weathering. Thus, it is considered that some chemicals dissolved from the fresh rock would be involved in the formation of secondary minerals and migrate interacting with them.

소양인 형방도적산과 양격산화탕의 항 스트레스효과에 관한 실험적 연구

이승엽,최애련,하진호,이정환,김판준,구덕모,Lee, Seung-Yeop,Choi, Ae-Ryun,Ha, Jin-Ho,Lee, Jung-Hwan,Kim, Pan-Joon,Goo, Deok-Mo 사상체질의학회 2008 사상체질의학회지 Vol.20 No.3

1. Objective This study was done to identify the anti-stress effect of Hyeongbangdojeok-san (HDS), Yanggyeoksanhwa-tang(YST) in Soyangin. 2. Methods Experimental animals were composed of YST, HDS+stress groups which were administered each by 200mg/kg, 400mg/kg and the Saline+stress group. On the 1st day, making the rats forced swim and on the 2nd day, applying Forced swimming test to the rats. After FST, the levels of Corticosterone in the blood were measured. For the study of learning retardation, memory ability and anxiety reaction, experimental animals were composed of YST, HDS+restraint stress groups which were administered each by 400mg/kg, no stress group and the Saline+restraint stress group. Restraint stress were applied 2 hours a day for 3 weeks. On the last day of the 3rd week, Elevated Plus Maze(EPM) was applied to the groups and Morris Water Maze(MWM) was applied to the groups for 7 days. 3. Results 1. As the results of measuring FST which reflects depression, the YST+stress group and the HDS+stress group showed significant effect in comparison with the Saline+stress group. The levels of Corticosterone in the blood were decreased only in the 400mg/kg YST+stress group. 2. As the results of measuring how long EPM which reflects anxiety reaction stayed in the open arm, there was the trend which can suppress anxiety reaction in the HDS+restraint stress group bur no statistical significance. But there was any suppression of anxiety reaction in the YST+restraint stress group. 3. According to the result of MWM, the saline+restraint stress group showed the learning retardation which means increased time arriving at goal compared to the normal group at the second and third day of measurement. On the contrary, a learning retardation was significantly decreased in the YST+restraint stress group at the third day of measurement. 4. Among the Probe trial test a memory loss occurred in the saline+restraint stress group, but memory ability was significantly increased in the YST+restraint stress group. 4. Conclusion: As the results above, Soyangin Yanggyeoksanhwa-tang has significant influence to the antidepression effect, the learning retardation, the anxiety reaction and also in the Hormone level. Hyeongbangdojeok-san has significant influence to the antidepression effect, in the Hormone level, bur not to the learning retardation and anxiety reaction. prefer to drink cold water, and who are suffering from chronic gastritis.

토착미생물의 생지화학적 활동에 의한 지하수의 산화/환원전위 변화 특성

이승엽,노열,정종태,Lee, Seung Yeop,Roh, Yul,Jeong, Jong Tae 대한자원환경지질학회 2014 자원환경지질 Vol.47 No.1

중금속류나 방사성 물질로 오염된 지하수를 원위치에서 처리(정화 혹은 고정화)하고자 할 때, 반드시 고려해야 할 지화학적 요소 중의 하나는 지하수의 산화/환원전위 값이다. 우리는 생지화학적 작용에 의한 현장 지하수의 산화/환원전위 변화 특성을 알아보기 위해 실험실 조건에서 한국원자력연구원의 심부지하수를 대상으로 전자공여체(젖산), 전자수용체(황산염) 및 토착미생물을 주입하여 시간별로 산화/환원전위 변화를 관찰하였다. 질소가스-충전 글로브박스에 있는 순수 지하수는 시간이 경과함에 따라 미약한 Eh 상승(약산화)이 있었다. 하지만, 젖산, 황산염 혹은 미생물이 주입된 지하수 대부분의 Eh는 감소(환원)하는 특성을 보여주었다. 특히, 국내 토착 황산염환원미생물인 '바쿨라텀'이 주입되었을 때, 지하수의 Eh가 -500 mV 근처까지 감소하여 강환원성 지하수로 바뀌었다. 이처럼 일반 금속환원박테리아에 비해 황산염환원박테리아의 지하수 환원화 능력이 매우 우수함에도 불구하고, 용존 황산철을 필요로 하였고 최종적으로 황화광물(예; 맥키나와이트)이 생성되면서 추후 반응에 관한 예측을 어렵게 하였다. 결과적으로, 미생물 외에도 미량의 영양물질 주입 여하에 따라 지하수의 산화/환원전위가 크게 달라졌으며, 이는 산화/환원전위의 영향을 받는 용존 오염 물질의 산화수, 용해도 및 수착 등의 특성들이 생물자극법에 의해 바뀌거나 조절될 수 있음을 의미한다. As we are trying to in-situ treat (purify or immobilize) heavy metals or radionuclides in groundwater, one of the geochemical factors to be necessarily considered is the value of oxidation/reduction potential (ORP) of the groundwater. A biogeochemical impact on the characteristic ORP change of groundwater taken from the KAERI underground was observed as a function of time by adding electron-donor (lactate), electron-acceptor (sulfate), and indigenous bacteria in a laboratory condition. There was a slight increase of Eh (slow oxidation) of the pure groundwater with time under a $N_2$-filled glove-box. However, most of groundwaters that contained lactate, sulfate or bacteria showed Eh decrease (reduction) characteristics. In particular, when 'Baculatum', a local indigenous sulfate-reducing bacterium, was injected into the KAERI groundwater, it turned to become a highly-reduced one having a decreased Eh to around -500 mV. Although the sulfate-reducing bacterium thus has much greater ability to reduce groundwater than other metal-reducing bacteria, it surely necessitated some dissolved ferrous-sulfate and finally generated sulfide minerals (e.g., mackinawite), which made a prediction for subsequent reactions difficult. As a result, the ORP of groundwater was largely affected even by a slight injection of nutrient without bacteria, indicating that oxidation state, solubility and sorption characteristics of dissolved contaminants, which are affected by the ORP, could be changed and controlled through in-situ biostimulation method.

한방병원에 내원한 파킨슨 증후군 환자 증례군 보고

이승엽,김미영,김영지,최원우,민인규,선종주,홍진우,나병조,정우상,문상관,조기호,김영석,Lee, Seung-yeop,Kim, Mi-young,Kim, Young-jee,Choi, Won-woo,Min, In-kyu,Sun, Jong-joo,Hong, Jin-woo,Na, Byong-jo,Jung, Woo-sang,Moon, Sang-kwan,Cho, Ki-h 대한중풍순환신경학회 2007 대한중풍.순환신경학회지 Vol.8 No.1

Objective : To report cases of patients with Parkinson's syndrome. Design : Case-series Patients and methods : 35 of patients with Parkinson's syndrome who visited Department of Cardiovascular and Neurologic Diseases of Kyunghee Oriental Medical Center were treated by acupuncture and herbal medicine from May until December 2007. 35 patients were participated in this study. 21 patients were dropped out during the trial, and we evaluated symptom progress of 14 patients by using several questionnaires such as Unified Parkinson's Disease Rating Scale(UPDRS), modified Hoehn & Yahr stage (H&Y stage) and Schwab & England ADL scale(S&E ADL scale). Results : The whole group consists of 14 male patients and 21 female patients. Mean±SD age range is 64.5±8.4. There were no significant differences of the demographic and clinical characteristics between the case group and drop-out group. The mean±SD medical treatment period of the Case group were 8.4±6.3weeks, the mean±SD of the total score in first medical treatment UPDRS section 1~3 were 29.6±11.0, the mean±SD of the final score were 27.1±12.6, all of which showed significant improvement(p=0.007). There were no significant changes on the H&Y stage and S&E ADL scale. Conclusion : Patients with Parkinson's syndrome who visited Department of Cardiovascular and Neurologic diseases of Kyunghee Oriental Medical Center had a tendency of showing improvement in clinical symptoms.

메니에르병 치험 1례

이승엽,김미영,김영지,최원우,민인규,박주영,정우상,문상관,조기호,김영석,Lee, Seung-Yeop,Kim, Mi-Young,Kim, Young-Jee,Choi, Won-Woo,Min, In-Kyu,Park, Joo-Young,Jung, Woo-Sang,Moon, Sang-Kwan,Cho, Ki-Ho,Kim, Young-Suk 대한중풍순환신경학회 2008 대한중풍.순환신경학회지 Vol.9 No.1

Meniere's disease is characterized by intermittent episodes of vertigo lasting from minutes to hours, with fluctuating hearing loss, tinnitus, and aural pressure. The primary histopathological correlate is endolymphatic hydrops, but its etiology is still disputed. Several medical therapies have been offered to patients with this disease since 1961 that the first report had been given by Prosper Meniere. Some will be helpful for relieving the symptoms but there is still no absolutely effective treatment to cure the disease. One male patient with Meniere's disease was hospitalized in Kyung-Hee medical center, and we treated him with oriental medical therapies. The treatment was effective to relieve his symptoms, and they had been successfully controlled until he was discharged from hospital. The result suggests that the oriental medical therapy is safe and helpful to patients with Meniere's disease, so we reported this case.

스와넬라균(Shewanella p.)에 의한 용존우라늄 제거 특성 및 방사성폐기물 처분에의 응용

이승엽,백민훈,송준규,Lee, Seung-Yeop,Baik, Min-Hoon,Song, Jun-Kyu 대한자원환경지질학회 2009 자원환경지질 Vol.42 No.5

물속에 우라닐이온(${UO_2}^{2+}$) 형태로 존재하는 산화우라늄을 철환원세균인 스와넬라균(Shewanella p.)을 이용하여 제거하는 실험을 수행하였다. 용액상의 우라늄 초기농도는 $50{\mu}M$ 이었으며 미생물과의 반응에 의해 점차 그 농도가 감소하였고, 약 2주 후에 거의 대부분의 우라늄이 제거되었다. 우라늄이 제거된 기작은 대부분 미생물 표면에 대한 흡착, 침전 및 광물화에 의한 것이었다. 투과전자현미경으로 관찰한 결과로는 미생물 표면에 흡착되어 점차 결정화되어가는 우라늄이 큰 광물로 성장하고 여러 미생물개체 및 유기분비물과의 결합을 통해 그 크기가 수 ${\mu}m$ 이상으로 커져가는 것을 확인하였다. 이러한 미생물에 의한 우라늄 광물의 성장 및 결합은 방사성폐기물처분장의 우라늄 거동에 큰 영향을 끼칠 수 있으며, 특별히 본 실험에서 관찰한 생지화학적인 금속환원미생물의 역할에 의해 지하 우라늄의 이동이 상당히 지연되는 효과를 거둘 수 있을 것으로 사료된다. An experimental removal of dissolved uranium (U) exsiting as uranyl ion (${UO_2}^{2+}$) was carried out using Shewanella p., iron-reducing bacterium. By the microbial reductive reaction, initial U concentration ($50{\mu}M$) was constantly decreased, and most U were removed from solution after 2 weeks. Major mechanism that U was removed from the solution was adsorption, precipitation and mineralization on the microbe surface. Under the transmission electron microscopy, the U adsorbed on the microbe was observed as being crystallized and eventually enlarged to several ${\mu}m$ sizes of minerals by combining with individual microbes and organic exudates. It seems that such U growth and mineralization on the microbial surface could affect the U behavior in a radioactive waste disposal site. Thus, the biogechemical reaction of metal-reducing bacteria observed in this experiment could give an affirmative measure that the microbial activity may retard U movement in subsurface environment.

셀레늄-미생물간의 반응 및 셀레늄 광물화 특성

이승엽 ( Seung Yeop Lee ),오종민 ( Jong Min Oh ),백민훈 ( Min Hoon Baik ) 한국광물학회 2011 광물과 암석 (J.Miner.Soc.Korea) Vol.24 No.3

철환원 박테리아인 미시가넨시스를 이용하여 용존 셀레늄을 제거할 때, 물 속의 다른 금속성분들인 철, 황산염, 그리고 구리가 미칠 수 있는 영향을 살펴보았다. 미시가넨시스 박테리아는 산화수가 4가인 산화 셀레나이트(2 mM)를 셀레나이드로 환원시키고 물속의 셀레늄 농도를 점차 감소시켰다. 환원된 셀레나이드는 용존 2가 철과 결합하여 나노입자 크기의 철-셀레나이드로 침전되었다. 용존 황산염과 구리는 미생물의 셀레나이트 환원작용에 부정적인 영향을 끼쳤는데, 특히 구리 성분은 미생물에 대해 독성으로 작용하여 셀레나이트 제거가 원활히 이뤄지지 못하게 하였다. 이러한 결과로부터 알 수 있는 것은 셀레늄으로 오염된 현장을 미생물로 정화할 때, 황산염 혹은 구리의 농도 분포와 양을 충분히 고려해야 한다는 사실이다. 궁극적으로, 미생물에 의한 철-셀레나이드 광물형성작용은 지하수를 따라 원거리로 이동할 수 있는 셀레늄의 확산을 억제하는 중요한 수단이라고 볼 수 있다. Removal of dissolved selenium by D. michiganensis, a iron-reducing bacterium, and effects of dissolved metal elements such as iron, sulfate, and copper were investigated. Selenide that was reduced from selenite (2 mM) by D. michiganensis was gradually removed from the aqueous medium. As the reduced selenide was combined with aqueous iron, it was precipitated as a nanoparticulate iron-selenide. Sulfate and copper negatively affected the microbial selenite reduction, and the copper was especially toxic to the bacterium, inhibiting a microbial removal of dissolved selenite. These results show that it should be carefully biotreated for a selenium-contaminated site considering in situ sulfate or copper distribution and concentration. Consequently, the formation of iron-selenide by bacteria will be an important measure for preventing a long-distance migration of selenium in the subsurface environments.

냉각수 순환 가열 방식을 이용한 요소수의 동결 및 해동 특성에 관한 수치적 연구

이승엽(Seung Yeop Lee),김남일(Nam Il Kim),박윤범(Yun Beom Park),김만영(Man Young Kim) 대한기계학회 2013 大韓機械學會論文集B Vol.37 No.8

Urea-SCR은 동절기, 북유럽과 북미지역과 같은 -20℃ 이하의 환경에서 요소수가 동결되는 문제점을 해결해야 한다. 따라서 이러한 요소수 저장탱크에 해동 시스템을 적용하여 시동 초기, 요소수를 적정 시간 내 분사하기 위한 기술의 확보가 필요하다. 본 연구에서는 저장탱크 내 요소수의 동결현상과 냉각수 순환 가열방식을 적용한 해동현상에 대하여 상용 소프트웨어인 Fluent 6.3을 이용하여 3차원 비정상상태 수치해석을 수행하였다. 이를 통하여 요소수의 동결 및 해동과정 중 나타난 온도분포, 상경계면, 그리고 액상분율을 분석하여 열전달 특성을 고찰하였다. 결론적으로 요소수의 동결은 저장탱크 벽면으로부터 중심부로 이루어졌으며, 해동현상은 순환 파이프와 인접할수록 요소수의 상변화가 빠르게 진행하였다. 또한, 냉각수의 70℃, 200ℓ/h 조건에서 1ℓ의 액상 요소수를 얻는데 약 190초의 시간이 필요하였다. Urea-SCR technology is known as one of the powerful NOx reduction systems for vehicles as well as stationary applications. For its consistent and reliable operation in vehicle applications, however, the freezing and melting of the urea solution in cold environments have to be resolved. In this study, therefore, a numerical study of three-dimensional unsteady problems was analyzed to understand the urea freezing and heating phenomena and heat transfer characteristics in terms of urea liquid volume fraction, temperature profiles, and phase change behavior in urea solutions with time by using the commercial software Fluent 6.3. As a result, it was found that the freezing phenomenon proceeds with a phase change from the tank wall to the center, whereas the melting phenomenon occurs faster in the upper part of the storage tank by natural convection and in the adjacent part of the coolant pipe than in other parts. Furthermore, approximately 190 s were required to obtain 1L of urea solution using a 4-coiled coolant heater under conditions of 70°C and 200 L/h.

페이스북의 각 기능 이용이 개인 직무 성과에 미치는 영향

이승엽(Seung Yeop Lee),이상우(Sang Woo Lee) SBS 2016 미디어경제와 문화 Vol.14 No.2

본 연구에서는 직장인들이 직장 내에서 페이스북상의 각 기능을 이용하는 것이 개인의 직무 성과에 어떠한 영향을 미치는지를 알아보았다. 또한 과업의 특성(task characteristics)에 따라 SNS에서의 각 기능 이용이 개인의 직무 성과에 미치는 영향이 다르게 나타나는지도 분석해 보았다. 연구 결과, 페이스북의 다양한 기능 중 메시지와 페이지를 이용하는 것만이 직무 성과에 정(+)적인 영향을 미치는 것으로 나왔다. 한편, 모호성이 높은 과업을 맡고 있는 직장인의 경우가 모호성이 낮은 과업을 맡고 있는 직장인의 경우보다 페이스북 내의 메시지(Messages) 이용이 직무 성과에 미치는 정(+)적인 영향이 더 큰 것으로 나왔다. 본 연구의 결과는 직원들의 SNS 이용에 대한 정책을 고민하는 기업에게 중요한 시사점을 제공해 줄 수 있다. 예를 들어 직장 내에서 페이스북상의 특정한 기능을 이용하는 것이 업무에 긍정적인 영향을 미친다면 기업은 그러한 기능을 포함하고 있는 SNS 서비스를 직원들에게 이용하도록 하거나, 자체적으로 그러한 SNS를 직접 개발하여 직원들에게 이용하도록 하는 정책을 생각 해 볼 수 있을 것이다. 그리고 만약 과업의 특성에 따라 특정 페이스북 기능이 직무 성과에 미치는 영향이 다르게 나타난다면, 기업은 여러 과업들 중 특정 페이스북 기능으로 인해 직무 성과가 증가하는 특성을 가진 과업에 대해서만 직원들에게 해당 페이스북 기능을 이용하도록 하거나 이와 유사한 SNS 서비스를 이용하도록 장려하는 정책을 고려할 수 있을 것이다. This study investigates the influences of Facebook uses at work on employees’ job performance and the moderating effect of task characteristics, such as task equivocality and task interdependence. The results reveal that ‘message feature use’ and ‘pages feature use’ at work positively affect job performance. The positive effect of ‘message feature use’ at work on job performance is stronger for office workers who are assigned tasks with a high level of equivocality, compared to those who are assigned tasks with a low level of equivocality. This study has important implications for companies that are concerned with employees’ SNS use. If employees’ usage of some Facebook features affected on job performance positively, companies could encourage employees to use those Facebook features.