http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
가학광산 주변 중금속 함유 토양입자의 이화학적·광물학적 특성연구
이충현,이선용,박찬오,김종원,이상환,박미정,정문영,이영재,Lee, Choong Hyun,Lee, Seon Yong,Park, Chan Oh,Kim, Jong Won,Lee, Sang Hwan,Park, Mi Jeong,Jung, Moon Young,Lee, Young Jae 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.4
Soil samples collected in an area of Gahak Mine were investigated for the characterization of mineralogical and physicochemical properties of contaminants in soils. It is found that soils in the study area are contaminated by lead (Pb), copper (Cu), zinc (Zn), cadmium (Cd), in which their concentrations are 595.3 mg/kg, 184.9 mg/kg, 712.8 mg/kg, and 10.64 mg/kg, respectively. All the concentrations exceed the concern criteria of Korean standard. Upon distribution patterns of metals identified by the sequential extraction procedure, our results show that more than 50% of metals are found as a residual type, and 30% are accounted for the association of Fe/Mn oxides. Interestingly, XRD results show that minium (Pb<sub>3</sub>O<sub>4</sub>) and cuprite (Cu<sub>2</sub>O) are identified in the soil samples, suggesting that the sources of the contaminants for Pb and Cu are these minerals. In SEM images, tens of µm of Pb oxides and Pb silicate-minerals are observed. We, therefore, note that the contamination of metals in the study area results from the direct influx and disturbance of tailings. Our findings indicate that the characterization of physicochemical and mineralogical properties of contaminated soils is a critical factor and plays an important role in optimizing recovery treatments of soils contaminated in mine development areas.
Collagen Gel을 이용한 사람의 고환 조직배양에 관한연구
이충현,이상철,이선주,손준웅,장성구,김진일,채수응,Lee, Choong-Hyun,Lee, Sang-Cheol,Lee, Sun-Joo,Sohn, Joon-Woong,Chang, Sung-Goo,Kim, Jin-Il,Chai, Soo-Eung 대한생식의학회 1993 Clinical and Experimental Reproductive Medicine Vol.20 No.1
A recently developed collagen gel culture technique has been applied to study on growth in tissue of human testicular tissue. Minimum Eagle's medium supplemented with amino acid, 10% Fetal Bovine Serum and 0.1mM non-essential amino acid are emploid. Tissue fragments on collagan gel are fixed at time intervals for the histologic findings of testis. The mature spermatids are maintained for 2 weeks and can be observed until four weeks. But the rate of glucose consumption is increased contrary to histologic findings.
이충현 ( Choong Hyun Lee ),한동훈 ( Dong Hun Han ),임춘성 ( Choon Seong Leem ) (주)엘지씨엔에스(구 LGCNS 엔트루정보기술연구소) 2014 Entrue Journal of Information Technology Vol.13 No.1
유비쿼터스 컴퓨팅 기술 및 서비스를 활용하여 도시를 개선하고 미래화하는 유비쿼터스 도시(이하 U-City) 개발이 정부의 신성장동력사업으로 추진되고 있으며, 도시민의 삶의 질 개선과 도시관리 기능의 효율화를 위한 차세대 서비스 사업이 활발히 전개되고 있다. 또한, 한국의 U-City 관련연구는 전 세계적으로도 미래도시 연구의 선도적인 역할을 하고 있으며 U-City 개발과 그 효과 등에 대한 연구가 지속적으로 이루어지고 있다. 그러나 U-City 사업은 표준화된 기술 및 서비스 모델의 부재와 사업 수행 방법론 등의 부재로 인해 난개발 및 중복투자에 대한 우려가 존재하고 기술 수명주기의 단축과 시장의 급변은 사업 전개에 커다란 부담으로 작용하고 있다. 이러한 문제점을 극복하기 위하여 사업 계획 단계에서부터 사업의 타당성에 대한 충분한 고려가 필요하다. Ubiquitous City(U-City) project has been promoted in Korea for several years. U-City is national wide project for future strategy to realize ubiquitous computing technologies and services, intended to provide residents not only with more conveni-ence, but also with effective urban management. Also, research about U-City of Korea has been conducted significant role in future city-related research around the world. However, existed U-City project has raised unsustainable development problem of indiscriminate promotion and visibility that causes lack of standardized technologies, service models, business operation methodologies. To solve this problem, it is important to consider business feasibility in business planning stage. In this study, we deducted evaluation model for successful construction of U-City project that composed perspectives and domain using literature related U-City characteristics. Developed evaluation model is applied to cities in Korea, we expect it to promote and provide implication to efficiently manage the U-City project
이충현(Choong Hyun Lee),김경천(Kyung Chun Kim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12
Dynamic behavior of impinging droplets onto inclined hot plate were studied experimentally. De-ionized water droplet was made through a 31G injection needle and the droplet size was 2 mm. A sapphire plate was heated up to 350ºC by a hotplate. Two high speed cameras were used for side and bottom visualization, and the frame rate was 20000 fps. Weber number was changed from 22.5 to 123.7 by changing initial height of droplet from 40 mm to 210 mm. Dynamic behaviour of droplet after impingement was strongly depended on surface temperature, inclination angle and Weber number. Micro-explosion was observed at the surface temperature of Leidenfrost condition in case of lower inclination angle. In case of higher inclination angle, the impinging droplet tended to recover its original spherical shape due to the vapour cushion at Lidenfrost condition. As increasing Weber number, both maximum spreading diameter and slip length were increased.
동적 수치해석을 통한 베이스먼트의 지진토압에 대한 매개변수 연구
이충현(Lee, Choong-Hyun),박두희(Park, Du-Hee) 한국지반공학회 2024 한국지반공학회논문집 Vol.40 No.4
동적 토압 해석은 지하 구조물의 내진 설계에서 핵심적인 파라미터이다. 그러나 기존 토압식들은 지반과 구조물의 상호작용, 상대적 유연성 비율(F) 및 구조물의 래킹 비율(R), 종횡비(L/H) 등 중요한 변수들을 종합적으로 고려하지 않은 것들이 대다수이다. 본 연구의 목적은 이러한 매개변수들이 동적 토압에 미치는 영향을 확인하여 기존의 옹벽토압식의 신뢰도를 평가하는 것이며, 이를 위해 베이스먼트에 대해 동적 수치해석을 통한 매개변수 연구를 수행하였다. 그 결과, 종횡비가 높고 유연성이 낮은 구조물이 종횡비가 낮고 유연성이 높은 구조물보다 지진 토압에 더 취약하다는 사실을 확인하였다. 따라서 베이스먼트의 지진 토압 또는 동적 토압 추정에 있어 종횡비 및 유연비를 고려하는 것이 필요하고, 기존 옹벽의 토압식 적용 시 주의가 필요하다고 판단된다. Dynamic earth pressure analysis is a key parameter in the seismic design of subterranean structures. However, existing solutions often lack a holistic approach, ignoring crucial elements like soil-structure interaction, the relative flexibility ratio (F) between the soil and a structure, the racking ratio (R) of a structure, and the structure aspect ratio (L/H). In this study, we conducted a thorough suite of dynamic numerical analyses on basements to understand how these factors influence seismic earth pressure. We found that structures with high aspect ratios and low flexibility were more susceptible to seismic pressure than those with lower aspect ratios and greater flexibility. Consequently, we recommend taking the aspect ratio and flexibility into account when estimating the seismic or dynamic earth pressure on basements and exercising caution when using traditional solutions proposed for retaining walls.