지양호의 오염원 및 수질 조사

하호성,서정윤,진종석,이근석 경상대학교 환경보전연구소 1994 環境保全硏究所報 Vol.2 No.1

The upper area of the Chinyang Lake was devided into four segments, the Gyeongho River, the Yangcheon River, the Deokcheon River and the vicinity of the Chinyang Lake. The water pollution sources and the water quality of four segments were investigated and evaluated. This region was composed of a Dong in a city and 141 Ries in 6 Guns except for Yurunggun and Namwongun. Population density is low in all area except for Hamyang Up and Sancheong Up. Population is 84.903(58%) in the vicinity of the Gyeongho River, 26,093(18%) in the Yangcheon River, 23,039(16%) in the Deokcheon River and 11,468(8%) in the Chinyang Lake. Total occurance of BOD in the upper area of the Chinyang Lake was 45,493 ㎏/day, whose 66% was generated from domestic animals, 17% from the land and 26% from human wastes, respectively. The occurance of BOD in the views of segments analysis showed that 57.1% originated from the vicinity of the Gyeongho River, 28.4% from that of the Yangcheon River, 9.8% from that of the Deokcheon River and 4.8% from that of the Chinyang Lake. The most amount of BOD was discharged to the Gyeongho River, the second to the Deokcheon River and the least to the Chinyang Lake. Total occurance of SS in the upper area of the Chinyang Lake was 137,445 ㎏/day. The most amount of SS was discharged to the Gyeongho River, the second to the Yangcheon River, and the least to the Chinyang Lake. The waste of domestic animal produced the 66% of BOD and the 92% of SS in their total occurance and the 31% of BOD and the 76% of SS in their total discharge. It is concluded that the waste of domestic animal is the important pollution sources, which greatly impact the water quality of the Chinyang Lake. Total nitrogen and phosphorous content in the water of the upstream of the Chinyang Lake were very high. The water quality of the Yangcheon and the Deokcheon River was classified as 4 grade by high pH and numbers of coliform group especially. The high nitrogen content in the upstream of the Gyeongho and the Yangcheon River implies that much nitrogen is originated from the farm land. It is found that the Chinyang Lake is in the process of the eutrophication.

Site Selection Process in Germany for Radioactive Waste Disposal

Jeoung Seok Yoon,Arno Zang,Ove Stephansson,Fabrice Cotton 한국방사성폐기물학회 2017 한국방사성폐기물학회 학술논문요약집 Vol.2017 No.05

Earthquake Modelling and Application to Long-term Safety Analysis of a Final Repository of Spent Nuclear Fuels in Forsmark Sweden

Jeoung Seok Yoon,Arno Zang,Ove Stephansson,Ki-Bok Min,Fabrice Cotton,Flavio Lanaro 한국방사성폐기물학회 2017 한국방사성폐기물학회 학술논문요약집 Vol.2017 No.05

Discrete bonded particle modelling of fault activation near a nuclear waste repository site and comparison to static rupture earthquake scaling laws

Yoon, Jeoung Seok,Stephansson, Ove,Zang, Arno,Min, Ki-Bok,Lanaro, Flavio Elsevier 2017 International journal of rock mechanics and mining Vol.98 No.-

<P><B>Highlights</B></P> <P> <UL> <LI> A work flow is developed for modelling fault rupture using discrete bonded particle modelling. </LI> <LI> Fault ruptures under various stress condition including future glaciation cycles simulated. </LI> <LI> Fault rupture properties are compared with scaling relations of natural tectonic earthquakes and show good agreement. </LI> </UL> </P>

Discrete element modeling of fluid injection-induced seismicity and activation of nearby fault

Yoon, Jeoung Seok,Zimmermann, Gü,nter,Zang, Arno,Stephansson, Ove Canadian Science Publishing 2015 Canadian geotechnical journal: Revue canadienne de Vol.52 No.10

<P> Enhanced geothermal systems, shale gas, and geological carbon sequestration all require underground fluid injection in high-pressure conditions. Fluid injection creates fractures, induces seismicity, and has the potential to reactivate nearby faults that can generate a large magnitude earthquake. Mechanisms of fluid injection-induced seismicity and fault reactivation should be better understood to be able to mitigate larger events triggered by fluid injection. This study investigates fluid injection, induced seismicity, and triggering of fault rupture using hydromechanical-coupled discrete element models. Results show that a small amount of fluid pressure perturbation can trigger fault ruptures that are critically oriented and stressed. Induced seismicity by rock failure shows in general higher b-values (slope of magnitude-frequency relation) compared to seismicity triggered by the fault fracture slip. Numerical results closely resemble observations from geothermal and shale-gas fields and demonstrate that discrete element modeling has the potential to be applied in the field as a tool for predicting induced seismicity prior to in situ injection. </P>

Modelling of Fault Deformation Induced by Fluid Injection using Hydro-Mechanical Coupled 3D Particle Flow Code: DECOVALEX-2019 Task B

Jeoung Seok Yoon(윤정석),Jian Zhou 한국암반공학회 2020 터널과지하공간 Vol.30 No.4

본 수치해석연구에서는 국제공동연구프로젝트 DECOVALEX2019의 Task B의 일환으로 PFC3D를 기반으로한 수리역학연계모델을 개발하여 스위스 Mont Terri 지하연구시설에서 수행된 단층의 유체주입으로 인한 슬립시험을 모사하였다. 이를통해, 개발한 PFC3D 수리역학연계모델이 가진 한계점과 향후 보완할 점을 검토하고자 하였다. PFC3D를 기반으로한 3차원 입자결합모델 내 공극-유동통로모델을 생성하였으며 이를 사용하여 Mont Terri Step 2 단층내 유체주입실험을 모사하였다. 모델링결과 단층대를 따라 주입유체의 유동에 의한 단층대의 변형을 확인하였지만, 관측정에서의 시간에 따른 수압변화는 현장측정치와 부분적으로 일치하는 경향을 확인하였다. 현장측정 관측수압은 초기 유체주입 압력증가에 거의 변화를 보이지 않고 주입수압이 최대치에 도달할때쯤 급격한 증가를 보이는반면, 모델링에서는 주입압력이 증가함에 따라 관측수압도 부드럽게 증가하는 경향을 보였다. 이러한 부분적으로 일치하는 결과의 원인으로는 Mont Terri 현장의 단층을 모사하는 방법에 기인하는 것으로 판단하다. PFC3D에서는 단층을 손상대와 코어균열의 조합으로 모사하였고 단층대의 두께가 약 2 m로 주입유체가 단층대를 통해 유동하도록 모사하였기에 현장에서의 주입유체의 단층내 유동보다 그 유동범위가 크게 모사되었다고 판단한다. 또한, 현장단층에서와 같이 단층내부에 존재하는 충진물질로 인해 단층내 수리유동이 제한되어 국부적으로 과잉공급수압이 형성될 수 있는 기재를 모사하지 못한 점 또한 모델링 결과와 현장측정결과가 부분적으로 일치하는 원인일 수 있다. 단층변형의 경우는 모델링결과와 현장측정결과 유사한 수준으로 일치하는 결과를 확인하였다. 수치모델을 변형하여 단층대의 두께를 감소시키고 단층내 충진 물질의 비균질적인분포를 모사할 수 있는 방법론에 대한 후속 연구를 통해 PFC3D 수리역학연계모델의 유체주입으로 인한 단층활성화 연구로의 적용성을 향상시키는 것을 제안하고 한다. This study presents an application of hydro-mechanical coupled Particle Flow Code 3D (PFC3D) to simulation of fluid injection induced fault slip experiment conducted in Mont Terri Switzerland as a part of a task in an international research project DECOVALEX-2019. We also aimed as identifying the current limitations of the modelling method and issues for further development. A fluid flow algorithm was developed and implemented in a 3D pore-pipe network model in a 3D bonded particle assembly using PFC3D v5, and was applied to Mont Terri Step 2 minor fault activation experiment. The simulated results showed that the injected fluid migrates through the permeable fault zone and induces fault deformation, demonstrating a full hydro-mechanical coupled behavior. The simulated results were, however, partially matching with the field measurement. The simulated pressure build-up at the monitoring location showed linear and progressive increase, whereas the field measurement showed an abrupt increase associated with the fault slip We conclude that such difference between the modelling and the field test is due to the structure of the fault in the model which was represented as a combination of damage zone and core fractures. The modelled fault is likely larger in size than the real fault in Mont Terri site. Therefore, the modelled fault allows several path ways of fluid flow from the injection location to the pressure monitoring location, leading to smooth pressure build-up at the monitoring location while the injection pressure increases, and an early start of pressure decay even before the injection pressure reaches the maximum. We also conclude that the clay filling in the real fault could have acted as a fluid barrier which may have resulted in formation of fluid over-pressurization locally in the fault. Unlike the pressure result, the simulated fault deformations were matching with the field measurements. A better way of modelling a heterogeneous clay-filled fault structure with a narrow zone should be studied further to improve the applicability of the modelling method to fluid injection induced fault activation.

지열에너지와 관련한 유럽에서의 연구프로젝트 소개와 유도지진에 관한 GEISER프로젝트의 주요연구결과에 대한 사례연구

윤정석(Jeoung Seok Yoon),다빗 부룬(David Bruhn),아노 짱(Arno Zang) 한국암반공학회 2013 터널과지하공간 Vol.23 No.6

본 사례연구논문에서는 유럽에서의 지열에너지개발과 관련된 연구프로젝트의 현황에 대한 개괄적인 내용과, 저자가 참여했던 GEISER프로젝트(Geothermal Engineering Integrating Mitigation of Induced Seismicity in Reservoirs)와 핵심세부과제인 유도지진(Induced Seismicity)에 관한 연구결과를 요약 정리하였다. 본 사례연구 논문에서 다룬 GEISER프로젝트의 연구결과와 교훈을 통해 수리자극에 의한 지열저류층 개발과 그에 수반되는 유도지진에 따른 문제가 예상되는 향후 지열에너지개발 프로젝트에 도움이 될 수 있기를 기대한다. This article provides an overview on the geothermal energy research in Europe and one of the EU funded projects ‘GEISER (Geothermal Engineering Integrating Mitigation of Induced Seismicity in Reservoirs)’ in which the authors were involved. More details are given for description of GEISER, in particular, about aims and discussions and how the project was managed. Emphasis is given to one of the work packages ‘Induced Seismicity and Large Magnitude Events (LME)’ and results of this work package are summarized. This article intends to summarize the lessons learned in the GEISER project and give recommendations to future geothermal projects by creating Enhanced Geothermal Systems hydraulic stimulation where induced seismicity issues are expected to be a major issue and obstacle.

수리자극에 의한 지열저류층에서의 유도지진과 단층대의 변형에 관한 입자기반 개별요소법 모델링 연구

윤정석(Jeoung Seok Yoon),아미르 하킴하쉐미(Amir Hakimhashemi),아노 짱(Arno Zang),귄터 찜머만(Gunter Zimmermann) 한국암반공학회 2013 터널과지하공간 Vol.23 No.6

본 수치해석논문에서는 절리와 단층대를 포함한 지열저류층에 수리자극을 가할 시 수반되는 유도지진과 단층대의 변형을 개별요소법을 사용하여 모델링하였다. 수채해석기법은 2차원 입자유동코드를 기반으로 하며 수리역학적 상호작용기법과 미소파괴음의 모멘트텐서 역산알고리즘이 결합되었다. 수치해석의 주요결과로는 시공간적으로 변하는 유도지진의 분포와 규모 그리고 단층대의 변형(파괴 및 전단변위)과 주입유체압력의 시공간적 분포와의 상관관계이다. 첫 번째 수치해석으로부터 절리가 분포하는 지열저류층에서의 수리자극에 의한 유도지진의 분포는 주입유체의 점성에 상당한 영향을 받는 것으로 나타났다. 주입유체의 점성이 낮은 경우 (1cP), 유도지진의 발생범위가 큰 것으로 나타났으며, 주입 후 발생하는 유도지진의 개수와 규모 또한 높게 나타났다. 단층대가 존재하는 지열저류층의 수리자극 모델링의 결과, 주입정의 위치가 단층대와 가까운 경우 작은 주입수 압력분포(<0.1 MPa)로도 단층대의 파괴와 전단변형을 일으킬 수 있는 것으로 나타났다. 본 논문에서 소개한 수치해석기법은 수리자극을 통한 지열저류층 개발 시 유도지진의 분포와 규모를 실제 유체주입작업 전에 예측할 수 있게 함으로써 지열에너지개발 분야에서 유용하게 사용될 수 있을 것으로 기대한다. This numerical study investigates seismicity and fault slip induced by fluid injection in deep geothermal reservoir with pre-existing fractures and fault. Particle Flow Code 2D is used with additionally implemented hydro-mechanical coupled fluid flow algorithm and acoustic emission moment tensor inversion algorithm. The output of the model includes spatio-temporal evolution of induced seismicity (hypocenter locations and magnitudes) and fault deformation (failure and slip) in relation to fluid pressure distribution. The model is applied to a case of fluid injection with constant rates changing in three steps using different fluid characters, i.e. the viscosity, and different injection locations. In fractured reservoir, spatio-temporal distribution of the induced seismicity differs significantly depending on the viscosity of the fracturing fluid. In a fractured reservoir, injection of low viscosity fluid results in larger volume of induced seismicity cloud as the fluid can migrate easily to the reservoir and cause large number and magnitude of induced seismicity in the post-shut-in period. In a faulted reservoir, fault deformation (co-seismic failure and aseismic slip) can occur by a small perturbation of fracturing fluid (<0.1 MPa) can be induced when the injection location is set close to the fault. The presented numerical model technique can practically be used in geothermal industry to predict the induced seismicity pattern and magnitude distribution resulting from hydraulic stimulation of geothermal reservoirs prior to actual injection operation.

Cloning and sequence analysis of the two different type carotenoid isomerase isolated from the Satsuma mandarin oranges (Citrus unshiu Marc. cv. Miyagawa)

Suh Su Jeoung,Kim Seong Woo,Hoon Seok Yoon,In-Jung Kim 한국육종학회 2012 한국육종학회 심포지엄 Vol.2012 No.07

Carotenoids are major secondary compounds in Citrus determining the color of fruit and nutritional values. Carotenoids are isoprenoic compounds, and function as color pigments in the flower and fruit to attract pollinators and seed-dispersing animal and chromophore for light harvest and photoprotectant during photosynthesis. In the aim of developing new cultivars with high value using molecular breeding technology, we had performed screening of flesh and peel specific genes by differentially expressed gene screening in Citrus unshiu fruits. From the screening, carotenoid isomerase (CRTISO)1, which converts pro-lycopene to all-trans-lycopene, was identified as peel-specifically expressed gene. In this study, the gene encoding the CRTISO1 was cloned, sequenced, and compared to the CRTISOs in other plant species. Comparison of the cds sequence to other plant species revealed 75% and 78% identity with CRTISO1 of Zea maize and CRTISO2 of Arabidopsis thaliana respectively. We also cloned CRTISO2 from C. unshiu which declines the expression while maturation (Kato et al., 2004), and the gene structure was analyzed. This is the first work reporting the full sequence and gene structure of CRTISOs in C. unshiu, and would give important information in understanding the carotenoid synthesis in the Citrus fruit.

열화상카메라를 이용한 LCD-TV의 열분포 분석 및 방열 성능 향상을 위한 연구

김윤석,김용재,이정권,정두환,고한서 한국비파괴검사학회 2004 학술대회 논문집 Vol.- No.-

In these days, demand of a LCD-TV is remarkably increasing with development of the LCD technology. However, there are thermal problems for improvement of efficiecy for the LCD-TV. Thus, this research analyzed thermal problems such as convection and conduction heat transfer characteristics in the LCD-TV using an infrared (IR) camera. The results using the IR camera have been compared with those using T-type thermocouples. The results of the experiment showed that; 1. surface temperatures of inverter modules, CCFL and electrodes were higher than any other parts in the LCD-TV. 2. temperature distributions of the LCD-TV appeared asymmetrically based on the center line. 3. results of the two testing equipments agreed well.