Degradation of endocrine disrupting chemicals by genetic transformants in Irpex lacteus with an inducible laccase gene of Phlebia tremellosa

Kum, Hyunwoo,Kim, Myung K.,Choi, Hyoung T. Springer-Verlag 2009 Biodegradation Vol.20 No.5

Degradation of Endocrine Disrupting Chemicals by Genetic Transformants with Two Lignin Degrading Enzymes in Phlebia tremellosa

Hyunwoo Kum,Sungsuk Lee,Sunhwa Ryu,최형태 한국미생물학회 2011 The journal of microbiology Vol.49 No.5

A white rot fungus Phlebia tremellosa produced lignin degrading enzymes, which showed degrading activity against various recalcitrant compounds. However, manganese peroxidase (MnP) activity, one of lignin degrading enzymes, was very low in this fungus under various culture conditions. An expression vector that carried both the laccase and MnP genes was constructed using laccase genomic DNA of P. tremellosa and MnP cDNA from Polyporus brumalis. P. tremellosa was genetically transformed using the expression vector to obtain fungal transformants showing increased laccase and MnP activity. Many transformants showed highly increased laccase and MnP activity at the same time in liquid medium, and three of them were used to degrade endocrine disrupting chemicals. The transformant not only degraded bisphenol A and nonylphenol more rapidly but also removed the estrogenic activities of the chemicals faster than the wild type strain.

Oxide Layer Rumpling Control Technology for High Efficiency of Eco-Friendly Combined-Cycle Power Generation System

Hyunwoo Song,Jeong-Min Lee,Junghan Yun,Soo Park,Yongseok Kim,Kyoung-Sup Kum,Young-Ze Lee,Chang-Sung Seok 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.1

Combined-cycle power generation is a high-efficiency power generation method using natural gas that can reduce the emissions of carbon dioxide and other harmful substances by increasing the power generation efficiency. Therefore, the turbine inlet temperature should be increased to improve the power generation efficiency. However, given that the operating environment becomes extreme as the turbine inlet temperature increases, ensuring the sufficient durability of the gas turbine components is a necessity. Thermal barrier coatings (TBCs) applied to ensure the durability of the gas turbine components in a high temperature environment can peel off by stress generated through the difference in the thermal expansion coefficient of each layer. Because internal gas turbine components are damaged if peeling occurs, it is essential to ensure sufficient durability of the TBC. In particular, to enhance the efficiency of the combined-cycle power plant, and to withstand higher operating temperatures, it is essential to develop a TBC with an improved durability performance, when compared with currently commercialized TBCs. In this study, we attempted to improve the durability of the TBCs by mitigating the stress concentration phenomenon by gently controlling the rumpling of the oxide layer. For this purpose, the vertical crack design conditions required to reduce the buckling stress were derived through a finite element analysis. Isothermal degradation and thermal fatigue tests were conducted on the fabricated specimens to verify whether the oxide layer rumpling of the designed TBC was controlled gently and whether the durability was improved. Base on the results, a TBC structure with improved durability using oxide layer rumpling control technology is proposed.

SATEEC system을 이용한 경안천 유역의 장기 유실량 평가

강현우 ( Hyunwoo Kang ),금동혁 ( Kum Donghyuk ),장춘화 ( Chunhwa Jang ),류지철 ( Jichul Ryu ),박화용 ( Hwa Yong Park ),김영석 ( Youngsug Kim ),임경재 ( Kyoung Jae Lim ) 한국농공학회 2012 한국농공학회 학술대회초록집 Vol.2012 No.-

토양 유실로 인한 경제적, 사회적, 환경적 문제 해결 및 적절한 대응 방안을 마련하기 위하여 전 세계적으로 많은 연구가 진행되어 왔으며, 지난 수 십년 동안 USLE(Universal Soil Loss Equation) 및 USLE 기반의 모형이 토양 유실량 모의에 널리 이용되고 있다. 또한 GIS 인터페이스를 기반으로 USLE 입력 자료를 이용하여 토양 유실량 및 최종/임의 지점에서의 유사량을 산정/분석 할 수 있는 SATEEC(Sediment Assessment Tool for Effective Erosion Control) system을 개발되어 토양 및 유사량 산정에 널리 이용되고 있으며, 최근 일별 강우인자 산정이 가능한 SATEEC system ver. 2.2가 개발되었다. 본 연구에서는 SATEEC system ver. 2.2를 이용하여 경안천 유역에 적용, 우심지역에서 산정된 일·연도별 토양 유실량을 비교/분석하였다. 모의 결과 선정된 우심지역에서의 토양 유실량은 연평균 2311.70 ton/ha/yr로 매우 높았으며, 연도별 강수량에 따른 토양 유실량의 편차는 매우 큰 것으로 나타났다. 특히 2006년도에 발생한 토양 유실이 2007년에 비해 무려 4.53 배 높았다. 연구의 결과에서 나타난 바와 같이, 연 강수량에 따른 토양 유실량의 편차는 매우 크며 USLE 모형으로 이를 모의하기에는 많은 한계가 있다. SATEEC system은 이러한 단점의 보완 할 수 있으며, 장기적 관점, 단일 강우, 그리고 미래 기후변화에 따른 표토 유실 가능성을 평가하는데 활용될 수 있을 것이라 판단된다.

Protective Effects of a New Phloretin Derivative against UVB-Induced Damage in Skin Cell Model and Human Volunteers

Shin, Seoungwoo,Kum, Hyunwoo,Ryu, Dehun,Kim, Minkyung,Jung, Eunsun,Park, Deokhoon MDPI 2014 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.15 No.10

<P>The phenolic compound phloretin is a prominent member of the chemical class of dihydrochalcones. Phloretin is specifically found in apple and apple juice and known for its biological properties. We were particularly interested in its potential dermo-cosmetic applications. However, practical limitations of phloretin do exist due to its poor water-solubility. Phloretin was sulfonated with sulfuric acid (98%, wt) and mixed with saturated salt water to produce phloretin 3',3-disulfonate in order to increase its water-solubility. Here we reported the photoprotective effect of phloretin 3',3-disulfonate (PS), a new semi-synthetic derivative of phloretin. Results showed that PS attenuated cyclobutane pyrimidine dimer (CPDs) formation, glutathione (GSH) depletion and apoptosis induced by ultraviolet B (UVB). The photoprotective effect of PS is tightly correlated to the enhancement of nucleotide excision repair (NER) gene expression. Furthemore, PS had inhibitory effects on UVB-induced release of the inflammatory mediators, such as IL-6 and prostaglandin-E<SUB>2</SUB>. We also confirmed the safety and clinical efficacy of PS on human skin. Overall, the results demonstrated significant benefits of PS on the protection of keratinocytes against UVB-induced injuries and suggested its potential use in skin photoprotection.</P>

HRSM4BPM 모형 유출/유사 자동 보정 툴 개발

금동혁 ( Donghyuk Kum ),유지철 ( Jichul Ryu ),최재완 ( Jaewan Choi ),강형우 ( Hyunwoo Kang ),장춘화 ( Chun Hwa Jang ),신동석 ( Dong Suk Shin ),이재관 ( Jae Kwan Lee ),임경재 ( Kyoung Jae Lim ) 한국물환경학회 2013 한국물환경학회지 Vol.29 No.1

Recently various Best Management Practices have been applied at a field to reduce soil erosion. Hourly Runoff and Sediment Model for Best Management Practices (HRSM4BMP) model could be used to evaluate soil erosion reduction for various agricultural BMPs at fields. Runoff and sediment yield from source areas have to be predicted with greater accuracies to evaluate sediment reduction efficiently with BMPs. To achieve this the best parameters related with runoff and sediment modules of the HRSM4BMP model should be identified with proper calibration processes. Although manual calibration is often utilized in calibrating runoff and sediment using the HRSM4BMP objective calibration method would be recommended. The purpose of the study was to develop an automatic calibration tool of the HRSM4BMP model with PARASOL method. This automatic calibration tool was applied to Bangdongri Chuncheon-si to evaluate its calibration performance. The R² NSE and RMSE value for runoff estimation were 0.92, 0.92, 0.3 m³ and for sediment yield estimation were 0.94 0.94 0.0027kg. As shown in this result automatic calibration tool of HRSM4BMP model would be used to determine the best parameters and can be used to simulate runoff and sediment yield with acceptable accuracies.

USLE모형과 시강우를 고려한 토양유실 평가 시스템을 이용한 연간 토양유실량 비교 분석

금동혁(Donghyuk Kum),류지철(Jichul Ryu),강현우(Hyunwoo Kang),장춘화(Chun Hwa Jang),신민환(Min Hwan Shin),신동석(Dong Shuk Shin),최중대(Joongdae Choi),임경재(Kyoung Jae Lim) 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.6

Soil erosion and sediment has been known as one of pollutants causing water quality degradation in water bodies. With global warming issues worldwide, various soil erosion studies have been performed. Although on-site monitoring of sediment loss would be an ideal method to evaluate soil erosion condition, modeling approaches have been utilized to estimate soil erosion and to evaluate various best management practices on soil erosion reduction. Although the USLE has been used in soil erosion estimation for the last 40 years, the USLE model has limitations in estimating event-based soil erosion reflecting rainfall intensity and rainfall duration for long-term period. Thus, the calibrated model, capable of simulating soil erosion using hourly rainfall data, was utilized in this study to evaluate the effects of rainfall amount and rainfall intensity on soil erosion. It was found that USLE soil erosion value is 3.06 ton ha<SUP>-1</SUP> yr<SUP>-1</SUP>, while soil erosion values from 2006 ~ 2010 were 2.469 ton ha<SUP>-1</SUP> yr<SUP>-1</SUP>, 0.882 ton ha<SUP>-1</SUP> yr<SUP>-1</SUP>, 1.489 ton ha<SUP>-1</SUP> yr<SUP>-1</SUP>, 2.158 ton ha<SUP>-1</SUP> yr<SUP>-1</SUP>, 1.602 ton ha<SUP>-1</SUP> yr<SUP>-1</SUP>, respectively. Especially, soil erosion from single storm event for 2008-2010 would be responsible for 30% or more of annual soil loss. As shown in this study, hourly soil erosion estimation system would provide more detailed output from the study area. In addition, the effects of rainfall intensity on soil erosion could be evaluated with this system.

강우강도를 고려한 필지별 장기 유출-유사 평가 시스템 개발

금동혁 ( Donghyuk Kum ),류지철 ( Jichul Ryu ),강현우 ( Hyunwoo Kang ),신동석 ( Dong Suk Shin ),최재완 ( Jaewan Choi ),임경재 ( Kyoung Jae Lim ) 한국농공학회 2011 한국농공학회 학술대회초록집 Vol.2011 No.-

세계적인 기후변화로 인하여 지역적 강우지속시간과 강우강도가 다양해지고 있다. 따라서 유역단위 및 소유역 단위로 유사량 평가가 이루어지기 보다는 강우강도를 고려한 필지별 유사량 평가가 더 효율적이다. 이번 연구에서 HUFF 4분위법과 SCS 유출수문곡선, Green-Ampt 침투능, AMC/SLOPE를 고려한 CN산정 그리고 MUSLE를 이용하여 필지별유사 평가 시스템을 개발하여 춘천시 서면지역에 적용하였다. 적용한 결과 SCS 방법에서는 유출과 유사가 0.00005㎥/s, 273.1ton/ha/yr, Green-Ampt 방법에서는 유출과 유사가 0.00008 ㎥/s, 477.1ton/ha/yr 발생하여 Green-Ampt 방법이 SCS 방법에 비해 유출과 유사 모두 높게 나타났다. 하지만 Green-Ampt 방법은 연속적 시간 흐름을 반영하지 못하기 때문에 SCS 방법이 Green-Ampt방법에 비해 좀 더 현실성 있는 예측 방법이라고 판단된다. 본 연구에서는 OpenSource GIS인 MapWindow를 기반으로 평가시스템을 개발하여 이용자들이 다른 상업용 소프트웨어에 비해 추가적인 비용 없이 시스템을 이용할 수 있고, 시스템 소스 코드에 쉽게 접근하여 이용 목적에 맞게 시스템 수정이 가능하기 때문에 활용도가 매우 클 것으로 기대된다. 향후 연구에서는 자동 검ㆍ보정 모듈을 개발하여 다양한 지역에 확대 적용할 것이다.

Analysis of Temporal Change in Soil Erosion Potential at Haean-myeon Watershed Due to Climate Change

Lee, Wondae,Jang, Chunhwa,Kum, Donghyuk,Jung, Younghun,Kang, Hyunwoo,Yang, Jae E.,Lim, Kyoung Jae,Park, Youn Shik 한국토양비료학회 2014 한국토양비료학회지 Vol.47 No.2

Climate change has been social and environmental issues, it typically indicates the trend changes of not only temperature but also rainfall. There is a need to consider climate changes in a long-term soil erosion estimation since soil loss in a watershed can be varied by the changes of rainfall intensity and frequency of torrential rainfall. The impacts of rainfall trend changes on soil loss, one of climate changes, were estimated using Sediment Assessment Tool for Effective Erosion Control (SATEEC) employing L module with current climate scenario and future climate scenario collected from the Korea Meteorological Administration. A 62 $km^2$ watershed was selected to explore the climate changes on soil loss. SATEEC provided an increasing trend of soil loss with the climate change scenarios, which were 182 ton/ha/year in 2010s, 169 ton/ha/year in 2020s, 192 ton/ha/year in 2030s,182 ton/ha/year in 2040s, and 218 ton/ha/year in 2050s. Moreover, it was found that approximately 90% of agricultural area in the watershed displayed the soil loss of 50 ton/ha/year which is exceeding the allow able soil loss regulation by the Ministry of Environment.

미래 강수량 자료만을 이용한 SWAT모형의 유출 예측

이지민 ( Jimin Lee ),금동혁 ( Donghyuk Kum ),강현우 ( Hyunwoo Kang ),최중대 ( Joong Dae Choi ),임경재 ( Kyoung Jae Lim ) 한국농공학회 2012 한국농공학회 학술대회초록집 Vol.2012 No.-

최근 이상기후 현상에 통해 가뭄 및 집중호우에 의한 피해가 급증하면서 수자원 관리에 대한 필요성이 증대되고 있다. 기후변화에 의한 미래 기온의 상승과 강수량 패턴변화는 증발산이나 토양수분 등의 변화로 이어져 궁극적으로는 물 순환 변화를 초래하며 유출량의 변화로 이어지고 있다. 폭우와 홍수피해 등 물로 인한 인명 및 재산 피해 예방하기 위해서, 향후 예상되는 물 부족에 관해 수자원관리의 중요성이 부각되고 있다. 기후변화에 따른 수자원관리체계 재정립 필요성이 증가됨으로 분석할 만한 미래 유출변화 기초자료가 구축되어야 가능하다. 이러한 유출변화를 산정하기 위한 방법 중 유역 수문-수질 모의 가능한 SWAT(Soil and water assessment tool) 모형을 이용하였다. SWAT모형을 이용하여 유출량에 미치는 영향을 분석한 결과 기상인자 중 강수량에 대해 가장 민감한 것으로 나타났다. 실측 기상자료를 그대로 적용한 시나리오1과 강수량을 제외한 나머지 기상인자는 장기평균으로 적용한 시나리오2 를 비교/분석한 결과 NSE 0.99로 나타났고, 나머지 기상 인자 중 온도 및 습도를 ±2 %, ±4 % 변화 시켜 본 결과 유출량에 영향을 주지 않았다. 이에 따라 본 연구에서는 RCP 시나리오 중 강수량 자료만을 활용하여 미래 기후변화에 따른 유출량 변화를 평가하였다. 시나리오1과 시나리오2를 홍천강 유역에 적용한 결과 유량에 대해서 보정 NSE 0.70 R2 0.73, 검정 NSE 0.80 R2 0.82로 똑같은 결과를 보였다. 또한 검·보정한 결과로 기후변화정보센터(CCIC)에서 제공 해주는 기후모델인 RCP8.5 시나리오를 편이보정(Bais-correction)한 후 미래 기후변화에 따른 유량을 분석하였다. 연구과정을 통하여 본 결과 강수량 자료만 가지고도 수문예측을 할 수 있으며, 미래 수자원의 변동성에 대해 전망해 볼 수 있을 것으로 판단된다. 본 연구의 결과에서 보이는 바와 같이 강수량 이외의 기상자료가 없는 유역에서도 SWAT 모형을 이용하여 장기유출량을 산정하는데 큰 문제가 없으리라 판단된다.