• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1944-1949
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• 2020

Mutant sugar transporter ScGAL2-N376F was overexpressed in Kluyveromyces marxianus for efficient utilization of xylose, which is one of the main components of cellulosic biomass. K. marxianus ScGal2_N376F, the ScGAL2-N376F-overexpressing strain, exhibited 47.04 g/l of xylose consumption and 26.55 g/l of xylitol production, as compared to the parental strain (24.68 g/l and 7.03 g/l, respectively) when xylose was used as the sole carbon source. When a mixture of glucose and xylose was used as the carbon source, xylose consumption and xylitol production rates were improved by 195% and 360%, respectively, by K. marxianus ScGal2_N376F. Moreover, the glucose consumption rate was improved by 27% as compared to that in the parental strain. Overexpression of both wild-type ScGAL2 and mutant ScGAL2-N376F showed 48% and 52% enhanced sugar consumption and ethanol production rates, respectively, when a mixture of glucose and galactose was used as the carbon source, which is the main component of marine biomass. As shown in this study, ScGAL2-N376F overexpression can be applied for the efficient production of biofuels or biochemicals from cellulosic or marine biomass.

• 신재생에너지
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• 제20권1호
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• pp.145-174
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• 2024

Addressing climate change necessitates evidence-based policies grounded in science. The use of forest biomass for energy production is based on a broad scientific consensus at the international level. However, some environmental groups in South Korea are opposing this system of energy production. Through this study, the authors aim to reduce unnecessary confusion and foster an atmosphere conducive to meaningful evidence-based policies. We have classified the issue into eight categories: biological carbon cycle, carbon debt, nature-based solutions, air emissions, cascading principles and sustainability certification, forest environmental impacts, climate change litigation, and the behavior of environmental groups and public perception. Consequently, the following key points were derived: (1) the actions of some environmental groups seem to follow a similar pattern to denialist behavior that denies climate change and climate science; (2) the quality of evidence for campaigns that oppose the use of forest biomass for energy production is low, with a tendency to overgeneralize information, high uncertainty, and difficulty in finding new claims.; (3) most of the public believes that forest biomass energy is necessary, and the governments of major countries are aware of its importance. Significantly, Forest biomass for energy is based on an overwhelming level of scientific consensus recognized internationally.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.41-44
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• 2014

This study focused on the effect of the biomass blended ratio on air-staged pulverized coal furnace. The hybrid NOx reduction technology between fuel blending and air staging has been applied in an air-staged pulverized coal fired furnace. The results indicated that co-firing biomass with coal could reduce NOx emissions in an air-staged combustion. In addition, carbon burnout and flame temperature increased under the air-staged condition. A dominant synergistic effect on NOx reduction and carbon burnout was observed when biomass co-firing with coal was applied in air staged combustion.

• 한국산림과학회지
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• 제96권5호
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• pp.591-601
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• 2007

Spatial information on forest biomass is an important factor to evaluate the capability of forest as a carbon sequestrator and is a core independent variable required to drive models which describe ecological processes such as carbon budget, hydrological budget, and energy flow. The objective of this study is to understand the relationship between satellite image and field data, and to quantitatively estimate and map the spatial distribution of forest biomass. Landsat Enhanced Thematic Mapper (ETM+) derived vegetation indices and field survey data were applied to estimate the biomass distribution of mountainous forest located in Gwangneung Experimental Forest (230 ha). Field survey data collected from the ground plots were used as the dependent variable, forest biomass, while satellite image reflectance data (Band 1~5 and Band 7), Normalized Difference Vegetation Index (NDVI), Soil-Adjusted Vegetation Index (SAVI), and RVI (Ratio Vegetation Index) were used as the independent variables. The mean and total biomass of Gwangneung catchment area were estimated to be about 229.5 ton/ha and $52.8{\times}10^3$ tons respectively. Regression analysis revealed significant relationships between the measured biomass and Landsat derived variables in both of deciduous forest ($R^2=0.76$, P < 0.05) and coniferous forest ($R^2=0.75$, P < 0.05). However, there still exist many uncertainties in the estimation of forest ecosystem parameters based on vegetation remote sensing. Developing remote sensing techniques with adequate filed survey data over a long period are expected to increase the estimation accuracy of spatial information of the forest ecosystem.

• 한국환경과학회지
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• 제23권6호
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• pp.1101-1109
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• 2014

In this study we followed biofilm formation and development in a granular activated carbon (GAC) filter on pilot-scale during the 12 months of operation. GAC particles and water samples were sampled from four different depths (-5, -25, -50 and -90 cm from surface of GAC bed) and attached biomass were measured with adenosine tri-phosphate (ATP) analysis and heterotrophic plate count (HPC) method. The attached biomass accumulated rapidly on the GAC particles of top layer throughout all levels in the filter during the 160 days (BV 23,000) of operation and maintained a steady-state afterward. During steady-state, biomass (ATP and HPC) concentrations of top layer in the BAC filer were $2.1{\mu}g{\cdot}ATP/g{\cdot}GAC$ and $3.3{\times}10^8cells/g{\cdot}GAC$, and 85%, 83% and 99% of the influent total biodegradable dissolved organic carbon ($BDOC_{total}$), $BDOC_{slow}$ and $BDOC_{rapid}$ were removed, respectively. During steady-state process, biomass (ATP and HPC) concentrations of middle layer (-50 cm) and bottom layer (-90 cm) in the BAC filter were increased consistently. Biofilm development (growth rate) proceed highest rate in the top layer of filter (${\mu}_{ATP}=0.73day^{-1}$; ${\mu}_{HPC}=1,74day^{-1}$) and 78%~87% slower in the bottom layer (${\mu}_{ATP}=0.14day^{-1}$; ${\mu}_{HPC}=0.34day^{-1}$). This study shows that the combination of different analytical methods allows detailed quantification of the microbiological activity in drinking water biofilter.

• 한국산림과학회지
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• 제95권1호
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• pp.50-54
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• 2006

Biomass 확장계수와 줄기밀도의 값은 임목축적 자료를 이용하여 국가단위의 총 탄소 저정량으로 전환하는데 일반적으로 사용되어왔다. 본 연구의 목적은 우리나라 남부지방에 식재된 편백 임분을 대상으로 임령이 Biomass 확장계수와 줄기밀도에 미치는 영향을 조사하였다. 연구 대상지는 동일한 임지에서 다양한 임령(8~54년생)이 분포하는 전라남도 장성군 편백 조림지를 기본 모델로 조사하였으며, 조사대상지 임분은 20년 단위를 1 영급단위로 분류하여 총 3개의 영급단위로 구분하였다. 각 영급단위별로 최소 5주 이상의 표준목을 선발하여 총 25주의 표준목을 벌채하였고 줄기, 잎, 가지, 뿌리의 생중량과 건중량, 줄기밀도, Biomass 확장계수, 줄기의 Biomass에 의한 부위별 Biomass 전환계수 등을 분석하였다. 본 연구 결과, 전체 Biomass 확장계수는 임령이 증가함에 따라 3.64에서 1.44로 급격히 감소하는 반면에, 줄기밀도는 $0.35(g/cm^3)$에서 $0.44(g/cm^3)$로 약간 증가하는 경향을 나티내었다. Biomass 확장계수와 줄기밀도의 경우 영급에 따라 유의적인 차이가 있었으나 영급단위2와 영급단위3은 차이를 나타내지 않았다. 그러나 평균적으로 임령이 30년 이상인 경우에는 전체 Biomass 확장계수와 줄기밀도가 약 1.44와 $0.44(g/cm^3)$라는 일정한 값들을 나타내었다. 본 연구 결과로 얻어진 Biomass 확장계수와 줄기밀도를 편백 임분의 영급별 축적에 적용함으로써 정확도 높은 총 Biomass 및 탄소 고정량을 추정하는데 기초 자료로 활용할 수 있을 것이다.

• Journal of Ecology and Environment
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• 제32권1호
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• pp.27-31
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• 2009

Organic carbon (OC) distribution in 32-year-old pitch pine plantation at Mt. Hotae in Kongju, Korea, was studied from August 2007 to July 2008. In order to investigate the OC distribution, OC in plant biomass, litterfall, litter layer on forest floor, and soil within 50cm depth were estimated. The density of P. rigida plantation was 3,200 trees/ha, average DBH was $18.7{\pm}5.53cm$ and average tree height was $11.1{\pm}1.85m$. Organic carbon stored in plant biomass, litterlayer on forest floor and soil in 2008 was 89.46 ton C/ha (46.09%), 4.32 ton C/ha (2.23%) and 100.32 ton C $ha^{-1}$ 50cm-$depth^{-1}$ (51.68%), respectively. Amount of OC returned to forest floor via litterfall was 2.21 ton C $ha^{-1}\;yr^{-1}$. Total amount of OC stored in this P. rigida plantation was 194.1 ton C/ha. Net increase of OC in above- and below-ground biomass in this pitch pine plantation was 4.82 ton C $ha^{-1}\;yr^{-1}$.

• 환경생물
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• 제33권4호
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• pp.459-467
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• 2015

지역적 규모의 탄소순환과 저장량 변화에 대한 자료는 지구적 규모의 탄소순환 형태 변화를 예측하는 중요한 자료가 된다. 따라서 다양한 지역적 규모의 생태계에 대한 자료 수집은 필수적이다. 본 연구는 국내 다양한 생태계 중 자연성이 높은 국립공원지역 산림 생태계의 탄소축적량을 산정하여 자연군락이 축적 가능한 탄소축적 잠재량을 평가하기 위해 진행되었다. 연구대상지인 덕유산국립공원은 신갈나무 우점군락 10,881.5 ha (47.2%), 굴참나무 우점군락 2,314.6 ha (10.0%), 소나무 우점군락 1,952.6 ha (8.5%), 졸참나무 우점군락 402.9 ha (1.7%) 등이 분포하고 있는 것으로 조사되었다. 조사구는 군락의 분포지역을 확인하고, 수목밀도와 종조성 등을 고려하여 선정하였고, biomass 탄소축적량을 산정하기 매목조사를 실시하였다. 각 매목조사구 내 토양샘플구 ($30cm{\times}30cm$)를 각 3개씩 설치하여 토양 탄소축적량을 조사하였다. Biomass 탄소축적량과 토양 탄소축적량은 신갈나무 우점군락에서 각각 1,749,000 tC와 7,776,000 tC로 가장 높은 값이 측정되었다. 군락별 전체 생태계에 축적되어 있는 탄소량은 신갈나무 우점군락과, 굴참나무 우점군락, 졸참나무 우점군락, 소나무 우점군락에서 각각 9,536,000 tC, 1,405,000 tC, 147,000 tC, 346,000 tC로 나타났다. 또한 덕유산국립공원의 전체 생태계 탄소축적량은 11,434,000 tC로 산정되었다.

• 임산에너지
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• 24권2호
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• pp.10-15
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• 2005

본 연구는 기후변화협약에 대응하기 위해 우리나라의 산지전용에 따른 탄소배출량을 측정할 목적으로 수행되었다. 산지전용자료는 2000년부터 2004년까지 최근 5년간 산림기본통계자료에서 추출하였으며, 임목바이오매스 탄소배출량은 임상별 바이오매스 확장계수와 탄소전환계수를 이용하였다. 최근 5년동안 산지전용면적은 연평균 약 7.2천ha가 타용도로 전용되었으며, 임목축적은 연평균 약 212천$m^3$이 벌채되었다. 최근 5년간 산지전용에 따른 임목바이오매스 총탄소배출량은 연평균 105천tC 배출한 것으로 나타났으며, 임상별 임목바이오매스 탄소배출량은 침엽수림이 54천tC, 활엽수림이 51천tC 배출한 것으로 나타났다. 최근 5년간 산지전용에 따른 ha 당 탄소배출량은 연평균 약 14.4tC/ha으로 나타났으며, 임상별로는 침엽수림이 약 13.3tC/ha, 활엽수림이 18.5tC/ha로 나타났다. 따라서 활엽수림이 단위면적당 탄소를 더 많이 배출하는 것으로 나타났다.

• Journal of Ecology and Environment
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• 제46권3호
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• pp.250-258
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• 2022

Background: To assess the carbon sequestration capacity and net ecosystem productivity (NEP) of Quercus glauca forests, we analyzed the net primary productivity (NPP), carbon storage, and carbon emission of soil in a Q. glauca forest on Jeju Island (South Korea) from 2016 to 2018. Results: The average carbon stock in the above- and below-ground plant biomass was 223.7 Mg C ha^-1, while the average amount of organic carbon fixed by photosynthesis was 9.8 Mg C ha^-1 yr^-1, and the average NPP was 9.6 Mg C ha^-1 yr^-1. Stems and branches contributed to the majority of the above- and below-ground standing biomass and NPP. The average heterotrophic carbon emission from the soil was 8.7 Mg C ha^-1 yr^-1, while the average NEP was 1.1 Mg C ha^-1 yr^-1. Although the carbon stock, carbon absorption, and soil respiration values were higher than those reported in other oak forests in the world, the NEP was similar or lower. Conclusions: These results indicator that Q. glauca forests perform the role of a large carbon sink through the CO₂ absorption in the plants in terms of carbon balance. And it is judged to be helpful as data for assessment of carbon storage and flux in the forests and mitigation of elevated CO₂ in the atmosphere.