• Korean Chemical Engineering Research
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• 제45권5호
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• pp.448-454
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• 2007

미세 $BaTiO_3$ 분말의 합성을 위해 함수 티타니아와 수산화바륨을 원료로 수열합성 실험을 수행하여, 반응시간, 온도, 농도 변화에 따른 전화율, 결정구조 및 생성 분말의 물성을 조사하였다. 전화율에 미치는 영향은 시간 < 온도 < 농도 순이었으며, 2.0 M의 원료를 $180^{\circ}C$에서 2 h 수열합성 시킬 때 최대 전화율을 99.5%를 얻을 수 있었다. 낮은 농도(0.25 M)에서는 고온에서도 미반응 $BaCO_3$와 미반응 $TiO_2$ 생성을 피할 수 없었으며, 이 미반응 물질들은 고온에서 $BaTi_2O_5$를 생성시켜 불순물로 존재하였다. 농도를 높일수록 합성 $BaTiO_3$ 분말의 크기는 작아졌으며, 분말의 Ba/Ti 비도 1에 접근하였다. 2.0M 이상의 농도에서는 $180^{\circ}C$, 2 h 반응에서 Ba/Ti 비는 $1{\pm}0.005$ 이였다.

• 자원ㆍ환경경제연구
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• 제20권1호
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• pp.61-98
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• 2011

본 연구는 화력발전회사의 $CO_2$ 감축대안에 대한 경제성을 평가하였다. 평가에 고려되는 $CO_2$ 감축대안은 신재생에너지의무할당제하에서 신재생에너지발전 의무공급량을 이행하는 방안과 이산화탄소포집처리기술을 적용하여 $CO_2$ 배출이 없는 그린화력발전소를 건설하는 방안의 두 가지이다. 경제성 평가에는 현금흐름할인법과 실물옵션가격결정법이 활용되었다. 분석 결과 전력수급기본계획에 적용하는 할인율(7.5%)에서 두 평가 방법 모두에 대해 그린화력발전 대안이 경제적 우위를 갖는 것으로 분석되었다. 본 연구의 결과는 일차적으로 신재생에너지 발전소의 건설을 고심하는 화력발전회사의 중 장기 전략수립에 도움을 줄 것으로 예상된다. 부가적으로 $CO_2$ 감축을 위한 실효성 있는 정부정책의 수립에 있어서 기초자료로 활용될 수 있을 것으로 판단된다.

• 한국토양비료학회지
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• 제46권3호
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• pp.143-152
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• 2013

No-till farming system has been extensively studied all over the world as the effective method for maintaining the soil fertility. The general advantages of this system have been well known for reducing the labor, fuel, machinery, and irrigation cost as well as for increasing the soil quality through soil aggregation, water infiltration, microbial population and etc. Recently, it becomes more popular with the increase of interest on sustainable agriculture, especially because of its higher carbon sequestration potential compared to conventional tillage. Crop residue management should be essentially included to look forward to achieving the positive effect on reduction of greenhouse gas. Nonetheless, there are also negative opinions on effect of no-till farming system. For example, some researchers reported that soil physical properties were not improved by no-till under certain soil and climatic conditions. This means no-till farming systems were strongly affected by the soil characters and climatic conditions. Therefore, the researches to meet the specific-regional characters are greatly needed in order for no-till farming system to successfully settle in Korea. The objective of the review article is to present the future direction and perspective on no-till farming system in Korea. For this purpose, we summarized the results of domestic and foreign researches about no-till farming system until now. Specifically, the chapter on foreign research consisted of four parts: positive and negative effects, the effect in paddy soil, and latest research direction (2012-2013) of no-till farming systems. Whereas, review for domestic researches was divided into two main parts: paddy and upland soils. In the final chapter, the priorities for the optimum conservation tillage in Korea were discussed and proposed through the previous researches.

• 한국토양비료학회지
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• 제49권5호
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• pp.434-439
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• 2016

Anthropogenic soil in cropland is formed in the process of subsoil reversal and the refill of soil into cropland. However, there was little information on the chemical properties within soil profiles in anthropogenic soil under rice paddy near the river. In this study, we investigated the chemical properties within soil profiles in the anthropogenic soil located at 4 sites in Gumi, Kimhae, Chungju, and Euiseong to compare with the natural paddy soil near the river. Among particle sizes, the sand content decreased under soil profiles but the silt and clay contents increased compared to the natural paddy soil in soil profiles. Organic matter content in topsoil of anthropogenic soil was lower than in that of natural soil, which was shown the contrary tendency within soil profiles. Also, the soil pH, available $P_2O_5$, and exchangeable cations were higher in anthropogenic soil compared to natural paddy soil at topsoil, which was maintained these tendency into soil depth. Nutrients may be equally distributed in anthropogenic soil during the process of refill in paddy soil near the river. This results indicated that anthropogenic soil would contribute to carbon sequestration, the mitigation of compaction, and reduction of fertilizer application in paddy soil. Therefore, characteristics of anthropogenic soil can be used for the soil management in cropland.

• 한국산학기술학회논문지
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• 제11권3호
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• pp.1016-1022
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• 2010

액상 중유 연료를 사용하는 고용량 증기 보일러에서 발생되어 연소기기 내부에 침적되는 슈트, 슬래그, 크랭커, 회분, 산화물의 on-line 세정을 위한 세정제 제조에 대한 연구를 수행하였다. 액상 중유 연료를 사용하는 보일러 및 가열로에 생성되는 슈트, 슬래그, 크랭커, 회분, 산화물을 제거하는 기존 기술은 보일러 및 가열로의 가동 중단 후 작업자들에 의한 기계적인 처리를 통하여 침적물을 제거하는 기술을 사용하고 있다. 기존 기술을 대치할 수 있고 보일러의 중단이 없는 상태에서 침적물을 세정할 수 있는 세정제의 최적 조성을 도출하였다. 질산암모늄과 질산마그네슘의 혼합물이 주 세정제로 도출되었으며, 각종 전이금속 화합물에 의한 영향을 영향을 연구하여, 세정에 의한 부식을 방지할 수 있으며, 연소효율의 증대를 얻을 수 있는 전이금속화합불 첨가제를 도출하였다.

• 한국토양비료학회지
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• 제44권6호
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• pp.1286-1294
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• 2011

This paper reviews the future directions and perspectives on the soil environmental researches in the 21 century. Previously, the principal emphasis of soil environmental researches had put on the enhancement of food and fiber productions. Beside the basic function of soil, however, the societal needs on soil resources in the 21st century have demands for several environmental and social challenges, occurring regionally or globally. Typical global issues with which soil science should deal include food security with increasing agronomic production to meet the exploding world population growth, adaptation and mitigation of climate change, increase of the carbon sequestration, supply of the biomass and bioenergy, securing the water resource and quality, protection of environmental pollution, enhancing the biodiversity and ecosystem health, and developing the sustainable farming/cropping system that improve the use efficiency of water and agricultural resources. These challenges can be solved through the sustainable crop production intensification (SCPI) or plant welfare concept in which soil plays a key role in solving the abovementioned global issues. Through implementation of either concept, soil science can fulfill the goal of the modern agriculture which is the sustainable production of crops while maintaining or enhancing the ecosystem function, quality and health. Therefore, directions of the future soil environmental researches should lie on valuing soil as an ecosystem services, translating research across both temporal and spatial scales, sharing and using data already available for other purposes, incorporating existing and new technologies from other disciplines, collaborating across discipline, and translating soil research into information for stakeholders and end users. Through the outcomes of these approaches, soil can enhance the productivity from the same confined land, increase profitability, conserve natural resource, reduce the negative impact on environment, enhance human nutrition and health, and enhance natural capital and the flow of ecosystem services. Soil is the central dogma, final frontier and new engine for the era of sustainability development in the $21^{st}$ century and thus soil environmental researches should be carried according to this main theme.

• 한국기후변화학회지
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• 제2권3호
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• pp.191-201
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• 2011

본 연구는 전 지구적 문제인 기후변화에 대응하기 위해 하천, 산림 등의 자연 지역과 공원, 녹지 등의 오픈스페이스 등을 녹색기반시설이라는 개념으로 통합하고, 이를 완화와 적응의 관점에서 녹색기반시설이 기후변화에 어떻게 효과적으로 대응할 수 있는지에 대한 연구를 실시하였다. 연구의 결과, 산림, 공원, 녹지, 텃밭, 옥상농장, 자전거로, 보행로 등의 녹색기반시설은 1) 탄소의 저감과 격리, 2) 화석연료 대체, 3) 원자재 대체, 4) 식량 생산, 5) 차량 이동의 감소 등을 통해서 기후변화를 완화시킬 수 있다. 둘째, 하천, 가로수, 저류지, 습지, 사구, 바람길 등의 녹색기반시설은 1) 폭염완화, 2) 물 공급 조절, 3) 강 범람 조절, 4) 해안 범람 조절, 5) 지표수 조절, 6) 토양 침식 감소, 7) 생물종 적응에 도움 등을 통해서 기후변화 적응의 역할을 할 수 있다.

• 터널과지하공간
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• 제29권1호
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• pp.12-29
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• 2019

최근의 이산화탄소 심지층 처분, 인공지열저류층 형성 및 발전, 원유회수증진 사업 등에는 고압의 유체를 주입하는 과정이 수반되고 이들 사업의 안전하고 성공적인 수행을 위해서는 대상 부지 절리 암반의 투수 특성 및 주입압에 의한 역학적 변형에 기인한 변화를 정확하게 평가하는 것이 중요하다. 본 고에서는 절리 암반 수리-역학 특성 파악을 위한 해석적 및 실험적 평가 방법에 대해 검토하였다. 먼저 유체 주입 전 절리 암반 초기 투과 특성 및 수리-역학 특성 평가에 고려해야 할 기술요소를 분석하고 현장 시추공 실험을 통해 이들 수리-역학 특성을 직접 측정하기 위한 최근의 SIMFIP 실험장치의 특징 및 활용방안에 대해서도 검토하였다.

• Molecules and Cells
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• 제42권6호
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• pp.460-469
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• 2019

Bacterial ${\alpha}-type$ carbonic anhydrase (${\alpha}-CA$) is a zinc metalloenzyme that catalyzes the reversible and extremely rapid interconversion of carbon dioxide to bicarbonate. In this study, we report the first crystal structure of a hyperthermostable ${\alpha}-CA$ from Persephonella marina EX-H1 (pmCA) in the absence and presence of competitive inhibitor, acetazolamide. The structure reveals a compactly folded pmCA homodimer in which each monomer consists of a 10-stranded ${\beta}-sheet$ in the center. The catalytic zinc ion is coordinated by three highly conserved histidine residues with an exchangeable fourth ligand (a water molecule, a bicarbonate anion, or the sulfonamide group of acetazolamide). Together with an intramolecular disulfide bond, extensive interfacial networks of hydrogen bonds, ionic and hydrophobic interactions stabilize the dimeric structure and are likely responsible for the high thermal stability. We also identified novel binding sites for calcium ions at the crystallographic interface, which serve as molecular glue linking negatively charged and otherwise repulsive surfaces. Furthermore, this large negatively charged patch appears to further increase the thermostability at alkaline pH range via favorable charge-charge interactions between pmCA and solvent molecules. These findings may assist development of novel ${\alpha}-CAs$ with improved thermal and/or alkaline stability for applications such as $CO_2$ capture and sequestration.

• 반도체디스플레이기술학회지
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• 제23권1호
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• pp.12-18
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• 2024

The accelerated pace of climate crisis due to continuous industrialization and greenhouse gas emissions necessitates sustainable solutions that simultaneously address mitigation and adaptation to climate change. Naturebased Solutions (NbS) have gained prominence as viable approaches, with Green Infrastructure being a representative NbS. Green Infrastructure involves securing green spaces within urban areas, providing diverse climate adaptation functions such as removal of various air pollutants, carbon sequestration, and isolation. The proliferation of Green Infrastructure is influenced by the quantification of improvement effects related to various projects. To support decision-making by assessing the climate vulnerability of Green Infrastructure, the U.S. Department of Agriculture (USDA) has developed i-Tree Tools. This study proposes a comprehensive evaluation approach for climate change adaptation types by quantifying the climate adaptation performance of urban Green Infrastructure. Using i-Tree Canopy, the analysis focuses on five urban green spaces covering more than 30 hectares, considering the tree ratio relative to the total area. The evaluation encompasses aspects of thermal environment, aquatic environment, and atmospheric environment to assess the overall eco-friendliness in terms of climate change adaptation. The results indicate that an increase in the tree ratio correlates with improved eco-friendliness in terms of thermal, aquatic, and atmospheric environments. In particular, it is necessary to prioritize consideration of the water environment sector in order to realize climate change adaptive green infrastructure, such as increasing green space in urban areas, as it has been confirmed that four out of five target sites are specialized in improving the water environment.