• Journal of Biosystems Engineering
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• 제41권4호
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• pp.365-372
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• 2016

Purpose: Tea is the most frequently consumed drink worldwide, next to water. About 75% of the total world tea production includes black tea, and withering is one of the major processing steps critical for the quality of black tea. There are two types of tea withering methods: physical and chemical withering. Withering can be achieved by using tat, tunnel, drum, and trough withering systems. Of these, the trough withering system is the most commonly used. This study focuses on the different types of withering, their effect on the various quality attributes of tea, and other aspects of withering methods that affect superior quality tea. Results: During physical withering, tea shoots loose moisture content that drops from approximately 70-80% to 60-70% (wet basis). This leads to increased sap concentration in tea leaf cells, and turgid leaves become flaccid. It also prevents tea shoots from damage during maceration or rolling. During chemical withering, complex chemical compounds break down into simpler ones volatile flavor compounds, amino acids, and simple sugars are formed. Withering increases enzymatic activities as well as the concentration of caffeine. Research indicates that about 15% of chlorophyll degradation occurs during withering. It is also reported that during withering lipids break down into simpler compounds and catechin levels decrease. Improper withering can cause adverse effects on subsequent manufacturing operations, such as maceration, rolling, fermentation, drying, and tea storage. Conclusion: Freshly harvested leaves are conditioned physically and chemically for subsequent processing. There is no specified withering duration, but 14-18 h is generally considered the optimum period. Proper and even withering of tea shoots greatly depends on the standards of plucking, handling, transportation, environmental conditions, time, and temperature. Thus, to ensure consumption of high quality tea, the withering step must be monitored carefully.

• 한국산학기술학회논문지
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• 제16권2호
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• pp.1579-1584
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• 2015

광촉매반응에서 티타니아에 금속물질을 담지하면 광촉매표면이 변화되며 담지된 금속물질은 반응속도를 증가시킨다. 회분식 광반응기를 이용하여 $TiO_2$ 광촉매에 대한 금속물질 담지와 담지된 촉매의 소성조건 영향을 조사하였다. 광분해 효율을 증진시키기 위해 $TiO_2$ 촉매에 여러 종류의 금속물질을 담지하였다. 모든 실험에서의 수분함량은 3wt%, 반응기 온도는 $40^{\circ}C$이었다. $TiO_2$에 팔라듐을 담지한 경우가 가장 우수하였으며, Pt와 W을 첨가한 경우도 양호하였다. Pd/$TiO_2$ 촉매에 백금 또는 텅스텐을 부가적으로 담지하여도 제거효율에서의 증가는 없었다. 적절한 소성조건을 얻기위해 소성온도와 소성시간에 대하여 다양하게 실험을 수행하였으며, 실험결과 최적의 소성조건은 소성온도 $400^{\circ}C$, 소성시간 1시간이었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.18-18
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• 2012

In Japan, about 67% of the land is covered by forests and about 41% of them consist of plantations. About 35% of the plantations consist of old-aged plantations of older than 50 yearsand the percentage is projected to 67% in ten years' time. Although the trees of these plantations are supposed to be cut for timber production, most of them remain unmanaged and thus overcrowded mainly due to declining domestic forest industry. Since the forests are mostly located in headwater watershed, there are growing concerns about the degradation of water resources by these unmanaged plantations. To understand the ecohydrological processes in these plantations and examine the effect of intensive 50-60 % thinning to increase infiltration rate and reduce overland flow and soil erosion by recovering understory vegetation, the JST-CREST project "Development of Innovative Technologies for Increasing in Watershed Runoff and Improving River Environment by the Management Practice of Devastated Forest Plantation (Representative: Yuichi Onda)" has been launched since 2009. The ultimate objective of this project is to provide potential scenario to enhance low flow discharge in drought period and reduce turbid material in high flow period. We have been conductingintensive field observation campaign in five research sites across Japan. In Fukuoka site, integrated ecohydrological observations have been conductedin two contrastive watersheds since 2010. Intensive 50% thinning was conducted from January to April 2012 and comparative studies of ecohydrological processes before and after thinning have been started. The interim results from all the sites of this project will be presented in the 3rd International Congress for Forest and Water in a Changing Environment held in Fukuoka during 18-20 September, 2012 (http://www.forest.kyushu-u.ac.jp/~ecohydrol/3ForestWater/index.html).

• 한국재료학회지
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• 제26권2호
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• pp.73-78
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• 2016

$TiO_2$ nanoparticles were synthesized by a sol-gel process using titanium tetra isopropoxide as a precursor at room temperature. Ag-doped $TiO_2$ nanoparticles were prepared by photoreduction of $AgNO_3$ on $TiO_2$ under UV light irradiation and calcinated at $400^{\circ}C$. Ag-doped $TiO_2$ nanoparticles were characterized for their structural and morphological properties by X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The photocatalytic properties of the $TiO_2$ and Ag-doped $TiO_2$ nanoparticles were evaluated according to the degree of photocatalytic degradation of gaseous benzene under UV and visible light irradiation. To estimate the rate of photolysis under UV (${\lambda}=365nm$) and visible (${\lambda}{\geq}410nm$) light, the residual concentration of benzene was monitored by gas chromatography (GC). Both undoped/doped nanoparticles showed about 80 % of photolysis of benzene under UV light. However, under visible light irradiation Ag-doped $TiO_2$ nanoparticles exhibited a photocatalytic reaction toward the photodegradation of benzene more efficient than that of bare $TiO_2$. The enhanced photocatalytic reaction of Ag-doped $TiO_2$ nanoparticles is attributed to the decrease in the activation energy and to the existence of Ag in the $TiO_2$ host lattice, which increases the absorption capacity in the visible region by acting as an electron trapper and promotes charge separation of the photoinduced electrons ($e^-$) and holes ($h^+$). The use of Ag-doped $TiO_2$ nanoparticles preserved the option of an environmentally benign photocatalytic reaction using visible light; These particles can be applicable to environmental cleaning applications.

• 한국토양비료학회지
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• 제37권6호
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• pp.357-364
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• 2004

우리나라 논과 밭토양의 질의 현황에 대한 평가방법을 개발하고자 2000년부터 2003년까지 실시한 농업환경변동조사사업의 결과를 이용하여 세부지표 즉 토양의 주요특성의 선정, 선정된 각 지표의 점수화 또는 등급화와 정량화 방법과 각 세부지표를 종합하여 한개의 토양의 질 지표로 만드는 방법을 검토하였다 한편, 본 시안을 이용하여 전국수준에서 우리나라 논 밭 시설원예지 토양의 질 현황에 대한 평가를 시도한 결과 논토양은 매우 높음, 밭토양은 높음, 그리고 시설원예지 토양은 보통으로 나타났다.

• 한국구조물진단유지관리공학회 논문집
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• 제14권1호
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• pp.182-189
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• 2010

본 논문에서는 FRP 복합체로 보강된 콘크리트 구조물의 동결융해 저항성을 평가하기 위하여 동결융해 진행에 따른 FRP 복합체의 인장강도 및 콘크리트에 대한 인발접착강도의 변화를 측정하였다. 주 실험변수는 동결융해 조건, FRP 복합체의 종류, 동결융해 싸이클로 설정하였다. KS F 2456의 동결융해 시험규격에 따라 실시된 탄소섬유복합체의 인장강도는 최종 싸이클까지 변화가 없었으며, 또한 접착성능의 저하도 관측되지 않아 CFRP의 동결융해 저항성은 매우 우수한 것으로 나타났다. 이에 대하여 유리섬유복합체의 경우는 최종 싸이클에서의 인장강도 및 인발접착강도가 각각 10%, 15% 저하된 것으로 나타나 부분적으로 성능이 저하되는 것으로 나타났다. 그러나 접착강도 평가시 지속적인 동결수가 공급되는 상황에서는 상이한 결과가 나타날 수 있으므로 이에 대한 주의가 필요할 것으로 판단된다.

• 한국지리정보학회지
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• 제5권1호
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• pp.1-19
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• 2002

디지털 기술의 발전과 사회 경제적인 성숙을 추구함과 더불어 주택과 토지에 대한소유 및 접근은 공간적 분포의 삶의 질과 빈곤을 평가하는데 있어 매우 중요하고 어려운 문제이다. 첨단 IT 기술과 매우 향상된 지리 및 토지정보 시스템이 공간적 인간 정주문제, 토지이용과 개발, 환경악화 등을 분석하는데 이용되고 있지만, 시공간 차원에서 발생하는 가난의 원인과 결과를 이해하는데 있어 초기연구 단계에 있는 듯 싶다. 이 연구는 육하원칙 인자를 이용하여 공간적 위치의 가난을 해석하고자 하였다. 또한 정보격차로 인하여 생기는 가난한 환경을 토지정보의 공간적 개념과 연계하고 빈곤을 해소하는 관점에서 새로운 모델을 제시하였다.

• 과학기술학연구
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• 제2권1호
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• pp.85-105
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• 2002

이 논문은 정책이념(policy ideas)의 관점에서 우리나라 과학기술의 성격과 발전을 검토한다. 제도주의 이론에 따르면 정책이념은 정책형성과 정책변화를 이해하는데 매우 유용하다. 행동 원칙과 인과관계에 대한 지식과 신념이 주요 내용인 정책이념은 그것이 정책참여자의 인지와 정부 제도에 배태되므로 정책목표와 정책수단의 선택, 즉 정책형성에 큰 영향을 주는 것이다. 우리나라 과학기술정책의 이념은 기술민족주의에 바탕을 두고 있는데 이것은 최근에 들어 산업경쟁력 향상의 이념으로 구체화되고 있다. 현대 과학기술기술은 점점 복잡해지고 대규모화되고 있어서 경제 발전에 기여하는 것 못지 않게 자연과 사회에 대해서 심각한 부정적인 외부효과를 가져다주고 있다. 이런 점에서 보면 산업경쟁력 이념에 지배되어 있는 우리나라 과학기술정책은 상당한 문제점을 가지고 있다. 서구 지역의 경우와 같이 우리도 산업경쟁력 이념 못지 않게 삶의 질의 향상과 같은 좀더 사회적이고 생태적인 가치를 추구하는 방향으로 과학기술정책의 변화를 모색할 필요가 있다. 이를 위해서는 국가와 기업에 의해 주도되어 온 과학기술정책의 형성에 시민사회가 적극적으로 참여하는 길이 모색되어야한다.

• 한국기후변화학회지
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• 제7권4호
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• pp.373-381
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• 2016

Before the Conference of Parties (COP) 21 of the United Nations Framework Convention on Climate Change (UNFCCC) in 2015, most parties of UNFCCC had submitted their intended nationally determined contributions (INDCs) and to achieve their voluntary targets, some parties consider using international market mechanisms. As one of such mechanisms, Japan promoted its own bilateral mechanism called Joint Crediting Mechanism (JCM). In this study, feasibility studies and projects under JCM have been analyzed by project type, sector, country and region, which could provide some implications in designing Korea's future climate policy to achieve Korea's targets of 11.7% using international market mechanism in INDC. Since 2010, JCM has promoted 542 projects and feasibility studies in 44 countries according to the Institute for Global Environmental Strategies (IGES) database. Among 542 projects, about 80% were feasibility studies implying that JCM was more focused on project identification. However, current trends of JCM show that more projects will be soon implemented based on these feasibility studies. For sectoral categorization, projects were categorized into seven sectors-energy technology, energy efficiency, renewable energy, waste management, city, strategic planning and projects related to the country's efforts to reduce emissions from deforestation and forest degradation (REDD+). JCM projects were mitigation focused with more than 70% of projects were related to energy efficiency, renewable energy and energy technology. At the regional and country level, JCM is highly focused on Asia and especially, more than 100 projects were developed in Indonesia. Based on the analysis of JCM, in order to develop bilateral international mechanism for Korea, it is worthwhile to emphasize that Korea considers Asian countries as her partner. In addition, Korea may consider the collaboration with Multilateral Development Banks (MDBs) to implement projects identified by Korea and Asian partner countries. Furthermore, strategically, it is recommendable to develop jointly with Japan who has already capacity and networks with other Asian countries to mitigate GHG emissions. Such financial resources from MDBs and Japan may contribute to meet the 11.3% of GHG reduction target from abroad according to INDC of Korea.

• Structural Engineering and Mechanics
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• 제55권6호
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• pp.1139-1155
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• 2015

In this study, a new retrofitting method for improving the seismic performance of reinforced concrete column was presented, in which prestressed steel strips were utilized as retrofitting stuff to confine the reinforced concrete column transversely. In order to figure out the seismic performance of concrete column specimen retrofitted by such prestressed steel strips methods, a series of quasi-static tests of five retrofitted specimens and two unconfined column specimen which acted as control specimens were conducted. Based on the test results, the seismic performance including the failure modes, hysteresis performance, ductility performance, energy dissipation and stiffness degradation of all these specimens were fully investigated and analyzed. And furthermore the influences of some key parameters such as the axial force ratios, shear span ratios and steel strips spacing on seismic performance of those retrofitted reinforced concrete column specimens were also studied. It was shown that the prestressed steel strips provided large transverse confining effect on reinforced concrete column specimens, which resulted in improving the shearing bearing capacity, ductility performance, deformation capacity and energy dissipation performance of retrofitted specimens effectively. In comparison to the specimen which was retrofitted by the carbon fiber reinforced plastics (CFRP) strips method, the seismic performance of the specimens retrofitted by the prestressed steel strips was a bit better, and with much less cost both in material and labor. From this research results, it can be concluded that this new retrofitting method is really useful and has significant advantages both in saving money and time over some other retrofitting methods.