• 한국산업보건학회지
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• 제30권2호
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• pp.236-248
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• 2020

Objectives: The purpose of this study was to evaluate the concentrations of particulate matter generated during coffee roasting and to study various factors affecting the concentrations. Methods: Differences in concentration levels were investigated based on various factors to understand the emission rates of particulate matter over time and to compare the mass and number concentrations according to their size. Sampling was performed in closed laboratories without the operation of air conditioning or ventilation. Optical Particle Sizer(OPS) was used as a measuring device. An OPS measures using a light-scattering method. Sampling was performed for sixty minutes at one-minute intervals. The background concentration was measured for about 30 minutes before starting of coffee roasting. The concentrations of particulate matter generated during coffee roasting were monitored until roasted coffee beans were removed from the roaster and cooled down. Several factors affecting the concentrations of particulate matter were investigated, which includes the origins of green beans, the roasting level, and the input amount of green beans. Results: The results of this study may be summarized as follows: 1) There was no difference in particulate matter concentration levels by the origin of the green beans, but a statistically significant difference in concentration levels by roasting level and the input amount of green beans; The higher the roasting level, the higher was the particulate matter concentration. The more green beans we put in the roaster, the higher were the concentrations; 2) The PM10 mass concentrations increased over time. The average concentration after roasting was higher than the average concentration during roasting; 3) In the distribution of mass and number concentration by particle diameter, the majority of particles was below 2.5 ㎛. Conclusions: Persons who work in roastery cafes can be exposed to high concentrations of particulate matter. Therefore, personal exposure and risk assessment should be conducted for roastery cafe workers.

• 한국식품영양학회지
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• 제10권1호
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• pp.44-52
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• 1997

요석증은 비뇨기과에서 흔히 관찰되는 질환으로서 30∼50대에 많이 발생하고, 남자가 여자보다 발생빈도가 높고, 좌측보다는 우측이 많으며, 문화가 발달한 나라에서는 상부요로 결석이 많으나 후진국에서는 하부요로 결석이 많다. 결석성분은 수산칼슘, 인산칼슘, 인산마그네슘암모늄, 요산, 시스틴 결석과 그들의 혼합결석으로 분류된다. 병태 생리학에 따르면, 결석의 발생원인은 요중의 무기질 농도가 과포화 상태가 되면 결정체핵이 생성된다는 과포화/결정체설, 기질관여설, 억제물질의 결핍설, 에피택시설 등이 있고, 상피소체기능항진중, 과칼슘뇨증, 과요산뇨증, 과수산뇨증, 시스틴뇨증 외에도 원위세뇨관 산증, 과비타민 D증, 소화기계 질환이 통계적으로 유의성 있게 관여된다는 것이다. 본 연구에서는 미란성 위염 환자 K43에서 화학분석법, 적외선 흡수 분석법, image analysis법을 사용하여 재발성 상부요로 결석성분을 분석한 결과 제2 수산칼슘과 인산칼슘의 혼합결석으로 확인되었고, 혈액화학 검사와 요 검사 등 임상검사 성적은 정상치를 유지하고 있었다. 따라서 K43의 재발성 요로결석은 보고된 생성원인이나 인자들에 대한 통계수치와는 연관성이 없었으며 미란성 위염으로부터 영향을 받았다는 증거도 없었다.

• 한국가스학회지
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• 제21권6호
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• pp.81-87
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• 2017

SOFC(Solid Oxide Fuel Cell)는 고온 연료전지 중 하나이며, SOFC 시스템과 스택은 고온 운전 특성을 가지고 있다. 이러한 특성 때문에 시스템 설계 및 재료의 선택, 내구성 확보, 안전성능 확보에 많은 어려움을 가지고 있다. 따라서 SOFC 연료전지의 상용화와 보급을 위해서는 안전성능 평가기술과 평가시스템의 개발이 병행되어야 한다. 본 연구에서는 스택 안전성능 평가시스템의 제작을 위하여 국내 외 SOFC 관련규격 및 스택의 위험요소를 분석하였다. 분석한 자료를 바탕으로 스택 안전성능 평가 시스템의 제작을 위한 평가항목을 도출하였다. 본 연구 결과를 통해 SOFC 연료전지의 보급 활성화와 안전한 사용 환경에 기여할 수 있기를 기대한다.

• Advances in environmental research
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• 제1권1호
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• pp.15-35
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• 2012

Mercury (Hg) is a global environmental pollutant that has been the cause of many public concerns. One particular concern about Hg in aquatic systems is its trophic transfer and biomagnification in food chains. For example, the Hg concentration increases with the increase of food chain level. Fish at the top of food chain can accumulate high concentrations of Hg (especially the toxic form, methylmercury, MeHg), which is then transferred to humans through seafood consumption. Various biological and physiochemical conditions can significantly affect the bioaccumulation of Hg-including both its inorganic (Hg(II)) and organic (MeHg) forms-in fish. There have been numerous measurements of Hg concentrations in marine and freshwater fish worldwide. Many of these studies have attempted to identify the processes leading to variations of Hg concentrations in fish species from different habitats. The development of a biokinetic model over the past decade has helped improve our understanding of the mechanisms underlying the bioaccumulation processes of Hg in aquatic animals. In this review, I will discuss how the biokinetic modeling approach can be used to reveal the interesting biodynamics of Hg in fish, such as the trophic transfer and exposure route of Hg(II) and MeHg, as well as growth enrichment (the increases in Hg concentration with fish size) and biomass dilution (the decreases in Hg concentration with increasing phytoplankton biomass). I will also discuss the relevance of studying the subcellular fates of Hg to predict the Hg bioaccessibility and detoxification in fish. Future challenges will be to understand the inter- and intra-species differences in Hg accumulation and the management/mitigation of Hg pollution in both marine and freshwater fish based on our knowledge of Hg biodynamics.

• Earthquakes and Structures
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• 제8권4호
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• pp.859-887
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• 2015

Structural health monitoring (SHM) has gained in popularity in recent years since it can assess the performance and condition of instrumented structures in real time and provide valuable information to the asset's manager and owner. Operational modal analysis plays an important role in SHM and it involves the determination of natural frequencies, damping ratios and mode shapes of a constructed structure based on measured dynamic data. This paper presents the operational modal analysis and seismic response characterization of the Tsing Ma Suspension Bridge of 2,160 m long subjected to different earthquake events. Three kinds of events, i.e., short-distance, middle-distance and long-distance earthquakes are taken into account. A fast Bayesian modal identification method is used to carry out the operational modal analysis. The modal properties of the bridge are identified and compared by use of the field monitoring data acquired before and after the earthquake for each type of the events. Research emphasis is given on identifying the predominant modes of the seismic responses in the deck during short-distance, middle-distance and long-distance earthquakes, respectively, and characterizing the response pattern of various structural portions (deck, towers, main cables, etc.) under different types of earthquakes. Since the bridge is over 2,000 m long, the seismic wave would arrive at the tower/anchorage basements of the two side spans at different time instants. The behaviors of structural dynamic responses on the Tsing Yi side span and on the Ma Wan side span under each type of the earthquake events are compared. The results obtained from this study would be beneficial to the seismic design of future long-span bridges to be built around Hong Kong (e.g., the Hong Kong-Zhuhai-Macau Bridge).

• 한국구조물진단유지관리공학회 논문집
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• 제15권1호
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• pp.226-234
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• 2011

해양환경 하에서 염화물의 침투를 억제하여 부식 위험을 최소화함으로써 콘크리트 구조물의 공용기간을 연장할 수 있다. 효과적으로 구조물을 관리하기 위해 적절하게 유지관리하는 것이 필요하다. 본 연구에서는 효과적인 유지관리 전략을 세우기 위한 보수된 구조물의 유지관리비용 평가와 연계하여 구조물의 사용수명을 정량적으로 평가하는 방법을 제안하였다. Fick의 제2법칙으로부터 Crank-Nicolson법에 기초한 유한 차분법을 제안하여 보수되지 않은 콘크리트 구조물과 보수된 콘크리트 구조물의 염화물 이온 분포를 예측하였다. 이를 이용하여 보수에 의해 연장 가능한 사용수명과 목표한 공용기간 동안에 필요한 보수 횟수를 평가하였다. 게다가 보수 횟수와 콘크리트 교체 비용을 고려하여 총 유지관리 비용을 산출하였다. 마지막으로 제안된 방법의 적용성 검토를 위해 수치해석 예제를 제시하였다.

• Journal of Applied Biological Chemistry
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• 제59권2호
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• pp.125-128
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• 2016

The chemical compositions of the essential oil extracted from Albizziae julibrissin barks were analyzed by Gas chromatography-Mass spectrometry spectrometry. Fourteen components were identified, representing 89.23 % of the total oil composition. The analysis of the essential oil revealed that the essential oil contains 14 compounds, accounting for 89.23 % of the total oil. Hexanoic acid was the principal component (41.43 %) of the essential oil, followed by 4,4,6-trimethyl-cyclohex-2-en-1-ol (11.16 %), palmitic acid (9.00 %), 2-pentylfuran (5.66 %), 2-butyl-2-octenal (4.12 %), linoleic acid (3.10%), amyl hexanoate (3.01%), (E,E)-2,4-decadienal (2.49 %), 2-hexylthiophene (2.47 %), caprylic acid (2.13 %), ${\delta}-undecalactone$ (1.52 %), heptanoic acid (1.27 %), 3,5-octadien-2-ol (0.99 %), and 2-octenal (0.88 %). The acaricidal activity of the A. julibrissin oil was tested against Dermatophagoides farina, D. pteronyssinus and Tyrophagus putrescentiae by the fumigant bioassay. Based on the $LD_{50}$ values, the essential oil exhibited strong acaricidal activities against D. farinae ($LD_{50}$, $4.88{\mu}g/cm^3$), D. pteronyssinus ($2.44{\mu}g/cm^3$), and T. putrescentiae ($1.22{\mu}g/cm^3$). These results indicate that A. julibrissin oil could be a source of acaricidal agents for mite control.

• 시큐리티연구
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• 제43호
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• pp.7-35
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• 2015

지난 세월호 참사를 계기로 재난안전에 대한 컨트롤타워 역할을 수행할 국민안전처가 신설되어 재난관리체계에 대한 근본적인 변화가 시작되고 있다. 국민안전처의 신설은 규모와 권한 강화 측면에서 미국의 국토안보부 창설과도 비견될 정도로 강력한 대응으로 볼 수 있지만, 안정적인 정착을 위해서는 앞으로 해결해야 할 과제들이 많은 것으로 판단된다. 특히 지금까지의 논의가 기관 출범을 위한 하드웨어적인 측면에서 논의되어 상대적으로 소프트웨어의 측면에 대한 논의가 소홀한 측면이 있다. 본 연구는 국민안전처를 중심으로한 국가 재난관리 체계의 혁신과정에 재난관리의 주요 원칙 중 하나인 모든 위험 접근법(All-hazard approach)을 적용하여 발생 가능한 모든 위험에 대해 분석과 평가를 통해 우선 순위를 정하고, 이를 기준으로 위험에 대비하는 체계를 마련할 필요가 있다는 것을 제안하며, 특히 우리나라의 환경적 특성을 감안한 효과적인 대안이 마련되어야 한다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1999년도 정기총회 및 춘계 공동 학술발표회
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• pp.149-156
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• 1999

In the United States (U.S.), the monitored natural attenuation (MNA) approach has been used as an alternative remedial option for organic and inorganic compounds retained in soil and dissolved in groundwater. The U.S. Environmental Protection Agency (EPA) defines the MNA as“in-situ naturally-occurring processes include biodegradation, diffusion, dilution, sorption, volatilization, and/or chemical and biochemical stabilization of contaminants and reduce contaminant toxicity, mobility or volume to the levels that are protective of human health and the environment”. The Department of Soil Environment. National Institute Environmental Research (NIER) is in the process for demonstrating the MNA approach as a potential remedial option for the BTEX contaminated site in Uiwang City. The project is charactering the research site in terms of the nature and extend of contamination, biological degradation rate, and geochemical and hydrological properties. The microbial-degradation rate and effectiveness of nutrient and redox supplements will be determined through laboratory batch and column tests. The geochemical process will be monitored for determining the concentration changes of chemical species involved in the electron transfer processes that include methanogenesis, sulfate and iron reduction, denitrification, and aerobic respiration. Through field works, critical soil and hydrogeologic parameters will be acquired to simulate the effects of dispersion, advection, sorption, and biodegradation on the fate and transport of the dissolved-phase BTEX plume using Bioplume III model. The objectives of this multi-years research project are (1) to evaluate the MNA approach using the BTEX contaminated site in Uiwang City, (2) to establish a standard protocol for future application of the approach, (3) to investigate applicability of the passive approach as a secondary treatment remedy after active treatments. In this presentation, the overall picture and philosophy behind the MNA approach will be reviewed. Detailed discussions of the site characterization/monitoring plans and risk-based decision-making processes for the demonstration site will be included.

• Journal of Plant Biotechnology
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• 제37권4호
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• pp.394-399
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• 2010

국내의 GM식물개발과 관련된 R&D사업 중 대표적이라고 할 수 있는 "바이오그린21사업"과 작물유전체기능연구사업단에서 지난 2007년부터 2009년 말 현재까지의 사업성과 중 논문과 동록 된 특허를 분석하여 본 결과 두개의 사업단을 통하여 총 1,212건의 SCI논문과 451건의 비 SCI논문, 그리고 348건의 특허를 등록한 것으로 조사되었다. 이중에서 바이오그린21사업단에서는 6.0%의 SCI 논문, 10.2%의 비SCI논문, 12.6%의 등록된 특허가 그리고 작물유전체기능연사업단의 경우에는 15.7%의 SCI논문, 21.1%의 비SCI 논문, 81.6%의 등록된 특허가 GM식물의 개발과 직접적으로 관련된 것으로 조사되었다. 개발하고자 하는 GM식물의 농업적 특성은 생물학적 스트레스 또는 무생물적 스트레스에 저항성을 갖는 작물 특히 벼와 고추가 가장 많았으나 포장시험까지 진행된 연구 성과는 아직 극히 저조한 것으로 밝혀졌다. 이러한 조사 결과는 국내에서 현재 실험실 또는 온실 단계에서 검정된 초기 단계의 GM식물의 조기상용화를 위하여 보다 많은 연구비가 투자되어야 할 것을 시사하였다.