• 한국환경보건학회지
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• 제43권6호
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• pp.478-490
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• 2017

Objectives: The association of air pollution levels and land-use types with changes in the prevalence of allergic diseases (allergic conjunctivitis, allergic rhinitis, asthma, and atopic dermatitis) was investigated for seven metropolitan cities in Korea Methods: Data on daily hospital visits and admissions (of those under 19 years old) for 2003-2012 were obtained from the National Health Insurance Cooperation. Meteorological data on daily mean temperature, humidity, and air pressure were obtained from the Korea Meteorological Administration. Daily mean or maximum concentration data for five pollutants ($PM_{10}$, $O_3$, $NO_2$, $SO_2$, and CO) as measured at air quality monitoring sites operated by the Ministry of Environment were used. We estimated excess risk and 95% confidence intervals for the increasing interquatile range (IQR) of each air pollutant using Generalized Additive Models (GAM) appropriate for time series analysis. Results: In this study, we observed a significant association between the IQR increases of air pollutants and the prevalence risk of allergic diseases (allergic conjunctivitis, allergic rhinitis, asthma, and atopic dermatitis) in all metropolitan cities after adjusting for temperature, humidity, and air pressure at sea level. Among the air pollutants, $NO_2$ and $PM_{10}$ were associated with the prevalence of asthma, and $O_3$ was associated with only allergic conjunctivitis in regression analysis. However, in GAM analysis considering land-use, $O_3$ and $SO_2$ were associated with allergic conjunctivitis, PM10, O3, NO2, and CO were associated with allergic rhinitis, and $PM_{10}$, $O_3$ and $NO_2$ were associated with asthma in industrial area. Conclusion: This study found a significant association between air pollution and the prevalence of allergic related diseases in industrial areas. More detailed research considering mixed traffic-related air pollution (TRAP) and conducting meta-analyses combining data of the all cities is required.

• 센서학회지
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• 제8권5호
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• pp.388-393
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• 1999

회토류 원소인 Eu로 활성화한 $CaSO_4:Eu$ TLD를 제작하였으며, 트랩 매개변수 등의 물리적 특성을 조사하였다. 제작한 $CaSO_4:Eu$ TLD는 활성제 Eu의 농도를 0.5 moi%로 하고, $600^{\circ}C$에서 2시간 동안 열처리하였을 때 최대의 열형광 강도를 나타내었으며, glow 곡선은 2개의 glow peak로 구성되었다. 두 glow peak를 분리하여 초기 상승법, peak 형상법, 가온율법, 최소자승법에 의한 glow 곡선의 fitting 방법 등을 사용하여 glow 곡선을 분석하였다. 두 glow peak의 활성화에너지는 각각 1.00 eV, 1.09 eV이고, 진동수인자는 각각 $7.04{\times}10^{11}\;s^{-1}$과 $5.12{\times}10^{11}\;s^{-1}$였으며, 1.11과, 1.33의 발광차수를 갖는 것으로 평가되었다.

• 한국식물병리학회지
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• 제11권3호
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• pp.230-237
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• 1995

Airborne and waterborne ascospores and conidia of Botryosphaeria dothidea were collected in apple orchards at Suwon and Chunan in 1992 through 1994. Both waterborne and airborne spores were first detected in mid April to early May. Thereafter, spores were abundant in early June to late August and present until early December. Rainwater collections contained much more conidia than ascospores during the apple growing seasons. Airborne ascospores catches, which were also detected on humid days without measurable rainfall, were much more than airborne conidia catches. High amounts of ascospores were detected in early times of apple growing season, whereas most conidia catches occurred in later times of the season. The number of waterborne conidia and airborne ascospores was positively correlated with mean daily maximum, minimum, and average air temperatures during the trapping periods (p=0.01). However, no significant correlation was found between the number of spores and the total precipitation during the trapping periods.

• 동력기계공학회지
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• 제17권1호
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• pp.19-26
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• 2013

The purpose of the study is carried out volume optimization of a combined system consisting of an LNT and SCR catalysts from the standpoint of its economic feasibility and de-NOx performance. Under the rich air-fuel ratio conditions for 5s (${\Phi}$=1.1), CO, $H_2$ and THC were generated at levels of 4%, 1.2% and $110ppmC_1$, respectively. The NOx conversion of the 1+1 combination was 5% lower than that of the 1.5+0.5 combination, however the reduced volume of the LNT catalyst decreased the total cost by about 6%. Therefore, the optimal volume ratio of the LNT and SCR catalysts was found to be the 1+1 catalyst combination, which has the highest total score in the terms of an economic feasibility and the NOx performance.

• Journal of Ecology and Environment
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• 제31권1호
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• pp.83-87
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• 2008

The small-scale dynamic of moth populations in spring was examined in a coniferous forest of southwestern Korea. Moths were collected with one 22-watt light trap for 29 days in April 2007. A total of 450 individuals of 38 species in 5 families were collected. The most abundant species was an epiplemid moth, Epiplema plagifera. The relationship between these dominant moths and their host plants is briefly discussed. We also examined influence of weather factors on the number of species and individuals collected. Multiple regression analyses showed that the two-day temperature difference explained 18% of the variance in the number of species collected, while air and ground temperatures explained 51% of the variance in the log-transformed number of individuals collected. This suggests that temperature affects local population sizes in spring, but variables other than weather may also affect the diversity of local moth populations.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.271-276
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• 2008

The oil trap in oil separator is one of the most important characteristics for normal operation of compressor. In this study, oil separation characteristics has been investigated for $CO_2$/PAG mixture using a gravity type of oil separator. The experimental study has been carried out in the range of oil concentration 0 to 5 weight-percent and the mixture temperature range of $0^{\circ}C$ to $15^{\circ}C$. The results obtained indicate that oil separation ratio in oil separator is increased with an increase in the oil concentration and mixture temperature.

• 대한수의학회지
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• 제54권1호
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• pp.59-62
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• 2014

A 12-year-old, castrated male Yorkshire terrier dog presented with frequent regurgitations that had begun 45 days earlier and become more progressive. Radiographs revealed an air-trap region behind the cranial esophageal sphincter muscle in the esophagus and esophagographies with barium contrast showed mild esophageal dilation with decreased motility. Esophageal motility increased within 5 min of neostigmine methylsulfate administration and acetylcholine receptor antibodies titer increased to beyond the normal range. Based on these findings, acquired myasthenia gravis with focal form was diagnosed, making this the first such case diagnosed by an acetylcholine receptor antibody test in Korea.

• 한국산학기술학회논문지
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• 제9권6호
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• pp.1494-1499
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• 2008

플라스틱은 양호한 내구성과 더불어 가벼우면서 장시간 경과하여도 변질이 없는 특성으로 인하여 자동차 내장 부품의 가장 주요한 소재로 활용되어지고 있다. Moldflow를 이용한 자동차 기어박스커버의 플라스틱 사출공정 시뮬레이션을 통해 충전시간, 웰드라인, 에어트랩 등 사출성형 공정에 대한 사전분석을 제시하였다.

• 한국가시화정보학회지
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• 제21권3호
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• pp.65-74
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• 2023

Compared to epifluorescence(EPI) microscopy which captures fluorescence from the entire depth of sample, total internal reflection fluorescence(TIRF) can selectively visualize only a single surface of it. TIRF uses a thin evanescent field generated by the total internal reflection of laser light on surface. However, conventional TIRF system are designed for total internal reflection to occur at the upper surface of sample, making them unsuitable for sessile droplet imaging. We designed a TIRF system suitable for a sessile droplet imaging by utilizing slide glass as a lightguide. We presented the details for constructing the TIRF system using a prism, slide glass, air slit, and optical trap. Then, we compared the TIRF with EPI by imaging the droplet with fluorescent particles during its drying process. As a result, TIRF allows us to distinctly visualize the drying pattern on the bottom surface of droplet.

• 자원환경지질
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• 제40권1호
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• pp.129-140
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• 2007

대기와 물에서의 CFCs(CFC-12, CFC-11, CFC-113)를 분석할 수 있는 시스템을 자체 제작된 퍼지-트랩 추출 장치와 전자포획검출기가 설치된 가스 크로마토그래피를 이용하여 구축하였다. 대기와 물에 대한 시료 채취방법도 확립되었다. 분석 시스템은 실험적으로 최적화되어 최근 대기 시료는 2% 이내, 제주도의 지하수 시료 (CFC-12 농도가 $160{\sim}180pg/kg$)는 5% 이내의 삼중복시료에 대한 재현성을 보였고, 미국지질조사소(USGS)의 분석시스템과 교차 분석을 실시하였으며, 10% 오차 범위내에서 일치하였다. 한반도 중부 지역의 세 지점에 대해 19개월에 걸쳐 대기 중의 CFCs를 관측하여 이 지역에서 국지적인 CFCs 근원이 크지 않음을 확인하였다. 제주도의 한 농업용 공공 관정에서 2개월 간격으로 1년 동안 지하수의 CFCs를 관측한 결과 8월까지 지하수의 CFCs 농도가 감소하고 10월 이후에 다시 증가하는 계절적인 변동을 보여 주었다. 이것은 여름철 우기에 발생한 지하수 함양이 수 개월 지연되어 나타난 결과로 볼 수 있으며, 제주도 현무암 대수층의 높은 투수성을 지시한다.