• 대한지하수환경학회지
• /
• 제7권1호
• /
• pp.55-58
• /
• 2000

휘발유의 첨가제인 Methyl Tertiary-Butyl Ether (MTBE)는 1970년대 이후 옥탄 향상제로 쓰이기 시작했다. 이후 자동차 연료 연소를 도와 도시 대기에 일산화탄소(CO)와 오존(O$_3$)을 줄인다는 이유로 1990년대에 그 사용이 급속도로 증가했다. 그러나 이 물질은 지하저장탱크 등으로부터 누출(leakage)로 인해 지하수를 오염시킴으로서 문제의 물질로 대두되기 시작했다. 이런 MTBE에 대해 국외에서는 그 유해성 즉, 발암가능성 및 돌연변이 유도성 연구가 많이 진행되었으며, 어느 정도 인간에 대한 유해성이 밝혀졌다. 이 물질로 오염된 실제 현장에서의 실험, 실내 실험 등에 의해서 분해 및 오염 저감 가능성, 특히 생분해(biodegradation)에 대해 연구가 활발히 이루어지고 있고 여러 가지 오염 저감 기술도 연구되고 있다. 그리고 오염원으로서 대기의 영향에 대한 연구, 미국 National Ground Water Association (NGWA), the United States Geological Survey (USGS), the United States Environmental Protection Agency (USEPA)의 최근 활동 등 다각도에서 이 물질이 지하수나 음용수에 미치는 영향이 연구되고 있다. 실제 국내에서도 이 MTBE에 의한 지하수 오염 가능성을 배제할 수 없고, 우리 생활 가까이에 다가와 있는 문제일 수 있다. 이런 문제임에도 불구하고, 국내에서는 이 오염물질에 대한 규제와 연구가 미흡한 형편이다. 그 자체로는 청정제로 사용되지만 이제는 오염물질로서 우리가 사용하는 지하수에서 검출될 수 있는 MTBE에 대한 전반적인 이해가 필요하고 그 위해성에 대한 국내 지하수 환경 연구자들의 더 많은 노력이 요구된다. 일치하지 않았다.발전의 평가체계의 구성요소와 어업에 대한 지속적 평가체계[sustainable development reference system(SDRS)]를 수립하는데 있어서 필요한 관련 절차에 관해 특별한 의미를 부여해 줄 것으로 생각한다. 마지막으로 본 논문에서 는 SDRS가 지역어업 협력체계 구축에 있어 서 어떠한 역할을 할 것인가를 강조함으로써 결론을 내리고 있다.을 시사한다.1}$의 농도로 첨가하여 5$^{\circ}C$, 15$^{\circ}C$, $25^{\circ}C$ 및 35$^{\circ}C$에서 배양한 후 미생물의 생균수를 측정한 결과 배양온도가 5$^{\circ}C$일 때는 어떤 종류의 미생물도 전혀 분리되지 않았으며, 15$^{\circ}C$, $25^{\circ}C$ 및 35$^{\circ}C$에서 배양한 경우는 모두 1gl$^{-1}$의 먹이 농도에서 가장 현저한 균체수의 증가를 보였다.여 Cash Power을 교수에게 주고 심사선정에 있어서도 실명제로 하여 심사선정하는 교수에게도 인센티브를 주거나 페널티를 물도록 하며, 대여 받은 교수는 성공실패에 관계없이 계약된 기간이 지나면 연구비를 갚는 제도이다. 성공시에는 연구자와 회사가 인센티브를 제일 많이 받게 된다. 이리하여 이 제도는 잘 수행되면 학교, 연구자, 회사, 심사선정자 모두에게 혜택을 주는 Win Win 연구비 관리제도이다. 또한 심사, 선정, 평가도 책임 있고 공정하게 유지될 수 있다. 대여 연구비 관리제도의 절차를 요약한 것이 Figure 1과 같다. 이런 점들을 볼 때 대여형 연구비관리 제도는 비즈니스형 연구비

• Asian Journal of Atmospheric Environment
• /
• 제12권3호
• /
• pp.232-243
• /
• 2018

The construction, development and maintenance of an economically, environmentally and socially sustainable campus involves the integration of measuring tools and technical information that invites and encourages the community to know the actual state to generate positive actions for reducing the negative impacts over the local environment. At the Universidad Nacional de Colombia - Campus $Bogot{\acute{a}}$, a public area with daily traffic of more than 25000 people, the Environmental Management Bureau has committed with the monitoring of the noise pollution and air quality, as support to the campaigns aiming to reduce the pollutant emissions associated to the student's activities and campus operation. The target of this study is based in the implementation of mobile air quality and sonometry monitoring equipment, the mapping of the actual air quality and noise pollution inside the university campus as a novel methodology for a sub-area inside a megacity. This results and mapping are proposed as planning tool for the institution administrative sections. A mobile Kunak$^{(R)}$ Air & OPC air monitoring station with the capability to measure particulate matter $PM_{10}$, $PM_{2.5}$, Ozone ($O_3$), Sulfur Oxide ($SO_2$), Carbon Monoxide (CO) and Nitrogen Oxide ($NO_2$) as well as Temperature, Relative Humidity and Latitude and Longitude coordinates for the data georeferenciation; and a sonometer Cirrus$^{(R)}$ 162B Class 2 were used to perform the measurements. The measurements took place in conditions of academic activity and without it, with the aim of identify the impacts generated by the campus operation. Using the free code geographical information software QGIS$^{(R)}$ 2.18, the maps of each variable measured were developed, and the impacts generated by the operation of the campus were identified qualitative and quantitively. For the measured variables, an increase of around 21% for the $L_{Aeq}$ noise level and around 80% to 90% for air pollution were detected during the operation period.

• 한국철도학회논문집
• /
• 제12권1호
• /
• pp.9-15
• /
• 2009

본 연구는 축소실험을 통하여 터널내 화재발생시 구난역 내 설계된 환기 시스템 성능을 검증 하였다. Froude 수 상사법칙을 적용하여 실제 터널 크기의 1/35로 축소된 모형터널을 사용하였다. 모형터널은 두께가 2mm인 철을 사용하여 총 길이 10m, 높이 0.19m, 폭 0.26m으로 제작되었다. Cross-passage는 사고터널과 구난 터널 사이에 연결되고 Cross-passage 중앙에는 방화문이 설치되어 있다. 실험에는 n-heptane, $4cm{\times}4cm$ 풀화재를 이용하였다. 화원의 발열량은 695.97W이고, 화원 위치는 터널 중앙과 가장 위험한 경우로써 터널 입구지점에 각각 설치하였다. 환기조건은 0.015cms이고 화원과 가장 인접한 곳에서만 배기하도록 하였다. 구난역 배기 성능을 검증하기 위해 온도와 CO농도를 측정하여 연기의 유무를 파악하였다. 본 실험의 결과는 다음과 같다. 첫째, 터널 중앙화원인 경우 환기가 없어도 구난 터널에 연기가 검출되지 않았다. 둘째, 구난역 입구 부근에 화원을 설치한 경우 환기 조건을 주지 않으면 연기가 구난 터널로 침투하지만, 설계된 배기 조건시 연기는 구난터널로 전파하지 않았다.

• 한국환경보건학회지
• /
• 제32권4호
• /
• pp.304-315
• /
• 2006

This study is performed to reexamine the association between ambient air pollution and daily mortality in seven major cities of Korea using a method of meta-analysis with the data filed for the period 1998-2001. These cities account for half of the Korean population (about 23 million). The observed concentrations of carbon monoxide (CO, mean=1.08 ppm), ozone ($O_3$, mean=33.97 ppb), particulate matter less than 10 ${\mu}m$ ($PM_{10},\;mean=57.11\;{\mu}g/m^3$), nitrogen dioxide ($NO_2$, mean=25.09 ppb), and sulfur dioxide ($SO_2$, mean=9.14 ppb) during the study period were at levels below Korea's current ambient air quality standards. Generalized additive models were applied to allow for the highly flexible fitting of seasonal and long-term time trends in air pollution as well as nonlinear associations with weather variables, such as air temperature and relative humidity. Also, we calculated a weighted mean as a meta-analysis summary of the estimates and its standard error. In city-specific analyses, an increase of $41.17{\mu}g/m^3(IQR)\;of\;PM_{10}$ corresponded to $1{\sim}12%$ more deaths, given constant weather conditions. Like most of air pollution epidemiologic studies, this meta-analysis cannot avoid fleeing from measurement misclassification since no personal measurement was taken. However, we can expect that a measurement bias be reduced in district-specific estimate since a monitoring station is better representative of air quality of the matched district. Significant heterogeneity was found for the effect of all pollutants. The estimated relative risks from meta-like analysis increased compared to those relative risks from pooled analysis. The similar results to those from the previous studies indicated existence of health effect of air pollution at current levels in many industrialized countries, including Korea.

• 한국환경보건학회지
• /
• 제8권1호
• /
• pp.67-80
• /
• 1982

In order to evaluate the psychosomatic health status of metal manufacturing industries workers and their working environments, the present study was conducted from March 1, 1981 to the end of September 1981. The data was obtained from the samples of metal manufacturing industries in Kyung-In Area and their 1, 162 employees. In addition, the 803 urban residents including students, office clerks, and general publics were sampled as control groups to compare with factory employees in psychosomatic analysis. The basic tool employed in the present study was the Todai Health Index (THI) which modified CMI and was developed by Tokyo University Research Team of Japan. The results of the present study were summarized as follows: 1. Working environments of the factories 1) The data shows that fabrication shop produced the highest noise level ranging from 91 to 96 dB (A) and iron and steel shop had the lowest noise level ranging from 81 to 86 dB (A). 2) Dust concentration was the highest in iron foundry shop ($3.8 mg/m^3$) and the lowest in fabrication shop ($1.2 mg/m^3$). 3) WBGT above threshold limit values (T.L.V.) was noted in steel shop (38$\circ$C) and iron foundry shop (34$\circ$C) 4) The concentration of Sulfur dioxide ($SO_2$)was 30.5ppm at steel shop and 12.0ppm at iron foundry shop. 5) The concentration of carbon monoxide (CO) was 140.0ppm at steel shop and 110.5ppm at iron foundry shop. 6) The atmospheric lead concentration was $0.49 mg/m^3$ at soldering shop. 2. The responses of psychosomatic complaints were much higher in steel shops group than in other manu-facturing group, except the response of aggressiveness. 3. The responses of psychosomatic complaints were much higher in industrial workers than in urban residents, except the responses of depression and aggressiveness (p < 0.01 ). 4. The psychosomatic symptoms which industrial workers and urban residents complained frequently were nervousness. agressiveness and lie scale in order. 5. The responses of psychosomatic complaints by sex were much higher in female group than in male group, except the response of aggressiveness. 6. The responses of psychosomatic complaints by age were that both the female and male group showed an increasing tendency in the all items, except the response of depression as age was increasing. 7. The responses of psychosomatic complaints by the length of services were that both the female and male group showed a tendency of increasing in physical symptoms as work years increased. 8. The responses of psychosomatic complaints were higher in unmarried group in the score of nervousness, aggressiveness, mental irritability and irregular life.

• 한국환경보건학회지
• /
• 제3권1호
• /
• pp.27-44
• /
• 1976

This study was carried out to evaluate the harmful factors in working environments and to investigate the labor productivity after improvement of environments, surveying 93 industrial establishments of 10 industries located in Youngdeungpo industrial area in Seoul. The results obtained were as follows: 1) The highest noise level of 125dB(A) was indicated at the rolling process of transport equipment manufacturing industry. 2) The best illumination level was shown in precise machinery industry and the worst was indicated in rubber products, metallic products and transport equipment manufacturing industries. 3) Thermal conditions were above threshold limit value (TLV) at more than two processes of all industries except printing industry. 4) The highest dust concentration was determined in textile and wearing manufacturing industry. 5) Organic solvents were detected at 52 processes in 93 industrial establishments and 33 processes of them showed higher than TLV. The results about harmful chemicals were as follows: a) sulfur dioxide ($SO_2$)was determined higher than TLV on welding process of metallic product manufacturing industry and heat treatment process of transport equipment manufacturing industry. b) Carbon monoxide (CO) concentration was 700ppm at heat treatment process of transport equipment manufacturing industry, indicating 14 times of TLV. c) vinylchloride concentration in the air of PVC raw material mixing process and PVC preparation process of chemical product manufacturing industry was determined higher than TLV. d) Hydrochloride (HCl) concentration in the air of wire expanding process of transport equipment manufacturing industry was determined higher than TLV. 7) Higher values of lead concentration than TLV were determined at lead welding metallic product manufacturing industry and type planting process of process of printing industry, $1.8mg/m^3$ and $0.3mg/m^3$ respectively. 9) 22, 968 of 52, 855 workers (i.e. 43.5%) in 93 industries were exposed to various harmful agents. 10) It was found that the improvement of illumination in electric apparatus manufacturing industry (from 20~40 lux to 420 lux) resulted in an increase in productivity of 6.5% per capita and a decrease in faulty products of 19%. 11) Improvement of environments using local exhaust ventilation system resulted in a decrease of harmful substances lower than TLV and an increase in productivity of 11.4%. 12) Improvement of shovelling tools based on ergonomics resulted in a reduction in energy expenditure of 25.3% and an increase in productivity of 32.2% per capita.

• Bulletin of the Korean Chemical Society
• /
• 제14권4호
• /
• pp.439-444
• /
• 1993

The aerobic oxidation of the Fe(II) complex of 1,4,8,11-tetraazacyclotetradecane, [Fe(cyclam)$(CH_3CN)_2](ClO_4)_2$, in MeCN in the presence of a few drops of $HClO_4$ leads to low spin Fe(III) species [Fe(cyclam)$(CH_3CN)_2](ClO_4)_3$. The Fe(III) cyclam complex is further oxidized in the air in the presence of a trace of water to produce the deep green binuclear bismacrocyclic Fe(II) complex $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$. The Fe(II) ions of the complex are six-coordinated and the bismacrocyclic ligand is extensively unsaturated. $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$ crystallizes in the monoclinic space group $P2_1/n$ with a= 13.099 (1) ${\AA}$, b= 10.930 (1) ${\AA}$, c= 17.859 (1) ${\AA}$, ${\beta}$= 95.315 $(7)^{\circ}$, and Z= 2. The structure was solved by heavy atom methods and refined anisotropically to R values of R= 0.0633 and $R_w$= 0.0702 for 1819 observed reflections with F > $4{\sigma}$ (F) measured with Mo K${\alpha}$ radiation on a CAD-4 diffractometer. The two macrocyclic units are coupled through the bridgehead carbons of ${\beta}$-diimitie moieties by a double bond. The double bonds in each macrocycle unit are localized. The average bond distances of $Fe(II)-N_{imine}$, $Fe(II)-N_{amine}$, and $Fe(II)-N_{MeCN}$ are 1.890 (5), 2.001 (5), and 1.925 (6) ${\AA}$, respectively. The complex is diamagnetic, containing two low spin Fe(II) ions in the molecule. The complex shows extremely intense charge transfer band in the near infrared at 868 nm with ${\varepsilon}$= 25,000 $M^{-1}cm^{-1}$. The complex shows a one-electron oxidation wave at +0.83 volts and two one-electron reduction waves at -0.43 and-0.72 volts vs. Ag/AgCl reference electrode. The complex reacts with carbon monoxide in $MeNO_2$ to form carbonyl adducts, whose $v_{CO}$ value (2010 $cm^{-1}$) indicates the ${\pi}$-accepting property of the present bismacrocyclic ligand.

• 한국건축시공학회지
• /
• 제19권4호
• /
• pp.289-297
• /
• 2019

현재 건축물에 사용되는 접착제는 주로 유기질 재료인 에폭시 수지 접착제가 사용되고 있다. 유기질 재료인 에폭시 수지 접착제는 유기성 물질로 접착제 생산 시 유해물질이 발생하며, 시공 후에도 유해물질이 실내거주공간에서 높게 나타난다. 또한 건축물 화재 시 유기 재료에서 발생되는 다량의 일산화탄소가 인명피해로 이어진다. 본 연구는 순수무기계 재료인 산화마그네시아, 인산염, 붕사를 사용한 무기 접착재에 대해 기존 유기 접착제를 대체 할 무기 접착재로의 활용가능성을 평가한 연구이다. 적정 인산염 선정에 관한 실험과 지연제로서 활용한 붕사의 첨가율에 대한 특성을 실험한 결과 적정 인산염으로 제1인산칼륨이 도출되었으며, 붕사 첨가율에 따른 특성을 측정한 결과 KS F 4923의 품질기준과 비교하여 경화수축률과 가열변화율은 품질기준을 만족하였으며, 인장강도는 붕사 첨가율 4% 이상에서 만족하는 결과가 나왔지만 접착강도의 경우 품질 기준을 충족하지 못하였다. 향후 접착강도 증진을 위한 추가적인 연구가 필요할 것으로 판단된다.

• 한국건설안전학회 논문집
• /
• 제3권1호
• /
• pp.1-8
• /
• 2020

농어촌 민박 이용객의 증가와 정부의 관련 정책에 대한 다양한 지원이 이루어지고 있다. 그러나 농어촌 민박의 숙박 서비스에 대한 안전기준이나 안전지표가 부족하여 2018년 12월 강릉 펜션 일산화탄소 누출사고, 2020년 1월 동해 펜션 가스폭발사고 등 대형사고가 발생하고 있으며 국민의 안전을 위협하고 있다. 숙박업소와 달리 농어촌 민박의 경우 소화기와 화재경보기 등의 일정 요건을 갖추면 영업이 가능하도록 되어있다. 농림축산식품부는 농어촌 민박 제도개선 대책으로 농어촌정비법 개정을 통해 가스와 전기안전 전문가가 안전점검을 하고 그 확인서를 제출하는 제도를 도입하고 있다. 본 연구의 목적은 농어촌 민박의 숙박시설에 대한 안전기준과 안전지표를 제시하여 농어촌 민박과 관련한 지방자치단체와 정부의 운영관리와 점검에 필요한 기준을 제시하는 데 있다. 숙박시설의 안전관리는 국민의 가장 기본적인 안전과 직결된다. 따라서 농어촌 민박에 대한 적절한 안전기준을 제시하고 신고필증을 배부할 필요가 있으며 지속적인 수시점검과 안전교육 및 소방, 질식사고 등에 대한 사전예방을 위한 대책을 세울 필요가 있다. 본 연구를 통해 농어촌 민박의 안전관리 실태에 대한 조사와 분석 결과를 바탕으로 안전관리 기준 및 안전지표, 수시점검 방법, 사고예방 교육을 제공하고 제도화 할 필요성이 있는 것으로 나타났다. 농어촌 민박의 숙박이용 국민에 대한 안전확보를 위해 반드시 안전관리 기준과 교육을 제도화하는 것이 시급한 것으로 보인다.

• Korean Journal of Radiology
• /
• 제22권10호
• /
• pp.1719-1729
• /
• 2021

Objective: Emphysema and small-airway disease are the two major components of chronic obstructive pulmonary disease (COPD). We propose a novel method of quantitative computed tomography (CT) emphysema air-trapping composite (EAtC) mapping to assess each COPD component. We analyzed the potential use of this method for assessing lung function in patients with COPD. Materials and Methods: A total of 584 patients with COPD underwent inspiration and expiration CTs. Using pairwise analysis of inspiration and expiration CTs with non-rigid registration, EAtC mapping classified lung parenchyma into three areas: Normal, functional air trapping (fAT), and emphysema (Emph). We defined fAT as the area with a density change of less than 60 Hounsfield units (HU) between inspiration and expiration CTs among areas with a density less than -856 HU on inspiration CT. The volume fraction of each area was compared with clinical parameters and pulmonary function tests (PFTs). The results were compared with those of parametric response mapping (PRM) analysis. Results: The relative volumes of the EAtC classes differed according to the Global Initiative for Chronic Obstructive Lung Disease stages (p < 0.001). Each class showed moderate correlations with forced expiratory volume in 1 second (FEV₁) and FEV₁/forced vital capacity (FVC) (r = -0.659-0.674, p < 0.001). Both fAT and Emph were significant predictors of FEV₁ and FEV₁/FVC (R² = 0.352 and 0.488, respectively; p < 0.001). fAT was a significant predictor of mean forced expiratory flow between 25% and 75% and residual volume/total vital capacity (R² = 0.264 and 0.233, respectively; p < 0.001), while Emph and age were significant predictors of carbon monoxide diffusing capacity (R² = 0.303; p < 0.001). fAT showed better correlations with PFTs than with small-airway disease on PRM. Conclusion: The proposed quantitative CT EAtC mapping provides comprehensive lung functional information on each disease component of COPD, which may serve as an imaging biomarker of lung function.