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        검색결과 2,417

        841.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we attempt to analyze for 4 compounds (MEK, MIBK, n-Butyl acetate, i-Butyl alcohol) in ambient air using on-line thermal desorber (on-line TD) with gas chromatograph/flame ionization detector (GC/FID). These compounds will be regulated by KMOE (Korean ministry of environment) within 2010. We tested two different experimentation. First, we try to find the influence of Nafion dryer for the 4 compounds. Second, we want to know basic analytical characteristic of target compounds through the linearity, reproducibility, and minimum detection limit. According to this study, target compounds are removed in Nafion dryer more than 80 percent, respectively. So, we progressed next experimentation progressed without Nafion dryer using hydrophobic cold trap. Results for each compounds showed good linearity (r²=0.99 upper) and good precision (RSD=1 % below). In additional, we analyzed the ozone precusors standard gas (56 compounds) using the same method to see if there are any peaks to be overlapped in ambient air. These results showed that there is no peak overlapped. This means that analytical system of this study could be used on-line analytical system. Minimum detection limit (MDL) value for this system are less than minimum malodor threshold concentration.
        4,000원
        844.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        터널 내 축적된 다양한 오염원들은 간헐적으로 수행되는 세척과정 중에 폐수로 배출되게 되며, 서울 시내 3개 터널 지점에서 수행된 수질분석결과 SS, CODCr, T-N, NH3-N, NO3-N, Zn, Cu, Cr(+6). Mn, Mg, Phenol. CN-, E-Coli 등이 고농도 형태로 배출되는 것으로 나타났다. 한편, 이러한 오염수질의 배출농도 특성은 터널 세척 폐수의 채취 방법, 세척횟수, 세척수량, 터널내벽 특성, 통행량, 배수 특성 등에 따라 다양한 농도범위를 보여주는 것으로 나타났다. 한편, 수집된 터널 세척폐수를 단순 중력침전을 이용하여 저감실험을 수행한 결과, CODCr는 80%, T-N, T-P는 각각 30, 90% 제거됨을 확인하였고, 중력침전 분리를 통하여 제거되지 않은 잔여 오염물질에 대하여 GAC 소재를 통한 흡착실험(터널 세척폐수 1l에 대하여 GAC를 50g을 투입) 결과, CODCr, T-N, Zn, Cu, Mn, Phenol, CN 항목에서 80% 이상 제거됨을 확인하였다.
        4,000원
        846.
        2007.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        먹는 물 내에 존재하는 발암원인으로 의심되는 유기화학물질을 재래식 정수처리방법으로 제거한다는 것은 불가능하다. 이들을 AOP산화 & M/F membrane 혼성공정법을 이용하여 목적하는 처리수로 처리하고자 지하수를 반응조에 유효용량으로 유입하고 유기화학물질을 인위적으로 투입 혼합하여 충분히 희석시키고 이것을 효율적으로 처리하기 위해 최적운전조건을 도출하였다. 유기 화학물질 중 VOCs는 페놀과 톨루엔을 그리고 농약은 파라치온, 다이아지논과 카바닐을 대상으로 조사하였다. 실험은 각각 분류별 단일용액과 혼합용액으로 수행하였으며, 실험결과 충분한 분해 및 제거를 위한 운전조건은 H2O2는 150 mL로 정량 주입하고, pH는 5.5~6.0, 온도는 12~16℃로 일정하게 유지하고, 용존오존량은 5.0 mg/L이상, 반응시간은 30~40분이 최적 조건이었으며 그리고 같은 반응기 내 분리막의 사용은 0.45 μm 공경크기의 M/F membrane을 이용하여 대량의 음용수를 얻기 위한 결정이었다.
        4,500원
        848.
        2007.06 구독 인증기관 무료, 개인회원 유료
        3,000원
        849.
        2007.06 구독 인증기관 무료, 개인회원 유료
        4,000원
        850.
        2007.04 구독 인증기관 무료, 개인회원 유료
        This paper presents contents of certificates, and use for reference materials. This study also introduces general requirements for the competence of reference material producers. Lastly this paper shows general and statistical principles for certification of reference materials.
        4,200원
        851.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A new blue phosphorescent material for organic light emitting diodes (OLEDs), Iridium(III)bis[2-(4-fIuoro-3-benzonitrile)-pyridinato-N,C2'] picolinate (Firpic-CN), was synthesized and studied. We compared characteristics of Firpic-CN and Bis(3,5-Difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl) iridium III (FIrpic) which has been used for blue dopant materials frequently. The devices structure were indium tin oxide (ITO) (1000 a)/N,N'-diphenyl-N,N'-(2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB) (500 a)/4,4'-N,N'-dicarbazole-biphyenyl (CBP) : FIrpic and FIrpic-CN (X wt%)/4,7-diphenyl-1,10-phenanthroline (BPhen) (300 a)/lithum quinolate (Liq) (20 a)/Al (1000 a). 15 wt% FIrpic-CN doped device exhibits a luminance of 1450 cd/m2 at 12.4 V, luminous efficiency of 1.31 cd/A at 3.58mA/cm2, and Commission Internationale d'Eclairage (CIEx,y) coordinates of (0.15, 0.12) at 12 V which shows a very deep blue emission. We also measured lifetime of devices and was presented definite difference between devices of FIrpic and FIrpic-CN. Device with FIrpic-CN as a dopant presented lower longevity due to chemical effect of CN ligand.
        4,000원
        852.
        2007.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Burning mosquito coils in indoor environments maygenerate smoke that can control mosquito effectively. This practice has been used in numerous households in Korea. However the smoke may contain air pollutants of health concern. We conducted the present study to characterize the emission from two common brands of mosquito coils from Vietnam and Malaysia, respectively. We measured mass emission of air pollutants of nitrogen oxides (NOx), fine particulate(PM2.5), formaldehyde (HCHO), total volatile organic compounds (TVOCs), carbon monoxide (CO) and carbon dioxide (CO2) in completely closed chamber. Air pollutants concentrations resulting from burning mosquito coils could substantially exceed health-based air quality standards orguidelines. Under the same condition, air pollutants were measured by cigarette smoking to compare mosquito coil. Burning one mosquito coil would release the same amount of PM2.5 mass as burning 20~58 cigarettes. The emission of HCHO from burning one coil can be as high as that released from burning 27 cigarettes.
        4,000원
        853.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Experiments were conducted to analyze the concentration of sulfur compounds present in ambient air at the pg or ppt level. The compounds were estimated using GC/PFPD (Gas Chromatography with Pulsed Flame Photometric Detector) analyses with a Thermal Desorber (TD). The analytical results showed very stable and precise retention time values (RSD: < 0.22%), peak area (RSD: < 3.9); the coefficients of the calibration curves were also determined (r²: > 0.991). Also, with respect to the recovery rates of the sulfur compounds from dry air, those for H₂S, MM, DMS and DMDS were 94, 100, 113 and 114%, respectively. In order to evaluate the sulfur chemicals in humid air, a study was conducted at RH of 55 and 100%. The recovery rate at a relative humidity of 55% was similar to that under dry conditions. However, recovery rates of H₂S and MM at RH 100% were reduced to 70 and 77%, respectively.
        4,000원
        854.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 제주지역 목장 토양 및 조사료 자원의 미량광물질 함량을 평가하기 위해 수행되었다. 제주지역 98 목장에서 187 토양시료(농암갈색 76, 흑색 111) 및 말 농가에서 활용되고 있는 이탈리안라이그라스 건초, 혼합목초 건초, 수입 알팔파 건초 각 60시료를 채취해서 분석했다. 토양시료는 화학특성(pH, 유효인산, 치환성 양이온 함량)과 미량광물질(Cu, Fe, Cd, Zn, Mo, Se, Mn, Cr, Co, Ni) 총 함량 및 가용성 함량이
        4,000원
        855.
        2007.03 구독 인증기관 무료, 개인회원 유료
        가축의 번식과 수요를 조절할 수 있는 생물학적 자극 통제 수단으로 새로운 돼지 페르몬성 냄새 물질를 탐색하고자, 기질 분자로서 2-cyclohexyloxytetrahydrofurane (A), 2-phenoxytetrahydrofurane (B) 유도체들의 설명인자인 물리화학 파라미터와 돼지 페로몬의 수용체 (pOBP)에 대한 결합 친화력 상수(p[Od.]50) 간의 2D-QSAR 모델을 유도하고 검토하였다. 2D-QSAR 모델은 결합 친화력 상수를 약 96.4% 설명하는 매우 양호한 모델(r2=0.964)로서 분자내 치환기의 소수성(SL) 상수에 관한 적정값이 (SL)opt.=1.418일 때 가장 높은 결합 친화력을 나타냄을 알았다. 그러므로 분자내 치환기의 소수성 인자가 결합 친화력 상수에 가장 큰 영향을 미치는 중요한 요소이었다.
        4,000원
        856.
        2007.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This study was to investigate distribution characteristics for air pollutants and to assess probability of health effect for children in kindergartens from August, 2006 to January, 2007. The mean concentrations for standards of maintenance in kindergartens were 91.5 ㎍/㎥ for PM10, 1,185 ppm for CO2, 69.3㎍/㎥ for formaldehyde, 174 CFU/㎥ for TBC and 0.41 ppm for CO, respectively. For NO2, Rn, TVOC, and O3, the mean concentrations in kindergartens were 29.40 ppb, 1.51 pCi/ℓ, 257.3 ㎍/㎥, and 3.74 ppb, respectively. The I/O ratio of every air pollutants exceeded "1" except for O3. In results of calculated safety factor to assess probability of health effect for children by air pollutants in kindergartens, safety factor for CO2 was 1.2 for fixed point. It means that children have probability of health effect caused by CO2. In cases of Monte-Carlo analysis, safety factor for PM10 was 1.0 and safety factor for CO2 was 1.2.
        4,000원
        857.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to investigate the legally-designated malodorous compounds at the plant boundary areas of 5 plants expected to emit high odor intensities, as well as! complaint area at the Yeosu petrochemical industrial complex in Korea. The sampling was carried out during spring and summer of 2003 and 2006. The concentrations of ammonia, sulfur compounds (hydrogen sulfide, methyl mercaptan, and dimethyl sulfide) and aldehydes (acetaldehyde and propionaldehyde) emitted during 2006 were higher than those emitted during 2003, and the concentrations emitted during summer were higher than those emitted during spring at the plant boundary areas. It was thought that the concentrations of odorants in the complaint area had been directly influenced by the concentrations of odorants in the plant boundary areas as they showed similar patterns of concentration variations. While the concentration of TMA during 2006 was lower than during 2003 at the all sampling sites, the concentration of styrene during 2006 was higher than during 2003 at the all sampling sites. The sites showed high concentrationsof odorous compounds at the plant boundary area of the related chemical and petrochemical refinery plants.
        4,000원
        858.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to obtain the emission characteristics of odor compounds generated from a livestock wastewater treatment process. The sampling of odor compounds was performed twice, on May 9th and June 14th 2006, at 4 and 5 sites in the boundary and source areas, respectively. The odor concentrations obtained from the air dilution sensory test ranged from 10 to 100 in the boundary area. Of the 5 source sites, the odor concentrations found at the pre-treatment building had the highest values, which were 14422 and 20800 for the first and second dates, respectively. To estimate the major odor compounds produced during a live wastewater process, the contributions of 12 odor compounds to the total odor were calculated from the concentration and odor threshold values of each compound. At the pre-treatment building and outlet of the activated carbon tower of the source sites, the contribution of sulfur compounds to the odor was 97%, and at the outlet of the biofilter that of NH₃ was 90%. The order of the contribution to the odor in the boundary area sites was; from highest to lowest: H₂S, C₂H₆S, i-C₅H10O, C₃H₉N, NH₃. The correlation coefficient between the theoretical odor concentration from the odor threshold of 12 odor compounds and that obtained from the air dilution sensory test was 0.73. This result indicated a limit to the correct analysis of the odor concentration obtained from the air dilution sensory test when only 12 odorous compounds at a livestock wastewater treatment process are used. The odor removal efficiency of the deodorization facilities showed that for the activation carbon tower, the odor concentration was reduced to 4% and the contributions of H₂S, C₂H₆S and NH₃, which were estimated to be the major odor compounds, were reduced to 20, 26 and 11%, respectively. With respect to the bio-filter, the removal efficiency of the odor compounds revealed an odor concentration of 0% because the major odor compounds were calculated as negative percentages.
        4,000원
        860.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        토마토 유묘의 생육에 미치는 glycine betaine의 엽면처리 효과를 분석한 결과, 초장이나 건물중 등의 생육이 대조구인 증류수 처리에 비해 촉진되는 경향을 보였으며 25mM glycine betaine 처리가 가장 좋았다. 저온스트레스 하에서 삼투조절 역할을 하는 가용성 당과 proline의 축적량이 증류수 처리에 비해 glycine betaine처리에서 낮은 경향을 보여 외부에서 엽면 처리한 glycine betaine이 삼투조절 역할을 한 것으로 판단되었으며 이러한 결과는 수용성 단백질과 유리 아미노산의 축적 양상에서도 잘 반영되었다. 이상의 결과로 보아 glycine betaine의 엽면 처리는 저온기 시설 토마토 재배 시 야간 저온장해를 극복할 수 있는 방법으로서 이용 가능성이 있을 것으로 사료된다.
        4,000원