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        검색결과 595

        202.
        2007.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Used polyurethane was chemically degraded by treatments with flame retardants such as tris(3-chloropropyl) phosphate (TCPP), triethyl phosphate (TEP), and trimethyl phosphate (TMP). The structure of degraded products (DEP) was analyzed by FT-IR and P-NMR and it turned out to be phosphorus containing oligourethanes. Rigid polyurethane foam was produced by using the degraded products (DEP) as flame retardants. The flammability of recycled rigid polyurethane was investigated. The recycled polyurethane shows a reduced flammability over virgin polyurethane. In order to evaluate flame retardant properties of the recycled polyurethane foams with various amounts of DEP, the combustion parameters of the foam was measured by a cone calorimeter. Scanning electron micrograph of recycled PU shows the same uniform cell morphology as virgin PU.
        4,000원
        203.
        2007.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Young children health problem were reported in a Korean daycare centers and supposedly attributed to the presence of air pollutants. This study attempted to characteristics of carbonyl compounds exposure of young children at the indoor spaces. The characteristics associated with the major indoor pollutants exposure included seasonal variation, and room location inside a daycare centers. As the results of investigation for daycare centers, the mean concentrations of formaldehyde, acetone, and acetaldehyde in daycare centers were 38.3㎍/m3, 33.9㎍/m3, 13.6㎍/m3, respectively. The indoor space carbonyl compounds concentrations were both higher for the summer than for the other seasons. The temperature and relative humidity measured along with the volatile organics measurements temperature and relative humidity increase volatile organics levels. This last suggestion is further supported by the correlations of the carbonyl compounds measured for daycare centers. Significant correlations between carbonyl compounds were exhibited for both the temperature and humidity, with at least p<0.05. The concentrations of formaldehyde in classroom were higher than lobby or dining room. Therefore, controlling indoor air pollutants exposure in daycare center should be given a high priority so as to minimize the potential sources of air pollutants in indoor space.
        4,300원
        205.
        2007.06 구독 인증기관·개인회원 무료
        산업적으로 이용 되지 못하고 폐기되거나 임지에 버려지는 수목으로부터 추출물을 분리하고 이들 추출물을 버섯산업에 이용하게 된다면 그 경제적인 중요성 및 가치는 무한하다고 판단된다. 천연물을 이용한 그린몰드 방제제의 제조 및 사용은 해외로부터 무분별하게 유입되는 방제제 및 화학약품의 수입을 억제할 수 있을 뿐만 아니라, 버섯소비자들에게 안전한 먹거리를 제공할 수 있으리라 판단된다. 본 연구의 목적은 버섯 균상에 침입하는 그린몰드의 생육을 억제하는 유효화합물을 침엽수재 톱밥으로부터 획득하기 위하여 최적의 추출방법을 도출하는 것이다. 수목 추출물로부터 그린몰드 생장 억제 화합물을 분리하기 위하여 추출 조건에 따른 그린몰드 생장 억제에 유효한 수목 원료의 추출 조건을 규명하였다. 미송 및 낙엽송 톱밥으로부터 분리한 추출물은 그린몰드 생장을 약 40% 수준에서 억제하였다.
        207.
        2007.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This study was to assess the health risk of VOCs in indoor air under uncontrolled Korean-IAQ regulation. We measured the concentrations of formaldehyde and 5 VOCs (benzene, toluene, ethylbenzene, xylene, and styrene) in indoor air at 232 public buildings for four kinds of public facility (32 wedding halls, 17 Gymnasiums, 20 Galleries, and 166 Welfare facilities) around the country. There were estimated the human exposure dose and health risk used average time and frequencies of questionaries for subjects such as facility users and office workers. There were estimated the lifetime excess cancer risk (ECR) for carcinogens (formaldehyde and benzene) and hazard quotient (HQ) for non-carcinogens (toluene, ethylbenzene, xylene and styrene). For the facility user, the average levels of ECRs were 10-4∼10-5 and 10-5 ∼10-6, respectively, for formaldehyde and benzene in all facilities. HQs of four non-carcinogens were not exceeded 1.0 in all facilities and subjects. In addition, there was showed the highest ECR in the smoking facility.
        4,200원
        208.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 굴 껍데기로 제조한 개미산 칼슘화합물에 몇 가지 활성제를 첨가한 용액 수관살포가 사과 '후지' 과실의 칼슘농도, 과점의 발육 및 품질에 미치는 영향을 구명코자 실시하였다. 굴 껍데기로부터 추출한 칼슘 화합물(Os-CaF, 52.4mg·kg-1)을 수관살포하였을 때 조직으로의 칼슘전이 효과는 무처리에 비하여 잎, 과피 및 과육에서 현저한 증가를 보였다. 그리고 Os-CaF에 활성제를 첨가하여 살포하였을 때 '후지' 과실의 칼슘함량은 증가되었다. 특히, 잎에서는 ascorbic acid, polyvinyl alcohol을, 과피에서는 Ag-colloidal, polyvinyl alcohol을, 과육에서는 ascorbic acid, Ag-colloidal, polyvinyl alcohol을 첨가한 칼슘화합물이 칼슘 흡수량을 현저히 증가시켰다. 칼슘화합물의 농도 및 활성제 종류에 따른 과실품질(과중, 경도, 가용성고형물, 산 함량, 과피색)은 차이가 없었다.
        4,000원
        210.
        2006.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This study was undertaken to investigate the concentration of VOCs from newly built apartments in three cities (Suncheon, Yeosu, and Gwangyang) of Honam province in Korea. VOCs were sampled using canister and analyzed by GC/MSD. The result of the canister blank test showed that, most VOCs were not detected when 5 ppb was cleaned once and 10 ppb was cleaned with two times. In case of the replicate alalysis to check for the precision of GC/MSD, RSD values were found to be excellent at 6%. The upper floor of C apartment (25 pyong) showed the highest concentration of TVOCs at 3,235 ㎍/㎥. The average concentration of TVOCs was the highest in C apartment (25 pyong) as 1,833±1,217 ㎍/㎥. The average concentration of TVOCs in K (52 pyong) and S apartment (16 pyong) were 1,820±1,035 ㎍/㎥ and 498±71 ㎍/㎥, respectively. The I/O ratio of TVOCs were 8.99∼35.90 (mean : 25.99), 11.51∼35.43 (mean : 20.07) and 6.03∼7.90 (mean : 6.92) in K, C and S apartment, respectively. From these results, it is believed that the concentration of TVOCs was comparatively high in new apartment. Therefore, it is important to use low VOC emission materials to reduce the emission concentration of VOCs from in new apartment. It is hence necessary that a scientific study is performed to secure clean indoor air quality.
        5,100원
        211.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The characteristics of odor and VOCs emitted from a sewage treatment plant was investigated to provide the basic informations in the design of odor and VOCs treatment processes. The sewage treatment plant which treated domestic wastewater only and consisted of a flow equalization tank, thicker, and sludge container was selected. Odor and VOCs sampled three times (June - July) at the temperatures ranging from 24℃ to 27℃ were analyzed by GC/MS and GC/FPD. Odors were hydrogen sulfide, dimethylsulfide, ammonia, and styrene. Among them, the main compounds were dimethyldisulfide (14.45~2,340.91 O.U.) and ammonia (18.51~16,520 O.U.). The order of odor dilution ratio and odor unit can be listed as follows : Sludge container > Flow equalization tank > Thicker. The main VOC produced from sewage treatment plant was benzenes, and the others were dichloromethane, toluene, ethylbenzene, m,p-xylene, styrene, 1,2,4,-trimethylbenzene, 1,3-dichlorobenzene, and 1,2-dichlorobenzene. The concentration of toluene of a flow equalization tank, thicker, and sludge container were produced from 70.38 ppb to 103.07 ppb, from 28.18 ppb to 40.35 ppb, and from 67.92 ppb to 180.26 ppb. The producing order of VOC can be listed as follows : Sludge container > Flow equalization tank > Thicker.
        4,000원
        212.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aliphatic amine compounds have very low detectable threshold value concentrations, and especially trimethyl amine is one of the main odor-active compounds in atmospheric environment. Concentration of a large amount (10~100 L) of air sample was needed to detect trace amounts of amine compounds by GC/FTD. Amine compounds in ambient air were absorbed in sulfuric acid solution by using impingers and sampling pump. Some amount of the absorption solution was injected in bubbling bottle which a concentration tube was connected with, and that amine gas which was isolated from bubbling bottle was trapped in a concentration tube dipped in liquid argon under a constant helium flow. A concentration tube was disjoined from the bubbling bottle and was connected to injection port of gas chromatograph. Amine compounds trapped in a concentration tube was introduced into the packed column by thermal desorption after flow rate of carrier gas and detector signal had been stabilized enough. Sampling volume of ambient air was different from place to place in the range of 10~100 L, and flow rate through impingers was 5 L/min. Atmospheric concentrations of trimethyl amine were below 16.0 ppbv in the boundary of business establishment and below 420.0 ppbv at the gas releasing port of business establishment in the industrial area.
        4,000원
        213.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        [ ] alloys with Al, B or Nb were prepared by an advanced consolidation process that combined mechanical alloying with pulse discharge sintering (complex forming) to improve the mechanical properties. Their microstructure and mechanical properties were investigated. The alloys fabricated by complex forming method showed very fine microstructure when compared with the sample sintered from commercial powders. Alloys made from powders milled in Ar gas had fewer silica or alumina phases as compared to their counterparts sintered from powders milled in air. In densification of the sintered body, addition of B was more effective than Al or Nb. Both Victors hardness and tensile test indicated that the alloy fabricated by the complex forming method showed better properties than the sample sintered from commercial powders. The Al added alloy sintered from the powders milled in air had the superior mechanical properties due to the suppression of and formation of fine particles.
        4,000원
        214.
        2006.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Uncertainty evaluation was performed for the measurement of Volatile Organic Compounds(VOC) in indoor air. The analytical procedure and result were validated by evaluating every uncertainty source related to the measurement method. An easy approach for uncertainty evaluation for indoor VOC measurement was tested using relative standard uncertainty method which is simple in the evaluation of a measurement uncertainty in case of indoor VOC measurement. The measurement uncertainties of toluene, ethylbenzene, m+p-xylene, styrene and o-xylene in indoor air are obtained as less than or close to 10%, and those results were validated by using Gum-workbench uncertainty evaluation program. Based on the evaluation, uncertainties were found to come largely from two major sources, uncertainty related to the concentration of standard Tenax tube which was used for calibration in measurement, and the to air sampling process. This study could be used as a good example in evaluating uncertainties in the measurement of indoor-air VOC at buildings including a newly-built apartment.
        4,500원
        215.
        2006.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This study was performed to estimate the emission rate of volatile organic compounds (VOCs) and to evaluate the risk level affected by indoor air pollutants (IAPs) in 27 new apartments (prior to residence) in Seoul City from December 2004 to March 2005. The indoor air pollutants investigated in this study include formaldehyde, several aromatic VOCs (benzene, toluene, styrene, xylene, and ethylbenzene). All measurements were made based on the standard method of Ministry of Environment in Korea. The indoor concentration levels for benzene, xylene, toluene, ethylbenzene, styrene, and formaldehyde have significant increase trend 5 hours after closing windows and doors. Levels of air pollutants did not exhibit significant difference between living rooms and bedrooms. The air exchange rates by the concentration decay method using SF6 were 0.37 for low floor, 0.32 for middle floor, and 0.75 for high floor. The emission rate showed the highest level in the middle floor and second one in the low floor, when estimated by the IAQ model for benzene, toluene, ethylbenzene, xylene, styrene, and formaldehyde. Considering the above result, it is suggested that the estimation of emission rate be considered when the new apartment is designed and constructed with respect to construction materials to emit low VOCs. Moreover, the related regulation should be established for IAQ management.
        4,500원
        216.
        2006.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        For indoor air quality at a newly built apartment before move-in, we monitored formaldehyde and VOCs and assessed human exposure and probabilistic health risk. We selected 801 newly built apartments all over the country. The results of the research on the condition show the mean concentrations of formaldehyde 294 ㎍/㎥, 210(median) 1497㎍/㎥(maximum), benzene 6㎍/㎥, (4 and 92㎍/㎥), toluene 1003㎍/㎥(773 and 5013 ㎍/㎥), ethylbenzene 120㎍/㎥, (62 and 1192㎍/㎥), xylene 287㎍/㎥(138 and 2723㎍/㎥) and styrene 64㎍/㎥, (42 and 531㎍/㎥). Formaldehyde from carcinogen and toluene and xylene from non-carcinogen were assessed the risk for human health. The excess cancer risk of formaldehyde for human beings between carcinogens is per 1.36 of average 1000 persons. This implies that it is over a level per 1.00 of 1000 persons demanding active risk reduction. Hence, we strongly need the active reduction plan and accurate source assumption. Among a variety of factors affecting indoor air quality for householders, closing construction or density of indoor air processing additional interior construction and indoor area, indoor air quality with a variety of districts show significant. The excess cancer risk for human beings of formaldehyde between carcinogens is per 1.36 of average 1000 persons. Non-carcinogen toxicity rate for human-beings with toluene and xylene among non-carcinogens is over HQ 1 from Seoul to local area.
        4,500원
        218.
        2006.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        4,000원
        219.
        2006.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        휘발성 유기화합물로서 3가 염소탄화수소인 트리클로로메탄, 트리클로로에탄, 트리클로로에틸렌을 MFI 구조인 소수성 제올라이트 ZSM-5 분리막으로 투과증발을 이용하여 물과의 이성분계 혼합물로부터 선택적으로 분리하고자 하였다. 직경 9.5 mm 다공성 스테인리스 스틸 튜브의 내부 표면에 수열합성법으로 ZSM-5 제올라이트 결정을 성장시켜 박막을 만들어 분리막으로 이용하였으며, 합성된 ZSM-5 제올라이트 분리막으로 공급되는 3가 염소화합물의 농도 및 실험 온도에 따른 분리 특성을 고찰하였다. 3가 염소화합물의 수용액상 농도를 0.0001 몰분율부터 0.001 몰분율로 변화하면서, 또한 실험 온도를 25에서 45℃로 바꾸면서 투과증발 실험을 수행한 결과 트리클로로메탄/물 이성분계에 대하여 약 16~66의 선택도를 얻었으며, 트리클로로에탄/물 이성분계에 대하여 3.3~4.6의 선택도와 트리클로로에틸렌/물 이성분계에 대하여 1.4~8의 선택도를 관찰할 수 있었다.
        4,000원
        220.
        2006.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Benzoxazolo carbocyanine compounds were synthesized by condensation of a suitable ortho-ester with an appropriately substituted 2-methylbenzoxazole in the presence of triethylamine. This compounds used as green sensitizing dyes in photographic emulsions. The compounds are characterized by fast atom bombardment mass spectrometry. The values(m/z) of structurally significant ions observed in FAB spectra. It was showed tentative fragmentation pattern in FAB spectroscopy of HN(C2H5)3 cations in glycerol/trifluoroacetic acid matrix.
        4,000원