검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 2,366

        2103.
        2003.04 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to develop the preliminary source fingerprints of volatile organic compounds (VOC). The source categories studied were vehicles, gasoline vapor, gasoline storage tank, coating, dry cleaning and road covering. The source samples were collected using 6L electro-polished stainless steel canisters for about 20 seconds. From this study, the main component emitted from VOC sources in Korea was toluene. The toluene proportion for road covering, vehicles, coating and gasoline vapor were 35, 18, 16 and 5%, respectively. The C2-C5 alkane and alkene compounds were mainly emitted from vehicles, gasoline vapor and gasoline storage tank. The main compounds of coating were m/p-xylene(34%), toluene(16%), 1,2,4-TMB(10%) and o-xylene(9%), which are aromatic hydrocarbons. In the case of dry cleaning, nonane(41%), 1,2,4-TMB (22%) and 1,3,5-TMB(13%) were mainly emitted.
        2104.
        2003.03 KCI 등재 서비스 종료(열람 제한)
        In this study, the material cycle model was applied to suggest alternative management of water quality for Jeju Harbor. The distribution of COD, DIN (dissolved inorganic nitrogen) and DIP (dissolved inorganic phosphorus) concentrations was reasonably reproduced by simulations on the model area of the Jeju Harbor using a material cycle model. The simulations of COD, DIN and DIP concentrations were performed under the conditions of 20~100% pollution loadings reductions from pollution sources. In case of the 100% reduction of the input loads from Sanzi river, concentrations of COD, DIN and DIP were reduced to 39%, 78% and 52%, respectively at Jeju harbor. In contrast, in case of the pollutant loadings reductions from sediment, the effect of DIN and DIP reduction relatively seemed to increase around the center of study area. The 95% reduction of the pollutant loadings from river and sediment is required to meet the COD and nutrients concentration of second grade of ocean water quality criteria.
        2105.
        2003.03 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to investigate the characteristics of water quality in Jeju harbor and to estimate pollutant loadings discharged into Jeju Harbor. To know characteristics of water quality in Jeju harbor and pollutant loadings of Sanzi river, we have investigated from August, 2000 to May, 2001. The results showed that the concentrations of COD, DIN and DIP were in the range of 1.00~4.85㎎/L (mean 2.15㎎/L), 2.14~74.0㎍-at/L(mean 12.20㎍-at/L) and 0.52~4.00㎍-at/L(mean 1.18㎍-at/L), respectively. These values were under Ⅲ class of seawater quality criteria. The ratio of nitrogen to phosphorus was lower than 16 except for Station 1 in Jeju harbor. Therefore, nitrogen was playing an important role in phytoplankton growth as limiting factor in Jeju harbor. The mean values of eutrophication index were exceeding 1, which was the eutrophication criteria. The results of estimating pollutant loadings at Sanzi river are 0.30 ton/day for COD, 300㎏/day for DIN and 18.0㎏/day for DIP, respectively.
        2106.
        2003.03 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        딸기를 항균소재에 침지 처리한 후 1% 농도로 항균성 소재를 첨가시킨 저밀도폴리에틸렌(LDPE) 필름에 의하여 딸기를 싸서 포장하고 5에 저장하면서 미생물 성장, 부패율, 텍스쳐, 화학적 품질을 측정한 결과 대조구에 비교해서 긍정적인 결과를 얻을 수 있었다. 즉, 항균성 소재를 포함시킨 LDPE 필름은 무첨가 대조 필름에 비해 호기성 총균수, 효모/곰팡이수로 측정된 미생물의 증식을 억제하는 것으로 나타났다. 이러한 미생물 증식억제의 효과로 인하여
        2107.
        2003.03 KCI 등재 서비스 종료(열람 제한)
        천연물로부터 항산화 활성물질을 목적으로 DPPH 자유 라디칼 소거활성 검색법을 이용하여 검색을 실사하고, 유의한 활성을 나타낸 산국 메탄올 추출물로부터 2종의 화합물을 분리하고 기기분석을 이용하여 화합물 1과 2의 구조를 apigenin과 acacetin-7-O-rutinoside (Linarin)으로 동정하였다. 이들 화합물은 각각 13.3 및 42.1μg의 농도에서 DPPH 라디칼을 50% 소거하는 활성을 나타내었으며, 화합물 1은 양성 대조양물인 L-ascorbic acid (RC50 = 13.1μg)에 비하여 강한 활성을 나타내었다.
        2108.
        2003.01 KCI 등재 서비스 종료(열람 제한)
        Urban air quality is usually worse than that of rural counterpart. The contrasting atmospheric properties seem to be direct result of different urban-rural air pollutant emission. Hence, the emission estimation of air pollutants plays an important role to the atmospheric environmental management. The main purpose of this study is to find out the temporal and spatial distribution of air pollutant emission in Daegu area. For the study, the Daegu statistical yearbook and data of waste facilities and the report on traffic survey issued by Daegu metropolitan city and the statistical yearbook on the road capacity issued by the ministry of construction and transportation are used. Each item for the emission estimation is SO2, CO, HC, NOx, PM-10 from point, line and area source. The result were as follow; (1) The air pollutants with the highest amount of emission from the emission source is CO fllowed by NOx, SO2, PM-10, HC in descending order of magnitude. (2) The annually totaled air pollutant emission consists of 81%(73,185 ton/year) of line, 11%(9,589% ton/year) of area and 8%(7,445 ton/year) of point source in Daegu. Air polluant emission was mainly due to line sources. (3) High-emission of the air pollutants of line source appeared ariond Bukgu, Dalseonggun, Dongu and Seogu ; the areas with highway networks.
        2109.
        2002.12 KCI 등재 서비스 종료(열람 제한)
        This study analyzes the surface ozone, NO and NO2 concentration data from 1997 to 1999 in Daegu. It investigates effect on precursor during high-ozone episode days. The high-ozone episode is defined when a daily maximum ozone concentration is higher than 100 ppb(ambient air quality standard of Korea) in at least one station among six air quality monitoring stations. The frequency of episodes is 13 days(33 hours). The frequency is the highest in May and September, and the area with the highest frequency is Nowondong and Manchondong. The average value of daily maximum ozone concentration with high ozone episode is 81.6 ppb, and that of 8-hour average ozone concentration is 58.6 ppb. It means that ozone pollution is continuous and wide-ranging in Daegu. The daily variation of NO, NO2 and O3 in high-ozone episodes are inversely proportional one another. Nowondong an industrial area, is affected by pollutants that are emitted from the primary sources, while Manchondong a residential area, is affected by the advection of O3 or by the primary pollutants like VOCs.
        2110.
        2002.12 KCI 등재 서비스 종료(열람 제한)
        This paper aims to find the characteristics of concentration distribution of coastal urban air pollutants. For this purpose, It was used the daily meteorological data and the hourly concentration data for O3 and NO2 in Busan metropolitan city from 1994 to 1996. It was investigated the annual and monthly distribution of ozone and nitrogen dioxide concentration at each site in Busan, and also investigated the characteristics of concentration change of air pollutants with time under the sea breeze. As a results, the concentration of nitrogen dioxide and ozone tend to be increased every year and nitrogen dioxide concentration is higher than ozone concentration at all sites in Busan. The concentration of ozone is high in summer season and low in winter season, but the concentration of nitrogen dioxide have a reversed trend. The monthly peak concentration of ozone occurred in April and September, while the monthly minimum concentration of nitrogen dioxide occurred in August. Their trend were identified by sites near the coastline than sites stands apart from the coastline. The sea breeze occurred annual mean 81 day in Busan from 1994 to 1996. The main wind direction of sea breeze was classified into southwesterly and southeasterly. In case of southwesterly, It was pronounced the south wind and southwest wind. In case of southeasterly, the occurrence frequency of east wind was high. Especially, the concentrations of urban air pollutants, such as ozone and nitrogen dioxide, were high on time which the sea breeze flow, and the areas that ozone concentration was high moved from outside part to central part of city with time. In costal urban such as Busan, the wind direction of sea breeze is influenced the change of ozone and nitrogen dioxide concentration on time which the sea breeze flow at each site and also influenced the change of air pollutants concentration of sites on the pathway of sea breeze.
        2111.
        2002.12 KCI 등재 서비스 종료(열람 제한)
        본 시험은 국내 재래종 정선시호와 일본에서 도입된 삼도시호를 공시하여 시호의 품질 향상을 위해 식물생장조절제 처리가 시호의 생육 및 saikosaponin 함량에 미치는 요인들을 구명하여 얻어진 결과를 요약하면 다음과 같다. 1. 정선시호는 삼도시호보다 분지수는 적었지만 경수는 많았고, 근경이 굵으며 생근중과 건근중은 무거웠고 지근수도 많은 경향이었다. SSa 및 TSS 함량에서 정선시호가 삼도시호보다 높았고, SSc 함량에서는 정선시호가 삼도시호보다 적었다. 2. 식물생장조절제 처리시기 간에서는 6월에 처리한 것이 7월에 처리한 것보다 경수가 많았고 건근중에서는 유의적인 차이가 없었으나, 6월에 처리한 것이 7월에 처리한 것보다 SSd 함량이 높았다. 3. 식물생장조절제 처리에서 GA3, 10, 50, 100 ppm, IAA 10, 50 ppm, kinetin 50 ppm 지상부 처리에서 지상부 생육을 촉진하였고, kinetin 50 ppm 처리구의 생근중과 건근중은 무처리구보다 무거웠으나 TSS 함량은 무처리구보다 낮았다. GA3, 10 ppm, IAA 10 ppm처리에서 SSa, SSd 및 TSS 함량이 증가되었으며 TSS 함량은 GA3, 50 및 100 ppm에서 높았다. 4. 무처리에 비하여 정선시호는 6월의 GA3, 100 rpm, IAA 10 및 50 ppm, kinetin 10 ppm 처리구에서, 삼도시호는 6월의 GA3, 10 ppm, IAA 10 및 100 ppm 처리구에서 생근중이나 근중은 차이가 없었지만 TSS 함량이 높아 시호생산에 가장 유리한 처리로 판단되었다.
        2114.
        2002.09 KCI 등재 서비스 종료(열람 제한)
        The recycled washwater, which has different water quality and is produced about 5 to 20% of the total water volume treated, affects the unit operation of water treatment, especially coagulation process. However, the effects of recycled washwater on unit operation of water treatment have not been fully investigated. In this study, effects of recycled washwater on coagulation process were investigated to find the optimum coagulation condition by analyzing turbidity, UV254, TOC removal efficiencies. In addition, effects of recycled washwater on residual Al after coagulation were studied by analyzing soluble and particulate Al. The size distribution and fractal dimension of coagulated also analyzed. The recycled washwater was lower pH than the raw water. And the recycled washwater had higher UV254, TOC and residual Al concentration than the raw water. Residual Al concentration of recycled washwater was about 50 times higher than that of raw water. Optimum coagulant dosages on the blending recycled washwater and the raw water for turbidity, UV254 and Al removal were lower than that on the raw water. However, TOC removal increased by increasing coagulant dosage. The size and fractal dimension of coagulated particle produced in the blending recycled washwater were larger, which imply faster settling velocity, than those produced in the raw water only.
        2115.
        2002.09 KCI 등재 서비스 종료(열람 제한)
        The urban pollution if affected by local environmental, so it is necessary to consider area characteristics such as emission source and meteorological phenomena, in studying urban air pollution. Ulsan is laocated on south-east coast and has many industrial facilities, so many people have concerned about air pollution. This study contain conducting numerical simulation of air pollutant concentration considered land and sea breeze in Ulsan area with the numerical model.
        2119.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        The absorption of benzene in nonpolar solution was studied in a laboratory-scale of bubble column varying of gas flow rates and gas-to-liquid ratios. A bubble column had a 0.8~1×10-3 m3 total volume (height 1500 mm, diameter 50 mm). Solution analysis was performed by GC-FID and GC-MSD. The objectives of this research were to select the best absorption fluid and to evaluate the mass transfer characteristics under specific conditions of each absorption. The results of this research were follow as: First, the heat transfer fluid is more efficient than the other nonpolar solution in removing VOC. Second, The benzene removal efficiency improved according to an increasing rate of gas flow. Also, volumetric mass transfer rate of column can be enhanced by increasing gas flow rate. Finally, the relation of gas flow rates, liquid amount, and volumetric mass transfer coefficient was obtained as follows. Kya=0.5906(Vg/L)0.7611 The following correlation of mass transfer coefficient and efficiency was proposed. η=0.06078 Kya0.2444
        2120.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        차광 및 광 강도별 맥문동의 광합성속도, 기공전도도 및 증산작용과 그 관련형질간의 상호연관성을 구명하였던 바는 다음과 같다. 맥문동의 광합성속도는 광 강도가 증가함에 따라 증가하였고 PAR 700-1000μmol/m2/s에서 최고치를 나타내었으며 차광에 의해 증가되는 경향이었다. 기공전도도는 광 강도가 증가함에 따라 증가되었고, 광합성속도, 증산작용 및 기공전도도의 일변화는 비슷한 경향의 양상을 띄었다. 광합성속도와 기공전도도와의 관계는 1차직선회귀관계로 고도의 정(正)의 상관이 인정되었으나 대조구와 차광구가 각각 다른 1차회귀직선을 보여 동일한 기공전도도에서 차광구의 광합성속도가 대조구보다 높은 경향으로 나타났다. 증산작용과 기공전도도 및 광합성속도와 증산작용의 관계는 양자간에 모두 1차회귀식의 정(正)의 상관관계가 인정되었다.