간행물
한국환경과학회지 KCI 등재 Journal of Environmental Science International
- 발행기관 한국환경과학회
- 자료유형 학술지
- 간기 월간
- ISSN 1225-4517 (Print)2287-3503 (Online)
- 수록기간 1992 ~ 2023
- 주제분류 자연과학 > 자연과학일반 자연과학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제17권 제12호 (2008년 12월) 12건
1.
2008.12
서비스 종료(열람 제한)
Hydrogen gas is used as a fuel for the proton exchange membrane fuel cell (PEMFC). Trace amount of carbon monoxide present in the reformate H₂ gas can poison the anode of the PEMFC. Therefore, preferential oxidation (PROX) of CO is essential for reducing the concentration of CO from a hydrogen-rich reformate gas. In this study, conventional Pt/Al₂O₃catalyst was prepared for the preferential oxidation of CO. The effects of catalyst preparation method, additive, and hydrogen on the performances of PROX reaction of CO were investigated. Water treatment and addition of Ce enhanced catalytic activity of the Pt/Al₂O₃ catalyst at low temperature below 100℃.
2.
2008.12
서비스 종료(열람 제한)
This study was investigated on the consciousness of middle school students in Jeju city about the environmental education through questionnaire, in order to understand the actual conditions of environmental education and to find out the solutions about them. Middle school students responded that environmental education in school was taken at the class for the special activity or voluntary service, not in regular class and was worked as in the form of the field trip. They generally obtain the knowledge and informations on the environmental problems from mass media such as TV, radio and newspaper than from regular environment class in school. And 36.0% of students perceive that environmental education is needed as a regular class and 31.3% of students perceive that the regular class in school is effective to the environmental education. These results suggest that many students are interested in the regular environment class in school. However, the most of students responded that the regular environment class in school is not worked or is not worked at all, suggesting that the environmental education in middle school is not worked effectively. Most of students prefer to take the environment class in the form of observation or field trip, and they think that observation or field trip is more effective to obtain environmental informations. In conclusion, the special activity such as observation or field trip needs to be supplemented to regular environment class in order to improve the environmental education in middle school more effectively.
3.
2008.12
서비스 종료(열람 제한)
This study was carried out with the detection for multiresidue of the carbamate pesticide such as carbaryl and cabofuran by enzyme-inhibition method. The check time for determination of acetylcholinesterase(AChE) activity was selected at 60 sec. The AChE activity in chicken brain determined by the Ellman's method was 162 μmol/min/g protein. I50 for AChE by carbamate pesticide with wet kit was 0.169 mg/L of carbaryl and 0.089 mg/L of cabofuran, respectively. The incubation time for enzyme kit with substrate kit was 30min for determination of AChE activity. Enzyme kit with substrate kit was stable at 4oC and 25℃ for 5 days. Limit detection concentration of carbaryl with dry kit for AChE was 0.05 mg/L. The dry kit such as wet kit applied Enzyme-Inhibition(EI) method with AChE was confirmed the multiresidue method to detect the carbamate pesticides.
4.
2008.12
서비스 종료(열람 제한)
For providing basic data on estuary conservation and pattern of vegetation succession of sand bar, the flora of delta was investigated from March 2004 to August 2006 in the Nakdong River estuary of Korea. The flora in the eight surveyed areas was composed of total 159 taxa that belonged to 46 families, 123 genera, 133 species, 1 subspecies, 20 varieties, and 5 forms. Among them, naturalized plants and evergreen broad trees were 31 taxa and 5 taxa, respectively. The communities of main species at delta of estuary were composed of 16 species such as Rosa rugusa community, Scirpus triqueter community, Phragmites communis community, Carex kobomugi community, Digitaria ciliaris community. Especially, Rosa rugusa community which are important to establish the southern limit line of distribution as the northern factor was distributed through Jinwoodo. The succession of main vegetation community in the new delta (Doyodeung) was in order of Carex scabrifolia, Scirpus triqueter, Phragmites communis, Imperata cylindrica var. koenigii and Miscanthus sinensis var. purpurascens. Therefore, the succession order of the surveyed area seems to predict the pattern of the vegetation succession of another deltas in Nakdong River estuary.
5.
2008.12
서비스 종료(열람 제한)
The activated sludge obtained from wastewater coke oven plant was immobilized by entrapment with polyethylene glycol (PEG). The effects of several factors on the biodegradation of CN- from synthetic wastewater were investigated using batch and continuous reactors. The degradation rate of CN- increased with increasing of the immobilized bead volume in the reactor. Approximately 7.65 mg/L of NH4-N was produced upon the degradation of 35 mg/L of CN-. When high concentrations of the toxic cyanide complex were used in the testing of cyanide degradation, the free activated sludge could be inhibited more than that of the immobilized activated sludge. When the phenol concentration was higher than 400 mg/L in the synthetic wastewater, approximately 98.4% of CN- was removed within 42 hours by the immobilized activated sludge. However, the cyanide was not completely degraded by the free activated sludge. This indicates that high phenol concentrations can act as a toxic factor for the free activated sludge. A CN- concentration of less than 1 mg/L was achieved by the immobilized sludge at the loading rate of 0.025 kg CN-/m3-d. Moreover, it was found that the HRT should be kept for 48 hours in order to obtain stable treatment conditions.
6.
2008.12
서비스 종료(열람 제한)
Quality control of Argo(Array for Real-time Geostrophic Oceanography) data is crucial by reason that salinity measurements are liable to experience some drift and offset due to biofouling, contamination of sensor and wash-out of biocide. The automated Argo real-time quality control has a limit of sorting data quality, so that WJO program is adopted as standardized method of Argo delayed mode quality control (DMQC) in the world that is a precise quality control method. We conducted DMQC on pressure, temperature and salinity measured by Argo floats in the Pacific Ocean including expert evaluation. Particularly, salinity data were corrected using WJO program. 4 salinity profiles of Argo delayed mode were compared with nearby in situ CTD data and other Argo data in deep layer where oceanographic conditions are stable in time and space. The differences of both salinities were lower than target accuracy of Argo. As compared with the difference of salinities before DMQC, those after DMQC decreased by 60-80 percent. Quality of delayed mode salinity data seemed to be improved correcting salinity data suggested by WJO program.
7.
2008.12
서비스 종료(열람 제한)
In this study, long term semi distributed hydrologic model SWAT-K(Korea) is applied to the Seolma- Cheon watershed to analyze the hydrological components. Seolma-Cheon watershed has been operated as the test watershed of Korea Institute of Constrcution Technology for 13 years. Therefore it has an enough hydrologic data to analyze the hydrologic characteristics of small watershed. Especially, for the proper runoff analysis of steep watershed, calibration is performed reflecting the regression equation of slope and slope length. The simulated discharge shows good agreement with the observed one and the simulated evapotranspiration and groundwater discharge also show satisfactory results. Finally we presents the ratio of major hydrologic components for 3 years with those obsrved ones. This study is the basic research for future analyses such as relationship between hydrologic components and vegetation, watershed sediment nonpoint sources discharge etc.
8.
2008.12
서비스 종료(열람 제한)
Anthracene appended new host compounds have been synthesized by imine reaction. Fluorescent open chain host compounds Trisanthryl-tris(2-aminoethyl)imine 1 was synthesized from the reaction of tris(2-aminoethyl)amine and anthracene-9-carboxaldehyde in EtOH. Tris-10-chloroanthryl-tris(2-aminoethyl)imine 2 was synthesized from tris(2-aminoethyl)amine and 10-chloro-9-anthraldehyde in EtOH. The structures of all reaction product were identified by 1H NMR, 13C NMR, GC/MS, FAB Mass, IR spectrum and DSC. Cation complexation behavior was investigated by fluorescence spectroscopy measurements. The capability of transition metals cation recognition between fluorescent open chain host compound 1, 2 were investigated with Co²+, Ni²+and Cu²+. The fluorescence intensity was increased by host compounds corresponding guest cations. The relative order of fluorescence intensity changes were Co²+ > Cu²+ > Ni²+ . Compound 2 is very sensitive fluorescent sensor of Co²+ ion.
9.
2008.12
서비스 종료(열람 제한)
Emission characteristics of volatile organic compounds (VOCs) were investigated in the flue gas emitted from wood drying process for plywood manufacturing. The moisture content of raw timber was average 48%, and its density was 831.55 kg/m3. But the moisture content of dried wood is needed less than around 10%, thus the moisture contents of flue gas should be remarkably high(about 18.2 V/V%). Therefore, the vapor in flue gas is equivalent to 320 ton-vapor/day when 1100 ton-wood/day is treated in the wood drying process. The temperature of flue gas ranges from 140℃ to 150℃ in each dryer stack with exception of the input site of wood(about 110℃). The velocity of flue gas in each stack ranges from 1.7 to 9.7 m/sec. In order to assess the concentrations and attribution rate of odorous compounds, it was analyzed about 40 VOCs in the flue gases. It was found that the major odorous compounds were 8 compounds, and the concentrations of major VOCs(ppm) were as follows; benzene: 0.054～0.052, toluene: 1.011～2.547, ethylbenzene: 0.472～2.023, m,p-xylene: 0.504～3.245, styrene: 0.015～0.148, o-xylene : 0.271～1.097, ethanol: 11.2～32.5, α-pinene: 0.908～10.578, β-pinene: 0.982～14.278. The attribution rate of terpenes (α-pinene, β-pinene) was about 60.56%, and that of aromatics and alcohols was about 22.77%, and 16.67%, respectively. It is suggested that the adequate control device should be used to control both the water soluble and non-soluble compounds because both compounds were mixed in flue gas.
10.
2008.12
서비스 종료(열람 제한)
Designating conservation sites is needed for the preservation and management of tidal flats, and also objective criteria, by which preservation values of tidal flats can be evaluated, are required to designate conservation sites. A set of new evaluation criteria for tidal flats was suggested in this study. The criteria, based on six items including scarcity, diversity, naturalness, uniqueness, destruction possibility and preservation will, have the advantages with which easy and economic assessments are possible by using basic data from the preceding studies. The evaluation results for the three different tidal flats (Muan, Jeungdo-1 and Jeungdo-2) in the southwestern coast of Korea reveal that all the tidal flats evaluated are classified into grade 2. The tidal flat which got the highest evaluation score was Jeungdo-1 tidal flat (86.7), and the next was Muan (85.0) and Jeungdo-2 (82.5). The Jeungdo-2 tidal flat was superior in uniqueness and destruction possibility, and the Muan tidal flat was superior in diversity and naturalness.
11.
2008.12
서비스 종료(열람 제한)
Wangdol-cho, located 23 km offshore of Hupo in southwest of East Sea, is underwater rock floor, called to Wangdol-Am or Wangdol-Jam and has three tops as Mat-Jam, Middle-Jam and Set-Jam. The composition, abundance, diversity and community structure were investigated in winter and summer in 2002 around Wangdol-cho. The temperature around the Northwest and Southeast part of Wangdol-cho was influenced by the North Korea Cold Current (NKCC) and East Korea Warm Current (EKWC), respectively. Nutrient and chlorophyll-a concentration were higher at the top of Wangdol-cho than other area. A total of 41 genera and 78 species of phytoplankton were identified. The average cell abundance of phytoplankton in winter and summer were 286×103 cells/㎥, 432×103 cells/㎥ respectively. The largest community was Bacillariophyta containing 52 taxa. The dominant species were Lauderia anulata and Coscinodiscus spp. which preferred cold water in winter. In contrast, warm water species such as Rhizosolenia stolterfothii and Ceratium spp. were dominant in summer. The average species diversity index of phytoplankton in winter was higher than that in summer. According to dominant species and standing crops, phytoplankton community resulted in a clear separation. One group was western area, which showed low density, and the other was eastern area, which showed the higher density. The abundance and species composition of phytoplankton were affected by topological characteristics around Wangdol-cho.
12.
2008.12
서비스 종료(열람 제한)
The Kyoto Protocol, that had been in force from February 16, 2005, requires significant reduction in CO₂emissions for all anthropogenic sources containing transportation, industrial, commercial, and residential fields, etc, and automotive emission standards for air pollutants such as particulate matter (PM) and nitrogen oxides (NOx) become more and more tight for improving ambient air quality. This paper has briefly reviewed homogeneous charge compression ignition (HCCI) combustion technology offering dramatic reduction in CO₂, NOx and PM emissions, compared to conventional gasoline and diesel engine vehicles, in an effort of automotive industries and their related academic activities to comply with future fuel economy legislation, e.g., CO₂emission standards and corporate average fuel economy (CAFE) in the respective European Union (EU) and United States of America (USA), and to meet very stringent future automotive emission standards, e.g., Tier 2 program in USA and EURO V in EU. In addition, major challenges to the widespread use of HCCI engines in road applications are discussed in aspects of new catalytic emissions controls to remove high CO and unburned hydrocarbons from such engine-equipped vehicles.
