• Journal of Korean Society on Water Environment
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• v.34 no.6
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• pp.569-578
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• 2018

To minimize the negative alterations in hydrologic and water quality environment in urban areas due to urbanization, Low Impact Development (LID) techniques are actively applied. In Korea, LID facilities are classified as Non-point Pollution Reduction Facilities (NPRFs), and therefore they are evaluated using the performance evaluation method for NPRFs. However, while LID facilities are generally installed in small, distributed configuration and mainly work with the infiltration process, the existing NPRFs are installed on a large scale and mainly work with the reservoir process. Therefore, some limitations are expected in assessing both facilities using the same method as they differ in properties. To solve these problems, in this study, a new method for performance evaluation was proposed with focus on bio-retention LID facilities. EPA SWMM was used to reproduce the hydrologic and water quality phenomena in study area, and SWMM-LID module used to simulate TP interception performance by installing a bio-retention cell under various conditions through long-term simulations. Finally, an empirical formula for Load Capture Ratio (LCR) was derived based on storm water interception ratio in the same form as the existing method. Using the existing formula in estimating the LCR is likely to overestimate the performance of interception for non-point pollutants in the extremely low design capacity, and also underestimate it in the moderate and high design capacity.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.1-11
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• 2005

This study applied EK method to remediate contaminated soil by lead (Pb), tried increasing efficiency of remediation using adsorbent (apatite and zeolite) as enhanced EK remediation method to overcome the limit of traditional EK remediation method. Adsorption tests on Pb were practiced to extract EK, making different concentration of contaminated soil, voltage condition, operating time etc., transferring Pb-ion into the position of adsorbent, then tried immobilization. On this results, the efficiency of remediation is different on its test conditions. In addition, the efficiency of remediation was not only improved by adding electrode revεrsal and install position of adsorbent but also satisfied TCLP regulation of EPA in USA through the whole sample range. Finally, absorption and immobilization capacity of apatite and zeolite proved on its excellence and confirmed the possibility of application of apatite and zeolite as enhanced EK remediation method.

• Analytical Science and Technology
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• v.21 no.4
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• pp.296-303
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• 2008

This study was performed to establish an analytical method of PAHs in oil contaminated soil of these methods by evaluating the PAHs test methods from US EPA and ISO etc. The application to domestic contaminated soil leads to a conclusion that alumina column is a more effective clean-up procedure for oil contaminated soil rather than the others. It is proposed with the new analytical method of 12 PAHs except for more volatile compounds (naphthalene, acenaphthylene, acenaphthene, fluorene). The recovery of PAHs in this method ranged 67~107%. The oil contaminated soil samples were analyzed using GC/MSD. The concentration of PAHs ranged $78.68{\sim}275.57{\mu}g/kg$. The predominated compounds were fluoranthene, pyrene and chrysene attributing about 70% of total concentration. The level of Benzo[a]pyrene ranged $1.76{\sim}24.65{\mu}g/kg$.

• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.69-77
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• 2019

Among the many factors that threaten the improvement of public health and quality of life, the proportion of fine dust is not so small, and the kinds and causes of the dust are also diversified. However, the domestic measuring instrument is in the initial stage and the certification system is insignificant. Recognizing the threat of fine dust for a long time, the United States has established a protocol of measurement standards and measurement methods and applied the developed fine dust measuring device authentication system. Through this system, the United States is leading the world's fine dust industry, technology and market. The EPA, FRM and FEM of the fine dust-related protocol were analyzed to reduce the harmful effects of repeated fine dust every year. In addition, light scattering method and spectroscopy method which can measure in real time by measuring method were examined, and the types and characteristics of fine dust measuring instrument of international certification level were analyzed. Finally, development and service plan of the domestic fine dust measuring instrument are presented.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.421-425
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• 2001

Among the many parameters describing water quality, total nitrogen content(TN) is regarded as important one in relation to water quality management of the waterbodies for its role in eutrophication process. This study evaluated for accuracy, convenience and promptness of nitrogen analysis methods : (1)UV spectrophotometric method, (2)summation method, (3)cadmium reduction method. And, the detection limit of each method was calculated using EPA method. The UV spectrophotometric method after oxidation appears to be more convenient and accurate in determination of the TN contents than the summation method and cadmium reduction method. The summation method is necessary to separate determinations of the organic nitrogen, ammonia, nitrite, and nitrate. And, because summation method has many other methods for each contents, it can be detected for wide range of concentration.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.57-62
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• 2000

This experiment was done to investigate the leaching and adsorption properties of heavy metals on porphyry. The comparison with respect to the leachability of heavy metals from porphyry between the Korea Standard Leaching Test (KSLT) and the Toxicity Characteristic Leaching Procedure (TCLP) was carried out. The fractional composition of leachate and the total concentration of heavy metal of porphyry were studied through Sequential Extraction Procedure (SEP) and EPA Method 3050. Adsorption experiment of porphyry has pointed out that the optimum dosage of porphyry for 50ppm Pb was over 10g/L, the effective particle size for absorption was below 200 mesh and the optimum pH was about 7. From the Freundlich' adsorption equation, 1/n was 1.0722, and k was 0.0041. After adsorption, the fractional composition of Pb was changed. The exchangeable, carbonate, reducible fractions were increased, and the organic fraction was not changed, and the residual fraction was decreased.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.1
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• pp.37-47
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• 2014

In this study, field measurement was carried out for reasonable improvement of asphalt concrete manufacturing facilities' PM emissions estimation method. Through those, this study calculated PM emission factor and tried to estimate PM emissions from asphalt concrete manufacturing facilities suitable for domestic characteristics. As a result, the efficiency of the PM control device was measured as 99.9%. Using this, uncontrolled PM emission factor was calculated. PM emission factor was calculated 10.97 kg/ton at 23 asphalt concrete manufacturing facilities of 22 workplaces. The PM current emission factor of the US Environment Protection Agency (EPA) is 14.4 kg/ton, the factor calculated from this study is about 24% lower than the EPA standard.

• Journal of the Korean Institute of Gas
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• v.20 no.4
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• pp.15-24
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• 2016

In the semiconductor industry, the risk of chemical accidents due to miscibility between the many types of chemicals and leakage of toxic chemicals has increased. In order to evaluate the reactivity with miscibility of chemicals, experimental method is the most reliable, but there is a time and cost limitations to be evaluated through experiment all the chemicals. In the study, the reactivity of process gases in the semiconductor industry was considered by the CRW (Chemical Reactivity Worksheets) 3.0 program developed by US NOAA (National Oceanic and Atmospheric Administration) and EPA. The reactivity informations with the miscibility of process gases for semiconductor industry provided, and also a KOSHA guide for the storage/separation of gas cylinders in dispensing cabinets in the semiconductor industry was proposed.

• Journal of the Korean Chemical Society
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• v.37 no.6
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• pp.590-598
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• 1993

The simultaneous analysis of samples, 16 organic pesticides in water among 129 priority pollutants listed by EPA, was performed by GC-ECD (electron capture detector) and GC/MS-SIM (selected ion monitoring). Two extraction procedures, liquid-liquid extraction (LLE) and solid-phase extraction (SPE), were studied as an extraction and concentration method. Accuracy and precision of the methods were measured by the calculation of mean recovery and mean relative standard deviation. Finally, the detection limits, the experimental limitations, and prospects were discussed.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.4
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• pp.85-89
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• 2021

AlGaN-based UV-C light-emitting diodes (LEDs) were applied for p-type activation by electrochemical potentiostatic activation (EPA). The p-type activation efficiency was increased by removing hydrogen atoms through EPA treatment using a neutral Mg-H complex that causes high resistance and low conductivity. A neutral Mg-H complex is decomposed into Mg^- and H⁺ depending on the key parameters of solution, voltage, and time. The improved hole carrier concentration was confirmed by secondary ion mass spectroscopy (SIMS) analysis. This mechanism eventually improved the internal quantum efficiency (IQE), the light extraction efficiency, the leakage current value in the reverse current region, and junction temperature, resulting in better UV-C LED lifetime. For systematic analysis, SIMS, Etamax IQE system, integrating sphere, and current-voltage measurement system were used, and the results were compared with the existing N₂-annealing method.