• Analytical Science and Technology
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• v.9 no.2
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• pp.210-219
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• 1996

Extraction of minerals in deionized water and elimination effect of heavy metals in water by Nohwado Quartz Porphyry were examined. When the Nohwado Quartz Porphyry was immersed and stirred in deionized water at 0.5, 1.0, 1.5 and 2.0% concentration for 3 hours, various minerals concentration of the all stirred water were suitable for potable water. Particularly, when the lead, copper, cadmium and arsenic solution were shaked with Quartz Porphyry at $20^{\circ}C$ for 24 hours, the elimination rate of each mineral was 99.5, 99.9, 95.0 and 66.5%, respectively.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.2 s.12
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• pp.59-67
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• 1998

This study deals with a auto-extraction of land characteristics using a GSIS. Major algorithm and a evaluation program was developed to automate the entire Process of land characteristics survey Through the automatic extraction of land information. To establish such a process, a method was provided to automatically extract detailed land information such as the shape, height, direction, road contact conditions, which could not be available in previous studies. The results showed that the adoption of such a automated process could lead the whole works related to the official land-value evaluation and securing residential complex to be more efficient and cost-saving in a scientific way comparing with existing process.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.9
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• pp.25-34
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• 1999

In spite of the advance of 3D solid modeling technology, there are some distinct areas where 2D CAD S/W are still dominant, and more competent comparing with 3D CAD S/W. For example, in the manufacturing of 2D-shaped electrical parts, most related manufacturing tools have 2D geometric features by nature, and 3D solid models applied to these parts have substantial overheads. Nevertheless, most 2D CAD S/W have no topological inquiry services because they have no such information on their geometrical database inherently. Thus, it is needed to extract such information from 2D CAD database for developing more advanced application such as automated drafting/design S/W. In this paper, the extraction of topological information from 2D CAD has been performed in general way using concept of B-rep. A general extraction algorithm, data structure and meta file format for 2D topological object have been developed and successfully applied to the development of the automated lead frame die design system in Samsung Aerospace. it is also possible to provide a flexible, powerful topology-oriented functionality on any common 2D CAD S/W.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.195-198
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• 2004

This study applied EK method to remediate contaminated soil by heavy metal(Pb), tried to increase the efficiency of remediation using zeolite as enhanced EK remediation method to overcome the limit of traditional EK remediation method. Adsorption tests on Pb were conducted to apply the EK extraction and test conditions which contained the electrode reversal, operating time were established. After tests, lead-ions were transported into the specific position of zeolite by EK phenomena, then the immobilization of lead-ions at zeolite was developed. Based on these tests, the efficiency of remediation is different with its test conditions. In addition, the efficiency of remediation was improved dramatically by adding zeolite without electrode reversal and satisfied TCLP regulation of EPA in USA through the whole sample range. Finally, absorption and immobilization capacity of zeolite were proved its excellence and confirmed the possibility of application as enhanced EK remediation method.

• Corrosion Science and Technology
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• v.5 no.6
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• pp.201-205
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• 2006

HYPER(Hybrid Power Extraction Reactor) is the accelerator driven subcritical transmutation system developed by KAERI(Korea Atomic Research Institute). HYPER is designed to transmute long-lived transuranic actinides and fission products such as Tc-99 and I-129. Liquid lead-bismuth eutectic (LBE). Has been a primary candidate for coolant and spallation neutron target due to its appropriate thermal-physical and chemical properties, However, it is very corrosive to the common steels used in nuclear installations at high temperature. This corrosion problem is one of the main factors considered to set the upper limits of temperature and velocity of HYPER system. In this study, a parametric study for a corrosion model was performed. And a preliminary corrosion model was also developed to predict the corrosion rate in isothermal Pb and LBE flow loops.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.466-468
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• 2002

본 논문은 신문기사를 추출(Extract)하는데 있어서, 신문기사의 구조적인 특징을 분석한 후, 6하원칙(5W1H)과 전문(Lead)과의 관계를 유추하여 신문기사를 효과적으로 요약하기 위한 방법과 알고리즘을 제안하였다. 본 연구에서는 먼저 신문기사에서 가장 중요한 단락인 전문에서 6하원칙의 각 구성성분을 추출하고, 본문에서는 전문에 나타난 6하원칙의 각 성분이 어떻게 재사용되며 강조되고 있는가를 파악하기 위래 제안된 방법과 알고리즘을 이용하여 중요한 문장을 추출하였다. 실험문서는 조선일보 웹사이트에서 제공하는 신문기사 100건을 대상으로 하였으며 요약율이 20%와 30%일 경우 제안한 방법의 정확률은 각각 82.4%와 74.1%로 기존의 전문기반(Lead-based)방법보다 3.6%와 6.3% 향상되었다.

• Journal of Soil and Groundwater Environment
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• v.24 no.6
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• pp.1-8
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• 2019

This study evaluated the relative extraction ratio (RER) of As and heavy metals (Cd, Cu and Pb) in paddy soils using the two types extractant, 0.05 M EDTA and 0.43 M HNO₃. The RER was calculated by dividing the concentrations of metals obtained by 0.05 M EDTA or 0.43 M HNO₃ extraction by those obtained by aqua regia extraction. The RER of 0.43 M HNO₃ was larger than that of 0.05 M EDTA. Correlation analysis indicated there was statistically significant correlation (p<0.001) between the concentration in aqua regia and 0.05 M EDTA or 0.43 M HNO₃. Especially, Cd showed the higher correlation than other metals. Stepwise multiple linear regression analyses indicated soil pH, CEC, organic matter content, and soil texture all influenced the metal extraction rates and bioavailability of the metals.

• Natural Product Sciences
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• v.23 no.2
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• pp.75-83
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• 2017

The optimization and microwave assisted extraction of stem bark of Terminalia arjuna, quantitative estimation of the marker compounds arjunic acid and arjunolic acid using HPTLC and the evaluation of free radical scavenging activity has been performed in this study. The central composite design was used for optimization and the values of parameters for optimized batch of microwave assisted extraction were 1000 W (Power), 3 minutes (Time) and 1/120 (Solid/solvent ratio). The solvent system to carry out the HPTLC was toluene: acetic acid: ethyl acetate (5: 5: 0.5) and quantitative estimation was done using standard equations obtained from the marker compounds. The in-vitro free radical scavenging activity was performed spectrophotometrically using ascorbic acid as standard. The value of estimated percentage yield of arjunic acid and arjunolic acid was 1.42% and 1.52% which upon experimentation was obtained as 1.38% and 1.51% respectively. The DPPH assay of the different batches of microwave assisted extraction and marker compounds taken suggested that the marker compounds arjunic acid and the arjunolic acid were responsible for the free radical scavenging activity as the batch having the maximum percentage yield of the marker compounds showed best free radical scavenging effect as compared to standard ascorbic acid. The $IC_{50}$ value of the optimized batch was found to be 24.72 while that of the standard ascorbic acid was 29.83. Hence, the yield of arjunic acid and arjunolic acid has direct correlation with the free radical scavenging activity of stem bark extract of Terminalia arjuna and have potential to serve as active lead compounds for free radical scavenging activity.

• Journal of Food Hygiene and Safety
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• v.1 no.1
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• pp.31-38
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• 1986

In order to investigate the harmful trace elements in Korean common vegetable, the contents of Lead, Cadmium, Copper, Zinc and Manganese are studied in this paper. As shown in the Table 1, the following vegetable samples collected from the agriculture-marine products market I Seoul were used; root vegetables-potato, sweet potato, carrot, radish, onion and garlic, fruit vegetables-cucumber, pumpkin, green pepper, egg plant, tomato and melon. The contents of the harmful trace elements were determinded by means of atomic absorption spectrophotometry. These elements were extracted from the vegetables with the DDTC-MIBK extraction method. The results were as follows; 1. The average contents of the harmful trace elements in the vegetables were as follows; Root vegetables-Lead, 0.387 ppm; Cadmium, 0.030 ppm; Copper, 1.267 ppm; Zinc, 7.395 ppm; Manganese, 5.380 ppm. Fruit vegetables-Lead, 0.259 ppm; Cadmium, 0.028 ppm; Copper, 1.155 ppm; Zinc, 3.732 ppm; Manganese, 3.532 ppm. 2. The contents of harmful trace elements in vegetables were significantly low compared with foreign standards. This means that vegetables contamination with those harmful trace elements is not significant at present.

• Journal of Soil and Groundwater Environment
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• v.18 no.7
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• pp.1-11
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• 2013

The actively soil pollution by the toxic heavy-metals like the arsenic, cadmium, lead due to the industrialization and economic activity. The uses the electrokinetic remediation of contaminated soil has many researches against the fine soil having a small size in the on going. However, it is the actual condition which the research result that is not effective due to the low surface charge of the particle and high permeability shows in the electrokinetic remediation in comparison with the fine soil in the case of the sandy soil in which the particle size is large. In this research, the electrokinetic remediation and ultrasonic wave fetch strategy is compound applied against the sandy soil polluted by the arsenic, cadmium, and lead removal efficiency of the sandy soil through the comparison with the existing electrokinetic remediation tries to be evaluated. First of all, desorption of contaminants in soil by ultrasonic extraction in the Pre-Test conducted to see desorption effective 5~15%. After that, By conducted Batch-Test results frequency output century 200 Khz, reaction time 30 min, contaminated soil used in experiment was 500 g. Removal efficiency of arsenic, cadmium, lead are 25.55%, 8.01%, 34.90%. But, As, Cd, Pb remediation efficiency less than 1% in EK1(control group).