• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.2
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• pp.63-71
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• 2011

A large volume of uranium electrokinetic leachate has been generated during the electrokinetic decontamination to remove uranium from contaminated soil. The treatment technology for the reuse of the uranium leachate was developed. The concentration of uranium in the generated uranium leachate was 180 ppm and concentrations of Mg(II), K(I), Fe(II), and Al(III) ions ranged from 20 ppm to 1,210 ppm. The treatment process for uranium leachate consisted mainly of mixing and cohesion, precipitation, concentration, and filtration. In order to obtain the pH=11 of a precipitate solution, the calcium hydroxide needs to be 3.0g/100ml and the sodium hydroxide needed to be 2.7g/100ml. The results of several precipitation experiments showed that a mixture of NaOH+0.2g alum+0.15g magnetite was an optimal precipitant for filtration. The average particle size of precipitate with NaOH+alum+0.15g magnetite was $600\;{\mu}m$. Because the total value of metal concentrations in supernatant at pH=9 was the smallest, sodium hydroxide should be added with 0.2g alum and 0.15g magnetite for pH=9 of leachate.

• Composites Research
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• v.37 no.3
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• pp.204-208
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• 2024

De-icing/anti-icing fluid is essential for removing ice formation on aircraft. It chemically removes ice using organic solvents, which can cause damage to the topcoat surface in the process. In this study, glycol-based deicing/anti-icing fluid was used to remove ice, and the resulting damage to the topcoat was examined. USB microscope was used to observe the formation and growth of ice, while a confocal microscope was employed to observe the surface morphology after treatment with de-icing/anti-icing fluid. Additionally, coating thickness measurements and Fourier transform infrared (FT-IR) analysis were conducted to investigate the physical and chemical changes on the surface. The repeated application of de-icing/anti-icing fluid showed a reduction in the ice formation rate and an increase in the growth rate. Damage during the pressurization process and surface damage to the polyurethane topcoat caused by ethylene glycol were observed during the de-icing process. Although no chemical changes were detected, the analysis revealed that surface uniformity decreased, with physical damage such as cracks and undulations forming on the surface. It was confirmed that while de-icing/anti-icing fluid is effective in removing ice, it also causes surface damage.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.122-122
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• 2017

재해로부터 국민의 인명과 재산을 보호하기 위해서는 재해 발생의 빈도 증가와 대형화 추세에 따라 예상되어지는 피해규모의 분석과 예측을 통한 대책 마련이 필요하다. 한국의 경우 피해지역 조사를 통하여 획득한 피해일시, 피해시설물, 피해내역, 피해액과 같은 피해액 정보를 관리하는 국가재난관리시스템(National Disaster Management System, NDMS)이 운영되고 있다. 그러나 공공시설물 중 가장 많은 피해액을 나타내고 있는 하천시설물에 대한 피해규모의 예측에 대한 연구는 전무한 실정이다. 본 연구에서는 국가재난관리시스템의 과거 하천 피해정보를 이용하여 하천의 구간별 평균유속과 피해연장으로부터 하천의 피해액을 추정할 수 있는 하천 손실함수를 개발하였으며, 시범 대상지역에 적용하여 검증하였다. 하천 손실함수는 향후 피해액 추정에 따른 피해규모 분석을 통하여 재해저감대책을 마련하는데 필요한 유용한 정보로 활용될 수 있을 것이다.

• Development and Reproduction
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• v.6 no.2
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• pp.97-104
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• 2002

In most mammals, mature oocyte-cumulus complexer(OCCs) ovulate into the oviduct where fertilization by sperm takes place. However, the complex that fail to fertilize eventually undergoes degeneration while they reside in the oviduct. Yet there is no blown mechanism how both oocyte and cumulus cells degenerate. Using human follicular fluid (hFF), bovine oviductal tissue extract (BOX) and mouse OCC, the present study aimed to find how the oviduct influence the viability of the oocyte and cumulus cells in vitro. There was no difference of oocyte maturation rate between the control and BOX-treated groups. However, there was a significant difference in the survival of cumulus cells between two groups. Cumulus cells cultured in the presence of hFF alone underwent initially expansion and then they formed monolayer in the culture dish. Even after 72 hr, they proliferated well and showed fibroblast-like morphology. Cumulus cells cultured in the presence of both hFF and BOX also expanded after 24 hr, however, after 72 hr culture, they eventually detached and degenerated. Cumulus cells cultured in the BOX alone gave a similar drastic result. When the cumulus cells cultured in the presence of BOX were stained with DAPI, their nuclei showed partial condensation and fragmentation. After detailed analysis of these cells by TUNEL assay, many nuclei of them exhibited well stained spots indicating the signs of apoptosis. Based upon these observations, it is suggested that BOX might possess a factor that leads mouse cumulus cells to undergo apoptosis in vitro.

• Fire Science and Engineering
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• v.30 no.6
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• pp.71-77
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• 2016

The electrolyte of the capacitor in mobile phone chargers leaks to the power input terminal resulting in tracking on the PCB board to form a carbonized conductive path. As a result of structural analysis of the cause of the tracking, It occurred when the power input terminal and the PCB board were connected directly using the connector. The larger the amount of electrolyte leaked from the capacitor into the power input terminal, or the lower the height of the partition provided between the plug pins of the power input terminal, the higher the tracking occurrence rate. Accordingly, to lower the occurrence rate of tracking in the charger, it is necessary to provide a partition on the capacitor or increase the height of the partition provided on the power input terminal so that the leaked electrolyte does not flow to the power input terminal. In addition, the tracking occurrence rate will be reduced further if the shape of the PCB board touching ther power connection terminal is changed to ${\Pi}$.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.431-437
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• 2005

In korea, Freight generation models developed in korea were estimated by spatial unit method which predict freight flow by traffic zone. But it is difficult to predict freight generation using these models, because there are the difference of the totality method of sampling data on freight volume and the variability of the variables by these models on each case study, This study developed new estimation model to predict freight flow which is generated from each company using the characteristics of each company such as the freight outbound & inbound volume, the number of employee, sales, gross area, land area. This model is simpler than the that of spatial unit and can apply to the other region. The subjects of study were companies in metropolitan area and types of model were exponential regression models. The adequate explanatory variable in the models were sales. this study have a uniqueness apply micro research method to estimate freight generation not use spatial unit method but use flow unit method by each company unit.

• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.180-184
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• 2013

Study on extraction and concentration of mulberry leaf were performed to increase utilization as new source of food additives. We analyzed extraction method in EtOH, sugar and hot water solution. The desirable method was 70% alcoholic extraction. Color of concentrate was comparatively stable in 70% alcoholic extraction solution and sugar solution. But hot water extraction was showed color change with brown. By filtering of concentrate in 70% alcoholic extraction and sugar extraction, we removed a deposits. Also, we investigated characteristics of the concentrate from mulberry leaf.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2016.11a
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• pp.203-204
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• 2016

최근 자연재난으로 인한 인명피해는 감소하는 추세를 나타내고 있으나, 기후변화 및 도시화 등으로 인해 재산피해는 점차 증가하고 있는 실정이다. 기존의 연구는 재난이 일어난 후 사후복구차원에서 피해액을 집계하거나 복구비를 추정하는 연구가 주를 이루고 있으며, 재난이 발생하기 전에 피해액을 추정하는 연구는 매우 미흡한 실정이다. 따라서 본 연구에서는 과거 통계자료를 기반으로 인공신경망과 다중회귀분석을 이용하여 전체 자연재난 피해액의 약 95%를 차지하는 호우피해액을 예측하기 위한 피해함수 개발하고자 한다. 대상지역으로는 경기도 지역으로 선정하였고, 1994년부터 2015년까지의 수문기상자료와 시군구별 재해통계자료를 수집하여 분석을 위한 함수개발을 위한 자료로 재구축하였다. 또한 시간별 최대 강우량과 피해액에 대한 상관분석을 실시하여 지속시간별(1~24시간) 최대강우 자료와 재해기간별 선행강우(1~5일)자료, 그리고 재해기간의 총강우량 자료가 상관성이 높다는 것을 파악했다. 이를 독립변수로 활용하고, 재해기간별 피해액을 종속변수로 사용하여 지역별 호우피해 예측함수를 개발하였다. 본 연구는 효율적이고, 효과적으로 재해예방을 위한 방재체계를 수립하는데 기초자료로 활용될 것으로 판단되며, 사전대비 차원의 재난관리를 통해 정책결정권자들의 의사결정에도 도움을 줄 수 있다고 판단된다.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.214-224
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• 1998

This study was conducted to develop labor and chemical cultural practice improvement for weed control in ginseng field. Five crop species were screened in vitro and three crop extracts were sprayed in the test allelopathic effect for weed species. Methyl alcohol extracts of rice, oat, rye and wheat straw showed inhibitory effect on the germination of six weed species, Amaranthus retroflexus, Chenopodium album, Arthraxon hispidus, Digitaria adscendens, Echinochloa crus-galli, and Setaria viridis. Especially, extract of oat straw was most effective to inhibit the germination of six weed species tested. Also, spraying the extract solution of rice, rye and wheat straw was effective to inhibit the growth of weeds in ginseng field. Ginseng root length, diameter, fresh and dry weight in extract spraying plot were higher than those of non-treatment plot.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.177-177
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• 2021

우리나라는 최근 이상기후로 유발되는 여름철 태풍과 집중호우로 인해 매년 심각한 홍수피해가 발생되고 있다. 또한, 도시화에 따른 자산 및 인구의 집중화로 인해 홍수피해 규모도 지속적으로 증가하고 있다. 이와 같은 재난 발생 시 위험도를 저감하기 위해서는 재난에 대한 예방이 선행되어야 한다. 한정된 예산에서 효율적인 재난관리의 일환으로 경제성 분석이 있는데, 이는 경제성이 높은 사업을 우선적으로 순위에 두고 시행하는 것이다. 다차원 홍수피해 산정법(이하 다차원법)은 2004년에 개발된 경제성 평가모형으로서, 예상피해액 산정 결과가 개선법에 비해 정확하다고 평가되고 있다. 하지만 다차원법에 적용되는 토지피복도는 동일한 구역에 있는 군집으로 나누어진 자료로 건물피해액 산정 시 도로면적까지 포함되는 경우가 있어 실제 피해액이 과대평가되는 문제가 있다. 이에 본 연구에서는 도로명주소 전자지도를 활용해 다차원법을 보완하고자 하였다. 여기서 도로명주소 전자지도는 폴리곤 객체 단위로 건물이 구현되는 공간분석 자료로 건물피해액 산정 방법을 개선할 수 있다. 본 연구에서는 경안천 유역의 홍수위험지도를 사용하여 도로명주소 전자지도와 토지피복도를 각각 적용했을 때 나타나는 경제성 분석 결과를 비교분석 하였다. 분석 결과, 기존의 토지피복도를 사용한 피해액 산정결과보다 개선된 공간분석 자료를 적용했을 때 더 정확한 예측피해액 산정결과를 얻을 수 있었다. 본 연구에서는 다차원법의 일반자산 피해항목 중 건물피해 산정방법만을 개선시켰는데, 향후 연구에서 농업지역, 산업지역, 공공시설물 피해 등의 산정방법의 보완이 필요할 것으로 사료된다.