• 지질공학
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• 제28권3호
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• pp.367-377
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• 2018

이 연구는 전기비저항 역산의 해상도를 높이기 위한 구조제약과 부등식 제약조건을 적용한 전기비저항역산법을 소개하고 적용한 결과를 보여준다. 이들 역산에서는 지하투과레이다와 표면파 탐사자료로부터 사전 해석된 층서구조를 전기비저항 참조모델로 도입하고 구조제약과 부등식 제약의 유용성을 합성모델을 이용한 역산실험으로 확인하였다. 연약지반 조건을 가정한 실험모델에 대한 구조제약과 부등식 제약 역산실험 모두 일반적인 전기비저항 역산보다 향상된 역산결과를 보여주었으나, 부등식제약 역산에서는 참조모델이 다소 부정확한 경우에도 배경층서구조를 정확히 재구성하는 동시에 천부(약 10 m 심도)의 전도성 이상체들도 정확히 나타내는 역산결과를 보여주었다.

• 자원리싸이클링
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• 제30권6호
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• pp.3-11
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• 2021

본 연구에서는 소듐바나데이트 수용액에 염화암모늄을 첨가하여 암모늄메타바나데이트를 침전시킬 때, 암모늄메타바나데이트의 용해도와 암모늄이온의 분해율이 침전반응에 미치는 영향을 알아보았다. 침전온도와 수용액 pH가 증가함에 따라 암모늄 이온의 분해율이 증가하였으며 45 ℃에서 수용액 pH 9.3일 때 분해율은 81% 이상으로 pH 8일 때와 비교하였을 때 약 4배 정도 증가하였다. 그러므로 침전 반응에 큰 영향을 미치는 침전온도와 수용액 pH 두 인자를 고려하여 침전반응을 수행한 결과, 침전온도가 증가함에 따라 침전속도가 증가하였으나 35 ℃ 이상에서는 침전온도의 영향이 크지 않았다. 침전반응 속도론적 고찰을 통하여 얻은 침전반응의 활성화 에너지는 42.3 kJ/mol이었다. 이와 같은 연구를 통하여 암모늄메타바나데이트의 용해도를 고려하였을 때 침전온도는 낮을수록 바나듐 회수율에 유리하였다. 또한 암모늄 이온의 분해를 고려하였을 때 수용액의 pH는 낮을수록 유리하나 pH 8 이하에서는 소듐폴리바나데이트가 침전되며 바나듐 산화물의 순도 저하가 야기될 수 있었다.

• 한국해양환경ㆍ에너지학회지
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• 제18권3호
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• pp.216-222
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• 2015

기존의 자동음파전달속도 측정시스템을 이용하여 해양퇴적물의 음향특성을 측정하는 경우 최초도달신호시간의 결정에 발생하는 오류와 측정 절차의 번거로움 등의 몇 가지 문제점들이 존재한다. 이러한 문제점을 개선하기 위하여 PXI모듈을 이용한 LabVIEW기반의 측정 시스템을 개발하였다. 새로운 측정시스템을 검증하기 위해 동일한 시료와 실험환경에서 기존 시스템과 병행하여 측정하였다. 그 결과 1~2%의 음파전달속도 측정오차를 보였으며 음파감쇠 역시 기존 시스템과 유사한 결과 값을 도출하였다. 새로이 개발된 PXI(PCI eXtentions for Instrumentation)를 이용한 LabVIEW 기반 음향특성 측정시스템은 퇴적물의 음향특성을 보다 신속하고 효율적으로 측정할 수 있고 측정 자료뿐만 아니라 분석된 신호의 원시자료에 대해서도 지속적인 데이터베이스를 구축할 수 있다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.847-854
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• 2004

The resistivity of soils depends on grains size, porosity, water saturation, pore fluid resistivity, caly contents and son on. It is very important to understand the relationship between resistivity and such physical properties of soils, in order to interpret and evaluate ground conditions by using resistivity data obtained from electrical resistivity prospecting. In this paper, to study the relationship between resistivity and physical properties of soils, the resistivity of glass beads and compacted soil samples both in saturated and unsaturated conditions is measured. As the results, the resistivity of saturated soils depends mainly on porosity and clay contents, while that of unsaturated soils is sensitive to compaction conditions, and decreases with increasing water content until the optimum water condition, that is the maximum dry density. But, the relationship between resistivity and water saturation for soils is unique, being independent of compaction energy. Also, the resistivity ratio decrease with increasing water saturation, followed by no significant change of resistivity ratio over 80 percent of water saturation (the optimum water content).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.409-412
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• 2001

The high purity manganese oxides were made from the dust, generated in AOD process that produces a medium-low carbon ferromanganese and collected in the bag filter. Manganese oxide content in the dust was about 90%, and its phase was confirmed as Mn₃O₄. In the extraction of manganese, because of remaining amorphous MnO₂, the dust was reduced to MnO by roasting with charcoal. The pulp density of the reduced dust can control pH of the solution more than 4 and then Fe ion is precipitated to a ferric hydroxide. Because a ferric hydroxide co precipitates with Si ion etc, Fe, Si ion was removed f개m the solution. Heating made water to be volatized and nitrates was left in reactor Then nitrates were a liquid state and stirring was possible. Among the nitrates in reactor, only the manganese nitrate which have the lowest pyrolysis temperature pyrolyzed into β-MnO₂powder and NO₂(g) at the temperature less than 200℃. When the pyrolysis of manganese nitrate has been completed about 90%, injection of water stopped the pyrolysis. Nitrates of impurity dissolved and the spherical high purity β-MnO₂powders were obtained by filtering and washing. Mn₂O₃or Mn₃O₄ powder could be manufactured from β-MnO₂powder by controlling the heating temperature. Lastly, a manufactured manganese oxide particle has 99.97% purity.

• 자원리싸이클링
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• 제7권1호
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• pp.7-13
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• 1998

The electric arc furnace (EAF) dust used in this experiment showed the formation of an irregular agglomerate of small spherical particles and consisted of 27.5% Fe, 18% Zn, 4.83% Pb and 10.2% CaO, and it also contained 3.26% Cl and 0.15% F. IR spectra peaks of Pb(OH)Cl were observed at 1630 and 1377 ${cm}^{-1}$ regions and the intensity decreased using an acid treatment (1N ${H}_{2}{SO}_{4}$) and thermal treatment at above 600℃, but it was not affected by washing process. Those of ${Zn}_{5}{(OH)}_{8}{Cl}_{2}$ treated by oxidation showed broad absorption peak at 3600∼3200 ${cm}^{-1}$, main peaks at 1136 and 1040 ${cm}^{-1}$ and a splitting peak at 991 and 921 ${cm}^{-1}$ which were believed to be due to ZnO by oxidation at about 700∼. The IR spectra of the dust residues by a washing process show the same peaks at 3449, 1635, 1439, 875, 571 and 455 ${cm}^{-1}$ regions, but the peaks at 2942, 2862, 1136 and 1040 ${cm}^{-1}$ decreased and disappeared using an acid treatment and washing process, which is believed to be due to the dissolution of zinc hydroxyl chloride.

• 자원환경지질
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• 제51권3호
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• pp.279-289
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• 2018

2017년 신정부 출범과 함께 문재인 정부 국정운영 5개년 계획 및 100대 국정과제가 발표된 바 있으며, 과학기술정보통신부, 산업통상자원부, 해양수산부, 국토교통부, 환경부, 행정안전부 등의 정부부처는 R&D 분야를 포함한 2018년 업무계획을 발표하였다. 정부 정책의 변화를 분석하고 그에 따른 연구개발을 추진하는 것은 공공 연구개발 기관의 주요 임무일 것이다. 이에 연구에서는 신정부의 R&D 정책 변화와 2018년도 지질자원 관련 정부부처 R&D 정책 방향 및 전략 계획을 분석하였다. 분석 결과 1) 과학기술 전반에서 4차 산업혁명을 통한 혁신성장 주도와 2) 환경 에너지 분야의 청정에너지 공급 및 기후변화 대응, 3) 국민생활문제 해결 및 재난 대응을 통한 국민 삶의 질 향상의 정부정책 방향을 확인할 수 있었다. 정부의 투자방향을 고려하여, 국가사회의 문제 해결 및 과학기술로 인한 성장을 위한 지질자원 분야 연구개발 주도가 필요하다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권2_spc호
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• pp.55-69
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• 2020

Permeability-analyzing methods commonly involve small-scale drilling, such as pumping or slug test, but it is difficult to identify overall distribution of permeability of the entire target sites due to high cost and time requirement. Spectral induced polarization (SIP) method is known to be capable of providing distributions of both the porosity and the pore size, the two major parameters determining permeability of the porous medium. The relationship between SIP variables and permeability has been studied to identify the hydrological characteristics of target sites. Kozeny-Carman formula has been improved through many experiments to better predict fluid permeability with electrical properties. In this work, the permeability prediction techniques based on SIP data were presented in accordance with the hydrogeological and electrical characteristics of a porous medium. Following the summary of the techniques, various models and related laboratory experiments were analyzed and examined. In addition, the field applicability of the prediction model was evaluated by field case analysis.

• 환경영향평가
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• 제22권4호
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• pp.381-387
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• 2013

In order to improve the environmental vibration, it is necessary to method for not only reduce the vibration source, but also control the vibration path. In this study, we used borebole for estimate the vibration reduction. And also, we analyzed displacement and vibration velocity caused by the position of borehole as well as the condition of borehole in ground structure. Visual FEA(Finite Element Analysis) program was used in this numerical analysis. The results are as follows : The displacement magnitude and X, Y direction displacement were represented to different results due to the condition and position of borehole, and were represented to the lowest values when the position of borehole is the most close condition from the vibration source. And also, the vibration velocity was decreased as using borebole in ground structure. The isolation efficiency of the vibration was calculated to maximum 18.40% when borehole was established to the most close position from the vibration source and the receive point.

• 산업기술연구
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• 제41권1호
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• pp.21-24
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• 2021

In this study, the development and production of electric vehicles and hydrogen vehicles are presented as a method for realizing carbon-neutral. Accordingly, the demand and need for development of underground metal mineral resources such as copper and nickel has increased. The research was carried out using MT survey, which is very useful for deep exploration such as mineral resources and oil exploration because of it's low cost and explorable depth. In Korea, there are very few cases of MT exploration in terms of mineral development, so the study was conducted based on the MT exploration conducted previously in AusLAMP, Australia. Through comparative analysis of the MT exploration data conducted to identify the ore body in the deep area of the Olympic Dam in Australia, with the data directly calculated in 2D inversion, it was confirmed that it can have a positive effect on the possibility of resource development and carbon neutrality using MT exploration in Korea.