• 제목/요약/키워드: earth environment

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토양 중 무기 오염물질의 용출 특성 (Dissolution Properties for the Inorganic Pollutants in Soils)

  • 정강섭;최병인;김상연;송덕영;김건한;성학제
    • 분석과학
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    • 제12권1호
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    • pp.53-60
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    • 1999
  • 토양 중에 존재하는 무기 오염물질의 용출 특성을 조사하였다. 현재 토양환경보전법에서 오염물질로 규정하고 있는 중금속들을 중심으로 As, Cd, Cu, Pb, Zn, Cr 등 6성분에 대하여 그 오염도를 측정하는 과정에서 수반되는 용출 시험의 기초자료 확보와 오염토양 분석법 개선을 위해 모래, 점토 및 양토 시료에 대해 다양한 용출 조건 변화에 따른 각 오염성분들의 용출 특성을 조사하였다. 용출 특성에 가장 큰 영향을 주는 요소는 용출시험시 사용되는 산 농도와 토양시료 자체의 흡착능력을 좌우하게 되는 구성 광물의 조성인 것으로 나타났다. 반면, 산의 종류나 용출 시간 및 토양을 구성하고 있는 입자의 크기는 용출 효율에 크게 영향을 주지 않았다. 실험 전반에 걸쳐 Cd 성분은 토양종류에 상관없이 매우 낮은 산 농도에서도 높은 용출 효율을 나타내었고 As 성분은 가장 낮은 용출 효율을 보였다.

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지구과학에서의 가상 현실의 사용에 따른 예비 과학교사의 학습환경 인식 연구: 시험적 적용 (A Study on Pre-Service Teachers' Perception of Learning Environment in Earth Science with Using Virtual Reality (VR): An Exploratory Case)

  • 신명경;김희수;김종헌
    • 한국지구과학회지
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    • 제27권3호
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    • pp.269-278
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    • 2006
  • 본 연구에서는 교양지구과학과목을 수강하는 36명의 예비과학교사를 대상으로 가상현실(VR)의 사용을 한 차시에 걸쳐 시도하였다. 수업을 하기 전과 후에 구성주의 학습환경 조사(CLES)를 실시하였다. CLES의 주된 초점은 수업이 학생중심 수업환경을 얼마나 잘 보조하고 지원하는가다. 학생의 자신의 수업환경에 대한 사전 및 사후검사는 여섯가지 하위 영역으로 나뉜다.: 학생적절성, 비판적 시각, 교실통제의 나눔, 학생 간의 타협, 과학적 불확정성, 태도이다. 아울러 가상현실에 대한 미래교사의 인식에 대한 설문지도 실시하였다. 미래의 과학교사들이 가상현실 자료를 교실에서 사용하는 것에 대하여 어떻게 생각하는가를 본 연구를 통해 알아보고자 했다. 이들 결과를 바탕으로 교사 주도의 수업환경을 학생의 적극적 참여를 유도하는 수업에로의 변화를 도모하는 것과 같은 기존에 연구되지 않은 측면을 제안하여가상현실의 잠재력에 대한 보다 완벽한 이해를 꾀하려 하였다.

복토 주택의 외벽면 복토 두께 변화에 따른 열부하 패턴에 관한 연구 (A Study on the Thermal Load Patterns for a Exterior Wall in a House According to a Variation of Earth Sheltering Thickness)

  • 이재혁;최원기;서승직;조동우
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.807-812
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    • 2008
  • The various attempts is made to solve the energy and environment problems. In addition, people interested in their life quality want the more eco-friendly living space. So we suggested that the earth-sheltered house could be one of the eco-friendly and low energy consuming houses to meet the social interest. And we also made data for design of the earth-sheltered house to be applicable to climate of Korea. In this study, a simulation was performed to estimate a boundary temperature according to earth sheltering thickness at the earth-sheltered part(exterior wall) in the case of earth sheltering on the plane ground not using a sloped site. And we analyzed the reduction of a thermal load by using this boundary temperature. We also compared a case of earth sheltering at the vertical wall with a case of earth sheltering at the roof to know the thermal reduction effect of a case of earth sheltering at the vertical wall.

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Effect of land use and urbanization on groundwater recharge in metropolitan area: time series analysis of groundwater level data

  • Chae, Gi-Tak;Yun, Seong-Taek;Kim, Dong-Seung;Choi, Hyeon-Su
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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    • pp.113-114
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    • 2004
  • In order to classify the groundwater recharge characteristics in an urban area, a time series analysis of groundwater level data was performed. For this study, the daily groundwater level data from 35 monitoring wells were collected for 3 years (Fig. 1). The use of the cross-correlation function (CCF), one of the time series analysis, showed both the close relationship between rainfall and groundwater level change and the lag time (delay time) of groundwater level fluctuation after a rainfall event. Based on the result of CCF, monitored wells were classified into two major groups. Group I wells (n=10) showed a fast response of groundwater level change to rainfall event, with a delay time of maximum correlation between rainfall and groundwater level near 1 to 7 days. On the other hand, the delay time of 17-68 days was observed from Group II wells (n=25) (Fig. 1). The fast response in Group I wells is possibly caused by the change of hydraulic pressure of bedrock aquifer due to the rainfall recharge, rather than the direct response to rainfall recharge.

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배치 실험을 이용한 암모니아 제거 기작 및 효율 평가 (Evaluation of Ammonia Removal Mechanisms and Efficiencies Through Batch Experiments)

  • 장지은;강지영;김혜원;신규진;진성욱
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제27권6호
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    • pp.37-46
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    • 2022
  • As the amount of livestock wastewater increases, ammonia contamination in surface water and groundwater is also increasing, and its treatment is urgently needed. In this study, indigenous soil bacteria was utilized for ammonia removal in artificial wastewater and associated removal mechanisms and efficiencies were evaluated. Two batch reactors were configurated to contain natural soil and artificial wastewater at 1:10 mass ratio, and incubated for 84 and 168 hours, respectively. The results showed that ammonia was completely removed within 48 and 72 hours in the first and second reactors, respectively. There were no significant changes in ammonia concentrations in the control groups without soil. Nitrate was formed in the reactors, indicating that the main removal mechanism of ammonia was nitrification by nitrifying bacteria. Nitrate was further converted to nitrogen gas by denitrification in the anaerobic environment, which was caused by consumption of oxygen during the nitrification process.

오염부지 최적 개념모델 수립을 위한 전략적 샘플링 기법 소개 (Introduction to the Strategic Sampling Approaches to Construct Optimal Conceptual Model of a Contaminated Site)

  • 박현지;김한석;윤성택;조호영;권만재
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제25권2_spc호
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    • pp.28-54
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    • 2020
  • Even though a systematic sampling approach is very crucial in both the general and detailed investigation phases to produce the best conceptual site model for contaminated sites, the concept is not yet established in South Korea. The U.S. Environmental Protection Agency (EPA) issued the 'Strategic Sampling Approaches Technical guide' in 2018 to help environmental professionals choose which sampling approaches may be needed and most effective for given site conditions. The EPA guide broadly defines strategic sampling as the application of focused data collection across targeted areas of the conceptual site model (CSM) to provide the appropriate amount and type of information needed for decision-making. These strategic sampling approaches can prevent the essential data from missing, minimize the uncertainty of projects and secure the data which are necessary for the important site-decisions. Furthermore, these provide collaborative data sets through the life cycle phases of projects, which can generate more positive proofs on the site-decisions. The strategic sampling approaches can be divided by site conditions. This technical guide categorized it into eight conditions; High-resolution site characterization in unconsolidated environments, High-resolution site characterization in fractured sedimentary rock environments, Incremental sampling, Contaminant source definition, Passive groundwater sampling, Passive sampling for surface water and sediment, Groundwater to surface water interaction, and Vapor intrusion. This commentary paper introduces specific sampling methods based on site conditions when the strategic sampling approaches are applied.

황토벽돌벽 주택의 실내온열환경에 관한 연구 (A Study on the Indoor Thermal Environment of House Using Earth Brick Wall)

  • 이재윤
    • 한국주거학회논문집
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    • 제15권1호
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    • pp.25-32
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    • 2004
  • The purpose of this study is to understand the indoor thermal environment in the earth brick wall building what is called a ecological Architecture. To investigate thermal performances of the earth brick walls, it measured indoor and outdoor air temperature, relative humidity, globe temperature and PMV in reference house. The result of this study were summarized as the followings; 1) When the outdoor average air temperature was $21.8^{\circ}$, livingroom was $24.9^{\circ}$, kitchen was $25.1^{\circ}$ and 2nd floor room was $25.6^{\circ}$ at 150 cm height from the floor. 2) Although the average outdoor relative humidity was 78%, the livingroom was 67.5%. 3) As the air temperature difference between at the top and bottom was $0.6^{\circ}$ in living room, this value was below 1 % of PPD by ASHRAE Handbook. 4) Predicted Mean Vote(PMV) by ISO-7730 was +0.41.

Forecasting solute breakthrough curves through the unsaturated zone using artificial neural network

  • Yoon Hee-Sung;Hyun Yun-Jung;Lee Kang-Kun
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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    • pp.348-351
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    • 2005
  • In this study, solute breakthrough curves through the unsaturated zone were predicted using artificial neural network (ANN) by numerical tests and laboratory experiments. In the numerical tests, applicability of ANN model to prediction of breakthrough curves was evaluated using synthetic data generated by HYDRUS-2D. An appropriate strategy of ANN application and input data form were recommended. The ANN model was validated by laboratory experiments comparing with HYDRUS-2D simulations. The results show that the ANN model can be an effective method for forecasting solute breakthrough curves through the unsaturated zone when hydraulic data are available.

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