• 제목/요약/키워드: Earth′s surface environment

검색결과 131건 처리시간 0.027초

Sumithion 분제의 성분 변화에 영향을 미치는 증량제의 특성에 관한 연구 (Studies on the Characteristics of Mineral Diluents Affecting the Decomposition of Sumithion in the Dust formulations)

  • 우기대;한성식;금소승;안신훈;이춘영
    • 한국응용곤충학회지
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    • 제10권2호
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    • pp.77-83
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    • 1971
  • 증량제의 특성 중 Sumithion 분제의 주성분 분해에 영향을 미치는 요인을 밝힐 목적으로 시험하여 다음과 같은 결과를 얻었다. 가. 증량제의 특성 중 수분함량, 흡습성, C.E.C. 활성천, 염기총량, 표면적 등이 Sumithion 분제의 주성분 분해에 영향을 미치는 요인이 됨을 알았고, 나. 증량제에 의한 Sumithion의 분해산물은 Dimethyl phosphorothionate와 3-methyl-4-nirophenol 및 이의 유연화함은, n-hexane, ethyl ether 불용, methyl alcohol, ethyl, alcohol가용의 화함물이 있음을 알았다. 다. 증량제의 종류별로는 벤토나이트, 규조로, 카올린, 활석의 순으로 분해율이 높았다. 라. 그리고 증랑제의 Sumithion 분제 주성분 변화에 영향을 미치는 특성 중 수분과 염기가 가장 대표적인 주성분 분해 요인으로 보인다.

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A Study on groundwater and pollutant recharge in urban area: use of hydrochemical data

  • Lee, Ju-Hee;Kwon, Jang-Soon;Yun, Seong-Taek;Chae, Gi-Tak;Park, Seong-Sook
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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    • pp.119-120
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    • 2004
  • Urban groundwater has a unique hydrologic system because of the complex surface and subsurface infrastructures such as deep foundation of many high buildings, subway systems, and sewers and public water supply systems. It generally has been considered that increased surface impermeability reduces the amount of groundwater recharge. On the other hand, leaks from sewers and public water supply systems may generate the large amounts of recharges. All of these urban facilities also may change the groundwater quality by the recharge of a myriad of contaminants. This study was performed to determine the factors controlling the recharge of deep groundwater in an urban area, based on the hydrogeochemical characteristics. The term ‘contamination’ in this study means any kind of inflow of shallow groundwater regardless of clean or contaminated. For this study, urban groundwater samples were collected from a total of 310 preexisting wells with the depth over 100 m. Random sampling method was used to select the wells for this study. Major cations together with Si, Al, Fe, Pb, Hg and Mn were analyzed by ICP-AES, and Cl, N $O_3$, N $H_4$, F, Br, S $O_4$and P $O_4$ were analyzed by IC. There are two groups of groundwater, based on hydrochemical characteristics. The first group is distributed broadly from Ca-HC $O_3$ type to Ca-C1+N $O_3$ type; the other group is the Na+K-HC $O_3$ type. The latter group is considered to represent the baseline quality of deep groundwater in the study area. Using the major ions data for the Na+K-HC $O_3$ type water, we evaluated the extent of groundwater contamination, assuming that if subtract the baseline composition from acquired data for a specific water, the remaining concentrations may indicate the degree of contamination. The remainder of each solute for each sample was simply averaged. The results showed that both Ca and HC $O_3$ represent the typical solutes which are quite enriched in urban groundwater. In particular, the P$CO_2$ values calculated using PHREEQC (version 2.8) showed a correlation with the concentrations of maior inorganic components (Na, Mg, Ca, N $O_3$, S $O_4$, etc.). The p$CO_2$ values for the first group waters widely ranged between about 10$^{-3.0}$ atm to 10$^{-1.0}$ atm and differed from those of the background water samples belonging to the Na+K-HC $O_3$ type (<10$^{-3.5}$ atm). Considering that the p$CO_2$ of soil water (near 10$^{-1.5}$ atm), this indicates that inflow of shallow water is very significant in deep groundwaters in the study area. Furthermore, the P$CO_2$ values can be used as an effective parameter to estimate the relative recharge of shallow water and thus the contamination susceptibility. The results of our present study suggest that down to considerable depth, urban groundwater in crystalline aquifer may be considerably affected by the recharge of shallow water (and pollutants) from an adjacent area. We also suggest that for such evaluation, careful examination of systematically collected hydrochemical data is requisite as an effective tool, in addition to hydrologic and hydrogeologic interpretation.ion.ion.

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경관의 다양성에 관한 고찰 (A Treatise on the Definitions of Ambiguous Landscape)

  • 황기원
    • 한국조경학회지
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    • 제17권1호
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    • pp.55-68
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    • 1989
  • ^x This paper focuses on clarifying the diverse conceptions of landscape, of which ambiguity gives rise to confusion to the theory and practice of landscape architecture. Landscape in the form of landscipe has once indicated land, a defined space or a humanized environment, cultivated and inhabited for the purpose of biological sustenance of ordinary people. With the advent of landschap(landscape) painting, its concept moved from the real world to the scenery, a prospect, 'a portion of earth's surface that can be seen at once by a man who is himself upon the surface. 'Once appeared, it remained as a central concept until the 19th century when the modern land-scape architecture, which claims to stand for the democratic planning and environmental design, emerged. However, it still survives as the most popular concept :a landscape is a man-made, beautiful scene. To the contrary, the geographers hold that a landscape is not an actual scene viewed by a particular observer, but is a generalization induced from the observation of many individual scene. Since it is not only very attractive to the general public, but also very important to the designers, scholars and artists, operational definitions of landscape are urgently needed.

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산악지역 도로건설에 따른 국지 대기순환의 변화에 관한 연구 (Study on Variation of Local Atmospheric Circulation Due to Road Development in Mountain Area)

  • 황수진;서광수;이순환
    • 한국지구과학회지
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    • 제25권2호
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    • pp.94-108
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    • 2004
  • 얼음골 주변의 지표면 변화에 따른 중규모 대기순환장에 미치는 효과를 보기위하여 수치실험을 실시하였다. 얼음골 남북 경사면에서 발생하는 순환장은 지형과 단파복사에 의한 영향으로 다르게 나타나며, 비대칭을 이룬다. 그리고 이러한 비대칭은 18시까지 계속된다. 야간의 경우, 도로건설에 따른 대기순환장의 차이는 크지 않다. 이것은 주간 단파 복사에 의한 현열플럭스가 감소하며, 현열플럭스외의 다른 요소는 크게 영향을 미치지 않는다는 것을 의미한다. 도로의 건설은 현열플러스의 증가와 관련되고, 주간의 경우, 지형에 의한 곡풍과 결합하여 도로가 없는 경우에 비하여 상승류가 강하여진다. 최대풍속은 4.67 m/s이다. 그리고 이때 도로의 위치역시 주요한 요인으로 작용한다.

지중건축의 활용에 관한 사례연구 (A Case Study on the Utilization of Underground Building)

  • 서응철;임상훈;장문석;유헌형
    • KIEAE Journal
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    • 제1권1호
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    • pp.17-26
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    • 2001
  • The purpose of this study is to develop an underground Building. Population tends to concentrate in large cities. In result, the cities lacks housings. Underground space may be a attractive space by being able to gain alternative energy and get a cheap site, protect environment at the same time. The earth or ground is a useful medium for a long-term heat source and storage of it's heat. Also the underground space has the status of stabilization, the lower heating load and the similar heat transfer coefficient of the inside wall surface comparing to that of residential space. Utilization of underground space has many advantages to cope with lack of building sites and energy conservation, etc. As a result, it is expected to provide a useful information for the practical use of Underground building.

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카테나리 전차선로 현수애자의 환경부식에 따른 안전성 연구 (A study on the safety of the Environment Corrosion of Suspension Insulater of a Catenary Trolley Wire Systems)

  • 이재봉;소선영
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 춘계학술대회 논문집
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    • pp.864-874
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    • 2007
  • Suspension insulator in Catenary Trolley Wire Systems must have two characteristics, electric insulation and mechanical endurance. Because suspension insulator is used in supporting and insulating position between power supply parts and earth conducted supporting parts. The insulator's electric characteristics can be influenced by surface pollution and damage from the environment such as humidity, dust, smoke, salt. etc. And, the insulating parts can be electrically short. These electrically damaged insulator can cause serious accidents that have far-reaching effect. So appropriate management basis of suspension insulator is needed. And we present appropriate cleaning and the changing period of suspension insulator on the basis of actual data.

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Extraction of Non-Point Pollution Using Satellite Imagery Data

  • Lee, Sang-Ik;Lee, Chong-Soo;Choi, Yun-Soo;Koh, June-Hwan
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.96-99
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    • 2003
  • Land cover map is a typical GIS database which shows the Earth's physical surface differentiated by standardized homogeneous land cover types. Satellite images acquired by Landsat TM were primarily used to produce a land cover map of 7 land cover classes; however, it now becomes to produce a more accurate land cover classification dataset of 23 classes thanks to higher resolution satellite images, such as SPOT-5 and IKONOS. The use of the newly produced high resolution land cover map of 23 classes for such activities to estimate non-point sources of pollution like water pollution modeling and atmospheric dispersion modeling is expected to result a higher level of accuracy and validity in various environmental monitoring results. The estimation of pollution from non-point sources using GIS-based modeling with land cover dataset shows fairly accurate and consistent results.

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제주도 고산에서의 미량기체 농도변화와 공기괴 특성과의 관계 (Variations of Trace Gases Concentrations and Their Relationship with the Air Mass Characteristic at Gosan, Korea)

  • 김인애;리선란;김경렬
    • 한국대기환경학회지
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    • 제24권5호
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    • pp.584-593
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    • 2008
  • The surface $O_3,\;CO,\;NO_x,\;and\;SO_2$ were measured at Gosan in Jeju Island from May 2004 to April 2005. Over this period, the mean concentrations $({\pm}s.d.)$ of each gas was 40.06 $({\pm}16.01)$ ppbv for $O_3,\;264.92({\pm}115.73)ppbv\;for\;CO,\;1.98({\pm}2.73)ppbv\;for\;SO)_2,\;and\;4.64 ({\pm}3.24) ppbv\;for\;NO_x$. The monthly variations and the diurnal variations of these gases show that the Gosan site is situated in a relatively clean region. However, there were episodic simultaneous peaks in CO and $SO_2$, especially in winter and early spring. Using cluster analysis with air mass back- ward trajectory analysis, we suggest that these episodes are due to the influence of transportation of polluted air mass from polluted regions. In the cluster, which was under the dominant influence of clean maritime air mass, low levels of $O_3,\;CO,\;and\;SO_2$ were observed. The levels of these species were elevated in the other two clusters which had the air mass influenced by polluted continental regions. In addition, ratios of the chemical species such as $CO/NO_x,\;SO_2/NO_x,\;and\;CO/SO_2$ revealed the somewhat different characteristics of emission sources influencing each cluster. The differences in concentration of trace gases among clusters with different origin and transport pathways imply that Gosan is under the effect of pollution transported from other regions.

Enhancement of Ozone and Carbon Monoxide Associated with Upper Cut-off Low during Springtime in East Asia

  • Moon, Yun-Seob;Drummond, James R.
    • 한국대기환경학회지
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    • 제26권5호
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    • pp.475-489
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    • 2010
  • In order to verify the enhancement of ozone and carbon monoxide (CO) during springtime in East Asia, we investigated weather conditions and data from remote sensors, air quality models, and air quality monitors. These include the geopotential height archived from the final (FNL) meteorological field, the potential vorticity and the wind velocity simulated by the Meteorological Mesoscale Model 5 (MM5), the back trajectory estimated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the total column amount of ozone and the aerosol index retrieved from the Total Ozone Mapping Spectrometer (TOMS), the total column density of CO retrieved from the Measurement of Pollution in the Troposphere (MOPITT), and the concentration of ozone and CO simulated by the Model for Ozone and Related Chemical Tracers (MOZART). In particular, the total column density of CO, which mightoriginate from the combustion of fossil fuels and the burning of biomass in China, increased in East Asia during spring 2000. In addition, the enhancement of total column amounts of ozone and CO appeared to be associated with both the upper cut-off low near 500 hPa and the frontogenesis of a surface cyclone during a weak Asian dust event. At the same time, high concentrations of ozone and CO on the Earth's surface were shown at the Seoul air quality monitoring site, located at the surface frontogenesis in Korea. It was clear that the ozone was invaded by the downward stretched vortex anomalies, which included the ozone-rich airflow, during movement and development of the cut-off low, and then there was the catalytic photochemical reaction of ozone precursors on the Earth's surface during the day. In addition, air pollutants such as CO and aerosol were tracked along both the cyclone vortex and the strong westerly as shown at the back trajectory in Seoul and Busan, respectively. Consequently, the maxima of ozone and CO between the two areas showed up differently because of the time lag between those gases, including their catalytic photochemical reactions together with the invasion from the upper troposphere, as well as the path of their transport from China during the weak Asian dust event.

달 착륙선의 착륙 후보지별 열 유입량 분석 (Heat Flux Analysis of Lunar Lander for Potential Landing Candidate Area)

  • 박태용;채봉건;이장준;김정훈;오현웅
    • 한국항공우주학회지
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    • 제46권4호
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    • pp.324-331
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    • 2018
  • 달 탐사를 위한 착륙선이 운용되는 열환경은 태양에 대한 달의 자전주기가 약 28일인 것에 기인하여 낮 시간과 밤 시간이 지구에 비하여 매우 장기간 지속 되는 등 지표나 지구 저궤도 환경에 비해 더욱 극단적이다. 달 착륙선의 초기 설계 단계에서는 착륙지 선정을 위해 각각의 후보 지역에서의 착륙선으로의 열 유입량 분석이 중요하다. 본 논문에서는 달 착륙선의 후보 착륙지에 따른 열적특성을 분석하고자 달의 표면온도를 모사할 수 있는 표토층의 열모델을 구축하였다. 그리고 상기 표토층에 착륙선을 적용하여 착륙지가 달의 적도, 중위도, 극지방에 위치한 경우, 바다 및 고지대에 위치한 조건에서의 열 유입량을 분석하였다. 또한 언덕의 경사진 지형조건이 착륙선의 열 유입량에 미치는 영향성 분석을 수행하였다.