• 한국토양비료학회지
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• 제29권4호
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• pp.411-418
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• 1996

대기오염물질에 대한 지표식물로서의 활용 가능성이 알려지고 있는 들깨 수원 16호를 대상으로 대기오염물질에 대한 식물의 반응에 중요하게 작용하는 기공의 개폐와 관련된 K와 EC를 주 변화요인으로하여 $NO_2$, $O_3$, $SO_2$ and $NO_2+SO_2$ 가스를 접촉시키면서 들깨의 가시적 지표성과 생장에 미치는 영향을 양액재배 실험으로 파악하고자 하였다. 들깨의 건물생산량은 55일 후에 K100 및 200mg/l 처리구에서 32.2 g/주로 가장 높았고, EC는 2.0 ds/m에서 16.3g/l으로 가장 높았다. 기공확산저항은 7-8위엽이 전개된 시기에 K 200mg/l와 2.0mg/l에서 가장 낮았다. 한편 K 50, 100mg/l, EC 0.5 ds/m 처리에서 대기오염가스의 접촉량의 증가에 따른 가시피해도의 증가가 가장 균일하게 나타났다. 따라서 K 50-100mg/l 수준, EC 0.5-1.0 dS/m 수준, 7-8위엽이 전개된 시에 들깨 수원 16호는 가장 뛰어난 대기오염 지표성을 나타내었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.445-448
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• 2007

Three boreholes (BE-1, BE-2 and BE-3) were drilled for geothermal resources development in Haengbok (Sejong) city. Monitoring of temperature, electric conductivity (EC) and piezometric head were carried out at each borehole. Temperatures were measured at 10 m depth, it ranges from 13.22$^{\cdot}C$ to 14.4$^{\cdot}C$. EC of BE-1 and BE-3 declined with time because groundwater flowed in boreholes. Barometric efficiency was analysed by piezometric head of groundwater and atmospheric pressure, it ranges from 44.8% to 71.5%. These parameters can be used for a geothermal modeling.

• Journal of Biosystems Engineering
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• 제20권4호
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• pp.383-389
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• 1995

This study was conducted to develop an automatic nutrient control system for trickle application of nutrient solution. Temperature, electric conductivity(EC). pH and dissolved oxygen(DO) were selected as control variables. A controller using single-chip microcomputer was constructed. An automatic control system for nutrient solution and a controller using single-chip microcomputer with control algorithm were developed. The control system was tested, and could control temperature, EC and pH within the error ranges of $pm 0.2^{circ} pm 0.2mS/cm, pm 0.1pH$, respectively.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.391-393
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• 2006

In this study, the performance of artificial neural network (ANN) models for estimating spatial distribution of water quality was evaluated using electric conductivity (EC) values in landfill site. For the ANN model development, feedforward neural networks and backpropagation algorithm with gradient descent method were used. In Test 1, the interpolation ability of the ANN model was evaluated. Results of the ANN model were more precise than those of the Kriging model. In Test 2, spatial distributions of EC values were predicted using precipitation data. Results seemed to be reasonable, however, they showed a limitation of ANN models in extrapolations.

• The Korean Journal of Ecology
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• 제20권2호
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• pp.133-143
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• 1997

From 1984 to 1989 reclaimed coastal lands in Choongnam Province of the western coast of Korea were studied for soil texture at three sites(Daeho, Hyundai A and Hyundai B) and for desalination one site(Hyundai B). The soil textures of varied sites in Hyundai A were horizontally similar and composed of 39-40% clay, 40-49% silt and 8-14% sand. But those in Da돼 and Hyundai B differed horizontally in the same area and vertically at the same site. Soil texures of Da돼 were composed of 15-17% clay, 30-45% silt and 40-55% sand and those of Hyundai B were composed of 22-45% clay, 26-49% silt and 17-31% sand. The measured electrical conductivity(EC), which represents whole salt content of the reclaimed soil, decreased year by year. The vertical distribution of the EC changed temporally and spatially in the upper zone above a 50 cm depth but not in The lower zone below a 50 cm depth. The EC valus of the soil were inversely proportional to the magnitued of annual precipitation, evaporation and the numbers of rainy days with r equalling -0.97. But the annual decrease of the EC was directly proportional to climatic factors with r=0.7. Salt in the reclaimed land was leached out by the percolative action of surplus rain water, or moved up by evaporation and carried away by running rain water. The running out of the salt on the soil surface was most efficiently carried out over 10 mm precipitation per day.

• 한국전기전자재료학회논문지
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• 제20권12호
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• pp.1099-1104
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• 2007

In order to develop non-heated STAl(super thermal resistant Aluminum alloy) for ampacity gain conductor, the systematic research was carried out. Especailly, the effect of a very small amount of Zr, Sc element in EC grade Al ingot on mechanical and electrical properties was our priority. As a result, it was found that the strength and recrystallization temperature of designed alloy was gradually increased with Zr, Sc addition up to 0.3 wt.%. However, the electric conductivity showed no drastic change. The tensile strength and recrystalliztion temperature, $17.75{\sim}20.05\;kgf/mm^2$ and $420{\sim}520\;^{\circ}C$, was obtained at 0.3 wt.% Zr, Sc addition, respectively. Particles of the $Al_3Zr$ and $Al_3Sc$ phase affected the ambient and elevated-temperature strength of the alloys.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.519-520
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• 2007

In order to develop non-heated STAl(super thermal resistant Aluminum alloy) for ampacity gain conductor, the systematic research was carried out. Especially, the effect of a very small amount of Zr element in EC grade Al ingot on mechanical and electrical properties was our priority. As a result, it was found that the strength and recrystallization temperature of designed alloy was gradually increased with Zr addition up to 0.3wt.%. However, the electric conductivity showed no drastic change. The tensile strength and recrystalliztion temperature, $17.75\;kgf/mm^2$ and $420^{\circ}C$, was obtained at 0.3 wt.% Zr addition, respectively.

• 대한수의사회지
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• 제26권1호
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• pp.32-37
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• 1990

Clinical signs and electric conductivity(EC) of blood were serutinzed for the detection of the cattle being afflicted with forced administration of excessive water or salt water in an abattoir. Test animais were divided into 3 groups such as 10 normal cat

• Journal of information and communication convergence engineering
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• 제20권1호
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• pp.49-57
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• 2022

Fertilizers have long been used to increase crop yields; however, farmers are still having difficulties in managing fertilizers for growing crops as well as economic problems. The conventional method of soil sampling and laboratory analysis to determine soil pH is time consuming and costly; therefore, a portable pH sensor is developed to characterize spatial or temporal variability within fields via rapid and dense data acquisition. The portable pH sensor comprises an electrode unit, a portable console, and a USB connector. The soil water content (SWC) and electrical conductivity (EC) affect the electrical resistance of soil. An artificial test soil is performed to evaluate the effect of SWC and EC on soil pH. The test results show that stable pH measurements are achieved at SWCs greater than 20 mL (16.3%). Regardless of the SWC, the electric potential difference (EPD) remains at 2.5 g of NaCl. As the EC increases in the soil samples, the EPD increases.

• 한국토양비료학회지
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• 제18권1호
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• pp.72-77
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• 1985

낙동강(洛東江) 하류수계(下流水系)의 관개수질(灌漑水質)이 벼 생육(生育)에 미치는 영향(影響)을 알기 위하여 경남지방(慶南地方)의 주요(主要) 관개수원(灌漑水源)인 6개 양수장(揚水場)을 대상(對象)으로 각(各) 지점별 수질(水質), 토양(土壤) 및 벼의 근활력(根活力)을 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. (1) COD는 지류(支流)<본류(本流)<하류(下流)의 순(順)으로 낙동강(洛東江) 하류(下流)인 김해(金海)에서 오염도(汚染度)가 가장 높았다. (2) 수질(水質)의 화학성분(化學成分) 중(中) electric conductivity, SAR, Cl, $NH_4-N$는 낙동강(洛東江) 하류(下流)인 김해(金海), $PO_4{^{-3}}$는 본류(本流)인 창녕(昌寧), $SiO_2$는 지류(支流)인 산청(山淸)에서 각각(各各) 가장 높았다. (3) 관개수중(灌漑水中)의 electric Conductivity 및 SAR는 논토양(土壤)의 electric Conductivity 및 SAR의 농도(濃度)와 정(正)의 상관(相關)을 보였다. ($r=0.98^{**}$, $r=0.91^*$) (4) 근활력(根活力)은 하류(下流)<본류(本流)<지류(支流)의 순(順)으로 높았으며 건물중(乾物重)($r=0.62^{**}$)과는 정상관(正相關), 토양(土壤)의 SAR($r=-0.67^{**}$) 및 electric conductivity($r=-0.62^{**}$)와는 부상관(負相關) 관계(關係)였다.