• 한국구조물진단유지관리공학회 논문집
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• 제14권5호
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• pp.87-92
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• 2010

본 연구에서는 실리카흄 대체재로 활용 가능한 실리카 흄 무혼입 결합재(SFFB)의 치환율에 따른 고강도 콘크리트의 품질특성을 비교 분석하기 위하여, 실리카흄, SFFB의 2수준과 물-결합재비는 25, 35% 치환율은 실리카 흄 10%, SFFB 5, 10, 15(%)의 4수준으로 설정하였다. 실험을 실시한 결과, 목표 유동성을 확보하기 위한 고성능감수제의 첨가율은 물-결합재비가 낮을수록 증가하였으며, SFFB가 실리카 흄 보다 저흡수성을 갖는 재료적 특성으로 인해 고성능감수제의 첨가율이 감소하는 경향을 나타내었다. 압축강도에서는 SFFB 치환율이 10%일 경우 인장강도에서는 치환율이 15%일 경우 가장 우수한 강도를 나타내었으며, 자기수축에서는 W/B와 SFFB의 치환율과 상관없이 Plain(SF)에 비해 수축이 저감하는 것으로 나타났다.

• 한국환경농학회지
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• 제1권1호
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• pp.22-30
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• 1982

본 조사(本 調査)는 김해평야(金海平野)외 농업용수(農業用水)로 사용(使用)하고 있는 낙동강지류(洛東江支流)의 수질(水質)을 주요(主要) 양수장부근(揚水場附近) 6척지점(個地點)(대저, 식만, 봉림, 녹산, 마찰, 장유)에서 1981년(年) 5월(月), 7월(月) 및 10월(月)의 3회(回)에 걸쳐 채수분석(採水分析)함으로서 수질보전대책(水質保全對策)과 이 지역(地域)의 농업(農業)에 참고자료(參考資料)를 제공(提供)코자 하였다. 시기별(時期別) 각(各) 지점(地點)의 수온(水溫), 탁도(濁度), 증발잔류물(蒸發殘留物), pH, BOD, COD, DO, 경도(硬度), $Cl-,\;SO_4--,\;PO_4---,\;NH_4+,\;NO_3-,\;K+,\;Na+$, 일반세균(一般細菌), 대장균(大腸菌), 중금속(重金屬)(Cd, Pb, Cr, Fe, Zn)을 분석(分析)한 결과(結果)를 요약(要約)하면 다음과 같다. 1) 시기별(時期別) 모든 지점(地點)의 평균치(平均値)는 pH 7.8, BOD 6.3 ppm, COD 6.5 ppm, DO 6.4 ppm, 경도(硬度) 231 ppm, Cl- 582 ppm, $SO_4--\;412\;ppm,\;PO_4---\;2.32\;ppm,\;NH_4+$ 3.8 ppm, Na+ 478 ppm, 대장세균(大腸細菌) 2964개(個)/100ml, Cd 0.0040 ppm, Pb 0.006 ppm이었다. 2) 지점별(地點別) 오염도(汚染度)가 가장 높은 곳은 식만 양수장부근(揚水場附近)이었고 그 다음이 대저, 봉림, 녹산이었으며 비교적 오염도(汚染度)가 덜한 곳은 마찰, 장유양수장(揚水場) 부근(附近)이었다. 3) 오염도(汚染度)가 가장 높은 식만양수장(揚水場) 부근(附近)의 수질(水質)은 약간의 취기(臭氣)가 있을 뿐만 아니라 외관상(外觀上) 약간의 흑색(黑色)을 띄고 있었고, 분석평균치(分析平均値)는 pH가 8.0, BOD 8.1 ppm, COD 8.2ppm, DO 5.3ppm으로 농업용수기준(農業用水基準)의 한계(限界)에 도달(到達)하고 있었다. 이곳이 오염도(汚染度)가 높은 것은 김해시(金海市)의 주요(主要) 공장폐수(工場廢水)가 이곳으로 집중(集中) 배출(排出)되기 때문인 것으로 본다. 4) 시기별(時期別) 각(各) 성분(成分)의 차리(差異)는 뚜렷한 경향(傾向)이 없었으며 다만 DO가 10월(月)이 5월(月) 및 7월(月)보다 높게 나타났고 $NH_4+$는 10월(月)이 5월(月) 및 7월(月)에 비(比)해서 낮게 나타났을 뿐이다. 5) 각(各) 지점(地點)이 $NH_4+$함양(含量)이 높아 실소질비료(室素質肥料)의 시비(施肥)에 이를 고려(考慮)해야 할 것이며, Cl- 및 Na+함양(含量)은 평수시(平水時)에는 별문제(別問題)가 없을 것이나 갈수기(渴水期)에는 관개(灌漑)에 주의(注意)를 해야 할 것으로 본다.

• 대한영양사협회학술지
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• 제1권1호
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• pp.31-42
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• 1995

The aims of this study are to enhance the students' knowledge of the drinking water and its reliability by investigating drinking water situation and the degree of students' knowledge on the drinking water. The results are as follows 1. Status and drinking behavior about school drinking water (1) 97.53% of the schools are using the tap water as the resource of drinking water (2) 46 schools are in possession of water tank and 18 schools of them are using the water tank as the resource of drinking water. The cleaning and sanitization of the tank are carried out once in a year with hypochloronatrium by the low-level officials, nurse teachers, and dietitian. 2. The degree of students' knowledge about drinking water (i) This survey represent that students favor the spring water best and think the tap water worst for drinking. (2) 83% of the students think that the tap water is polluted and these conception are formed mostly by the mass communication. 80% of boys and 90% of girls answered they don't drink plain tap water.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.75-78
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• 2003

This study is to investigate the probability to develop the AE Water-reducing agent which can decrease the bleeding by mixing melamine type super-plasticizer(SP) and methyl cellulose(MC) viscosity agent. According to the result, as the mixing ratio of melamine type SP and MC viscosity agent increases, the bleeding is reduced due to a increase of the air content. When the mixing ratio of melamine type SP and MC viscosity agent is 1:2 and 1;3 at the water content of 165kg/$m^3$ and 175kg/$m^3$ respectively, slump and air content are satisfied and bleeding is reduced to some extent, so this is determined as the mixing ratio of AE water reducing agent for reduction of bleeding. It is prove that the developed AE water reducing agent for reduction of bleeding can reduce the amount of bleeding and prohibit the plastic shrinkage crack by slowing down the bleeding speed. Compressive strength of hardened concrete does not make any difference in comparison with plain concrete.

• 한국환경과학회지
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• 제19권12호
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• pp.1343-1354
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• 2010

The purpose of the study was to analyze the persistence of HCH in atmosphere, soil, sediment and water of the western and southern regions of Korea. The samples from the western region were collected from Anmyeon Island, and the samples from the southern region were collected from Kimhae and Busan. The concentration of HCH isomers in atmosphere showed the pattern of $\alpha$-HCH>$\gamma$-HCH>$\beta$-HCH. The regions with high HCH concentration in the atmosphere are the regions that have been highly exposed to HCH used in the past, and the areas that have been influenced by the long range transport. The HCH that persists in the soil, water and sediment evaporates into the atmosphere, showing the characteristics of Air-Surface exchange. When the regional concentration distributions are compared, the concentration of HCH was higher in the atmosphere of a plain and the cities near the plain, than the urban areas. In this study, the ratio of $\alpha/\beta$-HCH was used as an indicator for estimating the source of Technical HCH and Lindane. According to the result, the contribution of Lindane was high in Kimhae plain and Kimhae urban areas. However, in Busan, the contribution of Technical HCH was higher than Lindane. In case of Anmyeon Island, the western region of Korea had high contribution from Tehcnical HCH. In soil and sediment, $\beta$-HCH was dominant. In water, $\gamma$-HCH was dominant among other isomers. Such results are due to $\gamma$-HCH inLindane. Furthermore, the source of $\gamma$-HCH in urban areas is assumed to be the use of medicine, medical supplies and other living supplies. Based on the results of this study, the management of HCH, a newly list up emerging POPs, should be strengthened by further research on sources, fate, persistency, accumulation and exposures and etc. to the risk assessments.

• 한국농공학회논문집
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• 제65권6호
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• pp.93-103
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• 2023

This study aimed to analyze the impact of water curtain cultivation in the greenhouse complexes on groundwater's electric conductivity and water temperature. The greenhouse complexes are mainly situated along rivers to secure water resources for water curtain cultivation. We classified the groundwater monitoring well into the greenhouse (riverside) and field cultivation areas (plain) to compare the groundwater impact of water curtain cultivation in the greenhouse complex. The groundwater observation network in Miryang, Gyeongsangnam-do, located downstream of the Nakdong River, was selected for the study area. As a result of analyzing the electric conductivity and water temperature, the following differences were found in the observed characteristics by region. 1) The electric conductivity and water temperature of the riverside area, where the permeability is high and close to rivers, showed a constant pattern of annual changes due to the influence of river flow and precipitation. 2) The flat land in general agricultural areas showed general characteristics of bedrock observation in the case of water temperature. Still, it seemed more affected by the surrounding well's water use and water quality. The electric conductivity did not show any particular trend and was influenced by the surrounding environment according to the location of each point.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.769-772
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• 2008

건설폐기물의 처리문제는 국가 사회적 문제로 제기되고 있으며 순환골재의 생산과정에서 발생하는 재생미분말은 전량 폐기 매립되고 있다. 재생미분말의 독성 시험결과 염기치환형 돌연변이원성을 포함하고 있다. 이와 같이 독성을 갖는 재생미분말이 매립 처분됨으로서 토양 및 지하수 오염등 2차 오염을 초래할 수 있다. 그러나 재생미분말을 재활용에 대한 연구가 매우 미흡한 실정이다. 본 연구에서는 재생미분말을 재활용하기 위한 방법으로 콘크리트의 혼화제를 활용하고자 시멘트 대신 재생미분말을 혼입하여 역학적 특성과 작업성을 비교 분석하였다. 실험은 CP, WCP, PCP로 배합비를 달리하여 공시체를 제작하여 실험을 실시하였다. CP은 재생미분말 혼입율에 따른 콘크리트 물리적 성질과 역학적 특성을 파악하고자 하였으며, WCP의 W자와 PCP의 P자는 각각 물과 혼화제의 이니셜로 슬럼프, 공기량을 표준배합에 맞게 제작하여 워커빌리티에 중점을 두고 재생미분말 혼입률에 따른 콘크리트의 역학적 특성을 보고자 하였다. CP는 치환율의 증가에 따라 강도 변화는 거의 일어나지 않았지만 슬럼프의 저하로 인해 워커빌리티가 좋지 않았다. WCP, PCP는 표준배합에 맞게 제작을 하여 실험한 결과 Plain에 비해 WCP는 강도저하가 일어났으며, PCP는 치환율이 10%일 때만 Plain과 거의 같은 값을 가지고 그 이상일 때는 강도저하가 일어났다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.2-11
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• 2006

In the processes of hydrological cycle, when precipitation reaches the ground surface, water may become surface runoff or infiltrate into soil and then possibly further percolate into groundwater aquifer. A part of the water is returned to the atmosphere through evaporation and transpiration. Soil moisture dynamics driven climate fluctuations plays a key role in the simulation of water transfer among ground surface, unsaturated zone and aquifer. In this study, a one-layer canopy and a four-layer soil representation is used for a coupled soil-vegetation modeling scheme. A non-zero hydraulic diffusivity between the deepest soil layer modeled and groundwater table is used to couple the numerical equations of soil moisture and groundwater dynamics. Simulation of runoff generation is based on the mechanism of both infiltration excess overland flow and saturation overland flow nested in a numerical model of soil moisture dynamics. Thus, a comprehensive hydrological model integrating canopy, soil zone and aquifer has been developed to evaluate water resources in the plain region of Huaihe River basin in East China and simulate water transfer among precipitation, surface water, soil moisture and groundwater. The newly developed model is capable of calculating hydrological components of surface runoff, evapotranpiration from soil and aquifer, and groundwater recharge from precipitation and discharge into rivers. Regional parameterization is made by using two approaches. One is to determine most parameters representing specific physical values on the basis of characterization of soil properties in unsaturated zone and aquifer, and vegetations. The other is to calibrate the remaining few parameters on the basis of comparison between measured and simulated streamflow and groundwater tables. The integrated modeling system was successfully used in the Linhuanji catchment of Huaihe plain region. Study results demonstrate that (1) on the average 14.2% of precipitation becomes surface runoff and baseflow during a ten-year period from 1986 to 1995 and this figure fluctuates between only 3.0% in drought years of 1986, 1988, 1993 and 1994 to 24.0% in wet year of 1991; (2) groundwater directly deriving from precipitation recharge is about 15.0% t of the precipitation amount, and (3) about half of the groundwater recharge flows into rivers and loses through evaporation.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.307-312
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• 1998

Recently the study on high flowing concrete which has high workability and Self-compacting is being proceeded actively in the university and corporative laboratory. There are some cases that has been applied to the field. This high flowing concrete has higher fluidity and segregation resistance than Plain of flowing concrete. And it is being focused as a remarkable know-how which can make high-quality concrete and reduction effect of labor force. This properties of high flowing concrete are influenced by the relationship of several factors; binder content, water binder ratio and unit water content. It is the aim of this study to propose reference data at mix design of high flowing concrete, after comparing and analyzing the fluidity and strength properties of high flowing concrete according to water binder content ratio and unit water content.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.257-262
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• 1996

Large amount of water is diverted annually for irrigation along the Yellow River. Owing to the tremendous sediment carried by the river , sediment deposits is an important problem in irrigation and drainage system. The sediment has to be taken out by machines from the irrigation system, otherwise water can not be available in the right place at the right time. In order to improve the sediment desilting efficiency, the sediments that settle in certain sites of a irrigation system must be removed by different desilting machines with special performance and working conditions. Those certain sites include : the diversion canal in the flood plain , the mouth of inlet, settling basin , irrigation and drainage system. In view of removal sediment above, the paper presents the ideas of type selection of desilting machines applied to certain sites. Proposals of making further improvement on performance for some desilting machines are also put forward.