• 한국환경복원기술학회지
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• 제13권2호
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• pp.124-137
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• 2010

This study was started with the objective of restoring abandoned embanked farms, which are recently increasing, to mud flat by putting in least amount of energy in the aspect of environmental restoration. For the direction and establishment of the proposal for the restoration of mud flat using embanked farms, a case of Maipo Wetland in Hongkong was analyzed, and a proposal was prepared considering the condition of mud flat in Gochang. The restoration of mud flat in Gochang is intended to create various wetland ecological spaces as well as to provide opportunities for experience, education, recreation, and tourism. Effort was made to development an environment closest to the local ecological environment considering the shape and topographical condition of existing abandoned farms. For construction of the habitat, a target species was chosen and the plan for selection, planting, and management of species of trees suitable for the target species was established. In addition, the water level will be controlled by water gates to conform to the resting, spawning, breeding, and migration period considering the behavioral pattern of waders, the target species. The research on the restoration of mud flat in Korea is in incipient stage and this study provided an opportunity to review the possibility of restoration of abandoned embanked farms to mud flat. For the success of mud flat restoration from a long-term perspective, development of acclimating design infrastructure, technology improvement for mud flat restoration, and basis of partnership for the maintenance should be prepared in a systematical way.

• 한국물환경학회지
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• 제20권3호
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• pp.245-250
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• 2004

This study investigated the micropollutants present in raw water supplied for the several drinking water treatment plants in Seoul. The target sample waters were collected from the several sites, such as Jayang (JY), Kuui (KI), Paldang (PD) and Kangbuk (KB) at the Han-River stream. The analytical method used in this study enable us to detect about 300 kinds of chemicals commonly found in surface water at ppt level by GC-ion trap MS. In this study, the consideration on the analytic results focused on the four hazardous organics, such as benzenes, phenols, phthalates and pesticides. The numbers of each detected micropollutant were 1~8 kinds for benzenes, 1~7 kinds for phenols, 5~7 kinds for phthalates and 1~9 kinds for pesticides. For the pesticides, the higher concentration was detected in the water samples collected from PD and KB adjacent to the farming area, and at June and July, which is the busy farming season. The total concentrations of each micropollutants detected at all the sites were significantly lower than those of drinking water regulation in Korea as well as other advanced countries. However, the frequently detected micropollutants requires the steady and precise monitoring for the effective management of drinking water source.

• 한국물환경학회지
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• 제33권6호
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• pp.650-660
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• 2017

In this study, pollutant emission characteristics by water damage period analyzed 11 items (water temperature, pH, DO, EC, BOD, COD, TOC, SS, T-N, T-P and flow) with load duration curve, time series load curve and factor analysis for three years (2014-2016). Load duration curve is applied to judge the level of impaired waterbody and estimate impaired level by pollutants such as BOD and T-P in this study depending on variation of stream flow. Water quality standard exceeded the flow of mid-range and low-range by flow condition evaluation using load duration curve. This watershed was influenced by point source more than non-point source. Cumulative excess rate of BOD and T-P kept water quality standard for all seasons (spring, summer, autumn and winter) except BOD 59% in spring. Water quality changes were influenced by pollutants of basic environmental treatment facilities and agricultural areas during spring and summer. Results of factor analysis were classified commonly first factor (BOD, COD, and TOC) and second factor (flow, water temperature and SS). Therefore, effects of artificial pollutants and maintenance water must be controlled seasonally and reduced relative to water damage caused by point pollution sources with effluent standard strengthened in the target watershed.

• Journal of the Korean Wood Science and Technology
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• 제51권6호
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• pp.493-508
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• 2023

Round timber materials of 600 mm length, cut from large-cross-section round timber of red pine (Pinus densiflora S. et Z.) of 450 mm width and 4.2 m length, were prepared as the target of kiln drying in this study. After treating the target materials through end sealing (ES), end sealing - kerfing (ES-K), lateral sealing - end sealing - boring (LS-ES-B), or lateral sealing - partial end sealing (LS-PES), the effects of the treatment on the incidence of drying defects were determined. The target materials with exposed lateral surface and sealed cross surface were steamed at the initial temperature of 65℃ above the official pest control temperature of 56℃, followed by kiln drying toward the final temperature of 75℃. The target materials with sealed lateral surfaces, on the other hand, were dried at the initial temperature of 90℃ at almost the maximum temperature of conventional kiln drying, as there is no risk of early check formation caused by surface moisture evaporation. The final temperature was set at approximately 100℃. The drying time, taken for the target materials with initial moisture content of 70%-80% to reach the target moisture content of 19%, varied across treatment conditions. The measured drying time was 1,146 hours (approximately 48 days) for the timber with sealed cross surface and 745 hours (approximately 31 days) for the timber with sealed lateral surface, until the moisture content reached the target level. The formation of surface checks could not be prevented in the control and ES groups, but a definite preventive effect was obtained for the LS-ES-B and LS-PES groups.

• 한국방사선학회논문지
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• 제7권3호
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• pp.213-219
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• 2013

현재 국내에서 가동 중인 싸이클로트론센터는 약 35개소에 이르며, 대부분의 싸이클로트론 센터는 주로 핵의학검사용 악성종양 추적자인 $^{18}FDG$ 등과 같은 방사성의약품을 생산하고 있다. 18F을 생산하기 위한 타겟으로서 산소동위원소비($^{18}O/O$)가 98%정도인 고농축 $H_2{^{18}}O$를 사용하고 있다. 고농축 $H_2{^{18}}O$는 1 gram당 가격이 약 60~70 USD 정도로 매우 고가이나 100% 수입에 의존하고 있는 상황이다. 양성자 빔 조사 전의 타겟(고농축 $H_2{^{18}}O$)은 비방사성이다. 하지만, "사용후 $H_2{^{18}}O$"는 불순물들의 방사화에 의해 방사능을 띄게 되므로 방사선안전 법규에 따라 적절한 관리가 이루어져야 한다. 최근의 핵의학검사 건수의 증가에 따라 사용 후 O-18의 발생량이 증가하고 있음에도 불구하고 국내에서는 현재까지 이에 대한 방사화분석이 이루어지지 않았다. 따라서, 본 연구에서는 $^{18}F$생산을 위해 양성자조사를 하고 난 타겟, 이른바 "사용후 O-18 water"의 방사화 분석을 실시하여 핵종별 방사능농도(Bq/g)를 확인하고자 하였다. 세 곳의 서로 다른 싸이클로트론 센터에서 보관 중인 "used $H_2{^{18}}O$" 중 20g 씩을 채취한 3개의 시료에 대해 방사화분석을 실시하였으며, 분석결과 사용후 O-18 water는 감마선 방출 방사성핵종인 $^{56}Co$, $^{57}Co$, $^{58}Co$, $^{54}Mn$ 등과 베타선 방출핵종인 $^3H$을 상당량 포함하고 있음을 확인할 수 있었다. 또한, 모든 시료에서 3H은 규제면제 농도 이하인 반면, 한 개 시료는 핵종별 규제면제농도 이상의 감마선 방출핵종을 포함하고 있음을 확인하였다. 시료에 포함된 감마선 방출핵종의 방사능 농도(Bq/g)는 조사 후 보관기간의 차이에 따라 달랐으며, 향후의 추가적인 연구가 더 필요하다고 판단되지만, 본 연구의 결과는 "사용후 O-18 water"의 합리적인 관리방안 수립을 위한 근거 자료로 활용될 수 있을 것이다.

• 농약과학회지
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• 제11권1호
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• pp.32-37
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• 2007

항공방제시 비표적생물에 대한 안전거리를 설정하고자 벼의 주요 병해충인 도열병, 잎집무늬마름병, 벼멸구 및 나방류를 동시에 방제할수 있는 훼림존 트리싸이클라졸 액상수화제+비피유제+바리신액제와 헥사코나졸유제+이소란유제+파프유제의 3종 혼용농약을 항공 살포한 후 논물중 농약 잔류량과 수서생물 및 꿀벌에 미치는 영향을 조사하였다. 항공방제시 대상지역 이외의 포장으로 분무입자가 비산하는 정도는 바람부는 방향으로는 30 m, 반대방향으로는 20 m 이내로 비교적 비산 정도가 낮았다. 항공살포 후 살포지역내 논물중 농약의 잔류량을 조사한 결과 항공방제 6일후에는 논물 중에서는 농약이 검출되지 않았다. 항공방제 지역의 수서생물에 미치는 영향을 조사한 결과, 송사리와 미꾸라지는 방제지역 내외를 막론하고 모든 지점에서 치사되지 않았다. 물벼룩은 항공방제지역으로부터 10 m 지점 이내에 노출된 경우 48시간후 모두 치사되었으나 30 m 이상 지점에서는 영향이 없었다. 꿀벌은 바람부는 방향으로 50 m와 반대방향으로 20 m까지 $7{\sim}100%$ 치사하여 항공 방제시 안전거리는 수서생물의 경우 50 m, 꿀벌의 경우는 100 m로 설정하였다.

• Archives of Pharmacal Research
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• 제29권12호
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• pp.1158-1163
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• 2006

More than 95% of lead, a environmental heavy metal, entering into blood accumulates in erythrocytes suggesting erythrocytes as an important target of lead toxicity. Recent studies reported that erythrocytes could contribute to blood coagulation via phosphatidylserine (PS) exposure in erythrocytes. However, in vivo effects of chronic lead exposure especially by drink-ing water on procoagulant activity of erythrocytes have not been studied yet. In the present study, we investigated the effects of chronic exposure of lead by drinking water on erythrocytes in rats. Groups of 40 male rats were provided with drinking water containing various concentrations of lead for 4 weeks and complete blood cell count, procoagulant activities of erythrocytes and platelets were evaluated with basic inspections on body weight and food/water consumption. The administration of lead containing drinking water increased the blood lead level (BLL) in a dose-dependent manner up to $22.39{\pm}2.26\;{\mu}g/dL$. Water consumption was significantly decreased while food consumption or body weight gain was not affected. In contrast to the previous findings with acute lead exposure, chronic lead exposure failed to increase PS exposure in erythrocytes with statistical significance although some trends of enhancement were observed. It implies that a certain adaptation might have happened in body during repeated exposure to lead, resulting in attenuation of PS exposure. With this study, we believe that a valuable information was provided for the study on the toxicological significance and the risk assessment of lead contaminated drinking water.

• 한국물환경학회지
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• 제34권5호
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• pp.462-469
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• 2018

There are differences in method and cycle of flow rate survey depending on purpose of the operating department. To verify and use results of flow data according to the purpose, flow data of the directly measured and tele monitoring system were compared to verify validity. Flow measurement in the Ministry of Environment is aimed at setting up a standard flow of target water quality for water quality management and securing flow data of low and normal water level seasons for water quality evaluation. In this study, correlation analysis result ($R^2$) of same time zone data by direct measurement and tele monitoring system (TMS) at Seombon D point, a unit watershed of Seomjin river, for six years ('10 ~ '15) according to implementation of Total Daily Maximum Load (TDML) was wading 0.716, boating 0.962 and on bridge 0.943, and effectiveness of measurement method was verified by characteristics of flow duration as a season of dry and low-water; normal and high water are appropriate for wading, boating, and on bridge respectively. Results revealed it is reasonable to use directly measured results using the wading and boating method for low water level and dry seasons, and TMS data for rainy seasons. It can be used important data for future policy decisions.

• 한국산업융합학회 논문집
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• 제23권3호
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• pp.507-513
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• 2020

Liquid filling machines are frequently used in packaging fields; however, there exists a problem in precisely measuring the quantity of the liquid. In the case where the liquid filling machine is not properly metered, there may be issues, such as the fluid exceeding the capacity or chemicals being exposed outside. In this paper, we propose a smart injection nozzle device that can solve the issues stated above. The proposed smart injection nozzle can raise the nozzle according to the water level to remove bubbles and inject the accurate amount of fluid. In addition, the efficiency of the logistics process is enhanced by the smart QR code. Through experiments using the developed smart injection nozzle device, we have noticed that the accuracy of injection capacity, nozzle position, reaction time and building data exceeded the target value. Therefore, it expected that this machine will give more production and save a lot of manpower for packaging industry.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.813-818
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• 2005

Cooling seawater of thermal power plant which amounts about 5 cms per 100 MWe has hydro energy of about 3,000 kW at the thermal power plant complex, but this useful hydro energy has not been developed. Therefore, the feasibility study on hydro energy development of three power plants located in the southern and western coast of Korea was performed. Three target power plants are Samcheonpo, Boryeong and Hadong thermal power plant. The design head to discharge cooling water by gravity and the head caused by tidal level in the southwestern coastal area, could be used for the production of electric power. The various alternatives were studied and technical feasibility and economical efficiency were clearly proved.