• 수산해양기술연구
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• 제56권2호
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• pp.114-125
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• 2020

In order to understand the currents around Hampyung Bay and Haeje Peninsula, 2D numerical simulations for tidal currents and tide-induced residual currents were carried out. Dominant semidiurnal tidal currents have reversing form and flow NNE-SSW from northern Haeje Peninsula to Songi Island, E-S at northern Haeje Peninsula and NNW-SSE in Hampyung Bay. In flood, a part of currents from Imja Island~Nakwhol Island flow along the main stream flowing northeast at offshore region and the rest flow into Hampyung Bay flowing east along the northern coast of Haeje Peninsula. In ebb, currents from Hampyung Bay flow west along the northern coast of Haeje Peninsula and run together with the main stream flowing southeast at offshore region. The currents create an anticyclonic circulation in flood and a cyclonic circulation in ebb around Haeje Peninsula including Hampyung Bay. Tidal currents are accumulated on Doripo which located at the entrance of Hampyung Bay and show high current velocities. Tidal currents and tide induced residual currents are weak at the inside of Hampyung Bay which has narrow entrance, shallow water depth and wide intertidal zone. An anticyclonic eddy is formed around Gaksi Island as a result of tide induced residual currents. In northern coast of Haeje Peninsula, slow constant currents flow east. It is expected that a gradual change of sediment and an increase of flushing time for suspended materials are carried by tidal currents occurring in Hampyung Bay.

• 한국환경과학회지
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• 제8권1호
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• pp.45-50
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• 1999

깨끗한 모래로 채워진 4개의 16갤론 크기 드럼통에 주물 파이프가 설치되었고 각 파이프에는 3개의 styrene butadiene rubber gasket(1개의 joint와 2개의 end caps)을 장치하였다. 각 파이프는 상수로 채워 내부의 압력을 약 40psi로 유지하였다. 첫 번째 드럼은 일정량의 휘발유로, 두 번째 드럼은 pyrene과 naphthalene을 포함한 휘발유로, 세 번째 드럼은 toluene으로 채워졌고, 네 번째 드럼은 대조군으로 사용되었다. 외부 오염물질의 이동에 의한 오염을 조사하기 위해 일정 간격으로 파이프 내의 물을 약 2년 간 조사하였다. 오염 물질이 투입된 3개의 드럼에서 약 100일 후부터 유기 오염 물질이 검출되었고 외부에 채워진 유기물이 고갈될 때까지 계속적으로 증가하는 추세를 보였다. 이미 오염된 물을 깨끗한 물로 청소한 후에도 오염된 gasket에 남아있는 유기물질이 유출되어 파이프 내의 물이 쉽게 오염되었으며 약 10일 후에는 청소 이전의 농도로 검출되어 gasket에 의한 오염이 오래 동안 지속되는 것으로 나타났다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권6호
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• pp.8-17
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• 2013

The contamination of chlorinated ethenes at an industrial complex, Wonju, Korea, was examined based on sixteen rounds of groundwater quality data collected from 2009 to 2013. Remediation technologies such as soil vapor extraction, soil flushing, biostimulation, and pumping-and-treatment have been applied to eliminate the contaminant sources of trichloroethylene (TCE) and to prevent the migration of TCE plume from remediation target zones. At each remediation target zone, temporal monitoring data before and after the application of remediation techniques showed that the aqueous concentrations of TCE plume present at and around the main source areas decreased significantly as a result of remediation technologies. However, the TCE concentration of the plumes at the downstream area remained unchanged in response to the remediation action, but it showed a great fluctuation according to seasonal recharge variation during the monitoring period. Therefore, variations in the contaminant flux across three transects were analyzed. Prior to the remediation action, the concentration and mass discharges of TCE at the transects were affected by seasonal recharge variation and residual DNAPLs sources. After the remediation, the effect of remediation took place clearly at the transects. By tracing a time-series of plume evolution, a greater variation in the TCE concentrations was detected at the plumes near the source zones compared to the relatively stable plumes in the downstream. The difference in the temporal profiles of TCE concentrations between the plumes in the source zone and those in the downstream could have resulted from remedial actions taken at the source zones. This study demonstrates that long term monitoring data are useful in assessing the effectiveness of remediation practices.

• Journal of Korean Neurosurgical Society
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• 제62권2호
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• pp.209-216
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• 2019

Objective : Hydatid cyst disease is caused by the parasite Echinococcus granulosus. It is rarely seen in the vertebral system, occurring at a rate of 0.2-1%. The aim of this study is to present 12 spinal hydatid cyst cases, and propose a new type of drainage of the cyst. Methods : Twelve cases of spinal hydatid cysts, surgical operations, multiple operations, chronic recurrences, and spinal hydatic cyst excision methods are discussed in the context of the literature. Patients are operated between 2005 and 2016. All the patients are kept under routine follow up. Patient demographic data and clinicopathologic characteristics are examined. Results : Six male and six female patients with a median age of 38.6 at the time of surgery were included in the study. Spinal cyst hydatid infection sites were one odontoid, one cervical, five thoracic, two lumbar, and three sacral. In all cases, surgery was performed, with the aim of total excision of the cyst, decompression of the spinal cord, and if necessary, stabilization of the spinal column. Mean follow up was 61.3 months (10-156). All the patients were prescribed Albendazole. Three patients had secondary hydatid cyst infection (one lung and two hepatic). Conclusion : The two-way drainage catheter placed inside a cyst provides post-operative chlorhexidine washing inside the cavity. Although a spinal hydatid cyst is a benign pathology and seen rarely, it is extremely difficult to achieve a real cure for patients with this disease. Treatment modalities should be aggressive and include total excision of cyst without rupture, decompression of spinal cord, flushing of the area with scolicidal drugs, and ensuring spinal stabilization. After the operation the patients should be kept under routine follow up. Radiological and clinical examinations are useful in spotting a recurrence.

• 한국포장학회지
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• 제28권3호
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• pp.217-221
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• 2022

저온에서 신선육을 보관 저장하는 용기의 기체조성을 고CO₂/저O₂ 농도로 자동적으로 제어하는 용기 시스템을 제작하고, 0℃에서 21일간 돼지고기 삼겹살을 담아 저장하면서 품질보전의 측면에서 진공 포장과 함기 대조구 조건과 비교하였다. CO₂ 주입 시간 프로그램에 의하여 CO₂ 농도는 47~60%, O₂ 농도는 7~10%로 유지될 수 있었고, 이는 호기적 세균 증식과 pH 증가의 억제의 효과와 함께 관능적 품질유지에 기여하였다. 진공포장은 함기 대조구에 비하여 낮은 미생물 성장과 pH 증가를 보여주었으나 높은 drip 손실의 단점을 보였다. 전체적 품질보존의 측면에서 고안된 고CO₂ 치환 용기는 육류의 품질유지에 효과적이며, 육류의 종류와 특성에 맞게 기체 농도 조건을 변경하여 활용범위를 확장할 수 있을 것이다.

• 한국수정란이식학회지
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• 제15권3호
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• pp.295-302
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• 2000

The objective of this study was to compare different superovulation treatments using PMSG or PG600$^{ }$ and to determine the optimal time of oocyte recovery after hCG administration. A total of 90 prepubertal Yorkshire x Landrace gilts crossed with Duroc, 6~7 months old and 100~120 kg of body weight, were used. PMSG (1,500 IU/head) or 5~7.5 ml of PG600$^{ }$(400 IU of PMSG and 200 IU of hCG) were administrated subcutaneously, and then 1,000 IU of hCG were administered intramuscularly at 72 hours after PMSG or PG600$^{ }$ injection. At carious time of 44, 46, 48 and 50 hours after hCG injection, superovulated gilts were slaughtered in a local abattoir. Ovaries together with oviducts were excised from the body immediately after slaughtered and transported to laboratory in 39$^{\circ}C$ saline. Ovaries were examined fur the number of corpus hemorrhagicum and unovulated follicles present in the surface of ovary. The unovulated follicles were categorized into small (1~3 mm in diameter) and large (4~8 mm) groups according to their diameter. Oocytes were recovered by flushing both oviducts with micropipette tip (1~100 $\mu$l) attached to a 10-ml disposable syringe. The number of CH on ovary and recovered oocytes at 46, 48 and 50 hr after hCG injection in PG600$^{ }$ treated groups were significantly higher than the other group. Group of phCG 50 hr among PMSG treated groups had a greater number of CH and recovered oocytes(P<0.05). The number of CH on ovary and recovered oocytes at 50 hr after hCG injection in 1$\frac{1}{2}$ vial(7.5 ml) of PG600$^{ }$ treated groups was significantly higher than 1 vial(5 ml) of PG600$^{ }$ treated group(P<0.05). In conclusions, considering a number of corpus hemorrhagicum and recovered oocytes after superovulation in gilts, effective time of oocyte recovery by treatment with PMSG and hCG was post-hCG 50 hr and with PG600$^{ }$ plus hCG was post-hCG 46, 48 and 50 hr. Also, admini-stration of 1$\frac{1}{2}$ vial(7.5 ml) of PG600$^{ }$ treated group had a great number of CH and recovered oocytes.covered oocytes.

• 멤브레인
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• 제9권3호
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• pp.178-184
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• 1999

폐수를 한외여과할 경우 발생하는 막오염 현상을 최소화하기 위하여 세척수로 주기적으로 역세척 하였을 때 그 효과와 최적 조건을 조사하는 것이 본 연구의 목적이다. 폐우우유팩을 재셍히여 화장지를 생산하는 A 회사 및 골판지를 재생하는 B회사의 응집 침전 처리수를 대상으로, 평균기공의 크기가 0.02${\mu}m$인관형 알루미나 세라믹 한외여과막으로 처리하면서 역세척 주기의 변화가 막오염과 투과수의 수질에 미치는 영향을 조사하였다. 이 대 역세척 시간은 모든 경우에 3초식 일정하게 행하였다. 원수 및 투과수의 부유 고형물 및 총용존 고형물, 화학적 산소요구량을 분석한결과, A회사의 폐수는 역세척 주기가 15초로 가장 짧은 경우 부유 물질의 배제율이 가장 우수하였다. 그러나, 화학적 산소요구량의 배제율은 A회사 및 B회사의 폐수가 모두 역세척 주기가 30인 경우 가장 높았다. 한편, 총용존 고형물의 배제율은 A회사 폐수가 역세척 주기 30초와 60초에서 유사한 값을 보였고, B회사 폐수가 역세척 주기 60초에서 가장 탁월하였다. 운전시간에 다른 투과 플럭스의 변화로 역세척이 막오염의 진행에 미치는 영향을 조사한 결과, A회사 및 B회사의 응집 침전 처리수 모두 역세척을 하였을 때 투과플럭스가 서서히 감소하였고, 정상 운전시 보다 높은 값을 나타내었다. 그러나, 가장 높은 투과플러스를 유지하는 조건은 A회사 폐수와 B회사의 폐수가 차이를 보였는데 수질조사 결과 A회사 폐수는 부유 고형물 및 화학적 산소요구량이 높았으나 B회사 폐수는 종용존 고형물이 상대적으로 많기 때문에 발생한 결과로 추정된다.

• 한국임상수의학회지
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• 제38권3호
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• pp.135-142
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• 2021

The aim of this study was to evaluate the contrast effect if a saline flush following low-volume contrast medium bolus improves vascular and parenchymal enhancement using a saphenous vein in abdominal CT for small animals. Six clinically healthy beagle dogs underwent abdominal contrast-enhanced CT. They were divided into nine groups (each group, n = 6), according to the volume of contrast medium 1, 2, and 3 mL/kg, and volume of the saline solution 0, 5, and 10 mL. Dynamic CT scanning was performed at the hepatic hilum level. The maximum contrast enhancement, time to maximum enhancement, and time to equilibrium phase were calculated from the time attenuation curves. Mean attenuation values for all groups were measured in the aorta, portal vein, and liver. After contrast enhancement, grading of image quality regarding surrounding artifacts and evaluation of the hepatic hilum structures was performed. For comparison of the effect of the contrast material and saline solution doses, differences in mean attenuation values between the contrast medium 2 mL/kg without saline flush group and the remaining groups, and between contrast medium 3 mL/kg without saline flush group and the remaining groups, were analyzed for statistical significance. There were no significant differences between with and without saline flushing at the same contrast medium dose groups. There were no significant differences in peak values between the 3 mL/kg dose of contrast medium alone and the 2 mL/kg dose of contrast medium with saline solution flush. However, there was a significant difference in peak values between the 3 mL/kg dose of the contrast medium without the saline flush group and the 2 mL/kg dose of the contrast medium alone group. Grades of the artifacts were not significantly different in the saline flush regardless of the dose of the contrast medium. Using 2 mL/kg of contrast medium with saline solution flush resulted in similar liver parenchyma attenuation, compared with using 3 mL/kg of contrast medium without saline solution flush. In CT evaluation of hepatic parenchymal diseases, using 2 mL/kg of contrast medium with saline solution flush may yield decreased risk of contrast nephropathy and cost-saving.

• 한국대기환경학회지
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• 제19권6호
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• pp.689-699
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• 2003

This study was to examine characteristics of treating toluene vapor, which gets to be problematic due to its harmful carcinogenicity and mass generation from various sources, through a biological treatment facility which is environment-friendly and adopts a high-efficient and low-cost clean technology. In order to identify whether Alnus Firma Fruit (AFF) can be used as a media for a bioreactor, its utility and basic operating factors, a study was conducted on pressure drop, supply of nutrient substances and retention time which are operating factors of a biofilter, and eliminating characteristics were compared between AFF and the conventional biological activatedcarbon (BAC) widely used as filter media. In the case of AFF, the initial microbial deposits was 2.3${\times}$10$^{7}$ CFU/g dry AFF, which represents the initial microbial density higher than the case of BAC showing 5.5${\times}$10$^{6}$ CFU/g dry BAC And it took about 2 weeks to acclimate until its eliminating rate got to be increased over 90%. As a result of comparing pressure loss taking place with the lapse of time between BAC and AFF, after 130 days passed at SV 25h$^{-1}$ , BAC showed that its eliminating efficiency had a tendency to drop greatly due to a great pressure loss (0.53\longrightarrow54.7 mm$H_2O$/m) caused by an excess of biomass as accumulated. On the other hand. AFF showed that the pressure drop was 0.53 mm$H_2O$/m, about 2 times as much as the initial pressure loss of 0.4 mm$H_2O$/m, which represents no great change in the pressure loss, and its eliminating efficiency was also shown to be continuously high. Therefore, when AFF was used as a filler for a biological treatment facility, a biological filter enabling improvement of the purifying efficiency to be promoted could be provided, and moreover, the pressure loss was so small that the filler replacement cycle or the back flushing cycle could be extended. So, even in terms of the operating cost, it was identified to be an economical filler When an inorganic material was used as a filler, the biofilters performance acted sensitively on whether nutrient substances were supplied or not. In the case of AFF with low adsorptivity, addition of ethyl-alcohol increased the solubility of toluene, and consequently, biodegradation got to be actively made by microbes, and thus, its eliminating rate could be increased. As the flow velocity and the inflow concentration got to be more increased, its eliminating rate got to be lower, and particularly, an increase in the flow velocity made its eliminating rate drop more greatly than an increase in the concentration.

• 한국수자원학회논문집
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• 제55권12호
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• pp.1065-1076
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• 2022

본 연구는 남강댐에서 대규모 선버들 군락의 확장과 고사가 수질에 미치는 영향을 파악하고자 하였다. 선버들 군락의 분포면적은 최초로 2003년에 0.12 km²였으나 2019년에는 3.58 km²로서 16 년 사이에 약 30 배로 급격하게 확장되었다. 그러나, 2013년에는 일부가 고탁도 장기 침수와 선버들 군락 내에서의 자기 솎음질(self-thining)에 의하여 분포면적이 0.17 km² 감소했다. 남강댐 저수지의 호소특성은 평균수심, 유역면적/호수 수면적 비, 체류시간, 회전율 및 성층화 등의 측면에서 호소형과 하천형이 복합적으로 나타났다. 호소수질에 대한 장기변동 특성을 분석한 결과, 대규모 선버들 군락지에서 COD, TP 및 엽록소 a 등이 남강댐 수역의 중앙부에 위치한 3 개 지점에 비하여 현저하게 크게 나타났다. 특히, 엽록소 a의 값이 남강댐 수질측정망 3 개 지점의 경향과 다르게 여름이 아닌 겨울에 최대값을 나타내는 것은 외부의 유입보다는 내부에서 발생된 것으로 사료된다. 이러한 남강댐 저수지에서 수질 악화의 한 가지 원인은 선버들 군락에서 낙엽, 가지 및 고사목 등 부산물의 분해과정에서 발생하는 막대한 양의 영양염류인 것으로 추정할 수 있다.