• 한국대기환경학회지
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• 제22권3호
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• pp.337-351
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• 2006

In this study, to describe the basic characteristics of strong odorous sources, the emissions of odorous compounds from a large-scale sewage treatment plant in K city were investigated. According to this study, the emission patterns of major odorous compounds were distinguished clearly by several factors such as treatment processing types, chemical compositions of odors released, and temporal changes (e.g., seasonal variations). For the purpose of this study, emission rates of odorous compounds were quantified using a dynamic flux chamber (DFC) method from three major treatment (T) processes including T1 (Grit sedimentation basin), T2 (Aeration tank), and T3 (Final sedimentation). When the relative strengths of each emission source were compared, the strongest one was seen from T1 with the maximum of $NH_{3}\;(34.5\;{\mu}g/m^{2}/min)$ followed by $H_{2}S\;(20.4\;{\mu}g/m^{2}/min)($. While the strongest emissions of most odorous compounds were seen commonly from T1, those seen from T2 and T3 were significantly reduced relative to the ones found in T1. Considering the general patterns of odorous emission, it is concluded that control of odors from T1 unit is most important because of its considerably high emission strengths.

• Journal of Ecology and Environment
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• 제29권4호
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• pp.389-398
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• 2006

To examine sediment characteristics and find anthropogenic effects on riverine wetland ecosystems, paleoecological study was carried out at Bam islands in Seoul. Three hundred cm deep sediment cores were retrieved and dated with the lamination analysis method until 36 cm depth (1986). Sediments were divided into three zones based on the depth profiles of physico-chemical variables: below 160 cm depth (before 1968), between 160 and 40cm depths and above 40cm depth (after 1986). Physico-chemical characteristics were very variable between 160 and 40cm depths and this indicates unstable sedimentation environment. Even though heavy metal concentrations were relatively low, Cd and As contents have increased continuously. Dry mass accumulation rates during $1968{\sim}1986\;and\;1987{\sim}2003$ were 140 and $21\;kg\;m^{-2}\;yr^{-1}$, respectively. This was related to flooding intensity and duration. Bulk density, water content, loss on ignition, N, C, C/N ratio were very similar to other river delta but Ca, Na and K contents were 2 to 4 times higher than others. Heavy metal contents except Pb were lower or similar to those in other studied marshes in Korea. Heavy metal and Mg contents were correlated with each other and this suggests that the source of heavy metals be parent rock. From $^{13}C$ dating dates of organic materials in sediment, it is suggested that organic matter originated from the watershed and flooding intensity in the watershed might be responsible for the source of sediments. This study provides reference data for the comparison of sediment characteristics at islands in river and for the management of Bam islands.

• Journal of Pharmaceutical Investigation
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• 제26권4호
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• pp.245-256
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• 1996

Solid lipid nanoparticles (SLN) have been developed as a new drug delivery system. Although many particulate drug carriers, such as microsphere, liposome, niosome, emulsion, etc. have been introduced, they have some disadvantage; low efficiency of incorporation and stability, lack of reproducibility, and so on. Meanwhile, SLN as a new drug delivery system is known to entrap rugs with a high efficiency and a good reproducibility. Moreover, small size SLN can circulate in blood for a prolonged time. Although many preparation methods were introduced, microfluidization method is recommended to be the most useful. This study was attempted to prepare and evaluate ketoprofen-incorporated SLNs (keto-SLN), which were prepared by two methods, ultrasonication and microfluidization. Keto-SLN was evaluated by measurement of particle size and zeta potential, efficacy of entrapment, sedimentation volume, in virto release pattern. The mean particle size was about $0.1\;{\mu}m$, and the size was dependent on the type and the amount of emulsifier. Zeta potential was negative, $-9{\sim}-13mV$ and entrapment efficacy was very high and stability was good for at least 60 days in the respect of particle size and sedimentation volume ratio. Analgesic effect was also determined as well as pharmacokinetic parameters. The former was comparable to that of that of ketoprofen loaded suspension (keto-sus) and the latter revealed that consistent with the delayed release of keto-SLN. $T_{max}$ was longer than keto-sus. Therefore, keto-SLN was favourable dosage forms in the field of drug delivery system such as anti-cancer, analgesics and anti-inflammatory agents.

• Archives of Plastic Surgery
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• 제37권4호
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• pp.346-350
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• 2010

Purpose: Diagnosis of diabetic foot infection is sometimes difficult, since the classical inflammatory signs and leukocytosis may be absent due to the decreased host immune response in diabetics. Therefore inflammatory blood markers, such as white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) have been commonly needed to confirm the diagnosis of infection. The purpose of this study is to evaluate the diagnostic usefulness of WBC, ESR and CRP for detection of diabetic foot infection. Methods: Peripheral blood samples were taken from 113 patients with diabetic foot ulcers admitted from June 2007 to April 2009. Diabetic foot infection was diagnosed according to the microbiological culture from soft tissue and bone specimens. Reference values of tests were 4500-11000 /${\mu}L$ for WBC count, 0-20 mm/hr for ESR, and 0-5 mg/L for $CRP^{13,14}$. Sensitivities, specificities, positive and negative predictive values of laboratory tests were calculated and analysed. Receiver-operator characteristic (ROC) curve was also created. Results: There was a significant difference in WBC, ESR, and CRP between infectious group and noninfectious group (p<0.05). The sensitivity of WBC>11,000 /${\mu}L$ ESR > 20 mm/hr, and CRP > 5 mg/L was 30%, 96%, and 84%. The specificity was 86%, 14%, and 50% for WBC, ESR, and CRP, respectively. Positive predictive value was 88%, 78%, and 84%, and negative predictive value was 28%, 50%, and 50% respectively. The areas under the ROC curve for WBC, ESR and CRP were 0.72, 0.75, and 0.78 respectively. Conclusion: Based on the results of this study, we conclude that CRP is more useful method in predicting and diagnosing infection than WBC, ESR in diabetic foot ulcer patients.

• 한국지반환경공학회 논문집
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• 제12권8호
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• pp.51-57
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• 2011

섬진강 하류지역은 1978년 이후 지속적인 하상 세굴로 인하여 염수 침입이 확대된 지역으로서, 본 연구에서는 지하댐 설치 시의 염수침입 차단 효과를 수치모델로서 평가하였다. 현재 섬진강 하류 지표수의 염소이온농도는 상류로 가면서 지수함수적으로 감소하며, 지하수내 농도는 지표수의 1/10 이내로 나타난다. 하구로부터 4.6km 지점에 암반 상부로부터 25m 높이의 지하댐을 설치하는 조건으로 FEM 모델인 FEFLOW를 수행한 결과, 지하댐 상류의 퇴적 작용으로 현재보다 충적층의 두께가 5m 정도 두꺼워진다면 하구로부터 25km 지점에서의 염소이온농도(0.25psu)가 하류로 약 3km 정도 이동하는 것으로 나타났다. 반면에, 지하댐 상류에 퇴적물이 쌓이지 않을 경우에는 지하댐 설치 효과가 미미한 것으로 해석되었다.

• 한국물환경학회지
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• 제25권4호
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• pp.597-605
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• 2009

Algae bloom occurred in reservoir in summer can cause taste and odor in water and disturb the flocculation and sedimentation processes in water treatment plant and cause sand filter plugging. It was also reported that microcystins, anatoxin and saxitoxin released from cyanobacteria had acute toxic effects on liver and nervous system. For these reasons, many advanced countries inclusive of WHO set the guideline for these toxins and cyanotoxins have been managed with regular monitoring in Korea as well. However, complex sample preparation steps such as a solid phase extraction (SPE) and derivatization are required with an existing analysis method with HPLC. We needed to improve an analysis method for low extraction efficiency and long sample preparation time. In this study, we have established a new LC/MS/MS method which can simultaneously determine 6 cyanotoxins (Microcystins-LR, Microcystins-RR, Microcystins-YR, Anatoxin-a, Saxitoxin, Neosaxitoxin) with only simple filtration step. When $75{\mu}L$ filterated sample was injected onto the LC-MS/MS, the recovery ranged from 86% to 112% and the MDL was $0.025{\sim}0.581{\mu}g/L$. We can make the MDL be lower than the guideline ($1{\sim}3{\mu}g/L$) of advanced countries with simple preparation.

• 한국환경과학회지
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• 제30권12호
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• pp.983-991
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• 2021

The role of the distribution basin role is to apportion incoming raw water to the primary sedimentation basin as part of the water treatment process. The purpose of this study was to calculate the amount of water in the distribution basin using computational fluid dynamics (CFD) analysis and to find a way to improve any non-uniformity. We used the Taguchi method and the minitab tool as optimization methods. The results of the CFD calculation showed that the distribution flow had a deviation of 5% at the minimum inflow, 10% at the average inflow, and 22% at the maximum inflow. At maximum flow, the appropriate heights of the 7 weirs(C, D, A, B, E, F, G) were 40 mm, 20 mm, 20 mm, 0, 0, 0, and 20 mm, respectively, according to the Taguchi optimization tool. Here, the maximum deviation of the distribution amount was 9% and the standard deviation was 23.7. The appropriate heights of the 7 weirs, according to the Minitab tool, were 40 mm, 20 mm, 20 mm, 0, 0, 0, and 20 mm, respectively, for weirs C, D, A, B, E, F, and G. Therefore, the maximum deviation of the distribution amount was 8% and the standard deviation was 17.1, which was slightly improved compared to the Taguchi method.

• 한국응용과학기술학회지
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• 제29권1호
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• pp.149-158
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• 2012

본 연구에서는 올레산을 표면개질제로 사용하여 수열법을 통해 수산화 마그네슘을 합성하였다. 수산화 마그네슘은 알카리 조건에서 올레인산과의 반응을 통해 표면 개질된 마이크로 크기의 플레이크 형상을 갖는다. 수열합성에서 수산화 마그네슘 입자 생성의 조건은 pH, 온도 그리고 반응시간이 표면개질과 입자 형상의 주요 변수임을 확인하였다. 생성된 수산화 마그네슘 입자는 FE-SEM, XRD, FT-IR 그리고 TGA를 통해 확인하였다. 유기 용매 내에서의 분산성의 확인은 개질되지 않은 수산화 마그네슘과의 침전 테스트 비교를 통해 확인하였다.

• 대한수의학회지
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• 제26권1호
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• pp.187-194
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• 1986

The purpose of this study is to develop a new method which enables the goat ESR to be used as an effective clinical test. Blood samples were taken from 61 Korean native goats aged above one year old and the effect of tube inclinations, tube bores, tube lengths, environmental temperatures during tests and packed erythrocyte volumes (PCV) on the ESR were observed. The results were summarized as follows. 1. The ESR/hr using capillary hematocrit tube (Micro-Ht-tube) was gradually increased as the tube angle inclined from 90 (vertical) to 15 degrees and the best angle in view of both security and fast sedimentation rate was found to be an angle of 45 degrees. 2. The 45-degree angled ESR ($45^{\circ}$-ESR) increased as the diameter of tube bore decreased. 3. The tube length did not affect the $45^{\circ}$-ESR in percent. 4. The $45^{\circ}$-ESR increased with the increased environmental temperature during the ESR test. 5. The heparinized Micro-Ht tubes did not affect the $45^{\circ}$-ESR of EDTA-blood in healthy group but in anemic group. In the anemic group, the ESRs by the heparinized Micro-Ht-tubes were slightly higher than those by non-heparinized Micro-Ht-tubes. 6. By using the autologous plasma, PCV of the blood was adjusted to be 10, 20, 30, 40 and 50ml/100ml and $45^{\circ}$-ESRs were determined in the Micro-Ht-tubes. The $45^{\circ}$-ESRs increased as the values of PCV decreased. The regression of the $45^{\circ}ESR$ to PCV was curvilinear with the second degree polynomial, $Y=42.1838-1.7355X+0.0180X^2$(r=0.9997). 7. The $45^{\circ}$-ESR/hr, using non-heparinized Micro-Ht-tubes at $20^{\circ}C$, was determined in 35 healthy Korean native goats. The average PCV was $30.6{\pm}1.4ml/100ml$. The observed ESR values averaged $6.8{\pm}1.7%$ and the corrected ESR values to the standard PCV of 31ml/100ml averaged $6.5{\pm}1.2%$. From these results, the angled capillary tube method was found to be desirable ESR test of goat blood in which EDTA-blood is filled in nonheparinized Micro-Ht-tubes held at an angle of 45 degrees for an hour at $20^{\circ}C$.

• 한국수자원학회논문집
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• 제44권12호
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• pp.975-990
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• 2011

본 연구에서는 하상의 시공간적변동에 대한 평가기법을 개발하고자, 1차원HEC-RAS 모델과 2차원CCHE2D 모델을 이용해 하상변동을 평가하였다. 실제하천의 장기간 하상변동의 결과를 해석함에 있어서 변동 특성을 일관적인 기준으로 평가하고, 변화량을 직관적으로 알 수있는 평가방법을개발하고자유사단면누가곡선, 유사단면모멘트, 유사확률분포함수의 세 가지 평가 방법을 개발하였다. 본 연구를 수행한 결과 유사단면 누가곡선법은 단면의 총량적 개념의 침식 또는 퇴적 여부를 판별하는데 효과적이며, 유사단면 모멘트법은 하천의 좌, 우안을 나누는 기준선을 중심으로 좌, 우안의 퇴적 또는 침식 정도를 하나의 척도로 제시하는 것이 가능하였다. 이러한 방법은 하천의 곡률 등과 연계한 하상변동 예측에 있어서 하나의 영향지표로 활용할 수 있을 것이다. 유사확률분포함수의 경우 하천 단면 구간에 대한 시간의 변화에 따른 변동 모의 결과를 직관적으로 도시하고, 해당 구간의 시공간적 변동 특성을 통계적 특성치인 평균과 신뢰 구간을 통해 정량화 할 수 있었다.