• 대한환경공학회지
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• 제36권1호
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• pp.58-66
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• 2014

도시화 및 산업화 등의 영향으로 인한 도시하천의 수질오염 문제가 사회적 관심의 대상이 되고 있다. 특히, 신도시의 개발로 인하여 유역 내 물순환 특성이 급격하게 변화한다는 사실을 고려할 때, 이에 영향을 받는 도시하천의 장래수질에 대해서도 많은 우려가 제기되고 있다. 그러나 아직 개발이 완료되지 않은 신도시의 장래수질을 정량적으로 예측하는 합리적인 방안은 현 시점까지도 제시되지 못하고 있는 실정이다. 따라서 본 연구에서는 환경부가 장기간의 모니터링 결과에 기반하여 제시한 토지계 지목별 발생부하 원단위를 분포형 강우유출모형인 SWMM (Storm Water Management Model)에 연계 적용함으로써 장래 신도시 내 도시하천의 수질을 거시적으로 예측하는 방법론을 제시하는 한편, 현재 신도시 개발이 진행되고 있는 G 신도시 내 대상유역의 장래수질 예측을 위하여 이를 활용함으로써 그 적용성을 검증하였다. '연단위 유량가중 평균농도 (Y-EMC; Yearly based Event Mean Concentration)' 개념을 도입하여 신도시 개발 이후의 장래수질을 예측한 결과, BOD 18.7 mg/L, T-N 16.2 mg/L 및 T-P 0.85 mg/L로 산정되어 목표수질인 하천생활기준 III등급의 달성이 어려운 것으로 나타났으며, 생활계 배출부하량을 80% 이상 저감시켰을 때 이 기준을 만족할 수 있는 것으로 예측되었다. 본 연구의 결과는 신도시 개발에 따른 장래 토지이용 특성의 변화에 대응하여 도시하천의 수질을 효율적으로 예측 관리하기 위한 기초적인 방법론으로 활용될 수 있을 것으로 판단된다.

• Fisheries and Aquatic Sciences
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• 제13권2호
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• pp.133-139
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• 2010

The effects of suspended solids size on culture water quality were determined in a commercial recirculating aquaculture system (RAS) for Japanese eel, Anguilla japonica. The particulate phase of the culture water was serially divided into six size fractions using 300, 200, 100, 75, 45, and 26 ${\mu}m$ pore size stainless sieves. The total, dissolved, and particulate nitrogen and phosphorus, and suspended solids for each fraction were determined. The concentration ranges in the fractions were: total nitrogen, 164-148 mg $L^{-1}$; total phosphorus, 20.4-15.5 mg $L^{-1}$; and total suspended solids, 8.1-6.1 mg $L^{-1}$. The concentration of total nitrogen and total phosphorus decreased significantly (P<0.05) with a 26 ${\mu}m$ and 200 ${\mu}m$ filter pore size, respectively. Nutrients from dissolved organic substances were much higher than from particulates. Analysis of particle size fractionation and its effects on water quality is useful to estimate removal efficiencies of a commercial effluent screening device for solid management and development of solid removal systems.

• Archives of Pharmacal Research
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• 제18권6호
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• pp.427-433
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• 1995

A microscopic mass balance approach has hsown that the initial saturation (Is), absorption number (An), dose number (Do), and dissolution number (Dn) are four fundamental dimensionless parameters that can be used to estimate the fraction dose absorbed (F)l of suspensions of poorly soluble drugs in humans. The dissolution number of a drug increases with decreasing its particle size. The effect of micronization on F for suspensions was investigated in terms of Dn. About 90% of maximal F can be achieved at $Dn{\approx}2$. Increasing the solubility of a drug results in better oral absorption through increasing Dn and decreasing the solubility of a drug results in better oral absorption through increasing Dn and decreasing Do. The fractions dose absorbed of digoxin, griseofulvin, and benoxaprofen agree with predicted F values sorbed by reducing particle size, while absorption of drugs with high Do and low Dn is limited by solubility and requires higher solubility to enhance the fraction dose absorbed in addition to micronization. Solubility at the physiological pH should be used for the estimation of the fraction dose absorbed.

• 한국축산식품학회지
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• 제30권6호
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• pp.946-950
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• 2010

This study evaluated the antimicrobial effects of meat processing-related organic acids on Burkholderia thailandensis (Burkholderia pseudomallei surrogate) with different water activities. B. thailandensis KACC12027 (4 log CFU/mL) was inoculated in microwell plates containing tryptic soy broth pH-adjusted to 4, 5, 6, and 7 with ascorbic acid, citric acid, and lactic acid and with water activities adjusted to 0.94, 0.96, 0.98, and 1.0 with NaCl, followed by incubation at $35^{\circ}C$ for 30 h. The optical density (OD) of the samples was measured at 0, 3, 6, 12, 24, and 30 h at 595 nm to estimate the growth of B. thailandensis. Growth of B. thailandensis was observed only at water activity of 1.0. In general, more bacterial growth (p<0.05) was observed at pH 6 than at pH 7, and the antimicrobial effects of the organic acids on B. thailandensis were in the following order: Ascorbic acid > lactic acid > citric acid after incubation at $35^{\circ}C$ for 30 h. These results indicate that organic acids in meat processing-related formulations should be useful in decreasing the risk related to an emerging high risk agent (B. pseudomallei).

• 자원환경지질
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• 제39권3호
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• pp.213-227
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• 2006

자연저감의 메커니즘을 설명하기 위하여 납과 비소 함량이 높은 세창광산 지역의 광산배수, 침출수 및 지표수의 지구화학적 변화를 연구하였다. 주요 오염원인 폐광석에서 미량원소의 분산 및 물리화학적인 조건의 변화에 따른 미량원소의 이동도를 평가하기 위하여 총함량 분석 및 연속추출을 수행하였다. 이러한 광산배수, 침출수 및 지표수의 화학성분은 시료채취의 위치 및 시기별로 변화가 컸으며, 특히 pH가 매우 낮고(pH 2.1-3.3), 황산염(최대 661mg/l) 및 미량원소의 함량(최대 169mg/l Zn, 27mg/l As, 3.97mg/l Pb, 2.99mg/l Cu and 1.88mg/l Cd)이 매우 높은 경우가 관찰되었다. 그러나 지표수에서의 비소와 미량원소의 함량은 특별한 처리를 하지 않아도 광산배수와 침출수가 배출되는 지점으로부터 가까운 거리인 지류와 합류되는 지점(8번, 16번)에서 자연배경값과 거의 유사한 함량으로 낮아졌다. 철-황화광물의 산화작용과 가수분해에 따른 비정질 철-2차광물의 침전작용은 하천으로 유입되는 미량원소의 이동을 크게 감소시켜주는 효과적인 자연저감 메커니즘이었다. 또한 오염되지 않은 지표수와의 합류에 의한 희석효과도 미량원소의 함량을 감소시키고 점진적으로 pH를 증가시켰다. 한편, 가장 용해성이 높은 원소인 아연은 pH가 거의 중성에 가까워질 때까지 상당량이 용해된 용질상태로 남아있었다. 환경독성학적인 관점으로 볼 때, 세창광산 지역에서는 아연에 의한 오염에 특별한 관심을 가져야 한다. 이러한 것은 수분을 함유한 폐광석에서 아연의 대부분이 양이 온교환형(전체 함량의 65-89%)으로 존재하고, 납은 전체함량의 65-89%가 산화광물 및 탄산염광물형태와 수반되었으며, 카드뮴, 구리 및 비소는 잔류형태가 우세한 것으로 나타난 연속추출실험 결과에 의해서도 확인되었다. 건조상태의 폐광석에서는 전체 납 함량의 34-48%가 쉽게 용출될 수 있는 양이온교환형태로 존재하였다. 양이온교환 및 탄산염광물 수반된 금속의 비율을 고려하면 각 미량원소의 상대적인 이동도는 Zn>Pb>Cd>As=Cu의 순서로 감소하는 것으로 판단된다.

• Asian Spine Journal
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• 제12권6호
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• pp.1060-1068
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• 2018

Study Design: Retrospective study. Purpose: Lumbar intervertebral disc degeneration is an important cause of low back pain. Overview of Literature: Spinal fusion is often reported to have a good course for adolescent idiopathic scoliosis (AIS). However, many studies have reported that adjacent segment degeneration is accelerated after lumbar spinal fusion. Radiography is a simple method used to evaluate the orientation of the vertebral column. magnetic resonance imaging (MRI) is the method most often used to specifically evaluate intervertebral disc degeneration. The Pfirrmann classification is a well-known method used to evaluate degenerative lumbar disease. After spinal fusion, an increase in stress, excess mobility, increased intra-disc pressure, and posterior displacement of the axis of motion have been observed in the adjacent segments. Methods: we retrospectively secured and analyzed the data of 15 patients (four boys and 11 girls) with AIS who underwent a spinal fusion surgery. We studied the full-length view of the spine (anterior-posterior and lateral) from the X-ray and MRI obtained from all patients before surgery. Postoperatively, another full-length spine X-ray and lumbosacral MRI were obtained from all participants. Then, pelvic tilt, sacral slope, curve correction, and fused and free segments before and after surgery were calculated based on X-ray studies. MRI images were used to estimate the degree to which intervertebral discs were degenerated using Pfirrmann grading system. Pfirrmann grade before and after surgery were compared with Wilcoxon signed rank test. While analyzing the contribution of potential risk factors for the post-spinal fusion Pfirrmann grade of disc degeneration, we used generalized linear models with robust standard error estimates to account for intraclass correlation that may have been present between discs of the same patient. Results: The mean age of the participant was 14 years, and the mean curvature before and after surgery were 67.8 and 23.8, respectively (p<0.05). During the median follow-up of 5 years, the mean degree of the disc degeneration significantly increased in all patients after surgery (p<0.05) with a Pfirrmann grade of 1 and 2.8 in the L2-L3 before and after surgery, respectively. The corresponding figures at L3-L4, L4-L5, and L5-S1 levels were 1.28 and 2.43, 1.07 and 2.35, and 1 and 2.33, respectively. The lower was the number of free discs below the fusion level, the higher was the Pfirrmann grade of degeneration (p<0.001). Conversely, the higher was the number of the discs fused together, the higher was the Pfirrmann grade. Conclusions: we observed that the disc degeneration aggravated after spinal fusion for scoliosis. While the degree of degeneration as measured by Pfirrmann grade was directly correlated by the number of fused segments, it was negatively correlated with the number of discs that remained free below the lowermost level of the fusion.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.473-476
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• 2004

In this study, hydrochemical studies of thermal waters in the Bugok and Magumsan areas showing geothermal anomalies were carried, and the applicability of ion seothermometers and multiple mineral equilibrium approach was examined to estimate their potential deep reservoir temperatures. Typical thermal waters of the two areas are clearly grouped into two major types, according to water chemistry: Na-Cl type (group A) and Na-SO4 type (group D). Compared to group A, group B and C waters show some modifications in chemistry. Group E waters show the modified chemistry from group D. Geothermal waters from the two areas showed some different chemical characteristics. The thermal waters of group A and B in Magumsan area are typically neutral to alkaline (pH=6.7 to 8.1) and Cl-rich (up to 446.1 mg/L), while the waters of group D and E in Bugok area are alkaline (pH=7.6 to 10.0) and SO$_4$-rich (up to 188.0 mg/L). The group A (Na-Cl type) and group D (Na-SO$_4$ type) waters correspond to mature or partially immature water, whereas the other types are immature water. The genesis of geothermal waters are considered as follows: group A and B waters were formed by seawater infiltration into reservoir rocks along faults and fracture zones and possibly affected by fossil connate waters in lithologic units through which deep hot waters circulate; on the other hand, group D and E waters were formed by the oxidation of sulfide minerals (mainly pyrite) in surrounding sedimentary rocks and/or hydrothermal veins occurring along restricted fracture channels and were possibly affected by the input and subsequent oxidation of S-bearing gases (e.g. H2S) from deep thermal reservoir (probably, cooling pluton). The application of quartz, Na-K, K-Mg geothermometers to the chemistry of representative group A and D waters yielded a reasonable temperature estimate (99-147$^{\circ}C$ and 90-142$^{\circ}C$) for deep geothermal reservoir. Aqueous liquid-rich fluid inclusions in fracture calcites obtained from drillcores in Bugok area have an average homogenization temperature of 128$^{\circ}C$, which corresponds to the results from ion geothermometers. The multiple mineral equilibrium approach yielded a similar temperature estimate (105-135$^{\circ}C$ and 100-14$0^{\circ}C$). We consider that deep reservoir temperatures of thermal waters in the Magumsan and Bugok areas can be estimated by the chemistry of typical Na-Cl and Na-SO$_4$ type waters and possibly approach 105-135$^{\circ}C$ and 100-14$0^{\circ}C$.

• 대한불안의학회지
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• 제9권2호
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• pp.106-112
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• 2013

Objective : Several reports have found abnormal levels of androgen in post-traumatic stress disorder (PTSD) patients. This abnormality in androgen is hypothesized to due to chronic psychological stress effects on the hypothalamic-pituitary-gonadal (HPG) system. The present study was conducted to estimate serum testosterone levels in PTSD patients in comparison with normal subjects. Methods : Seventy-five male Korean veterans of the Vietnam War volunteered for the study, of which eleven were excluded because of incomplete psychological assessment. To measure basal serum testosterone, blood samples were collected between 8.00 and 9.30 a.m. The clinician administered PTSD scale (CAPS), the structured clinical interview for DSM-IV (SCID), Hamilton Anxiety Rating Scale (HAM-A), Hamilton Rating Scale for Depression (HAM-D), Mini International Neuropsychiatric Interview Plus (Korean version of MINI-Plus), CES-K (Korean version of combat exposure scale). Results : The serum testosterone level of PTSD patients ($5.4{\pm}2.5ng/mL$) was higher than that of a control group ($3.1{\pm}1.7ng/mL$, p<0.001). Testosterone levels were significantly correlated with CAPS (r=.38, p<.01), HAM-A (r=.35, p<.01) and HAM-D (r=.28, p<.01) in all subjects. Conclusion : The results of the present study suggest that chronic psychological stress affects the HPG system.

• 한국연초학회지
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• 제23권2호
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• pp.149-155
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• 2001

This study was carried out to evaluate the correlations among degree of carbonization, chemical components and chromatic characteristics, and to establish the criterion of carbonizaion in leaf tobacco during aging storage. The flue-cured (B2O) and burley (B2T) leaf tobaccos were redried with conventional practices for each other type, and moisture contents of leaf tobaccos were adjusted to 13, 15, 17 and 19% after redrying. The leaf tobaccos were packed in carton box and stored for 8 months in the controlled-environment rooms($35^{\circ}C$, 65% R.H. and $40^{\circ}C$, 80% R.H.). Degree of carbonization, chemical components, and chromatic characteristics(L ; black-white, a ; red to green, b ; yellow to blue) were invetigated every month. Carbonization Index (C.I.) was established as (equation omitted) in accordance with degree of carbonization in two types. The C.I. value of flue-cured leaf(56.5) for slight carbonization was higher than that of burley leaf(48.0). C.I. and rate of usable leaf, L and b were positively correlated in two types. C.I. was significantly shown positive correlation with pH in two types. The correlations between the predicted and the observed values of slight carbonizating times(month after storage) using C.I. and pH were positive significant in two types. The results suggest that cabonization index may be useful to forecast and prevent the carbonization, and pH may be useful to estimate cabonization indirectly for flue-cured and burley leaves during aging storage.

• 한국해양학회지
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• 제26권3호
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• pp.291-294
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• 1991

이 컴퓨터는 프로그램은 생물량의 변화와 광합성율로부터 해조류의 년 생산량을 계산하기 위해 작성한 것이다. 서로 다른 광도, 온도조건 아래서 측정된 해조류의 단 위무게 당 광합성율을 광도, 수온의 년 변화와 연결시켜 광합성율의 년 변화를 계산하 였다. 이 때 해조류의 광합성율을 1년간 짧은 시간간격으로 측정한다면 좀더 정확한 값을 얻을 수 있을 것이다. 광합성율의 시간에 따른 변화를 생물량의 시간에 따른 변 화와 연결시켜 년 총생산량을 계산하였다. 어느 주어진 시간에서의 생물량을 알고 이 때의 단위무게당 광합성율을 알면 이들 값을 곱하여 이 시간에서의 총 생산량을 알 수 있기 때문이었다. 프로그램은 개인용을 이용하는데 편리하도록 파스칼 언어를 사용하 였으며, 계산결과를 데이터 베이스에 옮길 수 있도록 하여 다양한 프린터 사양을 가지게 한 것도 하나의 특징이다. 강원도 고성군 오호리에 서식하는 알쏭이 모자반을 대상으로 측정한 생물량, 광합성율의 값들을 이 프로그램에서 예로 사용하였다.