• 지질공학
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• 제24권2호
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• pp.201-215
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• 2014

본 연구에서는 창원시 강변여과수 개발사업(2단계)에서 얻어진 자료들을 이용하여 대수층의 수리전도도와 방사형집수정의 수평집수관에서 산출되는 유량과의 상관관계를 규명하고자 하였다. 연구지역인 낙동강 중하류 모래자갈층에서 수평적으로 채취한 미고결 퇴적물의 시료를 이용하여 경험식에 의한 수리전도도를 산정하였다. 여러 경험식을 이용하여 연구지역에서 수리전도도를 산정한 결과, Beyer식에 의한 수리전도도가 가장 적합한 것으로 판정되었다. 산정된 수리전도도는 0.083 ~ 0.264 cm/s의 범위, 평균 0.159 cm/s로 나타내고 있어 연구지역의 대수층 특성은 모래자갈층에 투수성이 양호한 것으로 나타났다. 산정된 수리전도도와 실측자료에 의한 스크린 내 지하수의 유입속도 및 유량과의 상관관계를 분석하고자 회귀분석을 실시하였다. 회귀분석 결과, 수리전도도와 지하수의 유입속도 및 유량은 약 72 %의 높은 상관관계를 가지는 것으로 나타났고, 각 변수들 간에 실측자료와의 검증에서도 약 72 %가 일치하는 것으로 분석되어 선형 회귀식은 높은 적합성을 나타내었다. 본 연구의 결과로서 선형 회귀식을 이용하여 수리전도도에 의한 방사형집수정의 수평집수관에서 산출되는 유량의 추정이 가능하고, 연구지역과 유사한 대수층에서 적용이 가능할 것이라고 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제2권2호
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• pp.91-97
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• 1989

The present experiment was carried out to investigate the effects of heat exposure on water metabolism and the passage of indigestible particles in sheep. Water intake, respiratory rate, rectal temperature and pH of ruminal fluid and urine were significantly higher (P<0.05) in the hot environment ($32\;^{\circ}C$) than in the control environment ($20\;^{\circ}C$). Urine osmolality and blood volume were increased, while glomerular filtration rate was decreased, in the hot environment. The liquid flow rate from reticulo-rumen and the excretion of indigestible particles of specific gravity 0.99 (but not 1.27 or 1.38) were increased in the hot environment. From these findings, it is suggested that an increased water intake evoked by heat exposure might affect the flow rate of digesta in sheep.

• 대한핵의학회지
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• 제23권1호
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• pp.55-61
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• 1989

While cisplatin has been widely used in the treatment of a variety of cancers, nephrotoxicity is one of the major problems which frequently limit clinical usefulness of cisplatin. This study has been conducted to investigate nephrotoxicity of cisplatin in terms of changes in glomerular filtration rate (GFR) and effective renal plasma flow (EFPF) measured by the simultaneous use of $^{99m}Tc-DTPA$ and $^{131}I-OIH$, before and after administration of cisplatin, in 12 patients with lung cancer and four patients with esophageal cancer. Cisplatin was administrated at total doses of $75\sim100mg/m^2$ with two hour hydration and diuresis method. GFR determined by the use of $^{99m}Tc-DTPA$ had a good correlation with 24-hour creatinine clearance rate (r=0.77, p<0.001). GFR and filtration fraction decreased immediately after administration of cisplatin, however, they showed a tendency to be in completely recovered four weeks after administration. ERPF was not changed immediately after and four weeks after administration of cisplatin. GFR before and immediately after administration of cisplatin were analyzed with regard to age, sex, performance status, previous adminstration of cisplatin and method of administration. None of these factors had any influence on the rate of decrease in GFR except method of administration. Administration of cisplatin as a single dose lowered GFR more compared with that as divided doses. In this study, we have also demonstrated that the simultaneous use of $^{99m}Tc-DTPA$ and $^{131}I-OIH$ was a useful tool for the measurement of GFR and ERPF respectively.

• 대한환경공학회지
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• 제37권3호
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• pp.152-158
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• 2015

본 연구는 소수성 막 재질에 대한 막오염도를 평가하고자 수동흡착의 개념을 도입하여 정상운전을 위한 막 모듈 이외에 수동흡착 시험용 막 모듈을 설치하여 유출을 시키지 않은 상태에서 막 표면에 부착되는 미생물에 의한 막오염 정도를 분석함으로써 소수성 막오염 잠재성을 평가하고자 하였으며, 이때 운전조건으로 유기물 유입부하를 변화시켜 평가하였다. 이와 더불어 오염된 멤브레인을 세 가지 세정방법(두가지 물리적 세정과 화학적 세정)을 통해 막 세정 전후의 막오염 회복률을 평가하였다. 막오염 평가인자로는 반응조 내 MLSS 농도와 EPS 농도를 조사하였으며, 여과저항 값을 산정하여 막오염 전과 후, 세정 3단계 전과 후를 비교 평가하였다. 실험 결과로서, COD 농도가 750 mg/L인 가장 높은 부하량 조건에서 반응조 내 EPS 농도와 수동흡착 시험용 멤브레인의 여과저항 값이 가장 높게 나타났다. 또한 여과저항 값이 초기 운전 시작 후 차이를 보였지만 60일 이후의 최종 여과저항은 거의 일정하게 나타났는데, 이는 막 표면에 부착된 미생물량이 임계점에 이르러 수동흡착만으로는 더 이상의 막오염은 진행되지 않은 것으로 판단된다. PAds 상태에서 유기물 유입부하에 따른 오염된 막의 세정 전후의 여과저항 측정 결과에서는 3단계 세정 후 평균 회복률이 각각 Run 1이 78%, Run 2가 72%, Run 2가 69%로 유기물 부하가 높을수록 회복률이 떨어지는 것으로 나타났으며, 반면에 물리적 세정에 의한 복원률이 40일 경부터 Run 2와 Run 3의 물리적 세정에 의한 회복률이 낮아지는 것으로 보아 높은 유기물 부하로 인한 막표면의 케이크 형성으로 막오염이 심화된 것으로 판단된다.

• 한국물환경학회지
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• 제16권4호
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• pp.523-532
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• 2000

The purpose of this study was to investigate the effects of the hydraulic retention time (HRT) and organic loading rate (OLR) on microbial characteristics and treatment efficiency in sewage treatment using aerated submerged biological filter (ASBF) reactor. This reactor combines biodegradation of organic substrates by fixed biomass with a physical separation of biomass by filtration in a single reactor. Both simulated wastewater and domestic wastewater were used as feed solutions. The experimental conditions were a temperature of 17 to $27^{\circ}C$, a hydraulic retention time of 1 to 9hr, an organic loading rate of 0.47 to $3.84kg\;BOD/m^3{\cdot}day$ in ASBF reactor. This equipment could obtain a stable effluent quality in spite of high variation of influent loading rate. Total biomass concentration. biofilm thickness and biofilm mass increased an exponential function according to the increasing OLR. The relationships between water content and biofilm density were in inverse proportion. The percentage of backwash water to influent flow was almost 9%. The separation efficiency of biomass was the percentage of 91 to 92 in ASBF reactor. The sludge production rates in feed solutions of simulated wastewater and domestic wastewater were 0.14~0.26 kg VSS/kg BODrem, 0.43~0.48 kg VSS/kg BODrem, respectively.

• 생물정신의학
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• 제3권2호
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• pp.149-155
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• 1996

Doctors who treat pregnant women ore usually cautious in writing their prescription for the drugs. The problem of which psychotropic medications ore sale during pregnancy seems to remain unsolved for many years. Although the rate of absorption is reduced due to a reduced rate of gastric emptying, the extent of absorption of drug is generally unchanged during pregnancy. Plasma volume and total body water increase during pregnancy. There is suggestion that drug metabolizing activity may be increased in pregnancy. Since the pregnancy increase the glomerular filtration rate significantly, drugs mainly eliminated by renal excretion will be cleared more quickly. Factors contributing to the potential teratogenecity of a drug include the type of compound, dose and duration of use, developmental stage of fetus at the time of exposure, and the effect of the drug on fetal pharmacokinetics. All major classes of psychotropic agents should be assumed to diffuse readily across the placenta to the fetus and to be present in some quantity in the breast milk. To decide when and how to start the drug treatment depends on an assessment of the risks related both with and without drug treatment of psychiatric disorders.

• 한국미생물·생명공학회지
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• 제25권4호
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• pp.391-395
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• 1997

It was proved that both ethanol extracts from Mori Folium from Kangwon do and silk worm had higher inhibition acitivity on $\alpha$-glucohydrolase than the water extracts. In adding above 8.5 (mg/L) of silkworm extracts, the inhibition rate on $\alpha$-1,4 glucosidase was saturated while the inhibition rate was continuously increased in adding the extracts from Moli Folium. It was also found that the diethyl ether fraction showed much better inhibition activity than water fraction from ethanol extracts, yielding ca. 85% of inhibition rate for the extract of Moli Folium, compared to 91% for a commercially available hypoglycemic drug, Chloropropamide. In separating the diethyl ether fractions by Consecutive Sephadex gel filtration and Thin layer chromatography, three and four active spots were obtained from Moli Folium and silkworm, respectively. It is interesting that the similar Rf spots from both species among several spots in TLC have the highest inhibition acitivity on a target enzyme, which can imply that the active substances from both species are same or similar molecular weight and structure. Glucose-lowering activities of both speciese were also examined in vivo, showing that the fraction from Moli Folium had better activity than that from silkworm, and its activity was similar to that of a commercial drug.

• 상하수도학회지
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• 제20권5호
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• pp.677-684
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• 2006

Electro-flotation(EF), a novel sludge thickening method, could improve the dewaterability of activated sludge. The gas(microbubbles) generated during EF decreased the solid-liquid separation time below 1/5 of the time required for gravity sedimentation. In addition, over 90% of the sludge volume reduction could be achieved by EF although the settling characteristics of the sludge was very poor. The SRF(specific resistance to filtration) of the thickened sludge by EF was much lower than that of the sludge thickened by gravity sedimentation. The SRF of the thickened sludge decreased exponentially with increase of gas generation rate of the EF system. Gas generation rate could be controlled by varying the current density of the electrode. Degasing of the microbubbles by vigorous mixing of the thickened sludge layer deteriorated the dewaterability of the sludge. Therefore, it is obvious that the gas bubbles entrapped in the thickened sludge play a key role in the observed dewaterability improvement.

• 한국환경과학회지
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• 제14권3호
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• pp.335-343
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• 2005

The objective of this research is to evaluate a feasibility of wastewater reuse by membrane treatment with vibrating membrane separation equipment. Molecular weight of compounds in wastewater, permeability of membrane and retentate characterization after membrane filtration were investigated in order to determine appropriate membrane pore size and materials for wastewater treatment. Selected membrane was evaluated with vibration membrane separation equipment to optimize operating conditions. The following conclusion are drawn. 1. We got as following test results after the distribution of particles in the semiconductor wastewater, are made up of $1\~20{\mu}m$. Si, gold and Al in turn are contained in semiconductor wastewater. 2. Recovery rate is changeless under increasing recovery rate in operation. Though a value can be if pressure can be changed, the highest value of permeate rate is presented in 150 psi. 3. The AS-100(polysulpone) was selected as the most appropriate membranes for the treatment of semi-conductor wastewater to VSEP system. The fouling almost did not occur during this experiments. The analyses of treated water with VSEP system showed conductivity: 0.059,us/cm, TDS: 40mg/l, COD: 20mg/l, SS : 5mg/l, n-Hexane: 8.3mg/l. Comparing previous systems, operating expenses is decreased by more $50\%$.

• 한국유체기계학회 논문집
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• 제14권6호
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• pp.35-44
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• 2011

Membrane filtration has become firmly established as a primary process for ensuring the purity, safety and efficiency of treatment of water or effluents. Several researches have been performed to develop and design membrane systems in order to increase the accuracy and performance of the processes. In this study, a lattice Boltzmann method for the cake layer has been developed using particle dynamics based on an immersed boundary method and the cake layer formation process on membrane has been numerically simulated. Case studies including various particle sizes were also performed for a microfiltration process. The growth rate of the cake layer thickness and the permeation flow rate along the membranes were predicted. The results of this study agreed well with that of previous experiments. Effects of various particle diameters on the membrane performance were studied. The cake layer of a large particle tended to be growing fast and the permeation flow going down rapidly at the beginning. The layer thickness of a small particle increased constantly and the flow rate was smaller than that of the large particle at the end of simulation time.