• 한국물환경학회지
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• 제33권5호
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• pp.572-579
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• 2017

Increased impervious surface caused by rapid urbanization serves to produce the discharge of non-point source pollutants such as total suspended solid (TSS). There exist various methods of removing TSS, including a filtration process using granular media (a well-known method to be practically used after the consideration of removal efficiency, clogging, and backwashing efficiency). To determine the TSS removal capability of the filter, we initially performed lab-scale experiments which assessed flow rates, influent concentrations, permeability co-efficients, the particular shapes of suspended solids and potential clogging, and also evaluated TSS removal efficiency when applied to filtration facility in a pilot-scale. In low filtration flux condition, the removal efficiency of suspended solids was more than 95 %, while decreased to 83% in high filtration flux. Regarding the clogging aspect of the experiment, total cumulative solids were loaded up to $19.15kg/m^2$, and TSS removal efficiency was noted to commence to decrease when the loaded solids exceeded $9.0kg/m^2$. It was also noted, however, that superior efficiency was maintained for six hours. In addition, for pilot-scale experiment, the removal efficiency was still high enough (83.4 %) for the solid concentration of 140 ~ 343 mg SS/L and after backwashing, head loss was recovered to 92 ~ 95 % during two hour filtration. With these results, It was confirmed that lifetime of the filter applied to the test was prolonged due to the high treatment efficiency and good backwashing efficiency for the cumulative solids load.

• Biomolecules & Therapeutics
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• 제9권1호
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• pp.26-32
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• 2001

This study was investigated about the effect of glibenclamide (GLY) which is $K^{+}$ channel blocker on renal function in rabbit, GLY, when given into the vein, produced the diuretic action accompanied with the increases of amounts of N $a^{+}$ and $K^{+}$ excreted into urine ( $E_{Na}$ , $E^{K}$), and then osmolar and negative free water clearances ( $C_{osm}$, $T^{C}$$_{H2O}$), fraction excretory rates of filtered N $a^{+}$ and $K^{+}$ ( $F_{Na}$ , $F_{K}$) and ratios of $E_{K}$ against $E_{Na}$ were augmented. Filtration fraction (FF) were reduced because renal plasma flow (RPF) were not changed but glomerular filtration rates (GFR) were diminished. GLY administered into a renal artery exhibited significant reduction of urine volume along with the decreases of GFR and RPF in only experimented kidney whereas changes of renal function was not observed in control kidney. GLY given intracerebroventricularly exhibited diuretic action along with the increase of $E_{Na}$ , $E_{K}$ and $F_{Na}$ , $F_{K}$ by small dose which was not affect on renal function when it given into the vein. Above results suggest that GLY given into the vein in rabbit produce the diuretic action by inhibition of electrolytes reabsorption in renal tubules through central function. function.n. function.ion.

• Journal of Korean Biological Nursing Science
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• 제15권2호
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• pp.82-89
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• 2013

Purpose: To examine the quality of life in pre-dialysis patients with chronic kidney disease. Methods: The subjects were 91 patients who visited the nephrology outpatient department of a tertiary hospital located in Seoul. Data on demographic and clinical characteristics, and quality of life (QOL) were collected between July 19 and 23, 2010. The relationship between QOL and various Stages of dependence on glomerular filtration rates (GFRs) and factors related to QOL were investigated. Collected data was analyzed with the SPSS WIN 12.0 program. Results: There was a significant difference in the quality of life of the subjects in different stages (F=18.12, p<.001). The Scheffe post hoc test confirmed that patients at higher stages had a lower level quality of life. In addition, GFRs, uremic symptoms, gender and age predicted value accounted for 38.5% of the variance on QOL (F=25.09, p<.001). Conclusion: Strategies to develop a systematic management program for improving QOL of pre-dialysis patients are urgently needed.

• 대한환경공학회지
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• 제27권12호
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• pp.1305-1310
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• 2005

하상여과에서 집수관의 최적 설계를 위한 방편으로 여러 개의 모래통을 이용하여 모형 집수관 실험을 수행하였다. 집수정의 수위, 집수관의 직경, 집수관의 길이, 그리고 모래의 투수계수를 변화시키면서 모형 집수관을 운영하였으며, 집수관 표면에서의 잔류 수두와 집수관 각 부위에서의 여과수 유입율, 그리고 집수정에서의 산출유량을 측정하였다. 실험결과 모래층에서의 저항에 비해 집수관에서의 저항이 작아서 집수관 표면에서의 잔류수두가 수평에 가까운 경우 효율적인 집수관임을 알 수 있었다. 집수관의 여과수 유입율은 집수정에 근접할수록 지수함수적으로 증가하였고, 집수관의 직경이 작을수록 그리고, 대수층의 투수계수가 클수록 이 지수함수의 기울기는 증가하였다. 집수관의 길이와 직경이 증가하면 산출유량은 증가하지만 그 한계생산성은 감소하였다. 효율적인 하상여과를 위해서는 집수관에서의 축방향 유속을 줄이는 것이 중요함을 알 수 있었으며, 본 연구의 조건에서는 이 유속이 1 m/sec를 넘을 경우 우물의 효율이 크게 감소함을 알 수 있었다.

• 한국토양비료학회지
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• 제44권3호
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• pp.425-433
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• 2011

자연정화공법에 의한 축산폐수처리장에서 효과적으로 축산폐수를 처리하기 위해 인공습지 축산폐수처리 시스템에 전처리방법으로 수생식물여과조와 활성슬러지조를 적용하여 최적 전처리방법을 조사하였다. 또한, 최적 전처리방법을 실제 현장 축산폐수처리장에 연계하여 시공한 후 전처리방법의 효율성과 안전성을 검토하였다. 수생식물여과조와 인공습지를 연계한 소형 축산폐수처리장치에서 최종방류수 중 COD, SS, T-N 및 T-P의 처리효율은 각각 83, 89, 63 및 87%이었다. 활성슬러지조와 자연정화공법을 연계한 소형 축산폐수처리장치에서 최종방류수 중 COD, SS, T-N 및 T-P의 처리효율은 각각 96, 95, 86 및 92%이었다. 수생식물여과조 및 활성슬러지조는 인공습지 축산폐수처리장의 전처리공법으로서 질소와 인 처리효율을 향상시킬 수 있어 고농도의 축산폐수를 안정적으로 처리하기 위해 필요할 것으로 판단된다. 최적 전처리방법을 연계한 실제 현장 축산폐수처리장에서 COD, SS, T-N 및 T-P 의 처리효율은 모든 조건에서 각각 99.8, 99.9, 99.2 및 99.9%으로 높은 처리효율을 보였다.

• 한국환경과학회지
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• 제27권10호
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• pp.831-844
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• 2018

Riverbank Filtration (RBF) is a kind of indirect artificial recharge method and is useful in obtaining higher-quality source water than surface water when procuring municipal water. This study evaluated optimal riverbank filtered water and the productivity of the radial collector wells on Ttansum Island in the area downstream of the Nakdong River, where Gimhae City is constructing a municipal water plant for the purpose of acquiring high-quality water. The RBF wells are planned to provide water to the citizens of Gimhae City through municipal water works. Groundwater flow modeling was performed with the following four scenarios: (a) 9 radial collector wells, (b) 10 radial collector wells, (c) 10 radial collector wells and two additional vertical wells, and (d) 12 radial collector wells. This study can be useful in determineing the optimum production rate of bank filtrated water not only in this study area but also in other places in Korea.

• 한국가축번식학회지
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• 제19권4호
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• pp.251-258
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• 1996

These studies were carried out to investigate the effect of gonadotropins (GTH), fetal calf serum (FCS), porcine follicular fluid (pFF) and FCS and pFF fractions obtained by the gel filtration on in vitro maturation of porcine follicular fluid. When the oocytes were cultured in TCM-199, the maturation rate was higher in pFF than in FCS in both with or without GTH and in pFF the maturation rate was higher in with GTH than in without GTH. In case of without GTH, pFF increased maturation rates in TCM-199, but not in Whitten's medium (WM). When the oocytes were cultured in WM supplemented with FCS fractions, the maturation rate(51.6%) of oocytes was significantly (P<0.05) higher in fraction B (about 30∼70 kDa) than in control, FCS and other fractions. When oocytes were cultured in WM supplemented with pFF fractions, fractions B (about 30∼70 kDa) and D (about 1∼10 kDa) were significantly (P<0.05) higher than in control, pFF and other fractions. In conclusiion, the addition of gonadotropins into the maturation media was effective for oocyte maturation. The addition of pFF was more effective than addition of FCS for maturation of porcine oocytes in vitro. And fraction B from FCS and fractions B and D from pFF was effective for oocyte maturation.

• Membrane and Water Treatment
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• 제5권2호
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• pp.73-86
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• 2014

Membrane fouling is a major challenge limiting the use of membrane applications. In this study high induced shear rates were utilized at the membrane surface in order to reduce the organic and inorganic scaling by using the torsional vibration of flat sheet membranes. The performances of a vibratory shear-enhanced processing (VSEP) system for the ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membrane filtration of industrial dairy wastewater were investigated. The vibration and non-vibration methods were compared with the same membrane and operational parameters during the purification of real dairy industrial process wastewater. In the initial experiments, short-term tests were carried out in which the effects of vibration amplitude, recirculation flow rate and transmembrane pressure were measured and compared. The permeate flux, turbidity, conductivity and chemical oxygen demand (COD) reduction of dairy wastewater were investigated by using UF, NF and RO membranes with vibration and non-vibration methods. In the subsequent experiments, concentration tests were also carried out. Finally, scanning electron microscopy (SEM) revealed that the vibration method gave a better performance, which can be attributed to the higher membrane shear rate, which reduces the concentration of solids at the membrane, and the transmission.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.443-447
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• 2001

A laboratory-scale electrodewatering system for enhancing conventional filter pressure dewatering by an electric field has been developed to decrease the water content of sludge generated in the wastewater treatment. It consists of a piston-typed filter press, a power supply and data acquisition system. The offset of electrodewatering is investigated as a function of applied pressure, applied voltage, sludge type and filtration time. Also the optimal conditions for maximizing the dewatering efficiency in the eletrodewatering system are investigated. Electric field strength and mechanical pressure are in the range of from 0 to 120 V/cm and from 98.1 to 392.4 kPa. The dewatering rates increased with increasing electric strength. These experiments produced a final sludge cake with water content of 60 wt% using electrodewatering technology, compared with a 80 wt% using pressure filtration alone. The conventional filtration system using the electrodewatering shows the potential to be effective method for improving dewatering Sludge.

• 한국패류학회지
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• 제26권3호
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• pp.171-177
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• 2010

We examined physiological responses related to the survival, oxygen consumption and filtration rate of the blood cockle, Tegillaarca granosa as a result of salinity changes. The 44-day $LS_{50}$ (median lethal salinity) at $10^{\circ}C$ for adult and juvenile was 15.8 (confidence limits 13.5-18.2 psu) and 16.2 (confidence limits 14.1-18.4 psu) psu respectively, whereas the 11-day $LS_{50}$ at $25^{\circ}C$ for adult and juvenile was 16.8 psu (confidence limits 12.9-21.2 psu) and 22.4 (confidence limits 20.5-24.7 psu) psu respictively. In conditions of decreasing salinity, Oxygen consumption and filtration rates decreased or varied irregularly as salinity decreased. The results of this study could prove important in investigating causes of mass mortality and managing shellfish aquaculture farms.