• 한국물환경학회지
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• 제33권4호
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• pp.403-408
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• 2017

In these days, wastewater reclamation and seawater desalination play essential role in addressing the challenge of worldwide water scarcity. Particularly, reverse osmosis (RO) for seawater desalination process is commonly used due to less energy consumption than conventional thermodynamic systems. However, membrane fouling and electrical energy consumption during operation of RO system for seawater desalination haver continued to be a obstruction to its application. In this study, therefore, wastewater secondary effluent is used for osmotic dilution of seawater. Firstly, fouling behaviour of RO by simulating wastewater effluent in osmotic dilution process was measured and we calculated energy consumption of overall desalination process by theoretical equations and commercial program. Our results reveal that RO membrane fouling can be efficiently controlled by pre-treatment systems such as nano filtration (NF) or forward osmosis (FO) process. Especially FO system for osmotic dilution process is a non-pressurized membrane system and, therefore, the operating energy consumption of overall desalination system was the lowest. Moreover, fouling layer on FO membrane is comparatively weak and reversible enough to be disrupted by physical cleaning. Thus, RO system with low salinity feed water through FO process is possible as a less energy consuming desalination system with efficient membrane fouling control.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.284-284
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• 1996

Titrated Extract of Centella asiatica (TECA) is a poorly water-soluble extract from the Centella asiatica. Despite excellent wound preparation causes pain due to a low aqueous solubility and high hypertonicity and therefore, the patient's compliance of this drug is low. The objective of this study is to design a formulation of TECA with an improved therapeutic applicability via an adequate solubilization. A mixture of propylene glycol and ethoxylated hydrogenated caster oil achieved an acceptable solubilization of TECA (i.e. 10%) via a formulation of micelle. A preparation of extemporaneous TECA micelle was achieved by a dilution of the original micellar formulation with either water or saline. An estimated distribution of particle size was between 15.9 and 32.6 ㎜. The osmotic pressure of the formulation was found to be much lower than that found In a commercially available injectable (i.e. Madecassole). The erthrocytic hemolysis of micellar solution was lower than that with the conventional dosage form, consistent with the osmotic pressure data. Pain score after an injection of the micellar solution was assessed by the hind-paw writhing test using ICR mice and compared with that found with the conventional injectable. The data indicated that the injection of the micellar solution was a significantly less painful. These results indicated that a micellar solubilization, followed by an extemporaneous dilution, is a novel formulation of TECA with an improved therapeutic applicability.

• Journal of Applied Biological Chemistry
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• 제49권3호
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• pp.90-94
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• 2006

Bactericidal activity of grapefruit seed extract (GSE)-based disinfectant, as a safe disinfectant, was measured against five bacteria by Korean Food & Drug Administration (KFDA) dilution-neutralization method. GSE-based disinfectant showed a 99.9999% bactericidal activity against Escherichia coli ATCC 10536, Salmonella typhi ATCC 29629, Staphylococcus aureus ATCC 6538, Bacillus cereus ATCC 11778, and Listeria monocytogenes ATCC 1911 at the concentration of 2.15% GSE. It showed better bactericidal activity against Gram-negative bacteria of E. coli ATCC 10536 and S. typhi ATCC 29629 at lower concentration of GSE (0.43%). Based on the results, it was suggested that a possible bactericidal mechanism of GSE active ingredients was due to the abrupt osmotic shift during the bactericidal activity test by KFDA method.

• 한국산학기술학회논문지
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• 제15권8호
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• pp.5124-5130
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• 2014

조영제의 희석률 변화에 따른 신호강도를 분석하여 조영증강 자기공명혈관조영검사 시 점도와 삼투압에 따른 부작용을 최소화하고 신호강도를 높여 영상의 질을 향상시키고자 하였다. 연구방법은 조영제가 혈관에 주입되면 혈액과 희석되어 mol 농도가 변화되고, 그에 따라 신호강도의 변화를 일으킴에 착안하여 phantom을 제작하였다. phantom 결과를 바탕으로 임상실험은 2013년 11월부터 2014년 1월까지 조영제를 희석한 군(30명)과 희석하지 않은 군(30명)으로 구분하여 뇌혈관의 신호강도를 비교하였다. 연구결과, 조영제 mol 농도 변화에 따른 phantom의 신호강도는 0.0125mmol부터 급격히 증가하다 20mmol에서 최고점을 이룬 후 200mmol부터 평형을 이루었다. 임상실험에서도 조영제를 희석하여 검사한 영상의 신호강도가 모두 높게 나타나, 1000mmol 조영제 사용에 비해 500mmol로 희석하여 사용함이 최고점인 20mmol에 근접하여 우수함을 알 수 있었다. 결론적으로 조영제를 희석하여 사용함으로써 점도와 삼투압을 저하시키고, 영상의 질을 향상시킬 수 있었으므로 임상적용의 유용성이 높다고 할 수 있다.

• 상하수도학회지
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• 제32권4호
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• pp.357-361
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• 2018

Forward osmosis (FO) process has been attracting attention for its potential applications such as industrial wastewater treatment, wastewater reclamation and seawater desalination. Particularly, in terms of fouling reversibility and operating energy consumption, the FO process is assumed to be preferable to the reverse osmosis (RO) process. Despite these advantages, there is a difficulty in the empirical step due to the lack of separation and recovery techniques of the draw solution. Therefore, rather than using FO alone, recent developments of the FO process have adapted a hybrid system without draw solution separation/recovery systems, such as the FO-RO osmotic dilution system. In this study, we investigated the performance of the hollow fiber FO module according to various operating conditions. The change of permeate flow rate according to the flow rates of the draw and feed solutions in the process operation is a factor that increases the permeate flow rate, one of the performance factors in the positive osmosis process. Our results reveal that flow rates of draw and feed solutions affect the membrane performance, such as the water flux and the reverse solute flux. Moreover, use of hydraulic pressure on the feed side was shown to yield slightly higher flux than the case without applied pressure. Thus, optimizing the operating conditions is important in the hollow fiber FO system.

• Biotechnology and Bioprocess Engineering:BBE
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• 제8권4호
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• pp.233-239
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• 2003

For the quantitative analysis of an unknown sample a calibration curve should be obtained, as analytical instruments give relative, rather than absolute measurements. Therefore, researchers should make standard samples with various known concentrations, measure each standard and the unknown sample, and then determine the concentration of the unknown by comparing the measured value to those of the standards. These procedures are tedious and time-consuming. Therefore, we developed a polymer based microfluidic device from polydimethylsiloxane, which integrates serial dilution and capillary electrophoresis functions in a single device. The integrated microchip can provide a one-step analytical tool, and thus replace the complex experimental procedures. Two plastic syringes, one containing a buffer solution and the other a standard solution, were connected to two inlet holes on a microchip, and pushed by a hydrodynamic force. The standard sample is serially diluted to various concentrations through the microfluidic networks. The diluted samples are sequentially introduced through microchannels by electro-osmotic force, and their laser-induced fluorescence signals measured by capillary electrophoresis. We demonstrate the integrated microchip performance by measuring the fluorescence signals of fluorescein at various concentrations. The calibration curve obtained from the electropherograms showed the expected linearity.

• 한국어병학회지
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• 제4권2호
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• pp.95-100
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• 1991

Saprolegnia diclina, which was the pathogen causing death in snake fishes(Channa argus) at culture farm, was investigated using scanning electron microscope. It was found that Saprolegnia diclina infection caused snake fishes to fail gas change in the gills. Cell lysis as well as edematous disease and hyperplasia as a result of Saprolegnea diclina attachment on the surface of gills were observed. The granules, the mean diameters of which ranged from 6 to $7\;{\mu}m$, attaching on the surface of gills were found to be secondary zoospores of Saprolegnia diclina. The failures of gas exchange in the gill cells and circulation as a result of the osmotic dilution of the blood were supposed to be the main cause of death.

• Asian-Australasian Journal of Animal Sciences
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• 제23권10호
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• pp.1276-1281
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• 2010

The present study was conducted to investigate the effects of butylated hydroxytoluene (BHT) supplementation on diluted, cooled and frozen-thawed ram spermatozoa. After primary evaluation of collected ejaculates, only semen samples with motility of more than 70% and sperm concentration higher than $3{\times}10^3$ sperm/ml were used for cryopreservation. The selected semen samples were then pooled and diluted 1:4 with Tris Citrate Fructose Yolk (TCFY) extender supplemented with different concentrations of BHT (0.5, 10, 2.0 and 3.0 mM). As the control, semen was diluted and frozen in the diluent without BHT. Motility, progressive motility, viability, membranes and acrosome integrity were evaluated after dilution (part 1), cooling (part 2) and freezing and thawing (part 3). The results of the first part of the experiment showed that there were no significant difference between treatments in the motility, progressive motility, viability, membranes and acrosome integrity of spermatozoa, but the results with 2.0 mM BHT were slightly better than obtained with other levels of BHT and control extender. Significantly better results (p<0.05) were observed in the second part of the experiment for cooled spermatozoa characteristics, when extender was supplemented with 2.0 and 3.0 mM BHT. Furthermore, the results obtained in the third part of the experiment indicated that, after freezing and thawing, all evaluated semen characteristics were improved significantly (p<0.05) by increasing BHT levels, with the best results obtained for extender containing 2 mM BHT. Comparison of these results with those of control diluent, the effects of supplementation were significantly (p<0.01) better. However, the higher concentration of BHT (3.0 mM) reduced the motility, acrosomal integrity, viability and hypo-osmotic swelling response of spermatozoa compared to extender containing 2.0 mM BHT. In conclusion, the results obtained in this study showed that the semen quality of rams was improved when BHT was added to extender used before the freezing process.

• 한국임상수의학회지
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• 제24권4호
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• pp.577-583
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• 2007

It is important to obtain semen with good quality for efficient fertilization and pregnancy. To obtain these semen, various methods have been developed but most of these methods are time consuming and require costly equipment. Therefore, the objective of this research is to investigate the usability of column filtration system as quick and simple method to get sperm with better quality. Ejaculates were obtained from 5 dogs and analyzed with basic quality parameters before each filtration. Sperm concentration was adjusted to $5{\times}10^7/ml$ after dilution. The experimental groups were divided into non-filtered group(control) and filtered groups(glass wool, Sephadex 5% and Sephadex 20%). Ejaculates were filtered through each filter system and assessed by recovery rate of sperm, motility, normal morphology, CFDA/PI stain and plasma membrane integrity(hypo-osmotic swelling test, HOST). The lowest recovery rate of spermatozoa was recorded in glass wool filtration group, followed by 20% Sephadex filtration group(p<0.05). There was no significant difference between control(non-filtered) and 5% Sephadex filtration poop. Also, there was no significant difference of sperm motility assessed under light microscope among experimental groups. Morphological normality of canine spermatozoa was the highest in the glass wool filtration group and the lowest in the 5% Sephadex filtration group with no significant differences versus 20% Sephadex filtration and control group, respectively(p<0.05). Viability of canine sperm assessed by CFCA/PI staining was the highest in the glass wool filtration poop with no significant difference versus the control group, and the lowest in the 20% Sephadex filtration group with no significant difference versus 5% Sephadex filtration group, respectively(p<0.05). HOS values of canine sperm was the highest in the 20% Sephadex filtration group with no significant difference versus 5% Sephadex filtration group, and the lowest in the control poop with no significant difference versus glass wool filtration group, respectively(p<0.05). Therefore, these results indicated that filtration treatment for extended canine sperm would be useful method to get sperm with better quality by trapping the damaged sperm, consequently filter would be physical barrier against injured or immotile sperm.

• 대한토목학회논문집
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• 제42권3호
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• pp.351-357
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• 2022

본 연구에서는 하수재이용과 해수담수화를 동시에 진행할 수 있는 규모 1,000 m³/d의 FO-RO 융합공정과 동일한 규모의 기존 SWRO 공정의 탄소배출량을 계산하여 비교 분석하였다. FO-RO 융합공정은 FO 공정을 도입하여 RO 공정 원수를 희석시킬 수 있기 때문에 RO 공정의 요구 압력이 감소되고 이는 곧 에너지소비량 감소로 이어진다. 에너지소비량에 따른 탄소배출량은 FO-RO 융합공정이 SWRO 공정보다 -0.73 kgCO₂(coal로 전력생산 시) 낮으며, FO 공정 추가 건설로 인해 발생되는 탄소배출량은 +0.16 kgCO₂로 계산되어 FO-RO 융합공정의 총 탄소 배출량이 더 낮은 것으로 나타났다. 하지만, Coal나 oil과 같은 화석연료로 전력을 생산하지 않고, 전력생산 시 탄소배출량이 적은 nuclear나 solar 등으로 사용하면 FO-RO 융합공정의 총 탄소배출량이 SWRO 공정보다 더 높은 것으로 나타났다. 즉, 탄소배출량 관점에서는 전력생산 시 필요 재료(예: coal, oil, nuclear, solar 등)에 따라 친환경적인 공정 판단 여부가 결정되므로 FO-RO 융합공정 도입 필요성을 좌우하는 핵심 요소라고 할 수 있다.