• Membrane and Water Treatment
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• 제7권5호
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• pp.433-449
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• 2016

The successful application of cleaning protocols is vital for optimized filtration processes. A series of experiments with an ultrafiltration ceramic tubular membrane were carried out for the foulants dextran and carboxymethyl cellulose. Firstly, the impact on fouling of concentration changes was investigated with the increase in resistance being used as the key parameter. In the second phase, removal of reversible fouling was also investigated by employing intermittent rinsing consisting of a cold water rinse followed by a hot one. A comparative analysis for both foulants is reported. Across a range of concentrations and for both foulants, the reduction in resistance due to rinsing was found to depend upon concentration (C); it changed as $C^n$ where n was found to be 0.3. A plausible semi-theoretical explanation is given. Thirdly, for both foulants, the application of a combination of strong alkaline solutions with oxidizing agent (mainly sodium hypochlorite) followed by acid was found to be appropriate for cleaning of the ceramic membrane. The effect of increased temperature for cleaning agents followed by a warm water rinse contributed positively to the cleaning capability.

• 한국염색가공학회지
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• 제21권6호
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• pp.56-63
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• 2009

In this study we have evaluated the separation characteristics and concentration of sericin using tubular type ultrafiltration membrane in silk degumming solution that extracted from electrolytic reduction water process. Ultrafiltration membranes have used in sericin separation performance and the separation characteristics of membrane satisfied typical Hagen-Poiseuille equation. It had the increase of flux according to the increase of feed pressure and temperature in occasion of pure water flux. And also the flux and solute rejection had about $25{\sim}60{\ell}/m^2{\cdot}h$ and more than 95% in sericin feed solution with concentration 1.00~1.89% at feed pressure force of $3{\sim}8kgf/cm^2$ respectively. In addition, the separation performance of tubular type ultrafiltration membrane for silk degumming solution was very steady-state with long experiment time.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 봄 학술발표회 논문집
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• pp.275-278
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• 2003

실크 세리신은 누에(Bombyx mori)로부터 얻어지는 천연 거대분자 단백질로서, 누에고치실의 20~30%를 차지하고 있다. 세리신은 외부로의 자극으로부터 피브로인을 보호하는 역할을 하지만, 견사나 견직물을 얻기 위해서는 정련 공정에서 반드시 제거하게 된다. 현재 생산 현장에서는 비누/알칼리 정련법으로 세리신을 제거하고 있는데, 정련 폐액중에 포함되어 있는 세리신 단백질에서 분해된 각종 아미노산과 비누 및 강알칼리 약제로 인해 환경오염의 주된 원인이 되고 있다. (중략)

• The Korean Journal of Physiology and Pharmacology
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• 제13권1호
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• pp.15-22
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• 2009

This study was undertaken to elucidate the underlying mechanisms of ATP depletion-induced membrane transport dysfunction and cell death in renal proximal tubular cells. ATP depletion was induced by incubating cells with 2.5 mM potassium cyanide(KCN)/0.1 mM iodoacetic acid(IAA), and membrane transport function and cell viability were evaluated by measuring $Na^+$-dependent phosphate uptake and trypan blue exclusion, respectively. ATP depletion resulted in a decrease in $Na^+$-dependent phosphate uptake and cell viability in a time-dependent manner. ATP depletion inhibited $Na^+$-dependent phosphate uptake in cells, when treated with 2 mM ouabain, a $Na^+$ pump-specific inhibitor, suggesting that ATP depletion impairs membrane transport functional integrity. Alterations in $Na^+$-dependent phosphate uptake and cell viability induced by ATP depletion were prevented by the hydrogen peroxide scavenger such as catalase and the hydroxyl radical scavengers(dimethylthiourea and thiourea), and amino acids(glycine and alanine). ATP depletion caused arachidonic acid release and increased mRNA levels of cytosolic phospholipase $A_2(cPLA_2)$. The ATP depletion-dependent arachidonic acid release was inhibited by $cPLA_2$ specific inhibitor $AACOCF_3$. ATP depletion-induced alterations in $Na^+$-dependent phosphate uptake and cell viability were prevented by $AACOCF_3$. Inhibition of $Na^+$-dependent phosphate uptake by ATP depletion was prevented by antipain and leupetin, serine/cysteine protease inhibitors, whereas ATP depletion-induced cell death was not altered by these agents. These results indicate that ATP depletion-induced alterations in membrane transport function and cell viability are due to reactive oxygen species generation and $cPLA_2$ activation in renal proximal tubular cells. In addition, the present data suggest that serine/cysteine proteases play an important role in membrane transport dysfunction, but not cell death, induced by ATP depletion.

• Korean Membrane Journal
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• 제10권1호
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• pp.26-32
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• 2008

The Gongji stream water of Chuncheon city was filtrated by 2 kinds of tubular alumina ceramic MF membranes with periodic $N_2$-back-flushing. $N_2$-back-flushing time (BT) was changed in $0{\sim}50$ sec at fixed filtration time (FT), or back-flushing period, of 4 min for NCMT-5231 membrane ($0.05\;{\mu}m$). Then, FT was changed in $0{\sim}32$ min at fixed BT of 40 sec for NCMT-7231 $0.1{\mu}m)$). In the viewpoints of total permeate volume ($V_T$), dimensionless permeate flux ($J/J_0$) and resistance of membrane fouling ($R_f$), the optimal $N_2$-BT was 50 sec, which was the longest BT, at 4 min FT for NCMT-5231. It means the longest BT was the most effective to minimize the membrane fouling, and we could acquire the most $V_T$. But the optimal FT for NCMT-7231 was 16 min in the viewpoint of $V_T$, and was 8 min in the viewpoints of $J/J_0$ and $R_f$ at fixed BT of 40 sec. The rejection rates were excellent as $80.6{\sim}96.6\;%$ for turbidity, $35.2{\sim}58.4%$ for $NH_3$-N, $16.3{\sim}45.2%$ for T-P and $16.3{\sim}45.2%$ for $COD_{Mn}$. However, the rejection rate of T-N was very low as $2.7{\sim}13.4%$ and it of TDS below 6.1%.

• 한국막학회:학술대회논문집
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• 한국막학회 2003년도 춘계 총회 및 학술발표회
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• pp.101-105
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• 2003

• 한국막학회:학술대회논문집
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• 한국막학회 1999년도 춘계 총회 및 학술발표회
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• pp.83-85
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• 1999

• Korean Chemical Engineering Research
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• 제49권6호
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• pp.804-809
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• 2011

$Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ 조성의 관형 분리막을 압출 성형 방법으로 제조하였다. 압출성형 직후 분리막의 TGA 분석결과 3단계의 무게감소로 첨가제와 탄산염이 분해되었고, 건조 수축율은 68 h 경과 후 변화가 없었으며 외경이 큰 분리막에서 높게 나타났다. 소결 후 분리막의 XRD 및 SEM 분석결과, 분리막은 단일상의 페롭스카이트 구조를 갖는 치밀한 막을 보였고, EDS 분석을 통해 $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$와 유사한 성분함량을 가짐을 확인하였다. 두께 0.95 mm $Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3-{\delta}}$ 관형 분리막의 압환강도(radial crushing strength)는 5.7 kgf/$mm^2$이였으며, $950^{\circ}C$에서 산소투과량은 146.85 mL/min($Jo_2$=2.33 mL/$min{\cdot}cm^2$)를 나타냈었다. 투과 측의 진공펌프 사용이 쓸개 가스를 활용한 것보다 산소 투과량 증진에 효과가 있음을 알 수 있었다.

• Journal of Electrochemical Science and Technology
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• 제14권2호
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• pp.120-130
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• 2023

PEMFC has high potential for future development due to its high energy density, eco-friendliness, and high energy efficiency. When it becomes small, light and flexible, it can be competitive as an energy source for portable devices or flexible electronic devices. However, the use of hard and heavy materials for structural rigidity and uniform contact pressure transmission has become an obstacle to reducing the weight and flexibility of PEMFCs. This review intends to provide an example of the application of a new structure and material for lightweight and flexibility. As a lightweight PEMFC, a tubular design is presented and structural advantages through numerical modeling are explained. Manufacturing methods to realize the structural advantages and possibilities of tubular PEMFCs are discussed. In addition, the materials and manufacturing processes used to fabricate lightweight and flexible PEMFCs are described and factors affecting performance are analyzed. Strategies and structural improvements of light and flexible movements are discussed according to the component parts.

• The Korean Journal of Physiology and Pharmacology
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• 제1권4호
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• pp.403-411
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• 1997

To elucidate the mechanism of gentamicin induced renal dysfunction, renal functions and activities of various proximal tubular transport systems were studied in gentamicin-treated rats (Fisher 344). Gentamicin nephrotoxicity was induced by injecting gentamicin sulfate subcutaneously at a dose of 100 $mg/kg{\cdot}day$ for 7 days. The gentamicin injection resulted in a marked polyuria, hyposthenuria, proteinuria, glycosuria, aminoaciduria, phosphaturia, natriuresis, and kaliuresis, characteristics of aminoglycoside nephropathy. Such renal functional changes occurred in the face of reduced GFR, thus tubular transport functions appeared to be impaired. The polyuria and hyposthenuria were partly associated with a mild osmotic diuresis, but mostly attributed to a reduction in free water reabsorption. In renal cortical brush-border membrane vesicles isolated from gentamicin-treated rats, the $Na^+$ gradient dependent transport of glucose, alanine, phosphate and succinate was significantly attenuated with no changes in $Na^+-independent$ transport and the membrane permeability to $Na^+$. These results indicate that gentamicin treatment induces a defect in free water reabsorption in the distal nephron and impairs various $Na^+-cotransport$ systems in the proximal tubular brush-border membranes, leading to polyuria, hyposthenuria, and increased urinary excretion of $Na^+$ and other solutes.