• The Korean Journal of Physiology
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• v.22 no.2
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• pp.319-332
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• 1988

The regulations of renal function and renin release are influenced by neural, humoral and physical factors. During the last decade, considerable progress has been made in the identification and characterization of these extrinsic renal control systems. Mechanisms intrinsic to the kidney are also important for renal function. These include the autoregulation of blood flow, and the local control of renin secretion. Fundamental questions regarding the mechanism of these intrinsic controls remain unanswered. Recently, endogenous renal adenosine has been claimed to influence the tubuloglomerular feedback control and renin release. Two subclasses of adenosine receptors $A_1{\;}and{\;}A_2$ have been described. The present experiment was carried out to evaluate the effects of $N_6-cyclohexyladenosine$ $(CHA,{\;}A_1{\;}selective)$ and 5'-N-ethylcarbox-amide adenosine $(NECA,{\;}A_2{\;}selective)$ on the renal function and renin release in the unanesthetized rabbit. Intra-renal arterial infusion of NECA $(0.3{\sim}10.0n{\;}mole/min/rabbit)$ or CHA $(0.03{\sim}10.0n{\;}mole/min/rabbit)$ caused a prompt and dose-dependent decrease in urine volume, glomerular filtration rate (GFR), renal plasma flow (RPF), filtration fraction (FF), electrolyte excretion and free water clearance $(CH_2O)$, the effect being much more profound with CHA than with NECA. The NECA infusion resulted in a profound decrease of systemic blood pressure, but the CHA infusion did not. Both NECA and GHA infusions caused a prompt and dose-dependent decrease in renin secretion rate, again the effect being greater with CHA than with NEGA. These results suggest that both $A_1{\;}and{\;}A_2$ adenosine receptors may be involved in the intrinsic control of renal function and renin release, and that the $A_1$ receptors plays a more important role than the $A_2$ receptor in the regulation of renal fnction.

• Membrane Journal
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• v.15 no.2
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• pp.132-140
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• 2005

The effects of electrical fields on the efficiencies in ultrafiltration for protein separation were explored. The experiments were proceeded under constant transmembrane pressure (THP) using protein (albumin and lysozyme) solutions. For ultrafiltrations, cellulose membranes with molecular weight cut off (MWCO) 30 kDa were used. It is found that electrical field improved the filtration flux of albumin solution. The electrical field showed another interesting effect for filtration of protein solution. Depending on the electrical charges of protein molecules, the electrical field promoted or hindered the permeation of proteins through membranes. With the effect of electrical field, not only the permeation flux but also the selectivity of ultrafiltration could be improved.

• Membrane Journal
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• v.18 no.4
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• pp.354-361
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• 2008

Effects of operational conditions and solution chemistry on permeate flux in a hybrid ozone-ceramic ultra-filtration (UF) membrane system treating natural organic matter (NOM) were investigated. Results showed that the extent of permeate flux decline was higher at higher cross-flow velocity and ozone dosage, but it was higher at lower transmembrane pressure (TMP). The mechanism of fouling mitigation was found to be more dependent upon reaction between ozone and natural organic matter at/near catalytic membrane surface than scouring effect due to ozone gas bubbles. Addition of calcium into model NOM solution at high pH led to significant decline in permeate flux while the calcium effect on permeate flux decline was less pronounced at lower pH. After permeate flux decline during the early stage of filtration, the flux started recovering and approached fully to the initial value of it due to degradation of NOM by catalytic ozonation at ceramic membrane surface in the hybrid ozone-ceramic membrane system.

• Korean Journal of Acupuncture
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• v.22 no.2
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• pp.127-149
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• 2005

This study is designed to investigate the method of manufacturing herbal acupuncture through literature of oriental medicine. The findings of this study are as follows; 1. The methods of manufacturing herbal acupuncture go through the process of abstraction, purification, mixing, filtration, putting and tight sealing in the container, sterilization, quality control, printing and packing 2. There are many ways to manufacturing herbal acupuncture, for example water-alcohol precipitation, alcohol-water precipitation, liquid-liquid abstract, acid-base abstract, metal base precipitation, distillation, molecular structure, polyamide absorption, dialysis, and ion exchange, etc. And popular method is water-alcohol precipitation. This is through alcohol precipitate extracting the principal ingredients from water abstraction. This is very simple and efficient way using melting characteristics of compounds in herb to water and ethanol. 3. Sterilization of herbal acupuncture is through heating-pressure, boiling, steam flowing, low temperature, filtering, radiation, cooling, and microwaves. Nowadays filtering is commonly used. And sterilization is estimated by an examination of asepsis . 4. Herbal acupuncture must be undergo study and experiment to clinical use. The problems of herbal acupuncture are turbidity, instability, causing hemolysis, pain, and fever. So many provisions (addition, sterilization, and filtration etc.) must be prepared. 5. The theory of manufacturing herbal acupuncture is from oriental medicine, not western. So it must be corresponded to oriental medical theory, for example Gimi(氣味), Guigyung(歸經), Ingyung(引經), Bosa(補瀉), and Match of Herb. It is recommended that further study of many other sided investigations in the future.

• Membrane Journal
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• v.25 no.2
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• pp.180-190
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• 2015

PVDF (polyvinylidene fluoride) nanofiber has the advantages such as excellent strength, chemical resistance, nontoxic, non-combustibility. Flat membranes with 0.3 and $0.4{\mu}m$ pore size respectively, were manufactured by PVDF nanofiber, and then each spiral wound module was prepared with them. A woven paper was not included in preparing the module with $0.3{\mu}m$ pore size; however, it was included the module with $0.4{\mu}m$ pore size. The permeate fluxes and rejection rates of the two modules were compared using pure water and simulation solution including kaolin and humic acid. The recovery rate and filtration resistance were calculated after water back-washing. In addition, the effect of flow rate and trans-membrane pressure on treatment efficiency and filtration resistance were investigated for the spiral wound module with $0.4{\mu}m$ pore size.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.591-595
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• 2007

The membrane filter coated with nanostructured porous surface layer was made by heat treatment after depositing nanoparticles onto a conventional micron-fibrous metal filter as a substrate filter. The nanostructured porous layer membrane filter (NSPL-MF), whose the filtration performance was improved compared with the conventional metal membrane filters, was developed by coating the nanoparticle agglomerates of dendrite structure onto the micron-fibrous metal filter. Pressure drop of nanostructured porous layer membrane filter decreased with increasing the heat treatment temperature to make the nanostructured porous layer adhered on the filter surface because the nanoparticle agglomerates shrank, but filtration efficiency did not decrease clearly.

• Membrane and Water Treatment
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• v.6 no.3
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• pp.225-235
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• 2015

During low-pressure membrane treatments of cyanobacterial cells, including microfiltration (MF) and ultrafiltration (UF), there have reportedly been releases of intracellular compounds including cyanotoxins and compounds with an earthy-musty odor into the water, probably owing to cyanobacterial cell breakage retained on the membrane. However, to our knowledge, no information was reported regarding the effect of growth phase of cyanobacterial cells on the release of the intracellular compounds. In the present study, we used a geosmin-producing cyanobacterium, Anabaena smithii, to investigate the effect of the growth phase of the cyanobacterium on the release of intracellular geosmin during laboratory-scale MF experiments with the cells in either the logarithmic growth or stationary phase. Separate detection of damaged and intact cells revealed that the extent of cell breakage on the MF membrane was almost the same for logarithmic growth and stationary phase cells. However, whereas the geosmin concentration in the MF permeate increased after 3 h of filtration with cells in the logarithmic growth phase, it did not increase during filtration with cells in the stationary phase: the trend in the geosmin concentration in the MF permeate with time was much different between the logarithmic growth and stationary phases. Adsorption of geosmin to algogenic organic matter (AOM) retained on the MF membrane and/or pore blocking with the AOM were greater when the cells were in the stationary phase versus the logarithmic growth phase, the result being a decrease in the apparent release of intracellular geosmin from the stationary phase cells. In actual drinking water treatment plants employing membrane processes, more attention should be paid to the cyanobacterial cells in logarithmic growth phase than in stationary phase from a viewpoint of preventing the leakage of intracellular earthy-musty odor compounds to finished water.

• Journal of the Korean GEO-environmental Society
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• v.14 no.4
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• pp.15-27
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• 2013

In order to plan out the Daegu G membrane filtration water treatment plant, water quantity, water quality and process stability were evaluated using the field pilot-scale tests, during the six months of continuous operation, including low water temperature period. The field model experiments, which were carried out according to the Installation Criteria of Ministry of Environment, consisted of two series : series 1 - water quality verification, and series 2 - membrane process evaluation. The process water quality met all drinking water standards with less than 0.03 NTU. Moreover, process operation showed a stable membrane pressure with 99% of recovery ratio. This shows that the tests were properly designed in terms of the influence of water loading and temperature. In conclusion, the purpose of this study is to establish core technology for advanced drinking water treatment, through on-going accumulation of engineering and construction know-how.

• Fashion & Textile Research Journal
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• v.22 no.6
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• pp.862-872
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• 2020

This study explores the effects of facemasks on respiratory, thermoregulatory, cardiovascular responses during exercise on a treadmill and at rest. Five male subjects (25.8 ± 0.8 y, 171.8 ± 9.2 cm in height, 79.8 ± 28.1 kg in weight) participated in the following five experimental conditions: no mask, KF80, KF94, KF99, and N95. Inhalation resistance was ranked as KF80 < KF94 < N95 < KF99 and dead space inside a mask was ranked as KF80 = KF94 < N95 < KF99. The surface area covered by a mask was on average 1.1% of the total body surface area. The results showed no significant differences in body core temperature, oxygen consumption (VO2), carbon dioxide production (VCO2), heart rate or subjective perception among the five experimental conditions; however, cheek temperature, respiratory ventilation and blood pressure were greater for KF80 or KF94 conditions when compared to KF99 or N95 conditions (p<0.05). The differences among mask conditions are attributed to the dead space or specific designs (cup type vs pleats type) rather than the filtration level. In addition, the results suggest that improving mask design can help mitigate respiratory resistance from increased filtration.

• Membrane Journal
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• v.33 no.1
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• pp.34-45
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• 2023

Two computational intelligence techniques namely artificial neural networks (ANN) and support vector machine (SVM) are employed to model the permeate flux based on seven input variables including time, transmembrane pressure, rotating velocity, the pore diameter of the membrane, dynamic viscosity, concentration and density of the feed fluid. The best-fit model was selected through the trial-error method and the two statistical parameters including the coefficient of determination (R²) and the average absolute relative deviation (AARD) between the experimental and predicted data. The obtained results reveal that the optimized ANN model can predict the permeate flux with R² = 0.999 and AARD% = 2.245 versus the SVM model with R² = 0.996 and AARD% = 4.09. Thus, the ANN model is found to predict the permeate flux with high accuracy in comparison to the SVM approach.