• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1655-1659
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• 2008

Using numerical models, we investigated the efficiency of toxin removal using pulsatile flow in blood purification systems that use semipermeable membranes. The model consisted of a three-compartmental mass transfer model for the inside body and a solute kinetics model for the dialyzer. The model predicted the toxin concentration inside the body during blood purification therapy, and the toxin removal efficiencies at different flow configurations were compared quantitatively. According to the simulation results, the clearances of urea and ${\beta}_2$ microglobulin (B2M) using a pulsatile pump were improved by up to 30.9% for hemofiltration, with a 2.0% higher urea clearance and 4.6% higher B2M clearance for high flux dialysis, and a 3.9% higher urea clearance and 8.2% higher B2M clearance for hemodiafiltration. These results suggest that using a pulsatile blood pump in blood purification systems with a semipermeable membrane improves the efficacy of toxin removal, especially for large molecules and hemofiltration treatment.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.3
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• pp.373-382
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• 2013

In this study, a biological odor treatment system was proposed to remove odor(foul smell) materials causing several problems in the closed sewage treatment plant. This odor treatment system was composed of a two-step biofilter system in one reactor. The two-step biofilter reactor was constructed with natural purification layer in upper part and artificial purification layer in lower part. The reed grasses of water purification plants were planted in the surface area and mixed porous ceramic media were filled with the lower part of biofilter reactor. By using the above experimental apparatus, the ammonia gas removal efficiency was attained to 98.3 % and the hydrogen sulfide gas removal efficiency was appeared more than 97.7 % which shows more effective than the conventional odor removal process.

• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.738-751
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• 2018

The effect of the reaction temperature and reaction time on the thermal oxidative purification quality of detonation nanodiamond (NDsoot) was investigated in a gas-solid fluidized bed reactor of a $0.10m-ID{\times}1.0m$-high stainless steel column with zirconia beads ($d_{SV}=99.2{\mu}m$). The carbon conversion increased with increasing the reaction temperature; however, when the reaction temperature was greater than 773 K, the carbon conversion did not increase. The content of $sp^3$-hybridized carbon at the reaction temperature of 703 K barely changed when the reaction time was more than 30 minutes, but at 773 K, the content decreased as preferred. At 703 K, the purification quality increased with the increasing reaction time; however, at 773 K, the purification quality increased up to 30 minutes and then decreased rapidly.

• Journal of Korea Foundry Society
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• v.11 no.4
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• pp.303-313
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• 1991

The Purification mechanism of high purity aluminum was studied through the variation of stirring speed and coolant flow rate in the stirring method. In the stirring method the degree of purification was changed as the following factors;the variation of diffusion boundary layer thickness the variation of growth rate and the solute concentration of the residual melt. The concentration of Fe and Si was decreased as the stirring speed and the radial distance increased. In a high stirring speed of 2000rpm with unidirectional stirring mode, the uniformity of solutes was obtained. On the other hand, the purification of Si was done by the combinations of stirring method, fractional melting and acid leaching. In the case of Si purification, the centrifugal force developed in the melt acted as the significant purification factor. It was possible to obtain the purified 3N grade Si crystal after the complete elimination of residual aluminum by fractional melting and acid leaching.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.566-569
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• 2005

A novel purification method was developed for producing homoharringtonine from Cephalotaxus koreana, to guarantee high purity and yield. Our simple, efficient procedure for isolating and purifying homoharringtonine from C. koreanabiomass consisted of solvent extraction, synthetic adsorbent treatment, low-pressure chromatography, followed by high performance liquid chromatography (HPLC). The use of active clay treatment and silica gel low-pressure chromatography in the pre-purification process allowed for the rapid, efficient separation of homoharringtonine from interfering compounds and dramatically increased the yield and purity of crude homoharringtonine for high-performance liquid chromatography (HPLC) purification steps compared with alternative processes. Homoharringtonine could be obtained simply with high yield and purity from biomass using this purification method, while minimizing solvent use and the scale and complexity of HPLC operations for homoharringtonine purification. Purified homoharringtonine was identified and characterized.

• Carbon letters
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• v.6 no.1
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• pp.31-40
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• 2005

The carbon nanofibers (CNFs) were synthesized through the catalytic decomposition of hydrocarbons in a quartz tube reactor. The CNFs prepared from $C_3H_8$ at $550^{\circ}C$ was selected as the purification sample due to the higher content of impurity than that prepared from other conditions. In this study, we carried out the purification of CNFs by oxidation in air or carbon dioxide after acid treatment, and investigated the influence of purification parameters such as kind of acid, concentration, oxidation time, and oxidation temperature on the structure of CNFs. The metal catalysts could be easily eliminated from the prepared CNFs by liquid phase purification with various acids and it was verified by ICP analysis, in which, for example, Ni content decreased from 2.51% to 0.18% with 8% nitric acid. However, the particulate carbon and heterogeneous fibers were not removed from the prepared CNFs by thermal oxidation in air and carbon dioxide. This result can be explained by that the direction of graphene sheet in CNFs is vertical to the fiber axis and the CNFs are oxidized at about the similar rate with the impurity carbon.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.174-186
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• 2001

Excessive outflow of pollutant loads resulting from rapid industrialization has unbalanced the water ecosystem, deteriorating the water quality environment severely. Therefore, measures for improving the water quality are necessary to maintain clean reservoir water and restore water-friendly spaces. A water quality model which is capable of simulating daily reservoir water quality was developed. The model had been applied to Masan reservoir and Wanggung reservoir in Korea. The model appeared to be satisfactory in representing the trend of water quality variations by comparing measured and simulated results. The model had been also applied to assess water purification techniques such as dredged pool, floating island and vegetation purification system. The model was considered to assess the effect of water purification techniques on reservoir water quality improvement. The results of water quality simulation for lake water purification techniques showed that a large facility would be needed to meet the targeted water quality of the reservoir when only one technique is applied. To effectively improve the quality of the polluted reservoir water, it is therefore recommended that pollutant sources should first be controlled, and a combination of the water purification techniques applied to make the utmost use of their secondary effects such as conservation of the reservoir volume capacity, establishment of a recreation space, promotion of bio-diversity, and improvement of the lake landscape.

• Journal of the Korean Wood Science and Technology
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• v.30 no.1
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• pp.34-39
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• 2002

This study examined the effect of carbonized wastewoods on purification of waste water. The purification ability of charcoals(lump-shaped, approximately 3×3×3 cm) maded by wood-based material for waste water from a kitchen and septic tank was superior to those of thinned wood. For lump-shaped charcoal, gaps between particles in particleboard, and gaps between fibers in MDF were much more effective than micropore in purification of waste water. After purification test, color of waste water from wood-based material charcoals were much more lighter than thinned wood charcoals. In addition, odors of waste water from both charcoals tended to be decreased.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.417-420
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• 2017

Hookworm infections are rare causes of acute gastrointestinal bleeding. We report a middle aged man with primary nephrotic syndrome and pulmonary embolism. During the treatment with steroids and anticoagulants, the patient presented acute massive hemorrhage of the gastrointestinal tract. The results of gastroscopy showed red worms in the duodenum. Colonoscopy and CT angiogram of abdomen were unremarkable. Capsule endoscopy revealed fresh blood and multiple hookworms in the jejunum and ileum. Hookworms caused the acute intestinal bleeding. The patient responded well to albendazole. Hematochezia was markedly ameliorated after eliminating the parasites. Hence, hookworm infection should be considered in the differential diagnosis of a patient with obscure gastrointestinal bleeding. Capsule endoscopy may offer a better means of diagnosis for intestinal hookworm infections.

• Journal of Ocean Engineering and Technology
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• v.21 no.2 s.75
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• pp.42-49
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• 2007

It has been known that shallow-water regions, such as tidal flats, sea grass and sea weed beds have water purification capability, and they also serve as nursery grounds for many fishes. On the other hand, tidal flat areas are economically attractive sites for reclamation, to be used for developing industries. When developing shallow-water areas, we have to propose a plan to mitigate the environmental impact associated with such a development plan. However, it is difficult to estimate the affects on the ecosystem and water purification, and the literature related to this matter is insufficient. In order to evaluate the ability of coastal tidal flat and to predict the future changes, it is necessary to develop a reliable prediction technique and construction of data by using a field investigation. In this study, we carried out a numerical model test for the tidal flat ecosystem, using the pelagic system and the benthic system, simultaneously, in order to show a change in the tidal flat ecosystem. The flow of nitrogen, phosphorus and carbon has been identified as a primary consideration of marine ecosystem components, and the capability of water purification and the change of the tidal flat were predicted using this flow. In order to make a more reliable prediction, a field investigation to determine tide, current and creatures of the object coastal area has been done. The purification capability of this shallow-water region is estimated from the model results. According to the results of experiments, the tidal flat has a capability of water purification (Sink) of 11mgN/m2/day, but the other area has a load (Source) of 20mgN/m2/day. As a result, we could confirm that the tidal flat of an object coastal area plays an important role in water purification.