• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.945-951
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• 2012

The effect of photocatalyst-carrying media porosity on the photocatalytic removal efficiency of malodor and VOC of waste air was evaluated when the photocatalytic removal efficiency of porous silica-based media was compared with that of glass bead as control. The amount of photocatalyst coated on the surface of porous silica-based media was observed to be $1,716.3{\mu}g/cm^2$, which was 250% as much as that of nonporous glass bead (control) of $670{\mu}g/cm^2$. The removal efficiencies of hydrogen sulfide and toluene in case of porous silica-based media were observed to be 22% and 82%, respectively, while the removal efficiencies of hydrogen sulfide and toluene in case of nonporous glass bead media were observed to be 19% and 53%, respectively. Therefore, the removal efficiencies of hydrogen sulfide and toluene increased by 16% and 55%, respectively, when the removal efficiencies of porous silica-based media were compared with those of nonporous glass bead media. Thus the increment ratio of the removal efficiency of toluene was observed to be 3.4 times higher than that of hydrogen sulfide.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.99-105
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• 2006

Purpose : The serotyping results of the Quellung reaction was compared with the newly developed multiplex latex assay and the sensitivity of the Quellung reaction was compared. Methods : We checked the serotypes of 35 samples obtained from patients treated at Yonsei University Medical Center using the multiplex latex bead method and compared the results with the serotypes previously obtained via the Quellung reaction. Results : A decrease in the mean fluorescence was detected in the samples tested with the multiplex assay. Seventeen samples out of the 27 samples agreed to the results of the Quellung assay. We were only able to confirm the concordance of 11 serotypes out of 14 serotypes available. Conclusion : The Quellung reaction is time consuming procedure and prone to errors even with expertise in the procedure, and other alternate methods in serotyping have been investigated to overcome these problems. The newly developed multiplex latex bead assay can test more samples at the same time and has a higher degree of sensitivity. A large scale trial is required to test the sensitivity of the new assay across various serotypes along with efforts to increase the sensitivity of the Quellung assay. The preliminary data suggests that this method may be widely used.

• Polymer(Korea)
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• v.38 no.6
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• pp.760-766
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• 2014

Bead type super-absorbent resins to be used for release-control were prepared by modification of the inverse suspension polymerization, and their physical properties were characterized. Acrylic acid and acrylamide were used as monomers, and N,N-methylenebisacrylamide was used as crosslinker, controlling the viscosity of monomer solution by adding hydroxyethylcellulose (HEC). SEM studies of the synthesized beads verified that the bead surfaces had many pores with their diameters of several tens nm. The bead sizes were in the range of $500{\sim}3000{\mu}m$, depending on the viscosity of the monomer solution. Both absorbent amount and absorbent rate of the beads were inversely proportional to the bead size, and the maximum water absorbent amount of 1 g beads was determined to be ca. 170~200 g for 5 hrs. The absorbent rate was also dependent on pH change of the aqueous solution, exhibiting the maximum rate in pH ranging from 5 to 11. The absorbent rate decreased as the concentration of salt (NaCl and $MgCl_2$) or ethanol and ethylene glycol increased. Release time of the water absorbed into the bead resins was 700 hrs, confirming the usefulness of the resin for the good release-control materials.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.3
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• pp.141-148
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• 2021

In this paper, we propose an algorithm of welding bead detection and evaluation using geodesic active contour algorithm and high pass filter with image processing technique. The algorithm uses histogram equalization and high pass filter as gaussian filter to improve contrast. The image processing techniques smoothens the welding beads reduce the noise on an image. Then, the algorithm detects the welding bead area by applying the geodesic active contour algorithm and morphological ooperation. It also applies the balloon force that either inflates in, or deflates out the evolving contour for a better segmentation. After that, we propose a method for determining the quality of welding bead using effective length and width of the detected bead. In the experiments, our algorithm achieved the highest recall, precision, F-measure and IOU as 0.9894, 0.9668, 0.9780, and 0.8957 respectively. We compared the proposed algorithm with the conventional algorithms to evaluate the performance of the proposed algorithm. The proposed algorithm achieved better performance compared to the conventional ones with a maximum computational time of 0.6 seconds for segmenting and evaluating one welding bead.

• Journal of Magnetics
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• v.19 no.1
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• pp.10-14
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• 2014

In this study, we fabricate an integrated microfluidic chip with a planar Hall effect (PHE) sensor for single magnetic bead detection. The PHE sensor was constructed with a junction size of $10{\mu}m{\times}10{\mu}m$ using a trilayer structure of Ta(3 nm)/NiFe(10 nm)/Cu(1.2 nm)/IrMn(10 nm)/Ta(3 nm). The sensitivity of the PHE sensor was 19.86 ${\mu}V/Oe$. A diameter of 8.18 ${\mu}m$ magnetic beads was used, of which the saturation magnetization was ~2.1 emu/g. The magnetic susceptibility ${\chi}$ of these magnetic beads was calculated to be ~0.14. The diluted magnetic beads solution was introduced to the microfluidic channel attributing a single bead flow and simultaneously the PHE sensor voltage was measured to be 0.35 ${\mu}V$. The integrated microchip was able to detect a magnetic moment of $1.98{\times}10^{-10}$ emu.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.750-753
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• 2003

A method for the mass production was designed by using a screw pumping system that can supply safe bifidobacteria. To prevent the inhibition of cell activity, various additives, which are able to preserve pore of an alginate bead, were used. When materials are sterilized, viscosity decreased below 300cp. Adding bifidobacteria, viscosity increased to 300cp. We manufactured various extrusion nozzles and tested mass productivity of the alginate bead. As a result, 18G, 4mm length sylinge with 13 multi-nozzle showed the best productivity which was about $308{\pm}3ea/min$.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.3
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• pp.253-259
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• 2018

Cu(II) can cause health problem for human being and phosphate is a key pollutant induces eutrophication in rivers and ponds. To remove of Cu(II) and phosphate from solution, chitosan as adsorbent was chosen and used as a form of hydrogel bead. Due to the chemical instability of hydrogel chitosan bead (HCB), the crosslinked HCB by glutaraldehyde (GA) was prepared (HCB-G). HCB-G maintained the spherical bead type at 1% HCl without a loss of chitosan. A variety of batch experiment tests were carried out to determine the removal efficiency (%), maximum uptake (Q, mg/g), and reaction rate. In the single presence of Cu(II) or phosphate, the removal efficiency was obtained to 17 and 16%, respectively. However, the removal efficiency of Cu(II) and phosphate was increased to 50~55% at a mixed solution. The maximum uptake (Q) for Cu(II) and phosphate was enhanced from 11.3 to74.4 mg/g and from 3.34 to 36.6 mg/g, respectively. While the reaction rate of Cu(II) and phosphate was almost finished within 24 and 6 h at single solution, it was not changed for Cu(II) but was retarded for phosphate at mixed solution.

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.129-133
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• 1992

Zooplankton feeding was investigated with epilluorescence microscope in Lake Soyang in August 1991. Zooplankton. which ingested fluorescence bead or fluorescently labeled bacteria (FLB). was regarded as bacterivore. The algavores wert. easily distinguished with autofluorescence of chlorophyll in gut. Copepoda nauplius and Copepodids. 7'hermocyclop.s spp, Pleosomcl spp. Brachionus spp were algavores. and DuphnB hpp. Bosmincr spp. Kerutrlla spp and Hrxuthru spp werc identified as bacterivc~res.T he mixo\ory was not detected. The percentages of algavores and bacterivores in Lake Hoyang were 65 7% and 34.3%. respectively. The bacterivorous zooplankton had trend to ingcst the beads bigger than 0.5 pm. Use of 0.5 pm bead as grazing tracer gave similar estin~ates of ingestion to FLR.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.8
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• pp.71-78
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• 2001

In GMA(Gas Metal Arc)Welding, the weld size that is a locally melted area of a workpiece is one of the most important considerations in determining the strength of a welded structure. Variations in the weld power and the welding heat flux may affect the weld pool formation and ultimately the size of the weld. Therefore, an accurate prediction of the weld size requires a precise analysis of the weld thermal cycle. In this study, a model which can estimate the weld bead geometry and a method for thermal analysis, including the model, are suggested. In order to analyze the weld bead geometry, a mathematical model was developed with transformed coordinates to apply to the horizontal fillet joints. A heat flow analysis was performed with a two dimensional finite element model that was adopted for computing the base metal melting zone. The reliability of the proposed model and the thermal analysis was evaluated through experiments, and the results showed that the proposed model was very effective for predicting the weld bead shape and good correspondence in melting zone of the base metal.

• Journal of Ocean Engineering and Technology
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• v.15 no.4
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• pp.73-79
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• 2001

Underwater wet bead-on-plate welds were experimentally performed on 11mm thick SS400 steel plate as base metal by using six different types of flux coated electrodes of 3.2mm diameter. Two kinds of different flux coated wet arc electrodes (UW-1, UW-2) were individually designed flux materials, three kinds of the electrodes (E4301, E4311, E4313) were terrestrial electrodes and the another one (TN20) was an imported underwater wet welding electrode. As results, the individually designed flux coated underwater electrode, UW-2 and TN20 had a good starting and the excellent arc stability compared with other electrodes. No significant difference of bead appearance could be detected, but the slag detachability of TN20 electrodes was relatively undesirable. By rapid cooling rate, the hardness value and the portion of martensite of HAZ were increased, but it was considerably maintain stable for TN20 and UW-2 electrodes. The individually designed flux coated electrode, UW-2 could be used in practice for underwater bead welds.