• Journal of Aquaculture
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• v.13 no.3
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• pp.267-275
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• 2000

To evaluate the characteristics and efficiency of oxygen transfer rate of a polystyrene foam bead as media in a packed column aerator was tested. This media has more surface area and cheaper than other ordinary plastic media. The polystyrene foam media was a sphere-shaped bead with 2.5 mm in diameter and specific surface area was 1,350 $m^2$/$m^3$. Oxygen transfer rate and standard aeration efficiency were tested under different hydraulic loading rates, depths of the media and temperatures. Experiment 1 was performed using a small packed column aerator with 10 cm in diameter and 1 m in length. The aerator filled with 0, 4.5, 9.0 and 18.0 cm of the media was tested under hydraulic loading rates of 2.0, 4.0 and 5.6 $m^3$/$m^2$/min at temperatures of 20, 25 and 3$0^{\circ}C$, respectively. In this experiment, standard oxygen transfer rate (SOTR) increased with the hydraulic loading rate and depth of the media increased. The maximum SOTR was reached at 5.6 $m^3$/$m^2$/min of hydraulic loading rate with 9 cm in depth of the media. However, standard aeration efficiency (SAE) decreased with the hydraulic loading rate increased because electricity consumed by pump increased as hydraulic loading rate increased. The highest SAE was reached at hydraulic loading rate of 2.0 $m^3$/$m^2$/min with 9.0 cm in depth of the media. Therefore, the highest SOTR and SAE were achieved at 9.0 cm in depth of the media regardless of the hydraulic loading rate. The maximum SAE was about 1.8 kg $O_2$/kW-hr with the hydraulic loading .ate of $m^3$/$m^2$/min at temperature of 20 $^{\circ}C$.Experiment 2 was performed using a larger aerator, 20 cm in diameter with 2 m in height. The aerator filled with 0, 9, 18, 27 and 36 cm of the media was operated under hydraulic loading rate of 2.0, 4.0 and 5.6 $m^3$/$m^2$/min at temperature of 27 $^{\circ}C$. The SAE reached to the highest efficiency (1.9 kg $O_2$/kW-hr) at 2.0 $m^3$/$m^2$/min of hydraulic loading rate and 36 cm in depth of the media. According to the above results, the polystyrene foam bead as a media in a packed column aerator was effective to increase oxygen transfer rate.

• Polymer(Korea)
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• v.33 no.1
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• pp.33-38
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• 2009

Monodisperse polystyrene and its copolymer beads containing amine function were prepared for the electroless silver plating using reduction of silver alkylcarbamate complex in organic solvent. Soap-free emulsion polymerization was adopted for the polymerization of styrene, divinylbenzene (DVB), and 2-(N,N-dimethylamino) ethyl methacrylate (DAEMA) in the presence of poly (vinyl alcohol) in a water/methanol solvent. The resulting poly (styrene/DVB/DAEMA), containing 30/0$\sim$1.5/0$\sim$3 wt% in monomer composition, were found to be a sphere-type particle with diameter of 1 ${\mu}m$. Silver Ag-coated polystyrene beads were prepared by in sito reduction of a silver 2-ethylhexylcarbamate (Ag-EHCB) complex solution with hydrazine without pretreatment of polystyrene beads. Robust Ag/polystyrene beads were analyzed by SEM, UV -visible spectrometer and XRD.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.21-22
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• 2018

Foamed concrete is a porous concrete that is cured by mixing bubbles into cement slurry. It is lighter than ordinary concrete and is characterized by higher insulation. Lightweight foamed concerte is mainly used as a sandwich panel in Korea, and is also used as a refractory filler in fireproof safes. Studies on lightwight foamed concrete have been carried out on strength,density and thermal conductivity. However, it is confirmed that the research on the fire resistance performance is very limited. Based on this study, fire resistance of lightweight foamed concrete using expanded polystyrene beads is investigated.

• Journal of the Korean Ceramic Society
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• v.52 no.5
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• pp.380-383
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• 2015

We prepared the $TiO_2$ layer with 0 ~ 4 wt% of polystyrene (PS) beads having a radius of 250 nm to increase the dye adsorption and energy conversion efficiency (ECE) of a dye sensitized solar cell (DSSC). Then, we fabricated DSSCs using $0.45cm^2$ active area. FE-SEM was used to characterize the microstructure consisting of $TiO_2$ layer and PS beads. UV-VIS-NIR was used to determine the optical absorbance of working electrodes (WEs). Solar simulator and potentiostat were used to determine the photovoltaic properties. We observed that pores having a radius of 250 nm were formed with the density of $0.15ea/{\mu}m^2$ in $TiO_2$ layers after conducting the sintering process. The absorbance in visible light regime was found to increase with the increase in the amount of PS beads. The ECE increased from 4.66% to 5.25% when the amount of PS beads was increased from 0 to 4 wt%. This is because the pores of PS beads increased the adsorption of dye. Our results indicate that the ECE of the DSSCs can be enhanced by the addition of an appropriate amount of PS beads into $TiO_2$ layers.

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.36-40
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• 2018

We have developed a nonlithographic patterning technique using polystyrene nanoparticles to form nanonet channel structures which is promising for high-performance TFT applications. Nanoparticles assisted patterning (NAP) is a technique to form uniform nano-patterns by applying lift-off and dry etch process. Oxygen plasma treatment was used to control the diameters of nanonet hole size to realize a branch width down to 100 nm. NAP technology can be very promising to fabricate nanonet structure with advantages of lower manufacturing cost and large-area patterning capability.

• Progress in Superconductivity and Cryogenics
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• v.12 no.3
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• pp.49-54
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• 2010

This paper presents apparent thermal conductivity of various powder at different vacuum levels for cryogenic insulation. Four kinds of powder insulator are examined by using boil-off calorimetry at pressure range from 50 Torr to 3 mTorr. The first material is perlite which is widely used in cryogenic application. Microsphere is the second one that is recently proposed as a replacement powder for liquid hydrogen storage tanks. It is a hollow sphere made of silica with the diameter in the order of 10 to $100{\mu}m$. Popped rice and polystyrene beads are also selected as candidates for powder insulation even though they are polymers. With their porous elliptic and spherical configuration and light density, they demonstrate fairly good thermal insulation performance at pressure range from 50 Torr to 3 mTorr. According to the experimental investigation in this paper, microsphere and polystyrene beads possess promising insulation characteristic as powder insulators and further study is desired.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.194-206
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• 1997

This paper was performed to evaluate the properties of no-coarse lightweight concrete using perlite and expanded polystyrene bead on fine aggregate. The results were shown that w/c and unit weight was affected by absorption ratio and unit weight of using aggregate itself. The compressive strength of no-coarse lightweight concrete was showed $187kgf/cm^2$ by using natural sand, $170kgf/cm^2$ by using perlite. Tensile and bending strength were showed the same tendency of compressive strength, but when expanded polystyrene bead concrete dose not have strength nearly. The pulse velocity and static modulus of elasticity of no-coarse lightweight concrete were smaller than that of normal cement concrete. And stress-strain curves were shown that was increased with increase of stress, and when the stress-strain curve using expanded polystyrene bead was repeated at short intervals increase and decrease irregularly.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.60-63
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• 2002

This paper presents bead-based microbiocihps to detect and separate target proteins. Micro beads coated with capture proteins were introduced into a microchamber, and target proteins flowing across the chamber were bound and concentrated. The chip was connected with an external fluid system. Bead surfaces were double-coated with photo-cleavable linkers and capture proteins. The proteins bound on the beads were photo-separated under UV irradiation, and excited to be measured in fluorescence. $38{\sim}50{\mu}m$ sized polystyrene beads were used. SOGs(silicon-on-glass) were used to fabricate the microchip having glasses bonded on both sides. 100 ${\mu}m$ thick silicon channel was formed through silicon deep RIE process. The upper glass cover had holed through to have inlets and outlets fabricated by powder-blastings. In this study, biotin and streptavidin were used as capture proteins and detection proteins, respectively. The protein mixtures of streptavidin, HSA(human serum albumin) and ovalbumin were applied for selective detection test.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.77-78
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• 2022

To improve the fire vulnerability of the organic insulation sandwich panel core, which is the main culprit of the large-scale fire disaster, an experiment was conducted to examine the thermal conductivity properties of the core material mixed with the organic insulation material EPS Bead and the inorganic insulation material glass wool. As the Additional ratio of glass wool increased, the thermal conductivity decreased, and it was determined that the replacement of glass wool of 3% or more had little effect on the decrease in thermal conductivity. In addition, it can be seen that the most ideal thermal conductivity is exhibited when 1% Replacement ratio of EPS and 3% glass wool are added. The core material of such organic and inorganic insulation materials is judged to be a core material that can compensate for the fire vulnerability of existing insulation materials. Therefore, in order to determine whether it is used as a core material for sandwich panels, additional studies such as fire resistance experiments and sound absorption experiments are needed in the future.

• Analytical Science and Technology
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• v.23 no.2
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• pp.172-178
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• 2010

Glutathione S-transferase is known to play a crucial role in detoxification in many cases. To develop a herbicide detection biosensor, we in this study attempted to immobilize glutathione S-transferase enzyme on solid supports, polystyrene and agarose, and Na-alginate. These matrixes were attractive materials for the construction of biosensors and might also have utility for the production of immobilized enzyme bioreactors. We also compared the activities of glutathione-S-transferase immobilized OsGSTF3 and free OsGSTF3. The specific activity of the free enzyme in solution was 3.3 higher than the immobilized enzyme. These results suggest that 50% of the enzyme was bound with the catalytic site in polystyrene-alkylamine bead and immobilized enzymes showed 80% remaining activity until 3 times reuse.