• Bulletin of the Korean Chemical Society
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• v.25 no.9
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• pp.1366-1370
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• 2004

Controlled pore glass bead was modified with bovine serum albumin (BSA), and glutathione (GSH) was immobilized through three kinds of linkers on top of BSA. Bis(3-sulfo-N-hydroxysuccinimide suberate) sodium salt $(BS^3)$, N-hydroxysuccinimide 3-(2-pyridyldithio)propionate (SPDP), or N-hydroxysuccinimide 4-maleimidobutyrate (GMBS) was introduced into the BSA-bound matrix. Subsequently, GSH was immobilized by addition of thiol side chain into the maleimido moiety, replacing a disulfide group, or formation of an amide group upon releasing 3-sulfo-N-hydroxysuccimide group. It was observed that conjugation methodology played a critical role for activity of the immobilized GSH. SDS-PAGE chromatogram showed that the matrix of glutathione immobilized on BSA through GMBS manifested high selectivity towards glutathione-S-transferase (GST) in cell lysate.

• KSBB Journal
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• v.31 no.1
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• pp.79-84
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• 2016

Biofuel has been considered as promising renewable energy to solve various problems that result from increasing usage of fossil fuels since the early 20th century. In terms of chemical and physical properties as fuel, biobutanol has more merits than bioethanol. It could replace gasoline for transportation and industrial demand is increasing significantly. Production of butanol can be achieved by chemical synthesis or by microbial fermentation. The water hyacinth, an aquatic macrophyte, originated from tropical South America but is currently distributed all over the world. Water hyacinth has excellent water purification capacity and it can be utilized as animal feed, organic fertilizer, and biomass feedstock. However, it can cause problems in the rivers and lakes due to its rapid growth and dense mats formation. In this study, the potential of water hyacinth was evaluated as a lignocellulosic biomass feedstock in biobutanol fermentation by using Clostridium beijerinckii. Water hyacinth was converted to water hyacinth hydrolysate medium through pretreatment and saccharification. It was found that productivity of water hyacinth hydrolysate medium on biobutanol production was comparable to general medium.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.1
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• pp.109-115
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• 2004

The spatter and porosity could be occurred during$CO_2$CW laser welding of Primer- coated steel for shipbuilding. This study has suggested an alternative idea by examining of weld-defect formation mechanism. The primer-coated plate induced the spatter humping bead and porosity and these are main part of the welding defect. attributed to the powerful vaporizing pressure of primer attached on the base metal The zinc of Primer has a boiling point that is the lower temperature than melting point of steel zinc vapor will build up at the interface between the two sheets and this tends to deteriorate the quality of the weld by ejecting weld material from lap position or leaving porosity. Therefore introducing a small gap clearance in the lap position. the zinc vapor could escape through it and sound weld beads can be acquired. In conclusion, we suggested the occurred and prevented mechanism of weld defects with searching the factor.

• 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.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.51-51
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• 2010

Recently just as in the automobile industry, shipbuilders also try to reduce material consumption and weight in order to keep operating costs as low as possible and improve the speed of production. Naturally industry is ever searching for welding techniques offering higher power, higher productivity and a better quality. Therefore it is important to have a details research based on the various welding process applied to steel and other materials, and to have the ability both to counsel interested companies and to evaluate the feasibility of implementation of this process. Submerged-arc welding (SAW) process is usually used about 20% of shipbuilding. Similar to gas metal arc welding(GMAW), SAW involves formation of an arc between a continuously-fed bare wire electrode and the work-piece. The process uses a flux to generate protective gases and slag, and to add alloying elements to the weld pool and a shielding gas is not required. Prior to welding, a thin layer of flux powder is placed on the work-piece surface. The arc moves along the joint line and as it does so, excess flux is recycled via a hopper. Remaining fused slag layers can be easily removed after welding. As the arc is completely covered by the flux layer, heat loss is extremely low. This produces a thermal efficiency as high as 60% (compared with 25% for manual metal arc). SAW process offers many advantages compared to conventional CO2 welding process. The main advantages of SAW are higher welding speed, facility of workers, less deformation and better than bead shape & strength of welded joint because there is no visible arc light, welding is spatter-free, fully-mechanized or automatic process, high travel speed, and depth of penetration and chemical composition of the deposited weld metal. However it is difficult to application of thin plate according to high heat input. So this paper has been focused on application of the field according to SAW process for thin plate in ship-structures. For this purpose, It has been decided to optimized welding condition by experiments, relationship between welding parameters and bead shapes, mechanical test such as tensile and bending. Also finite element(FE) based numerical comparison of thermal history and welding residual stress in A-grade 3.2 thickness steel of SAW been made in this study. From the result of this study, It makes substantial saving of time and manufacturing cost and raises the quality of product.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.156-163
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• 1987

In these experiment, the conditions of entrapping immobilization of Zygosaccharomyces rouxii that participate in the soysauce brewing are investigated. And carried out the fermentation and aging test by immobilized Zygosaccharomyces rouxii with the hydrolyzed solution prepared from soysauce koji. The results obtained were as follows: 1. Immobilizing conditions of Zygosaccharomyces rouxii. 1) When the concentration of Na-alginate solution is 2.0-2.5%, the bead formation was very good. And the concentration of Na-alginate solution not influenced on the fermentation activity of immobilized Zygosaccharomyces rouxii. 2) Effect of ratio of the precultured Zygosaccharomyces rouxii solution and Na-alginate solution on the fermentation activity of immobilized Zygosaccharomyces rouxii was not highly recognized. But if the ratio of precultured Zygosaccharomyces rouxii solution increased, the fermentation activity of immobilized Zygosaccharomyces rouxii was slightly high. 3) The fermentation activity of immobilized Zygosaccharomyces rouxii that grew over 36hrs was higher than that grew below 24hrs. 4) Increasing the ratio of immobilized Zygosaccharomyces rouxii gel to the fermentative medium, the fermentation activity of Zygosaccharomyces rouxii was higher. 2. The fermentation test by immobilized Zygosaccharomyces rouxii with the hydrolyzed solution of soysauce koji. 1) When fermented for about 96 hrs, the alcoholic fermentation almost stopped and alcohol concentration into the hydrolyzed solution of soysauce koji was 2.6%(v/v) approximately.

• Polymer(Korea)
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• v.29 no.1
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• pp.74-80
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• 2005

To use the filter materials for reduction of carbonyl compounds in cigarette mainstream smoke, the bead type cation and anion exchangers were synthesized by the suspension polymerization of GMA and DVB followed by the subsequent functionalization with sodium sulfite and diethylamine, respectively. FT-IR/ATR was used to characterize functionalized copolymer formation by sulfonation and amination, and the morphology change of ion exchangers according to the adsorption of cigarette mainstream smoke were observed by SEM. Ion exchange capacity, functionalization yield and adsorption properties of carbonyl compounds in cigarette mainstream smoke were investigated. The highest functionalization yields and ion exchange capacity were obtained at 5 wt% DVB content in co-monomer. The adsorption amount of carbonyl compounds in cigarette mainstream smoke of anion exchanger was higher than that of cation exchanger because of its electron delocalization in carbonyl group. The adsorption efficiency was increased in the presence of moisture. This results indicated that the anion exchanger was applicable for cigarette filter material because of its large ion exchange capacity and rapid ion exchange reaction.

• KSBB Journal
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• v.14 no.5
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• pp.585-592
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• 1999

This study was aimed to enhance the Fe(II) oxidation rate using immobilized cells of Thiobacillus ferroxidans. For this purpose, a medium for the minimization of jarosite formation was developed first. Secondly, cell immobilization in celite beads was carried out. And then, repeated-batch and continuous operatons of Fe(II) oxidation by using immobilization cells were performed. In a series of flask cultures, three types of media were tested: media with a much lower salt concentration than that of the 9K medium; media which contained different nitrogen sources from that of the 9K medium, that is $(NH_4)_2HPO_4$, $NH_4Cl and HNO$_3$; media which contained $(NH_4)_2HPO_4$ as nitrogen and phosphate source, but without $K_2HPO_4$ as nitrogen and phosphate source in the 9K medium. As a result, the M16 medium which contained 3 g/L of $(NH_4)_2HPO_4$ as nitrogen and phosphate source was found to be the optimal one. It sustained good cell growth allowing no jarosite formation. In the repeated-batch operations, the rate of Fe(II) oxidation gradually increased to reach a maximum value as the batch was repeated. As a result of repeated-batch operations. a maximum Fe(II) oxidation rate was 2.33 g/L . h. In the continuous operations, the iron oxidation rate could be increased to 2.14 g/L .h at a dilution rate of 0.25 $h^{-1}$ which is greater than the maximum specific growth rate (0.12 $h^{-1}$) of the bacteria.

• Laser Solutions
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• v.7 no.2
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• pp.1-10
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• 2004

This work was attempted to join SCP sheet and STS304 sheet by using Nd:YAC laser beam. SCP sheet has good formability and low cost, while STS304 has excellent corrosion resistance and mechanical properties in high temp. In this experiment, butt joint type was used to develop the tailored blank welding for dissimilar steel. Sheets which have different thermal properties. Computer simulation was conducted to obtain the off-set position for efficient welding by considering laser power, scanning speed, focal length and basic properties. The result showed that the optimum thermal distribution was obtained when the laser beam was irradiated at $0.05{\sim}0.1$ mm off-set toward the SCP sheet side. The experiment was conducted based on the result of computer simulation to show the same optimum conditions. Optimum conditions were 3KW in laser beam power, 6m/min in scanning speed, -0.5mm in focal position, 0.1mm off-set toward SCP. Microhardness test, tensile test, bulge test, optical microscopy, EDS, and XRD were performed to observe the microstructure around fusion zone and to evaluate the mechanical properties of optimum conditions, The weld zone had high microhardness values by the formation of the martensitic structure. Tensile test measured the strength of welded region by vertical to strain direction and the elongation of welded region by parallel to strain direction. Bulge test showed $52\%$ formability of the original materials. Bead shape, grain size, and martensitic structure were observed by the optical microscopy in the weld zone. Detailed results of EDS, XRD confirmed that the welded region was connected of martensitic structure.

• Journal of the Korean Chemical Society
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• v.56 no.4
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• pp.431-439
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• 2012

Dissipative particle dynamics (DPD) was carried out to study the nucleation and crystal growth process of $CeO_2$ nanoparticles in different alcohol aqueous solutions. The results showed that the nucleation and crystal growth process of $CeO_2$ can be classified into three stages: nuclei growth, crystal stabilization and crystal aggregation except the initial induction stage, which could be reproduced by collecting simulation results after different simulation time. Properly selecting the sizes of $CeO_2$ and water bead was crucial in the simulation system. The influence of alcohol type and content in solutions, and precipitation temperature on the particle dimension were investigated in detail and compared with the experimental results. The consistency between simulation results and experimental data verify that the simulation can reproduce the macroscopic particle aggregation process. The effect of solvent on the nucleation and crystal growth of $CeO_2$ nanoparticles are different at three stages and can not be simply described by Derjaguin-Landau-Verwey-Overbeek (DLVO) theory or nucleation thermodynamics theory. Our work demonstrated that DPD methods can be applied to study nanoparticle forming process.