• 한국환경과학회지
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• 제6권4호
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• pp.335-350
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• 1997

Numerical simulations of photochemical air pollution (CBM: Carbon-Bond Mechanisms under a theoretical three-dimensional local wind system are carried to clarify the fundamental characteristics of the effects of local wind on photochemical air pollution. According to the AWS data of Pusan coastal area and KMA, the surface wind of Pusan during summertime showed a very remarkable land and sea breeze circulation. The ozone concentration distribution using local wind model showed that high ozone concentration zone near coastal area moved toward inland In the afternoon. This change implies a sea breeze Increases the ozone concentration, but a land breeze decreases it in Pusan coastal area.

• 한국의류학회지
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• 제28권7호
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• pp.1029-1036
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• 2004

The fragrant fabrics were prepared by treatment with eucalyptus microcapsules. 100% cotton fabric, 100% polyester fabric and 100% wool fabric were used as test specimens. Using pad-dry-cure method, microcapsules were attached on each specimen by acrylic binder under conditions of varying concentration. Surface property, stiffness, and air permeability of fragrant fabrics were evaluated. As increasing concentration of binder, add-on yield was increased. Add-on yield was decreased with increasing laundering cycle, especially in polyester fabric. As the concentration of binder was increased, the properties of stiffness and air permeability were decreased. Also it fumed out that pad-dry-cure method was not suitable to polyester fabric.

• 한국염색가공학회지
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• 제18권2호
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• pp.1-7
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• 2006

In order to prepare PAN nano fiber web, PAN/DMF solution was prepared and electrospun. The diameter of fiber was depended on the polymer concentration (7.5-15wt%) and the applied voltage (10-16kV). The average diameter of fiber increased with an increase of the polymer concentration and decreased with the applied voltage. At 7.5wt% concentration, many beads were found. So, we prepared a nano PAN fiber by electrospinning at concentration of 10wt% and 16kV. PAN fibers were reduced with litium aluminium hydride and the dyeability to acid dye was checked. The reduced nano PAN fiber showed much better dyeability compared with the reduced ordinary PAN fiber. It was considered that the increase of specific surface area have an important role in dyeing with acid dye.

• Carbon letters
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• 제1권1호
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• pp.17-21
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• 2000

Catalytic reduction and oxidation of NO over polyacrylonitrile based activated carbon fibers (PAN-ACF) under various conditions were carried out to develop removal process of NO from the flue gas. The effect of temperature, oxygen concentration and the moisture content for the reduction of NO with ammonia as a reducing agent was investigated. The reduction of NO increased with the oxygen concentration, but decreased with the increased temperature. The moisture content in the flue gas affects the reduction of NO as the inhibition of the adsorption of the other components and the reaction on the surface of ACE For the oxidation of NO to $NO_2$ over PAN-ACF without using a reducing gas, it showed the temperature and the oxygen concentration of the flue gas are the important factors for the NO conversion in which the conversion increased with oxygen concentration and decreased with the temperature increase and might be the alternative option for the selective catalytic reduction process.

• 제어로봇시스템학회논문지
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• 제19권10호
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• pp.891-895
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• 2013

This paper proposes the development of a new method for online analysis which measured acid concentration in a pickling line. Pickling is the most important step to remove surface scale layers and is strongly depending on the exactly controlled pickling liquor composition. Today, there is no feasible system available for the online control of pickling lines. Within this paper, new methods for online analysis of pickling liquors have been tested and implemented into an overall pickling process control tool. This method measured simultaneously the hydrochloric acid and iron ion concentration in a solution of hydrochloric acid by measuring the ultrasonic speed, the solution temperature, and the electrical conductivity. Experimental results showed excellent precision and the measurement error was ${\pm}2g/l$ compared with the neutralization titration measurement.

• 한국환경과학회지
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• 제5권1호
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• pp.35-41
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• 1996

For studying of coagulation and sedimentation in estuarine clay, we obtained several flow curves with various concentrations of sea water by using Coutte type rotational rheometer. The initial shear stress on high concentration of sea water was observed big, but after this, its value is decreasing with increasing shear rate. The maximum pick of shear stress is decreasing with the decreasing of concentration of sea water The trend is same totally above for viscosity. The sedimentation times with the concentration of sea water vary in $\infty$ ~ 5 minutes. The zeta potential is changed dramatically between 114 and 118 concentration of sea water. That is consistent with the sedimentation graph. From these results, the phenomena of coagulation and sedimentation can be explained with viscoelastic terms on structual formation among particles by the changes of surface potential affected from contacting sea water to dispersed particles.

• 한국염색가공학회지
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• 제19권5호
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• pp.30-36
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• 2007

Cypermethrin-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and Ethylene diamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation. The mean size of the polyurea microcapsules was smaller and the surface morphology of the PVA was much smoother than gelatin. In addition the release behavior was much more controlled and better sustained. As the concentration of protective colloid increased, the wall membrane of the polyurea microcapsules became more stable, the thermal stability of the wall membrane increased, the mean particle size became smaller, and the particle distribution was more uniform. The release behavior of the core material changed according to the concentration. As the gelatin concentration was increased, a more controlled and sustained release behavior was observed. However, in the case of PVA, the increase of PVA concentration lead to a more rapid release rate.

• Bulletin of the Korean Chemical Society
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• 제22권2호
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• pp.189-193
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• 2001

The irreversible capacities caused by the reduction of solvent on the surface of a negative electrode (KMFC:Kawasaki Mesophase Fine Carbon) were examined during the initial cycle in ethylene carbonate (EC)-diethyl carbonate (DEC) electrolyte solut ions at various concentrations of LiPF6. Chronopotentiograms, linear sweep voltammograms, and impedance spectra clearly showed differences in irreversible capacity and that those differences are related to the concentration of electrolyte during the initial charge. These differences were caused by the amount of solvent decomposition as a function of the concentration of LiPF6 electrolytic salt. The data are discussed with reference to the concentration of electrolytic salt and the properties of passivation film formed by solvent decomposition.

• 대한전자공학회논문지
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• 제24권2호
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• pp.248-253
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• 1987

Boron diffusion into silicon through poly\ulcorneri-SiO2 was carried out for the diffusion with low concentration using CVD-BN. The result of direct boron diffusion from BN into silicon and that of boron diffusion through SiO2 from BN into silicon was compared with the result of boron diffusion through poly-Si-SiO2 from BN into silicon. In the case of boron diffusion through poly Si-SiO2, the low concentration diffusion was obtained, that is the boron surface concentration in silicon Cs=10**16 Cm**-3, and the glassy compounds were not seen.

• Corrosion Science and Technology
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• 제6권4호
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• pp.154-158
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• 2007

For the application of flexible printed circuit board (FPCB), electroplated copper is required to have low surface roughness and residual stress. In the paper, the effects of surface roughness and residual stress of electroplated copper as thick as $8{\mu}m$ were studied on organic additives such as inhibitor, leveler and accelerator. Polyimide film coated with sputtered copper was used as a substrate. Surface roughness and surface morphology were measured by 3D-laser surface analysis and FESEM, respectively. Residual stress was calculated by Stoney's equation after measuring radius curvature of specimen. The addition of additives except high concentration of accelerator in the electrolyte decreased surface roughness of electroplated copper film. Such a tendency was explained by the function of additives among which the inhibitor and the leveler inhibit electroplating on a whole surface and prolusions, respectively. The accelerator plays a role in accelerating the electroplating in valley parts. The inhibitors and the leveler increased residual stress, whereas the accelerator decreased it. It was thought to be related with entrapped additives on electroplated copper film rather than the preferred orientation of electroplated copper film. The reason why additives lead to residual stress remains for the future work.