• Journal of Sensor Science and Technology
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• v.25 no.4
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• pp.243-246
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• 2016

The characteristics of a bimetallic surface plasmon resonance (SPR) chip were investigated to detect a tumor biomarker, carcinoembryonic antigen (CEA). The linewidth and the tangential slope of the reflectance curve of the bimetallic SPR chip was compared with those of the reflectance curve of a conventional gold (Au) SPR chip. The changes in reflectance in response to the variation in CEA in the critical concentration range were analyzed at an angle where the tangential slope of the reflectance curve was maximum. From linear regression analysis, the sensitivity of the bimetallic SPR chip with respect to the CEA in critical concentration was obtained.

• Journal of the Korean Society of Industry Convergence
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• v.6 no.3
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• pp.239-245
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• 2003

This study is to research on printing method by use of colorants extracted from Sappan wood. As for the research, the stability of paste added by mordants, steaming condition, optimal mordant concentration, change of surface color and colorfastness were measured. The experiment showed that guar gum were stability among the sodium-alginate, modified starch, guar gum. And the surface color was best when the streaming time was 60 minutes, mordant concentration 3g/l. And for colorfastness experiment, colorfastness to drycleaning was good, but colorfastness to light and colorfastness to washing showed no desirable result.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E2
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• pp.83-91
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• 2008

This work investigated the methodology to simultaneously optimize the ozone and relative humidity composition for the $NO_x$ degradation using soil biofilter. Experiments were made as a function of inlet ozone concentration ($0{\sim}1,770\;ppb$) and relative humidity ($38{\sim}81%$). Factorial design ($2^2+3$) and response surface methodology by central composite designs were used to examine the role of two factors and optimal response condition on $NO_x$ degradation. It was found that a second-order response surface model can properly interpret the experimental data with an $R^2$-value of 0.9730 and F-value of 71.83, based on which the maximum $NO_x$ degradation was predicted up to 92.8% within our experimental conditions.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.8
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• pp.38-43
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• 1998

An analytical model for the surface field distribution of the RESURF (reduced surface field)LD(lateral double-diffused) MOS is presented in terms of the doping concentration, the thickness of the n epi layer, the p substrate concentration, and the epi layer length. The reuslts are used to determine the breakdown voltage due to the surface field as a function of the epi layer length. The maximum breakdown voltage of the device is found to be that of the vertical n$^{+}$n$^{[-10]}$ p$^{[-10]}$ junction. Analytical results of the breakdown voltage vs. the epi layer length agree well with the numerical simulation results using MEDICI.I.

• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.32-38
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• 1999

A biosurfactant produced by Tsukamurella sp. 26A was purified by procedures including acid precipitation, ethylacetate extraction, and adsorption chromatography. The purified biosurfactant reduced the surface tension of water from 72 mN/m to 30 mN/m at a concentration of 250 mg/l, whereas the minimum interfacial tension against n-hexadecane was lowered to 1.5 mN/m at a concentration of 40 mg/i. The compound stabilized oil-in-water emulsions with a variety of commercial oils and had strong emulsification and stabilization activities when compared to those of commercial emulsifiers and stabilizers. Surface tension was stable over a broad range of pH (2-12) and temperature ($100^{\circ}C$, 3h). The biosurfactant was identified as glycolipid having a hydrophilic moiety of trehalose.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.2
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• pp.139-144
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• 1999

Hydrogen concentration depth profiles in homoepitaxial Si(001) films grown from hyper-thermal Si beams generated by ultrahigh vacuum (UHV) ion-beam sputtering have been measured by nuclear reaction analyses as a function of film growth temperature and deposition rate. Bulk H concentrations CH in the crystalline Si layers were found tio be below detection limits, 1${\times}$1019cm-3, with no indication of significant H surface segregation at the crystalline/amorphous interface region. This is quite different than the case for growth by molecular-beam epitaxy (MBE) where strong surface segregation was observed for similar deposition conditions with average CH values of 1${\times}$1020cm-3 in the amorphous overlayer. The markedly decreased H concentrations in the present experiments are due primarily to hydrogen desorption by incident hyperthermal Si atoms. Reduced H surface coverages during growth combined with collisionally-induced filling of interisland trenches and enhanced interlayer mass transport provide an increase in critical epitaxial thicknesses by up to an order of magnitude over previous MBE results.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.165-168
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• 2006

The major cause of deterioration for the bare concrete bridge decks exposed to de-icing chemicals would be chloride-induced reinforcement corrosion. Thus, in this paper, in order to predict time to corrode for concrete bridge decks on highways, the chloride concentration was measured with depth from the surface. Then, the surface chloride concentration and apparent diffusion coefficient were calculated by regression. The premature failure of bare concrete decks were mostly related with thin cover depth and poor concrete property(high permeability). The good protection of deck surface might contribute to the prolongation of the service life of bare concrete bridge decks.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.106-109
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• 2003

With the variation of Ag concentration in bath, current density, additive and agitation for electroplating of Sn-Ag solder, the compositions and the morphologies of solder were studied. It was possible to control Ag content in Sn-Ag solder by varying Ag concentration in bath and current density The microstructure size of Sn-Ag solder decreased with increasing current density. Duty cycle of pulse electroplating and quantity of additive affected on Ag content of deposit and surface roughness. In this work eutectic Sn-Ag solder bumps with fine pitch of 30m and height of 15m was formed successfully. The Ag content of electrodeposited solder was confirmed by EDS and WDS analyses and the surface morphologies was analyzed by SEM and 3D surface analyzer.

• Journal of Environmental Science International
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• v.11 no.12
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• pp.1307-1313
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• 2002

This study was performed to investigate the single and combined effect of concentrations of garlic juice according to the pH and temperature on the growth of Salmonella enteritidis in brain heart infusion broth, and to develope Response surface model for the effect of concentrations of garlic extract. The results of electric conductibility of Salmonella enteritidis growing in the range of incubation temperature ($25~42^{\circ}C$), pH (5.5~9.0) and concentration of garlic Juice (0~0.8%) showed that a badge with high temperature had low D.T.value and concentration of garlic extract were significantly correlated with D.T.value (p<0.01). Growth of Salmonella enteritidis in the condition of $37^{\circ}C$ and pH 7.0 presented the lowest D.T.value.

• Journal of the Korean Society of Safety
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• v.15 no.4
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• pp.88-94
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• 2000

The adsorption characteristics of Tharonil on granular activated carbon were experimentally investigated in an adsorber and in a packed column. It was estabilished that the adsorption equilibrium of Tharonil on granular activated carbon was more successfully fitted by Freundlich isotherm equation than Langmuir isotherm equation in the concentration range from 1 to 1000 mg/1. Intraparticle diffusivities (pore and surface diffusivity) of Tharonil were estimated by the concentration-time curve and adsorption isotherm. The estimated values of pore diffusivity and surface diffusivity are $6.70{\times}10^{-6}$ and $2.0{\times}10^{-9}cm^2/s$, respectively. From comparison of intraparticle diffusivities, it was found that surface diffusion was the limiting step for adsorption rate. The break time and breakthrough curve predicted by constant pattern-linear driving force model were shown to agree with the experimental results.