• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.513-522
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• 1999

DNA hybridization assay using probes prepared from liver was carried out to identify species characterization of the domestic animals. Gel electrophoresis showed that the target DNA extracted from raw muscle were 1kb and uniform pattern while fragments size of heated muscle were irregular. Hybridization was performed by adding 200ng/ml probe in hybridization solution and incubating for 12 hours at $68^{\circ}C$. To obtain good discrimination, applied washing buffer and washing step differently depending on the species. The probes of pig, horse and dog formed the specific hybrids with each target DNA respectively. Although cross reaction was detected in cattle, goat and sheep but signal intensity among these species made the discrimination possible each other. Such pattern was the same in the cases of chicken, turkey and duck. The hybridization pattern of heated muscle was similar to that of raw muscle in general, but the signal intensity was inferior to that of raw muscle. Species identification between closely related animal species, hybridized using the target DNA of such closely related animal species as a blocking agent, remarkable increase of discrimination from the evident decrease of non specific reaction compared with the control group. In addition, in the admixture where certain meat was included in the beef, pork, chicken meat, we could find whether any unjust meat was admixed or not. In this case, detection limit of certain meat in admixture was 1%.

• Journal of the Korean Chemical Society
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• v.46 no.2
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• pp.145-150
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• 2002

A Method to determine Cr(III)ion in aqueous solution by chemiluminescence method using a stopped flow system has been studied. The method is based on the increased chemiluminescence intensity with the addition of Cr(III) to a solution of lucigenin a nd hyrogen peroxide. The effects of pH, injection volumes of reagent and sample, and concentration of lucigenin and hyrogen peroxide on the chemiluminescence intensity have been investigated. The calibration curve for Cr(III) ion was linear over the range from 1.0${\times}$$10^{-6}$ to 1.0${\times}$$10^{-3}$M and the detection limit was 5.2${\times}$$10^{-8}$M under the optimal experimental condition of 437nm, 12.8,and 1.0${\times}$$10^{-6}$ and 2.0M for emission wavelength, pH, and concentration of lucigenin and hyrogen peroxide, respectively.

• Bulletin of the Korean Chemical Society
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• v.25 no.8
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• pp.1177-1181
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• 2004

The determination of uric acid in urine samples was studied by a chemiluminescence measurement using tris (2,2'-bipyridine)ruthenium(II)-octylphenylpolyglycolether [Ru$(bpy)_3^{2+}$ -OPE] system. The oxidized uric acid by Ce(IV) excited Ru$(bpy)_3^{2+}$ to emit a chemiluminescence in this system so that the intensity was stoichio-metrically dependent upon the concentration of uric acid. In a reaction cell, a luminescent reagent, oxidant, surfactant and sulfuric acid were flowed into and mixed with a taken sample. Experimental conditions were optimized to obtain the maximum intensity of chemiluminescence. Each reactant solution of more than the following concentration gave a good result: $2\;{\times}\;10^{?4}$ M Ru$(bpy)_3^{2+}$ , 0.01 M Ce(IV), 6% OPE, and 0.33 M $H_2SO_4$. Any interferences were not shown in this process by the investigation of concomitant constitutes such as albumin, creatine, lactic acid, glucose, urea, $Cl^?,\; Mg^{2+},\;Ca^{2+}$ and so on. The linearity of a calibration curve was good with r = 0.998, the relative standard deviation of the slope was 3.3% and the detection limit was 5.6ng/mL. The recoveries of 80 to 91% were obtained from the standard spiked samples. The values were little bit low, but this procedure could be considered to be reliable for the determination of trace uric acid in urine samples.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.932-935
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• 2011

Using tetrabutyl titanate as precursor, $Eu^{3+}$ doped $TiO_2$ nano-powder was prepared by sol-gel method, the nature of luminescence of nano-powder was studied. The interaction of chlorpyrifos with $Eu^{3+}$ doped $TiO_2$ was studied by absorption and fluorescence spectroscopy. The results indicated the fluorescence intensity of $Eu^{3+}$ doped $TiO_2$ was quenched by chlorpyrifos and the quenching rate constant ($k_q$) was $1.24{\times}10^{11}\;L/mol{\cdot}s$ according to the Stern-Volmer equation. The dynamics of photoinduced electron transfer from chlorpyrifos to conduction band of $TiO_2$ nanoparticle was observed and the mechanism of electron transfer had been confirmed by the calculation of free energy change (${\Delta}G_{et}$) by applying Rehm-Weller equation as well as energy level diagram. A new rapid method for detection of chlorpyrifos was established according to the fluorescence intensity of $Eu^{3+}$ doped $TiO_2$ was proportional to chlorpyrifos concentration. The range of detection was $5.0{\times}10^{-10}-2.5{\times}10^{-7}mol/L$ and the election limit ($3{\sigma}$) was $3.2{\times}10^{-11}$ mol/L.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.3 s.49
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• pp.1-11
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• 2006

This paper presents a seismic fragility analysis method for a cable-stayed bridge with energy dissipation devices. Model uncertainties represented by random variables include input ground motions, characteristics of energy dissipation devices and the stiffness of cable-stayed bridge. Using linear regression, we established demand models for the fragility analysis from the relationship between maximum responses and the intensity of input ground motions. For capacity models, we considered the moment and shear force of the main tower, longitudinal displacement of the girder, deviation of the stay cables tension and the local buckling of the main steel tower as the limit states for cable-stayed bridge. As a numerical example, fragility analysis results for the 2nd Jindo bridge are presented. The effect of energy dissipation devices is also briefly discussed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.3
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• pp.355-361
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• 1987

Creep and fatigue tests were carried out on crack growth properties of small surface cracks in 304 stainless steel at 538.deg.C, 593.deg. C and 650.deg. C in air, by using small plate specimens with a small artificial pit. All the data of the crack growth rate per hour obtained in the present tests were correlated with the maximum stress intensity factor, so that the applicability of linear fracture mechanics to the crack growth of surface cracks at elevated temperature was investigated. In the creep test, relatiion of .sigma.$\^$n/.t$\_$f/=C is obtained between failure time and nominal stress at each temperature level, where n has the value of 11-14 depending on the temperature level. In the creep and fatigue crack growth properties of surface cracks at the elevated temperatures, the maximum stress intensity factor, $_{4}$$\_$max/, is some extent applicable parameter to describe the surface crack growth rate under the present experimental conditions. The crack growth rate per hour increases when the holding time decreases, and creep crack growth rate per hour becomes the lowest limit of crack growth rate per hour in this tests.

• Korean Journal of Optics and Photonics
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• v.7 no.2
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• pp.89-95
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• 1996

Superresolution optics, employing Gaussian apodization, is rigorously treated at the soft X-ray wave-length(λ=0.013 ${\mu}{\textrm}{m}$) region. In the diffraction integral, the line integral along the imaginary axis is found small, and it is ignored, so that the diffraction integral consists of the integration along the real axis. The resolution of the diffracted image is not effected by the pupil angular frequency bandwidth $2{\omega}_0$, which is one of the most important the characteristic features of Gaussian apodization ($e^{-o^2x^2}$ optics. The superresolution optics has resolution ($\frac{1}{2}{\times}FWHM)$=$\Delta$x=0.008 $\mu$m which is smaller than the Rayleigh criterion of 2λ=0.026 ${\mu}{\textrm}{m}$ for NA=0.25. The optical system has ${\omega}_0{\ge}\frac{1}{2}{\sigma}$, which gives the peak intensity of the diffracted image larger than $e^{-2}$ times intensity obtainable by the infinite sperture.

• Bulletin of the Korean Chemical Society
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• v.12 no.5
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• pp.499-504
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• 1991

EPR spectra of the high $T_c$ superconductor $YBa_2Cu_3O_{7-y}$ (YBCO) doped with $Pd^{2+} or Zn^{2+}$ have been measured at several temperatures and dopant concentrations. The spectral intensity of $YBa_2({Cu_{1-x}}{Pd_x})_3O_{7-y}$ is proportional to the dopant concentration. The behavior of $YBa_2(Cu_{1-x}Zn_x)_3O_{7-y}$ is quite different: the spectral intensity remains almost constant up to x=0.10 and then increases rapidly above x=0.10. The results are interpreted in terms of localized and antiferromagnetically spin-paired d holes in both CuO chain and planes. The $Pd_{2+}$ ion substitutes on the CuO chain consisting of "CuOCu dimers", and a $Cu_{2+}$ ion with an unpaired spin is gene rated for each $Pd_{2+}$ ion substituted. On the other hand, $Zn_{2+}$ substitutes on the CuO planes, and all or most of the spins in the two-dimensional plane manage to pair up in the region of low dopant concentration. When the dopant concentration exceeds a certain limit, it becomes more difficult for the spins to find partners, and the number of unpaired spins increases rapidly with increasing dopant concentration. The $Zn_{2+}$ ion is more effective than the $Pd_{2+}$ ion in suppressing the superconductivity of YBCO. This is attributed to the fact that $Zn_{2+}$ substitutes on the CuO planes which are mainly responsible for the superconductivity, while $Pd_{2+}$ substitutes on the CuO chain which is of secondary importance in the superconductivity.

• Nano
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• v.13 no.12
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• pp.1850147.1-1850147.14
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• 2018

In this work, water-soluble and blue-emitting carbon nanodots (CDs) were synthesized from apple peels for the first time via one-step hydrothermal method. The synthetic route is facile, green, economical and viable. The as-prepared CDs were characterized thoroughly by transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman, Fourier transform infrared (FT-IR), X-ray photoelectron (XPS), fluorescence and UV-Vis absorption spectroscopy in terms of their morphology, surface functional groups and optical properties. The results show that these CDs possessed ultrasmall size, good dispersivity, and high tolerance to pH, ionic strength and continuous UV irradiation. Significantly, the CDs had fast and reversible response towards temperature, and the accurate linear relationship between fluorescence intensity and temperature was used to design a novel nanothermometer in a broad temperature range from 5 to $65^{\circ}C$ facilely. In addition, the fluorescence intensity of CDs was observed to be quenched immediately by Cr(VI) ions based on the inner filter effect. A low-cost Cr(VI) ions sensor was proposed employing CDs as fluorescent probe, and it displayed a wide linear range from 0.5 to $200{\mu}M$ with a detection limit of $0.73{\mu}M$. The practicability of the developed Cr(VI) sensor for real water sample assay was also validated with satisfactory recoveries.

• The Journal of the Acoustical Society of Korea
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• v.42 no.1
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• pp.1-6
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• 2023

Sound radiated from a structure in vibration is an important physical characteristic to evaluate vibro-acoustic problem. Although sound radiation power can be typically obtained by intensity measurement, long measuring time and strict measuring condition remain difficult. As an alternative method, simulation-based estimation can be taken into account and its accuracy is known to be acceptable. However, difficulty still lies in that specialized softwares may be necessary to obtain sound radiation power and radiation efficiency. In this context, this study suggests two methods using an ordinary FE method to calculate sound radiation power. They are well-known reciprocity technique and p-p method, which are basically test methods. It is shown that either method can practically estimate sound radiation in the frame of conventional Finite Element Method (FEM). The methods and their corresponding limit are discussed with some results.