• Journal of the Korean Ceramic Society
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• v.35 no.8
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• pp.813-818
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• 1998

A simple method to measure the elastic modulus E and Poisson's ratio v of diamod-like carbon (DLC) films deposited on Si wafer was suggested. Using the anisotropic etching technique of Si we could make the edge of DLC overhang free from constraint of Si substrate. DLC film is chemically so inert that we could not on-serve any surface damage after the etching process. The edge of DLC overhang free from constraint of Si substrate exhibited periodic sinusoidal shape. By measuring the amplitude and the wavelength of the sinu-soidal edge we could determine the stain of the film required to adhere to the substrate. Since the residual stress of film can be determine independently by measurement of the curvature of film-substrate com-posite we could calculated the biaxial elastic modulus E/(1-v) using stress-strain relation of thin films. By comparing the biaxial elastic modulus with the plane-strain modulus E/(1-{{{{ { v}^{2 } }}) measured by nano-in-dentation we could further determine the elastic modulus and Poisson's ratio independently. This method was employed to measure the mechanical properties of DLC films deposited by {{{{ { {C }_{6 }H }_{6 } }} rf glow discharge. The was elastic modulus E increased from 94 to 169 GPa as the {{{{ { V}_{ b} / SQRT { P} }} increased from 127 to 221 V/{{{{ {mTorr }^{1/2 } }} Poisson's ratio was estimated to be abou 0.16∼0.22 in this {{{{ { V}_{ b} / SQRT { P} }} range. For the {{{{ { V}_{ b} / SQRT { P} }} less than 127V/{{{{ {mTorr }^{1/2 } }} where the plastic deformation can occur by the substrate etching process however the present method could not be applied.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.145-155
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• 1997

The large scaled field test by prefabricated vertical drains was performed to evaluate the superiority of vertical discharge capacity for drain materials through compare and analyze the time-settlement behavior with drain spacing and the compression index and consolidation coefficient obtained by laboratory experiments and field monitoring system. 1. The relation of measurement settlement($S_m$) versus design settlement($S_t$) and measurement consolidation ratio($U_m$) versus design consolidation ratio($U_t$) were shown $S_m=(1.0{\sim}1.1)S_t$, $U_m=(1.13{\sim}1.17)U_t$ at 1.0m drain spacing and $S_m=(0.7{\sim}0.8)S_t$, $U_m=(0.92{\sim}0.99)U_t$ at l.5m drain spacing, respectively. 2. The relation of field compressing index($C_{cfield}$) and virgin compression index($V_{cclab.}$) was shown $C_{cfield}=(1.0{\sim}1.2)V_{cclab.}$, But it was nearly same value when considered the error with determination method of virgin compression index and prediction method of total settlement. 3. Field consolidation coefficient was larger than laboratory consolidation coefficient, and the consolidation coefficient ratio($C_h/C_v$) were $C_h=(2.4{\sim}3.0)C_v$. $C_h=(3.5{\sim}4.3)C_v$ at 1.0m and 1.5m drain spacing and increased with increasing of drain spacing. 4. The evaluation of vertical discharge capacity with drain spacing from the results of the consolidation coefficient ratio showed largely superior in case the Mebra drain and Amer drain than other drain materials at 1.0m and 1.5m drain spacing, while the values showed nearly same value in case same drain spacing.

• Journal of IKEEE
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• v.15 no.4
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• pp.330-338
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• 2011

In this paper, a current-mode buck-boost converter using Multiple switching devices is presented. The efficiency of the proposed converter is higher than that of conventional buck-boost converter. In order to improve the power efficiency at the high current level, the proposed converter is controlled with PWM(pulse width modulation) method. The converter has maximum output current 300mA, input voltage 3.3V, output voltage from 700mV to 12V, 1.5MHz oscillation frequency, and maximum efficiency 90%. Moreover, this paper proposes watchdog circuits in order to ensure the reliability and to improve the performance of dc-dc converters. An electrostatic discharge(ESD) protection circuit for deep submicron CMOS technology is presented. The proposed circuit has low triggering voltage using gate-substrate biasing techniques. Simulated result shows that the proposed ESD protection circuit has lower triggering voltage(4.1V) than that of conventional ggNMOS(8.2V).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.1
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• pp.54-61
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• 2003

This paper shows the results of emissive electromagnetic field characteristics on medium voltage power line(22.9 kV). The measurements were taken when communications signals were coupled into the 22.9 kV main wire of medium voltage power-line in a frequency range of 9 kHz to 30 MHz. The results of the measurement are as follows-emissive electromagnetic Held characteristics from multi carrier signals were superior to a single carrier signal. And we confirmed the PLC transmission distance was 1.8 km when multi-carrier transmission power was 20 dBm. Electric field strength was under the 40 dBuV/m at 30 MHz when 10 m method was measured.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.254-255
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• 2005

In this paper, we investigated electrical characteristics of the X-ray detector of mercuric iodide (HgI2) film fabricated by PIB(Particle-in-Binder) Method on ITO substrates 17cm$\times$20cm in size with thicknesses ranging from approximately 200${\mu}m$ to 240${\mu}m$. In the present study, using I-V measurements, their electrical properties such as leakage current, X-ray sensitivity, and signal-to-noise ratio (SNR),were investigated. The results of our study can be useful in the future design and optimization of direct active-matrix flat-panel detectors (AMFPD) for various digital X-ray imaging modalities.

• Analytical Science and Technology
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• v.17 no.2
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• pp.117-129
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• 2004

Amitrole in environment, difficult to be analyzed by GC or GC/MS due to high polarity and low volatility, was analyzed by LC/ESI/MS in the study. Maximum peak intensity of amitrole in LC/MS/ESI mass spectrum is m/z 85 of protonated molecular ion $(M+H)^+$ with 30V of cone voltage at SIR mode. It was confirmed that ratios between main ion of amitrole, 85 of protonated molecular ion, and m/z 58 fragmented ion of amitrole, had increased corresponding with the increment of cone voltage from 20V to 70V. The isotope molecular weight of amitrole was $86([M+H])^+$ at LC/MS analysis and the mass spectrum ratio between 85 mass and 86 mass was not different by the change of concentration but similar to theoretical ratio(less than 10% standard deviation).The linearity of standard calibration curve under same condition with sample treatment method had $y=1.09354e^6X+26947.2$ and $r^2=0.99$. Recovery rates in water and soil samples were 77.64~83.44% and 71.11~79.44%, respectively. Reliability of the analysis was performed with 5 repeated measurements at each level of standard concentration and the result showed that relative standard deviation was less than 10%; therefore, the extraction and analysis method in the study suggested that it would be reliable to measure amitrole in water and soil media.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.230-233
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• 2004

The stochiometric mix of evaporating materials for the $CuInS_2$ single crystal thin films was prepared from horizontal furnance. Using extrapolation method of X-ray diffraction patterns for the $CuInS_2$ polycrystal, it was found tetragonal structure whose lattice constant $a_0$ and $c_0$ were $5.524\;{\AA}$ and $11.142\;{\AA}$, respectively. To obtain the single crystal thin films, $CuInS_2$ mixed crystal was deposited on throughly etched semi-insulator GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperature were 640 t and 430 t, respectively and the thickness of the single crystal thin films was $2{\mu}m$. Hall effect on this sample was measured by the method of van dot Pauw and studied on carrier density and temperature dependence of mobility. The carrier density and mobility deduced from Hall data are $9.64{\times}10^{22}/m^3,\;2.95{\times}10^{-2}\;m^2/V{\cdot}s$ at 293 K, respectively The optical energy gaps were found to be 1.53 eV at room temperature. From the photocurrent spectrum by illumination of perpendicular light on the c - axis of the thin film, we have found that the values of spin orbit coupling splitting ${\Delta}So$ and the crystal field splitting ${\Delta}Cr$ were 0.0211 eV and 0.0045 eV at 10 K, respectively. From PL peaks measured at 10K, 807.7nm (1.5350ev) mean Ex peak of the free exciton emission, also 810.3nm (1.5301eV) expresses $I_2$ peak of donor-bound exciton emission and 815.6nm (1.5201eV) emerges $I_1$ peak of acceptor-bound exciton emission. In addition, the peak observed at 862.0nm (1.4383eV) was analyzed to be PL peak due to donor-acceptor pair(DAP).

• Journal of fish pathology
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• v.32 no.2
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• pp.97-104
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• 2019

The purpose of this study was to investigate the antimicrobial resistance and resistance transfer of Vibrio parahaemolyticus and Morganella morganii isolated from fish products purchased from fish markets in Yeosu April - December 2017. These bacteria were identified by biochemical test and PCR results, and the transfer of antimicrobial resistance was confirmed by the broth mating method. To isolate the transconjugants formed during conjugation, TSA medium containing 50 ㎍/ml of ampicillin (AMP), and 150 ㎍/ml of streptomycin (SM) or 30 ㎍/ml of oxytetracycline (OT) was used. M. morganii isolates showed low susceptibility to AMP, amoxicillin (AML), and colistin (CT), erythromycin, OT, and tetracycline, compared to V. parahaemolyticus resistance to AMP, AML, and CT. The conjugation of V. parahaemolyticus or M. morganii with Escherichia coli resulted in the separation of V. parahaemolyticus and M. morganii showing SM resistance as transconjugants. Meanwhile, Edwardsiella tarda transconjugants showing AMP and AML resistance were obtained from the broth mating of V. parahaemolyticus and E. tarda. But the transfer of the VPA0477 which is a β-lactamase gene of V. parahaemolyticus was not confirmed. These results suggest that resistance transfer between pathogenic bacteria is bidirectional and progresses in a wide variety of patterns.

• KSBB Journal
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• v.21 no.5
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• pp.371-375
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• 2006

Frontal analysis(FA) and Pulsed input method(PIM) have been frequently utilized to measure isotherm of single solute, as well as non-competitive isotherms of two solutes in chromatography(1). FA and PIM were used in this study as complementary methods to measure adsorption isotherms of loxoprofen racemate in HPLC. Prior to FA and PIM experiments, measurements of loxoprofen solubility were made at hexane/ethanol=50/50, 80/20, 95/5(v/v) with acetic acid(0.5%) for adjusting pH. The last composition(95/5) of hexane/ethanol allows us to separate loxoprofen racemate into two forms(retentate, extract). PIM and FA were used to determine the isotherms of re-and ex-loxoprofen.

• Journal of the Korean GEO-environmental Society
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• v.8 no.4
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• pp.47-55
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• 2007

Using the results of the Piezocone Penetration Test (PCPT) which were executed at the Yangsan-Mulgum site, the applicability of the interpretation methods for estimating the coefficient of consolidation ($C_v$) of soft clay was evaluated. At the same time, laboratory soil tests using the total of 172 undisturbed soft clay samples from the 44 regions of the Yangsan-Mulgum site were performed to study the differency in the coefficient of consolidation ($C_v$) compared to the results of PCPT. The calculated constrained modulus ($M_{\varepsilon}$) and coefficient of consolidation ($C_v$) using the results of consolidation laboratory tests which are based upon the consolidation theory of Terzaghi were compared with the predicted constrained modulus ($M_p$) and coefficient of consolidation ($C_{v-{M_p}}$) from the PCPT. The relationship between the predicted constrained modulus ($M_p$) and the calculated constrained modulus($M_c$) were showed good correlation. The $M_p$ by the Jones & Rust method were showed mostly similar to the calculated constrained modulus ($M_c$). The relationship between the coefficient of consolidation ($C_v$) obtained from the consolidation tests and the calculated coefficient of consolidation ($C_{v-{M_p}}$) were showed a linear relationship. The results of the calculated coefficient of consolidation ($C_{v-{M_p}}$) were about 54% of the value of the coefficient of consolidation ($C_v$) obtained from the consolidation tests.