• Corrosion Science and Technology
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• 제17권2호
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• pp.54-59
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• 2018

The effect of external DC electric field on atmospheric corrosion behavior of zinc under a thin electrolyte layer (TEL) was investigated by measuring open circuit potential (OCP), cathodic polarization curve, and electrochemical impedance spectroscopy (EIS). Results of OCP vs. time curves indicated that the application of external DC electric field resulted in a negative shift of OCP of zinc. Results of cathodic polarization curves measurement and EIS measurement showed that the reduction current of oxygen increased while charge transfer resistance ($R_{ct}$) decreased under the external DC electric field. Variation of OCP negative shift, reduction current of oxygen, and $R_{ct}$ increase with increasing of external DC electric field strength as well as the effect of external DC electric field on double-layer structure in the electrode/electrolyte interface and ions distribution in thin electrolyte layer were analyzed. All results showed that the external DC electric field could accelerate the corrosion of zinc under a thin electrolyte layer.

• 한국환경과학회지
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• 제10권1호
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• pp.35-39
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• 2001

The mutagenicity of the river water of Nakdong river estuary was determined by Ames test using the blue rayon suspension method. Samples were collected from 10 sites in the estuary once in each season of 1998. The samples collected from the sites where industrial waste discharge on May were mutagenic, but the other samples were not mutagenic. The sample collected from the site 1 located near the industrial area (Hadan-dong) were highly mutagenic in the TA98 with (+S9) and without (-S9) mix as well as in the TA100 with (+S9) and without (-S9) S9 mix, suggesting that the river water of this site is polluted by direct and indirect mutagens of frame-shift type as well as direct and indirect mutagens of base-replacement type. The positive mutagenicity, although relatively low, was also detected in TA98 with (+S9) and without (-S9) S9 mix in the extract of the site 4 near the industrial area(Jangrim-dong), suggesting that the primary mutation type is frame-shift. The negative mutagenicity from July to December at the sites (1-4) near the industrial area seems to be affected by the low economic growth rate in 1998 in Korea. On the other hand, the negative mutagenicity in all extracts collected from the sites 5-10 near the residential area where living sewage discharge, suggests that the river water was not polluted by mutagens.

• E2M - 전기 전자와 첨단 소재
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• 제7권1호
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• pp.57-63
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• 1994

Aluminum oxide($Al_2{O_3}$) offers some unique advantages over the conventional silicon dioxide( $SiO_{2}$) gate insulator: greater resistance to ionic motion, better radiation hardness, possibility of obtaining low threshold voltage MOS FETs, and possibility of use as the gate insulator in nonvolatile memory devices. We have undertaken a study of the dielectric breakdown of $Al_2{O_3}$ on Si deposited by GAIVBE technique. In our experiments, we have varied the $Al_2{O_3}$ thickness from 300.angs. to 1400.angs. The resistivity of $Al_2{O_3}$ films varies from 108 ohm-cm for films less than 100.angs. to 10$_{13}$ ohm-cm for flims on the order of 1000.angs. The flat band shift is positive, indicating negative charging of oxide. The magnitude of the flat band shift is less for negative bias than for positive bias. The relative dielectric constant was 8.5-10.5 and the electric breakdown fields were 6-7 MV/cm(+bias) and 11-12 MV/cm (-bias).

• 한국식품영양학회지
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• 제33권3호
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• pp.266-278
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• 2020

This study was conducted with 375 workers in Changwon to examine the effects of working patterns on dietary habits and health. A self-administered questionnaire was conducted July 22 October 30, 2019. According to the results of the dietary habits and health related factors analysis, non-shift administrative workers showed significantly higher rates of green tea intake (p<0.05), and shift production workers showed significantly higher smoking rates (p<0.001) and waist circumferences (p<0.01). According to the results of the Pearson's correlation coefficient analysis, work hours showed negative correlations with job satisfaction (r=0.22, p<0.01) and positive correlations with perceived stress level (r=0.14, p<0.01). Temporary workers showed negative correlations with feel job satisfaction(r=0.14, p<0.01), perceived stress level (r=0.12, p<0.05), and concern about health (r=0.13, p<0.05). Diabetes showed positive correlations with hypertension (r=0.20, p<0.01), low HDL cholesterolemia (r=0.22, p<0.01), abdominal obesity (r=0.13, p<0.05), and hypertriglyceridemia(r=0.22, p<0.01). Based on these results, this researcher proposes that continuous attention and support of industries and communities are necessary for nutritional education and counseling relative to improving workers' dietary lives as well as disease prevention and control.

• 국제지역연구
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• 제13권3호
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• pp.145-161
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• 2009

본 논문은 변이할당분석모형을 이용하여 2003-2006 기간중 한국으로 유입된 외국인직접투자를 세계성장효과, 산업구성효과, 경쟁효과, 배분효과 등의 요인으로 분해한다. 2003-2006 기간중 한국으로 유입된 외국인직접투자는 세계추세에 못미치는 수준인 것으로 나타났다. 그 결과 산업구성효과와 경쟁효과는 모두 부(負)(-)의 효과를 기록한 것으로 나타났다. 또한 분석결과 다음의 산업들은 양(+)의 경쟁력효과를 기록한 것으로 나타났다: 전기 및 전자장비, 자동차 및 운송장비, 음식숙박업, 운수, 창고 및 통신, 금융, 사업서비스. 이와 같은 분석결과를 종합하면, 한국은 일부 제조업분야와 대부분의 서비스분야에서 외국인직접투자를 유치하는데 경쟁력을 지니고 있다고 평가할 수 있다. 향후 한국의 외국인직접투자 유치정책은 경쟁력을 지닌 산업을 중심으로 시행되는 것이 적절할 것이다.

• Transactions on Electrical and Electronic Materials
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• 제18권1호
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• pp.51-54
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• 2017

TFTs (thin film transistors) were fabricated using a-SIZO (amorphous silicon-indium-zinc-oxide) channel by RF (radio frequency) magnetron sputtering at room temperature. We report the influence of various channel thickness on the electrical performances of a-SIZO TFTs and their stability, using TS (temperature stress) and NBTS (negative bias temperature stress). Channel thickness was controlled by changing the deposition time. As the channel thickness increased, the threshold voltage ($V_{TH}$) of a-SIZO changed to the negative direction, from 1.3 to -2.4 V. This is mainly due to the increase of carrier concentration. During TS and NBTS, the threshold voltage shift (${\Delta}V_{TH}$) increased steadily, with increasing channel thickness. These results can be explained by the total trap density ($N_T$) increase due to the increase of bulk trap density ($N_{Bulk}$) in a-SIZO channel layer.

• Bulletin of the Korean Chemical Society
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• 제19권4호
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• pp.449-457
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• 1998

We compared various spectroscopic properties of a norfloxacin-single stranded DNA complex with those of norfloxacin-double stranded DNA complex. Norfloxacin binds to both double-and single stranded DNA, and we observed the following spectroscopic changes for both complexes: hypochromism in the norfloxacin absorption region in the absorption spectrum, the characteristic induced CD spectrum consisting of a weak positive band at 323 nm and a strong positive band at 280-300 nm followed by a negative band in the 260 nm region, a strong decrease in the fluorescence intensity and a red-shift in the fluorescence emission spectrum, and shorter fluorescence decay times. These results indicate that the environments of the bound norfloxacin in both DNAs are similar, although the equilibrium constant of the norfloxacin-single stranded DNA was twice as high as the norfloxacin-double stranded DNA complex. Both complexes were thermodynamically favored with similar negative Δ$G^o$. Negative Δ$H^o$ terms contribute to these spontaneous reactions; Δ$S^o$ term was unfavorable.

• 한국진공학회지
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• 제9권4호
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• pp.428-435
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• 2000

정전 탐침을 이용하여 유도 결합형 반응기에서 발생하는 산소 플라즈마의 음이온 발생 특성을 관찰하였다. 입력전력과 운전압력 조건에 따른 산소 플라즈마에서 electronegative 음이온 플라즈마의 입력전력과 운전압력에 따른 정전 탐침에 흐르는 포화 양 전류 대 포화 음 전류(전자 전류와 음 이온 전류의 합)의 전류 비율과 플라즈마 부유 전위와 플라즈마 전위 차의 변화로부터 음이온 발생 특성관찰을 하였다. 전류비의 증가와 전위차 값의 감소는 입력전력이 증가함에 따라 약 30∼60 mTorr 운전압력 영역에서 나타났으며 이 조건에서 음이온의 발생량이 증가함을 의미하고, 플라즈마내의 이온들은 음이온과 재결합에 의한 손실이 증가하여 플라즈마 밀도가 감소함을 알 수 있었다.

• 한국재료학회지
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• 제12권1호
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• pp.75-81
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• 2002

The ferroelectric properties of Pb(Zr,Ti)O$_3$[PZT] films degrade when the films with Pt top electrodes are annealed in hydrogen containing environment. This is due to the reduction activity of atomic hydrogen that is generated by the catalytic activity of the Pt top electrode. At the initial stage of hydrogen annealing, oxygen vacancies are formed by the reduction activity of hydrogen mainly at the vicinity of top Pt/PZT interface, resulting in a shift of P-E (polarization-electric field) hysteresis curve toward the negative electric field direction. As the hydrogen annealing time increases, oxygen vacancies are formed inside the PZT film by the inward diffusion of hydrogen ions, as a result, the polarization degrades significantly and the degree of P-E curve shift decreases gradually. The direction and the magnitude of the remnant polarization in the PZT film affect the motion of hydrogen ions which determines the degradation of polarization characteristics and the shift in the P-E hysteresis curve of the PZT capacitor during hydrogen annealing. When the remnant polarization is formed in the PZT film by applying a pre-poling voltage prior to hydrogen annealing, the direction of the P-E curve shift induced by hydrogen annealing is opposite to the polarity of the pre-poling voltage. The hydrogen-induced degradation behavior of the PZT capacitor is also affected by the internal field that has been generated in the PZT film by the charges located at the top interface prior to hydrogen annealing.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권5호
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• pp.526-532
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• 2015

We quantitatively investigated instability mechanisms under simultaneous positive gate and drain bias stress (SPGDBS) in self-aligned top-gate amorphous indium-zinc-oxide thin-film transistors. After SPGDBS ($V_{GS}=13V$and $V_{DS}=13V$), the parallel shift of the transfer curve into a negative $V_{GS}$ direction and the increase of on current were observed. In order to quantitatively analyze mechanisms of the SPGDBS-induced negative shift of threshold voltage (${\Delta}V_T$), we experimentally extracted the density-of-state, and then analyzed by comparing and combining measurement data and TCAD simulation. As results, 19% and 81% of ${\Delta}V_T$ were taken to the donor-state creation and the hole trapping, respectively. This donor-state seems to be doubly ionized oxygen vacancy ($V{_O}^{2+}$). In addition, it was also confirmed that the wider channel width corresponds with more negative ${\Delta}V_T$. It means that both the donor-state creation and hole trapping can be enhanced due to the increase in self-heating as the width becomes wider. Lastly, all analyzed results were verified by reproducing transfer curves through TCAD simulation.