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Kim, Hyeon-Yeong
- Journal of the Korean Institute of Gas
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- v.17 no.4
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- pp.18-25
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- 2013
It may occur health hazards or death by suffocation or acute poisoning in case of oxygen deficiency in ambient or exposure to harmful gas. As a part of accident prevention, we studied the change of activity and lethal dose by changing the concentration of several hazardous gas with inhalation exposure chamber and laboratory animals. We investigated the lethality and motility change during either the 4 hrs whole body exposure to oxygen, nitrogen, toluene, $H_2S$, CO and 48 recovery. As results, it is estimated that 5% oxygen concentration as lethal concentration and 5.5% as $LC_{50}$ (rat, 4 hrs) with statistics for dose-response. The results of lethality in oxygen deficient condition (approximately 6%), the lethalities were 40%, 20% with 20 ppm $H_2S$, 600 ppm CO respectively, and was not increased the lethality with 8% CO. Thus, it was confirmed that the $H_2S$, CO had influence to lethal dose, while toluene had low fluence.
https://doi.org/10.7842/kigas.2013.17.4.18 인용 PDF KSCI

Park, Young-Ran;Kim, Kwang-Joo;Yang, Woo-Il;Lee, Sang-Young;Kim, Chul-Sung
- Journal of the Korean Magnetics Society
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- v.16 no.4
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- pp.206-210
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- 2006
A room-temperature ferromagnetism has been observed for oxygen-deficient rutile and anatase $TiO_{2-{\delta}}$ films. XPS data revealed the existence of $Ti^{3+}$ ions, for compensating the charge imbalance caused by oxygen vacancies in the film. The observed ferromagnetism is attributable to the spin ($3d^1$) alignment of the $Ti^{3+}$ ions. Such spin alignment can happen through magnetic polaron formed by trapped electron in oxygen vacancy and magnetic $Ti^{3+}$ ions around it.
https://doi.org/10.4283/JKMS.2006.16.4.206 인용 PDF KSCI

김일중;이희철
- Journal of the Korean Institute of Telematics and Electronics D
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- v.36D no.4
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- pp.63-69
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- 1999
The electrical properties of rf-magnetron sputtered $Ba_{0.5}Sr_{0.3}TiO_3$ (BST) capacitors were investigated by varying annealing temperature and atmosphere of the rapid thermal annealing (RTA). The electrical properties of Pt/BST/Pt capacitors were found to strongly depend on the RTA condition. It seems that the dependence of the electrical properties of the Pt/BST/Pt capacitors on the RTA condition is related to the oxygen vacancies in BST thin films. In order to clarify the relation between the oxygen vacancies and the electrical properties of Pt/BST/Pt capacitors, we have examined the two different annealing methods. One annealing method was performed in $O_2$ gas and the other was done in $O_2$-plasma at the same condition of 450$^{\circ}C$, 20 mtorr. It was found that the leakage current densities of $O_2$-plasma annealed capacitor were much lower than those of $O_2$ annealed capacitor. The dielectric constants of $O_2$ annealed capacitor decreased about 14% comparing with those of as-deposited. In contrast, there was no decrease in the dielectric constant of $O_2$-plasma annealed. These results indicate that $O_2$-plasma annealing is very effective in compensation the oxygen vacancies in BST thin films. It can be also concluded that the oxygen vacancies greatly affect the electrical properties of Pt/BST/Pt capacitors.
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