• Title/Summary/Keyword: Plasma Spary

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Effect of Heat Treatment of Fatigue Crack Growth of Plasma-Sprayed Coating Steels (플라즈마 용사코팅강재의 피로균열성장에 미치는 감화열처리의 영향)

  • Kim, G.S.;Hyun, C.H.;Kim, Y.S.
    • Journal of Power System Engineering
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    • v.7 no.4
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    • pp.55-60
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    • 2003
  • This paper is to investigate the fatigue crack growth of plasma-sprayed coating steels according to heat treatments. The experimental materials are carbon steels(substrate: S45C) with plasma-sprayed coating layers of Ni-4.5%Al and $TiO_2$. The fatigue test is conducted on compact tension specimen by a servo-hydraulic fatigue testing machine. The specimens are heat-treated at $400^{\circ}C\;and\;800^{\circ}C$, respectively. Loading condition is a constant amplitude sinusoidal wave with a frequency of 10Hz and a load ratio of 0.1. The fatigue crack growth length is automatically measured by a compliance method. In the case of non-heat treated specimens, the fatigue crack growth rates of both substrate and coating specimen are almost same. The crack growth rates of substrates and coating steels by heat treatment are larger than those of the non-heat treated one, because the ductile property increase by heat treatment. In ${\Delta}K<18MPa{\cdot}m^{1/2}$, the crack growth rates of the heat-treated specimens are slightly taster than non-heat treated one. But the both heated and non-heated one are almost same in ${\Delta}K>18MPa{\cdot}m^{1/2}$.

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A COMPARATIVE STUDY ON THE VITAL SIGN AND BEHAVIOR APPEARANCE DEPENDING ON THE ROUTE OF FLUMAZENIL ADMINISTRATION IN CONSCIOUS SEDATION BY MIDAZOLAM (Midazolam을 이용한 의식진정시 flumazenil의 투여경로에 따른 생징후 및 행동양상의 비교 연구)

  • Kim, Hyun-Sik;Lee, Chang-Seop;Lee, Sang-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.29 no.2
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    • pp.159-167
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    • 2002
  • The purpose of this study was to evaluate the efficacy and safety depending on the route of flumazenil, as an antagonist against midazolam. The subjects of this study were 15 volunteers of $22{\sim}24$ years old. They were sedated with midazolam 0.2mg/Kg intranasal spray, and then 40 minutes after midazolam administration, they were given flumazenil 0.2mg intranasal spray for their reversal. For evaluation of the efficacy and safety of intranasal spray for flumazenil, they were monitored with pulse-oxymeter(Nellcor symphony N-3000, Nellcor Puritan CO. USA) and electric sphygmomanometer (Heartcare 200, National CO. Japan), and were assessed themselves using visual analogue scale(VAS) for tranquilization, sleep, fatigue and attitude. All of these subjects were reduced completely without any undesired situations. The results from this study can be summarized as follows ; 1. Nasaly administered flumazenil using spray device produced much more rapid reduction than intravenously administered flumazenil, but soon after fell in more deep sedated state than intravenously administered flumazenil. 2. There were no considerable side effects or bad influence on vital signs of both nasaly administered flumazenil and intravenously administered flumazenil. These results suggested that the flumazenil administered nasaly using spray device for reversal, we could treat patients safely and effectively under conscious sedation using midazolam administration. But, We will have to research about its optimal dosages for flumazenil, used as intranasal spray for reversal agents against the midazolam by evaluating the blood plasma concentration of midazolam and flumazenil.

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