• Title/Summary/Keyword: low oxygen pressure

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Change of Oxygen Uptake, Heart Rate, Blood Pressure with Body Fat Rate in AM and PM (체지방에 따른 오전과 오후의 산소섭취량, 심박수, 혈압의 변화)

  • Lee, Jung-Sug;Kim, Seong-Suk;Kim, Hee-Eun
    • Fashion & Textile Research Journal
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    • v.7 no.3
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    • pp.321-326
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    • 2005
  • The purpose of this study was to investigate the effect of body fat on energy metabolic response and subjective sensations under the hot environment. Fifteen female university students volunteered as subjects. We organized subjects into three groups: low body fat group(group L : less than 20% of body fat), medium body fat group(group M : 20%~30% of body fat) and high body fat group(group H: more than 30% of body fat). The experiment was conducted with $32^{\circ}C$, 60%RH. The subjects repeated 'Exercise' and 'Rest' period. The results of this study are as follows ; The oxygen uptake value of AM is higher than PM. The value of group H is the highest in three fat groups. But it showed group L is the highest in oxygen uptake per weight. %body fat is the lower, oxygen uptake is the higher. In Calorie, group L has higher value in AM in than in PM. In M group and group H, a value of PM is higher than AM. In group H, difference of AM and PM is the highest. From a view point of three groups, a value of group H is the highest. This support that calorie increases as oxygen uptake increase. The heart rate values of group L and group H are the higher in AM than in PM. This support that heart rate was relation to oxygen uptake. In all three groups, the value of blood pressure is higher in AM than in PM. Subjective sensations of temperature sensation, thermal comfort, and wetness sensation are higher in Am than in Pm. This explains that subject sensations are similar to experimental data, such as oxygen uptake, heart rate, blood pressure. In oxygen uptake, heart rate and blood pressure, general tend to showed higher AM than PM. This showed that heart rate, oxygen uptake increase in AM, as blood pressure increase, too. From a view point of %body fat, group H is higher than the others in oxygen uptake, heart rate and blood pressure.

Fabrication of High-resistive ZnO Films Using Zinc acetate as Precursor and Their Humidity-sensing Properties (Zinc acetate를 precursor로 한 고저항 ZnO막의 제조 및 습도감지 특성)

  • Ma, T.Y.;Kim, S.H.;Kim, Y.I.
    • Journal of Sensor Science and Technology
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    • v.5 no.1
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    • pp.37-42
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    • 1996
  • ZnO films have been deposited on oxide grown Si wafers by the conventional thermal evaporation method. Anhydrous zinc acetate was directly heated and sublimed in the laboratory-made brass boat. The substrates temperature varied from $200^{\circ}C$ to $600^{\circ}C$. Oxygen has been flowed into the deposition chamber to change the partial pressure of oxygen. The films deposited at high oxygen pressure exhibited higher resistivity than films at low pressure. X-Ray Diffraction(XRD), Energy Dispersive Spectroscopy(EDS) and Rutherford Backscattering Spectrometry (RBS) were conducted on the films to reveal the crystallinity and composition of the ZnO films. The ZnO films deposited at high oxygen pressure were extremly sensitive to the humidity of higher than 70 % RH.

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Preparation of ATO Thin Films by DC Magnetron Sputtering (I) Deposition Characteristics (DC Magnetron Sputtering에 의한 ATO 박막의 제조 (I)증착특성)

  • Yoon, C.;Lee, H.Y.;Chung, Y.J.
    • Journal of the Korean Ceramic Society
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    • v.33 no.4
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    • pp.441-447
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    • 1996
  • Sb doped SnO2(ATO:Antinomy doped Tin Oxide) thin films were prepared by a DC magnetron spttuering method using oxide target and the deposition characteristics were investigated. The experimental conditions are as follows :Ar flow rate : 100 sccm oxygen flow rates ; 0-100 sccm deposition temperature ; 250 -40$0^{\circ}C$ DC sputter powder ; 150~550 W and sputtering pressure ; ; 2~7 mTorr. Deposition rate greatly depends not on the deposition temperature but on the reaction pressure oxygen flow rate and sputter power,. when the sputter powder is low ATO thin films with (110) preferred orientation are deposited. And when the sputter power is high (110) prefered orientation appeares with decreasing of oxygen flow rate and increasing of suputte-ring pressure.

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Helium/Oxygen Atmospheric Pressure Plasma Treatment on Poly(ethylene terephthalate) and Poly(trimethylene terephthalate) Knitted Fabrics: Comparison of Low-stress Mechanical/Surface Chemical Properties

  • Hwang Yoon Joong;McCord Marian G.;Kang Bok Choon
    • Fibers and Polymers
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    • v.6 no.2
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    • pp.113-120
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    • 2005
  • Helium-oxygen plasma treatments were conducted to modify poly(trimethylene terephthalate) (PIT) and poly(ethylene terephthalate) (PET) warp knitted fabrics under atmospheric pressure. Lubricant and contamination removals by plasma etching effect were examined by weight loss $(\%)$ measurements and scanning electron microscopy (SEM) analysis. Surface oxidation by plasma treatments was revealed by x-ray photoelectron spectroscopy (XPS) analyses, resulting in formation of hydrophilic groups and moisture regain $(\%)$ enhancement. Low-stress mechanical properties (evaluated by Kawabata evaluation system) and bulk properties (air permeability and bust strength) were enhanced by plasma treatment. Increasing interfiber and interyarn frictions might play important roles in enhancing surface property changes by plasma etching effect, and then changing low-stress mechanical properties and bulk properties for both fabrics.

Effect of O2 Partial Pressure on AlOx Thin Films Prepared by Reactive Ion Beam Sputtering Deposition

  • Seong, Jin-Wook;Yoon, Ki-Hyun;Kim, Ki-Hwan;Beag, Young-Whoan;Koh, Seok-Keun
    • Journal of the Korean Ceramic Society
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    • v.41 no.5
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    • pp.364-369
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    • 2004
  • The barrier and optical properties of AlO$_{x}$ thin films on polycarbonate deposited by Reactive Ion Beam Sputtering (RIBS) were investigated at different oxygen partial pressure. We measured the deposition rate of AlO$_{x}$ thin films. As the oxygen partial pres-sure increased, the deposition rate increased then decreased. The changes of deposition rate are associated with the properties of deposited films. The properties of deposited AlO$_{x}$ thin films were studied using X-ray Photoelectron Spectroscopy (XPS), Scan-ning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). Optimum deposition parameters were found for fabricat-ing aluminum oxide thin films with high optical transparency for visible light and low Oxygen Transmission Rate (OTR). The optical transmittance of AlO$_{x}$ thin film deposited on polycarbonate (PC) showed the same value of bare PC.bare PC.

Oxygen Permeability Measurement of $ZrO_2-TiO_2-YB_2O_3$ Mixed Conductor

  • Hitoshi Naito;Kim, Hitoshi ishima;Toru Takahashi;Hiroo Yugami
    • The Korean Journal of Ceramics
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    • v.6 no.2
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    • pp.124-128
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    • 2000
  • Electrical properties of $ZrO_2-TiO_2Yb_2O_3$mixed conductor (Ti-YbSZ) were investigated. This mixed conductor can be applied as a membrane for gas separation at high temperatures. The total conductivity decreased with increasing the $TiO_2$concentration. At high temperatures, the rate of the conductivity degradation became smaller than that at low temperatures. From the oxygen partial pressure dependence of the total conductivity of Ti-YbSZ, the electronic conductivity increased with increasing $TiO_2$concentration at low oxygen partial pressures and at high temperatures. Both 15 and 20 mol% $TiO_2$doped YbSZ showed high oxygen permeability. Mixed conductors, which has high $TiO_2$concentration in YbSZ, are promising materials for using as a membrane for gas separation at high temperatures.

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Processing of Tin Oxide Nanoparticles by Inert Gas Condensation Method and Characterization

  • Simchi, Abdolreza;Kohi, Payam
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.122-123
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    • 2006
  • Tin oxide nanoparticles (n-SnO and $n-SnO_2$) were synthesized by the inert gas condensation (IGC) method under dynamic gas flow of oxygen and argon at various conditions. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) method were used to analysis the size, shape and crystal structure of the produced powders. The synthesized particles were mostly amorphous and their size increased with increasing the partial pressure of oxygen in the processing chamber. The particles also became broader in size when higher oxygen pressures were applied. Low temperature annealing at $320^{\circ}C$ in air resulted to crystallization of the amorphous n-SnO particles to $SnO_2$.

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Reduction of the Flow Accelerated Corrosion within Low Pressure Evaporator Connection Pipe by Interception of Hydrazine for Water Treatment (탈산소제 차단 수처리에 의한 배열회수보일러 저압증기발생기 연결배관내의 유동가속부식 저감)

  • Son, Byung-Gwan;Lee, Jae-Heon
    • Plant Journal
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    • v.9 no.4
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    • pp.26-30
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    • 2013
  • Based on case that HRSG low pressure steam generator tube was damaged by FAC in 500 MW A CCPP. This case analyzed the effect of application about the block of hydrazine water treatment which is applied for increasing dissolved oxygen. And also try to deduce the major factor of FAC Which is caused by lacking of dissolved oxygen of boiler feed system. After 1 year of water treatment, the figure of dissolved oxygen in the boiler feed water has increased from 0.15 ppb to 3~5 ppb and the figure of oxidation reduction potential has increased from -245 mV to 170 mV. And Iron content, the corrosion products by FAC has decreased from 18.5 ppb to 5~7 ppb. According to the result of experiment, we could able to confirm that the interception of hydrazine of water treatment is effective to reduce FAC.

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Low Temperature Growth of Silicon Oxide Thin Film by In-direct Contacting Process with Photocatalytic TiO2 Layer on Fused Silica (광촉매 TiO2 층의 비접촉식 공정을 통한 저온 실리콘 산화박막 성장)

  • Ko, Cheon Kwang;Lee, Won Gyu
    • Applied Chemistry for Engineering
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    • v.19 no.2
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    • pp.236-241
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    • 2008
  • The possibility of silicon oxidation through the aerial-diffusion of active oxygen species has been evaluated. The species originate from the surface of $TiO_2$ exposed by UV. Among process parameters such as UV intensity, substrate temperature and chamber pressure with oxygen, UV intensity was a major parameter to the influence on the oxide growth rate. When 1 kW high pressure Hg lamp was used as a UV source, the growth rate of silicon oxide was 8 times as faster as that of a 60 W BLB lamp. However, as the chamber pressure increased, the growth rate was declined due to the suppression of aerial diffusion of active oxygen species. According to the results, it could be confirmed that the aerial-diffusion of active oxygen species from UV-irradiated photocatalytic surface can be applied to a new method for preparing an ultra-thin silicon oxide at the range of relatively low temperature.

Electrical Conduction in $SrZr_{0.95}Y_{0.05}O_{2.975}$ Ceramics

  • Baek, Hyun-Deok;Noh, Jin-Hyo
    • The Korean Journal of Ceramics
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    • v.5 no.3
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    • pp.288-295
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    • 1999
  • Partial conductivities contributed by electron holes, oxygen ions, and protons were caluclated in $SrZr_{0.95}Y_{0.05}O_{2.975}$, using the reported formulae derived from the defect chemistry of HTPCs. Required parameters were obtained from the graphical analysis of total conductivity variation against partial pressure of water vapor and oxygen. Predicted overall conductivities showed a reasonable agreement with experimental measurements. The conductivity of the material showed a linear increase with square root of the water vapor pressure. This increase was due to proton conduction in an almost pure ionic conductivity. The calculation of partial conductivities at $800^{\circ}C$ resulted in an almost pure ionic conductivity at $P_{02}=10^{-10}$ atm and a predominant hole conductivity at $P_{02}=10^{-10}$ atm. Pure proton conduction was not expected at this temperature, contrary to the earlier reports. Discussions were made in relation with reported thermodynamic data and defect structure of the material. It was shown that from the total conductivity dependence on water vapor pressure, the pure ionic conductivity at low oxygen partial pressures could be separated into protonic and oxygen ionic conductivity in $ZrO_2$-based HTPCs.

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