• Title/Summary/Keyword: oxygen gas

Search Result 2,290, Processing Time 0.031 seconds

Prevention of Nausea and Vomiting: Methods and Utility after Surgery in Cancer Patients?

  • Firoozabadi, Mehdi Dehghani;Rahmani, Hossein
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.7
    • /
    • pp.2629-2635
    • /
    • 2015
  • Most cancer patients experience nausea and vomiting after surgery. Today, many methods of treatment have been developed and used for the control of such symptoms. The most important are drug therapy, relaxation, oxygen therapy and gas therapy. In addition, dexamethasone, massage therapy and using a Venturi mask have also proven effective. Due to the nature of gas consumption which leads to nausea it is recommended that use of N2O in the operating room be avoided or applied in combination with oxygen or other gases with fewer complications.

Diamond Film Deposition by Microwave Plasma CVD Using a Mixture of $CH_4$, $H_2$, $O_2$, (마이크로웨이브 플라즈마 화학증착법에 의해 메탄, 수소, 산소의 혼합가스로부터 다이아몬드 박막의 합성)

  • 이길용;제정호
    • Journal of the Korean Ceramic Society
    • /
    • v.27 no.4
    • /
    • pp.513-520
    • /
    • 1990
  • Diamond film was deposited on Si wafer substrate from a gas mixture of methane, hydrogen and oxygen by microwave plasma-assisted chemical vapor deposition. The effects of the pre-treatments of the substrate and of the oxygen addition on the diamond film synthesis are described. In order to obtain diamond film, the substrate was pre-treated with 3 kinds of methods. When the substrate was ultrasonically vibrated within the ethyl alcohol dispersed with 25${\mu}{\textrm}{m}$ diamond powder, the denset diamond film was deposited. Addition of oxygen in the gas mixture of methane and hydrogen improved the crystallinity of the deposited diamond film and also increased the deposition rate of the diamond film more than two times.

  • PDF

Flame Stabilization and Control in Gas Turbine Combustor (가스터어빈 연소기의 화염 안정화와 제어)

  • Choi, G.M.
    • Journal of ILASS-Korea
    • /
    • v.8 no.4
    • /
    • pp.24-30
    • /
    • 2003
  • This paper presents the characteristics of lifted height and flame length from non-premixed jet flames in highly preheated air to investigate the detail combustion mechanism in the gas turbine or HCCI engine, etc. Special attention was paid to the effect of preheated air temperature, oxygen concentration and fuel injection flow rate on flame length and lifted hight. By using highly preheated air, stable flames were formed even in low oxygen concentration condition. The lifted height increased with decreasing preheated air temperature, where the flame length showed opposed phenomena. The flamelet model, which is thought to have very thin flamelet, is difficult to applicable to the present flame conditions which is formed In low oxygen concentration in highly preheated air.

  • PDF

Effect of Oxygen on Mechanical Properties of Metal Injection Molded Titanium and Titanium Alloy

  • Doi, Kenji;Hanami, Kazuki;Tanaka, Hideki;Teraoka, Tsuneo;Terauchi, Shuntaro
    • Proceedings of the Korean Powder Metallurgy Institute Conference
    • /
    • 2006.09b
    • /
    • pp.771-772
    • /
    • 2006
  • Mechanical properties of metal injection molded titanium and titanium alloy parts were investigated in this study. Material powders with low oxygen content and spherical shape were obtained by electrode induction-melting gas atomization which could melt and atomize titanium and titanium alloy bars with no touch on crucible or tundish. Tensile specimens were fabricated from obtained powders by metal injection molding process. Tensile strength of the specimens increases with increasing oxygen content. This result corresponds to a tendency of wrought metal.

  • PDF

Electrical characteristics of ZnO Thin Film according to deposition conditions (증착조건에 따른 ZnO 박막의 전기적 특성)

  • Lee, Dong-Yoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.05c
    • /
    • pp.131-135
    • /
    • 2003
  • Zinc Oxide(ZnO) thin films on Si (100) substrate were deposited by RF magnetron sputter with changing sputtering conditions such as argon/oxygen gas ratios, RF power, and substrate temperature, chamber pressure and target-substrate distance. To analyze a crystallographic properties of the films, $\theta/2\theta$ mode X-ray diffraction, SEM, and AFM analyses. C-axis preferred orientation, resistivity, and surface roughness highly depended on $Ar/O_2$ gas ratios. The resistivity of ZnO thin films rapidly increased with increasing oxygen ratio and the resistivity value of $9{\times}10^7{\Omega}cm$ was obtained at a working pressure of 10 mTorr with $Ar/O_2$=50/50. The surface roughness was also improved with increasing oxygen ratio and the ZnO films deposited with $Ar/O_2$=50/50 showed the excellent roughness value of $28.7{\AA}$.

  • PDF

Simultaneous Reduction of Smoke and NOx with Oxygenated Fuel(DMC) and Cooled EGR method in Diesel Engine (디젤기관에서 함산소연료(DMC)와 Cooled EGR방법에 의한 매연과 NOx의 동시저감)

  • Oh, Y.T.;Choi, S.H.
    • Journal of Power System Engineering
    • /
    • v.6 no.1
    • /
    • pp.27-35
    • /
    • 2002
  • In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for direct injection diesel engine. It is tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenate blended fuel which has four kinds of mixed ratio. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission and brake specific fuel consumption rate have been investigated. Dimethyl carbonate(DMC) contains oxygen component 53.3% in itself, and it is a kind of effective oxygenated fuel of carbonate group that the smoke emission of DMC is reduced remarkably in comparison with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in diesel engine. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel and EGR method.

  • PDF

COMBUSTION TOXICITY ANALYSIS: ADVANCES USING A SPECIALIZED SAMPLING TECHNIQUE FOR FOURIER TRANSFORM INFRARED (FTIR) ANALYSIS

  • Talandis, Jonas;Innes, J.D.;Cox, A.W.
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
    • /
    • 1997.11a
    • /
    • pp.178-184
    • /
    • 1997
  • The cone calorimeter as defined by ISO 5660, ASTM 1354, and NFPA 264A is used to assess the reaction to fire of almost any material that must be evaluated in the fire science field. Typical combustion gas analyses include oxygen, CO and CO2. Oxygen consumption is used to determine rate of heat release. Analysis of combustion gases other than oxygen, CO and CO2 has been attempted using filters to remove the solid smoke particles before analysis. This method has generated unreliable results due to the adsorption of many gas components on the active carbon . particles deposited on the filters. A technique using fourier Transform Infrared (FTIB) analysis without filtration will be disclosed and a discussion will be presented of the analytical results of toxic gases produced from various flame retarded polymeric materials. Use of such data in lethal toxic potency determinations is also reviewed.

  • PDF

Effect of post-annealing on single-walled carbon nanotubes synthesized by arc-discharge

  • Park, Suyoung;Choi, Sun-Woo;Jin, Changhyun
    • Journal of Ceramic Processing Research
    • /
    • v.20 no.4
    • /
    • pp.388-394
    • /
    • 2019
  • In this study, high-purity single-walled carbon nanotubes (SWCNTs) were prepared by removing the unreacted metal constituents and amorphous carbon impurities using a post-annealing process. Unlike conventional thermal processing techniques, this technique involved different gas atmospheres for efficient removal of impurities. A heat treatment was conducted in the presence of chlorine, oxygen, and chlorine + oxygen gases. The nanotubes demonstrated the best characteristics, when the heat treatment was conducted in the presence of a mixture of chlorine and oxygen gases. The scanning electron microscopy, transmission electron microscopy, ultraviolet absorbance, and sheet resistance measurements showed that the heat treatment process efficiently removed the unreacted metal and amorphous carbon impurities from the as-synthesized SWCNTs. The high-purity SWCNTs exhibited improved electrical conductivities. Such high-purity SWCNTs can be used in various carbon composites for improving the sensitivity of gas sensors.

Review on the water-gas shift process for a coal SNG project (석탄 SNG 생산설비의 수성가스전환 공정 분석)

  • Kim, Youngdo;Shin, Yongseung
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2011.11a
    • /
    • pp.75.1-75.1
    • /
    • 2011
  • Coal gasification is considered as one of the most prospective technologies in energy field since it can be utilized for various products such as electricity, SNG (Synthetic Natural Gas or Substitute Natural Gas) and other chemical products. Among those products from coal gasification, SNG is emerging as a very lucrative product due to the rising prices of oil and natural gas, especially in Asian countries. The process of SNG production is very similar to the conventional IGCC in that the overall process is highly dependent on the type of gasifier and coal rank. However, there are some differences between SNG production and IGCC, which is that SNG plant requires higher oxygen purity from oxygen plant and more complex gas cleanup processes including water-gas shift reaction and methanation. Water-gas shift reaction is one of the main process in SNG plant because it is a starting point for the latter gas cleanup processes. For the methanation process, syngas is required to have a composition of $H_2$/CO = 3. This study reviewed various considerations for water-gas shift process in a conceptual design on an early stage like a feasibility study for a real project. The factors that affect the design parameters of water-gas shift reaction include the coal properties, the type of gasifier, the overall thermal efficiency of the plant and so on. Water-gas shift reaction is a relatively proven technology compared to the other processes in SNG plant so that it can reduce technological variability when designing a SNG project.

  • PDF

Development of a High Efficiency Polymer Electrolyte Membrane Fuel Cell Stack under Pressurized Operating Conditions (고효율 가압형 고분자전해질 연료전지 셀스택 개발)

  • Han, In-Su;Seo, Hakyu;Jung, Jeehoon;Kim, Minsung;Shin, Hyunkhil;Hur, Taeuk;Cho, Sungbaek
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2010.06a
    • /
    • pp.125.1-125.1
    • /
    • 2010
  • A high efficiency polymer electrolyte membrane (PEM) fuel cell stack was developed for pressurized pure hydrogen and oxygen supplying conditions. The design objective for the cell stack was to maximize the electric efficiency and to minimize exhaust-gas emissions from it simultaneously. To achieve this objective, the cell stack was designed to use pure hydrogen and oxygen as fuel and oxidant, respectively, and to be operated under high gas inlet pressures and in a stage-wise dead-end operation mode. Major components constituting the cell stack, such as membrane electrode assembly, bipolar-plate, and gasket, have been developed to meet a target durability even in severe operating conditions: high gas inlet pressures and usage of pure oxygen. A high-power fuel cell stack was assembled using these components to verify the performance. The cell stack showed a good performance in terms of the efficiency and maximum power output.

  • PDF