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Showing 1 to 20 of 75 for “"Carrier gas"”.
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The effects of carrier gas viscosity on column efficiency in capillary gas chromatography
… of this study is to determine the effects of carrier gas viscosity of hydrogen and helium on column efficiency; particularly when employing thin films. When using thin films, mass transfer in the stationary phase becomes negligible and mass transfer in the mobile phase predominates. It was …
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Preparation, characterization and carrier gas transport characteristics of inorganic and organic membranes for application in lactic acid esterification with ethanol.
… resin catalysts. The product was analysed using gas chromatograph coupled with mass spectrometry detector (GC-MS). The analytical methods used for the characterisation of the cation-exchange resins and membrane include Fourier transform infrared coupled with attenuated total reflectance …
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Homogeneous nucleation of water vapor in inert gas atmospheres
… of the nucleation rate on the particular inert carrier gas was observed. At present the only dependence upon the nature of the carrier gas included in classical nucleation theories is a small factor arising from kinetic considerations which is in the wrong direction to explain the observations. …
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Effects of catalyst pretreatment for carbon nanotube growth
… furnace. During CVD, the sample was exposed to a carrier gas (Argon) for the 35-minute temperature ramp, and 15-minute anneal, then to a mix of carrier gas and ethylene for a 15-minute growth stage. Experiments were performed varying the amount of oxygen contaminant in the carrier gas, and the …
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Capture and recovery of organic gases with electrothermal swing adsorption and post-desorption treatment
… packaging manufacturing, use liquefied organic gases (boiling points (Tb) < 20°C) as inert feedstocks. These processes produce low concentration (e.g., 2,000 ppmv) organic gas streams that must be treated to prevent emissions of the organic gases to the atmosphere. The organic gases are …
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A study of HETP and efficiency for an annular preparative-scale gas-liquid chromatographic column
… was to test the effect of sample size and carrier gas flowrate on the efficiency (relative to an analytical column) of an annular preparative-scale column. The chromatographic system for this investigation consisted of η-methyl-butyrate injections with nitrogen carrier gas and a liquid …
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A study of special line intensities and excited atom populations in a hollow cathode discharge
… with cylindrical mild steel cathodes and neon carrier gas were investigated for a range of discharge currents and different neon pressures.
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Conditions for Observing Infrared Chemiluminescence and the Role of Condensation in Metal Oxidation Reactions
… reactions wherein metal atoms entrained in a carrier gas were mixed with an oxidizer by means of a nozzle system are described. One goal of the work was to determine the vibrational distribution of the product molecule produced by the chemical reaction.
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The Luminometer: A Sensitive Instrument for Measuring Low Amounts of Oxygen, and Some Applications to Problems Involving the Measurement of Photosynthesis
… the study of photosynthetic systems. An inert carrier gas flows at a controlled rate through a cuvette, then over a solution of luminol and potassium t-butoxide in dimethylsulfoxide (DMSO). The light generated by the chemiluminescent reaction of luminol with oxygen is measured with a …
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Characterization of carbon nanotubes grown by chemical vapour deposition
… Vapour Deposition (CVD) and argon was used as a carrier gas. The iron particles from ferrocene acted as catalysts for growth. The substrates used for the growth of CNTs were crystalline Si and SiO2 (Quartz) placed in a quartz tube in a horizontal furnace. Several parameters have been found to …
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Experimental and Numerical Evaluation of Electrothermal-Swing Adsorption for Capture and Recovery or Destruction of Organic Vapors
… and (b) energy balances for the adsorbent, carrier gas, vapor, and fittings. The model predicts outlet vapor concentrations, temperature profiles, power requirements, voltage requirements, and current requirements for ESA desorption cycles. The model is very helpful in the initial stages of …
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Development of a multi-stage bubble column dehumidifier for application in a hymidification dehumidification desalination system
… drinking water. One of the main hindrances with carrier gas based desalination systems over traditional thermal desalination systems like multi-flash distillation (MSF) systems is that there is a large thermal resistance in the dehumidifier between the carrier gas and the condensing coils …
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Microwave Spectroscopy of Weakly Bound Molecular Complexes
… consisting of a polar linear molecule and a rare gas atom or other molecule as the bound partner, have binding energies ranging from 0.2 to 6.0 kcal/mole. Formation of the complexes is achieved by a molecular free jet expansion of the monomeric components in an inert carrier gas. The expanding gas …
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Evaluation of the atomization-based cutting fluid spray system in milling of titanium alloy
… the presence of carbon dioxide in the droplet carrier gas is responsible for cooling the cutting zone more effectively in milling than what could be achieved in its absence. As a result, tool life increases by 50% when the droplet carrier gas is a mixture of air and carbon dioxide as compared …
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The impact of pathological ventilation on aerosol deposition : imaging, insight and intervention
… ventilation. Using helium-oxygen as a carrier gas for aerosol has been considered as a potential intervention to homogenize deposition in the lung periphery. To investigate this, we repeated the PET-CT measurements in a second group of bronchoconstricted asthmatic subjects breathing …
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Fast GC: Applications and Theoretical Studies
… of the compressibility of the mobile phase in gas chromatography and presents an equation derived from only two mutually independent variables. Solutions of decane and tridecane in hexane were analyzed at pressures ranging from 15 to 150 psi. Six different columns were used that varied in …
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Numerical extrapolations for retention time prediction in capillary gas chromatography
If the gas chromatographic retention behavior of a compound is known under isothermal conditions at several temperatures, then it is possible to predict accurately the retention time under temperature programmed conditions. This work details the calculations required to perform such predictions. A …
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Ionic Liquids in Micro Extractions and Gas Chromatographic Stationary Phases
… <p>The interest of using ionic liquids as gas chromatographic stationary phase has increased in recent years. The low volatility, tailorable physico-chemical property and high thermal stability of ionic liquids make them an ideal choice for gas chromatographic stationary phase. For the …
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Thermodynamic Measurements by Gas-Liquid Chromatography
… the large scale continuous and semi-continuous gas liquid chromatographs (G.L.C.) in operation in this department by using analytical G.L.C. equipment. A commercial dual-channel chromatograph was modified to enable the partition coefficients of various solutes in polymer stationary phases to be …
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