Decrease of breakdown voltages for micrometer-scale gap electrodes for carbon dioxide near the critical point: Temperature and pressure dependences

2003 ◽  
Vol 94 (8) ◽  
pp. 5411 ◽  
Author(s):  
Tsuyohito Ito ◽  
Hideyuki Fujiwara ◽  
Kazuo Terashima
Keyword(s):  
Carbon Dioxide ◽  
Critical Point ◽  
Point Temperature ◽  
Temperature And Pressure ◽  
Micrometer Scale

Correlation of Interfacial Tension of Hydrocarbons

1966 ◽  
Vol 6 (04) ◽  
pp. 345-349 ◽  
Author(s):  
E.W. Hough
Keyword(s):  
Carbon Dioxide ◽  
Binary System ◽  
Interfacial Tension ◽  
Critical Point ◽  
Degrees Of Freedom ◽  
Direct Function ◽  
Molal Volumes ◽  
Temperature And Pressure ◽  
Specific Free Surface Energy ◽  
Modified Formula

Abstract Correlation of interfacial tension of the methane-n-pentane and methane-n-decane systems was made by Hough and Stegemeier by the use of the Weinaug and Katz equation. The methane-n-heptane and ethylene-n-heptane systems were investigated by the authors. Additional systems taken from the literature were the methane-propane system by Weinaug and Katz, the methane-n-butane system by Pennington and Hough, and the n-butane-carbon dioxide system by Brauer and Hough. These systems were analyzed by the Weinaug-Katz equation and the Sugden equation on the IBM 1620 II computer using a regression analysis program. Parachor and exponent values for each component and system were determined. The experimental work was close to the critical point of the light component in the n-butane-carbon dioxide and ethylene-n-heptane systems, between the critical points of the light and heavy components in the methane-n-pentane, methane-n-heptane and methane-n-decane systems, and close to the critical point of the heavy component in the methane-propane and methane-n-butane systems. An empirical formula was developed to find a value of the constant B in the Sugden equation for binary hydrocarbon systems from the parachor values of the two components. interfacial tension for binary hydrocarbon Systems was found to be a direct function of liquid-vapor phase density difference in the same manner as a single-component system. Discussion Interfacial tension may be defined as the measure of the specific free surface energy between two phases having different compositions. The interfacial tension (IFT) for a binary system may be predicted for any temperature and pressure if the mole fractions and molal volumes of the liquid and gaseous phases are known. One method of correlating IFT was proposed by Weinaug and Katz and modified by Hough and Stegemeier. The modified formula is: (1) where y = interfacial tension, dynes/cmP1 = parachor of the first componentP2 = parachor of the second componentx1, x2 = mole fractions in the liquid phasey1, y2 = mole fractions in the vapor phaseVL, Vv = molal volumes (cu ft/lb mole)1/62.43 = conversion factor, lb/cu ft to gm/ccK = exponent of the parachor relation and subscriptsL = liquidV = vapor1 = component 12 = component 2. In a binary system, there are two degrees of freedom; that is, the values of x1, x2 y1, y2, VL and Vv are determined at any particular temperature and pressure. Therefore, for each temperature and pressure at which an experimental value of IFT was measured, the values of x1, y1, VL and Vv were found, and the following values were calculated: (2) (3) SPEJ P. 345ˆ

Dew points of quaternary ethane + carbon dioxide + water + methanol mixtures — Measurement and modelling

2005 ◽  
Vol 83 (3) ◽  
pp. 220-226 ◽  
Author(s):  
C Jarne ◽  
S T Blanco ◽  
S Avila ◽  
C Berro ◽  
S Otín ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Equation Of State ◽  
Temperature Data ◽  
Dew Point ◽  
Zeroth Approximation ◽  
Excess Function ◽  
Point Temperature ◽  
Dew Point Temperature ◽  
Point Equation ◽  
Temperature And Pressure

Dew points have been measured for eight ethane + carbon dioxide + water + methanol mixtures at pressures from 0.11 to 2.17 MPa and temperatures from 249.0 to 288.7 K. The results are analysed in terms of a predictive excess-function equation of state (EF-EOS) method based on the zeroth approximation of Guggenheim's reticular model. This method can be used to adequately predict the dew points of the mixtures in the temperature and pressure ranges used in the present study. In fact, the model reproduces the experimental dew point temperature data with ≤3.1 K average absolute deviation.Key words: dew point, equation of state, excess function.

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

The viscocity of carbon dioxide in the neighbourhood of the critical point

Physica ◽  
1964 ◽  
Vol 30 (1) ◽  
pp. 161-181 ◽  
Author(s):  
J. Kestin ◽  
J.H. Whitelaw ◽  
T.F. Zien
Keyword(s):  
Carbon Dioxide ◽  
Critical Point

Numerical Simulation of the Performance of an Axial Compressor Operating With Supercritical Carbon Dioxide

2018 ◽  
Author(s):  
Jinlan Gou ◽  
Wei Wang ◽  
Can Ma ◽  
Yong Li ◽  
Yuansheng Lin ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Numerical Simulation ◽  
Supercritical Carbon Dioxide ◽  
Critical Point ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Axial Compressor ◽  
Brayton Cycle ◽  
Supercritical Carbon

Using supercritical carbon dioxide (SCO2) as the working fluid of a closed Brayton cycle gas turbine is widely recognized nowadays, because of its compact layout and high efficiency for modest turbine inlet temperature. It is an attractive option for geothermal, nuclear and solar energy conversion. Compressor is one of the key components for the supercritical carbon dioxide Brayton cycle. With established or developing small power supercritical carbon dioxide test loop, centrifugal compressor with small mass flow rate is mainly investigated and manufactured in the literature; however, nuclear energy conversion contains more power, and axial compressor is preferred to provide SCO2 compression with larger mass flow rate which is less studied in the literature. The performance of the axial supercritical carbon dioxide compressor is investigated in the current work. An axial supercritical carbon dioxide compressor with mass flow rate of 1000kg/s is designed. The thermodynamic region of the carbon dioxide is slightly above the vapor-liquid critical point with inlet total temperature 310K and total pressure 9MPa. Numerical simulation is then conducted to assess this axial compressor with look-up table adopted to handle the nonlinear variation property of supercritical carbon dioxide near the critical point. The results show that the performance of the design point of the designed axial compressor matches the primary target. Small corner separation occurs near the hub, and the flow motion of the tip leakage fluid is similar with the well-studied air compressor. Violent property variation near the critical point creates troubles for convergence near the stall condition, and the stall mechanism predictions are more difficult for the axial supercritical carbon dioxide compressor.

The Propagation of Sound in Carbon Dioxide Near the Critical Point

1951 ◽  
Vol 23 (4) ◽  
pp. 423-429 ◽  
Author(s):  
N. S. Anderson ◽  
L. P. Delsasso
Keyword(s):  
Carbon Dioxide ◽  
Critical Point

scholarly journals The risk of static electricity at handling diesel fuel

2021 ◽  
Vol 343 ◽  
pp. 10013
Author(s):  
Mihaela Părăian ◽  
Emilian Ghicioi ◽  
Niculina Vătavu ◽  
Dan Gabor ◽  
Sorin Iuliu Mangu
Keyword(s):  
Electrical Conductivity ◽  
Diesel Fuel ◽  
Static Electricity ◽  
Fuel Type ◽  
Point Temperature ◽  
Flammability Characteristics ◽  
Fuel Tanks ◽  
Temperature And Pressure ◽  
A Company

Diesel fuel in motion when is transporting by pipes when is mixing, pumping, filtering, agitating or by pouring them from one vessel to another can generate static charges. Also, static electricity may occur if the liquid is splashes and forms a mist inside the tank. Accumulation of static electricity can, under certain conditions, be discharge and ignite the flammable/explosive atmosphere. Ignition hazards from static discharges can be eliminated by controlling the generation or accumulation of static charges or by eliminating a flammable mixture where static electricity may be discharged. Factors that need to be considered to reduce the risk of ignition sunt flammability characteristics of explosive atmosphere (the vapor pressure, flash point, temperature, and pressure) and the factors that determine the charging of static electricity (fuel type, electrical conductivity, sulfur content, viscosity, vehicle process: flow rate, pipe diameter, filters, pumps, spark promoters). In this paper are presented some aspects regarding the technical, organizational requirements and responsibilities of the personnel designated to prevent the formation and accumulation of static electricity when loading diesel fuel tanks, starting from a case study, respectively some explosions which occurred to a company during the loading operation.

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