Effect of gas expansion on the velocity of individual Taylor bubbles rising in vertical columns with water: Experimental studies at atmospheric pressure and under vacuum

2008 ◽  
Vol 63 (18) ◽  
pp. 4464-4474 ◽  
Author(s):  
L.M.T. Santos ◽  
M.T.M. Sena Esteves ◽  
M.N. Coelho Pinheiro
Keyword(s):  
Atmospheric Pressure ◽  
Experimental Studies ◽  
Gas Expansion ◽  
Taylor Bubbles

scholarly journals Uptake of HO<sub>2</sub> radicals onto Arizona test dust particles using an aerosol flow tube

2014 ◽  
Vol 14 (14) ◽  
pp. 7397-7408 ◽  
Author(s):  
P. S. J. Matthews ◽  
M. T. Baeza-Romero ◽  
L. K. Whalley ◽  
D. E. Heard
Keyword(s):  
Atmospheric Pressure ◽  
Room Temperature ◽  
Reaction Times ◽  
Dust Particles ◽  
Partial Saturation ◽  
Flow Tube ◽  
Aerosol Flow ◽  
Uptake Coefficients ◽  
Gas Expansion ◽  
Dust Surface

Abstract. Uptake coefficients for HO2 radicals onto Arizona test dust (ATD) aerosols were measured at room temperature and atmospheric pressure using an aerosol flow tube and the sensitive fluorescence assay by gas expansion (FAGE) technique, enabling HO2 concentrations in the range 3–10 × 108 molecule cm−3 to be investigated. The uptake coefficients were measured as 0.031 ± 0.008 and 0.018 ± 0.006 for the lower and higher HO2 concentrations, respectively, over a range of relative humidities (5–76%). A time dependence for the HO2 uptake onto the ATD aerosols was observed, with larger uptake coefficients observed at shorter reaction times. The combination of time and HO2 concentration dependencies suggest either the partial saturation of the dust surface or that a chemical component of the dust is partially consumed whilst the aerosols are exposed to HO2. A constrained box model is used to show that HO2 uptake to dust surfaces may be an important loss pathway of HO2 in the atmosphere.

Al-rich pyroxene and melilite in a blast-furnace slag and a comparison with the Allende meteorite

1977 ◽  
Vol 41 (320) ◽  
pp. 493-499 ◽  
Author(s):  
B. C. M. Butler
Keyword(s):  
Blast Furnace ◽  
Atmospheric Pressure ◽  
Blast Furnace Slag ◽  
Experimental Studies ◽  
Furnace Slag

SummaryFassaitic diopside containing 22–23 wt% Al2O3 (approximately 41–43% calcium Tschermak's molecule, CaAl2SiO6) and melilite containing 69–43% gehlenite crystallized from a blast-furnace slag at atmospheric pressure between about 1450°C and 1250°C. The occurrence is of petrological interest because the association of pyroxene with gehlenite-rich melilite has not been recorded from experimental studies in the system CaO-MgO-Al2O3-SiO2, and because of the similarity of the compositions of both minerals to pyroxene and melilite in the Ca-Al-rich inclusions of the Allende meteorite.

Experimental studies on the unsteadiness of atmospheric pressure plasma jet

2002 ◽  
Vol 35 (21) ◽  
pp. 2815-2822 ◽  
Author(s):  
Wenhua Zhao ◽  
Kuo Tian ◽  
Huangzai Tang ◽  
Di Liu ◽  
Guanzhong Zhang
Keyword(s):  
Atmospheric Pressure ◽  
Experimental Studies ◽  
Atmospheric Pressure Plasma ◽  
Plasma Jet ◽  
Atmospheric Pressure Plasma Jet ◽  
Pressure Plasma

scholarly journals On formation of subnanosecond electron beams in air under atmospheric pressure

2004 ◽  
Vol 22 (1) ◽  
pp. 75-82 ◽  
Author(s):  
V.F. TARASENKO ◽  
V.S. SKAKUN ◽  
I.D. KOSTYRYA ◽  
S.B. ALEKSEEV ◽  
V.M. ORLOVSKII
Keyword(s):  
Electron Beam ◽  
Atmospheric Pressure ◽  
Electron Beams ◽  
Experimental Studies ◽  
Maximum Amplitude ◽  
Beam Current ◽  
High Energy ◽  
Critical Importance ◽  
Critical Fields ◽  
Energy Pulse

This article reports on experimental studies of subnanosecond electron beams formed in air under atmospheric pressure. An electron beam with an amplitude of ∼170 A with a duration at FWHM of ∼0.3 ns has been obtained. Based on beam temporal characteristics and discharge spatial characteristics, the critical fields were supposed to be reached at plasma approach to anode. Simultaneously, the sharp high-energy pulse of e-beam current is generated. Of critical importance is the cathode type and occurrence on the cathode of plasma protrusions. It is shown that to get maximum amplitude of the electron beam in the gas diode, the discharge in the gas diode should be volumetric.

scholarly journals Динамика горения пропан-воздушной газовой смеси при ее поджиге стримерным сверхвысокочастотным разрядом

2019 ◽  
Vol 89 (10) ◽  
pp. 1529
Author(s):  
П.В. Булат ◽  
Л.П. Грачев ◽  
И.И. Есаков ◽  
А.А. Раваев ◽  
Л.Г. Северинов
Keyword(s):  
Atmospheric Pressure ◽  
Discharge Plasma ◽  
Microwave Discharge ◽  
Combustion Process ◽  
Experimental Studies ◽  
Gaseous Mixture ◽  
Process Dynamics ◽  
Microwave Beam ◽  
Linearly Polarized ◽  
Transparent Tube

AbstractThe results of experimental studies of combustion of propane–air gaseous mixture when it was ignited by a microwave discharge have been described. The mixture with different propane content fills a sealed radio-transparent tube placed along the axis of a focused linearly polarized quasi-optical microwave beam at atmospheric pressure. Multi-point ignition of the mixture is carried out near one end of the tube by a pulsed microwave discharge with a surface-developed streamer structure. The growth of gas pressure in the tube as propane burned was recorded in the experiments. The microwave pulse energy being invested in high-temperature discharge plasma has been estimated in them. The minimum percentage of propane in the mixture at which the microwave discharge ignites it has been determined in experiments. The time dependence of the pressure increase in the tube as the propane burns determines the combustion process dynamics.

scholarly journals Uptake of HO<sub>2</sub> radicals onto Arizona Test Dust aerosols

2014 ◽  
Vol 14 (4) ◽  
pp. 4229-4261 ◽  
Author(s):  
P. S. J. Matthews ◽  
M. T. Baeza-Romero ◽  
L. K. Whalley ◽  
D. E. Heard
Keyword(s):  
Time Dependence ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Reaction Times ◽  
Box Model ◽  
Partial Saturation ◽  
Flow Tube ◽  
Uptake Coefficients ◽  
Gas Expansion ◽  
Dust Surface

Abstract. Uptake coefficients for HO2 radicals onto Arizona Test Dust (ATD) aerosols were measured at room temperature and atmospheric pressure using an aerosol flow tube and the sensitive Fluorescence Assay by Gas Expansion (FAGE) technique, enabling HO2 concentrations in the range 3–10 × 108 molecule cm−3 to be investigated. The uptake coefficients were measured as 0.031 ± 0.008 and 0.018 ± 0.006 for the lower and higher HO2 concentrations, respectively, over a range of relative humidities (5–76%). A time dependence for the HO2 uptake onto the ATD aerosols was observed, with larger uptake coefficients observed at shorter reaction times. The combination of time and HO2 concentration dependencies suggest either the partial saturation of the dust surface or that a chemical component of the dust is partially consumed whilst the aerosols are exposed to HO2. A constrained box model is used to show that HO2 uptake to dust surfaces may be an important loss pathway of HO2 in the atmosphere.

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