scholarly journals The influence of natural convection on the temporal development of the temperature and concentration fields for Sal’nikov's reaction, P→A→B, occurring batchwise in the gas phase in a closed vessel

2005 ◽  
Vol 60 (21) ◽  
pp. 5705-5717 ◽  
Author(s):  
A.N. Campbell ◽  
S.S.S. Cardoso ◽  
A.N. Hayhurst
Keyword(s):  
Natural Convection ◽  
Gas Phase ◽  
Temporal Development ◽  
Closed Vessel

The effect of natural convection on the gas-phase Sal'nikov reaction in a closed vessel

2004 ◽  
Vol 6 (8) ◽  
pp. 1687 ◽  
Author(s):  
S. S. S Cardoso ◽  
P. C. Kan ◽  
K. K. Savjani ◽  
A. N. Hayhurst ◽  
J. F. Griffiths
Keyword(s):  
Natural Convection ◽  
Gas Phase ◽  
Closed Vessel

scholarly journals On approach for homogeneity increasing of films grown from the gas phase with account natural convection and changes in the rate of chemical interaction between materials

2019 ◽  
Vol 8 (3) ◽  
pp. 195
Author(s):  
Evgeny L. Pankratov
Keyword(s):  
Natural Convection ◽  
Gas Phase ◽  
Analytical Approach ◽  
Chemical Interaction

<span>We analyzed growth of films by gas phase epitaxy. Based on the analysis we formulate conditions to increase of homogeneity of properties of obtained films. We also present an analytical approach for analysis processes framework gas phase epitaxy with account natural convection and the possibility of changing the rate of chemical interaction between reagents.</span>

The Effect of Convective Heat Transfer Instabilities on the Diameter of Polymer Optical Fiber

2002 ◽  
Author(s):  
Hayden M. Reeve ◽  
Ann M. Mescher ◽  
Ashley F. Emery
Keyword(s):  
Natural Convection ◽  
Gas Phase ◽  
Fiber Diameter ◽  
Time Dependent ◽  
Polymer Optical Fiber ◽  
Chaotic Flow ◽  
Temperature Oscillations ◽  
Phase Temperature ◽  
Cylindrical Furnace ◽  
Regime Transitions

The effect of various natural convection regimes on the diameter of drawn polymer fiber was studied experimentally. Results indicate that as the buoyant potential of air within a cylindrical furnace enclosure is increased the natural convection regime transitions from laminar to oscillatory, and finally, to chaotic flow. The time-dependent heating caused by the oscillatory and chaotic regimes alters the rheology of the elongating polymer preform, causing detrimental time-dependent variations in the fiber diameter. The gas-phase temperature oscillations recorded on opposite sides of the necking perform were not identically in-phase indicating the convective flow is asymmetric in nature. The period of the recorded oscillations was found to be a function of the driving temperature difference, consistent with prior investigations. Furthermore, near the transition to chaotic flow sub-harmonics were observed within the recorded oscillations. When subjected to oscillatory and chaotic natural convection the standard deviation of the fiber diameter variations was up to 2.5 to 10 times greater, respectively, than that measured under laminar heating conditions. This represents a significant instability mechanism, one that has not been investigated within the context of the fiber drawing process to date.

scholarly journals Effects of natural convection on thermal explosion in a closed vessel

2008 ◽  
Vol 10 (36) ◽  
pp. 5521 ◽  
Author(s):  
Ting-Yueh Liu ◽  
Alasdair N. Campbell ◽  
Silvana S. S. Cardoso ◽  
Allan N. Hayhurst
Keyword(s):  
Natural Convection ◽  
Thermal Explosion ◽  
Closed Vessel

scholarly journals Rapid Alloy Surface Engineering through Closed-Vessel Reagent Pyrolysis

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1764
Author(s):  
Cyprian Illing ◽  
Zhe Ren ◽  
Anna Agaponova ◽  
Arthur Heuer ◽  
Frank Ernst
Keyword(s):  
Gas Phase ◽  
Surface Engineering ◽  
Surface Film ◽  
Alloy Surface ◽  
Second Phase ◽  
Closed Vessel ◽  
Laboratory Equipment ◽  
Carbon And Nitrogen ◽  
Subsurface Zone ◽  
Gas Atmosphere

For rapid surface engineering of Cr-containing alloys by low-temperature nitrocarburization, we introduce a process based on pyrolysis of solid reagents, e.g., urea, performed in an evacuated closed vessel. Upon heating to temperatures high enough for rapid diffusion of interstitial solute, but low enough to avoid second-phase precipitation, the reagent is pyrolyzed to a gas atmosphere containing molecules that (i) activate the alloy surface by stripping away the passivating Cr2O3-rich surface film (diffusion barrier) and (ii) rapidly infuse carbon and nitrogen into the alloy. We demonstrate quantitatively that this method can generate a subsurface zone with concentrated carbon and nitrogen comparable to what can be accomplished by established (e.g., gas-phase- or plasma-based) methods, but with significantly reduced processing time. As another important difference to established gas-phase processing, the interaction of gas molecules with the alloy surface can have auto-catalytic effects by altering the gas composition in a way that accelerates solute infusion by providing a high activity of HNCO. The new method lends itself to rapid experimentation with a minimum of laboratory equipment.

Effect of natural convection of the reacting gas on exothermal reactions in a closed vessel

1981 ◽  
Vol 16 (5) ◽  
pp. 639-645
Author(s):  
G. M. Makhviladze ◽  
I. P. Nikolova
Keyword(s):  
Natural Convection ◽  
Closed Vessel
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