THE SOOT OPTICAL PROPERTIES IN PREMIXED ACETYLENE/AIR FLAME MEASURED BY LASER-INDUCED INCANDESCENCE

2020 ◽  
Author(s):  
A. V. Eremin ◽  
◽  
E. V, Gurentsov ◽  
E. Yu. Mikheyeva ◽  
R. N. Kolotushkin ◽  
...  
Keyword(s):  
Optical Properties ◽  
Heat Exchange ◽  
Carbon Black ◽  
Radiation Heat ◽  
Practical Applications ◽  
Laser Induced Incandescence ◽  
Radiation Heat Exchange ◽  
Formation Conditions ◽  
Combustion Processes

Data on the optical properties of soot are necessary to calculate the amount of sunlight absorbed by nanoparticles in the atmosphere and on the surface of the ice. Such information is used for calculating the radiation heat exchange in combustion processes, assessing the quality of carbon black, and other applications. To date, a large amount of data on the optical properties of soot has been accumulated due to its importance in practical applications. However, a wide variation of soot's optical properties is observed under different formation conditions.

N-Doped Graphene Quantum Dots Using Different Bases

2019 ◽  
Vol 18 (01) ◽  
pp. 1850017
Author(s):  
M. Jaya Prakash Naik ◽  
Sourajit Mohanta ◽  
Peetam Mandal ◽  
Mitali Saha
Keyword(s):  
Quantum Dots ◽  
Particle Size ◽  
Optical Properties ◽  
Graphene Quantum Dots ◽  
Ammonium Hydroxide ◽  
Particle Size Analyzer ◽  
Vis Spectroscopy ◽  
Doped Graphene ◽  
Formation Conditions

Photoluminescent graphene quantum dots (GQDs) have received tremendous attention due to their sui generis chemical, electronic and optical properties but fabricating the pristine quality of GQD is extremely challenging. Herein, we have reported the pyrolysis of citric acid which in the presence of different bases viz. triethylamine, ammonium hydroxide and urea, produced N-doped GQDs at different pH. The effect of different pH has been studied in detail to optimize the formation conditions of the GQD. Ultraviolet–visible (UV–Vis) spectroscopy and normalized fluorescence spectra were applied to analyze the optical properties of the GQD. The mean particle size was analyzed by a particle size analyzer (dynamic light dispersion).

scholarly journals Numerical modeling of radiation heat exchange in combustion chambers and heat exchangers of power installations

2020 ◽  
Vol 209 ◽  
pp. 03018
Author(s):  
Nikolay Moskalenko ◽  
Ibragim Dodov ◽  
Azat Akhmetshin
Keyword(s):  
Numerical Modeling ◽  
Heat Exchange ◽  
Radiation Heat Transfer ◽  
Combustion Products ◽  
Spectral Lines ◽  
Spectral Transmission ◽  
Radiation Heat ◽  
Combustion Chambers ◽  
Two Phase ◽  
Radiation Heat Exchange

The application of numerical modeling is considered to solve the problems of radiation heat exchange in structurally inhomogeneous two-phase media which are realized during the combustion of fuel in boiler units atmospheric emissions from air carriers when they move at supersonic speeds. The optically active ingredients of the gas phase of the combustion products have a sharp selection of spectral absorption lines (radiation) which causes a difference in the spectral transmission functions for selective radiation from the spectral transmission functions for non-selective radiation (gray body). In the presence of a dispersed phase of the combustion products acute selection is subjected to such a parameter of the radiation propagation medium as the probability of quantum survival. The number of spectral lines determining the spectral transmission functions increases with temperature and is determined by hundreds of thousands of lines at high temperatures. In this paper we consider a closed simulation of radiation heat transfer in combustion chambers when the temperature field in the combustion chambers is calculated first and then the flux of thermal radiation to the tube heat-receiving surfaces.

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