scholarly journals Energy and Technological Aspects of the Combustion of Ionized Gas-Dispersed Systems

2016 ◽  
Vol 18 (3) ◽  
pp. 215 ◽  
Author(s):  
N.I. Poletaev ◽  
V.G. Shevchuk ◽  
M.E. Khlebnikova

This paper discusses the fl ame ionization effect on the combustion processes in gaseous suspensions of the dispersed fuels. It is shown that the two-phase fl ame ionization<br />affects almost all the processes of the fuel conversion – kinetics of the dispersed fuel combustion, processes of the interphase heat and mass transfer, processes of the nucleation and coagulation in the fl ame, formation of nanoscale products of the metal particles combustion. It is shown that the electrostatic interaction between the charged nanoparticles and ions or polar molecules in the gaseous phase leads to the appearance of molecular “pumps” that can signifi cantly change the kinetics of the heterogeneous chemical reactions and the heat exchange between particles and gas. The infl uence of the thermal ionization of the fl ame on the nucleation mechanism<br />and rate in gas-dispersed systems is discussed. The possibility of a barrier-free homogenous and heterogeneous nucleation in the dusty fl ame of metallic particles is shown. The effect of electrostatic and polarizing interactions of ions and molecules<br />on the kinetics of the ternary gas-phase reactions is considered. The infl uence of the monodisperse aerosol ionization degree on the kinetics of its coagulation is analyzed. It is concluded that electrostatic interaction between the particles strongly affects the inhibition of the coagulation process in gas-phase combustion products and the possibility of very fast (explosive) charged particle coagulation of monodisperse aerosols. The possibility of the targeted size of metal oxides nanoparticles control, controlled ionizing of dusty fl ames and the role of ion particle entrainment, the dependency of their size of the fl ame ionization degree are discussed. Some effects arising in complex plasma of condensed combustion products under its own electric fi elds in fl ames, also when the burning dust is entrained into a constant electric field and their practical applications for diagnosis are considered.

Author(s):  
L. J. Chen ◽  
L. S. Hung ◽  
J. W. Mayer

When an energetic ion penetrates through an interface between a thin film (of species A) and a substrate (of species B), ion induced atomic mixing may result in an intermixed region (which contains A and B) near the interface. Most ion beam mixing experiments have been directed toward metal-silicon systems, silicide phases are generally obtained, and they are the same as those formed by thermal treatment.Recent emergence of silicide compound as contact material in silicon microelectronic devices is mainly due to the superiority of the silicide-silicon interface in terms of uniformity and thermal stability. It is of great interest to understand the kinetics of the interfacial reactions to provide insights into the nature of ion beam-solid interactions as well as to explore its practical applications in device technology.About 500 Å thick molybdenum was chemical vapor deposited in hydrogen ambient on (001) n-type silicon wafer with substrate temperature maintained at 650-700°C. Samples were supplied by D. M. Brown of General Electric Research & Development Laboratory, Schenectady, NY.


Author(s):  
A. Korotkikh ◽  
◽  
I. Sorokin ◽  
◽  

The paper presents the results of thermodynamic calculations of the effect of pure boron additives on combustion characteristics of high-energy materials (HEM) based on ammonium perchlorate, ammonium nitrate, active fuel-binder, and powders of aluminum Al, titanium Ti, magnesium Mg, and boron B. The combustion parameters and the equilibrium composition of condensed combustion products (CCPs) of HEM model compositions were obtained with thermodynamic calculation program “Terra.” The compositions of solid propellants with different ratios of metals (Al/B, Ti/B, Mg/B, and Al/Mg/B) were considered. The combustion temperature Tad in a combustion chamber, the vacuum specific impulse J at the nozzle exit, and the mass fraction ma of the CCPs for HEMs were determined.


1991 ◽  
Vol 56 (10) ◽  
pp. 2020-2029
Author(s):  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma ◽  
Rudolf Hladina

The authors proposed and treated quantitatively a kinetic model for deposition of epitaxial GaAs layers prepared by reaction of trimethylgallium with arsine in hydrogen atmosphere. The transport of gallium to the surface of the substrate is considered as the controlling process. The influence of the rate of chemical reactions in the gas phase and on the substrate surface on the kinetics of the deposition process is neglected. The calculated dependence of the growth rate of the layers on the conditions of the deposition is in a good agreement with experimental data in the temperature range from 600 to 800°C.


2006 ◽  
Vol 71 (4) ◽  
pp. 567-578 ◽  
Author(s):  
Alicja Stachelska ◽  
Zbigniew J. Wieczorek ◽  
Janusz Stępiński ◽  
Marzena Jankowska-Anyszka ◽  
Harri Lönnberg ◽  
...  

Second-order rate constants for the hydroxide-ion-catalyzed imidazolium ring-opening of several mono- and dinucleosidic analogs of mRNA 5'-cap have been determined. Intramolecular stacking of the two nucleobases in the dinucleosidic analogs, m7GpppN (m7G = 7-methylguanosine, N = 5'-linked nucleoside), and electrostatic interaction between the N-alkylated imidazolium ring and phosphate moiety have been shown to shield the m7G moiety against the nucleophilic attack of hydroxide ion. In addition, the effect of methylation of the nucleobase amino groups and replacement of the 7-methyl group with other alkyl groups have been studied. The influence of all the structural modifications studied turned out to be modest, the cleavage rates of the most and least reactive analogs (with the exception of non-phosphorylated nucleosides) differing only by a factor of 5.


2021 ◽  
Vol 125 (10) ◽  
pp. 2069-2076
Author(s):  
Brendan C. Sweeny ◽  
David C. McDonald ◽  
Nicholas S. Shuman ◽  
Albert A. Viggiano ◽  
Juergen Troe ◽  
...  

2006 ◽  
Vol 19 (12) ◽  
pp. 836-840 ◽  
Author(s):  
Rafael Añez ◽  
Rodolfo Izquierdo ◽  
Alba Vidal ◽  
Tania Cordova ◽  
Aníbal Sierraalta ◽  
...  

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