CARS and Fluorescent study of ignition of H2/O2 mixtures upon photodissociation of O2 molecular

The research is devoted to gas mixtures ignition by UV laser radiation. The dissociation of O2 molecules by a pulse of excimer ArF laser radiation at 193-nm wavelength with formation of the chemically active oxygen atoms initiating chain reactions which cause ignition of H2/O2 mixture was employed. The experimental test bench was created with CARS and fluorescent techniques for experimental investigation of some peculiarities of mixture ignition and combustion caused by such photo-dissociation, at conditions typical for combustion chamber. Two-dimensional numerical modeling of combustion process in model combustion chamber, based on kinetic mechanism of H2 oxidation including atom O(1P) and radicals OH(A2Σ+), was performed.

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COHERENT ANTI-STOKES RAMAN SCATTERING AND FLUORESCENT STUDY OF IGNITION AND COMBUSTION OF H2/O2 MIXTURES UPON PHOTODISSOCIATION OF O2 MOLECULES

NONEQUILIBRIUM PROCESSES. Vol. 2. Fundamentals of combustion ◽

10.30826/nepcap2018-2-04 ◽

2020 ◽

Author(s):

K. A. Vereshchagin ◽

◽

S. Yu. Volkov ◽

V. D. Kobtsev ◽

S. A. Kostritsa ◽

...

Keyword(s):

Laser Radiation ◽

Low Temperature ◽

Raman Scattering ◽

Combustion Chamber ◽

Laser Energy ◽

Diagnostic Techniques ◽

Oh Radicals ◽

Ignition And Combustion ◽

193 Nm ◽

Anti Stokes

The low-temperature ignition of H2/O2 mixture promoted by resonant laser radiation leading to the photodissociation of O2 molecules was studied experimentally. The experimental test bench involving the model combustion chamber, coherent anti-Stokes Raman scattering (CARS) and fluorescent diagnostic techniques was created for the experimental investigation of mixture ignition and combustion at conditions typical for gas turbine engines. For the production of chemically active oxygen atoms which initiate ignition in the H2/O2 mixture, the pulsed excimer ArF-laser emitting at a wavelength of 193 nm was employed. Complementary experiments on measuring the temperature and recording the emission of OH and OH* radicals indicate that it is possible to ignite the H2/O2 mixture with ф = 1-3 and P0 = 1-3 atm at a rather low temperature of ~ 700 K under the action of focused laser radiation (A = 193 nm) with the energy in the laser pulse of E = 30-150 mJ. The induction time varies in the range of 8-50 s depending on the laser energy and mixture parameters. Two-dimensional (2D) numerical simulation of ignition and combustion processes in the model combustion chamber was performed. A good agreement of calculation results with experimental data was obtained.

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UV Laser-Initiated Formation of Si3N4

MRS Proceedings ◽

10.1557/proc-17-129 ◽

1982 ◽

Vol 17 ◽

Cited By ~ 14

Author(s):

T. F. Deutsch ◽

D. J. Silversmith ◽

R. W. Mountain

Keyword(s):

Optical Properties ◽

Laser Radiation ◽

Vapor Deposition ◽

Chemical Vapor ◽

Uv Laser ◽

Pressure Chemical ◽

Excimer Laser Radiation ◽

Arf Excimer Laser ◽

193 Nm ◽

Substrate Temperatures

ABSTRACTSi3N4 films have been deposited on Si by using 193 nm ArF excimer laser radiation to initiate the reaction of SiH4 and NH3 at substrate temperatures between 200–600°C. Stoichiometric films having physical and optical properties comparable to those produced using low-pressure chemical vapor deposition (LPCVD) have been produced. The dielectric properties of the films are at present inferior to those of LPCVD material.

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UV Laser-Induced Metal Deposition on Semiconductors From Electroplating Solutions

MRS Proceedings ◽

10.1557/proc-75-173 ◽

1986 ◽

Vol 75 ◽

Cited By ~ 1

Author(s):

Joseph Zahavi ◽

Pehr E. Pehrsson

Keyword(s):

Laser Radiation ◽

Schottky Barrier ◽

Excimer Laser ◽

Pulse Energy ◽

Metal Deposition ◽

Uv Laser ◽

Sample Characterization ◽

Excimer Laser Radiation ◽

193 Nm

AbstractWe have demonstrated metal deposition on semiconductors immersed in electroplating solution by exposure to UV laser radiation. N-type β-SiC and Si in gold or Pd/Ni electroplating solutions were exposed to 20 ns pulses of 193 nm or 248 nm excimer laser radiation. The energy per pulse was 20–100 mJ. Au and Pd/Ni metallizations deposited in lines and circles on SiC showed leaky Schottky barrier I-V characteristics. The thickness increased with increasing pulse energy or number. Both masked and maskless deposition were demonstrated without apparent damage to the substrate. Details of the process, potential mechanisms, and sample characterization are discussed.

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Derivation of a global chemical kinetic mechanism for methane ignition and combustion

Journal de Chimie Physique ◽

10.1051/jcp/1994910365 ◽

1994 ◽

Vol 91 ◽

pp. 365-382 ◽

Cited By ~ 45

Author(s):

J Revel ◽

JC Boettner ◽

M Cathonnet ◽

JS Bachman

Keyword(s):

Kinetic Mechanism ◽

Chemical Kinetic ◽

Chemical Kinetic Mechanism ◽

Ignition And Combustion

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Micro-structuring of photo resists by UV laser radiation

International Congress on Applications of Lasers & Electro-Optics ◽

10.2351/1.5066218 ◽

2002 ◽

Cited By ~ 1

Author(s):

Andreas Ostendorf ◽

Klaus Körber ◽

Frank Meyer

Keyword(s):

Laser Radiation ◽

Uv Laser ◽

Micro Structuring

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Combustion Thermodynamics of Ethanol, n-Heptane, and n-Butanol in a Rapid Compression Machine with a Dual Direct Injection (DDI) Supply System

Energies ◽

10.3390/en14092729 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2729

Author(s):

Ireneusz Pielecha ◽

Sławomir Wierzbicki ◽

Maciej Sidorowicz ◽

Dariusz Pietras

Keyword(s):

Heat Release ◽

Combustion Chamber ◽

Internal Combustion Engines ◽

Direct Injection ◽

Combustion Process ◽

Combustion Efficiency ◽

Injection System ◽

Rapid Compression Machine ◽

Process Indicators ◽

Rapid Compression

The development of internal combustion engines involves various new solutions, one of which is the use of dual-fuel systems. The diversity of technological solutions being developed determines the efficiency of such systems, as well as the possibility of reducing the emission of carbon dioxide and exhaust components into the atmosphere. An innovative double direct injection system was used as a method for forming a mixture in the combustion chamber. The tests were carried out with the use of gasoline, ethanol, n-heptane, and n-butanol during combustion in a model test engine—the rapid compression machine (RCM). The analyzed combustion process indicators included the cylinder pressure, pressure increase rate, heat release rate, and heat release value. Optical tests of the combustion process made it possible to analyze the flame development in the observed area of the combustion chamber. The conducted research and analyses resulted in the observation that it is possible to control the excess air ratio in the direct vicinity of the spark plug just before ignition. Such possibilities occur as a result of the properties of the injected fuels, which include different amounts of air required for their stoichiometric combustion. The studies of the combustion process have shown that the combustible mixtures consisting of gasoline with another fuel are characterized by greater combustion efficiency than the mixtures composed of only a single fuel type, and that the influence of the type of fuel used is significant for the combustion process and its indicator values.

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Stability studies on Promethazine unexposed and exposed to UV laser radiation

10.1117/12.2189289 ◽

2015 ◽

Cited By ~ 1

Author(s):

Adriana Smarandache ◽

Agota Simon ◽

Tatiana Tozar ◽

Viorel Nastasa ◽

Mihail Lucian Pascu

Keyword(s):

Laser Radiation ◽

Uv Laser ◽

Stability Studies

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Maximization of the Signal Impulsiveness Combining Envelope Technique with Minimum Entropy Deconvolution

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.392.725 ◽

2013 ◽

Vol 392 ◽

pp. 725-729 ◽

Cited By ~ 2

Author(s):

Rafael José Gomes de Oliveira ◽

Mauro Hugo Mathias

Keyword(s):

Test Bench ◽

Minimum Entropy ◽

Combined Application ◽

Recent Developments ◽

Gear Trains ◽

The Subject ◽

Using Data ◽

High Frequency Resonance ◽

Combined Technique ◽

Experimental Test Bench

The application of the HFRT (High-Frequency Resonance Technique), a demodulation based technique, is a technique for evaluation the condition of bearings and other components in rotating machinery. Another technique MED (Minimum Entropy Deconvolution) has been the subject of recent developments for application in condition monitoring of gear trains and roller bearings. This article demonstrates the effectiveness of the combined application of the MED technique with HFRT in order to enhance the capacity of HFRT to identify the characteristic fault frequencies of damaged bearings by increasing the signal impulsivity. All tests were done using data collected from an experimental test bench in laboratory. The Kurtosis value is used as an indicator of effectiveness of the combined technique and the results shown an increase of five times the original kurtosis value with the application of MED filter together with the HFRT.

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