scholarly journals CHARACTERIZATION OF Ca2 THROUGH RESONANT EXCITATION AND DISPERSED LASER-INDUCED FLUORESCENCE (LIF) SPECTROSCOPY

2020 ◽  
Author(s):  
Joel Schmitz ◽  
Michael Heaven ◽  
Sean Bresler
Keyword(s):  
Laser Induced Fluorescence ◽  
Resonant Excitation ◽  
Lif Spectroscopy

scholarly journals Анализатор спектра флуоресценции на основе оптоволоконного Y-циркулятора

2018 ◽  
Vol 44 (14) ◽  
pp. 50
Author(s):  
Э.К. Алгазинов ◽  
В.А. Шульгин ◽  
И.А. Лавриненко ◽  
А.А. Сирота
Keyword(s):  
Experimental Investigation ◽  
Fiber Optic ◽  
Laser Induced Fluorescence ◽  
Biological Media ◽  
Passive Fiber ◽  
Radiation Losses ◽  
Probe Analysis ◽  
Optical Beams ◽  
Lif Spectroscopy

AbstractWe consider a method of probe analysis employing fiber-optic a composite Y-circulator design for the implementation of laser-induced fluorescence (LIF) spectroscopy diagnostics. The proposed principle of the LIF analyzer is based on spatially separated directed optical beams of excitation and fluorescence radiations. Conditions of the effective Y-circulator operation as a passive fiber-optic switch are determined. Experimental investigation of the switched radiation losses is performed. An example of using the proposed analyzer for LIF diagnostics of biological media is presented.

Laser-Induced Fluorescence Measurements in Venturi-Cascaded Propane Gas Jet Flames

1999 ◽  
Author(s):  
Ala R. Qubbaj ◽  
S. R. Gollahalli
Keyword(s):  
Diffusion Flames ◽  
Concentration Field ◽  
Laser Induced Fluorescence ◽  
Pollutant Emissions ◽  
Average Decrease ◽  
Burner Exit ◽  
Fluorescence Measurements ◽  
Air Mixing ◽  
Flame Region ◽  
Lif Spectroscopy

Abstract “Venturi-cascading” technique is a means to control pollutant emissions of diffusion flames by modifying air infusion and fuel-air mixing rates through changing the flow dynamics in the combustion zone with a set of venturis surrounding the flame. A propane jet diffusion flame at a burner-exit Reynolds number of 5100 was examined with a set of venturis of specific sizes and spacing arrangement. The venturi-cascading technique resulted in a decrease of 33% in NO emission index along with a 24% decrease in soot emission from the flame, compared to the baseline condition (same flame without venturis). In order to understand the mechanism behind these results, Laser Induced Fluorescence (LIF) spectroscopy was employed to study the concentration field of the radicals (OH, CH and CN) in the baseline and venturi-cascaded flames. The LIF measurements, in the near-burner region of the venturi-cascaded flame, indicated an average decrease of 18%, 24% and 12% in the concentrations of OH, CH and CN radical, respectively, from their baseline values. However, in the mid-flame region, a 40% average increase in OH, from its baseline value, was observed. In this region, CH or CN radicals were not detected. The OH radical, in the downstream locations, was mostly affected by soot rather than by temperature. In addition, prompt-NO mechanism appeared to play a significant role besides the conventional thermal-NO mechanism.

Laser-Induced Fluorescence Photogrammetry for Dynamic Characterization of Membrane Structures

AIAA Journal ◽  
2004 ◽  
Vol 42 (10) ◽  
pp. 2124-2129 ◽  
Author(s):  
Adrian A. Dorrington ◽  
Thomas W. Jones ◽  
Paul M. Danehy ◽  
Richard S. Pappa
Keyword(s):  
Laser Induced Fluorescence ◽  
Dynamic Characterization ◽  
Membrane Structures

scholarly journals Laser-induced fluorescence of organic matter from a Brazilian Oxisol under sewage-sludge applications

2006 ◽  
Vol 63 (3) ◽  
pp. 269-275 ◽  
Author(s):  
Martha González Pérez ◽  
Débora Marcondes Bastos Pereira Milori ◽  
Ladislau Martin-Neto ◽  
Luiz Alberto Colnago ◽  
Otávio Antonio de Camargo ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sewage Sludge ◽  
Agricultural Soils ◽  
Size Fraction ◽  
Laser Induced Fluorescence ◽  
Natural Ecosystem ◽  
Mineral Matrix ◽  
High Fluorescence ◽  
Lif Spectroscopy ◽  
Pi System

Sludge applications have been used to maintain fertility of agricultural soils without damaging the natural ecosystem. The aim of this study was evaluating the influence of sewage-sludge addition on the quality of organic matter (OM) of a Brazilian Oxisol by Laser Induced Fluorescence (LIF). LIF was used to analyze OM of whole soil and different soil fractions separated by chemical and physical methods. The high fluorescence contribution of humin fraction to the fluorescence of whole soils was shown, stressing the importance of studying OM associated to mineral matrix of soil. Spectra with different shapes were obtained for every particle size fraction, indicating differences in organic compounds bounded to them. The fraction with the higher carbon content was the 2-20 µm, that contains ~5% C and represents only 10% in soil, but stores 34-39 % of total C and shows the highest fluorescence intensity. The spectrum of this fraction shows its heterogeneity and a higher concentration of compounds which fluorescence is centered at 510 nm. This indicates a higher concentration of unsaturated bond systems capable of high degree of resonance, increased conjugation of the electron pi system, and higher aromaticity comparing with other fractions. No differences were detected for treatments of sewage-sludge applications. LIF spectroscopy is a promising technique for OM studies in whole soils, allowing to study spatial distribution of OM within the soil's mineral matrix, including Oxisols.

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