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Light Sources
Published in Toru Yoshizawa, Handbook of Optical Metrology, 2015
Chemiluminescence is the emission of light as a result of excitation via a chemical reaction. Under certain circumstances, the energy released during a chemical reaction might be sufficient to excite the reaction product, which fluoresces as it decays to a lower energy level. For example, one typical chemiluminescence reaction is the luminol reaction: Luminol+H2O2→3-APA*→3-APA+light
Spectroscopic analysis
Published in John P. Dakin, Robert G. W. Brown, Handbook of Optoelectronics, 2017
Günter Gauglitz, John P. Dakin
In order to detect chemiluminescence and measure this weak luminol green light, it is best to use a photomultiplier, with some form of light-reflecting cavity (light-integrating chamber) to ensure most of the light hits the sensitive photocathode. Because photomultipliers have good green-light sensitivity and can even detect single photon events in the darkened state, very low concentrations of oxidizing agents can be measured, including hazardous oxidizing gases such as ozone, chlorine, and nitrogen dioxide. Numerous biochemicals can also cause a light-emitting reaction and hence be detected. Chemiluminescence is the basis of a number of commercial chemical sensors for important biochemicals.
Ambient Air Sampling
Published in Howard E. Hesketh, Air And Waste Management, 2019
The reference method for the measurement of ambient ozone is the C2H4-chemiluminescence method. (See Federal Register, Vol. 41, No. 826, Appendix F, 12-1-76: “Measurement Principle and Calibration Procedure for the Measurement of Nitrogen Dioxide in the Atmosphere.”) Chemiluminescence is a term describing chemical reactions which emit light energy. A sample stream of ambient air and user-supplied ethylene are delivered simultaneously to a reaction chamber where the O3 in the air reacts with the ethylene. The light energy emitted from this reaction is then measured by a photomultiplier tube which converts the light energy to an electrical signal.
Probing the equivalence ratio in partially premixed flames by combining optical techniques and modeling results
Published in Combustion Science and Technology, 2018
Laura Merotto, Mariano Sirignano, Mario Commodo, Andrea D’Anna, Francesca Migliorini, Roberto Dondè, Silvana De Iuliis
Concerning nonintrusive techniques, progresses have been made on the use of optical techniques to study combustion evolution (De Iuliis et al., 2006, 2007). In particular, chemiluminescence spectroscopy has been proved as reliable approach to track the principal radical species involved in the combustion kinetics. Chemiluminescence has been found to be particularly attractive for its capability to be applied in many combustion systems and its relative simplicity compared to laser-based diagnostics (Hardalupas and Orain, 2004; Ikeda et al., 2002; Kojima et al., 2000; Merotto et al., 2015; Migliorini et al., 2014; Panoutsos et al., 2009; Roby et al., 1998; Tinaut et al., 2010). Chemiluminescence is linked to the presence of radical species, such as OH*, CH*, and C2*, which are chemically formed in an excited state and returned to a lower energy state by radiative emission. This process, known as radical chemiluminescence emission, is characterized by emission bands in a specific spectral range. Since reactions that form these radicals occur on the flame front, the chemiluminescence emission is indicative of the reacting conditions. Previous investigations have shown that the ratio of the emission from excited radical species, such as CH*/OH*, can be a useful tool to track the heat release during combustion, i.e., the flame front evolution (Lauer and Sattelmayer, 2008; Panoutsos et al., 2009).
Carbon dots-enhanced luminol chemiluminescence and its application to 2-methoxyestradiol determination
Published in Green Chemistry Letters and Reviews, 2018
Min Zhang, Yulei Jia, Jianhua Cao, Guanghui Li, Huacheng Ren, Hui Li, Hanchun Yao
In recent years, more and more attentions have been paid to the nanomaterials-based chemiluminescence (CL) systems to improve sensitivity and stability (1). As semiconductor nanomaterials, quantum dots (QDs) have been widely investigated for their unique optical properties and their potential applications in CL. Currently, the study of quantum dots applied in CL mainly should be focused on metal quantum dots such as CdS QDs (2), CdTe QDs (3, 4) and CdSe/CdS QDs (5), but these quantum dots containing heavy metals and other toxic elements are harmful to the environment and have strong cytotoxicity which limited its application.
Effects of nitrogen film cooling on ignition transition of gaseous oxygen/kerosene spray combustor
Published in Combustion Science and Technology, 2023
Wooseok Song, Dongsoo Shin, Min Son, Jaye Koo
Chemiluminescence refers to the phenomenon of spontaneous photon emission, i.e., light, including ultraviolet and infrared rays. Data pertaining to chemiluminescence are significant from the viewpoint of flame visualization. The representative species related to the combustion process are OH, CH, and C2. In this study, only CH* chemiluminescence images were recorded using the high-speed camera with a 430-nm band-pass filter. The camera was setup with an acquisition rate of 1,000 fps, a shutter speed of 1/1,000 s, and a resolution of 1024 × 1024 pixels.