Infrared emission spectra from a heterogeneous catalyst system in reaction conditions 2: Infrared spectroscopic aspects

Infrared emission spectra from metal samples with oxide surface layers are shown to be very advantageously studied using the spectrum-ratioing facility of a recording infrared interferometer. The emission from a given sample is ratioed against that from a black-body emitter at the same temperature so as to give emittance as a function of wavenumber directly. This method has very useful application to irregularly shaped metal emitters. In the absence of selective reflection there is a direct correspondence between emission and absorption spectra for thin layers of an emitting substance. However, the presence of selective reflection leads to reduced emission and to considerable differences in the appearance of “absorption” and emission spectra in regions of strong absorption. Emission spectra obtained from copper plates heated, above 150°C, for different periods in air are shown clearly to indicate the presence of cuprous, Cu(I), and cupric, Cu(II), oxides in the surface layer.

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Infrared emission spectra of BeH2 and BeD2

The Journal of Chemical Physics ◽

10.1063/1.1539850 ◽

2003 ◽

Vol 118 (8) ◽

pp. 3622-3627 ◽

Cited By ~ 44

Author(s):

A. Shayesteh ◽

K. Tereszchuk ◽

P. F. Bernath ◽

R. Colin

Keyword(s):

Emission Spectra ◽

Infrared Emission

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Temperature Gradients Through EHD Films and Molecular Alignment Evidenced By Infrared Spectroscopy

Journal of Lubrication Technology ◽

10.1115/1.3251615 ◽

1981 ◽

Vol 103 (1) ◽

pp. 65-73 ◽

Cited By ~ 16

Author(s):

V. W. King ◽

J. L. Lauer

Keyword(s):

Absorption Spectrum ◽

Emission Spectra ◽

Infrared Emission ◽

Molecular Alignment ◽

Temperature Gradients ◽

Spectral Change ◽

Continuum Source ◽

Polyphenyl Ether ◽

Elementary Analysis ◽

Gap Width

Partial and complete emission band reversals have been observed in the infrared emission spectra from portions of operating sliding contacts. An elementary analysis has been carried out to show that partial reversals are due to temperature gradients in the fluid film—the film acts both as a radiation-emitter and absorber, and that total reversals—an emission spectrum appears as an absorption spectrum—are likely to be due to a continuum source, such as hot solid asperities. The total energy radiated under the latter conditions exceeds that under the others. A decrease in gap width with increased load was accompanied by a dramatic spectral change in the case of 5P4E polyphenyl ether, which is indicative of molecular alignment.

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Near-surface thermal gradients and their effects on mid-infrared emission spectra of planetary surfaces

Journal of Geophysical Research Atmospheres ◽

10.1029/94je01861 ◽

1994 ◽

Vol 99 (E9) ◽

pp. 19063 ◽

Cited By ~ 45

Author(s):

Bradley G. Henderson ◽

Bruce M. Jakosky

Keyword(s):

Emission Spectra ◽

Infrared Emission ◽

Thermal Gradients ◽

Planetary Surfaces ◽

Near Surface ◽

Mid Infrared

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Modeling the Anharmonic Infrared Emission Spectra of PAHs: Application to the Pyrene Cation

PAHs and the Universe ◽

10.1051/978-2-7598-2482-3.c011 ◽

2020 ◽

pp. 95-102

Author(s):

M. Basire ◽

P. Parneix ◽

T. Pino ◽

Ph. Bréchignac ◽

F. Calvo

Keyword(s):

Emission Spectra ◽

Infrared Emission

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Gas Turbine Exhaust Emissions Monitoring Using Nonintrusive Infrared Spectroscopy

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2818175 ◽

1998 ◽

Vol 120 (3) ◽

pp. 514-518 ◽

Cited By ~ 5

Author(s):

M. Hilton ◽

A. H. Lettington ◽

C. W. Wilson

Keyword(s):

Gas Turbine ◽

Molecular Species ◽

Tomographic Reconstruction ◽

Emission Spectra ◽

Exhaust Emissions ◽

Infrared Emission ◽

High Spectral Resolution ◽

Rotational Line ◽

Spectroscopic Techniques ◽

Reconstruction Procedure

Infrared (IR) spectra of the exhaust emissions from a static gas turbine engine have been studied using Fourier Transform (FT) spectroscopic techniques. Passive detection of the infrared emission from remote (range ∼ 3 m) hot exhaust gases was obtained nonintrusively using a high spectral resolution (0.25 cm−1) FTIR spectrometer. Remote gas temperatures were determined from their emission spectra using the total radiant flux method or by analysis of rotational line structure. The HITRAN database of atmospheric species was used to model the emission from gas mixtures at the relevant temperatures. The spatial distribution of molecular species across a section transverse to the exhaust plume ∼10 cm downstream of the jet pipe nozzle was studied using a tomographic reconstruction procedure. Spectra of the infrared emission from the plume were taken along a number of transverse lines of sight from the centerline of the engine outwards. A mathematical matrix inversion technique was applied to reconstruct the molecular concentrations of CO and CO2 in concentric regions about the centerline. Quantitative measurement of the molecular species concentrations determined nonintrusively were compared with results from conventional extractive sampling techniques.

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Efficient synthesis of pyrido[2,3-d]pyrimidine-7-carboxylic acids catalyzed by a TiO2/SiO2 nanocomposite in aqueous media at room temperature

Zeitschrift für Naturforschung B ◽

10.1515/znb-2018-0076 ◽

2018 ◽

Vol 73 (9) ◽

pp. 641-645 ◽

Cited By ~ 1

Author(s):

Sepehr Sadegh-Samiei ◽

Shahrzad Abdolmohammadi

Keyword(s):

Heterogeneous Catalyst ◽

Carboxylic Acids ◽

Room Temperature ◽

Aqueous Media ◽

Reaction Times ◽

Molar Ratio ◽

Efficient Synthesis ◽

Reaction Conditions ◽

Moderate Reaction ◽

Recyclable Heterogeneous Catalyst

AbstractA novel and efficient synthesis of eight 5-aryl-1,3-dimethyl-2,4-dioxo-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids using a TiO2/SiO2 nanocomposite with a molar ratio of 1:1 as a recyclable heterogeneous catalyst is described. The desired products, five of which are new, are formed in short reaction times (2–3 h) with high to excellent yields (94%–98%) under very moderate reaction conditions (room temperature, aqueous media).

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A New Sensitive Fluorirnetric Method for the Determination of Heptaminol and Mexiletine in Pharmaceuticals

Scientia Pharmaceutica ◽

10.3797/scipharm.aut-02-07 ◽

2002 ◽

Vol 70 (1) ◽

pp. 57-65 ◽

Cited By ~ 1

Author(s):

EI-Adl Sobhy M.

Keyword(s):

Sodium Salt ◽

Emission Spectra ◽

Reaction Conditions ◽

Pharmaceutical Excipients ◽

Reference Methods ◽

Acid Sodium Salt ◽

Spectrofluorimetric Method

An accurate and very sensitive spectrofluorimetric method is proposed for the estimation of heptaminol (HP) and mexiletine (MX) in their pure forms and in pharlnaceutical formulations. The method is based on the reaction of these drugs with the strong fluorigenic reagent [9,1O-Dimethoxy-2-anthracenesulfonic acid sodium salt (DAS)] at pH (2.5). The formed complexes are extracted into chloroform and measured spectrofluori~netrically. The maximum wavelengths of excitation and emission spectra of heptaminol complex are 381 and 441 m, respectively. While those of mexiletine complex are 385 and 450 nrn, respectively. Heptaminol can be determined in the concentration range of 0.016-0.144 µg ml−1 and that of mexiletine in the range of 0.024-0.176 µg ml−1, when extracted from the solutions into chloroform. Different parameters affecting the reaction conditions were thoroughly studied. No interference was observed in the presence of common pharmaceutical excipients. The proposed method has been successfully applied to the analysis of commercial pharmaceutical fonnulations and the results have been statistically compared with those obtained by the reference methods.

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