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Journal articles on the topic 'Infrared emission spectra'

Author: Grafiati

Published: 4 June 2021

Last updated: 18 February 2022

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1

Nemes, László. "INFRARED EMISSION SPECTROSCOPY OF CARBON VAPORS AND PLASMAS, A SHORT OVERVIEW." Contributions, Section of Natural, Mathematical and Biotechnical Sciences 38, no. 1 (2017): 27. http://dx.doi.org/10.20903/csnmbs.masa.2017.38.1.98.

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A short review is given about infrared emission spectroscopy of hot carbon vapors and plasmas obtained using Fourier transform infrared emission and laser induced breakdown LIB spectroscopies in the mid-infrared range. Labor-atory FTIR emission spectra contain vibrational bands from fullerenes C60, C70 whereas laboratory mid-infrared LIB spectra show bands that belong to mostly unidentified carbon molecules and clusters. Both kinds of spectra are com-pared to spectral results from infrared astronomy. The spectra are discussed with a view for possible applications in carbon nanostructure research and in infrared astronomy. Possible extensions for laser induced breakdown (plasma) spectroscopy are suggested.

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2

Roche, P. F. "Observations of Infrared Emission from Galaxies." Symposium - International Astronomical Union 135 (1989): 303–10. http://dx.doi.org/10.1017/s0074180900125318.

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Aspects of the infrared emission from galaxies obtained from ground-based observations are described. There are clear differences between the dust in galaxies with active nuclei and those dominated by nuclear HII regions. In particular the family of unidentified emission bands between 3 and 13 μm dominate the spectra in the latter objects, but are rarely evident in spectra of active nuclei. However results from spatial, spectral and polarization measurements show that many of the dust properties in galaxies are broadly similar to those in the Milky Way.

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3

Hilton, M., A. H. Lettington, and C. W. Wilson. "Gas Turbine Exhaust Emissions Monitoring Using Nonintrusive Infrared Spectroscopy." Journal of Engineering for Gas Turbines and Power 120, no. 3 (1998): 514–18. http://dx.doi.org/10.1115/1.2818175.

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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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4

Siebenmorgen, R., P. Scicluna, and J. Krełowski. "Far-infrared emission of massive stars." Astronomy & Astrophysics 620 (November 23, 2018): A32. http://dx.doi.org/10.1051/0004-6361/201833546.

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We present results of the analysis of a sample of 22 stars of spectral types from O7 to B5 and luminosity classes I–V for which spectra from the Infrared Spectrograph (IRS) of Spitzer are available. The IRS spectra of these stars are examined for signs of excess infrared (IR) emission by comparison with stellar atmospheric spectra. We find that the spectra of half of the studied stars are dominated by excess emission in the far-IR, including all six super- and bright giants. In order to examine the origin of the far-IR excess, we supplement the Spitzer data with optical high-resolution echelle spectroscopy (λ∕Δλ ~ 105), near-IR high-contrast coronagraphic imaging taken with the SPHERE instrument at VLT with a spatial resolution of 0.′′05, and WISE and Herschel photometry. In the optical region, we detect various absorption and emission lines (H α, C III, and N III) irrespective of the far-IR excess. Pfund α and Humphrey α lines are observed at the same time as the far-IR excess. These lines are stronger in stars with far-IR excess than in stars without excess. A scattered-light disk in the central r ≲ 2.5′′ region of the far-IR excess stars HD 149404, HD 151804, and HD 154368 can be excluded from H band imaging down to a 1σ contrast of F(r)∕F∗~ 10−6. The far-IR excess is fit either by a free–free component from ionized gas as for the winds of hot stars or a large (1 pc) circumstellar dust shell. The putative dust envelopes required to explain the excess have a visual extinction as low as a few hundred μ-mag.

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5

van den Ancker, M. E. "Protoplanetary disks around Herbig Ae/Be stars: Indications from ISO spectroscopy." Symposium - International Astronomical Union 202 (2004): 381–83. http://dx.doi.org/10.1017/s0074180900218329.

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An analysis of solid-state features in infrared spectra of 46 Herbig Ae/Be stars is presented. The presence of solid-state emission bands is compared to other indicators of circumstellar material, such as Hα emission, optical variability and sub-mm continuum fluxes. The correlation between these different indicators is weak, if present at all, in our sample. However, a strong dependence on spectral type of the central star seems to be present: stars with spectral type earlier than B9 show either amorphous silicate in absorption or infrared spectra dominated by PAH emission, whereas more than 70% of the stars of later spectral type show silicate emission. We conclude that the infrared spectrum of Herbig Be stars is in general dominated by emission from the circumstellar envelope, whereas the lower-mass Herbig Ae stars show a spectrum that is dominated by a disk that is passively heated by the central star.

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6

Lee, Chien-De, Wen-Ping Chen, and Daisuke Kinoshita. "Near-infrared excess and emission characteristics of classical Be stars." Proceedings of the International Astronomical Union 6, S272 (2010): 404–5. http://dx.doi.org/10.1017/s1743921311010933.

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AbstractClassical Be (CBe) stars are fast-rotating emission-line stars associated with infrared excess often attributed to plasma free-free emission. A few with exceptionally large near-infrared excess, namely with (J–H) and (H–Ks) both greater than 0.6 mag, however, must be accounted for by thermal emission from circumstellar dust. From 2007 to 2009, spectra of more than 100 CBe stars have been collected. We present some of these spectra and discuss how temporal correlation (or lack of) among spectral features would provide possible diagnosis of the origin of the CBe phenomena.

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7

Sola, Daniel, Adrián Miguel, Eduardo Arias-Egido, and Jose I. Peña. "Spectroscopy and Near-Infrared to Visible Upconversion of Er3+ Ions in Aluminosilicate Glasses Manufactured with Controlled Optical Transmission." Applied Sciences 11, no. 3 (2021): 1137. http://dx.doi.org/10.3390/app11031137.

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In this work we report on the spectroscopic properties and the near-infrared to visible upconversion of Er3+ ions in aluminosilicate glasses manufactured by directionally solidification with the laser floating zone technique. Glasses were manufactured in a controlled oxidizing atmosphere to provide them with high optical transmission in the visible spectral range. Absorption and emission spectra, and lifetimes were assessed in both the visible and the near infrared spectral range. Green upconversion emissions of the 2H11/2→4I15/2 and 4S3/2→4I15/2 transitions at 525 nm and 550 nm attributed to a two-photon process were observed under excitation at 800 nm. Mechanisms responsible for the upconversion luminescence were discussed in terms of excited state absorption and energy transfer upconversion processes. Excitation spectra of the upconverted emission suggest that energy transfer upconversion processes are responsible for the green upconversion luminescence.

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8

Ohta, Koji, Robert T. Graf, and Hatsuo Ishida. "Evaluation of Space Radiator Performance by Simulation of Infrared Emission." Applied Spectroscopy 42, no. 1 (1988): 114–20. http://dx.doi.org/10.1366/0003702884428635.

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The total performance of a droplet space radiator has been predicted by simulation of infrared emission spectra. Emission spectra for a droplet are simulated with the use of exact optical theory from the optical constant spectra of a low-molecular-weight silicone, which is a candidate for use as an emission medium of the radiator. Emissive power and total emittance are calculated from the simulated emission spectra for a droplet at different temperatures. It is found that the fourth-power temperature dependence of the emissive power of the blackbody and the temperature dependence of the emissivity inherent to the materials govern the emissive power of the droplet. The progressive decreases in temperature of a droplet and a droplet sheet in space are also simulated. A droplet with a diameter of 1 μm is predicted to cool from 500 K to 252 K in two seconds. The effects of the size of a droplet and the number density of the droplets in the sheet on the cooling rate are estimated. A smaller droplet is essential for obtaining effective radiation in the liquid droplet radiator. A dense cloud of the droplet sheet will retard the cooling rate of the droplets because of the reabsorption of the emitted light.

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9

Rohe-Koths, D., and J. Dachs. "Continuous spectra of circumstellar envelopes of Be stars." Symposium - International Astronomical Union 162 (1994): 425–26. http://dx.doi.org/10.1017/s0074180900215568.

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Line emission in Be star spectra is accompanied by continuous emission both in the Balmer continuum and in the infrared spectral region, due to the same process that is responsible for Balmer line emission, i.e. to recombination radiation from ionized hydrogen in the extended circumstellar disks surrounding the hot central stars.

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10

Campbell, J. M., D. Klapstein, M. Dulick, P. F. Bernath, and L. Wallace. "Infrared Absorption and Emission Spectra of SiO." Astrophysical Journal Supplement Series 101 (November 1995): 237. http://dx.doi.org/10.1086/192238.

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11

Scott, A. D., W. W. Duley, and H. R. Jahani. "Infrared Emission Spectra from Hydrogenated Amorphous Carbon." Astrophysical Journal 490, no. 2 (1997): L175—L177. http://dx.doi.org/10.1086/311030.

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12

Shayesteh, A., K. Tereszchuk, P. F. Bernath, and R. Colin. "Infrared emission spectra of BeH2 and BeD2." Journal of Chemical Physics 118, no. 8 (2003): 3622–27. http://dx.doi.org/10.1063/1.1539850.

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13

Shayesteh, A., K. Tereszchuk, P. F. Bernath, and R. Colin. "Infrared emission spectra of BeH and BeD." Journal of Chemical Physics 118, no. 3 (2003): 1158–61. http://dx.doi.org/10.1063/1.1528606.

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14

White, J. B., M. Dulick, and P. F. Bernath. "Infrared Emission Spectra of InH and InD." Journal of Molecular Spectroscopy 169, no. 2 (1995): 410–20. http://dx.doi.org/10.1006/jmsp.1995.1033.

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15

Rinehart, S. A., and J. R. Houck. "Mid-Infrared Spectra of Be Stars." International Astronomical Union Colloquium 175 (2000): 476–79. http://dx.doi.org/10.1017/s0252921100056293.

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AbstractWe present medium-resolution (R ~ 600) mid-infrared (8-13.3μm) spectra of γ Cas and a coadded spectrum of nine Be stars. A large number of lines have been observed and identified in these spectra, including 39 hydrogen recombination lines in the spectrum of γ Cas. In the majority of our spectra, all of the observed lines are attributable to hydrogen recombination. Two additional sources, β Lyr and MWC 349, show [Ne II] emission and β Lyr also displays [He I] emission. We tabulate the effective line strength and line widths for the observed lines, and briefly discuss the physical implications of the observed line series. We also use a simple model of free-free emission to characterize the disks around these sources.

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16

Hill, Allison R., S. C. Gallagher, R. P. Deo, E. Peeters, and Gordon T. Richards. "High Signal-to-Noise Ratio Mid-Infrared Quasar Spectral Templates." Proceedings of the International Astronomical Union 9, S304 (2013): 315–18. http://dx.doi.org/10.1017/s1743921314004153.

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AbstractMid-infrared (MIR) quasar spectra exhibit a suite of emission features including high ionization coronal lines from the narrow line region (NLR) illuminated by the ionizing continuum, and hot dust features from grains, as well as polycyclic aromatic hydrocarbons (PAH) features from star formation in the host galaxy. Few features are detected in most spectra because of typically low signal-to-noise ratio (S/N) data. By generating spectral composites in three different luminosity bins from over 180 Spitzer Ifnfrared Spectrograph (IRS) observations, we boost the S/N and reveal important features in the complex spectra. We detect high-ionization, forbidden emission lines in all templates, PAH features in all but the most luminous objects, and broad silicate and graphite features in emission whose strength increases relative to the continuum with luminosity. We find that the intrinsic quasar spectrum for all luminosity templates is consistent, and the differences in the spectra can be explained by host galaxy contamination in the lower luminosity templates. We also posit that star formation may be active in most quasar host galaxies, but the spectral features of star formation are only detectable if the quasar is faint.

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17

MacRae, C. M., N. C. Wilson, A. Torpy, and C. J. Davidson. "Hyperspectral Cathodoluminescence Imaging and Analysis Extending from Ultraviolet to Near Infrared." Microscopy and Microanalysis 18, no. 6 (2012): 1239–45. http://dx.doi.org/10.1017/s1431927612013505.

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AbstractThe measurement of near-infrared (NIR) cathodoluminescence (CL) with sufficient sensitivity to allow full spectral mapping has been investigated through the application of optimized grating spectrometers that allow the ultraviolet (UV), visible, and NIR CL spectra to be measured simultaneously. Two optical spectrometers have been integrated into an electron microprobe, allowing simultaneous collection of hyperspectral CL (UV-NIR), characteristic X-rays, and electron signals. Combined hyperspectral CL spectra collected from two natural apatite (Ca5[PO4]3[OH,F]) samples from Wilberforce (Ontario, Canada) and Durango (Mexico) were qualitatively analyzed to identify the emission centers and then deconvoluted pixel-by-pixel using least-squares fitting to produce a series of ion-resolved CL intensity maps. Preliminary investigation of apatite has shown strong NIR emissions associated primarily with the rare-earth element Nd. Details of growth and alteration were revealed in the NIR that were not discernable with electron-induced X-ray mapping. Intense emission centers from Nd3+ and Sm3+ were observed in the spectra from both apatites, along with minor emissions from other 3+ rare-earth elements. Quantitative electron probe microanalysis was performed on points within the mapped area of the Durango apatite to produce a calibration line relating cathodoluminescent intensity of the fitted peak centered at 1,073 nm (1.156 eV) to the Nd concentration.

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18

Zhuang, Yixi, Jin Luo, Yu Teng, Song Ye, Bin Zhu, and Jianrong Qiu. "Broadband infrared luminescence of Cr3+-doped LiInSiO4 phosphors." Journal of Materials Research 25, no. 2 (2010): 224–28. http://dx.doi.org/10.1557/jmr.2010.0026.

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Cr3+-doped LiInSiO4 phosphors were prepared by a solid-state reaction method. X-ray diffraction measurement was carried out for crystalline phase identification. Absorption, photoluminescence, excitation, and time-resolved spectra were measured to investigate the optical properties of the phosphors. Two broadband near-infrared emissions centered at 920 and 1172 nm were observed. Time-resolved spectra show that the emission at 1172 nm decays more quickly than the emission at 920 nm. The electron spin resonance spectra exhibit a broad resonance signal at g = 1.96 because of exchange-coupled Cr3+ pairs. The value of Dq/B for low and intermediate crystal fields was evaluated. We suggest that Cr3+ incorporated into different octahedral sites of the crystal is responsible for the different near-infrared luminescence.

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19

Yu, Shanshan, Dejian Fu, Alireza Shayesteh, Iouli E. Gordon, Dominique R. T. Appadoo, and Peter Bernath. "Infrared and near infrared emission spectra of SbH and SbD." Journal of Molecular Spectroscopy 229, no. 2 (2005): 257–65. http://dx.doi.org/10.1016/j.jms.2004.09.012.

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20

Yu, Shanshan, Alireza Shayesteh, Dejian Fu, and Peter F. Bernath. "Infrared and near infrared emission spectra of TeH and TeD." Journal of Molecular Spectroscopy 230, no. 2 (2005): 105–16. http://dx.doi.org/10.1016/j.jms.2004.11.004.

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21

Etz, Edgar S., Steven J. Choquette, Wilbur S. Hurst, and Douglas H. Blackburn. "Raman Microprobe Study of the Visible and Near-Infrared Excited Fluorescence Spectra of Glasses Examined as Potential Raman Intensity Calibration Standards." Microscopy and Microanalysis 4, S2 (1998): 508–9. http://dx.doi.org/10.1017/s1431927600022662.

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In previous work with the Raman microprobe, we have examined the fluorescence emissions of rareearth (RE) bearing glasses to study the phenomena of structural resonances in the spectra of glass microspheres and the energy upconversion processes for RE ions in such glasses that give rise to anti- Stokes fluorescence emission. Presently, we are revisiting these same fluorescent glasses to study their laser excited emissions as potential radiometric sources for the calibration of Raman spectral intensities. Many of the rare earth ions produce interesting fluorescence spectra on laser excitation depending on the type of ordered or disordered (solid) host matrix. These fluorescence spectra, depending on RE concentration and quenching effects, can be intense and may consist of either narrow-band (or line) emissions or broad-band spectra covering a wide spectral range. These spectra, acquired at laser wavelengths from the ultraviolet (UV) to the near-infrared (NIR), provide a practical means for the calibration of Raman instrumentation for both Raman frequency and intensity.

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22

Onaka, T., I. Sakon, R. Ohsawa, et al. "Near-Infrared Spectroscopy of the Diffuse Galactic Emission." Proceedings of the International Astronomical Union 10, H16 (2012): 703–4. http://dx.doi.org/10.1017/s1743921314012976.

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AbstractThe near-infrared (NIR) spectral range (2–5 μm) contains a number of interesting features for the study of the interstellar medium. In particular, the aromatic and aliphatic components in carbonaceous dust can be investigated most efficiently with the NIR spectroscopy. We analyze NIR spectra of the diffuse Galactic emission taken with the Infrared Camera onboard AKARI and find that the aliphatic to aromatic emission band ratio decreases toward the ionized gas, which suggests processing of the band carriers in the ionized region.

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23

Foschino, Sacha, Olivier Berné, and Christine Joblin. "Learning mid-IR emission spectra of PAH populations from observations." Proceedings of the International Astronomical Union 15, S350 (2019): 406–7. http://dx.doi.org/10.1017/s1743921319007786.

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AbstractObservations of the mid-infrared (mid-IR, 3-15 μm) spectra of photo-dissociation regions reveal ubiquitous, broad and intense emission bands, the aromatic infrared bands (AIBs), attributed to polycyclic aromatic hydrocarbons (PAHs). Studies of the AIBs showed spectral variations (e.g. in the band positions) between different astrophysical objects, or even within single object, thanks to hyperspectral images. The James Webb Space Telescope (JWST) will allow to get further spectral and spatial details compared to former space observatories. This will come with large data sets, which will require specific tools in order to perform efficient scientific analysis.We propose in this study a method based on blind signal separation to reduce the analysis of such large data set to that of a small number of elementary spectra, spectrally representative of the data set and physically interpretable as the spectra of populations of mid-IR emitters. The robustness and fastness of the method are improved compared to former algorithms. It is tested on a ISO-SWS data set, which approaches the best the characteristics of JWST data, from which four elementary spectra are extracted, attributed to cationic, neutral PAHs, evaporating very small grains and large and ionized PAHs.

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24

Cheng, Shuying, Martin Tjahjono, D. Rajarathnam, et al. "Remote Monitoring of a Multi-Component Liquid-Phase Organic Synthesis by Infrared Emission Spectroscopy: The Recovery of Pure Component Emissivities by Band-Target Entropy Minimization." Applied Spectroscopy 61, no. 10 (2007): 1057–62. http://dx.doi.org/10.1366/000370207782217734.

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A liquid-phase cycloaddition reaction near ambient temperature involving dimethyl acetylenedicarboxylate (DMAD) and cyclopentadiene (CP) as reactants was measured using a conventional Fourier transform infrared (FT-IR) spectrometer with an emission accessory. Two semi-batch experiments were performed and a total of 55 spectra were collected using a DTGS detector. Band-target entropy minimization (BTEM), a pure component spectral reconstruction technique, was applied to analyze the data set to retrieve the pure component emission spectrum from the reaction system. The estimated emission spectra of the solvent chloroform, DMAD, CP, and product, namely dimethyl bicyclo[2.2.1]-2,5-heptadiene-2,3-dicarboxylate, were all reconstructed with rather good quality. The estimated emission spectra are similar to independent FT-IR spectra of the same cycloaddition reaction. Using a least squares fit, the relative concentration profiles of the species are obtained. Because this appears to be the first time that a liquid-phase reaction has been monitored by infrared emission spectroscopy, further improvements and opportunities for general multi-phase liquid reaction monitoring are discussed.

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25

Ueda, Shigeru, Hirotaka Koyo, Takashi Ikeda, Yoshiharu Kariya, and Masafumi Maeda. "Infrared Emission Spectra of CaF2-CaO-SiO2 Melt." ISIJ International 40, no. 8 (2000): 739–43. http://dx.doi.org/10.2355/isijinternational.40.739.

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26

Rebours, B. "Far infrared emission spectra from stratospheric hydrogen peroxide." International Journal of Infrared and Millimeter Waves 16, no. 9 (1995): 1465–80. http://dx.doi.org/10.1007/bf02274810.

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27

Gordon, Iouli E., Robert J. Le Roy, and Peter F. Bernath. "Near infrared emission spectra of CoH and CoD." Journal of Molecular Spectroscopy 237, no. 1 (2006): 11–18. http://dx.doi.org/10.1016/j.jms.2006.02.011.

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28

Park, Jae H., and Bruno Carli. "Analysis of far-infrared emission Fourier transform spectra." Applied Optics 25, no. 19 (1986): 3490. http://dx.doi.org/10.1364/ao.25.003490.

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29

Cook, D. J., S. Schlemmer, N. Balucani, D. R. Wagner, B. Steiner, and R. J. Saykally. "Infrared emission spectra of candidate interstellar aromatic molecules." Nature 380, no. 6571 (1996): 227–29. http://dx.doi.org/10.1038/380227a0.

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30

Kunde, V. G., J. C. Brasunas, W. C. Maguire, et al. "Measurement of nighttime stratospheric N2O5from infrared emission spectra." Geophysical Research Letters 15, no. 11 (1988): 1177–80. http://dx.doi.org/10.1029/gl015i011p01177.

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31

Hedderich, H. G., C. I. Frum, R. Engleman Jr., and P. F. Bernath. "The infrared emission spectra of LiF and HF." Canadian Journal of Chemistry 69, no. 11 (1991): 1659–71. http://dx.doi.org/10.1139/v91-244.

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The high resolution infrared spectrum of LiF has been measured in emission with the McMath Fourier transform interferometer at Kitt Peak. A total of 800 lines with ν = 1 → 0 to ν = 8 → 7 of the main isotopomer, 7LiF, and 250 lines with ν = 1 → 0 to ν = 3 → 2 of the minor isotopomer, 6LiF, were observed. These ro-vibrational transitions and the pure rotational transitions from the literature were fit to a set of Dunham coefficients Yij and a set of mass-reduced Dunham coefficients Uij. The same spectrum shows 13 pure rotational emission transitions of HF in the vibrational ground state with J = 13 → 12 to J = 25 → 24. These transitions were used to determine an improved set of rotational constants for HF. Key words: infrared spectra, LiF, HF.

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Kelly, Douglas M., and Bruce J. Hrivnak. "Near-Infrared Spectroscopy of H2 in Proto-Planetary Nebulae." Symposium - International Astronomical Union 209 (2003): 269–70. http://dx.doi.org/10.1017/s007418090020870x.

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We measured 2.1 – 2.3 μm spectra for a fairly complete sample of known proto-planetary nebulae (PPN) at declinations greater than -30°. This spectral range includes the H2 emission lines 1-0 S(1), 1-0 S(0), 2-1 S(1), 2-1 S(2), and 3-2 S(3). We detected H2 emission from 16 of the 51 nebulae in our survey, including radiatively-excited H2 from several non-bipolar PPN.

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33

Pastori, L. "Near Infrared Spectra of Southern Be Stars." International Astronomical Union Colloquium 92 (August 1987): 239–41. http://dx.doi.org/10.1017/s0252921100116306.

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Spectra of northern Be stars in the near infrared region have been already described by some authors (see Slettebak, 1979 for a brief review). This paper presents general results for southern Be stars obtained from more than 100 spectrograms in the region λλ7750-9000 Å the spectra were taken in four nights of February 1985 at the 1.5m ESO telescope with the reticon instrumentation; the dispersion is 58 Åmm-1. All the available southern Be stars (right ascension between 4h and 17h) listed in the Bright Star Catalogue (Hoffleit and Jaschek, 1982) were observed. Table 1 lists the number of stars vs. spectral type (columns 1 and 2) and the number of stars which display emission at the Paschen series, 0I λ8446 Å and Call triplet (columns 3 to 5).

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34

Alias, Ahmad Nazib, T. I. Tunku Kudin, Z. M. Zabidi, M. K. Harun, Ab Malik Marwan Ali, and Mohamad Faizul Yahya. "Excitation and Emission Properties of Poly(N-Carbazole)/Poly(vinylpyrrolidone) Blends Characterized by Fluorescence Spectroscopy." Advanced Materials Research 652-654 (January 2013): 550–53. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.550.

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We present the results concerning the excitation and emissions spectra of Poly (N-carbazole) (PVK) blend with different compositions of polyvinylpyrrolidone (PVP). Doctor blade technique was used to coat the blended polymer on a quartz substrate. The influences of polymer composition to the excitation and emission spectra were observed under UV excitation source of a xenon lamp. The result shows a discrepancy in the maximum excitation, emission and Stokes shift for each samples. The variation of Full Width at Half Maximum (FWHM) for excitation and emission indicate that the variation in composition has affected on the fluorescence properties of the blended thin film polymer system. Fourier Transform Infrared (FTIR) spectroscopy reveals that the discrepancy in the emission and excitation properties of this polymer blending system is due to the discrepancy of infrared absorption peak in the carbazole functional group.

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35

Torres, R. M., A. Damineli-Neto, and J. A. de Freitas Pacheco. "Infrared spectroscopy of Be stars." Symposium - International Astronomical Union 162 (1994): 412–13. http://dx.doi.org/10.1017/s0074180900215507.

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FeII emission lines are present in a variety of astrophysical objects and, in particular, in Be stars, where in some situations they can also be seen in absorption. Selvelli & Araujo (1984) studied a sample of classical Be stars that have FeII emission lines in the optical region. The analysis of IUE spectra of those stars revealed that, for the majority of the objects, neither absorption nor emission FeII features were present in the UV. The conclusion was that their data could not support excitation of FeII by continuum fluorescence. On the other hand, FeIII of circumstellar origin is often seen in absorption in the UV spectra of Be stars (Snow & Stalio 1987 and references therein). This could be an indication that the optical FeII emission lines are originated from recombination and cascade. However, Selvelli & Araujo (1984) argued that, since the multiplet UV 191 of FeII does not appear in emission, that mechanism is probably not relevant. In the present work we report new spectroscopic observations in the near infrared of a sample of 60 Be stars, including the prominent FeII 999.7 nm emission line. This line is also present in the spectra of superluminous B stars for which mass loss rates have recently been estimated (Lopes, Damineli-Neto & Freitas Pacheco 1992). We derived mass loss rates from the infrared line luminosities, in agreement with those derived by other methods. We also found a new evidence of the Be envelope flattening through the FeII/Paδ line ratio.

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36

Martin, Margarita, Marta Castillejo, Ricardo Torres, and Diego Silva. "Analytical Studies of Polychromes by Time-Integrated Laser-Induced Breakdown Spectroscopy." Laser Chemistry 18, no. 3 (1999): 155–65. http://dx.doi.org/10.1155/1999/48171.

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Time integrated Laser Induced Breakdown Spectroscopy was applied to the study of real samples of polychromes. Two samples respectively from the Spanish Baroque and from the XV century were analysed. The time integrated spectra showed negligible contribution of continuum background emission. The spectra of the Baroque sample indicated the presence of vermilion; this was confirmed by Near Infrared Fourier Transform Spectroscopy. LIBS spectra of the XV century sample showed Ca, Al, Mg, Na and Pb lines and the molecular emissions CN(B-X) and C2(d-a). Relative spectral intensities were measured as a function of the number of laser pulses delivered on the same position of the sample. The LIBS analysis was compared to an exhaustive analytical study.

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37

Schleisman, A. J. J., D. E. Pivonka, W. G. Fateley, and R. C. Fry. "Red/Near-Infrared Atomic Analysis for H, C, N, O, S, Cl, and Br with a Fourier Transform Inductively Coupled Plasma Emission Spectrometer." Applied Spectroscopy 40, no. 4 (1986): 464–73. http://dx.doi.org/10.1366/0003702864508845.

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Medium resolution (0.25 cm−1) Fourier transform atomic emission reference spectra of H, C, N, O, S, Cl, Br, and Ar are presented in the red/near-infrared (15,800–8300 cm−1) region for a “pure” argon inductively coupled plasma. A silicon photodiode detector provided the red response needed to measure atomic hydrogen emissions simultaneously with near-infrared lines of the other nonmetals. Several new ICP excited lines of sulfur and carbon are reported. A list of relative intensities for all observed lines in this region is presented, and an 84-page appendix containing labelled medium resolution plots of the entire spectral region for seven elements and the argon background is available upon request. Transparent master overlays of the appendix are also available. Phase error with single-sided interferograms is studied, and the application of standard correction methods prior to power spectrum plotting is explored for red/near-infrared atomic emissions. The interaction between spectral line intensity and resolution is studied in this region.

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Li, Li, Yongjie Wang, Jun Shen, et al. "Near-Infrared Downconversion in LuPO4: Tm3+, Yb3+ Phosphors." Journal of Nanoscience and Nanotechnology 16, no. 4 (2016): 3511–16. http://dx.doi.org/10.1166/jnn.2016.11828.

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Tm3+ and Yb3+ codoped LuPO4 phosphors were synthesized by the reverse-strike co-precipitation method. The obtained LuPO4:Tm3+, Yb3+ phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectra, photoluminescence (PL) spectra, and decay lifetime to understand the observed near-infrared downconversion (DC) phenomena. The XRD results show that all the prepared phosphors can be readily indexed to the pure tetragonal phase of LuPO4 and exhibit good crystallinity. The experimental results showed that the strong visible emission around 649 nm from Tm3+(1G4 → 3F4) and near-infrared (NIR) emission around 1003 nm from Yb3+(2F5/2 → 2F7/2) of LuPO4:Tm3+, Yb3+ phosphors were observed under 468 nm excitation, respectively. The Yb3+ concentration dependence of luminescent properties and lifetimes of both the visible and NIR emissions have also been investigated. The quenching concentration of Yb3+ ions approaches 30 mol%. The DC mechanism is also discussed in detail.

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39

Umarkhodgaev, R. M., V. A. Liperovsky, V. V. Mikhailin, V. V. Bogdanov, C. V. Meister, and E. V. Liperovskaya. "IR spectral analysis for the diagnostics of crust earthquake precursors." Natural Hazards and Earth System Sciences 12, no. 11 (2012): 3269–74. http://dx.doi.org/10.5194/nhess-12-3269-2012.

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Abstract. Some possible physical processes are analysed that cause, under the condition of additional ionisation in a pre-breakdown electric field, emissions in the infrared (IR) interval. The atmospheric transparency region of the IR spectrum at wavelengths of 7–15 μm is taken into account. This transparency region corresponds to spectral lines of small atmospheric constituents like CH4, CO2, N2O, NO2, NO, and O3. The possible intensities of the IR emissions observable in laboratories and in nature are estimated. The acceleration process of the electrons in the pre-breakdown electrical field before its adhesion to the molecules is analyzed. For daytime conditions, modifications of the adsorption spectra of the scattered solar emissions are studied; for nighttime, variations of emission spectra may be used for the analysis.

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40

Belz, H. H., H. Gutberlet, B. Schallert, and B. Schrader. "Continuous-Wave CO2 Laser-Excited Infrared Emission Spectroscopy." Applied Spectroscopy 41, no. 6 (1987): 1009–19. http://dx.doi.org/10.1366/0003702874447806.

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Radiation of a cw CO2 laser can be used to excite infrared emission spectra of nearly all molecular gases by adding small amounts of SF6 as a sensitizer. These emission spectra show a thermal equilibrium between vibrational, rotational, and translational states with temperatures up to 1200 K. Temperature profiles of these gases about a focused cw CO2 laser beam are analyzed by Raman spectroscopy. The detection of small amounts of sample and investigations of cw laser-induced chemical reactions are interesting potential applications.

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41

Wangmaneerat, B., J. A. McGuire, T. M. Niemczyk, D. M. Haaland, and J. H. Linn. "Quantitative Infrared Emission Spectroscopy of Phosphosilicate Glass on Silicon Wafers Using Multivariate Calibration." Applied Spectroscopy 46, no. 2 (1992): 340–44. http://dx.doi.org/10.1366/0003702924125546.

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Phosphosilicate glass (PSG) is widely used in the microelectronics industry as a dielectric thin film. Determination of phosphorus concentration in these films is important for quality control. Data are presented here indicating that infrared emission spectroscopy combined with multivariate calibration can produce concentration determinations with a precision comparable to that of the electron microprobe reference method. Partial least-squares multivariate calibration methods applied to infrared emission spectra of twelve calibration standards of PSG films on silicon wafers at 225°C yielded a cross-validated standard error of prediction of 0.11 wt % P. It was found that the precisions of the phosphorus determinations were comparable for the use of absorbance spectra, single-beam emission spectra, or single-beam emission spectra ratioed to a blackbody at the same temperature.

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42

Downare, Taggart D., and Oliver C. Mullins. "Visible and Near-Infrared Fluorescence of Crude Oils." Applied Spectroscopy 49, no. 6 (1995): 754–64. http://dx.doi.org/10.1366/0003702953964462.

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Fluorescence emission spectra and absolute quantum yields have been measured for ten diverse crude oils at various concentrations over a broad range of excitation and emission wavelengths in the visible and the near-infrared. Energy transfer produces large red shifts and large widths in the fluorescence emission spectra for shorter wavelength excitation particularly for heavier crude oils. However, the effects of energy transfer are nearly absent for near-infrared excitation; all crude oils exhibit nearly the same emission spectra for long wavelength excitation. In addition, the fraction of emission resulting from collisional energy transfer relative to nascent emission is almost independent of oil type; it is governed by quantum yield characteristics. Absolute fluorescence quantum yields of ten crude oils (and three rhodamine dyes for validation) were measured with respect to scattering of latex microspheres in distilled water. Fluorescence quantum yields vary systematically with crude oil type as well as excitation wavelength; quantum yields are lower for high fluorophore concentrations (heavy crude oils) and for longer wavelength excitation. Stern-Volmer analyses of the quantum yields indicate that simple models apply and show the relative quenching rates for different excitation wavelengths.

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43

d'Hendecourt, L. B., A. Léger, P. Boissel, and F. X. Désert. "Infrared Emission Mechanism in Large Isolated Molecules." Symposium - International Astronomical Union 135 (1989): 207–19. http://dx.doi.org/10.1017/s0074180900125240.

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The physics which governs the IR emission of a large isolated molecule (e. g. an interstellar PAH) after the absorption of an UV photon is described. We show that the simple thermal approximation is valid and we give the method to calculate emission spectra from absorption spectroscopy data.

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44

Lindermeir, E. "Evaluation of infrared emission spectra of aircraft exhaust with the FitFas software." Annales Geophysicae 12, no. 5 (1994): 417–21. http://dx.doi.org/10.1007/s00585-994-0417-5.

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Abstract. A Fourier transform spectrometer was used to measure infrared spectra of the exhaust gas of an aircraft's jet engine. The measured spectra were modelled by use of the program FASCODE. For this simulation, the inhomogeneous gas mixture is divided into several homogenous layers which are characterized by their geometrical extents, temperatures, pressures and chemical compositions. To obtain values for the temperatures and the CO, NO, H2O and CO2 concentrations of the layers a nonlinear least-squares algorithm was implemented. The program (FITFAS) not only changes the parameters to find the minimum of the squared differences between measurement and calculation; it also provides the variances and covariances of the parameters. Thus information is obtained to which parameters (besides the interesting ones) must be fitted (or be accurately known). It also tells us whether or not another spectral interval is more suitable for the determination of a specific parameter.

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45

Smit, Kenneth J., Leo V. De Yong, and Rodney Gray. "Observation of infrared emission spectra from silicon combustion products." Chemical Physics Letters 254, no. 3-4 (1996): 197–202. http://dx.doi.org/10.1016/0009-2614(96)00305-3.

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46

Gordon, Iouli E., Dominique R. T. Appadoo, Alireza Shayesteh, Kaley A. Walker, and Peter F. Bernath. "Fourier transform infrared emission spectra of MnH and MnD." Journal of Molecular Spectroscopy 229, no. 1 (2005): 145–49. http://dx.doi.org/10.1016/j.jms.2004.08.010.

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47

Tokaryk, D. W., G. R. Wagner, R. L. Brooks, and J. L. Hunt. "Infrared emission spectra from cryogenic proton‐irradiated helium gas." Journal of Chemical Physics 103, no. 24 (1995): 10439–44. http://dx.doi.org/10.1063/1.469893.

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48

White, J. B., M. Dulick, and P. F. Bernath. "High resolution infrared emission spectra of AlH and AlD." Journal of Chemical Physics 99, no. 11 (1993): 8371–78. http://dx.doi.org/10.1063/1.465612.

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49

Campbell, J. M., M. Dulick, D. Klapstein, J. B. White, and P. F. Bernath. "High resolution infrared emission spectra of GaH and GaD." Journal of Chemical Physics 99, no. 11 (1993): 8379–84. http://dx.doi.org/10.1063/1.465613.

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50

Shayesteh, A., D. R. T. Appadoo, I. Gordon, R. J. Le Roy, and P. F. Bernath. "Fourier transform infrared emission spectra of MgH and MgD." Journal of Chemical Physics 120, no. 21 (2004): 10002–8. http://dx.doi.org/10.1063/1.1724821.

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