The Use of Reverse Mirage Spectroscopy to Determine the Absorption Coefficient of Liquid Methanol at CO2 Laser Wavelengths

An experimental setup for performance of reverse mirage spectroscopy at CO2 laser wavelengths on liquid samples having high values of absorption coefficients is described. One and the same liquid is used as both the absorbing and deflecting medium. The Rosencwaig-Gersho theory has been applied, and the choice of experimental conditions that would enable determination of absorption coefficient β from the magnitude of photothermal signals measured at two different probe beam distances (probing locations) is discussed. The usefulness of this technique (essentially not inhibited by the requirements imposed on the sample's thickness) is tested on methanol having absorption coefficients β close to 300 cm−1 in the wavelength region covered by CO2 laser emission.

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Infrared Absorption and Its Sources of CdZnTe at Cryogenic Temperature

Journal of Electronic Materials ◽

10.1007/s11664-021-09361-1 ◽

2022 ◽

Author(s):

Hiroshi Maeshima ◽

Kosei Matsumoto ◽

Yasuhiro Hirahara ◽

Takao Nakagawa ◽

Ryoichi Koga ◽

...

Keyword(s):

Absorption Coefficient ◽

Infrared Absorption ◽

Cryogenic Temperature ◽

Room Temperature ◽

Wavelength Region ◽

Room Temperature Resistivity ◽

Absorption Model ◽

Acceptor Level ◽

Absorption Coefficients ◽

Temperature Resistivity

AbstractTo reveal the causes of infrared absorption in the wavelength region between electronic and lattice absorptions, we measured the temperature dependence of the absorption coefficient of p-type low-resistivity ($$\sim 10^2~ \Omega \mathrm{cm}$$ ∼ 10 2 Ω cm ) CdZnTe crystals. We measured the absorption coefficients of CdZnTe crystals in four wavelength bands ($$\lambda =6.45$$ λ = 6.45 , 10.6, 11.6, 15.1$$~\mu $$ μ m) over the temperature range of $$T=8.6$$ T = 8.6 -300 K with an originally developed system. The CdZnTe absorption coefficient was measured to be $$\alpha =0.3$$ α = 0.3 -0.5 $$\mathrm{cm}^{-1}$$ cm - 1 at $$T=300$$ T = 300 K and $$\alpha =0.4$$ α = 0.4 -0.9 $$\mathrm{cm}^{-1}$$ cm - 1 at $$T=8.6$$ T = 8.6 K in the investigated wavelength range. With an absorption model based on transitions of free holes and holes trapped at an acceptor level, we conclude that the absorption due to free holes at $$T=150$$ T = 150 -300 K and that due to trapped-holes at $$T<50$$ T < 50 K are dominant absorption causes in CdZnTe. We also discuss a method to predict the CdZnTe absorption coefficient at cryogenic temperature based on the room-temperature resistivity.

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Determination of Planck Mean Absorption Coefficients for HBr, HCl, and HF

Journal of Heat Transfer ◽

10.1115/1.1416689 ◽

2001 ◽

Vol 124 (1) ◽

pp. 26-29 ◽

Cited By ~ 16

Author(s):

S. P. Fuss ◽

A. Hamins

Keyword(s):

Absorption Coefficient ◽

Narrow Band ◽

Band Model ◽

Absorption Coefficients ◽

Temperature Range ◽

Average Value ◽

Integrated Intensity ◽

Using Data ◽

Narrow Band Model

The Planck mean absorption coefficient, ap, has been calculated for HBr, HCl, and HF over a temperature range from 300 K–2300 K using data from the 1996 edition of the HITRAN molecular database. Plots of ap versus temperature showed monotonically decreasing behavior over this temperature range, with peak values at 300 K of 45.9 (atm-m)−1, 5.3 (atm-m)−1, and 1.95 (atm-m)−1 for HF, HCl, and HBr, respectively. The magnitude of these values suggests that HBr, HCl, and HF can significantly impact calculations of radiative transfer in flames containing these species. Two sets of additional calculations were performed for CO to validate the methodology used for calculation of ap for HBr, HF, and HCl. In the first approach, which employed the narrow band model RADCAL, the calculation procedure was similar to that of the present calculations. The second approach utilized tabulated values of the integrated intensity for each CO band and an average value of the Planck function within each band. Results from the three methods showed general agreement. Polynomial expressions are provided as fits to ap as a function of temperature for HBr, HCl, HF, and CO.

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Determination of the characteristic inactivation fluence for SARS-CoV-2 under UV-C radiation considering light absorption in culture media

Scientific Reports ◽

10.1038/s41598-021-94648-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Juan Carlos Martínez-Antón ◽

Alejandro Brun ◽

Daniel Vázquez ◽

Sandra Moreno ◽

Antonio A. Fernández-Balbuena ◽

...

Keyword(s):

Spatial Distribution ◽

Optical Absorption ◽

Absorption Coefficient ◽

Culture Media ◽

Optical Absorption Coefficient ◽

Geometrical Shape ◽

Experimental Conditions ◽

Optical Irradiation ◽

Uv C

AbstractThe optical absorption coefficient of culture media is critical for the survival analysis of pathogens under optical irradiation. The quality of the results obtained from experiments relies on the optical analysis of the spatial distribution of fluence which also depends on the geometry of the sample. In this contribution, we consider both the geometrical shape and the culture medium’s absorption coefficient to evaluate how the spatial distribution of optical radiation affects pathogens/viruses. In this work, we exposed SARS-CoV-2 to UV-C radiation ($$\lambda$$ λ = 254 nm) and we calculated—considering the influence of the optical absorption of the culture medium—a characteristic inactivation fluence of $$F_i$$ F i = 4.7 J/m2, or an equivalent 10% survival (D90 dose) of 10.8 J/m2. Experimentally, we diluted the virus into sessile drops of Dulbecco’s Modified Eagle Medium to evaluate pathogen activity after controlled doses of UV irradiation. To validate the optical absorption mode, we carried out an additional experiment where we varied droplet size. Our model—including optical absorption and geometrical considerations—provides robust results among a variety of experimental situations, and represents our experimental conditions more accurately. These results will help to evaluate the capability of UV disinfecting strategies applied to a variety of everyday situations, including the case of micro-droplets generated by respiratory functions.

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Determination of Absorption Coefficient of a Solution by a Simple Experimental Setup

10.1063/1.3643553 ◽

2011 ◽

Cited By ~ 1

Author(s):

Deepak Gopalakrishnan ◽

C. Akhildev ◽

P. V. Sreenivasan ◽

K. K. Leelamma ◽

Lyjo K. Joseph ◽

...

Keyword(s):

Absorption Coefficient ◽

Experimental Setup

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On the absorption of X-rays in copper and aluminium

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1918.0041 ◽

1918 ◽

Vol 94 (664) ◽

pp. 567-575 ◽

Cited By ~ 5

Keyword(s):

Absorption Coefficient ◽

Electromagnetic Radiation ◽

Experimental Work ◽

Atomic Structure ◽

Wave Length ◽

X Rays ◽

Absorption Coefficients

Much experimental work has been directed towards the determination of the absorption coefficients of X-rays in elements—especially with respect to the relation existing between the absorption coefficient and the wave-length—owing to the importance of the bearing of the results on the theories of electromagnetic radiation and atomic structure. Nevertheless, on account of the experimental difficulties encountered in this work, serious discrepancies appear among the results of different observers. The method described below appears to offer a reliable and accurate means of measuring the absorption coefficients of homogeneous X-rays in various materials and the wave-lengths of the rays employed. Among the difficulties experienced in the experimental arrangements, two of the chief are:— ( a ) The heterogeneity of the source. ( b ) The variations in intensity of the source.

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Antithrombin-mediated Inhibition of Factor Vlla-Tissue Factor Complex by the Synthetic Pentasaccharide Representing the Heparin Binding Site to Antithrombin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650512 ◽

1996 ◽

Vol 76 (01) ◽

pp. 005-008 ◽

Cited By ~ 22

Author(s):

Jean Claude Lormeau ◽

Jean Pascal Herault ◽

Jean Marc Herbert

Keyword(s):

Binding Site ◽

Tissue Factor ◽

Residual Activity ◽

Coagulation Factors ◽

Heparin Binding ◽

Experimental Conditions ◽

First Order ◽

Heparin Binding Site ◽

Coagulant Activity

SummaryWe examined the effect of the synthetic pentasaccharide representing the minimal binding site of heparin to antithrombin on the antithrombin-mediated inactivation of factor Vila bound to tissue factor. This effect was compared to the effect of unfractionated heparin. Using purified recombinant human coagulation factors and either a clotting or an amidolytic assay for the determination of the residual activity of factor Vila, we showed that the pentasaccharide was an efficient antithrombin-dependent inhibitor of the coagulant activity of tissue factor-factor Vila complex. In our experimental conditions, assuming a mean MW of 14,000 for heparin, the molar pseudo-first order rate constants for ATIII-mediated FVIIa inhibition by ATIII-binding heparin and by the synthetic pentasaccharide were found to be similar with respective values of 104,000 ± 10,500 min-1 and 112,000 ± 12,000 min-1 (mean ± s.e.m., n = 3)

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