Measurements of the total scattering and absorption cross‐sections of the human body

2003 ◽  
Vol 114 (4) ◽  
pp. 2357-2357 ◽  
Author(s):  
Stephane G. Conti ◽  
Philippe Roux ◽  
David A. Demer ◽  
Julien de Rosny
Keyword(s):  
Cross Sections ◽  
Human Body ◽  
Absorption Cross ◽  
Total Scattering

Measurement of the scattering and absorption cross sections of the human body

2004 ◽  
Vol 84 (5) ◽  
pp. 819-821 ◽  
Author(s):  
Stéphane G. Conti ◽  
Philippe Roux ◽  
David A. Demer ◽  
Julien de Rosny
Keyword(s):  
Cross Sections ◽  
Human Body ◽  
Absorption Cross

Photoelectric cross sections derived from the measured total absorption cross sections at 52.2 and 84.3 keV in Al, Cu, Zr, Ag, Sn, Ta, Au, and Pb

1976 ◽  
Vol 54 (21) ◽  
pp. 2170-2172 ◽  
Author(s):  
Ramakrishna Gowda ◽  
K. S. Puttaswamy ◽  
B. Sanjeevaiah
Keyword(s):  
Cross Sections ◽  
Total Absorption ◽  
Absorption Cross ◽  
Total Scattering ◽  
Scattering Cross ◽  
Scattering Cross Sections ◽  
Theoretical Results

Photoelectric cross sections for 52.2 and 84.3 keV photons in Al, Cu, Zr, Ag, Sn, Ta, Au, and Pb are obtained by subtracting the total scattering cross sections from the measured total absorption cross sections. The scattering cross sections are taken from the recent tabulated values of Veigele, for subtracting purpose. The results are compared with the values interpolated from the theoretical results of (1) Schmickley and Pratt and (2) Scofield.

Extinction and Scattering Properties of Soot Emitted From Buoyant Turbulent Diffusion Flames

2000 ◽  
Vol 123 (2) ◽  
pp. 331-339 ◽  
Author(s):  
S. S. Krishnan ◽  
K.-C. Lin ◽  
G. M. Faeth
Keyword(s):  
Refractive Index ◽  
Cross Sections ◽  
Turbulent Diffusion ◽  
Diffusion Flames ◽  
Absorption Cross ◽  
Fuel Type ◽  
Total Scattering ◽  
Turbulent Diffusion Flames ◽  
Near Ultraviolet ◽  
Good Agreement

Extinction and scattering properties at wavelengths of 250–5200 nm were studied for soot emitted from buoyant turbulent diffusion flames in the long residence time regime where soot properties are independent of position in the overfire region and characteristic flame residence times. Flames burning in still air and fueled with gas (acetylene, ethylene, propane, and propylene) and liquid (benzene, toluene, cyclohexane, and n-heptane) hydrocarbon fuels were considered. Measured scattering patterns and ratios of total scattering/absorption cross sections were in good agreement with predictions based on the Rayleigh-Debye-Gans (RDG) scattering approximation in the visible. Measured depolarization ratios were roughly correlated by primary particle size parameter, suggesting potential for completing RDG methodology needed to make soot scattering predictions as well as providing a nonintrusive way to measure primary soot particle diameters. Measurements of dimensionless extinction coefficients were in good agreement with earlier measurements for similar soot populations and were independent of fuel type and wavelength except for reduced values as the near ultraviolet was approached. The ratios of the scattering/absorption refractive index functions were independent of fuel type within experimental uncertainties and were in good agreement with earlier measurements. The refractive index function for absorption was similarly independent of fuel type but was larger than earlier reflectometry measurements in the infrared. Ratios of total scattering/absorption cross sections were relatively large in the visible and near infrared, with maximum values as large as 0.9 and with values as large as 0.2 at 2000 nm, suggesting greater potential for scattering from soot particles to affect flame radiation properties than previously thought.

Spectroscopy Fundamentals

2017 ◽  
Author(s):  
Kelly Chance ◽  
Randall V. Martin
Keyword(s):  
Vibrational Spectroscopy ◽  
Cross Sections ◽  
Nuclear Spin ◽  
Electronic Spectroscopy ◽  
Rotational Spectroscopy ◽  
Absorption Cross ◽  
Transfer Processes ◽  
Atmospheric Spectroscopy ◽  
Quantitative Spectroscopy ◽  
Broad Overview

This chapter provides a broad overview of the spectroscopic principles required in order to perform quantitative spectroscopy of atmospheres. It couples the details of atmospheric spectroscopy with the radiative transfer processes and also with the assessment of rotational, vibrational, and electronic spectroscopic measurements of atmospheres. The principles apply from line-resolved measurements (chiefly microwave through infrared) through ultraviolet and visible measurements employing absorption cross sections developed from individual transitions. The chapter introduces Einstein coefficients before in turn discussing rotational spectroscopy, vibrational spectroscopy, nuclear spin, and electronic spectroscopy.

scholarly journals Ultraviolet Absorption Cross-Sections of Ammonia at Elevated Temperatures for Nonintrusive Quantitative Detection in Combustion Environments

2021 ◽  
pp. 000370282199044
Author(s):  
Wubin Weng ◽  
Shen Li ◽  
Marcus Aldén ◽  
Zhongshan Li
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Elevated Temperatures ◽  
Uv Absorption ◽  
Energy Utilization ◽  
Quantitative Detection ◽  
Absorption Cross ◽  
Hot Gas

Ammonia (NH3) is regarded as an important nitrogen oxides (NOx) precursor and also as an effective reductant for NOx removal in energy utilization through combustion, and it has recently become an attractive non-carbon alternative fuel. To have a better understanding of thermochemical properties of NH3, accurate in situ detection of NH3 in high temperature environments is desirable. Ultraviolet (UV) absorption spectroscopy is a feasible technique. To achieve quantitative measurements, spectrally resolved UV absorption cross-sections of NH3 in hot gas environments at different temperatures from 295 K to 590 K were experimentally measured for the first time. Based on the experimental results, vibrational constants of NH3 were determined and used for the calculation of the absorption cross-section of NH3 at high temperatures above 590 K using the PGOPHER software. The investigated UV spectra covered the range of wavelengths from 190 nm to 230 nm, where spectral structures of the [Formula: see text] transition of NH3 in the umbrella bending mode, v2, were recognized. The absorption cross-section was found to decrease at higher temperatures. For example, the absorption cross-section peak of the (6, 0) vibrational band of NH3 decreases from ∼2 × 10−17 to ∼0.5 × 10−17 cm2/molecule with the increase of temperature from 295 K to 1570 K. Using the obtained absorption cross-section, in situ nonintrusive quantification of NH3 in different hot gas environments was achieved with a detection limit varying from below 10 parts per million (ppm) to around 200 ppm as temperature increased from 295 K to 1570 K. The quantitative measurement was applied to an experimental investigation of NH3 combustion process. The concentrations of NH3 and nitric oxide (NO) in the post flame zone of NH3–methane (CH4)–air premixed flames at different equivalence ratios were measured.

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