Absorption cross sections, saturated vapor pressures, sublimation energies, and evaporation energies of some organic laser dye vapors

1989 ◽  
Vol 91 (3) ◽  
pp. 1403-1409 ◽  
Author(s):  
J. Schmidt ◽  
A. Penzkofer
Keyword(s):  
Cross Sections ◽  
Saturated Vapor ◽  
Absorption Cross ◽  
Vapor Pressures ◽  
Laser Dye ◽  
Organic Laser

Mass Spectrometric Studies of Physical, Thermochemical and Reactive Properties of Xenon Fluorides, Xenon Oxides and Xenon Oxyfluorides

2002 ◽  
Vol 8 (3) ◽  
pp. 233-246 ◽  
Author(s):  
Vladislav V. Zelenov ◽  
Elena V. Aparina ◽  
Alexander V. Loboda ◽  
Alexander S. Kukui ◽  
Alexander F. Dodonov ◽  
...  
Keyword(s):  
Gas Phase ◽  
Electron Impact ◽  
Cross Sections ◽  
Impact Ionization ◽  
Saturated Vapor ◽  
Electron Impact Ionization ◽  
Binding Energies ◽  
Ionization Mass ◽  
Vapor Pressures ◽  
Gas Phase Reactions

Using a reactor with a flowing diffusion cloud coupled to a high-resolution, low-energy electron-impact ionization mass spectrometer, mechanistic, kinetic and thermochemical characteristics of gas-phase reactions with the participation of charged and neutral xenon oxides, xenon fluorides and xenon oxyfluorides have been investigated. Ionization energies for XeF, XeF2, XeF4, XeO3, XeO4, XeOF4 molecules and appearance energies for the ions formed from these molecules were obtained. Based on experimental and reference data, the enthalpies of XeO3 and XeOF4 formation were refined and a number of binding energies in the parent and fragment ions were calculated. For electron-impact ionization, the ionization cross-sections for Xe, XeF2, XeF4 and XeOF4 proved to correlate with a semi-empirical principle of full ionization. Based on the temperature dependencies of saturated vapor pressures for XeO4, XeOF4 and XeO2F2, their enthalpies of evaporation, sublimation and melting were determined. The mechanisms of gas-phase reactions between H atoms and neutral XeF2, XeF4, XeF6, XeO4 and XeOF4 were studied.

Purity and Uv Absorption Cross Sections of TMA, TMG, and TMAs

1989 ◽  
Vol 145 ◽  
Author(s):  
Hideo Okabe ◽  
M.K. Emadi-Babaki
Keyword(s):  
Absorption Spectrum ◽  
Cross Sections ◽  
Uv Absorption ◽  
Absorption Cross ◽  
Vapor Pressures ◽  
Uv Absorption Spectrum

AbstractVapor pressures of commercial electronic grade TMA,.TMG and TMAs samples have been measured at various temperatures and compared with those of known pure samples. Only TMA showed the presence of impurities. The UV absorption spectrum of impure TMA shows toluene to be an impurity. The UV absorption cross sections of TMA, TMG and TMAs have been measured and tabulated at several wavelengths.

Scanning electron microscopy of plant cells using a variable-pressure SEM and cryogenic techniques

1993 ◽  
Vol 51 ◽  
pp. 260-261
Author(s):  
M. Yamada ◽  
K. Ueda ◽  
K. Kuboki ◽  
H. Matsushima ◽  
S. Joens
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Saturated Vapor ◽  
Plant Cells ◽  
Variable Pressure ◽  
Specimen Preparation ◽  
Operating Pressure ◽  
Vapor Pressures ◽  
Low Temperature Microscopy ◽  
Scanning Electron

Use of variable Pressure SEMs is spreading among electron microscopists The variable Pressure SEM does not necessarily require specimen Preparation such as fixation, dehydration, coating, etc which have been required for conventional scanning electron microscopy. The variable Pressure SEM allows operating Pressure of 1˜270 Pa in specimen chamber It does not allow microscopy of water-containing specimens under a saturated vapor Pressure of water. Therefore, it may cause shrink or deformation of water-containing soft specimens such as plant cells due to evaporation of water. A solution to this Problem is to lower the specimen temperature and maintain saturated vapor Pressures of water at low as shown in Fig. 1 On this technique, there is a Published report of experiment to have sufficient signal to noise ratio for scondary electron imaging at a relatively long working distance using an environmental SEM. We report here a new low temperature microscopy of soft Plant cells using a variable Pressure SEM (Hitachi S-225ON).

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.

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
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