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Updated: Jul 6, 2026

High-Pressure NMR Experiments for Detecting Protein Low-Lying Conformational States
Published on: June 29, 2021
Shock-tube study of high-pressure H2O spectroscopy
V Nagali1, J T Herbon, D C Horning
1High Temperature Gasdynamics Laboratory, Department of Mechanical Engineering, Stanford University, Stanford, California 94305-3032, USA. venu@oma-inc.com
Abstract:
Water-vapor absorption features near 7117, 7185, and 7462 cm(-1) were probed at pressures to 65 atm (1 atm = 760 Torr) and temperatures to 1800 K in shock-heated mixtures of H(2)O in N(2) and Ar with a diode-laser source. Calculated absorbances based on Voigt line shapes and measured line parameters were in good agreement, within 10%, with measured absorbances at 7185.4 and 7117.4 cm(-1). We obtained temperature-dependent N(2) and Ar shift parameters for H(2)O absorption features by shifting the calculated spectra to match the recorded absorption scan. Absorbance simulations based on line parameters from HITRAN and HITEMP were found to be similar over the range of temperatures 600-1800 K and were within 25% of the measurements. The combined use of Toth's [Appl. Opt. 36, 4851 (1994)] line positions and strengths and HITRAN broadening parameters resulted in calculated absorption coefficients that were within 15% of the measurements at all three probed wavelengths.
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