Near Infrared Absorption of Pure Carbon Dioxide up to 3100 bar and 500 K. II. Wavenumber Range 5600 cm-1 to 7400 cm-1

1986 ◽  
Vol 41 (3) ◽  
pp. 512-518 ◽  
Author(s):  
M. Buback ◽  
J. Schweer ◽  
H. Tups
Keyword(s):  
Infrared Absorption ◽  
Near Infrared ◽  
Optical Path ◽  
Maximum Pressure ◽  
Band Maximum ◽  
High Pressure High Temperature ◽  
Pure Carbon ◽  
Density Band ◽  
Path Lengths ◽  
Pure Carbon Dioxide

Near infrared absorption of pure CO2 in the 3v1 + v3, 2v1 + 2v20 + v3, v1 + 4v20 + v3, 6v20 + v3 Fermi tetrad region around 6300 cm-1 and in the 3v3 second overtone region around 6970 cm-1 was measured at temperatures between 298 K and 500 K to a maximum pressure of 3100 bar. The 3v3 bandshape, at moderate compression up to 0.1 g · cm-3, is adequately represented by summing over individual rotation-vibration lines with half-widths proportional to the density. Band maximum positions and vibrational intensities between gaseous and liquid-like states are reported and discussed. Promising applications of high-pressure high-temperature near infrared spectroscopy to the quantitative analysis of CO2 are illustrated for the 3200 cm-1 to 7400 cm-1 region. The technique can be used for CO2 concentrations or at optical path lengths differing by several orders of magnitude.

Near Infrared Absorption of Pure Carbon Dioxide up to 3100 bar and 500 K. I. Wavenumber Range 3200 cm-1 to 5600 cm-1

1986 ◽  
Vol 41 (3) ◽  
pp. 505-511 ◽  
Author(s):  
M. Buback ◽  
J. Schweer ◽  
H. Tups
Keyword(s):  
Infrared Absorption ◽  
Near Infrared ◽  
Critical Density ◽  
Fermi Resonance ◽  
Maximum Pressure ◽  
High Pressure High Temperature ◽  
Pure Carbon ◽  
Temperature And Pressure ◽  
Pure Carbon Dioxide ◽  
Rotational Freedom

Near infrared absorption of pure CO2 in the v1 + v3, 2v20 + v3 Fermi diad region around 3650 cm-1 and in the 2v1 + v3, v1 + 2v20 + v3, 4v20 + v3 Fermi triad region around 5000 cm-1 was measured at temperatures between 298 K and 500 K to a maximum pressure of 3100 bar. Density tuning of Fermi resonance is studied and compared with literature data on gaseous, liquid, and solid CO2. Band maximum positions determined within an extended temperature and density range indicate appreciable rotational freedom up to about the critical density (0.45 g · cm-3) and repulsive interactions clearly coming into play above 0.9 g · cm-3. The vibrational intensity of the Fermi triad, up to about 1.0 g · cm-3 is found to be independent of temperature and pressure within ± 2.5%, wich enables (pure) CO2 concentrations in a large region of states to be precisely and directly measured via quantitative high-pressure high-temperature near infrared spectroscopy.

scholarly journals Near Infrared Absorption of Ethylene between 8200 cm-1 and 9500 cm-1 to High Pressures and Temperatures

1976 ◽  
Vol 31 (12) ◽  
pp. 1690-1695 ◽  
Author(s):  
F. W. Nees ◽  
M. Buback
Keyword(s):  
Infrared Absorption ◽  
High Frequency ◽  
Near Infrared ◽  
High Pressures ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Experimental Conditions ◽  
High Pressure High Temperature ◽  
Wide Range ◽  
Integrated Intensity

AbstractThe near infrared absorption of pure ethylene in the region of the second overtone of the C-H stretching fundamentals (8200 cm-1 to 9500 cm-1) was measured at supercritical temperatures (Tc = 9.5 °C) between 22 °C and 200 °C from 0.7 bar to 3000 bar. The density and temperature dependence of bandshape, maximum frequency and absorption intensity are reported and discussed. The bands observed within a wide range of experimental conditions are assigned to combination and overtone modes. The molar integrated intensity B̅λ determined between the wavelength of maximum absorption and the high frequency absorption boundary was observed to be independent of pressure and temperature. This enables spectroscopic concentration determinations on ethylene in high pressure - high temperature phase equilibria and reactions.

Near Infrared Absorption of Pure n-Heptane between 5000 cm 1 and 6500 cm-1 to High Pressures and Temperatures

1983 ◽  
Vol 38 (5) ◽  
pp. 528-532 ◽  
Author(s):  
M. Buback ◽  
A. A. Harfoush
Keyword(s):  
High Pressure ◽  
Infrared Absorption ◽  
Near Infrared ◽  
High Pressures ◽  
Kinetic Studies ◽  
Molar Absorptivity ◽  
High Pressure High Temperature ◽  
High Pressures And Temperatures ◽  
Combination Mode ◽  
Better Than

The near infrared absorption of pure n-heptane between 5000 cm-1 and 6500 cm-1 was measured up to 250 °C and to pressures of 2000 bar. The procedure for measuring vibrational intensities at high pressures and temperatures with a precision of better than ± 1% is described. The integrated “molar absorptivity of the combination mode va + vs of the methylene stretching fundamentals turns out to be independent of temperature and density. This offers important applications for high-pressure high-temperature thermodynamic and kinetic studies via quanti­tative near infrared spectroscopy.

Study on the Near-infrared Absorption Properties of ZnGeP2 Single Crystals

2010 ◽  
Vol 25 (10) ◽  
pp. 1029-1033
Author(s):  
Shi-Xing XIA ◽  
Chun-Hui YANG ◽  
Chong-Qiang ZHU ◽  
Tian-Hui MA ◽  
Meng WANG ◽  
...  
Keyword(s):  
Single Crystals ◽  
Infrared Absorption ◽  
Near Infrared ◽  
Absorption Properties

Pyrrole-bridged quinones: π-electronic systems that modulate electronic structures by tautomerism and deprotonation

2021 ◽  
Author(s):  
Shinya Sugiura ◽  
Hiromitsu Maeda
Keyword(s):  
Infrared Absorption ◽  
Electronic Structures ◽  
Near Infrared ◽  
Ion Pairing ◽  
Anion Binding ◽  
Electronic Systems

A new series of π-extended quinone derivatives containing a pyrrole bridge exhibited NH/OH-type tautomerization and anion binding along with deprotonation that induced near-infrared absorption and ion-pairing assemblies.

scholarly journals Characterization and mapping of hematite ore mineral classes using hyperspectral remote sensing technique: a case study from Bailadila iron ore mining region

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Ibrahim Shaik ◽  
S. K. Begum ◽  
P. V. Nagamani ◽  
Narayan Kayet
Keyword(s):  
Infrared Absorption ◽  
Near Infrared ◽  
Spectral Feature ◽  
Absorption Feature ◽  
X Ray ◽  
Remote Sensing Technique ◽  
Ore Minerals ◽  
Feature Fitting ◽  
Hematite Ore

AbstractThe study demonstrates a methodology for mapping various hematite ore classes based on their reflectance and absorption spectra, using Hyperion satellite imagery. Substantial validation is carried out, using the spectral feature fitting technique, with the field spectra measured over the Bailadila hill range in Chhattisgarh State in India. The results of the study showed a good correlation between the concentration of iron oxide with the depth of the near-infrared absorption feature (R2 = 0.843) and the width of the near-infrared absorption feature (R2 = 0.812) through different empirical models, with a root-mean-square error (RMSE) between < 0.317 and < 0.409. The overall accuracy of the study is 88.2% with a Kappa coefficient value of 0.81. Geochemical analysis and X-ray fluorescence (XRF) of field ore samples are performed to ensure different classes of hematite ore minerals. Results showed a high content of Fe > 60 wt% in most of the hematite ore samples, except banded hematite quartzite (BHQ) (< 47 wt%).

scholarly journals Light-curve properties of SN 2017fgc and HV SNe Ia

2021 ◽  
Vol 502 (3) ◽  
pp. 4112-4124
Author(s):  
Umut Burgaz ◽  
Keiichi Maeda ◽  
Belinda Kalomeni ◽  
Miho Kawabata ◽  
Masayuki Yamanaka ◽  
...  
Keyword(s):  
Light Curve ◽  
Near Infrared ◽  
Light Curves ◽  
Normal Velocity ◽  
External Effects ◽  
Band Maximum ◽  
Bolometric Luminosity ◽  
V Band ◽  
Photometric And Spectroscopic Observations ◽  
Type Ia

ABSTRACT Photometric and spectroscopic observations of Type Ia supernova (SN) 2017fgc, which cover the period from −12 to + 137 d since the B-band maximum are presented. SN 2017fgc is a photometrically normal SN Ia with the luminosity decline rate, Δm15(B)true  = 1.10 ± 0.10 mag. Spectroscopically, it belongs to the high-velocity (HV) SNe Ia group, with the Si ii λ6355 velocity near the B-band maximum estimated to be 15 200 ± 480 km s−1. At the epochs around the near-infrared secondary peak, the R and I bands show an excess of ∼0.2-mag level compared to the light curves of the normal velocity (NV) SNe Ia. Further inspection of the samples of HV and NV SNe Ia indicates that the excess is a generic feature among HV SNe Ia, different from NV SNe Ia. There is also a hint that the excess is seen in the V band, both in SN 2017fgc and other HV SNe Ia, which behaves like a less prominent shoulder in the light curve. The excess is not obvious in the B band (and unknown in the U band), and the colour is consistent with the fiducial SN colour. This might indicate that the excess is attributed to the bolometric luminosity, not in the colour. This excess is less likely caused by external effects, like an echo or change in reddening but could be due to an ionization effect, which reflects an intrinsic, either distinct or continuous, difference in the ejecta properties between HV and NV SNe Ia.

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