An Approximate Method for the Calculation of the Infrared Molar Absorption Coefficient and Absorption Index Spectra of Liquids from Transmission Measurements

1997 ◽  
pp. 295-296
Author(s):  
John E. Bertie ◽  
Yoram Apelblat
Keyword(s):  
Absorption Coefficient ◽  
Approximate Method ◽  
Absorption Index ◽  
Molar Absorption Coefficient ◽  
Transmission Measurements

Infrared Intensities of Liquids XIII: Accurate Optical Constants and Molar Absorption Coefficients between 6500 and 435 cm−1 of Toluene at 25°C, from Spectra Recorded in Several Laboratories

1994 ◽  
Vol 48 (1) ◽  
pp. 127-143 ◽  
Author(s):  
John E. Bertie ◽  
R. Norman Jones ◽  
Yoram Apelblat ◽  
C. Dale Keefe
Keyword(s):  
Refractive Index ◽  
Absorption Coefficient ◽  
Primary Standard ◽  
Extensive Study ◽  
Absorption Index ◽  
Molar Absorption Coefficient ◽  
Weak Band ◽  
The Real ◽  
Average Accuracy ◽  
Integrated Intensities

This paper presents accurate infrared absorption intensities of liquid toluene at 25°C. The accuracy is estimated from the agreement between the intensities measured by different spectroscopists using the same instrument in the same laboratory and also by different spectroscopists in different laboratories using instruments made by different manufacturers. The average agreement between integrated intensities over specific wavenumber ranges is about ±1.8%. The spectra from the different laboratories have been averaged, unweighted, to give intensity spectra of toluene that are presented as the best available. The use of data from different instruments in different laboratories has included the influence of systematic instrumental errors, so that the precision of the intensity data presented should be a better approximation to its accuracy than would be the case from an extensive study by one person on one instrument. The results obtained agree with the only measurements that have been made against a primary standard, the estimated accuracy of which is about 6%. The results are presented as graphs and tables of the molar absorption coefficient spectrum and the real and imaginary refractive index spectra between 6500 and 435 cm−1. The peak heights and the areas under the bands in the imaginary refractive index (i.e., absorption index) and molar absorption coefficient spectra are reported. The absorption index, k(ν˜), and molar absorption coefficient, Em (ν˜), values are believed to be accurate to an average ±2.5% at the peaks of 39 strong, medium, and weak bands and ±1.9% at the peaks of 51 very weak bands below 4100 cm−1. Above 4100 cm−1, 11 very weak bands have an average accuracy of ±1.3%. The baseline k(ν˜) values are accurate to between ±3 and ±10%. The areas under bands or band groups in k(ν˜) and εm (ν˜) spectra are accurate to 2.4% on average, or 1.2% for strong, medium, and weak band groups between 3150 and 775 cm−1 with 0.002 < kmax < 0.112. The real refractive index, n(ν˜), values are believed to be accurate to 0.2%.

Infrared Intensities of Liquids XIV: Accurate Optical Constants and Molar Absorption Coefficients between 4800 and 450 cm−1 of Chlorobenzene at 25°C from Spectra Recorded in Several Laboratories

1994 ◽  
Vol 48 (1) ◽  
pp. 144-159 ◽  
Author(s):  
John E. Bertie ◽  
R. Norman Jones ◽  
Yoram Apelblat
Keyword(s):  
Refractive Index ◽  
Absorption Coefficient ◽  
Optical Constants ◽  
Absorption Index ◽  
Molar Absorption Coefficient ◽  
Refractive Indices ◽  
The Real ◽  
Infrared Intensities ◽  
Refractive Index Spectrum ◽  
Liquid Chlorobenzene

Accurate infrared absorption intensities of liquid chlorobenzene at 25°C are presented. Their accuracy was estimated from the agreement between the intensities measured by different spectroscopists using different instruments in different laboratories and by different spectroscopists using the same instrument in the same laboratory. The spectra from different spectroscopists have been averaged, unweighted, to give intensity spectra of chlorobenzene that are presented as the best available. The results are presented as graphs and tables of the molar absorption coefficient, Em (ν˜), and the real and imaginary refractive indices, n(ν˜) and k(ν˜), between 4800 and 450 cm−1. The peak heights and the areas under the bands in the absorption index (imaginary refractive index) spectrum are reported, as are areas under the molar absorption coefficient spectrum. Absorption index, k(ν˜), and molar absorption coefficient, Em (ν˜), values are believed accurate to an average ±2.4% at the peaks of bands with kmax > 0.002 and ±3.3% at the peaks of bands with kmax < 0.002. In the baseline k(ν˜) is accurate to ∼ ±5% above 3000 cm−1 and ∼ ±2.5% below 3000 cm−1. The areas under bands in k(ν˜) and Em (ν˜) spectra for which kmax > 0.002 are accurate to ±1.3% on average. The real refractive index, n(ν˜), values are believed to be accurate to ±0.2%.

The Electrically Controlled Birefringence Measurement Influence of Liquid Crystal Caused by Absorption Effect in Infrared Region

2014 ◽  
Vol 875-877 ◽  
pp. 467-471
Author(s):  
Ning Wang ◽  
Xiao Xia Li
Keyword(s):  
Liquid Crystal ◽  
Absorption Coefficient ◽  
Approximate Method ◽  
Nematic Liquid Crystal ◽  
Infrared Region ◽  
Interference Method ◽  
Absorption Coefficients ◽  
Absorption Effect ◽  
Ordinary Light

The electrically controlled birefringence of nematic liquid crystal BL-009 was measured by polarized interference method. The influence of LC absorption effect, the birefringence variation, is discussed in this paper. The experiments results showed the influence to birefringence is big in infrared region. Not only the birefringence value is greatly different with that of unconsidering absorption effect, but also the gradient changing of birefringence curves is obvious. Furthermore, the electrically controlled birefringences of two conditions are compared when the absorption coefficients of ordinary light and the extraordinary light are nearly same and greatly different. The analysis demonstrated the approximate method of absorption coefficient is feasible.

scholarly journals A soluble NADH dehydrogenase (NADH: ferricyanide oxidoreductase) from Thermus aquaticus strain T351

1983 ◽  
Vol 209 (2) ◽  
pp. 427-433 ◽  
Author(s):  
K A J Walsh ◽  
R M Daniel ◽  
H W Morgan
Keyword(s):  
Absorption Coefficient ◽  
Molecular Mass ◽  
Half Life ◽  
Nadh Dehydrogenase ◽  
Molar Absorption Coefficient ◽  
Effect Of Temperature ◽  
Thermus Aquaticus ◽  
Membrane Bound ◽  
The Stability

A soluble NADH dehydrogenase (NADH:ferricyanide oxidoreductase) has been obtained by simple disruption of cells of Thermus aquaticus strain T351, and purified. The enzyme is of low molecular mass, 50 000 Da, and displays many of the properties of the membrane-bound enzyme, including inhibition by both NADH and ferricyanide, and the same Km for ferricyanide. The enzyme contains 0.05 mol of FMN, 0.16 mol of labile sulphur and 2.2 mol of iron per mol of protein. The enzyme is inhibited by NAD and cupferron competitively with ferricyanide, and by ATP (but not ADP) competitively with NADH. The enzyme is particularly thermostable, having a half-life at 95 degrees C of 35 min. The effect of temperature on the molar absorption coefficient and the stability of NADH was determined.

scholarly journals Absorption Coefficient and Refractive Index of GaN, AlN and AlGaN Alloys

1999 ◽  
Vol 4 (S1) ◽  
pp. 502-507 ◽  
Author(s):  
J. F. Muth ◽  
J. D. Brown ◽  
M. A. L. Johnson ◽  
Zhonghai Yu ◽  
R. M. Kolbas ◽  
...  
Keyword(s):  
Refractive Index ◽  
Absorption Coefficient ◽  
Band Gap ◽  
Optoelectronic Devices ◽  
Optical Absorption Coefficient ◽  
Solar Blind ◽  
Single Crystal Films ◽  
Crystal Films ◽  
Transmission Measurements ◽  
Reflectance Measurements

The design of optoelectronic devices fabricated from III-nitride materials is aided by knowledge of the refractive index and absorption coefficient of these materials. The optical properties of GaN, AlN and AlGaN grown by MOVPE on sapphire substrates were investigated by means of transmittance and reflectance measurements. Thin (less than 0.5 μm) single crystal films were employed to insure that transmission measurements could be obtained well above the optical band gap. The influence of alloy broadening on the absorption edge was investigated by using a series of AlGaN alloy samples with a range of Al compositions. The optical absorption coefficient above the band gap was obtained for AlGaN having up to 38% Al composition. The refractive index below the band gap was determined for the same series of samples. These properties provide information critical to the optimal design of solar blind detectors or other optoelectronic devices.

Absorption Coefficient and Refractive Index of GaN, AIN and AlGaN Alloys

1998 ◽  
Vol 537 ◽  
Author(s):  
J. F. Muth ◽  
J. D. Brown ◽  
M. A. L. Johnson ◽  
Zhonghai Yu ◽  
R. M. Kolbas ◽  
...  
Keyword(s):  
Refractive Index ◽  
Absorption Coefficient ◽  
Band Gap ◽  
Optoelectronic Devices ◽  
Optical Absorption Coefficient ◽  
Solar Blind ◽  
Single Crystal Films ◽  
Crystal Films ◽  
Transmission Measurements ◽  
Reflectance Measurements

AbstractThe design of optoelectronic devices fabricated from III-nitride materials is aided by knowledge of the refractive index and absorption coefficient of these materials. The optical properties of GaN, AIN and A1GaN grown by MOVPE on sapphire substrates were investigated by means of transmittance and reflectance measurements. Thin (less than 0.5 μm) single crystal films were employed to insure that transmission measurements could be obtained well above the optical band gap. The influence of alloy broadening on the absorption edge was investigated by using a series of AlGaN alloy samples with a range of Al compositions. The optical absorption coefficient above the band gap was obtained for AIGaN having up to 38% Al composition. The refractive index below the band gap was determined for the same series of samples. These properties provide information critical to the optimal design of solar blind detectors or other optoelectronic devices.

Raman and Optical Properties of the Pulsed Laser Annealing Phase of SI

1981 ◽  
Vol 4 ◽  
Author(s):  
A. Compaan ◽  
A. Aydinli ◽  
M. C. Lee ◽  
H. W. LO
Keyword(s):  
Optical Properties ◽  
Laser Pulse ◽  
Absorption Coefficient ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Experimental Tests ◽  
Small Temperature ◽  
Pulsed Laser Annealing ◽  
Near Ir ◽  
Transmission Measurements

ABSTRACTRaman measurements of temperature reported earlier have been repeated using a doubled Nd: YAG pulse for excitation and an electronically delayed dye laser pulse. These results, together with a variety of experimental tests of the Raman method, confirm the validity of the small temperature rise during pulsed laser annealing. Transmission measurements spanning the visible and near IR show that there exists a thin (∼ 70 nm) layer at the surface in which the induced absorption coefficient is ∼ 7 × 105 cm−1.

Sign in / Sign up

Export Citation Format

Share Document