A Theoretical and Experimental Investigation of the Effective Gas Absorption Path Length Exhibited By an Integrating Sphere Containing CO_2

2006 ◽  
Author(s):  
E. Hawe ◽  
P. Chambers ◽  
C. Fitzpatrick ◽  
E. Lewis
Keyword(s):  
Experimental Investigation ◽  
Path Length ◽  
Gas Absorption ◽  
Integrating Sphere ◽  
Absorption Path Length ◽  
Absorption Path

Integrating sphere effective optical path length calibration by gas absorption spectroscopy

2013 ◽  
Vol 114 (3) ◽  
pp. 341-346 ◽  
Author(s):  
Qiang Gao ◽  
Yungang Zhang ◽  
Jia Yu ◽  
Zhiguo Zhang ◽  
Shaohua Wu ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Path Length ◽  
Optical Path Length ◽  
Optical Path ◽  
Gas Absorption ◽  
Integrating Sphere ◽  
Effective Optical Path Length

An Infrared Spectrum of CO2 Dimers in the "Locked" Configuration

1971 ◽  
Vol 49 (23) ◽  
pp. 3056-3057 ◽  
Author(s):  
L. Mannik ◽  
J. C. Stryland ◽  
H. L. Welsh
Keyword(s):  
Infrared Spectrum ◽  
Quadrupole Interaction ◽  
Path Length ◽  
Complex Structure ◽  
Intermolecular Distance ◽  
Absorption Path Length ◽  
Residual Spectrum ◽  
Absorption Path ◽  
Computational Procedures ◽  
Symmetric Patterns

The two components of the (ν1, 2ν2) Fermi doublet of gaseous CO2 in an absorption path length of 56 m at 192 °K show a complex structure. When the allowed C16O18O absorption and the pressure-induced CO2 absorption are removed by computational procedures, the residual spectrum consists of two similar symmetric patterns of five maxima. These are interpreted in terms of the rotation and vibration of (CO2)2 dimers held by quadrupole–quadrupole interaction in the locked T position at an intermolecular distance of 4.1 Å.

On-chip cavity-enhanced absorption spectroscopy using a white light-emitting diode and polymer mirrors

Lab on a Chip ◽  
2015 ◽  
Vol 15 (3) ◽  
pp. 711-717 ◽  
Author(s):  
Cathy M. Rushworth ◽  
Gareth Jones ◽  
Martin Fischlechner ◽  
Emma Walton ◽  
Hywel Morgan
Keyword(s):  
Absorption Spectroscopy ◽  
White Light ◽  
Microfluidic Chip ◽  
Path Length ◽  
Light Emitting Diode ◽  
Absorption Path Length ◽  
Light Emitting ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
On Chip

We have integrated disposable polymer mirrors within a microfluidic chip to form a multi-pass cell, which increases the absorption path length by a maximum of 28 times, providing micromolar detection limits in a probed volume of 10 nL.

Experimental Investigation on Photothermal Properties of MWCNT-H2O Nanofluids for Direct Absorption Solar Collectors

2014 ◽  
Vol 521 ◽  
pp. 19-22
Author(s):  
Qin Bo He
Keyword(s):  
Experimental Investigation ◽  
Solar Radiation ◽  
Mass Fraction ◽  
Solar Spectrum ◽  
Energy Systems ◽  
Deionized Water ◽  
Integrating Sphere ◽  
Direct Absorption ◽  
Solar Thermal Energy ◽  
Heat Gain

Optical and photothermal properties of MWCNT-H2O nanofluids were investigated in the present work. The transmittance of nanofluids over solar spectrum (250 to 2500nm) was measured by the UV-Vis-NIR spectrophotometer based on integrating sphere principle. The photothermal properties of nanofluids were studied expose to the solar radiation. The experimental results show that the transmittance of MWCNT-H2O nanofluids is much less than that of deionized water, and decreases with increasing nanoparticle mass fraction. The highest temperature and heat gain of MWCNT-H2O nanofluids (0.02wt%) can increased up to 31.87% and 54.14% compared with deionized water, respectively. From the results it can be concluded that MWCNT-H2O nanofluids is suitable for direct absorption solar thermal energy systems.

scholarly journals FLASH early science – discovery of an intervening H i 21-cm absorber from an ASKAP survey of the GAMA 23 field

2020 ◽  
Vol 494 (3) ◽  
pp. 3627-3641 ◽  
Author(s):  
J R Allison ◽  
E M Sadler ◽  
S Bellstedt ◽  
L J M Davies ◽  
S P Driver ◽  
...  
Keyword(s):  
Path Length ◽  
Column Density ◽  
Radio Sources ◽  
Early Type ◽  
Absorption Path Length ◽  
Spin Temperature ◽  
Upper Limits ◽  
Blind Search ◽  
Cross Matching ◽  
Early Type Galaxy

ABSTRACT We present early science results from the First Large Absorption Survey in H i (FLASH), a spectroscopically blind survey for 21-cm absorption lines in cold hydrogen (H i) gas at cosmological distances using the Australian Square Kilometre Array Pathfinder (ASKAP). We have searched for H i absorption towards 1253 radio sources in the GAMA 23 field, covering redshifts between z = 0.34 and 0.79 over a sky area of approximately 50 deg2. In a purely blind search, we did not obtain any detections of 21-cm absorbers above our reliability threshold. Assuming a fiducial value for the H i spin temperature of Tspin = 100 K and source covering fraction cf = 1, the total comoving absorption path-length sensitive to all Damped Lyman α Absorbers (DLAs; NH i ≥ 2 × 1020 cm−2) is ΔX = 6.6 ± 0.3 (Δz = 3.7 ± 0.2) and super-DLAs (NH i ≥ 2 × 1021 cm−2) is ΔX = 111 ± 6 (Δz= 63 ± 3). We estimate upper limits on the H i column density frequency distribution function that are consistent with measurements from prior surveys for redshifted optical DLAs, and nearby 21-cm emission and absorption. By cross-matching our sample of radio sources with optical spectroscopic identifications of galaxies in the GAMA 23 field, we were able to detect 21-cm absorption at z = 0.3562 towards NVSS J224500−343030, with a column density of $N_{\rm H\,\small{I}} = (1.2 \pm 0.1) \times 10^{20}\, (T_{\rm spin}/100\, \mathrm{K})$ cm−2. The absorber is associated with GAMA J22450.05−343031.7, a massive early-type galaxy at an impact parameter of 17 kpc with respect to the radio source and which may contain a massive (MH i ≳ 3 × 109 M⊙) gas disc. Such gas-rich early types are rare, but have been detected in the nearby Universe.

Effective optical path length investigation for cubic diffuse cavity as gas absorption cell

2013 ◽  
Vol 116 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Jia Yu ◽  
Fu Zheng ◽  
Qiang Gao ◽  
Yinjie Li ◽  
Yungang Zhang ◽  
...  
Keyword(s):  
Path Length ◽  
Optical Path Length ◽  
Optical Path ◽  
Gas Absorption ◽  
Absorption Cell ◽  
Effective Optical Path Length

The induced infrared fundamental band of hydrogen dissolved in solid argon

1968 ◽  
Vol 46 (10) ◽  
pp. 1181-1189 ◽  
Author(s):  
R. J. Kriegler ◽  
H. L. Welsh
Keyword(s):  
Path Length ◽  
Lattice Site ◽  
Lattice Vibration ◽  
Liquid Solution ◽  
Absorption Path Length ◽  
Slow Cooling ◽  
Zero Phonon Line ◽  
Fundamental Band ◽  
Difference Tones ◽  
Solid Argon

The induced infrared fundamental band of hydrogen dissolved (~1:100) in solid argon was studied with a 20-cm absorption path length at −191 °C. Transparent crystals were prepared by slow cooling of the liquid solution saturated with hydrogen at ~25 atm pressure. The H2 transitions, Q, S(0), and S(1), show similar patterns of five maxima, each of which can be analyzed as a zero-phonon line at the H2 frequency and summation and difference tones with lattice transition frequencies, 112 and 22 cm−1. The 112-cm−1 frequency is interpreted as arising from a localized lattice vibration involving an H2 molecule on a substitutional lattice site. Calculation from a model of an H2 molecule moving in the field of its argon neighbors, considered stationary, gave 109 cm−1 for this frequency. The origins of the zero-phonon lines and the 22-cm−1 lattice transition frequency are not so clear, and several possibilities are discussed. The H2 frequencies are shifted from their free-molecule values by the sum of a vibrational shift, Δνvlb = −17 cm−1, and rotational shifts corresponding to ΔB = −0.52 cm−1.

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