Correlation between the infrared and visible extinction coefficients of fog

1982 ◽  
Vol 7 (10) ◽  
pp. 471 ◽  
Author(s):  
G. G. Gimmestad ◽  
L. W. Winchester ◽  
W. K. Choi ◽  
S. M. Lee
Keyword(s):  
Extinction Coefficients

scholarly journals On the vertical distribution of smoke in the Amazonian atmosphere during the dry season

2016 ◽  
Vol 16 (4) ◽  
pp. 2155-2174 ◽  
Author(s):  
Franco Marenco ◽  
Ben Johnson ◽  
Justin M. Langridge ◽  
Jane Mulcahy ◽  
Angela Benedetti ◽  
...  
Keyword(s):  
Vertical Structure ◽  
Atmospheric Measurements ◽  
Extinction Coefficients ◽  
Smoke Plumes ◽  
Model Predictions ◽  
Research Aircraft ◽  
The Vertical Distribution ◽  
Lidar Observations ◽  
Aerosol Extinction Coefficient ◽  
Assimilation System

Abstract. Lidar observations of smoke aerosols have been analysed from six flights of the Facility for Airborne Atmospheric Measurements BAe-146 research aircraft over Brazil during the biomass burning season (September 2012). A large aerosol optical depth (AOD) was observed, typically ranging 0.4–0.9, along with a typical aerosol extinction coefficient of 100–400 Mm−1. The data highlight the persistent and widespread nature of the Amazonian haze, which had a consistent vertical structure, observed over a large distance ( ∼ 2200 km) during a period of 14 days. Aerosols were found near the surface; but the larger aerosol load was typically found in elevated layers that extended from 1–1.5 to 4–6 km. The measurements have been compared to model predictions with the Met Office Unified Model (MetUM) and the ECMWF-MACC model. The MetUM generally reproduced the vertical structure of the Amazonian haze observed with the lidar. The ECMWF-MACC model was also able to reproduce the general features of smoke plumes albeit with a small overestimation of the AOD. The models did not always capture localised features such as (i) smoke plumes originating from individual fires, and (ii) aerosols in the vicinity of clouds. In both these circumstances, peak extinction coefficients of the order of 1000–1500 Mm−1 and AODs as large as 1–1.8 were encountered, but these features were either underestimated or not captured in the model predictions. Smoke injection heights derived from the Global Fire Assimilation System (GFAS) for the region are compatible with the general height of the aerosol layers.

ASSOCIATION OF CERIC IONS WITH SULPHATE (A SPECTRAL STUDY)

1951 ◽  
Vol 29 (10) ◽  
pp. 828-837 ◽  
Author(s):  
T. J. Hardwick ◽  
E. Robertson
Keyword(s):  
Spectral Study ◽  
Association Constants ◽  
Extinction Coefficients ◽  
Ceric Ion ◽  
Molar Extinction Coefficients

Ceric ion has been shown to associate with sulphate ion to form successively Ce(SO4++, Ce(SO4)2, and Ce(SO4)3−. The association constants relating these species have been determined at 25 °C. The molar extinction coefficients of each associated complex have been found between 395 and 430 mμ. Migration experiments bear out the results qualitatively.

Synthesis and characterization of meso-to-meso directly linked porphyrin-diazaporphyrin triads

2018 ◽  
Vol 22 (09n10) ◽  
pp. 814-820
Author(s):  
Yingying Jia ◽  
Ling Xu ◽  
Bangshao Yin ◽  
Mingbo Zhou ◽  
Jianxin Song
Keyword(s):  
Nickel Complex ◽  
High Resolution Mass Spectrometry ◽  
Dihedral Angles ◽  
X Ray Diffraction ◽  
Extinction Coefficients ◽  
X Ray ◽  
H Nmr ◽  
First Time ◽  
Molar Extinction Coefficients

Beginning with 5,10,15-triarylporphyrin-nickel complex, five meso-to-meso directly linked porphyrin-diazaporphyrin triads were successfully prepared for the first time through a series of reactions including formylation via Vilsmeier–Haack reaction, condensation with pyrrole, bromination with [Formula: see text]-Bromosuccinimide (NBS), oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), metal-templated cyclization of dibromodipyrrin-metal complexes with NaN[Formula: see text] and demetalization. All these triads were comprehensively characterized by [Formula: see text]H NMR, high-resolution mass spectrometry and UV-vis absorption. In addition, the structure of compound 6Ni was unambiguously determined by X-ray diffraction analysis, which showed that the two dihedral angles are both 86.65 (4)[Formula: see text] between each mean plane of porphyrin and that of central diazaporphyrin The UV-vis absorption spectra disclosed that the longest wavelengths of Soret bands and Q bands for these triads were observed at 429 and 642 nm, respectively. In contrast to diazaporphyrin-porphyrin dyads, diazaporphyrin dimers and diazaporphyrin monomers reported previously the molar extinction coefficients, particularly for triad 8Ni are much higher.

scholarly journals Quantification of acidic sites of nanoscopic hydroxylated magnesium fluorides by FTIR and 15N MAS NMR spectroscopy

RSC Advances ◽  
2015 ◽  
Vol 5 (109) ◽  
pp. 89659-89668 ◽  
Author(s):  
Felix Hemmann ◽  
Iker Agirrezabal-Telleria ◽  
Christian Jaeger ◽  
Erhard Kemnitz
Keyword(s):  
Nmr Spectroscopy ◽  
Mas Nmr ◽  
New Method ◽  
Extinction Coefficients ◽  
Surface Sites ◽  
Acidic Sites ◽  
Molar Extinction Coefficients

A new method is described for the calculation of molar extinction coefficients for quantitative FTIR measurements of acidic surface sites.

scholarly journals A spectrophotometric method for determination of fluorophore-to-protein ratios in conjugates of the blue fluorophore 7-amino-4-methylcoumarin-3-acetic acid (AMCA)

1990 ◽  
Vol 38 (1) ◽  
pp. 87-94 ◽  
Author(s):  
M W Wessendorf ◽  
S J Tallaksen-Greene ◽  
R M Wohlhueter
Keyword(s):  
Acetic Acid ◽  
Optical Density ◽  
Extinction Coefficient ◽  
Spectrophotometric Method ◽  
Extinction Coefficients ◽  
Beer's Law ◽  
Beer’S Law ◽  
The Given

7-Amino-4-methylcoumarin-3-acetic acid (AMCA) has been found to be a useful fluorophore for immunofluorescence. The present study describes a spectrophotometric method for determining the ratio of moles AMCA to moles protein (or the f/p ratio) in an AMCA-conjugated IgG. The concentration of a substance absorbing light can be determined spectrophotometrically using Beer's Law: Absorbance = Concentration x Extinction coefficient. From Beer's law, one can derive the following formula for determining the f/p ratio of AMCA-IgG conjugates: f/p = (epsilon 280IgG).A350 - (epsilon 350IgG).A280/(epsilon 350AMCA).A280 - (epsilon 280AMCA).A350 where A is the optical density of the conjugate at the given wavelength and epsilon is the extinction coefficient of a substance at the wavelength specified. Using conjugates of model proteins, it was found that the extinction coefficients of the AMCA moiety of AMCA-conjugated protein were 1.90 x 10(4) at 350 nm and 8.29 x 10(3) at 280 nm. Similarly, it was found that the extinction coefficients of swine IgG were 1.56 x 10(3) at 350 nm and 1.26 x 10(5) at 280 nm. Thus, for AMCA-conjugated swine IgG: f/p = (1.26 x 10(5)).A350 - (1.56 x 10(3)).A280/(1.47 x 10(4)).A280 - (6.42 x 10(3)).A350 [corrected]. Based on this formula, the f/p ratios of some AMCA-IgG conjugates useful for immunohistochemistry have been found to range between 6 and 24.

scholarly journals Atmospheric Extinction Coefficients in the IcBand for Several Major International Observatories: Results from the BiSON Telescopes, 1984–2016

2017 ◽  
Vol 154 (3) ◽  
pp. 89 ◽  
Author(s):  
S. J. Hale ◽  
W. J. Chaplin ◽  
G. R. Davies ◽  
Y. P. Elsworth ◽  
R. Howe ◽  
...  
Keyword(s):  
Atmospheric Extinction ◽  
Extinction Coefficients
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