Light Scattering and Extinction Measurements Combined with Laser-Induced Incandescence for the Real-Time Determination of Soot Mass Absorption Cross Section

2013 ◽  
Vol 85 (19) ◽  
pp. 9181-9188 ◽  
Author(s):  
Yiyi Wei ◽  
Lulu Ma ◽  
Tingting Cao ◽  
Qing Zhang ◽  
Jun Wu ◽  
...  
Keyword(s):  
Light Scattering ◽  
Real Time ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Absorption Cross ◽  
The Real ◽  
Soot Mass ◽  
Laser Induced Incandescence ◽  
Time Determination

scholarly journals A new optical-based technique for real-time measurements of mineral dust concentration in PM<sub>10</sub> using a virtual impactor

2020 ◽  
Vol 13 (7) ◽  
pp. 3799-3813
Author(s):  
Luka Drinovec ◽  
Jean Sciare ◽  
Iasonas Stavroulas ◽  
Spiros Bezantakos ◽  
Michael Pikridas ◽  
...  
Keyword(s):  
Real Time ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Mineral Dust ◽  
Dust Concentration ◽  
Absorption Cross ◽  
Mass Absorption ◽  
Aerosol Absorption ◽  
Virtual Impactor

Abstract. Atmospheric mineral dust influences Earth's radiative budget, cloud formation, and lifetime; has adverse health effects; and affects air quality through the increase of regulatory PM10 concentrations, making its real-time quantification in the atmosphere of strategic importance. Only few near-real-time techniques can discriminate dust aerosol in PM10 samples and they are based on the dust chemical composition. The online determination of mineral dust using aerosol absorption photometers offers an interesting and competitive alternative but remains a difficult task to achieve. This is particularly challenging when dust is mixed with black carbon, which features a much higher mass absorption cross section. We build on previous work using filter photometers and present here for the first time a highly time-resolved online technique for quantification of mineral dust concentration by coupling a high-flow virtual impactor (VI) sampler that concentrates coarse particles with an aerosol absorption photometer (Aethalometer, model AE33). The absorption of concentrated dust particles is obtained by subtracting the absorption of the submicron (PM1) aerosol fraction from the absorption of the virtual impactor sample (VI-PM1 method). This real-time method for detecting desert dust was tested in the field for a period of 2 months (April and May 2016) at a regional background site of Cyprus, in the Eastern Mediterranean. Several intense desert mineral dust events were observed during the field campaign with dust concentration in PM10 up to 45 µg m−3. Mineral dust was present most of the time during the campaign with an average PM10 of about 8 µg m−3. Mineral dust absorption was most prominent at short wavelengths, yielding an average mass absorption cross section (MAC) of 0.24±0.01 m2 g−1 at 370 nm and an absorption Ångström exponent of 1.41±0.29. This MAC value can be used as a site-specific parameter for online determination of mineral dust concentration. The uncertainty of the proposed method is discussed by comparing and validating it with different methods.

scholarly journals Experimental Determination of the Absorption Cross-Section and Molar Extinction Coefficient of Colloidal CdSe Nanoplatelets

2015 ◽  
Vol 119 (47) ◽  
pp. 26768-26775 ◽  
Author(s):  
Aydan Yeltik ◽  
Savas Delikanli ◽  
Murat Olutas ◽  
Yusuf Kelestemur ◽  
Burak Guzelturk ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Cross Section ◽  
Extinction Coefficient ◽  
Absorption Cross Section ◽  
Molar Extinction Coefficient ◽  
Absorption Cross

scholarly journals Determination of the absorption cross-sections of higher order iodine oxides at 355 nm and 532 nm

2020 ◽  
Author(s):  
Thomas R. Lewis ◽  
Juan Carlos Gómez Martin ◽  
Mark A. Blitz ◽  
Carlos A. Cuevas ◽  
John M. C. Plane ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Atmospheric Chemistry ◽  
Absorption Cross Section ◽  
Absorption Cross ◽  
Time Resolved ◽  
Flight Mass Spectrometry ◽  
Iodine Oxides ◽  
Photo Ionization

Abstract. Iodine oxides (IxOy) play an important role in the atmospheric chemistry of iodine. They are initiators of new particle formation events in the coastal and polar boundary layer and act as iodine reservoirs in tropospheric ozone-depleting chemical cycles. Despite the importance of the aforementioned processes, the photochemistry of these molecules has not been studied in detail previously. Here, we report the first determination of the absorption cross sections of IxOy, x = 2, 3, 5, y = 1–12 at λ = 355 nm by combining pulsed laser photolysis of I2/O3 gas mixtures in air with time-resolved photo-ionization time-of-flight mass spectrometry, using NO2 actinometry for signal calibration. The oxides selected for absorption cross section determinations are those presenting the strongest signals in the mass spectra, where signals containing 4 iodine atoms are absent. The method is validated by measuring the absorption cross section of IO at 355 nm, σ355 nm, IO = (1.2 ± 0.1) ×  10–18 cm2, which is found to be in good agreement with the most recent literature. The results obtained are: σ355 nm, I2O3 

On the determination of absorption cross section of colloidal lead halide perovskite quantum dots

2019 ◽  
Vol 151 (15) ◽  
pp. 154706 ◽  
Author(s):  
Joseph Puthenpurayil ◽  
Oscar Hsu-Cheng Cheng ◽  
Tian Qiao ◽  
Daniel Rossi ◽  
Dong Hee Son
Keyword(s):  
Quantum Dots ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Absorption Cross ◽  
Perovskite Quantum Dots ◽  
Halide Perovskite ◽  
Colloidal Lead ◽  
Lead Halide
Sign in / Sign up

Export Citation Format

Share Document