scholarly journals Temporal Variation of Radiocarbon Concentration in Airborne Particulate Matter in Tokyo

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 485-490 ◽  
Author(s):  
Ken Shibata ◽  
Michio Endo ◽  
Naomichi Yamamoto ◽  
Jun Yoshinaga ◽  
Yukio Yanagisawa ◽  
...  
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Size Fraction ◽  
Airborne Particulate Matter ◽  
Coarse Particles ◽  
Particle Size Fraction ◽  
Airborne Particulate ◽  
Carbonaceous Particles ◽  
Secondary Particles ◽  
Insight Into

The temporal radiocarbon variation (in terms of percent Modern Carbon: pMC) of size-fractionated airborne particulate matter (APM) collected in Tokyo between April 2002 and February 2003 was analyzed in order to get an insight into the sources of carbonaceous particles. Results indicated significant biogenic origins (approximately 40 pMC on average). In general, the seasonal and particle size variations in pMC were relatively small, with 2 exceptions: elevated pMC in coarse particles in April and October 2002, and relatively low pMC in the finest particle size fraction collected in August 2002. The former finding could be tentatively attributed to the abundance of coarse particles of biological origins, such as pollen; the latter might be due to an increased fraction of anthropogenic secondary particles.

ANALYSIS OF AIRBORNE PARTICULATE MATTER COLLECTED AFTER AN ERUPTION EPISODE OF THE POPOCATÉPETL VOLCANO

2003 ◽  
Vol 13 (03n04) ◽  
pp. 133-139 ◽  
Author(s):  
F. ALDAPE ◽  
J. FLORES M.
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Mexico City ◽  
Airborne Particulate Matter ◽  
Airborne Particulate ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Two Samples ◽  
Popocatépetl Volcano ◽  
Popocatepetl Volcano

Samples of airborne particulate matter were collected in four sites along an east-west line from the Popocatépetl volcano after the eruption episode of June 30, 1997. The Popocatépetl volcano, with variable activity since it was known, is currently under low but continuous activity prolonged for almost one decade, with occasional moderate eruption episodes producing mainly fumes, ashes and volcanic dusts. The main objective of this study is to determine whether or not some elements have increased their presence in the atmosphere as a result of the volcanic activity, and also if some others, not usually found in urban aerosols, have appeared because of the same reason. In addition, the information obtained will be a source of scientific data for health risk assessment of the population exposed to volcanic emanations. The sample collection was performed on alternate days from July 10 to August 13 1997 in Puebla and Atlixco in Puebla State. Tlalpan within Mexico City, and Salazar in the State of Mexico. Two samples a day were taken in two periods: 7-19 h and 19-7 h. The samplers separated particles into two particle size fractions. PM25 and PM15. Elemental concentrations were determined by PIXE and the results obtained showed increased concentrations of mainly Ti and Fe in all sampling sites, thus indicating a long range transportation of volcanic dusts in both particle size fractions. Concentrations of Ti were found clearly above the average values of urban areas such as Mexico City, and although this element can be considered of low toxicity, the biological, metabolic and toxic effects on human beings are still under investigation.

Size distribution and single particle characterization of airborne particulate matter collected in a silicon carbide plant

2019 ◽  
Vol 21 (3) ◽  
pp. 564-574 ◽  
Author(s):  
Torunn Kringlen Ervik ◽  
Nathalie Benker ◽  
Stephan Weinbruch ◽  
Yngvar Thomassen ◽  
Dag G. Ellingsen ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Particle Size ◽  
Particulate Matter ◽  
Size Range ◽  
Airborne Particulate Matter ◽  
Aerodynamic Diameter ◽  
Particle Characterization ◽  
Airborne Particulate ◽  
Detailed Characterization

A detailed characterization of particles as a function of particle size in the size range of 10 nm to 10 µm (aerodynamic diameter) collected from a silicon carbide plant in Norway.

Investigation of the Christiansen Effect in the Mid-Infrared Region for Airborne Particles

2007 ◽  
Vol 61 (8) ◽  
pp. 860-866 ◽  
Author(s):  
Matthew J. Pollard ◽  
Peter R. Griffiths ◽  
Koichi Nishikida
Keyword(s):  
Particulate Matter ◽  
Airborne Particulate Matter ◽  
Wavelength Dependence ◽  
Infrared Region ◽  
Incident Radiation ◽  
Airborne Particles ◽  
Airborne Particulate ◽  
Mid Infrared ◽  
Airborne Dust ◽  
Insight Into

During measurements of open-path Fourier transform infrared spectra, airborne dust may be present in the infrared beam. We have investigated the feasibility of identifying and quantifying the airborne particulate matter from spectra measured in this way. Although the results showed that analysis of the particulate matter was not able to be performed from these spectra, insight into the size and wavelength dependence of the Christiansen effect at wavelengths where the particles absorb strongly was obtained. Airborne particles larger than or equal to the wavelength of the incident radiation give rise to asymmetrical features in the spectrum caused by the Christiansen effect. However, the transmittance at wavelengths where the refractive index of the particles equals that of the atmosphere never reaches 1.0 because of absorption by the particles. As the particle size becomes much smaller than the wavelength of the incident radiation, the Christiansen effect becomes less pronounced and eventually is not exhibited.

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