A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Nanometric-sized atmospheric particulate studied by magnetic analyses
Abstract The PM10 particulate collected on filters from four air-quality monitoring stations in the city of Torino (Italy) has been investigated by means of detailed magnetic measurements, transmission electron microscopy and energy-dispersive X-ray analysis. The magnetic fraction mainly consists of magnetite-like ferrimagnetic phase and a minor contribution from a high-coercivity phase, which probably results from oxidation of the smallest magnetite grains. The magnetic particles have a grainsize mostly comprised in the single-domain/superparamagnetic range with a large prevalence of the latter. A large fraction of superparamagnetic particles of nanometric dimension were identified in the particulate matter by magnetic techniques and directly observed by electron microscopy. Energy dispersive X-ray elemental analysis showed that ultrafine Fe-rich particles have a spherical shape and are often associated with other metals. The analysis of daily-average variations of magnetic particle concentration found a close correlation of magnetic moment with total nitrogen oxides suggesting that the largest part of magnetic minerals in particulate matter originates from anthropogenic combustion processes. A simple model linking total nitrogen oxides with magnetic particles, for the city of Torino, is proposed. The correlation of magnetic moments and PM10 mass is generally poor because of the different sources of the latter, therefore in the studied contest PM10 is not a good proxy for ultrafine magnetic particles.
Nanometric-sized atmospheric particulate studied by magnetic analyses
Abstract The PM10 particulate collected on filters from four air-quality monitoring stations in the city of Torino (Italy) has been investigated by means of detailed magnetic measurements, transmission electron microscopy and energy-dispersive X-ray analysis. The magnetic fraction mainly consists of magnetite-like ferrimagnetic phase and a minor contribution from a high-coercivity phase, which probably results from oxidation of the smallest magnetite grains. The magnetic particles have a grainsize mostly comprised in the single-domain/superparamagnetic range with a large prevalence of the latter. A large fraction of superparamagnetic particles of nanometric dimension were identified in the particulate matter by magnetic techniques and directly observed by electron microscopy. Energy dispersive X-ray elemental analysis showed that ultrafine Fe-rich particles have a spherical shape and are often associated with other metals. The analysis of daily-average variations of magnetic particle concentration found a close correlation of magnetic moment with total nitrogen oxides suggesting that the largest part of magnetic minerals in particulate matter originates from anthropogenic combustion processes. A simple model linking total nitrogen oxides with magnetic particles, for the city of Torino, is proposed. The correlation of magnetic moments and PM10 mass is generally poor because of the different sources of the latter, therefore in the studied contest PM10 is not a good proxy for ultrafine magnetic particles.
Nanometric-sized atmospheric particulate studied by magnetic analyses
Saragnese, F. (author) / Lanci, L. (author) / Lanza, R. (author)
Atmospheric Environment ; 45 ; 450-459
2010-09-24
10 pages
Article (Journal)
Electronic Resource
English
Nanometric Si~3N~4 particulate-reinforced aluminum composite
| British Library Online Contents | 1996
Nanometric powders and sintered ceramics studied by atomic force microscopy
| British Library Online Contents | 1998
The performance of aluminium-matrix composites with nanometric particulate Si-N-C reinforcement
| British Library Online Contents | 1999
High temperature creep behavior of nanometric Si~3N~4 particulate reinforced aluminium composite
| British Library Online Contents | 1997
Nanometric Architecture of SmCo~5 Related Magnetic Properties
| British Library Online Contents | 2001