The scale includes a measurement known as PM2.5, which quantifies the concentration of particles smaller than 2.5 micrometres.
Dr. Prezant said the reason that the symptoms were so severe was probably that the concentration of particles was very high, and the exposures prolonged and repeated.
The ten areas with the highest concentration of particles are close to main roads, including Marylebone High Street, the City of London, Hyde Park, and King's Cross.
The researchers, who describe their work in The Proceedings of the National Academy of Sciences, say that by varying the concentration of particles and the strength of the magnetic field, the polymers can be made to work at different temperatures.
The concentration of particles with a diameter of 2.5 microns or less, hit 900 parts per million—40 times the level the World Health Organisation deems safe.
This process is used for the concentration of particles that have sufficiently different colours (the best contrast being black and white) to be detected by the naked eye.
Concentration of particles.
(b) The concentration of particles deposited on the QCM after exposure.
No obvious concentration of particles was observed in this regime (streaming DEP).
In this section, the effect of volume fraction, i.e., the concentration of particles, is studied.
where (widetilde {c}_{0}) indicates a reference number concentration of particles in the suspension.
