Showing papers by "Prashant Kumar published in 2008"

TL;DR: The PNCs in each size range, during all wind directions, were better described by a proposed two regime model (traffic-dependent and wind-dependent mixing) than by simply assuming that the PNC was inversely proportional to the wind speed or by fitting the data with a best-fit single power law.

TL;DR: In this paper, a fast-response differential mobility spectrometer (DMS500) was used to measure the vertical variation of particle number distributions (PNDs) and concentrations in a street canyon is the result of the competing influences of meteorology, traffic and transformation processes.

TL;DR: The main aims of the measurements were to investigate the dependence of particle number distributions and concentrations and their vertical variations on wind speed, wind direction, traffic volume, and to estimate the particle number flux (PNF) and the particles number emission factors (PNEF) for typical urban streets and driving conditions.

TL;DR: In this paper, the authors used a particle spectrometer with various lengths of sampling tube to measure the particle number distributions in the 5-2738 nm range. But the results showed that the laminar flow model did not reflect the observations for small Re. This may be due to the sampling tubes not being kept straight or other complications.