Ultrafine particles (UFP; diameter less than 100 nm) are ubiquitous in urban air, and an acknowledged risk to human health. At the same time, little is known about immission situation at typical sites such as high-traffic roads, residential areas with a high amount of solid fuels for home heating or commercial industrial due missing legal requirements measurements UFP. Therefore, UFP were measu...

Air pollution caused by particulate matter (PM) is a current problem in many cities. With the introduction of strict emission limits and electric cars, lower particle production expected future. However, there are sources particles that cannot be easily influenced. These include resuspension, where deposited on surfaces re-enter air, causing multiple times. Resuspension can account for up to 18...

Urban street patterns form planar networks whose empirical properties cannot be accounted for by simple models such as regular grids or Voronoi tesselations. Striking statistical regularities across different cities have been recently empirically found, suggesting that a general and detail-independent mechanism may be in action. We propose a simple model based on a local optimization process co...

Drivers in urban neighborhoods who patrol streets, seeking inexpensive on-street parking create a significant fraction of measured traffic congestion. The pool of drivers patrolling at any time can be modeled as a queue, where ‘queue service’ is the act of parking in a recently vacated parking space and queue discipline is SIRO – Service In Random Order. We develop a queueing model of such driv...

Large-eddy simulation (LES) equipped with the one-equation subgrid-scale (SGS) model is employed to investigate the mean flows and turbulence over idealized two-dimensional (2D) street canyons in various unstable thermal stratifications. The building-height-tostreet-width (aspect) ratio is equalto unity so the flows inside a street canyon are in the skimming flow regime. Periodic boundaries are...

Abstract In this study, the effects of roadside building roof shapes and tree plantings on dispersion vehicle exhaust gas pollution in urban street have been carefully explored. Three typical shapes, i.e., flat, triangle round are considered present work. Firstly, numerical simulations air transport atmospheric turbulent boundary layer with/without vegetation canopy performed using Computationa...

In recent years, the impact of surface heat islands in urban street canyons has become increasingly apparent. However, research on use trees to mitigate remains limited. To address this gap, study combines experiments and simulations analyze cooling effect temperatures under varying timeframes layouts an east–west canyon. The results reveal that temperature road decreases by 10–15 °C, which is ...