prediction of spatial and temporal variation of water quality is vital for managing pollutantsdisposal into the rivers. depletion of dissolved oxygen (do) takes place due to the consumption of oxygen bymicrobes to digest bio-degradable pollutants which enter a water course. reaeration takes place in a specificrate depending on do deficit. many investigators have formulated models as an alternat...

The decay features of thirty-nine monuments built with granite stones and presenting diverse architectural characteristics, date of construction and environment characteristics (including exposition conditions, traffic intensity, etc) are compare in order to discuss decay patterns and susceptibility of granite types applied in architectural works. Decay patterns of biotite-rich medium to fine-g...

Understanding local-scale transport and dispersion of pollutants emitted from traffic sources is important for urban planning and air quality assessments. Predicting pollutant concentration patterns in complex environments depends on accurate representations of local features (e.g., noise barriers, trees, buildings) affecting near-field air flows. This study examined the effects of roadside bar...

A method to calculate geometrical input parameters for urban dispersion models is presented. Two cases are considered according to the relative size of the pollutant plume compared to the building size. Applying image processing techniques to urban Digital Elevation Models (DEMs, 3-D urban databases), simple geometrical parameters over extensive urban areas are calculated. Some preliminary resu...

Despite the improvement made in controlling local air pollution, urban areas are undergoing increasing environmental pressures and poor air quality is one of the major concerns. Recently, much attention has focused on the relationship between urban form and sustainability. There are indications that the density and the overall shape of cities can have implications on street level ventilation an...

his investigation was carried out to reveal the impact of solar radiation on wind flow structure and pollutant dispersion in an urban street canyon of aspect ratio of one using the computational fluid dynamic (cfd) technique. the simulation results (velocity and concentration data) show that heating from building wall surfaces and ground lead to strong buoyancy forces as the air is heated by th...

Due to the chaotic nature of atmospheric dispersion, small deviations, e.g., numerical errors in dispersion simulations, increase rapidly over time. Therefore, the accuracy of backward simulations is limited. In the paper, the degree of the fulfillment of time-reversibility over different time periods is investigated by a Lagrangian dispersion model at a global scale using pollutant clouds cons...

Air pollution caused by motor vehicles is one of the most serious problems of civilized society. The aim of this paper is to develop a decision support system that can be used by authorities to reduce air pollution from road transport. The essence of this system consists of mathematical sub-models based on the computer program methodology for calculating emissions from road transport, (COPERT I...