نتایج جستجو برای: pollution dispersion
تعداد نتایج: 130544 فیلتر نتایج به سال:
nowadays, air pollution is one of the main challenges worldwide. there have been significant improvements in air quality dispersion modelling. aermod is one of these models which is based upon the gaussian model. however, aermod has some limitations in terms of data input and output. therefore improving this model as well as developing new models adopted to our country is required to be address...
Detailed computational simulations of turbulent flows and pollution dispersion in city canyons have been carried out using the computational fluid dynamics package CFX-5, which is capable of using unstructured meshes and a variety of turbulence closure schemes. The simulations have been done for city canyons with simple to complex structures. As a validation of CFX-5, a roof garden test is cond...
Numerical solutions of the Helmholtz equation suffer from numerical pollution especially for the case of high wavenumbers. The major component of the numerical pollution is, as has been reported in the literature, the dispersion error which is defined as the phase difference between the numerical and the exact wave. The dispersion error for the meshless methods can be a priori determined at an ...
The simulation of radioactive pollutants dispersion is critical for emergency response of the nuclear terrorism. The radioactive “dirty bomb”, also called radiological dispersion device (RDD), produced and used by the terrorist to make fearful and radioactive pollution in general, has a great risk on humans. Numerical investigation of the impact of different configurations on radioactive pollut...
Air pollution predictions for environmental impact assessments are usually generated by Gaussian plume/puff models driven by observationally-based meteorological inputs. An alternative approach is to use prognostic meteorological and air pollution models, which are better founded than the Gaussian approach, but tend to require much expertise and time to set up and large computing resources to r...
Three dimensional simulations are carried out to estimate the effect of wind direction, wind speed and geometry on the flow and dispersion of vehicular pollutant in a street canyon. The pollutant sources are motor vehicles passing between the two buildings. Suitable emission factors for petrol and diesel vehicles at varying vehicle speed are used for the estimation of the rate of emission from ...
We welcome the Subcommittee’s review of “Air Pollution Modelling in Hong Kong”. Hong Kong’s air quality is a topic of great public concern. The lack of progress in improving air quality has led many to question the effectiveness of our air quality management system. Most people understand that air quality modelling is important for our air quality management system because of its role in air qu...
With the acceleration of urbanization and industrialization, urban air pollution has become a serious threat to the health of urban residents. In this study, to investigate health hazards caused by air pollution for urban residents, concentrations of main air pollutants and annual coal consumption amounts during the period from 2000 to 2013 were analyzed. Our results showed that economic losses...
This paper examines conditions under which domestic political institutions mediate the effect of trade competition on regulatory races in the environmental area. We focus on the role of domestic veto players in shaping governments' policy responses to trade competition which are reflected eventually in air (Sulphur dioxide, SO2) and water pollution (Biochemical Oxygen Demand, BOD) intensity lev...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید