Background: Air pollution and concerns about health impacts have been raised in metropolitan cities like Tehran. Trend and prediction of air pollutants can show the effectiveness of strategies for the management and control of air pollution. Artificial neural network (ANN) technique is widely used as a reliable method for modeling of air pollutants in urban areas. Therefore, the aim of current ...

Process control charts are proven techniques for improving quality. Specifying the control limits is the most important step in designing a control chart. The presence of outliers may extremely affect the estimates of parameters using classical methods. Robust estimators which are not affected by outliers or the small departures from the model assumptions are applied in this paper to specify th...

Currently, within the National Emissions Inventory (NEI), airport, including aircraft, emissions are estimated at the county level as area sources and are represented only in the surface layer of air quality models. In reality, however, aircraft release their emissions both on the surface and while airborne. Therefore, in order to provide a realistic representation of all emissions from aircraf...

The two dimensional with a triangular-lattice cross sectional pattern of elliptic air holes photonic crystal fiber (PCF) is investigated in detail by use of plan wave expansion (PWE) method. Using PWE method, the dependence of dispersion on structure parameters is calculated. We compared the dispersion relations between the circular air holes PCF and the elliptic one. We find that the flatter d...

it is well known that, contaminant transportation is a major problem in coastal zones and has to be faced when coastal structures are being planned. sea pollution not only causes environmental damage, but also impacts quality and population of sea resources. oil is the most important pollutant, pollutants emanating from industries, ships, drilling and exploration in the seabed, ship sewage, tox...

This study investigates the effect of air inlet size on (i) the flowfield generated in a dry powder inhaler, and (ii) the device-specific resistance, and the subsequent effect on powder deagglomeration. Computational fluid dynamics (CFD) analysis was used to simulate the flowfield generated in an Aerolizer with different air inlet sizes at 30, 45, and 60 l/min. Dispersion performance of the mod...

 This article addresses the analysis of the mechanism of natural air flow around the residential buildings  and the effect of the form of residential buildings on air flow among four building forms in Tehran. The aim of this research is to study the effect of the form of residential buildings on the mechanism of natural air flow with the purpose of optimally utilizing clean air. The research me...

Rapid urbanization and severe air quality deterioration in Pakistan have increased citizens’s concern towards air pollution. This study, conducted in November, 2016, aimed to develop relationship between degraded air quality and resident’s willingness to pay for improved air quality in city of Lahore, Pakistan through contingent valuation method to quantify an individual’s willingness to pay fo...