polycyclic aromatic hydrocarbons (pahs) are a group of organic compounds made up of two or more fused benzene rings in linear, angular or cluster arrangements. the pahs are formed by incomplete combustion or high temperature pyrolytic process involving organic matter. thirty sampling sites were selected to characterize the pahs concentrations in ambient air in tehran. sixteen pahs were measured...

fuzzylogic computes a multi-criteria evaluation by means of either a boolean analysis, weightedlinear combination (wlc) and ordered weighted averaging (owa) of factor images. owa works withstandardized factor images and employs a variant of the wlc. it takes into account the risk associated withthe decision and degree of tradeoff associated with the variables in the analysis. in this research, ...

In general, Geographical Information System (GIS) has four main components, namely data input, data model, data analysis and manipulation, and data presentation. These components are vital in order to make GIS fully functional. This paper is centred upon the research activities of selecting, synthesis, designing and implementing the data model components. The primary research issue is to develo...

background and purpose: an appropriate solid waste (sw) disposal has been a major problem in municipal environment. the use of landfills is the most economical and environmentally acceptable method for the disposal of sws all over the world. however, landfill leachate can cause environmental issues such as soil and ground water pollution. so, finding suitable land fill site is one of the most s...

Assessment of soil erosion is expensive and intensively long exercise. A number of parametric models have been developed to forecast soil erosion at drainage basins, yet Universal Soil Loss Equation, popularly known as USLE model is most widely used empirical formula for estimating annual soil loss from agricultural basins. With the advance of Remote Sensing technique it becomes possible to mea...