introduction air pollution is one of the critical challenges in metropolitans around the world. according to world health organization (who), three millions people die from air pollution annually. in some studies mortality costs by air pollution was estimated. social cost of air pollution was estimated 28990 billions rials in tehran city. the mortality cost by air pollution was estimated about ...

A network induced by wealth is a social network model in which wealth induces individuals to participate as nodes, and every node in the network produces and accumulates wealth utilizing its links. More specifically, at every time step a new node is added to the network, and a link is created between one of the existing nodes and the new node. Innate wealthproducing ability is randomly assigned...

Environmental monitoring and classification of rivers in the northern hemisphere is frequently hampered by lack of infrastructure in the scarcely populated areas of the north. Carefully designed economical methods are important. Analysis of 15 constituents in 14 rivers in Iceland show that monthly samples for a period of 1 year are sufficient for 5 classification provided that the correct stati...

One of the least understood qualities of radon and its associated risk is the relationship between its concentration at the source and the statistical distribution of concentrations found in indoor environments. In this presentation I will clarify several of the important factors and provide a simple statistical model for discussing and communicating distribution qualities of our primary source...