Small cities, as a link among big and middle cities and urban villages, can be influential on service giving centers in urban hierarchy and regional development as a result, they are in many planners, focus of attention. Urban system in Iran, besides, are revealing the fact that small cities do not enjoy a great influence in giving services to their own boundaries. This also holds true in the c...

In this study, thermal Casimir-Polder potential is calculated for an atom in the presence of a dielectric sphere using the formula given in terms of the Green’s function. Then, the limiting cases of large and small sphere are investigated. In the limiting case of a large sphere, the formula of thermal potential for an excited atom in the presence of a dielectric half-space and then a perfectly ...