background & objectives: with regard to the mediastinum importance as a central region of thorax and its physiologic traffic of vital structures,the knowledge of mediastinal masses is necessary. this survey was conducted to determine the prevalence of different kinds of mediastinal tumors in patients who underwent surgical procedures at taleghani hospital between 2002 and 2006. methods & materi...

there has been a highly significant increase in the number of patients with malignant mediastinal tumors in the last four decades. since these lesions are infrequently encountered and there are very few reports in iran concerning this issue, we performed this study to review our institutional experience of medias-tinal masses and to compare differences in the clinical spectrum between our study...

In this paper, the dynamic stability analysis of a simply supported beam carrying a sequence of moving masses is investigated. Many applications such as motion of vehicles or trains on bridges, cranes transporting loads along their span, fluid transfer pipe systems and the barrel of different weapons can be represented as a flexible beam carrying moving masses. The periodical traverse of masses...

A functional relationship between two variables, applied mass to a weighing platform and estimated mass using Multi-Layer Perceptron Artificial Neural Networks is approximated by a linear function. Linear relationships and correlation rates are obtained which quantitatively verify that the Artificial Neural Network model is functioning satisfactorily. Estimated mass is achieved through recallin...

Having knowledge of stability of an underground space depends on stresses and strains around it. Creating underground tunnels leads to significant changes in the rock mass stress. Therefore, to achieve the necessary stability, stresses and deformations around the tunnel must be examined carefully. Usually, stress-strain behavior analysis is conducted in two-dimensional mode. This paper was cond...