objective: an important factor in the prevention of industrial accidents is the employees’ ability to maintain their awareness of the work situation, understand the information it holds, and predict the development of the situations. in this study, we examined the role of work stress and sleepiness in predicting work situation awareness among workers.  methods: the present study was a cross-sec...

This paper investigates the effect of different methods of carbon nanotubes distribution in a thin matrix on static and dynamic behavior of the nanocomposite. Five different symmetric patterns of distribution are considered, including four parabolic patterns and a linear one. For each pattern, the effective mechanical properties of the resultant nanocomposite are calculated using the rule of mi...

One of the common failure modes of thin cylindrical shell subjected external pressure is buckling. The buckling pressure of these shell structures are dominantly affected by the geometrical imperfections present in the cylindrical shell which are very difficult to alleviate during manufacturing process. In this work, only three types of geometrical imperfection patterns are considered namely (a...

This paper investigates the effect of different methods of carbon nanotubes distribution in a thin matrix on static and dynamic behavior of the nanocomposite. Five different symmetric patterns of distribution are considered, including four parabolic patterns and a linear one. For each pattern, the effective mechanical properties of the resultant nanocomposite are calculated using the rule of mi...

In this work, the method of iterative Fourier transform phase reconstruction, conventionally used in holography and optical image reconstruction, is applied to phase only synthesis of antenna patterns. The method is applied to two types of pattern synthesis problems: "main lobe beam shaping" and "side-lobe-level reduction". The proposed method is most useful in the efficient employment of attai...

introduction : the purpose of this study was to examine and compare the social adjustment in balanced and non-balanced patterns of the parent-child relationship.  methods : the research population was all female gifted students in the farzanegan high school in the first educational district of tehran in 2013-14. the sample research included 96 female gifted students who answered the parent-chil...