welders exposure to nickel and hexavalent chromium in welding fumes is associated with increase of cancer risk in welders. in this study we calculated cancer risk due to exposure to these compounds in welders.the role of exposure parameters in welders on derived incremental lifetime cancer risk were determined by stochastic modeling of cancer risk. input parameters were determined by field inve...

Introduction: Solar radiation has a major role in design, utilization, development, and planning of solar energy. The most important source of natural ultraviolet radiation is the sun, which has an important role in many biologic processes. Some of these processes are useful, like the production of vitamin D in the body, or curing rickets, and some of them are not, such as ski...

Audiovisual devices such as satellite and conventional televisions can offer easy access to authentic programs which are considered to be a rich source of language input for SLA (Second Language Acquisition). The immediacy of various audiovisual programs ensures that language learners’ exposure is up-to-date and embedded in the real world of native speakers. In the same line, in the present pap...

Audiovisual devices such as satellite and conventional televisions can offer easy access to authentic programs which are considered to be a rich source of language input for SLA (Second Language Acquisition). The immediacy of various audiovisual programs ensures that language learners’ exposure is up-to-date and embedded in the real world of native speakers. In the same line, in the present pap...