Accelerated life testing (ALT) is widely conducted to obtain failure-time data in a much shorter time and to make inference about reliability at normal conditions. The accuracy of the reliability prediction is dependent on well-designed ALT plans. A stepstress ALT allows the test condition to change at a given time or upon the occurrence of a specified number of failures. In this paper, we prop...

Introduction: The Detection of Microbial Life: If we are to find extant life on another planet, it is most likely to be extremely simple in nature, the equivalent of microbial life on Earth. Accordingly, strategies to detect extant life are focused on analyses for biological signatures in the soil zone. This was attempted in the Viking labeled release experiment on Mars, and more recently has i...

the goal of this study was to compare depression and quality of life in three auto immune diseases: psoriasis, vitiligo, and alopecia areata. from january 2009 until january 2010, 300 patients (100 with alopecia areata, 100 with psoriasis and 100 with vitiligo) who were randomly selected (by simple random selection) from outpatient clinic of razi hospital (center of skin diseases of tehran univ...