Portrait of Mark

Portrait

Born in 1944, I grew up in a world in which polio was both a gripping fear and real threat. Then in a matter of a few years-polio was eradicated by a vaccine developed by Jonas Salk. Later I learned that Salk's efforts were built on pioneering work of many others, including John Enders, Thomas Weller and Frederick Robbins (Nobelists, 1954), and David Bodian, who pioneered studies of polio patho...

فرایند دریافت E- Mark

با گسترش روزافزون صنعت حمل‌و‌نقل درجهان و ارتقای استانداردها، تدوین و اجرای استانداردهای بین‌المللی، یک امر ضروری به‌نظر می‌رسد. E- Mark یک مجموعه قانون‌های هماهنگ بین‌المللی برای خودرو و قطعه‌های آن است که تمامی تولیدکنندگان وسیله‌های نقیله و قطعه‌ها ملزم به رعایت آن هستند. تولیدکنندگان تایر نیز از این امر مستثنی نیستند و باید برای تایرهای خود این مجوز را دریافت کنند. در این مقاله روش دریافت E...

Self Portrait of Youth

Google Portrait

A portrait of cadmium.

In early-nineteenth-century Prussia, quality control of pharmaceuticals was entrusted to government-appointed physicians. In 1817, one such physician, Johann Roloff, became suspicious of a batch of zinc oxide that could be traced back to the factory of Karl Hermann. Roloff’s preliminary tests suggested that the samples contained arsenic, and so Hermann — worried about the reputation of his busi...