pdf creator Elsevier 1 pdf encrypted no 1 pdf files total 1 pdf optimized no 1 pdf pages avg 13 pdf pages max 13 pdf pages min 13 pdf pages total 13 pdf size avg 1700652 pdf size max 1700652 pdf size min 1700652 pdf size total 1700652 pdf type SHA-256 1 pdf version 1.4 1