. ▁His ▁areas ▁of ▁research ▁were : ▁▁ ▁F ract ure ▁mechan ics ▁ ▁The ▁theory ▁of ▁fluid ▁and ▁gas ▁flows ▁in ▁por ous ▁media ▁ ▁The ▁mechan ics ▁of ▁a ▁non - class ical ▁de form able ▁sol ids ▁ ▁Tur bul ence ▁ ▁Self - similar ities , ▁non linear ▁waves ▁and ▁intermediate ▁asympt ot ics . ▁ ▁Awards ▁and ▁hon ors ▁▁▁ 1 9 7 5 ▁– ▁Foreign ▁Honor ary ▁Member , ▁American ▁Academy ▁of ▁Arts ▁and ▁Sciences ▁▁ 1 9 8 4 ▁– ▁Foreign ▁Member , ▁Dan ish ▁Center ▁of ▁App lied ▁Mathemat ics ▁& ▁Mechan ics ▁▁ 1 9 8 8 ▁– ▁Foreign ▁Member , ▁Polish ▁Society ▁of ▁The oret ical ▁& ▁App lied ▁Mechan ics ▁▁ 1 9 8 9 ▁– ▁Doctor ▁of ▁Technology ▁Honor is ▁C aus a ▁at ▁the ▁Royal ▁Institute ▁of ▁Technology , ▁Stockholm , ▁Sweden ▁▁ 1 9 9 2 ▁– ▁Foreign ▁Associ ate , ▁U . S . ▁National ▁Academy ▁of ▁Engineering ▁▁ 1 9 9 3 ▁– ▁Fellow , ▁Cambridge ▁Philosoph ical ▁Society ▁▁ 1 9 9 3 ▁– ▁Member , ▁Academia ▁Europ ae a ▁▁ 1 9 9 4 ▁– ▁Fellow , ▁Gon ville ▁and ▁C ai us ▁College , ▁Cambridge ; ▁( since ▁ 1 9 9 9 , ▁Honor ary ▁Fellow ) ▁▁ 1 9 9 5 ▁– ▁Lag range ▁Medal , ▁Acc adem ia ▁Nazionale ▁dei ▁L ince i ▁▁ 1 9 9 5 ▁– ▁Mod esto ▁Pan etti ▁Prize ▁and ▁Medal ▁▁ 1 9 9 6