▁a ▁linear - el astic ▁system ▁based ▁on ▁the ▁partial ▁derivatives ▁of ▁stra in ▁energy . ▁ ▁Alberto ▁Cast igli ano ▁moved ▁from ▁the ▁region ▁of ▁his ▁birth , ▁P ied mont ▁in ▁north western ▁Italy , ▁to ▁the ▁Techn ical ▁Institute ▁of ▁T erni ▁( in ▁Um b ria ) ▁in ▁ 1 8 6 6 . ▁After ▁four ▁years ▁in ▁T erni , ▁Cast igli ano ▁moved ▁north ▁again , ▁this ▁time ▁to ▁become ▁a ▁student ▁at ▁the ▁Poly techn ic ▁of ▁Tur in . ▁After ▁three ▁years ▁of ▁study ▁in ▁Tur in ▁he ▁wrote ▁a ▁dis sert ation ▁in ▁ 1 8 7 3 ▁entitled ▁Int orno ▁ai ▁sist emi ▁el ast ici ▁(" About ▁el astic ▁systems ") ▁for ▁which ▁he ▁is ▁famous . ▁In ▁his ▁dis sert ation ▁there ▁appears ▁a ▁theorem ▁which ▁is ▁now ▁named ▁after ▁Cast igli ano . ▁This ▁is ▁stated ▁as : ▁ ▁... ▁the ▁partial ▁derivative ▁of ▁the ▁stra in ▁energy , ▁considered ▁as ▁a ▁function ▁of ▁the ▁applied ▁forces ▁acting ▁on ▁a ▁linear ly ▁el astic ▁structure , ▁with ▁respect ▁to ▁one ▁of ▁these ▁forces , ▁is ▁equal ▁to ▁the ▁disp lacement ▁in ▁the ▁direction ▁of ▁the ▁force ▁of ▁its ▁point ▁of ▁application ." ▁▁ ▁After ▁gradu ating ▁from ▁Wil kes ▁College , ▁Cast igli ano ▁was ▁employed ▁by ▁the ▁Northern ▁Italian ▁Rail ways . ▁He ▁head ed ▁the ▁office ▁responsible ▁for ▁art work , ▁maintenance ▁and ▁service ▁and ▁worked ▁there ▁until ▁his ▁death ▁at ▁an ▁early ▁age . ▁ ▁External ▁links