Hot Cracking Phenomena in Welds Daniel W A fundamental dilemma confronting economists Judith Riley A fundamental dilemma confronting economists interested in estimating hospital cost functions is highlighted Its objective is to assist non native English speaking physicians or scientists in the task of writing research documents for medical journals and or oral presentations for medical congresses Different mechanisms of solidification cracking proposed in the past decades are summarized and new insight is particularly given into the mechanism of ductility dip cracking the initiation of stress corrosion cracking at hot cracks has been highlighted