Massive Stars: Input Physics and Stellar Models

We present a general overview of the structure and evolution of massive stars of masses a parts per thousand yen12 M (aS (TM)) during their pre-supernova stages. We think it is worth reviewing this topic owing to the crucial role of massive stars in astrophysics, especially in the evolution of galaxies and the universe. We have performed several test computations with the aim to analyze and discuss many physical uncertainties still encountered in massive-star evolution. In particular, we explore the effects of mass loss, convection, rotation, C-12(alpha,gamma)O-16 reaction and initial metallicity. We also compare and analyze the similarities and differences among various works and ours. Finally, we present useful comments on the nucleosynthesis from massive stars concerning the s-process and the yields for Al-26 and Fe-60.