Fabrication techniques are the foundation of physical technology, and are thus of fundamental interest. Physical principles indicate that nanoscale systems will be able to fabricate a wide range of structures, operating with high productivity and precise molecular control. Advanced systems of this kind will require intermediate generations of system development, but their components can be desi...

The analysis of physical properties connected to the electron spin in terms of spin densities requieres some caution : i) Spin densities cannot be always calculated or discussed in the frame of standard independentparticle model (as the restricted Hartree-Fock theory), neither in the frame of amended spin-unrestricted independent particle models. The former/ neglecting spin-polarization effects...

astrophysics is becoming now an integral part of general physics. considering the black hole theory ,which is a new and exciting branch of relativistic astrophysics, we see many connections between elementary particle physics and astrophysics. in this article we attempt to explain the development of star physics ,in an easy ,understandable manner. previous knowledge of relativistic theory or cl...