Recent abundance determinations based on recombination lines in several emission-line nebulae yield ionic abundances several times larger than those derived from forbidden lines. These results cast uncertainty over all abundance determinations in such objects. One possible explanation for these discrepancies frequently cited in the literature is the presence of chemical inhomogeneities. We have...

We continue our analysis of the physics of quantum lattice gas automata (QLGA). Previous work has been restricted to periodic or in nite lattices; simulation of more realistic physical situations requires nite sizes and non-periodic boundary conditions. Furthermore, envisioning a QLGA as a nanoscale computer architecture motivates consideration of inhomogeneities in the `substrate'; this transl...

MRI intensity inhomogeneities can be attributed to imperfections in the RF coils or some problems associated with the acquisition sequences. The result is a slowly-varying shading artifact over the image that can produce errors with conventional intensity-based classification. The removal of the spatial intensity inhomogeneities from MR images is difficult because the inhomogeneities could chan...

The origin of the microscopic inhomogeneities in InxGa12xAs layers grown on GaAs by molecular beam epitaxy is analyzed through the optical absorption spectra near the band gap. It is seen that, for relaxed thick layers of about 2.8 mm, composition inhomogeneities are responsible for the band edge smoothing into the whole compositional range (0.05,x,0.8). On the other hand, in thin enough layers...

This contribution to the Proceedings is based on the talk given at the Conference on Birth of the Universe and Fundamental Physics, Rome, May 18-21, 1994. Some selected topics of the subject are reviewed: Models of Primordial Fluctuations; Reconstruction of the Cosmological Density Probability Distribution Function (PDF) from Cumulants; PDFs in the Zel’dovich Approximation and from Summarizing ...