The range distributions of low-energy nitrogen and oxygen (2-3 keV) ions is silicon are measured and compared with these available in theories. The nitrogen distribution is very close to a Gaussian distribution as predicted by theory. The oxygen profile however, indicates a surface localized peak along with a shoulder and a long tail into the sample. The surface peak is beleived to he the resul...

The principle of surface segregation and subsequent self-assembly of mixtures of molecules has been utilized to create cellulosic films that have properties characteristic of smart materials. This has been achieved by solventcasting a blend of cellulose propionate and an fluorine (F)-containing cellulose ester derivative. Evidence suggests that surface segregation of the F-containing species ta...

We study segregation of granular mixtures in the continuous avalanche regime (for frequencies above 1 rpm) in thin rotating drums using a continuum theory for surface flows of grains. The theory predicts profiles in agreement with experiments only when we consider a flux-dependent velocity of flowing grains. We find the segregation of species of different size and surface properties, with the s...

In texture segregation, an example of scene segmentation, we can discern two different processes: texture boundary detection and subsequent surface segregation [Lamme, V. A. F., Rodriguez-Rodriguez, V., & Spekreijse, H. Separate processing dynamics for texture elements, boundaries and surfaces in primary visual cortex of the macaque monkey. Cerebral Cortex, 9, 406-413, 1999]. Neural correlates ...

We have explored the Escherichia coli chromosome architecture by genetic dissection, using a site-specific recombination system that reveals the spatial proximity of distant DNA sites and records interactions. By analysing the percentages of recombination between pairs of sites scattered over the chromosome, we observed that DNA interactions were restricted to within subregions of the chromosom...

Tests are reported of the possibility that local information from contour junctions and from corners of intersecting surfaces is used for perceived surface segregation. Stimuli were two intersecting squares with small disks occluding different parts of the squares. The perceived segregation of the squares from one another decreased as the amount of occlusion of parts of the squares increased. T...