Conical refraction was produced by a transparent biaxial crystal of KGd(WO4)2 illuminated by a laser beam. The ring patterns at different distances from the crystal were magnified and projected onto a screen, giving rings whose diameter was 265 mm. Comparison with theory revealed all predicted geometrical and diffraction features: close to the crystal, there are two bright rings of internal con...

A novel approach based on the Poisson spot effect in a conventional optical lithography system is presented for fabricating large-scale ordered ring patterns at low cost, in which the pattern geometries are tuned by controlling the exposure dose and deliberate design of the mask patterns. Following this by cryogenic deep etching, the ring patterns are transferred into Si substrates, resulting i...

PURPOSE To analyze corneal curvature and visual acuity after asymmetric intrastromal corneal rings implantation, not following the nomogram proposed by the manufacturer. METHODS Seven eyes of seven keratoconus patients which had asymmetric corneal rings implanted in their corneal stroma were studied. RESULTS A flattening of the average corneal keratometry was noted in all patients, as well ...

Rapid and unplanned urbanisation can lead to altered local climate by increasing land surface temperature (LST), particularly in summer months. This study investigates the Urban Heat Island (UHI) Greater Cairo, Egypt, using remote sensing techniques estimate LST of months over 45 years (1986, 2000, 2017, predicted year 2030). The research objectives steps were, 1- mapped use/ cover (LULC), 2- c...

A protein interface can be as "wet" as a protein surface in terms of the number of immobilized water molecules. This important water information has not been explicitly taken by computational methods to model and identify protein binding hot spots, overlooking the water role in forming interface hydrogen bonds and in filing cavities. Hot spot residues are usually clustered at the core of the pr...

BACKGROUND An actomyosin-based contractile ring plays a pivotal role in cytokinesis. Despite the identification of many components of the ring, the steps involved in its assembly are unknown. The fission yeast Schizosaccharomyces pombe is an attractive organism in which to study cytokinesis because its cell cycle has been well characterized; it divides by medial fission using an actomyosin ring...

in this paper, we study some ring theoretic properties of the amalgamated duplication ring $rbowtie i$ of a commutative noetherian ring $r$ along an ideal $i$ of $r$ which was introduced by d'anna and fontana. indeed, it is determined that when $rbowtie i$ satisfies serre's conditions $(r_n)$ and $(s_n)$, and when is a normal ring, a generalized cohen-macaulay ring and finally a filter ring.