We present this case because of its rarity, as we have not found anything similar in young non-neoplastic patients. We describe the case of a 36 years-old woman with long-term dysphagia for solids. Her past medical history reveals an esophagoplasty with subcutaneous colon interposition, which was performed in Romania 15 years before, due to caustic stricture. Stenosis of the cologastric anastom...

A method to design Ronchi-Hartmann screens for improved alignment in the testing of fast plano-convex spherical lenses is presented. We design null screens that produce aligned straight fringes for observed patterns. The designs of these null screens are based on knowledge of the caustic by refraction. A qualitative test for a lens is presented.

We present the influence of the special relativistic effects of aberration and light travel time delay on pulsar high-energy lightcurves and polarization characteristics predicted by three models: the two-pole caustic model, the outer gap model, and the polar cap model. Position angle curves and degree of polarization are calculated for the models and compared with the optical data on the Crab ...

We consider the problem of lensing by binary galaxies idealized as two isothermal spheres. This is a natural extension of the problem of lensing by binary point masses first studied by Schneider & Weiss (1986). In a wide binary, each galaxy possesses individual tangential, nearly astroidal, caustics and roundish radial caustics. As the separation of the binary is made smaller, the caustics unde...

Cotton fibres were subjected to cleaning process and then characterized for maturity. Decrystallisation and swelling processes with caustic soda, ethanol, propan-2-ol and Trichloroethene on the native fibres were carried out. The effects of these on the strength and moisture regain were investigated. The activation energies of the dyeings were also analysed with Durazol Scarlet Red 4 BAS. The r...

A quasilinear system of elliptic-hyperbolic partial differential equations arising from the uniformly asymptotic approximation of solutions to the Helmholtz equation is discussed. These equations produce a model for high-frequency waves which is stable on both sides of a smooth, convex caustic. We prove the existence of strong solutions to a class of inhomogeneous boundary-value problems for an...

Urine samples must be acidified if accurate calcium analyses are to be obtained (1). In many institutions the nursing staff is not permitted to dispense the strong acids traditionally used to decrease the pH of urine, so that the acid must be transferred into the collection vessels in the clinical laboratory. To avoid the dangerous practice of using a caustic liquid acid as a preservative, we h...

We propose an original method for determining suitable refracting profiles between two media to solve two related problems: to produce a given wave front from a single point source after refraction at the refracting profile, and to focus a given wave front in a fixed point. These profiles are obtained as envelopes of specific families of Cartesian ovals. We study the singularities of these prof...