BACKGROUND The elliptical excision is a common surgical procedure. The dermatologic literature predominantly describes an excisional geometry with a 3:1 length:width ratio and an apical angle of 30 degrees. OBJECTIVE To analyze the elliptical excision by applying mathematical principles and define the apical angle and its relationship to the length:width ratio. METHODS We examined numerous ...

Elliptical galaxies outside dense clusters are observed to contain small amounts (relative to spiral galaxies) of cold interstellar gas. This review discusses the atomic gas, the molecular gas, and the dust in elliptical galaxies. Field elliptical galaxies contain about 0.01 to 0.1 of the cold interstellar matter content of spiral galaxies of similar luminosity, and support a low level of star ...

Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used to produce optical devices, including the use of reflective and refractive components or inverse engineering techniques. However, many of these optical components are based on translational symmetries, rota...

In this research, a method for producing gum tragacanth (GT) fibers is presented. Ribbon type GT of Astragalus Gummifer species were obtained from local production lands. The gum was treated with alkali to increase its process ability, and allowed to stand for a period of time to reach the proper viscosity and/or to "ripen". Samples with different ripening times were prepared and their viscosit...

We give a parameterization, using Jacobi’s elliptic functions, of Alfred Gray’s Elliptical Catenoid and Elliptical Hellicoid that avoids some problems present in the original depiction of these surfaces.

Background: Semi-recumbent cycling exercise has been used as a strategy to complement gait retraining in individuals with disordered walking ability. However, seated elliptical stepping might be a more potent exercise modality for this purpose. Yet, there has not been a kinematic analysis of elliptical stepping exercise, whereby the movement path is produced by a slider-crank mechanism. This st...

The local parameters of linear, circular, and elliptical birefringence of backscattered light along a single-mode fiber are analyzed, and the twist-bending-induced elliptical birefringence in an extremely low birefringent single-mode fiber is measured using the backscattering method. The experimental results are in good agreement with the theoretical calculations. For a 130-microm-diameter fibe...