The time-dependent equation of radiative transfer is solved for a participating medium housed in an axisymmetric cylindrical enclosure by both the discrete-ordinates method and the finite volume method. Many heat transfer processes, including absorption of renewable and sustainable solar energy in a solar receiving tube for use in power plants, can be modeled in a cylindrical enclosure. Steady-...

In the scope of miniaturized optical sensors for liquid refractometry, this work details the design, numerical simulation, and experimental characterization of a Fabry-Pérot resonator consisting of two deeply-etched silicon cylindrical mirrors with a micro-tube in between holding the liquid analyte under study. The curved surfaces of the tube and the cylindrical mirrors provide three-dimensiona...

‘‘PolyCAD’’, a CAD program designed for X-ray photon tracing in polycapillary optics, is described. To understand the PolyCAD code and its results, the theoretical bases of X-ray transmission by a single cylindrical channel (monocapillary) are discussed first. Then cases of cylindrical, lens and semi-lens shaped polycapillary optics are examined. PolyCAD allows any type of X-ray source to be us...

This paper assesses the feasibility of transferring a laboratory-based electromagnetic (EM) sensor technique, which has already proved sensitive to significant (e.g. phase balance) or subtle (e.g. number density of fine precipitates) microstructural changes in steel, to non-destructive evaluation of the microstructure of power generation components such as tubes/pipes. It has been found that Gr...

Tracheostomy can influence the work of breathing by introducing additional resistance to airflow through the native airway. In a 1996 study, Hussey and Bishop determined that the presence of a deflated cuff in the airway significantly increased the work of breathing and theorized that a lower profile cuff would introduce less resistance to airflow. Hussey and Bishop also demonstrated that the p...

The response of vacuum to the presence of external conditions is the subject of this work. We consider a generalization of the Casimir effect in the presence of curved boundaries on which a sharp potential is concentrated. The profile of the potential is a delta function, which has some features in common with a hard boundary and some with a smooth background field. The boundaries investigated ...

We present experiments and theory for flows of sugar or salt solutions in cylindrical tubes with semipermeable walls (hollow fiber membranes) immersed in water, quantifying the strength of the osmotic driving force in relation to the dimensionless parameters that specify the system. The pumping efficiency of these flows is limited by the presence of "unstirred" concentration boundary layers nea...

Previous research of the authors pointed out that side-resonators can be applied to reduce fan noise. However, the noise reduction capabilities of most resonator geometries, e.g. tube resonators, cylindrical resonators (cylindrical air layers) and circular resonators (disc shaped air layers), are relatively narrow banded. This is disadvantageous in case resonators are used in combination with a...