The energy efficiency of a small-scale solar concentrating thermal device is investigated, based on Monte-Carlo Ray-Tracing (MCRT) and Computational Fluid Dynamics (CFD) modeling. consists Fresnel lens collector—engraved 1 m rectangular plate—and 10 cm sized plate receiver, with drilled cylindrical channels diameter mm. Inlet velocities heat transfer fluid (HTF) temperatures lie within the rang...

In many cases, a torsional shaft may be a thick-walled radially inhomogeneous cylindrical object. The hollow shafts made of functionally graded materials (FGMs) are such kind of compositions which were studied in this paper. Cylindrical FG shafts are composed of ceramic and metallic parts with power function distribution across the radial direction. The ceramic phase is isotropic elastic and th...

Volumetric integral and integro-differential equations are considered that describe problems of diffraction by three-dimensional bodies with given macroscopic permittivity magnetic permeability, as well on free vibrations such bodies. Similar obtained for waveguide structures: hollow shielded waveguides dielectric filling, (optical beamguides), photonic-crystal waveguides. Dominantly stationary...

This study is devoted to the morphological, chemical and physical characterization of raw material of the fruit of Luffa Cylindrica. By microscopic analysis, it can be observed that the fruit is composed of an assembly of dependent cords, where four parts are differentiated: external, internal wall, core and bond. Each cord consists of hollow and flexible cylindrical fibers.The external par...