A computer-implemented method, system and computer program product are provided for utilizing feedback in generating an optimal price. The present invention is directed to a silicon epitaxial wafer having an excellent gettering capability all over the radial direction thereof, wherein density of oxide precipitates detectable in the interior of a silicon single crystal substrate after epitaxial growth is 1\xd7109cm3 or higher at any position in the radial direction. Elliptical cross trainers guide the feet along a generally elliptical shaped curve to simulate the motions of jogging and climbing. The snap-fit connection between the RF screen and the irradiator is provided by a snap-fit fastener. The longitudinal reinforcing bars, having continuous, external thread-like deformations along their length are installed into the internally threaded sleeves or into threads of locking nuts holding the bars within optional smooth sleeves during the fabrication. The provided alloy contains the following components, in weight percentages: molybdenum\u201425 to 27; vanadium\u201425 to 27; chromium\u201414 to 16; titanium\u20149 to 11; with balance aluminum and iron and zirconium in the form of commercially pure metals.