Investigating the optical properties of polycrystalline AgCl(1-x)Br(x) (0≤x≤1) and Ag(0.95)Tl(0.05)Br(0.95)I(0.05) for IR engineering.
Using the Michelson technique we measured the refractive indices for the plane-parallel thin plates made of AgCl1-xBrx(0≤x≤1) and, to the best of our knowledge, for the first time for the Ag0.95Tl0.05Br0.95I0.05 plate, manufactured by hot embossing, at 632.8 nm. We recorded their absorption spectra within the range of 0.19-41.67 μm using UV-Vis spectrophotometry and Fourier transform infrared spectroscopy, which demonstrated that the increase of substituent silver bromide or thallium monoiodide mole fraction in the corresponding solid solution causes the optical density to grow. As the result it moves the transmission edges toward longer wavelengths, while slightly reducing the transmission peak.
Crystals of AgBr – (TlBr0.46I0.54) system for the fabrication of IR photonic crystal fibers
In this paper we examined materials based on crystals of AgBr – (TlBr0.46I0.54) system suitable for manufacturing single mode and multimode fibers. We studied phase diagram of this system, grew the crystals and investigated their functional properties. The results obtained will serve as basic information for manufacturing Mid-IR fibers including PCFs, which will be applicable in various fields.
Neutron Residual Stress Measurements on Rail Sections for Different Production Conditions
Rail sectioning with subsequent neutron diffraction experiments has been used to assess residual stresses in the rails. In this study we present the results of neutron stress measurements performed at the NIST Center for Neutron Research (NCNR) on rail sections from rails that were produced under various conditions. Specifically, these are air-cooled, air-cooled and roller-straightened, head-hardened and head-hardened and roller-straightened. More significantly, a head-hardened and roller-straightened rail was also studied after service to elucidate evolution of the service-induced residual stresses. In the latter case both a transverse-cut slice and the central region of a 0.53 m long piece were studied. Measurements on this piece are the first in which triaxial stresses have been determined for an intact rail. Neutron strain measurements with 3×3×3 mm3 spatial resolution were successfully employed for transversally cut slices to verify the difference in the stress state depending on the production process. Although examination of slices allows determination of only two-dimensional stresses in the plane of the slice, additional measurements on obliquely-cut slices, which were also carried out, and utilization of FEM gives the possibility of reconstructing the full triaxial stress distribution. Together, these approaches provide a better understanding of rail fabrication and the possibility of improving the durability and safety of rails in the future.Copyright © 2004 by ASME