Thermodynamic assessment in heavy metal migration at El-Akader landfill site, North Jordan.

Thermodynamic analysis of subsoil pore water indicates that Fe, Cu, Zn, and Pb exist as a metal hydroxy complex of the forms [Me OH] + and [Me(OH2)]o, although a complex of [PbCl]+ is also significant, but not predominant. The analysis also demonstrates that the dissolved transition metal concentration of the subsoil pore waters are controlled at carbonate minerals saturation levels, whereas Fe concentration in leachate solutions associated with waters are controlled at FeS2 saturation levels. Thermodynamic calculations and Eh-pH diagrams suggest that Fe(OH)2, Zn(OH)2 and Pb(OH)2 are not stable phases in the solids of the subsoil.

Transmission of a Gaussian beam through a Fabry-Perot interferometer.

The transmission of a Gaussian beam through a Fabry-Perot interferometer (FPI) has been investigated. The equation for the electric field of the transmitted beam was derived and then the transmitted irradiance I(t) was numerically calculated for different selected parameters of both the FPI and the beam. The results show that the energy profile of the transmitted beam has been distorted to different degrees depending on the various parameters of the Gaussian beam and the FPI. Moreover the results show that the positions of the peaks of the transmitted beam are shifted, especially for intermediate waists for which the arctan term is nonlinear. The results also show that for nonnormal incidence successive transmitted beams are spatially separated and are not interfering appreciably with each other.

Rugate filter sidelobe suppression using half-apodization.

Rugate filters reflectance spectra were calculated for various index profiles with half-Gaussian modulation; graded-index as well as step-index profiles were used. The results show excellent sidelobe suppression around the stopbands, relatively high optical density, and good flatness in the reflectance band.