Sulfur oxides are removed from an oxygen-containing acid gas in configurations and methods in which oxygen is removed from the acid gas using reducing gases at relatively high temperature. In order to suppress side bands and the carrier frequency, which may occur as a result of excessive matching tolerances between the components which are used, a feedback path couples the modulator output to the digital signal processing unit. One of the plurality of pretilt angle directions is then selected by exposing the alignment layer to UV light a second time. The first and second portions being displaced laterally from said axis by different respective distances. The vias may be plated, paste- filled, filled with a low melting point alloy and may have a conical profile for improved plating performance. The longer fibers help bind the wad together into a cohesive mass that has a substantial volume of internal interstices.