A method of coating of steel products such as plate and sheet using an aluminum-zinc coating alloy includes modifying the coating bath with a particulate compound constituent in effective amounts to control the spangle facet size of the coated product, improve tension bend rust stain performance, and improve coated product paintability. The leg members, plurality of brace members and at least one connecting plate are sized and configured for attachment to one another to form a panel or a plurality of panels so that the two leg members bear at least a portion of the section load when installed. Therefore, the present invention provides a laser irradiation apparatus including a galvanometer mirror and an f\u03b8 lens that can offset the change of the energy due to the change of transmissivity of the f\u03b8 lens and can scan the laser light while controlling the change of the energy on the object to be irradiated. The system and methods employ chamfer distance and orientation distance provides reasonable verification performance, as well as an appearance model for the taillights of the car to increase the robustness of the system. It also relates to methods of purifying phycocyanin from blue-green algae extracts.