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Through a comparison of fingermark sweat corrosion of α phase brass in both the U.K. and Iraq, we show how samples from Iraq have improved fingermark corrosion over U.K. samples that require no additional enhancement prior to visualization. Over 50% of Iraqi samples produced fingermark corrosion with full ridge detail compared with 0% from the U.K. X-ray photoelectron spectroscopy analysis of the fingermark corrosion products showed that Iraqi samples exhibit more dezincification with the Zn:Cu ratio averaging 1:1.82 compared with 1:3.07 for U.K. samples. Auger spectroscopy showed the presence of both zinc oxide and copper (I) oxide. No copper (II) was observed on the surface of the corroded brass. Opportunities to exploit the optical properties of these thin film oxides to enhance the visualization of fingermark corrosion are considered, and the potential to use fingermark corrosion of metal as a means of visualizing fingerprints in war zones is discussed. [ABSTRACT FROM AUTHOR]

CO molecules possess three valence orbitals, 5σ, 1π, and 4σ in the ground state X1Σ+. These orbitals show intense absorptions due to the presence of Rydberg transitions, which exhibit sharp features in the photoionization curve. The autoionization to these orbitals causes a sudden increase in the photoionization cross section. Shape resonances are also detected in valence shell photoionization. Our aim is to resolve the autoionizing Rydberg structures of CO and study their effect on the photoionization cross section, assigning the correct symmetry responsible for the resonances occurring in valence state photoionization. For the present study we have employed the UK R-matrix formalism. In this article, we report a valence state photoionization cross section for 5σ, 1π, and 4σ orbitals of CO, which produces X2Σ+, A2Π, and B2Σ+ ionic states and compared it with existing results, wherever available. The photoionization rate coefficients for these valence states are also calculated and the effect of Rydberg transitions on the rate is discussed. We have observed a major contribution of the Rydberg series coming from the ground state of CO and a shape resonance was found for the B2Σ+ ionic state. This is the first report of high-resolution valence state photoionization of CO. The near threshold features in the photoionization curve (which are absent in previous studies) are produced with high precision. We have reported a detailed study of the photoionization cross section for three valence orbitals of CO in the vicinity of complex autoionizing Rydberg series transitions. [ABSTRACT FROM AUTHOR]