The effect of applying a negative bias during deposition of a previously designed multilayer solar selective absorber coating was studied on two types of substrates (316L stainless steel and Inconel 625). The solar selective coating is composed of different chromium aluminum nitride layers deposited using a combination of radiofrequency (RF), direct current (DC), and high-power impulse magnetron sputtering (HiPIMS) technologies. The chemical composition is varied to generate an infrared reflective/absorber layer (with low Al addition and N vacancies) and two CrAlN intermediate layers with medium and high aluminum content (Al/Cr = 0.
View Article and Find Full Text PDFObjective: World Health Organization deem Chronic Obstructive Pulmonary Disease as the fourth leading cause of death in the world. Because of its impact on Public Health, it represents a great burden from an international economic point of view, despite it is an avoidable and treatable disease. Hence it is suitable to use Clinical Practice Guidelines which are recommendations systematically developed to aid decision making about health care to improve quality, and they must be subject to a review and update of an enriching methodological rigor.
View Article and Find Full Text PDFTribological coatings made of MoS and WSe phases and their corresponding combinations with tungsten carbide (WC) were prepared by non-reactive magnetron sputtering of individual targets of similar composition. A comparative tribological analysis of these multiphase coatings was done in both ambient air (30-40% relative humidity, RH) and dry nitrogen (RH<7%) environments using the same tribometer and testing conditions. A nanostructural study using advanced transmission electron microscopy of the initial coatings and examination of the counterfaces after the friction test using different analytical tools helped to elucidate what governs the tribological behavior for each type of environment.
View Article and Find Full Text PDFA combination of transmission electron microscopy techniques and spatially resolved microanalysis is used to investigate the nanostructure, constituting phases, and chemical elemental distribution in CrAlYN multilayered coatings. The location of the metallic elements and their chemical state are needed to understand their functional properties. Samples were prepared with variable Al (4-12 at%) and Y (2-5 at%) contents by direct current reactive magnetron sputtering on silicon substrates using metallic targets and Ar/N2 mixtures under different deposition parameters (power applied to the target and rotation speed of the sample holder).
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