The microstructural features of variable polarity plasma arc welded Al-Cu-Mg 2024-T351 with 2319 filler have been studied by TEM, SEM and DSC. Fusion zone, partial melting zone, resolutionising zone, overageing (for S phase), peak ageing (for S phase) and under ageing zones (for S phase) have been identified. The Ω phase has been observed between re-solutionising zone and peak ageing zone. The ...

tory disturbance in untreated patients with obstructive sleep apnea syndrome. Chest 1993; 104:340–343 16 Lindberg E, Elmasry A, Gislason T, et al. Evolution of sleep apnea syndrome in sleepy snorers: a population-based study. Am J Respir Crit Care Med 1999; 159:2024–2027 17 Krakow B, Lowry C, Germain A, et al. A retrospective study on improvements in nightmares and posttraumatic stress disorder...

The article presents the results of low-(LCF) and high (HCF) fatigue in samples aluminum alloy 2024-T4, which is used aircraft construction, mainly for highly loaded structural components, including plating fuselage frames girders rotor blades helicopters. This where it required a strength to weight ratio product resistance fatigue. Moreover, poorly weldable has low corrosion resistance. tests ...

Laser direct metal deposition is an advanced additive manufacturing technology suitably applicable in maintenance, repair, and overhaul of high-cost products, allowing for minimal distortion of the workpiece, reduced heat affected zones, and superior surface quality. Special interest is growing for the repair and coating of 2024 aluminum alloy parts, extensively utilized for a wide range of app...

Potential mapping measurements have been performed on passive surfaces in air using an Atomic Force Microscopy based technique, the Scanning Kelvin Probe Force Microscope (SKPFM). A linear relation was found between the potential measured this way and the corrosion potential in aqueous solution for a range of pure metals. The SKPFM can be considered to map the practical nobility of the surface....

We point out a loophole problem in some recent experimental claims to produce three-particle entanglement. The problem consists in the question whether mixtures of two-particle entangled states might suffice to explain the experimental data. In an attempt to close this loophole, we review two sufficient conditions that distinguish between N -particle states in which all N particles are entangle...