Recrystallization in an Mg-Nd alloy processed by high-pressure torsion: a calorimetric analysis

Differential scanning calorimetry (DSC) was used to evaluate the recrystallization temperature and activation energy for an Mg-1.43Nd (wt.%) alloy after severe plastic deformation by high-pressure torsion (HPT) at room temperature up to 10 turns. The recrystallization kinetics were determined from DSC analysis. The results show that the recrystallization temperature increases with increasing heating rate and decreases with increasing numbers of HPT turns. Severe plastic deformation by HPT significantly reduces the recrystallization temperature. The estimated activation energy for recrystallization was in the range of ~ 84-89 kJ mol-1

On the groove pressing of Ni-W alloy: microstructure, texture and mechanical properties evolution

International audienceThe microstructure, texture and mechanical properties of the Ni-14%W(wt.%) alloy with two different initial grain sizes and textures were investigated after groove pressing (GP) at 450 °C to 4 cycles using Electron Back Scatter Diffraction (EBSD) and microhardness measurements. The initial first series was characterized by small equiaxed grains and Cube dominant texture component. The second series has elongated grains and β-fiber texture. EBSD analysis has shown that GP processing led to a slight refinement (less than 15%) of equiaxed grains in series I while greater refinement (~55%) of the mean spacing along normal direction was observed in series II. The texture did not drastically change from the initial ones and was characterized by the weakening of the Cube component in series I and rapid decrease of Copper component for series II. GP processing reduces very slightly the plastic anisotropy of the alloy with initial elongated granular microstructure

Cr cluster characterization in Cu-Cr-Zr alloy after ECAP processing and aging using SANS and HAADF-STEM

International audienceThe precipitation of nano-sized Cr clusters was investigated in a commercial Cu-1Cr-0.1Zr (wt.%) alloy processed by Equal-Channel Angular Pressing (ECAP) and subsequent aging at 550 °C for 4 hours using small angle neutron scattering (SANS) measurements and high-angle annular dark-field-scanning transmission electron microscopy (HAADF-STEM). The size and volume fraction of nano-sized Cr clusters were estimated using both techniques. These parameters assessed from SANS (d~3.2 nm, Fv~1.1 %) agreed reasonably with those from HAADF-STEM (d ~2.5 nm, Fv~2.3%). Besides nano-sized Cr clusters, HAADF-STEM technique evidenced the presence of rare cuboid and spheroid sub-micronic Cr particles about 380-620 nm mean size. Both techniques did not evidence the presence of intermetallic CuxZry phases within the aging conditions

The Potential Offered by Smart Cities to Promote Smart Tourist Destinations

. The digital revolution has radically changed the world, as new digital technologies have introduced important innovations in factories, hospitals and schools, especially cities, improving the efficiency of city operations and life quality of its citizens and visitors. This study is a demonstration of the capabilities provided by smart cities to promote smart tourism through global experiences, where the study concluded that the inclusion of smart city determinants will make it a smart tourism destination and thus realize the concept of smart tourism as part of smart city, and improve the Provided tourism services quality and tourism experiences, since the innovation and sustainability are the only way to improve life quality and social value of both  local residents and tourists

PCR Detection of Viral Nucleic Acid in Fatal Asthma: Is the Lower Respiratory Tract a Reservoir for Common Viruses?

BACKGROUND: There is indirect evidence implicating viral respiratory tract infections in the pathogenesis of fatal asthma. However, it is unknown whether viruses are present within the lower respiratory tract in fatal asthma.OBJECTIVES: To apply a nine-virus polymerase chain reaction (PCR) panel to postmortem specimens of lower airway secretions and compare the prevalence of viral nucleic acid among patients who died of asthma, asthmatic patients who died of other causes and persons who died without lung disease.PATIENTS AND METHODS: Postmortem specimens of lower airway secretions from patients who died of asthma (fatal asthma [n=10]), asthmatic patients who died of other causes (n=4) and nonasthma controls (n=6) underwent PCR for nine common respiratory viruses. The prevalence of each virus was compared among the three groups.RESULTS: PCR was positive for at least one virus in 19 of 20 cases, and multiple viruses were detected in 14 of 20 cases. The prevalence of each virus was similar in the three groups studied.CONCLUSIONS: In fatal asthma, lower airway secretions do not show a specific pattern of viral nucleic acid. Intriguingly, these results suggest that the lower respiratory tract may act as a potential reservoir for common respiratory viruses.Peer Reviewe

Grain boundary character distribution of CuNiSi and FeNi alloys processed by severe plastic deformation

In this work the Grain Boundary Character Distribution (GBCD) in general and the relative proportion of low-? CSL (Coincidence Site Lattice) grain boundaries are determined through EBSD in Cu-2.5Ni-0.6Si (wt.%) and Fe-36Ni (wt.%) alloys after processing by high-pressure torsion, equal- channel angular pressing and accumulative roll bonding