Cu-Au type orderings in the staggered quadrupolar region of the fcc Blume Emery Griffiths model

The spin-1 Ising (BEG) model has been simulated using a cellular automaton (CA) algorithm improved from the Creutz cellular automaton (CCA) for a face-centered cubic (fcc) lattice. The ground state diagram ($k$, $d$) of the fcc BEG model has ferromagnetic ($F$), quadrupolar ($Q$) and staggered quadrupolar ($SQ$) ordering regions. The simulations have been made in the staggered quadrupolar region for the parameter values in the intervals $-24\leq d=D/J<0$ and $-3\leq k=K/J\leq 0$ . The phase diagrams on the ($kT_{C}/J$, $d$) and the ($kT_{C}/J$, $k$) planes have been obtained through $k=-3$ and $d=-4$ lines, respectively. The staggered quadrupolar ordering region separates into five ordering regions ($A_{3}B(a)$, $A_{3}B(f)$, $AB$ (type-I), $AB$(type-II) and $AB_{3}(f)$) which have the different stoichiometric Cu-Au type structures.Comment: 24 pages, 11 figure

Thermo-mechanical factors influencing annealing twin development in nickel during recrystallization

Abstract The effects of prior stored energy level, annealing temperature, heating velocity, and initial grain size on annealing twin development during static recrystallization of commercially pure nickel (99.999 %) are investigated. The twin content (measured as the twin boundary density or as the number of twins per grain) at the end of recrystallization is shown to be primarily influenced by the prior stored energy level and by the initial grain size, but the effects of heating rate and the annealing temperature are negligible. Taken together, the results are consistent with a new proposition that roughness of the recrystallization front promotes the formation of annealing twins during recrystallization

Recrystallization mechanisms and associated microstructure evolution during billet conversion of a gamma-gamma' nickel based superalloy

A partially recrystallized sample of the Ni-based superalloy AD730 was taken from an intermediate stage of the ingot to billet conversion process and isothermally forged in a single stroke compression test at a sub-solvus temperature (1080 °C). The as-received material had a heterogeneous microstructure, containing a mixture of coarse and much finer recrystallized grains as well as unrecrystallized ones, and also heterogeneous γ′ precipitation. The recrystallization mechanisms occurring dynamically in the different grain populations were investigated via electron backscatter diffraction (EBSD). It was found that local microstructure could affect the operative recrystallization mechanism, with different mechanisms seen in the deformed and recrystallized regions, owing to their different precipitate distributions. Within a single deformed grain, three apparently distinct dynamic recrystallization (DRX) mechanisms were identified. The interaction of recrystallization with precipitates plays a central role in DRX. In certain cases precipitates may stimulate discontinuous DRX by providing recrystallization nuclei, alternatively they may impede and limit the growth of recrystallized grains, or in other cases still they promote continuous recrystallization

Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both

Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81&nbsp;years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16–2.61) and patients with dementia (HR 1.75, 95% CI 1.06–2.90) had a higher risk of death at one year. The Kaplan–Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population

Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both

Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81&nbsp;years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16-2.61) and patients with dementia (HR 1.75, 95% CI 1.06-2.90) had a higher risk of death at one year. The Kaplan-Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population

Recommendations for the quantitative analysis of landslide risk

This paper presents recommended methodologies for the quantitative analysis of landslide hazard, vulnerability and risk at different spatial scales (site-specific, local, regional and national), as well as for the verification and validation of the results. The methodologies described focus on the evaluation of the probabilities of occurrence of different landslide types with certain characteristics. Methods used to determine the spatial distribution of landslide intensity, the characterisation of the elements at risk, the assessment of the potential degree of damage and the quantification of the vulnerability of the elements at risk, and those used to perform the quantitative risk analysis are also described. The paper is intended for use by scientists and practising engineers, geologists and other landslide experts

A simplified intragranular description of dislocation density heterogeneities to improve dynamically recrystallized grain size predictions

International audienceIn current mesoscopic mean-field and full-field models, nucleation of recrystallized grains remains poorly described compared to the physical complexity of the phenomenon, leading to noticeable discrepancy with regards to the size of recrystallized grains. In the present work, a simplified intragranular description of dislocation density heterogeneities is introduced in a recrystallization model in order to improve recrystallized grain size predictions. A detailed material-dependent model parameters identification procedure is provided and discussed. Experimental microstructure evolutions of an Inconel 718 Ni-base superalloy are compared to the model predictions as a validation case