Formability of ultra-fine grained metallic materials

Ultra-fine grained (UFG) metallic materials have been a hot topic in materials science for the last 25 years. There is a significant body of research showing that the UFG materials have very high mechanical strength, but their commercialisation is limited due to their low uni-axial tensile ductility. The main objective of this PhD thesis is to study the bi-axial stretching formability of the UFG metallic materials. It is demonstrated that there is a significant effect of the stress state (stress triaxiality) on mechanisms operating during plastic deformation in the UFG commercially pure (CP) Cu and the deformation mechanisms are determined by the stress state. The microstructure of the UFG CP Cu can be designed in such a way so as to show very high formability, even exceeding that of its coarse-grained counterpart. The effect of metallographic and crystallographic texture on the bi-axial stretching formability of the UFG CP Ti has been analysed. It is shown that the UFG CP Ti can show bi-axial stretching formability sufficient for metalforming operations. Coarse dispersoids and fractured particles in the Al 2024 alloy significantly limit its formability, acting as sites for the formation of cracks leading to sample failure at the early stages of deformation. Based on the analysis of the experimental results, a general recipe to improve formability of the UFG metallic materials is proposed. ------------------------------------------------------------------------------------En los últimos 25 años, los materiales metálicos de grano ultra-fino han levantado una gran expectación en el mundo de la ciencia de materiales. A pesar de que ya existe un importante trabajo de investigación que demuestra la alta resistencia mecánica de estos materiales, su comercialización se ha visto restringida por su baja ductilidad cuando están sometidos a tracción uniaxial. El principal objetivo de esta tesis es estudiar lo que se conoce en inglés como “stretching formability” bajo un estado de tensiones bi-axial para distintos materiales metálicos de grano ultra-fino. Se ha demostrado que el estado tensional, “stress triaxiality”, influye considerablemente en los mecanismos que operan durante la deformación plástica en el cobre puro comercial (CP Cu, por sus siglas en inglés) de grano ultra-fino. Asimismo, estos mecanismos de deformación están determinados por el estado tensional. La microestructura del CP Cu de grano ultra-fino podría diseñarse de modo que su “stretching formability” supere incluso a su homólogo de grano grueso. En el presente trabajo se analiza el efecto de la textura metalográfica y cristalográfica del CP Ti de grano ultra-fino. Se ha comprobado que su “stretching formability” se adecúa a las exigencias de los procesos industriales de conformado. Por otro lado, los dispersoides gruesos y las partículas fracturadas en una aleación de aluminio Al 2024 limitan su “formability” al actuar como lugares preferentes para la nucleación de fisuras, promoviendo entonces el fallo de la muestra en las etapas iniciales de deformación. En base al análisis de los resultados experimentales, se realiza una propuesta general para mejorar la habilidad al conformado de materiales metálicos de grano ultra-fino.Presidente: David Gareth Morris; Vocal: Anton Hohenwarter; Secretario: José Manuel Torralba Castell

Anisotropy of uni-axial and bi-axial deformation behavior of pure Titanium after hydrostatic extrusion

Coarse-grained commercially pure (CP) Titanium is subjected to hydrostatic extrusion resulting in the formation of ultrafine lamellar-type microstructure having very strong fiber texture. Uni-axial tensile tests of longitudinal and transverse specimens are carried out to study anisotropy of uni-axial deformation behavior of hydrostatically extruded CP Titanium. Small punch testing of longitudinal and transverse specimens is performed to study the anisotropy of its bi-axial deformation behavior. It is demonstrated that there is significant anisotropy of both uni-axial and bi-axial deformation of CP Titanium after hydrostatic extrusion which is related to the specific microstructure and texture developed in the material during hydrostatic extrusion.This work was carried out in frames of the European project LIMEDU (FP7 ERA-NET MATERA+2009, Project No MATERA/ESM- 1889) funded by Fundacion MADRI+D and by the National Centre for Research and Development (Project NCBiR/ERA-NET MATERA+/03/ 2011)

IgG4-related disease: results from a multicenter Spanish registry

IgG4-related disease (IgG4-RD) is a rare entity consisting of inflammation and fibrosis that has been described in multiple organs. Concrete diagnostic criteria have been established recently and there is a lack of large series of patients.To describe the clinical presentation, histopathological characteristics, treatment and evolution of a series of IgG4-RD Spanish patients.A retrospective multicenter study was performed. Twelve hospitals across Spain included patients meeting the current 2012 consensus criteria on IgG4-RD diagnosis.Fifty-five patients were included in the study, 38 of whom (69.1%) were male. Median age at diagnosis was 53 years. Thirty (54.5%) patients were included in the Histologically Highly Suggestive IgG4-RD group and 25 (45.5%) in the probable IgG4-RD group. Twenty-six (47.3%) patients had more than 1 organ affected at presentation. The most frequently affected organs were: retroperitoneum, orbital pseudotumor, pancreas, salivary and lachrymal glands, and maxillary sinuses.Corticosteroids were the mainstay of treatment (46 patients, 83.6%). Eighteen patients (32.7%) required additional immunosuppressive agents. Twenty-four (43.6%) patients achieved a complete response and 26 (43.7%) presented a partial response (<50% of regression) after 22 months of follow-up. No deaths were attributed directly to IgG4-RD and malignancy was infrequent.This is the largest IgG4-RD series reported in Europe. Patients were middle-aged males, with histologically probable IgG4-RD. The systemic form of the disease was frequent, involving mainly sites of the head and abdomen. Corticosteroids were an effective first line treatment, sometimes combined with immunosuppressive agents. Neither fatalities nor malignancies were attributed to IgG4-RD

Sustracción internacional de menores y violencia de género

[ES]La sustracción internacional de menores es el traslado de un menor a un país donde no reside llevado a cabo de forma ilícita dentro de un contexto de crisis familiar; además, constituye un delito tipificado en el artículo 225 bis del Código Penal, a cuyos efectos la sustracción puede tener una doble consideración: 1. Traslado ilícito del menor: uno de los progenitores traslada al menor a un lugar diferente al de su residencia sin consentimiento del progenitor con quien convive (otras personas o una institución, en su caso, a quien se confía su guarda o custodia). El fin de este traslado es obtener una resolución judicial que capacite al progenitor que lleva a cabo la sustracción a convivir legalmente con su hijo. 2. Retención ilícita del menor: se trata del supuesto en que el progenitor sustractor retiene al menor en un Estado diferente al de la residencia de los hijos

Healthcare workers hospitalized due to COVID-19 have no higher risk of death than general population. Data from the Spanish SEMI-COVID-19 Registry

Aim To determine whether healthcare workers (HCW) hospitalized in Spain due to COVID-19 have a worse prognosis than non-healthcare workers (NHCW). Methods Observational cohort study based on the SEMI-COVID-19 Registry, a nationwide registry that collects sociodemographic, clinical, laboratory, and treatment data on patients hospitalised with COVID-19 in Spain. Patients aged 20-65 years were selected. A multivariate logistic regression model was performed to identify factors associated with mortality. Results As of 22 May 2020, 4393 patients were included, of whom 419 (9.5%) were HCW. Median (interquartile range) age of HCW was 52 (15) years and 62.4% were women. Prevalence of comorbidities and severe radiological findings upon admission were less frequent in HCW. There were no difference in need of respiratory support and admission to intensive care unit, but occurrence of sepsis and in-hospital mortality was lower in HCW (1.7% vs. 3.9%; p = 0.024 and 0.7% vs. 4.8%; p<0.001 respectively). Age, male sex and comorbidity, were independently associated with higher in-hospital mortality and healthcare working with lower mortality (OR 0.211, 95%CI 0.067-0.667, p = 0.008). 30-days survival was higher in HCW (0.968 vs. 0.851 p<0.001). Conclusions Hospitalized COVID-19 HCW had fewer comorbidities and a better prognosis than NHCW. Our results suggest that professional exposure to COVID-19 in HCW does not carry more clinical severity nor mortality

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

All-cause mortality in the cohorts of the Spanish AIDS Research Network (RIS) compared with the general population: 1997Ł2010

Abstract Background: Combination antiretroviral therapy (cART) has produced significant changes in mortality of HIVinfected persons. Our objective was to estimate mortality rates, standardized mortality ratios and excess mortality rates of cohorts of the AIDS Research Network (RIS) (CoRIS-MD and CoRIS) compared to the general population. Methods: We analysed data of CoRIS-MD and CoRIS cohorts from 1997 to 2010. We calculated: (i) all-cause mortality rates, (ii) standardized mortality ratio (SMR) and (iii) excess mortality rates for both cohort for 100 personyears (py) of follow-up, comparing all-cause mortality with that of the general population of similar age and gender. Results: Between 1997 and 2010, 8,214 HIV positive subjects were included, 2,453 (29.9%) in CoRIS-MD and 5,761 (70.1%) in CoRIS and 294 deaths were registered. All-cause mortality rate was 1.02 (95% CI 0.91-1.15) per 100 py, SMR was 6.8 (95% CI 5.9-7.9) and excess mortality rate was 0.8 (95% CI 0.7-0.9) per 100 py. Mortality was higher in patients with AIDS, hepatitis C virus (HCV) co-infection, and those from CoRIS-MD cohort (1997. Conclusion: Mortality among HIV-positive persons remains higher than that of the general population of similar age and sex, with significant differences depending on the history of AIDS or HCV coinfection