The Influence of Thermal History on the Multistage Transformation of NiTi Shape-Memory Alloys

The multistage martensitic phase transformation of a polycrystalline NiTi shape-memory alloy (50.3 at. %Ni-49.7 at. % Ti) has been studied by means of calorimetric measurements. After a conventional thermal treatment followed by successive thermal cycles, the initial two-step forward transformation splits into four-overlapping stages. However, the reverse martensitic transformation maintains the initial two-step sequence, usually assigned to the B19'-> R -> B2 transformation. The correlation between the forward and reverse steps has been established by means of selected thermal cycles together with an estimation of their enthalpy and thermal hysteresis. These results have also provided information about the storage of the elastic strain energy and the frictional works associated with the variants' nucleation. Moreover, the study around the forward transformation temperature range by means of uncompleted thermal cycles undoubtedly shows the presence of temperature memory effects in both stages.This work has been supported by the Spanish Ministry of Economy and Competitiveness, MINECO, CONSOLIDER-INGENIO 2010 CSD2009-00013, as well as by the Consolidated Research Group IT-1090-16 and the ELKARTEK-ACTIMAT project from the Education and Industry Departments of the Basque Government. The University of the Basque Country has also supported this work with the Research Group grant: UPV/EHU GIU17/071. The authors appreciate the cooperation of J. Rodriguez-Aseguinolaza in the thermal treatments of the samples

Strain Relaxation in Cu-Al-Ni Shape Memory Alloys Studied by in Situ Neutron Diffraction Experiments

In situ neutron diffraction is used to study the strain relaxation on a single crystal and other powdered Cu-Al-Ni shape memory alloys (SMAs) around martensitic transformation temperatures. This work is focused on the analysis of the strain evolution along the temperature memory effect appearing in these alloys after partial thermal transformations. A careful study of the influence of partial cycling on the neutron diffraction spectra in the martensitic phase is presented. Two different effects are observed, the d-spacing position shift and the narrowing of various diffraction peaks, along uncompleted transformation cycles during the thermal reverse martensitic transformation. These changes are associated with the relaxation of the mechanical stresses elastically stored around the martensitic variants, due to the different self-accommodating conditions after uncompleted transformations. The evolution of the stresses is measured through the strain relaxation, which is accessible by neutron diffraction. The observed effects and the measured strain relaxations are in agreement with the predictions of the model proposed to explain this behavior in previous calorimetric studies. In addition, the thermal expansion coefficients of both martensite and austenite phases were measured. The neutron experiments have allowed a complete description of the strains during martensitic transformation, and the obtained conclusions can be extrapolated to other SMA systems. (c) 2019 Author(s).This work was supported by the Spanish Ministry of Economy and Competitiveness (No. MINECO MAT2017-84069-P), as well as by the Consolidated Research Group (No. IT-1090-16) and the ELKARTEK-ACTIMAT project from the Education and Industry Departments of the Basque Government. The University of the Basque Country (UPV/EHU) also supported this work with the Research Group GIU17/071. This work has benefited from the use of NPDF at the Lujan Center at Los Alamos Neutron Science Center, funded by the Department of Energy (DOE) Office of Basic Energy Sciences. Los Alamos National Laboratory is operated by Los Alamos National Security LLC, under DOE Contract No. DE-AC52-06NA25396. The upgrade of NPDF was funded by the National Science Foundation (NSF) through Grant No. DMR 00-76488

Desarrollo y Validación Clínica de un Hisopo Monolítico para Toma de Muestra Nasofaríngea en el diagnóstico de COVID-19

La empresa PS Anesthesia S.A. (PSA) solicito asesoramiento en el desarrollo de un kit para toma de muestra nasofaríngea. En mayo de 2020 comenzaron las actividades de investigación y desarrollo, que se materializaron en un hisopo nasofaríngeo prototipo integrante de un kit que contiene los insumos para la toma, recolección y transporte de muestras microbiológicas. La particularidad del hisopo nasofaríngeo desarrollado es su construcción monolítica (HNM) adaptada al proceso de moldeo por inyección, que prescinde del proceso de adhesión de microfibras para la captura de muestra.Facultad de Ingenierí

Experimental and Computational Studies on the Performance of Solar Trackers Under Vortex Shedding, Torsional Divergence, and Flutter

[Abstract] The current development of renewable energies has originated a number of new structural typologies that are the physical support of the energy production systems. Photovoltaic energy is a very mature source and it is obtained using rows of panels implemented in a longitudinal grillage. Many studies have been carried out in the past with an aim to improve the capacity to obtain electrical power, but another important issue is the need to guarantee the performance of these industrial facilities under the phenomena induced by the turbulent wind flow, taking into account the fact that they are usually built in wide open spaces. This paper describes an extensive research carried out on two configurations of solar trackers by experimental and computational methods. The former was composed of a number of tests of reduced models of segments of the solar trackers, which were carried out in an aerodynamic wind tunnel. The latter consisted of a series of structural analyses worked out through a finite element model of the full panel subjected to aerodynamic and aeroelastic loads. Several angles of attack of the wind flow and a wide range of wind speeds were included in the study. This approach allowed to clearly evaluate the structural and dynamic performance of both the configurations of solar trackers under the most important wind-induced phenomena such as vortex shedding, torsional divergence, and flutter. The paper relates the phases of the study and informs about the more relevant numerical results obtained in the experiments and the computer analysis

Correction : Chaparro et al. Incidence, Clinical Characteristics and Management of Inflammatory Bowel Disease in Spain: Large-Scale Epidemiological Study. J. Clin. Med. 2021, 10, 2885

The authors wish to make the following corrections to this paper [...]

Incidence, Clinical Characteristics and Management of Inflammatory Bowel Disease in Spain : Large-Scale Epidemiological Study

(1) Aims: To assess the incidence of inflammatory bowel disease (IBD) in Spain, to describe the main epidemiological and clinical characteristics at diagnosis and the evolution of the disease, and to explore the use of drug treatments. (2) Methods: Prospective, population-based nationwide registry. Adult patients diagnosed with IBD-Crohn's disease (CD), ulcerative colitis (UC) or IBD unclassified (IBD-U)-during 2017 in Spain were included and were followed-up for 1 year. (3) Results: We identified 3611 incident cases of IBD diagnosed during 2017 in 108 hospitals covering over 22 million inhabitants. The overall incidence (cases/100,000 person-years) was 16 for IBD, 7.5 for CD, 8 for UC, and 0.5 for IBD-U; 53% of patients were male and median age was 43 years (interquartile range = 31-56 years). During a median 12-month follow-up, 34% of patients were treated with systemic steroids, 25% with immunomodulators, 15% with biologics and 5.6% underwent surgery. The percentage of patients under these treatments was significantly higher in CD than UC and IBD-U. Use of systemic steroids and biologics was significantly higher in hospitals with high resources. In total, 28% of patients were hospitalized (35% CD and 22% UC patients, p < 0.01). (4) Conclusion: The incidence of IBD in Spain is rather high and similar to that reported in Northern Europe. IBD patients require substantial therapeutic resources, which are greater in CD and in hospitals with high resources, and much higher than previously reported. One third of patients are hospitalized in the first year after diagnosis and a relevant proportion undergo surgery

Thermal treatments and transformation behavior of Cu–Al–Be shape memory alloys

Among the different Cu-based shape memory alloys, the Cu–Al–Be family exhibits a particular technological interest for intermediate and low temperature applications. In this work we studied the martensitic transformation behavior of Cu–Al–Be single crystalline shape memory alloys with three different concentrations. The influence of four specific thermal treatments of quenching and aging on the transformation temperatures has been studied by differential scanning calorimetry and compared with similar studies by mechanical spectroscopy. The analysis of the influence of thermal treatments on the martensitic transformation behavior allows optimize a treatment useful for all the alloys transforming between 200K and 400K, avoiding both stabilization and precipitation. In addition, an anomalous jerky behavior has been reported for the alloy with low transformation temperatures, which is discussed in terms of the possible mechanisms.This work was supported by the Spanish MICINN Project MAT2009-12492 and the CONSOLIDER-INGENIO 2010 CSD2009-00013, by the Consolidated Research Group ITR-10-310 from the Education Department and by the project ETORTEK ACTIMAT-2010 from the Industry Department of the Basque Government. I.L.-F. thanks to the Education Department of the Basque Government for the pre-doctoral grant

Ultrahigh Superelastic Damping at the Nano-Scale: a Robust Phenomenon to Improve Smart MEMS Devices

Micro and nano pillars of Copper-based shape memory alloys (SMAs) with feature sizes between about 2 mu m and 250 nm are known to exhibit ultra-high mechanical damping due to the nucleation and motion of stress-induced martensite interfaces during superelastic straining. While this behavior could be extremely useful to protect micro electro-mechanical systems (MEMS) against vibrations in aggressive environments, a fundamental question must yet be answered in order to envisage further applications, namely, whether this damping is reproducible and stable over long times and many cycles, or whether the damping is a signal of accumulating damage that could compromise long-term usage. In the present paper this crucial question is answered; we show that micropillar arrays of Cu-Al-Ni SMAs exhibit a completely recoverable and reproducible superelastic response, with an ultra-high damping loss factor eta > 0.1, or even higher for sub-micrometer pillars, eta > 0.2, even after thousands of cycles (>5000) and after long times spanning more than four years. Furthermore, the first high-frequency tests on such nanoscale SMAs show that their superelastic response is very fast and relevant to ultra-high damping even at frequencies as high as 1000 Hz. This paves the way for the design of micro/nano dampers, based on SMAs, to improve the reliability of MEMS in noisy environments. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).This work was supported by the Spanish Ministry of Economy and Competitiveness, MINECO, projects MAT2012-36421, MAT2017-84069P, CONSOLIDER-INGENIO 2010 CSD2009-00013, as well as by the Consolidated Research Group IT-10-310 and the ELKARTEK-ACTIMAT project from the Education and Industry Departments of the Basque Government, Spain, and GIU-17/071 from the University of the Basque Country, UPV/EHU. Co-funding from H2020 REACT Project Grant No 640241 from European Community and EOARD Grant No FA8655-10-1-3074 (USA) are also acknowledged. This work made use of the FIB facilities of the SGIKER from the UPV/EHU. CAS acknowledges the support of the Institute for Soldier Nanotechnologies, funded by the U.S. Army Research Office at MIT, under contract number W911NF-13-D-0001

Tratamientos Psicológicos Empíricamente Apoyados Para la Infancia y Adolescencia: : Estado de la Cuestión

Background: The empirical evidence accumulated on the effi cacy, effectiveness, and effi ciency of psychotherapeutic treatments in children and adolescents calls for an update. The main goal of this paper objective was to carry out a selective review of empirically supported psychological treatments for a variety of common psychological disorders and problems in childhood and adolescence. Method: A review was carried out of the psychological treatments for different psychological disorders and problems in socialemotional or behavioral adjustment in the child-adolescent population according to the Spanish National Health System (Clinical Practice Guidelines) levels of evidence and degrees of recommendation. Results: The fi ndings suggest that psychological treatments have empirical support for addressing a wide range of psychological problems in these developmental stages. The degree of empirical support ranges from low to high depending on the phenomenon analyzed. The review suggests unequal progress in the different fi elds of intervention. Conclusions: From this update, psychologists will be able to make informed decisions when implementing those empirically supported treatments to address the problems that occur in childhood and adolescence.Antecedentes: la evidencia empírica acumulada en los últimos años sobre la efi cacia, efectividad y efi ciencia de los tratamientos psicológicos en la infancia y adolescencia reclama una actualización. El principal objetivo de este artículo es el de llevar a cabo una revisión de los tratamientos psicológicos empíricamente apoyados para una diversidad de problemas psicológicos habituales en la infancia y la adolescencia. Método: se revisan los tratamientos psicológicos para diferentes trastornos psicológicos y problemas en el ajuste socioemocional o conductual en población infanto-juvenil en función de los niveles de evidencia y grados de recomendación del Sistema Nacional de Salud de España (Guías de Práctica Clínica). Resultados: los hallazgos sugieren que los tratamientos psicológicos específi camente dirigidos a niños, niñas y adolescentes disponen de apoyo empírico para el abordaje de un amplio elenco de problemas psicológicos. Este grado de apoyo empírico oscila de bajo a alto en función del problema analizado. La revisión muestra un avance desigual en los diferentes campos de intervención. Conclusiones: a partir de esta actualización, los profesionales de la psicología podrán tomar decisiones informadas a la hora de implementar aquellas intervenciones psicológicas con apoyo empírico para el abordaje de los problemas en la infancia y la adolescenci