Stability behaviour of composite magnetorheological fluids by an induction method

Este artículo puede consultarse en la siguiente dirección de la editorial: http://jim.sagepub.com/content/early/2015/03/26/1045389X15577656.full.pdf+htmlIn this work we study the stability behaviour of composite magnetorheological (MR) fluids consisting of magnetic (iron) and non-magnetic (poly (methylmethacrylate), PMMA) particles dispersed in mineral oil. Because of the opacity of the suspensions, optical methods traditionally employed for evaluation of the gravitational settling in colloidal suspensions are not suitable for sedimentation follow-up in this case. For this reason, we use an alternative method based on the evaluation of the resonant frequency of the inductance of a thin coil surrounding the sample The movement of the coil along the height of the container at specified steps and time intervals allows obtaining information about the local volume fraction of particles inside the tube. The obtained successive profiles for the multi-component suspensions show a decrease of the iron particle settling and of the initial rate of settling as the PMMA volume fraction is increased. Finally, the increase of the PMMA concentration gives rise to an improvement of the rheological properties upon magnetic field application for a given concentration of iron. Both a strongrheological response and a good colloidal stability are essential for practical applications.Proyectos PE2012-FQM694 (Junta de Andalucía, Spain)y FIS2013-47666-C3-1-R (Ministerio de Economía y Competitividad, Spain). L. R.-A. agrradece a la Universidad de Granada su contrato puente (Plan Propio de Investigación, UGR)

Monitoring of Carbon Fiber-Reinforced Old Timber Beams via Strain and Multiresonant Acoustic Emission Sensors

This paper proposes the monitoring of old timber beams with natural defects (knots, grain deviations, fissures and wanes), reinforced using carbon composite materials (CFRP). Reinforcement consisted of the combination of a CFRP laminate strip and a carbon fabric discontinuously wrapping the timber element. Monitoring considered the use and comparison of two types of sensors: strain gauges and multi-resonant acoustic emission (AE) sensors. Results demonstrate that: (1) the mechanical behavior of the beams can be considerably improved by means of the use of CFRP (160% in bending load capacity and 90% in stiffness); (2) Acoustic emission sensors provide comparable information to strain gauges. This fact points to the great potential of AE techniques for in-service damage assessment in real wood structures.The experiments were supported by the companies DÁVILA Restauración de Monumentos and DRIZORO® S.A.U, under research contract No. 3546. The authors also gratefully acknowledge the important contribution of lab technicians David Jiménez and Ismael Romero

Impact of the COVID-19 Pandemic on Inappropriate Use of the Emergency Department

Background: Inappropriate use of the emergency department (IEDU)—consisting of the unnecessary use of the resource by patients with no clinical need—is one of the leading causes of the loss of efficiency of the health system. Specific contexts modify routine clinical practice and usage patterns. This study aims to analyse the influence of COVID-19 on the IEDU and its causes. Methods: A retrospective, cross-sectional study conducted in the emergency department of a high-complexity hospital. The Hospital Emergency Suitability Protocol (HESP) was used to measure the prevalence of IEDU and its causes, comparing three pairs of periods: (1) March 2019 and 2020; (2) June 2019 and 2020; and (3) September 2019 and 2020. A bivariate analysis and multivariate logistic regression models, adjusted for confounding variables, were utilized. Results: In total, 822 emergency visits were included (137 per period). A total prevalence of IEDU of 14.1% was found. There was a significant decrease in IEDU in March 2020 (OR: 0.03), with a prevalence of 0.8%. No differences were found in the other periods. A mistrust in primary care was the leading cause of IEDU (65.1%). Conclusions: The impact of COVID-19 reduced the frequency of IEDU during the period of more significant population restrictions, with IEDU returning to previous levels in subsequent months. Targeted actions in the field of population education and an improvement in primary care are positioned as strategies that could mitigate its impact

Resistive Switching and Charge Transport in Laser-Fabricated Graphene Oxide Memristors: A Time Series and Quantum Point Contact Modeling Approach

This work investigates the sources of resistive switching (RS) in recently reported laser-fabricated graphene oxide memristors by means of two numerical analysis tools linked to the Time Series Statistical Analysis and the use of the Quantum Point Contact Conduction model. The application of both numerical procedures points to the existence of a filament connecting the electrodes that may be interrupted at a precise point within the conductive path, resulting in resistive switching phenomena. These results support the existing model attributing the memristance of laser-fabricated graphene oxide memristors to the modification of a conductive path stoichiometry inside the graphene oxide.The authors thank the support of the Spanish Ministry of Science, Innovation and Universities under projects TEC2017-89955-P, TEC2017-84321-C4-3-R, MTM2017-88708-P and project PGC2018-098860-B-I00 (MCIU/AEI/FEDER, UE), and the predoctoral grant FPU16/01451

Una mirada interdisciplinar sobre los retos actuales de la infancia en un mundo globalizado (RETIN)

El concepto de infancia ha ido evolucionando a lo largo de la historia. En el siglo XX, especialmente en sus últimos años, se ha prestado mayor atención al desenvolvimiento de los seres humanos en esta etapa de la vida, atención que se ha concretado, entre otras cuestiones, en el interés creciente hacia los derechos de la infancia. En 1989 este proceso se ve reforzado por la aprobación de la Convención de las Naciones Unidas sobre los Derechos de los niños y las niñas, que reconoce a las personas menores de 18 años de edad derechos civiles, sociales, económicos, culturales y políticos, derechos de ciudadanía en suma para el colectivo infantil, considerado previamente como puro objeto de protección. En el ámbito de las ciencias sociales se ha producido también una transformación. Desde un enfoque sociológico se considera que la infancia es un espacio temporal en la trayectoria de vida de las personas, y también el espacio social definido para el desarrollo de la vida de los niños. Se reconoce que también los niños, como grupo social, no sólo pueden actuar, sino que actúan de hecho, y se relacionan con los demás grupos sociales, modificando, construyendo y contribuyendo a los cambios que se producen en la sociedad. En este marco, el objetivo del presente proyecto es la elaboración y difusión de materiales audiovisuales pedagógicos basados en entrevistas sobre los retos actuales de la infancia en un mundo globalizado, como son: cuidados en la ciudad, infancia migrante no acompañada, desigualdades socioeconómicas, nuevas tecnologías y género

I Congreso - Convergencias y divergencias. Hacia educaciones y desarrollo otros.

La presente colección, en su primera publicación, recoge la experiencia del I Congreso Internacional de Educación para el Desarrollo en Perspectiva Latinoamericana- EpDl “Convergencias y divergencias. Hacia educaciones y desarrollos otros.” organizado por el Centro de Educación para el Desarrollo-CED de UNIMINUTO, específicamente en relación con las ponencias, libros e iniciativas fotográficas presentadas en las seis líneas temáticas de este evento académico, a saber: (a) experiencias y prácticas pedagógicas; (b) acciones colectivas, movimientos y redes sociales; (c) perspectivas críticas al desarrollo; (d) producción de conocimiento; (e) diferencias, identidades y ciudadanía; (f) cuerpos, emociones y espiritualidades; a partir de éstas propuestas y en el marco de estas líneas, se reflexionó sobre las dinámicas y problemáticas derivadas del desarrollo hegemónico, así como sobre la posibilidad de diálogo entre saberes y conocimientos construidos de forma contextualizada, que permitan agenciar apuestas y proyectos alternativos disidentes en la búsqueda de “desarrollos y educaciones otras” desde América Latina

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

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Simulación de circuitos basada en la implementación de modelos avanzados de dispositivos y sensores electrónicos en Verilog-A

Tesis Univ. Granada. Departamento de Electrónica y Tecnología de Computadores. Leída el 26 de abril de 201

Dispositivo posicionador de anillos distanciadores para herramientas de fresado o taladrado

Número de publicación: ES2408029 B1. Número de solicitud: 201330502.Se describe un posicionador manual de anillos distanciadores que permite la instalación inicial del anillo distanciador en herramientas no anilladas, la corrección de la posición del anillo y la restitución a su posición normalizada según el fabricante del equipo de prototipado rápido. El dispositivo descrito también permite la recuperación de los anillos de herramientas inservibles o agotadas.Universidad de Granad