Comportamiento mecánico de la aleación W+1%Y2O3 en función de la atmósfera y la temperatura

Mediante ensayos de flexión en tres puntos se compara y evalúa el comportamiento mecánico de la aleación W- 1wt%Y2O3 con el W puro fabricados ambos mediante HIP. Se ha obtenido la tenacidad de fractura, la resistencia a flexión y el límite elástico en atmósfera oxidante y de vacío en un intervalo de temperaturas comprendido entre -196 ºC, ensayos de inmersión en nitrógeno líquido, y 1200 ºC. Previamente, se ha medido la densidad, la dureza mediante ensayos Vickers y el módulo de elasticidad dinámico de los materiales. Además, la dureza y el módulo de elasticidad se han comparado con los obtenidos mediante ensayos instrumentados de nanoindentación. Finalmente se ha realizado un pequeño estudio de las superficies de fractura de las muestras ensayadas mediante microscopía electrónica de barrido para poder relacionar el modo de rotura de los materiales y las propiedades mecánicas macroscópicas con los micromecanismos de fallo involucrados en función de la temperatura

Mechanical characterisation of tungsten-1wt.% yttrium oxide as a function of temperature and atmosphere

This study evaluates the mechanical behaviour of an Y2O3-dispersed tungsten (W) alloy and compares it to a pure W reference material. Both materials were processed via mechanical alloying (MA) and subsequent hot isostatic pressing (HIP). We performed non-standard three-point bending (TPB) tests in both an oxidising atmosphere and vacuum across a temperature range from 77 K, obtained via immersion in liquid nitrogen, to 1473 K to determine the mechanical strength, yield strength and fracture toughness. This research aims to evaluate how the mechanical behaviour of the alloy is affected by oxides formed within the material at high temperatures, primarily from 873 K, when the materials undergo a massive thermal degradation. The results indicate that the alloy is brittle to a high temperature (1473 K) under both atmospheres and that the mechanical properties degrade significantly above 873 K. We also used Vickers microhardness tests and the dynamic modulus by impulse excitation technique (IET) to determine the elastic modulus at room temperature. Moreover, we performed nanoindentation tests to determine the effect of size on the hardness and elastic modulus; however, no significant differences were found. Additionally, we calculated the relative density of the samples to assess the porosity of the alloy. Finally, we analysed the microstructure and fracture surfaces of the tested materials via field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). In this way, the relationship between the macroscopic mechanical properties and micromechanisms of failure could be determined based on the temperature and oxides forme

Regulación emocional e identidad de género: Un análisis más allá del sexo

XX Congreso Internacional del Institut d’ Estudis Feministes i de Génere «Purificación Escribano»: Emociones, Salud y GéneroLas investigaciones sobre salud y emociones incorporan cada vez más la perspectiva de género, aunque la mayoría se centran en estudiar las diferencias en función del sexo, dejando de lado la identidad de género. Este es el caso del estudio de las estrategias de regulación emocional. Nuestro estudio tiene como objetivo analizar la identidad de género (masculinidad/feminidad) como predictora de la estrategia de regulación emocional de supresión. Para ello se ha empleado una muestra de 257 jóvenes en situación de desempleo (51 % hombres) menores de 30 años (media = 26.7, DT = 2.4). La identidad de género se ha medido a partir del Bem Sex Role Inventory (BSRI), y la regulación emocional con el Emotion Regulation Questionnaire (ERQ). Los resultados de regresiones multivariantes con interacción indican que las interacciones entre las identidades de masculinidad y feminidad se relacionan de manera significativa con los mecanismos de supresión emocional. Aquellas personas que tienen una masculinidad con valores altos, ante puntuaciones altas en feminidad disminuyen el uso de la estrategia de supresión, mientras que con puntuaciones bajas la aumentan. Por su parte, las personas con valores bajos en masculinidad aumentan el uso de la estrategia de supresión a niveles altos de feminidad, mientras que la reducen a niveles bajos. Si bien los estudios sobre supresión emocional sugieren que los hombres tienden a suprimir sus emociones más que las mujeres, los resultados de la presente investigación hacen patente la necesidad de incluir análisis que vayan más allá del mero enfoque de las diferencias sexuales

Mechanical behaviour at high temperature of alkali-activated aluminosilicates (geopolymers)

This study was designed to determine the effect of temperature on the mechanical strength (in both in vivo and post-exposure trials) of two alkaline cements (without OPC): (a) 100% fly ash (FA) and (b) 85% FA + 15% bauxite, the activated alkaline solution used was 85% 10-M NaOH + 15% sodium silicate. A Type I 42.5 R Portland cement was used as a control. Two series of trials were conducted: (i) in vivo trials in which bending and compressive strength, fracture toughness and modulus of elasticity were determined at different temperatures; and (ii) post-firing trials, assessing residual bending and compres-sive strength after a 1-h exposure to high temperatures and subsequent cooling. The findings showed that from 25 to 600 C, irrespective of the type of test (in vivo or post-firing), compressive mechanical strength rose, with the specimens exhibiting elastic behaviour and consequently brittle failure. At tem-peratures of over 600 C, behaviour differed depending on the type of test: (i) in the in vivo trials the high temperature induced pseudo-plastic strain and a decline in mechanical strength that did not necessarily entail specimen failure; (ii) in the post-firing trials, compressive strength rose

Ligamento arcuato mediano como hallazgo incidental

Introducción: debido al uso de técnicas de imagen de alta resolución se ha incrementado el diagnóstico incidental de la compresión del tronco celiaco por el ligamento arcuato mediano. Si tenemos en cuenta que en solo un 1 % de los casos se produce sintomatología, su hallazgo casual puede llevar a diagnósticos erróneos en pacientes con sintomatología a nivel abdominal. Caso clínico: presentamos el caso de un varón de 47 años con dolor abdominal pospandrial secundario a una perforación esofágica que inicialmente pasó desapercibida, e imágenes en angiografía por tomografía computarizada sugestivas de síndrome de ligamento arcuato mediano, con abundante circulación colateral, pero sin signos de sufrimiento de asas ni trombosis arterial. Discusión: el síndrome del ligamento arcuato mediano es una patología muy infrecuente y, en su mayor parte, solo constituye una imagen radiológica; por ello es necesario descartar cualquier otra patología antes de identifi carlo como el responsable de cualquier cuadro clínico digestivo. Background: due to high resolution imaging techniques there has been an increase in incidental diagnosis of celiac trunk compression by median arcuate ligament. In fact, only 1 % of the cases of abdominal pain are attached to coeliac trunk compression. Therefore, its incidental finding might lead to a misdiagnosis in those patients with abdominal symptoms. Case report: we report a case of a 47 year-old male with abdominal post-pandrial pain, as a result of an esophageal perforation which was initially misdiagnosed, and image techniques suggesting a median arcuate ligament syndrome, with abundant collateral circulation but without signs of intestinal ischemia or arterial thrombosis. Discussion: median arcuate ligament syndrome is very uncommon and it is mainly a radiological image finding. Thus it is needed to rule out any other digestive pathology before median arcuate ligament syndrome is diagnosed in patients with abdominal symptoms. © 2021 Viguera Editores S.L.. All rights reserved

Review of sciaenid culture around the world, with a special focus on the meagre Argyrosomus regius (Asso, 1801)

Interest in culture of sciaenid fishes has grown rapidly in recent years. The present paper reviews the literature on several species belonging to Sciaenidae, cultured around the world: red drum Sciaenops ocellatus (L., 1766), Japanese meagre or mulloway Argyrosomus japonicus (Temminck y Schlegel, 1843), shi drum Umbrina cirrosa (L., 1758), and meagre Argyrosomus regius (Asso, 1801). The meagre is a commercially important fish species whose distribution extends along the Eastern Atlantic coast and the Mediterranean Sea. Experiments carried out in sea cages and indoor tanks have shown similar results in growth rate, but the food conversion rate was higher in cages (2,73) than in tanks (13,88).El interés por el cultivo de peces esciénidos se ha visto incrementado en los últimos años. Se realiza aquí una revisión bibliográfica de cultivos de varias especies de la familia Sciaenidae en el mundo: corvinón ocelado Sciaenops ocellatus (L., 1766), corvina japonesa Argyrosomus japonicus (Temminck y Schlegel, 1843), verrugato Umbrina cirrosa (L., 1758) y corvina Argyrosomus regius (Asso, 1801). La corvina ha adquirido una importancia comercial notable, y se distribuye a lo largo de las costas del Atlántico y el Mediterráneo. Experiencias de cultivo en jaulas y tanques demostraron similares índices de crecimiento, obteniéndose, sin embargo, un mejor factor de conversión del alimento en jaulas (2,73) que en tanques (13,88).Instituto Español de Oceanografí

Nucleus accumbens functional connectivity and circulating endocannabinoids levels in anorexia nervosa

Introduction: Neuroimaging findings have reported aberrant functional connectivity in brain regions involved reward system in individuals with anorexia nervosa (AN) altering hedonic processing over food. Likewise, endocannabinoids such as Anandamide (AEA) and 2-Arachidonoylglycerol (2-AG) have been involved in rewarding aspects of food intake. Objectives: To identify nucleus accumbens (NAcc) functional connectivity with whole-brain comparing between individuals with AN and controls. Furthermore, in a sub-study, to explore the interaction between NAcc functional connectivity and peripheral AEA and 2-AG levels

Comparative fruit quality parameters of ‘Ninfa’ apricot (Prunus armeniaca L.) grafted on two different rootstocks in a newly established organic orchard

The fruit quality parameters of Prunus armeniaca L. cv ‘Ninfa’ grafted on ‘Myrobalan 29C’ (Prunus cerasifera Ehrh.) and ‘Real Fino’ apricot seedling (Prunus armeniaca L.) were analysed in an experimental orchard under organic management. The study was performed between 2010 and 2012 in the province of Seville (SW Spain). Colour, fruit and stone weights, firmness, soluble solid concentration, and acidity were measured for fruit quality evaluation. Trunk cross-sectional area, main branches, and fruit yield were also determined. In general, ‘Myrobalan 29C’ rootstock produced fruit slightly larger in size and with a bigger weight. By contrast, apricots on ‘Myrobalan 29C’ had less firmness and a lower solid soluble concentration than on ‘Real Fino’. There was little difference in the colour, acidity, and stone dry weights. Trees on ‘Real Fino’ had larger areas of trunk and branches but no significant differences were obtained in relation to fruit yields

The Imaging Magnetograph eXperiment (IMaX) for the Sunrise balloon-borne solar observatory

The Imaging Magnetograph eXperiment (IMaX) is a spectropolarimeter built by four institutions in Spain that flew on board the Sunrise balloon-borne telesocope in June 2009 for almost six days over the Arctic Circle. As a polarimeter IMaX uses fast polarization modulation (based on the use of two liquid crystal retarders), real-time image accumulation, and dual beam polarimetry to reach polarization sensitivities of 0.1%. As a spectrograph, the instrument uses a LiNbO3 etalon in double pass and a narrow band pre-filter to achieve a spectral resolution of 85 mAA. IMaX uses the high Zeeman sensitive line of Fe I at 5250.2 AA and observes all four Stokes parameters at various points inside the spectral line. This allows vector magnetograms, Dopplergrams, and intensity frames to be produced that, after reconstruction, reach spatial resolutions in the 0.15-0.18 arcsec range over a 50x50 arcsec FOV. Time cadences vary between ten and 33 seconds, although the shortest one only includes longitudinal polarimetry. The spectral line is sampled in various ways depending on the applied observing mode, from just two points inside the line to 11 of them. All observing modes include one extra wavelength point in the nearby continuum. Gauss equivalent sensitivities are four Gauss for longitudinal fields and 80 Gauss for transverse fields per wavelength sample. The LOS velocities are estimated with statistical errors of the order of 5-40 m/s. The design, calibration and integration phases of the instrument, together with the implemented data reduction scheme are described in some detail.Comment: 17 figure