2,589 research outputs found
Estudi sobre la possible utilització de la borra de cotó com a adob orgà nic mitjançant un procés de compostatge
Aplicación del modelo de daño de Gurson-Tvergaard-Needleman (GTN) para la simulación del ensayo miniatura de punzonado sobre probetas prefisuradas
The impact of financial insecurity on self-reported health: Europe in cross-national perspective
Using the EU-SILC 2008 module on over-indebtedness and financial exclusion, this paper analyses how perceived future-orientated economic insecurity alters individual self-assessed health (SAH), once controlling for past and current financial situation in a range of European countries. Those effects differ by gender and by country. Our results also suggest that country characteristics explain a larger part of the unknown variability of individual levels of SAH than individual-household characteristics. Thus, our findings might be of help in designing the most effective policies intended to alleviate the individual welfare costs of perceived financial insecurity provoked by upcoming business-cycle downturnsPID2019111765GB-I0
Photon to axion conversion during Big Bang Nucleosynthesis
We investigate how the resonant conversion at a temperature -
keV of a fraction of the CMB photons into an axion-like majoron affects BBN.
The scenario, that assumes the presence of a primordial magnetic field and the
subsequent decay of the majorons into neutrinos at eV, has been
proposed to solve the tension. We find two main effects. First, since we
lose photons to majorons at , the baryon to photon ratio is smaller at
the beginning of BBN than during decoupling and structure
formation (). This relaxes the mismatch between the
observed deuterium abundance and the one predicted by the standard CDM
model. Second, since the conversion implies a sudden drop in the temperature of
the CMB during the final phase of BBN, it interrupts the synthesis of lithium
and beryllium and reduces their final abundance, possibly alleviating the
lithium problem.Comment: 12 pages, 3 figures; new section added, matches version accepted by
JCA
Notch Fracture predictions using the Phase Field method for Ti-6Al-4V produced by Selective Laser Melting after different post-processing conditions
Ti-6Al-4V is a titanium alloy with excellent properties for lightweight
applications and its production through Additive Manufacturing processes is
attractive for different industrial sectors. In this work, the influence of
mechanical properties on the notch fracture resistance of Ti-6Al-4V produced by
Selective Laser Melting is numerically investigated. Literature data is used to
inform material behaviour. The as-built brittle behaviour is compared to the
enhanced ductile response after heat treatment (HT) and hot isostatic pressing
(HIP) post-processes. A Phase Field framework is adopted to capture damage
nucleation and propagation from two different notch geometries and a discussion
on the influence of fracture energy and the characteristic length is carried
out. In addition, the influence of oxygen uptake is analysed by reproducing
non-inert atmospheres during HT and HIP, showing that oxygen shifts fracture to
brittle failures due to the formation of an alpha case layer, especially for
the V-notch geometry. Results show that a pure elastic behaviour can be assumed
for the as-built SLM condition, whereas elastic-plastic phenomena must be
modelled for specimens subjected to heat treatment or hot isostatic pressing.
The present brittle Phase Field framework coupled with an elastic-plastic
constitutive analysis is demonstrated to be a robust prediction tool for notch
fracture after different post-processing routes
Aprenentatge entre iguals: mentre tu aprens jo consolido els meus coneixements
Els alumnes de primer curs de Podologia acostumen a accedir al Grau per vies diverses i un gran nombre no ha estudiat el Batxillerat CientÃfic. Aquesta diversitat es tradueix en un alumnat heterogeni a l’aula, tant pel que fa als seus coneixements previs com pel seu interès en les matèries bà siques que es treballen en l’assignatura BioquÃmica i BiofÃsica. En conseqüència, el professorat repetidament havia posat de manifest que era difÃcil dur a terme les classes a un bon ritme i acabar el programa, ja que mentre uns alumnes es desmotivaven per no poder seguir les classes, d’altres s’avorrien.
Amb la finalitat d’homogeneïtzar els coneixements de l’alumnat i afavorir-ne la transmissió transversal, durant el curs 2015-2016 vam incloure diverses sessions amb la metodologia docent d’aprenentatge entre iguals. Les sessions eren de carà cter voluntari i consistien en què alguns alumnes amb un nivell inicial de coneixements alt (determinat en una prova de nivell realitzada el primer dia de classe) tutoritzaven a companys amb un nivell més baix.
Com a resultat d’aquesta experiència, si bé el professorat no va percebre millores substancials en el desenvolupament de les classes, sà que es va observar una menor incidència de suspesos entre els alumnes que havien estat tutoritzats
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