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Estudio numérico y experimental del frente de grieta de especímenes tubulares de aluminio sujetos a cargas de tracción - Modo I
Full text linkEl estudio del comportamiento en fractura de especímenes tubulares es fundamental debido a su aplicación industrial, en componentes de máquina, estructuras entre otros. A diferencia de los especímenes planos, los tubulares presentan una distribución de tensiones tridimensional influenciada por su geometría curva. Para abordar esta complejidad, se combinó análisis numérico mediante el método de elementos finitos (FEM) con ensayos experimentales en especímenes de aleación de aluminio con tres espesores distintos (2, 3 y 4 mm) y un concentrador de tensiones de 1.5 mm perpendicular al eje de carga.
El análisis FEM se realizó en ANSYS APDL, con refinamientos basados en el radio plástico de Dugdale. Se evaluaron la deformación plástica y la distribución de tensiones, destacando un comportamiento asimétrico de la zona plástica hacia el radio externo. Posteriormente, los datos se procesaron en MATLAB para su normalización y análisis comparativo. El espesor mostró influencia directa en la forma y extensión de la zona plástica.
En paralelo, los ensayos en modo I bajo carga cíclica (3 Hz) revelaron diferentes patrones de propagación de grieta: crecimiento hacia el interior en paredes delgadas, trayectorias tridimensionales en paredes gruesas y comportamiento mixto en espesores intermedios. El uso de sobrecargas y visión artificial permitió caracterizar las fases de nucleación, crecimiento acelerado y fractura.
La validación cruzada entre simulaciones y experimentos confirmó la influencia clave de la geometría tubular en la propagación de grietas. Los resultados, publicados en las revistas Materials y Metals, sientan las bases en el estudio de especímenes tubulares sometidos a cargas cíclicas
La biblioteca escolar: espacio de encuentro para la interculturalidad y formación del lector crítico y competente.
No full textEn el presente artículo se analiza el papel de la biblioteca escolar como un espacio fundamental para el encuentro intercultural y la formación de lectores críticos y competentes. En un contexto social cada vez más diverso, se defiende que las bibliotecas escolares, más allá de su función como centros de acceso a la información, se configuran como escenarios que favorecen el diálogo, la comprensión de la diversidad y el desarrollo del pensamiento crítico. La biblioteca no solo ofrece un entorno físico acogedor y abierto, sino que también actúa como recurso pedagógico que dinamiza actividades inclusivas y promueve la alfabetización informacional y mediática.
Se destaca su capacidad para integrar contenidos de diferentes culturas, facilitando el acercamiento entre el alumnado y favoreciendo la cohesión social. Además, contribuye al desarrollo de las competencias lectoras mediante prácticas adaptadas a la realidad digital, fomentando una lectura crítica, reflexiva y colaborativa.
El artículo propone tres iniciativas principales: la producción de materiales y proyectos interdisciplinares, los clubes de lectura y el debate escolar. Estas actividades permiten no solo mejorar la competencia lectora, sino también fortalecer el diálogo intercultural mediante el intercambio de perspectivas y la reflexión conjunta.
Finalmente, se subraya que la biblioteca escolar, por su dimensión educativa y social, debe considerarse un espacio esencial en el ámbito educativo para formar ciudadanos libres, críticos y comprometidos, capaces de desenvolverse en una sociedad plural y diversa, enfrentando así los retos de la globalización y de la educación inclusiva
Victorian Poetry and Contemporary Issues
Full text linkAs part of the coursework within the mandatory subject “Literatura Inglesa III (Poesía)”,
taught in the final year of the degree in English Studies at the University of Málaga,
students were asked to analyse the poems here. These poems are all from the Victorian era (1837-1901).
Students were asked to carefully read these poems and to transform them into
contemporary versions of themselves. They were required not to alter the style or themes of the poems but to ‘update’ them so that they represent what concerns they might have as related to these topics. This exercise (carried out in English, as the subject is taught in this language) had as its aim to show students the continuity of literary themes, the relevance and impact of poetry when commenting social causes and, furthermore, to grant them a wider understanding of rhythm and rhyme, as well as an insight into the difficulties of writing poetry. The exercise was positively received by students and those who voluntarily participated in it alleged that it had been helpful for their overall understanding of the subject
Accurate Prediction and Understanding of ECD Spectra Through Jahn-Teller or Exciton-Exciton Effects in Symmetric Cyclic Systems.
No full textStrong chiroptical responses are a requirement for the development of chiral electronics devices. A promising design strategy utilizes repetitive monomeric units in a cyclic and symmetric chiral arrangement assembled into a molecular system. This strategy is inspired by the exciton coupling mechanism of electronic circular dichroism.1,2 However, the computational prediction of optical and chiroptical properties is challenging because such properties are ruled by nonadiabatic effects beyond the widely used Born-Oppenheimer approximation. In the particular case of systems with symmetry axis of order equal or larger than 3, symmetry imposes degenerate state whose potential energy profile is largely affected by nuclear coordinates and determined by Jahn-Teller (JT) and pseudo Jahn-Teller (pJT) effects.
The present study focuses on trigonal systems showing that JT and particularly pJT effects must be properly accounted to reproduce the experimental spectra since such effects are responsible of the optical and chiroptical properties. Our approach applies diabatization procedures combined with quantum dynamical wavepacket propagations,3 according to two possible alternative pictures: 1) a delocalized approach defining diabatic states coincident with the adiabatic states of the trimeric system in the equilibrium geometry and 2) a localized approach based on idealized monomers and their excitonic coupling. The predictions provided by both approaches converge in remarkable agreement with the experimental results. The proposed method is easily extensible to other symmetries, allowing to estimate the most favorable arrangements in the search of strong chiroptical response
Performance assessment of population-based multiobjective optimization algorithms using composite indicators
Full text linkThe performance of population-based multiobjective
optimization algorithms is usually evaluated using indicators
assessing the quality of the approximation set generated according
to convergence, cardinality, spread, and uniformity (the
combination of the last two known as diversity). Since not all
quality indicators can capture all these properties, we propose
to aggregate already-existing indicators into a single measure
informing about the algorithm’s performance from a general
perspective. To synthesize the desired quality indicators, we build
three composite quality indicators (weak, strong, and mixed)
based on the reference point approach. This approach enables
the use of desirable value ranges for the aggregated quality
indicators, defined by aspiration and reservation levels, that
allow knowing which algorithms perform better, within, or worse
than the desired limits. Each of the composite quality indicators
proposed enables a different compensation degree among the
aggregated indicators, and their joint use permits a deep insight
into the algorithms’ performance. In addition, we show that
the weak and mixed composite indicators are Pareto-compliant,
and the strong one is weakly Pareto-compliant if at least one
of the aggregated indicators is Pareto-compliant. Finally, we
demonstrate the benefits of our proposal when comparing many
population-based algorithms on three-, five-, and eight-objective
optimization problems.Funding for open access charge: Universidad de Málaga/CBUA
A decision framework for privacy-preserving synthetic data generation
No full textAccess to realistic data is essential for various purposes, including training machine learning models, conducting simulations, and supporting data-driven decision making across diverse domains. However, the use of real data often raises significant privacy concerns, as it may contain sensitive or personal information. Generative models have emerged as a promising solution to this problem by generating synthetic datasets that closely resemble real data. Nevertheless, these models are typically trained on original datasets, which carries the risk of leaking sensitive information. To mitigate this issue, privacy-preserving generative models have been developed to balance data utility and privacy guarantees. This paper examines existing generative models for synthetic tabular data generation, proposing a taxonomy of solutions based on the privacy guarantees they provide. Additionally, we present a decision framework to aid in selecting the most suitable privacy-preserving generative model for specific scenarios, using privacy and utility metrics as key selection criteria.Funding for open access charge: Universidad de Málaga / CBU
Comparing analytically propulsion by pitching and heaving flexible foils near the first two natural modes
Full text linkAn analytical formulation is provided that describes the first two natural modes of the
fluid–structure interaction of an incompressible current with a pitching and heaving
flexible plate. The objective is twofold: first, to present a general derivation of analytical
expressions for the lift, moment and the flexural moments exerted by an inviscid flow on
a pitching and heaving plate whose deformation is general enough that the coupling of
the flexural moments with the structural equations allows solving analytically the first two
natural modes of the system; second, to analyse the propulsion performance of the foil
when actuated near the first two natural frequencies. For the second purpose, one also
needs the thrust force generated through the motion and the general deformation of the
foil considered, which is analytically derived using the linearized vortex impulse theory,
extending and systematizing previous works. The analytical expressions, once viscous
effects are taken into consideration through nonlinear transverse damping and offset drag
coefficients, are compared with small-amplitude available experimental data, discussing
their limitations. It is found that low stiffness pitching and heaving are quite different,
with a pitching flexible foil only generating thrust near the second resonant frequency,
whereas heaving always generates thrust, with the maximum slightly below the second
natural frequency. Maximum thrust for large stiffness pitching is around the first natural
frequency. The maximum efficiency occurs at frequencies close to the first natural mode
if the foil is sufficiently rigid, but it is not related to the natural frequencies as the rigidity
decreases.Funding for open access charge: Universidad de Málag
Distribution pattern and biochemical variability of Irish invasive seaweed across a spatial gradient
Full text linkThis study updates the distribution of seaweed invasive alien species (IAS) in Ireland and demonstrates the natural spatial variation of their phenolic compounds and fatty acid profiles, coupled with an assessment of biomass availability. We examined the intertidal area of 68 coastal locations and detected the presence of six IAS, but abundant populations (30–50 % cover) were only recorded for Sargassum muticum in some western and southern locations along the Irish coast. However, the fact that so many invasive species were widely distributed represents a dormant threat to Irish coastal ecosystems. Regarding distribution, we detected a spatial expansion of Colpomenia peregrina and Codium fragile, while a contraction was recorded for S. muticum and Asparagopsis armata. Undaria pinnatifida represents a recent introduction, and Gracilaria vermiculophylla is spreading to new locations in the south and west. In general, saturated fatty acid content was high in C. fragile and C. peregrina samples, and higher monounsaturated fatty acid content occurred in the latter. Sargassum muticum and G. vermiculophylla presented more polyunsaturated fatty acids and n-3 fatty acids (together with C. fragile). Statistical analyses showed that, for to S. muticum, higher water temperatures decreased metabolite content in all areas sampled, and higher concentrations of metabolites were generally found in northern populations. However, biomass was not abundant at these sites, which poses challenges facing valorisation of these natural resources. This study provides important baseline information of fatty acid profiles and phenolic content of Irish IAS, an essential preliminary step in industrial sourcing of marine bioactive metabolites.Funding for open access charge: Universidad de Málaga / CBU
Integrating energy consumption in the development of serverless applications
No full textContext:
The increasing environmental impact of Information and Communication Technologies (ICTs), particularly the energy consumption associated with serverless applications, necessitates the development of methodologies to optimize energy efficiency. This study addresses the need for energy-aware design and runtime adaptation in serverless architectures.
Objective:
To develop and validate a methodology that integrates energy monitoring into the development and runtime management of serverless applications, thereby enabling significant reductions in energy consumption while maintaining functionality.
Methods:
A new version of FUSPAQ, a framework for the optimization of serverless applications, was developed. This version incorporates tools like Kepler for real-time energy monitoring and employs an energy-aware orchestration mechanism to dynamically select energy-efficient function configurations. Validation was conducted through a facial recognition case study and benchmark experiments, comparing energy consumption across different scenarios with and without the proposed adaptations.
Results:
The enhanced FUSPAQ framework successfully integrated energy consumption metrics into the decision-making process for function selection and runtime adaptation. Benchmark tests confirmed the scalability of the solution, with energy-efficient outcomes even in complex applications.
Conclusion:
The study highlights the potential of integrating energy-aware practices in serverless applications, presenting a scalable and practical approach to reducing their environmental footprint. By leveraging tools like Kepler and frameworks like FUSPAQ, developers can achieve significant energy savings without compromising application performance. This work contributes to the advancement of Green Software Engineering by emphasizing runtime energy adaptation in Function-as-a-Service (FaaS) architectures.Funding for open access charge: Universidad de Málaga / CBU