Exploring magnetic fluctuations effects in QED gauge fields: implications for mass generation

In this work, we calculate the one-loop contribution to the polarization tensor for photons (and gluons) in the presence of a classical background magnetic field with white-noise stochastic fluctuations. The magnetic field fluctuations are incorporated into the fermion propagator in a quasi-particle picture, which we developed in previous works using the {\it replica trick}. By focusing on the strong-field limit, here we explicitly calculate the polarization tensor. Our results reveal that it does not satisfy the transversality conditions outlined by the Ward identity, thus breaking the $U(1)$ symmetry. As a consequence, in the limit of vanishing photon four-momenta, the tensor coefficients indicate the emergence of an effective magnetic mass induced on photons (and gluons) by these stochastic fluctuations, leading to the interpretation of a dispersive medium with a noise-dependent index of refraction.Comment: 18 pages, 5 figure

Inversion symmetry breaking in the probability density by surface-bulk hybridization in topological insulators

We analyze the probability density distribution in a topological insulator slab of finite thickness, where the bulk and surface states are allowed to hybridize. By using an effective continuum Hamiltonian approach as a theoretical framework, we analytically obtained the wave functions for each state near the $\Gamma$-point. Our results reveal that, under particular combinations of the hybridized bulk and surface states, the spatial symmetry of the electronic probability density with respect to the center of the slab can be spontaneously broken. This symmetry breaking arises as a combination of the parity of the solutions, their spin projection, and the material constants.Comment: Main text (8 pages). The calculations are now included in the main text. The discussion was improved and expande

Multi-probe analysis of the galaxy cluster CL J1226.9+3332: Hydrostatic mass and hydrostatic-To-lensing bias

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMThe precise estimation of the mass of galaxy clusters is a major issue for cosmology. Large galaxy cluster surveys rely on scaling laws that relate cluster observables to their masses. From the high-resolution observations of ∼45 galaxy clusters with the NIKA2 and XMM-Newton instruments, the NIKA2 Sunyaev-Zela'dovich Large Program should provide an accurate scaling relation between the thermal Sunyaev-Zela'dovich effect and the hydrostatic mass. In this paper we present an exhaustive analysis of the hydrostatic mass of the well-known galaxy cluster CL J1226.9+3332, the highest-redshift cluster in the NIKA2 Sunyaev-Zela'dovich Large Program at z=0.89. We combined the NIKA2 observations with thermal Sunyaev-Zela'dovich data from the NIKA, Bolocam, and MUSTANG instruments and XMM-Newton X-ray observations, and tested the impact of the systematic effects on the mass reconstruction. We conclude that slight differences in the shape of the mass profile can be crucial when defining the integrated mass at R500, which demonstrates the importance of the modelling in the mass determination. We prove the robustness of our hydrostatic mass estimates by showing the agreement with all the results found in the literature. Another key factor for cosmology is the bias of the masses estimated assuming the hydrostatic equilibrium hypothesis. Based on the lensing convergence maps from the Cluster Lensing And Supernova survey with Hubble (CLASH) data, we obtain the lensing mass estimate for CL J1226.9+3332. From this we are able to measure the hydrostatic-To-lensing mass bias for this cluster, which spans from 1-bHSE/lens∼0.7 to 1, presenting the impact of data sets and mass reconstruction models on the bia

Remote teaching in construction engineering management during COVID-19

[EN] This paper describes the impact of the change from face-to-face classes to non-face-to-face classes with students of a postgraduate course at the Universitat Politècnica de València. This study is carried out in the subjects of installation, organization and quality assurance in construction and construction procedures of both degree in public works engineering and civil engineering. This course develops the student's skills to integrate into the studies department of a construction company, as Site Manager or Production Director, from a journey through the different phases of the project-construction process. As part of this topic, the methods of scheduling activities on site are discussed. In the traditional face to-face method, several problems are solved, requiring that students have previously learned programming techniques: arrow networks, precedence networks, and how to apply the PERT method to statistically obtain the probability of completion of a building or the completion of activities related. Due to the current situation of the pandemic caused by COVID-19, face-to-face teaching has changed virtual classes in a very short time. This has required a radical shift towards distance education. This paper explains how this change has been made, what new methods have been used to teach the contents corresponding to the scheduling of assignments, and what the students' perception has been. The quality of the education received and the difficulties encountered in obtaining the knowledge and skills attributed to this subject are analyzed.The authors acknowledge the support for the Ministry of Economy and Company and FEDER funding (Project BIA2017-85098-R).Martínez-Muñoz, D.; Martí Albiñana, JV.; Yepes, V. (2021). Remote teaching in construction engineering management during COVID-19. IATED Academy. 879-887. https://doi.org/10.21125/inted.2021.0205S87988

Application of the response surface methodology in a postgraduate optimization course

[EN] This paper describes the introduction of response surface methodology in a postgraduate course. This case study is carried out in the subject of the predictive models of optimization of concrete structures subject. This subject is inside the curricula of concrete engineering master. In this course students learn concepts such as structures¿ optimization using algorithms, multi-criteria decision making, techniques do design of experiments, and metamodels such as the response surface in order to obtain optimum results. In this case study, the objective is to obtain a design solution of a reinforced concrete wall, using the CO2 emissions as an objective function to reduce its impact. In order to apply this methodology, the students need to use specific software. On the one hand, to carry out the statistical analysis that allow obtaining the response surface Minitab software has been used by students. On the other hand, students need to check the strength of the structure using Cype structural calculation software. As a result of applying this methodology to obtain an optimum reinforced concrete wall allow students to reach a better level in transversal competencies, such as design and project, critical thinking, analysis and problem solving or the use of specific software. This paper will introduce future research studies related to the use of structures optimization techniques by students applying other different optimization techniques.The authors acknowledge the support for the Ministry of Economy and Company and FEDER funding (Project BIA2017-85098-R).Yepes, V.; Martínez-Muñoz, D.; Martí Albiñana, JV. (2021). Application of the response surface methodology in a postgraduate optimization course. IATED Academy. 869-878. https://doi.org/10.21125/inted.2021.0204S86987

Educar en la finitud. Contribuciones para pensar el fundamento de la educación con Heidegger y Sartre

This article aims to reflect on the foundation of education from a movement of thought that is oriented on finite. For this he takes categories such as Heideggerian Dasein, mainly the existential being-for-death, and Sartrean for-himself, which, with all its nuances, take the being from its own forgetfulness and allow a pedagogical reflection that welcomes finite as an alternative to maintain the open state of existence. Through a hermeneutical exercise, some concepts of existential philosophy were linked to a diagnosis of education on the horizon of forgetting being, envisioning in turn an exercise of foundation, which broadens the horizon to think about it and transform it.Este artículo pretende reflexionar acerca del fundamento de la educación a partir de un movimiento del pensar que se orienta en la finitud. Para ello, toma categorías como el Dasein heideggeriano, principalmente el existenciario ser-para-la-muerte, y el para-sí sartreano, que, con todos sus matices, sacan el ser de su propio olvido y posibilitan una reflexión pedagógica que acoge la finitud como alternativa para mantener el estado de apertura de la existencia. Mediante un ejercicio hermenéutico, se vincularon algunos conceptos de la filosofía existencial a un diagnóstico de la educación en el horizonte del olvido del ser, vislumbrando a su vez un ejercicio de fundamentación que amplía el horizonte para pensarla y transformarla

Social Impact Assessment Comparison of Composite and Concrete Bridge Alternatives

[EN] The definition of sustainability includes three fundamental pillars: economic, environmental, and social. Studies of the economic impact on civil engineering infrastructures have been focused on cost reduction. It is not necessarily in line with economic sustainability due to the lack of other economic factors. Moreover, the social pillar assessment has been weakly developed compared to the economic and the environmental ones. It is essential to focus on the social pillar and evaluate clear indicators that allow researchers to compare alternatives. Furthermore, bridge life cycle assessment studies have been focused on concrete options. This has resulted in a lack of analysis of the impact of composite bridge alternatives. This study is conducted in two stages. The first part of the study makes a cradle-to-grave social and environmental sustainability evaluation with the SOCA v2 and ecoinvent v3.7.1 databases. This assessment is carried out on four concrete and composite bridge alternatives with span lengths between 15 and 40 m. The social impact weighting method and recipe have been used to obtain the social and environmental indicators. The second part of the study compares the results obtained from the social and environmental assessment of the concrete and the composite alternatives varying the steel recycling rate. The bridge alternatives are prestressed concrete solid slab, prestressed concrete lightened slab, prestressed concrete box-girder, and steel¿concrete composite box-girder. The results show that composite options are the best for environmental impact, but the concrete box girder solutions are better for social impact. Furthermore, an increase in the steel recycling rate increases the social impact and decreases the environmental one.This research was funded by: Grant PID2020-117056RB-I00 funded byMCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe". Grant FPU-18/01592 funded by MCIN/AEI/10.13039/501100011033 and by "ESF invests in your future".Martínez-Muñoz, D.; Martí Albiñana, JV.; Yepes, V. (2022). Social Impact Assessment Comparison of Composite and Concrete Bridge Alternatives. Sustainability. 14(9):1-19. https://doi.org/10.3390/su1409518611914

Steel-Concrete Composite Bridges: Design, Life Cycle Assessment, Maintenance, and Decision-Making

[EN] Steel-concrete composite bridges are used as an alternative to concrete bridges because of their ability to adapt their geometry to design constraints and the possibility of reusing some of the materials in the structure. In this review, we report the research carried out on the design, behavior, optimization, construction processes, maintenance, impact assessment, and decision-making techniques of composite bridges in order to arrive at a complete design approach. In addition to a qualitative analysis, a multivariate analysis is used to identify knowledge gaps related to bridge design and to detect trends in research. An additional objective is to make visible the gaps in the sustainable design of composite steel-concrete bridges, which allows us to focus on future research studies. *eresults of this work show how researchers have concentrated their studies on the preliminary design of bridges with a mainly economic approach, while at a global level, concern is directed towards the search for sustainable solutions. It is found that life cycle impact assessment and decision-making strategies allow bridge managers to improve decision-making, particularly at the end of the life cycle of composite bridges.This study was funded by the Spanish Ministry of Economy and Competitiveness, along with FEDER funding (DIMALIFE Project BIA2017-85098-R).Martínez-Muñoz, D.; Martí Albiñana, JV.; Yepes, V. (2020). Steel-Concrete Composite Bridges: Design, Life Cycle Assessment, Maintenance, and Decision-Making. Advances in Civil Engineering. 2020:1-13. https://doi.org/10.1155/2020/8823370S113202

La filosofía como una mística de acogida. Una lectura de la filosofía y la mística en Plotino y Pierre Hadot

This paper tries to go in depth in to the meaning of the expression of philosophy as a way of life in Pierre Hadot in the Eneadas III and Plotino V, that relate One, the first hypostasis with the need of embarking and conversion of the human soul as telos of philosophy. In other words, there is an exploration of the indivisible union between philosophy as a discourse and as an experience of transformation through the mystic approach, that is, a reinterpretation of Plotinian philosophy that integrates our thirst for knowledge and the need to become others.Esta reflexión pretende ahondar en el sentido de la expresión filosofía como modo de vida de Pierre Hadot y en las Enéadas III y V de Plotino, que justamente vinculan el Uno, la hipóstasis primera, con la necesidad de embarcamiento y de conversión del alma humana en tanto telos de la filosofía. Lo que explora, en otras palabras, es la unidad indisoluble entre la filosofía como discurso y como experiencia de transformación mediante la fórmula mística de acogida, esto es, una reinterpretación de la filosofía plotiniana que integra nuestra sed de conocimiento con la necesidad de hacernos-otros

Comparative Life Cycle Analysis of Concrete and Composite Bridges Varying Steel Recycling Ratio

[EN] Achieving sustainability is currently one of the main objectives, so a consensus between different environmental, social, and economic aspects is necessary. The construction sector is one of the main sectors responsible for environmental impacts worldwide. This paper proposes the life cycle assessment (LCA) and comparison of four bridge deck alternatives for different span lengths to determine which ones are the most sustainable solutions. The ReCiPe method is used to conduct the life cycle analysis, by means of which the impact value is obtained for every alternative and span length. The Ecoinvent 3.3 database has been used. The life cycle has been divided into four phases: manufacturing, construction, use and maintenance, and end of life. The associated uncertainties are considered, and the results are shown in both midpoint and endpoint approaches. The results of our research show that for span lengths less than 17 m, the best alternative is the prestressed concrete solid slab. For span lengths between 17 and 25 m, since the box-girder solution is not used, then the prestressed concrete lightened slab is the best alternative. For span lengths between 25 and 40 m, the best solution depends on the percentage of recycled structural steel. If this percentage is greater than 90%, then the best alternative is the composite box-girder bridge deck. However, if the percentage is lower, the cleanest alternative is the prestressed concrete box-girder deck. Therefore, the results show the importance of recycling and reusing structural steel in bridge deck designs.This research was funded by Spanish Ministry of Economy and Business (Project: BIA201785098-R), the Spanish Ministry of Science and Innovation (Project: PID2020-117056RB-I00), along with FEDER funding and Spanish Ministry of Science, Innovation and Universities for David MartinezMunoz's University Teacher Training Grant (FPU-18/01592).Martínez-Muñoz, D.; Martí Albiñana, JV.; Yepes, V. (2021). Comparative Life Cycle Analysis of Concrete and Composite Bridges Varying Steel Recycling Ratio. Materials. 14(15):1-22. https://doi.org/10.3390/ma14154218S122141