A numerical analysis of weakening of a granitic rock by piezoelectric excitation of quartz

This work presents a numerical model to simulate intergranular damage in a granitic rock by oscillating piezoelectric excitation of quartz dispersed in the structure. The damage evolution at grain boundaries was assumed to be related to fatigue and it was modelled using cohesive elements and a damage evolution model formulated in terms of discipation of mechanical work. An explicit representation of the granular mesostructure was built, and it was subjected to high-voltage alternating-current exitation. The effect of the fatigue damage on the mechanical properties was quantified by simulated tension and compression tests. The numerical results show that the electrical treatment can potentially cause rock weakening due to fatigue, but the model needs to be calibrated with experimental data for a quantitative analysis.Peer reviewe

Weakening of tensile strength of granitic rock by HV-HF-AC actuation of piezoelectric properties of Quartz : a 3D numerical study

High-voltage and high-frequency alternating current (HV-HF-AC) excitation of piezoelectric properties of Quartz is a potential method to induce cracks in granite. This was recently shown in a numerical feasibility study [6], where cracking was induced on cylindrical rock samples made of granite by sinusoidal AC excitation at the frequency of ~100 kHz and the amplitude of ~10 kV. However, this study did not investigate the weakening effect due to this cracking on the tensile strength of the sample. The present study addresses this topic numerically. For this end, a numerical method based on 3D embedded discontinuity finite elements for rock fracture and an explicit time stepping scheme to solve the coupled piezoelectro-mechanical problem is adopted. Rock heterogeneity and anisotropy are accounted for at the mineral mesotructure level. A preliminary numerical simulation demonstrates that the HV-HF-AC treatment reduces the tensile strength of a cylindrical granite sample by 12 %, making it thus a potential non-conventional pre-treatment method in comminution and excavation of Quartz bearing rocks and ores.publishedVersionPeer reviewe

Digitalización y visualización 3D de cerámica arqueológica

[ES] El sistema de documentación y registro del material arqueológico ha experimentado un notable desarrollo gracias a la aplicación de nuevas tecnologías. Estas innovaciones han resultado bastante útiles en el campo de la documentación, análisis y visualización del material arqueológico. En este artículo se expone una metodología de trabajo para la realización de modelos 3D de cerámica arqueológica. Esta metodología se encuadra dentro del proyecto CATA (Cerámica Arqueológica a Torno de Andalucía), cuyo principal objetivo es la realización de una colección de referencia de formas cerámicas completas documentadas en intervenciones arqueológicas de Andalucía. Dicha colección de referencia contiene información concerniente no sólo al proceso de fabricación, la descripción del tratamiento de superficie, o el contexto de hallazgo de la pieza, sino que también se pueden visualizar modelos 3D, permitiendo un mejor conocimiento de la pieza.[EN] The documentation system of the archaeological material has development in the last years thanks to the application of new technologies. These innovations have been quite useful in the field of the documentation, analysis and visualization of the archaeological artefacts.In this article a methodology for the achievement of 3D model of archaeological pottery is exposed. This methodology fits within the CATA project (Archaeological Wheel Pottery of Andalusia in its acronyms in Spanish). The main objective of the project is the implementation of a database which is accessible by Internet, containing assorted information about pottery vessels and fragments found in Andalusia in different periods. This reference collection contains information concerning not only the manufacture process, the description of the surface treatment, or the context of finding of the ceramics, but also 3D models that allows a better knowledge of the vessel.El desarrollo de todo este trabajo ha sido posible gracias a la concesión por parte de la Consejería de Innovación, Ciencia y Empresa de la Junta de Andalucía del Proyecto de Excelencia HUM 890 Corpus Virtual de Cerámica Arqueológica.Martínez Carrillo, A.; Ruiz Rodríguez, A.; Rubio Paramio, MÁ. (2010). Digitalización y visualización 3D de cerámica arqueológica. Virtual Archaeology Review. 1(2):133-136. https://doi.org/10.4995/var.2010.4715OJS13313612BERMÚDEZ RODRÍGUEZ, Francisco et al. (2000): Intervención virtual en el patrimonio arquitectónico. Las termas romanas de Sant Boi de Llobregat (Barcelona). Actas del XII Congreso INGEGRAF. Valladolid. Junio 2000.IMMLER, Christian (1997): El gran libro de 3D Studio Max. Marcombo. Barcelona.KARASIK, A.; SMILANSKY, U. (2006): Computation of the Capacity of Pottery Vessels Based on Drawn Profiles, Excavations at Tel Beth Shean 1989-1996, vol. I, Mazar A. (ed.), Jerusalem (Israel).LAUDON, K.C.; LAUDON, J.P. (1996): Management Information Systems, Organization and Technology (B.4) Prentice-Hall, Inc., New Jersey (United States).LOUISE, M.S. , DUNBAR, P.B. (1995): Accurately Estimation Vessel Volume from Profile Illustrations, American Atiquity 60/2, pp. 319-334. http://dx.doi.org/10.2307/282143MAGALLÓN LACARTA, J.A. (1999): Generación por ordenador de modelos tridimensionales correspondientes a distintas etapas de la catedral de la Seo. Actas del XI Congreso INGEGRAF. Logroño-Pamplona.MILLER, Phillip et al. (1996-1997): Inside 3D Studio Max.. New Riders Publishing, cop. Indianapolis.RUBIO PARAMIO, M.A. et al. (2002): "Baños Árabes del Palacio de Villardompardo (Jaén). Estudio gráfico-cronológico y diseño de una herramienta multimedia para su promoción". XII Congreso INGEGRAF. Santander

Libro de Bienvenida 2023. Premio de creacion literaria El Drag

Esta publicación tiene como objetivo potenciar la lectura, dentro del Plan anual de Fomento de la Lectura y el Libro del Servicio de Biblioteca, así como proporcionar visibilidad a los trabajos ganadores del Premio de creación Literaria “El Drag” organizados por Extensión Universitaria, unos premios consolidados y con una amplia trayectoria que merecen una edición como esta, además de obsequiar a nuestros alumnos de nuevo ingreso con un libro como símbolo de la cultura y el conocimiento del que la Universidad es productora y garante

Genome-wide association analysis of dementia and its clinical endophenotypes reveal novel loci associated with Alzheimer's disease and three causality networks : The GR@ACE project

Introduction: Large variability among Alzheimer's disease (AD) cases might impact genetic discoveries and complicate dissection of underlying biological pathways. Methods: Genome Research at Fundacio ACE (GR@ACE) is a genome-wide study of dementia and its clinical endophenotypes, defined based on AD's clinical certainty and vascular burden. We assessed the impact of known AD loci across endophenotypes to generate loci categories. We incorporated gene coexpression data and conducted pathway analysis per category. Finally, to evaluate the effect of heterogeneity in genetic studies, GR@ACE series were meta-analyzed with additional genome-wide association study data sets. Results: We classified known AD loci into three categories, which might reflect the disease clinical heterogeneity. Vascular processes were only detected as a causal mechanism in probable AD. The meta-analysis strategy revealed the ANKRD31-rs4704171 and NDUFAF6-rs10098778 and confirmed SCIMP-rs7225151 and CD33-rs3865444. Discussion: The regulation of vasculature is a prominent causal component of probable AD. GR@ACE meta-analysis revealed novel AD genetic signals, strongly driven by the presence of clinical heterogeneity in the AD series

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019

Altres ajuts: Spanish AIDS Research Network; European Funding for Regional Development (FEDER).Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population

Diseño para el desarrollo sustentable y la habitabilidad segura e incluyente

Este libro se divide en dos partes que permiten permear en el campo de la enseñanza del diseño; la primera se enfoca en temáticas que se desprenden del diseño en la educación para la sustentabilidad; en la segunda, se identifican las tendencias del diseño como un modo de verlo y sentirlo: va desde el diseño emocional hacia uno de conservación, reúso y reparación de objetos para reducir el consumo de recursos materiales

Diseño estratégico de vanguardia

La integración del diseño con la vanguardia se observa natural, esto es, el diseño es una disciplina abductiva y la vanguardia persigue fines prospectivos, es decir, en ambos casos se trata de objetivos de posibilidad futura. De tal suerte, este libro, emanado de una parte de las ponencias rigurosamente arbitradas del Coloquio Internacional de Diseño 2016, está dividido en tres secciones o capítulos, a saber, el capítulo uno relacionado con la teoría y metodología para proyectos de diseño de vanguardia, el segundo sobre la tecnología, la innovación y la sostenibilidad de vanguardia de dichos proyectos, y finalmente el último capítulo, vinculado con la gestión estratégica de proyectos de vanguardia.La historia se forja de hechos e interpretaciones, de pasados construidos y de presentes en procesos constantes, estudiados en forma estricta por las ciencias. Por su parte, el futuro ostenta la posibilidad de ser indefinidamente planeado con base en las variopintas aproximaciones teóricas y empíricas que dan fundamento a este tipo de ciencia; éstas son denominadas prospectivas y sus bases vanguardias. Resulta importante señalar, que estas posibilidades sólo permiten tener una idea hipotética de lo que será la realidad y el mundo de vida de los seres vivos y su contexto, no obstante, se trata de la única manera racional que tiene el ser humano de prever ese futuro posible. Las distintas ciencias y disciplinas nos permiten construir históricamente estas posibilidades partiendo de datos, hechos, significados y un sinfín de informaciones que le dan cuerpo y sentido a tales posibilidades. En este sentido, la vanguardia, como base del conocimiento prospectivo, observa la necesidad de ser escrita, leída y discutida en los términos más estrictos con el fin de volver las predicciones más precisas. El diseño por su parte, es definido de manera sucinta como la disciplina proyectual estratégica y sistémica de la posibilidad, dirigida a procesos de significación utilitaria y simbólica para la comprensión –o interpretación– y modificación –o proyectación– de niveles de realidad (referentes y sujetos) desde diversos aparatos teóricos y empíricos –perspectivas disciplinarias–