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A new general correlation for the influence parameter in density gradient theory and Peng–Robinson equation of state for n-Alkanes
No full textThe Density Gradient Theory (DGT) permits obtaining the surface tension by using an equation of state and the so-called influence parameter. Different correlations of the influence parameter versus temperature have been proposed, with the two-coefficient ones from Zuo and Stenby (full temperature range) and Miqueu et al. (valid for the lower temperature range) being widely used. Recently, Cachadiña et al. applied the DGT with the Peng-Robinson Equation of State to esters. They proposed a new two-coefficient correlation that uses a universal exponent related to the critical exponent associated with the dependence of coexistence densities on temperature near the critical point. When applied to n-alkanes, it is shown that the Cachadiña et al. correlation must be modified to improve the lower temperature range behavior. The proposed modification results in a three-coefficient correlation that includes the triple point temperature as an input parameter and incorporates the Zuo and Stenby and Miqueu et al. correlations as particular cases. Firstly, the correlation coefficients for each of the 32 n-alkanes considered are obtained by fitting the selected values for the surface tension obtained from different databases, books, and papers. The results obtained are comparable to other specific correlations reported in the literature. The overall mean absolute percentage deviation (OMAPD) between the selected and calculated data is just 0.79%. Secondly, a general correlation with three adjustable coefficients valid for all the n-alkanes is considered. Despite the OMAPD of 4.38% obtained, this correlation is discarded due to the high deviations found for methane. Finally, it is found that a new six-coefficient general correlation, including the radius of gyration as an input fluid parameter, leads to an OMAPD of 1.78% for the fluid set considered. The use of other fluid properties as an alternative to the radius of gyration is briefly discussed.This research was funded by Junta de Extremadura and Programa Feder Extremadura 2021-27 of the European Union through project GR24101.peerReviewe
Biological control of “Pseudomonas syringae” in tomato using filtrates and extracts produced by “Alternaria leptinellae”
No full textEndophytic fungi offer promising alternatives for sustainable plant disease management strategies, often through the production of bioactive secondary metabolites. This study investigated the biocontrol potential of filtrates and extracts, produced under controlled conditions, from “Alternaria leptinellae” E138 against “Pseudomonas syringae” in tomato plants under greenhouse conditions. To understand the main mechanisms involved in biocontrol, the direct inhibition of bacterial growth and disruption of quorum sensing activity caused by metabolites were studied in vitro, as well as indirect mechanisms, such as their capacity to produce phytohormone-like substances, nutrient mobilization, and antioxidant activity, which can enhance plant growth and fitness. Moreover, a mass spectrometry analysis was used to tentatively identify the secondary metabolites present in the extract with antimicrobial properties, which could explain the biocontrol effects observed. Mycopriming assays, involving the direct treatment of tomato seeds with the fungal “A. leptinellae” E138 extracts, produced increased germination rates and seedling vigor in tomato seeds. As another treatment, postemergence application of the extracts in greenhouse conditions significantly improved plant health and resulted in a 41% decrease in disease severity. Overall, this study underscores the potential of “A. leptinellae” E138 extract as a plant growth promoter with biocontrol capabilities, offering promising avenues for sustainable plant disease management.Carlos García-Latorre has been financed by a pre-doctoral grant (PD18037) from the Regional Government of Extremadura (Spain) and by the European Social Fund (ESF).peerReviewe
Surrogate modelling assisted bayesian inference for uncertainty quantification analysis of computationally intensive engineering problems
No full textTesis por compendio de publicacionesPrograma de Doctorado en Modelización y Experimentación en Ciencia y TecnologíaLa presente tesis se enmarca en el ámbito de la Cuantificación de la Incertidumbre, un campo multidisciplinar con una marcada orientación práctica que integra conceptos provenientes de diversas disciplinas como la Matemática Aplicada, la Ingeniería, la Computación y la Estadística. La Cuantificación de la Incertidumbre puede definirse como el proceso de análisis de las incertidumbres asociadas a las predicciones basadas en modelos matemáticos.
Una de las principales dificultades inherentes a la realización de tales análisis es que una buena parte de los modelos empleados utilizados en ingeniería son altamente demandantes computacionalmente, lo que resulta en que muchas técnicas comunes de análisis como la simulación Montecarlo o los algoritmos MCMC resulten inviables. Una estrategia capaz de sortear estas dificultades consiste en la sustitución los modelos originales por metamodelos, es decir, aproximaciones computacionalmente livianas del modelo original. No obstante, en entornos prácticos son frecuentes los problemas mal condicionados y los comportamientos no lineales de los modelos involucrados, los cuáles comprometen la efectividad del enfoque propuesto. Además, muchos fenómenos incorporan una incertidumbre intrínseca no directamente observable o medible, cuya naturaleza requiere el empleo de simuladores estocásticos, añadiendo una capa de dificultad al tratamiento estadístico del problema en cuestión.
La presente investigación aborda el análisis de la incertidumbre en el marco de problemas de ingeniería complejos que enfrentan los desafíos mencionados anteriormente. Con este fin, se propondrán diferentes metamodelos capaces de reemplazar eficientemente los modelos computacionalmente intensivos originales. Además, se presentará una nueva técnica para la construcción de metamodelos en contextos estocásticos.This thesis is situated within the realm of Uncertainty Quantification, a multidisciplinary field with a pronounced practical orientation that integrates concepts from various disciplines such as Applied Mathematics, Engineering, Computer Science, and Statistics. Uncertainty Quantification can be defined as the process of analysing the uncertainties associated with predictions based on mathematical models.
One of the primary challenges inherent in such analyses is that a significant part of the models employed in engineering are highly computationally demanding, rendering many common analysis techniques such as Monte Carlo simulation or MCMC algorithms unfeasible. A strategy capable of overcoming these difficulties involves substituting the forward models with metamodels, i.e., computationally lightweight approximations of the original model. However, in practical environments, ill-conditioned problems and nonlinear behaviours of the involved models are common, compromising the effectiveness of the proposed approach. Additionally, many phenomena incorporate intrinsic uncertainty that is not directly observable or measurable, whose nature requires the use of stochastic simulators, adding a layer of difficulty to the statistical treatment of the problem at hand.
This research addresses the analysis of uncertainty within the framework of complex engineering problems that face the aforementioned challenges. To this end, various metamodels capable of efficiently replacing the computationally intensive original models will be proposed. Additionally, a new technique for constructing metamodels in stochastic contexts will be presented
(Ir) Religiosity and lexical semantic innovations in Antiphon: second tetralogy
No full textAntifonte de Ramnunte es un orador de talla excepcional cuya contribución al estudio de la (ir)religiosidad en Atenas, una faceta de importancia primordial en el siglo V a.C., resulta fundamental. Mediante el presente artículo, que afecta a la Tetralogía Segunda (pieza maestra donde Antifonte despliega admirablemente su pericia retórico-judicial), comentamos y estudiamos ciertas innovaciones léxico-semánticas de nuestro rétor que inciden en la originalidad de Antifonte sobre el manejo de aspectos relevantes para la comprensión del fenómeno (ir)religioso en el siglo V a.C.Antiphon of Rhamnus is an exceptional orator and his contribution to the study of (ir)religiosity in Athens, an aspect of paramount importance in the 5th century BC, is fundamental. In this article, which concerns the Second Tetralogy (a masterpiece in which Antiphon admirably displays his judicial rhetorical skills), we will comment and analyze certain lexical and semantic innovations by our orator which underline Antiphon's originality in the use of relevant aspects for the understanding of the (ir)religious phenomenon in the 5th century BC.Proyecto de Investigación de Excelencia PID2021-123069NB-100peerReviewe
Utilización de nanopartículas de hierro como adsorbentes y/o catalizadores en procesos de eliminación de colorantes en disolución acuosa
No full textPrograma de doctorado en Modelización y Experimentación en Ciencia y Tecnología.Tesis por compendio de Publicaciones.La Tesis se centra en la síntesis y aplicación de nanopartículas de hierro de valencia cero
(nZVI) para la eliminación de colorantes orgánicos en soluciones acuosas. Utilizando
métodos de síntesis verde basados en extractos de hoja o residuos de té, se ha logrado
obtener nZVI de manera sostenible y económica. A lo largo del trabajo, se evaluó la
eficiencia de estas nanopartículas en la eliminación de cuatro colorantes: crisoidina, azul
de metileno, naranja de metilo y naranja G. Además, se propuso un mecanismo de
degradación de la crisoidina utilizando nanopartículas de hierro y se demostró que la
degradación ocurre fundamentalmente por mecanismos radicalarios. Los resultados
indican que las nZVI sintetizadas de manera ecológica, combinadas con peróxido de
hidrógeno en procesos tipo Fenton, son altamente eficaces en la eliminación de
colorantes, alcanzando eficiencias cercanas al 100% bajo condiciones optimizadas. Se
enfatiza la relevancia de la optimización de variables como las concentraciones de
polifenoles y peróxido de hidrógeno para maximizar la eficiencia. En conjunto, esta investigación presenta una solución innovadora, sostenible y eficiente para la remediación
de aguas contaminadas con colorantes, al tiempo que promueve la economía circular al
reutilizar residuos de la industria alimentaria.This Ph.D. Thesis focuses on the synthesis and application of zero-valent iron nanoparticles
(nZVI) for the removal of organic dyes from aqueous solutions. Using green synthesis
methods based on tea leaf or waste extracts, sustainable and cost-effective nZVI were
successfully produced. Throughout the research, the efficiency of these nanoparticles in
the removal of four dyes—chrysoidine, methylene blue, methyl orange, and orange G—was
evaluated. Additionally, the degradation mechanism of chrysoidine using iron nanoparticles was proposed, revealing that degradation predominantly occurs through
radical-based mechanisms. The results indicate that ecologically synthesized nZVI,
combined with hydrogen peroxide in Fenton-like processes, are highly effective in dye
removal, achieving removal efficiencies close to 100% under optimized conditions. The
optimization of variables such as polyphenol and hydrogen peroxide concentrations is
emphasized to maximize efficiency. Overall, this research presents an innovative,
sustainable, and efficient solution for the remediation of dye-contaminated waters while
promoting circular economy by reutilizing waste from the food industry
Palace for the people. Proposal for a state network of shared cultural spaces for historic villages. The example of Trujillo
No full textLa presente investigación tiene por objeto principal la confección de un modelo teórico de infraestructura cultural para villas históricas de mediano tamaño. Para ello, se plantean varios objetivos específicos: analizar cómo los denominados “Palacios para el Pueblo”, en expresión de David Klinenberg, resultan ser infraestructuras culturales que tienen por objeto la preservación del conocimiento y la protección del patrimonio, proponer conceptualmente la posibilidad de crear una red de “Palacios para el Pueblo” y justificar que todo ello sirve para potenciar el capital social de las localidades en las que se asienten.
Los recursos metodológicos seguidos han sido múltiples: por un lado, la revisión bibliográfica de los estudios relacionados con los conceptos de “capital social”, “sociedad civil”, “infraestructura sociocultural” y “ciudades patrimoniales”; en segundo lugar, el análisis empírico de aquellos centros culturales que han servido de ejemplo para nuestra propuesta; en tercer lugar, la metodología cualitativa de carácter comparativo para la elaboración de un modelo teórico de “Palacio para el Pueblo”; y, por último, el método deductivo, llevándose a cabo un estudio de caso para la consecución de un “Palacio para el Pueblo” en Trujillo (Cáceres).
Se concluye que las infraestructuras culturales facilitan la interacción de los ciudadanos; que los municipios históricos de mediano tamaño resultan ser candidatos idóneos para desarrollar políticas culturales; se propone la creación de una red estatal de centros culturales denominados “Palacios para el Pueblo”, ubicados en dichos municipios; y se propone la creación de un prototipo de “Palacio del Pueblo” en la ciudad de Trujillo, ubicado en el Palacio de los Duques de San Carlos.The main objective of this research is to develop a theoretical model of cultural infrastructure for medium-sized historic villages. To this end, several specific objectives are proposed: to analyse how the so-called "Palaces for the People", in the expression of David Klinenberg, turn out to be cultural infrastructures that aim to preserve knowledge and protect heritage, to conceptually propose the possibility of creating a network of "Palaces for the People" and to justify that all this serves to enhance the social capital of the localities in which they are located.
The methodological resources followed have been multiple: on the one hand, the bibliographic review of studies related to the concepts of "social capital", "civil society", "sociocultural infrastructure" and "heritage cities"; secondly, the empirical analysis of those cultural centres that have served as examples for our proposal; thirdly, the qualitative methodology of a comparative nature for the elaboration of a theoretical model of "Palace for the People"; and, finally, the deductive method, carrying out a case study for the achievement of a "Palace for the People" in Trujillo (Cáceres).
It is concluded that cultural infrastructures facilitate the interaction of citizens; whereas medium-sized historic municipalities are ideal candidates for developing cultural policies; it is proposed to create a state network of cultural centres called "Palaces for the People", located in these municipalities; and the creation of a prototype of a "People's Palace" in the city of Trujillo, located in the Palace of the Dukes of San Carlos, is proposed.Máster Universitario en Gestión de la Información en Redes Sociales y de los Productos Digitales en Internet. Universidad de Extremadur
Electronic Nose and Gas Chromatograph Devices for the Evaluation of the Sensory Quality of Green Coffee Beans
No full textEl objetivo de este trabajo es discriminar entre las características de los compuestos orgánicos volátiles (COV) de diferentes calidades de granos de café verde (Coffea arabica) utilizando dos enfoques de análisis para clasificar el producto fresco. El café de alta calidad presentó los valores más altos para los atributos positivos, siendo los más destacados los frutales, herbales y dulces. Las muestras de baja calidad mostraron atributos negativos relacionados con tostado, ahumado y fermentación anormal. Los alcoholes y compuestos aromáticos fueron más abundantes en las muestras de alta calidad, mientras que los ácidos carboxílicos, pirazinas y piridinas fueron más abundantes en las muestras de baja calidad. Los COV con atributos positivos fueron alcohol feniletil, nonanal y ácido 2-metil-propanoico, y éster de octilo, mientras que los que presentaron atributos negativos fueron piridina, ácido octanoico y sulfuro de dimetilo. La calidad del aroma de los granos de café fresco también se discriminó utilizando instrumentos de nariz electrónica. El modelo PLS-DA obtenido de los datos de la nariz electrónica pudo clasificar las diferentes calidades de los granos de café verde y explicó el 96.9% de la varianza total. Se evaluó un enfoque quimiométrico PLS para cuantificar el aroma frutal de los granos de café verde, obteniendo un R²P de 0.88. Por lo tanto, se puede concluir que la nariz electrónica representa un dispositivo preciso, económico y no destructivo para discriminar entre diferentes calidades de café durante el procesamiento.The aim of this work is to discriminate between the volatile org9anic compound (VOC) characteristics of different qualities of green coffee beans (Coffea arabica) using two analysis approaches to classify the fresh product. High-quality coffee presented the highest values for positive attributes, the highest of which being fruity, herbal, and sweet. Low-quality samples showed negative attributes
related to roasted, smoky, and abnormal fermentation. Alcohols and aromatic compounds were most abundant in the high-quality samples, while carboxylic acids, pyrazines, and pyridines were most abundant in the samples of low quality. The VOCs with positive attributes were phenylethyl alcohol, nonanal and 2-methyl-propanoic acid, and octyl ester, while those with negative attributes
were pyridine, octanoic acid, and dimethyl sulfide. The aroma quality of fresh coffee beans was also discriminated using E-nose instruments. The PLS-DA model obtained from the E-nose data was able to classify the different qualities of green coffee beans and explained 96.9% of the total variance. A PLS chemometric approach was evaluated for quantifying the fruity aroma of the green coffee beans, obtaining an R 2 P of 0.88. Thus, it can be concluded that the E-nose represents an accurate, inexpensive, and non-destructive device for discriminating between different coffee qualities during processing.This research was funded by the National University of Agriculture (Honduras), the local government of Extremadura (ref. GR21121—AGA008) and the European Regional Development Fund (FEDER).peerReviewe
Oxidative stress in dogs with chronic inflammatory enteropathy treated with allogeneic mesenchymal stem cells
No full textOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer NatureThe search for new biomarkers in patients with chronic inflammatory enteropathy (CIE) is ongoing in the human and veterinary medicine fields. Oxidative stress biomarkers (malondialdehyde [MDA], reduced glutathione [GSH], and albumin) have been studied in humans with chronic enteropathies, but among them, only albumin has been studied in dogs with CIE. Moreover, the effect of mesenchymal stem cell (MSCs) treatment with or without prednisone on these parameters has never been studied in dogs with CIE. These parameters were compared between healthy dogs (n = 12) and dogs with CIE, and before and 1, 3, 6, and 12 months after the treatment with MSCs alone (n = 9) or together with prednisone (n = 11). The relationship between the Canine Inflammatory Bowel Disease Activity Index (CIBDAI) and oxidative stress was evaluated. Albumin was the only parameter that significantly differed between dogs with CIE and healthy dogs (p = 0,037). Differences were observed only in albumin values after combined treatment with MSCs and prednisone. No differences were observed in MDA and GSH after treatment with MSCs with or without prednisone. Albumin could help stage canine CIE, as well as its prognosis, as has already been demonstrated, although it is essential to evaluate this parameter for its antioxidant capacity, and therefore it could be a good biomarker of oxidative stress in this pathology. However, the treatment with MSCs seems unable to modify any of the analyzed oxidative stress parameters.The Consejería de Economía e Infraestructuras de la Junta de Extremadura with Feder funds has financed this research (IB16133). The Junta de Extremadura (research group number GR21085) and the European Regional Development Funds "Una forma de hacer Europa" have financed the editing process.peerReviewe
Inepti centones a diuinis Aeneidos carminibus exploduntur: Sanctius Brocensis, Textual Critic of the Aeneid
No full textAl final de sus escolios a las Bucólicas de Virgilio (1591) encontramos unas notas misceláneas que Sánchez de las Brozas tenía seguramente entre sus borradores o cuadernos de notas y que constituyen unos auténticos escolios de crítica textual, expurgaciones y castigationes al texto de determinados versos de la Eneida. El título que el humanista les puso es Inepti centones a diuinis Aeneidos carminibus exploduntur. La intención del Brocense en estas breves notas es demostrar que en la Eneida hay numerosas interpolaciones que deben ser eliminadas y que, no sólo hay cincuenta y ocho versos incompletos, inacabados o truncos, sino al menos una veintena más.At the end of his scholia to Virgil’s Bucolics (1591) we find some miscellaneous notes that Sanctius Brocensis surely had among his drafts or notebooks and which constitute authentic scholia of textual criticism, expurgations and castigationes to the text of certain verses of the Aeneid. The title that the humanist gave them is Inepti centones a diuinis Aeneidos carminibus exploduntur. Sanctius’s intention in these brief notes is to demonstrate that in the Aeneid there are numerous interpolations that must be eliminated and that there are not only fifty-eight incomplete, unfinished or truncated verses, but at least twenty more.Este trabajo se ha realizado al amparo del Proyecto de Investigación PID2023-150135NB-I00, financiado por el Ministerio de Ciencia, Innovación y Universidades y por la Unión Europea.peerReviewe
Impact of the common agricultural policy (CAP) on the development of rural territories: principal component analysis in SW Spain, Extremadura (2007–2020)
No full textThe Common Agricultural Policy (CAP) is a European Union (EU) policy aimed at supporting farmers, guaranteeing food security, and promoting sustainable rural development, which has undergone numerous reforms to adapt to the needs of the agricultural sector and society in general. The main objective of this work is to statistically analyse CAP aid in southwest Spain, specifically in Extremadura, a region characterised by areas at risk of depopulation and deep rural areas, during the last two periods of European aid (2007–2013 and 2014–2020). In this study, by means of principal component analysis (PCA), agricultural, economic, and demographic variables were interrelated, together with geographic information systems (GIS), to evaluate their impact on the development of the regional agricultural sector. This methodology will help to identify areas with improvements in their territorial structures and can therefore serve as a basis for their application in other European territories. Through the analysis, we identified areas where the interrelation of the variables showed improvements in their demographic, social, and economic structures, with the municipalities of populations over 10,000 inhabitants in Extremadura being the ones that compose the territorial substructure A. Therefore, this work shows how European agricultural aid can disproportionately favour the most dynamic territories and leave the less developed regions at a disadvantage.peerReviewe