Influence of the Polarity of the Electric Field on Electrorheometry

Uniaxial extensional flow is a canonical flow typically used in rheological characterization to provide complementary information to that obtained by imposing simple shear flow. In spite of the importance of having a full rheological characterization of complex fluids, publications on the rheological characterization of mobile liquids under extensional flow have increased significantly only in the last 20 years. In the case of the rheological characterization of electrorheological fluids, the situation is even more dramatic, as the ERFs have been exclusively determined under simple shear flow, where an electrorheological cell is attached to the rotational rheometer generating an electric field perpendicular to the flow direction and that does not allow for inverting the polarity. The very recent work published by Sadek et al., who developed a new electrorheological cell to be used with the commercial Capillary Breakup Extensional Rheometer (CaBER), allows for the very first time performing electrorheometry under extensional flow. By means of the same experimental setup, this study investigates the influence of the polarity of the imposed electric field on the filament thinning process of a Newtonian and an electrorheological fluid. Results show that a polarity against the gravity results in filament thinning processes that live longer or reach a stable configuration at lower intensities of the applied electric field

Handling Imbalanced Classification Problems With Support Vector Machines via Evolutionary Bilevel Optimization

Support vector machines (SVMs) are popular learning algorithms to deal with binary classification problems. They traditionally assume equal misclassification costs for each class; however, real-world problems may have an uneven class distribution. This article introduces EBCS-SVM: evolutionary bilevel cost-sensitive SVMs. EBCS-SVM handles imbalanced classification problems by simultaneously learning the support vectors and optimizing the SVM hyperparameters, which comprise the kernel parameter and misclassification costs. The resulting optimization problem is a bilevel problem, where the lower level determines the support vectors and the upper level the hyperparameters. This optimization problem is solved using an evolutionary algorithm (EA) at the upper level and sequential minimal optimization (SMO) at the lower level. These two methods work in a nested fashion, that is, the optimal support vectors help guide the search of the hyperparameters, and the lower level is initialized based on previous successful solutions. The proposed method is assessed using 70 datasets of imbalanced classification and compared with several state-of-the-art methods. The experimental results, supported by a Bayesian test, provided evidence of the effectiveness of EBCS-SVM when working with highly imbalanced datasets.Comment: Copyright 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other work

Extensional Magnetorheology as a Tool for Optimizing the Formulation of Ferrofluids in Oil-Spill Clean-Up Processes

In this study, we propose a new way of optimising the formulation of ferrofluids for oil-spill clean-up processes, based on the rheological behaviour under extensional flow and magnetic fields. Different commercial ferrofluids (FFs), consisting of a set of six ferrofluids with different magnetic saturation and particle concentration, were characterised in a Capillary Break-Up Extensional Rheometer (CaBER) equipped with two magnetorheological cells that allow imposing a homogeneous and tunable magnetic field either parallel or perpendicular to the flow direction. The filament thinning process with different intensities and orientation of the magnetic field with respect to the flow direction was analysed, and the results showed that the perpendicular configuration did not have a significant effect on the behaviour of the ferrofluids, as in shear magnetorheometry. However, the parallel configuration allowed to determine that the formulation of ferrofluids for oil-spill cleaning processes should consist of a 4% vol concentration of magnetic nanoparticles with a magnetic saturation of Ms> 20 mT

Comunicación digital : estrategias integradas de marketing

Los avances tecnológicos han modificado los modelos de comportamiento de la nueva sociedad digital, en la que surgen nuevas oportunidades de negocio, entre ellas relacionadas la publicidad online. Este libro aporta una visión integradora de la comunicación digital como estrategia de marketing para las organizaciones. Esta obra nos aproxima al usuario del ecosistema digital y a sus nuevas formas de consumo de información, para posteriormente sumergirle en las estrategias, formatos y tendencias de este campo. En este recorrido, los autores proporcionan las claves para el diseño de estrategias que fomenten compromisos afectivos entre marcas y consumidores.Technological advances have modified the behaviour models of the new digital society, in which new business opportunities arise, including online advertising. This book provides an integrative vision of digital communication as a marketing strategy for organizations. This work brings the reader closer to the user of the digital ecosystem and its new forms of information consumption, to later immerse them in the strategies, formats and trends in this field. In this tour, the authors provide the keys to the design of strategies that promote affective commitments between brands and consumers.Obra ressenyada: N. ABUÍN VENCES, L. MAESTRO ESPÍNOLA, D. CORDÓN BENITO, Comunicación digital. Estrategias integradas de marketing, Madrid : Editorial Síntesis, 2019

An efficient implementation of the synchronization likelihood algorithm for functional connectivity

Measures of functional connectivity are commonly employed in neuroimaging research. Among the most popular measures is the Synchronization Likelihood which provides a non-linear estimate of the statistical dependencies between the activity time courses of different brain areas. One aspect which has limited a wider use of this algorithm is the fact that it is very computationally and memory demanding. In the present work we propose new implementations and parallelizations of the Synchronization Likelihood algorithm with significantly better performance both in time and in memory use. As a result both the amount of required computational time is reduced by 3 orders of magnitude and the amount of memory needed for calculations is reduced by 2 orders of magnitude. This allows performing analyses that were not feasible before from a computational standpoint

An efficient implementation of the synchronization likelihood algorithm for functional connectivity

Measures of functional connectivity are commonly employed in neuroimaging research. Among the most popular measures is the Synchronization Likelihood which provides a non-linear estimate of the statistical dependencies between the activity time courses of different brain areas. One aspect which has limited a wider use of this algorithm is the fact that it is very computationally and memory demanding. In the present work we propose new implementations and parallelizations of the Synchronization Likelihood algorithm with significantly better performance both in time and in memory use. As a result both the amount of required computational time is reduced by 3 orders of magnitude and the amount of memory needed for calculations is reduced by 2 orders of magnitude. This allows performing analyses that were not feasible before from a computational standpoint

The use of hypertextuality, multimedia, interactivity and updating on the websites of Spanish political parties

This work presents the results of a research aiming to analyze the presence of the four cardinal points of the cyberspace (hypertextuality, multimedia, interactivity and updating) in the Spanish political parties’ websites. These parameters determine the effectiveness of the communication in a web space, and until what extent political formations use them to connect with their audiences in the digital environment. To achieve this goal, an analysis of the content of the websites of the political groups with parliamentary representation has been carried out. The results confirm the absence of tools and resources related to these characteristics in the web spaces under study. The use of hypertext, beyond its simpler structure, and the use of multimedia elements is scarce. The possibilities of interaction between different users and political parties are minimal. The information published and the level of updating of the contents is insufficient. The conclusions allow us to affirm that there is a lack of exploitation of the possibilities offered by the web to promote communication and interaction with users by different political groups.Este trabajo presenta los resultados de una investigación cuyo objetivo fundamental es analizar la presencia de los cuatro puntos cardinales del ciberespacio (hipertextualidad, multimedialidad, interactividad y actualización) en las páginas web de los partidos políticos españoles. Estos parámetros determinan la eficacia comunicativa de un espacio web, por lo que se trata de averiguar en qué medida son aprovechados por las formaciones políticas para conectar con sus públicos en el entorno digital. Para conseguir este objetivo, se ha llevado a cabo un exhaustivo análisis de contenido de las webs de las formaciones políticas con representación parlamentaria. Los resultados obtenidos confirman la ausencia de herramientas y recursos relacionados con estas características en los espacios web objeto de estudio. El uso del hipertexto, más allá de su estructura más simple, y la utilización de elementos multimedia son escasos. Las posibilidades de interacción entre los distintos usuarios y los partidos políticos son mínimas a través de este medio. La información publicada y el nivel de actualización de los contenidos resultan insuficientes. Las conclusiones nos permiten afirmar la existencia de un desaprovechamiento de las posibilidades que brinda la web para fomentar la comunicación y la interacción con los usuarios por parte de las diferentes formaciones políticas

Populist strategies on Twitter: analysis of the political discourse during the campaign for the general elections in Spain on November 10th, 2019

In recent years we have witnessed a resurgence of populism, which has relied on the virality of social networks to deepen its roots in society and spread its ideas. This paper analyses the populist strategies used by all parties to viralise their messages in the online environment, regardless of ideology. The present research has also examined the possible existence of complementary strategies used by the parties’ organisational profiles and those of their leaders. To this end, a content analysis has been carried out regarding the publications made on Twitter during the 2019 election campaign. The posts have been delimited to those made by the parties and candidates that attained the highest percentage of representation in the Congress of Deputies, which include the PSOE, PP, Vox, and Unidas Podemos. The findings show that all the parties under study resorted to this type of strategy. The parties closest to centre of the political spectrum, both right and left, used mostly a populist strategy aimed predominantly at attacking their adversaries, while Vox and Unidas Podemos articulated their discourse beyond this argument, with Vox appealing to the emotions of the nation and Podemos positioning itself as the peoples’ advocate. Furthermore, a complementary strategy used by both the parties and their leaders has been identified, which fosters the expansion of these kinds of populist ideas

Simultaneous Effect of Temperature and Irradiance on Growth and Okadaic Acid Production from the Marine Dinoflagellate Prorocentrum belizeanum

Benthic marine dioflagellate microalgae belonging to the genus Prorocentrum are a major source of okadaic acid (OA), OA analogues and polyketides. However, dinoflagellates produce these valuable toxins and bioactives in tiny quantities, and they grow slowly compared to other commercially used microalgae. This hinders evaluation in possible large-scale applications. The careful selection of producer species is therefore crucial for success in a hypothetical scale-up of culture, as are appropriate environmental conditions for optimal growth. A clone of the marine toxic dinoflagellate P. belizeanum was studied in vitro to evaluate its capacities to grow and produce OA as an indicator of general polyketide toxin production under the simultaneous influence of temperature (T) and irradiance (I0). Three temperatures and four irradiance levels were tested (18, 25 and 28 °C; 20, 40, 80 and 120 µE·m−2·s−1), and the response variables measured were concentration of cells, maximum photochemical yield of photosystem II (PSII), pigments and OA. Experiments were conducted in T-flasks, since their parallelepipedal geometry proved ideal to ensure optically thin cultures, which are essential for reliable modeling of growth-irradiance curves. The net maximum specific growth rate (µm) was 0.204 day−1 at 25 °C and 40 µE·m−2·s−1. Photo-inhibition was observed at I0 > 40 μEm−2s−1, leading to culture death at 120 µE·m−2·s−1 and 28 °C. Cells at I0 ≥ 80 µE·m−2·s−1 were photoinhibited irrespective of the temperature assayed. A mechanistic model for µm-I0 curves and another empirical model for relating µm-T satisfactorily interpreted the growth kinetics obtained. ANOVA for responses of PSII maximum photochemical yield and pigment profile has demonstrated that P. belizeanum is extremely light sensitive. The pool of photoprotective pigments (diadinoxanthin and dinoxanthin) and peridinin was not able to regulate the excessive light-absorption at high I0-T. OA synthesis in cells was decoupled from optimal growth conditions, as OA overproduction was observed at high temperatures and when both temperature and irradiance were low. T-flask culture observations were consistent with preliminary assays outdoors

Alkali-Activated Stainless Steel Slag as a Cementitious Material in the Manufacture of Self-Compacting Concrete

This work develops the manufacture of self-compacting concrete (SCC) with 50% cement reduction. As an alternative binder to cement, the viability of using an alkali-activated combination of stainless steel slag (SSS) and fly ash (FA) has been demonstrated. SSS was processed applying three different treatments. Binders were manufactured mixing 35% SSS with 65% FA, as precursors, and a hydroxide activating solution. This binder was replaced by the 50% cement for the manufacture of SCC. The results obtained show good mechanical properties and durability. The study shows a reduction in the use of cement in the manufacture of SCC reusing two wastes