Optimal ductility enhancement of RC framed buildings considering different non-invasive retrofitting techniques

Existing RC framed buildings lack significant ductility, especially when they have been built with pre-code criteria. Improving their ductile capacity can help to prevent them from the brittle collapse mechanism and to reduce the seismic damage expected. This paper aims to investigate the enhancement of the ductile response behaviour of RC framed buildings considering different non-invasive retrofitting techniques. To do so, a pre-code RC framed school located in the Spanish province of Huelva has been selected as a case study. Five non-invasive retrofitting techniques have been tested: FRP wraps and steel jackets in columns, steel beams and plates under RC beams and single steel braces. They have been selected so that they can be easily implemented in the building. Some of them have been studied in detail in previous works and others have been included for further research in this paper. In order to compare the results obtained, the most typical technique in the seismic retrofitting of RC framed buildings, the addition of X-bracings in bays, has also been tested. Most previous studies on the seismic retrofitting of RC buildings are focused on validating a method based on artificial models. This paper compares the different techniques in terms of the capacity improvement and the damage reduction, performing analyses in detail and adding them in an existing RC building. A sensitivity analysis has been carried out to determine the influence of each technique in the building’s ductile capacity considering the finite element method. Nonlinear static analyses have been performed to obtain the capacity, the displacement ductility factor (μ) and the behaviour factor (q) of each model defined. The damage expected has been determined considering the ductile and fragile failure of the elements according to the Eurocode-8 (EC8) requirements. To analyse the suitability and the efficiency of each solution, a benefit/cost ratio has been obtained taking into account the ductility improvement and the damage reduction with regards to the retrofitting costs. The results have shown that the best benefit has been obtained with the addition of steel braces. However, the optimal solutions have been single braces and steel jackets due to their combination between benefit and cost. It has been observed that the solutions that increase the stiffness of the joints have had a higher improvement due to the key role that joints have in the resistant capacity of RC structurers. Also, it has been obtained that the values of the fundamental periods have been reduced, when adding the retrofitting elements and materials, up to 30% owing to the increase of the stiffness of the system. Finally, it must be highlighted that a detailed analysis of the behaviour of the whole building must be conducted in order to avoid additional rotation effects and shear forces that could worsen the building’s seismic behaviour

Assessment of specific structural and ground-improvement seismic retrofitting techniques for a case study RC building by means of a multi-criteria evaluation

Existing reinforced concrete (RC) structures might not comply with current seismic codes due to their aseismic design and construction date. By seismically retrofitting them, it is possible to improve their seismic performance to resist the expected seismic loads. However, selecting the best solution is challenging since social and economic issues can affect the choice. Multi-criteria decision making (MCDM) provides an opportunity to overcome the challenge but there are some drawbacks in the available MCDM techniques. This paper reports an improved MCDM-based seismic retrofit: Additional criteria have been included and weighted according to their importance (ductility improvement and damage reduction); Finite element modelling of the case study building has been carried out instead of following methods based on different simplifications; iii) Structural performances have been assessed by determining the damage in local elements instead of following global assessment procedures; Effects of soil-structure interaction (SSI) have been taken into account to ultimately compare different structural and ground-improvement techniques. Consistency and sensitivity analyses have proved the stability of the results and the robustness of the method. It is shown that SSI can increase the seismic damage up to 17%, and regarding the seismic safety verification, the building needs to be retrofitted. Adding fibre reinforcement polymers and steel bracings are the best solutions due to the minimum architectural impact and the outstanding structural improvement, respectively. Nevertheless, the solution preferred is the addition of single steel braces in beam- column joints despite its high maintenance costs. The sensitivity analysis indicates that the most sensitive criteria are the functional compatibility and the reduction of the collapse risk

Formulación de proyectos en stevia como producto endulzante para el mejoramiento de la calidad de vida en población con obesidad y diabetes

Con la tendencia Mundial en el aumento de los casos de obesidad y diabetes, los productos alimentarios se tienen que adaptar a las características que tiene la dieta de este tipo de población, como lo es consumir bebidas y alimentos sin azúcar, miel o panela, y es cuando se hace necesario buscar información de los proyectos que se han realizado sobre stevia, para obtener datos confiables y determinar la seguridad de este endulzante en la salud de las personas. El presente estudio es el resultado de un minucioso análisis bibliográfico, donde se quiso buscar los diferentes proyectos que muestran cómo es el papel de la stevia en enfermedades de tanta prevalencia como lo son la obesidad y la diabetes. Se realizó un estudio de tipo cualitativo, donde se buscaron diversas fuentes bibliográficas, de las cuales se dio una opinión crítica sobre los resultados obtenidos, siguiendo los parámetros del enfoque de la hermenéutica. Entre los resultados encontrados sobre los diversos estudios consultados, se logró evidenciar varios beneficios para la salud del consumo de esta planta, entre los más destacados está, el efecto antioxidante, control de peso corporal, antihiperglucemico, Antibacterial y prevención de caries dentales. Además del consumo como endulzante, la stevia también se utiliza a nivel cosmetológico, mejorador de suelos, utilización en dietas animales, entre otros.With the World trend in the increase of cases of obesity and diabetes, food products have to adapt to the characteristics of the diet of this type of population, such as consuming drinks and foods without sugar, honey or brown sugar, and is when it becomes necessary to look for information on the projects that have been done on stevia, to obtain reliable data and determine the safety of this sweetener in the health of people. The present study is the result of a meticulous bibliographical analysis, where we wanted to look for the different projects that show how is the role of stevia in diseases of as much prevalence as obesity and diabetes are. A qualitative study was carried out, where diverse bibliographical sources were searched, of which a critical opinion was given on the obtained results, following the parameters of the hermeneutic approach. Among the results found on the various studies consulted, it was possible to demonstrate several health benefits of the consumption of this plant, among the most outstanding is the antioxidant effect, body weight control, antihyperglycemic, antibacterial and dental caries prevention. In addition to consumption as a sweetener, stevia is also used at the cosmetological level, soil improver, use in animal diets, among others

Analysis of the soil structure-interaction effects on the seismic vulnerability of mid-rise RC buildings in Lisbon

Soil-structure interaction (SSI) effects are usually omitted in the seismic vulnerability analyses of buildings. However, it has been proved that they might notably affect their seismic performance. In fact, European seismic codes establish that they should be included in the analyses of certain structures: with considerable second order (p-Δ) effects or mid/high-rise buildings. These characteristics are shared by reinforced concrete (RC) buildings in Portugal, which represent a considerable amount of its building stock. Moreover, a significant percentage (50%) have been constructed prior to restrictive seismic codes, i.e., without adequate seismic design. To obtain reliable results when including the SSI effects, the state-of-the-art reveals that a proper modelling of soil and foundations should be carried out. Nevertheless, most of the related studies are based on ideal structural and soil configu- rations. In addition, it has been found that there is a lack of studies and guidance, even in codes, on the quantification of the SSI effects. Therefore, this paper focuses on quantifying the SSI effects in RC buildings seismic vulnerability analyses by means of two approaches: the Beam on Nonlinear Winker method (BNWM) and the direct modelling of soil. The aim is to propose a method to practically include the SSI effects and to thor- oughly characterise the soil behaviour. The method has been applied to a case study RC mid-rise building of Lisbon. A clay-type soil commonly found in Lisbon has been characterised, carrying the analyses out under undrained conditions. 3D finite elements procedures have been proposed to reproduce the complex soil nonlinear constitutive law to represent the behaviour of the entire system (soil + foundation + structure) as realistically as possible. The results have been compared in terms of the seismic safety verification and the fragility assessment. The results have shown that the modal behaviour and the deformed shape of the building are the same with and without the SSI. Nonetheless, it has been demonstrated that increasing the soil flexibility leads to higher periods and higher seismic damage. For this case study, the maximum capacity of the models can be reduced by up to 15% if the SSI effects are considere

Protein Fold Recognition from Sequences using Convolutional and Recurrent Neural Networks

The identification of a protein fold type from its amino acid sequence provides important insights about the protein 3D structure. In this paper, we propose a deep learning architecture that can process protein residue-level features to address the protein fold recognition task. Our neural network model combines 1D-convolutional layers with gated recurrent unit (GRU) layers. The GRU cells, as recurrent layers, cope with the processing issues associated to the highly variable protein sequence lengths and so extract a fold-related embedding of fixed size for each protein domain. These embeddings are then used to perform the pairwise fold recognition task, which is based on transferring the fold type of the most similar template structure. We compare our model with several template-based and deep learning-based methods from the state-of-the-art. The evaluation results over the well-known LINDAHL and SCOP_TEST sets,along with a proposed LINDAHL test set updated to SCOP 1.75, show that our embeddings perform significantly better than these methods, specially at the fold level. Supplementary material, source code and trained models are available at http://sigmat.ugr.es/~amelia/CNN-GRU-RF+/

Preliminary structural and seismic performance assessment of the Mosque-Cathedral of Cordoba: The Abd al-Rahman I sector

This manuscript discusses some preliminary results on the structural and the seismic performance of the Mosque-Cathedral of Cordoba, a UNESCO World Heritage. The area is characterized by a moderate seismic hazard. The building was built from the 8th to the 16th century and it has undergone several transformations. Owing to the complexity of the building, this work has focused on the assessment of the Abd al-Rahman I sector, which is the most aged part of the complex. For that, first, a 3D numerical finite element model of the sector has been done in the OpenSees framework and calibrated. To do so, an experimental non-destructive campaign has been carried out. Second, the model has been used to evaluate the structural behaviour, under vertical and horizontal loads, considering different scenarios. Finally, the crack patterns and the seismic safety have been obtained. The results showed that the numerical damage obtained for the gravitational loads is in good agreement with the data collected from the in situ surveys. Also, particular attention should be paid to the cymatiums, as they are the most demanded part of the system. Regarding its seismic performance, the building presents a higher capacity in the direction of the arcades. For the seismic demand, slight damage is expected in both principal directions of the building, which could be easily repaired. Damage concentration is expected in the contact between the perimetral wall and the arcades. This work has expanded the study of the features of the Mosque-Cathedral of Cordoba to the structural and seismic analysis with advanced numerical FE computing, which has not been done to date. To the authors’ knowledge, this is the first time that a macro-modelling approach with solid elements is presented for the seismic assessment of heritage buildings using the OpenSees framework. The methodology to do so is also presented. Apart from showing how advanced numerical analyses can provide useful information to assess the existing damage on monumental buildings, this work aims at contributing to the assessment of the vulnerability and the safety of one of the most emblematic mosque-like buildings of the world.20 página

Potential valorization of waste cooking oils into sustainable bio-lubricants

This work explores the feasibility of using waste cooking oils (WCO) as eco-lubricants. Five WCO from different food facilities were studied. Three of them were fractionated into both lighter and heavier fractions by molecular distillation. A comprehensive chemical characterization (fatty acids distribution, polar compounds and acidity) was carried out on all WCOs and their fractions, which led to set relationships with the oils’ properties (such as viscosity index, low temperature viscous flow behavior, oxidation resistance, etc.). It is worth mentioning the high viscosity index values found in waste cooking oils with both low total polar compounds and acidity level, as well as the benefit which acidity had on their fluidity at low temperature and their lubricity. Moreover, it was also noteworthy that the lighter fractions, merely constituted by free fatty acids (FFA), presented an improved oxidative resistance. The largest OOT enhancement, 12.4%, was found for the light fraction of a non-segregated oil. Moreover, a better thermal stability was shown by the heavier fractions. Finally, both fractions exhibited enhanced friction-reducing capability as compared to their parent WCO. The light fractions from a nonsegregated oil, a fast food restaurant oil and a deep-fried food establishment oil yielded wear reductions of 11.7%, 44.3% and 36.8%, respectively. Therefore, molecular distillation has been proved to be a key strategy to obtain more efficient liquid eco-lubricants.This work explores the feasibility of using waste cooking oils (WCO) as eco-lubricants. Five WCO from different food facilities were studied. Three of them were fractionated into both lighter and heavier fractions by molecular distillation. A comprehensive chemical characterization (fatty acids distribution, polar compounds and acidity) was carried out on all WCOs and their fractions, which led to set relationships with the oils’ properties (such as viscosity index, low temperature viscous flow behavior, oxidation resistance, etc.). It is worth mentioning the high viscosity index values found in waste cooking oils with both low total polar compounds and acidity level, as well as the benefit which acidity had on their fluidity at low temperature and their lubricity. Moreover, it was also noteworthy that the lighter fractions, merely constituted by free fatty acids (FFA), presented an improved oxidative resistance. The largest OOT enhancement, 12.4%, was found for the light fraction of a non-segregated oil. Moreover, a better thermal stability was shown by the heavier fractions. Finally, both fractions exhibited enhanced friction-reducing capability as compared to their parent WCO. The light fractions from a non- segregated oil, a fast food restaurant oil and a deep-fried food establishment oil yielded wear reductions of 11.7%, 44.3% and 36.8%, respectively. Therefore, molecular distillation has been proved to be a key strategy to obtain more efficient liquid eco-lubricants.This work was supported by “Programa Operativo FEDER-Andalucía 2014–2020 from "Consejería de Economía y Conocimiento de la Junta de Andalucía” and the University of Huelva [grant numbers UHU- 1255843 and UHU-202008]. Also, the Social Innovation Chair of “Aguas de Huelva” at the University of Huelva. Funding for open access charge: Universidad de Huelva / CBUA. The authors gratefully acknowledge the recollected waste cooking oil and kindly supplied by the authorized waste manager (GRU 2066) BIOLIA

Lysophosphatidic Acid and Several Neurotransmitters Converge on Rho-Kinase 2 Signaling to Manage Motoneuron Excitability

Intrinsic membrane excitability (IME) sets up neuronal responsiveness to synaptic drive. Several neurotransmitters and neuromodulators, acting through G-protein-coupled receptors (GPCRs), fine-tune motoneuron (MN) IME by modulating background K+ channels TASK1. However, intracellular partners linking GPCRs to TASK1 modulation are not yet well-known. We hypothesized that isoform 2 of rho-kinase (ROCK2), acting as downstream GPCRs, mediates adjustment of MN IME via TASK1. Electrophysiological recordings were performed in hypoglossal MNs (HMNs) obtained from adult and neonatal rats, neonatal knockout mice for TASK1 (task1(-/-)) and TASK3 (task3(-/-), the another highly expressed TASK subunit in MNs), and primary cultures of embryonic spinal cord MNs (SMNs). Small-interfering RNA (siRNA) technology was also used to knockdown either ROCK1 or ROCK2. Furthermore, ROCK activity assays were performed to evaluate the ability of various physiological GPCR ligands to stimulate ROCK. Microiontophoretically applied H1152, a ROCK inhibitor, and siRNA-induced ROCK2 knockdown both depressed AMPAergic, inspiratory-related discharge activity of adult HMNs in vivo, which mainly express the ROCK2 isoform. In brainstem slices, intracellular constitutively active ROCK2 (aROCK2) led to H1152-sensitive HMN hyper-excitability. The aROCK2 inhibited pH-sensitive and TASK1-mediated currents in SMNs. Conclusively, aROCK2 increased IME in task3(-/-), but not in task1(-/-) HMNs. MN IME was also augmented by the physiological neuromodulator lysophosphatidic acid (LPA) through a mechanism entailing G(alpha i/o)-protein stimulation, ROCK2, but not ROCK1, activity and TASK1 inhibition. Finally, two neurotransmitters, TRH, and 5-HT, which are both known to increase MN IME by TASK1 inhibition, stimulated ROCK2, and depressed background resting currents via G(alpha q)/ROCK2 signaling. These outcomes suggest that LPA and several neurotransmitters impact MN IME via G(alpha i/o)/G(alpha q)-protein-coupled receptors, downstream ROCK2 activation, and subsequent inhibition of TASK1 channels

La economía circular como atributo de la marca. Su evaluación mediante Ecological Neuromarketing Test

En los primeros párrafos se desarrollará el concepto de economía circular y se describirán las diferentes escuelas que han ido apareciendo a lo largo del tiempo alrededor del concepto. El lector conocerá los puntos de vista desde los que se ha tratado y podrá hacerse una idea de la relevancia que posee este tipo de gestión para el medioambiente y para los seres humanos en general. Posteriormente se describirá la atribución que podría realizar la economía circular a la marca de los productos y empresas mediante el branding, como estrategia de diferenciación y cómo la neurociencia puede ayudar a evaluar las asociaciones de los atributos a las marcas para poder mejorar desde su evaluación, la incorporación de este atributo en las marcas y nombres de las empresas (el proceso de incorporación del atributo a la marca no es objeto del presente trabajo de investigación)

Satisfacción laboral del capital humano (docentes de educación secundaria) durante la pandemia por Covid 19

Job satisfaction in the teaching field is essential to meet the objectives of the teaching-learning process. During the Covid 19 pandemic, teachers faced three moments: fully online, hybrid and face-to-face education, these being determinants of their job satisfaction. This research aimed to analyze the satisfaction of secondary school teachers in a public school, located in the City of Puebla, in the three modalities described, through a cross-sectional methodology (2020 to 2022). The null hypothesis H₀ of this research is that teachers are more satisfied teaching classes face-to-face. The methodology used in this study is based on the proposal of Gil-Villa et al. (2020). A quantitative study was carried out through a questionnaire that was applied to all the teachers of this institution and a qualitative study through an in-depth interview, which was applied to the director of the school. It was possible to observe that in all the variables there is a relationship. Most agree that when classes are face-to-face there is better communication, greater adaptation, motivation, relationship, happiness and, therefore, satisfaction in teachers and their activities.La satisfacción laboral en el ámbito docente resulta fundamental para cumplir los objetivos del proceso de enseñanza-aprendizaje. Durante la pandemia por Covid 19 los maestros se enfrentaron a tres momentos: la educación totalmente en línea, la híbrida y la presencial, siendo estos determinantes en su satisfacción laboral. Esta investigación tuvo como objetivo analizar la satisfacción de los docentes de educación secundaria en una escuela pública, ubicada en la Ciudad de Puebla, en las tres modalidades descritas, a través de una metodología transversal (2020 a 2022). La hipótesis nula H₀ de esta investigación es que los docentes se encuentran más satisfechos impartiendo clases en la modalidad presencial. La metodología usada en este estudio está basada en la propuesta de Gil-Villa et al. (2020). Se realizó un estudio cuantitativo a través de un cuestionario que se aplicó a todos los docentes de esta institución y un estudio cualitativo mediante una entrevista a profundidad, que se aplicó al director del plantel. Se pudo observar que en todas las variables existe una relación. La mayoría concuerda en que cuando las clases son presenciales hay una mejor comunicación, mayor adaptación, motivación, relación, felicidad y, por tanto, satisfacción en los docentes y sus actividades