Removable, reconfigurable, and sustainable steel structures: a state-of-the-art review of clamp-based steel connections

In this review paper, first of all, an analysis of the circular economy and its application to steel structures is carried out. It highlights the need to apply the philosophy of Design for Deconstruction or Design for Disassembly (DfD) from the conception of the structure so that it can be truly reconfigurable. Then, a brief review of the different types of connections for steel structures is conducted, comparing the level of research and development of each of them and the degree of reconfiguration that is possible to obtain. Subsequently, the article focuses on the type of connection using clamps, a key point of this work and on which, to date, there are no state-of-the-art studies. It describes the types of clamps, their principle of operation, the types of connections developed with them, and the results of the different investigations that allow for calculating these types of connections. A summary is also given of how these connection types work according to the geometrical characteristics of the clamp and the bolt so that this review work can serve as a driver for the widespread use of clamp-based connections by researchers and engineers in the design and manufacturing of demountable and reconfigurable steel structures. Finally, some conclusions are given, indicating the advantages and disadvantages of this connection system and future lines of research.Ministerio de Ciencia e Información | Ref. TED2021-130497A-I0

Deterministic and probabilistic-based model updating of aging steel bridges

Numerical modeling is a very useful tool in different fields of bridge engineering, such as load-carrying capacity assessment or structural health monitoring. Developing a reliable computational model that accurately represents the actual bridge mechanical behavior entails advanced FEM-based modeling complemented by a comprehensive experimental campaign that provides the necessary supporting information and allows validating simulation outcomes. This paper proposes a unified approach aimed at the experimental characterization and FE model updating of aging steel bridges. It first involves the realization of an extensive experimental campaign aimed at the bridge's geometrical, material, and dynamic behavior characterization. Then, a model calibration framework is developed, where deterministic (optimization) and probabilistic (Bayesian inference) approaches are employed, and techniques such as global variance-based sensitivity analysis and Kriging-based surrogate modeling are further implemented in order to enhance the identification process and reduce the overall computational burden. The methodology has been validated in a historical riveted steel bridge in O Barqueiro, north of Galicia, Spain. The results show a good agreement in the identified model parameter values and a noticeable correlation between numerical and experimental modal properties, with an average relative error in frequencies of 0.34% and 0.44% for the deterministic and probabilistic approaches and an average MAC (Modal Assurance Criterion) ratio of 0.96.Fundación BBVAAgencia Estatal de Investigación | Ref. PRE2019-087331Universidade de Vigo/CISU

Design and testing of a decision tree algorithm for early failure detection in steel truss bridges

This paper develops a methodology for damage identification in steel truss bridges that uses vibration-based monitoring data and a model-based decision tree algorithm. The methodology resorts to a calibrated FE model with an optimization-based parameter identification procedure to simulate and analyze all the potential damages that might affect the structure. The effect of environmental conditions on the modal parameters is also accounted for, which is modeled as structure stiffness variations using the Young’s modulus and forecasted using a surrogate modeling strategy. The feasibility of the methodology is demonstrated on a full-scale bridge in Vilagarcía de Arousa, Spain. The underlying hypotheses used in the algorithm implementation were validated, and the error ponderation and selection bound employed to detect and identify damage were optimized. The results show an average success rate of 95.0% and an average false positive rate of 1.0% in identifying damage indicating its robustness to be extrapolated to other case studies.Agencia Estatal de Investigación | Ref. PRE2019-087331Fundación BBVAUniversidade de Vigo/CISUGMinisterio de Universidades | Ref. CAS21/0020

A novel fully removable walkway system with non-invasive anchors for structural health inspection and maintenance of historic steel structures

Historic steel structures are generally heritage constructions that must be preserved, where invasive operations such as welding or drilling cannot be performed. Any auxiliary structures installed on these constructions must be easily removable. In addition, historic steel structures such as riveted bridges are difficult to access, making it very difficult to take measurements using contact techniques or to perform structural health inspections. One of the most common needs is the installation of walkways for inspection and especially for maintenance and repair purposes. In this sense, clamp-based connections are a technique for fabricating dismountable systems that allow anchoring to existing structures without performing invasive operations such as welding or drilling. This study proposes, develops, simulates, and tests a novel non-invasive detachable anchorage system for the assembly of temporary walkways for inspecting and maintaining historic steel structures without additional scaffolding. In addition, a methodology is proposed for the easy and correct installation of the proposed system by combining it with LiDAR techniques. The developed system has been assembled and tested in laboratory tests and two real case studies.Agencia Estatal de Investigación | Ref. TED2021-130497A-I00Universidade de Vigo/CISU

Multi-objective optimization-based model calibration of masonry bridges

Multi-objective optimization-based model calibration can be an intermediate solution between the computationally expensive probabilistic approaches and the single-objective optimization strategies that do not allow uncertainty quantification of the obtained solutions. This work addresses the multi-objective model calibration of two historic stone arch bridges using high-fidelity computational FE models. To implement the methodology, a five-step approach is proposed: experimental characterization through non-destructive testing techniques, non-parametric asbuilt geometric modeling, macro-finite element modeling, sensitivity analysis, and multiobjective optimization. The preferred solution among the Pareto front solutions is selected based on two different classical criteria, and the set of optimal solutions is further statistically analyzed to assess the validity of the identification process. The results show an average frequency error of 0.97 % and 0.70 % and an average MAC of 0.97 and 0.96 for each case study, respectively, thus highlighting the adequacy of the proposed methodology.Agencia Estatal de Investigación | Ref. PID2021-124236OB-C33Agencia Estatal de Investigación | Ref. PRE2019-087331Agencia Estatal de Investigación | Ref. RYC2019-026604-IXunta de Galicia | Ref. ED431F 2021/08Universidade de Vigo/CISU

Extracting extremophilic lipases from aqueous streams by using biocompatible ionic liquids

Financiado para publicación en acceso aberto:Universidade de Vigo/CISUGIn this work, biocompatible ionic liquids based on aminoacids were employed as extractants to separate extremolipases from aqueous streams. First, the influence of aminoacid and dipeptide-based ionic liquids (cholinium glycinate, ChGly, and cholinium glycylglycinate, ChGlygly) on the lipolytic activity of a commercial lipase from Candida antarctica (CaLB) and in-house synthesized extremophilic lipases from Thermus thermophilus HB27 (TtHB27L) and Halomonas sp. LM1C (HL) was investigated. The combination of thermophilic enzyme with ChGly turned out to be the optimum combination for maximizing the biocatalytic performance, clearly improving the levels attained when water was exclusively employed as solvent and also surpassing the activity levels provided for the commercial enzyme CaLB. The salting out capacity of ChGly in aqueous solutions of biodegradable surfactants Tergitol 15S7 and Tergitol 15S9 was discussed, recording immiscibility areas almost covering all the ternary diagrams. The aqueous biphasic systems were experimentally characterized by determining both tie-lines and solubility curves at several temperatures and the data was modelled with relevant equations like Merchuk, Othmer-Tobias and Bancroft ones, as they are the most common ones to describe this kind of equilibrium data. So, ChGly was applied to extract thermophilic and commercial lipases from aqueous solutions at 313.15 K, achieving very high extraction levels (about 100 %) for TtHB27L, which clearly surpasses the maximum extraction values observed for the commercial enzyme (about 80 %). Finally, the process was simulated at real scale through SuperPro Designer v.8.5 for the production of 385 Kg/year of extremolipaseXunta de Galicia | Ref. ED481D-2019/017Ministerio de Ciencia, Innovación y Universidades | Ref. RTI2018-094702-B-I0

Creating a new biocatalytic complex with extremolipases and biocompatible ionic liquids for improved transesterification reactions

The ongoing energy crisis has spurred increased research into sustainable and more competitive methods for producing biofuels, including biodiesel. In this context, the focus of the current study is to underscore the viability of investing in a novel biocatalytic complex. This complex incorporates extremophilic lipases and biocompatible ionic liquids with the aim of achieving exceptionally high conversions in transesterification reactions without generating glycerol. Through a meticulous screening process encompassing various amino acid and dipeptide-based ionic liquids from the ammonium family, cholinium glycinate turned out to be the optimal choice. This selection was driven not only by its enhanced compatibility with a commercially available Candida antarctica lipase B (CaLB) but also with extremophilic enzymes synthesized in-house, derived from halophilic (Halomonas spLM1C) and thermophilic (Thermus thermophilus HB27) strains. Following rigorous testing of both free and immobilized enzymes, the ideal concentration of the ionic liquid in transesterification reactions was determined to be 1% relative to the sunflower oil content. Comparative analysis of conversion rates between immobilized thermophilic lipase and immobilized CaLB revealed the efficacy of the proposed approach. Maximum conversions were found to increase by 20%, with specific conversion rates soaring by approximately 180% when utilizing the immobilized thermophilic lipase. In conclusion, this research ushers in new prospects for advancing the competitiveness of biocatalytic solutions in glycerol-free transesterification reactions, underscoring its potential to revolutionize the landscape of sustainable energy production.Agencia Estatal de Investigación | Ref. RTI2018-094702-B-I00Xunta de Galicia | Ref. ED481D-2019/017Universidade de Vigo/CISU

Model updating of in‐service bridges using multidisciplinary research ‐ case studies in Spain

This paper presents several experiences focused to create and update accurate numerical models of ageing bridges in Spain. The experimental campaigns included integration of various NDT technologies such as laser scanning, ultrasounds, etc., combined with vibration‐based methods such as Operational Modal Analysis. From these multi‐source data it was possible to create an accurate numerical model of each structure, which was lately subjected to a calibration using the actual dynamic response of the structure. Thus, the updated structural model presents the same behaviour as the real construction, offering a powerful tool to more accurately predict the safety level of the structure. On the other hand, structural assessments based on reliability analysis has been proved to improve the quality and accuracy of safety analysis due to the consideration of the possible deviations presented in the parameters of a structure. These works were compiled as case‐studies in Spain within IM‐SAFE project.Agencia Estatal de Investigación | Ref. PRE2019-08733

Apolipoproteína AI e lipoproteínas de alta densidade: estrutura e papel na homeostase do colesterol celular

La apolipoproteína A-I (apoAI) es el componente proteico mayoritario de las lipoproteínas de alta densidad (HDL), cuyo nivel sérico se correlaciona inversamente con el riesgo aterogénico. Las propiedades antiaterogénicas son atribuidas en gran parte al rol protagónico que tiene en el transporte reverso de colesterol (RCT), proceso que remueve el exceso de colesterol de los tejidos periféricos. La apoAI es una proteína anfitrópica formada casi en exclusividad por a-hélices anfipáticas, y presenta una gran flexibilidad conformacional que es crucial para su ciclo funcional, en el que se interconvierte entre diferentes estados: libre, unida a membranas, o a una gran variedad de complejos lipoproteicos de diferente tamaño, morfología y composición. En este reporte se revisa el conocimiento actual sobre la estructura y propiedades de interacción con lípidos de apoAI, en relación a la biogénesis de HDL y su función en el RCT. Se trata en particular la configuración de apoAI en HDL discoidales, así como la interacción con lípidos y la importancia para la remoción celular de colesterol de un par de a-hélices anfipáticas que presentan una distribución particular de los residuos cargados y se localizan en el centro de la molécula de apoAI.Apolipoprotein A-I (apoAI) is the major protein component of high density lipoprotein (HDL), whose serum level is inversely correlated with atherogenic risk. Antiatherogenic properties are largely attributed to its key role in reverse cholesterol transport (RCT), a process that removes cholesterol excess from peripheral tissues. ApoAI is an amphitropic protein that almost exclusively contains amphipathic a-helices, and presents a large conformational flexibility that is crucial for its functional cycle, in which it inter-converts into different states: free or bound to membranes, or into a lipoprotein complex variety of different sizes, compositions and morphologies. This report reviews the current knowledge of the structure and lipid interaction properties of apoAI, in relation with HDL biogenesis and function in RCT. In particular, focus is made on the apoAI configuration in discoidal HDL; as well as on the interaction with lipids, and the importance for cellular cholesterol efflux, of an amphipathic a-helix pair having a particular distribution of the charged residues and that locate at the center of the apoAI molecule.Apolipoproteína A-I (apoAI) é o principal componente proteico das lipoproteínas de alta densidade (HDL), cujo nível sérico se correlaciona inversamente com o risco aterogênico. As propriedades antiaterogênicas são atribuídas, em grande parte, a seu papel principal no transporte reverso de colesterol (RCT), um processo que remove o excesso de colesterol dos tecidos periféricos. A ApoAI é uma proteína anfitrópica constituída quase exclusivamente por α-hélices anfipáticas, e apresenta uma grande flexibilidade conformacional que é essencial para seu ciclo funcional, no qual se interconverte entre diferentes estados: livre, ligada a membranas ou a uma grande variedade de complexos lipoproteicos de diferente tamanho, morfologia e composição. Este relatório analisa o conhecimento atual sobre a estrutura e propriedades de interação com lipídios de apoAI, com relação à biogênese de HDL e sua função no RCT. Em particular, trata-se a configuração de apoAI em HDL discoidais; bem como a interação com lipídios e a importância para a remoção celular de colesterol de um par de α-hélices anfipáticas que apresentam uma distribuição específica dos resíduos carregados e se localizam no centro da milécula de apoAI.Fil: Garda, Horacio Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Investigaciones Bioquímicas de La Plata; Argentina; ArgentinaFil: Toledo, Juan Domingo.Fil: Gonzalez, Maria Cecilia.Fil: Prieto, Eduardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Cuellar, Luz Ángela.Fil: Cabaleiro, Laura Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Instituto de Investigaciones Bioquímicas de La Plata; Argentina; ArgentinaFil: Chirillano, Lucio Alfonso.Fil: Almeyra, Carla Mariel

Bipolar multiplex families have an increased burden of common risk variants for psychiatric disorders

Multiplex families with a high prevalence of a psychiatric disorder are often examined to identify rare genetic variants with large effect sizes. In the present study, we analysed whether the risk for bipolar disorder (BD) in BD multiplex families is influenced by common genetic variants. Furthermore, we investigated whether this risk is conferred mainly by BD-specific risk variants or by variants also associated with the susceptibility to schizophrenia or major depression. In total, 395 individuals from 33 Andalusian BD multiplex families (166 BD, 78 major depressive disorder, 151 unaffected) as well as 438 subjects from an independent, BD case/control cohort (161 unrelated BD, 277 unrelated controls) were analysed. Polygenic risk scores (PRS) for BD, schizophrenia (SCZ), and major depression were calculated and compared between the cohorts. Both the familial BD cases and unaffected family members had higher PRS for all three psychiatric disorders than the independent controls, with BD and SCZ being significant after correction for multiple testing, suggesting a high baseline risk for several psychiatric disorders in the families. Moreover, familial BD cases showed significantly higher BD PRS than unaffected family members and unrelated BD cases. A plausible hypothesis is that, in multiplex families with a general increase in risk for psychiatric disease, BD development is attributable to a high burden of common variants that confer a specific risk for BD. The present analyses demonstrated that common genetic risk variants for psychiatric disorders are likely to contribute to the high incidence of affective psychiatric disorders in the multiplex families. However, the PRS explained only part of the observed phenotypic variance, and rare variants might have also contributed to disease development