Numerical modelling of the seismic performance of Romanian traditional timber-framed buildings

Traditional architecture made of timber-framed masonry (TFM) system is widespread around the world and has already been recognized as a unique cultural heritage to be preserved. These structures have shown a good seismic performance compared to other typologies because their configuration and construction details were constantly updated as soon as the builders addressed the causes of damage mechanisms when earthquakes occurred. Regarding this typology, Romanian TFM structures can be considered a representative example also because they experienced several seismic events showing their good earthquake-resistance. Although these buildings are still constructed and inhabited nowadays, no recommendation is provided in the Romanian building code and its structural behaviour is not properly characterized yet. Bearing in mind that the building’s global response depends on many parameters such as the performance of its structural elements and their interaction, the calibration of shear walls is crucial to define the non-linear behaviour under cyclic loading. A simplified modelling strategy was chosen to simulate TFM wall response consisting of an equivalent frame with linear elastic elements and non-linearities lumped at the joints by using OpenSees. After calibrating the wall response according to the experimental campaign performed at Technical University of Civil Engineering of Bucharest, the panel was adapted to model a representative Romanian TFM building whose dynamic properties were evaluated by eigenvalue analysis and their potential calibration is proposed based on the ambient vibration tests

Assessment and mitigation of seismic risk at the urban scale: an application to the historic city center of Leiria, Portugal

Preprint versionThe implementation of a culture of seismic risk preparedness is becoming increasingly critical in Europe as the building stock ages and the awareness about seismic risk rises. In this context, the assessment of the seismic vulnerability of existing buildings, followed by the implementation of appropriate retrofitting solutions, can help to substantially reduce the levels of physical damage and economic impact of future events. The central region of Portugal is particularly susceptible to large seismic events and is characterized by the prevalence of historic masonry buildings. This work aims to validate assessment methods for the risk of historical city centers in order to propose management strategies for municipalities and assess the economic impact of large-scale seismic retrofitting. To do this, an application of these methods was performed on the historical city center of Leiria. An in-depth inspection was performed of the entire center and the results were compiled into a database. Using an index-based seismic vulnerability assessment approach, a vulnerability assessment was made for each building. Based on vulnerability and predicted damage, estimates of human and economic losses were made for the city center before and after retrofitting to justify interventions on a broad scale.- This work was enabled and funded by the Advanced Masters in Structural Analysis of Monuments and Historic Constructions (SAHC) at the University of Minho and by the Portuguese Foundation for Science and Technology (FCT) through the postdoctoral fellowship SFRH/BPD/122598/2016. The authors would like to thank the students at the Polytechnic Institute of Leiria for their assistance in coordinating and executing fieldwork. Additionally, many thanks to the Municipality of Leiria for providing access to their records and support of the work

Reduced lysosomal acid lipase activity in blood and platelets is associated with nonalcoholic fatty liver disease

OBJECTIVES: To investigate whether blood total lysosomal acid lipase activity (BT-LAL) levels are uniquely associated with the noncirrhotic and cirrhotic stages of nonalcoholic fatty liver disease (NAFLD) and with protection from NAFLD in metabolically/genetically predisposed subjects and a normal liver. To clarify which enzyme-carrying circulating cells are involved in reduced BT-LAL of NAFLD.METHODS: In a cross-sectional study, BT-LAL was measured by a fluorigenic method in patients with NAFLD (n = 118), alcoholic (n = 116), and hepatitis C virus-related disease (n = 49), in 103 controls with normal liver and in 58 liver transplant recipients. Intracellular platelet and leukocyte LAL was measured in 14 controls and 28 patients with NAFLD.RESULTS: Compared with controls, (i) BT-LAL and LAL in platelets, but not in leukocytes, were progressively reduced in noncirrhotic NAFLD and in nonalcoholic steatohepatitis-related cirrhosis; (ii) platelet and leukocyte counts did not differ in patients with noncirrhotic NAFLD; and (iii) BT-LAL did not differ in alcoholic and hepatitis C virus noncirrhotic patients. BT-LAL progressively increased in controls with metabolic syndrome features according to their PNPLA3 rs738409 steatosis-associated variant status (II vs IM vs MM), and their BT-LAL was higher than that of noncirrhotic NAFLD, only when carriers of the PNPLA3 unfavorable alleles were considered. Liver transplant recipients with de novo NAFLD compared with those without de novo NAFLD had lower BT-LAL.DISCUSSION: LAL in blood and platelets is progressively and uniquely reduced in NAFLD according to disease severity. High BT-LAL is associated with protection from NAFLD occurrence in subjects with metabolic and genetic predisposition. Low LAL in platelets and blood could play a pathogenetic role in NAFLD

Severity of Hepatocyte Damage and Prognosis in Cirrhotic Patients Correlate with Hepatocyte Magnesium Depletion

We aimed to evaluate the magnesium content in human cirrhotic liver and its correlation with serum AST levels, expression of hepatocellular injury, and MELDNa prognostic score. In liver biopsies obtained at liver transplantation, we measured the magnesium content in liver tissue in 27 cirrhotic patients (CIRs) and 16 deceased donors with healthy liver (CTRLs) by atomic absorption spectrometry and within hepatocytes of 15 CIRs using synchrotron-based X-ray fluorescence microscopy. In 31 CIRs and 10 CTRLs, we evaluated the immunohistochemical expression in hepatocytes of the transient receptor potential melastatin 7 (TRPM7), a magnesium influx chanzyme also involved in inflammation. CIRs showed a lower hepatic magnesium content (117.2 (IQR 110.5–132.9) vs. 162.8 (IQR 155.9–169.8)  g/g; p < 0.001) and a higher percentage of TRPM7 positive hepatocytes (53.0 (IQR 36.8–62.0) vs. 20.7 (10.7–32.8)%; p < 0.001) than CTRLs. In CIRs, MELDNa and serum AST at transplant correlated: (a) inversely with the magnesium content both in liver tissue and hepatocytes; and (b) directly with the percentage of hepatocytes stained intensely for TRPM7. The latter also directly correlated with the worsening of MELDNa at transplant compared to waitlisting. Magnesium depletion and overexpression of its influx chanzyme TRPM7 in hepatocytes are associated with severity of hepatocyte injury and prognosis in cirrhosis. These data represent the pathophysiological basis for a possible beneficial effect of magnesium supplementation in cirrhotic patients

Biologically driven cut-off definition of lymphocyte ratios in metastatic breast cancer and association with exosomal subpopulations and prognosis

High neutrophil to lymphocyte ratio (NLR) and monocyte to lymphocyte ratio (MLR) are respectively associated with systemic inflammation and immune suppression and have been associated with a poor outcome. Plasmatic exosomes are extracellular vesicles involved in the intercellular communication system that can exert an immunosuppressive function. Aim of this study was to investigate the interplay between the immune system and circulating exosomes in metastatic breast cancer (MBC). A threshold capable to classify patients according to MLR, NLR and PLR, was computed through a receiving operator curve analysis after propensity score matching with a series of female blood donors. Exosomes were isolated from plasma by ExoQuick solution and characterized by flow-cytometry. NLR, MLR, PLR and exosomal subpopulations potentially involved in the pre-metastatic niche were significantly different in MBC patients with respect to controls. MLR was significantly associated with number of sites at the onset of metastatic disease, while high levels of MLR and NLR were found to be associated with poor prognosis. Furthermore, exosomal subpopulations varied according to NLR, MLR, PLR and both were associated with different breast cancer subtypes and sites of distant involvement. This study highlights the nuanced role of immunity in MBC spread, progression and outcome. Moreover, they suggest potential interaction mechanisms between immunity, MBC and the metastatic niche

Investigating the seismic response of URM walls with irregular opening layout through different modeling approaches

TThe façade and internal walls of unreinforced masonry (URM) buildings often present an irregular opening layout, due to architectural reasons or modifications to the structure, which make the expected seismic damage pattern less predictable a priori. Therefore, the discretization of the walls in structural components is not standardized, conversely to cases with a regular opening layout for which the available modeling methods are corroborated by seismic damage surveys reporting recurrent failure patterns. The structural component discretization is a relevant step for the code-conforming seismic assessment, typically based on comparing the internal forces and drifts of each component to strength criteria and drift thresholds. Therefore, the lack of well-established approaches can significantly influence the assessment. The issue is even more evident when the structural components must be identified a priori in the modeling stage, namely for equivalent frame models. The applicability of available methods for discretization of URM walls with irregular opening layout has been already investigated in literature, but a conclusive judgment requires further studies. In this context, this paper presents an overview of the preliminary results addressing the numerical modeling of this type of walls within the framework of the DPC-ReLUIS 2022-2024 project (Subtask 10.3), funded by the Italian Department of Civil Protection. The Subtask aims to propose consensus-based recommendations for researchers and practitioners which can contribute to harmonize the use of different modeling approaches. Seven research groups are involved in the research, adopting different modeling approaches and computer codes, but similar assumptions and the same analysis method (pushover) are used. The benchmark URM structure illustrated in the paper is a two-story wall from which four configurations with increasing irregularity of opening layout were derived. The results of four modeling approached are presented. Three of them reproduce the mechanical response of masonry at the material scale by means of FE models implemented in OpenSees, DIANA and Abaqus software, while the remaining approach describes the mechanical response of masonry at the macro-element scale in 3DMacro software. Results were compared in terms of capacity curves, predicted failure mechanisms and evolution of internal forces in piers. The adoption of consistent assumptions among the different approaches led to an overall agreement of predictions at both wall and pier scales, particularly in terms of damage pattern with higher concentration of damage at the ground story. Despite that, differences on the pushover curves have been highlighted. They are mainly due to some deviations of the internal forces in squat piers deriving from a complex load flow in these elements.DPC - Dipartimento della Protezione Civile, Presidenza del Consiglio dei Ministri(LA/P/0112/2020

Shake‑table testing of a stone masonry building aggregate: overview of blind prediction study

City centres of Europe are often composed of unreinforced masonry structural aggregates, whose seismic response is challenging to predict. To advance the state of the art on the seismic response of these aggregates, the Adjacent Interacting Masonry Structures (AIMS) subproject from Horizon 2020 project Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe (SERA) provides shake-table test data of a two-unit, double-leaf stone masonry aggregate subjected to two horizontal components of dynamic excitation. A blind prediction was organized with participants from academia and industry to test modelling approaches and assumptions and to learn about the extent of uncertainty in modelling for such masonry aggregates. The participants were provided with the full set of material and geometrical data, construction details and original seismic input and asked to predict prior to the test the expected seismic response in terms of damage mechanisms, base-shear forces, and roof displacements. The modelling approaches used differ significantly in the level of detail and the modelling assumptions. This paper provides an overview of the adopted modelling approaches and their subsequent predictions. It further discusses the range of assumptions made when modelling masonry walls, floors and connections, and aims at discovering how the common solutions regarding modelling masonry in general, and masonry aggregates in particular, affect the results. The results are evaluated both in terms of damage mechanisms, base shear forces, displacements and interface openings in both directions, and then compared with the experimental results. The modelling approaches featuring Discrete Element Method (DEM) led to the best predictions in terms of displacements, while a submission using rigid block limit analysis led to the best prediction in terms of damage mechanisms. Large coefficients of variation of predicted displacements and general underestimation of displacements in comparison with experimental results, except for DEM models, highlight the need for further consensus building on suitable modelling assumptions for such masonry aggregates

Modellazione numerica del comportamento sismico dell’architettura tradizionale rumena con sistema misto legno-muratura

Dissertação de mestrado em Structural Analysis of Monuments and Historical ConstructionsTraditional architecture made of timber-framed masonry (TFM) system is widespread around the world and has already been recognized as a unique cultural heritage to be preserved. These structures have shown a good seismic performance compared to other typologies because their configuration and construction details were constantly updated as soon as the builders addressed the causes of damage mechanisms when earthquakes occurred. Romanian TFM structures can be considered a representative example of this typology also because they experienced several seismic events showing their good earthquake-resistance. Although these buildings are still inhabited nowadays and constructed, no recommendation is provided in the Romanian building code and its structural behavior is not properly characterized and modelled yet. Thus, bearing in mind that the building’s global response depends on many parameters such as TFM walls, floor and roofing system as well as the connections between them, the calibration of shear walls is crucial to define the non-linear behavior under cyclic loading. A simplified modelling strategy was chosen to simulate TFM wall response consisting of an equivalent frame with linear elastic elements and non-linearities lumped at the joints. The present thesis aimed at investigating the seismic performance of Romanian TFM walls and a representative TFM building located originally in Sarbova area, Timis County, but relocated to the National Village Museum “Dimitrie Gusti” in Bucharest, by comparing the numerical results with the measurements taken during the experimental campaign performed at Technical University of Civil Engineering of Bucharest and the in situ dynamic investigation, respectively. The wall numerical model was calibrated by performing the procedure of inverse fitting to obtain a good approximation between the experimental hysteretic curve and the numerical one in terms of initial stiffness, maximum base shear and total dissipated energy. This model was built in the FEM software OpenSees concentrating at the joints a non-linear hysteretic spring per degree of freedom and updating its parameters starting from some experimental tests performed on comparable types of connections. Once the wall response was matched, the Romanian traditional building was modelled by applying the same equivalent frame method, but, in this case, the dynamic properties did not match perfectly to those recorded by ambient vibration tests since microtremors involve the wall in the elastic range while the wall calibration was carried out for its non-linear one. Thus, the model was updated considering an additional contribution of infill since the type of masonry was different from the one infilling the tested wall. Eventually, non-linear static analysis was performed to assess the maximum shear and deformation capacity and predict some local failures at the timber joints. The simplified equivalent frame model shows a good performance in simulating the wall response, but, for the already explained reasons, it was not completely capable of approximating the building dynamic properties. However, this strategy allows to reduce the computational efforts and, at the same time, provide information about the behavior of each connection.A arquitetura vernacular constituída por paredes madeira com enchimento de alvenaria com estrutura de madeira (TFM) é difundida em todo o mundo e já foi reconhecida como um patrimônio cultural único que precisa de ser preservado. Essas estruturas mostraram um bom desempenho sísmico em comparação com outras tipologias, porque as suas configurações e os seus detalhes constitutivos foram constantemente atualizados assim que os construtores abordaram as causas dos mecanismos de danos quando os terremotos ocorreram. As estruturas TFM Romenas podem ser consideradas um exemplo representativo desta tipologia também porque experimentaram vários eventos sísmicos mostrando a sua boa resistência a sismos. Se bem que estes edifícios ainda sejam habitados hoje em dia e continuem a ser construídos, nenhuma recomendação é fornecida no código de construção romeno e o seu comportamento estrutural ainda não está devidamente caracterizado e modelado. Assim, tendo em conta que a resposta global do edifício depende de muitos parâmetros, tais como paredes TFM, piso e sistema de cobertura, bem como as ligações entre eles, a calibração das paredes de corte é crucial para definir o comportamento não linear sob carga cíclica. Uma estratégia simplificada de modelação foi escolhida para simular a resposta da parede TFM constituída por uma estrutura equivalente com elementos elásticos lineares e não-linearidades concentradas nas ligações. A presente tese tem como objetivo investigar o desempenho sísmico das paredes romenas TFM e de um edifício TFM representativo localizado originalmente na área de Sarbova, no distrito de Timis, mas transferido para o National Village Museum “Dimitrie Gusti” em Bucareste, comparando os resultados numéricos com os resultados obtidos durante a campanha experimental realizada na Universidade Técnica de Engenharia Civil de Bucareste e na investigação dinâmica in situ, respetivamente. O modelo numérico da parede foi calibrado utilizando um procedimento de ajuste inverso para obter uma boa aproximação entre a curva histerética experimental e a curva numérica em termos de rigidez inicial, capacidade máxima e energia total dissipada. Este modelo foi desenvolvido no software a elementos finitos OpenSees, concentrando nas ligações uma mola histerética não linear por grau de liberdade e atualizando os parâmetros a partir de alguns ensaios experimentais existentes realizados em ligações comparáveis. Uma vez que a resposta da parede foi calibrada, o edifício tradicional romeno foi modelado aplicando o mesmo método da estrutura equivalente, mas, neste caso, as propriedades dinâmicas não se ajustaram perfeitamente àquelas obtidas através dos ensaios de vibração ambiental, pois os microtremores envolvem a parede na fase elástica inicial, enquanto a calibração da parede foi realizada para a sua resposta não-linear. Assim, o modelo foi atualizado considerando uma contribuição adicional do preenchimento de alvenaria, uma vez que o tipo de alvenaria foi diferente daquele da parede ensaiada. Após desta calibração, foi realizada uma análise estática não linear para avaliar a capacidade máxima e deformação e prever alguns danos locais nas ligações de madeira. O modelo simplificado equivalente da parede mostra um bom desempenho na simulação da resposta da parede, mas, pelas razões acima explicadas, não foi completamente possível aproximar as propriedades dinâmicas do edifício. No entanto, essa estratégia permite reduzir os esforços computacionais e, ao mesmo tempo, fornecer informações sobre o comportamento de cada ligação.La tipologia architettonica tradizionale a sistema misto legno-muratura è ampiamente diffusa in ogni parte del mondo. La sua unicità è stata riconosciuta come patrimonio culturale da salvaguardare. Tali edifici hanno dimostrato un buon comportamento sismico se paragonati ad altre tipologie strutturali. La loro configurazione, nonché I loro dettagli costruttivi, si sono costantemente evoluti per opera dei costruttori, non appena questi ultimi hanno compreso le cause dei principali meccanismi di danno che si verificano a seguito di un terremoto. Il sistema misto Rumeno può essere considerato rappresentativo di questa tipologia strutturale, soprattutto perchè il territorio è stato soggetto ad innumerevoli eventi sismici dimostrando la sua capacità resistente. Nonostante molti di questi edifici siano attualmente abitati o in costruzione, non è presente nessuna informazione riguardo la loro progettazione nel codice edilizio Rumeno, inoltre il loro comportamento non è stato ancora propriamente caratterizzato ne modellato numericamente. La risposta globale di un edificio è funzione di diverse variabili tra cui la tecnologia costruttiva di pannelli murari, diaframmi orizzontali, sistema di copertura, nonché del loro grado di connessione. Per questo motivo, la calibrazione del comportamento non lineare delle pareti resistenti soggette a carichi ciclici è di fondamentale importanza per approssimare tale risposta globale. A questo proposito è stata scelta una strategia di modellazione semplificata basata su un telaio equivalente con elementi lineari elastici e non linearità concentrate nelle connessioni. Il lavoro di tesi si rivolge in particolare allo studio del comportamento sismico dei pannelli murari Rumeni a sistema misto legno-muratura e di un edificio rappresentativo localizzato originariamente nell’area di Sarbova, contea di Timis (poi successivamente riassemblato nel Museo Nazionale “Dimitrie Gusti” di Bucarest). Tale ricerca è condotta attraverso la comparazione dei risultati numerici con quelli misurati sperimentalmente nelle prove di laboratorio eseguite su un pannello murario rappresentativo presso il Dipartimento di Ingegneria Civile di Bucarest e i test di identificazione dinamica eseguiti in situ sull’edificio. Il modello numerico relativo alla parete è stato calibrato attraverso una procedura iterativa per ottenere una buona approssimazione tra la curva isteretica ottenuta sperimentalmente e quella numerica, in termini di rigidezza iniziale, forza di taglio massima alla base ed energia totale dissipata. Tale schema è stato realizzato nel software OpenSees modellando molle non lineari per ogni grado di libertà ed aggiornando i relativi parametri che definiscono la risposta isteretica partendo da test sperimentali condotti su connessioni simili. Una volta calibrato il pannello murario, è stato modellato l’edificio con la stessa strategia a telaio equivalente. In questo caso, tuttavia , le proprietà dinamiche non sono risultate perfettamente comparabili con quelle ottenute dall’identificazione dinamica, i muri dell’edificio rispondono in campo lineare elastico, mentre le proprietà delle connessioni sono state calibrate in campo non lineare plastico. Per questo motivo, il modello è stato modificato considerando il contributo di rigidezza aggiuntivo dato da una muratura in mattoni pieni, più rigida di quella presente nelle maglie del telaio testato. Infine, è stata svolta un’analisi non lineare statica al fine di stimare la massima forza alla base, la capacità deformativa del muro nonché alcune rotture locali nelle connessioni. Il modello semplificato a telaio equivalente ha evidenziato un buon grado di approssimazione con la risposta del pannello murario, ma, per le ragioni precedentemente esposte, non è stato in grado di caratterizzare dal punto di vista dinamico l’edificio. Ad ogni modo tale strategia di modellazione permette di ridurre l’onere computazionale e, allo stesso tempo, fornisce informazioni sul comportamento di ogni connessione

I percorsi di sviluppo della PMI tra ricchezza familiare e patrimonio aziendale. Ruolo, funzioni e rilevanza del Family Office

L'elaborato affronta la nascita e lo sviluppo della piccola e media impresa e cosa ha caratterizzato nell'economia italiana a partire dagli anni ottanta fino ai giorni odierni. Si affrontano le varie problematiche riguardanti il family business e le sue possibili classificazioni nonché le sue implicazioni ed interazioni non soltanto con il soggetto fondatore ma anche con i suoi eventuali eredi. La governance svolge un ruolo di primaria importanza all'interno del family business in quanto è in grado con i vari strumenti a sua disposizione di garantire la stabilità, la serenità, l'adattamento e lo sviluppo dell'impresa nei vari contesti politici-economici. Si affrontano anche i temi del patrimonio e della ricchezza familiare in base all'analisi di governace basata sulla teoria Three Circle Model e gli strumenti a disposizione della famiglia per la tutela e lo sviluppo e salvaguardia dello stesso. Infine si analizzano le implicazioni tra azienda e banca in tema di tutela del patrimonio e gli strumenti e servizi messi a dispozione dalla banca alle imprese familiari particolarmente benestanti