challenging aspects in removing the influence of environmental factors on modal parameter estimates

Abstract Modal based damage detection is a well-established procedure for Structural Health Monitoring (SHM) of civil structures. The development of robust algorithms for automated output-only modal parameter identification and tracking has renewed the interest towards modal based damage detection. However, the influence of environmental and operational variables on modal parameter estimates still represents a relevant shortcoming to their extensive use for SHM, because it can yield changes in the experimental estimates of the same order of magnitude of those induced by damage. As a consequence, there is the need to remove the effects of those factors in order to effectively detect damage. Different approaches can be adopted, some of which do not require measurements of the environmental and operational variable influencing the modal parameter estimates. Nevertheless, the effective removal of the environmental influence on modal parameters still remains a challenging aspect in SHM. In the present paper, different approaches for compensation of environmental effects are applied to a very large database of modal parameter estimates from a bridge in operational conditions. The objective of the paper is to investigate their performance under the concurrent influence of different environmental/operational variables (for instance, temperature and traffic) on modal parameter estimates. Static (effect on the estimate at time t depends only on the value of the variable at the same time instant) as well as dynamic (effect on the estimate at time t depends on the values of the variable at time t and also at previous time instants) methods are considered. The results of the study remark the relevance of identifying all sources of variability of the modal parameters in operational conditions

Automated Operational Modal Analysis and Its Applications in Structural Health Monitoring

n/

À SOMBRA DE UMA REPRESENTAÇÃO DIVINA: IGREJISMO E A POLÍTICA INTERNACIONAL NA MODERNIDADE

O presente artigo busca abordar o papel do Cristianismo na Política Internacional durante a Modernidade. Como objetivo geral, verificaremos a aplicabilidade conceito de Igrejismo proposto por Wallace de Moraes  ao campo internacional e específicamente, vislumbraremos seus impactos na condução de um projeto civilizacional europeu pretensamente universal. Utilizaremos como referencial teórico, as perspectivas filosóficas decolonial e libertária. A lógica da Colonialidade Global projeta uma estrutura de poder/saber que se impõe hegemonicamente pelo globo, em especial, na América Latina,  submetendo e  colonizando corpos e almas de seus habitantes

O ESTADO DE MAL ESTAR SOCIAL: UMA ANÁLISE DA POLÍTICA NEOLIBERAL E SEUS SUSTENTÁCULOS MILITARISTAS E IGREJISTAS

O presente artigo busca realizar um mergulho no conceito intitulado Estado do Mal Estar Social apresentando os seus principais fundamentos de forma a demonstrar que o modelo econômico baseado na lógica do liberalismo é incapaz de promover um bem estar coletivo. Entendemos que as propostas de John Maynard Keynes, que salvaram o capitalismo do colapso, chamadas de Estado do Bem Estar Social, configuram-se como uma exceção do papel histórico do Estado. A regra é a adoção de uma pauta econômica centrada nas ideias liberais/neoliberais que, em nenhum momento, atenderam aos anseios populares. O que chamamos de Estado do Mal Estar Social é uma compilação entre as pautas econômicas liberais sustentadas historicamente pela força através das instituições militares repressivas que colonizam os corpos e pelo Igrejismo e suas instituições religiosas que colonizam as almas dos indivíduos

How social power and its perceived legitimacy affect motivations and behaviour

This thesis aims to investigate how powerless and powerful individuals and groups perceive and experience social inequalities and how they are motivated to respond to them. By combining existing knowledge of the effects of interpersonal power on motivations and behaviour with an account of the structure of intergroup relations (social identity theory), I examine the socio-psychological processes underlying these responses in power structures. Across four experiments, I investigate the perspective of both powerful and powerless individuals and show that the motivations and behaviour elicited by their power (or lack of it) are not invariant, but can be modified by the perceived legitimacy of their power position. Additionally, I also show that the powerless' behaviour is responsive not only to perceptions of legitimacy but also to concerns regarding impression management. I then focus on the perspective of powerful group members and demonstrate how perceptions of legitimacy and individual differences in social dominance orientation (SDO) interact to predict their willingness to engage in positive behaviour (i.e., helping intentions towards the powerless). Additionally, I demonstrate across two experiments that the help-providers position in the power structure (internal power holders vs. external observer) moderate how the interplay between legitimacy and SDO shape helping intentions. In sum, the six experiments reported in this thesis illustrate how the effects of social power on individuals responses to power imbalances is modified by perceptions of legitimacy, and also how illegitimate power promotes strategic responses that are reflective of specific identify-related concerns. Theoretical and practical implications are discussed.Portuguese Foundation for Science and Technolog

Cellulose-based edible films for probiotic entrapment

Encapsulation with edible films is a promising approach that may solve the disadvantages associated with the use of bioactive compounds as food additives. This is particularly relevant in the case of probiotics, since their stability in food matrices and in the gastrointestinal tract may be rather poor. Therefore, new cellulose-based edible films have been successfully developed and characterized. Sodium carboxymethyl cellulose (CMC) and hydroxyethyl cellulose (HEC) were used for the film preparation and cross-linked with citric acid (CA) under reasonably mild conditions. Model probiotic bacteria (Lactobacillus rhamnosus GG) were incorporated in the films either during the film formation and casting or after the film synthesis, via bacteria diffusion and adsorption. The later approach could efficiently entrap and preserve viable bacteria. The mechanical properties and swelling ability could be tuned by varying the HEC/CMC ratio and the amount of CA. Moreover, the surface area and total pore volume of the films considerably decreased after cross-linking. Overall, these novel films are regarded as promising inexpensive and friendly matrices for food protection and packaging applications.People Program (Marie Curie Actions) of the European Union's Seventh Framework Program FP7/2007-2013/under REAEuropean Union (EU) [606713 BIBAFOODS]Portuguese Foundation for Science and Technology (FCT)Portuguese Foundation for Science and Technology [PTDC/AGR-TEC/4814/2014, IF/01005/2014]FCTPortuguese Foundation for Science and Technology [PEstOE/QUI/UI0313/2013

Ambient vibration re-testing and operational modal analysis of the Humber Bridge

An ambient vibration survey of the Humber Bridge was carried out in July 2008 by a combined team from the UK, Portugal and Hong Kong. The exercise had several purposes that included the evaluation of the current technology for instrumentation and system identification and the generation of an experimental dataset of modal properties to be used for validation and updating of finite element models for scenario simulation and structural health monitoring. The exercise was conducted as part of a project aimed at developing online diagnosis capabilities for three landmark European suspension bridges. Ten stand-alone tri-axial acceleration recorders were deployed at locations along all three spans and in all four pylons during five days of consecutive one-hour recordings. Time series segments from the recorders were merged, and several operational modal analysis techniques were used to analyse these data and assemble modal models representing the global behaviour of the bridge in all three dimensions for all components of the structure. The paper describes the equipment and procedures used for the exercise, compares the operational modal analysis (OMA) technology used for system identification and presents modal parameters for key vibration modes of the complete structure. The results obtained using three techniques, natural excitation technique/eigensystem realisation algorithm, stochastic subspace identification and poly-Least Squares Frequency Domain method, are compared among themselves and with those obtained from a 1985 test of the bridge, showing few significant modal parameter changes over 23 years in cases where direct comparison is possible. The measurement system and the much more sophisticated OMA technology used in the present test show clear advantages necessary due to the compressed timescales compared to the earlier exercise. Even so, the parameter estimates exhibit significant variability between different methods and variations of the same method, while also varying in time and having inherent variability. (C) 2010 Elsevier Ltd. All rights reserved

Sunk cost effect: An exploratory approach through a sample of Spanish graduates

[ES]El efecto de costo irrecuperable (ECI) ha sido definido como una tendencia a elegir o continuar un curso de acción una vez que se ha hecho una inversión previa de dinero, tiempo o esfuerzo. El objetivo de esta investigación fue la aplicación, con leves variaciones, del experimento original de efecto de costo irrecuperable en una muestra de 108 estudiantes universitarios de varias titulaciones con una media de edad de 28.79 (DT= 11.34), donde el 62% eran mujeres y el 38% hombres. Los resultados confirman la existencia del Efecto de Costo Irrecuperable en dicha muestra, aunque el término ECI deja abierto un abanico a posibles controversias que se han tenido en cuenta a la hora de establecer las conclusiones de esta investigació