Multisensor inspection of laser-brazed joints in the automotive industry

Funding Information: Acknowledgments: Authors acknowledge the European Regional Development Fund (ERDF), Programa Operacional Regional de Lisboa (Lisb@2020 e Portugal2020), for its financial support via the project PROBING (POCI-01-0247-FEDER-040042, Ref. 40042) and the Portuguese company INTROSYS—Integration for Robotic Systems (www.introsys.eu accessed 3 November 2021) for technical collaboration. Authors also acknowledge FCT—MCTES for its financial support via the project UIDB/00667/2020 (UNIDEMI).Automobile laser brazing remains a complex process whose results are affected by several process variables that may result in nonacceptable welds. A multisensory customized inspection system is proposed, with two distinct non-destructive techniques: the potential drop method and eddy current testing. New probes were designed, simulated, produced, and experimentally validated in automobile’s laser-brazed weld beads with artificially introduced defects. The numerical simulations allowed the development of a new four-point probe configuration in a non-conventional orthogonal shape demonstrating a superior performance in both simulation and experimental validation. The dedicated inspection system allowed the detection of porosities, cracks, and lack of bonding defects, demonstrating the redundancy and complementarity these two techniques provide.publishersversionpublishe

Warm little inflaton becomes cold dark matter

We present a model where the inflaton can naturally account for all the dark matter in the Universe within the warm inflation paradigm. In particular, we show that the symmetries of the Warm Little Inflaton scenario (i) avoid large thermal and radiative corrections to the scalar potential, (ii) allow for sufficiently strong dissipative effects to sustain a radiation bath during inflation that becomes dominant at the end of the slow-roll regime, and (iii) enable a stable inflaton remnant in the post-inflationary epochs. The latter behaves as dark radiation until parametrically before matter-radiation equality, leading to a non-negligible contribution to the effective number of relativistic degrees of freedom during nucleosynthesis, becoming the dominant cold dark matter component in the Universe for inflaton masses in the $10^{-4}-10^{-1}$ eV range. Cold dark matter isocurvature perturbations, anti-correlated with the main adiabatic component, provide a smoking gun for this scenario that can be tested in the near future.publishe

Sweet peppers discrimination according to agronomic production mode and maturation stage using a chemical-sensory approach and an electronic tongue

Supplementary data to this article can be found online at https://doi.org/10.1016/j.microc.2020.105034.The demand for organic foods has increased worldwide, in particular due to the association with healthier, more nutritious and tasty products, being a clear trend on sweet peppers consumption. Thus, this study aimed to evaluate the effects of agronomic production mode (conventional and organic) and maturation stage (associated to green, turning and red colours) on the chemical-sensory attributes of peppers grown in open field. It was found that organic peppers had a better visual/tactile aspect (greater firmness and more intense colours) but lower chemical quality (lower titratable acidity and total soluble solids). On the other hand, red peppers (higher maturation stage) had lower visual-tactile quality but higher chemical quality. From sensory analysis, conventional peppers had better overall aspect, colour intensity-homogeneity and brightness. Then again, the maturation stage of peppers mostly influenced the sensory visual attributes, being turning colour peppers the less appreciated, although organic red peppers were less succulent and had a lower global quality. Even so, the chemical-sensory parameters could be used to discriminate peppers taking into account the agronomic production mode and the maturation stage/colour (79±12% of correct classifications for the repeated K-fold cross-validation procedure). However, a trained sensory panel is required, which can be a major drawback considering their scarcity. This limitation was successfully overcome by using a potentiometric electronic tongue, which allowed discriminating the peppers with a higher predictive sensitivity (85±9%), showing that this device could be used as an accurate taste sensor for the qualitative analysis of sweet peppers.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Program PT2020 for financial support to CIMO (UIDB/00690/2020) and to CEB (UIDB/04469/2020) units and to BioTecNorte operation (NORTE‐01‐0145‐FEDER‐000004) funded by the European Regional Development Fund under the scope of Norte2020 ‐ Programa Operacional Regional do Norte. Nuno Rodrigues thanks to National funding by FCT- Foundation for Science and Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio

Liquid mixtures involving hydrogenated and fluorinated alcohols: thermodynamics, spectroscopy, and simulation

This article reports a combined thermodynamic, spectroscopic, and Computational study on the interactions and structure of binary mixtures of hydrogenated and fluorinated substances that simultaneously interact through strong hydrogen bonding. Four binary mixtures of hydrogenated and fluorinated alcohols have been studied, namely, (ethanol + 2,2,2-trifluoroethanol (TFE)), (ethanol + 2,2,3,3,4,4,4-heptafluoro-1-butanol), (1-butanol (BuOH) + TFE), and (BuOH + 2,23,4,4,4-heptafluoto-1-butanol). Excess molar volumes and vibrational spectra of all four binary mixtures have been measured as a function of composition at 298 K, and molecular dynamics simulations have been performed. The systems display a complex behavior when compared with mixtures of hydrogenated alcohols and mixtures of alkanes and perfluoroalkanes. The combined analysis of the results from different approaches indicates that this results from a balance between preferential hydrogen bonding between the hydrogenated and fluorinated alcohols and the unfavorable dispersion forces between the hydrogenated and fluorinated chains. As the chain length increases, the contribution of dispersion increases and overcomes the contribution of H-bonds. In terms of the liquid structure, the simulations suggest the possibility of segregation between the hydrogenated and fluorinated segments, a hypothesis corroborated by the spectroscopic results. Furthermore, a quantitative analysis of the infrared spectra reveals that the presence of fluorinated groups induces conformational changes in the hydrogenated chains from the usually preferred all-trans to more globular arrangements involving gauche conformations. Conformational rearrangements at the CCOH dihedral angle upon mixing are also disclosed by the spectra

Ultrafast nonlinear effects in organic compounds and organic hybrids materials

Synthesis and solution-processing of specialized chemical compounds can facilitate the fabrication of nano-electronic devices. Many of these emerging applications require organic materials with well-characterized optical properties, specifically, large two-photon absorption (2PA) and nonlinear optical (NLO) responses. The most common strategy to achieve a strong second order nonlinear optical response is to link donor and acceptor moieties on opposite ends of a π-conjugated aromatic spacer. This configuration promotes spatial charge transfer and a strong difference in dipole moments between the ground and excited electronic states. Individual organic molecules, tailor made following this strategy, can often exhibit exceptionally large intrinsic nonlinear optical properties, but the translation to a macroscopic electro-optic activity is often extremely difficult. Roughly more than 80% of all π-conjugated organic molecules crystallize in centrosymmetric space groups producing materials with no second order bulk susceptibility. Our group has demonstrated that is possible overcome this restriction by embedding organic molecules, which normally crystallize in centrosymmetric structures, into nanostructured polymeric matrix. Recently, we observed greatly enhance the nonlinearities of nominally weak nonlinear materials when insert in a polymeric nanofibers, one-dimensional nanostructures. These types of nanostructures are attracting attention because of the unique optical interactions that arise from their sub wavelength size. To explore this phenomena in detail we take advantage of our state of the art custom built Fluorescence Lifetime Imaging Microscope (FLIM). The temporal resolution of the FLIM is about 25 picoseconds and less than a 1 micron of spatial resolution. This system allows us to monitor the effects of nano-structured environments and their localized optical response. Other systems of current interest in our research group are graphene quantum dots both in solution and dispersed in a thin film of PVA, the interaction of excited dye molecules with a single layer graphene surface and tailor designed molecules for two photon absorption in the near infrared portion of the spectrum.info:eu-repo/semantics/publishedVersio

Validation of the ‘Test of the Adherence to Inhalers’ (TAI) for Asthma and COPD Patients

Background: To validate the ‘Test of Adherence to Inhalers’ (TAI), a 12-item questionnaire designed to assess the adherence to inhalers in patients with COPD or asthma. Methods: A total of 1009 patients with asthma or COPD participated in a cross-sectional multicenter study. Patients with electronic adherence ≥80% were defined as adherents. Construct validity, internal validity, and criterion validity were evaluated. Self-reported adherence was compared with the Morisky-Green questionnaire. Results: Factor analysis study demonstrated two factors, factor 1 was coincident with TAI patient domain (items 1 to 10) and factor 2 with TAI health-care professional domain (items 11 and 12). The Cronbach's alpha was 0.860 and the test-retest reliability 0.883. TAI scores correlated with electronic adherence (ρ=0.293, p=0.01). According to the best cut-off for 10 items (score 50, area under the ROC curve 0.7), 569 (62.5%) patients were classified as non-adherents. The non-adherence behavior pattern was: erratic 527 (57.9%), deliberate 375 (41.2%), and unwitting 242 (26.6%) patients. As compared to Morisky-Green test, TAI showed better psychometric properties. Conclusions: The TAI is a reliable and homogeneous questionnaire to identify easily non-adherence and to classify from a clinical perspective the barriers related to the use of inhalers in asthma and COPD

TASKA: A modular task management system to support health research studies

Background: Many healthcare databases have been routinely collected over the past decades, to support clinical practice and administrative services. However, their secondary use for research is often hindered by restricted governance rules. Furthermore, health research studies typically involve many participants with complementary roles and responsibilities which require proper process management. Results: From a wide set of requirements collected from European clinical studies, we developed TASKA, a task/workflow management system that helps to cope with the socio-technical issues arising when dealing with multidisciplinary and multi-setting clinical studies. The system is based on a two-layered architecture: 1) the backend engine, which follows a micro-kernel pattern, for extensibility, and RESTful web services, for decoupling from the web clients; 2) and the client, entirely developed in ReactJS, allowing the construction and management of studies through a graphical interface. TASKA is a GNU GPL open source project, accessible at https://github.com/bioinformatics-ua/taska. A demo version is also available at https://bioinformatics.ua.pt/taska. Conclusions: The system is currently used to support feasibility studies across several institutions and countries, in the context of the European Medical Information Framework (EMIF) project. The tool was shown to simplify the set-up of health studies, the management of participants and their roles, as well as the overall governance process

one-step extraction and separation of betalains and chlorophylls using thermoreversible aqueous biphasic systems

This work was partly developed within the scope of the projects CICECO-Aveiro Institute of Materials, LA/P/0006/2020 and the Associate Laboratory for Green Chemistry-LA/P/0008/2020, financed by national funds through the FCT/MCTES (PIDDAC). Publisher Copyright: © 2023 The Royal Society of Chemistry.Globally, up to 50% of root crops, fruits and vegetables produced is wasted. Beetroot stems and leaves fit into this scenario, with only a small fraction being used in cattle food. One way of approaching this problem is through their valorisation, by extracting and recovering valuable compounds present in this type of waste that could be used in other applications, while contributing towards a circular economy. In this work, a new integrated process using thermoreversible aqueous biphasic systems (ABS) composed of quaternary ammonium-based ionic liquids (ILs) and polypropyleneglycol 400 g mol−1 (PPG) is shown to allow the one-step extraction and separation of two pigment classes—betalains and chlorophylls—from red beet stems and leaves. The pigment extraction was carried out with a monophasic aqueous solution of the IL and PPG, whose phase separation was then achieved by a temperature switch, resulting in the simultaneous separation of chlorophylls and betalains into opposite phases. A central composite design was used to optimise the extraction parameters (time, temperature, and solid : liquid (S/L) ratio) of both pigment extraction yields, reaching at 20 °C, 70 min and a S/L ratio of 0.12 a maximum extraction yield of 6.67 wt% for betalains and 1.82 wt% for chlorophylls (per weight of biomass). Moreover, it is shown that aqueous solutions of ILs better stabilise betalains than the gold standard solvent used for the extraction method. Among the studied systems, the ABS comprising the IL N-ethyl-N-methyl-N,N-bis(2-hydroxyethyl) bromide ([N21(2OH)(2OH)]Br) presented the best separation performance, with an extraction efficiency of 92% and 95% for chlorophylls and betalains, respectively, for opposite phases. The pigments were removed from the respective phases using affinity resins, with high recoveries: 96% for betalains and 98% for chlorophylls, further allowing the IL reuse. Finally, the cyto- and ecotoxicities of the quaternary ammonium-based ILs were determined. The obtained results disclosed low to negligible toxicity in the thousands of mg L−1 range, with [N21(2OH)(2OH)]Br being harmless from an ecotoxicological point of view. Overall, it is shown here that the developed process is an innovative approach for the one-step extraction and selective separation of pigments contributing to the valorisation of waste biomass.publishersversionpublishe

Interwoven migration narratives: identity and social representations in the Lusophone world

First published online: 17 Oct 2016This article provides an exploratory analysis of the life narratives of migrants in the Portuguese-speaking world. By interweaving the life experiences of eight participants in three thematic clusters – ‘shared past’, language and sense of community – we propose a critique of the deep-seated idea of the Lusophone space as a community constructed by the harmonious conviviality of different countries and people. Drawing on contributions from cultural studies, social psychology, anthropology and sociology, we first aim to give voice to the human subjects who embark on migrations and then to understand how the engendered process of identity construction is framed by their social world, simultaneously reframing it. Thus, we aim at shedding light on the ways in which aspects of the political discourses on Lusophony are used (and are instrumental) to the migrants’ identity narrative (re)construction.This work was supported by Fundacao para a Ciencia e a Tecnologia: [Grant Number PTDC/CCI-COM/105100/2008]

Association between serum lactate levels and mortality in patients with cardiogenic shock receiving mechanical circulatory support : a multicenter retrospective cohort study

Background: To evaluate the prognostic value of peak serum lactate and lactate clearance at several time points in cardiogenic shock treated with temporary mechanical circulatory support (MCS) using veno-arterial extracorporeal membrane oxygenation (VA-ECMO) or Impella CP®. Methods: Serum lactate and clearance were measured before MCS and at 1 h, 6 h, 12 h, and 24 h post-MCS in 43 patients at four tertiary-care centers in Southern Brazil. Prognostic value was assessed by univariable and multivariable analysis and receiver operating characteristic (ROC) curves for 30-day mortality. Results: VA-ECMO was the most common MCS modality (58%). Serum lactate levels at all time points and lactate clearance after 6 h were associated with mortality on unadjusted and adjusted analyses. Lactate levels were higher in non-survivors at 6 h, 12 h, and 24 h after MCS. Serum lactate >1.55 mmol/L at 24 h was the best single prognostic marker of 30-day mortality [area under the ROC curve=0.81 (0.67–0.94); positive predictive value=86%). Failure to improve serum lactate after 24 h was associated with 100% mortality. Conclusions: Serum lactate was an important prognostic biomarker in cardiogenic shock treated with temporary MCS. Serum lactate and lactate clearance at 24 h were the strongest independent predictors of short-term survival