A semi-structured approach to curvilinear mesh generation around streamlined bodies

We present an approach for robust high-order mesh generation specially tailored to streamlined bodies. The method is based on a semi-sructured approach which combines the high quality of structured meshes in the near-field with the flexibility of unstructured meshes in the far-field. We utilise medial axis technology to robustly partition the near-field into blocks which can be meshed coarsely with a linear swept mesher. A high-order mesh of the near-field is then generated and split using an isoparametric approach which allows us to obtain highly stretched elements aligned with the flow field. Special treatment of the partition is performed on the wing root juntion and the trailing edge --- into the wake --- to obtain an H-type mesh configuration with anisotropic hexahedra ideal for the strong shear of high Reynolds number simulations. We then proceed to discretise the far-field using traditional robust tetrahedral meshing tools. This workflow is made possible by two sets of tools: CADfix, focused on CAD system, the block partitioning of the near-field and the generation of a linear mesh; and NekMesh, focused on the curving of the high-order mesh and the generation of highly-stretched boundary layer elements. We demonstrate this approach on a NACA0012 wing attached to a wall and show that a gap between the wake partition and the wall can be inserted to remove the dependency of the partitioning procedure on the local geometry.Comment: Preprint accepted to the 2019 AIAA Aerospace Sciences Meetin

Contributo para o estudo psicométrico da versão portuguesa do Cuestionario de Satisfacción Laboral S20/23

Job satisfaction is understood through its dual role on organization productivity and employees achievement (Smith, 1998). The use of instruments to measure it in Portugal, has been the subject of several studies, such as the adaptation of the Cuestionario de Satisfacción Laboral S20/23 (Meliá & Peiró, 1989) to Portuguese population carried out by Pocinho and García (2008). This study is a further contribution to the study of the psychometric qualities of this instrument. The results on a sample of 136 Portuguese employees show that the questionnaire presents the adequate requirements of internal consistency (.95), test-retest reliability, and convergent validity (correlation of .84 with the Minnesota Satisfaction Questionnaire - Short Form of Weiss, Dawis, England, & Lofquist, 1967). The factorial structure is consistent with the original version. Some issues to be explored in further investigations are also discussed, taking into account the limitations inherent to this study.La satisfaction au travail est comprise dans le double rôle de la productivité de l’organisation et de la réalisation des travailleurs (Smith, 1998). L’utilisation d’ instruments pour l’évaluer dans un contexte national, a fait l’objet de certaines études, en soulignant l’adaptation à population portugaise du Cuestionario de Satisfacción Laboral S20/23 (Meliá & Peiró, 1989) réalisée par Pocinho et García (2008). Cette étude est une contribution supplémentaire à l’étude des qualités psychométriques de cet instrument. Les résultats d’un groupe de 136 travailleurs portugais montrent que le questionnaire représente les exigences appropriés au niveau de la cohérence interne (.95), stabilité coefficients et la validité convergente (corrélation de .84 avec le Minnesota Satisfaction Questionnaire – Short Form de Weiss, Dawis, England, & Lofquist, 1967). La structure factorielle est compatible avec la version originale. Certains sujets sont encore en discussion pour être explorer dans de futures recherches, tout en tenant compte des limites inhérentes à cette étude.A satisfação com o trabalho é entendida como preponderante no binómio da produtividade da organização e da realização dos trabalhadores (Silva, 1998). A utilização de instrumentos que permitam avaliá-la em contexto nacional, tem vindo a ser alvo de alguns estudos, salientando-se a adaptação à população portuguesa do Cuestionario de Satisfacción Laboral S20/23 (Meliá & Peiró, 1989a) efectuada por Pocinho e Garcia (2008). Este trabalho constitui-se como mais um contributo para o estudo das qualidades psicométricas deste instrumento. Os resultados obtidos numa amostra de 136 trabalhadores portugueses, revelam que o questionário apresenta qualidades psicométricas satisfatórias ao nível da consistência interna (.95), da estabilidade temporal e da validade convergente (correlação de .84 com o Minnesota Satisfaction Questionnaire – Short Form de Weiss, Dawis, England, & Lofquist, 1967). A estrutura factorial é consistente com a da versão original. Discutem-se ainda algumas questões a ser exploradas em próximas investigações, tendo em conta as limitações inerentes a este estudo

Persistence of Zika virus in semen 93 days after the onset of symptoms

INTRODUCTION: Zika virus is mainly transmitted through the bites of infected Aedes mosquitoes, although mother-to-child and sexual transmission have also been described. The presence of Zika virus in semen after infection seems to be not uncommon, but the duration of viral persistence has not been well-determined. METHODS: Molecular, serological and cell culture methods were used for the diagnosis and follow up of a case of Zika virus infection imported from Venezuela. Serial samples of serum, urine and semen were analyzed to investigate the persistence of the Zika virus. RESULTS: Zika virus was detected in semen samples up to 93 days after the onset of symptoms. CONCLUSIONS: Our results confirm the persistence of Zika virus in semen samples for long periods after infection

Energy and territory. Criteria for a new balance in Catalonia

La humanitat està a les portes d’una doble crisi energètica i ambiental a causa de la finitud dels combustibles fòssils i de les repercussions del seu ús sobre el clima. Durant els més de 200 anys des de la Revolució Industrial, i gràcies a la seva energia abundant i disponible, els combustibles fòssils han anat adquirint un paper cada cop més decisiu (avui dia el 80 % del sistema energètic humà), alhora que han permès un gran desenvolupament tècnic, econòmic i també poblacional. En la transició vers les energies renovables, cal de nou destinar importants superfícies de territori per captar energia, requeriment que no és necessari en els combustibles fòssils, ja que la captació es va produir fa centenars de milions d’anys; a més, s’han de cobrir necessitats energètiques molt superiors a les de l’època preindustrial, quan les poblacions eren molt menors i les activitats molt menys necessitades d’energia. A Catalunya, on hi ha una elevada població distribuïda de forma molt desequilibrada, una economia desenvolupada i una orografia accidentada, la cobertura d’aquests nous requeriments territorials resulta complexa. L’objectiu d’aquest article és exposar criteris i establir prioritats sobre les necessitats territorials de l’energia i el seu repartiment tot respectant els altres usos i funcions, especialment les ecosistèmiques. Aquests criteris i prioritats emmarquen el projecte «Transició energètica i territori» (TeiT), que el Col·lectiu per a un Nou Model Energètic i Social Sostenible (CMES) està duent a terme en els darrers anys en col·laboració amb centres d’estudis locals i altres organitzacions.Humanity is at the gates of a double energy and environmental crisis due to the finiteness of fossil fuels and the repercussions of their use on the climate. For more than 200 years since the industrial revolution, fossil fuels, thanks to the abundance and availability of the energy which they provide, have been acquiring an increasingly decisive role (forming 80% of the human energy system today). Likewise, they have allowed great technical, economic and population development. In the transition towards renewable energies, though, it is necessary to allocate again large areas of land to the capture of energy, something which is not necessary with fossil fuels since the capture took place hundreds of millions of years ago. Moreover, it is necessary to cover energy needs that are much larger than those of pre-industrial times, when populations were much smaller and activities required much less energy. In Catalonia, where there is a large population distributed in a very unbalanced way, together with a developed economy and a rugged terrain, the coverage of these new territorial requirements is complex. This article presents criteria and establishes priorities on the territorial needs of energy and on its distribution, which should respect other uses and functions, especially ecosystemic ones. These criteria and priorities form the framework of the «Energy transition and territory» project that the CMES collective has been carrying out in recent years in collaboration with local study centres and other organizations

Three-dimensional reconstruction of autologous vein bypass graft distal anastomoses imaged with magnetic resonance: clinical and research applications

AbstractHigh-resolution magnetic resonance imaging was combined with computational modeling to create focused three-dimensional reconstructions of the distal anastomotic region of autologous vein peripheral bypass grafts in a preliminary series of patients. Readily viewed on a personal computer or printed as hard copies, a detailed appreciation of in vivo postoperative features of the anastomosis is possible. These reconstructions are suitable for analysis of geometric features, including vessel caliber, tortuosity, anastomotic angles, and planarity. Some potential clinical and research applications of this technique are discussed

Three-dimensional reconstruction of autologous vein bypass graft distal anastomoses imaged with magnetic resonance: clinical and research applications

AbstractHigh-resolution magnetic resonance imaging was combined with computational modeling to create focused three-dimensional reconstructions of the distal anastomotic region of autologous vein peripheral bypass grafts in a preliminary series of patients. Readily viewed on a personal computer or printed as hard copies, a detailed appreciation of in vivo postoperative features of the anastomosis is possible. These reconstructions are suitable for analysis of geometric features, including vessel caliber, tortuosity, anastomotic angles, and planarity. Some potential clinical and research applications of this technique are discussed

Prevalence and prognostic implications of myocardial injury across different waves of COVID-19

IntroductionThe prognostic ability of myocardial injury across different waves of the COVID-19 pandemic is not well established. The purpose of this study was to evaluate the prevalence and prognostic implications of myocardial injury in the first and sixth wave of COVID-19.MethodsWe conducted a retrospective observational study that included patients admitted to the emergency department with COVID-19 with data on concentrations of cardiac troponin during the first and sixth wave. We compared the prevalence of myocardial injury and its predictive capacity for 30-day all-cause death in both waves.Results and discussionA total of 346 patients were included (1st wave 199 and 6th wave 147 patients). The prevalence of myocardial injury was 21% with non-significant differences between waves. Myocardial injury was associated, in both waves, with a higher prevalence of comorbidities and with an increased risk of 30-day all-cause death [1st wave HR: 3.73 (1.84–7.55); p < 0.001 and 6th wave HR: 3.13 (1.23–7.92); p = 0.016], with non-significant differences in predictive capacity between groups after ROC curve analysis [AUC: 1st wave 0.829 (95% CI: 0.764–0.895) and 6th wave 0.794 (95% CI: 0.711–0.876)]. As limitations, this is a retrospective study with a relatively small simple size and troponin assay was performed at the discretion of the emergency physician so selection bias could be present. In conclusion, the prevalence of myocardial injury and its prognostic capacity was similar in both waves despite vaccination programs. Myocardial injury predicts short-term mortality in all COVID-19 patients, so they should be treated intensively