Catalytic flow with a coupled Finite Difference -- Lattice Boltzmann scheme

Many catalyst devices employ flow through porous structures, which leads to a complex macroscopic mass and heat transport. To unravel the detailed dynamics of the reactive gas flow, we present an all-encompassing model, consisting of thermal lattice Boltzmann model by Kang et al., used to solve the heat and mass transport in the gas domain, coupled to a finite differences solver for the heat equation in the solid via thermal reactive boundary conditions for a consistent treatment of the reaction enthalpy. The chemical surface reactions are incorporated in a flexible fashion through flux boundary conditions at the gas-solid interface. We scrutinize the thermal FD-LBM by benchmarking the macroscopic transport in the gas domain as well as conservation of the enthalpy across the solid-gas interface. We exemplify the applicability of our model by simulating the reactive gas flow through a microporous material catalysing the so-called water-gas-shift reaction

White-Water III Rafting Guide at Faszinatour

Relatório de estágio apresentado para obtenção do grau de Mestre em Desporto Natureza, na Escola Superior de Desporto e Lazer do Instituto Politécnico de Viana do CasteloNature and adventure sports has seen a great increase in the past years, not only as a personal practice but also in the tourism sector. Among these sports it is possible to find two which are further characterized in the present work: rafting and canyoning. A common point between the two is the role played by white-water, even if the interaction with the element differs. A highly qualified company in Haiming, Tirol, provided the set for a 5-month internship as a white-water rafting guide. It allowed an up-close field view on how these sports are applied in the tourism sector. A study was preformed among canyoning guides in Tirol, allowing the characterization of the population in question, regarding physical activity levels, nutrition and certification. The internship was essential to apply knowledge previously acquired during the master’s lessons and to understand how it is applied in a “real life” setting.O desporto de natureza e aventura tem visto a sua prática aumentar nos últimos anos, não apenas como prática pessoal, mas também no setor de turismo. Entre estes desportos é possível encontrar dois que serão caracterizados no presente trabalho: o rafting e o canyoning. Um ponto em comum entre os dois é o papel desempenhado pelas águas bravas. Aqui difere a interação entre o desporto e o elemento. Uma das empresas mais bem classificadas na zona do Tirol, em Haiming, permitiu a realização de um estágio de 5 meses como guia de rafting. Assim, foi possível ter uma visão de perto de como estes desportos são aplicados no setor de turismo. Foi realizado um estudo com guias de canyoning do Tirol, permitindo a caracterização da população em questão, tanto quanto aos seus níveis de atividade física, à nutrição e à certificação obtida. O estágio foi essencial para aplicar o conhecimento adquirido anteriormente no mestrado, e entender como este deverá ser aplicado num contexto de “vida real”

Anizotropna termoelektrična svojstva (TaSe4)2I

Measurements of temperature dependence of the electrical conductivity and thermopower along the chain and perpendicular-to-chain directions of the inorganic conductor (TaSe4)2I, exhibiting the charge density wave transition, are reported. The electrical conductivity and thermopower along the chain and perpendicular-to-the chain direction were measured for the first time on the same sample. Measurements in both directions enable obtaining an information on the predominant carriers along different crystallographic directions which may be different due to different energy gaps.Načinili smo mjerenja temperaturne ovisnosti električne vodljivosti i termostruje uzduž i poprečno na smjer lanaca neorganskog vodiča (TaSe4)2I koji pokazuje prijelaz na valove nabojne gustoće. Ovo su prva mjerenja električne vodljivosti i termostruje uzduž i poprečno na smjer lanaca na istom uzorku. Mjerenja u oba smjera omogućuju dobivanje podataka o nositeljima naboja duž dviju kristalografskih osi koji mogu biti uzrokovani različitim energijskim procjepima

Anizotropna termoelektrična svojstva (TaSe4)2I

Measurements of temperature dependence of the electrical conductivity and thermopower along the chain and perpendicular-to-chain directions of the inorganic conductor (TaSe4)2I, exhibiting the charge density wave transition, are reported. The electrical conductivity and thermopower along the chain and perpendicular-to-the chain direction were measured for the first time on the same sample. Measurements in both directions enable obtaining an information on the predominant carriers along different crystallographic directions which may be different due to different energy gaps.Načinili smo mjerenja temperaturne ovisnosti električne vodljivosti i termostruje uzduž i poprečno na smjer lanaca neorganskog vodiča (TaSe4)2I koji pokazuje prijelaz na valove nabojne gustoće. Ovo su prva mjerenja električne vodljivosti i termostruje uzduž i poprečno na smjer lanaca na istom uzorku. Mjerenja u oba smjera omogućuju dobivanje podataka o nositeljima naboja duž dviju kristalografskih osi koji mogu biti uzrokovani različitim energijskim procjepima

Two-dimensional conical dispersion in ZrTe5 evidenced by optical spectroscopy

Zirconium pentatelluride was recently reported to be a 3D Dirac semimetal, with a single conical band, located at the center of the Brillouin zone. The cone's lack of protection by the lattice symmetry immediately sparked vast discussions about the size and topological/trivial nature of a possible gap opening. Here we report on a combined optical and transport study of ZrTe5, which reveals an alternative view of electronic bands in this material. We conclude that the dispersion is approximately linear only in the a-c plane, while remaining relatively flat and parabolic in the third direction (along the b axis). Therefore, the electronic states in ZrTe5 cannot be described using the model of 3D Dirac massless electrons, even when staying at energies well above the band gap 6 meV found in our experiments at low temperatures.Comment: Physical Review Letters 122, 217402 (2019). Corrected acknowledgment

Design as a positive stimulus in a Brazilian hospital environment

The new coronavirus pandemic has put healthcare professionals, patients and family members under pressure and stress, causing mental health issues especially in the healthcare community. Studies show that a positive environment plays an important role in the well-being of individuals, impacting physical and psychological security of people. This article presents a project developed for the Hospital de Clínicas de Porto Alegre, that through graphic interventions softened the effects of combating COVID-19 for the healthcare staff and patients throughout the pandemic. The project is detailed and the discussion presents the main points considered in the process of decision making. Results show how design can play an important role in helping, not only the Covid-2019 pandemic, but also in making hospitals more hospitable places

The mechanisms used by enteropathogenic Escherichia coli to control filopodia dynamics

Enteropathogenic Escherichia coli (EPEC) subverts actin dynamics in eukaryotic cells by injecting effector proteins via a type III secretion system. First, WxxxE effector Map triggers transient formation of filopodia. Then, following recovery from the filopodial signals, EPEC triggers robust actin polymerization via a signalling complex comprising Tir and the adaptor proteins Nck. In this paper we show that Map triggers filopodia formation by activating Cdc42; expression of dominant-negative Cdc42 or knock-down of Cdc42 by siRNA impaired filopodia formation. In addition, Map binds PDZ1 of NHERF1. We show that Map–NHERF1 interaction is needed for filopodia stabilization in a process involving ezrin and the RhoA/ROCK cascade; expression of dominant-negative ezrin and RhoA or siRNA knock-down of RhoA lead to rapid elimination of filopodia. Moreover, we show that formation of the Tir-Nck signalling complex leads to filopodia withdrawal. Recovery from the filopodial signals requires phosphorylation of a Tir tyrosine (Y474) residue and actin polymerization pathway as both infection of cells with EPEC expressing TirY474S or infection of Nck knockout cells with wild-type EPEC resulted in persistence of filopodia. These results show that EPEC effectors modulate actin dynamics by temporal subverting the Rho GTPases and other actin polymerization pathways for the benefit of the adherent pathogen