Stability results for 2D Navier-Stokes equations with unbounded delay

Some results related to 2D Navier-Stokes equations when the external force contains hereditary characteristics involving unbounded delays are analyzed. First, the existence and uniqueness of solutions is proved by Galerkin approximations and the energy method. The existence of stationary solution is then established by means of the Lax-Milgram theorem and the Schauder fixed point theorem. The local stability analysis of stationary solutions is studied by several different methods: the classical Lyapunov function method, the Razumikhin-Lyapunov technique and by constructing appropriate Lyapunov functionals. Finally, we also verify the polynomial stability of the stationary solution in a particular case of unbounded variable delay. Exponential stability in this infinite delay setting remains as an open problem.Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo RegionalJunta de AndalucíaNational Science Foundation of ChinaScience and Technology Commission of Shanghai MunicipalityShanghai Leading Academic Discipline Projec

Martí y la lírica de la modernidad de la angustia de la influencia a la ética de la ruptura.

Sin resume

Time-dependent attractors for non-autonomous nonlocal reaction-diffusion equations

In this paper, the existence and uniqueness of weak and strong solutions for a non-autonomous nonlocal reaction-diffusion equation is proved. Next, the existence of minimal pullback attractors in the L2 -norm in the frameworks of universes of fixed bounded sets and those given by a tempered growth condition, and some relationships between them are established. Finally, we prove the existence of minimal pullback attractors in the H1-norm and study relationships among these new families and those given previously in the L2 - context. The results are also new in the autonomous framework in order to ensure the existence of global compact attractors, as a particular case.Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo RegionalJunta de Andalucí

Robustness of time-dependent attractors in H1-norm for nonlocal problems

In this paper, the existence of regular pullback attractors as well as their upper semicontinuous behaviour in H1-norm are analysed for a parameterized family of non-autonomous nonlocal reaction-diffusion equations without uniqueness, improving previous results [Nonlinear Dyn. 84 (2016), 35–50].Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo RegionalJunta de Andalucí

Thermal and electrohydrodynamic plumes: a compartive study

This paper deals with self similar thermal and electrohydrodynamic (EHD) plumes. The former arises from hot lines or points, whereas the latter arises when sharp metallic contours submerged in non conducting liquids support high electrostatic potential, resulting in charge injection. Although the motive force is buoyancy in one case and Coulomb force in the other, it is shown that the solution for EHD plumes is the same as for thermal plumes in the limit of large Prandtl numbers. We present the analysis of axisymmetric plumes for large values of Prandtl number, and this analysis is subsequently applied to EHD plumes. The validity of the approximations for EHD plumes is discussed in the light of experimental data.Ministerio de ciencia y tecnología PB93-118

La visión conflictiva de la sociedad cubana: Tema y estructura de Cecilia Valdés.

Sin resume

Gestão sustentável e segura de fluxos de passageiros no corredor suburbano Aveiro – Porto

In 2019 the transport sector was responsible for 25.8% of EU-27 greenhouse gas (GHG) emissions. While urban transport has received much attention from policy makers and the scientific community, intercity passenger transport has not received as much attention. In 2019, intercity trips accounted for 65% of the total kilometres travelled in Portugal and contributed to more than 55% of carbon dioxide (CO₂) and nitrogen oxide (NOᵪ) emissions. The COVID-19 pandemic has negatively affected mobility due to people’s fear of infection and government restrictions and recommendations. The main objectives of this dissertation are to model the supply and demand of passenger transport in the suburban corridor between Aveiro and Porto, determination of the COVID-19 pandemic impact on travelling behaviour and mode choice for different socio-economic levels and travel purposes and estimate the emissions and the impact per passenger before and during the pandemic. An online survey was designed to understand travelling behaviour and preferences and how these factors changed towards the pandemic. Transport was modelled recurring to a logit model based on the utilities of each transport mode, which were calculated considering the mode choice, travel time, and travel cost of each alternative. The output of the transport modelling was the modal split. The impacts considered were CO₂, NOᵪ, PM₂﮳5, PM₁₀, VOC, NMVOC and CO emissions. The emission values were estimated using the fleet characteristics and average speed as input. Results from the survey show a 70% reduction in travel frequency during the pandemic, with teleworking and online classes being the main reasons for this decrease. Before the pandemic, 65% of trips were made by train and 31% by car. During the pandemic, these shares shifted to 37% and 60%, respectively, and 27% of participants stopped travelling. The logit model was revealed to be a helpful tool for transport modelling. However, the network characteristics, availability of transport modes and sample size limited the statistical significance and accuracy of the model. Air pollution costs decreased by about 53% during the pandemic, primarily due to a decrease in travel frequency.Em 2019, o sector dos transportes foi responsável por 25,8% das emissões de gases com efeito de estufa (GEE) da UE-27. Embora os transportes urbanos tenham recebido muita atenção dos decisores políticos e da comunidade científica, o transporte interurbano de passageiros não tem recebido tanta atenção. Em 2019, as viagens em estradas rurais e autoestradas representaram 65% do total de quilómetros percorridos em Portugal e contribuíram para mais de 55% das emissões de dióxido de carbono (CO₂) e óxidos de azoto (NOᵪ). A pandemia COVID-19 afetou negativamente a mobilidade devido ao medo de infeção das pessoas e restrições e recomendações governamentais. Os principais objetivos desta dissertação são modelar a oferta e a procura de transporte de passageiros no corredor suburbano entre Aveiro e Porto, a determinação do impacto da pandemia COVID-19 nos hábitos de deslocações e escolha de modo para diferentes níveis socioeconómicos e propósitos de deslocação e estimar as emissões e o impacto por passageiro por passageiro antes e durante a pandemia. Um inquérito online foi concebido para compreender os hábitos e preferências de transporte, e como estes fatores mudaram durante a pandemia. O transporte foi modelado recorrendo a um modelo logit baseado nas utilidades de cada modo de transporte, que foram calculados considerando a escolha do modo, o tempo de viagem e o custo de viagem de cada alternativa. O produto desta modelação de transportes foi a distribuição modal. Os impactos considerados foram as emissões de CO₂, NOᵪ, PM₂﮳5, PM₁₀, VOC, NMVOC e CO. As emissões foram estimadas utilizando como dados as características da frota e a velocidade média. Os resultados do inquérito mostram uma redução de 70% na frequência de deslocações durante a pandemia, sendo o teletrabalho e as aulas online as principais razões desta diminuição. Antes da pandemia, 65% das viagens eram feitas de comboio e 31% de carro. Durante a pandemia, estas percentagens mudaram para 37% e 60%, respetivamente, e 27% dos participantes deixaram de viajar. O modelo logit foi revelou-se uma ferramenta útil para a modelação de transporte. No entanto, as características da rede, a disponibilidade de modos de transporte e o tamanho da amostra limitaram a significância estatística e a precisão do modelo. Os custos da poluição atmosférica diminuíram cerca de 53% durante a pandemia, principalmente devido à diminuição da frequência de viagem.Mestrado em Engenharia Mecânic

Equity research – BMW AG

Mestrado em FinançasEste projeto aborda uma extensa e detalhada avaliação da BMW AG, obedecendo à estrutura de Trabalho Final de Mestrado, neste caso projeto, do Mestrado de Finanças do ISEG. O relatório foi escrito tendo conta as recomendações do Instituto CFA.This project represents a detailed evaluation of BMW AG, guided by the structure of ISEG's Master in Finance final work project. This equity report was written according to CFA Institute's recommendations. The reason behind choosing BMW AG lies on my personnel interest on auto industry and the curiosity to analyze how the reality of it is changing nowadays. This report was written in accordance with the public information available on August 30, 2018, and any information or event subsequent to this specific date will not be reflected on this valuation.info:eu-repo/semantics/publishedVersio

BARRACA: a shelter for cultural heritage in Algarve: business plan

This project addresses the need to protect the cultural heritage in places with less global influence and how to generate revenue from it, exploring the current trends on cultural and creative tourism. To do so it is used the example of Algarve, a destination often linked with sun and beach tourism, despite havinbg plenty and various other resources capable of providing its visitors a complete and memorable experience. BARRACA is a project that proposes a simple and laidback space where the local youth and visitors can interact and be exposed to Algarve’s cultural heritage while fulfilling the standards demanded these days for an establishment directed at this target audience. For that to happen, the idea is to organize exhibitions and events using the region's landscape, traditional economic activities, gastronomy, as well as products and works from local artists, craftsmen and producers, and many other activities always using the local cultural heritage as background. This document presents the entire business plan necessary to put this project into practice, from the theoretical base behind the whole concept to the financial analysis on it.Este projeto explora a importância de proteger a herança cultural local em destinos de menor expressão a nível global e como lucrar com esta necessidade, explorando as atuais tendências no turismo criativo e cultural. Para tal, é usado o exemplo do Algarve, destino muitas vezes associado ao turismo de sol e praia, mas que possui muitos outros e variados recursos capazes de proporcionar aos visitantes uma experiência completa e memorável. A BARRACA propõe um espaço, simples e descontraído, onde os jovens locais e visitantes possam interagir e estar expostos à herança cultural local enquanto vêm cumpridos os padrões que hoje em dia se pedem a um estabelecimento direccionado a este público. Para que tal aconteça, serão organizadas exposições e eventos usando a paisagem, as atividades económicas tradicionais da região, gastronomia e produtos, obras e trabalhos de artistas, artesãos e produtores locais e muitas outras atividades usando diversos elementos da cultura Algarvia como pano de fundo. Neste documento é então apresentado todo o plano de negócios necessário para que este projeto possa ser posto em prática, começando pela base teórica e conceito e terminando na análise financeira do mesmo