On the Optimal Control of a Class of Non-Newtonian Fluids

We consider optimal control problems of systems governed by stationary, incompressible generalized Navier-Stokes equations with shear dependent viscosity in a two-dimensional or three-dimensional domain. We study a general class of viscosity functions including shear-thinning and shear-thickening behavior. We prove an existence result for such class of optimal control problems

Existence of optimal boundary control for the Navier-Stokes equations with mixed boundary conditions

Variational approaches have been used successfully as a strategy to take advantage from real data measurements. In several applications, this approach gives a means to increase the accuracy of numerical simulations. In the particular case of fluid dynamics, it leads to optimal control problems with non standard cost functionals which, when constraint to the Navier-Stokes equations, require a non-standard theoretical frame to ensure the existence of solution. In this work, we prove the existence of solution for a class of such type of optimal control problems. Before doing that, we ensure the existence and uniqueness of solution for the 3D stationary Navier-Stokes equations, with mixed-boundary conditions, a particular type of boundary conditions very common in applications to biomedical problems

Improving Blood Flow Simulations Using Known Data

preprintNumerical simulations applied to blood flow together with the imaging processing advances are a powerful tool in the prevention and treatment of some diseases. The inclusion of real data in the numerical blood flow simulations allowsthe achievementofmore realistic and accurate results. In the literature, these techniques areknown asData Assimilation (DA)techniques.In this work we solve a variational DA problem to numerically reconstruct the blood flow circulation inside a real artery,deformed by a saccular aneurysm obtained from medical images and then importedto COMSOL Multiphysics®.We propose a weighted cost function that accurately recovers both the velocity and the wall shear stress profiles. The robustness of such cost function is tested with respect to different velocity inlet profilesinfo:eu-repo/semantics/submittedVersio

Aplicação de problemas de controlo a uma estenose idealizada

preprintNeste trabalho apresentamos, de forma sucinta, simulações numé-ricas de fluidos, de problemas do tipo Assimilação de Dados numa aborda-gem variacional. Apresentamos resultados aplicados à Hemodinâmica consi-derando uma geometria tridimensional na forma de uma estenose idealizadae recuperamos o perfil da velocidade do sangue nesta geometria.In this work, numerical simulations of fluids of Data Assimilationproblems in a variational approach are briefly presented. We obtain someresults applied to Hemodynamics in a 3D idealized stenosis and we recoverthe blood velocity profile in this geometry.info:eu-repo/semantics/submittedVersio

Optimal Control in Blood Flow Simulations

preprintBlood flow simulations can be improved by integrating known data into thenumerical simulations. Data assimilation techniques based on a variationalapproach play an important role in this issue. We propose a nonlinear optimalcontrol problem to reconstruct the blood flow profile from partial observationsof known data in idealized 2D stenosed vessels. The wall shear stress isincluded in the cost function, which is considered as an important indicatorfor medical purposes. To simplify we assume blood flow as an homogeneousfluid with non-Newtonian behavior. Using a Discretize then Optimize (DO)approach, we solve the nonlinear optimal control problem and we proposea weighted cost function that accurately recovers both the velocity and thewall shear stress profiles. The robustness of such cost function is tested withrespect to different velocity profiles and degrees of stenosis. The filteringeffect of the method is also confirmed. We conclude that this approach canbe successfully used in the 2D caseinfo:eu-repo/semantics/submittedVersio

A velocity tracking approach for the Data Assimilation problem in blood flow simulations

preprintSeveral advances have been made in Data Assimilation techniques applied to blood flow modeling. Typically,idealized boundary conditions, only verified in straight parts of the vessel, are assumed. We present ageneral approach, based on a Dirichlet boundary control problem, that may potentially be used in differentparts of the arterial system. The relevance of this method appears when computational reconstructions ofthe 3D domains, prone to be considered sufficiently extended, are either not possible, or desirable, due tocomputational costs. Based on taking a fully unknown velocity profile as the control, the approach uses adiscretize then optimize methodology to solve the control problem numerically. The methodology is appliedto a realistic 3D geometry representing a brain aneurysm. The results show that this DA approach may bepreferable to a pressure control strategy, and that it can significantly improve the accuracy associated totypical solutions obtained using idealized velocity profilesinfo:eu-repo/semantics/submittedVersio

Electron-neutral collision cross sections for H2O: I. Complete and consistent set

This work proposes a complete and consistent set of cross sections (CSs) for electron collisions with water molecules to be published in the IST-Lisbon database on LXCat. The set is validated from the comparison between experimental and computed electron swarm parameters. The former are collected from literature while the latter are calculated using a space-homogeneous two-term Boltzmann solver, assuming isotropic scattering in inelastic collisions. Rotational CSs, based on the Born approximation, are optimised by means of the electron swarm analysis technique. Superelastic rotational and vibrational collisions are accounted for in the calculations and found to be particularly important for low-energy electrons interacting with water molecules. The set can be used with codes assuming space-homogeneous conditions, in particular common two-term Boltzmann solvers, ensuring a good agreement with experiments. Therefore, it constitutes an important tool for fast calculations and modelling of complex plasma chemistries

A TRAJETÓRIA DA EDUCAÇÃO DE JOVENS E ADULTOS EM GUARULHOS: MARCAS E LEGADOS

Este ensaio apresenta um histórico sobre a Educação de Jovens e Adultos da cidade de Guarulhos – SP, enfocando os principais aspectos do trajeto desta modalidade de ensino tendo o município como realizador desta política pública. O estudo parte de um levantamento bibliográfico, de documentos oficiais para realizar uma contextualização histórica, indicando alguns apontamentos e legados dessas políticas para a cidade de Guarulhos. Utilizou como principais referências para análise da história das políticas públicas para o ensino de Jovens e Adultos os seguintes autores: Miguel Arroyo, Maria Clara Di Pierro, Vanilda Paiva, Sérgio Haddad e Celso Beisiegel. Como conclusão, indicamos que a trajetória da educação de jovens e adultos na cidade de Guarulhos, tendo raízes em uma educação popular, legou características singulares nas formas de fazer escola, havendo um protagonismo relevante dos educadores nesta prática, além do crescimento do número de pessoas atendidas

Os Caminhos De Uma Experiência Na Educação De Jovens E Adultos De Guarulhos: O Projeto Autonomia Do Saber E A Formação De Professores (2014-2017)

This Research Sought To Understand The Trajectory Of Teacher Formation In The Construction Of The Projeto Autonomia Do Saber (Project Autonomy Of Knowledge), In The Youth And Adults Education In The City Of Guarulhos, São Paulo, Between The Years 2014 And 2017. This Project Started In A School In The Periphery Area Of Guarulhos And Later It Was Institutionalized By The Education Secretary (Se) Of The City. We Analysed The Process Of Constitution Of The Pas, Focused On In The Role Of The Continuing Education Programme For Those Teachers Who Were Acting In These Schools, Considering The Formative Spaces, The Meetings, And Activities Hours, As Well As The Forms Of Organization Of The Curriculum Of The Schools. This Last, Has Proved As Essential Aspects Of The Formation Course. This Research Was Based On A Qualitative Method, Which Allowed Us A Better Understanding Of The Context Analysed. In This Work, We Described The Pas In The Three Schools That Were Part Of The Project Between 2014 And 2017, Opting For Semi-Esta Pesquisa Buscou Compreender O Percurso Da Formação Dos Professores Na Construção Do Projeto Autonomia Do Saber (Pas), Na Educação De Jovens E Adultos Da Cidade De Guarulhos " Sp, Entre Os Anos De 2014 E 2017. Analisamos O Processo De Constituição Do Pas, Projeto Surgido Em Uma Escola Da Periferia De Guarulhos E Depois Institucionalizado Pela Secretaria De Educação (Se) Da Cidade, Enfocando Principalmente O Papel Da Formação Continuada Do Docente Para Atuação Nessas Escolas, Considerando Os Espaços Formativos, Tais Como Os Encontros E As Horas Atividades, Assim Como As Formas De Organização Do Currículo Das Escolas, Que Se Revelaram Importantes Para O Percurso Formativo. Ancoramos O Estudo Na Pesquisa Qualitativa, O Que Implicou Em Um Aprofundamento No Contexto Em Que O Fenômeno É Observado. Neste Sentido, Fizemos Uma Descrição Do Desenvolvimento Do Pas Nas Escolas, Optando Por Entrevistas Semiestruturadas E Uso De Fontes Documentais. Os Sujeitos Da Pesquisa Foram Seis Professores, Sendo Escolhidos Dois DDados abertos - Sucupira - Teses e dissertações (2018