Alexandre Tavares - Academia.edu (original) (raw)

Papers by Alexandre Tavares

Research paper thumbnail of Low drop-out voltage regulator with dynamic voltage control

Research paper thumbnail of Experimental Study on the Performance of Electrical Submersible Pump Operating with Ultraviscous Oil

SPE Journal, 2022

Summary The production of high-viscosity crude oil can be challenging owing to portfolio limitati... more Summary The production of high-viscosity crude oil can be challenging owing to portfolio limitations and lack of energy efficiency in artificial lift systems, especially for ultraheavy oil in deepwater fields. In recent decades, the electrical submersible pump (ESP) has improved significantly, and this technology is commonly applied in this context. However, few studies in the literature discuss the behavior of these pumps with nonconventional oils such as ultraviscous ones. This work investigates the performance of a 10-stage ESP, when it operates with a single-phase flow of ultraviscous oil. For this purpose, an experimental circuit was set up; the pump was submitted to tests in which the viscosity of the fluid varied from 8 to 4,170 cp and rotational speed between 1,200 and 3,500 rev/min. A subsequent analysis compared the pump’s experimental viscous performance and the theoretical performance calculated by the methods available in the literature. This analysis highlighted the la...

Research paper thumbnail of Experimental Study and Modeling of Heating Effect in Electrical Submersible Pump Operating With Ultra-Heavy Oil

Volume 8: Polar and Arctic Sciences and Technology; Petroleum Technology, 2018

A notable trend in the realm of oil production in harsh environments is the increasing use of Ele... more A notable trend in the realm of oil production in harsh environments is the increasing use of Electrical Submersible Pump (ESP) systems. ESPs have even been used as an artificial-lift method for extracting high-viscosity oils in deep offshore fields. As a way of reducing workover costs, an ESP system may be installed at the well bottom or on the seabed. A critical factor, however, in deep-water production is the low temperature at the seabed. In fact, these low temperatures constitute the main source for many flow-assurance problems, such as the increase in friction losses due to high viscosity. Oil viscosity impacts pump performance, reducing the head and increasing the shaft power. This study investigates the influence of a temperature increase of ultra-heavy oil on ESP performance and the heating effect through a 10-stage ESP. Using several flow rates, tests are performed at four rotational speeds and with four viscosity levels. At each rotational speed curve, researchers keep co...

Research paper thumbnail of Risco, vulnerabilidade social e cidadania

Revista Crítica de Ciências Sociais, 2011

Research paper thumbnail of Challenges in ESP Operation in Ultra-Deepwater Heavy Oil Atlanta Field

Day 2 Wed, November 11, 2020, 2020

Atlanta is a post-salt oil field located offshore Brazil in the Santos Basin, 185 km southeast of... more Atlanta is a post-salt oil field located offshore Brazil in the Santos Basin, 185 km southeast of Rio de Janeiro. The combination of ultra-deepwater (1,550 m) and heavy and viscous oil (14 °API and 228 cP at reservoir conditions) composes a unique challenging scenario for Electrical Submersible Pump (ESP) application. The paper discusses the performance of the ESP system utilizing field data and software simulations. The in-well ESP is the main production method and mudline ESP boosting is the backup one. Both concepts proved to be effective artificial lift solutions for the harsh flowing conditions. The in-well ESP is installed inside a capsule in a close to horizontal slant section of around 70 m. The mudline ESP boosting is readily available to become the main production method in case the in-well ESP fails. This paper discusses the challenges and solutions that proved to be successful after more than 18 months of continuous production. Software simulations and continuous product...

Research paper thumbnail of Robust Artificial Lift Solution for Ultra-Deepwater Heavy Oil Atlanta Field

Offshore Technology Conference Brasil, 2019

Most of the artificial lift strategies in deepwater environments require sophisticated and robust... more Most of the artificial lift strategies in deepwater environments require sophisticated and robust solutions, aiming to improve the system's run life and reliability. Due to that, oil companies choose only trustable technology and field-proven solutions for artificial lift design. This is the case of Atlanta Field's artificial lift project, with electrical submersible pumps (ESP) installed at more than 1,550 m water depth, to produce heavy oil. For Atlanta Field, the ESP must handle high viscous oil and emulsions at high flow rates to be economically feasible. To achieve this goal, it was deployed one of the most powerful ESP in the world with 1,550 HP induction motor and more than one hundred pump stages into the well. This is the largest ESP in-well successfully installed in Brazil. The artificial lift strategy adopted for Atlanta Field was an in-well ESP as primary method and an artificial lift skid (ALS) installed on the seabed for back-up. When the primary method fails, ...

Research paper thumbnail of The role of media between expert and lay knowledge: A study of Iberian media coverage on climate change

Science of The Total Environment, 2019

• Media is a mediator between expert and lay knowledge. • Media may be crucial in engaging indivi... more • Media is a mediator between expert and lay knowledge. • Media may be crucial in engaging individuals and governments with climate change. • Iberian media's coverage on climate change shows an important journalistic bias. • Iberian media's discourse tend to nonresilient and non-democratic.

Research paper thumbnail of Peri-Urbanization and Rurbanization in Leiria City: the Importance of a Planning Framework

Sustainability, 2018

The objective of this study is to evaluate the spatial and temporal dynamics of land use in the c... more The objective of this study is to evaluate the spatial and temporal dynamics of land use in the city of Leiria, which is located in central Portugal, and its relation to the planning framework. The analysis is based on land-use change recognition in the period 1958–2011, calculation of the stability grade indicator, the losses and gains between classes, and the rate of artificialization. The results show an increase of the artificial areas, namely in continuous and discontinuous urban fabric, contrasting with a continuous decrease of the agricultural land-use classes, giving origin to peri-urbanization and rurbanization processes. We can also observe a large fragmentation of the landscape in the city of Leiria, representing rapid urban expansion that is fundamentally related to the increase of residential and industrial areas, and afterwards, tertiary growth. This study also demonstrated the relation of a land-use and planning framework that works as a driving force for land-use cha...

Research paper thumbnail of O "julgamento" geomorfológico de Coimbra: o testemunho dos depósitos quaternários

Cadernos de Geografia, 1999

Research paper thumbnail of Intervenções recentes e avaliação de impactes ambientais no Baixo Mondego

Cadernos de Geografia, 1999

* 0 presente artigo integra-se num conjunto diversificado de actividades de investigaçao desenvol... more * 0 presente artigo integra-se num conjunto diversificado de actividades de investigaçao desenvolvida por uma equipa interdisciplinar de ge610gos e ge6grafos da Universidade de Coimbra no âmbito de um projecto de investigaçao em tïnanciamento pelo Programa PRAXIS XXI (2/21/CTA/156/94). Este projecto intitula-se "Estrutura geol6gica, evoluçao quaternaria da paisagem e recursos no espaço do Baixo Mondego" e tem como objectivos estudar naD s6 os processos geol6gicos e geomorfol6gicos envolvidos na evoluçao dos espaços e paisagens do Baixo Mondego durante 0 Quaternario, mas também proceder a um inventario dos recursos naturais entao gerados e a uma avaliaçao dos impactes ambientais decorrentes das principais actividades humanas aqui desenvolvidas.

Research paper thumbnail of What is the Influence of the Planning Framework on the Land Use Change Trajectories? Photointerpretation Analysis in the 1958–2011 Period for a Medium/Small Sized City

Sustainability, 2015

Medium/small sized cities create a polycentric urban system representing the backbone of their te... more Medium/small sized cities create a polycentric urban system representing the backbone of their territory, characterized by profound changes on land use. The objective of this study is to evaluate the spatial and temporal dynamics of land use in a medium/small city in Portugal during the period 1958-2011, and the relation with the planning framework. The assessment involves land use changes recognition in the period 1958-2011, calculation of the stability grade indicator, and the losses and gains between classes. The rate of artificialization and its relation with the planning framework was also evaluated. The results for the city of Viseu showed a main decrease in annual crops and arable lands, with an increase of the continuous and discontinuous urban fabric. The changes are systematic transitions, marked by planning framework and its typology, objectives and scale enforcement. A plan addressing the city encouraged land use changes in the fringe, while a municipal Master Plan determined sequent transformation in all areas. The land use changes and the artificialization processes enabled the identification of three periods where planning framework was forthright. The study underlines the importance of a planning framework for medium/small sized cities for urban sprawl and artificialization processes.

Research paper thumbnail of Modelação de processos de queda de blocos em vertentes na região de Alvaiázere: dois estudos caso

Modelação de sistemas geológicos: livro de homenagem ao Professor Manuel Maria Godinho

A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitali... more A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos. Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença. Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso. Modelação de processos de queda de blocos em vertentes na região de Alvaiázere: dois estudos caso

Research paper thumbnail of Processos de perigosidade natural no município de Câmara de Lobos – Madeira: contributo para a gestão do risco e da emergência

Territorium, 2008

O presente estudo aborda a área temática dos riscos naturais, no Município de Câmara de Lobos, no... more O presente estudo aborda a área temática dos riscos naturais, no Município de Câmara de Lobos, nomeadamente uma análise dos processos de perigosidade natural, na qual serão identificados os elementos socioeconómicos/ estruturais com maior grau de exposição. Tem como objectivo a optimização das políticas de gestão do território, através da aplicação de um sistema de gestão municipal do risco e de emergência.

Research paper thumbnail of A bacia hidrográfica do rio Arunca: factores condicionantes e cartografia dos processos de cheia/inundação

Trunfos de uma Geografia Activa: desenvolvimento local, ambiente, ordenamento e tecnologia, 2011

Research paper thumbnail of Hydraulic modelling of the flood prone area in a basin with a historical report of urban inundation

Research paper thumbnail of A vulnerabilidade social aos perigos naturais e tecnológicos em Portugal

Revista Crítica de Ciências Sociais, 2011

A vulnerabilidade social aos perigos naturais e tecnológicos em Portugal neste artigo apresenta-s... more A vulnerabilidade social aos perigos naturais e tecnológicos em Portugal neste artigo apresenta-se um novo modelo de análise da vulnerabilidade social aos perigos naturais e tecnológicos. o índice utilizado nesta análise permite a estruturação da avaliação da vulnerabilidade em duas dimensões: as vulnerabilidades das populações e comunidades (criticidade) e a vulnerabilidade territorial (capacidade de suporte), os quais reflectem a exposição ou a vulnerabilidade biofísica, a resiliência social e a capacidade de suporte infraestrutural. este novo índice de vulnerabilidade social é aplicado ao sistema territorial de Portugal continental, tendo por base a escala municipal e submunicipal, apreendendo a resiliência social dos indivíduos, dos grupos e das comunidades face a acontecimentos extremos. os resultados obtidos evidenciam o papel crucial da escala na análise dos processos relacionados com a vulnerabilidade social. Propõe-se que a cartografia das áreas e dos grupos mais vulneráveis, bem como a identificação dos factores desencadeantes, podem constituir um contributo relevante para os programas de ordenamento e de planeamento destinados a mitigar os riscos e as vulnerabilidades do território. Palavras-chave: desastres naturais; escalas de avaliação; factores de risco; resiliência; riscos naturais e tecnológicos; território; vulnerabilidade social.

Research paper thumbnail of Percepção dos riscos naturais e tecnológicos, confiança institucional e preparação para situações de emergência: O caso de Portugal continental

Revista Crítica de Ciências Sociais, 2011

Research paper thumbnail of Polyomavirus - an emergent pathogen in transplant recipients Poliomavírus - um patógeno emergente para receptores de transplantes

Medical centers that work with transplants often face opportunistic infections that demand specif... more Medical centers that work with transplants often face opportunistic infections that demand specific tools to make diagnosis. The prevalence of latent polyomavirus infections is high, and the most common site of latency of the most prevalent polyomavirus in humans, BK virus (BKV), is the renal tissue. Hence, renal transplanted patients are particularly vulnerable to the damage caused by viral reactivation

Research paper thumbnail of Profile of phosphoprotein labelling in organotypic slice cultures of rat hippocampus

Neuroreport, 2001

In recent years organotypic slice cultures of hippocampal tissue of rats have been widely used to... more In recent years organotypic slice cultures of hippocampal tissue of rats have been widely used to study factors involved in neuronal death. Here we used 2D electrophoresis to study the phosphoprotein profile in such cultures and the effect of oxygen/glucose deprivation on this profile. Cultures were prepared from 7-day-old rats. After 14 days in culture the phosphorylation profile in the cultures, as shown by phospho-protein markers undergoing developmental change, closely resembled the profile of fresh tissue from 23-day-old rats. The results suggest that this model could be a good method to observe the development of the tissue and its response to an ischaemic lesion

Research paper thumbnail of Estradiol Protects Against Oxygen and Glucose Deprivation in Rat Hippocampal Organotypic Cultures and Activates Akt and Inactivates GSK-3?

Neurochemical Research, 2005

Here we investigated the neuroprotective effect of 17b-estradiol in an in vitro model of ischemia... more Here we investigated the neuroprotective effect of 17b-estradiol in an in vitro model of ischemia. We used organotypic hippocampal slice cultures, acute or chronically treated with 17b-estradiol (10 nM), and exposed to oxygen and glucose deprivation (OGD). Cellular death was quantified by measuring uptake of propidium iodide (PI), a marker of dead cells. In OGD exposed cultures, treated only with vehicle, about 70% of the CA1 area of hippocampus was labeled with PI, indicating a great percentage of cellular death. When cultures were treated with 17b-estradiol (acute or chronically), this cellular death was reduced to 15%. This effect was prevented by LY294002 but was not by PD98059. Immunoblotting revealed that both, chronic and acute, treatments with 17b-estradiol induced the phosphorylation/activation of Akt and the phosphorylation/inactivation of GSK-3b. Our results show a clear neuroprotective effect of 17b-estradiol and suggest that this effect could involve PI3-K pathway.

Research paper thumbnail of Low drop-out voltage regulator with dynamic voltage control

Research paper thumbnail of Experimental Study on the Performance of Electrical Submersible Pump Operating with Ultraviscous Oil

SPE Journal, 2022

Summary The production of high-viscosity crude oil can be challenging owing to portfolio limitati... more Summary The production of high-viscosity crude oil can be challenging owing to portfolio limitations and lack of energy efficiency in artificial lift systems, especially for ultraheavy oil in deepwater fields. In recent decades, the electrical submersible pump (ESP) has improved significantly, and this technology is commonly applied in this context. However, few studies in the literature discuss the behavior of these pumps with nonconventional oils such as ultraviscous ones. This work investigates the performance of a 10-stage ESP, when it operates with a single-phase flow of ultraviscous oil. For this purpose, an experimental circuit was set up; the pump was submitted to tests in which the viscosity of the fluid varied from 8 to 4,170 cp and rotational speed between 1,200 and 3,500 rev/min. A subsequent analysis compared the pump’s experimental viscous performance and the theoretical performance calculated by the methods available in the literature. This analysis highlighted the la...

Research paper thumbnail of Experimental Study and Modeling of Heating Effect in Electrical Submersible Pump Operating With Ultra-Heavy Oil

Volume 8: Polar and Arctic Sciences and Technology; Petroleum Technology, 2018

A notable trend in the realm of oil production in harsh environments is the increasing use of Ele... more A notable trend in the realm of oil production in harsh environments is the increasing use of Electrical Submersible Pump (ESP) systems. ESPs have even been used as an artificial-lift method for extracting high-viscosity oils in deep offshore fields. As a way of reducing workover costs, an ESP system may be installed at the well bottom or on the seabed. A critical factor, however, in deep-water production is the low temperature at the seabed. In fact, these low temperatures constitute the main source for many flow-assurance problems, such as the increase in friction losses due to high viscosity. Oil viscosity impacts pump performance, reducing the head and increasing the shaft power. This study investigates the influence of a temperature increase of ultra-heavy oil on ESP performance and the heating effect through a 10-stage ESP. Using several flow rates, tests are performed at four rotational speeds and with four viscosity levels. At each rotational speed curve, researchers keep co...

Research paper thumbnail of Risco, vulnerabilidade social e cidadania

Revista Crítica de Ciências Sociais, 2011

Research paper thumbnail of Challenges in ESP Operation in Ultra-Deepwater Heavy Oil Atlanta Field

Day 2 Wed, November 11, 2020, 2020

Atlanta is a post-salt oil field located offshore Brazil in the Santos Basin, 185 km southeast of... more Atlanta is a post-salt oil field located offshore Brazil in the Santos Basin, 185 km southeast of Rio de Janeiro. The combination of ultra-deepwater (1,550 m) and heavy and viscous oil (14 °API and 228 cP at reservoir conditions) composes a unique challenging scenario for Electrical Submersible Pump (ESP) application. The paper discusses the performance of the ESP system utilizing field data and software simulations. The in-well ESP is the main production method and mudline ESP boosting is the backup one. Both concepts proved to be effective artificial lift solutions for the harsh flowing conditions. The in-well ESP is installed inside a capsule in a close to horizontal slant section of around 70 m. The mudline ESP boosting is readily available to become the main production method in case the in-well ESP fails. This paper discusses the challenges and solutions that proved to be successful after more than 18 months of continuous production. Software simulations and continuous product...

Research paper thumbnail of Robust Artificial Lift Solution for Ultra-Deepwater Heavy Oil Atlanta Field

Offshore Technology Conference Brasil, 2019

Most of the artificial lift strategies in deepwater environments require sophisticated and robust... more Most of the artificial lift strategies in deepwater environments require sophisticated and robust solutions, aiming to improve the system's run life and reliability. Due to that, oil companies choose only trustable technology and field-proven solutions for artificial lift design. This is the case of Atlanta Field's artificial lift project, with electrical submersible pumps (ESP) installed at more than 1,550 m water depth, to produce heavy oil. For Atlanta Field, the ESP must handle high viscous oil and emulsions at high flow rates to be economically feasible. To achieve this goal, it was deployed one of the most powerful ESP in the world with 1,550 HP induction motor and more than one hundred pump stages into the well. This is the largest ESP in-well successfully installed in Brazil. The artificial lift strategy adopted for Atlanta Field was an in-well ESP as primary method and an artificial lift skid (ALS) installed on the seabed for back-up. When the primary method fails, ...

Research paper thumbnail of The role of media between expert and lay knowledge: A study of Iberian media coverage on climate change

Science of The Total Environment, 2019

• Media is a mediator between expert and lay knowledge. • Media may be crucial in engaging indivi... more • Media is a mediator between expert and lay knowledge. • Media may be crucial in engaging individuals and governments with climate change. • Iberian media's coverage on climate change shows an important journalistic bias. • Iberian media's discourse tend to nonresilient and non-democratic.

Research paper thumbnail of Peri-Urbanization and Rurbanization in Leiria City: the Importance of a Planning Framework

Sustainability, 2018

The objective of this study is to evaluate the spatial and temporal dynamics of land use in the c... more The objective of this study is to evaluate the spatial and temporal dynamics of land use in the city of Leiria, which is located in central Portugal, and its relation to the planning framework. The analysis is based on land-use change recognition in the period 1958–2011, calculation of the stability grade indicator, the losses and gains between classes, and the rate of artificialization. The results show an increase of the artificial areas, namely in continuous and discontinuous urban fabric, contrasting with a continuous decrease of the agricultural land-use classes, giving origin to peri-urbanization and rurbanization processes. We can also observe a large fragmentation of the landscape in the city of Leiria, representing rapid urban expansion that is fundamentally related to the increase of residential and industrial areas, and afterwards, tertiary growth. This study also demonstrated the relation of a land-use and planning framework that works as a driving force for land-use cha...

Research paper thumbnail of O "julgamento" geomorfológico de Coimbra: o testemunho dos depósitos quaternários

Cadernos de Geografia, 1999

Research paper thumbnail of Intervenções recentes e avaliação de impactes ambientais no Baixo Mondego

Cadernos de Geografia, 1999

* 0 presente artigo integra-se num conjunto diversificado de actividades de investigaçao desenvol... more * 0 presente artigo integra-se num conjunto diversificado de actividades de investigaçao desenvolvida por uma equipa interdisciplinar de ge610gos e ge6grafos da Universidade de Coimbra no âmbito de um projecto de investigaçao em tïnanciamento pelo Programa PRAXIS XXI (2/21/CTA/156/94). Este projecto intitula-se "Estrutura geol6gica, evoluçao quaternaria da paisagem e recursos no espaço do Baixo Mondego" e tem como objectivos estudar naD s6 os processos geol6gicos e geomorfol6gicos envolvidos na evoluçao dos espaços e paisagens do Baixo Mondego durante 0 Quaternario, mas também proceder a um inventario dos recursos naturais entao gerados e a uma avaliaçao dos impactes ambientais decorrentes das principais actividades humanas aqui desenvolvidas.

Research paper thumbnail of What is the Influence of the Planning Framework on the Land Use Change Trajectories? Photointerpretation Analysis in the 1958–2011 Period for a Medium/Small Sized City

Sustainability, 2015

Medium/small sized cities create a polycentric urban system representing the backbone of their te... more Medium/small sized cities create a polycentric urban system representing the backbone of their territory, characterized by profound changes on land use. The objective of this study is to evaluate the spatial and temporal dynamics of land use in a medium/small city in Portugal during the period 1958-2011, and the relation with the planning framework. The assessment involves land use changes recognition in the period 1958-2011, calculation of the stability grade indicator, and the losses and gains between classes. The rate of artificialization and its relation with the planning framework was also evaluated. The results for the city of Viseu showed a main decrease in annual crops and arable lands, with an increase of the continuous and discontinuous urban fabric. The changes are systematic transitions, marked by planning framework and its typology, objectives and scale enforcement. A plan addressing the city encouraged land use changes in the fringe, while a municipal Master Plan determined sequent transformation in all areas. The land use changes and the artificialization processes enabled the identification of three periods where planning framework was forthright. The study underlines the importance of a planning framework for medium/small sized cities for urban sprawl and artificialization processes.

Research paper thumbnail of Modelação de processos de queda de blocos em vertentes na região de Alvaiázere: dois estudos caso

Modelação de sistemas geológicos: livro de homenagem ao Professor Manuel Maria Godinho

A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitali... more A navegação consulta e descarregamento dos títulos inseridos nas Bibliotecas Digitais UC Digitalis, UC Pombalina e UC Impactum, pressupõem a aceitação plena e sem reservas dos Termos e Condições de Uso destas Bibliotecas Digitais, disponíveis em https://digitalis.uc.pt/pt-pt/termos. Conforme exposto nos referidos Termos e Condições de Uso, o descarregamento de títulos de acesso restrito requer uma licença válida de autorização devendo o utilizador aceder ao(s) documento(s) a partir de um endereço de IP da instituição detentora da supramencionada licença. Ao utilizador é apenas permitido o descarregamento para uso pessoal, pelo que o emprego do(s) título(s) descarregado(s) para outro fim, designadamente comercial, carece de autorização do respetivo autor ou editor da obra. Na medida em que todas as obras da UC Digitalis se encontram protegidas pelo Código do Direito de Autor e Direitos Conexos e demais legislação aplicável, toda a cópia, parcial ou total, deste documento, nos casos em que é legalmente admitida, deverá conter ou fazer-se acompanhar por este aviso. Modelação de processos de queda de blocos em vertentes na região de Alvaiázere: dois estudos caso

Research paper thumbnail of Processos de perigosidade natural no município de Câmara de Lobos – Madeira: contributo para a gestão do risco e da emergência

Territorium, 2008

O presente estudo aborda a área temática dos riscos naturais, no Município de Câmara de Lobos, no... more O presente estudo aborda a área temática dos riscos naturais, no Município de Câmara de Lobos, nomeadamente uma análise dos processos de perigosidade natural, na qual serão identificados os elementos socioeconómicos/ estruturais com maior grau de exposição. Tem como objectivo a optimização das políticas de gestão do território, através da aplicação de um sistema de gestão municipal do risco e de emergência.

Research paper thumbnail of A bacia hidrográfica do rio Arunca: factores condicionantes e cartografia dos processos de cheia/inundação

Trunfos de uma Geografia Activa: desenvolvimento local, ambiente, ordenamento e tecnologia, 2011

Research paper thumbnail of Hydraulic modelling of the flood prone area in a basin with a historical report of urban inundation

Research paper thumbnail of A vulnerabilidade social aos perigos naturais e tecnológicos em Portugal

Revista Crítica de Ciências Sociais, 2011

A vulnerabilidade social aos perigos naturais e tecnológicos em Portugal neste artigo apresenta-s... more A vulnerabilidade social aos perigos naturais e tecnológicos em Portugal neste artigo apresenta-se um novo modelo de análise da vulnerabilidade social aos perigos naturais e tecnológicos. o índice utilizado nesta análise permite a estruturação da avaliação da vulnerabilidade em duas dimensões: as vulnerabilidades das populações e comunidades (criticidade) e a vulnerabilidade territorial (capacidade de suporte), os quais reflectem a exposição ou a vulnerabilidade biofísica, a resiliência social e a capacidade de suporte infraestrutural. este novo índice de vulnerabilidade social é aplicado ao sistema territorial de Portugal continental, tendo por base a escala municipal e submunicipal, apreendendo a resiliência social dos indivíduos, dos grupos e das comunidades face a acontecimentos extremos. os resultados obtidos evidenciam o papel crucial da escala na análise dos processos relacionados com a vulnerabilidade social. Propõe-se que a cartografia das áreas e dos grupos mais vulneráveis, bem como a identificação dos factores desencadeantes, podem constituir um contributo relevante para os programas de ordenamento e de planeamento destinados a mitigar os riscos e as vulnerabilidades do território. Palavras-chave: desastres naturais; escalas de avaliação; factores de risco; resiliência; riscos naturais e tecnológicos; território; vulnerabilidade social.

Research paper thumbnail of Percepção dos riscos naturais e tecnológicos, confiança institucional e preparação para situações de emergência: O caso de Portugal continental

Revista Crítica de Ciências Sociais, 2011

Research paper thumbnail of Polyomavirus - an emergent pathogen in transplant recipients Poliomavírus - um patógeno emergente para receptores de transplantes

Medical centers that work with transplants often face opportunistic infections that demand specif... more Medical centers that work with transplants often face opportunistic infections that demand specific tools to make diagnosis. The prevalence of latent polyomavirus infections is high, and the most common site of latency of the most prevalent polyomavirus in humans, BK virus (BKV), is the renal tissue. Hence, renal transplanted patients are particularly vulnerable to the damage caused by viral reactivation

Research paper thumbnail of Profile of phosphoprotein labelling in organotypic slice cultures of rat hippocampus

Neuroreport, 2001

In recent years organotypic slice cultures of hippocampal tissue of rats have been widely used to... more In recent years organotypic slice cultures of hippocampal tissue of rats have been widely used to study factors involved in neuronal death. Here we used 2D electrophoresis to study the phosphoprotein profile in such cultures and the effect of oxygen/glucose deprivation on this profile. Cultures were prepared from 7-day-old rats. After 14 days in culture the phosphorylation profile in the cultures, as shown by phospho-protein markers undergoing developmental change, closely resembled the profile of fresh tissue from 23-day-old rats. The results suggest that this model could be a good method to observe the development of the tissue and its response to an ischaemic lesion

Research paper thumbnail of Estradiol Protects Against Oxygen and Glucose Deprivation in Rat Hippocampal Organotypic Cultures and Activates Akt and Inactivates GSK-3?

Neurochemical Research, 2005

Here we investigated the neuroprotective effect of 17b-estradiol in an in vitro model of ischemia... more Here we investigated the neuroprotective effect of 17b-estradiol in an in vitro model of ischemia. We used organotypic hippocampal slice cultures, acute or chronically treated with 17b-estradiol (10 nM), and exposed to oxygen and glucose deprivation (OGD). Cellular death was quantified by measuring uptake of propidium iodide (PI), a marker of dead cells. In OGD exposed cultures, treated only with vehicle, about 70% of the CA1 area of hippocampus was labeled with PI, indicating a great percentage of cellular death. When cultures were treated with 17b-estradiol (acute or chronically), this cellular death was reduced to 15%. This effect was prevented by LY294002 but was not by PD98059. Immunoblotting revealed that both, chronic and acute, treatments with 17b-estradiol induced the phosphorylation/activation of Akt and the phosphorylation/inactivation of GSK-3b. Our results show a clear neuroprotective effect of 17b-estradiol and suggest that this effect could involve PI3-K pathway.