142 documents found, page 1 of 15
Ordovician–Silurian transition in the Central-Iberian Zone: Just a stratigraphi...
Tereso, Vitor; Dias, Rui; Roseiro, José; Romão, José; Coke, Carlos; Fonseca, Rita; Ribeiro, AntónioABSTRACT: The Ordovician-Silurian boundary in the Central-Iberian Zone is often considered a normal stratigraphic transition. Nevertheless, in studies carried out in Portugal (e.g. Espinhosela, São Mamede and Buçaco areas) and Spain (e.g. Alcañices Synform) this contact is marked by the development of shear zones subparallel to the lithostratigraphic units. Ongoing structural mapping in Celorico de Basto (Marão...
Influence of sulphide mine tailings on drainage water quality, 60 years after i...
Fonseca Araújo, Joana; Fonseca, Rita; Albuquerque, Maria Teresa; Silva, Natália; da Silva, RobertoABSTRACT: The GeoMatRe project aims to find low-cost solutions for water and sediment rehabilitation using raw geomaterials, in abandoned mines of the Iberian Pyritic Belt. One of our case studies is the Caveira mine in southwestern Portugal, where large piles of mining waste, containing significant amounts of metals, record the long history of its exploitation for gold (Au) and silver (Ag). After the exhaustio...
Avaliação do nível de contaminação nos sedimentos de cursos de água do Sistema ...
da Silva, Roberto; Fonseca, Rita; Fonseca Araújo, Joana; Silva, Natália; Albuquerque, Maria TeresaRESUMO: O presente trabalho, inserido no Projeto GeoMatRe, visa o levantamento das condições mais atualizadas no que toca aos parâmetros físico-químicos numa mina de drenagem ácida. Uma situação crítica que ocorre na área mineira de Caveira, em Grândola, Portugal, abandonada desde a década de 60 do século passado. O objetivo passa por analisar as condições de contaminação de Elementos Potencialmente Tóxicos (EP...
Life on Mars? Contaminação por Metais na Mina do Trimpancho
Nogueira, Pedro; Roseiro, José; Silva, Marcelo; Onyealisi, Obinna; Araujo, Joana; Silva, Roberto; São Pedro, Diogo; Araujo, Alexandre; Fonseca, RitaA Faixa Piritosa Ibérica constitui uma das províncias metalogenéticas mais relevantes da Europa, caracterizada por mineralizações de sulfuretos maciços e um longo historial de atividade mineira. A mina do Trimpancho, situada na zona fronteiriça entre Portugal e Espanha, integra este contexto geológico e apresenta vestígios de exploração antiga, com escombreiras remanescentes que constituem fontes de contaminaçã...
Ordovician – Silurian transition in the Central-Iberian Zone: Just a stratigrap...
Tereso, Vitor; Dias, Rui; Roseiro, José; Romão, José; Coke, Carlos; Fonseca, Rita; Ribeiro, AntónioThe Ordovician-Silurian boundary in the Central-Iberian Zone is often considered a normal stratigraphic transition. Nevertheless, in studies carried out in Portugal (e.g. Espinhosela, São Mamede and Buçaco areas) and Spain (e.g. Alcañices Synform) this contact is marked by the development of shear zones subparallel to the lithostratigraphic units. Ongoing structural mapping in Celorico de Basto (Marão region) s...
Relations between river sediments and dissolved matter
Egozcue, Juan José; Pawlowsky-Glahn, Vera; Fonseca, Rita; Albuquerque, Maria TeresaA typical but actually unsolved problem is relating dissolved ions in water and the chemical composition of the corresponding sediments. Our first assumption is that botH ion concentrations and the sediments are compositional in nature. Data from the 2022 and 2023 campaigns in the Trimpancho river (Mining System) (Huelva, Spain) are used to illustrate the possibilities and the challenges of such an analysis. Th...
A global dataset of near-natural basins for climate change detection
Turner, Steve; Hannaford; Berker, Lucy; Dixon, Harry; Griffin, Adam; Kumar, Amit; Suman, Gayatri; Goula, Albert Bi Tié; Watson, AndrewAs hydrological extremes become more severe in the warming world, impacts to livelihoods, infrastructure, and economies worsen. To attribute emerging trends to climate change, we need to remove the signal of anthropogenic activities, such as, the presence of dams, land-cover change, channelisation and the abstraction of water for public water supplies, industry and agriculture. These human disturbances can obsc...
Stream sediment pollution: a compositional baseline assessment
Albuquerque, Teresa; Fonseca, Rita; Araújo, Joana; Silva, Natália; Araújo, AntónioA high concentration of potentially toxic elements (PTEs) can affect ecosystem health in many ways. It is therefore essential that spatial trends in pollutants are assessed and monitored. Two questions must be addressed when quantifying pollution: how to define a non-polluted sample and how to reduce the problem’s dimensionality. A geochemical dataset is a composition of variables (chemical elements), where the...
Stream sediment pollution: a compositional baseline assessment
Albuquerque, M.T.D.; Fonseca, Rita; Araújo, Joana; Silva, Natália; Araújo, AntónioA high concentration of potentially toxic elements (PTEs) can affect ecosystem health in many ways. It is therefore essential that spatial trends in pollutants are assessed and monitored. Two questions must be addressed when quantifying pollution: how to define a non-polluted sample and how to reduce the problem’s dimensionality. A geochemical dataset is a composition of variables (chemical elements), where the...
The relevance of retention strategies in IT organizations
Fonseca, RitaEmployee retention is a critical challenge for IT organizations, which face high turnover rates due to the competitive nature of the industry and the scarcity of skilled professionals. This research explores the effectiveness of retention strategies within IT organizations, focusing on the roles of employer branding, internal communication, and flexibility in reducing turnover intention. Through a quantitative ...