15 documents found, page 1 of 2
Influence of the Preparation Method on the Structural, Morphological and Dielec...
Devesa, Susana; Gonçalves, Filipa; Graça, ManuelIn this work, iron niobate (FeNbO4) was prepared via two processes based on the sol-gel method: colloidal gel and polymeric gel. The obtained powders were submitted to heat treatments at different temperatures based on the results obtained via differential thermal analysis. The structures of the prepared samples were characterized via X-ray diffraction and the morphology was characterized via scanning electron ...
Patterns of Distribution of Bivalve Populations in a Mediterranean Temporary Ri...
Gama, Mafalda; Banha, Filipe; Moreira, Cristina; Gama, Henrique; Graça, Manuel; Anastácio, PedroIn the south of the Iberian Peninsula, many rivers are intermittent, a state most likely to be exacerbated by climate change, strongly affecting river biota. An additional challenge for native biota in this area is the arrival of new species, frequently aided by humans, and bivalves are particularly at risk. Here we assessed whether the native (Unio delphinus) and invasive (Corbicula fluminea) bivalves differed...
Invasion of temperate deciduous broadleaf forests by N-fixing tree species – co...
Ferreira, Verónica; Figueiredo, Albano; Graça, Manuel; Marchante, Elizabete; Pereira, AnaBiological invasions are a major threat to biodiversity and ecosystem functioning. Forest invasion by alien woody species can have cross-ecosystem effects. This is especially relevant in the case of stream–riparian forest meta-ecosystems as forest streams depend strongly on riparian vegetation for carbon, nutrients and energy. Forest invasion by woody species with dissimilar characteristics from native species ...
Molybdenum oxide thin films grown on flexible ITO-coated PET substrates
Marciel, Alice; Graça, Manuel; Bastos, Alexandre; Pereira, Luiz; Suresh Kumar, Jakka; Borges, Joel; Vaz, F.; Peres, Marco; Magalhães, SergioMolybdenum oxide thin films were deposited on stiff and flexible substrates by reactive DC magnetron sputtering. Two sets of samples were prepared. The first with different O<sub>2</sub>/Ar flow rate ratios and the second, fixing the oxygen content, with different time of deposition. As the O<sub>2</sub>/Ar flow rate ratio varies from 0 up to 0.56, a threshold was found, ranging from crystalline to amorphous na...
Patterns of Distribution of Bivalve Populations in a Mediterranean Temporary River
Gama, Mafalda; Banha, Filipe; Moreira, Cristina; Gama, Henrique; Graça, Manuel; Anastácio, PedroIn the south of the Iberian Peninsula, many rivers are intermittent, a state most likely to be exacerbated by climate change, strongly a ecting river biota. An additional challenge for native biota in this area is the arrival of new species, frequently aided by humans, and bivalves are particularly at risk. Here we assessed whether the native (Unio delphinus) and invasive (Corbicula fluminea) bivalves di ered i...
Electric and dielectric Behavior of Purified Galactomannan Films
Amaral, F.; Neto, Silva; Cavalcante, Lincoln; Santos, Adenilson; Graça, Manuel; Mendes, Fernando; Macêdo, AnaThis work aimed to extract, purify, and to characterize galactomannan from Adenanthera pavonina L. by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and impedance spectroscopy (IS).
Strategic Design, Design-Driven Innovation and Haute Cuisine: contributes for i...
Wielewicki, Patrícia; Roda, Rui; Graça, ManuelThis paper presents the proposal formulation process of a PhD research "through design" under the metaprojectual lens. The study derived from the interface between the domains of Design, Management and Haute Cuisine and difficulties faced by Small Enterprises (SEs) in what concerns the creativity management in innovation. With basis in design systemic and transdisciplinary approaches, the investigation question...
Adsorbed water clusters in garnet cracks detected by impedance and Raman spectr...
Prezas, Pedro; Silva, Hugo; Vinagre, Ana; Graça, Manuel; Moita, Patrícia; Bezzeghoud, MouradThe combination of electric impedance and Raman spectroscopies at the analysis of the supercooled water phase transition enables the detection of adsorbed water clusters in garnet minerals of leucogranite samples. This transition is revealed by a change in the parameters measured by both techniques at low temperatures, Tc ∼ 220 K, and it is attributed to adsorbed water clusters in the walls of garnet cracks. Th...
Tipologia de rios em Portugal Continental no âmbito da implementação da Directi...
Alves, Maria Helena; Ferreira, João; Pádua, João; Martins, João Pedro; Rafael, Teresa; Tomaz, Gonçalo; Figueiredo, Hélio; Bernardo, João ManuelOs tipos são grupos de massas de água com características geográficas e hidrológicas relativamente homogéneas, consideradas relevantes para a determinação das condições ecológicas. O objectivo da definição de tipos é permitir que sejam correctamente estabelecidas condições de referência e que sejam comparáveis as classificações de estado ecológico dentro de cada grupo de rios com características semelhantes. Na...
Structural, optical and magnetic resonance properties of TiO2 fibres grown by l...
Rodrigues, Joana; Peres, Marco; Fernandes, António; Graça, Manuel; Sobolev, Nicolai; Costa, Florinda; Monteiro, TeresaTiO2 fibres grown by the laser floating zone technique show the rutile crystalline phase as identified by X-ray diffraction and Raman spectroscopy. Scanning electron microscopy evidences a uniform surface, free of inclusions and without low-angle grain boundaries and bubbles. At low temperatures, the fibres luminescence is dominated by a richly structured optical centre with two well-defined zero-phonon lines a...