14 documents found, page 1 of 2
Irradiation damage on CrNbTaVWx high entropy alloys
Martins, Ricardo; Correia, J.B.; Czarkowski, P.; Miklaszewski, R.; Malaquias, A.; Mateus, R.ABSTRACT: CrNbTaVWx high-entropy alloys have been developed for plasma facing components to be applied in nuclear fusion reactors. The CrNbTaVWx (x = 1 and 1.7) compositions were prepared by ball milling and consolidated at 1600 degrees C under 90 MPa. To study the irradiation resistance of these materials, deuterium plasmas were used to irradiate the samples in the PF-1000U facility with 1 and 3 discharges. St...
Irradiation damage on CrNbTaVWx high entropy alloys
Martins, Ricardo; Correia, J.B.; Czarkowski, P.; Miklaszewski, R.; Malaquias, A.; Mateus, R.ABSTRACT: CrNbTaVWx high-entropy alloys have been developed for plasma facing components to be applied in nuclear fusion reactors. The CrNbTaVWx (x = 1 and 1.7) compositions were prepared by ball milling and consolidated at 1600 degrees C under 90 MPa. To study the irradiation resistance of these materials, deuterium plasmas were used to irradiate the samples in the PF-1000U facility with 1 and 3 discharges. St...
Ser ou não ser praxado? A teoria da ação planeada como modelo para compreender ...
Correia, I.; Alves, D.; Jarego, M.; Lopes, K.; Rodrigues, D.; Abrantes, L.; Boloca, A.; Carvalho, B.; Diogo, M.; Grosso, C.; Massa, M. F.; Mateus, R.Com este estudo pretendemos investigar quais são os preditores da intenção de participação dos caloiros na praxe académica. Para tal, recorremos à teoria da ação planeada (Ajzen, 1991) que permite analisar o peso relativo das atitudes, da norma subjetiva, e do controlo comportamental percebido nas intenções de ser praxado. Os participantes, estudantes universitários (N = 353) a frequentar o 1º ano de uma Licenc...
Evaluation of an in-house molecular HIV-1 test to assess mother-to-child HIV-1 ...
Martin, F.; Palladino, C.; Mateus, R.; Clemente, S.; Gomes, P.; Taveira, N."Mother-to-child-transmission (MTCT) rate has decreased sharply in recent years in most of the sub-Saharan Africa, however 220,000 children acquired HIV-1 in 2014. PCR detection of proviral DNA is the most sensitive method for early infant diagnosis (EID) of HIV-1 infection. Commercial kits are available but they have poor sensitivity with divergent non-B subtypes and high costs (≈30€ per test) which limit thei...
A decision support system for a multi stakeholder's decision process in a Portu...
Garcia-Gonzalo, J.; Palma, J.H.N.; Freire, J.P.A.; Tome, M.; Mateus, R.; Rodriguez, L.C.E; Bushenkov, V.; Borges, J.G.Aim of study: In this paper, we present a decision support system (DSS) to support decision making where different stakeholders have to generate landscape and forest level strategic plans. We further present an interactive approach that may take advantage of a posteriori preference modelling (i.e. Pareto frontier technique) to facilitate the specification of the levels of achievement of various objectives. Area...
Blistering of W-Ta composites at different irradiation energies
Mateus, R.; Dias, M.; Lopes, J.; Rocha, J.; Catarino, N.; Duarte, P.; Gomes, R. B.; Silva, C.; Fernandes, H.; Livramento, V.; Carvalho, P. A.; Alves, E.Pure tungsten and tantalum plates and tungsten-tantalum composites produced via mechanical alloying and spark plasma sintering were bombarded with He+ and D+ energetic ion beams and deuterium plasmas. The aim of this experiment is to study the effects caused by individual helium and deuterium exposures and to evidence that the modifications induced in the composites at different irradiation energies could be fo...
Effects of helium and deuterium irradiation on SPS sintered W–Ta composites at ...
Mateus, R.; Dias, Marta; Lopes, J.; Rocha, J.; Catarino, N.; Franco, N.; Livramento, Vanessa; Almeida Carvalho, Patricia; Correia, J.B.; Hanada, K.Energetic He+ and D+ ions were implanted into different W–Ta composites in order to investigate their stability under helium and deuterium irradiation. The results were compared with morphological and chemical modifications arising from exposure of pure W and Ta. Special attention was given to tantalum hydride (Ta2H)formation due to its implications for tritium inventory. Three W–Ta composites with 10 and 20 at...
Synergistic helium and deuterium blistering in tungsten–tantalum composites
Dias, Marta; Mateus, R.; Catarino, N.; Franco, N.; Nunes, D.; Correia, J.B.; Carvalho, Patricia Almeida; Hanada, K.; Sârbu, C.; Alves, E.Tungsten–tantalum composites with 10 and 20 at.% Ta were prepared by ball milling W powder with Ta fibers and by consolidating the milled materials with spark plasma sintering. The composites were implanted at room temperature with He+ (30 keV with a fluence 5 1021 at/m2) and/or D+ (15 keV with a fluence 5 x 1021 at/m2) ion beams. The materials were studied by scanning and high-resolution transmission electron ...
Elemental interdiffusion in W-Ta composites developed for fusion applications
Mateus, R.; Dias, Marta; Livramento, Vanessa; Nunes, D.; Almeida Carvalho, Patricia; Hanada, K.; Correia, J.B.Tungsten (W) was select for an extensive use in nuclear fusion devices due to its low neutron activation, high melting point and sputtering threshold as well as low hydrogen inventory. Nevertheless, W is brittle at low and moderate temperatures, which results in abnormal thermal stress, component fracture and extra erosion under reactor operation due to inherent thermal cycling events. An attractive way to solv...
Blistering of W–Ta composites at different irradiation energies
Mateus, R.; Dias, Marta; Lopes, J.; Rocha, J.; Catarino, N.; Duarte, P.; Gomes, R. B.; Silva, C.; Fernandes, H.; Livramento, VanessaPure tungsten and tantalum plates and tungsten–tantalum composites produced via mechanical alloying and spark plasma sintering were bombarded with He+ and D+ energetic ion beams and deuterium plasmas. The aim of this experiment is to study the effects caused by individual helium and deuterium exposures and to evidence that the modifications induced in the composites at different irradiation energies could be fo...