Encontrados 39 documentos, a visualizar página 1 de 4
A Ni hyperaccumulator and a congeneric non-accumulator reveal equally effective...
Boas, Mariana Vilas; Gonçalves, Susana C.; Portugal, Antonio; Freitas, Helena; Gonçalves, M. TeresaThe defense hypothesis is commonly used to explain the adaptive role ofmetal hyperaccumulation. We tested this hypothesis using two Brassicaceae congeneric species: Alyssum pintodasilvae, a Ni hyperaccumulator, and the non-accumulator Alyssum simplex both growing on serpentine soils in Portugal. Artificial diet disks amended with powdered leaves from each plant species were used to compare the performance (mort...
Poly(ethylene glycol)-block-poly(4-vinyl pyridine) as a versatile block copolym...
Rocha, Nuno; Mendes, Joana; Durães, Luisa; Maleki, Hajar; Portugal, Antonio; Geraldes, C. F. G. C.; Serra, Arménio; Coelho, JorgeThis work reports an efficient method for the preparation of aqueous dispersions of superparamagnetic iron oxide nanoparticles (SPIONs), involving the use of an amphiphilic block copolymer, poly(ethylene glycol)- block-poly(4-vinyl pyridine) (mPEG-b-P4VP). The iron oxide nanoparticles are easily and efficiently dispersed due to the strong direct interaction of the hydrophobic P4VP segments, through complexation...
Simulation of two-dimensional combustion propagation on Fe2O3/Al thermite non-h...
Brito, Paulo; Durães, Luísa; Portugal, AntónioIn previous works, a two-dimensional model was constructed and tested in a successful attempt to simulate the nonsteady radial combustion propagation on thin disk shaped samples of Fe2O3/Aluminum thermite mixtures. The main characteristics of the model can be summarized as: pseudo-homogeneous medium considering the contribution of air to simulate a porous medium; zero order, non-temperature dependent beyond a g...
Fungal isolates from the archive of the University of Coimbra: ionizing radiati...
Nunes, Inês Marques, 1988-; Portugal, António; Carolino, M. Manuela, 1954-Tese de mestrado. Biologia (Biologia Celular e Biotecnologia). Universidade de Lisboa, Faculdade de Ciências, 2011 ; A problemática da biodeterioração nos diferentes tipos de obras de arte tem vindo a tornar-se um dos pontos centrais nas áreas da conservação e restauro. Entende-se por biodeterioração, a degradação causada nos materiais por acção directa de organismos vivos ou por consequência de produtos das s...
Modeling and simulation of radial combustion propagation of Fe2O3/Al thermite s...
Brito, Paulo; Durães, Luísa; Portugal, AntónioIn previous works, a one-dimensional model was built to simulate the non-steady radial combustion propagation on thin disk shaped samples of Fe2O3/Aluminum thermite mixtures and was successfully tested. Now, the purpose is to extend the referred model to the more sensible two-dimensional features of the samples, maintaining the main characteristics of the previous model: zero order kinetics, conductive/radiativ...
Adaptive collocation methods for the numerical solution of differential models
Brito, Paulo; Portugal, AntónioA PDE integration algorithm that associates a Method of Lines (MOL) strategy based on finite differences or high resolution space discretizations, with a collocation strategy based on increasing level one or two-dimensional dyadic grids is presented. It reveals potential either as a grid generation procedure for predefined steep localised functions, and as an integration scheme for moving steep gradient PDE pro...
Modeling and simulation of radial combustion propagation of Fe2O3/Al thermite s...
Brito, Paulo; Durães, Luísa; Portugal, AntónioIn previous works, a one-dimensional model was built to simulate the non-steady radial combustion propagation on thin disk shaped samples of Fe2O3/Aluminum thermite mixtures and was successfully tested. Now, the purpose is to extend the referred model to the more sensible two-dimensional features of the samples, maintaining the main characteristics of the previous model: zero order kinetics, conductive/radiativ...
Adaptive collocation methods for the numerical solution of differential models
Brito, Paulo; Portugal, AntónioA PDE integration algorithm that associates a Method of Lines (MOL) strategy based on finite differences or high resolution space discretizations, with a collocation strategy based on increasing level one or two-dimensional dyadic grids is presented. It reveals potential either as a grid generation procedure for predefined steep localised functions, and as an integration scheme for moving steep gradient PDE pro...
Adaptive collocation methods for the solution of partial differential equations
Brito, Paulo; Portugal, AntónioAn integration algorithm that conjugates a Method of Lines (MOL) strategy based on finite differences space discretizations, with a collocation strategy based on increasing level dyadic grids is presented. It reveals potential either as a grid generation procedure and a Partial Differential Equation(PDE) integration scheme. It copes satisfactorily with a example characterized by a steep travelling wave and a ex...
Simulation of membrane separations using a modified Maxwell-Stefan model
Brito, Paulo; Gando-Ferreira, Licínio M.; Portugal, AntónioIn this work, a modified Maxwell-Stefan model, which considers both the concentration polarization and the transport through the membrane, is tested for the simulation of Dextran T70 aqueous solutions filtration. Numerical simulations by solving the model equations with an adaptive resolution algorithm, based on the Adaptive Method of Lines, determined the concentration profiles in the polarization layer and in...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||