Setting-up rules to characterize microsegregation

Characterization of chemical heterogeneities such as microsegregation resulting from solidification of metallic alloys is most often performed by EDS or WDS microanalysis with spot measurements located at corners of a regular grid. Rather than attempting a theoretical treatment of the statistics of such analyses, the quality of the procedure has been investigated by implementing “measurement” grids on numerical images that mimic solidification structures. Microstructures either with no geometrical constraints (uniform distribution of the solid nuclei) or with limited constraints that give some periodicity have been investigated. Systematic analysis of the effect of the location and size of the “measurement” grid enlightens the procedures which should be followed to minimize bias

Depinning of domain walls with an internal degree of freedom

Taking into account the coupling between the position of the wall and an internal degree of freedom, namely its phase $\phi$, we examine, in the rigid wall approximation, the dynamics of a magnetic domain wall subject to a weak pinning potential. We determine the corresponding force-velocity characteristics, which display several unusual features when compared to standard depinning laws. At zero temperature, there exists a bistable regime for low forces, with a logarithmic behavior close to the transition. For weak pinning, there occurs a succession of bistable transitions corresponding to different topological modes of the phase evolution. At finite temperature, the force-velocity characteristics become non-monotonous. We compare our results to recent experiments on permalloy nanowires

Cognitive behaviour therapy for schizophrenia

Schizophrenia is one of the major and potentially severe mental illnesses. Even with best practices, there are limitations to the effectiveness of treatments that include medications for this disorder. Relapse rates are high and often those with the illness remain symptomatic and functionally impaired. All the evidence suggests that individuals with schizophrenia do best with a combination of pharmacological and psychosocial intervention. One psychosocial treatment that has received much attention is cognitive behaviour therapy (CBT). This brief review will address what we know about the use and effectiveness of CBT at all phases of schizophrenia and its strengths, weaknesses and its future

Effects of grazing exclusion and shrub encroachment on the ecosystem ecology of evergreen oak woodland

Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de AgronomiaShrub encroachment, an increase in density and cover of shrub plant communities, is affecting biodiversity and functioning of ecosystems around the world. Through feeding and trampling ungulates affect the structure and species composition of plant communities, including shrublands, and are key drivers in shrub encroachment processes. This thesis, conducted within a long-term browsing exclosure experiment, investigates the effects of ungulates (red deer Cervus elaphus and fallow deer Dama dama) on the encroachment of C. ladanifer, a dominant Mediterranean shrub, into a mixed cork (Quercus suber) and holm (Quercus rotundifolia) evergreen oak woodland in Southern Portugal. Five paired fenced (ungulate-excluded) and unfenced (ungulate-allowed) plots of 25 m x 25 m were established in the study area in July 2001. Fenced plots had a 2.20 m height fence to exclude deer occurring in the site. Data on C. ladanifer reproduction structures (buds, fruits and flowers), soil seed bank, population density and biomass, were collected in fenced and open plots in 2007, 2013 and 2015. Ungulates consumed buds, flowers and fruits and decreased the soil seed bank of C. ladanifer. Plant reproductive costs (loss of fruits) were higher than potential benefits (seed dissemination) and the population density and biomass of C. ladanifer, decreased in the open plots by the end of the experiment. Ungulates decreased above-ground carbon (C) storage but also the amount of fine fuel loads reducing fire hazard and the probability of crown fires, and consequent adult oak mortality, in open plots. Therefore ungulate may potential benefit long-term ecosystem C storage. A drought year during data monitoring allowed quantifying jointly effects of ungulate browsing and drought on C. ladanifer mortality which increased in open plots. Changes in live:dead plant biomass affected fire hazard. Results show that ungulate ecology needs to be considered when investigating shrub encroachment processesN/

Semiautomatic determination of orientations and elastic strain from Kossel microdiffraction

The technique of divergent beam X-ray (Kossel) diffraction is being used for determination of local lattice orientations and lattice distortions (elastic strains). The Kossel patterns are recorded in a scanning electron microscope using a digital camera. The advancement in automation of the of the system relies on computerized interpretation of the Kossel patterns. The paper reports on a package of computer programs facilitating computation of orientations and the strain tensors from the geometry of Kossel conics. The orientation and strain parameters are determined based on conics marked manually on experimental patterns; these marked conics are matched with simulated patterns. The program can simultaneously match multiple patterns originating from the same sample location. The software does not require special orientations, and it is not limited to any particular material. Tests on simulated patterns have been used to confirm the internal consistency of the program. These tests also indicate the achievable accuracy; with the current approach, it is estimated to be about 3×10-4