Electromagnetic prospection in time domain applied to Olhos da Fervença, Cantanhede (Central Portugal)

Poster apresentado ao VIII Congresso Nacional de Geologia, em Braga (9-16 de Julho 2010)A exsurgência cársica do sistema Jurássico Olhos da Fervença localiza-se no concelho de Cantanhede, distrito de Coimbra e ocorre no leito da Ribeira da Corujeira, sob uma forma borbulhante, como se fervesse. A formação jurássica está subjacente a uma cobertura de areias de duna, que impede a sua observação directa, recorrendo-se neste estudo à utilização de prospecção electromagnética no domínio do tempo, com o equipamento TEM-FAST 48. Realizaram-se 24 sondagens electromagnéticas cuja interpretação permitiu identificar estruturas de fracturação associadas à ocorrência da exsurgência.The karstic exsurgence of the Jurassic system Olhos da Fervença is located in Cantanhede region, Coimbra district (centre of Portugal) and occurs sparkling in the Ribeira da Corujeira stream. The Jurassic formation is under dune sands and is not possible to observe it directly. This study with electromagnetic prospection in the time domain uses TEM-FAST 48 equipment. The results of the interpretation of the 24 electromagnetic soundings allow the identification of fracture structures associated to the exsurgence

Acceptance of the bodypainting as supportive method to learn the surface locomotor apparatus anatomy of the horse

Although bodypainting has been reported as a great resource for teaching surface anatomy of humans, its use in veterinary anatomy has not been scientifically reported. In the present study, bodypainting was performed on 4 horses for anatomy teaching purposes of the equine locomotor apparatus. We aimed to use the bodypainting method as an additional tool to classic teaching and to test the relevance of our purpose. Twenty one Brazilian veterinary students were given a 90-min session, which included a presentation of painted horses, with opportunities for the students to ask questions and to palpate anatomic locations on the horses. Based on a questionnaire, there was unanimous student satisfaction with this technique. Furthermore, student scores on practical tests to evaluate the attention retain given immediately before and 1 h after the session were 33.9 ± 19.8% and 69.0 ± 18.4%, respectively (p < 0.001). We concluded that bodypainting has great potential for support the classic lectures of the equine locomotor apparatus

Modelling the particle contact influence on the Joule heating and temperature distribution during FLASH sintering

FLASH sintering is a field-assisted technique that allows the densification of ceramics in a few seconds at temperatures significantly lower than those of conventional cycles. There is still discussion among the scientific community about the mechanism behind this sintering process, that has been typically attributed to Joule heating, defect creation and movement or liquid phase assisted sintering. Computational modelling can be a powerful tool in helping to explain and predict this process. Using potassium sodium niobate (KNN) as a case study, a lead-free piezoelectric, this work explores Finite Element Modelling to evaluate the dependence of Joule heating generation and temperature distribution as a function of the cubic particle orientation

The role of particle contact in densification of FLASH sintered potassium sodium niobate

Potassium sodium niobate, K0.5Na0.5NbO3 (KNN) is a lead‐free piezoelectric with the potential to replace lead zirconate titanate (PZT) in electromechanical applications. Due to its cuboid particle morphology and volatile elements, monophasic and dense ceramics are difficult to obtain via conventional sintering. In this work, isothermal FLASH sintering produced uniformly densified KNN ceramics at 900 °C, 200 °C lower than conventional sintering. Specific surface area (SSA) analysis of pre‐FLASH ceramics revealed that a 30 min isothermal hold at 900 °C, before the application of electric field, increased the contact area between particles and was crucial to promote uniform densification. Finite element modelling (FEM) revealed why density is more uniform when using isothermal heating compared with a constant heating rate, commonly used in FLASH sintering. These results extend our understanding of FLASH sintering and illustrate its relevance for the development of lead‐free piezoelectrics

Gross morphometry of the heart of the Common marmoset

  The Callithrix jacchus is a Brazilian endemic species that has been widely used asan experimental model in biomedical research. Anatomical data are necessary to support experimental studies with this species. Eleven hearts of C. jacchus from the German Primate Centre (DPZ) have been studied in order to characterize their gross morphometry and compare them with other animal models and human. Biometric data were also obtained. The mean values for morphometry of the hearts did not show any significant difference between male and female. The relative heart weight was similar to human, bovine and equine species. Considering those aspects, the C. jacchus could be used as non-human primate experimental modelfor biomedical studies on heart.

Unravelling the effect of SrTiO3 antiferrodistortive phase transition on the magnetic properties of La0.7Sr0.3MnO3 thin films

Epitaxial La0.7Sr0.3MnO3 (LSMO) thin films, with different thicknesses ranging from 20 to 330 nm, were deposited on (1 0 0)-oriented strontium titanate (STO) substrates by pulsed laser deposition, with their structure and morphology characterized at room temperature. The magnetic and electric transport properties of the as-processed thin films reveal an abnormal behaviour in the temperature dependent magnetization M(T) below the antiferrodistortive STO phase transition (TSTO), and also an anomaly in the magnetoresistance and electrical resistivity close to the same temperature. Films with thickness ≤100 nm show an in-excess magnetization and pronounced changes in the coercivity due to the interface-mediated magnetoelastic coupling with antiferrodistortive domain wall movement occurring below TSTO. However, in thicker LSMO thin films, an in-defect magnetization is observed. This reversed behaviour can be understood with the emergence in the upper layer of the film, of a columnar structure needed to relax the elastic energy stored in the film, which leads to randomly oriented magnetic domain reconstructions. For enough high-applied magnetic fields, as thermodynamic equilibrium is reached, a full suppression of the anomalous magnetization occurs, wherein the temperature dependence of the magnetization starts to follow the expected Brillouin behaviour.This work was supported by the Fundação para a Ciencia e Tecnologia and COMPETE/QREN/EU, through the project PTDC/CTM/099415/2008. The authors are very grateful to Maria Joao Pereira and Maria Rosario Soares from CICECO, University of Aveiro, for the HR-XRD measurements and discussion of the results. F Figueiras acknowledges FCT grant SFRH/BPD/80663/2011. The authors also acknowledge Projeto Norte-070124-FEDER-000070 and Professor J Fontcuberta for their fruitful discussions

Microstructure evaluation of titanate based layered perovskites: Constrained vs. free sintering

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