45 research outputs found

    Modelling of sea-ice phenomena Introduction

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    Effect of the C/N ratio modification on the corrosion behavior and performance of carbonitride coatings prepared by cathodic arc deposition

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    This study focuses on investigating carbonitride coatings, specifically CNTi-(Zr, ZrNb, and ZrSi), as promising candidates for enhancing the durability and efficiency of Ti6Al4V materials used in nuclear fusion technology. X-ray diffraction analysis identified distinct phases, including TiN, ZrN, ZrC, and TiC. The corrosion studies showed complete degradation of the TiN, ZrC, and ZrN phases in the TiZrCN coating after tests, while the TiC phase exhibited relative stability. The surface morphologies and elemental mapping analysis demonstrated the loss of homogeneity in element distribution after corrosion process. The addition of Si and Nb elements into TiZrCN significantly influenced the coatings' corrosion behavior, with breakaway corrosion observed in CNTi- (Zr and ZrSi) coatings and localized corrosion in CNTi-(ZrNb) coatings. Notably, the CNTi-(ZrSi) coating formed an oxide phase in the presence of NaCl, whereas the CNTi-(ZrNb) coating exhibited continuous resistance and a low corrosion rate. Irradiation was carried out for the generation of active isotopes, showing that no radioactive isotopes were formed in any of the investigated samples

    Markers for tumor margin assessment through raman spectroscopy in comparative oncology

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    The occurrence of tumour diseases in both animals and humans is continuously increasing. Research in nanosciences and molecular biology has put lately an intense effort to identify the aetiology factors and seek for new ways of diagnostic and targeted therapies aimed at reducing mortality and increasing chances to healing. Extensive development of cancer tumours is frequently counteracted through surgery. Assessment of a clean surgical margin is vital and a precise and rapid diagnostic down to molecule level represents a technical challenge with important clinical implications. We present a new way of using surgery instruments and surface enhanced Raman spectroscopy for direct ex vivo (no freezing, no staining) and in vivo diagnostic of clean margins in mammary tumour surgery of pets (dogs and cats).Raman spectroscopy extracts chemical information with reported 100%sensitivity, 100% specificity and overall accuracy of 93% in identifying carcinomas. Our main result stays in identification of a set of molecular markers (carotenoids, lipids and intramolecular water) for Raman diagnostic in cat and dog mammary tumour surgery. Those markers have already been confirmed for human patients

    Personality and morphological traits affect pigeon survival from raptor attacks

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    Personality traits have recently been shown to impact fitness in different animal species, potentially making them similarly relevant drivers as morphological and life history traits along the evolutionary pathways of organisms. Predation is a major force of natural selection through its deterministic effects on individual survival, but how predation pressure has helped to shape personality trait selection, especially in free-ranging animals, remains poorly understood. We used high-precision GPS tracking to follow whole flocks of homing pigeons (Columba livia) with known personalities and morphology during homing flights where they were severely predated by raptors. This allowed us to determine how the personality and morphology traits of pigeons may affect their risk of being predated by raptors. Our survival model showed that individual pigeons, which were more tolerant to human approach, slower to escape from a confined environment, more resistant to human handling, with larger tarsi, and with lighter plumage, were more likely to be predated by raptors. We provide rare empirical evidence that the personality of prey influences their risk of being predated under free-ranging circumstances.publishe

    Multifunctional Ti based carbonitride coatings for applications in severe environments

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    In this work, the influence of NbZr and ZrSi addition to TiCN coatings are studied, aiming for their use as protective layers for parts subjected to severe corrosion and wear. The coatings with C/N ratios ranging from 0.4 to 2.5 were deposited using the cathodic arc technique in a mixture of N2 and CH4 gases, on 316 stainless steel discs and Si (111) wafers. All the coatings exhibited residual compressive stresses, with values ranging from approximately-2.4 GPa to −3.5 GPa. The addition of Si led to an increase in hardness, regardless of the C/N ratio. All coatings with high C/N ratio (~2.5) presented slightly lower stress values and superior performance in 3.5% NaCl corrosive solutions, the best performance being obtained for the TiSiZrCN coating, which exhibited the highest protective efficiency to corrosion (97.8%), due to its low corrosion current density (1.734 μA/cm2) and high polarization resistance (31.775 kΩ). The tribological tests, performed at 23 °C and 250 °C, indicated that abrasion and oxidation were the predominant wear mechanism for all coatings. At 23 °C, the friction coefficients of the coated specimens were significantly lower than those of the uncoated samples. When the collective performance across all of the experimental parameters was assessed, the coatings with C/N of about 2.5 proved to be the most suitable candidates to be used in severe service conditions

    Europeanisation as empowerment of civil society: all smoke and mirrors?

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    The full-text of this book chapter is not available in ORA. Citation: Parau, C. E. & Bains, J. W. (2008). Europeanisation as empowerment of civil society: all smoke and mirrors? In: Maloney, W. A. & van Deth, J. W. (eds.) Civil society and governance in Europe: from national to international linkages. Cheltenham: Edward Elgar, pp. 109-126
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