972 resultados para work teams


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado em Sistemas de Informação

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Noble metal powders containing gold and silver have been used for many centuries, providing different colours in the windows of the medieval cathedrals and in ancient Roman glasses. Nowadays, the interest in nanocomposite materials containing noble nanoparticles embedded in dielectric matrices is related with their potential use for a wide range of advanced technological applications. They have been proposed for environmental and biological sensing, tailoring colour of functional coatings, or for surface enhanced Raman spectroscopy. Most of these applications rely on the so-called localised surface plasmon resonance absorption, which is governed by the type of the noble metal nanoparticles, their distribution, size and shape and as well as of the dielectric characteristics of the host matrix. The aim of this work is to study the influence of the composition and thermal annealing on the morphological and structural changes of thin films composed of Ag metal clusters embedded in a dielectric TiO2 matrix. Since changes in size, shape and distribution of the clusters are fundamental parameters for tailoring the properties of plasmonic materials, a set of films with different Ag concentrations was prepared. The optical properties and the thermal behaviour of the films were correlated with the structural and morphological changes promoted by annealing. The films were deposited by DC magnetron sputtering and in order to promote the clustering of the Ag nanoparticles the as-deposited samples were subjected to an in-air annealing protocol. It was demonstrated that the clustering of metallic Ag affects the optical response spectrum and the thermal behaviour of the films.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The ternary aluminium oxynitride (AlNxOy) system offers the possibility to obtain a wide range of properties by tailoring the ratio between pure Al, AlNx and AlOy and therefore opening a significant number of possible applications. In this work the thermal behaviour of AlNxOy thin films was analysed by modulated infrared radiometry (MIRR), taking as reference the binary AlOy and AlNx systems. MIRR is a non-contact and non-destructive thermal wave measurement technique based on the excitation, propagation and detection of temperature oscillations of very small amplitudes. The intended change of the partial pressure of the reactive gas (N2 and/or O2) influenced the target condition and hence the deposition characteristics which, altogether, affected the composition and microstructure of the films. Based on the MIRR measurements and their qualitative and quantitative interpretation, some correlations between the thermal transport properties of the films and their chemical/physical properties have been found. Furthermore, the potential of such technique applied in this oxynitride system, which present a wide range of different physical responses, is also discussed. The experimental results obtained are consistent with those reported in previous works and show a high potential to fulfil the demands needed for the possible applications of the systems studied. They are clearly indicative of an adequate thermal response if this particular thin film system is aimed to be applied in small sensor devices or in electrodes for biosignal acquisition, such as those for electroencephalography or electromyography as it is the case of the main research area that is being developed in the group.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this work, the thermal stability of TiAgx thin films, deposited by magnetron sputtering, was evaluated, envisaging their application in biomedical devices, namely as electrodes for biosignal acquisition. Based on the composition and microstructural characterization, a set of four representative TiAgx thin films was selected in order to infer whether they are thermally stable in terms of functional properties. In order to achieve this purpose, the structural and morphological evolution of the films with annealing temperature was correlated with their electrical, mechanical and thermal properties. Two distinct zones were identified and two samples from each zone were extensively analysed. In the first zone (zone I), Ti was the main component (Ti-rich zone) while in the second, zone II, the Ag content was more significant. The selected samples were annealed in vacuum at four different temperatures up to 500 oC. For the samples produced within zone I, small microstructural changes were observed due to the recrystallization of the Ti structure and grain size increment. Also, no significant changes were observed with annealing temperature regarding the f l ’ functional properties, being thermally stable up to 500 oC. For higher Ag contents (zone II) the energy supplied by thermal treatments was sufficient to activate the crystallization of Ti-Ag intermetallic phases. A strong increase of the grain size of these phases was also reported. The structural and morphological organization proved to be determinant for the physical responses of the TiAgx system. The hardness and Y g’s modulus were significantly improved with the formation of the intermetallic phases. The silver addition and annealing treatments also played an important role in the electrical conductivity of the films, which was once again improved by the formation of Ti-Ag phases. The thermal diffusivity of the films was practically unchanged with the heat-treatment. This set of results shows that this intermetallic-like thin film system has good thermal stability up to high temperatures (as high as 500 oC), which in case of the highest Ag content zone is particularly evident for electrical and mechanical properties, showing an important improvement. Hardness increases about three times, while resistivity values become half of those from the lowest Ag contents zone. These set of characteristics are consistent with the targeted applications, namely in terms of biomedical sensing devices.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado em Engenharia Mecânica

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Genome-scale metabolic models are valuable tools in the metabolic engineering process, based on the ability of these models to integrate diverse sources of data to produce global predictions of organism behavior. At the most basic level, these models require only a genome sequence to construct, and once built, they may be used to predict essential genes, culture conditions, pathway utilization, and the modifications required to enhance a desired organism behavior. In this chapter, we address two key challenges associated with the reconstruction of metabolic models: (a) leveraging existing knowledge of microbiology, biochemistry, and available omics data to produce the best possible model; and (b) applying available tools and data to automate the reconstruction process. We consider these challenges as we progress through the model reconstruction process, beginning with genome assembly, and culminating in the integration of constraints to capture the impact of transcriptional regulation. We divide the reconstruction process into ten distinct steps: (1) genome assembly from sequenced reads; (2) automated structural and functional annotation; (3) phylogenetic tree-based curation of genome annotations; (4) assembly and standardization of biochemistry database; (5) genome-scale metabolic reconstruction; (6) generation of core metabolic model; (7) generation of biomass composition reaction; (8) completion of draft metabolic model; (9) curation of metabolic model; and (10) integration of regulatory constraints. Each of these ten steps is documented in detail.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado integrado em Engenharia Industrial

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado em Educação Especial (área de especialização em Intervenção Precoce)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de mestrado em Educação Especial (área de especialização em Intervenção Precoce)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The last four decades have seen a dramatic increase in the number of women entering employment. This is particularly true in Europe and although more European women are working outside the home, the patterns of female employment have changed very little. An analysis of these patterns is presented. It was found that women continue to dominate specific fields, particularly teaching and service providing. An investigation of the interpersonal behavior differences among 117 American women from the southeastern United States in three work roles--homemakers, women in traditional occupations, and in nontraditional occupations--was conducted and the sex-role orientation, attitudes toward success, and demographic indicators were examined in order to consider the interplay of these variables with female occupational role and interpersonal behavior. A second focus of the study is on the cross-cultural comparison of the psychological and work variables in women of two different cultures: America and Portugal. Thirty-one Portuguese women were a preliminary comparison sample. The American results showed significant differences between groups in self-perceived interpersonal behaviors and the findings contradicted current stereotypes. The cross-cultural data, although preliminary, indicates differences between the countries in social desirability, aggressive and assertive behaviors, and in sex-role attitudes, which seem to reflect the different stages of economic development. (MKA)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This chapter identifies and analyzes some characteristics of working situations that are important in the construction of professional identities. It is claimed that professional identity presumes a dynamic process and is constructed and reconstructed in social situations and interactions. Work has a central place in the life of individuals and societies. The contexts of work are places par excellence for investment, expression, negotiation and recognition of the actor themselves and of others. They are, thus, situations for the attribution offeelings about work, ofrelational transactions, oflearning and production of professional know ledge, which are fundamental elements in the (re )construction of professional identity and which are emphasized here below.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação de Mestrado em Políticas de Desenvolvimento de Recursos Humanos