Perspetivas dos professores do 1º ciclo sobre a supervisão no processo de avaliação de desempenho e os seus efeitos no desenvolvimento profissional

Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ciências da Educação, especialização Supervisão em Educação

Branching points in the low-temperature dipolar hard sphere fluid

In this contribution, we investigate the low-temperature, low-density behaviour of dipolar hard-sphere (DHS) particles, i.e., hard spheres with dipoles embedded in their centre. We aim at describing the DHS fluid in terms of a network of chains and rings (the fundamental clusters) held together by branching points (defects) of different nature. We first introduce a systematic way of classifying inter-cluster connections according to their topology, and then employ this classification to analyse the geometric and thermodynamic properties of each class of defects, as extracted from state-of-the-art equilibrium Monte Carlo simulations. By computing the average density and energetic cost of each defect class, we find that the relevant contribution to inter-cluster interactions is indeed provided by (rare) three-way junctions and by four-way junctions arising from parallel or anti-parallel locally linear aggregates. All other (numerous) defects are either intra-cluster or associated to low cluster-cluster interaction energies, suggesting that these defects do not play a significant part in the thermodynamic description of the self-assembly processes of dipolar hard spheres. (C) 2013 AIP Publishing LLC.

Optical processing devices based on a-SiCH multilayer architectures

Red, green and blue optical signals were directed to an a-SiC:H multilayered device, each one with a specific transmission rate. The combined optical signal was analyzed by reading out, under different applied voltages, the generated photocurrent. Results show that when a chromatic time dependent wavelength combination with different transmission rates irradiates the multilayered structure, the device operates as a tunable wavelength filter and can be used in wavelength division multiplexing systems for short range communications. An application to fluorescent proteins detection is presented. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Optoelectronic properties of a-Si(1-x)C(x)H films grown in hydrogen diluted silane-methane plasma

This work reports on the optoelectronic properties and device application of hydrogenated amorphous silicon carbide (a-Si(1-x)C(x):H) films grown by plasma-enhanced chemical vapour deposition (PECVD). The films with an optical bandgap ranging from about 1.8 to 2.0 eV were deposited in hydrogen diluted silane-methane plasma by varying the radio frequency power. Several n-i-p structures with an intrinsic a-Si(1-x)C(x):H layer of different optical gaps were also fabricated. The optimized devices exhibited a diode ideality factor of 1.4-1.8, and a leakage current of 190-470 pA/cm(2) at -5 V. The density of deep defect states in a-Si(1-x)C(x):H was estimated from the transient dark current measurements and correlated with the optical bandgap and carbon content. Urbach energies for the valence band tail were also determined by analyzing the spectral response within sub-bandgap energy range. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Monte Carlo modeling and simulations of the High Definition (HD120) micro MLC and validation against measurements for a 6 MV beam

Purpose: The most recent Varian® micro multileaf collimator(MLC), the High Definition (HD120) MLC, was modeled using the BEAMNRCMonte Carlo code. This model was incorporated into a Varian medical linear accelerator, for a 6 MV beam, in static and dynamic mode. The model was validated by comparing simulated profiles with measurements. Methods: The Varian® Trilogy® (2300C/D) accelerator model was accurately implemented using the state-of-the-art Monte Carlo simulation program BEAMNRC and validated against off-axis and depth dose profiles measured using ionization chambers, by adjusting the energy and the full width at half maximum (FWHM) of the initial electron beam. The HD120 MLC was modeled by developing a new BEAMNRC component module (CM), designated HDMLC, adapting the available DYNVMLC CM and incorporating the specific characteristics of this new micro MLC. The leaf dimensions were provided by the manufacturer. The geometry was visualized by tracing particles through the CM and recording their position when a leaf boundary is crossed. The leaf material density and abutting air gap between leaves were adjusted in order to obtain a good agreement between the simulated leakage profiles and EBT2 film measurements performed in a solid water phantom. To validate the HDMLC implementation, additional MLC static patterns were also simulated and compared to additional measurements. Furthermore, the ability to simulate dynamic MLC fields was implemented in the HDMLC CM. The simulation results of these fields were compared with EBT2 film measurements performed in a solid water phantom. Results: Overall, the discrepancies, with and without MLC, between the opened field simulations and the measurements using ionization chambers in a water phantom, for the off-axis profiles are below 2% and in depth-dose profiles are below 2% after the maximum dose depth and below 4% in the build-up region. On the conditions of these simulations, this tungsten-based MLC has a density of 18.7 g cm− 3 and an overall leakage of about 1.1 ± 0.03%. The discrepancies between the film measured and simulated closed and blocked fields are below 2% and 8%, respectively. Other measurements were performed for alternated leaf patterns and the agreement is satisfactory (to within 4%). The dynamic mode for this MLC was implemented and the discrepancies between film measurements and simulations are within 4%. Conclusions: The Varian® Trilogy® (2300 C/D) linear accelerator including the HD120 MLC was successfully modeled and simulated using the Monte CarloBEAMNRC code by developing an independent CM, the HDMLC CM, either in static and dynamic modes.

Comunicação nas relações de longa distância: documentário "But it's Okay"

Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Audiovisual e Multimédia.

Consciencialização dos operadores turísticos para a consulta do viajante

Partindo de uma hipótese que se veio a demonstrar válida, de que os Operadores Turísticos em Portugal têm muito pouca informação sobre a consulta do viajante e o seu papel em responsabilidade na promoção da saúde dos seus clientes, apresenta-se neste trabalho não só uma análise da situação anteriormente referida como uma estratégia de comunicação visando consciencializar os Operadores Turísticos para a necessidade de fomentarem a adesão dos seus clientes à consulta do viajante. Dois temas emergem como centrais, nomeadamente a questão do turismo na nossa contemporaneidade e a saúde dos que viajem essencialmente para fora da Europa em turismo. Transversal a todo o trabalho encontra-se a noção de comunicação e saúde, especialmente na sua vertente de comunicação para a saúde. Defende-se que a comunicação para a saúde pode ser pensada como um fator competitivo para os Operadores Turísticos e apresenta-se uma estratégia de comunicação subordinada ao título: “Projeto de Consciencialização dos Operadores para a Consulta do Viajante”. Na primeira parte apresenta-se uma revisão da literatura e de outras fontes sobre os temas: Turismo, Consulta do Viajante e Comunicação para a Saúde, e na segunda parte o projeto que já referi. Partindo da hipótese inicialmente formulada, para uma análise completa da situação utilizaram-se metodologias de análise qualitativa e quantitativa junto dos principais públicos envolvidos a saber os Operadores Turísticos.

Radiatively induced Lorentz and CPT violation in Schwinger constant field approximation

The Schwinger proper-time method is an effective calculation method, explicitly gauge-invariant and nonperturbative. We make use of this method to investigate the radiatively induced Lorentz- and CPT-violating effects in quantum electrodynamics when an axial-vector interaction term is introduced in the fermionic sector. The induced Lorentz- and CPT-violating Chern-Simons term coincides with the one obtained using a covariant derivative expansion but differs from the result usually obtained in other regularization schemes. A possible ambiguity in the approach is also discussed. (C) 2001 Published by Elsevier Science B.V.

Reflexões em torno do ensino da sociologia em cursos de tecnologias da saúde

Com este artigo, pretende-se dar conta da reflexão resultante da experiência de ensino da sociologia na Escola Superior de Tecnologia da Saúde de Lisboa, nos últimos 12 anos. Após um breve enquadramento do contexto em que decorre esta experiência e da sua especificidade, procuram identificar-se os principais constrangimentos e questões que se foram colocando durante a prática lectiva das disciplinas de sociologia, relacionados com obstáculos epistemológicos e dificuldades referentes à articulação entre a mobilização de uma linguagem necessariamente compreensível para os estudantes e o imperativo de apresentação rigorosa dos temas propostos bem como com às vantagens e potenciais riscos da introdução de componentes de investigação. Por outro lado, abordam-se os objectivos e analisa-se o contributo do ensino da sociologia para a formação de técnicos de saúde, considerando a variabilidade do alcance das aprendizagens realizadas pelos (ex)estudantes.

James W. Carey as critical theorist of the information age

This paper suggests that the thought of the North-American critical theorist James W. Carey provides a relevant perspective on communication and technology. Having as background American social pragmatism and progressive thinkers of the beginning of the 20th century (as Dewey, Mead, Cooley, and Park), Carey built a perspective that brought together the political economy of Harold A. Innis, the social criticism of David Riesman and Charles W. Mills and incorporated Marxist topics such as commodification and sociocultural domination. The main goal of this paper is to explore the connection established by Carey between modern technological communication and what he called the “transmissive model”, a model which not only reduces the symbolic process of communication to instrumentalization and to information delivery, but also politically converges with capitalism as well as power, control and expansionist goals. Conceiving communication as a process that creates symbolic and cultural systems, in which and through which social life takes place, Carey gives equal emphasis to the incorporation processes of communication.If symbolic forms and culture are ways of conditioning action, they are also influenced by technological and economic materializations of symbolic systems, and by other conditioning structures. In Carey’s view, communication is never a disembodied force; rather, it is a set of practices in which co-exist conceptions, techniques and social relations. These practices configure reality or, alternatively, can refute, transform and celebrate it. Exhibiting sensitiveness favourable to the historical understanding of communication, media and information technologies, one of the issues Carey explored most was the history of the telegraph as an harbinger of the Internet, of its problems and contradictions. For Carey, Internet was seen as the contemporary heir of the communications revolution triggered by the prototype of transmission technologies, namely the telegraph in the 19th century. In the telegraph Carey saw the prototype of many subsequent commercial empires based on science and technology, a pioneer model for complex business management; an example of conflict of interest for the control over patents; an inducer of changes both in language and in structures of knowledge; and a promoter of a futurist and utopian thought of information technologies. After a brief approach to Carey’s communication theory, this paper focuses on his seminal essay "Technology and ideology. The case of the telegraph", bearing in mind the prospect of the communication revolution introduced by Internet. We maintain that this essay has seminal relevance for critically studying the information society. Our reading of it highlights the reach, as well as the problems, of an approach which conceives the innovation of the telegraph as a metaphor for all innovations, announcing the modern stage of history and determining to this day the major lines of development in modern communication systems.

Tunnig optical A-Sic/A-Si active filters by UV bias light in the visible and infrared spectral ranges

Visible range to telecom band spectral translation is accomplished using an amorphous SiC pi'n/pin wavelength selector under appropriate front and back optical light bias. Results show that background intensity works as selectors in the infrared region, shifting the sensor sensitivity. Low intensities select the near-infrared range while high intensities select the visible part according to its wavelength. Here, the optical gain is very high in the infrared/red range, decreases in the green range, stays close to one in the blue region and strongly decreases in the near-UV range. The transfer characteristics effects due to changes in steady state light intensity and wavelength backgrounds are presented. The relationship between the optical inputs and the output signal is established. A capacitive optoelectronic model is presented and tested using the experimental results. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Viability of the use of an A-SiC:H multiplayer device in a domestic VLC application

In this paper the viability of an integrated wavelength optical filter and photodetector for visible light communication (VLC) is discussed. The proposed application uses indoor warm light lamps lighting accomplished by ultra-bright light-emitting diodes (LEDs) pulsed at frequencies higher than the ones perceived by the human eye. The system was analyzed at two different wavelengths in the visible spectrum (430 nm and 626 nm) with variable optical intensities. The signals were transmitted into free space and measured using a multilayered photodetector based on a-SiC:H/a-Si:H. The detector works as an optical filter with controlled wavelength sensitivity through the use of optical bias. The output photocurrent was measured for different optical intensities of the transmitted optical signal and the extent of each signal was tested. The influence of environmental fluorescent lighting was also analysed in order to test the strength of the system. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Viability of the use of thin-film A-SiC:H photodiodes for protein identification

In this paper, we present a multilayer device based on a-Si:H/a-SiC:H that operates as photodetector and optical filter. The use of such device in protein detection applications is relevant in Fluorescence Resonance Energy Transfer (FRET) measurements. This method demands the detection of fluorescent signals located at specific wavelengths bands in the visible part of the electromagnetic spectrum. The device operates in the visible range with a selective sensitivity dependent on electrical and optical bias. Several nanosensors were tested with a commercial spectrophotometer to assess the performance of FRET signals using glucose solutions of different concentrations. The proposed device was used to demonstrate the possibility of FRET signals detection, using visible signals of similar wavelength and intensity. The device sensitivity was tuned to enhance the wavelength band of interest using steady state optical bias at 400 nm. Results show the ability of the device to detect signals in this range. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Are there hidden scalars in LHC Higgs results?

The Higgs boson recently discovered at the Large Hadron Collider has shown to have couplings to the remaining particles well within what is predicted by the Standard Model. The search for other new heavy scalar states has so far revealed to be fruitless, imposing constraints on the existence of new scalar particles. However, it is still possible that any existing heavy scalars would preferentially decay to final states involving the light Higgs boson thus evading the current LHC bounds on heavy scalar states. Moreover, decays of the heavy scalars could increase the number of light Higgs bosons being produced. Since the number of light Higgs bosons decaying to Standard Model particles is within the predicted range, this could mean that part of the light Higgs bosons could have their origin in heavy scalar decays. This situation would occur if the light Higgs couplings to Standard Model particles were reduced by a concomitant amount. Using a very simple extension of the SM - the two-Higgs doublet model we show that in fact we could already be observing the effect of the heavy scalar states even if all results related to the Higgs are in excellent agreement with the Standard Model predictions.