RF Receiver Front End for 28.5 GHz Applications on a 70 GHz F-T SiGe BiCMOS Process

This article presents the design and test of a receiver front end aimed at LMDS applications at 28.5 GHz. It presents a system-level design after which the receiver was designed. The receiver comprises an LNA, quadrature mixer and quadrature local oscillator. Experimental results at 24 GHz center frequency show a conversion voltage gain of 15 dB and conversion noise figure of 14 5 dB. The receiver operates from a 2 5 V power supply with a total current consumption of 31 mA.

Cork processing wastewater treatment/valorisation by nanofiltration

Nanofiltration process for the treatment/valorisation of cork processing wastewaters was studied. A DS-5 DK 20/40 (GE Water Technologies) nanofiltration membrane/module was used, having 2.09 m(2) of surface area. Hydraulic permeability was determined with pure water and the result was 5.2 L.h(-1).m(-2).bar(-1). The membrane presents a rejection of 51% and 99% for NaCl and MgSO4 salts, respectively. Two different types of regimes were used in the wastewaters filtration process, total recycling mode and concentration mode. The first filtration regime showed that the most favourable working transmembrane pressure was 7 bar working at 25 degrees C. For the concentration mode experiments it was observed a 30% decline of the permeate fluxes when a volumetric concentration factor of 5 was reached. The permeate COD, BOD5, colour and TOC rejection values remained well above the 90% value, which allows, therefore, the concentration of organic matter (namely the tannin fraction) in the concentrate stream that can be further used by other industries. The permeate characterization showed that it cannot be directly discharged to the environment as it does not fulfil the values of the Portuguese discharge legislation. However, the permeate stream can be recycled to the process (boiling tanks) as it presents no colour and low TOC (< 60 ppm) or if wastewater discharge is envisaged we have observed that the permeate biodegradability is higher than 0.5, which renders conventional wastewater treatments feasible.

Innovation through virtual communities of Practice: motivation and constraints in the knowledge-creation process

Communities of Practice are places which provide a sound basis for organizational learning, enabling knowledge creation and acquisition thus improving organizational performance, leveraging innovation and consequently increasing competitively. Virtual Communities of Practice (VCoP‟s) can perform a central role in promoting communication and collaboration between members who are dispersed in both time and space. The ongoing case study, described here, aims to identify both the motivations and the constraints that members of an organization experience when taking part in the knowledge creating processes of the VCoP‟s to which they belong. Based on a literature review, we have identified several factors that influence such processes; they will be used to analyse the results of interviews carried out with the leaders of VCoP‟s in four multinationals. As future work, a questionnaire will be developed and administered to the other members of these VCoP‟s

Educational characteristics of adult students in portuguese technological schools

Despite a massive expansion of education in Portugal, since the 1970’s, educational attainment of the adult population in the country remains low. The numbers of working-age people in some form of continuing education are among the lowest, according to the OECD and EU-27 statistics. Technological Schools(TS), initially created in the 1990’s, under the umbrella of the Ministry of Economy in partnership with industry and industrial associations, aimed to prepare qualified staff for industries and services in the country, particularly in the engineering sector, through the provision of post secondary non-university programmes of studies, the CET (Technological Specialization Courses). Successful CET students are awarded a DET(Diploma of Technological Specialization), which corresponds to Vocational Qualification level IV of the EU, according to the latest alteration (2005) of the Education Systems Act (introduced in 1986). In this, CET’s are also clearly defined as one of the routes for access to Higher Education (HE), in Portugal. The PRILHE (Promoting Reflective and Independent Learning in Higher Education) multinational project, funded by the European Socrates Grundtvig Programme, aimed to identify the learning processes which enable adult students in higher education to become autonomous reflective learners and search best practices to support these learning processes. During this research, both quantitative and qualitative methods were used to determine how students organise their studies and develop their learning skills. The Portuguese partner in the project’ consortium used a two case studies approach, one with students of Higher Education Institutions and other with students of TS. This paper only applies to students of TS, as these have a predominant bias towards engineering. Results show that student motivation and professional teaching support contribute equally to the development of an autonomous and reflective approach to learning in adult students; this is essential for success in a knowledge economy, where lifelong learning is the key to continuous employment.

Virtual communities of practice: investigating motivations and constraints in the processes of knowledge creation and transfer

With accelerated market volatility, faster response times and increased globalization, business environments are going through a major transformation and firms have intensified their search for strategies which can give them competitive advantage. This requires that companies continuously innovate, to think of new ideas that can be transformed or implemented as products, processes or services, generating value for the firm. Innovative solutions and processes are usually developed by a group of people, working together. A grouping of people that share and create new knowledge can be considered as a Community of Practice (CoP). CoP’s are places which provide a sound basis for organizational learning and encourage knowledge creation and acquisition. Virtual Communities of Practice (VCoP's) can perform a central role in promoting communication and collaboration between members who are dispersed in both time and space. Nevertheless, it is known that not all CoP's and VCoP's share the same levels of performance or produce the same results. This means that there are factors that enable or constrain the process of knowledge creation. With this in mind, we developed a case study in order to identify both the motivations and the constraints that members of an organization experience when taking part in the knowledge creating processes of VCoP's. Results show that organizational culture and professional and personal development play an important role in these processes. No interviewee referred to direct financial rewards as a motivation factor for participation in VCoPs. Most identified the difficulty in aligning objectives established by the management with justification for the time spent in the VCoP. The interviewees also said that technology is not a constraint.

CVD of CrO(2): Towards a lower temperature deposition process

The deposition of highly oriented a-axis CrO(2) films onto Al(2)O(3)(0001) by atmospheric pressure (AP)CVD at temperatures as low as 330 C is reported. Deposition rates strongly depend on the substrate temperature, whereas for film surface microstructures the dependence is mainly on film thickness. For the experimental conditions used in this work, CrO(2) growth kinetics are dominated by a surface reaction mechanism with an apparent activation energy of (121.0 +/- 4.3) kJ mol(-1). The magnitude and temperature dependence of the saturation magnetization, up to room temperature, is consistent with bulk measurements.

The (well) informed piano : internalization and growth process

The subject matter of this book is about piano methodology, including technical, musical, artistic, ethical and philosophical issues and reflections. The purpose of this work is to share a personal professional experience insight in the field of piano performance. This text assumes a certain continuity to the major contributions of artists like Ludwig Deppe, Tobias Matthay, Grigory Kogan, Heinrich Neuhaus and George Kochevitsky. At the same time, it tries to integrate and complement this selected literature, bringing new ideas and hints to specific professional issues.

Human interaction with technology for working, communicating, and learning: advancements

The way humans interact with technology is undergoing a tremendous change. It is hard to imagine the lives we live today without the benefits of technology that we take for granted. Applying research in computer science, engineering, and information systems to non-technical descriptions of technology, such as human interaction, has shaped and continues to shape our lives. Human Interaction with Technology for Working, Communicating, and Learning: Advancements provides a framework for conceptual, theoretical, and applied research in regards to the relationship between technology and humans. This book is unique in the sense that it does not only cover technology, but also science, research, and the relationship between these fields and individuals' experience. This book is a must have for anyone interested in this research area, as it provides a voice for all users and a look into our future.

A perspetiva dos terapeutas ocupacionais sobre os seu trabalho enquanto elemento da equipa escolar

Atualmente, as escolas regem o seu funcionamento de acordo com o paradigma inclusivo, uma vez que a legislação em vigor assim o indica. A mudança entre o paradigma segregador (em que a crianças com problemáticas diversas eram ensinadas separadamente) para o paradigma inclusivo (em que todas as crianças deveriam usufruir de uma educação igualitária) surgiu decorrente das progressivas mudanças a nível social que vieram encorajar a aceitação da diferença e o reconhecimento da diversidade (Correia M. , 2008). Consequentemente, os serviços e apoios prestados pelas equipas escolares também sofreram alterações, passando a considerar cada criança como um individuo com necessidades únicas, às quais o contexto deve proporcionar um ensino igualitário e de qualidade (Pape, Ryba, & Case-Smith, 2004; Jenkinson, Hyde, & Ahmad, 2008). Nestas equipas escolares, encontra-se presente como elemento ativo, o terapeuta ocupacional. Assim, o presente estudo pretende conhecer a perspetiva dos terapeutas ocupacionais a trabalhar nas equipas escolares em contexto inclusivo quanto às experiências de colaboração com a equipa que intervém com a criança. Esteve na sua base uma metodologia qualitativa, em que amostra é constituída por cinco terapeutas ocupacionais, a trabalhar em escolas e jardins-de-infância contemplando a zona norte do país. Foi utilizado o método de amostragem estratégica, de forma a contemplar várias realidades. Como instrumento de recolha de dados foi utilizada a entrevista semiestruturada, com posterior análise de conteúdo para interpretação e discussão dos dados obtidos. Os principais resultados indicam que os terapeutas descrevem o seu papel com base na passagem de estratégias e promoção da autonomia. Reconhecem, ainda, vários benefícios decorrentes do trabalho em equipa de forma colaborativa. Contudo, relatam as experiências de colaboração, maioritariamente pela negativa, tendo por base as barreiras e desafios que encontram para efetivar este processo. Deixam, também, sugestões de aspetos a melhorar, embora não contemplem todas as barreiras/desafios sentidos na colaboração com a restante equipa escolar.

Organization knowledge management change from a complex adaptive systems perpective with ability for ambidexeterity

We are working on the confluence of knowledge management, organizational memory and emergent knowledge with the lens of complex adaptive systems. In order to be fundamentally sustainable organizations search for an adaptive need for managing ambidexterity of day-to-day work and innovation. An organization is an entity of a systemic nature, composed of groups of people who interact to achieve common objectives, making it necessary to capture, store and share interactions knowledge with the organization, this knowledge can be generated in intra-organizational or inter-organizational level. The organizations have organizational memory of knowledge of supported on the Information technology and systems. Each organization, especially in times of uncertainty and radical changes, to meet the demands of the environment, needs timely and sized knowledge on the basis of tacit and explicit. This sizing is a learning process resulting from the interaction that emerges from the relationship between the tacit and explicit knowledge and which we are framing within an approach of Complex Adaptive Systems. The use of complex adaptive systems for building the emerging interdependent relationship, will produce emergent knowledge that will improve the organization unique developing.

O papel da supervisão na avaliação de desempenho docente

Com as várias reformulações do processo de avaliação de desempenho docente (ADD), passou-se de um processo de avaliação dos professores assente na autoavaliação do docente, para um sistema de heteroavaliação que visa a prestação de contas e a seleção, mas também a melhoria de práticas e o desenvolvimento profissional, através do acompanhamento supervisivo. No entanto, a conciliação entre estas duas perspetivas não é fácil e tem gerado perplexidades e inquietações entre os avaliadores e entre os avaliados. Com este estudo, pretendemos conhecer a perspetiva de avaliadores e avaliados sobre o papel que a Supervisão detém no processo de avaliação de desempenho do professor e o seu contributo para o desenvolvimento profissional do professor e melhoria das práticas. Assim desenhou-se um plano de estudo qualitativo, exploratório e descritivo procurando captar o ponto de vista dos principais intervenientes no processo. O principal meio de recolha de dados foi a entrevista semiestruturada a 4 professores avaliadores e 4 professores avaliados do Departamento de Matemática e Ciências Experimentais de um Agrupamento de Escolas. Os resultados mostram que os docentes discordam do modelo de ADD, mas que o processo vivenciado teve caraterísticas positivas, dando os avaliadores especial relevância à oportunidade de conhecer outros processos de trabalho, a partir da observação de aulas. Avaliadores e avaliados referem ainda o bom relacionamento estabelecido entre ambos, contradizendo as preocupações expressas quando se pronunciaram sobre os problemas do modelo de avaliação. No entanto, ambos os subgrupos focam a falta de formação e qualificação profissional dos avaliadores. Em termos gerais, é possível concluir que a maior parte das dificuldades atribuídas pelos docentes ao modelo de ADD não foi depois sentida na implementação prática. Por outro lado, na opinião dos docentes, o processo experienciado não teve verdadeiro impacto na melhoria das práticas ou no desenvolvimento profissional dos docentes envolvidos. - Abstract The several reformulations of the process of the teacher performance evaluation made the process of evaluating teachers, which was first based on a self-evaluation change into a straight assessment system, which aims not only accountability and selection, but also the improvement of the practice and professional development through the supervision of the teaching practice. However, the conciliation between these perspectives has not been easy and has generated anxieties and perplexities among evaluators and evaluated. With this study we intend to know the perspective of the evaluators and of the evaluated concerning the role supervision has hold in the process of evaluating a teacher’s performance and its contribution to the professional development of the teacher and to the improvement of his practices. Thus, a qualitative, exploratory and descriptive study plan was drawn to get to know the viewpoint of the intervening ones in the process. The main means for data collection was based on a semi structured interview, targeting 4 teacher evaluators and 4 evaluated teachers of the Experimental Sciences and Mathematics Department of a group of Schools. The results show that teachers disagree with the teacher’s evaluation model, but the experienced process had positive characteristics. Besides, evaluators have given special relevance to the opportunity of getting to know other working methods thanks to the lessons’ observations. Evaluators and evaluated also refer the good relationship between both parts contradicting the fears they had when they first pronounced themselves about this evaluation model. However, both subgroups focus the lack of training and professional qualifications of the evaluators. So it’s possible to conclude that most worries mentioned by the teachers when referring to this model of teacher performance evaluation were not verified during its practical implementation. On the other hand, in the opinion of the involved teachers, the experienced process had no real impact on their practice improvement or on their professional development.

A entrada na profissão do educador de infância: percursos singulares

Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção do grau de Mestre em Ciências da Educação - Especialidade Supervisão em Educação

Health and psychosocial effects of flexible working hours

OBJECTIVE: To examine whether any impairments in health and social lives can be found under different kinds of flexible working hours, and whether such effects are related to specific characteristics of these working hours. METHODS: Two studies - a company based survey (N=660) and an internet survey (N=528) - have been conducted. The first one was a questionnaire study (paper and pencil) on employees working under some 'typical' kinds of different flexible working time arrangements in different companies and different occupational fields (health care, manufacturing, retail, administration, call centres). The second study was an internet-based survey, using an adaptation of the questionnaire from the first study. RESULTS: The results of both studies consistently show that high variability of working hours is associated with increased impairments in health and well-being and this is especially true if this variability is company controlled. These effects are less pronounced if variability is self-controlled; however, autonomy does not compensate the effects of variability. CONCLUSIONS: Recommendations for an appropriate design of flexible working hours should be developed in order to minimize any impairing effects on health and psychosocial well-being; these recommendations should include - besides allowing for discretion in controlling one's (flexible) working hours - that variability in flexible working hours should be kept low (or at least moderate), even if this variability is self-controlled.

Working hours, work-life conflict and health in precarious and "permanent" employment

OBJECTIVE: The expansion of precarious employment in OECD countries has been widely associated with negative health and safety effects. Although many shiftworkers are precariously employed, shiftwork research has concentrated on full-time workers in continuing employment. This paper examines the impact of precarious employment on working hours, work-life conflict and health by comparing casual employees to full-time, "permanent" employees working in the same occupations and workplaces. METHODS: Thirty-nine convergent interviews were conducted in two five-star hotels. The participants included 26 full-time and 13 casual (temporary) employees. They ranged in age from 19 to 61 years and included 17 females and 22 males. Working hours ranged from zero to 73 hours per week. RESULTS: Marked differences emerged between the reports of casual and full-time employees about working hours, work-life conflict and health. Casuals were more likely to work highly irregular hours over which they had little control. Their daily and weekly working hours ranged from very long to very short according to organisational requirements. Long working hours, combined with low predictability and control, produced greater disruption to family and social lives and poorer work-life balance for casuals. Uncoordinated hours across multiple jobs exacerbated these problems in some cases. Health-related issues reported to arise from work-life conflict included sleep disturbance, fatigue and disrupted exercise and dietary regimes. CONCLUSIONS:This study identified significant disadvantages of casual employment. In the same hotels, and doing largely the same jobs, casual employees had less desirable and predictable work schedules, greater work-life conflict and more associated health complaints than "permanent" workers.