Optimal behavior of responsive residential demand considering hybrid phase change materials

Due to communication and technology developments, residential consumers are enabled to participate in Demand Response Programs (DRPs), control their consumption and decrease their cost by using Household Energy Management (HEM) systems. On the other hand, capability of energy storage systems to improve the energy efficiency causes that employing Phase Change Materials (PCM) as thermal storage systems to be widely addressed in the building applications. In this paper, an operational model of HEM system considering the incorporation of more than one type of PCM in plastering mortars (hybrid PCM) is proposed not only to minimize the customerâ s cost in different DRPs but also to guaranty the habitantsâ  satisfaction. Moreover, the proposed model ensures the technical and economic limits of batteries and electrical appliances. Different case studies indicate that implementation of hybrid PCM in the buildings can meaningfully affect the operational pattern of HEM systems in different DRPs. The results reveal that the customerâ s electricity cost can be reduced up to 48% by utilizing the proposed model.

The impact of poor power quality in solar photovoltaic microgeneration: technical problems and losses of revenue

This paper presents a critical and quantitative analysis of the influence of the Power Quality in grid connected solar photovoltaic microgeneration installations. First are introduced the main regulations and legislation related with the solar photovoltaic microgeneration, in Portugal and Europe. Next are presented Power Quality monitoring results obtained from two residential solar photovoltaic installations located in the north of Portugal, and is explained how the Power Quality events affect the operation of these installations. Afterwards, it is described a methodology to estimate the energy production losses and the impact in the revenue caused by the abnormal operation of the electrical installation. This is done by comparing the amount of energy that was injected into the power grid with the theoretical value of energy that could be injected in normal conditions. The performed analysis shows that Power Quality severally affects the solar photovoltaic installations operation. The losses of revenue in the two monitored installations M1 and M2 are estimated in about 27% and 22%, respectively.

Sustainable mortars with incorporation of microencapsulated phase change materials

The construction industry is responsible for high energy and raw materials consumption. Thus, it is important to minimize the high energy consumption by taking advantage of renewable energy sources and reusing industrial waste, decreasing the extraction of natural materials. The mortars with incorporation of phase change materials (PCM) have the ability to regulate the temperature inside buildings, contributing to the thermal comfort and reduction of the use of heating and cooling equipment, using only the energy supplied by the sun. The simultaneous incorporation of PCM and fly ash (FA) can reduce the energy consumption and the amount of materials landfilled. However, the addition of these materials in mortars modifies its characteristics. The main purpose of this study was the production and characterization in the fresh and hardened state of mortars with incorporation of different contents of PCM and FA. The binders studied were aerial lime, hydraulic lime, gypsum and cement. The proportion of PCM studied was 0%, 20%, 40% and 60% of the mass of the sand. The content of fly ash added to the mortars was 0%, 20%, 40% and 60% of the mass of the binder. It was possible to observe that the incorporation of PCM and fly ash in mortars caused differences in properties such as workability, microstructure, water absorption, compressive strength, flexural strength and adhesion.

Assessing the feasibility of impregnating phase change materials in lightweight aggregate for development of thermal energy storage systems

This paper assesses the feasibility of impregnation/encasement of phase change materials (PCMs) in lightweight aggregates (LWAs). An impregnation process was adopted to carry out the encasement study of two different PCMs in four different LWAs. The leakage of the impregnated/encased PCMs was studied when they were submitted to freeze/thawing and oven drying tests, separately. The results confirmed that, the impregnation/encasement method is effective with respect to the large thermal energy storage density, and can be suitable for applications were PCMs cannot be incorporated directly such as asphalt road pavements.

A construção de um currículo de project-based learning: o currículo ideal e o currículo formal

O objetivo deste trabalho é apresentar os resultados da análise das concepções de dois protagonistas de uma reforma curricular que está sendo implementada numa escola de engenharia. A principal característica do novo currículo é o uso de projetos e oficinas como atividades complementares a serem realizadas pelos estudantes. As atividades complementares acontecerão em paralelo ao trabalho realizado nas disciplinas sem que haja uma relação de interdisciplinaridade. O novo currículo está sendo implantado desde fevereiro de 2015. Segundo Pacheco (2005) há dois momentos, dentre outros, no processo de mudança curricular, o currículo “ideal”, determinado por dimensões epistemológica, política, econômica, ideológica, técnica, estética, e histórica e, que recebe influência direta daquele que idealiza e cria o novo currículo e, o currículo “formal” que se traduz na prática implementada na escola. São essas duas etapas estudadas nesta pesquisa. Para isso serão considerados como fontes de dados dois protagonistas, um mais ligado à concepção do currículo e outro da sua implementação, a partir dos quais se busca compreender as motivações, crenças e percepções que, por sua vez, determinam a reforma curricular. Entrevistas semiestruturadas foram utilizadas como técnica de pesquisa, com o propósito de se entender a gênese da proposta e as mudanças entre essas duas etapas. Os dados revelam que mudanças aconteceram desde a idealização até a formalização do currículo, motivadas por demandas do processo de implementação, revela ainda diferenças na visão de currículo e a motivação para romper com padrões na formação de engenheiros no Brasil.

Benefits from energy related building renovation beyond costs, energy and emissions

The relevance of the building sector in the global energy use as well as in the global carbon emissions, both in the developed and developing countries, makes the improvement of the overall energy performance of existing buildings an important part of the actions to mitigate climate changes. Regardless of this potential for energy and emissions saving, large scale building renovation has been found hard to trigger, mainly because present standards are mainly focused on new buildings, not responding effectively to the numerous technical, functional and economic constraints of the existing ones. One of the common problems in the assessment of building renovation scenarios is that only energy savings and costs are normally considered, despite the fact that it has been long recognized that investment on energy efficiency and low carbon technologies yield several benefits beyond the value of saved energy which can be as important as the energy cost savings process. Based on the analysis of significant literature and several case studies, the relevance of co-benefits achieved in the renovation process is highlighted. These benefits can be felt at the building level by the owner or user (like increased user comfort, fewer problems with building physics, improved aesthetics) and should therefore be considered in the definition of the renovation measures, but also at the level of the society as a whole (like health effects, job creation, energy security, impact on climate change), and from this perspective, policy makers must be aware of the possible crossed impacts among different areas of the society for the development of public policies.

Green composites for advanced technical applications

This paper provides an overview of properties and application of natural fibre composites. Natural fibre market, merits and demerits, surface treatment techniques, properties of some recently developed natural fibre composites and applications have been discussed.

Recensão de Lee, E. (2005). How internet radio can change the world : an activist’s handbook. Nova Iorque : iUniverse, Inc.

(Excerto) O entusiasmo pela comunicação digital percorre transversalmente a obra How Internet Radio Can Change the World: An Activist’s Handbook, de Eric Lee. Esta postura tão apologista das possibilidades comunicativas oferecidas pela Internet reforça provavelmente um conjunto alargado de entendimentos sobre a conquista do quotidiano pelo digital. Em 1967, McLuhan e Fiore já se referiam aos circuitos eletrónicos como ‘extensões do sistema nervoso central’. Numa leitura mais contemporânea, José Bragança de Miranda refere: “vivemos, nos nossos dias, no meio de conexões, de links, do on‑line, estamos votados à participação, à ‘interactividade’, etc. Algo de novo está a emergir” (2001, p. 265). Maria Teresa Cruz (2001) define a convergência tecnológica das relações sociais como a ‘mobilização erótica da técnica’. Esta obra aqui recenseada pretende, assim, desafiar a utilização da rádio digital para “melhorar a comunicação e solidificar as organizações” (p. 1), em torno de três grupos de reflexão.

Fashion communication: a way to change comsumption behaviour towards ethical fashion

In view of the major social and environmental problems, with which we are faced nowadays, we noticed a certain absence of values in society, where man draws many more resources than nature can replace in the short or medium term. Within the framework of fashion emerges the ethical fashion as a movement in this direction, intending to change this current paradigm. Ethical fashion encompasses different concepts such as fair trade, sustainability, working conditions, raw materials, social responsibility and the protection of animals. This study aims to determine which type of communication are fashion brands using in this context, and if this communication aims at educating the consumer for a more ethical consumer behavior. For this study were selected 44 fashion brands associated with the Ethical Trade Initiative. The method used for the research development was content analysis for which first was made a data collection of the information provided on the websites and social networks of the selected fashion brands. The data was analyzed taking into account the quality and type of information published related to ethical fashion, for which an ordinal scale was created as a way of measuring and comparing results.

Development and psychometric properties of ECPICID-AVC to measure informal caregivers’ skills when caring for older stroke survivors at home

Introduction: Informal caregivers provide a significant part of the total care needed by dependent older people poststroke. Although informal care is often the preferred option of those who provide and those who receive informal care, informal caregivers often report lack of preparation to take care of older dependent people. This article outlines the development and psychometric testing of informal caregivers’ skills when providing care to older people after a stroke – ECPICID-AVC. Design: Prospective psychometric instrument validation study. Methods: Eleven experts participated in a focus group in order to delineate, develop and validate the instrument. Data were gathered among adult informal caregivers (n = 186) living in the community in Northern Portugal from August 2013 to January 2014. Results: The 32-item scale describes several aspects of informal caregiver’s skills. The scale has eight factors: skill to feed/hydrate by nasogastric feeding, skill to assist the person in personal hygiene, skill to assist the person for transferring, skill to assist the person for positioning, skill to provide technical aids, skill to assist the person to use the toilet, skill to feed/hydrate and skill to provide technical aids for dressing/undressing. Analysis demonstrated adequate internal consistency (Cronbach’s alpha = 0.83) and good temporal stability 0.988 (0.984–0.991). Conclusion: The psychometric properties of the measurement tool showed acceptable results allowing its implementation in clinical practice by the nursing community staff for evaluating practical skills in informal caregivers when providing care to older stroke survivors living at home.

Narrative change in Gloria Films: Comparing various processes of therapeutic innovation

Aims: The present study focuses on the analysis of novelty emergence in classic Gloria Films with Rogers, Perls, and Ellis to understand how the same client formulated her own problem and if and how change occurred in those three sessions. Method: The Innovative Moments Coding System was applied to track innovative moments (IMs) and their themes. Results: The session with Rogers showed more diversity in disclosed problems and themes of IMs, as well as a higher proportion of reflection IMs. The session with Perls demonstrated a high proportion of protest IMs. The session with Ellis showed less innovation than other sessions. The changes found were based mostly on reflection and protest IMs in three sessions. Conclusion: Narrative innovations occurred in the three single sessions. The type of dominant innovation is consistent with the therapeutic model and the IMs model. The exploration of the IMs’ themes allowed a more precise identification of Gloria's new narrative positions and their development throughout those sessions.

Thin films composed of gold nanoparticles dispersed in a dielectric matrix: the influence of the host matrix on the optical and mechanical responses

Gold nanoparticles were dispersed in two different dielectric matrices, TiO2 and Al2O3, using magnetron sputtering and a post-deposition annealing treatment. The main goal of the present work was to study how the two different host dielectric matrices, and the resulting microstructure evolution (including both the nanoparticles and the host matrix itself) promoted by thermal annealing, influenced the physical properties of the films. In particular, the structure and morphology of the nanocomposites were correlated with the optical response of the thin films, namely their localized surface plasmon resonance (LSPR) characteristics. Furthermore, and in order to scan the future application of the two thin film system in different types of sensors (namely biological ones), their functional behaviour (hardness and Young's modulus change) was also evaluated. Despite the similar Au concentrations in both matrices (~ 11 at.%), very different microstructural features were observed, which were found to depend strongly on the annealing temperature. The main structural differences included: (i) the early crystallization of the TiO2 host matrix, while the Al2O3 one remained amorphous up to 800 °C; (ii) different grain size evolution behaviours with the annealing temperature, namely an almost linear increase for the Au:TiO2 system (from 3 to 11 nm), and the approximately constant values observed in the Au:Al2O3 system (4–5 nm). The results from the nanoparticle size distributions were also found to be quite sensitive to the surrounding matrix, suggesting different mechanisms for the nanoparticle growth (particle migration and coalescence dominating in TiO2 and Ostwald ripening in Al2O3). These different clustering behaviours induced different transmittance-LSPR responses and a good mechanical stability, which opens the possibility for future use of these nanocomposite thin film systems in some envisaged applications (e.g. LSPR-biosensors).

Portuguese internet radio from 2006 to 2009: technical readiness and openness to interaction

[Extrat] The advent of thc internet raised questions about the role of radio in a fast-changing media environment. Many voices forecast its end but in the summer of 2008 the Swedish Radio and TV Authority published a study named 'The Future of Radio', which clearly opposed the pessimism of recent analysis. While the study anticipates the exhaustion of the FM model, it clearly broadens perspectives for DAB and internet radio, highlighting digitalization as the key element for the future relevance of radio. The Portuguese researcher and radio professional João Paulo Meneses states that 'the future of radio relies upon the internet', calling the broad service offerings of the net the pathway for the survival of radio from the threats to its two essential aspects: rnobility and accumulation (Meneses 2008). Accumulation is radio's capability to be used in a non­exclusive manner, which means that a listener can use the radio while performing other activities, like cooking, sewing, reading, writing or jogging.

Utilização de gás natural comprimido em veículos pesados de passageiros

Dissertação de mestrado em Engenharia Mecânica

Technical requirements for the use of C&DW recycled aggregates in municipal and rural roads and trenches

The use of construction and demolition waste (C&DW) in the construction industry is an important contribution to attain sustainability in the sector. The roads are among the civil engineering works which can use larger quantities of C&DW recycled aggregates. In Portugal, the limit values for the properties of C&DW recycled aggregates that can be used in the roads of Portuguese Road Network are defined by two Laboratório Nacional de Engenharia Civil (LNEC) technical specifications (TS), in accordance to Portuguese Decree-law no. 46/2008 of May 12th. Municipal and rural roads and trenches have specific characteristics that can enable the use of C&DW of lower quality than those required by existing LNEC TS, and even then ensuring an adequate performance. However, given the absence of specific regulation for those applications, the Portuguese Environment Agency requires compliance with the existing LNEC TS, which represents an obstacle to recycling a significant part of the C&DW, in particular at a local government level. This paper presents guidelines for the recycling of C&DW in municipal and rural roads and in trenches, which could be considered in a new forthcoming LNEC TS. In the preparation of the guidelines, the bibliography collected and analysed, the information gathered from the application of C&DW in a municipal and rural roads of a Portuguese municipality and in the roadways of a Portuguese resort, and the results of laboratory tests carried out on samples collected in the Portuguese municipality were taken into consideration.