Reabilitação térmica e energética de edifício antigo: aplicação ao antigo edifício dos CTT em Coruche

O estudo desenvolvido no presente documento teve como alvo um edifício antigo construído entre 1930 e 1940 no concelho de Coruche, com construção característica da sua época. Numa fase inicial analisou-se de que forma se comporta o edifício em termos térmicos e energéticos, com base nas metodologias de cálculo apresentadas pelo regulamento térmico em vigor (RCCTE, 2006), e de seguida foram analisadas várias soluções existentes para a reabilitação térmica e energética do edifício que poderá ser concretizada, essencialmente devido às soluções para isolamento térmico das paredes, pavimentos e cobertura, assim como devido às soluções para vidros e caixilharia dos vãos envidraçados. Numa fase posterior, foi estudada a aplicação isolada das várias soluções de reabilitação consideradas, tendo sido simulada a aplicação de várias espessuras de isolante para as soluções da envolvente opaca e vários tipos de vidro duplo e caixilharia para as soluções da envolvente envidraçada, de forma a perceber-se a implicação que cada uma tem quanto à variação das necessidades energéticas do edifício. Por fim, foram calculados os custos de aplicação das várias soluções estudadas, com auxílio de um software de orçamentação, de forma que estas possam ser comparadas em termos da relação custo/benefício, em que, o benefício de cada solução será a variação provocada nas necessidades energéticas do edifício com aplicação da mesma. Assim, procurará encontrar-se para o edifício em estudo não só as soluções mais vantajosas em termos energéticos mas também as mais rentáveis, e procurará perceber-se se um investimento numa intervenção de reabilitação deste género conduzirá a um período de retorno do investimento reduzido, que possa ser considerado aceitável.

Optimização de recursos na construção de linhas de caminhos de ferro

Os Caminhos-de-ferro representam um conjunto de abordagens quase ilimitadas, nestes termos, o tema proposto – “A optimização de recursos na construção de linhas de Caminhos de Ferro”, incidirá particularmente sobre a optimização dos recursos: i) materiais; ii) mão-de-obra; iii) equipamentos, afectos a construção da via e da catenária. O presente estudo pretende traçar um encadeamento lógico e intuitivo que permita manter um fio condutor ao longo do todo o seu desenvolvimento, razão pela qual, a sequência dos objectivos apresentados constitui um caminho que permitira abrir sucessivas janelas de conhecimento. O conhecimento da via e da catenária, a compreensão da forma como os trabalhos interagem com os factores externos e a experiência na utilização das ferramentas de planeamento e gestão, são qualidades que conduzem certamente a bons resultados quando nos referimos a necessidade de optimizar os recursos na construção da via e da catenária. A transmissão e reciprocidade da informação, entre as fases de elaboração de propostas e de execução da obra, representam um recurso que pode conduzir a ganhos de produtividade. A coordenação e outro factor determinante na concretização dos objectivos de optimização dos recursos, que se efectua, quer internamente, quer exteriormente. A optimização de recursos na construção da via e da catenária representa o desafio permanente das empresas de construção do sector ferroviário. E neste pressuposto que investem na formação e especialização da sua mão-de-obra e na renovação tecnológica dos seus equipamentos. A optimização dos materiais requer aproximações distintas para o caso da via e para o caso da catenária, assim como, os equipamentos e a mão-de-obra não podem ser desligados, pois não funcionam autonomamente, no entanto a respectiva optimização obedece a pressupostos diferentes.

Eastwards / westwards: which direction for gender studies in the 21st century?

Eastwards / Westwards: Which Direction for Gender Studies in the XXIst Century? is a collection of essays which focus on themes and methods that characterize current research into gender in Asian countries in general. In this collection, ideas derived from Gender Studies elsewhere in the world have been subjected to scrutiny for their utility in helping to describe and understand regional phenomena. But the concepts of Local and Global – with their discoursive productions – have not functioned as a binary opposition: localism and globalism are mutually constitutive and researchers have interrogated those spaces of interaction between the ‘self’ and the ‘other’, bearing in mind their own embeddedness in social and cultural structures and their own historical memory. Contributors to this collection provided a critical transnational perspective on some of the complex effects of the dynamics of cultural globalization, by exploring the relation between gender and development, language, historiography, education and culture. We have also given attention to the ideological and rhetorical processes through which gender identity is constructed, by comparing textual grids and patterns of expectation. Likewise, we have discussed the role of ethnography, anthropology, historiography, sociology, fiction, popular culture and colonial and post-colonial sources in (re)inventing old/new male/female identities, their conversion into concepts and circulation through time and space. This multicultural and trans-disciplinary selection of essays is totally written in English, fully edited and revised, therefore, it has a good potential for an immediate international circulation. This project may trace new paths and issues for discussion on what concerns the life, practices and narratives by and about women in Asia, as well as elsewhere in the present day global experience. Academic readership: Researchers, scholars, educators, graduate and post-graduate students, doctoral students and general non-fiction readers, with a special interest in Gender Studies, Asia, Colonial and Post-Colonial Literature, Anthropology, Cultural Studies, History, Historiography, Politics, Race, Feminism, Language, Linguistics, Power, Political and Feminist Agendas, Popular Culture, Education, Women’s Writing, Religion, Multiculturalism, Globalisation, Migration. Chapter summary: 1. “Social Gender Stereotypes and their Implication in Hindi”, Anjali Pande, Jawaharlal Nehru University, New Delhi, India. This essay looks at the subtle ways in which gender identities are constructed and reinforced in India through social norms of language use. Language itself becomes a medium for perpetuating gender stereotypes, forcing its speakers to confirm to socially defined gender roles. Using examples from a classroom discussion about a film, this essay will highlight the underlying rigid male-female stereotypes in Indian society with their more obvious expressions in language. For the urban woman in India globalisation meant increased economic equality and exposure to changed lifestyles. On an individual level it also meant redefining gender relations and changing the hierarchy in man-­woman relationships. With the economic independence there is a heightened sense of liberation in all spheres of social life, a confidence to fuzz the rigid boundaries of gender roles. With the new films and media celebrating this liberated woman, who is ready to assert her sexual needs, who is ready to explode those long held notions of morality, one would expect that the changes are not just superficial. But as it soon became obvious in the course of a classroom discussion about relationships and stereotypes related to age, the surface changes can not become part of the common vocabulary, for the obvious reason that there is still a vast gap between the screen image of this new woman and the ground reality. Social considerations define the limits of this assertiveness of women, whereas men are happy to be liberal within the larger frame of social sanctions. The educated urban woman in India speaks in favour of change and the educated urban male supports her, but one just needs to scratch the surface to see the time tested formulae of gender roles firmly in place. The way the urban woman happily balances this emerging promise of independence with her gendered social identity, makes it necessary to rethink some aspects of looking at gender in a gradually changing, traditional society like India. 2. “The Linguistic Dimension of Gender Equality”, Alissa Tolstokorova, Kiev Centre for Gender Information and Education, Ukraine. The subject-matter of this essay is gender justice in language which, as I argue, may be achieved through the development of a gender-related approach to linguistic human rights. The last decades of the 20th century, globally marked by a “gender shift” in attitudes to language policy, gave impetus to the social movement for promoting linguistic gender equality. It was initiated in Western Europe and nowadays is moving eastwards, as ideas of gender democracy progress into developing countries. But, while in western societies gender discrimination through language, or linguistic sexism, was an issue of concern for over three decades, in developing countries efforts to promote gender justice in language are only in their infancy. My argument is that to promote gender justice in language internationally it is necessary to acknowledge the rights of women and men to equal representation of their gender in language and speech and, therefore, raise a question of linguistic rights of the sexes. My understanding is that the adoption of the Universal Declaration of Linguistic Rights in 1996 provided this opportunity to address the problem of gender justice in language as a human rights issue, specifically as a gender dimension of linguistic human rights. 3. “The Rebirth of an Old Language: Issues of Gender Equality in Kazakhstan”, Maria Helena Guimarães, Polytechnic Institute of Porto, Portugal. The existing language situation in Kazakhstan, while peaceful, is not without some tension. We propose to analyze here some questions we consider relevant in the frame of cultural globalization and gender equality, such as: free from Russian imperialism, could Kazakhstan become an easy prey of Turkey’s “imperialist dream”? Could these traditionally Muslim people be soon facing the end of religious tolerance and gender equality, becoming this new old language an easy instrument for the infiltration in the country of fundamentalism (it has already crossed the boarders of Uzbekistan), leading to a gradual deterioration of its rich multicultural relations? The present structure of the language is still very fragile: there are three main dialects and many academics defend the re-introduction of the Latin alphabet, thus enlarging the possibility of cultural “contamination” by making the transmission of fundamentalist ideas still easier through neighbour countries like Azerbaijan, Uzbekistan and Turkmenistan (their languages belong to the same sub-group of Common Turkic), where the Latin alphabet is already in use, and where the ground for such ideas shown itself very fruitful. 4. “Construction of Womanhood in the Bengali Language of Bangladesh”, Raasheed Mahmood; University of New South Wales, Sydney. The present essay attempts to explore the role of gender-based language differences and of certain markers that reveal the status accorded to women in Bangladesh. Discrimination against women, in its various forms, is endemic in communities and countries around the world, cutting across class, race, age, and religious and national boundaries. One cannot understand the problems of gender discrimination solely by referring to the relationship of power or authority between men and women. Rather one needs to consider the problem by relating it to the specific social formation in which the image of masculinity and femininity is constructed and reconstructed. Following such line of reasoning this essay will examine the nature of gender bias in the Bengali language of Bangladesh, holding the conviction that as a product of social reality language reflects the socio-cultural behaviour of the community who speaks it. This essay will also attempt to shed some light on the processes through which gender based language differences produce actual consequences for women, who become exposed to low self-esteem, depression and systematic exclusion from public discourse. 5. “Marriage in China as an expression of a changing society”, Elisabetta Rosado David, University of Porto, Portugal, and Università Ca’Foscari, Venezia, Italy. In 29 April 2001, the new Marriage Law was promulgated in China. The first law on marriage was proclaimed in 1950 with the objective of freeing women from the feudal matrimonial system. With the second law, in 1981, values and conditions that had been distorted by the Cultural Revolution were recovered. Twenty years later, a new reform was started, intending to update marriage in the view of the social and cultural changes that occurred with Deng Xiaoping’s “open policy”. But the legal reform is only the starting point for this case-study. The rituals that are followed in the wedding ceremony are often hard to understand and very difficult to standardize, especially because China is a vast country, densely populated and characterized by several ethnic minorities. Two key words emerge from this issue: syncretism and continuity. On this basis, we can understand tradition in a better way, and analyse whether or not marriage, as every social manifestation, has evolved in harmony with Chinese culture. 6. “The Other Woman in the Portuguese Colonial Empire: The Case of Portuguese India”, Maria de Deus Manso, University of Évora, Portugal. This essay researches the social, cultural and symbolic history of local women in the Portuguese Indian colonial enclaves. The normative Portuguese overseas history has not paid any attention to the “indigenous” female populations in colonial Portuguese territories, albeit the large social importance of these social segments largely used in matrimonial and even catholic missionary strategies. The first attempt to open fresh windows in the history of this new field was the publication of Charles Boxer’s referential study about Women in lberian Overseas Expansion, edited in Portugal only after the Revolution of 1975. After this research we can only quote some other fragmentary efforts. In fact, research about the social, cultural, religious, political and symbolic situation of women in the Portuguese colonial territories, from the XVI to the XX century, is still a minor historiographic field. In this essay we discuss this problem and we study colonial representations of women in the Portuguese Indian enclaves, mainly in the territory of Goa, using case studies methodologies. 7. “Heading East this Time: Critical Readings on Gender in Southeast Asia”, Clara Sarmento, Polytechnic Institute of Porto, Portugal. This essay intends to discuss some critical readings of fictional and theoretical texts on gender condition in Southeast Asian countries. Nowadays, many texts about women in Southeast Asia apply concepts of power in unusual areas. Traditional forms of gender hegemony have been replaced by other powerful, if somewhat more covert, forms. We will discuss some universal values concerning conventional female roles as well as the strategies used to recognize women in political fields traditionally characterized by male dominance. Female empowerment will mean different things at different times in history, as a result of culture, local geography and individual circumstances. Empowerment needs to be perceived as an individual attitude, but it also has to be facilitated at the macro­level by society and the State. Gender is very much at the heart of all these dynamics, strongly related to specificities of historical, cultural, ethnic and class situatedness, requiring an interdisciplinary transnational approach.

Criação de um Microtesauro na área da Dança

Dissertação realizada no âmbito do Mestrado em Ciências Documentais, Variante Bibliotecas e Centros de Documentação, da Universidade Lusófona de Humanidades e Tecnologias(ULHT). [O documento original encontra-se depositado no Repositório Científico Lusófona]

Estudo do paradigma: computação em nuvem

Na atual conjuntura económica, onde a globalização convive com a crise, as empresas confrontam-se com dois indeclináveis desafios, a expansão para novos mercados e a redução dos custos. A inevitabilidade de lidar com uma crescente quantidade de informação, na manutenção dos serviços prestados e na implementação de outros, obriga a uma sofisticada evolução dos meios informáticos. Para evoluir de forma pouco onerosa, é imprescindível a adoção de infraestruturas computacionais ágeis. Neste contexto emergem estratégias sustentadas na adoção do paradigma Computação em Nuvem (CN). Este paradigma sugere infraestruturas virtuais, escaláveis e com gestão automática de recursos, partilhadas no mesmo modelo de negócio. A forma de definir os custos, designada por pay as you go, é baseada no uso. Procurando garantir uma constante adaptação às exigências do negócio, a CN proporciona confiança e qualidade de serviço, reduzindo o risco associado ao lançamento de aplicações e o tempo de resposta. O objetivo deste trabalho é estudar o paradigma CN e perscrutar a sua projeção num futuro próximo, analisando as suas vantagens e inconvenientes. Nesse âmbito, é proposta uma arquitetura para integrar equipamentos de bilhética empregues para, designadamente, vender, validar e fiscalizar títulos de transportes. Para avaliar a arquitetura proposta foi implementado um demonstrador na plataforma Windows Azure.

Caminhamento fotogramétrico com arranjo triangular de câmaras fotográficas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Monte Carlo simulation of the basic features of the GE Millennium MG single photon emission computed tomography gamma camera

Objective - To describe and validate the simulation of the basic features of GE Millennium MG gamma camera using the GATE Monte Carlo platform. Material and methods - Crystal size and thickness, parallel-hole collimation and a realistic energy acquisition window were simulated in the GATE platform. GATE results were compared to experimental data in the following imaging conditions: a point source of 99mTc at different positions during static imaging and tomographic acquisitions using two different energy windows. The accuracy between the events expected and detected by simulation was obtained with the Mann–Whitney–Wilcoxon test. Comparisons were made regarding the measurement of sensitivity and spatial resolution, static and tomographic. Simulated and experimental spatial resolutions for tomographic data were compared with the Kruskal–Wallis test to assess simulation accuracy for this parameter. Results - There was good agreement between simulated and experimental data. The number of decays expected when compared with the number of decays registered, showed small deviation (≤0.007%). The sensitivity comparisons between static acquisitions for different distances from source to collimator (1, 5, 10, 20, 30cm) with energy windows of 126–154 keV and 130–158 keV showed differences of 4.4%, 5.5%, 4.2%, 5.5%, 4.5% and 5.4%, 6.3%, 6.3%, 5.8%, 5.3%, respectively. For the tomographic acquisitions, the mean differences were 7.5% and 9.8% for the energy window 126–154 keV and 130–158 keV. Comparison of simulated and experimental spatial resolutions for tomographic data showed no statistically significant differences with 95% confidence interval. Conclusions - Adequate simulation of the system basic features using GATE Monte Carlo simulation platform was achieved and validated.

Arte Pública: divulgação do património cultural da cidade do Porto

Mestrado em Engenharia Informática. Sistemas Gráficos e Multimédia

Gestão do risco em mercados de energia eléctrica recorrendo ao VaR por simulação de Monte Carlo

Mestrado em Engenharia Electrotécnica – Sistemas Eléctricos de Energia.

Reabilitação sustentável de edifício de habitação, em construção tradicional, no Baixo Alentejo

Dissertação de Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil Especialização em Edificações

Metal deposition using Ionic liquids

There is an interest to create zinc/tin alloys to replace cadmium as a corrosion protective coating material. Existing aqueous electroplating systems for these alloys are commercially available but have several limitations. Dangerous and highly toxic complexing agents are uses e.g. cyanides. To overcome these problems, ionic liquids could provide a solution to obtain an alloy containing 20 to 30% of zinc. Ionic liquids (IL’s) often have wider electrochemical windows which allow the deposition of e.g. refractive metals that can not be deposited from aqueous solutions. In IL’s it is often not necessary to add complexing agents. The Zn/Sn alloy deposition from IL’s is therefore a promising application for the plating industry. Nevertheless, there are some issues with this alternative for aqueous systems. The degradation of the organic components, the control of the concentration of two metals and the risk of a two phase deposition instead of an alloy had to be overcome first. It is the main purpose of this thesis to obtain a Zn/Sn alloy with 20% zinc using IL’s as an electrolyte. First a separate study was performed on both the zinc and the tin deposition. Afterwards, an attempt to deposit a Zn/Sn alloy was made. An introduction to a study about the electrodeposition of refractive metals concludes this work. It initiated the research for oxygen-free IL’s to deposit molybdenum or tungsten. Several parameters (temperature, metal source and concentration, organic complexing agents,…) were optimized for both the zinc, tin and zinc/tin deposition. Experiments were performed both in a parallel plate cell and a Hull cell, so as to investigate the effect of current density as well. Ethaline200 was selected as electrolyte. As substrate, brass and iron were selected, while as anode a plate of the metal to deposit was chosen, tin for the alloy. The best efficiencies were always obtained on brass; however the iron substrate resulted in the best depositions. A concentration of 0.27M ZnCl2, 0.07M SnCl2 with 0.015M of K3-HEDTA as complexant resulted in a deposition containing the desired alloy with the amount of 20% zinc and 80% tin with good appearance. Refractory metals as molybdenum and tungsten cannot be electrodeposited from aqueous solutions without forming a co-deposition with Ni, Co or Fe. Here, IL’s could again provide a solution. A first requirement is the dissolution of a metal source. MoO3 could be suitable, however there are doubts about using oxides. Oxygen-free IL’s were sought for. A first attempt was the combination of ZnCl2 with chlormequat (CCC), which gave liquids below 150°C in molar ratios of 2 : 1 and 3 : 1. Unfortuna tely, MoO3 didn’t dissolve in these IL’s. Another route to design oxygen-free IL’s was the synthesis of quaternary ammonium salts. None of the methods used, proved viable as reaction time was long and resulted in very low yields. Therefore, no sufficient quantities were obtained to perform the possible electrochemical behavior of refractive metals.

Comparison of Aspergillus species-complexes detected in different environmental settings

Purpose: Samples from different environmental sources were screened for the presence of Aspergillus, and the distribution of the different species-complexes was determined in order to understand differences among that distribution in the several environmental sources and which of these species complexes are present in specific environmental settings. Methods: Four distinct environments (beaches, poultries, swineries and hospital) were studied and analyzed for which Aspergillus complexes were present in each setting. After plate incubation and colony isolation, morphological identification was done using macro- and microscopic characteristics. The universal fungal primers ITS1 and ITS4 were used to amplify DNA from all Aspergillus isolates, which was sequenced for identification to species complex level. SPSS v15.0 for Windows was used to perform the statistical analysis. Results: Thirty-nine isolates of Aspergillus were recovered from both the sand beach and poultries, 31 isolates from swineries, and 80 isolates from hospital environments, for a total 189 isolates. Eleven species complexes were found total. Isolates belonging to the Aspergillus Versicolores species-complex were the most frequently found (23.8%), followed by Flavi (18.0%), Fumigati (15.3%) and Nigri (13.2%) complexes. A significant association was found between the different environmental sources and the distribution of the several species-complexes (p<0.001); the hospital environment had a greater variability of species-complexes than other environmental locations (10 in hospital environment, against nine in swine, eight in poultries and seven in sand beach). Isolates belonging to Nidulantes complex were detected only in the hospital environment, whereas the other complexes were identified in more than one setting. Conclusion: Because different Aspergillus complexes have different susceptibilities to antifungal drugs, and different abilities in producing mycotoxins, knowledge of the species-complex epidemiology for each setting may allow preventive or corrective measures to be taken toward decreasing professional workers or patient exposure to those agents.

NZEB e os novos revestimentos

Dissertação de natureza científica para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Edificações

MyListBox

As redes sociais são estruturas compostas por indivíduos ou grupos que estão relacionados por gostos e preferências, culturas ou origens e valores ou ideais. Há alguns anos para cá, o conceito de rede social expandiu-se para a internet, e de um modo geral as redes sociais online têm como objectivo a criação de um perfil e a partilha do mesmo com amigos. Hoje em dia, há redes sociais que cumprem vários objectivos diferentes, seja apenas para partilhar o perfil de uma identidade (pessoa, grupo ou organização), seja para atingir um serviço específico, por exemplo partilhar o Curriculum Vitae. Embora haja muitos cépticos, as redes sociais ganham novos adeptos todos os dias, como tal, as redes sociais disponibilizam aplicações para dispositivos móveis para assim os seus utilizadores poderem obter a informação mais rápido, em qualquer altura, em qualquer lugar, no seu smartphone ou tablet. É imperativo que as aplicações para dispositivos móveis estão continuamente fornecer funcionalidades mais ricas, e mesmo apesar da actual aceitação das pessoas em relação aos dispositivos móveis, a tendência é para continuarem neste ritmo, ou até mesmo aumentar, pois os utilizadores estarão sempre a pedir mais, além disso, a concorrência entre os vendedores irá manter viva a evolução natural da tecnologia. Para construir uma empresa por trás de uma rede social exige um perfil empreendedor, e a vocação para o empreendedorismo não é baseada em Dna, cultura, origem ou religião, em breves palavras, não se nasce empreendedor. É algo que se desenvolve no tempo, e que se melhora com os erros cometidos, não só com os nossos mas como os erros de outros empreendedores. O espírito empreendedor é algo que cresce após a primeira ideia, e até mesmo antes, de forma inconsciente, através do desenvolvimento de competências específicas. A MyListBox é uma rede social que fornece um serviço específico, de criação de listas de presentes e partilha das mesmas com amigos e familiares, que disponibiliza aplicações para dispositivos móveis com iOS e Android, e futuramente aplicação para Windows Phone 7, que permitem os utilizadores acederem às suas listas, e às listas dos seus amigos a qualquer hora, em qualquer lugar mesmo não estando ligado à internet. No contexto do projecto MyListBox, o trabalho resultante desta tese teve como principais objectivos: - Apresentar as experiências no mundo do empreendedorismo - Resultados dos concursos de empreendedorismo - Estado da arte no universo das aplicações móveis - Avaliação dos mecanismos de segurança para aplicações móveis - Critérios da decisão na implementação dos métodos de consistência e replicação de dados.

Sistema de teste de transístores bipolares de junção e de efeito de campo

O estudo das curvas características de um transístor permite conhecer um conjunto de parâmetros essenciais à sua utilização tanto no domínio da amplificação de sinais como em circuitos de comutação. Deste estudo é possível obter dados em condições que muitas vezes não constam na documentação fornecida pelos fabricantes. O trabalho que aqui se apresenta consiste no desenvolvimento de um sistema que permite de forma simples, eficiente e económica obter as curvas características de um transístor (bipolar de junção, efeito de campo de junção e efeito de campo de metal-óxido semicondutor), podendo ainda ser utilizado como instrumento pedagógico na introdução ao estudo dos dispositivos semicondutores ou no projecto de amplificadores transistorizados. O sistema é constituído por uma unidade de condicionamento de sinal, uma unidade de processamento de dados (hardware) e por um programa informático que permite o processamento gráfico dos dados obtidos, isto é, traçar as curvas características do transístor. O seu princípio de funcionamento consiste na utilização de um conversor Digital-Analógico (DAC) como fonte de tensão variável, alimentando a base (TBJ) ou a porta (JFET e MOSFET) do dispositivo a testar. Um segundo conversor fornece a variação da tensão VCE ou VDS necessária à obtenção de cada uma das curvas. O controlo do processo é garantido por uma unidade de processamento local, baseada num microcontrolador da família 8051, responsável pela leitura dos valores em corrente e em tensão recorrendo a conversores Analógico-Digital (ADC). Depois de processados, os dados são transmitidos através de uma ligação USB para um computador no qual um programa procede à representação gráfica, das curvas características de saída e à determinação de outros parâmetros característicos do dispositivo semicondutor em teste. A utilização de componentes convencionais e a simplicidade construtiva do projecto tornam este sistema económico, de fácil utilização e flexível, pois permite com pequenas alterações