Management and Control of Water Supply Systems

The fast increase in the energy’s price has brought a growing concern about the highly expensive task of transporting water. By creating an hydraulic model of the Water Supply System’s (WSS) network and predicting its behaviour, it is possible to take advantage of the energy’s tariffs, reducing the total cost on pumping activities. This thesis was developed, in association with a technology transfer project called the E-Pumping. It focuses on finding a flexible supervision and control strategy, adaptable to any existent Water Supply System (WSS), as well as forecasting the water demand on a time period chosen by the end user, so that the pumping actions could be planned to an optimum schedule, that minimizes the total operational cost. The OPC protocol, associated to a MySQL database were used to develop a flexible tool of supervision and control, due to their adaptability to function with equipments from various manufacturers, being another integrated modular part of the E-Pumping project. Furthermore, in this thesis, through the study and performance tests of several statistical models based on time series, specifically applied to this problem, a forecasting tool adaptable to any station, and whose model parameters are automatically refreshed at runtime, was developed and added to the project as another module. Both the aforementioned modules were later integrated with an Graphical User Interface (GUI) and installed in a pilot application at the ADDP’s network. The implementation of this software on WSSs across the country will reduce the water supply companies’ running costs, improving their market competition and, ultimately, lowering the water price to the end costumer.

Characterization of RSOA modulators in radio over fiber links

In this work physical and behavioral models for a bulk Reflective Semiconductor Optical Amplifier (RSOA) modulator in Radio over Fiber (RoF) links are proposed. The transmission performance of the RSOA modulator is predicted under broadband signal drive. At first, the simplified physical model for the RSOA modulator in RoF links is proposed, which is based on the rate equation and traveling-wave equations with several assumptions. The model is implemented with the Symbolically Defined Devices (SDD) in Advanced Design System (ADS) and validated with experimental results. Detailed analysis regarding optical gain, harmonic and intermodulation distortions, and transmission performance is performed. The distribution of the carrier and Amplified Spontaneous Emission (ASE) is also demonstrated. Behavioral modeling of the RSOA modulator is to enable us to investigate the nonlinear distortion of the RSOA modulator from another perspective in system level. The Amplitude-to-Amplitude Conversion (AM-AM) and Amplitude-to-Phase Conversion (AM-PM) distortions of the RSOA modulator are demonstrated based on an Artificial Neural Network (ANN) and a generalized polynomial model. Another behavioral model based on Xparameters was obtained from the physical model. Compensation of the nonlinearity of the RSOA modulator is carried out based on a memory polynomial model. The nonlinear distortion of the RSOA modulator is reduced successfully. The improvement of the 3rd order intermodulation distortion is up to 17 dB. The Error Vector Magnitude (EVM) is improved from 6.1% to 2.0%. In the last part of this work, the performance of Fibre Optic Networks for Distributed and Extendible Heterogeneous Radio Architectures and Service Provisioning (FUTON) systems, which is the four-channel virtual Multiple Input Multiple Output (MIMO), is predicted by using the developed physical model. Based on Subcarrier Multiplexing (SCM) techniques, four-channel signals with 100 MHz bandwidth per channel are generated and used to drive the RSOA modulator. The transmission performance of the RSOA modulator under the broadband multi channels is depicted with the figure of merit, EVM under di erent adrature Amplitude Modulation (QAM) level of 64 and 254 for various number of Orthogonal Frequency Division Multiplexing (OFDM) subcarriers of 64, 512, 1024 and 2048.

Novel hardware and software combination for automotive motorsport vehicles based on direct processing of graphical functions

The main motivation for the work presented here began with previously conducted experiments with a programming concept at the time named "Macro". These experiments led to the conviction that it would be possible to build a system of engine control from scratch, which could eliminate many of the current problems of engine management systems in a direct and intrinsic way. It was also hoped that it would minimize the full range of software and hardware needed to make a final and fully functional system. Initially, this paper proposes to make a comprehensive survey of the state of the art in the specific area of software and corresponding hardware of automotive tools and automotive ECUs. Problems arising from such software will be identified, and it will be clear that practically all of these problems stem directly or indirectly from the fact that we continue to make comprehensive use of extremely long and complex "tool chains". Similarly, in the hardware, it will be argued that the problems stem from the extreme complexity and inter-dependency inside processor architectures. The conclusions are presented through an extensive list of "pitfalls" which will be thoroughly enumerated, identified and characterized. Solutions will also be proposed for the various current issues and for the implementation of these same solutions. All this final work will be part of a "proof-of-concept" system called "ECU2010". The central element of this system is the before mentioned "Macro" concept, which is an graphical block representing one of many operations required in a automotive system having arithmetic, logic, filtering, integration, multiplexing functions among others. The end result of the proposed work is a single tool, fully integrated, enabling the development and management of the entire system in one simple visual interface. Part of the presented result relies on a hardware platform fully adapted to the software, as well as enabling high flexibility and scalability in addition to using exactly the same technology for ECU, data logger and peripherals alike. Current systems rely on a mostly evolutionary path, only allowing online calibration of parameters, but never the online alteration of their own automotive functionality algorithms. By contrast, the system developed and described in this thesis had the advantage of following a "clean-slate" approach, whereby everything could be rethought globally. In the end, out of all the system characteristics, "LIVE-Prototyping" is the most relevant feature, allowing the adjustment of automotive algorithms (eg. Injection, ignition, lambda control, etc.) 100% online, keeping the engine constantly working, without ever having to stop or reboot to make such changes. This consequently eliminates any "turnaround delay" typically present in current automotive systems, thereby enhancing the efficiency and handling of such systems.

Estudo da maquinabilidade das ligas Ti-6Al-4V e Co-28Cr-6Mo na fresagem de dispositivos biomédicos

Os estudos de maquinabilidade de biomateriais e outros materiais aplicados na área médica são extensos. Todavia, muitos destes estudos recorrem a modelos de geometria regular e operações elementares de maquinagem. Relativamente a estas, os estudos académicos atualmente disponíveis mostram que a tecnologia preferencial é o torneamento, opção que se fundamenta na simplicidade de análise (corte ortogonal). Saliente-se ainda que, neste contexto, a liga de titânio Ti-6Al-4V constitui o biomaterial mais utilizado. Numa perspetiva complementar, refira-se que as publicações científicas evidenciam que a informação disponível sobre a fresagem Ti-6Al-4V não é muito extensa e a do Co-28Cr-6Mo é quase inexistente. A presente dissertação enquadra-se neste domínio e representa mais uma contribuição para o estudo da maquinabilidade das ligas de Titânio e de crómio-cobalto. A aplicação de operações de maquinagem complexas, através do recurso a programas informáticos de fabrico assistido por computador (CAM), em geometrias complexas, como é o caso das próteses femorais anatómicas, e o estudo comparativo da maquinabilidade das ligas Co-28Cr-6Mo e Ti-6Al-4V, constituem os objetivos fundamentais deste trabalho de doutoramento. Neste trabalho aborda-se a problemática da maquinabilidade das ligas metálicas usadas nos implantes ortopédicos, nomeadamente as ligas de titânio, de crómiocobalto e os aços Inoxidáveis. Efetua-se ainda um estudo da maquinagem de uma prótese femoral com uma forma geométrica complexa, onde as operações de corte foram geradas recorrendo às tecnologias de fabrico assistido por computador (CAD/CAM). Posteriormente, procedeu-se ao estudo da maquinabilidade das duas ligas usadas neste trabalho, dando uma atenção particular à determinação das forças de corte para diferentes velocidades de corte. Para além da monitorização da evolução da força de corte, o desgaste das ferramentas, a dureza e a rugosidade foram avaliadas, em função da velocidade de corte imposta. Por fim, com base nas estratégias de maquinagem adotadas, analisa-se a maquinabilidade e selecionam-se os parâmetros de corte mais favoráveis para as ligas de Titânio e Crómio-cobalto. Os resultados obtidos mostram que a liga de crómio-cobalto induz maior valor de força de corte do que a liga de titânio. Observa-se um aumento progressivo das forças de corte quando a velocidade de corte aumenta, até atingir o valor máximo para a velocidade de corte de 80m/min, após a qual, a força de corte tende a diminuir. Apesar do fabricante das ferramentas recomendar a velocidade de corte de 50 m/min para ambos os materiais, conclui-se que a velocidade de corte de 65 m/min induz o mesmo desgaste na ferramenta de corte no caso da liga de titânio, e menor desgaste no caso da liga de crómio-cobalto.

Ferroelectric : CNTs structures fabrication for advanced functional nano devices

This work is about the combination of functional ferroelectric oxides with Multiwall Carbon Nanotubes for microelectronic applications, as for example potential 3 Dimensional (3D) Non Volatile Ferroelectric Random Access Memories (NVFeRAM). Miniaturized electronics are ubiquitous now. The drive to downsize electronics has been spurred by needs of more performance into smaller packages at lower costs. But the trend of electronics miniaturization challenges board assembly materials, processes, and reliability. Semiconductor device and integrated circuit technology, coupled with its associated electronic packaging, forms the backbone of high-performance miniaturized electronic systems. However, as size decreases and functionalization increases in the modern electronics further size reduction is getting difficult; below a size limit the signal reliability and device performance deteriorate. Hence miniaturization of siliconbased electronics has limitations. On this background the Road Map for Semiconductor Industry (ITRS) suggests since 2011 alternative technologies, designated as More than Moore; being one of them based on carbon (carbon nanotubes (CNTs) and graphene) [1]. CNTs with their unique performance and three dimensionality at the nano-scale have been regarded as promising elements for miniaturized electronics [2]. CNTs are tubular in geometry and possess a unique set of properties, including ballistic electron transportation and a huge current caring capacity, which make them of great interest for future microelectronics [2]. Indeed CNTs might have a key role in the miniaturization of Non Volatile Ferroelectric Random Access Memories (NVFeRAM). Moving from a traditional two dimensional (2D) design (as is the case of thin films) to a 3D structure (based on a tridimensional arrangement of unidimensional structures) will result in the high reliability and sensing of the signals due to the large contribution from the bottom electrode. One way to achieve this 3D design is by using CNTs. Ferroelectrics (FE) are spontaneously polarized and can have high dielectric constants and interesting pyroelectric, piezoelectric, and electrooptic properties, being a key application of FE electronic memories. However, combining CNTs with FE functional oxides is challenging. It starts with materials compatibility, since crystallization temperature of FE and oxidation temperature of CNTs may overlap. In this case low temperature processing of FE is fundamental. Within this context in this work a systematic study on the fabrication of CNTs - FE structures using low cost low temperature methods was carried out. The FE under study are comprised of lead zirconate titanate (Pb1-xZrxTiO3, PZT), barium titanate (BaTiO3, BT) and bismuth ferrite (BiFeO3, BFO). The various aspects related to the fabrication, such as effect on thermal stability of MWCNTs, FE phase formation in presence of MWCNTs and interfaces between the CNTs/FE are addressed in this work. The ferroelectric response locally measured by Piezoresponse Force Microscopy (PFM) clearly evidenced that even at low processing temperatures FE on CNTs retain its ferroelectric nature. The work started by verifying the thermal decomposition behavior under different conditions of the multiwall CNTs (MWCNTs) used in this work. It was verified that purified MWCNTs are stable up to 420 ºC in air, as no weight loss occurs under non isothermal conditions, but morphology changes were observed for isothermal conditions at 400 ºC by Raman spectroscopy and Transmission Electron Microscopy (TEM). In oxygen-rich atmosphere MWCNTs started to oxidized at 200 ºC. However in argon-rich one and under a high heating rate MWCNTs remain stable up to 1300 ºC with a minimum sublimation. The activation energy for the decomposition of MWCNTs in air was calculated to lie between 80 and 108 kJ/mol. These results are relevant for the fabrication of MWCNTs – FE structures. Indeed we demonstrate that PZT can be deposited by sol gel at low temperatures on MWCNTs. And particularly interesting we prove that MWCNTs decrease the temperature and time for formation of PZT by ~100 ºC commensurate with a decrease in activation energy from 68±15 kJ/mol to 27±2 kJ/mol. As a consequence, monophasic PZT was obtained at 575 ºC for MWCNTs - PZT whereas for pure PZT traces of pyrochlore were still present at 650 ºC, where PZT phase formed due to homogeneous nucleation. The piezoelectric nature of MWCNTs - PZT synthesised at 500 ºC for 1 h was proved by PFM. In the continuation of this work we developed a low cost methodology of coating MWCNTs using a hybrid sol-gel / hydrothermal method. In this case the FE used as a proof of concept was BT. BT is a well-known lead free perovskite used in many microelectronic applications. However, synthesis by solid state reaction is typically performed around 1100 to 1300 ºC what jeopardizes the combination with MWCNTs. We also illustrate the ineffectiveness of conventional hydrothermal synthesis in this process due the formation of carbonates, namely BaCO3. The grown MWCNTs - BT structures are ferroelectric and exhibit an electromechanical response (15 pm/V). These results have broad implications since this strategy can also be extended to other compounds of materials with high crystallization temperatures. In addition the coverage of MWCNTs with FE can be optimized, in this case with non covalent functionalization of the tubes, namely with sodium dodecyl sulfate (SDS). MWCNTs were used as templates to grow, in this case single phase multiferroic BFO nanorods. This work shows that the use of nitric solvent results in severe damages of the MWCNTs layers that results in the early oxidation of the tubes during the annealing treatment. It was also observed that the use of nitric solvent results in the partial filling of MWCNTs with BFO due to the low surface tension (<119 mN/m) of the nitric solution. The opening of the caps and filling of the tubes occurs simultaneously during the refluxing step. Furthermore we verified that MWCNTs have a critical role in the fabrication of monophasic BFO; i.e. the oxidation of CNTs during the annealing process causes an oxygen deficient atmosphere that restrains the formation of Bi2O3 and monophasic BFO can be obtained. The morphology of the obtained BFO nano structures indicates that MWCNTs act as template to grow 1D structure of BFO. Magnetic measurements on these BFO nanostructures revealed a week ferromagnetic hysteresis loop with a coercive field of 956 Oe at 5 K. We also exploited the possible use of vertically-aligned multiwall carbon nanotubes (VA-MWCNTs) as bottom electrodes for microelectronics, for example for memory applications. As a proof of concept BiFeO3 (BFO) films were in-situ deposited on the surface of VA-MWCNTs by RF (Radio Frequency) magnetron sputtering. For in situ deposition temperature of 400 ºC and deposition time up to 2 h, BFO films cover the VA-MWCNTs and no damage occurs either in the film or MWCNTs. In spite of the macroscopic lossy polarization behaviour, the ferroelectric nature, domain structure and switching of these conformal BFO films was verified by PFM. A week ferromagnetic ordering loop was proved for BFO films on VA-MWCNTs having a coercive field of 700 Oe. Our systematic work is a significant step forward in the development of 3D memory cells; it clearly demonstrates that CNTs can be combined with FE oxides and can be used, for example, as the next 3D generation of FERAMs, not excluding however other different applications in microelectronics.

Barrier properties of poly(lactic acid) based films

In recent years, the search for a environmentally friendly products has increased. One of the major challenges has been the demand for biodegradable materials that can replace plastic. If a few decades ago, plastic replaced, for example, the ivory in billiard balls, and in other products, saving the lives of thousands elephants, nowadays a replacement for that plastic is being searched, to prevent the change of the environmental conditions, essential to life in harmonly with the fauna and flora that the human specie has, in recent years, destroyed. Plastic is a petroleum derivate, whose price has been growing exponentially, mainly due to the fact of beind a cheap material and also to enable the production of products that are essential to modern life. Therefore, the petrochemical era is going to come to an end and a new environmentally sustainable era, based on biodegradable materials from renewable sources, will follow. The change to green routes only will be possible with the support of the major companies, and the implementation of drastic governmental law. Poly(lactic acid), PLA, is produced from the lactose present in the corn or sugarcane and has been intensively studied in recent years because if some limitants properties required its extrusion are overcome, it has the potential to replace the traditional polymers. PLA have high brittleness, low toughness and low tensile elongation. In this work, natural antioxidant (alpha-tocopherol) and synthetics antioxidants (BHT ant TBHQ) were added to the PLA with the aim not only to improve their flexibility, but also to create an active packaging to extend the shelf life of the foods and improve the organoleptic properties by preventing food losses. The impact of the addition of antioxidants into the PLA films, in its mechanical, thermal and barrier properties were studied by FTIR, DSC, SEM, AFM, DMA, TGA, QCM and time-lag techniques.

Alkaline-earth aluminosilicate-based glass and glass-ceramic sealants for functional applications

The planar design of solid oxide fuel cell (SOFC) is the most promising one due to its easier fabrication, improved performance and relatively high power density. In planar SOFCs and other solid-electrolyte devices, gas-tight seals must be formed along the edges of each cell and between the stack and gas manifolds. Glass and glass-ceramic (GC), in particular alkaline-earth alumino silicate based glasses and GCs, are becoming the most promising materials for gas-tight sealing applications in SOFCs. Besides the development of new glass-based materials, new additional concepts are required to overcome the challenges being faced by the currently existing sealant technology. The present work deals with the development of glasses- and GCs-based materials to be used as a sealants for SOFCs and other electrochemical functional applications. In this pursuit, various glasses and GCs in the field of diopside crystalline materials have been synthesized and characterized by a wide array of techniques. All the glasses were prepared by melt-quenching technique while GCs were produced by sintering of glass powder compacts at the temperature ranges from 800−900 ºC for 1−1000 h. Furthermore, the influence of various ionic substitutions, especially SrO for CaO, and Ln2O3 (Ln=La, Nd, Gd, and Yb), for MgO + SiO2 in Al-containing diopside on the structure, sintering and crystallization behaviour of glasses and properties of resultant GCs has been investigated, in relevance with final application as sealants in SOFC. From the results obtained in the study of diopside-based glasses, a bilayered concept of GC sealant is proposed to overcome the challenges being faced by (SOFCs). The systems designated as Gd−0.3 (in mol%: 20.62MgO−18.05CaO−7.74SrO−46.40SiO2−1.29Al2O3 − 2.04 B2O3−3.87Gd2O3) and Sr−0.3 (in mol%: 24.54 MgO−14.73 CaO−7.36 SrO−0.55 BaO−47.73 SiO2−1.23 Al2O3−1.23 La2O3−1.79 B2O3−0.84 NiO) have been utilized to realize the bi-layer concept. Both GCs exhibit similar thermal properties, while differing in their amorphous fractions, revealed excellent thermal stability along a period of 1,000 h. They also bonded well to the metallic interconnect (Crofer22APU) and 8 mol% yttrium stabilized zirconium (8YSZ) ceramic electrolyte without forming undesirable interfacial layers at the joints of SOFC components and GC. Two separated layers composed of glasses (Gd−0.3 and Sr−0.3) were prepared and deposited onto interconnect materials using a tape casting approach. The bi-layered GC showed good wetting and bonding ability to Crofer22APU plate, suitable thermal expansion coefficient (9.7–11.1 × 10–6 K−1), mechanical reliability, high electrical resistivity, and strong adhesion to the SOFC componets. All these features confirm the good suitability of the investigated bi-layered sealant system for SOFC applications.

14º Encontro Internacional de Arte e Tecnologia: #14.ART: arte e desenvolvimento humano

#14ART: Arte e Desenvolvimento Humano propõe-se discutir novos territórios para uma maior sustentabilidade, assim como debater futuras evoluções criativas. O evento procurará entrepor-se em zonas de contato entre domínios tradicionalmente separadas - a arte e a ciência, pesquisa acadêmica e práticas criativas independentes, politicas sustentáveis e engajamento social, para o século XXI. Pretende-se que a discussão se centre, sobretudo, sobre como explorar o potencial transformativo da arte na pós-média. Hoje, de acordo com vários pensadores - Rosalind Krauss, a Lev Manovich, Peter Weibel – estamos numa fase pós- média; não existe um só meio, nos nossos dias, que domine o discurso da pratica artística contemporânea no campo dos média, bem pelo contrário os média encontram-se, hoje, engajados no pensamento critico do discurso da contemporaneidade. Através dos eventos anteriores deste Encontro Internacional, ficou claro que a arte hoje - com as condições proporcionadas pelo discurso do pós-média - oferece um potencial muito mais inteligente e interessante elocução para as artes. No entanto, as qualidade simbólicas e estéticas, bem como o pensamento critico e os aspectos investigativos e de confronto teórico da “pré-média arte”, também se apresentam ser tão importantes para a “pós-media arte”, obrigando o discurso artístico a manter um fio condutor entre o físico (a obra) e o mental (conceito) - realidades e utopias.

Estudo experimental da aplicação de pré-esforço orgânico em cimbres autolançáveis

O presente artigo descreve o estudo experimental dum modelo reduzido de um cimbre autolançável reforçado com recurso à tecnologia de pré-esforço orgânico (OPS). Analisam-se os resultados obtidos e comprova-se que este sistema confere aos cimbres um significativo aumento da capacidade de carga, reduzindo simultaneamente as flechas de serviço. Confirmase também a exequibilidade técnica do sistema.

Intervenção da Escola Superior de Tecnologia na reabilitação estrutural do Teatro Lethes

O presente artigo descreve duma forma sumária a cooperação estabelecida entre a Universidade do Algarve (UAlg), através da Escola Superior de Tecnologia (EST), com a Delegação Regional do Algarve do Ministério da Cultura, no processo de reabilitação do Teatro Lethes, em Faro (Figura 1), levada a cabo pela empresa S.T.A.P. – Reparação, consolidação e modificação de estruturas, S.A.

Métodos dos momentos

Os métodos utilizados na resolução de problemas, nos vários ramos da Engenharia ou ciências aplicadas, baseiam-se, actualmente, em uma de duas categorias: métodos analíticos e métodos numéricos. É preferível a utilização dos métodos analíticos, na resolução de equações ou outros modelos matemáticos, sempre que possível, uma vez que formamões gerais em vez de particularizadas, para além de uma maior informação.

Valorização de aguardentes de fruto e licores tradicionais como suporte de desenvolvimento na Serra Algarvia

Durante séculos, os segredos envolvidos no fabrico de produtos tradicionais, passaram verbalmente de geração em geração. Contudo, a busca de melhores condições sociais levou, nas últimas décadas, ao desenvolvimento de grandes centros urbanos, onde praticamente tudo o que se consome provém de outras regiões do país ou do estrangeiro.

Início do estudo do envelhecimento da aguardente de medronho

A cor nos destilados indica geralmente um prévio envelhecimento. Os consumidores associam tal facto a um produto de qualidade. Refiram-se os casos dos whiskies e dos brandies. A aguardente de medronho não foge à regra, sendo preferida nos casos em que apresenta cor. No entanto a qualidade deve ser confirmada pelo aroma e sabor, bem como pelas análises químicas. Com efeito, o processo da obtenção da cor nem sempre é o mais adequado. Com o duplo objectivo de estudar o processo mais adequado para obter uma aguardente medronheira velha de qualidade e de a tipificar de modo a identificar eventuais fraudes, a Escola Superior de Tecnologia da Universidade do Algarve (EST-UAlg) em parceria com a Direcção Regional de Agricultura do Algarve (DRAALG) candidataram-se a um projecto PAMAF-IE

Contribuição para a avaliação do risco sísmico: aplicação à cidade de Faro

O programa SRAPOR permite a realização de rápidas avaliações de risco sísmico de aglomerados habitacionais. A presente versão é constituída por uma base de dados de sismos, por um sistema simplificado de informação geográfica e por um módulo de avaliação da casualidade sísmica. A aplicação do programa é ilustrada com a análise da casualidade sísmica da cidade de Faro.

O novo perfil do engenheiro civil: o profissional de síntese

O Homem tem modificado consideravelmente o meio natural e transformado profundamente as paisagens primitivas. As vias de comunicação e os aglomerados populacionais constituem referências evidentes da sua presença e denotam o percurso do homem no tempo. Neste processo de mudança contínua o papel dos engenheiros foi fundamental pois a sua prática remonta às civilizações anteriores à era Cristã da qual temos o testemunho de Arquimedes (287-212 a.C.) que foi um grande cientista e engenheiro da Antiguidade. O termo engenharia em termos semânticos tem a sua origem da palavra latina ingeniatorum significando “engenhoso na arte de projectar” (Duffell, 1990). De facto a engenharia tem sido definida como uma arte que permite que os principais recursos da natureza sejam transformados, adaptados e aplicados para o uso ou conveniência do homem (The New Caxton Encyclopedia, 1986).