Com o crescente consumo de energia elétrica são cada vez mais os países que procuram fontes de energia renovável e limpa, entre elas a eólica. A quantidade de energia produzida é influenciada pela altura das torres, dimensões das pás e potência dos aerogeradores. Quanto maior for a elevação da turbina maiores são a velocidade e estabilidade dos ventos alcançados. A solução de torre treliçada em concreto armado pré-moldado idealizada por Lúcio e Chastre [2] permite a construção de torres altas e é competitiva em relação aos outros sistemas estruturais.As ligações têm uma importância fundamental no comportamento global das estruturas pré-moldadas. A viabilidade da ligação (fácil execução, baixo custo, comportamento/capacidade resistente) é preponderante na viabilização da construção destas torres.Até à data foram estudadas quatro ligações (S1, S2, S3 e S4), sendo neste artigo abordadas apenas as ligações do modelo S3 com junta de 3mm (barras salientes/bainhas corrugadas/selagem com grout) e do modelo S4 com junta de 50 mm (ligações aparafusadas produzidas comercialmente).Através dos resultados experimentais pode-se concluir que o mecanismo de rutura foi o mesmo nos dois modelos e que as soluções estudadas preenchem os requisitos para a sua utilização em estruturas pré-moldadas de concreto armado para suporte de aerogeradores.

Este artigo avalia se, para especificações de betão correntes, a resistência à compressão de betão pronto é significativamente dependente da central que o produziu, bem como se a variabilidade entre amassaduras de uma determinada composição é dependente da classe de resistência especificada. É apresentado um parâmetro probabilístico que converte a resistência à compressão característica especificada para a resistência à compressão expectável em provetes de betão cúbicos em condições padronizadas.É feita uma análise estatística e probabilística dos resultados de ensaios de resistência à compressão aos 28 dias de betão pronto produzido em três centrais de betão portuguesas durante o ano de 2017. Após a avaliação da representatividade da base de dados analisada, é feito um estudo comparativo dos parâmetros estatísticos dos dados de produção das diferentes centrais e é avaliada a influência da classe de resistência à compressão do betão nestes parâmetros. Define-se e analisa-se um parâmetro probabilístico que converte a resistência à compressão especificada para a resistência potencial de betão, para cubos de 150 mm. Este parâmetro contribui para uma futura proposta de um modelo probabilístico, a ser utilizado em análises de fiabilidade, que converte a resistência à compressão especificada para a resistência à compressão de elementos de betão em obra.Quer a análise estatística dos ensaios de resistência à compressão, quer o parâmetro de conversão são comparados com os resultados de investigações internacionais na área, aferindo-se se a qualidade da produção de betão pronto nacional é semelhante à de outras regiões.

Concrete structures Externally Bonded Reinforced (EBR) with Fibre Reinforced Polymers (FRP) have been studied and used since the end of the last century. However, several issues need to be better studied in order to improve performance. The influence of size of anchorage plates used on Reinforced Concrete (RC) structures strengthened with EBR FRP composites, the external compressive stress to be applied on the anchorage plate and the numerical simulation of this region are some of the topics that need to be more carefully studied in order to clarify the performance of the FRP-to-concrete interface within the anchorage plate region. This study proposes a design methodology to estimate the amount of external compressive stress necessary to be applied on the anchorage plate of EBR systems with FRP composites, in order to avoid premature debonding. The external compressive stress imposed on the FRP composite is intended to simulate the effect produced by a mechanical anchorage system tightened to the EBR system. The results from the design proposal, when compared with the numerical ones, were efficient enough on the prediction of the bond strength improvement of FRP-to-concrete interfaces.

Power Hardware-in-the-Loop (PHiL) system for asynchronous electric drives application based on power inverter with Field Programmable Gate Array (FPGA)-based control system is discussed. Proposed PHiL structure and scheme for asynchronous electric drives are under discussion as well. Described PHiL can be used for power inverters multi-stage testing.

A low power wireless sensor network utilizing the neutral to earth voltage as a power source is developed and analyzed. It consists of a batteryless energy harvesting powered wireless sensor nodes, a gateway (if needed) and a local or remote server (if used). An invasive energy harvesting method to use the voltage between the neutral conductor and the ground conductor is used for the sensor module. A test network is built in a household. Statistics of the household's electric current and the corresponding neutral conductor's voltage is obtained during a two months period. The statistics is further processed to verify the working principle of the proposed network and to enlighten its strengths and weaknesses. The sensor nodes are developed using widely existing electronic components and don't require specialized devices.

Problem of the reliability increasing of the vehicles electric drives is discussed in context of the reduction of the electric motor heating during variable character of movement. Opportunities of the induction motor stator winding heating reduction by means of the control of the vehicles electric drives in transient and steady state modes of movement are shown. Analytical expressions for dynamic torque, optimal on minimal of the winding temperature rise during acceleration, as well as expressions for dynamic torque and value of the motor torque limitation, optimal on energy consumption during acceleration are presented. It is shown that desire to reduce the stator winding temperature rise by means of dynamic torque optimal value selection or motor torque limitation can lead to the rise of energy consumption. Results of the modeling are presented.

This paper presents a wireless energy transfer system operating at the frequency values of kHz order: modeling, simulation, and comparison with prototype measurement results. Wireless energy transfer system model using finite element method was carried out to simulate the electric field and the magnetic flux density for different air gap sizes between the transmitter and the receiver coils. Results are presented and compared with the electromagnetic emission measurements radiated by the wireless energy transfer system prototype. The electric field comparison between the simulated and the prototype measurement values shows an error of roughly 8.7{%}. In the recent years, the interest in the wireless energy transfer technology, especially for electric vehicles batteries charging, is rapidly increasing. As a result of the increasing application of this technology in the industrial and consumer electronic products, more concerns are raised about the electromagnetic compatibility, since the wireless energy transfer systems produce electromagnetic emissions in the surrounding environment.

Although tourism is a major engine of economic growth, it also creates a burden hard to manage, and has a great impact on the conservation of the heritage. The HERIT-DATA project aims to reduce the impact of human activities, related to tourism, on cultural heritage, with a special focus on two kind of cultural destinations that can benefit from and be affected by mass tourism: Old towns and places of specific cultural heritage or archaeological interest for visitors, including UNESCO World Heritage Sites. In that framework, HERIT-DATA plans to develop of a sustainable and responsible tourism management towards cultural heritage in MED regions, in particular by taking advantage of technology and innovation in management tools (Smart Cities), as well as other policy and social measures.

The use of adhesively bonded joints between Fiber Reinforced Polymers (FRP) and concrete elements have been spread out in the past decades. However, due to their recent applications, the durability aspects related with these bonded joints requires the use of high safety factors which strongly restricts the mechanical capacity of the FRP composites. The experimental assessment of the degradation of FRP-to-concrete interfaces is an important task because it provides useful data that can be used to calibrate analytical or numerical models with the aim of helping on the correct understanding of the interfacial degradation. In this work, a new and simple interfacial bond-slip model that needs only one parameter to be experimentally defined is proposed. Compared to unaged Glass (G) FRP-to-concrete interfaces, the relative degradation of these bonded interfaces is studied after being subjected to: (i) salt fog cycles; (ii) wet-dry cycles; (iii) temperature cycles between -10ºC and +30ºC; and (iv) between +7.5ºC and +47.5ºC. The subsequent full debonding processes are predicted through an analytical model that takes into account the degradations experimentally determined from the tests.

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The effective stress transfer between the fiber reinforced polymers (FRP) and the steel substrate is crucial for the successful retrofit of existing steel structures with FRP composites. However, there are no standard tests for FRP-to-steel interfaces, wherefore different test configurations have been used in recent years to assess the bond behaviour in these interfaces. The present study shows that the choice of test configuration is highly important and leads to different transfer stresses between the FRP and steel composites and consequently, has a direct influence on the strength of the bonded joint. Therefore, it is important to understand the debonding process that occurs in each test and avoid misinterpretations, erroneous analyses and dangerous characterizations of the interfacial behaviour of these interfaces. The current study presents a new analytical approach for the prediction of the debonding of FRP-to-steel interfaces when double-lap pull or double-strap tests are used.

This article presents a nonlinear analytical solution for the prediction of the full-range debonding response of mechanically anchored, fiber-reinforced polymer (FRP) composites from the substrate. The nonlinear analytical approach predicts, for any monotonic loading history or bonded length, the relative displacements (or slips) between materials, the strains in the FRP composite, the bond stresses within the interface, and the stresses developed in the substrate. The load-slip responses of FRP-to-substrate interfaces with short and long bonded lengths are motives of analysis and discussion. The solutions obtained from the proposed approach are also compared with other experimental results found in the literature.

Additive manufacturing (commonly known as 3D printing or rapid prototyping) refers to processes used to produce parts in an additive manner by means of computer-aided design (CAD). While additive manufacturing is a technology that can be used in many different application areas, this project focuses on future trends in additive manufacturing (AM) aimed at improving biological functionality (bio-AM) and on its opportunities, barriers and challenges. The big advantage of this technique is that small batches can be produced more economically than with any other manufacturing process. Virtually any structure can be customized, which is particularly important in the healthcare sector. Possible applications include biological implants such as organs and tissues, nutrients, drugs and their transport mechanisms, equipment such as surgical knives and drilling guides, tissues for research, development and training, and personalized prostheses, supports and exoskeletons. Besides exploring such applications, the project will also systematically analyze potential "human enhancement" uses of AM technology and developments in the emerging do-it-yourself (DIY) cultures ("bio/body-hacking"; cyborgism; open source 3D printing movement).

In the first phase of the project, the technological state of the art will be analyzed, as will a wide variety of non-technical aspects, regulatory issues and future trends, also with a special focus on sociotechnical imaginaries (e.g., in science fiction), human enhancement and DIY cultures. This horizon scanning will be accomplished partly by means of expert and stakeholder interviews.

In the second phase, the project will use a variety of foresight and technology assessment methods and will carry out a 360° envisioning exercise with contributions by external experts, entailing an in-depth analysis of selected applications of bio-AM.

The project work will end with a scenario development phase in which the focus will be on likely outcomes of already emerging developments, though further-reaching future perspectives will be taken into account to a certain extent. Taken together, these scenarios will allow for both a broader understanding of the wide range of potential impacts of AM applications and a clearer picture of potential policy challenges relevant to the Members of the European Parliament.

ABSTRACTThe fossil record of post-Paleozoic lungfishes in Greenland is currently restricted to a few brief reports of isolated and undetermined tooth plates coming from the uppermost Fleming Fjord Formation (late Norian) in Jameson Land, central East Greenland. Here, we describe Ceratodus tunuensis, sp. nov., a new dipnoan from a thin bed of calcareous lake mudstone from the ?rsted Dal Member of the Fleming Fjord Formation. The Ceratodus fossil record indicates that during the Late Triassic, this genus was restricted to the middle latitudes of the Northern Hemisphere. This record matches previous paleobiogeographical analyses and indicates that terrestrial biota during the Late Triassic was strongly influenced by paleolatitude.Citation for this article: Agnolin, F. L., O. Mateus, J. Milàn, M. Marzola, O. Wings, J. Schulz Adolfssen, and L. B. Clemmensen. 2018. Ceratodus tunuensis, sp. nov., a new lungfish (Sarcopterygii, Dipnoi) from the Upper Triassic of central East Greenland. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1439834.

ABSTRACT Diplodocid sauropods had a unique skull morphology, with posteriorly retracted nares, an elongated snout, and anteriorly restricted, peglike teeth. Because of the lack of extant analogs in skull structure and tooth morphology, understanding their feeding strategy and diet has been difficult. Furthermore, the general rarity of sauropod skulls and the fragility of their facial elements resulted in a restricted knowledge of cranial anatomy, in particular regarding the internal surface of the facial skull. Here, we describe in detail a well-preserved diplodocid skull visible in medial view. Diagnostic features recognized in other skulls observable in lateral view, such as the extended contribution of the jugal to the antorbital fenestra, are obliterated in medial view due to extensive overlapping joints between the maxilla, jugal, quadratojugal, and the lacrimal. These overlapping joints permitted limited anterior sliding movement of the snout, which likely served as a kind of ?shock-absorbing? mechanism during feeding. Diplodocid skulls therefore seem to have evolved to alleviate stresses inflicted on the snout during backward movements of the head, as would be expected during branch-stripping or raking.ABSTRACT Diplodocid sauropods had a unique skull morphology, with posteriorly retracted nares, an elongated snout, and anteriorly restricted, peglike teeth. Because of the lack of extant analogs in skull structure and tooth morphology, understanding their feeding strategy and diet has been difficult. Furthermore, the general rarity of sauropod skulls and the fragility of their facial elements resulted in a restricted knowledge of cranial anatomy, in particular regarding the internal surface of the facial skull. Here, we describe in detail a well-preserved diplodocid skull visible in medial view. Diagnostic features recognized in other skulls observable in lateral view, such as the extended contribution of the jugal to the antorbital fenestra, are obliterated in medial view due to extensive overlapping joints between the maxilla, jugal, quadratojugal, and the lacrimal. These overlapping joints permitted limited anterior sliding movement of the snout, which likely served as a kind of ?shock-absorbing? mechanism during feeding. Diplodocid skulls therefore seem to have evolved to alleviate stresses inflicted on the snout during backward movements of the head, as would be expected during branch-stripping or raking.

The adhesively bonded joints behaviour under cyclic loading is not yet well understood due to its inherent complexity. Numerical approaches appear, therefore, as the easiest way to simulate such mechanical behaviour. In this work, double strap bonded joints with Carbon Fibres Reinforced Polymers (CFRP) and aluminium are numerically simulated and subjected to a cyclic loading history. In the numerical simulation, the Distinct Element Method (DEM) is used and it is assumed cohesive bi-linear bond-slip models with local damage of the interface. The evaluation of the bonded joints under cyclic loading is made by comparing the results with those simulated with a monotonic loading.