Produção de pastilhas cerâmicas combustíveis de UO2 dopadas para aplicação nuclear /

The performance of UO2 fuel pellets is mainly limited by the fission gas release. A fuel that retain more of these fission gases lead to a decrease in the internal rod pressure at the end of its life cycle, improving the safety and operational margins. In order to overcoming the limitation mentioned, pellets with high average grain sizes (≥ 30 µm) and sintered densities (≥ 10.53 g/cm3 ) have been manufactured using doping technology. Considering the exposed scenario, the goal of this study was to manufacture doped UO2 fuel ceramic pellets using 0.05, 0.10, 0.20 and 0.30 wt% of alumina, niobia and chromia as additives to the standard fuel. The results showed that the alumina decreased the densities almost linearly and did not promoted any significant changes in average grain sizes. The niobia provided an increase in densities close to linear (≥ 0,10 wt%) and, for the grains sizes, the highest value of this study was obtained (52.31 µm; 0.30 wt%). Using chromia as additive, the sintered densities were improved (10,60 g/cm3 ; 0,10 %p) and then diminished until the minimum for the system (10.56 g/cm3 ; 0.30 %p). The grains grew till 0.20 wt% (37.51 µm), with a slight decrease in 0.30 %p (34.83 µm). To sum up, chromia is the most promising dopant because, with the lowest amount (≤ 0.20 wt%), it promoted the highest densification and grain growth.O desempenho de pastilhas combustíveis de UO2 está limitado, principalmente, pela liberação dos gases de fissão. Um combustível que retém mais desses gases proporciona uma diminuição da pressão interna da vareta ao final do seu ciclo de vida, melhorando a segurança e as margens operacionais. Para superar essa limitação, pastilhas com elevados tamanhos médios de grãos (≥ 30 µm) e densidades sinterizadas (≥ 10,53 g/cm3 ) têm sido produzidas pela técnica de dopagem. Diante do cenário exposto, o objetivo deste trabalho foi produzir pastilhas cerâmicas combustíveis de UO2 com tamanhos de grãos e densidades sinterizadas elevados utilizando 0,05; 0,10; 0,20 e 0,30 %p de alumina, nióbia e crômia como aditivo ao combustível padrão. Os resultados mostraram que a alumina reduziu as densidades quase que linearmente e não gerou nenhuma variação significativa nos tamanhos de grãos. A nióbia proporcionou aumento próximo ao linear das densidades (≥ 0,10 %p) e, para os tamanhos de grãos, foi obtido o valor máximo do estudo (52,31 µm; 0,30 %p). Com a crômia, as densidades aumentaram (10,60 g/cm3 ; 0,10 %p) e depois reduziram até o valor mínimo do sistema (10,56 g/cm3 ; 0,30 %p). Os grãos cresceram até 0,20 %p (37,51 µm), com ligeira queda em 0,30 %p (34,83 µm). Portanto, a crômia é o dopante mais promissor pois, com os menores teores adicionados (≤ 0,20 %p), promoveu as maiores densificações e crescimentos de grãos

Falando com professoras das séries iniciais do ensino fundamental sobre sexualidade na sala de aula : a presença do discurso biológico

Neste artigo questiono o entendimento da sexualidade como universal e biologicamente determinada. Discuto a sexualidade como uma construção histórica e cultural a partir da análise das narrativas das professoras das séries iniciais do Ensino Fundamental sobre suas experiências de sala de aula relacionadas a tal questão. Nas experiências narradas, tornou-se marcante o discurso biológico como a maneira «correta» para ser abordada a sexualidade nas práticas escolares. Relacionados a esse discurso estruturado na biologia apareceram outros que atuam na mídia, nos grupos sociais, na família, engendrando a sexualidade como efeito de práticas culturais de inscrição nos corpos. No estudo, estabeleço algumas conexões com os Estudos Culturais, nas suas vertentes pós-estruturalistas, e com algumas proposições de Foucault.In this article, I challenge the understanding of sexuality as universal and biologically structured. I discuss sexuality as a historical and cultural construct, from the narratives of primary school teachers at initial grades, on their classroom experiences related to such issue. In the experiences narrated, the biological discourse stood out as the «correct» way to approach sexuality in school practices. Also related to that discourse structured on biology, some other discourses came up, which act in the media, in social groups, in the family, therefore engendering sexuality as an effect of cultural practices inscribed on bodies. In the study, I establish some connections with Cultural Studies, in their post-structuralist views, and with some of Foulcault's propositions

Multi-robot coordination for a heterogeneous fleet of robots

There is an increasing need for autonomous mobile robots (AMRs) in industrial environments. The capability of autonomous movement and transportation of items in industrial environments provides a significant increase in productivity and efficiency. This need, coupled with the possibility of controlling groups of heterogeneous robots, simultaneously addresses a wide range of tasks with different characteristics in the same environment, further increasing productivity and efficiency. This paper will present an implementation of a system capable of coordinating a fleet of heterogeneous robots with robustness. The implemented system must be able to plan a safe and efficient path for these different robots. To achieve this task, the TEA* (Time Enhanced A*) graph search algorithm will be used to coordinate the paths of the robots, along with a graph decomposition module that will be used to improve the efficiency and safety of this system. The project was implemented using the ROS framework and the Stage simulator. Results validate the proposed approach since the system was able to coordinate a fleet of robots in various different tests efficiently and safely, given the heterogeneity of the robots.This work is financed by the ERDF - European Regional Development Fund, through the Operational Programme for Competitiveness and Internationalisa tion - COMPETE 2020 Programme under the Portugal 2020 Partnership Agree ment, within project CrossLog, with reference POCI-01-0247-FEDER-039895info:eu-repo/semantics/publishedVersio

Kinetic Identities como meio de inovação e adaptação ao paradigma social e tecnológico atual: o caso da sala de espetáculos Avenida

O desenvolvimento tecnológico e social a que temos assistido fez com que passássemos a encarar o mundo de outra forma, abrindo as portas a um conjunto de novas oportunidades estéticas que fizeram o design, como disciplina orgânica, evoluir. Esta evolução levou à criação de novos sistemas de identidade visual, como é o caso das identidades visuais flexíveis – onde se inclui a kinetic identity –, que são dotadas de características que vão ao encontro da sociedade contemporânea. A presente dissertação visa refletir sobre a forma como o uso de sistemas de identidade visual flexíveis, como é o caso da kinetic identity, se transformaram em estratégias de comunicação válidas e eficazes, adequadas às características desta sociedade em que nos inserimos. O resultado do conhecimento obtido foi materializado, através do desenvolvimento de um sistema de identidade visual flexível, para uma entidade do setor cultural, o Avenida Café-Concerto. Desta forma, foi criada uma marca diferente, dinâmica, versátil, coesa e adequada ao seu público alvo e, nomeadamente, o desenvolvimento de todos os seus materiais gráficos necessários para a comunicação da marca nos diferentes suportes de comunicação.The technological and social development we have been witnessing has made us face the world in a different way, opening the doors to a set of new aesthetic opportunities that have made design, as an organic discipline, evolve. This evolution has led to the emergence of new visual identity systems, such as flexible visual identities - where kinetic identity is included - which are endowed with characteristics that are in line with contemporary society. This dissertation aims to reflect on how the use of flexible visual identity systems, such as kinetic identity, has become valid and effective communication strategies, suitable for the characteristics of this society in which we are part. The result of the knowledge acquired was materialized through the development of a flexible visual identity system for an entity of the cultural sector, Avenida Café-Concerto. In this way, a different, dynamic, versatile, cohesive and appropriate for its target audience brand was created, and namely the development of all its graphic materials necessary for brand communication in the different communication media.Mestrado em Desig

Shifting capsule networks from the cloud to the deep edge

Capsule networks (CapsNets) are an emerging trend in image processing. In contrast to a convolutional neural network, CapsNets are not vulnerable to object deformation, as the relative spatial information of the objects is preserved across the network. However, their complexity is mainly related to the capsule structure and the dynamic routing mechanism, which makes it almost unreasonable to deploy a CapsNet, in its original form, in a resource-constrained device powered by a small microcontroller (MCU). In an era where intelligence is rapidly shifting from the cloud to the edge, this high complexity imposes serious challenges to the adoption of CapsNets at the very edge. To tackle this issue, we present an API for the execution of quantized CapsNets in Arm Cortex-M and RISC-V MCUs. Our software kernels extend the Arm CMSIS-NN and RISC-V PULP-NN to support capsule operations with 8-bit integers as operands. Along with it, we propose a framework to perform post-training quantization of a CapsNet. Results show a reduction in memory footprint of almost 75%, with accuracy loss ranging from 0.07% to 0.18%. In terms of throughput, our Arm Cortex-M API enables the execution of primary capsule and capsule layers with medium-sized kernels in just 119.94 and 90.60 milliseconds (ms), respectively (STM32H755ZIT6U, Cortex-M7 @ 480 MHz). For the GAP-8 SoC (RISC-V RV32IMCXpulp @ 170 MHz), the latency drops to 7.02 and 38.03 ms, respectively

Estudo da influência do número de ciclos por projecção no cálculo da fracção de ejecção ventricular esquerda em estudos Gated-SPECT

Introdução - Gated-Single Photon Emission Computed Tomography (Gated-SPECT) do miocárdio usa-se cada vez mais na avaliação conjunta da perfusão do miocárdio e da função ventricular esquerda. O objectivo deste estudo é analisar a possível interferência do número de ciclos cardíacos (ciclos/projecção) e contagens totais por aquisição no cálculo da FEVE (fracção de ejecção do ventrículo esquerdo). Material e métodos - Foram incluídos 35 indivíduos a quem foram realizados estudos Gated-SPECT do miocárdio por indicação clínica. Em todos os pacientes foram adquiridos dois estudos em esforço: um com 25 ciclos! projecção (ES-25) e outro com 50 ciclos! projecção (ES-50), e dois estudos em repouso: um com 25 ciclos/projecção (ER-25) e outro com 12 ciclos! projecção (ER-1 2). Os valores da FEVE obtidos nos diferentes estudos foram tratados estatisticamente com o recurso à versão 14 SPSS. Resultados - Não houve diferenças estatisticamente significativas entre os valores de FEVE ES-25 e ES-50 (p=0.504) nem entre os valores de FEVE ER-25 e ER-12 (p=O.243). Conclusão - No caso da nossa amostra, o número de ciclos!projecção e consequentemente as contagens totais por aquisição não parecem ter influência de forma significativa no cálculo da FEVE%, nem em repouso nem após esforço

Fish communities in the lower Tagus inland wetlands: from anthropogenic pressures to conservation management

Inland wetlands are important biodiversity hotspots and amongst the most impacted ecosystems worldwide. Conservation management and restauration actions in wetlands are thus urgently needed to reverse trends in species loss and habitat degradation, particularly in regions harbouring already endangered endemic species. Inland wetlands may play an important role in supporting endemic endangered fishes in the Lower Tagus basin, where anthropogenic pressures have been increasing, but there is a lack of studies on fish communities, and few areas are identified as inland wetlands. Here, we aim to identify small inland wetlands in the Lower Tagus River and their potential role in supporting fish species, constituting the first study to identify and evaluate the most important fish communities. Inland wetlands were identified through the usage of remote sensing techniques and the calculation of a Normalized Difference Water Index (NDWI) with Sentinel-2 imagery for the Lower Tagus region. From a total of 486 locations identified, 31 were recognized as wetlands as having potential to host fish communities, with 11 being selected for sampling after in loco assessment. Fish sampling was conducted between 6 May and 11 June 2021. Furthermore, for each wetland, we evaluated anthropogenic stressors and land use changes between 2007 and 2018, using national land use data (i.e., Carta de Uso e Ocupação do Solo). A total of 7727 fishes from eight non-native and five native species were captured. Overall, fish communities were dominated by non-native species (97% catches), but both European eel (Anguilla anguilla) and Lisbon arched-mouth nase (Iberochondrostoma olisiponense), which are globally classified as critically endangered (CR), were found in at least two wetlands. Our results suggest that, over the last 10 years, intensive agriculture decreased (on average ≈ 3%) in the areas surrounding these wetlands, being replaced by extensive agriculture or natural uses. Despite non-native fish prevalence, some wetlands may act as refuge habitats for CR fish species. These results are important for guiding the restoration of inland wetlands and promoting conservation management actions to help reverse fish diversity loss.info:eu-repo/semantics/publishedVersio

A case report

INTRODUCTION: Calcaneal osteomyelitis poses a tough challenge for any reconstructive surgeon. The eradication of the infection and the reconstruction of the defect are the main goals of treatment. PRESENTATION OF CASE: We present the case of a 53-year-old male with chronic calcaneal osteomyelitis. The patient was submitted to several bone and soft tissue debridements and twice the application of gentamicin/sulfate implants at the wound bed with no success. He was then submitted to a partial calcanectomy followed by obliteration of the bone defect (4.5 × 2 × 1.5 cm) with a free vascularized fibula-flexor hallucis longus osteomuscular flap (bone dimension:4.5 × 1.5 × 1.2 cm; muscle size: 4 × 1.5 × 0.5 cm). The flap remained viable, and the post-operative period was uneventful. Bone incorporation was evident nine months after the surgery with no signs of recurrent infection or avascular necrosis. Final follow up, at one year, showed an excellent functional result. The patient was able to ambulate without assistance and referred occasional minimal foot pain. Donor site morbidity was minimal. CONCLUSION: The authors believe that this osteomuscular flap may be a valuable option to reconstruct calcaneal defects after chronic osteomyelitis.publishersversionpublishe