285 research outputs found

    Flexible Baseband Modulator Architecture for Multi-Waveform 5G Communications

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    The fifth-generation (5G) revolution represents more than a mere performance enhancement of previous generations: it will deeply transform the way humans and/or machines interact, enabling a heterogeneous expansion in the number of use cases and services. Crucial to the realization of this revolution is the design of hardware components characterized by high degrees of flexibility, versatility and resource/power efficiency. This chapter proposes a field-programmable gate array (FPGA)-oriented baseband processing architecture suitable for fast-changing communication environments such as 4G/5G waveform coexistence, noncontiguous carrier aggregation (CA) or centralized cloud radio access network (C-RAN) processing. The proposed architecture supports three 5G waveform candidates and is shown to be upgradable, resource-efficient and cost-effective. Through hardware virtualization, enabled by dynamic partial reconfiguration (DPR), the design space exploration of our architecture exceeds the hardware resources available on the Zynq xc7z020 device. Moreover, dynamic frequency scaling (DFS) enables the runtime adjustment of processing throughput and power reductions by up to 88%. The combined resource overhead for DPR and DFS is very low, and the reconfiguration latency stays two orders of magnitude below the control plane latency requirements proposed for 5G communications

    Autonomous RPCs for a Cosmic Ray ground array

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    We report on the behaviour of Resistive Plate Chambers (RPC) developed for muon detection in ultra-high energy cosmic ray (UHECR) experiments. The RPCs were developed for the MARTA project and were tested on field conditions. These RPCs cover an area of 1.5×1.2m21.5 \times 1.2\,{m^2} and are instrumented with 64 pickup electrodes providing a segmentation better than 2020\,cm. By shielding the detector units with enough slant mass to absorb the electromagnetic component in the air showers, a clean measurement of the muon content is allowed, a concept to be implemented in a next generation of UHECR experiments. The operation of a ground array detector poses challenging demands, as the RPC must operate remotely under extreme environmental conditions, with limited budgets for power and minimal maintenance. The RPC, DAQ, High Voltage and monitoring systems are enclosed in an aluminium-sealed case, providing a compact and robust unit suited for outdoor environments, which can be easily deployed and connected. The RPCs developed at LIP-Coimbra are able to operate using a very low gas flux, which allows running them for few years with a small gas reservoir. Several prototypes have already been built and tested both in the laboratory and outdoors. We report on the most recent tests done in the field that show that the developed RPCs have operated in a stable way for more than 2 years in field conditions.Comment: To appear in the proceedings of the 35th International Cosmic Ray Conference (ICRC2017), Busan, South Korea. Presented by R. Concei\c{c}\~{a}o. 8 page

    Earthquakes in central Italy in 2016: comparison between Norcia and Amatrice

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    Trabalho apresentado em 16th European Conference on Earthquake Engineering (16ECEE), 18-21 june 2018, Thessaloniki, GreeceIn this paper lessons are extracted from the comparison between the very different consequences that a set of earthquakes had on the neighbouring towns of Amatrice and Norcia during the 2016 central Italy earthquake sequence. The paper initially describes the prevention programs implemented in Amatrice and Norcia starting from the reconstruction after the 1860 Norcia earthquake. The earthquake intensities in Amatrice and Norcia during the 2016 Central Italy events were considering accelerometric recordings of the Italian Strong Motion Network. In the same municipalities, the damage has been assessed through site visits and analysis of the results of the post-earthquake safety assessment performed after the events. It was found that the differences in damage were essentially due to the strengthening of most houses in Norcia done during the previous decades. This is also likely to lead to a much faster recover of the economy and livelihood in Norcia, as Amatrice needs to be entirely rebuilt.N/

    Gadolinium ecotoxicity is enhanced in a warmer and acidified changing ocean as shown by the surf clam Spisula solida through a multibiomarker approach

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    Funding Information: This work was supported by Fundação para a Ciência e Tecnologia (FCT) , through the project Climatoxeel ( PTDC/AAG-GLO/3795/2014 ), by the Junior Researcher contract ( CEECIND/03517/2017 ), both awarded to Tiago F. Grilo, and the strategic project UIDB/04292/2020 granted to MARE and through project LA/P/0069/2020 granted to the Associate Laboratory ARNET . The work was also supported by the European Union's operation program Mar 2020 through the research project CEIC ( MAR-01.04.02-FEAMP-0012 ) awarded to Joana Raimundo. The Applied Molecular Biosciences Unit UCIBIO was financed by national funds from FCT ( UIDP/04378/2020 ). This work was also supported by the European Union through the grant ERC-2016-COG-725034 -ecotox awarded to Inês João Ferreira. Cátia Figueiredo acknowledges the FCT-PhD grant SFRH/BD/130023/2017 and the Early Career Research Grant awarded by National Geographic Society. Publisher Copyright: © 2022 The Author(s)Humans have exhaustively combusted fossil fuels, and released pollutants into the environment, at continuously faster rates resulting in global average temperature increase and seawater pH decrease. Climate change is forecasted to exacerbate the effects of pollutants such as the emergent rare earth elements. Therefore, the objective of this study was to assess the combined effects of rising temperature (Δ = + 4 °C) and decreasing pH (Δ = − 0.4 pH units) on the bioaccumulation and elimination of gadolinium (Gd) in the bioindicator bivalve species Spisula solida (Surf clam). We exposed surf clams to 10 µg L−1 of GdCl3 for seven days, under warming, acidification, and their combination, followed by a depuration phase lasting for another 7 days and investigated the Gd bioaccumulation and oxidative stress-related responses after 1, 3 and 7 days of exposure and the elimination phase. Gadolinium accumulated after just one day with values reaching the highest after 7 days. Gadolinium was not eliminated after 7 days, and elimination is further hampered under climate change scenarios. Warming and acidification, and their interaction did not significantly impact Gd concentration. However, there was a significant interaction on clam's biochemical response. The augmented total antioxidant capacity and lipid peroxidation values show that the significant impacts of Gd on the oxidative stress response are enhanced under warming while the increased superoxide dismutase and catalase values demonstrate the combined impact of Gd, warming & acidification. Ultimately, lipid damage was greater in clams exposed to warming & Gd, which emphasizes the enhanced toxic effects of Gd in a changing ocean.publishersversionpublishe

    Ocean warming, acidification, and rare earth elements exposure triggers a superior antioxidant response and pigment production in the adaptable Ulva rigida

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    European Union's operation program Mar 2020 through the research project CEIC (MAR-01.04.02-FEAMP-0012). Inês João Ferreira acknowledges the European Union research grant ERC-2016-COG-725034-ecotox. Publisher Copyright: © 2022 The Author(s)Anthropogenic increased atmospheric CO2 concentrations will lead to a drop of 0.4 units of seawater pH and ocean warming up to 4.8°C by 2100. Contaminant's toxicity is known to increase under a climate change scenario. Rare earth elements (REE) are emerging contaminants, that until now have no regulation regarding maximum concentration and discharge into the environment and have become vital to new technologies such as electric and hybrid-electric vehicle batteries, wind turbine generators and low-energy lighting. Studies of REE, namely Lanthanum (La) and Gadolinium (Gd), bioaccumulation, elimination, and toxicity in a multi-stressor environment (e.g., warming and acidification) are lacking. Hence, we investigated the algae phytoremediation capacity, the ecotoxicological responses and total chlorophyll and carotenoid contents in Ulva rigida during 7 days of co-exposure to La or Gd (15 µg L−1 or 10 µg L−1, respectively), and warming and acidification. Additionally, we assessed these metals elimination, after a 7-day phase. After one day of experiment La and Gd clearly showed accumulation/adsorption in different patterns, at future conditions. Unlikely for Gd, Warming and Acidification contributed to the lowest La accumulation, and increased elimination. Lanthanum and Gd triggered an adequate activation of the antioxidant defence system, by avoiding lipid damage. Nevertheless, REE exposure in a near-future scenario triggered an overproduction of ROS that requested an enhanced antioxidant response. Additionally, an increase in total chlorophyll and carotenoids could also indicate an unforeseen energy expense, as a response to a multi-stressor environment.publishersversionpublishe

    GROWTH, YIELD AND POST-HARVEST EVALUATION OF LETTUCE PLANTS SUBJECTED TO DIFFERENT LEAF SILICON CONCENTRATIONS

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    Lettuce is considered the most produced and consumed leafy vegetable; however, it has short post-harvest life, which generates significant losses for both producers and consumers. Studies have proven the beneficial effect of silicon on fruits and vegetables. Therefore, the aim of the current study is to evaluate the influence of leaf calcium silicate application on the growth, biomass production and postharvest conservation of curly lettuce. The experiment was carried out in greenhouse at Federal Rural University of Amazonia, Parauapebas Campus / PA. It followed a completely randomized design (CRD) with five Si concentrations (0.0, 2.0, 4.0, 6.0 and 8.0 mg L-1) and eight repetitions, which totaled 40 plants. Plants were grown in plastic pots (capacity = 3 dm3) filled with soil classified as Red-Yellow Argisol. Different Si concentrations were applied to plant leaves, at the 20th and 27th days after transplantation (DAT). Silicon has favored the growth and development of lettuce plants, as well as reduced their post-harvest weight loss. It was possible concluding that the herein tested Si concentrations, which were applied to leaves - in the form of calcium silicate - had beneficial effect on lettuce plants

    ANÁLISE ESTRATIGRÁFICA DO ALBIANO-TURONIANO DA BACIA DE PERNAMBUCO: CONSIDERAÇÕES SOBRE A PALEOGEOGRAFIA E GERAÇÃO DE HIDROCARBONETOS

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    More and more, the exploration of the petroleum in Brazil is driven for deep sea areas, where the presence of thick Cretaceous limestone layers of potential interest for petroliferous reservoirs of this age, mainly for the generation in Lower Albian and Cenomanian-Turonian. The presence of limestones and sandstones of these ages in the Pernambuco Basin induces a detailed study of the Estiva Formation (Upper Albian/Santonian), which deposicional processes and paleogeographic implications are analyzed.Cada vez mais, a exploração do petróleo está dirigida para regiões de mar profundo, onde a presença de espessas camadas cretácicas representa potencial para reservatórios petrolíferos, principalmente para a geração no Albiano Inferior e Cenomaniano- Turoniano. Aqui são analisados os processos deposicionais e implicações paleogeográficas da Formação Estiva (Albiano Superior/Santoniano), da Bacia de Pernambuco

    Endothelialization of chitosan porous conduits via immobilization of a recombinant fibronectin fragment (rhFNIII7–10)

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    The present study aimed to develop a pre-endothelialized chitosan (CH) porous hollowed scaffold for application in spinal cord regenerative therapies. CH conduits with different degrees of acetylation (DA; 4% and 15%) were prepared, characterized (microstructure, porosity and water uptake) and functionalized with a recombinant fragment of human fibronectin (rhFNIII7–10). Immobilized rhFNIII7–10 was characterized in terms of amount (125I-radiolabelling), exposure of cell-binding domains (immunofluorescence) and ability to mediate endothelial cell (EC) adhesion and cytoskeletal rearrangement. Functionalized conduits revealed a linear increase in immobilized rhFNIII7–10 with rhFNIII7–10 concentration, and, for the same concentration, higher amounts of rhFNIII7–10 on DA 4% compared with DA 15%. Moreover, rhFNIII7–10 concentrations as low as 5 and 20 lgml 1 in the coupling reaction were shown to provide DA 4% and 15% scaffolds, respectively, with levels of exposed cell-binding domains exceeding those observed on the control (DA 4% scaffolds incubated in a 20 lgml 1 human fibronectin solution). These grafting conditions proved to be effective in mediating EC adhesion/cytoskeletal organization on CH with DA 4% and 15%, without affecting the endothelial angiogenic potential. rhFNIII7–10 grafting to CH could be a strategy of particular interest in tissue engineering applications requiring the use of endothelialized porous matrices with tunable degradation rates
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