A Framework for Analyzing Fog-Cloud Computing Cooperation Applied to Information Processing of UAVs

Unmanned aerial vehicles (UAVs) are a relatively new technology. Their application can often involve complex and unseen problems. For instance, they can work in a cooperative-based environment under the supervision of a ground station to speed up critical decision-making processes. However, the amount of information exchanged among the aircraft and ground station is limited by high distances, low bandwidth size, restricted processing capability, and energy constraints. These drawbacks restrain large-scale operations such as large area inspections. New distributed state-of-the-art processing architectures, such as fog computing, can improve latency, scalability, and efficiency to meet time constraints via data acquisition, processing, and storage at different levels. Under these amendments, this research work proposes a mathematical model to analyze distribution-based UAVs topologies and a fog-cloud computing framework for large-scale mission and search operations. The tests have successfully predicted latency and other operational constraints, allowing the analysis of fog-computing advantages over traditional cloud-computing architectures.Comment: Volume 2019, Article ID 7497924, 14 page

New multifunctional isolated microinverter with integrated energy storage system for PV applications

This paper proposes a novel multifunctional isolated microinverter which is able to extract the maximum available power from a solar photovoltaic module and inject it into the power grid, while simultaneously charging a battery energy storage system (BESS). The proposed microinverter integrates a novel DC–DC power converter and a conventional DC–AC power converter. The DC–DC power converter is able to send electrical energy to the secondary side of a high-frequency transformer and to the BESS, using only two power switches. Throughout this paper, the converter topology, the operation modes, the control algorithms, and the development of a laboratory prototype of the proposed microinverter are described in detail. Moreover, simulation and experimental results are presented to demonstrate the feasibility of the proposed solution.This work has been supported by FCT—Fundação para a Ciência e Tecnologia within the R&DUnits Project Scope: UIDB/00319/2020. This work has been supported by the FCT Project QUALITY4POWERPTDC/EEI-EEE/28813/2017. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018 granted by the Portuguese FCT foundation. Mohamed Tanta was supported by FCT PhD grant with a reference PD/BD/127815/2016 granted by the Portuguese FCT agency. Tiago J. C. Sousa is supported by the doctoralscholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency

Nanoparticle-based assays in automated flow systems: A review

Nanoparticles (NPs) exhibit a number of distinctive and entrancing properties that explain their ever increasing application in analytical chemistry, mainly as chemosensors, signaling tags, catalysts, analytical signal enhancers, reactive species generators, analyte recognition and scavenging/separation entities. The prospect of associating NPs with automated flow-based analytical is undoubtedly a challenging perspective as it would permit confined, cost-effective and reliable analysis, within a shorter timeframe, while exploiting the features of NPs. This article aims at examining state-of-the-art on continuous flow analysis and microfluidic approaches involving NPs such as noble metals (gold and silver), magnetic materials, carbon, silica or quantum dots. Emphasis is devoted to NP format, main practical achievements and fields of application. In this context, the functionalization of NPs with distinct chemical species and ligands is debated in what concerns the motivations and strengths of developed approaches. The utilization of NPs to improve detector's performance in electrochemical application is out of the scope of this review. The works discussed in this review were published in the period of time comprised between the years 2000 and 2013

A new improved optimization of perturbation theory: applications to the oscillator energy levels and Bose-Einstein critical temperature

Improving perturbation theory via a variational optimization has generally produced in higher orders an embarrassingly large set of solutions, most of them unphysical (complex). We introduce an extension of the optimized perturbation method which leads to a drastic reduction of the number of acceptable solutions. The properties of this new method are studied and it is then applied to the calculation of relevant quantities in different $\phi^4$ models, such as the anharmonic oscillator energy levels and the critical Bose-Einstein Condensation temperature shift $\Delta T_c$ recently investigated by various authors. Our present estimates of $\Delta T_c$, incorporating the most recently available six and seven loop perturbative information, are in excellent agreement with all the available lattice numerical simulations. This represents a very substantial improvement over previous treatments.Comment: 9 pages, no figures. v2: minor wording changes in title/abstract, to appear in Phys.Rev.

New multifunctional push-pull converter operating with MPPT and integrated energy storage system for PV micro-inverter applications

This paper presents a novel multifunctional push-pull converter for micro-inverter applications, used to interface photovoltaic (PV) modules and an battery energy storage system with the power grid (PG). The push-pull DC-DC power converter requires only two switching devices. It uses a specific algorithm to control the batteries charging process, preserving their lifetime, and also to operate as maximum power point tracker, optimizing the energy production from the PVs modules. The push-pull DC-AC power converter operates in coordination with the DC-DC converter, injecting all available energy from the PVs modules into the PG. If the produced energy exceeds the consumed energy, the surplus is used to charge the batteries for latter consumption. The proposed topology aims to contribute to the technological development in terms of power converters for micro-inverter applications. Throughout the paper is given a detailed explanation on the principle of operation of the new topology, as well as on the proposed digital control algorithm.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT - Fundação para a Ciância e Tecnologia within the Project Scope: UID/CEC/00319/2013. This work is financed by the ERDF - European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciância e a Tecnologia, within project SAICTPAC/0004/2015- POCI- 01-0145-FEDER-016434.info:eu-repo/semantics/publishedVersio

Sutureless bioprosthesis for aortic valve replacement: surgical and clinical outcomes

© 2022 The Authors. Journal of Cardiac Surgery published by Wiley Periodicals LLC. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.Background: Aortic valve stenosis is the most common adult valve disease in industrialized countries. The aging population and the increase in comorbidities urge the development of safer alternatives to the current surgical treatment. Sutureless bioprosthesis has shown promising results, especially in complex procedures and in patients requiring concomitant surgeries. Objectives: Assess the clinical and hemodynamic performance, safety, and durability of the Perceval® prosthetic valve. Methods: This single-center retrospective longitudinal cohort study collected data from all adult patients with aortic valve disease who underwent aortic valve replacement with a Perceval® prosthetic valve between February 2015 and October 2020. Of the 196 patients included (mean age 77.20 ± 5.08 years; 45.4% female; mean EuroSCORE II 2.91 ± 2.20%), the majority had aortic stenosis. Results: Overall mean cross-clamp and cardiopulmonary bypass times were 33.31 ± 14.09 min and 45.55 ± 19.04 min, respectively. Mean intensive care unit and hospital stay were 3.32 ± 3.24 days and 7.70 ± 5.82 days, respectively. Procedural success was 98.99%, as two explants occurred. Four valves were reimplanted due to intraoperative misplacement. Mean transvalvular gradients were 7.82 ± 3.62 mmHg. Pacemaker implantation occurred in 12.8% of patients, new-onset atrial fibrillation in 21.9% and renal replacement support was necessary for 3.1%. Early mortality was 2.0%. We report no structural valve deterioration, strokes, or endocarditis, and one successfully treated valve thrombosis. Conclusions: Our study confirms the excellent clinical and hemodynamic performance and safety of a truly sutureless aortic valve, up to a 5-year follow-up. These results were consistent in isolated and concomitant interventions, solidifying this device as a viable option for the treatment of isolated aortic valve disease.info:eu-repo/semantics/publishedVersio

Optical and digital key enabling techniques for SDM-based optical networks

In order to support, in a cost-effective way, the data capacity demand in the context of future 5G networks, a new set of advanced technologies need to be explored, as it is the case of space-division multiplexing (SDM) along with energy efficient coherent detection based modulation formats. This paper presents the recent results on enabled optical networks based on SDM for high capacity optical networks compatible with 5G network infrastructure and data center connectivity. In particular, we demonstrate the viability of using Long-Period Gratings (LPGs) in multicore fibers (MCFs) to develop different components for multicore-based SDM systems, such as pump couplers and core/wavelength selective multi-core switches and couplers. Moreover, we also present and characterize the performance of different digital signal processing (DSP) algorithms and subsystems supporting optical coherent detection in SDM systems.publishe

Photoelectrocatalytic degradation of pharmaceuticals promoted by a metal-free g‑C3N4 catalyst

Graphitic carbon nitride (g-C3N4) recently emerged as a remarkable photoelectrocatalyst for water treatment. Advanced oxidation processes (AOPs) consisting of photoelectrocatalytic (PEC) systems are being researched towards the development of sustainable strategies for the complete removal of refractory contaminants from effluents of urban wastewater treatment plants (WWTPs). This work consists of the optimisation of a PEC system, composed of a boron-doped diamond (BDD) anode, titanium cathode, and a suspended g-C3N4 photoelectrocatalyst, for the treatment of both synthetic and real urban waste waters spiked with pharmaceutical active compounds (PhACs). Different working parameters were considered and optimised to improve degradation and mineralisation rates, such as the cathode material, anode-to-cathode distance, electrolyte resistivity, and matrix composition. The optimal conditions allowed removals of 100 % diclofenac, 88 % fluoxetine and 77 % ibuprofen in the complex wastewater matrix. Moreover, it was observed that the presence of other refractory organic molecules offered a greater impediment to PEC treatment than residual co-existing substances. The main oxidative agents were investigated by scavenging experiments, showing that generated holes and reactive oxy-species, i.e. hydroxyl and superoxide radicals, take a major role in the degradation of PhACs. The recyclability of the g-C3N4 suspension as photoelectrocatalyst in the PEC process provides a promising perspective for the development of wastewater treatment units.Agencia Estatal de Investigación | Ref. PID2020-113667GB-I00Xunta de Galicia | Ref. ED481D-2023/015Deputación Provincial de PontevedraFundação para a Ciência e a Tecnologia | Ref. 2022.08738.PTDCFundação para a Ciência e a Tecnologia | Ref. 2022.04682.PTDCUniversidade de Vigo/CISU

Tuning graphitic carbon nitride (g-C3N4) electrocatalysts for efficient oxygen evolution reaction (OER)

Nowadays, energy conversion and storage technologies are essential research topics due to the necessity of more sustainable processes. Specifically, water splitting is highly affected by slow kinetics and limited knowledge of the oxygen evolution reaction (OER). This work envisages the preparation of graphitic carbon nitride (g-C3N4) electrocatalysts for efficient OER by a facile one-pot method. The impact of the preparation temperature (450–650 ◦C) of g-C3N4 was assessed for the first time on water splitting processes and explained by different characterisation techniques. The unique crystal structure, surface chemistry, and electronic properties of the material prepared at 550 ◦C lead to a remarkable OER efficiency, with an overpotential of 355 mV at 10 mA cm− 2 and a Tafel slope of 46.8 mV dec− 1. Interestingly, three major differences were observed when comparing the material prepared at 550 ◦C with those obtained at other temperatures: the reduced structural distortion, the superior composition in oxygen and the presence of terminal functional groups. Also, compared to other metalfree g-C3N4 electrocatalysts reported in the literature, we achieved lower Tafel slope values without additional post-treatments or co-catalysts. Hence, for the first time a metal-free catalyst defeats benchmark IrO2. The prepared electrodes were stable for up to 45 h, even when increasing the applied current density to 100 mA cm− 2 for 15 h. Thus, this work provides a simple route for the fabrication of highly-efficient and long-lasting electrocatalysts for a remarkable OER performance.Agencia Estatal de Investigación | Ref. PID2020-113667 GB-I00Fundação para a Ciência e a Tecnologia | Ref. UIDB/50020/2020Fundação para a Ciência e a Tecnologia | Ref. UIDP/50020/2020Xunta de Galicia | Ref. ED481D-2023/015Universidade de Vigo/CISU