Sol-Gel Synthesis, Structural Characterization and Microwave Dielectric Properties of Bismuth Niobate Modified by Iron Inclusion

The current progress in communication technologies is leading to extensive studies on the development of miniaturized electronic devices with high electromagnetic performances, reliability, and low cost. Contributing to this purpose, the development and study of new materials, with promising electric properties in radio and microwave ranges, have been subject of our research in particular niobate-based materials. Bismuth niobate, BiNbO4, is a low-firing ceramic that has been studied for a variety of applications in the microelectronic industry. In this work, the microwave dielectric characterization of (Bi1−x Fex )NbO4 (0.00 ≤ x ≤ 1.00) samples, prepared by the sol-gel method and heat treated at specific temperatures, is performed and related with their structure and morphology. The structural data were obtained by X-ray diffraction and Raman spectroscopy and the morphology by scanning electron microscopy. The dielectric characterization in the microwave region was made using the small perturbation theory, with a resonant cavity operating in TE105 mode, at the frequency of 2.7 GHz. The results show that the sol-gel method has the advantage of allowing the formation of α-BiNbO4 phase at lower temperatures when compared with conventional preparation methods, and that the inclusion of iron inhibits the formation of low- and high-temperature β-BiNbO4 phases

Riscos da manipulação de citotóxicos

Os medicamentos citotóxicos têm como função a inibição do crescimento e/ou processos vitais das células tumorais contudo, estes não são selectivos, não atingindo apenas as células afectadas. Assim, e acrescido ao facto de sabermos que estes são também carcinogénicos, mutagénicos e teratogénicos para quem os manipula, desenvolvemos este estudo com o objectivo de percebermos o risco que estes correm. Para tal, realizamos um estudo descritivo e transversal, onde o instrumento de recolha de dados foi um inquérito, reunindo assim, uma amostra de 35 profissionais de três hospitais diferentes. Os dados obtidos permitem-nos concluir que todos os manipuladores de citotóxicos presentes na amostra, conhecem os efeitos adversos advindos da manipulação, o que significa que todos têm a percepção do risco que correm. Com este estudo, pretende-se alertar os profissionais de saúde que contactam directamente com esta realidade para a execução de boas práticas, a fim de reduzir o risco a que estão expostos

Aerial river management by smart cross-border reforestation

In the face of increasing socio-economic and climatic pressures in growing cities, it is rational for managers to consider multiple approaches for securing water availability. One often disregarded option is the promotion of reforestation in source regions supplying important quantities of atmospheric moisture transported over long distances through aerial rivers, affecting water resources of a city via precipitation and runoff (‘smart reforestation’). Here we present a case demonstrating smart reforestation's potential as a water management option. Using numerical moisture back-tracking models, we identify important upwind regions contributing to the aerial river of Santa Cruz de la Sierra (Bolivia). Simulating the effect of reforestation in the identified regions, annual precipitation and runoff reception in the city was found to increase by 1.25% and 2.30% respectively, while runoff gain during the dry season reached 26.93%. Given the city's population growth scenarios, the increase of the renewable water resource by smart reforestation could cover 22–59% of the additional demand by 2030. Building on the findings, we argue for a more systematic consideration of aerial river connections between regions in reforestation and land planning for future challenges. © 2019 The Author

Visualização da topologia do escoamento na vizinhança de uma porta vedada por um aparelho de cortina de ar

Descrevem-se as metodologias utilizadas num estudo que teve por objectivo a avaliação do efeito de vedação promovido por um aparelho de cortina de ar. Foi utilizada uma instalação experimental à escala real em que, através de um jacto de ar descendente gerado por cima da porta, se procurou manter uma dada diferença de temperatura entre duas salas contíguas. Recorrendo a 16 sondas anemométricas, efectuou-se o mapeamento da temperatura e da velocidade do ar em diversos planos considerados de interesse e, através da aquisição desses dados em contínuo, avaliou-se o desenvolvimento e a estabilidade do jacto durante os primeiros minutos de funcionamento da instalação. Recorreu-se igualmente a uma técnica de medida do tipo “whole-field” em que o campo de temperaturas do ar é medido indirectamente através de um ecrã de baixa massa térmica que serve de alvo a uma câmara termográfica de infra-vermelhos. Ao longo do artigo serão apresentados vários exemplos elucidativos das potencialidades das técnicas descritas anteriormente

Mechanical characterization of dry-stack interlocking compressed earth masonry

Earth has been a traditional building material to construct houses in Africa. One of the most common techniques is the use of sun dried or kiln fired adobe bricks with mud mortar. Although this technique is low-cost, the bricks vary largely in shape, strength and durability. This leads to weak houses which suffer considerable damage during floods and seismic events. A solution is the use of dry-stack masonry with stabilized interlocking compressed earth blocks (ICEB). These blocks are manufactured by compacting cement stabilized earth in a manual or hydraulic press into a mould and then air dried. The resulting blocks present uniform shapes and higher values of strength and durability. This work presents the work made in the context of the HiLoTec project. It focuses on the experimental campaign of the project to characterize the strength of ICEBs and the behaviour of dry-stack masonry

Engineering the application of machine learning in an IDS based on IoT traffic flow

Internet of Things (IoT) devices are now widely used, enabling intelligent services that, in association with new communication technologies like the 5G and broadband internet, boost smart-city environments. Despite their limited resources, IoT devices collect and share large amounts of data and are connected to the internet, becoming an attractive target for malicious actors. This work uses machine learning combined with an Intrusion Detection System (IDS) to detect possible attacks. Due to the limitations of IoT devices and low latency services, the IDS must have a specialized architecture. Furthermore, although machine learning-based solutions have high potential, there are still challenges related to training and generalization, which may impose constraints on the architecture. Our proposal is an IDS with a distributed architecture that relies on Fog computing to run specialized modules and use deep neural networks to identify malicious traffic inside IoT data flows. We compare our IoT-Flow IDS with three other architectures. We assess model generalization using test data from different datasets and evaluate their performance in terms of Recall, Precision, and F1-Score. Results confirm the feasibility of flowbased anomaly detection and the importance of network traffic segmentation and specialized models in the AI-based IDS for IoT.info:eu-repo/semantics/publishedVersio

Influence of seesaw permanent movement of a person on the performance of an air curtain device

In commercial and industrial activities, there is often a need for reducing or controlling heat and mass transfer between outside environment and indoor compartments with controlled atmosphere, warranting, simultaneously, an easy circulation of people and equipments. In practical terms, the confinement of a given space can be achieved with aerodynamic barriers (air curtains) constituted by one or more air jets. In the present paper, the loss of efficiency of a vertical downward air curtain due to the seesaw permanent movement of a person is analyzed. Results show a systematic loss of the sealing efficiency (10 to 20%) of the air curtain device when the doorway is periodically crossed by a computer controlled manikin “Roberta” relatively to the results obtained without this traversing movement

Modelling a portable personal health record

Active and responsible involvement of patients in their own health is accepted as an important contribution towards an increased quality of health services in general. Management of Personal Health Information by the patient can play an important role in the improvement in quality of the information available to health care professionals and as a means of patient involvement. Electronic Health Records are a means of storing this kind of information but their management usually falls under the responsibility of an institution and not on the patient himself. A Personal Health Record under the direct control and management of the patient is the natural solution for the problem. When implemented in a storage hardware portable device, a PHR, allows for total mobility. Personal Health Information is very sensitive in nature so any implementation has to address security and privacy issues. With this in mind we propose a structure for a secure Patient Health Record stored in a USB pen device under the patient’s direct management and responsibility

Efficacy and safety of non-invasive ventilation in the treatment of acute cardiogenic pulmonary edema – a systematic review and meta-analysis

INTRODUCTION: Continuous positive airway pressure ventilation (CPAP) and non-invasive positive pressure ventilation (NPPV) are accepted treatments in acute cardiogenic pulmonary edema (ACPE). However, it remains unclear whether NPPV is better than CPAP in reducing the need for endotracheal intubation (NETI) rates, mortality and other adverse events. Our aim was to review the evidence about the efficacy and safety of these two methods in ACPE management. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials on the effect of CPAP and/or NIPV in the treatment of ACPE, considering the outcomes NETI, mortality and incidence of acute myocardial infarction (AMI). We searched six electronic databases up to May 2005 without language restrictions, reviewed references of relevant articles, hand searched conference proceedings and contacted experts. RESULTS: Of 790 articles identified, 17 were included. In a pooled analysis, 10 studies of CPAP compared to standard medical therapy (SMT) showed a significant 22% absolute risk reduction (ARR) in NETI (95% confidence interval (CI), -34% to -10%) and 13% in mortality (95%CI, -22% to -5%). Six studies of NPPV compared to SMT showed an 18% ARR in NETI (95%CI, -32% to -4%) and 7% in mortality (95%CI, -14% to 0%). Seven studies of NPPV compared to CPAP showed a non-significant 3% ARR in NETI (95%CI, -4% to 9%) and 2% in mortality (95%CI, -6% to 10%). None of these methods increased AMI risk. In a subgroup analysis, NPPV did not lead to better outcomes than CPAP in studies including more hypercapnic patients. CONCLUSION: Robust evidence now supports the use of CPAP and NPPV in ACPE. Both techniques decrease NETI and mortality compared to SMT and none shows increased AMI risk. CPAP should be considered a first line intervention as NPPV did not show a better efficacy, even in patients with more severe conditions, and CPAP is cheaper and easier to implement in clinical practice

The Coaches’ perceptions and experience implementing a long-term athletic development model in competitive swimming

The aim of this study was to analyze the association between coaches’ experience and their perceptions on the implementation of a long-term athletic development (LTAD) model created in 2016 by the Portuguese Swimming Federation. Eighty-six swimming coaches were assembled in groups according to their experience level: “novice” (n = 24), “intermediate” (n = 26), and “experienced” (n = 36), and they answered a questionnaire with the following items: (i) awareness of the existing model (ii) acceptance (iii) usefulness for practice, and (iv) implementation of this model by their peers. Regardless of experience, ~67% of the coaches were aware of the model. Among those, a large number showed acceptance (~95%) and confidence in its usefulness (~83%) for their daily practice. Most coaches (92%) showed concerns about the fact that their peers do not respect the model frameworks, declaring the search for their swimmers’ immediate success (~58%) as the main cause for such behavior. The results also showed an association between experience and knowledge about the model’s existence [χ2 (2) = 10.223, p < 0.01, V = 0.345], and experienced coaches exhibited better knowledge than their intermediate [χ2 (2) = 9.555, p < 0.01, V = 0.393] or novice [χ2 (2) = 5.926, p = 0.02, V = 0.314] counterparts. While there was an association between the coaches’ experience and knowledge about the LTAD model’s existence, this situation does not seem to influence the way coaches accept and understand the usefulness of the model for their daily practice.This project was supported by the National Funds through the Portuguese Foundation for Science and Technology (FCT), I.P (UIDB04045/2020). This work was also supported by the Portuguese Swimming Federation.info:eu-repo/semantics/publishedVersio