3,356 research outputs found
The Importance of Preventive and Corrective Maintenance in Works
The present study addresses the problems brought by the lack of preventive and corrective maintenance. The purpose of this work is to focus on the importance of preventive and corrective maintenance, for the prevention and conservation of engineering works. This work will focus and indicate some guidelines and measures that must be taken to keep the engineering works in order and in a good state of repair. The importance of the implementation of preventive and corrective maintenance for engineering works will also be mentioned, as well as the importance of always having at disposal a specialized team to be always ready to attend such eventualities that may occur in the facilities of this type of service and what are the basic requirements for a good manutentor
Broadband UHF RFID passive tag antenna for near-body applications
WOS:000316792500036 (Nº de Acesso Web of Science)One challenge for UHF RFID passive tag design is to obtain a low-profile antenna that minimizes the influence of near-body or attached objects without sacrificing both read range and universal UHF RFID band interoperability. A new improved design of a RFID passive tag antenna is presented that performs well near problematic surfaces (human body, liquids, metals) across most of the universal UHF RFID (840-960 MHz) band. The antenna is based on a low-profile printed configuration with slots, and it is evaluated through extensive simulations and experimental tests
XIV Conference on Technology, Teaching and Learning of Electronics
Livro de atas da TAEE2020.A conferencia TAEE conhecerá na sua 14ª edição um momento histórico. Não só é a primeira vez que
a será organizada fora do território Espanhol, como terá lugar a verdadeiramente pioneira experiência
de realizar esta conferência num formato puramente virtual no Instituto Superior de Engenharia do
Porto.
Esta opção representa a solução possível para um evidente problema mundial, que surgiu de forma
repentina durante a preparação desta edição. Optamos por aplicar a típica abordagem de engenharia,
instintivamente encarando este novo problema como uma verdadeira oportunidade, e aproveitando as
limitações impostas para experimentar novas soluções para novas questões.
Tentamos criar uma TAEE diferente, não melhor nem pior, mas indo buscar proveitos às tecnologias
de comunicação emergentes de forma a criar e dinamizar um evento onde não estaremos fisicamente
juntos, mas poderemos comunicar e conviver de forma virtual. A grande motivação da TAEE será
sempre os visíveis entrosamentos, dedicação e motivação da comunidade e serão estes fatores que
permitirão o sucesso nesta nova forma de estarmos e trabalharmos juntos, mas à distância.info:eu-repo/semantics/publishedVersio
Transistor teaching back to Transfer-Resistor : A summary table of definitions and students’ perceptions
The Bipolar Junction Transistor (BJT) study is a regular subject on analog electronic subjects taught in the initial phase of electronic engineering courses. This electronic component, often considered elementary, is far from being simple to explain because it covers several concepts, such as three Regions of Operation, two Working Regimes, and two Region of Operation Boundaries. It is not surprising then that students often find it difficult to understand the functioning of this component. The present article describes partially the work developed by a team with a number of students in order to understand the difficulties of teaching/learning the BJT. We present the students’ perceptions from the analysis of several traditional and modern means to support the learning of the BJT. Interestingly, the learning BJT model considered simpler for beginner students corresponds to the model that originally gave it the name i.e. Trans-Resistor (Transistor).info:eu-repo/semantics/publishedVersio
Avaliação dos métodos de suscetibilidade antifúngica: Etest e macrodiluição em caldo para leveduras do gênero Candida isoladas da cavidade bucal de pacientes com AIDS
A comparison of the Etest and the reference broth macrodilution susceptibility test for fluconazole, ketoconazole, itraconazole and amphotericin B was performed with 59 of Candida species isolated from the oral cavities of AIDS patients. The Etest method was performed according to the manufacturer's instructions, and the reference method was performed according to National Committee for Clinical Laboratory Standards document M27-A guidelines. Our data showed that there was a good correlation between the MICs obtained by the Etest and broth dilution methods. When only the MIC results at ± 2 dilutions for both methods were considered, the agreement rates were 90.4% for itraconazole, ketoconazole and amphotericin B and 84.6% for fluconazole of the C. albicans tested. In contrast, to the reference method, the Etest method classified as susceptible three fluconazole-resistant isolates and one itraconazole-resistant isolate, representing four very major errors. These results indicate that Etest could be considered useful for antifungal sensitivity evaluation of yeasts in clinical laboratories.Foram comparados dois testes de suscetibilidade in vitro, macrodiluição em caldo e Etest através da determinação das concentrações inibitórias mínimas de fluconazol, cetoconazol, itraconazol e anfotericina B para 59 isolados de Candida obtidos da cavidade bucal de pacientes com AIDS. O método de Etest foi feito de acordo com as instruções do fabricante e o método de macrodiluição em caldo foi realizado seguindo as normas do NCCLS (National Committee for Clinical Laboratoratory Standards), documento M27-A, considerado método de referência. Nossos dados mostraram uma boa correlação entre os valores de concentração inibitória mínima encontrados para o Etest e o método de macrodiluição em caldo. Foi verificada concordância entre os resultados de CIM, de 90,4% para itraconazol, cetoconazol e anfotericina B e de 84,6% para fluconazol, quando se analisou isolados de C. albicans. A comparação de breakpoints mostrou que havia quatro grandes discrepâncias de resultados entre os dois métodos, sendo que pelo método de referência três isolados de Candida albicans classificados como resistentes ao fluconazol e um de C. krusei considerado resistente ao itraconazol foram sensíveis ao Etest. Estes resultados mostraram que o Etest é de grande valor nos testes de suscetibilidade antifúngica para leveduras do gênero Candida
Miniature implantable antennas for biomedical telemetry: from simulation to realization
WOS:000310154700019 (Nº de Acesso Web of Science)“Prémio Científico ISCTE-IUL 2013”We address numerical versus experimental design and testing of miniature implantable antennas for biomedical telemetry in the medical implant communications service band (402-405 MHz). A model of a novel miniature antenna is initially proposed for skin implantation, which includes varying parameters to deal with fabrication-specific details. An iterative design-and-testing methodology is further suggested to determine the parameter values that minimize deviations between numerical and experimental results. To assist in vitro testing, a low-cost technique is proposed for reliably measuring the electric properties of liquids without requiring commercial equipment. Validation is performed within a specific prototype fabrication/testing approach for miniature antennas. To speed up design while providing an antenna for generic skin implantation, investigations are performed inside a canonical skin-tissue model. Resonance, radiation, and safety performance of the proposed antenna is finally evaluated inside an anatomical head model. This study provides valuable insight into the design of implantable antennas, assessing the significance of fabrication-specific details in numerical simulations and uncertainties in experimental testing for miniature structures. The proposed methodology can be applied to optimize antennas for several fabrication/testing approaches and biotelemetry applications
A remote lab to support e-learning on FPAA
Teaching analog and digital electronic subjects is
not a trivial task because is necessary to use opposite
methodologies. The electronic design in the digital field is
centered in the use of microprocessor and FPGA based
circuits using high level programing/configuring languages.
The counterpart analog design is traditionally based in the
use of elementary components associated with macroblocks
such operational amplifiers in order to built-up the wanted
mission circuit. Some few components, as the FPAA, are
analogically configurable in a similar manner already used
with the FPGA. However the use of this kind of components
is not straightforward once is necessary to acquire some
concepts not taught in the traditionally analog electronic
classes.N/
Taxonomy, distribution and ecology of the order Phyllodocida (Annelida, Polychaeta) in deep-sea habitats around the Iberian margin
The polychaetes of the order Phyllodocida (excluding Nereidiformia and
Phyllodociformia incertae sedis) collected from deep-sea habitats of the Iberian
margin (Bay of Biscay, Horseshoe continental rise, Gulf of Cadiz and Alboran Sea),
and Atlantic seamounts (Gorringe Bank, Atlantis and Nameless) are reported herein.
Thirty-six species belonging to seven families – Acoetidae, Pholoidae, Polynoidae,
Sigalionidae, Glyceridae, Goniadidae and Phyllodocidae, were identified. Amended
descriptions and/or new illustrations are given for the species Allmaniella
setubalensis, Anotochaetonoe michelbhaudi, Lepidasthenia brunnea and Polynoe sp..
Relevant taxonomical notes are provided for other seventeen species. Allmaniella
setubalensis, Anotochaetonoe michelbhaudi, Harmothoe evei, Eumida longicirrata
and Glycera noelae, previously known only from their type localities were found in
different deep-water places of the studied areas and constitute new records for the
Iberian margin. The geographic distributions and the bathymetric range of thirteen
and fifteen species, respectively, are extended. The morphology-based biodiversity
inventory was complemented with DNA sequences of the mitochondrial barcode
region (COI barcodes) providing a molecular tag for future reference. Twenty new
sequences were obtained for nine species in the families Acoetidae, Glyceridae and
Polynoidae and for three lineages within the Phylodoce madeirensis complex
(Phyllodocidae). A brief analysis of the newly obtained sequences and publicly
available COI barcode data for the genera herein reported, highlighted several cases
of unclear taxonomic assignments, which need further study.Thanks are due to the chief-scientists, scientific parties and crews of the 17 cruises
that originated the material examined herein. We would like to thank Clara F.
Rodrigues who participated in most of the cruises, often assisting with sample
collection and sorting, and also provided the map with the location of sampling sites,
and João Gil for his very useful comments and indispensable help with bibliography.
This work was funded by Fundação para a Ciência e a Tecnologia (FCT) under the
strategic programmes PEst-C/MAR/LA0017/2013 and UID/AMB/50017/2013, and
the projects CHEMECO (EURODEEP/0001/2007, ESF EuroDEEP programme)
SWIMGLO; the European Commission under the projects HERMES (EC contract
GOCE-CT-511234 FP6) and HERMIONE (EC contract 226354, FP7). The first
author was supported by the postdoctoral grants BPD/UI88/2911/2013 (Universidade
de Aveiro, project MARES (CENTRO-07-ST24 FEDER-002033) co-funded by
QREN Mais Centro (Programa Operacional do Centro) and EU structural funds
(European Regional Development Funds)), and SFRH/BPD/112408/2015 (FCT).
Sequencing at the Biodiversity Institute of Ontario was supported by funding of the
International Barcode of Life Project (iBOL) through the Canadian Centre for DNA
Barcoding, from the Ontario Genomics Institute, Genome Canada, the Ontario Ministry of Research and Innovation, and the Natural Sciences and Engineering
Research Council of Canada. CBMA researchers were supported by the strategic
programme UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by
national funds through the FCT I.P. and by the ERDF through the COMPETE2020 -
Programa Operacional Competitividade e Internacionalização (POCI).info:eu-repo/semantics/publishedVersio
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