49 research outputs found
Solutions for detection of non-technical losses in the electricity grid: a review
This paper is a review of literature with an analysis on a selection of scienti c
studies for detection of non-technical losses. Non-technical losses occurring
in the electric grid at level of transmission or of distribution have negative impact on economies, affecting utilities, paying consumers and states.
The paper is concerned with the lines of research pursued, the main techniques
used and the limitations on current solutions. Also, a typology for
the categorization of solutions for detection of non-technical losses is proposed and the sources and possible attack/vulnerability points are identifi ed. The selected literature covers a wide range of solutions associated with
non-technical losses. Of the 103 selected studies, 6 are theoretical, 25 propose
hardware solutions and 72 propose non-hardware solutions. Data based
classi cation models and data from consumption with high resolution are
respectively required in about 47% and 35% of the reported solutions. Available
solutions cover a wide range of cases, with the main limitation found being the lack of an uni ed solution, which enables the detection of all kinds of non-technical losses
Um olhar dos atores das escolas oficiais de idiomas da Extremadura-Espanha sobre as questões transfronteiriças
A presente proposta de investigação, ao abordar os dilemas inerentes à cooperação transfronteiriça, no âmbito da educação/formação, no Alentejo-Extremadura, traduz-se assim, num diagnóstico a nível meso, já que aborda em termos micro, o papel dos professores das Escolas Oficiais de Idiomas da Extremadura (Espanha) enquanto potenciais agentes de regulação da cooperação transfronteiriça, através das suas relações interpessoais, funcionando esta regulação como uma ponte ou forma intermediária de atingir a regulação macro, entendida aqui como a regulação nacional e internacional, no panorama transfronteiriço Portugal/Espanha
Um olhar dos atores das escolas oficiais de idiomas da Extremadura-Espanha sobre as questões transfronteiriças
A presente proposta de investigação, ao abordar os dilemas inerentes à cooperação transfronteiriça, no âmbito da educação/formação, no Alentejo-Extremadura, traduz-se assim, num diagnóstico a nível meso, já que aborda em termos micro, o papel dos professores das Escolas Oficiais de Idiomas da Extremadura (Espanha) enquanto potenciais agentes de regulação da cooperação transfronteiriça, através das suas relações interpessoais, funcionando esta regulação como uma ponte ou forma intermediária de atingir a regulação macro, entendida aqui como a regulação nacional e internacional, no panorama transfronteiriço Portugal/Espanha
The effects of field inoculation of arbuscular mycorrhizal fungi through rye donor plants on grapevine performance and soil properties
Grapevines are highly dependent on arbuscular mycorrhizal fungi (AMF) for normal growth and development. However, vineyard soils may have low AMF abundance and diversity due to conventional soil management practices that are detrimental for these fungi. In this context, the establishment of AMF-inoculated cover crops can be a highly convenient strategy to reestablish soil mycorrhizal potential, as it combines the advantages of a vigorous inoculum source coming from mycorrhizal donor plants with the overall benefits of green covers for grape quality, microbial diversity and soil health. In this work, the potential benefits of Funneliformis mosseae-inoculated under-vine cover crops on grapevine growth, physiology and production were compared to those derived from 1) the establishment of non-inoculated under-vine cover crops, and 2) conventional herbicide-based weed control in the under-vine space. In addition, grapevine root AMF community composition was analyzed to assess if the introduction of a non-native AMF species induced changes on resident mycorrhizal community assemblies and to unveil potential variations in AMF diversity associated to herbicide replacement by green covers. Results indicated that under-vine cover crops, inoculated or not, led to a general vigor decrease in grapevines, probably due to competition between the two species. However, after a heat wave that occurred at harvest time in the second year of the experiment, grapevines growing in plots with inoculated cover crops had the highest photochemical reflectance indices and net photosynthesis rates, and partially compensated production losses due to berry sunburn. Root mycorrhizal community analysis by the end of the experiment revealed that the inoculated F. mosseae isolate colonized grapevine roots from inoculated plots, while it was absent in the other ones. Moreover, inoculation of this AMF did not lead to a replacement of native root AMF communities, but allowed further colonization by other resident Glomeraceae and non-Glomeraceae AMF taxa. Overall, the work herein demonstrates that the introduction of F. mosseae through donor plants is a suitable field inoculation method for grapevines and can help them to better withstand heat wavesinfo:eu-repo/semantics/submittedVersio
Instrumentos de Ajuda à Mediação do Professor Para Promover a Apredizagem dos Alunos e o Desenvolvimento Profissional dos Professores
Melhorar as práticas de ensino é um desígnio que carece da reflexão dos
professores sobre a sua experiência e da investigação didática. Apresenta-se um
quadro teórico das práticas de ensino que concebe o professor como mediador
em contexto de aprendizagem formal, construído no âmbito de um projeto de
investigação sobre as práticas de ensino. Neste âmbito foram concebidos e validados
cinco instrumentos de ajuda à mediação do professor. Estes instrumentos
de ajuda à mediação podem servir de referência para a melhoria progressiva das
práticas de ensino em cinco dimensões importantes para o ensino de ciências
e tecnologia: envolvimento produtivo dos alunos, avaliação e feedback, uso de
contextos científicos e tecnológicos, trabalho realmente solicitado aos alunos e
práticas epistémicas. Finalmente, apresentam-se os cinco instrumentos de ajuda, largamente ilustrados com excertos de práticas de ensino reais.Improve teaching practices is a purpose that requires the teachers’ reflection
on their experience and the research of teaching. We present a theoretical
framework of teaching practices that face the teacher as mediator in formal learning
contexts, constructed as part of a research project on teaching practices.
Within this framework were designed and validated five instruments to help
teacher mediation. These tools to help teacher mediation can be used as a reference
for the progressive improvement of teaching practices in five important
dimensions to the teaching of science and technology: productive engagement
of students, evaluation and feedback, use of scientific and technological contexts,
the work really demanded to students and epistemic practices. Finally,
we present the five aid instruments, widely illustrated with excerpts from actual teaching practices
Abstracts
Tradução, para a língua inglesa dos resumos dos artigos incluídos no número 12 da Revista Lusófona de Educação
Novel hydroxyapatite/chitosan bilayered scaffold for osteochondral tissue-engineering applications : scaffold design and its performance when seeded with goat bone marrow stromal cells
Recent studies suggest that bone marrow stromal cells are a potential source of osteoblasts and chondrocytes and can be used to
regenerate damaged tissues using a tissue-engineering (TE) approach. However, these strategies require the use of an appropriate scaffold
architecture that can support the formation de novo of either bone and cartilage tissue, or both, as in the case of osteochondral defects.
The later has been attracting a great deal of attention since it is considered a difficult goal to achieve. This work consisted on developing
novel hydroxyapatite/chitosan (HA/CS) bilayered scaffold by combining a sintering and a freeze-drying technique, and aims to show the
potential of such type of scaffolds for being used in TE of osteochondral defects. The developed HA/CS bilayered scaffolds were
characterized by Fourier transform infra-red spectroscopy, X-ray diffraction analysis, micro-computed tomography, and scanning
electron microscopy (SEM). Additionally, the mechanical properties of HA/CS bilayered scaffolds were assessed under compression. In
vitro tests were also carried out, in order to study the water-uptake and weight loss profile of the HA/CS bilayered scaffolds. This was
done by means of soaking the scaffolds into a phosphate buffered saline for 1 up to 30 days. The intrinsic cytotoxicity of the HA scaffolds
and HA/CS bilayered scaffolds extract fluids was investigated by carrying out a cellular viability assay (MTS test) using Mouse
fibroblastic-like cells. Results have shown that materials do not exert any cytotoxic effect. Complementarily, in vitro (phase I) cell culture
studies were carried out to evaluate the capacity of HA and CS layers to separately, support the growth and differentiation of goat
marrow stromal cells (GBMCs) into osteoblasts and chondrocytes, respectively. Cell adhesion and morphology were analysed by SEM
while the cell viability and proliferation were assessed by MTS test and DNA quantification. The chondrogenic differentiation of
GBMCs was evaluated measuring the glucosaminoglycans synthesis. Data showed that GBMCs were able to adhere, proliferate and
osteogenic differentiation was evaluated by alkaline phosphatase activity and immunocytochemistry assays after 14 days in osteogenic
medium and into chondrocytes after 21 days in culture with chondrogenic medium. The obtained results concerning the physicochemical
and biological properties of the developed HA/CS bilayered scaffolds, show that these constructs exhibit great potential for their use in
TE strategies leading to the formation of adequate tissue substitutes for the regeneration of osteochondral defects
Special revitalization procedures: additional empirical contribution on the results of troika's experiment in the portuguese ministry of justice
Este artigo constitui a III parte de uma série de avaliações do impacto de medidas
aprovadas e implementadas pelo Ministério da Justiça, em Portugal. O presente artigo relata
predominantemente os resultados obtidos ao nível dos Processos Especiais de Revitalização
(PER), que constituem um novo tipo de ação civil criada em resultado dos objetivos do
Memorando de Entendimento (MdE) ratificado por Portugal e pela chamada Troika (CE/ BCE
/ FMI). A investigação incorpora análises de inferência estatística dos resultados obtidos, não só
para o período da Troika, como ainda para o período pós-Troika. Tal como se verificou para as
ações de execução civil, os resultados confirmam a existência de diferenças estatísticas entre os
dois períodos em análise e sugerem um impacto tangível das medidas do MdE implementadas
no sistema judicial Português.info:eu-repo/semantics/publishedVersio