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Digital Future Classroom: the physical space and the inclusion of the NEET/Refugee population: conceptual and theoretical frameworks and methodology
No full textThe classroom is one of the privileged environments aiming knowledge construction and the
establishment of social relationships as well as of cultural exchanges. Studies regarding classroom
environment, focusing the pedagogical approaches, are countless; however, studies regarding the
classroom environment as the physical space are significantly fewer. Nevertheless, a new classroom
physical space – the Future Classroom Lab (FCL) - has been developed based, in part, on 21st
Century Skills. Spaces like the FCL are spreading throughout Europe, existing already more than
2,600 FCL’s. The Information and Communications Technology (ICT) advent and the ICT-based
emergent pedagogical approaches contributed to the increase of studies concerning the physical
classroom environment, as the classroom space and layout became no longer the most suitable. But
are these new spaces suitable for the Non in Education, Employment or Training (NEET)/Refugee
population and are they being designed and conceived to promote the inclusion of these populations?
Considering this scenario and the NEET and Refugee populations’ current crisis in the European
Union [1], [2]) the research that this paper presents aims to investigate innovative interior design
strategies to the classroom architectural space in order to promote the inclusion of these specific
populations: through the analysis of how the FCL spaces are being used in the European Schoolnet
FCL network and through the observation of some of these spaces in Portugal, a Digital Future
Classroom (DFC) is going to be designed. Privileging the enabling spaces approach [3] on the
classroom complexity spaces (architectural, social, cognitive, emotional, epistemological,
cultural and
organizational, technological and the virtual space), this ongoing research aims at understanding how
to “translate” these concepts into the classroom interior design, aiming the promotion of the user’s
inclusion. This analysis also gathers the spatial and pedagogical semiotics as well as the spatial
pedagogy inherent to the classroom.
This article presents the relevance of the research supported by its theoretical and conceptual
frameworks and the methodology that is being adopted. The present research, mainly qualitative, can
be considered under the constructivist (or socio-constructivist) paradigm and with a slight nuance of
the critical theory paradigm. Considering also that “The researcher-as-bricoleur-theorist works
between and within competing and overlapping perspectives and paradigms” [4, p. 5] the research
design resorts to triangulation, as it uses “different methods in an attempt to confirm, cross-validate, or
corroborate findings” [5, p. 24] in order to respond to each of the set objectives fulfilling all the
requests
Analysis of the metal adhesively bonded double cantilever beam specimen
No full textThe double cantilever beam specimen is currently standardized for measuring the mode I fracture energy of adhesive joints. In addition, it has been increasingly employed to evaluate the adhesive traction-separation law by the direct method, which involves crack tip separation measurements. The three-dimensional finite element analyses here conducted showed that significant anticlastic deformations of the metal adherends compromise the accuracy of the direct method in the elastic domain. It was also seen that the adherend plane stress and adhesive uni-axial strain hypotheses are adequate for the typical specimen geometries. Finally, the new elastic crack length correction derived from a beam model can be used to predict accurately the initial specimen compliance, to obtain conservative fracture energy values and to gain additional insight into the adhesive fracture behaviour
Protein-protein interactions between small heat shock proteins and cell lysates from D. melanogaster
No full textMestrado em Métodos Biomoleculares AvançadosOs níveis de expressão das pequenas proteínas de choque térmico variam em
resposta a vários indutores de stress, como temperaturas elevadas ou
compostos tóxicos. Estas proteínas podem também desempenhar vários
papéis in vivo, durante o desenvolvimento normal. Foram identificadas quatro
pequenas proteínas de choque térmico em Drosophila melanogaster (Hsp22,
Hsp23, Hsp26 e Hsp27), que partilham sequências homologas. Os seus níveis
de expressão variam consoante os órgãos e o estágio de desenvolvimento,
sendo que cada uma delas tem uma localização intracelular e um padrão de
expressão específico. O presente trabalho pretende estudar duas destas
proteínas: as Hsp27 e Hsp22. A primeira é expressa ao longo de todo o ciclo
de vida, enquanto que a expressão da Hsp22 varia com o envelhecimento,
mesmo na ausência de stress. A primeira etapa deste trabalho foi a expressão
de Hsp22 e Hsp27 recombinantes (com uma cauda de seis histidinas) em
sistemas bacterianos, seguida pela purificação das mesmas recorrendo a
vários métodos cromatográficos (cromatografia de afinidade, com a resina Ni-
NTA, e cromatografia de troca iónica). As proteínas purificadas foram
incubadas com lisados celulares de Drosophila, e a mistura foi submetida a
uma cromatografia de afinidade, com a resina Ni-NTA. As fracções eluidas,
contendo Hsps e as proteínas que com elas interagiram, foram analisadas por
electroforese bidimensional e espectrometria de massa (MALDI-TOF). As
proteínas identificadas vêm confirmar o envolvimento das pequenas proteínas
de choque térmico na manutenção da integridade celular.The expression levels of small heat shock proteins change in response to
various stressors including high temperatures and toxic compounds. They may
also play distinct functional roles in vivo during normal development. Four small
heat shock proteins have been identified in D. melanogaster (Hsp22, Hsp23,
Hsp26 and Hsp27). They share high sequence homology and their expression
patterns differ depending on the organs and developmental stage, each
showing specificity of expression and intracellular localization. The present
work is focused on two of these proteins: Hsp27 and Hsp22. The first is
expressed throughout the life cycle, while Hsp22 expression is known to
change with aging, even in the absence of stress. The first stage of this work
was the expression of polyhistidine-tagged Drosophila Hsp27 and Hsp22 in
bacterial systems and subsequent purification using chromatographic methods
(Ni-NTA affinity chromatography and ion exchange chromatography). The
purified proteins were incubated together with fly lysates, and this mixture was
resolved in a Ni-NTA affinity chromatography column. Eluted fractions
containing purified Hsps together with their interacting proteins were analysed
by 2D PAGE gels and mass spectrometry (MALDI-TOF). Proteins thus
identified support the involvement of small Hsps in the maintenance of cell
integrity
Influência dos cloretos de sódio, potássio e magnésio na formação da hidroxiapatite e seus percursos
No full textMestrado em Ciência e Engenharia de MateriaisCom este trabalho pretende-se contribuir para o estudo da formação de
precursores de hidroxiapatite (HA) - hidrogenofosfato de cálcio di-hidratado
(DCPD) e fosfato octacálcico (OCP ) - na presença e ausência dos iões Na+,
K+,Mg2+ e Cl-, para a gama de pH entre 5 e 9 e às temperaturas de 37 e 45 ºC.
Iniciou-se o trabalho pela realização de um conjunto de sínteses efectuadas
aos diferentes valores de pH e temperatura que se pretendiam estudar e na
ausência dos iões Na+, K+, Mg2+ e Cl-. Nesta fase inicial do trabalho pretendiase
investigar a influência do pH e da temperatura na fase de fosfato de cálcio
formada. Concluíu-se que a pH 5, nestas condições experimentais, não ocorre
precipitação a nenhuma das duas temperaturas estudadas. Para a
temperatura fisiológica (37 ºC) houve formação de DCPD (CaHPO4.2H2O) a
pH 6, para valores de pH entre 6,5 e 7 formou-se OCP (Ca8H2(PO4)6.5H2O),
enquanto que para valores de pH iguais ou superiores a 8 a fase formada foi a
HA (Ca5(PO4)3OH). Para a temperatura mais elevada (45 ºC) verificou-se que
houve formação de DCPD a pH 5,5. Ainda para esta temperatura observou-se
a precipitação de OCP para o intervalo de pH entre 6 e 7 e a formação de HA
para valores de pH iguais ou superiores a 8.
Numa segunda etapa deste trabalho realizaram-se sínteses semelhantes às
primeiras, mas desta vez na presença de cloreto de sódio, misturas de cloreto
de sódio e cloreto de potássio ou cloreto de magnésio. Estes sais foram
usados na concentração existente no plasma humano de forma a mimetizar as
condições existentes neste. Os resultados obtidos foram idênticos aos
descritos anteriormente, com a diferença que os sólidos obtidos contêm, na
sua estrutura, os iões Na+ e Mg2+ em concentrações vestigiais. Verificou-se
que o ião K+ não entra na rede dos fosfatos de cálcio sintetizados, mas fica
adsorvido na sua superfície.
Por fim realizou-se uma série de experiências de envelhecimento no período
máximo da 10 dias de alguns dos sólidos sintetizados em solução aquosa de
pH inicial 7,4 de fluído fisiológico simulado.This work is intended to contribute for the study of the formation of
hydroxyapatite precursors (HA) - dicalcium phosphate dihydrate (DCPD) and
octacalcium phosphate (OCP) - in the presence and absence of Na+, K+, Mg2+
and Cl- ions, for the range of pH between 5 and 9 and to temperatures of 37
and 45 ºC.
The work was initiated with the accomplishment of a set of syntheses at
different values of pH and temperature that were intended to be studied and in
the absence of the Na+, K+, Mg2+ and Cl- ions. In this initial phase of the work,
the objective was to investigate the influence of pH and the temperature in the
formed phase of calcium phosphate. The results indicated that at pH 5
precipitation does not occur to any of the two studied temperatures under these
experimental conditions. For physiological temperature (37 ºC) DCPD
(CaHPO4.2H2O) was formed at pH 6, for values of pH between 6.5 and 7 OCP
(Ca8H2(PO4)6.5H2O) was formed, while for values of pH of 8 or upper the
formed phase was HA (Ca5(PO4)OH). For the higher temperature of 45 ºC, it
was verified that at pH 5.5 DCPD was formed. Still for this temperature it was
observed precipitation of OCP for the interval of pH between 6 and 7 and the
formation of HA for equal or upper values of pH 8.
In the second stage of this work, similar syntheses to the previous ones were
accomplished, but this time in the presence of sodium chloride, mixtures of
sodium chloride and potassium chloride or magnesium chloride. These salts
were used in the existing concentration in the human plasma so that the
existing conditions in the human body could be matched. The results obtained
were identical to the ones described previously, with the difference that the
resulting solids contained in their structure Na+, K+, Mg2+ and Cl- ions in trace
concentrations.
Finally, a series of ageing experiments, lasting no more than ten days, of
selected solids in aqueous solution with initial pH of 7.7 of simulated body fluid
has been made
Degradation of imidazolium-based ionic liquids in aqueous solution by Fenton oxidation
No full textBACKGROUND: The breakdown of imidazolium ionic liquids (ILs) by Fenton oxidation has been demonstrated, but using unaffordable doses of hydrogen peroxide (H2O2). The literature studies so far do not report on the evolution of total organic carbon (TOC) and ecotoxicity. Therefore, the potential application of the process for the degradation of ILs still remains an open question. This work investigates the feasibility of the Fenton process for the treatment of aqueous effluents containing imidazolium-based ILs of different structures, represented by the length of the alkyl chain and the nature of the anion. Special attention is paid to the evolution of the ecotoxicity and the consumption of H2O2 as a critical issue for the economy of the process. The experiments were performed at 70 degrees C. RESULTS: With the stoichiometric H2O2 dose, the complete conversion of the starting imidazolium-based ILs was achieved in less than 5 min, at 70 degrees C, with 60% of TOC reduction after 4 h, except in the [C(4)mim][CH3CO2] case, where iron precipitation was observed, thus inhibiting its catalytic action. Low ecotoxicity effluents were obtained at the stoichiometric H2O2 dose, even in the cases of the highly ecotoxic ILs of long alkyl chain with chloride anion. CONCLUSION: Fenton oxidation is shown to be a promising solution for the degradation of imidazolium-based ILs in water, allowing deep detoxification with the stoichiometric H2O2 dose. (C) 2014 Society of Chemical Industr
Characterization of concrete surface in relation to graffiti protection coatings
No full textThe removal of graffiti causes irreversible deterioration of fair-faced concrete. The protective products are often selected without counting the properties of concrete surface leading to its insufficient protection. Chemical and micro-structural effects of anti-graffiti products on the concrete surface were analyzed in relation to its protection efficiency against graffiti, paints. Contact angles and wetting envelope graphs were examined, allowing the understanding and prediction of wetting behavior of concrete surfaces. The obtained results revealed the changes on the concrete surface produced by graffiti, graffiti protection and graffiti removal products, showing the advantage of permanent protection coating over sacrificial one. (C) 2015 Elsevier Ltd. All rights reserved
Effect of Surface Treatment on the Performance of LDH Conversion Films
No full textThe preparation of layered double hydroxide (LDH) conversion films on aluminum alloy 2024 substrates is reported. The substrates were subjected to four different surface pre-treatments and the corresponding effect on the obtained films studied by scanning electron microscopy (SEM). The corrosion protection conferred to the underlying substrate was investigated by electrochemical impedance spectroscopy (EIS) and by the scanning vibrating electrode technique (SVET). The results show that the best performances are obtained when a laboratory mixed alkaline/acidic procedure or an industrial pre-treatment are applied before the LDH growth, which contribute for the increase of native oxide aluminum stability. (C) 2013 The Electrochemical Society. All rights reserved
Cellular ceramics by gelatin gelcasting of emulsified suspensions with sunflower oil
No full textHighly porous cellular ceramics were prepared by a versatile method combining emulsification of sunflower oil in alumina suspension, using collagen as surfactant, stabilizer and gelcasting additive. Emulsified suspensions show shear thinning behavior at emulsification temperatures, and their rheology was related to the volume fraction of dispersed oil droplets, collagen contents and stirring rate, based on a suitable Taguchi plan. This provides guidelines for the dependence of microstructural features on these processing parameters. The robustness of the method was demonstrated by the ability to perform early stages of burnout at relatively high heating rates, without risks of collapse or onset of factures in the resulting cellular ceramics. Combined DTG/DTA/FTIR studies were used to analyse the burnout stages, and provide guidelines to minimize emissions of gases with safety or environmental risks. (C) 2015 Elsevier Ltd. All rights reserved
Impedance Analysis and Conduction Mechanisms of Lead Free Potassium Sodium Niobate (KNN) Single Crystals and Polycrystals: A Comparison Study
No full textImpedance spectroscopy (IS) is used to compare defects and charge transport in (001) oriented K0.5Na0.5NbO3 (KNN) single crystals and its polycrystalline counterpart. KNN single crystals show lower conductivity than polycrystalline counterpart from room temperature up to 200 degrees C, but above this temperature polycrystalline KNN displays lower conductivity. The low temperature (T 200 degrees C) single crystals become more conductive than polycrystalline samples in which grain boundaries act as barriers to charge transport. For even higher temperatures, the conductivity difference between both is increased because of the contribution of ionic conduction in single crystals. Indeed the values of activation energy calculated to the high temperature range (T > 300 degrees C) were 1.60 and 0. 97 eV, confirming the charge transport because of ionic conduction and ionized oxygen vacancies in single crystals and polycrystalline KNN, respectively. It is suggested that single crystals with low defects content and improved electromechanical properties could be a better choice for room temperature applications, though at high temperatures less conductive ceramics may be the choice, depending on the targeted use
In Situ Observation of the Humidity Controlled Polymorphic Phase Transformation in Glycine Microcrystals
No full textGlycine is a model crystal exhibiting three polymorphic phases and important functional properties such as piezoelectricity and ferroelectricity. We report here in situ observation of the irreversible transformation of the solution-grown glycine crystals from a beta phase into a gamma phase. The slow transformation process was monitored by piezoresponse force microscopy at room temperature. The process of beta to gamma conversion was entirely controlled by the variation of relative humidity in the sample chamber. The results show that the rate of phase transformation in glycine is humidity dependent with a threshold of about 25% RH. It is demonstrated that the phase boundary is highly rugged and the transformation front propagates inhomogeneously along the polar axis of the beta phase. The mechanism of the phase transformation is discussed