Laminados de CFRP pré-tensionados para o reforço à flexão de vigas de betão armado

No presente trabalho explora-se o desempenho de uma nova estratégia de reforço à flexão com laminados de fibras de carbono aplicados sob determinada pré-tensão e segundo a técnica NSM (“Near Surface Mounted”). Para tal foi necessário encontrar e caracterizar as propriedades de um adesivo de cura rápida que permitisse transferir a pré-tensão do laminado para o betão envolvente no mais curto período de tempo possível. O programa experimental que se apresenta neste trabalho é exploratório, pretendendo evidenciar as vantagens e potencialidades desta técnica. O programa é descrito e os resultados são apresentados e analisados

CFRP group effect and interaction between stirrups and strips on the NSM-shear strengthening of RC beams

Available experimental research shows that the technique based on installing Carbon Fibre Reinforced Polymer (CFRP) strips into slits opened on the cover concrete of the beam’s lateral faces, designated as Near Surface Mounted (NSM), is very effective to increase the shear resistance of reinforced concrete (RC) beams. However, recent research has revealed that, in terms of NSM shear strengthening effectiveness, a detrimental effect can occur between existing steel stirrups and applied strips, as well as amongst the strips when the distance between strips, sf, is lower than a certain limit. In the present work, a test setup was developed and an experimental program was carried out to assess the influence of both sf and interaction between existing steel stirrups and strips on the shear strengthening of RC beams. The experimental program is described and the main results are presented and analyzed.(13-05-04-FDR-00031

Mayday, Mayday, Direito à Educação inclusiva em tempos de confinamento pela pandemia Covid-19

O reconhecimento do direito à educação, de crianças e jovens com necessidades especiais, proclamado em diversos documentos normativos e legislativos, desde a Declaração Mundial sobre a Educação para Todos, da UNESCO, em 1990, até à Declaração de Salamanca (1994), um importante marco para a Educação Especial. Neste contexto, surge a, considerada, na época, utópica ideia, da UNESCO, de “escola inclusiva”, espaço onde todos os alunos aprendem juntos, sempre que possível independentemente das dificuldades e das diferenças que apresentem”. A Convenção Internacional sobre os Direitos das Pessoas com Deficiência (2006) vem criar um consenso internacional que nega os modelos educativos centrados nos défices e em espaços e práticas segregadoras e promove respostas eficazes na inclusão de todas as crianças, com base no respeito pelas diferenças. Para a concretização do paradigma emergente, Portugal tem vindo a desenvolver politicas e a criar meios para o devido enquadramento legal de novas práticas. O Programa do XXI Governo Constitucional estabelece como uma das prioridades da ação governativa a aposta numa escola inclusiva, onde todos e cada um dos alunos, independentemente da sua situação pessoal e social, encontrem respostas que lhes possibilitem a aquisição de um nível de educação e formação facilitadores da sua plena inclusão. O Decreto-Lei n.º 54/2018, publicado a 6 de julho revoga legislação anterior, nomeadamente o Decreto-Lei 3/2008, de 7 de janeiro e introduz medidas específicas, subjacentes à conceptualização, ao processo de avaliação e elegibilidade que responsabiliza e envolve toda a comunidade educativa. A situação emergência provocada pela covid-19, retirando as crianças da escola e obrigando ao confimnamento, vem colocar em risco a educação inclusiva, acentuando, ainda mais, as disigualdades pessoais e sociais de alunos com algum tipo de vulnerabilidade. Com o nosso trabalho, procuramos, então, refletir sobre o impacto do ensino à distância (E@D) sinalizando as barreiras que deixam alguns para trás.info:eu-repo/semantics/publishedVersio

Towards customized footwear with improved comfort

A methodology enabling the customization of shoes for comfort improvement is proposed and assessed. For this aim, 3D printed graded density inserts were placed in one of the critical plantar pressure zones of conventional insoles, the heel. A semi-automated routine was developed to design the 3D inserts ready for printing, which comprises three main stages: (i) the definition of the number of areas with different mesh density, (ii) the generation of 2D components with continuous graded mesh density, and (iii) the generation of a 3D component having the same 2D base mesh. The adequacy of the mesh densities used in the inserts was previously assessed through compression tests, using uniform mesh density samples. Slippers with different pairs of inserts embedded in their insoles were mechanically characterized, and their comfort was qualitatively assessed by a panel of users. All users found a particular pair, or a set, of prototype slippers more comfortable than the original ones, taken as reference, but their preferences were not consensual. This emphasizes the need for shoe customization, and the usefulness of the proposed methodology to achieve such a goal.This work was funded by National Funds through FCT—Portuguese Foundation for Science and Technology, Reference UID/CTM/50025/2019 and UIDB/04436/2020, and Project FAMEST, Reference POCI-01-0247-FEDER-024529, co-financed by COMPETE2020 through PT2020 and FEDER

Tunable magnetocaloric effect around room temperature by Fe doping in Mn0.98Cr(0.02-x)FexAs compound

In this work, we present an investigation of the magnetic and magnetocaloric properties of Mn0.98Cr(0.02-x)FexAs compounds with x = 0.002, 0.005 and 0.010. Our findings show that as Fe content increases the unit cell volume decreases, which indicates that Fe doping emulates the pressure effect on the crystalline structure. The transition temperature TC decreases as x increases and it can be set at approximate value of room temperature by changing the doping level. In addition, the magnetic entropy change ΔSM was determined using a discontinuous measurement protocol, and realistic values from the magnetocaloric effect presented by MnAs-type compounds under pressure (emulated pressure) could be obtained. The values of ΔSMMAX are very large, around −11 Jkg−1K−1 with ΔH = 15 kOe, which is higher than that observed for most compounds with TC around room temperature. However, ΔSM is confined to a narrow temperature range of 11 K. To overcome this drawback, the composition of a theoretical composite formed by our samples was calculated in order to obtain a table-shaped ΔSM curve. The simulated composite showed a high value of full width at half maximum δTFWHM of 33 K, which is much higher than that of single sample.Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro - FAPERJ E-26/110.393/2014, E-16/210.263/2014Coordenação de aperfeiçoamento de pessoal de nivel superior - CAPES 485200/2013-9Fundación de Apoyo a la Investigación del Estado de São Paulo - FAPESP 2012/03480-0Ministerio de Economía y Competitividad MAT2013-45165-

Prediction of total acid number in distillation cuts of crude oil by ESI(-) FT-ICR MS coupled with chemometric tools

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESCompetitive adaptive reweighted sampling-partial least squares (CARS-PLS) and negative-ion mode electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI(-) FT-ICR MS) data were adopted to assess the total acid number (TAN)28918221829FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESSEM INFORMAÇÃOSEM INFORMAÇÃOSEM INFORMAÇÃOThis research was generously funded by PETROBRAS/CENPES, FAPESP, CNPq, CAPES, and FINE

Monitoring the degradation and the corrosion of naphthenic acids by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and atomic force microscopy

AbstractAlthough the term “naphthenic acids” was originally used to describe acids that contain naphthenic rings, today this term is used in a more general sense and refers to all components in the acid extractable fraction. In crude oil, naphthenic acids exist as a complex mixture of compounds with broad polydispersity with respect to both molecular weight and structure. There has been increasing interest in the naphthenic acids in crude oil because of the corrosion problems that cause during oil refining. Herein, two powerful analytical tools, negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, ESI(-)FT-ICR MS and atomic force microscopy (AFM), were combined to monitor the thermal degradation of naphthenic acids and their corrosion effects on AISI 1020 steel, respectively. Two different acidic crude oils (TAN=2.38 and 4.79mgKOHg−1, and total sulfur=0.7993 and 1.0220wt%) have been submitted to thermal treatment at 280, 300 and 350°C during 2, 4 and 6h, and characterized by ESI(-)-FT-ICR MS, total acid number (TAN), and total sulfur. The AISI 1020 steel was analyzed by scanning electron microscopy (SEM) and AFM. Generally, heating the crude oil at 350°C in a period of 6h, it was observed that a high efficiency (≅80%) and selectivity of thermal decarboxylation process was monitored by decay of TAN (4.79→0.44mgKOHg−1). ESI(-)-FT-ICR MS results showed that naphthenic acid species remained after the heating have DBE ranging 1–12 and carbon number from C15 to C45. AFM topographic profile evidenced that the naphthenic acid corrosion of the crude oil with TAN of 4.73mgKOHg−1 on AISI 1020 steel was profoundly altered and a marked reduction in peak to peak height values (obtained by subtracting the value of the lowest peak by the highest peak in the topographic area examined). Optical images and microphotographs confirmed the presence of irregularities, characterizing the corrosion mechanism as pitting type. The naphthenic corrosion was also evidenced in samples with low TAN value (0.44mgKOHg−1)

Ferroelectric orthorhombic ZrO2 thin films achieved through nanosecond laser annealing

A new approach for the stabilization of the ferroelectric orthorhombic ZrO2 films is demonstrated through nanosecond laser annealing (NLA) of as-deposited Si/SiOx/W(14 nm)/ZrO2(8 nm)/W(22 nm), grown by ion beam sputtering at low temperatures. The NLA process optimization is guided by COMSOL multiphysics simulations. The films annealed under the optimized conditions reveal the presence of the orthorhombic phase, as confirmed by X-ray diffraction, electron backscatter diffraction, and transmission electron microscopy. Macroscopic polarization-electric field hysteresis loops show ferroelectric behavior, with saturation polarization of 12.8 mu C cm(-2), remnant polarization of 12.7 mu C cm(-2) and coercive field of 1.2 MV cm(-1). The films exhibit a wake-up effect that is attributed to the migration of point defects, such as oxygen vacancies, and/or a transition from nonferroelectric (monoclinic and tetragonal phase) to the ferroelectric orthorhombic phase. The capacitors demonstrate a stable polarization with an endurance of 6.0 x 10(5) cycles, demonstrating the potential of the NLA process for the fabrication of ferroelectric memory devices with high polarization, low coercive field, and high cycling stability.A.P.S.C. and M.C.I. contributed equally to this work. This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding Contract UIDB/04650/2020. This work has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 958174 (M-ERA-NET3/0003/2021-NanOx4EStor). M. C. I. and C. G. acknowledge the financial support by a grant of the Ministry of Research, Innovation and Digitization, CNCS/CCCDI - UEFISCDI, project number COFUND-M-ERANET-3-NanOx4Estor, within PNCDI III and POC 332/390008/29.12.2020-SMIS 109522. The authors acknowledge the CERIC-ERIC Consortium for access to experimental facilities and financial support under proposals 20202037, 20202038, and 20192055. The authors would also like to thank Jose Santos for technical support in the Thin Film Laboratory at CF-UM-UP. J.L.M-D. thanks the ERC grant, EU-H2020-ERC-ADG #882929, EROS. And the Royal Academy of Engineering, grant CIET1819_24. MOH thanks the Herchel Smith foundation of Cambridge for a research fellowship. This work made use of the University of Cambridge Wolfson Electron Microscopy Suite

Analysis of physical performance in children of seven to ten years old.

Capacidade f?sica ? o termo utilizado para agrupar as capacidades for?a, velocidade, resist?ncia, flexibilidade e coordena??o. O desempenho f?sico de crian?as ? preocupa??o permanente entre os especialistas da ?rea da sa?de. Esse interesse justifica-se j? que a atividade f?sica desempenha importante papel na preven??o de doen?as e melhoria da capacidade funcional. O objetivo do presente estudo foi analisar as capacidades f?sicas em crian?as de ambos os sexos. Ap?s consentimento por escrito dos pais, participaram do estudo 232 crian?as de ambos os sexos entre as idades de sete e 10 anos. A capacidade f?sica foi avaliada utilizando-se os testes de sentar e alcan?ar, resist?ncia abdominal, salto horizontal e corrida de 30 metros. Foi utilizado ANOVA two way e post hoc de Tukey para compara??o das vari?veis entre as idades e o sexo. O n?vel de signific?ncia foi de 5%. A flexibilidade n?o foi modificada pela idade e sexo. O salto horizontal e o n?mero de abdominais foram maiores nos meninos comparados ?s meninas e nas idades de 10, nove e oito anos comparados a idade de sete anos. O tempo para percorrer 30 m foi menor nos meninos comparado ?s meninas, sendo que a idade de 10 anos apresentou valores menores comparado as demais idades e as idades de nove e oito anos demonstraram menores valores comparado a idade de sete anos. De modo geral, os meninos apresentam melhor desempenho f?sico comparado ?s meninas na faixa et?ria avaliada. A idade de sete anos parece representar um per?odo de transi??o no desempenho f?sico.Physical performance is the term used to group strength, speed, endurance, flexibility and coordination capacities. The physical performance in the children is concern among experts in the field of health. This interest justified because physical activity can prevent illness and increase functional capacity. The aim of present study was assessment physical capacity in children of both sex, boys and girls. After consent of parents, concerns of study 232 children among seven and 10 years-old of both sexes. The performance motor was assessment using sit-and-reach, horizontal jump, abdominal endurance and 30 meters tests run. ANOVA Two-way and Tukey post hoc was used to compared variables among sex and ages. The significant level was 5%. Flexibility did not differ among ages and sex. The horizontal jump distance and abdominals number were higher in male group compared to the female group and eight, nine and 10 years-old were higher compared to seven years-old. The abdominals number was higher in male group compared to female group and eight, nine and 10 years-old are higher compared to seven years-old. The time to going 30 meters was small in the male group compared to female group and running time was small in the 10 years-old compared to other ages and the nine and eight years-old was small than seven years-old. In general, the boys presented better performance than girls in the ages assessment. The age seven years-old apparent represented a period of transition in the physical performance

Influence of the apical enlargement size on the endotoxin level reduction of dental root canals

Gram-negative bacteria play an essential role in endodontic infections because they have virulence factors such as endotoxin. Due to its potential cytotoxic activity, special attention has been given to the removal/neutralization of this endotoxin in the root canal system. OBJECTIVE: The aim of this study was to evaluate the influence of the apical enlargement size (AES) by using rotary instruments on the endotoxin level reduction of dental root canals. MATERIAL AND METHODS: Forty root canals of the mandibular premolar teeth were used. Escherichia coli endotoxin (055: B55) was inoculated into thirty root canals. Ten teeth served as the negative control group. After the incubation period, the first endotoxin samples were collected from the root canals with a sterile/apyrogenic paper point for the analysis of the endotoxin units (EU/mL) present before instrumentation (S1). Specimen instrumentation was performed with the Mtwo(®) rotary system in the sequence 10/.04, 15/.05, 20/.06, 25/.06, 30/.05, 35/.04 and 40/.04. To monitor the effectiveness of increasing apical enlargement on endotoxin removal, the second endotoxin samples were collected from all the root canals after instrumentation with the following instruments: #25/.06- (S2); #30/.05- (S3); # 35/.04- (S4); and #40/.04- (S5). Limulus amebocyte lysate (LAL) was used to quantify the levels of endotoxin. The results were statistically compared by using repeated measures of ANOVA with post hoc Tukey testing. RESULTS: Increasing levels of endotoxin removal was achieved by large sized apical enlargement: S2 (AES #25/.06)- 89.2%, S3 (AES #30/.05)- 95.9%, S4 (AES #35/.04)- 97.8% and S5 (AES #40/.04)- 98.2%. Substantial reduction of endotoxin content was obtained in S4 and S5 compared to S2 (p<0.05), however, the root canal preparation was not able to eliminate the endotoxin. CONCLUSIONS: Under the conditions of this study, it was concluded that the reduction of endotoxin levels of the dental root canals could be predicted by increasing the apical enlargement size