1,083 research outputs found

    Experimental study of twin air impinging jets

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    This work is devoted to the visualization and characterization of twin air jet flow when impinging vertically to a solid surface, which is important to understand the phenomenon relevant to Vertical/Short Take-Of and Landing (V/STOL) type of aircraft when they are operating on short distances from the ground, landing or taking-off, and could be helpful to improve the performance and stability of this kind of aircrafts. The major concern of this work is characterizing the fountain upwash region, which is a distinctive fan-shape flow that is formed on the collision region. The parameters analysed on this work are the separation distance between the jets and the jet height. Have been observed significant changes in the flow pattern and properties in the fountain upwash region due to the changes in the parameter studied. To be possible the realization of this work an experimental facility has been built. The facility supports an adjustable mechanical system which can accommodate twin stainless steel barrels with different diameters, which are the jets. Within this mechanical system, the barrels horizontal distance and height can be independently adjusted. The working fluid is the air, and to be possible the flow visualization a seeding generator have been projected and built. The flow visualization has been supported by an algorithm developed on the “Image Processing toolbox of Matlab” software, where have been made the post processing of the images.Este trabalho baseia-se na visualização e caracterização do escoamento desenvolvido por dois jactos paralelos e verticalmente disposto em relação a uma superfície sólida. Estes fenómenos estão associados com aeronaves de descolagem e aterragem vertical ou curta (V/STOL – vertical/short take-of and landing). Particularmente, interessa a caracterização da região conhecida como “fountain upwash”, que é uma forma característica do escoamento que se forma na região da colisão. Os parâmetros analisados neste trabalho foram a distância horizontal entre os jactos e a altura destes à superfície de impacto. Foram observados diferenças significativas no padrão e propriedades do escoamento na região de “fountain upwash” devido à variação dos parâmetros em estudo. Para a realização deste estudo foi construída uma instalação experimental. A instalação é ajustável mecanicamente, contendo dois tubos de aço, com diâmetro variável. O sistema mecânico permite o ajustamento, independentemente, a distância horizontal entre os jactos e a altura dos mesmos. Como neste trabalho se vai trabalhar com ar, para ser possível visualizar o escoamento é necessário marcar o escoamento. Nesse sentido foi desenvolvido um gerador de “seeding”. Para uma melhor e mais precisa visualização do escoamento foi desenvolvido um algoritmo no “Matlab” usando “Image Processing toolbox”, onde as imagens captadas foram pós processadas

    Application of remote sensing techniques to hydrography with emphasis on bathymetry

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    Remote sensing techniques are utilized for the determination of hydrographic characteristics, with emphasis in bathymetry. Two sensor systems were utilized: the Metric Camera Wild RC-10 and the Multispectral Scanner of LANDSAT Satellite (MSS-LANDSAT). From photographs of the metric camera, data of photographic density of points with known depth are obtained. A correlation between the variables density x depth is calculated through a regression straight line. From this line, the depth of points with known photographic density is determined. The LANDSAT MSS images are interpreted automatically in the Iterative Multispectral Analysis System (I-100) with the obtention of point subareas with the same gray level. With some simplifications done, it is assumed that the depth of a point is directly related with its gray level. Subareas with points of the same depth are then determined and isobathymetric curves are drawn. The coast line is obtained through the sensor systems already mentioned. Advantages and limitations of the techniques and of the sensor systems utilized are discussed and the results are compared with ground truth

    Educação e literacia sexual: representações de professores (estudo de caso)

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    A Lei n.º 60/2009 generalizou a Educação Sexual (ES) nas escolas do ensino básico e secundário. Os modelos de ES caracterizam diferentes posições perante a sexualidade, sejam socioeconómicas, profissionais ou religiosas. Hoje, a ES tem como desafio a promoção de competências, baseadas na responsabilidade e na autonomia, para usar o conhecimento e estimular o desenvolvimento pessoal. A capacidade de aplicar o conhecimento e as aptidões, para analisar, raciocinar e comunicar eficazmente, interpretar e resolver problemas em situações variadas é hoje indispensável. A ES deve seguir uma orientação baseada na literacia sexual ou ser um receituário de prevenção e saúde pública? Num estudo de caso, verificou-se que para os professores inquiridos a educação da sexualidade de crianças até aos 11/12 anos deve valorizar conhecimentos (gerais básicos) sob supervisão dos pais, complementada pela escola, em contexto estruturado, o que corresponde ao previsto no nível 1 do QEQ (EU, 2008). A partir dos 12 anos os professores inquiridos continuam a valorizar o papel educativo dos pais em relação à sexualidade, considerando, no entanto, que deve haver um certo grau de autonomia e responsabilidade por parte dos alunos, o que corresponde ao previsto no nível 2 do QEQ. Globalmente os professores inquiridos apontam para uma educação sexual baseada no modelo de formação pessoal e social, reforçando-se progressivamente a autonomia e a responsabilidade dos alunos para a literacia sexual

    Photodynamic therapy for diffuse choroidal hemangioma in sturge-weber syndrome

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    Purpose. To report the treatment outcome of photodynamic therapy with verteporfin (PDT) for exudative retinal detachment (RD) associated with diffuse choroidal hemangioma in Sturge-Weber syndrome (SWS). Methods. An interventional case report of a 10-year-old girl with SWS who developed an exudative RD (visual acuity hand motions) that was treated with PDT. She was treated with a first session of multispot PDT. Posteriorly, a choroidotomy for drainage of subretinal fluid was created, combined with an intravitreal injection of gas (SF6) and cryoapplication. Finally, a second session of PDT was applied. Results. Subretinal fluid resolved over a period of one year and visual acuity increased to 20/125. Conclusions. PDT is an effective therapeutic option for exudative RD associated with diffuse choroidal hemangioma

    Retaining Expression on De-identified Faces

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    © Springer International Publishing AG 2017The extensive use of video surveillance along with advances in face recognition has ignited concerns about the privacy of the people identifiable in the recorded documents. A face de-identification algorithm, named k-Same, has been proposed by prior research and guarantees to thwart face recognition software. However, like many previous attempts in face de-identification, kSame fails to preserve the utility such as gender and expression of the original data. To overcome this, a new algorithm is proposed here to preserve data utility as well as protect privacy. In terms of utility preservation, this new algorithm is capable of preserving not only the category of the facial expression (e.g., happy or sad) but also the intensity of the expression. This new algorithm for face de-identification possesses a great potential especially with real-world images and videos as each facial expression in real life is a continuous motion consisting of images of the same expression with various degrees of intensity.Peer reviewe

    O PEQUENO PRÍNCIPE COMO OBRA DA RESISTÊNCIA: ANÁLISE DO ROMANCE DE SAINT-ÉXUPERY À LUZ DA ESTÉTICA DA RECEPÇÃO

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    Essa pesquisa busca compreender aspectos históricos e estéticos da obra O pequeno príncipe, do aviador e escritor francês Saint-Éxupery, apoiando-se em conceitos teóricos da estética da recepção, de Hans-Robert Jauss. Objetiva-se delinear o possível horizonte de expectativas em que se insere a primeira recepção dessa obra, no momento de sua publicação para os públicos americano e francês. O estudo dos contextos histórico, social e artístico da primeira à segunda guerras mundiais será o ponto de apoio para abarcar as transformações no horizonte das expectativas literárias acarretadas pelos avanços e recuos políticos do período. Desse ponto de vista, O pequeno príncipe é encarado como obra da Resistência francesa contra o governo de Vichy e a dominação alemã, evidenciando como o romance contrariasse expectativas literárias comuns àquele momento histórico

    Sustained-Release Bupropion Overdose: A Case Report

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    Bupropion is an atypical antidepressant with a unique aminoketone structure similar to amphetamines. A narrow therapeutic margin is evident from observational studies that show seizure activity with doses of 400-600 mg or higher. A 38-year old woman took an overdose of 6 grams of bupropion with 110 grams of alcohol. She presented to the Emergency Department with agitation, visual hallucinations and myoclonus of the upper limbs; eyes spontaneously open with isochoric and light reactive pupils with horizontal nystagmus; afebrile, normotensive (121/63 mm Hg) and tachycardic (120 beats/minute). The electrocardiogram revealed a sinus tachycardia with prolonged QT interval (QT/QTc: 0.46/ 0.537) and a QRS complex length in the upper limit of normal. Arterial blood gases revealed metabolic acidosis (pH = 7.16) with increased anion-gap (value=18). She developed mal epilepticus needing thiopental induced coma and Intensive Care Unit (ICU) admission. She suffered prolonged symptoms including seizures before fully recovering. The narrow therapeutic range and the increasing use in the treatment of smoking cessation boosted the number of intentional and unintentional poisoning by this drug. Previous reports of bupropion overdose almost all involve the immediate release formulation. There are some reports of overdose with sustained-release formulation, but there is limited information on its spectrum of toxicity

    Stabilin-1 plays a protective role against Listeria monocytogenes infection through the regulation of cytokine and chemokine production and immune cell recruitment

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    Scavenger receptors are part of a complex surveillance system expressed by host cells to efficiently orchestrate innate immune response against bacterial infections. Stabilin-1 (STAB-1) is a scavenger receptor involved in cell trafficking, inflammation, and cancer; however, its role in infection remains to be elucidated. Listeria monocytogenes (Lm) is a major intracellular human food-borne pathogen causing severe infections in susceptible hosts. Using a mouse model of infection, we demonstrate here that STAB-1 controls Lm-induced cytokine and chemokine production and immune cell accumulation in Lm-infected organs. We show that STAB-1 also regulates the recruitment of myeloid cells in response to Lm infection and contributes to clear circulating bacteria. In addition, whereas STAB-1 appears to promote bacterial uptake by macrophages, infection by pathogenic Listeria induces the down regulation of STAB-1 expression and its delocalization from the host cell membrane. We propose STAB-1 as a new SR involved in the control of Lm infection through the regulation of host defense mechanisms, a process that would be targeted by bacterial virulence factors to promote infection.This work was funded by National Funds through FCT—Fundação para a Ciência e a Tecnologia, I.P., under the project UIDB/04293/2020. R.P. and J.P. were supported by doctoral fellowships from FCT (SFRH/BD/89542/2012 and SFRH/BD/86871/2012). S.S. was supported by the FCT in the framework of the CEEC-Institutional 2017 program. The authors acknowledge the support of i3S Scientific Platforms: Advanced Light Microscopy, member of the national infrastructure PPBI-Portuguese Platform of BioImaging (supported by POCI-01-0145-FEDER-022122), and Translational Cytometry Unit (Tracy);Fundação para a Ciência e a Tecnologia [UIDB/04293/2020]
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