7,469 research outputs found
La Nueva Novela Histórica y sus insuficiencias teóricas: el emplazamiento negroafricano / The New Historical Novel and its theoretical insufficiencies: the Black African site
El presente trabajo se sitúa en el ámbito de la Nueva Novela Histórica (NNH) y los estudios postcoloniales con el fin de examinar la pertinencia y las características de los modos de lectura que se usan para leer narrativas historiográficas. La hipótesis principal sostiene que hay un hiato en el aparato teórico utilizado para leer las narrativas historiográficas que ficcionalizan el universo negroafricano. Se deduce que es menester extender los modos de lectura teórico-críticas que tomen en cuenta las dimensiones culturales de la memoria oral dentro de los imaginarios de origen africanos. Para este reto, se propone una confluencia entre los estudios literarios, históricos y aquellos sobre memoria y tradición oral, a través de una perspectiva transdisciplinar que contribuya a ampliar la comprensión de las narrativas con este perfil.Positioned within the scope of the New Historical Novel (NHN) and postcolonial studies, this article examines the relevance and characteristics of methods used to read historiographical narratives. It argues that there is a hiatus in the theoretical apparatus used to read historiographical narratives that fictionalizes the universe of African origin. It is necessary, therefore, to expand theoretical-critical reading methods to take into account the cultural dimensions of oral memory within the imaginaries of African origin. To meet this challenge, I propose a confluence between literary and historical studies, and those on memory and oral tradition through a transdisciplinary perspective that contributes to an increased understanding of these types of narratives
Redes de sensores de fibra ótica para monitorização in situ de baterias de ião de lítio
In this work, fiber optic sensor networks were developed to be integrated in commercially available lithium-ion batteries (cylindrical and prismatic) and pre-fabricated batteries in a laboratory environment (pouch cells), with the objective of monitoring in situ, operando and in real time, the internal and external variations of temperature and strain, under different environmental conditions and different charge and discharge rates.
To this end, and in order to show the improved performance of fiber optic sensors in relation to the electronic ones, typically used in this type of application, their response time and resolution were compared. An improvement of 28% of the response time and a better resolution are attained with fiber optic sensors.
Monitorization studies of the temperature and strain variations using fiber Bragg gratings (FBGs) in the cylindrical configuration have been made, as well as temperature and bi-directional strain variations in the prismatic configuration, under normal or abusive operating conditions, using the FBG method strain free. When the batteries were subjected to abusive operating conditions, it was evident that greater temperature and strain variations occur, being promoted by the rapid transport of lithium ions between the positive and negative electrodes. Due to the thermal expansion of the materials that compose the battery, its internal structure is an important parameter to consider and that can influence its behavior in terms of expansion and contraction.
In order to monitor the thermal performance of lithium-ion prismatic batteries in different environmental conditions, studies were performed in which the battery operated at different discharge rates over different conditions of temperature and relative humidity, in order to simulate the performance of the battery in three distinct climates: cold, temperate, and dry. From these studies, the poor performance of this type of batteries in the cold climate, and consequent lower thermal performance was verified.
A network of 37 FBG sensors has also been used to monitor the interfaces of a pack of 3 lithium polymer batteries connected in series. It was possible to perform a spatial and temporal thermal mapping under different discharge rates, and to identify areas that are more susceptible to the appearance of hot spots and that are capable of endanger its normal functioning. Hotter zones were detected near the current collectors, due to the higher density of lithium ions in this region.
For the first time, the simultaneous discrimination of internal temperature and strain variations in lithium-ion batteries in the pouch cell configuration was carried out, through the incorporation of hybrid sensors, which combine the operational characteristics of the Fabry-Perot and FBG sensors. The evolution of the strain and temperature signals was followed by the proposed sensors and the largest strain variations were detected at the beginning of the discharge process, in the bottom position of the pouch cell.
With the work developed in this Thesis, it is concluded that the integration of optical fiber sensors into lithium-ion batteries contributes to a better internal and external knowledge of the thermal performance and volume variations under different operating conditions. This might improve the safety conditions and optimize the design of the next generation of lithium-ion batteries.No presente trabalho, desenvolveram-se redes de sensores em fibra ótica para integrar em baterias comerciais de ião de lítio (cilíndricas e prismáticas) e em baterias pré-fabricadas em ambiente de laboratório (pouch cells), com o objetivo de monitorizar in situ, em funcionamento e em tempo real variações internas e externas de temperatura e deformação, sob diferentes condições ambientais e diferentes taxas de carga e descarga.
Para tal, e de maneira a mostrar o melhor desempenho dos sensores de fibra ótica em relação aos eletrónicos tipicamente usados neste tipo de aplicação, os seus tempos de resposta e resolução foram comparados, obtendo-se uma melhoria de 28% do tempo de resposta e uma resolução superior com os sensores em fibra ótica.
Foram feitos estudos da monitorização de variações de temperatura e deformação através de redes de Bragg em fibra (FBG) na configuração cilíndrica e variações de temperatura e deformação bidirecional na configuração prismática, aquando do seu funcionamento em condições normais e abusivas, através do método FBG strain-free. Quando as baterias foram submetidas a condições operacionais abusivas, ficou evidente que ocorrem maiores variações de temperatura e de deformação, sendo promovidas pelo rápido transporte dos iões de lítio entre os elétrodos positivo e negativo. Devido à expansão térmica dos materiais que compõem a bateria, a sua estrutura interna é um importante parâmetro a ter em consideração e que pode influenciar o seu comportamento em termos de expansão e contração.
A fim de monitorizar o desempenho térmico de baterias prismáticas de ião de lítio em diferentes condições ambientais, realizaram-se estudos nos quais a bateria operou sob diferentes taxas de descarga em diferentes condições de temperatura e humidade relativa, por forma a simular o desempenho da bateria em três climas distintos: frio, temperado e seco. Destes estudos, constatou-se o fraco desempenho deste tipo de baterias no clima frio, e consequente inferior desempenho térmico.
Uma rede de 37 sensores FBG foi ainda usada para monitorizar as interfaces de um pack de 3 baterias poliméricas de lítio, conectadas em série. Foi possível realizar um mapa térmico espacio-temporal para diferentes taxas de descarga, e identificar as zonas mais suscetíveis ao aparecimento de pontos quentes e capazes de colocar em risco o seu normal funcionamento. As zonas mais quentes foram detetadas próximas dos coletores de corrente, devido à superior densidade dos iões de lítio nesta região.
Pela primeira vez, foi realizada a discriminação simultânea de variações internas de temperatura e deformação em baterias de ião lítio na configuração pouch cell, através da incorporação de sensores híbridos, que combinam as características operacionais dos sensores Fabry-Perot e FBG. A evolução da deformação e temperatura foi seguida pelos sensores propostos e as maiores variações de deformação foram detetadas no início do processo de descarga, na posição inferior da pouch cell.
Com o trabalho desenvolvido nesta Tese, conclui-se que a integração de sensores em fibra ótica em baterias de ião de lítio contribui para um melhor conhecimento, interno e externo, do desempenho térmico e de variações de volume sob diferentes condições de funcionamento. Assim, poder-se-á melhorar as condições de segurança e otimizar o design da próxima geração de baterias de ião de lítio.Programa Doutoral em Engenharia Físic
The Impacts of Yeast Fermentation and Bacillus Subtilis Dietary Products on Sperm Quality and Semen Microbiota of Aged White Leghorn Roosters
Alternatives to antibiotic growth promoters have been widely exploited due to concerns about antimicrobial resistance. These feed additives improve growth, in part, by modulating intestinal microbiota. However, their impact on male reproductive performance is not well elucidated. Therefore, the objective of this study was to evaluate the impacts of a yeast fermentation product (YP) and Bacillus subtilis on rooster semen quality and microbiota. Dietary supplementation of YP linearly increased the concentration of yeast and bacteria in semen, whereas it linearly decreased sperm motility, suggesting that bacteria attached to yeast were excreted from the gut, contaminated semen at the cloaca and then decreased sperm movement. However, direct in vitro exposure of semen or dietary supplementation with B. subtilis did not affect semen quality or seminal concentration of this bacterium, likely because Bacillus naturally occur in semen. In conclusion, unlike B. subtilis, dietary YP can alter semen quality by altering semen microbiota
A (in)visibilidade dos professores de técnica de dança : manifesto reflexivo
Delimitado ao Ensino Especializado da Dança esta reflexão aborda, especificamente, o “agente” que, a longo prazo e de forma menos visível para o público, participa e contribui, de forma “oculta” para o ato de dançar – o professor de Dança.
Fundamenta-se a importância e a especificidade do corpo na Dança - enquanto arte performativa – e os processos de aprendizagem, expressão e representação. Defende-se a prática sistemática da Técnica de Dança, enquanto meio de adestrar o corpo, tornando-se imperiosa a sua valência na formação de bailarinos.
O Ensino Especializado da Dança, em Portugal é anunciado de forma resumida. São identificadas as Escolas em funcionamento no ano letivo de 2012/ 2013, apresentando-se a cronologia de criação de cada uma, os diferentes níveis de ensino ministrados, assim como a sua localização geográfica.
Concluímos este manifesto reflexivo com a identificação de algumas singularidades indispensáveis a um professor de Técnica de Dança
Modos de Gestão e Liderança Nas Escolas Básicas Cabo-verdianas – Estudo de Caso Das Escolas/Pólos Com Satélites No Concelho da Praia
“Dançar dói, mas dói mais quando estou parada": Reflexões sobre o corpo na dança
O documento integral está disponível através do link que se encontra no campo Versão do Editor.A dança, enquanto arte performativa, utiliza o corpo como instrumento
fundamental do discurso artístico e como forma de comunicação e relação com o mundo.
Partindo-se do facto do bailarino ser detentor do corpo que dá corpo à dança, entendemos
(re)visitar autores aos quais reconhecemos afinidades e partilhar algumas reflexões
sobre o corpo, a sua importância, significância e inscrição nos vastos domínios da dança.
Assumimos o corpo enquanto instrumento “afinado” de um bailarino que é capaz de
ter domínio sobre esse corpo e que tem competências para criar um novo vocabulário
de movimento, respondendo de forma mais eficaz e concordante com a pluralidade e
mutabilidade das solicitações do mercado da dança.ABSTRACT: As a performance art, dance uses the body as a core instrument of artistic
discourse and as a way to communicate and relate to the world. Starting from the fact that
dancers hold the bodies that embody dance, we intend to (re)visit authors with whom we
share affinities and reflections about the body, its importance, significance and inscription
in the vast domains of Dance. We take the body as the “tuned” instrument of a dancer
who is able to master that body and who has the skills to create a new vocabulary for
movement, thus responding more effectively and in accordance with the plurality and
changeability of Dance market requests.info:eu-repo/semantics/publishedVersio
Cultural adaptation to Brazil of the questionnaire Costs of caring for children with cancer.
Objectiveto present the cultural adaptation of the questionnaire Costs of caring for children with cancer, offering a valid and reliable tool to assess the economic repercussions of childhood cancer for Brazilian families.Methodit is a methodological research with a cross-sectional design. The methodological framework to validate the questionnaire was a combined process that included seven steps: translation to Portuguese; first translated consensus version; evaluation by Expert Committee; consensus on the Expert Committee version; back-translation; consensus of back-translated versions; semantic validation. The study was conducted in two phases: phase one was the translation and back-translations process, with five expert committee members. Phase two was the semantic validation, with 24 participants, who answered an instrument about their impressions of the questionnaire and suggested modifications.Resultsin phase one, items were included, excluded, and replaced to make the content equivalent and valid for use with Brazilian context. In phase two, the majority of the participants were mothers, who made suggestions about the relevance and clarity of the items in the questionnaire.Conclusionsthe authors discussed these recommendations and made adaptations, turning the questionnaire into a valid and reliable tool for application
Lean six sigma approach for COVID-19 demand growth. A Case Study in a Rio de Janeiro hospital respirator company.
The current economic scenario shows a major recession caused by the crisis in public health due to the proliferation of the new coronavirus. However, companies operating in the hospital segment have high demands and their products are widely used. However, old mistakes in operations management inhibited several production lines and achieving their manufacturing goals due to waste generated in the production processes. This article aims to increase the production capacity by 70% of the production line of surgical tubes in a hospital instrument industry located in the state of Rio de Janeiro. To achieve this objective, a lean six sigma project will be developed, conducted by the DMAIC methodology. From the 36-days analysis of the process, it was possible to reach the main low production problems and precisely find a way to increase production capacity by 55%, making it possible to attend to the new increasing demand from COVID-19 engaged hospitals. Also, due to directed actions, operators could increase their productivity ratio from 89 to145 products per hour by the end of May 2020
Orbitally stable standing waves of a mixed dispersion nonlinear Schr\"odinger equation
We study the mixed dispersion fourth order nonlinear Schr\"odinger equation
\begin{equation*} %\tag{\protect{4NLS}}\label{4nls} i \partial_t \psi -\gamma
\Delta^2 \psi +\beta \Delta \psi +|\psi|^{2\sigma} \psi =0\ \text{in}\ \R
\times\R^N, \end{equation*} where and . We
focus on standing wave solutions, namely solutions of the form , for some . This ansatz yields the
fourth-order elliptic equation \begin{equation*}
%\tag{\protect{*}}\label{4nlsstar} \gamma \Delta^2 u -\beta \Delta u +\alpha u
=|u|^{2\sigma} u. \end{equation*} We consider two associated constrained
minimization problems: one with a constraint on the -norm and the other on
the -norm. Under suitable conditions, we establish existence of
minimizers and we investigate their qualitative properties, namely their sign,
symmetry and decay at infinity as well as their uniqueness, nondegeneracy and
orbital stability.Comment: 37 pages. To appear in SIAM J. Math. Ana
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