986 resultados para Symmetry Viewpoint
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We examine the constraints on the two Higgs doublet model (2HDM) due to the stability of the scalar potential and absence of Landau poles at energy scales below the Planck scale. We employ the most general 2HDM that incorporates an approximately Standard Model (SM) Higgs boson with a flavor aligned Yukawa sector to eliminate potential tree-level Higgs-mediated flavor changing neutral currents. Using basis independent techniques, we exhibit robust regimes of the 2HDM parameter space with a 125 GeV SM-like Higgs boson that is stable and perturbative up to the Planck scale. Implications for the heavy scalar spectrum are exhibited.
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A sample of P. brasiliensis isolated from the spleen and the liver of an armadillo (Dasipus novencinctus) has been analysed under a mycological and immunochemical viewpoint. The armadillo was captured in an area of Tucuruí (State of Pará, Brazil), the animal being already established as an enzootic reservoir of P. brasiliensis at that region of the country. This sample maintained in the fungal collection of the Tropical Medicine Institute of São Paulo (Brazil) numbered 135, has got all the characteristics of P. brasiliensis, with a strong antigenic power and low virulence for guinea-pigs and Wistar rats. The specific exoantigen of P. brasiliensis - the glycoprotein with a molecular weight of 43 kDa - was easily demonstrated with double immunodiffusion, immunoelectrophoresis, SDS-PAGE and immunobloting techniques.
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Tendo por referência a diretiva 2006/95/CE, o trabalho desenvolvido no contexto da disciplina de Dissertação/Projeto/Estágio do Mestrado de Engenharia de Instrumentação e Metrologia, decorreu nas instalações do IEP (Instituto Electrotécnico Português) e teve como objetivo principal o desenvolvimento de um procedimento de avaliação dos efeitos fotobiológicos no olho e pele provocados por fontes de emissão contínua (LED), doravante designado método alternativo ao de referência. Os dois métodos, alternativo e de referência, utilizam respectivamente um foto-radiómetro multicanal e um espetro-radiómetro. O procedimento desenvolvido (método alternativo) de acordo com a norma EN/IEC62471) consiste na aquisição dos valores de irradiância com recurso a um foto-radiómetro e posterior determinação dos valores da radiância, com os quais se faz a avaliação dos efeitos fotobiológicos, para fontes de luz LED (Light Emitting Diode) ou GLS (General Lighting Service). A consulta detalhada da norma EN/IEC62471 e a pesquisa sobre os conceitos, definições, equipamentos e metodologias relacionadas com o tema em causa, constituiu o primeiro passo deste projecto. Com recurso aos dois equipamentos, uma fonte de luz LED (módulo de 12 lâmpadas LED) é avaliada em relação aos perigos (ou riscos) actínico UV e UV-A, ao perigo da luz azul e ainda o perigo térmico na retina e térmico na pele, permitindo fazer uma análise comparativa dos resultados. O método alternativo revelou-se bastante flexível e eficaz, proporcionando bons resultados em termos da irradiância e radiância dos referidos efeitos fotobiológicos. A comparação destes resultados com os valores limites de exposição mencionados na norma EN/IEC6247 permitiu afirmar que a fonte de luz LED avaliada não representa perigo fotobiológico para a saúde humana e classifica-se no grupo de risco “isento”. Uma vez cumpridos os objectivos, entendeu-se que seria uma mais-valia para o trabalho já realizado, estudar outro caso prático. Sendo assim, fez-se a avaliação da radiação de apenas um dos LED´s que constituíam a fonte usada nos ensaios anteriores, com o espetro-radiómetro (método de referência) e com uma distância de 200 mm entre a fonte e o medidor. Neste caso verificaram-se diferenças significativas nas quantidades obtidas quando comparadas com os valores normativos. Concluiu-se que o efeito fotobiológico da luz azul insere-se no grupo de “isento”, sem perigo para a saúde. Contudo, o efeito térmico da retina apresenta um aumento considerável da quantidade de radiância, embora dentro do grupo de risco “isento”. Esta classificação de grupos de risco. Face aos resultados obtidos, pode confirmar-se que as lâmpadas LED apresentam segurança fotobiológica, atendendo aos baixos valores de irradiância e radiância dos efeitos fotobiológicos estudados. Pode ainda afirmar-se que a utilização do foto-radiómetro em alternativa ao espetro-radiómetro se revela mais eficaz do ponto de vista de metodologia prática. Este trabalho demonstra a robustez desses dois equipamentos de avaliação dos efeitos fotobiológicos, e procura estabelecer uma linha de orientação para a prevenção dos efeitos adversos na pele e olhos de todos os seres humanos sujeitos à radiação ótica artificial. Quanto às incertezas de medições, em relação ao processo de medição com foto-radiómetro, a sua estimação não se realizou, devido a não rastreabilidade entre as medições indicadas pelo fabricante, no certificado de calibração e as medidas realizadas por outras entidades. Contudo, é propõe-se a sua realização em trabalhos futuros dentro desse âmbito. As incertezas dos resultados de medições com espetro-radiómetro foram parcialmente estimadas. Atendendo às potencialidades do sistema de medição, propõe-se como trabalho futuro, a aplicação da norma IEC62478, que faz parte da aplicação da norma EN/IEC62471 na avaliação do efeito da luz azul, com base na determinação da temperatura de cor correlacionada (CCT) de lâmpadas ou sistemas de lâmpadas incluindo luminárias. Os valores de irradiância e radiância adquiridos nos processos de avaliação, tanto com foto-radiómetro como espectro-radiómetro foram gravados em ficheiro Excel para um CD e anexados a este trabalho.
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A dissertation submitted in partial fulfilment of the requirements for the degree of Master in Arts
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Systematics is the study of diversity of the organisms and their relationships comprising classification, nomenclature and identification. The term classification or taxonomy means the arrangement of the organisms in groups (rate) and the nomenclature is the attribution of correct international scientific names to organisms and identification is the inclusion of unknown strains in groups derived from classification. Therefore, classification for a stable nomenclature and a perfect identification are required previously. The beginning of the new bacterial systematics era can be remembered by the introduction and application of new taxonomic concepts and techniques, from the 50s and 60s. Important progress were achieved using numerical taxonomy and molecular taxonomy. Molecular taxonomy, brought into effect after the emergence of the Molecular Biology resources, provided knowledge that comprises systematics of bacteria, in which occurs great evolutionary interest, or where is observed the necessity of eliminating any environmental interference. When you study the composition and disposition of nucleotides in certain portions of the genetic material, you study searching their genome, much less susceptible to environmental alterations than proteins, codified based on it. In the molecular taxonomy, you can research both DNA and RNA, and the main techniques that have been used in the systematics comprise the build of restriction maps, DNA-DNA hybridization, DNA-RNA hybridization, sequencing of DNA sequencing of sub-units 16S and 23S of rRNA, RAPD, RFLP, PFGE etc. Techniques such as base sequencing, though they are extremely sensible and greatly precise, are relatively onerous and impracticable to the great majority of the bacterial taxonomy laboratories. Several specialized techniques have been applied to taxonomic studies of microorganisms. In the last years, these have included preliminary electrophoretic analysis of soluble proteins and isoenzymes, and subsequently determination of deoxyribonucleic acid base composition and assessment of base sequence homology by means of DNA-RNA hybrid experiments beside others. These various techniques, as expected, have generally indicated a lack of taxonomic information in microbial systematics. There are numberless techniques and methodologies that make bacteria identification and classification study possible, part of them described here, allowing establish different degrees of subspecific and interspecific similarity through phenetic-genetic polymorphism analysis. However, was pointed out the necessity of using more than one technique for better establish similarity degrees within microorganisms. Obtaining data resulting from application of a sole technique isolatedly may not provide significant information from Bacterial Systematics viewpoint
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The authors report two cases of onychomycosis in the dystrophic form, one of them involving an HIV-positive patient, provoked by Scytalidium dimidiatum, previously called Scytalidium lignicola. The subject is reviewed from the taxonomic viewpoint, considering the anamorph Hendersonula toruloidea as a synonym of Nattrassia mangiferae, and having Scytalidium dimidiatum as the major synanamorph. According to many mycologists, Scytalidium hyalinum may be a separate species or a hyaline mutant of Scytalidium dimidiatum. Scytalidium lignicola Pesante 1957 was considered to be the type-species of the genus by ELLIS (1971)13 and later to be a "conidial state" of Hendersonula toruloidea by the same author, today known as Nattrassia mangiferae. The microorganism lives only on the roots of certain plants (mainly Platanus and Pinus). It produces pycnidia and is not considered to be a pathogen, although it is considered as a possible emerging agent capable of provoking opportunistic fungal lesions. The importance of this topic as one of the most outstanding in fungal taxonomy, so likely to be modified over time, as well as its interest in the field of dermatologic mycology, are emphasized.
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Work presented in the context of the European Master in Computational Logics, as partial requisit for the graduation as Master in Computational Logics
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ISCAP’s Information Systems Department is composed of about twenty teachers who have, for several years, been using an e-learning environment (Moodle) combined with traditional assessment. A new e-assessment strategy was implemented recently in order to evaluate a practical topic, the use of spreadsheets to solve management problems. This topic is common to several courses of different undergraduate degree programs. Being e-assessment an outstanding task regarding theoretical topics, it becomes even more challenging when the topics under evaluation are practical. In order to understand the implications of this new type of assessment from the viewpoint of the students, questionnaires and interviews were undertaken. In this paper the analysis of the questionnaires are presented and discussed.
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The goal of this project, one of the proposals of the EPS@ISEP 2014 Spring, was to develop an Aquaponics System. Over recent years Aquaponics systems have received increased attention due to its possibilities in helping reduce strain on resources within 1st and 3rd world countries. Aquaponics is the combination of Hydroponics and Aquaculture and mimics a natural environment in order to successfully apply and enhance the understanding of natural cycles within an indoor process. By using this knowledge of natural cycles it was possible to create a system with the capabilities similar to that of a natural environment with the benefits of electronic adaptions to enhance the overall efficiency of the system. The multinational team involved in its development was composed of five students, from five countries and fields of study. This paper covers their solution, involving overall design, the technology involved and the benefits it could bring to the current market. The team was able to achieve the final rendered Computer Aided Design (CAD) drawings, successfully performed all the electronic testing, and designed a solution under budget. Furthermore, the solution presented was deeply studied from the sustainability viewpoint and the team also developed a product specific marketing plan. Finally, the students involved in this project obtained new knowledge and skills.
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Currently excessive fossil fuel consumption has become a serious problem. People are searching for new solutions of energy production and there are several options to obtain alternative sources of energy without further devastating the already destroyed environment. One of these solutions is growing microalgae, from which biodiesel can be obtained. The microalgae production is a growing business because of its many useful compounds. In order to collect these compounds microalgae must first be harvested and then dried. Nowadays the solutions used for drying use too much energy and therefore are too expensive and not sustainable. The goal of this project, one of the possible choices during the EPS@ISEP 2013 Spring, was to develop a solar microalgae dryer. The multinational team involved in its development was composed of five students, from distinct countries and fields of study, and was the responsible for designing a solar microalgae dryer prototype for the microalgae laboratory of the chemical engineering department at ISEP, suitable for future tests and incorporating control process (in order not to destroy the microalgae during the drying process). The solar microalgae dryer was built to work as a distiller that gets rid of the excess water from the microalgae suspension. This paper presents a possible solution for this problem, the steps to create the device to harvest the microalgae by drying them with the use of solar energy (also used as an energy source for the solar dryer control system), the technologies used to build the solar microalgae dryer, and the benefits it presents compared to current solutions. It also presents the device from the ethical and sustainable viewpoint. Such alternative to already existing methods is competitive as far as energy usage is concerned.
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This paper addresses limit cycles and signal propagation in dynamical systems with backlash. The study follows the describing function (DF) method for approximate analysis of nonlinearities and generalizes it in the perspective of the fractional calculus. The concept of fractional order describing function (FDF) is illustrated and the results for several numerical experiments are analysed. FDF leads to a novel viewpoint for limit cycle signal propagation as time-space waves within system structure.
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This paper studies forest fires from the perspective of dynamical systems. Burnt area, precipitation and atmospheric temperatures are interpreted as state variables of a complex system and the correlations between them are investigated by means of different mathematical tools. First, we use mutual information to reveal potential relationships in the data. Second, we adopt the state space portrait to characterize the system’s behavior. Third, we compare the annual state space curves and we apply clustering and visualization tools to unveil long-range patterns. We use forest fire data for Portugal, covering the years 1980–2003. The territory is divided into two regions (North and South), characterized by different climates and vegetation. The adopted methodology represents a new viewpoint in the context of forest fires, shedding light on a complex phenomenon that needs to be better understood in order to mitigate its devastating consequences, at both economical and environmental levels.
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Proceedings of the 10th Conference on Dynamical Systems Theory and Applications
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We study the peculiar dynamical features of a fractional derivative of complex-order network. The network is composed of two unidirectional rings of cells, coupled through a "buffer" cell. The network has a Z3 × Z5 cyclic symmetry group. The complex derivative Dα±jβ, with α, β ∈ R+ is a generalization of the concept of integer order derivative, where α = 1, β = 0. Each cell is modeled by the Chen oscillator. Numerical simulations of the coupled cell system associated with the network expose patterns such as equilibria, periodic orbits, relaxation oscillations, quasiperiodic motion, and chaos, in one or in two rings of cells. In addition, fixing β = 0.8, we perceive differences in the qualitative behavior of the system, as the parameter c ∈ [13, 24] of the Chen oscillator and/or the real part of the fractional derivative, α ∈ {0.5, 0.6, 0.7, 0.8, 0.9, 1.0}, are varied. Some patterns produced by the coupled system are constrained by the network architecture, but other features are only understood in the light of the internal dynamics of each cell, in this case, the Chen oscillator. What is more important, architecture and/or internal dynamics?
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Este estudo insere-se no âmbito da Geometria e pretende compreender a influência dos recursos didáticos utilizados no reconhecimento de propriedades e relações geométricas em figuras planas. De acordo com o objetivo do estudo formulamos duas questões orientadoras que se articulam entre si. - Que fragilidades apresentam os alunos, no reconhecimento de propriedades geométricas em figuras planas? - Que contributos resultam da utilização de materiais manipuláveis, na visualização espacial e investigação de propriedades geométricas? Com este estudo pretendemos reunir informação que contribua para aprofundar o conhecimento sobre o raciocínio geométrico dos alunos. Em termos metodológicos segue um método de investigação misto, com recolha de informação qualitativa de natureza interpretativa e quantitativa, na modalidade de estudo de caso. A recolha de dados foi realizada numa turma de 4.º ano do ensino básico onde foi desenvolvida a experiência didática. A informação recolhida resultou da observação direta e as fontes dos dados foram as produções dos alunos, as notas de campo, registos fotográficos, vídeo e áudio. A docente assumiu o papel de investigadora e orientadora das tarefas propostas aos alunos tendo estes desempenhado um papel ativo na construção do seu próprio conhecimento. Os resultados obtidos permitem evidenciar as fragilidades dos alunos no reconhecimento de propriedades geométricas de figuras planas em diferentes posições. Destacam ainda os contributos da utilização da Mira e do Tangram, no estudo da simetria e no desenvolvimento da visualização espacial para a concretização de aprendizagens concretas, motivadoras e significativas.