14 research outputs found

    Teatro e ensino da matemática: atividade desenvolvida num curso de formação docente

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    Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014Este trabalho relata uma aula desenvolvida pelas alunas do Curso de Formação de Docentes do Instituto Estadual de Educação de Londrina com a colaboração dos Bolsistas do Programa Institucional de Bolsas de Iniciação à Docência – PIBID – Subprojeto de Matemática, para alunos de primeiro ano do Ensino Fundamental utilizando o teatro como forma de apresentar conteúdos matemáticos como números, sequência de números, operações básicas como adição, subtração e conteúdos de língua portuguesa como leitura e escrita de número

    Influence of recirculation rate on the performance of a combined anaerobic-aerobic reactor applied to the removal of carbon and nitrogen from poultry slaughterhouse wastewater

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    The objective of this study was to evaluate a combined anaerobic-aerobic upflow fixed-bed reactor with liquid phase recirculation for the removal of nitrogen and organic matter from poultry slaughterhouse wastewater. The reactor performance was evaluated with a hydraulic retention time (HRT) of 11 h and three different recirculation rates (R=0.5; 1 and 2). The highest nitrogen removal efficiency value was obtained with an HRT of 11 h (6.8 h in the anaerobic zone and 4.2 h in the aerobic zone) and a recirculation rate of 2. In this condition, the total nitrogen removal efficiency was 69%,  with effluent concentrations of 6 mg NH4+ L-1 and 12 mg NO3- L-1. For all tested conditions, there was good chemical oxygen demand (COD) removal, with efficiency above 95%. The effect of dilution and the favoring of mass transfer caused by the increase in the recirculation rate positively influenced reactor performance.Key words: Anaerobic degradation, nitrification, denitrification, combined reactor

    Waveguide-integrated and portable optomechanical magnetometer

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    Optomechanical magnetometers enable highly sensitive magnetic field sensing. However, all such magnetometers to date have been optically excited and read-out either via free space or a tapered optical fiber. This limits their scalability and integrability, and ultimately their range of applications. Here, we present an optomechanical magnetometer that is excited and read out via a suspended optical waveguide fabricated on the same silicon chip as the magnetometer. Moreover, we demonstrate that thermomechanical noise limited sensitivity is possible using portable electronics and laser. The magnetometer employs a silica microdisk resonator selectively sputtered with a magnetostrictive film of galfenol (FeGa) which induces a resonant frequency shift in response to an external magnetic field. Experimental results reveal the retention of high quality-factor optical whispering gallery mode resonances whilst also demonstrating high sensitivity and dynamic range in ambient conditions. The use of off-the-shelf portable electronics without compromising sensor performance demonstrates promise for applications.Comment: 9 pages, 4 figure

    Chalcones and Azomethynes derivativies: a study of the first and second hiperpolarizabilities

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    A utilização de laser para estudo, análise e caracterização de materiais é de imensa importância no desenvolvimento e progresso da ciência e tecnologia, melhorando ciclicamente a área de ótica não linear (ONL). Estudos do comportamento de compostos orgânicos cujas estruturas são π conjugadas mostram sua ampla aplicabilidade em dispositivos eletrônicos e na área medicinal. A adição de grupos laterias doadores ou aceitadores de elétrons têm a capacidade de aumentar os efeitos ópticos não lineares nestes compostos, otimizando suas propriedades. Nesta dissertação de mestrado, foram realizados estudos em compostos orgânicos focados em suas características ópticas não lineares. Nove derivados de chalconas e quatro derivados de azometinas foram analisadas através da técnica de espalhamento hiper-Rayleigh (HRS) e da técnica de varredura-z, cujos efeitos óticos não lineares observados correspondem à segunda e terceira ordem da polarizabilidade, respectivamente. Com o espalhamento hiper-Rayleigh, foram determinadas a primeira hiperpolarizabilidade βHRS cujo valor mais alto foi 24×10−30 cm5/esu para as chalconas e 273×10−30 cm5/esu para as azometinas. A técnica de varredura-z foi utilizada para determinar o espectro da seção de choque de absorção de dois fótons (σ2PA) cujos valores de pico das moléculas derivadas de chalconas são de aproximadamente 15 GM e algumas apresentaram estados excitados que são permitidos apenas por absorção de dois fótons. Duas das moléculas derivadas de azometinas apresentaram valores de pico da ordem de 12 GM, uma não apresentou absorção de dois fótons e uma apresentou valor de pico de 55 GM. Além disso, foi utilizado o método de Soma-Sobre-Estados (SOS - do inglês Sum-Over-States) para determinar os momentos de dipolo de transição e diferença de momentos de dipolo permanente de todos os derivados.The use of lasers for study, analyses and characterization of materials are of great importance for progress and development of science and technology, improving in a cyclic way the nonlinear optics area (NLO). Studies of the behave of π-conjugated organic compounds show its wide applicability in electronic devices and in the medicinal area. Adding electron donor or acceptor lateral groups to these compounds may alter its nonlinear optical effects, optimizing its properties. In this Master dissertation, studies on organic compounds focused in its nonlinear optical characteristics were realized. Nine chalcone derivatives and four azomethines derivatives were analyzed using the Hyper-Rayleigh Scattering technique (HRS) and Z-Scan technique, by which the nonlinear optical effects observed corresponds to the second and third order of the polarizabilities, respectively. With the HRS the first hyperpolarizability βHRS was determined, which the highest values was of 24×10−30 cm5/esu for the chalcones, and 273×10−30 cm5/esu for the azomethines. The Z-Scan technique was utilized for determining the two-photon cross-section σ2PA which peak values of the chalcone derivatives were of approximately 15 GM and some of them presented excited states that are only allowed by two-photon absorption. Two of the azomethines derivatives molecules presented peak values of the order of 12 GM, one of them did not present two-photon absorption, and one presented peak value of 55 GM. Furthermore, the Sum-Over-States (SOS) method was used to determine the transition dipole momentums and the difference of permanent dipole momentum of all of the derivatives

    Precision Magnetometers for Aerospace Applications: A Review

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    Aerospace technologies are crucial for modern civilization; space-based infrastructure underpins weather forecasting, communications, terrestrial navigation and logistics, planetary observations, solar monitoring, and other indispensable capabilities. Extraplanetary exploration—including orbital surveys and (more recently) roving, flying, or submersible unmanned vehicles—is also a key scientific and technological frontier, believed by many to be paramount to the long-term survival and prosperity of humanity. All of these aerospace applications require reliable control of the craft and the ability to record high-precision measurements of physical quantities. Magnetometers deliver on both of these aspects and have been vital to the success of numerous missions. In this review paper, we provide an introduction to the relevant instruments and their applications. We consider past and present magnetometers, their proven aerospace applications, and emerging uses. We then look to the future, reviewing recent progress in magnetometer technology. We particularly focus on magnetometers that use optical readout, including atomic magnetometers, magnetometers based on quantum defects in diamond, and optomechanical magnetometers. These optical magnetometers offer a combination of field sensitivity, size, weight, and power consumption that allows them to reach performance regimes that are inaccessible with existing techniques. This promises to enable new applications in areas ranging from unmanned vehicles to navigation and exploration

    TGF-β1 Reduces Neutrophil Adhesion and Prevents Acute Vaso-Occlusive Processes in Sickle Cell Disease Mice

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    Sickle cell disease (SCD) patients experience chronic inflammation and recurrent vaso-occlusive episodes during their entire lifetime. Inflammation in SCD occurs with the overexpression of several inflammatory mediators, including transforming growth factor beta-1 (TGF-β1), a major immune regulator. In this study, we aimed to investigate the role played by TGF-β1 in vascular inflammation and vaso-occlusion in an animal model of SCD. Using intravital microscopy, we found that a daily dose of recombinant TGF-β1 administration for three consecutive days significantly reduced TNFα-induced leukocyte rolling, adhesion, and extravasation in the microcirculation of SCD mice. In contrast, immunological neutralization of TGF-β, in the absence of inflammatory stimulus, considerably increased these parameters. Our results indicate, for the first time, that TGF-β1 may play a significant ameliorative role in vascular SCD pathophysiology, modulating inflammation and vaso-occlusion. The mechanisms by which TGF-β1 exerts its anti-inflammatory effects in SCD, however, remains unclear. Our in vitro adhesion assays with TNFα-stimulated human neutrophils suggest that TGF-β1 can reduce the adhesive properties of these cells; however, direct effects of TGF-β1 on the endothelium cannot be ruled out. Further investigation of the wide range of the complex biology of this cytokine in SCD pathophysiology and its potential therapeutical use is needed

    Mechanism of the Zn(II)Phthalocyanines’ Photochemical Reactions Depending on the Number of Substituents and Geometry

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    In this work, the synthesis and the nonlinear absorption and population dynamics investigation of a series of zinc phthalocyanines (ZnPcs) dissolved in chloroform are reported. In order to determine the relevant spectroscopic parameters, such as absorption cross-sections of singlet and triplet excited states, fluorescence relaxation times, intersystem crossing, radiative decay and internal conversion, different optical and spectroscopic techniques were used. By single pulse and pulse train Z-scan techniques, respectively, singlet and triplet excited states‘ absorption cross-section were determined at 532 nm. Furthermore, the intersystem crossing time was obtained by using both techniques combined with the fluorescence lifetime determined by time-resolved fluorescence. The radiative and internal conversion rates were determined from the fluorescence quantum yield of the samples. Such spectroscopy parameters are fundamental for selecting photosensitizers used in photodynamic therapy, as well as for many other applications
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