39 research outputs found

    Qualidade do sêmen criopreservado e fertilidade de fêmeas bovinas em programas de IATF: dados preliminares.

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    O estudo foi conduzido com objetivo de correlacionar os distintos métodos de avaliações laboratorial da criopreservação espermática com a taxa de prenhez de vacas zebuínas submetidas a protocolos de IATF, através de análise de regressão logística múltipla entre prenhez e parâmetros avaliados individualmente. Foram realizadas 19 análises de rotina laboratoriais de aspectos físicos, funcionais e morfológicos por meio de meios subjetivos, CASA e citometria de fluxo em amostras de sêmen de 20 touros utilizados nas 1.542 vacas Nelore submetidas à IATF. Foi observado o efeito da VCL (velocidade curvilínea), velocidade retilínea (VSL), linearidade (LIN) e concentração espermática (mL) na probabilidade de prenhez de vacas Nelore submetido à IATF. Os outros parâmetros avaliados não tiveram efeito na taxa de prenhez

    Generation and manipulation of Schrödinger cat states in Rydberg atom arrays

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    Quantum entanglement involving coherent superpositions of macroscopically distinct states is among the most striking features of quantum theory, but its realization is challenging because such states are extremely fragile. Using a programmable quantum simulator based on neutral atom arrays with interactions mediated by Rydberg states, we demonstrate the creation of “Schrödinger cat” states of the Greenberger-Horne-Zeilinger (GHZ) type with up to 20 qubits. Our approach is based on engineering the energy spectrum and using optimal control of the many-body system. We further demonstrate entanglement manipulation by using GHZ states to distribute entanglement to distant sites in the array, establishing important ingredients for quantum information processing and quantum metrology

    Effects of Redispersible Polymer Powder on Mechanical and Durability Properties of Preplaced Aggregate Concrete with Recycled Railway Ballast

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    The rapid-hardening method employing the injection of calcium sulfoaluminate (CSA) cement mortar into voids between preplaced ballast aggregates has recently emerged as a promising approach for the renovation of existing ballasted railway tracks to concrete tracks. This method typically involves the use of a redispersible polymer powder to enhance the durability of the resulting recycled aggregate concrete. However, the effects of the amount of polymer on the mechanical and durability properties of recycled ballast aggregate concrete were not clearly understood. In addition, the effects of the cleanness condition of ballast aggregates were never examined. This study aimed at investigating these two aspects through compression and flexure tests, shrinkage tests, freezing-thawing resistance tests, and optical microscopy. The results revealed that an increase in the amount of polymer generally decreased the compressive strength at the curing age of 28 days. However, the use of a higher polymer ratio enhanced the modulus of rupture, freezing-thawing resistance, and shrinkage resistance, likely because it improved the microstructure of the interfacial transition zones between recycled ballast aggregates and injected mortar. In addition, a higher cleanness level of ballast aggregates generally improved the mechanical and durability qualities of concrete

    Cast-in-place concrete walls: thermal comfort evaluation of one-storey housing in São Paulo State

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    This paper presents a proposal of thermal performance evaluation of a one-storey housing typology (TI24A) executed by CDHU - Companhia de Desenvolvimento Habitacional e Urbano do Estado de São Paulo, considering the use of cast-in-place monolithic panels of concrete, with different thicknesses panels (8, 10 and 12 cm) and density between 1600 and 2400 kg/m³. In this study, the specific purpose was discussing the influence of the characteristic of concrete walls on the housing thermal performance without slab. Was defined of first parameters of study (definition of the one-storey housing typology, survey about housing users behavior and cities choose) and executed computational simulation (winter and summer), for four São Paulo State cities (São Paulo, São Carlos, Santos e Presidente Prudente), with the software Arquitrop 3.0 in a one-storey housing. Was observed that in winter and summer the typologies analyzed, the panels thickness variation had more influence about results than different concrete densities. The minimum level of thermal performance (M) in winter has been granted for some cities, with exception of Santos. In summer one of São Paulo city’s typology was attended the minimum level of thermal performance in agreement with standard “NBR 15575 Residential buildings up to five storied - Performance, Part 1: General requirements”

    Open-plan offices: the impact of different facade solutions on energy efficiency

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    In Brazil, open-plan office buildings are increasingly using fully glazed facades, an aspect that can directly impact air-conditioning consumption. Thisstudy aims at classifying and characterising the energy performance of open-plan office buildings in three Brazilian climates. Computational simulations were performed in the EnergyPlus program to verify the impact of various parameters (climate, type of facade, WWR, type of glass, shading device and setpoint temperature) on air-conditioning consumption. The results, classified in energy performance levels, showed that changing from traditional facades (masonry) to curtain facades (fully glazed), increased energy consumption with air-conditioning by an average of 25% in Curitiba and São Paulo and 15% in Manaus; the WWR was the parameter that most impacted this consumption, and the glass type had most impact in the larger openings; using a shading device always generated savings and a 1°C increase in the cooling setpoint reduced consumption by an average of 16.4%. The results allowed to identify the best combinations of these parameters for each climate which can help designers to create more energy efficient buildings.No Brasil, os edifícios de escritórios de planta livre têm se destacado pela utilização de fachadas totalmente envidraçadas, aspecto que pode impactar diretamente o consumo de energia do ar condicionado. O objetivo deste estudo é classificar e caracterizar o desempenho energético de edifícios de escritório de planta livre em três climas brasileiros. Simulações computacionais foram realizadas no programa EnergyPlus, a fim de verificar o impacto de vários parâmetros (clima, tipo de fachada, PAF, tipo de vidro, dispositivo de sombreamento e temperatura de setpoint) no consumo de energia do ar condicionado. Os resultados, classificados em faixas de desempenho energético, mostraram que alterar de uma fachada tradicional (alvenaria) para uma fachada cortina (totalmente envidraçada) elevou o consumo de energia do ar condicionado em média 25% para Curitiba e São Paulo e 15% para Manaus; que o PAF foi o parâmetro que mais impactou esse consumo, e o tipo de vidro teve mais impacto nas maiores aberturas; que utilizar um dispositivo de sombreamento sempre gerou economia e a elevação em 1 ºC do setpoint de resfriamento reduziu o consumo, em média, até 16,4%. Tais resultados geraram as melhores combinações desses parâmetros para cada clima, podendo servir de suporte aos projetistas, no sentido de se criar edifícios energeticamente mais eficiente
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