2,896 research outputs found

    Capacitive Coupling of Two Transmission Line Resonators Mediated by the Phonon Number of a Nanoelectromechanical Oscillator

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    Detection of quantum features in mechanical systems at the nanoscale constitutes a challenging task, given the weak interaction with other elements and the available technics. Here we describe how the interaction between two monomodal transmission-line resonators (TLRs) mediated by vibrations of a nano-electromechanical oscillator can be described. This scheme is then employed for quantum non-demolition detection of the number of phonons in the nano-electromechanical oscillator through a direct current measurement in the output of one of the TLRs. For that to be possible an undepleted field inside one of the TLR works as a amplifier for the interaction between the mechanical resonator and the remaining TLR. We also show how how the non-classical nature of this system can be used for generation of tripartite entanglement and conditioned mechanical coherent superposition states, which may be further explored for detection processes.Comment: 6 pages, 5 figure

    Redesign of machine component in polymeric matrix composite towards increased productivity

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    This work is focused in the maximization of the acceleration a 2D Industrial Laser Cutting Machine (ILCM). The changes to be implemented are centered in the replacement of a metallic critical component: the gantry. This component largely influences precision and maximum acceleration. Finite Elements Analysis was performed to the current metallic part. From this analysis the maximum allowed deformations were established. A replacement composite component capable of an equally valid behavior was designed in carbon fiber. To establish the maximum increase in acceleration that does not lead to precision losses, the working conditions were simulated and the acceleration to which the component was subjected to was varied. The variation of the thickness of layers with different orientations and locations in the part allowed for the understanding of how the mass varies along with the maximum possible acceleration. This analysis, asides with considering the maximum force allowed by the linear motor that is responsible by the gantry motion, establishes the limit in terms of maximum acceleration of the machine. An increase of 22% in the maximum acceleration while maintaining the precision is possible due to the higher specific rigidity of composite materials and the use of an optimization heuristic

    Gerenciamento de resíduos biológicos de laboratórios: adequação às normas de Boas Práticas Laboratoriais.

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    Redesign of an industrial laser cutting machine’s gantry in composite material

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    This work is focused in the design stage of a composite structure intended to replace a metallic critical component in a 2D Industrial Laser Cutting Machine (ILCM). The component is the gantry, largely responsible for most of the ILCM’s characteristics. These include precision and maximum acceleration, which are critical. The dimensioning of the component is initially performed based on analytical models, but latter stages use the numerical capabilities of Finite Elements Method. In the end it is possible to take advantage of the higher specific rigidity of composite materials to increase the maximum acceleration that the machine allows for while maintaining the precision.(undefined

    Aspectos econômico, ambiental e social da utilização do amendoim forrageiro em pastagens consorciadas para recria-engorda de bovinos de corte no Acre.

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    Analisa o retorno econômico e os impactos ambientais e sociais resultantes da utilização da leguminosa Arachis pintoi cv. Belmonte (amendoim forrageiro) em pastos consorciados com gramíneas sobre a atividade de recria e engorda de bovinos de corte no Acre. Foi estimado o benefício econômico gerado pelo sistema que utiliza pastagens já estabelecidas constituídas pelo consórcio do amendoim forrageiro com o capim-estrela-africana. A avaliação dos impactos ambientais e sociais foi realizada com base no sistema de avaliação de impacto ambiental da inovação tecnológica agropecuária (AMBITEC-AGRO) e no sistema de avaliação de impacto social da inovação tecnológica (AMBITECSOCIAL). Os resultados mostraram que os Índices de Impactos Ambiental e Social médios da inovação tecnológica foram positivos, contribuindo para a melhoria do meio ambiente e das condições de vida nas propriedades que adotaram a tecnologia. No aspecto econômico, a adoção da leguminosa contribuiu para o aumento da produtividade do rebanho, proporcionando ganhos econômicos anuais de R$ 543,31 por hectare

    Triaza-based amphiphilic chelators : synthetic route, in vitro characterization and in vivo studies of their Ga(III) and Al(III) chelates

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    Radiogalium chelates are important for diagnostic imaging in nuclear medicine (PET and ƴ-scintigraphy). Micelles are adequate colloidal vehicles for the delivery of therapeutic and diagnostic agents to organs and tissues. In this paper we describe the synthesis and in vitro and in vivo studies of a series of micelles-forming Ga(III) chelates targeted for the liver. The amphiphilic ligands are based on NOTA (NOTA = 1,4,7-triazacyclonoane-N,N’N’’-triacetic acid) and bear a α-alkyl chain in one of the pendant acetate arms (the size of the chain changes from four to fourteen carbon atoms). A multinuclear NMR study (1H, 13C, 27Al and 71Ga) gave some insights into the structure and dynamics of the metal chelates in solution, consistent with their rigidity and octahedral or pseudo-octahedral geometry. The critical micellar concentration of the chelates was determined using a fluorescence method and 27Al NMR spectroscopy (Al(III) was used as a surrogate of Ga(III)), both showing similar results and suggesting that the chelates of NOTAC6 form pre-micellar aggregates. The logP (octanol-water) determination showed enhancement of the lipophilic character of the Ga(III) chelates with the increase of the number of carbons in the α-alkyl chain. Biodistribution and Ƴ-scintigraphic studies of the 67Ga(III) labeled chelates were performed on Wistar rats, showing higher liver uptake for [67Ga](NOTAC8) in comparison to [67Ga](NOTAC6), consistent with a longer α-alkyl chain and a higher lipophilicity. After 24 hours both chelates were completely cleared off from the tissues and organs with no deposition in the bones and liver/spleen. [67Ga](NOTAC8) showed high kinetic stability in blood serum.Fundação para a Ciência e a Tecnologia (FCT

    Rotating Boson Star with Large Self-interaction in (2+1) dimensions

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    Solutions for rotating boson stars in (2+1) dimensional gravity with a negative cosmological constant are obtained numerically. The mass, particle number, and radius of the (2+1) dimensional rotating boson star are shown. Consequently we find the region where the stable boson star can exist.Comment: 14 pages, 6 figures, RevTe
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