27,949 research outputs found

    Meson production in two-photon interactions at energies available at CERN Large Hadron Collider

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    The meson production cross sections are estimated considering photon-photon interactions in hadron - hadron collisions at CERN LHC energies. We consider a large number of mesons with photon-photon partial decay width well constrained by the experiment and some mesons which are currently considered as hadronic molecule and glueball candidates. Our results demonstrate that the experimental analysis of these states is feasible at CERN - LHC.Comment: 5 pages, 1 figure, 4 tables. Version published in Physical Review

    Espécies de Anastrepha Schiner (Diptera: Tephritidae), seus hospedeiros e parasitóides nos Estados do Acre e Rondônia, Brasil.

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    Durante o mês de março de 2009 foram realizadas amostragens de frutos carnosos nos Estados do Acre (municípios de Brasiléia, Bujari, Capixaba, Epitaciolândia, Rio Branco, Sena Madureira, Senador Guiomard e Xapuri) e Rondônia (Ariquemes, Candeias do Jamari, Itapuã do Oeste, Ouro Preto do Oeste e Porto Velho) visando ampliar o conhecimento sobre a diversidade de moscas-das-frutas (Diptera: Tephritidae), seus hospedeiros e parasitóides. Este trabalho constitui o primeiro registro de Anastrepha coronilli Carrejo & González (Tephritidae) para o Estado do Acre, e das espécies A. coronilli, A. distincta Greene (Tephritidae), e dos himenópteros Doryctobracon areolatus (Szépligeti) e Opius bellus Gahan (Braconidae) para Rondônia. Palavras-chave: Amazônia, Braconidae, Hymenoptera, moscas-das-frutas, Tephritoidea

    Data-driven load disturbance rejection

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    Data-driven direct methods are still growing in popularity almost three decades after they were introduced. These methods use data collected from the process to identify optimal controller's parameters with little knowledge about the process itself. However, most of those works focus on the problem of reference tracking, whereas many of the problems faced in real-life are of disturbance rejection or attenuation. Also, the vastly majority of those works identify the parameters of linearly parametrized controllers, which amounts to fixing the poles of the controller's transfer function. Although the identification of the controller's poles is not prohibitive, as hinted by some of the papers, there is little effort on presenting a data-driven solution capable of doing so. With all that in mind, this work proposes a data-driven approach which is able to identify the zeros and the poles of a linear controller aiming at disturbance rejection. Two different one-step ahead predictors are proposed, one that is linear on the parameters and another that is non-linear. Also, two different techniques are employed to estimate the controller parameters, the first one minimizes the quadratic norm of the prediction error while the second one minimizes the correlation between the prediction error and an external signal. Simulations show the effectiveness of the proposed methods to estimate the optimal controller parameters of restricted order controllers aiming at disturbance rejection

    Achieving minimum-error discrimination of an arbitrary set of laser-light pulses

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    Laser light is widely used for communication and sensing applications, so the optimal discrimination of coherent states--the quantum states of light emitted by a laser--has immense practical importance. However, quantum mechanics imposes a fundamental limit on how well different coher- ent states can be distinguished, even with perfect detectors, and limits such discrimination to have a finite minimum probability of error. While conventional optical receivers lead to error rates well above this fundamental limit, Dolinar found an explicit receiver design involving optical feedback and photon counting that can achieve the minimum probability of error for discriminating any two given coherent states. The generalization of this construction to larger sets of coherent states has proven to be challenging, evidencing that there may be a limitation inherent to a linear-optics-based adaptive measurement strategy. In this Letter, we show how to achieve optimal discrimination of any set of coherent states using a resource-efficient quantum computer. Our construction leverages a recent result on discriminating multi-copy quantum hypotheses (arXiv:1201.6625) and properties of coherent states. Furthermore, our construction is reusable, composable, and applicable to designing quantum-limited processing of coherent-state signals to optimize any metric of choice. As illustrative examples, we analyze the performance of discriminating a ternary alphabet, and show how the quantum circuit of a receiver designed to discriminate a binary alphabet can be reused in discriminating multimode hypotheses. Finally, we show our result can be used to achieve the quantum limit on the rate of classical information transmission on a lossy optical channel, which is known to exceed the Shannon rate of all conventional optical receivers.Comment: 9 pages, 2 figures; v2 Minor correction

    Microbial biomass and activity in two cultivation systems on the SHIFT experimental area near Manaus.

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    In two different cultivation systems we investigated the microbial biomass and activity in the rhizosphere of Theobroma grandiflorum and Bactris gasipaes, two important crop plants in sustainable agriculture in Brazil during rainy and dry season 1998

    Remote Sensing and Control of Phase Qubits

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    We demonstrate a remote sensing design of phase qubits by separating the control and readout circuits from the qubit loop. This design improves measurement reliability because the control readout chip can be fabricated using more robust materials and can be reused to test different qubit chips. Typical qubit measurements such as Rabi oscillations, spectroscopy, and excited-state energy relaxation are presented.Comment: 3 pages, 4 figure

    Avaliação de genótipos de mandioca para mesa em Ivinhema, MS.

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    O desenvolvimento de variedades de mandioca é hoje considerado o fator de maior demanda por parte da cadeia produtiva da mandiocultura do mundo. Basicamente, pode-se dividir as variedades como de dois tipos, baseando-se na concentração de compostos cianogênicos nas raízes: as mandiocas bravas (ou para indústria), possuem uma concentração mais alta, normalmente acima de 100 ppm, e são destinadas ao processamento (fécula, farinha, amidos modificados, etc.); já as mandiocas mansas, também conhecidas como aipins, macaxeiras e para mesa, possuem concentração de cianeto nas raízes mais baixa, o que permite o seu consumo após cozimento e/ou fritura (SCHWENGBER, 2002; FUKUDA & OTSUBO, 2003). Os programas de melhoramento genético das grandes culturas são conduzidos em várias etapas, abrangendo desde a gestão dos recursos genéticos, seleção, cruzamentos, até as avaliações de adaptação em diversos ambientes (FUKUDA & IGLESIAS, 2006). A partir de 2008, com o desenvolvimento das ações do projeto ?Rede Cooperativa de Avaliação e Transferência de genótipos de Mandioca?, passou-se a avaliar os genótipos de mandioca de forma sistematizada, com metodologia clara, em todas as regiões do Brasil. O presente trabalho consta da avaliação de genótipos de mandioca para mesa, na região de Ivinhema, MS, no período entre 2010 e 2011.Melhoramento genético. Resumo n. 242
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