4,295 research outputs found

    Ultralong Photon Echo Storage Using Optical Locking

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    An ultralong photon storage with more than 50% retrieval efficiency is presented in the three-pulse photon echoes by using a pair of control pulses, where the control pulses play to freeze atoms dephasing process conditionally by transferring excited atoms to an auxiliary state and returning them back later. The observed photon echo decay time much longer than the spin homogeneous decay time is potential for long distance quantum communications

    Method of extending hyperfine coherence times in Pr^3+:Y_2SiO_5

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    In this letter we present a method for increasing the coherence time of praseodymium hyperfine ground state transitions in Pr^3+:Y_2SiO_5 by the application of a specific external magnetic field. The magnitude and angle of the external field is applied such that the Zeeman splitting of a hyperfine transition is at a critical point in three dimensions, making the first order Zeeman shift vanishingly small for the transition. This reduces the influence of the magnetic interactions between the praseodymium ions and the spins in the host lattice on the transition frequency. Using this method a phase memory time of 82ms was observed, a value two orders of magnitude greater than previously reported. It is shown that the residual dephasing is amenable quantum error correction

    Measurement of Evapotranspiration in Turfgrass: Recommended Techniques and Adjustment Coefficients

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    Evapotranspiration (ET) from turfgrass can be measured directly using lysimeters (LYS), estimated from weather data using models, or approximated using atmometers. Evapotranspiration measurements from LYS were compared with ET estimates from four variations of the American Society of Civil Engineers (ASCE) standardized ET equation including the use of: 1) hourly steps of measured net radiation (Rn) (ASCEHM); 2) hourly steps of Rn calculated from global irradiance (ASCEHC); 3) daily steps of measured Rn (ASCEDM); and 4) daily steps of Rn calculated from global irradiance (ASCEDC); ET from LYS was also compared with the Priestley-Taylor (PT) model and atmometers. All collections were from a sward of tall fescue (Schedonorus arundinaceus Schreb.) turfgrass at the Rocky Ford Turfgrass Research Center, Manhattan, KS. Results indicate the ASCEDC could improve irrigation scheduling in turfgrass by providing accurate ET estimates from standard weather station data where measured Rn is not available. Adjustment factors for several of the methods are recommended below

    Neutral Higgs bosons in the MNMSSM with explicit CP violation

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    Within the framework of the minimal non-minimal supersymmetric standard model (MNMSSM) with tadpole terms, CP violation effects in the Higgs sector are investigated at the one-loop level, where the radiative corrections from the loops of the quark and squarks of the third generation are taken into account. Assuming that the squark masses are not degenerate, the radiative corrections due to the stop and sbottom quarks give rise to CP phases, which trigger the CP violation explicitly in the Higgs sector of the MNMSSM. The masses, the branching ratios for dominant decay channels, and the total decay widths of the five neutral Higgs bosons in the MNMSSM are calculated in the presence of the explicit CP violation. The dependence of these quantities on the CP phases is quite recognizable, for given parameter values.Comment: 25 pages, 8 figure

    Healthcare choice: Discourses, perceptions, experiences and practices

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    Policy discourse shaped by neoliberal ideology, with its emphasis on marketisation and competition, has highlighted the importance of choice in the context of healthcare and health systems globally. Yet, evidence about how so-called consumers perceive and experience healthcare choice is in short supply and limited to specific healthcare systems, primarily in the Global North. This special issue aims to explore how choice is perceived and utilised in the context of different systems of healthcare throughout the world, where choice, at least in policy and organisational terms, has been embedded for some time. The articles are divided into those emphasising: embodiment and the meaning of choice; social processes associated with choice; the uncertainties, risks and trust involved in making choices; and issues of access and inequality associated with enacting choice. These sociological studies reveal complexities not always captured in policy discourse and suggest that the commodification of healthcare is particularly problematic
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