The Experts below are selected from a list of 76314 Experts worldwide ranked by ideXlab platform

Hilmi Volkan Demir - One of the best experts on this subject based on the ideXlab platform.

  • efficient nonradiative Energy Transfer from ingan gan nanopillars to cdse zns core shell nanocrystals
    Applied Physics Letters, 2011
    Co-Authors: Sedat Nizamoglu, Burak Guzelturk, Dae-woo Jeon, Hilmi Volkan Demir
    Abstract:

    In this study, we propose and demonstRate efficient electron-hole pair injection from InGaN/GaN multiple quantum well nanopillars (MQW-NPs) to CdSe/ZnS core/shell nanocrystal quantum dots (NQDs) via Forster-type nonradiative Energy Transfer. For that we hybridize blue-emitting MQW-NPs with red-emitting NQDs and the resultant exciton Transfer reaches a maximum Rate of (0.192 ns)−1 and a maximum efficiency of 83.0%. By varying the effective bandgap of core/shell NQDs, we conveniently control and tune the excitonic Energy Transfer Rate for these NQD integRated hybrids, and our measured and computed exciton Transfer Rates are found to be in good agreement for all hybrid cases.

  • Efficient nonradiative Energy Transfer from InGaN/GaN nanopillars to CdSe/ZnS core/shell nanocrystals
    Applied Physics Letters, 2011
    Co-Authors: Sedat Nizamoglu, Burak Guzelturk, Dae-woo Jeon, Hilmi Volkan Demir
    Abstract:

    In this study, we propose and demonstRate efficient electron-hole pair injection from InGaN/GaN multiple quantum well nanopillars (MQW-NPs) to CdSe/ZnS core/shell nanocrystal quantum dots (NQDs) via Forster-type nonradiative Energy Transfer. For that we hybridize blue-emitting MQW-NPs with red-emitting NQDs and the resultant exciton Transfer reaches a maximum Rate of (0.192 ns)−1 and a maximum efficiency of 83.0%. By varying the effective bandgap of core/shell NQDs, we conveniently control and tune the excitonic Energy Transfer Rate for these NQD integRated hybrids, and our measured and computed exciton Transfer Rates are found to be in good agreement for all hybrid cases.

B. Bavassano - One of the best experts on this subject based on the ideXlab platform.

  • heating the solar wind by a magnetohydrodynamic turbulent Energy cascade
    The Astrophysical Journal, 2008
    Co-Authors: Raffaele Marino, Alain Noullez, L Sorrisovalvo, Roberto Bruno, Vincenzo Carbone, B. Bavassano
    Abstract:

    Solar wind plasma is known to cool down more slowly while it is blown away from the Sun than expected from an adiabatic spherical expansion. Some source of heating is thus needed to explain the observed temperature radial profile. The presence of a nonlinear turbulent magnetohydrodynamic Energy cascade has been recently observed in solar wind plasma. This provides for the first time a direct estimation of the turbulent Energy Transfer Rate, which can contribute to the in situ heating of the wind. The value of such contribution is shown to represent an important fraction (from 5% to 100%) of the total heating, and is strongly correlated with the wind temperature.

Sedat Nizamoglu - One of the best experts on this subject based on the ideXlab platform.

  • efficient nonradiative Energy Transfer from ingan gan nanopillars to cdse zns core shell nanocrystals
    Applied Physics Letters, 2011
    Co-Authors: Sedat Nizamoglu, Burak Guzelturk, Dae-woo Jeon, Hilmi Volkan Demir
    Abstract:

    In this study, we propose and demonstRate efficient electron-hole pair injection from InGaN/GaN multiple quantum well nanopillars (MQW-NPs) to CdSe/ZnS core/shell nanocrystal quantum dots (NQDs) via Forster-type nonradiative Energy Transfer. For that we hybridize blue-emitting MQW-NPs with red-emitting NQDs and the resultant exciton Transfer reaches a maximum Rate of (0.192 ns)−1 and a maximum efficiency of 83.0%. By varying the effective bandgap of core/shell NQDs, we conveniently control and tune the excitonic Energy Transfer Rate for these NQD integRated hybrids, and our measured and computed exciton Transfer Rates are found to be in good agreement for all hybrid cases.

  • Efficient nonradiative Energy Transfer from InGaN/GaN nanopillars to CdSe/ZnS core/shell nanocrystals
    Applied Physics Letters, 2011
    Co-Authors: Sedat Nizamoglu, Burak Guzelturk, Dae-woo Jeon, Hilmi Volkan Demir
    Abstract:

    In this study, we propose and demonstRate efficient electron-hole pair injection from InGaN/GaN multiple quantum well nanopillars (MQW-NPs) to CdSe/ZnS core/shell nanocrystal quantum dots (NQDs) via Forster-type nonradiative Energy Transfer. For that we hybridize blue-emitting MQW-NPs with red-emitting NQDs and the resultant exciton Transfer reaches a maximum Rate of (0.192 ns)−1 and a maximum efficiency of 83.0%. By varying the effective bandgap of core/shell NQDs, we conveniently control and tune the excitonic Energy Transfer Rate for these NQD integRated hybrids, and our measured and computed exciton Transfer Rates are found to be in good agreement for all hybrid cases.

Raffaele Marino - One of the best experts on this subject based on the ideXlab platform.

  • On the Statistical Properties of Turbulent Energy Transfer Rate in the Inner Heliosphere
    Solar Physics, 2018
    Co-Authors: Luca Sorriso-valvo, Raffaele Marino, Francesco Carbone, Silvia Perri, A Greco, Roberto Bruno
    Abstract:

    The Transfer of Energy from large to small scales in solar wind turbulence is an important ingredient of the long-standing question of the mechanism of the interplanetary plasma heating. Previous studies have shown that magnetohydrodynamic (MHD) turbulence is statistically compatible with the observed solar wind heating as it expands in the heliosphere. However, in order to understand which processes contribute to the plasma heating, it is necessary to have a local description of the Energy flux across scales. To this aim, it is customary to use indicators such as the magnetic field partial variance of increments (PVI), which is associated with the local, relative, scale-dependent magnetic Energy. A more complete evaluation of the Energy Transfer should also include other terms, related to velocity and cross-helicity. This is achieved here by introducing a proxy for the local, scale-dependent turbulent Energy Transfer Rate $\epsilon_{\Delta t}(t)$ , based on the third-order moment scaling law for MHD turbulence. Data from Helios 2 are used to determine the statistical properties of such a proxy in comparison with the magnetic and velocity fields PVI, and the correlation with local solar wind heating is computed. PVI and $\epsilon_{\Delta t}(t)$ are generally well correlated; however, $\epsilon_{\Delta t}(t)$ is a very sensitive proxy that can exhibit large amplitude values, both positive and negative, even for low amplitude peaks in the PVI. Furthermore, $\epsilon_{\Delta t}(t)$ is very well correlated with local increases of the temperature when large amplitude bursts of Energy Transfer are localized, thus suggesting an important role played by this proxy in the study of plasma Energy dissipation.

  • heating the solar wind by a magnetohydrodynamic turbulent Energy cascade
    The Astrophysical Journal, 2008
    Co-Authors: Raffaele Marino, Alain Noullez, L Sorrisovalvo, Roberto Bruno, Vincenzo Carbone, B. Bavassano
    Abstract:

    Solar wind plasma is known to cool down more slowly while it is blown away from the Sun than expected from an adiabatic spherical expansion. Some source of heating is thus needed to explain the observed temperature radial profile. The presence of a nonlinear turbulent magnetohydrodynamic Energy cascade has been recently observed in solar wind plasma. This provides for the first time a direct estimation of the turbulent Energy Transfer Rate, which can contribute to the in situ heating of the wind. The value of such contribution is shown to represent an important fraction (from 5% to 100%) of the total heating, and is strongly correlated with the wind temperature.

Philippe Thomas - One of the best experts on this subject based on the ideXlab platform.

  • Strong Influences of Melting Time and Tm3+ Concentration on Blue Up-Conversion Photoluminescence for Tm3+/Yb3+ Co-Doped TeO2–TlO0.5–ZnO Glass
    International Journal of Applied Glass Science, 2014
    Co-Authors: Masayuki Uchida, Tomokatsu Hayakawa, Toshiki Suhara, Jean-rené Duclere, Philippe Thomas
    Abstract:

    In this study, by a conventional melt quenching method, we synthesized novel up-conversion phosphors of 60TeO2–30TlO0.5–(9−x)ZnO–xTm2O3–1Yb2O3 (x = 0.1–0.5) glasses, whose system was recently developed in our collaborative group, and their blue up-conversion photoluminescence (UCPL) of Tm3+ ions via three-step Energy Transfer from near-infrared (NIR) sensitizer of Yb3+ ions was observed. In particular, the substantial Rate of the Energy Transfer in the third step from Yb3+ to Tm3+ under excitation at 975 nm, which determined the final blue UCPL intensity, was estimated as a function of the rare-earth concentration. With an aid of analytical methods of PL lifetime and Judd–Ofelt theory, it was revealed that the highest Energy Transfer Rate was achieved to be 2.07 × 10−17 cm3/s for x = 0.2, and further increasing Tm2O3 content x in the fixed Yb2O3 resulted in the decrease in the Energy Transfer Rate . One of the plausible causes was concentration quenching of Yb3+ ions. The other was back-Transfer from Tm3+ to Yb3+ ions. The influence of the condition of glass synthesis and the melting time on was also discussed.