Search results for "Toe"
showing 10 items of 3824 documents
Effects of InAlN underlayer on deep traps detected in near-UV InGaN/GaN single quantum well light-emitting diodes
2019
Two types of near-UV light-emitting diodes (LEDs) with an InGaN/GaN single quantum well (QW) differing only in the presence or absence of an underlayer (UL) consisting of an InAlN/GaN superlattice (SL) were examined. The InAlN-based ULs were previously shown to dramatically improve internal quantum efficiency of near-UV LEDs, via a decrease in the density of deep traps responsible for nonradiative recombination in the QW region. The main differences between samples with and without UL were (a) a higher compensation of Mg acceptors in the p-GaN:Mg contact layer of the sample without UL, which correlates with the presence of traps with an activation energy of 0.06 eV in the QW region, (b) the…
Odorant-binding protein-based optoelectronic tongue and nose for sensing volatile organic compounds
2019
International audience; We developed an array of odorant-binding protein mutants with various binding properties. The same design is suitable for the detection and identification of volatile organic compounds (VOCs) both in the liquid phase and in the gas phase by surface plasmon resonance imaging. The obtained optoelectronic tongue is highly selective at low concentrations of VOCs with a low detection limit, but a narrow linear range. In comparison, the optoelectronic nose gives a much higher signal to noise ratio, but the discrimination of VOCs from different chemical classes requires kinetic data to get rid of non-specific signals. This work shows that these optoelectronic tongue and nos…
Embedded-atom calculations of Auger and x-ray photoemission shifts for metallic elements
1982
Change in self-consistent-field energy density-functional calculations are reported for Auger and core-level binding-energy shifts in sp-bonded metals. The basic model, atom in jellium vacancy, gives good agreement with experiment, especially in the Auger case. The chemical and relaxation contributions to the shifts are discussed, and the extra-atomic response is analyzed in detail, both in position and energy space. The adequacy of the "excited-atom" approach to the energy shifts is discussed. Peer reviewed
Daidzein has neuroprotective effects through ligand-binding-independent PPARγ activation.
2011
Phytoestrogens are a group of plant-derived compounds that include mainly isoflavones like daidzein. Phytoestrogens prevent neuronal damage and improve outcome in experimental stroke; however, the mechanisms of this neuroprotective action have not been fully elucidated. In this context, it has been postulated that phytoestrogens might activate the peroxisome proliferator-activated receptor-γ (PPARγ), which exerts neuroprotective effects in several settings. The aim of this study was to determine whether the phytoestrogen daidzein elicits beneficial actions in neuronal cells by mechanisms involving activation of PPARγ. Our results show that daidzein (0.05-5 μM) decreases cell death induced b…
Acute neuromuscular, cardiorespiratory and endocrine responses and chronic adaptations to combined strength and endurance training in recreationally …
2013
Efficient Conversion of Light to Chemical Energy : Directional, Chiral Photoswitches with Very High Quantum Yields
2020
Abstract Photochromic systems have been used to achieve a number of engineering functions such as light energy conversion, molecular motors, pumps, actuators, and sensors. Key to practical applications is a high efficiency in the conversion of light to chemical energy, a rigid structure for the transmission of force to the environment, and directed motion during isomerization. We present a novel type of photochromic system (diindane diazocines) that converts visible light with an efficiency of 18 % to chemical energy. Quantum yields are exceptionally high with >70 % for the cis–trans isomerization and 90 % for the back‐reaction and thus higher than the biochemical system rhodopsin (64 %). T…
Trade-off Performance of Optical Nanoantennas for Solar Energy Harvesting Applications
2019
In this paper, the optimum behaviour of optical nanoantennas, in terms of impedance, directivity, available power, and field enhancement, at a resonance frequency of about 350 THz, will be shown. Optimum configurations are obtained by varying nanoantennas geometry in order to maximize the available power, enhancing the electric field in gap proximity and so the absorptivity. Moreover, the simulation results for aluminum nanoantennas on a three-layers substrate, will be reported, and a trade-off performance comparison among different antennas will be discussed. This study can guide both the engineering and the fabrication of plasmonic nanoantennas.
Improving nanoscale terahertz field localization by means of sharply tapered resonant nanoantennas
2020
Abstract Terahertz resonant nanoantennas have recently become a key tool to investigate otherwise inaccessible interactions of such long-wavelength radiation with nano-matter. Because of their high-aspect-ratio rod-shaped geometry, resonant nanoantennas suffer from severe loss, which ultimately limits their field localization performance. Here we show, via a quasi-analytical model, numerical simulations, and experimental evidence, that a proper tapering of such nanostructures relaxes their overall loss, leading to an augmented local field enhancement and a significantly reduced resonator mode volume. Our findings, which can also be extended to more complex geometries and higher frequencies,…
Predicción de la intención de abandono en futbolistas adolescentes desde la teoría de las metas de logro y la teoría de la autodeterminación
2017
El objetivo general de esta tesis doctoral fue estudiar los antecedentes motivacionales de la intención de abandono en jugadores de fútbol adolescentes desde los postulados de la teoría de las metas de logro (AGT, Achievement Goal Theory; Ames, 1992; Nicholls, 1989) y de la teoría de la autodeterminación (SDT, Self-Determination Theory; Deci y Ryan, 1985, 2000; Ryan y Deci, 2007, 2017), poniendo especial énfasis en el clima motivacional que los entrenadores crean en los equipos, evaluado tanto a través de la percepción individual de los jugadores como a través de la observación sistemática de la conducta de los entrenadores. Con una muestra de 552 jugadores (M edad = 11.23, DT = 1.14) y de …