Search results for "COPI"
showing 10 items of 2618 documents
Electron refrigeration in hybrid structures with spin-split superconductors
2017
Electron tunneling between superconductors and normal metals has been used for an efficient refrigeration of electrons in the latter. Such cooling is a nonlinear effect and usually requires a large voltage. Here we study the electron cooling in heterostructures based on superconductors with a spin-splitting field coupled to normal metals via spin-filtering barriers. The cooling power shows a linear term in the applied voltage. This improves the coefficient of performance of electron refrigeration in the normal metal by shifting its optimum cooling to lower voltage, and also allows for cooling the spin-split superconductor by reverting the sign of the voltage. We also show how tunnel couplin…
Mesoscopic structural organization in fluorinated pyrrolidinium-based room temperature ionic liquids
2019
Abstract In this contribution the microscopic and mesoscopic structural organization in a series of fluorinated room temperature ionic liquids, based on N-methyl-N-alkylpyrrolidinium cations and on bis(perfluoroalkylsulfonyl)imide anions, is investigated, using a synergy of experimental (X-ray and neutron scattering) and computational (Molecular Dynamics) techniques. The proposed ionic liquids are of high interest as electrolyte media for lithium battery applications. Together with information on their good ion transport properties in conjunction with low viscosity, we also describe the existence of nm-scale spatial organization induced by the segregation of fluorous moieties into domains. …
Advanced microscopy analysis of the micro-nanoscale architecture of human menisci
2019
AbstractThe complex inhomogeneous architecture of the human meniscal tissue at the micro and nano scale in the absence of artefacts introduced by sample treatments has not yet been fully revealed. The knowledge of the internal structure organization is essential to understand the mechanical functionality of the meniscus and its relationship with the tissue’s complex structure. In this work, we investigated human meniscal tissue structure using up-to-date non-invasive imaging techniques, based on multiphoton fluorescence and quantitative second harmonic generation microscopy complemented with Environmental Scanning Electron Microscopy measurements. Observations on 50 meniscal samples extract…
Communication: anion-specific response of mesoscopic organization in ionic liquids upon pressurization
2018
One of the outstanding features of ionic liquids is their inherently hierarchical structural organization at mesoscopic spatial scales. Recently experimental and computational studies showed the fading of this feature when pressurising. Here we use simulations to show that this effect is not general: appropriate anion choice leads to an obstinate resistance against pressurization. Published by AIP Publishing.
Porous Aluminium Oxide Coating for the Development of Spectroscopic Ellipsometry Based Biosensor: Evaluation of Human Serum Albumin Adsorption
2020
An electrochemically synthesised porous anodic aluminium oxide (pAAO) layer has been analysed by means of spectroscopic ellipsometry. The determined thickness of the formed pAAO layer obtained from spectroscopic ellipsometry measurements and modelling was 322.75 ±
Self-assembled metal-oxide nanoparticles on GaAs: infrared absorption enabled by localized surface plasmons
2021
Abstract Metal-oxides hold promise as superior plasmonic materials in the mid-infrared compared to metals, although their integration over established material technologies still remains challenging. We demonstrate localized surface plasmons in self-assembled, hemispherical CdZnO metal-oxide nanoparticles on GaAs, as a route to enhance the absorption in mid-infrared photodetectors. In this system, two localized surface plasmon modes are identified at 5.3 and 2.7 μm, which yield an enhancement of the light intensity in the underlying GaAs. In the case of the long-wavelength mode the enhancement is as large as 100 near the interface, and persists at depths down to 50 nm. We show numerically t…
Spectroscopic method to study low charge state ion and cold electron population in ECRIS plasma
2018
The results of optical emission spectroscopy experiments probing the cold electron population of a 14 GHz Electron Cyclotron Resonance Ion Source (ECRIS) are reported. The study has been conducted with a high resolution spectrometer and data acquisition setup developed specifically for the diagnostics of weak emission line characteristic to ECRIS plasmas. The optical emission lines of low charge state ions and neutral atoms of neon have been measured and analyzed with the line-ratio method. The aforementioned electron population temperature of the cold electron population (Te < 100 eV) is determined for Maxwell-Boltzmann and Druyvesteyn energy distributions to demonstrate the applicability …
Microwave photoassisted dissipation and supercurrent of a phase-biased graphene-superconductor ring
2021
Irradiating normal-superconducting junctions with microwave photons produce spectacular effects, such as Shapiro steps and photoinduced modifications of the dc supercurrent. Moreover, microwave irradiation can also have other, hitherto unexplored consequences, such as a photoassisted dissipation which is phase dependent. Here we present a finite-frequency measurement of both the dissipation and the supercurrent of a phase-biased graphene-superconductor junction in response to microwave photons. We find that, while the supercurrent response is well described by existing theory, the dissipation exhibits unexpected effects which need new theoretical elucidation. Especially with high frequency …
Microscopic structural and dynamic features in triphilic room temperature ionic liquids
2019
Here we report a thorough investigation of the microscopic and mesoscopic structural organization in a series of triphilic fluorinated room temperature ionic liquids, namely [1-alkyl, 3-methylimidazolium][(trifluoromethanesulfonyl)(nonafluorobutylsulfonyl)imide], with alkyl=ethyl, butyl, octyl ([C(n)mim][IM14], n = 2, 4, 8), based on the synergic exploitation of X-ray and Neutron Scattering and Molecular Dynamics simulations. This study reveals the strong complementarity between X-ray/neutron scattering in detecting the complex segregated morphology in these systems at mesoscopic spatial scales. The use of MD simulations delivering a very good agreement with experimental data allows us to g…
Maternal coping strategies in response to a child's chronic and oncological disease: a cross-cultural study in Italy and Portugal
2013
A child's oncological or chronic disease is a stressful situation for parents. This stress may make it difficult for appropriate management strategies aimed at promoting the child's wellbeing and helping him or her cope with a disease to be adopted. In particular, this study focuses on the possible connections between the variable national cultural influences and the parental strategies used to cope with a child's severe disease by comparing the experiences of Italian and Portuguese mothers. The study investigates differences and cross-cultural elements among the coping strategies used by Italian and Portuguese mothers of children with oncological or chronic disease. Two groups of mothers t…