Search results for "dynamics."

Electrical conductivity as a state indicator for the start-up period of anaerobic fixed-bed reactors.

2016

The aim of this work was to analyse the applicability of electrical conductivity sensors for on-line monitoring the start-up period of an anaerobic fixed-bed reactor. The evolution of bicarbonate concentration and methane production rate was analysed. Strong linear relationships between electrical conductivity and both bicarbonate concentration and methane production rate were observed. On-line estimations of the studied parameters were carried out in a new start-up period by applying simple linear regression models, which resulted in a good concordance between both observed and predicted values. Electrical conductivity sensors were therefore identified as an interesting method for monitori…

Spin and charge currents driven by the Higgs mode in high-field superconductors

2020

The Higgs mode in superconducting materials describes slowly decaying oscillations of the order parameter amplitude. We demonstrate that in superconductors with a built-in spin-splitting field the Higgs mode is strongly coupled to the spin degrees of freedom, allowing for the generation of time-dependent spin currents. Converting such spin currents to electric signals by spin-filtering elements provides a tool for the second-harmonic generation and the electrical detection of the Higgs mode generated by the external irradiation. The nonadiabatic spin torques generated by these spin currents allow for the magnetic detection of the Higgs mode by measuring the precession of the magnetic moment…

Effect of disorder on Majorana localization in topological superconductors: a quasiclassical approach

2020

Two-dimensional (2D) topological superconductors (TS) host chiral Majorana modes (MMs) localized at the boundaries. In this work, we study the effect of disorder on the localization length of MMs in two-dimensional spin-orbit (SO) coupled superconductors within quasiclassical approximation. We find nonmonotonic behavior of the Majorana localization length as a function of disorder strength. At weak disorder, the Majorana localization length decreases with an increasing disorder strength. Decreasing the disorder scattering time below a crossover value ${\ensuremath{\tau}}_{c}$, the Majorana localization length starts to increase. The crossover scattering time depends on the relative magnitud…

Organizational Performance Dynamics : a preliminary model

2023

The main objective of this model (an Interactive Learning Environment) is to help the reader understand how employees' motivational dynamics influence organizational performance. The model will allow you, through an iterative learning process, to understand: - the feedback structure of dynamic organizational performance system - the main motivational variables that influence the organizational performance - the organizational levers able to affect the employees' motivational dynamics The model will allow the reader to figure out the complex relationship between employee motivation and organizational performance through an "experimental" approach, using the simulation features provided by th…

Thermal-hydraulic behaviour of the DEMO divertor plasma facing components cooling circuit

2017

Abstract Within the framework of the Work Package DIV 1 – “Divertor Cassette Design and Integration” of the EUROfusion action, a research campaign has been jointly carried out by ENEA and University of Palermo to investigate the thermal-hydraulic performances of the DEMO divertor cassette cooling system. A comparative evaluation study has been performed considering three different options for the cooling circuit layout of the divertor Plasma Facing Components (PFCs). The potential improvement in the thermal-hydraulic performance of the cooling system, to be achieved by modifying cooling circuit layout, has been also assessed and discussed in terms of optimization strategy. The research acti…

Immobility in appearance only: Ricoeur and identity dynamics in workplace experiences

2016

International audience; Immobility in one’s career, marked by a long period of stability in the same position, is not synonymous with the absence of identity mobility, on the contrary. This can be deduced from the information collected from 23 employees in a French association in the social sector. In this research we draw on the notions of idem, ipse and capacity developed by Ricoeur. A model of the cyclical identity dynamics in daily work experience has been developed, while contributing to the topics of identification and career choice. It also questions the impact of dominant social norms that favour professional mobility on managerial practices and deprive employees from a critical for…

Electric Field Orientation Dependence of Electron Spin Relaxation in Wurtzite GaN

2012

Pressure-Driven Isostructural Phase Transition in InNbO4: In Situ Experimental and Theoretical Investigations

2017

[EN] The high-pressure behavior of technologically important visible-light photocatalytic semiconductor In.NbO4, adopting a monoclinic wolframite-type structure at ambient conditions, was investigated using synchrotron-based X-ray diffraction, Raman spectroscopic measurements, and first-principles calculations. The experimental results indicate the occurrence of a pressure-induced isostructural phase transition in the studied compound beyond 10.8 GPa. The large volume collapse associated with the phase transition and the coexistence of two phases observed over a wide range of pressure shows the nature of transition to be first-order. There is an increase in the oxygen anion coordination num…

The Use of X-ray Absorption Spectra for Validation of Classical Force-Field Models

2015

Abstract Extended X-ray absorption fine structure (EXAFS) spectroscopy and molecular dynamics (MD) simulations are two complementary techniques widely used to study the atomic structure of materials. Their combined use, known as the MD-EXAFS approach, allows one to access the structural information, encoded in EXAFS, far beyond the nearest coordination shells and to validate the accuracy of the interaction potential models. In this study we demonstrate the use of the MD-EXAFS method for a validation of several force-field models on an example of the cubic-perovskite SrTiO3 and hexagonal wurtzite-type ZnO crystals.

X-ray absorption spectroscopy study of local dynamics and thermal expansion in ReO3

2015

The thermal expansion of polycrystalline ${\mathrm{ReO}}_{3}$ is studied in vacuum by x-ray diffraction from 300 to 600 K and by extended x-ray absorption fine structure (EXAFS) at the Re ${L}_{3}$ edge from 30 to 600 K. A detailed EXAFS analysis is presented up to the sixth coordination shell around Re. The crystal thermal expansion is weak throughout the explored range, negative below 100 K, positive from 150 to 500 K, and negative again above 500 K. The analysis of mean square relative displacements obtained by EXAFS and of mean square displacements available from x-ray and neutron diffraction measurements confirms the presence of significant static disorder in the investigated samples. …