The Experts below are selected from a list of 55872 Experts worldwide ranked by ideXlab platform

G Barbezat - One of the best experts on this subject based on the ideXlab platform.

  • characterization of supersonic low Pressure plasma jets with electrostatic probes
    Plasma Sources Science and Technology, 2004
    Co-Authors: Malko Gindrat, J L Dorier, Ch Hollenstein, A Refke, G Barbezat
    Abstract:

    Measurement of key plasma jet properties, such as the Mach number, electron density and temperature, in a low Pressure environment, were performed using double Langmuir probes and Mach probes. In particular, under-expanded jets are studied in detail by performing complete mappings of plasma jet properties at chamber Pressures of 10 and 2 mbar. These results show that the measured physical properties are consistent with the jet flow phenomenology, such as the presence of periodic expansion and compression zones, the effect of the Pressure and the location of the shocks. It is shown, in particular, that for a highly under-expanded jet at 2 mbar, the Mach number reaches 2.8 in the first expansion zone followed by a strong drop to subsonic flow revealing the presence of a Mach reflection. The flow is accelerated further and a periodic structure of compression/expansion cells is observed until the local static Pressure is in equilibrium with the Surrounding Pressure. These results contribute to the understanding of the supersonic plasma jet behaviour at low Pressure and can be used to quantify the deviation from local thermodynamic equilibrium. The extensive mapping of the measured physical properties of the jet will also serve as input for modelling.

Malko Gindrat - One of the best experts on this subject based on the ideXlab platform.

  • characterization of supersonic low Pressure plasma jets with electrostatic probes
    Plasma Sources Science and Technology, 2004
    Co-Authors: Malko Gindrat, J L Dorier, Ch Hollenstein, A Refke, G Barbezat
    Abstract:

    Measurement of key plasma jet properties, such as the Mach number, electron density and temperature, in a low Pressure environment, were performed using double Langmuir probes and Mach probes. In particular, under-expanded jets are studied in detail by performing complete mappings of plasma jet properties at chamber Pressures of 10 and 2 mbar. These results show that the measured physical properties are consistent with the jet flow phenomenology, such as the presence of periodic expansion and compression zones, the effect of the Pressure and the location of the shocks. It is shown, in particular, that for a highly under-expanded jet at 2 mbar, the Mach number reaches 2.8 in the first expansion zone followed by a strong drop to subsonic flow revealing the presence of a Mach reflection. The flow is accelerated further and a periodic structure of compression/expansion cells is observed until the local static Pressure is in equilibrium with the Surrounding Pressure. These results contribute to the understanding of the supersonic plasma jet behaviour at low Pressure and can be used to quantify the deviation from local thermodynamic equilibrium. The extensive mapping of the measured physical properties of the jet will also serve as input for modelling.

Terence C Amis - One of the best experts on this subject based on the ideXlab platform.

G Fabbris - One of the best experts on this subject based on the ideXlab platform.

  • evidence for a Pressure induced antiferromagnetic quantum critical point in intermediate valence ute2
    Science Advances, 2020
    Co-Authors: S M Thomas, F B Santos, M H Christensen, Tomoya Asaba, F Ronning, J D Thompson, E D Bauer, Rafael M Fernandes, G Fabbris
    Abstract:

    UTe2 is a recently discovered unconventional superconductor that has attracted much interest because of its potentially spin-triplet topological superconductivity. Our ac calorimetry, electrical resistivity, and x-ray absorption study of UTe2 under applied Pressure reveals key insights on the superconducting and magnetic states Surrounding Pressure-induced quantum criticality at Pc1 = 1.3 GPa. First, our specific heat data at low Pressures, combined with a phenomenological model, show that Pressure alters the balance between two closely competing superconducting orders. Second, near 1.5 GPa, we detect two bulk transitions that trigger changes in the resistivity, which are consistent with antiferromagnetic order, rather than ferromagnetism. Third, the emergence of magnetism is accompanied by an increase in valence toward a U4+ (5f2) state, which indicates that UTe2 exhibits intermediate valence at ambient Pressure. Our results suggest that antiferromagnetic fluctuations may play a more substantial role on the superconducting state of UTe2 than previously thought.

  • evidence for a Pressure induced antiferromagnetic quantum critical point in intermediate valence ute2
    arXiv: Strongly Correlated Electrons, 2020
    Co-Authors: S M Thomas, F B Santos, M H Christensen, Tomoya Asaba, F Ronning, J D Thompson, E D Bauer, Rafael M Fernandes, G Fabbris
    Abstract:

    UTe$_2$ is a recently discovered unconventional superconductor that has attracted much interest due to its many intriguing properties - a large residual density-of-states in the superconducting state, re-entrant superconductivity in high magnetic fields, and potentially spin-triplet topological superconductivity. Our ac calorimetry, electrical resistivity, and x-ray absorption study of UTe$_2$ under applied Pressure reveals key new insights on the superconducting and magnetic states Surrounding Pressure-induced quantum criticality at P$_{c1}$ = 1.3 GPa. First, our specific heat data at low Pressures, combined with a phenomenological model, show that Pressure alters the balance between two closely competing superconducting orders. Second, near 1.5 GPa we detect two bulk transitions that trigger changes in the resistivity which are consistent with antiferromagnetic order, rather than ferromagnetism. The presence of both bulk magnetism and superconductivity at Pressures above P$_{c2}$ = 1.4 GPa results in a significant temperature difference between resistively and thermodynamically determined transitions into the superconducting state, which indicates a suppression of the superconducting volume fraction by magnetic order. Third, the emergence of magnetism is accompanied by an increase in valence towards a U$^{4+}$ (5f2) state, which indicates that UTe$_2$ exhibits intermediate valence at ambient Pressure. Our results suggest that antiferromagnetic fluctuations may play a more significant role on the superconducting state of UTe$_2$ than previously thought.

Qibin Li - One of the best experts on this subject based on the ideXlab platform.

  • molecular simulation of thermal energy storage of mixed co2 irmof 1 nanoparticle nanofluid
    International Journal of Heat and Mass Transfer, 2018
    Co-Authors: Jieyao Hu, Qibin Li
    Abstract:

    Abstract Thermal energy storage capacity of working fluid can be enhanced by using energy conversion of adsorption/desorption process of working fluid in nanoporous materials. Molecular simulation including molecular dynamics and grand canonical Monte Carlo are employed to investigate the energy storage of CO2/IRMOF-1 (isoreticular metal organic framework) nanoparticle mixture. The results show that the calculated heat capacity by molecular dynamics simulation agrees with experimental data. The thermal energy storage capacity of CO2 increases with the increase of mass ratio of IRMOF-1 nanoparticles. IRMOF-1 is conducive to enhance the capacity of thermal energy storage when the Surrounding Pressure is low.