Electric-Field Induced Formation of Superconducting Granular Balls

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2529-2535
Author(s):  
R. Tao ◽  
X. Xu ◽  
Y. C. Lan
Keyword(s):  
Surface Energy ◽  
Electric Field ◽  
Liquid Nitrogen ◽  
Applied Electric Field ◽  
Strong Electric Field ◽  
Particle Surface ◽  
Cooper Pairs ◽  
Surface Charges

When a strong electric field is applied to a suspension of micron-sized high T c superconducting particles in liquid nitrogen, the particles quickly aggregate together to form millimeter-size balls. The balls are sturdy, surviving constant heavy collisions with the electrodes, while they hold over 106 particles each. The phenomenon is a result of interaction between Cooper pairs and the strong electric field. The strong electric field induces surface charges on the particle surface. When the applied electric field is strong enough, Cooper pairs near the surface are depleted, leading to a positive surface energy. The minimization of this surface energy leads to the aggregation of particles to form balls.

Electrohydrodynamic Kelvin-Helmholtz Instability of Two Rotating Dielectric Fluids

1998 ◽  
Vol 53 (1-2) ◽  
pp. 17-26
Author(s):  
Mohamed Fahmy El-Sayed
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Applied Electric Field ◽  
Rotation Frequency ◽  
Short Wave ◽  
Surface Charges ◽  
Rotation Surface ◽  
Dielectric Fluids ◽  
Fluid Velocities ◽  
Conditions Of Stability

Abstract A linear stability analysis of a novel electrohydrodynamic Kelvin-Helmholtz system consisting of the superposition of two uniformly rotating dielectric media is presented. The characteristic equation for such an arrangement is derived, which in turn yields a stability criterion for velocity differences of disturbances at a given rotation frequency. The conditions of stability for long and short wave perturbations are obtained, and their dependence on rotation, surface tension and applied electric field is discussed. Limiting cases for vanishing fluid velocities, rotation frequency, and applied electric field are also discussed. Under suitable limits, results of previous works are recovered. A detailed analysis for tangential and normal applied electric fields, in the presence and absence of surface charges, is carried out.

Two-Fluid Electroosmotic Flow in Microchannels

2008 ◽  
Author(s):  
T. N. Wong ◽  
Y. Gao ◽  
C. Wang ◽  
C. Yang ◽  
N. T. Nguyen ◽  
...  
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Electroosmotic Flow ◽  
Viscosity Ratio ◽  
Experimental Investigations ◽  
Fluid Interface ◽  
Surface Charges ◽  
Interface Position ◽  
Proposed Model ◽  
Two Fluid

This paper presents theoretical and experimental investigations of the pressure-driven two-liquid flow in microchannels with the electroosmosis effect. For a fully developed, steady state, laminar flow of two liquids combined the pressure gradient, electroosmosis and surface charges at the liquid-liquid interface, we have derived analytical solutions that relate the velocity profiles and flow rates to the liquid holdup, the aspect ratio of the microchannel, the viscosity ratio of the two liquids and the externally applied electric field. It was shown that adjusting the externally applied electric field could control the fluid interface position precisely. The prediction from the proposed model compares very well with measured data.

Modeling and Simulation of Microscale Bipolar Particle Dynamics in an Applied Electric Field

2013 ◽  
Author(s):  
Mohammad Robiul Hossan ◽  
Robert Dillon ◽  
Prashanta Dutta
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Applied Electric Field ◽  
Numerical Study ◽  
Particle Dynamics ◽  
Opposite Polarity ◽  
Surface Charges ◽  
Ellipsoidal Particles ◽  
Polar Moment ◽  
String Formation

The colloidal dynamics of bipolar microparticles is of growing theoretical interest in understanding and advancement of electrorheology and ferroelectric research. In this paper we present an interface resolved numerical study to analyze dynamics of ellipsoidal bipolar microparticles for various initial configurations. The bipolarity is imposed by providing surface charges of opposite polarity at the two ends of ellipsoidal particles. The numerical simulations show that in the absence of an external electric field, ellipsoidal particles form a head-to-tail chain or stay apart from each other depending on the inter-particle distance, as well as the magnitude and direction of the inherent polar moment. On the other hand, in presence of an external electric field, the assembly or clustering mechanism primarily depends on the magnitude and direction of the applied electric field. Simulation results also show that the electrorotation process is a function of initial configuration. This comprehensive numerical study will help to better understand the mechanisms of clustering, string formation, and the disaggregation of bipolar microparticles.

Activation of CO2 on Copper Surfaces: The Synergy Between Electric Field, Surface Morphology and Excess Electrons

2020 ◽  
Author(s):  
Amin Jafarzadeh ◽  
Kristof M. Bal ◽  
Annemie Bogaerts ◽  
Erik C. Neyts
Keyword(s):  
Surface Morphology ◽  
Electric Field ◽  
Surface Charge ◽  
External Electric Field ◽  
Electric Fields ◽  
Applied Electric Field ◽  
Marginal Effect ◽  
Electric Field Effect ◽  
Surface Charges ◽  
Copper Surfaces

<p>In this work we use DFT calculations to study the combined effect of external electric fields, surface morphology and surface charge on CO<sub>2</sub> activation over Cu (111), Cu (211), Cu (110) and Cu (001) surfaces. We observe that the binding energy of the CO<sub>2</sub> molecule on Cu surfaces rises significantly upon increasing the applied electric field strength. In addition, rougher surfaces respond more effectively to the presence of the external electric field towards facilitating the formation of a carbonate-like CO<sub>2</sub> structure and the transformation of the most stable adsorption mode from physisorption to chemisorption. The presence of surface charges further strengthens the electric field effect and consequently gives rise to an improved bending of the CO<sub>2</sub> molecule and C-O bond length elongation. On the other hand, a net charge in the absence of externally applied electric field shows only a marginal effect on CO<sub>2</sub> binding. The chemisorbed CO<sub>2</sub> is more stable and further activated when the effects of an external electric field, rough surface and surface charge are combined. These results can help to elucidate the underlying factors that control CO<sub>2</sub> activation in heterogeneous and plasma catalysis, as well as in electrochemical processes.</p>

Activation of CO2 on Copper Surfaces: The Synergy Between Electric Field, Surface Morphology and Excess Electrons

2020 ◽  
Author(s):  
Amin Jafarzadeh ◽  
Kristof M. Bal ◽  
Annemie Bogaerts ◽  
Erik C. Neyts
Keyword(s):  
Surface Morphology ◽  
Electric Field ◽  
Surface Charge ◽  
External Electric Field ◽  
Electric Fields ◽  
Applied Electric Field ◽  
Marginal Effect ◽  
Electric Field Effect ◽  
Surface Charges ◽  
Copper Surfaces

<p>In this work we use DFT calculations to study the combined effect of external electric fields, surface morphology and surface charge on CO<sub>2</sub> activation over Cu (111), Cu (211), Cu (110) and Cu (001) surfaces. We observe that the binding energy of the CO<sub>2</sub> molecule on Cu surfaces rises significantly upon increasing the applied electric field strength. In addition, rougher surfaces respond more effectively to the presence of the external electric field towards facilitating the formation of a carbonate-like CO<sub>2</sub> structure and the transformation of the most stable adsorption mode from physisorption to chemisorption. The presence of surface charges further strengthens the electric field effect and consequently gives rise to an improved bending of the CO<sub>2</sub> molecule and C-O bond length elongation. On the other hand, a net charge in the absence of externally applied electric field shows only a marginal effect on CO<sub>2</sub> binding. The chemisorbed CO<sub>2</sub> is more stable and further activated when the effects of an external electric field, rough surface and surface charge are combined. These results can help to elucidate the underlying factors that control CO<sub>2</sub> activation in heterogeneous and plasma catalysis, as well as in electrochemical processes.</p>

Features of the edge photoconductivity of gamma-irradiated layered crystals GaS and GaS:Yb under the strong electric field

2019 ◽  
Vol 33 (09) ◽  
pp. 1950066
Author(s):  
R. S. Madatov ◽  
A. S. Alekperov ◽  
N. N. Gadzhieva ◽  
F. G. Asadov ◽  
Sh. A. Allahverdiev ◽  
...  
Keyword(s):  
Surface Energy ◽  
Electric Field ◽  
Transverse Electric ◽  
Strong Electric Field ◽  
Edge Region ◽  
Energy Bands ◽  
Impurity Atoms ◽  
Layered Crystals ◽  
Surface Electric Field ◽  
Gamma Irradiated

The influence of the surface electric field on the edge photoconductivity (PC) in undoped and ytterbium-doped (N[Formula: see text][Formula: see text] 10[Formula: see text] cm[Formula: see text]) layered GaS crystals at T = 77 K irradiated with gamma quanta was investigated. It was found that the PC of layered crystals in the absorption edge region due to charge exchange of surface levels is formed as a result of electric smoothing of fluctuations in the potential of surface energy bands. The degree of smoothing of the surface bending of the zones depends on the dose of [Formula: see text]-irradiation, the concentration of impurity atoms and also on the magnitude and direction of the transverse electric field.

LIQUID CRYSTLASLIGHT SCATTERING BY FLUCTUATIONS INDUCED BY AN APPLIED ELECTRIC FIELD IN A NEMATIC LIQUID CRYSTAL (APAPA)

1972 ◽  
Vol 33 (C1) ◽  
pp. C1-63-C1-67 ◽  
Author(s):  
M. BERTOLOTTI ◽  
B. DAINO ◽  
P. Di PORTO ◽  
F. SCUDIERI ◽  
D. SETTE
Keyword(s):  
Liquid Crystal ◽  
Electric Field ◽  
Nematic Liquid Crystal ◽  
Applied Electric Field

Bubble motion in liquid nitrogen under a non-uniform electric field in a microgravity environment

1997 ◽  
Vol 117 (11) ◽  
pp. 1109-1114
Author(s):  
Yoshiyuki Suda ◽  
Kenji Mutoh ◽  
Yosuke Sakai ◽  
Kiyotaka Matsuura ◽  
Norio Homma
Keyword(s):  
Electric Field ◽  
Liquid Nitrogen ◽  
Microgravity Environment ◽  
Uniform Electric Field ◽  
Bubble Motion

Improved technique for measuring mechanical deformations induced by an applied electric field to an organic insulator

2012 ◽  
Vol 15 (2-3) ◽  
pp. 127-139
Author(s):  
Tung Tran Anh ◽  
Laurent Berquez ◽  
Laurent Boudou ◽  
Juan Martinez-Vega ◽  
Alain Lacarnoy
Keyword(s):  
Electric Field ◽  
Applied Electric Field ◽  
Mechanical Deformations ◽  
Improved Technique
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