scholarly journals Current Density Impedance Imaging of an Anisotropic Conductivity in a Known Conformal Class

2014 ◽  
Vol 46 (3) ◽  
pp. 1820-1842 ◽  
Author(s):  
Nicholas Hoell ◽  
Amir Moradifam ◽  
Adrian Nachman
Keyword(s):  
Current Density ◽  
Conformal Class ◽  
Anisotropic Conductivity ◽  
Impedance Imaging ◽  
Current Density Impedance Imaging

scholarly journals Stability of Current Density Impedance Imaging

2020 ◽  
Vol 52 (5) ◽  
pp. 4506-4523
Author(s):  
Robert Lopez ◽  
Amir Moradifam
Keyword(s):  
Current Density ◽  
Impedance Imaging ◽  
Current Density Impedance Imaging

Current Density Impedance Imaging

2008 ◽  
Vol 27 (9) ◽  
pp. 1301-1309 ◽  
Author(s):  
K.F. Hasanov ◽  
A.W. Ma ◽  
A.I. Nachman ◽  
M.L.G. Joy
Keyword(s):  
Current Density ◽  
Impedance Imaging ◽  
Current Density Impedance Imaging

scholarly journals Stability of current density impedance imaging II

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Amir Moradifam ◽  
Robert Lopez
Keyword(s):  
Vector Field ◽  
Numerical Simulations ◽  
Current Density ◽  
Current Density Vector ◽  
Density Independence ◽  
Impedance Imaging ◽  
Voltage Potential ◽  
Density Vector ◽  
Current Density Impedance Imaging ◽  
The Stability

<p style='text-indent:20px;'>This paper is a continuation of the authors earlier work on stability of Current Density Impedance Imaging (CDII) [R. Lopez, A. Moradifam, Stability of Current Density Impedance Imaging, SIAM J. Math. Anal. (2020).] We show that CDII is stable with respect to errors in both measurement of the magnitude of the current density vector field in the interior and the measurement of the voltage potential on the boundary. This completes the authors study of the stability of Current Density Independence Imaging which was previously shown only by numerical simulations.</p>

Activated Prominences; Mechanisms for Activation and Eruption

1979 ◽  
Vol 44 ◽  
pp. 307-313
Author(s):  
D.S. Spicer
Keyword(s):  
Pressure Gradient ◽  
Density Gradient ◽  
Current Density ◽  
Convective Instability ◽  
Tearing Mode ◽  
Magnetic Shear ◽  
Long Wavelength ◽  
Ideal Mhd ◽  
Gradient Change ◽  
Accelerated Particles

A possible relationship between the hot prominence transition sheath, increased internal turbulent and/or helical motion prior to prominence eruption and the prominence eruption (“disparition brusque”) is discussed. The associated darkening of the filament or brightening of the prominence is interpreted as a change in the prominence’s internal pressure gradient which, if of the correct sign, can lead to short wavelength turbulent convection within the prominence. Associated with such a pressure gradient change may be the alteration of the current density gradient within the prominence. Such a change in the current density gradient may also be due to the relative motion of the neighbouring plages thereby increasing the magnetic shear within the prominence, i.e., steepening the current density gradient. Depending on the magnitude of the current density gradient, i.e., magnetic shear, disruption of the prominence can occur by either a long wavelength ideal MHD helical (“kink”) convective instability and/or a long wavelength resistive helical (“kink”) convective instability (tearing mode). The long wavelength ideal MHD helical instability will lead to helical rotation and thus unwinding due to diamagnetic effects and plasma ejections due to convection. The long wavelength resistive helical instability will lead to both unwinding and plasma ejections, but also to accelerated plasma flow, long wavelength magnetic field filamentation, accelerated particles and long wavelength heating internal to the prominence.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

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