Magnetic field shielding by a superconducting cylindrical tube of finite length

1976 ◽  
Vol 47 (3) ◽  
pp. 387-388 ◽  
Author(s):  
J. W. Thomasson ◽  
D. M. Ginsberg
2010 ◽  
Vol 7 (3) ◽  
pp. 169-176 ◽  
Author(s):  
S. K. Pandey ◽  
Dharmendra Tripathi

The paper presents an analytical investigation of the peristaltic transport of a viscous fluid under the influence of a magnetic field through a tube of finite length in a dimensionless form. The expressions of pressure gradient, volume flow rate, average volume flow rate and local wall shear stress have been obtained. The effects of the transverse magnetic field and electrical conductivity (i.e. the Hartmann number) on the mechanical efficiency of a peristaltic pump have also been studied. The reflux phenomenon is also investigated. It is concluded, on the basis of the pressure distribution along the tubular length and pumping efficiency, that if the transverse magnetic field and the electric conductivity increase, the pumping machinery exerts more pressure for pushing the fluid forward. There is a linear relation between the averaged flow rate and the pressure applied across one wavelength that can restrain the flow due to peristalsis. It is found that there is a particular value of the averaged flow rate corresponding to a particular pressure that does not depend on the Hartmann number. Naming these values ‘critical values’, it is concluded that the pressure required for checking the flow increases with the Hartmann number above the critical value and decreases with it below the critical value. It is also inferred that magneto-hydrodynamic parameters make the fluid more prone to flow reversal. The conclusion applied to oesophageal swallowing reveals that normal water is easier to swallow than saline water. The latter is more prone to flow reversal. A significant difference between the propagation of the integral and non-integral number of waves along the tube is that pressure peaks are identical in the former and different in the latter cases.


1978 ◽  
Vol 56 (16) ◽  
pp. 2178-2183 ◽  
Author(s):  
Fred Y. Fujiwara ◽  
Leonard W. Reeves

Lyotropic mesophases of both positive (type I) and negative (type II) diamagnetic anisotropy have been prepared. The deuterium magnetic resonance signal from D2O in the sample bas been studied during the process of orientation in a magnetic field. A type II mesophase oriented by a magnetic field in a cylindrical tube perpendicular to the lines of force does not achieve a uniform distribution of directors in a plane perpendicular to the field. The re orientation of a type I mesophase after an initial displacement of the director at an angle to the field has been studied. Previous equations derived for thermotropic liquid crystals are applicable but the velocity of re-orientation was found to be an inverse function of the radius, for nmr tubes of less than 4 mm in diameter, indicating that liquid crystal/glass interface effects are important.


1999 ◽  
Vol 11 (7) ◽  
pp. 1821-1826 ◽  
Author(s):  
L. Martin Witkowski ◽  
J. S. Walker ◽  
P. Marty

2016 ◽  
Vol 99 (3) ◽  
pp. 979-986 ◽  
Author(s):  
J. M. Ferreira ◽  
Joaquim Anacleto

1965 ◽  
Vol 20 (10) ◽  
pp. 1268-1273
Author(s):  
A. Eberhagen ◽  
H. Glaser

The influence of the finite length of the discharge coil on the axial behaviour of a theta pinch plasma column is investigated by measuring electron density profiles at various distances from the midplane of the coil along the discharge axis. The resulting line densities were then checked by an independent method. For a parallel trapped magnetic field it was possible in this way to measure end losses and also the collection rate of the contraction wave in the case of an antiparallel trapped magnetic field.


2011 ◽  
Vol 32 (10) ◽  
pp. 1231-1244 ◽  
Author(s):  
D. Tripathi ◽  
N. Ali ◽  
T. Hayat ◽  
M. K. Chaube ◽  
A. A. Hendi

Sign in / Sign up

Export Citation Format

Share Document