Propagation and amplification of auroral kilometric radiation in finite width auroral cavities

1992 ◽  
Vol 97 (A12) ◽  
pp. 19299 ◽  
Author(s):  
R. Gaelzer ◽  
L. F. Ziebell ◽  
R. S. Schneider
1997 ◽  
Vol 51 (8) ◽  
pp. 77-84
Author(s):  
L. M. Buzik ◽  
O. F. Pishko ◽  
S.A. Churilova ◽  
O. I. Sheremet

2020 ◽  
Vol 60 (5) ◽  
pp. 538-546
Author(s):  
D. V. Chugunin ◽  
A. A. Chernyshov ◽  
I. L. Moiseenko ◽  
M. E. Viktorov ◽  
M. M. Mogilevsky

Author(s):  
Frank S. Levin

Quantum tunneling, wherein a quanject has a non-zero probability of tunneling into and then exiting a barrier of finite width and height, is the subject of Chapter 13. The description for the one-dimensional case is extended to the barrier being inverted, which forms an attractive potential well. The first application of this analysis is to the emission of alpha particles from the decay of radioactive nuclei, where the alpha-nucleus attraction is modeled by a potential well and the barrier is the repulsive Coulomb potential. Excellent results are obtained. Ditto for the similar analysis of proton burning in stars and yet a different analysis that explains tunneling through a Josephson junction, the connector between two superconductors. The final application is to the scanning tunneling microscope, a device that allows the microscopic surfaces of solids to be mapped via electrons from the surface molecules tunneling into the tip of the STM probe.


2004 ◽  
Vol 85 (21) ◽  
pp. 4834-4836 ◽  
Author(s):  
Zhaofeng Li ◽  
Haibo Chen ◽  
Zhitang Song ◽  
Fuhua Yang ◽  
Songlin Feng

1999 ◽  
Vol 121 (3) ◽  
pp. 385-392 ◽  
Author(s):  
Robert J. Stango ◽  
Lienjing Chen ◽  
Vikram Cariapa

In this paper, a dynamic model for removal of edge burrs with a compliant brushing tool is reported. Description of the burr geometry is assumed to be known through on-line measurement methods such as a computer vision system in the flexible manufacturing cell. Dynamic response of the brush/workpiece system is evaluated on the basis of experimentally obtained data. Master Curves are introduced as machining descriptors which characterize the incremental burr removal performance of the brush/workpiece system, leading to the development of an analytical dynamic model for orthogonal burr removal using a finite-width brushing tool. Based upon the dynamic model for material removal, a control strategy for automatic deburring is presented for burr configurations having constant height as well as variable height. A closed-form solution for transverse brush feed rate is obtained which is applicable for removal of burrs having variable height, as described by suitable geometry functions. For illustrative purposes, simulations are carried out for a straight-edge burr profile and sinusoidal burr geometry. Results are reported which identify important relationships among brush feed rate, brush penetration depth, and brush rotational speed. In order to help assess the validity of the proposed analytical model and control strategy, experimental results are reported for a combination ramp/straight-edge burr configuration. The results demonstrate generally good correlation between the predicted and actual profile for the edge burr that has been machined. In addition, some important observations include; (1) burr removal is most rapidly carried out by using the highest brush speed and deepest brush/workpiece penetration depth, subject to the condition that the brush fiber is not damaged, (2) Currently available polymer abrasive brushing tools exhibit very slow machining characteristics and must be improved in order to be used in a production environment where burr size is appreciable, (3) Material removal characteristics of the leading and trailing edge of brushes may be a source of error which merits further investigation.


1987 ◽  
Vol 109 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Patrick Bourgin ◽  
Joseph-Marc Francois

The working characteristics of a finite width slider bearing lubricated by a non-Newtonian fluid are computed. The analysis proposed here allows its performances to be evaluated by means of a pocket calculator. For that purpose, a computer code based on a finite element method is used. The program runs for different values of pertinent kinematical, geometrical and rheological parameters. The corresponding results are fitted by means of adequate analytical formulas, which are very easy to handle. The accuracy of these empirical formulas is investigated in several typical cases. The agreement with the numerical solution is proven to be satisfactory.


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