A Generalized Method of Rotational Superposition for Problems With Elliptical Distribution of Boundary Values

1996 ◽  
Vol 63 (4) ◽  
pp. 911-918 ◽  
Author(s):  
Gwolong Lai ◽  
A. R. Robinson
Keyword(s):  
Elasticity Problem ◽  
New Technique ◽  
Two Dimensional ◽  
Elliptical Distribution ◽  
Boundary Values ◽  
Axially Symmetric ◽  
Circular Area ◽  
Static Elasticity ◽  
Circular Case ◽  
Elliptical Boundary

An extension of the usual rotational superposition is developed from geometrical considerations. This approach relates the solution of any dynamic or static elasticity problem which corresponds to boundary values on a circular area to the solution of the problem in which the same boundary values are “stretched” in one direction. From the two-dimensional problems that correspond by rotational superposition to the circular case, new two-dimensional problems are formulated which, when super-posed properly, result in the solution for the elliptical boundary distribution. This new technique is first presented for stretching the boundary values of axially symmetric problems, and then extended to others, including the elliptical shear dislocation problem.

Two-Dimensional Local Deep-Level Transient Spectroscopy Imaging Using Super-Higher-Order Scanning Nonlinear Dielectric Microscopy

2016 ◽  
Author(s):  
N. Chinone ◽  
Y. Cho ◽  
R. Kosugi ◽  
Y. Tanaka ◽  
S. Harada ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Higher Order ◽  
Trap Density ◽  
New Technique ◽  
Two Dimensional ◽  
Nonlinear Dielectric ◽  
Annealing Conditions ◽  
Transient Spectroscopy ◽  
A New Technique

Abstract A new technique for local deep level transient spectroscopy (DLTS) imaging using super-higher-order scanning nonlinear dielectric microscopy is proposed. Using this technique. SiCVSiC structure samples with different post oxidation annealing conditions were measured. We observed that the local DLTS signal decreases with post oxidation annealing (POA), which agrees with the well-known phenomena that POA reduces trap density. Furthermore, obtained local DLTS images had dark and bright areas, which is considered to show the trap distribution at/near SiCVSiC interface.

scholarly journals On the Bean critical-state model in superconductivity

1996 ◽  
Vol 7 (3) ◽  
pp. 237-247 ◽  
Author(s):  
L. Prigozhin
Keyword(s):  
Variational Inequalities ◽  
Critical State ◽  
Existence And Uniqueness ◽  
Critical State Model ◽  
Type Ii ◽  
Two Dimensional ◽  
Axially Symmetric ◽  
Uniqueness Of The Solution ◽  
Type Ii Superconductivity ◽  
Special Case

We consider two-dimensional and axially symmetric critical-state problems in type-II superconductivity, and show that these problems are equivalent to evolutionary quasi-variational inequalities. In a special case, where the inequalities become variational, the existence and uniqueness of the solution are proved.

Motion of a charged particle in superposed Heliotron and biconical cusp fields

1969 ◽  
Vol 3 (2) ◽  
pp. 255-267 ◽  
Author(s):  
M. P. Srivastava ◽  
P. K. Bhat
Keyword(s):  
Magnetic Field ◽  
Charged Particle ◽  
Magnetic Moment ◽  
Particle Trajectory ◽  
Three Dimensional ◽  
Equation Of Motion ◽  
Neutral Point ◽  
Two Dimensional ◽  
Axially Symmetric ◽  
Hybrid Type

We have studied the behaviour of a charged particle in an axially symmetric magnetic field having a neutral point, so as to find a possibility of confining a charged particle in a thermonuclear device. In order to study the motion we have reduced a three-dimensional motion to a two-dimensional one by introducing a fictitious potential. Following Schmidt we have classified the motion, as an ‘off-axis motion’ and ‘encircling motion’ depending on the behaviour of this potential. We see that the particle performs a hybrid type of motion in the negative z-axis, i.e. at some instant it is in ‘off-axis motion’ while at another instant it is in ‘encircling motion’. We have also solved the equation of motion numerically and the graphs of the particle trajectory verify our analysis. We find that in most of the cases the particle is contained. The magnetic moment is found to be moderately adiabatic.

scholarly journals LOW- TO MID-FREQUENCY SCATTERING FROM ELASTIC OBJECTS ON A SAND SEA FLOOR: SIMULATION OF FREQUENCY AND ASPECT DEPENDENT STRUCTURAL ECHOES

2012 ◽  
Vol 20 (02) ◽  
pp. 1240007 ◽  
Author(s):  
MARIO ZAMPOLLI ◽  
AUBREY L. ESPANA ◽  
KEVIN L. WILLIAMS ◽  
STEVEN G. KARGL ◽  
ERIC I. THORSOS ◽  
...  
Keyword(s):  
Scattering Problem ◽  
Three Dimensional ◽  
Element Model ◽  
Propagation Model ◽  
Target Strength ◽  
Unexploded Ordnance ◽  
Two Dimensional ◽  
Axially Symmetric ◽  
Sea Floor ◽  
Spectral Integral

The scattering from roughly meter-sized targets, such as pipes, cylinders and unexploded ordnance shells in the 1–30 kHz frequency band is studied by numerical simulations and compared to experimental results. The numerical tool used to compute the frequency and aspect-dependent target strength is a hybrid model, consisting of a local finite-element model for the vicinity of the target, based on the decomposition of the three-dimensional scattering problem for axially symmetric objects into a series of independent two-dimensional problems, and a propagation model based on the wavenumber spectral integral representation of the Green's functions for layered media.

The Role of Three Dimension Computerized Imaging in Hand Surgery

1987 ◽  
Vol 12 (3) ◽  
pp. 349-352
Author(s):  
J. ENGEL ◽  
M. SALAI ◽  
B. YAFFE ◽  
R. TADMOR
Keyword(s):  
Three Dimensional ◽  
Hand Surgery ◽  
New Technique ◽  
Silicone Implants ◽  
Three Dimension ◽  
Two Dimensional ◽  
Radiological Imaging ◽  
Preliminary Results ◽  
Dimensional Picture

Three-dimensional computerized imaging is a new modality of radiological imaging. This new technique transforms the two-dimensional slices of bi-plane CT into a three-dimensional picture by a computer’s monitor adjusted to the system. This system enables the physician to rotate the angle of viewing of the desired region to any desired angle. Moreover, this system can delete certain features of different densities from the picture, such as silicone implants, thus improving visualization. Our preliminary results using this technique are presented. The advantages, pitfalls, and suggested future applications of this new technique in hand surgery are discussed.

Field Computation for Two-Dimensional Array Transducers with Limited Diffraction Array Beams

2005 ◽  
Vol 27 (4) ◽  
pp. 237-255 ◽  
Author(s):  
Jian-Yu Lu ◽  
Jiqi Cheng
Keyword(s):  
Continuous Wave ◽  
Weighting Function ◽  
Near Field ◽  
Bessel Beam ◽  
Two Dimensional ◽  
Axially Symmetric ◽  
Computationally Efficient ◽  
Annular Array ◽  
Array Transducer ◽  
Analytical Expressions

A method is developed for calculating fields produced with a two-dimensional (2D) array transducer. This method decomposes an arbitrary 2D aperture weighting function into a set of limited diffraction array beams. Using the analytical expressions of limited diffraction beams, arbitrary continuous wave (cw) or pulse wave (pw) fields of 2D arrays can be obtained with a simple superposition of these beams. In addition, this method can be simplified and applied to a 1D array transducer of a finite or infinite elevation height. For beams produced with axially symmetric aperture weighting functions, this method can be reduced to the Fourier-Bessel method studied previously where an annular array transducer can be used. The advantage of the method is that it is accurate and computationally efficient, especially in regions that are not far from the surface of the transducer (near field), where it is important for medical imaging. Both computer simulations and a synthetic array experiment are carried out to verify the method. Results (Bessel beam, focused Gaussian beam, X wave and asymmetric array beams) show that the method is accurate as compared to that using the Rayleigh-Sommerfeld diffraction formula and agrees well with the experiment.

Nonlinear Thermodynamics of Moving Material Surfaces in Electric Fields

1988 ◽  
Vol 43 (10) ◽  
pp. 829-846
Author(s):  
H. Wallschlager
Keyword(s):  
Electric Fields ◽  
Physical Meaning ◽  
Constitutive Equations ◽  
Practical Importance ◽  
Two Dimensional ◽  
Boundary Values ◽  
Surface Geometry ◽  
Mechanical Formalism ◽  
Material Surfaces ◽  
Nonlinear Thermodynamics

Abstract A continuum-mechanical formalism is presented for the phenomenological description of moving, curvilinear, material surfaces in electric fields in interaction with volume-phases. In addition to conventional equations (balance and constitutive laws) the explicit use of relations for the surface geometry is introduced. A method to establish nonlinear constitutive equations by tensorial and thermodynamical considerations is proved to be applicable to two-dimensional continua. The resulting equations for boundaries interacting with adjacent volumes are of practical importance for the selfconsistent calculation of boundary values. The physical meaning of the different relations is discussed.

The Role of Three-Dimension Computerized Imaging in Hand Surgery

1992 ◽  
Vol 17 (6) ◽  
pp. 702-702
Author(s):  
J. Engel ◽  
M. Salai ◽  
B. Yaffe ◽  
R. Tadmor
Keyword(s):  
Three Dimensional ◽  
Hand Surgery ◽  
New Technique ◽  
Silicone Implants ◽  
Three Dimension ◽  
Two Dimensional ◽  
Radiological Imaging ◽  
Preliminary Results ◽  
Dimensional Picture

Three-dimensional computerized imaging is a new modality of radiological imaging. This new technique transforms the two-dimensional slices of bi-plane CT into a three-dimensional picture by a computer's monitor adjusted to the system. This system enables the physician to rotate the angle of viewing of the desired region to any desired angle. Moreover, this system can delete certain features of different densities from the picture, such as silicone implants, thus improving visualization. Our preliminary results using this technique are presented. The advantages, pitfalls, and suggested future applications of this new technique in hand surgery are discussed.

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