scholarly journals Viscous effects on the attenuation of a plane wave by an acoustic lining in shear flow

2017 ◽  
Vol 141 (4) ◽  
pp. 2408-2417 ◽  
Author(s):  
Doran Khamis ◽  
Edward James Brambley
Keyword(s):  
Shear Flow ◽  
Plane Wave ◽  
Viscous Effects ◽  
Acoustic Lining

Modified Tietjens Function for Asymptotic Analysis of Shear Flow Stability

1977 ◽  
Vol 99 (1) ◽  
pp. 256-258
Author(s):  
A. K. M. F. Hussain ◽  
W. C. Reynolds
Keyword(s):  
Shear Flow ◽  
Velocity Profile ◽  
Asymptotic Analysis ◽  
Shear Flows ◽  
Present Note ◽  
Normal Modes ◽  
Viscous Effects ◽  
Stability Of Shear Flows ◽  
Arbitrary Velocity

In asymptotic analysis of the hydrodynamic stability of shear flows, the viscous effects enter through the modified Tietjens Function, which is used in the graphical determination of the eigenvalues. For neutral normal modes the argument of this function is real, and values of the function have been calculated previously. For non-neutral normal modes the argument is complex; the present note gives the modified Tietjens Function for complex arguments. This function is particularly useful in investigating the behavior of lightly damped eigenmodes for shear flows of arbitrary velocity profile.

Theory and Errors in Stereo Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 336-337
Author(s):  
J. M. Pankratz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Plane Wave ◽  
Focal Length ◽  
Foil Thickness ◽  
Points Of Interest ◽  
Transmission Electron ◽  
Vertical Spacing ◽  
Illuminating System

It is often desirable in transmission electron microscopy to know the vertical spacing of points of interest within a specimen. However, in order to measure a stereo effect, one must have two pictures of the same area taken from different angles, and one must have also a formula for converting measured differences between corresponding points (parallax) into a height differential.Assume (a) that the impinging beam of electrons can be considered as a plane wave and (b) that the magnification is the same at the top and bottom of the specimen. The first assumption is good when the illuminating system is overfocused. The second assumption (the so-called “perspective error”) is good when the focal length is large (3 x 107Å) in relation to foil thickness (∼103 Å).

A hybrid Gaussian and plane wave density functional scheme

1997 ◽  
Vol 92 (3) ◽  
pp. 477-487 ◽  
Author(s):  
GERALD LIPPERT ◽  
JuRG HUTTER ◽  
MICHELE PARRINELLO
Keyword(s):  
Plane Wave ◽  
Density Functional ◽  
Functional Scheme

Evolution of the electronic structure of metallic multilayers from two to threedimensionality. A Full Potential Linearized Augmented Plane Wave calculation.

2002 ◽  
Vol 727 ◽  
Author(s):  
A. M. Mazzone
Keyword(s):  
Plane Wave ◽  
Density Of States ◽  
Noble Metals ◽  
Full Potential ◽  
Metallic Multilayers ◽  
Augmented Plane Wave ◽  
Narrow Bandwidth ◽  
Epitaxial Multilayers ◽  
Linearized Augmented Plane Wave ◽  
Wave Calculation

AbstractFull Potential Linearized Augmented Plane Wave calculations have been performed for epitaxial multilayers formed by the noble metals Ag and Cu with a thickness n up to 10 layers. The multilayers have a fcc lattice and are pure or compositionally modulated with a structure of the type Agn Cun or (AgCu)n. For n in the range 2,3 the density of states, evaluated at paramagnetic level, exhibits a sharp reduction of the bandwidth which is consistent with the reduced coordination of these structures. For n ≤ 5 the density of states in the central layers converges to the bulk value while the outer layers retain the narrow bandwidth found at n=2. Due to the absence of charge intermixing and hybridization, these features are shared by multilayers of all composition.

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