Measurement of normal surface displacements for the characterization of rectangular acoustic array elements

1984 ◽  
Vol 76 (2) ◽  
pp. 516-524 ◽  
Author(s):  
R. L. Jungerman ◽  
P. Bennett ◽  
A. R. Selfridge ◽  
B. T. Khuri‐Yakub ◽  
G. S. Kino
Keyword(s):  
Normal Surface ◽  
Surface Displacements ◽  
Acoustic Array

scholarly journals The Abel map for surface singularities III: Elliptic germs

2021 ◽  
Author(s):  
János Nagy ◽  
András Némethi
Keyword(s):  
General Theory ◽  
Present Note ◽  
Affine Subspace ◽  
Normal Surface ◽  
Rational Homology ◽  
Surface Singularities ◽  
Abel Map ◽  
Appl Math ◽  
Rational Homology Sphere

AbstractThe present note is part of a series of articles targeting the theory of Abel maps associated with complex normal surface singularities with rational homology sphere links (Nagy and Némethi in Math Annal 375(3):1427–1487, 2019; Nagy and Némethi in Adv Math 371:20, 2020; Nagy and Némethi in Pure Appl Math Q 16(4):1123–1146, 2020). Besides the general theory, by the study of specific families we wish to show the power of this new method. Indeed, using the general theory of Abel maps applied for elliptic singularities in this note we are able to prove several key properties for elliptic singularities (e.g. the statements of the next paragraph), which by ‘old’ techniques were not reachable. If $$({\widetilde{X}},E)\rightarrow (X,o)$$ ( X ~ , E ) → ( X , o ) is the resolution of a complex normal surface singularity and $$c_1:{\mathrm{Pic}}({\widetilde{X}})\rightarrow H^2({\widetilde{X}},{\mathbb {Z}})$$ c 1 : Pic ( X ~ ) → H 2 ( X ~ , Z ) is the Chern class map, then $${\mathrm{Pic}}^{l'}({\widetilde{X}}):= c_1^{-1}(l')$$ Pic l ′ ( X ~ ) : = c 1 - 1 ( l ′ ) has a (Brill–Noether type) stratification $$W_{l', k}:= \{{\mathcal {L}}\in {\mathrm{Pic}}^{l'}({\widetilde{X}})\,:\, h^1({\mathcal {L}})=k\}$$ W l ′ , k : = { L ∈ Pic l ′ ( X ~ ) : h 1 ( L ) = k } . In this note we determine it for elliptic singularities together with the stratification according to the cycle of fixed components. E.g., we show that the closure of any $$W(l',k)$$ W ( l ′ , k ) is an affine subspace. For elliptic singularities we also characterize the End Curve Condition and Weak End Curve Condition in terms of the Abel map, we provide several characterization of them, and finally we show that they are equivalent.

scholarly journals Surface Displacements due to a Steadily Moving Point Force

1996 ◽  
Vol 63 (2) ◽  
pp. 245-251 ◽  
Author(s):  
J. R. Barber
Keyword(s):  
Closed Form ◽  
Half Space ◽  
Elastic Half Space ◽  
Point Force ◽  
Two Dimensional ◽  
Normal Surface ◽  
Displacement Fields ◽  
Linear Superposition ◽  
Surface Displacements ◽  
Stress And Displacement Fields

Closed-form expressions are obtained for the normal surface displacements due to a normal point force moving at constant speed over the surface of an elastic half-space. The Smirnov-Sobolev technique is used to reduce the problem to a linear superposition of two-dimensional stress and displacement fields.

Tissue printing for scanning electron microscopy and microanalysis

1993 ◽  
Vol 51 ◽  
pp. 140-141
Author(s):  
Barbara A. Reine
Keyword(s):  
Critical Point ◽  
Chemical Constituents ◽  
Plant Cells ◽  
Plant Morphology ◽  
Specimen Preparation ◽  
Normal Surface ◽  
Tissue Printing ◽  
Critical Point Drying ◽  
Scanning Electron

The study of plant morphology and plant cells in the scanning electron microscope is often compromised by the limitations of specimen preparation techniques. Simple natural dehydration usually results in unacceptable shrinkage and distortion of the normal surface morphology of plant cells. Chemical fixation followed by critical point drying or some substitute for critical point drying such as Peldri II or HMDS (hexamethyldisilazane) improves morphological results but still imparts artifacts, adds chemical constituents to the specimen, and requires the use of toxic chemicals, a hood, and much time.One technique that eliminates many of these disadvantages and is even suitable for specimen preparation in the field is tissue printing. For low magnification imaging and chemical analysis its “elegant simplicity” (2) is compelling. Historically, the application of tissue printing has been in connection with optical microscopy (1,2). However, this technique works very well for low magnification SEM and associated elemental characterization of residues by x-ray microanalysis.

A Three-Dimensional Thermomechanical Model of Contact Between Non-Conforming Rough Surfaces

2000 ◽  
Vol 123 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Shuangbiao Liu ◽  
Qian Wang
Keyword(s):  
Rough Surfaces ◽  
Frictional Heating ◽  
Three Dimensional ◽  
Point Contact ◽  
Numerical Algorithms ◽  
Normal Surface ◽  
Thermomechanical Model ◽  
Influence Coefficients ◽  
Surface Displacements ◽  
Thermomechanical Contact

A necessary step in understanding failure problems of tribological elements is to investigate the contact performance of rough surfaces subjected to frictional heating. It is essential that the interfacial variables are obtained through solving the interactive thermomechanical contact problem. This paper studies the three dimensional thermomechanical contact of non-conforming rough surfaces, the model of which includes the normal surface displacements caused by the contact pressure, frictional shear, and frictional heating. Influence coefficients and frequency response functions for elastic and thermoelastic displacements, as well as those for temperature rises, are investigated for model construction. In order to develop an accurate and efficient solver, the numerical algorithms with the discrete convolution and fast Fourier transform techniques and the single-loop conjugated gradient method are used. The model modules are numerically verified and the thermomechanical performance of the rough surfaces in a point contact is studied.

Geomechanical Characterization of Storage Reservoirs by Assimilation of Surface Displacements

2014 ◽  
Author(s):  
C. Zoccarato ◽  
A. Alzraiee ◽  
D. Baù ◽  
M. Ferronato ◽  
G. Gambolati ◽  
...  
Keyword(s):  
Surface Displacements ◽  
Storage Reservoirs ◽  
Geomechanical Characterization

Deformation of an Elastic Spherical Wedge

1966 ◽  
Vol 33 (1) ◽  
pp. 52-56 ◽  
Author(s):  
R. M. Christensen
Keyword(s):  
Mechanical Properties ◽  
Analytical Solutions ◽  
Viscoelastic Solid ◽  
Surface Displacements ◽  
Full Discussion ◽  
Mechanical Properties Characterization ◽  
Properties Characterization

Analytical solutions are presented for two separate modes of deformation of an infinite elastic spherical wedge. In part, these solutions take the form of the stresses on the boundaries of the wedge caused by prescribed surface displacements. Full discussion is given to the means of utilizing these two solutions, along with corresponding tests, to determine the complete mechanical-properties characterization of a linear isotropic viscoelastic solid.

Identification of Critical Surface Displacement Parameters for Characterization of Subsurface Flaws

2002 ◽  
Author(s):  
Paul D. Herrington ◽  
Paul J. Schilling ◽  
Melody A. Verges ◽  
Prashanth K. Durgam
Keyword(s):  
Plane Surface ◽  
Surface Displacement ◽  
Homogeneous Material ◽  
Critical Surface ◽  
Near Surface ◽  
Surface Displacements ◽  
Measuring Surface ◽  
Out Of Plane ◽  
Subsurface Geometry

Several NDE methods provide accurate techniques for measuring surface displacements. While these techniques have been successful in identification of near-surface embedded flaws, they generally offer little in terms of characterization of the flaws. The ability to characterize embedded flaws from measurements of surface displacements would offer substantial benefits, especially in terms of remaining life predictions. This paper focuses on the identification of critical out-of-plane surface displacement parameters, and assessment of the potential to characterize subsurface flaw geometry based on these parameters. Finite element models of a homogeneous material have been created that vary the embedded flaw size and edge distance. The results suggest that there is potential to characterize the subsurface geometry from the surface displacement parameters.

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