Singularities Interacting With a Coated Circular Inhomogeneity Revisited

2008 ◽  
Vol 75 (6) ◽  
Author(s):  
Seung Tae Choi
Keyword(s):  
Analytic Continuation ◽  
Building Block ◽  
Homogeneous Medium ◽  
Circular Inclusion ◽  
Specific Information ◽  
General Solutions ◽  
Alternating Technique ◽  
Circular Inhomogeneity

Singularities interacting with a coated circular inhomogeneity are analyzed with the method of analytic continuation and the Schwarz–Neumann’s alternating technique. It is shown that the solution for singularities in a homogeneous medium can be used as a building block of the solution for the same singularities interacting with a coated circular inclusion. The obtained solutions have series forms independent of any specific information about singularities, and thus they can be interpreted as general solutions for a variety of singularities.

Thermoelastic Interaction Between Singularities and Interfaces in an Anisotropic Trimaterial

2007 ◽  
Vol 74 (6) ◽  
pp. 1285-1288
Author(s):  
Seung Tae Choi
Keyword(s):  
Analytic Continuation ◽  
Anisotropic Medium ◽  
Dissimilar Materials ◽  
Infinite Body ◽  
Series Form ◽  
Alternating Technique ◽  
Thermoelastic Interaction ◽  
General Plane ◽  
Homogeneous Anisotropic Medium ◽  
Plane Deformations

The method of analytic continuation and Schwarz-Neumann’s alternating technique were applied to the thermoelastic interaction problems of singularities and interfaces in an anisotropic “trimaterial,” which denotes an infinite body composed of three dissimilar materials bonded along two parallel interfaces. It was assumed that the linear thermoelastic materials are under general plane deformations in which the plane of deformation is perpendicular to the planes of the two parallel interfaces. The author then showed that by alternately applying the method of analytic continuation across two parallel interfaces the solution for the thermoelastic singularities in an anisotropic trimaterial can be obtained in a series form from a solution for the same singularities in a homogeneous anisotropic medium.

Matrix Cracking in Fiber-Reinforced Composite Materials

1991 ◽  
Vol 58 (3) ◽  
pp. 846-848 ◽  
Author(s):  
H. A. Luo ◽  
Y. Chen
Keyword(s):  
Composite Materials ◽  
Volume Fraction ◽  
Matrix Material ◽  
Homogeneous Medium ◽  
Circular Inclusion ◽  
Matrix Cracking ◽  
Phase Model ◽  
Infinite Matrix ◽  
Finite Concentration ◽  
Three Phase

Matrix cracking is a major pattern of the failure of composite materials. A crack can form in the matrix during manufacturing, or be produced during loading. Erdogan, Gupta, and Ratwani (1974) first considered the interaction between an isolated circular inclusion and a line crack embedded in infinite matrix. As commented by Erdogan et al., their model is applicable to the composite materials which contain sparsely distributed inclusions. For composites filled with finite concentration of inclusions, it is commonly understood that the stress and strain fields near the crack depend considerably on the microstructure around it. One notable simplified model is the so-called three-phase model which was introduced by Christensen and Lo (1979). The three-phase model considers that in the immediate neighborhood of the inclusion there is a layer of matrix material, but at certain distance the heterogeneous medium can be substituted by a homogeneous medium with the equivalent properties of the composite. Thus, for the problems of which the interest is in the field near the inclusion, it can reasonably be accepted as a good model. The two-dimensional version of the three-phase model consists of three concentric cylindrical layers with the outer one, labeled by 3, extended to infinity. The external radii a and b of the inner and intermediate phases, labeled by 1 and 2, respectively, are related by (a/b)2 =c, where c is the volume fraction of the fiber in composite.

Circular inclusion in an infinite elastic medium with a circular inhomogeneity

1966 ◽  
Vol 62 (1) ◽  
pp. 113-127 ◽  
Author(s):  
R. D. Bhargava ◽  
O. P. Kapoor
Keyword(s):  
Fixed Point ◽  
General Problem ◽  
Complex Potential ◽  
Auxiliary Problem ◽  
Circular Inclusion ◽  
The Other ◽  
Inclusion Problem ◽  
Circular Cavity ◽  
Two Dimensional ◽  
Circular Inhomogeneity

AbstractIn a previous paper ((l)) the authors gave the solution for the two-dimensional circular inclusion problem in a medium containing a circular cavity. This paper seeks to solve the more general problem of a similar inclusion when the cavity is replaced by an inhomogeneity which could be of a different elastic material. The solution consists in finding three sets of suitable complex potential functions ø(z) and ψ(z) for three regions: the inhomogeneity, the inclusion and the rest of the material. The solution depends upon the evaluation of the complex potentials for a material containing the inhomogeneity when on the former a finite force is acting at some fixed point. It may be noted that two sets of ø(z) and ψ(z) have to be found in this case: one for the inhomogeneity and the other for the rest of the material. This may be taken as an auxiliary problem.

A Color Coded STEM/SEM Image Storage System

1981 ◽  
Vol 39 ◽  
pp. 272-273
Author(s):  
Y. Kokubo ◽  
W. H. Hardy ◽  
J. Dance ◽  
K. Jones
Keyword(s):  
Image Processing ◽  
Electron Beam ◽  
Storage System ◽  
Particle Analysis ◽  
Specific Information ◽  
X Rays ◽  
Sem Image ◽  
Backscattered Electrons ◽  
Wide Range ◽  
Scanning Electron

A color coded digital image processing is accomplished by using JEM100CX TEM SCAN and ORTEC’s LSI-11 computer based multi-channel analyzer (EEDS-II-System III) for image analysis and display. Color coding of the recorded image enables enhanced visualization of the image using mathematical techniques such as compression, gray scale expansion, gamma-processing, filtering, etc., without subjecting the sample to further electron beam irradiation once images have been stored in the memory.The powerful combination between a scanning electron microscope and computer is starting to be widely used 1) - 4) for the purpose of image processing and particle analysis. Especially, in scanning electron microscopy it is possible to get all information resulting from the interactions between the electron beam and specimen materials, by using different detectors for signals such as secondary electron, backscattered electrons, elastic scattered electrons, inelastic scattered electrons, un-scattered electrons, X-rays, etc., each of which contains specific information arising from their physical origin, study of a wide range of effects becomes possible.

Electron Microscopy in the Study of Natural Phytoplankton Assemblages

1985 ◽  
Vol 43 ◽  
pp. 620-623
Author(s):  
Linda Sicko-Goad
Keyword(s):  
Electron Microscopy ◽  
Aquatic Environment ◽  
Size Range ◽  
Physical Parameters ◽  
Specific Information ◽  
Phytoplankton Assemblages ◽  
Phytoplankton Productivity ◽  
Ecosystem Effects ◽  
Time Of Year ◽  
Species Specific

Although the use of electron microscopy and its varied methodologies is not usually associated with ecological studies, the types of species specific information that can be generated by these techniques are often quite useful in predicting long-term ecosystem effects. The utility of these techniques is especially apparent when one considers both the size range of particles found in the aquatic environment and the complexity of the phytoplankton assemblages.The size range and character of organisms found in the aquatic environment are dependent upon a variety of physical parameters that include sampling depth, location, and time of year. In the winter months, all the Laurentian Great Lakes are uniformly mixed and homothermous in the range of 1.1 to 1.7°C. During this time phytoplankton productivity is quite low.

Interindividual Differences in Cognitive Functioning Are Associated with Autobiographical Memory Retrieval Specificity in Older Adults

GeroPsych ◽  
2020 ◽  
Vol 33 (1) ◽  
pp. 15-29 ◽  
Author(s):  
Sarah Peters ◽  
Signy Sheldon
Keyword(s):  
Older Adults ◽  
Cognitive Functioning ◽  
Autobiographical Memory ◽  
Memory Retrieval ◽  
Cognitive Status ◽  
Specific Information ◽  
Generation Task ◽  
Interindividual Differences ◽  
Retrieval Cues ◽  
Contextual Support

Abstract. We examined whether interindividual differences in cognitive functioning among older adults are related to episodic memory engagement during autobiographical memory retrieval. Older adults ( n = 49, 24 males; mean age = 69.93; mean education = 15.45) with different levels of cognitive functioning, estimated using the Montreal Cognitive Assessment (MoCA), retrieved multiple memories (generation task) and the details of a single memory (elaboration task) to cues representing thematic or event-specific autobiographical knowledge. We found that the MoCA score positively predicted the proportion of specific memories for generation and episodic details for elaboration, but only to cues that represented event-specific information. The results demonstrate that individuals with healthy, but not unhealthy, cognitive status can leverage contextual support from retrieval cues to improve autobiographical specificity.

Sign in / Sign up

Export Citation Format

Share Document