On the formulation of rheological equations of state

1950 ◽  
Vol 200 (1063) ◽  
pp. 523-541 ◽  
Keyword(s):  
Equations Of State ◽  
Anisotropic Materials ◽  
Structural Theory ◽  
Frame Of Reference ◽  
Simple Experiment ◽  
Invariance Properties ◽  
Fixed Frame ◽  
The Right ◽  
Universal Application

The invariant forms of rheological equations of state for a homogeneous continuum, suitable for application to all conditions of motion and stress, are discussed. The right invariance properties can most readily be recognized if the frame of reference is a co-ordinate system convected with the material, but it is necessary to transform to a fixed frame of reference in order to solve the equations of state simultaneously with the equations of continuity and of motion. An illustration is given of the process of formulating equations of state suitable for universal application, based on non-invariant equations obtained from a simple experiment or structural theory. Anisotropic materials, and materials whose properties depend on previous rheological history, are included within the scope of the paper.

On the use of convected coordinate systems in the mechanics of continuous media

1951 ◽  
Vol 47 (3) ◽  
pp. 575-584 ◽  
Author(s):  
A. S. Lodge
Keyword(s):  
Coordinate System ◽  
Strain Energy ◽  
Equations Of State ◽  
Equations Of Motion ◽  
Strain Energy Function ◽  
Elastic Solid ◽  
Moving Medium ◽  
Coordinate Systems ◽  
Invariance Properties ◽  
The Right

The use of a coordinate system convected with the moving medium for describing its mechanics, first proposed by Hencky (5), has since been extended by several authors, and has several advantages over the more conventional use of a coordinate system fixed in space; Brillouin(1) has shown that the relation between the strain-energy function for an ideally elastic solid and the stress tensor takes a very simple form when the latter is referred to a convected coordinate system; Oldroyd(8) has given a very general discussion of the formulation of rheological equations of state and has shown that the right invariance properties are most readily recognized when the equations are referred to a convected coordinate system; Green and Zerna (4) have similarly expressed the equations of motion and boundary conditions; and Gleyzal (2), and Green and Shield (3) have applied the formalism to certain problems in elasticity theory.

Finite strains in an anisotropic elastic continuum

1950 ◽  
Vol 202 (1070) ◽  
pp. 345-358 ◽  
Keyword(s):  
Equations Of State ◽  
Elastic Solid ◽  
Finite Strains ◽  
Free Energy Function ◽  
Elastic Solids ◽  
Elastic Continuum ◽  
Invariance Properties ◽  
Anisotropic Elastic ◽  
Necessary And Sufficient ◽  
Thermodynamic Restrictions

The discussion in a previous paper (Oldroyd 1950), on the invariance properties required of the equations of state of a homogeneous continuum, is extended by taking into account thermodynamic restrictions on the form of the equations, in the case of an elastic solid deformed from an unstressed equilibrium configuration. The general form of the finite strainstress-temperature relations, expressed in terms of a free-energy function, is deduced without assuming that the material is isotropic. The results of other authors based on the assumption of isotropy are shown to follow as particular cases. The equations of state are derived by considering quasi-static changes in an elastic solid continuum; the results then apply to non-ideally elastic solids in equilibrium, or subjected to quasi-static changes only, and to ideally elastic solids in general motion. A necessary and sufficient compatibility condition for the finite strains at different points of a continuum is also derived. As a simple illustration of the derivation and use of equations of state involving anisotropic physical constants, the torsion of an anisotropic cylinder is discussed briefly.

Core concepts in palliative care

2021 ◽  
pp. 44-54
Author(s):  
Nathan I. Cherny ◽  
Russell K. Portenoy
Keyword(s):  
Palliative Care ◽  
Core Values ◽  
Frame Of Reference ◽  
Good Death ◽  
Clear Understanding ◽  
Life Care ◽  
Basic Principles ◽  
The Core ◽  
Core Concepts ◽  
The Right

Having a clear understanding of why we do what we do in palliative care is one of the factors that mitigates against burnout. This chapter explores some of the core values and central concepts in palliative care. The chapter focuses on underlying basic principles including, care, compassion, and empathy and how they influence the right to effective palliative care. Other less commonly addressed core concepts such as resilience, humility, audacity, and sensitivity to differences are discussed. The chapter then explores the issues around goal-focused care and how it is applied in palliative care and the contentious issues as to what constitutes a good death. It is the hope of the editors that this new contribution will provides a frame of reference that can assist clinicians as we navigate many of the challenges confronted in the delivery of palliative and end of life care.

3-D forward looking sonar with fixed frame of reference for navigation

2006 ◽  
Vol 120 (4) ◽  
pp. 1757
Author(s):  
Matthew Jason Zimmerman ◽  
James Henry Miller
Keyword(s):  
Frame Of Reference ◽  
Fixed Frame ◽  
Forward Looking

Political Science and Science Fiction

1958 ◽  
Vol 52 (4) ◽  
pp. 1026-1029 ◽  
Author(s):  
John P. Roche
Keyword(s):  
Science Fiction ◽  
Supreme Court ◽  
Political Science ◽  
Public Law ◽  
Frame Of Reference ◽  
Board Of Education ◽  
The Social ◽  
The Supreme Court ◽  
The World ◽  
The Right

I want to dissent initially from the rather constricting frame of reference that Schubert has established in his paper. He has every right in the world to set rhetorical snares, but I have no intention of walking into them. If I may summarize, Schubert asserts that he is a spokesman for a radical new direction in the study of public law, claiming that the old ways are moribund. He further urges that we should look with envy at the creative function of the social psychologists who supplied the Supreme Court with the banners it carried in Brown v. Board of Education while we were bumbling around with historical and philosophical trivia. He concludes that instead of wasting our time with talmudic disputations on whether the Supreme Court reached the “right” or the “wrong” decisions in specific cases, we should settle down to build a firm “scientific” foundation for our discipline.Not the least amusing aspect of this indictment is that I find myself billed as the defender of the ancien régime, as the de Maistre of public law. Therefore, for the benetfit of the young and impressionistic, let me break loose from Schubert's rhetorical trap: I too think that much of the research done in public law—and, for that matter, in political science generally—has been trivial.

scholarly journals Toward Improved Communication in Laparoscopic Surgery: Accounting for Multiple Frames of Reference and Mental Rotations

2005 ◽  
Vol 49 (11) ◽  
pp. 999-1003 ◽  
Author(s):  
Cristina Rivera ◽  
Caroline G.L. Cao
Keyword(s):  
Laparoscopic Surgery ◽  
Collaborative Work ◽  
Frame Of Reference ◽  
Frames Of Reference ◽  
Mental Rotations ◽  
Multiple Frames ◽  
Vantage Points ◽  
The Right ◽  
Display Control ◽  
Common Frame Of Reference

This work is an examination of barriers to communication between the attending and assisting surgeons during laparoscopic surgery, where the same image of the surgical site is viewed from different vantage points with respect to the patient. Part of the problem lies with the multiple frames of reference each surgeon holds, and the mental rotations each must perform to construct a common frame of reference for communication and collaborative work. An experiment was conducted to demonstrate the effects of display-control incongruency on the performance of an aiming task in a simulated laparoscopic environment. Aiming performance was best when the camera was oriented at 0° perspective and worsened as the angle of deviation from 0° increased. Performance was affected to a greater degree by viewing perspectives from the left of the subject than viewing perspectives from the right. Results also suggest that when surgeons are facing each other, as is the case in many laparoscopic surgeries, one surgeon's performance will be worse than the other's. The mismatched display-control perspectives are compounded by ambiguous spatial references in verbal communication. From these findings, a case can be made for the importance of vocabulary that forces a common frame of reference during laparoscopic surgery.

Two-dimensional plastic flow of a Bingham solid

1947 ◽  
Vol 43 (3) ◽  
pp. 383-395 ◽  
Author(s):  
J. G. Oldroyd
Keyword(s):  
Stress Tensor ◽  
Plastic Flow ◽  
Equations Of State ◽  
Variable Viscosity ◽  
Frame Of Reference ◽  
Two Dimensional ◽  
Tensor Form ◽  
Yield Value ◽  
Image Position ◽  
Strain Tensors

The rheological equations of state for an isotropic Bingham solid may be written in tensor form:whereThe notation is explained fully in a previous paper (1). The frame of reference is essentially Eulerian. Primes denote deviatoric components of the stress, strain and rate of strain tensors, pik, εik and eik (for example, ). The dilatation is denoted by Δ. The rigidity and bulk moduli μ and κ are, if not constants, essentially scalar functions of the stress tensor. The variable viscosity η involves two constants, the yield value ϑ and the reciprocal mobility η1.

scholarly journals How to address the Puzzle of Military Intervention into Politics in Developing Democracies by Taking Pakistan as Case Study: A Theoretical Debate

2019 ◽  
Vol IV (II) ◽  
pp. 92-104
Author(s):  
Ayaz Ali Shah ◽  
Shaukat ◽  
Hina Malik
Keyword(s):  
Military Intervention ◽  
Structural Theory ◽  
Opportunity Theory ◽  
Developing Democracies ◽  
External Threats ◽  
To Come ◽  
The Right ◽  
Civilian Leadership ◽  
The Military

This paper discusses why military intervention takes place in developing democracies by taking Pakistan as a case study with a focus on theoretical intricacies. There may be different theoretical explanations as to why the military imposes martial laws and takes the affairs of the state into their own hands. It discusses Samuel P. Huntington's Professionalism, Michael Desch's Structural Theory, based on internal and external threats and other theories of military takeover but what is found in the context of Pakistan but found Samuel Edward Finer's Disposition and Opportunity theory of military takeover more suitable. It suggests that the military in developing democracies where it has historically imposed martial laws is always ready to take over the country but wait for the right opportunity to come. And when the opportunity is presented in the shape of poor governance on the part of civilian leadership, the army makes a comeback and takes over the country.

Number-Fixed Frame of Reference

2016 ◽  
Author(s):  
M. Kizilyalli ◽  
J. Corish ◽  
R. Metselaar
Keyword(s):  
Frame Of Reference ◽  
Fixed Frame

scholarly journals Tactile-Visual Links in Exogenous Spatial Attention under Different Postures: Convergent Evidence from Psychophysics and ERPs

2001 ◽  
Vol 13 (4) ◽  
pp. 462-478 ◽  
Author(s):  
Steffan Kennett ◽  
Martin Eimer ◽  
Charles Spence ◽  
Jon Driver
Keyword(s):  
Spatial Attention ◽  
Frame Of Reference ◽  
Right Visual Field ◽  
Brain Potentials ◽  
Left Hand ◽  
Visual Events ◽  
Brain Responses ◽  
Spatial Coordinates ◽  
Tactile Cues ◽  
The Right

Tactile-visual links in spatial attention were examined by presenting spatially nonpredictive tactile cues to the left or right hand, shortly prior to visual targets in the left or right hemifield. To examine the spatial coordinates of any cross-modal links, different postures were examined. The hands were either uncrossed, or crossed so that the left hand lay in the right visual field and vice versa. Visual judgments were better on the side where the stimulated hand lay, though this effect was somewhat smaller with longer intervals between cue and target, and with crossed hands. Event-related brain potentials (ERPs) showed a similar pattern. Larger amplitude occipital N1 components were obtained for visual events on the same side as the preceding tactile cue, at ipsilateral electrode sites. Negativities in the Nd2 interval at midline and lateral central sites, and in the Nd1 interval at electrode Pz, were also enhanced for the cued side. As in the psychophysical results, ERP cueing effects during the crossed posture were determined by the side of space in which the stimulated hand lay, not by the anatomical side of the initial hemispheric projection for the tactile cue. These results demonstrate that crossmodal links in spatial attention can influence sensory brain responses as early as the N1, and that these links operate in a spatial frame-of-reference that can remap between the modalities across changes in posture.

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