Roger D. Roger and Miles A. Whittington
- Published in print:
- 2010
- Published Online:
- May 2010
- ISBN:
- 9780195342796
- eISBN:
- 9780199776276
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195342796.003.0009
- Subject:
- Neuroscience, Molecular and Cellular Systems, Development
Gap junctions are an evolutionarily ancient form of intercellular communication, present in a variety of tissues, and essential to life. A variety of types of experimental evidence indicates that gap ...
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Gap junctions are an evolutionarily ancient form of intercellular communication, present in a variety of tissues, and essential to life. A variety of types of experimental evidence indicates that gap junctions can occur on axons, and can (at least in some circumstances) permit the spread of action potentials from cell to cell. Very fast oscillations at ~200 Hz occur in hippocampal slices in conditions where chemical synapses are blocked, but requiring gap junctions.Less
Gap junctions are an evolutionarily ancient form of intercellular communication, present in a variety of tissues, and essential to life. A variety of types of experimental evidence indicates that gap junctions can occur on axons, and can (at least in some circumstances) permit the spread of action potentials from cell to cell. Very fast oscillations at ~200 Hz occur in hippocampal slices in conditions where chemical synapses are blocked, but requiring gap junctions.
Pierre M. Adler, Jean-François Thovert, and Valeri V. Mourzenko
- Published in print:
- 2012
- Published Online:
- January 2013
- ISBN:
- 9780199666515
- eISBN:
- 9780191748639
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199666515.001.0001
- Subject:
- Physics, Condensed Matter Physics / Materials
This book aims to estimate the macroscopic properties of fractures, fracture networks and fractured porous media from easily measurable quantities. Attention is focused on geological media where ...
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This book aims to estimate the macroscopic properties of fractures, fracture networks and fractured porous media from easily measurable quantities. Attention is focused on geological media where rocks are necessarily fractured at various scales by the slow but constant motion of continental masses. This book is situated between three disciplines. First, geology and geophysics provide most of the data and most applications; a characteristic feature is that one never has a complete knowledge of the studied objects — such as an oil reservoir — in contrast with a laboratory experiment where every quantity can be measured. Second, engineering develops the main tools of analysis for one- and two-phase flows, and calculations of permeability (absolute and relative). Third, statistical physics plays a major role in concepts such as the excluded volume, dimensionless density, percolation threshold and power laws. In view of this interdisciplinary character, the general results presented in this book may have unexpected applications in many different domains. This book is based on courses which have been taught in several countries at Master and Ph.D. levels in universities, in research centers and at conferences. It should provide, in a compact form, all the necessary tools to achieve the general objective. The mathematical level in this book has been kept as low as possible. The interested reader can always go further, thanks to the references that are provided, where the mathematical level is not restricted. The colloquial aspect of a course has been preserved where one tries to explain abstract concepts in simple terms.Less
This book aims to estimate the macroscopic properties of fractures, fracture networks and fractured porous media from easily measurable quantities. Attention is focused on geological media where rocks are necessarily fractured at various scales by the slow but constant motion of continental masses. This book is situated between three disciplines. First, geology and geophysics provide most of the data and most applications; a characteristic feature is that one never has a complete knowledge of the studied objects — such as an oil reservoir — in contrast with a laboratory experiment where every quantity can be measured. Second, engineering develops the main tools of analysis for one- and two-phase flows, and calculations of permeability (absolute and relative). Third, statistical physics plays a major role in concepts such as the excluded volume, dimensionless density, percolation threshold and power laws. In view of this interdisciplinary character, the general results presented in this book may have unexpected applications in many different domains. This book is based on courses which have been taught in several countries at Master and Ph.D. levels in universities, in research centers and at conferences. It should provide, in a compact form, all the necessary tools to achieve the general objective. The mathematical level in this book has been kept as low as possible. The interested reader can always go further, thanks to the references that are provided, where the mathematical level is not restricted. The colloquial aspect of a course has been preserved where one tries to explain abstract concepts in simple terms.
Andrea Braides
- Published in print:
- 2002
- Published Online:
- September 2007
- ISBN:
- 9780198507840
- eISBN:
- 9780191709890
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198507840.003.0008
- Subject:
- Mathematics, Applied Mathematics
This chapter introduces the space of piecewise-Sobolev functions, which is the one-dimensional version of the De Giorgi-Ambrosio SBV space. Sample applications to Signal Reconstruction (the ...
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This chapter introduces the space of piecewise-Sobolev functions, which is the one-dimensional version of the De Giorgi-Ambrosio SBV space. Sample applications to Signal Reconstruction (the Mumford-Shah functional) and Fracture Mechanics (Griffith fracture energy) are given. The Ambrosio compactness theorem is proved, and the necessary conditions are given for free-discontinuity energies. Existence results are derived.Less
This chapter introduces the space of piecewise-Sobolev functions, which is the one-dimensional version of the De Giorgi-Ambrosio SBV space. Sample applications to Signal Reconstruction (the Mumford-Shah functional) and Fracture Mechanics (Griffith fracture energy) are given. The Ambrosio compactness theorem is proved, and the necessary conditions are given for free-discontinuity energies. Existence results are derived.
Andrea Braides
- Published in print:
- 2002
- Published Online:
- September 2007
- ISBN:
- 9780198507840
- eISBN:
- 9780191709890
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198507840.003.0012
- Subject:
- Mathematics, Applied Mathematics
This chapter shows how general non-convex difference schemes can give rise to functionals defined by piecewise-Sobolev functions with interactions between surface and volume terms. Different ...
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This chapter shows how general non-convex difference schemes can give rise to functionals defined by piecewise-Sobolev functions with interactions between surface and volume terms. Different identification of discrete schemes with energies on suitable piecewise-Sobolev interpolations are given, leading to a continuous limit energy. As examples, softening and fracture problems with size effects are obtained as limits of convex/concave discrete energies; fracture is described as a phase-transition phenomenon starting from Lennard-Jones potentials; and the Malik-Perona approximation of free-discontinuity problems is considered.Less
This chapter shows how general non-convex difference schemes can give rise to functionals defined by piecewise-Sobolev functions with interactions between surface and volume terms. Different identification of discrete schemes with energies on suitable piecewise-Sobolev interpolations are given, leading to a continuous limit energy. As examples, softening and fracture problems with size effects are obtained as limits of convex/concave discrete energies; fracture is described as a phase-transition phenomenon starting from Lennard-Jones potentials; and the Malik-Perona approximation of free-discontinuity problems is considered.
Robert E. Rudd
- Published in print:
- 2009
- Published Online:
- February 2010
- ISBN:
- 9780199233854
- eISBN:
- 9780191715532
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199233854.003.0005
- Subject:
- Mathematics, Applied Mathematics
Coarse-grained molecular dynamics (CGMD) is a computer modeling technique that couples conventional molecular dynamics (MD) in some spatial regions of the simulation to a more coarse-grained ...
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Coarse-grained molecular dynamics (CGMD) is a computer modeling technique that couples conventional molecular dynamics (MD) in some spatial regions of the simulation to a more coarse-grained description in others. This concurrent multiscale modeling approach allows a more efficient use of computer power as it focuses only on those degrees of freedom that are physically relevant. In the spirit of finite element modeling (FEM), the coarse-grained regions are modeled on a mesh with variable mesh size. CGMD is derived solely from the MD model, however, and has no continuum parameters. As a result, it provides a coupling that is smooth and provides control of errors that arise at the coupling between the atomistic and coarse-grained regions. In this chapter, we review the formulation of CGMD, describing how coarse graining, the systematic removal of irrelevant degrees of freedom, is accomplished for a finite temperature system. We then describe practical implementation of CGMD for large-scale simulations and some tests of validity. We conclude with an outlook on some of the directions future development may take.Less
Coarse-grained molecular dynamics (CGMD) is a computer modeling technique that couples conventional molecular dynamics (MD) in some spatial regions of the simulation to a more coarse-grained description in others. This concurrent multiscale modeling approach allows a more efficient use of computer power as it focuses only on those degrees of freedom that are physically relevant. In the spirit of finite element modeling (FEM), the coarse-grained regions are modeled on a mesh with variable mesh size. CGMD is derived solely from the MD model, however, and has no continuum parameters. As a result, it provides a coupling that is smooth and provides control of errors that arise at the coupling between the atomistic and coarse-grained regions. In this chapter, we review the formulation of CGMD, describing how coarse graining, the systematic removal of irrelevant degrees of freedom, is accomplished for a finite temperature system. We then describe practical implementation of CGMD for large-scale simulations and some tests of validity. We conclude with an outlook on some of the directions future development may take.
Nasr Ghoniem and Daniel Walgraef
- Published in print:
- 2008
- Published Online:
- May 2008
- ISBN:
- 9780199298686
- eISBN:
- 9780191720222
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199298686.001.0001
- Subject:
- Physics, Condensed Matter Physics / Materials
In materials, critical phenomena such as phase transitions, plastic deformation and fracture are intimately related to self-organization. Understanding the origin of spatio-temporal order in systems ...
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In materials, critical phenomena such as phase transitions, plastic deformation and fracture are intimately related to self-organization. Understanding the origin of spatio-temporal order in systems far from thermal equilibrium and the selection mechanisms of spatial structures and their symmetries is a major theme of present day research on the structure of continuous matter. Furthermore, the development of methods for producing spatially-ordered and self-assembled microstructure in solids by non-equilibrium methods opens the door to many technological applications. In order to describe and understand the behaviour of such materials, dynamical concepts related to non-equilibrium phenomena, irreversible thermodynamics, nonlinear dynamics, and bifurcation theory, are required. The generic presence of defects and their crucial influence on pattern formation and critical phenomena in extended systems is now well-established. Similar to observations in hydrodynamical, liquid crystal, and laser systems, defects in materials have a profound effect. This book is divided into two volumes. The first volume is devoted to the most basic concepts of the physics, mechanics, and mathematical theory utilized in the analysis of non-equilibrium materials. The book presents a background on material deformation, defect theory, transport processes, and the statistical mechanics and thermodynamics of phase transitions. Mathematical concepts of non-linear dynamics, such as bifurcation and instability theory, the dynamics of complex systems near pattern forming instabilities, the generic aspects of pattern formation, selection and stability are presented. Stochastic and numerical methods used in this field are also introduced. The methods and techniques developed in the first volume are applied in the second volume to specific problems in various advanced technologies.Less
In materials, critical phenomena such as phase transitions, plastic deformation and fracture are intimately related to self-organization. Understanding the origin of spatio-temporal order in systems far from thermal equilibrium and the selection mechanisms of spatial structures and their symmetries is a major theme of present day research on the structure of continuous matter. Furthermore, the development of methods for producing spatially-ordered and self-assembled microstructure in solids by non-equilibrium methods opens the door to many technological applications. In order to describe and understand the behaviour of such materials, dynamical concepts related to non-equilibrium phenomena, irreversible thermodynamics, nonlinear dynamics, and bifurcation theory, are required. The generic presence of defects and their crucial influence on pattern formation and critical phenomena in extended systems is now well-established. Similar to observations in hydrodynamical, liquid crystal, and laser systems, defects in materials have a profound effect. This book is divided into two volumes. The first volume is devoted to the most basic concepts of the physics, mechanics, and mathematical theory utilized in the analysis of non-equilibrium materials. The book presents a background on material deformation, defect theory, transport processes, and the statistical mechanics and thermodynamics of phase transitions. Mathematical concepts of non-linear dynamics, such as bifurcation and instability theory, the dynamics of complex systems near pattern forming instabilities, the generic aspects of pattern formation, selection and stability are presented. Stochastic and numerical methods used in this field are also introduced. The methods and techniques developed in the first volume are applied in the second volume to specific problems in various advanced technologies.
J. S. Langer
- Published in print:
- 2004
- Published Online:
- September 2007
- ISBN:
- 9780198528531
- eISBN:
- 9780191713415
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198528531.003.0028
- Subject:
- Physics, Theoretical, Computational, and Statistical Physics
Sam Edwards has very successfully brought new insights and methods of theoretical study to many areas of condensed matter physics where clear quantitative formation did not earlier exist. This ...
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Sam Edwards has very successfully brought new insights and methods of theoretical study to many areas of condensed matter physics where clear quantitative formation did not earlier exist. This chapter argues the case for an Edwardsian approach to the theory of solid mechanics and fracture.Less
Sam Edwards has very successfully brought new insights and methods of theoretical study to many areas of condensed matter physics where clear quantitative formation did not earlier exist. This chapter argues the case for an Edwardsian approach to the theory of solid mechanics and fracture.
Rosemary Foot
- Published in print:
- 2000
- Published Online:
- November 2003
- ISBN:
- 9780198297765
- eISBN:
- 9780191599279
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/0198297769.003.0007
- Subject:
- Political Science, International Relations and Politics
Over the period 1995–1998, China's main objectives in the human rights area was to shift the venue of the discursive debate on its record away from a public, multilateral forum in which China was ...
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Over the period 1995–1998, China's main objectives in the human rights area was to shift the venue of the discursive debate on its record away from a public, multilateral forum in which China was placed under critical scrutiny, to a private dialogue that symbolized a more equal exchange of views on such questions. Beijing also attempted to constrain the operations of the UN Commission, its Special Rapporteurs and Working Groups, by stressing their failure to deal with lapses in the protection of economic, social, and cultural rights, and their overweening focus on developing country behaviour; it also alleged that the Commission's approach was unacceptably confrontational and unlikely to reach the targets that it set itself. Possibly in response to this critique, new UN Special Rapporteurs were created and the High Commissioner for Human Rights deemed it necessary to give more priority to the right to development. In the course of moving towards bilateral dialogues, it became apparent that there were areas of softness in some governments’ commitment to the universalism of human rights and that ambiguities inherent in the language surrounding these rights could be exploited, suggesting considerable room for manoeuvre within the international human rights regime when it came to verbal compliance. Here Chinese leaders played their hand carefully and with considerable skill, timing statements, agreements, and releases to coincide with debate at the UN Commission, thus breaking apart the coalition of governments that had been working together. Nevertheless, Beijing did see the need to sign the International Covenant on Economic, Social, and Cultural Rights (ICESCR) to ward off some of the criticism and ensure a productive summit in the USA between President Jiang Zemin and President Bill Clinton. China's success in persuading some Western leaders to adopt particular features of the cultural relativist–developmentalist rhetoric in joint statements can be explained by economic and strategic interests of these governments, together with a more generalized EU belief that it had to raise its profile in China, while other states found convincing Chinese official arguments that it was deserving of special consideration. The different sections of the chapter are: The Fracturing of the UN Coalition; The Resurgence of Bilateralism; The Clinton–Jiang Summit; The UN's Thematic Mechanisms; and Conclusion.Less
Over the period 1995–1998, China's main objectives in the human rights area was to shift the venue of the discursive debate on its record away from a public, multilateral forum in which China was placed under critical scrutiny, to a private dialogue that symbolized a more equal exchange of views on such questions. Beijing also attempted to constrain the operations of the UN Commission, its Special Rapporteurs and Working Groups, by stressing their failure to deal with lapses in the protection of economic, social, and cultural rights, and their overweening focus on developing country behaviour; it also alleged that the Commission's approach was unacceptably confrontational and unlikely to reach the targets that it set itself. Possibly in response to this critique, new UN Special Rapporteurs were created and the High Commissioner for Human Rights deemed it necessary to give more priority to the right to development. In the course of moving towards bilateral dialogues, it became apparent that there were areas of softness in some governments’ commitment to the universalism of human rights and that ambiguities inherent in the language surrounding these rights could be exploited, suggesting considerable room for manoeuvre within the international human rights regime when it came to verbal compliance. Here Chinese leaders played their hand carefully and with considerable skill, timing statements, agreements, and releases to coincide with debate at the UN Commission, thus breaking apart the coalition of governments that had been working together. Nevertheless, Beijing did see the need to sign the International Covenant on Economic, Social, and Cultural Rights (ICESCR) to ward off some of the criticism and ensure a productive summit in the USA between President Jiang Zemin and President Bill Clinton. China's success in persuading some Western leaders to adopt particular features of the cultural relativist–developmentalist rhetoric in joint statements can be explained by economic and strategic interests of these governments, together with a more generalized EU belief that it had to raise its profile in China, while other states found convincing Chinese official arguments that it was deserving of special consideration. The different sections of the chapter are: The Fracturing of the UN Coalition; The Resurgence of Bilateralism; The Clinton–Jiang Summit; The UN's Thematic Mechanisms; and Conclusion.
Elizabeth Weiss
- Published in print:
- 2017
- Published Online:
- May 2018
- ISBN:
- 9780813054988
- eISBN:
- 9780813053707
- Item type:
- book
- Publisher:
- University Press of Florida
- DOI:
- 10.5744/florida/9780813054988.001.0001
- Subject:
- Archaeology, Archaeological Methodology and Techniques
Do skeletal indicators used to reconstruct past people’s activity patterns actually reflect biological differences? This book reviews the literature on the most commonly utilized activity pattern ...
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Do skeletal indicators used to reconstruct past people’s activity patterns actually reflect biological differences? This book reviews the literature on the most commonly utilized activity pattern indicators in bioarchaeology to answer this genes versus environment question. Chapter 2, for example, focuses on cross-sectional geometries, which have been used to look at mobility, and asks whether these measures of bone may also be influenced by climate-driven body shape adaptions. Chapters 3 and 4 look at entheseal changes, which are locations of muscle attachments, and osteoarthritis, which is also known as degenerative joint disease, to determine whether these features can be applied by bioarchaeologists to reconstruct activity patterns, especially when one considers that the best predictors for these features is age. Stress fractures (such as spondylolysis), which are covered in chapter 5, and activity indicator facets (such as kneeling facets), which are discussed in chapter 6, are more likely related to anatomical variation and other hereditary factors than activities previously linked to these skeletal features. After looking at all the evidence, which comes from research by bioarchaeologists, medical and sports studies, experimental animal research, genetic twin studies, and occupational studies on the living and the deceased, it appears that not all skeletal activity indicators will prove fruitful when reconstructing past people’s activity patterns.Less
Do skeletal indicators used to reconstruct past people’s activity patterns actually reflect biological differences? This book reviews the literature on the most commonly utilized activity pattern indicators in bioarchaeology to answer this genes versus environment question. Chapter 2, for example, focuses on cross-sectional geometries, which have been used to look at mobility, and asks whether these measures of bone may also be influenced by climate-driven body shape adaptions. Chapters 3 and 4 look at entheseal changes, which are locations of muscle attachments, and osteoarthritis, which is also known as degenerative joint disease, to determine whether these features can be applied by bioarchaeologists to reconstruct activity patterns, especially when one considers that the best predictors for these features is age. Stress fractures (such as spondylolysis), which are covered in chapter 5, and activity indicator facets (such as kneeling facets), which are discussed in chapter 6, are more likely related to anatomical variation and other hereditary factors than activities previously linked to these skeletal features. After looking at all the evidence, which comes from research by bioarchaeologists, medical and sports studies, experimental animal research, genetic twin studies, and occupational studies on the living and the deceased, it appears that not all skeletal activity indicators will prove fruitful when reconstructing past people’s activity patterns.
Pierre M. Adler, Jean-François Thovert, and Valeri V. Mourzenko
- Published in print:
- 2012
- Published Online:
- January 2013
- ISBN:
- 9780199666515
- eISBN:
- 9780191748639
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199666515.003.0001
- Subject:
- Physics, Condensed Matter Physics / Materials
This chapter details the point of view adopted by this book which is based on a course. For pedagogical purposes, the bulk of this book deals with the isotropically oriented and uniformly distributed ...
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This chapter details the point of view adopted by this book which is based on a course. For pedagogical purposes, the bulk of this book deals with the isotropically oriented and uniformly distributed networks of fractures; in addition, the fractures are supposed to be of the same size. The corresponding developments are accessible with a relatively low mathematical level. But, most real fracture networks are obviously different! Therefore, most chapters end with a section called ‘Extensions’ which is devoted to more complex and more recent developments and which can be skipped by the beginner. Short exercises propose systematic applications of the major concepts and results right after their introduction. Some general terminology about fractures, fracture networks and fractured porous media is presented. The basic concept of permeability is defined in simple terms. Finally, the scientific topics which are addressed in the successive chapters, are detailed.Less
This chapter details the point of view adopted by this book which is based on a course. For pedagogical purposes, the bulk of this book deals with the isotropically oriented and uniformly distributed networks of fractures; in addition, the fractures are supposed to be of the same size. The corresponding developments are accessible with a relatively low mathematical level. But, most real fracture networks are obviously different! Therefore, most chapters end with a section called ‘Extensions’ which is devoted to more complex and more recent developments and which can be skipped by the beginner. Short exercises propose systematic applications of the major concepts and results right after their introduction. Some general terminology about fractures, fracture networks and fractured porous media is presented. The basic concept of permeability is defined in simple terms. Finally, the scientific topics which are addressed in the successive chapters, are detailed.
Derek Doyle, David Jeffrey, and Kenneth Calman
- Published in print:
- 2000
- Published Online:
- November 2011
- ISBN:
- 9780192632272
- eISBN:
- 9780191730245
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780192632272.003.0006
- Subject:
- Palliative Care, Patient Care and End-of-Life Decision Making, Pain Management and Palliative Pharmacology
Palliative care, in an ideal sense, should be proactive. It should be able to anticipate problems and take the necessary action to prevent them if possible. However, there are instances in palliative ...
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Palliative care, in an ideal sense, should be proactive. It should be able to anticipate problems and take the necessary action to prevent them if possible. However, there are instances in palliative care when crises and genuine emergencies develop. Like any other medical emergency, failure to act instantly and appropriately can result to tragedy and disaster. It can also leave the relatives with sadder memories, often coloured with anger and surprise because of the sense and perception of negligence and inattention on the part of the physician. This chapter describes the most common emergencies encountered when providing palliative care at home. Such emergencies are spinal cord compression (SCC), superior vena caval obstrauction (SVCO), convulsions, haemorrhage, acute hypercalcaemia, acute urinary retention, pathological fractures, acute intestinal obstruction, and acute panic attacks.Less
Palliative care, in an ideal sense, should be proactive. It should be able to anticipate problems and take the necessary action to prevent them if possible. However, there are instances in palliative care when crises and genuine emergencies develop. Like any other medical emergency, failure to act instantly and appropriately can result to tragedy and disaster. It can also leave the relatives with sadder memories, often coloured with anger and surprise because of the sense and perception of negligence and inattention on the part of the physician. This chapter describes the most common emergencies encountered when providing palliative care at home. Such emergencies are spinal cord compression (SCC), superior vena caval obstrauction (SVCO), convulsions, haemorrhage, acute hypercalcaemia, acute urinary retention, pathological fractures, acute intestinal obstruction, and acute panic attacks.
Richard M. Christensen
- Published in print:
- 2013
- Published Online:
- May 2013
- ISBN:
- 9780199662111
- eISBN:
- 9780191748387
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199662111.001.0001
- Subject:
- Physics, Condensed Matter Physics / Materials
This book provides a complete and comprehensive development of failure theory for homogeneous materials. The resultant failure criteria to be used for applications with isotropic materials are ...
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This book provides a complete and comprehensive development of failure theory for homogeneous materials. The resultant failure criteria to be used for applications with isotropic materials are calibrated by only two properties: the uniaxial tensile and compressive strengths, T and C. From these data the entire family of failure envelopes can be generated for all states of stress. The account begins with a historical survey that includes the efforts of many of history’s greatest scientists. The complete inadequacy for general applications of all the historical forms are detailed. The center point of the book is the derivation of the failure theory for isotropic materials. The new and enabling technical insight is that of an organizing principle whereby the entire spectrum of isotropic materials types can be characterized by their strengths ratio, T/C, with stress being non-dimensionalized by C. Two coordinated but competitive failure criteria then emerge. One of several unique features of the book is a full and complete treatment of ductile versus brittle behavior for isotropic materials. Along with the experimental evaluation of the failure theory, many examples of failure behavior and applications are presented. The relationship to fracture mechanics is also included. The overall coverage is very broad, but with no compromise in quality or rigor. Reasonably extensive treatments are given for fiber composites failure as well as investigations into microscale and nanoscale aspects of failure. The book is completed with a probe into damage models and a fairly complete derivation of probabilistic failure and life prediction.Less
This book provides a complete and comprehensive development of failure theory for homogeneous materials. The resultant failure criteria to be used for applications with isotropic materials are calibrated by only two properties: the uniaxial tensile and compressive strengths, T and C. From these data the entire family of failure envelopes can be generated for all states of stress. The account begins with a historical survey that includes the efforts of many of history’s greatest scientists. The complete inadequacy for general applications of all the historical forms are detailed. The center point of the book is the derivation of the failure theory for isotropic materials. The new and enabling technical insight is that of an organizing principle whereby the entire spectrum of isotropic materials types can be characterized by their strengths ratio, T/C, with stress being non-dimensionalized by C. Two coordinated but competitive failure criteria then emerge. One of several unique features of the book is a full and complete treatment of ductile versus brittle behavior for isotropic materials. Along with the experimental evaluation of the failure theory, many examples of failure behavior and applications are presented. The relationship to fracture mechanics is also included. The overall coverage is very broad, but with no compromise in quality or rigor. Reasonably extensive treatments are given for fiber composites failure as well as investigations into microscale and nanoscale aspects of failure. The book is completed with a probe into damage models and a fairly complete derivation of probabilistic failure and life prediction.
G. A. D. Briggs and O. V. Kolosov
- Published in print:
- 2009
- Published Online:
- February 2010
- ISBN:
- 9780199232734
- eISBN:
- 9780191716355
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199232734.003.0012
- Subject:
- Physics, Condensed Matter Physics / Materials
Surface cracks and boundaries give contrast in acoustic microscopy even when they are so fine that by conventional resolution criteria they would be expected to be scarcely visible. The contrast ...
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Surface cracks and boundaries give contrast in acoustic microscopy even when they are so fine that by conventional resolution criteria they would be expected to be scarcely visible. The contrast arises from the scattering of Rayleigh waves, and the evidence for this is the tell‐tale presence of fringes parallel to cracks, with spacing equal to half a Rayleigh wavelength. Contrast theory based on separating the specular and Rayleigh components of the signal give a good account of the fringes which are observed. Time‐resolved measurements can be made of crack‐tip diffracted signals. The remarkable contrast from cracks is useful in the study of indentation and fracture of low‐ductility materials.Less
Surface cracks and boundaries give contrast in acoustic microscopy even when they are so fine that by conventional resolution criteria they would be expected to be scarcely visible. The contrast arises from the scattering of Rayleigh waves, and the evidence for this is the tell‐tale presence of fringes parallel to cracks, with spacing equal to half a Rayleigh wavelength. Contrast theory based on separating the specular and Rayleigh components of the signal give a good account of the fringes which are observed. Time‐resolved measurements can be made of crack‐tip diffracted signals. The remarkable contrast from cracks is useful in the study of indentation and fracture of low‐ductility materials.
Aihwa Ong
- Published in print:
- 2003
- Published Online:
- March 2012
- ISBN:
- 9780520229983
- eISBN:
- 9780520937161
- Item type:
- chapter
- Publisher:
- University of California Press
- DOI:
- 10.1525/california/9780520229983.003.0007
- Subject:
- Sociology, Migration Studies (including Refugee Studies)
This chapter discusses the effects of the gender and racial fracturing and introduces the concept of refugee love. This is an attitude and set of practices that can be traced to the paternalism of ...
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This chapter discusses the effects of the gender and racial fracturing and introduces the concept of refugee love. This is an attitude and set of practices that can be traced to the paternalism of plantation owners toward their slaves, the “benevolent assimilation” of Pacific conquest, and the compassionate domination that is modeled by Christianity. The chapter shows that these practices were aimed at saving refugee women and their children from the patriarchy in Asia and these practices also were often found in feminism-inspired social workers. In the case of the Cambodian refugees however, these practices were partially undermined by their motivations. This chapter concludes that while refugee women did try to free themselves from certain aspects of domestic patriarchy, they accepted some of what was offered and rejected the rest.Less
This chapter discusses the effects of the gender and racial fracturing and introduces the concept of refugee love. This is an attitude and set of practices that can be traced to the paternalism of plantation owners toward their slaves, the “benevolent assimilation” of Pacific conquest, and the compassionate domination that is modeled by Christianity. The chapter shows that these practices were aimed at saving refugee women and their children from the patriarchy in Asia and these practices also were often found in feminism-inspired social workers. In the case of the Cambodian refugees however, these practices were partially undermined by their motivations. This chapter concludes that while refugee women did try to free themselves from certain aspects of domestic patriarchy, they accepted some of what was offered and rejected the rest.
Lallit Anand and Sanjay Govindjee
- Published in print:
- 2020
- Published Online:
- September 2020
- ISBN:
- 9780198864721
- eISBN:
- 9780191896767
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198864721.003.0026
- Subject:
- Physics, Condensed Matter Physics / Materials
This chapter introduces the basics of linear elastic fracture mechanics. It starts by recalling the asymptotic elastic crack tip solutions and the concept of stress intensity factors for Mode-I, ...
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This chapter introduces the basics of linear elastic fracture mechanics. It starts by recalling the asymptotic elastic crack tip solutions and the concept of stress intensity factors for Mode-I, Mode-II, and Mode-III loading. The concept of critical stress intensity factor is next introduced as a model for fracture under small scale yielding conditions. In this context the limits of linear elastic facture mechanics are discussed. Further, methods and requirements for fracture toughness testing are discussed.Less
This chapter introduces the basics of linear elastic fracture mechanics. It starts by recalling the asymptotic elastic crack tip solutions and the concept of stress intensity factors for Mode-I, Mode-II, and Mode-III loading. The concept of critical stress intensity factor is next introduced as a model for fracture under small scale yielding conditions. In this context the limits of linear elastic facture mechanics are discussed. Further, methods and requirements for fracture toughness testing are discussed.
K. B. E. E. Eimeleus
- Published in print:
- 2019
- Published Online:
- May 2020
- ISBN:
- 9781501747403
- eISBN:
- 9781501747427
- Item type:
- chapter
- Publisher:
- Cornell University Press
- DOI:
- 10.7591/cornell/9781501747403.003.0008
- Subject:
- History, Russian and Former Soviet Union History
This chapter shows how to repair skis, especially during emergency situations. Lately, modern and complex ski-binding systems frequently sustain damage. Broken binding straps, especially if they are ...
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This chapter shows how to repair skis, especially during emergency situations. Lately, modern and complex ski-binding systems frequently sustain damage. Broken binding straps, especially if they are wet, are impossible to tie with the usual knot. A single knife does not suffice anymore, hence requiring the use of a greater number of tools in order to avoid that damages to skis or their accessories. The chapter shows various methods for mending ski fractures in different sections. However, the chapter also warns that these repairs cannot fully restore a broken ski's original beauty and durability. They can also cause an increase in friction. In such instances, the chapter recommends having skis mended professionally rather than having them replaced.Less
This chapter shows how to repair skis, especially during emergency situations. Lately, modern and complex ski-binding systems frequently sustain damage. Broken binding straps, especially if they are wet, are impossible to tie with the usual knot. A single knife does not suffice anymore, hence requiring the use of a greater number of tools in order to avoid that damages to skis or their accessories. The chapter shows various methods for mending ski fractures in different sections. However, the chapter also warns that these repairs cannot fully restore a broken ski's original beauty and durability. They can also cause an increase in friction. In such instances, the chapter recommends having skis mended professionally rather than having them replaced.
Victor F. Petrenko and Robert W. Whitworth
- Published in print:
- 2002
- Published Online:
- February 2010
- ISBN:
- 9780198518945
- eISBN:
- 9780191707247
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198518945.003.0008
- Subject:
- Physics, Crystallography: Physics
Ice is a material that exhibits both ductile flow, as in the flow of a glacier, and also brittle fracture, as in the crushing of ice under impact from an icebreaker. This chapter considers ...
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Ice is a material that exhibits both ductile flow, as in the flow of a glacier, and also brittle fracture, as in the crushing of ice under impact from an icebreaker. This chapter considers laboratory-scale experiments on the deformation of single crystals and of polycrystalline ice and their interpretation. Creep of single crystals occurs by the glide and multiplication of dislocations on the basal plane and is thus highly anisotropic. In polycrystalline specimens deformed under constant load the creep accelerates, reaches a steady state and finally accelerates again. The deformation of individual grains is confined by those around them, and large stresses build up which may be relieved by diffusion or by cracking. The theory of fracture involves both the nucleation of cracks and their propagation.Less
Ice is a material that exhibits both ductile flow, as in the flow of a glacier, and also brittle fracture, as in the crushing of ice under impact from an icebreaker. This chapter considers laboratory-scale experiments on the deformation of single crystals and of polycrystalline ice and their interpretation. Creep of single crystals occurs by the glide and multiplication of dislocations on the basal plane and is thus highly anisotropic. In polycrystalline specimens deformed under constant load the creep accelerates, reaches a steady state and finally accelerates again. The deformation of individual grains is confined by those around them, and large stresses build up which may be relieved by diffusion or by cracking. The theory of fracture involves both the nucleation of cracks and their propagation.
Lallit Anand and Sanjay Govindjee
- Published in print:
- 2020
- Published Online:
- September 2020
- ISBN:
- 9780198864721
- eISBN:
- 9780191896767
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198864721.001.0001
- Subject:
- Physics, Condensed Matter Physics / Materials
Continuum mechanics of Solids presents a unified treatment of the major concepts in Solid Mechanics for beginning graduate students in the many branches of engineering. The fundamental topics of ...
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Continuum mechanics of Solids presents a unified treatment of the major concepts in Solid Mechanics for beginning graduate students in the many branches of engineering. The fundamental topics of kinematics in finite and infinitesimal deformation, mechanical and thermodynamic balances plus entropy imbalance in the small strain setting are covered as they apply to all solids. The major material models of Elasticity, Viscoelasticity, and Plasticity are detailed and models for Fracture and Fatigue are discussed. In addition to these topics in Solid Mechanics, because of the growing need for engineering students to have a knowledge of the coupled multi-physics response of materials in modern technologies related to the environment and energy, the book also includes chapters on Thermoelasticity, Chemoelasticity, Poroelasticity, and Piezoelectricity. A preview to the theory of finite elasticity and elastomeric materials is also given. Throughout, example computations are presented to highlight how the developed theories may be applied.Less
Continuum mechanics of Solids presents a unified treatment of the major concepts in Solid Mechanics for beginning graduate students in the many branches of engineering. The fundamental topics of kinematics in finite and infinitesimal deformation, mechanical and thermodynamic balances plus entropy imbalance in the small strain setting are covered as they apply to all solids. The major material models of Elasticity, Viscoelasticity, and Plasticity are detailed and models for Fracture and Fatigue are discussed. In addition to these topics in Solid Mechanics, because of the growing need for engineering students to have a knowledge of the coupled multi-physics response of materials in modern technologies related to the environment and energy, the book also includes chapters on Thermoelasticity, Chemoelasticity, Poroelasticity, and Piezoelectricity. A preview to the theory of finite elasticity and elastomeric materials is also given. Throughout, example computations are presented to highlight how the developed theories may be applied.
Pierre M. Adler, Jean-François Thovert, and Valeri V. Mourzenko
- Published in print:
- 2012
- Published Online:
- January 2013
- ISBN:
- 9780199666515
- eISBN:
- 9780191748639
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199666515.003.0005
- Subject:
- Physics, Condensed Matter Physics / Materials
This chapter is devoted to the permeability of fracture networks. The general equations and boundary conditions which apply to networks are given. The flow inside each fracture is described by a two ...
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This chapter is devoted to the permeability of fracture networks. The general equations and boundary conditions which apply to networks are given. The flow inside each fracture is described by a two dimensional Darcy equation. The Snow equation which is valid for infinite fractures is derived. Then, the meshing of one fracture is described when the intersections with the other fractures are taken into account. The discretization of the local equations and of the boundary conditions is made by the familiar finite volume technique. The numerical tools are first applied to isotropically and uniformly distributed networks of monodisperse fractures. The most important result is that when expressed in terms of the dimensionless density, permeability depends only very slightly on the fracture shape when it is convex. The chapter ends with a survey of the major extensions of this result to other kinds of fracture networks.Less
This chapter is devoted to the permeability of fracture networks. The general equations and boundary conditions which apply to networks are given. The flow inside each fracture is described by a two dimensional Darcy equation. The Snow equation which is valid for infinite fractures is derived. Then, the meshing of one fracture is described when the intersections with the other fractures are taken into account. The discretization of the local equations and of the boundary conditions is made by the familiar finite volume technique. The numerical tools are first applied to isotropically and uniformly distributed networks of monodisperse fractures. The most important result is that when expressed in terms of the dimensionless density, permeability depends only very slightly on the fracture shape when it is convex. The chapter ends with a survey of the major extensions of this result to other kinds of fracture networks.
Pierre M. Adler, Jean-François Thovert, and Valeri V. Mourzenko
- Published in print:
- 2012
- Published Online:
- January 2013
- ISBN:
- 9780199666515
- eISBN:
- 9780191748639
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199666515.003.0006
- Subject:
- Physics, Condensed Matter Physics / Materials
This chapter extends Chapter 5 to fractured porous media and its structure is basically the same, namely a general section with the governing Darcy equations, the meshing of the solid porous matrix ...
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This chapter extends Chapter 5 to fractured porous media and its structure is basically the same, namely a general section with the governing Darcy equations, the meshing of the solid porous matrix located in between the fractures, the discretization, the applications to isotropically and uniformly distributed networks of monodisperse fractures and the extensions. The major difficulty in these studies is the meshing of the three dimensional solid matrix and it was quite difficult to obtain a numerical program which worked correctly and efficiently. Again the dimensionless density is shown to play an essential role in macroscopic permeability and it is used systematically to rationalize the results. Extensions are presented for networks with power law size distributions and for slightly compressible fluids.Less
This chapter extends Chapter 5 to fractured porous media and its structure is basically the same, namely a general section with the governing Darcy equations, the meshing of the solid porous matrix located in between the fractures, the discretization, the applications to isotropically and uniformly distributed networks of monodisperse fractures and the extensions. The major difficulty in these studies is the meshing of the three dimensional solid matrix and it was quite difficult to obtain a numerical program which worked correctly and efficiently. Again the dimensionless density is shown to play an essential role in macroscopic permeability and it is used systematically to rationalize the results. Extensions are presented for networks with power law size distributions and for slightly compressible fluids.
