Search results for: reversal-and-no-time

Time Reversal Symmetry

Author : Ion I. Geru
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This book introduces new developments in the field of Time-Reversal Symmetry presenting, for the first time, the Wigner time-reversal operator in the form of a product of two- or three time-reversal operators of lower symmetry. The action of these operators leads to the sign change of only one or two angular momentum components, not of all of them. It demonstrates that there are six modes of time-reversal symmetry breaking that do not lead to the complete disappearance of the symmetry but to its lowering. The full restoration of the time-reversal symmetry in the six cases mentioned is possible by introducing six types of metaparticles. The book also confirms the presence of six additional time-reversal operators using a group-theoretical method. The problem is only where to seek these metaparticles. The book discusses time-reversal symmetry in classical mechanics, classical and relativistic electrodynamics, quantum mechanics and theory of quantized fields, including dynamical reversibility and statistical irreversibility of the time, Wigner’s and Herring’s criteria, Kramers theorem, selection rules due to time-reversal symmetry, Onsager’s relations, Poincaré recurrence theorem, and CPT theorem. It particularly focuses attention on time-reversal symmetry violation. It is proposed a new method of testing the time-reversal symmetry, which is confirmed experimentally by EPR spectroscopy data. It shows that the traditional black-white point groups of magnetic symmetry are not applicable to magnetic systems with Kramers degeneration of energy levels and that magnetic groups of four-color symmetry are adequate for them. Further, it addresses the predicted structural distortions in Kramers three-homonuclear magnetic clusters due to time-reversal symmetry that have been identified experimentally. Lastly, it proposes a method of synthesis of two-nuclear coordination compounds with predictable magnetic properties, based on the application of the time-reversal transformation that was confirmed experimentally.

Reciprocity Spatial Mapping and Time Reversal in Electromagnetics

Author : C. Altman
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The choice of topics in this book may seem somewhat arbitrary, even though we have attempted to organize them in a logical structure. The contents reflect the path of 'search and discovery' followed by us, on and off, for the in fact last twenty years. In the winter of 1970-71 one of the authors (C. A. ), on sah baticalleave with L. R. O. Storey's research team at the Groupe de Recherches Ionospheriques at Saint-Maur in France, had been finding almost exact symme tries in the computed reflection and transmission matrices for plane-stratified magnetoplasmas when symmetrically related directions of incidence were com pared. At the suggestion of the other author (K. S. , also on leave at the same institute), the complex conjugate wave fields, used to construct the eigenmode amplitudes via the mean Poynting flux densities, were replaced by the adjoint wave fields that would propagate in a medium with transposed constitutve tensors, et voila, a scattering theorem-'reciprocity in k-space'-was found in the computer output. To prove the result analytically one had to investigate the properties of the adjoint Maxwell system, and the two independent proofs that followed, in 1975 and 1979, proceeded respectively via the matrizant method and the thin-layer scattering-matrix method for solving the scattering problem, according to the personal preferences of each of the authors. The proof given in Chap. 2 of this book, based on the hindsight provided by our later results, is simpler and much more concise.

Time Reversal Acoustics

Author : Woon Siong Gan
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This book highlights time reversal acoustics, techniques based on the symmetry properties of acoustic fields. It has the unique feature that the first eleven chapters of the book are on the indepth studies of the theories of time reversal acoustics. The remaining chapters are on the four major applications of time reversal acoustics, together with their experimental setups and case studies: underwater communication, seismic exploration,nondestructive evaluation, and medical ultrasound imaging.. The gauge invariance approach to acoustic fields, proposed by the author in 2007, is confirmed by the successful fabrication of acoustical metamaterials and the applications of time reversal acoustics to superresolution. The book also presents groundbreaking applications of time reversal acoustics to underwater communication technology and the application of metamaterials to time reversal acoustics.

Electromagnetic Time Reversal

Author : Farhad Rachidi
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The aim of this book is to familiarize the reader with the concept of electromagnetic time reversal, and introduce up-to-date applications of the concept found in the areas of electromagnetic compatibility and power systems. It is original in its approach to describing propagation and transient issues in power networks and power line communication, and is the result of the three main editors' pioneering research in the area.

Counselling Athletes Applying Reversal Theory

Author : John Kerr
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Reversal theory is an innovative psychological theory exploring human motivation, emotion and personality. This is the first book in the field to examine how reversal theory can be used by practitioners in applied sport psychology in their counselling work with athletes. Counselling Athletes explores the key elements of reversal theory, and comprehensively demonstrates how reversal theory can improve understanding in the following key areas: * athletes' motivational states when performing * athletes' motivational characteristics * identifying performance problems * athletes' experiences of stress * intervention strategies * eating disorders * exercise addiction. Each chapter includes real-life case study material from elite performers in sport, as well as guides to further reading and questions for discussion. Counselling Athletes is essential reading for all practising sport psychologists and coaches, and for any student of sport psychology.

Accurate Predictions of Mean Geomagnetic Dipole Excursion and Reversal Frequencies Mean Paleomagnetic Field Intensity and the Radius of Earth s Core Using McLeod s Rule

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Parity And Time Reversal Violation In Compound Nuclear States And Related Topics Proceedings Of The International

Author : Auerbach Naftali
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The book contains the Proceedings of the 2010 Conference of the Italian Systems Society. Papers deal with the interdisciplinary study of processes of changing related to a wide variety of specific disciplinary aspects. Classical attempts to deal with them, based on generalising approaches used to study the movement of bodies and environmental influence, have included ineffective reductionistic simplifications. Indeed changing also relates, for instance, to processes of acquisition and varying properties such as for software; growing and aging biological systems; learning/cognitive systems; and socio-economic systems growing and developing through innovations. Some approaches to modelling such processes are based on considering changes in structure, e.g., phase-transitions. Other approaches are based on considering (1) periodic changes in structure as for processes of self-organisation; (2) non-periodic but coherent changes in structure, as for processes of emergence; (3) the quantum level of description. Papers in the book study the problem considering its transdisciplinary nature, i.e., systemic properties studied per se and not within specific disciplinary contexts. The aim of these studies is to outline a transdisciplinary theory of change in systemic properties. Such a theory should have simultaneous, corresponding and eventually hierarchical disciplinary aspects as expected for a general theory of emergence. Within this transdisciplinary context, specific disciplinary research activities and results are assumed to be mutually represented as within a philosophical and conceptual framework based on the theoretical centrality of the observer and conceptual non-separability of context and observer, related to logically open systems and Quantum Entanglement. Contributions deal with such issues in interdisciplinary ways considering theoretical aspects and applications from Physics, Cognitive Science, Biology, Artificial Intelligence, Economics, Architecture, Philosophy, Music and Social Systems.

Wave Propagation and Time Reversal in Randomly Layered Media

Author : Jean-Pierre Fouque
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The content of this book is multidisciplinary by nature. It uses mathematical tools from the theories of probability and stochastic processes, partial differential equations, and asymptotic analysis, combined with the physics of wave propagation and modeling of time reversal experiments. It is addressed to a wide audience of graduate students and researchers interested in the intriguing phenomena related to waves propagating in random media. At the end of each chapter there is a section of notes where the authors give references and additional comments on the various results presented in the chapter.

The Reagan Reversal

Author : Beth A. Fischer
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It is often assumed that Ronald Reagan's administration was reactive in bringing about the end of the cold war, that it was Mikhail Gorbachev's "new thinking" and congenial personality that led the administration to abandon its hard-line approach toward Moscow. In The Reagan Reversal, Beth A. Fischer convincingly demonstrates that President Reagan actually began seeking a rapprochement with the Kremlin fifteen months before Gorbachev took office. She shows that Reagan, known for his longstanding antipathy toward communism, suddenly began calling for "dialogue, cooperation, and understanding" between the superpowers. What caused such a reversal in policy? Fischer considers three explanations for the reversal. First, she considers the possibility that the administration reversed course simply to cater to public opinion during an election year. Second, she investigates whether new personnel, namely Secretary of State George Shultz and National Security Adviser Robert McFarlane, took control of U.S. policy and made changes more in line with their personal views. Third, Fischer considers the possibility that Reagan himself redirected U.S. policy out of his fear of nuclear war. This is the explanation Fischer defends as most significant.

Progress in Reversal Theory

Author : M.J. Apter
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Reversal Theory is a new general theory of motivation, emotion, personality, psychopathology and stress which challenges previous ideas in these fields and sets up an unusually broad and integrative conceptual framework of its own. The papers in the six sections which make up this volume are concerned with: - developing the theory itself - looking at different research areas, or psychological problems, from the perspective of reversal theory - describing empirical studies of different kinds aimed at testing ideas drawn from the theory.