bluuebunny/crossref_metadata_2025 huggingface dataset:
Research methods in detecting deception research
Authors: Frank Mark G
Published: November 2023

The methodology involved in nonverbal deception research has recently come under scrutiny due to the importance of catching liars in real-world counter-terrorism efforts. This chapter will examine the pros and cons associated with the design of a deception scenario, particularly in terms of ecological validity, the execution of the scenario, as well as later judge and behavioral scoring studies.
Weak Solutions For Steady Navier–Stokes Equations Of Compressible Barotropic Flow
Authors: Novotný A , Straškraba I
Published: November 2023

This chapter is devoted to the weak solvability of steady compressible Navier– Stokes equations in the barotropic regime in different geometrical situations. After the formulation of the problem and the main statements for bounded and exterior domains in the first section, we explain, in the second section, the main ideas of the proof, and in the third section, the way the original system is approximated. In Section 4.4 we investigate weak compactness of the effective viscous flux which is the main tool of the proofs.
Global Behavior Of Weak Solutions
Authors: Novotný A , Straškraba I
Published: November 2023

In this chapter the asymptotic behavior of weak solutions to problem (7.1.1), (7.1.2), (7.1.3), (7.1.5), (7.1.6), (7.1.7), as time tends to infinity will be investigated. The solution will be supposed to have the regularity as in Theorem 7.7. The corresponding theorem on asymptotic behavior (Theorem 8.1 below) will be formulated for a general pressure law p = p(ρ) satisfying a certain growth condition. The hypotheses are formulated so that we have generic coincidence of hypotheses assumed in known existence theorems and those assumed here. This allows us to have both the existence of a solution and its asymptotic behavior, unconditionally. For a discussion of the existence for general pressure laws (i.e. not necessarily γ-law p(ρ) = Cργ) see Sections 7.12.1.2 and 7.12.3.
Strong Solutions Of Nonsteady Compressible Navier–Stokes Equations
Authors: Novotný A , Straškraba I
Published: November 2023

In this chapter we prove a version of the global existence theorem for compressible Navier–Stokes equations assuming the initial data sufficiently small in suitable norms. We choose the equations of viscous barotropic flow (see Section 1.2.18) in three space dimensions as a relatively simple illustrative example rather than equations including temperature as is the case in the pioneering papers (Matsumura and Nishida, 1979) and (Matsumura and Nishida, 1980); cf. also (Valli, 1983). For many other versions we refer the reader to references given in comments at the end of this chapter (see Section 9.10).
Vassiliev Invariants and the Loop States in Quantum Gravity
Authors: Kauffman Louis H
Published: November 2023

This paper derives (at the physical level of rigor) a general switching formula for the link invariants defined via the Witten functional integral. The formula is then used to evaluate the top row of the corresponding Vassiliev invariants and it is shown to match the results of Bar-Natan obtained via perturbation expansion of the integral. It is explained how this formalism for Vassiliev invariants can be used in the context of the loop transform for quantum gravity.
Topological Field Theory as the Key to Quantum Gravity
Authors: Crane Louis
Published: November 2023

Motivated by the similarity between CSW theory and the Chern-Simons state for general relativity in the Ashtekar variables, we explore what a universe would look like if it were in a state corresponding to a 3d TQFT. We end up with a construction of propagating states for parts of the universe and a Hilbert space corresponding to a certain approximation. The construction avoids path integrals, using instead recombination diagrams in a very special tensor category.
BF Theories and 2-knots
Authors: Cotta-Ramusino Paolo , Martellini Maurizio
Published: November 2023

The assumption that large mammal hunting and scavenging are economically advantageous to hominid foragers is examined in the light of data collected among the Hadza of northern Tanzania. Hadza hunters disregard small prey in favour of larger forms (mean adult mass 40 kg). Here we report experimental data showing that hunters would reduce their mean rates if they included small animals in the array they target. Still, daily variance in large animal hunting returns is high, and the risk of failure correspondingly great, significantly greater than that associated with small game hunting and trapping. Sharing large kills reduces the risk of meatless days for big game hunters, and obviates the problem of storing large amounts of meat. It may be unavoidable if large carcasses cannot be defended economically against the demands of other consumers. If so, then large prey are common goods. A hunter may gain no consumption advantage from his own big game acquisition efforts. We use Hadza data to model this ‘collective action’ problem, and find that an exclusive focus on large game with extensive sharing is not the optimal strategy for hunters concerned with maximizing their own chances of eating meat. Other explanations for the emergence and persistence of this practice must be considered.
Some basic concepts and theorems of probability theory
Authors: Petrov Valentin V
Published: November 2023

This chapter contains a summary of some basic concepts and theorems of probability theory that are needed in the following chapters. The proofs of many statements are omitted; they can be found in the books of, among others, Chung [78], Feller [133], Gnedenko [146], Loèeve [256], Lukacs [257] and Shiryaev [424]. Some more specialized results that border on the basic facts are also presented here.
Solid State Phenomena
Authors: Karlsson Erik b.
Published: November 2023

Solid state physics is a complex area which needs a full arsenal of experimental techniques to uncover all its intriguing aspects. The present book presents selected results from a couple of methods where phenomena in solids are observed from points of view that fall somewhat outside the experimental mainstream, but have contributed with unique information to the understanding of magnetism, supercondivity, point defects in metals, surface and interface physics and the physics and chemistry of metal/hydrogen systems, in particular diffusion phenomena. The PAC and USR methods described here are based on the observations of local magnetic and electric fields and their dynamic behaviour by recording the spin motion of excited nuclei and implanted positive muons, respectively; another method utilizes the electrostatic interaction of protons for the study of metallic multilayers and their interfaces. The text is centered on the relevant physical problems rather than being method-oriented and puts the specific, and sometimes unique, information gained by the above mentioned methods into a general perspective.
The Optical Model
Authors: Fröbrich P , Lipperheide R
Published: November 2023

In Chapter I we introduced the optical potential in order to account for the loss of current in the elastic channel owing to the coupling to non-elastic channels. The treatment there was purely phenomenological. It was based on an analogy with optics, where a complex index of refraction fulfils the function of a scattering potential for light waves in the presence of absorption.
What is a Logical System?
Authors: Gabbay Dov M
Published: November 2023

There is an increasing demand from computer science, linguistics and philosophy for a variety of logical systems. This is prompted by the extensive applications of logic in theoretical computer science, artificial intelligence and logic programming. In these fields there is a growing need for a diversity of semantically meaningful and algorithmically presented logical systems which can serve various applications. Therefore renewed research activity is being devoted to analysing and tinkering with old and new logics.
The Method of Hypersequents in the Proof Theory of Propositional Non-classical Logics
Authors: Avron Amon
Published: November 2023

Until not too many years ago, all logics except classical logic (and, perhaps, intuitionistic logic too) were considered to be things esoteric. Today this state of affairs seems to have been completely changed. There is a growing interest in many types of nonclassical logics: modal and temporal logics, substructural logics, paraconsistent logics, non-monotonic logics-the list is long. The diversity of systems that have been proposed and studied is so great that a need is felt by many researchers to try to put some order in the present logical jungle. Thus [Cleave, 1991], [Epstein, 1990] and [Wojcicki, 1988] are three recent books in which an attempt is made to develop a general theoretical framework for the study of logics. On the more pragmatic side, several systems have been developed with the goal of providing a computerized logical framework in which many different logical systems can be implemented in a uniform way. An example is the Edinburgh LF [Harper et al., 1993].
Subalgebras of Cohen Algebras Need Not be Cohen
Authors: Koppelberg Sabine , Shelah Saharon
Published: November 2023

Let us denote by CK the standard Cohen algebra of 7r-weight K, i.e. the complete Boolean algebra adjoining”‘ Cohen reals, where K is an infinite cardinal or 0. More generally, we call a Boolean algebra A a Cohen algebra if (for technical convenience in Theorems 0.3 and 0.4 below) it satisfies the countable chain condition and forcing with A (more precisely with the partial ordering A\ (O) is equivalent to Cohen forcing, i.e. if every generic extension of the universe of set theory arising from forcing with A arises from forcing with some standard Cohen algebra. Since forcing with an arbitrary Boolean algebra is equivalent to forcing with its completion and forcing with a product of algebras is equivalent to forcing with one of the factors, an algebra is Cohen iff its completion is isomorphic to a product of at most countably many standard Cohen algebras; we will use this description as the definition of a Cohen algebra in the rest of the paper.
Independence Structures in Set Theory
Authors: Lambalgen Michiel van
Published: November 2023

The axioms for ‘independent choices’ presented in [Lambalgen, 1992) are strengthened here, so that they can be seen as introducing a new type of indiscernibles in set theory. The resulting system allows for the construction of natural inner models. The article is organised as follows. Section 1 introduces the axioms, some preliminary lemmas are proved and the relation with the axiom of choice is investigated. Section O gives a philosophical motivation for the axioms; the reader who is not interested in such matters can skip this part. In section 2 we compare the structure introduced by the axioms, here called an independence structure, with two constructions from model theory, indiscernibles and minimal sets. Section 3 contains the construction of inner models, while section 4 presents some concluding philosophical remarks.
Open Questions around BÜchi and Presburger Arithmetics
Authors: Michaux Christian , Villemaire Roger
Published: November 2023

BÜchi characterized sets of natural numbers recognizable by finite automata in base k as the sets of natural numbers definable in W Sl S, the weak monadic second-order theory of one successor.
From Logic Programs to Inductive Definitions
Authors: Stark Robert F
Published: November 2023

The three-valued Fitting/Kunen semantics is one of the best declarative semantics for negation as failure in logic programming. We show that the three-valued consequences of the completion of a logic program are exactly the four-valued consequences of the completion. Since a four-valued relation can be represented by two two-valued relations, the four-valued completion semantics, and hence the three-valued Fitting/Kunen semantics, can be expressed in terms of classical consequences of an appropriate theory, which we call the partial completion of a logic program. We prove that SLDNF resolution is sound and complete with respect to the partial completion for a large class of normal logic programs, covering most programs of practical interest. This result can even be extended to SLDNF-resolution with builtin predicates. The partial completion, which is always consistent, leads in a natural way to formal theories of inductive definitions. We argue that such theories are appropriate for verification and termination proofs of logic programs.
Methods for the Multiple-Scattering
Authors: Molisch Andreas F , Oehry Bernhard P
Published: November 2023

For the multiple-scattering (MS) representation, we have to solve for the probability that a photon escapes after suffering i absorption/reemisison processes.9 For this computation, we have two possible approaches: Monte Carlo simulations, which have been used for 30 years, and analytical methods (Wiorkowski 1988), (Wiorkowski and Hartmann 1988), (Falecki et al. 1989, 1991). A Monte Carlo (MC) simulation is a very general, purely numerical algorithm for the modelling of complex physical processes. In the case of radiation trapping, it means tracing one photon after the other on its path through the vapour (House and Avery 1969), (Avery and House 1968). The photon’s emission frequency, direction, and path length before reabsorption are taken at random, according to the appropriate probability distributions. This means that the numbers are taken at random, but in such a way that they fulfil the statistics of the described physical process.
Simulation of optically pumped gas lasers
Authors: Molisch Andreas F , Oehry Bernhard P
Published: November 2023

The invention of the laser in the early 1960s has completely changed not only optics, but also all other sciences where light is required for experiments. This is especially true for atomic and molecular spectroscopy, but also for such diverse fields as remote sensing, material processing, and astronomy. Most of the millions of lasers currently in use around the world are semiconductor lasers (by far the largest group, due to their applications in consumer electronics and data storage) or solid state lasers with a crystalline host. Gas lasers are in use for special applications, where they cannot be replaced by solid-state lasers yet.
The renormalization group
Authors: Bellac Michel Le , Barton G
Published: November 2023

The renormalization-group method, invented by Wilson, consists in systematically reducing the number of degrees of freedom, by integrating over short wavelength fluctuations.
Two-dimensional models
Authors: Bellac Michel Le , Barton G
Published: November 2023

The case where the dimensionality D of space equals 2 has interesting peculiarities, because it is a limiting case with the behaviour of a spin system depending qualitatively on the dimensionality n of the order parameter.
Renormalization
Authors: Bellac Michel Le , Barton G
Published: November 2023

We saw in the last chapter that, if the dimensionality of space is high enough, then correlation functions often suffer from ‘ultraviolet divergences’ as the momenta q circulating round closed loops tend to infinity.
The Callan-Symanzik equations
Authors: Bellac Michel Le , Barton G
Published: November 2023

In Chapter 3 we met the word ‘renormalization’ through the expression ‘renor malization group’; recall that our strategy was to follow the evolution of the parameters defining the Hamiltonian through successive contractions of the cutoff &aiming to obtain the long-distance &1/A) behaviour of the theory. By contrast, the last chapter seemed to feature renormalization in the completely different context of eliminating a nonphysical (i.e. not directly applicable) bare theory in favour of a renormalized theory depending on just a few parameters. But we can observe already at this point that the renormalized theory, being finite as &-oo, is approximately independent of &when &is large but still finite; at least this is so in the long-distance region &l/ &Therefore one may hope to find a connection between the theory found by integrating over short-wavelength fluctuations, and the renormalized theory: both can be characterized as theories for long distances.
Path integrals in quantum and in statistical mechanics
Authors: Bellac Michel Le , Barton G
Published: November 2023

This chapter links Parts I and II, which were devoted to statistical mechanics, and Part III, which deals with quantum field theory. In Part III we shall revert to the tools developed for studying critical phenomena, namely functional integrals (often called path integrals in this new connection); Feynman diagrams; renormalization; and the renormalization group. A few adaptations are all that these tools need in their new context, and we shall use some elementary examples to illustrate the links between problems in statistical and in quantum mechanics.
Quantization of the Klein-Gordon field
Authors: Bellac Michel Le , Barton G
Published: November 2023

Quantum field theory was born of the need to describe processes where particles are created or destroyed (annihilated). One elementary example is the radiative transition of an atom from an excited state &to the ground state &emitting a photon (y): &+ &+ &+ &Reactions where particles are created or destroyed are basically different from chemical reactions, which correspond to rearrangements of the atoms within the molecules; and different also from nuclear reactions, where the nucleons redistribute themselves to yield new nuclei. In both cases there is rearrangement rather than creation or destruction. However, the distinction may not be as sharp as it seems, because the process of rearrangement can be quite complex, with (virtual) destruction or creation of particles in its intermediate stages. The Schroedinger equation, which assumes that the number of particles is fixed, cannot describe creation or annihilation processes; but already in the 1930s the founders of quantum mechanics discovered how this could be done through the quantization of classical fields (improperly called ‘second quantization’, for historical reasons).
Quantization of the Dirac field and of the electromagnetic field
Authors: Bellac Michel Le , Barton G
Published: November 2023

Modern elementary-particle physics is dominated by gauge theories, whose prototype is quantum electrodynamics (QED). The fundamental particles in such theories are These particles are assumed to be elementary, &In electrodynamics, the spin 1/2 particles are electrons (and their antiparticles, i.e. positrons), while the gauge particles are photons. In this case the interactions between spin 1/2 particles are mediated by photons: Fig. 11.1 shows a Feynman graph contributing to electron-electron scattering.
Of maps and monkeys: an introduction to the maximum entropy method
Authors: Daniell G J
Published: November 2023

We present a tutorial introduction explaining why an approach like maximum entropy is essential in a wide range of problems in image and data processing. The simple ‘monkey argument’ and Bayes’ theorem are used to justify the use of entropy and a typical application is discussed which illustrates the philosophy of the maximum entropy approach.
Enhanced information recovery in spectroscopy using the maximum entropy method
Authors: Davies S , Packer K J , Baruya A , Grant A I
Published: November 2023

The maximum entropy method for the reliable extraction of information from spectroscopic data is outlined. Examples are shown from Raman and nuclear magnetic resonance spectroscopies, with particular reference to the selection and parameterization of suitable lineshape functions for deconvolution. An account is also given of our experiences with a proposed definition of the entropy function different from the usual form.
Maximum entropy and plasma physics
Authors: Cottrell G A
Published: November 2023

Experiments on magnetically confined fusion plasmas, for example the Joint European Torus (JET) tokamak, require a range of diagnostic techniques for measurement of plasma quantities such as temperature and density. Usually, some kind of inverse transform is needed to convert measured raw signals into useful data. Also, there are often problems arising from inadequately sampled data and instrumental resolution limitations. It will be explained how the maximum entropy method (MaxEnt) can be applied in such cases with three advantages over conventional analysis: the generation of positive solutions, the suppression of noise and the suppression of spurious transform-related artefacts. MaxEnt is illustrated using a number of examples from the field, involving: the Fourier transform (for example, Michelson interferometry), deconvolution of spectra, and two-dimensional tomography of atomic beams. The advantages of MaxEnt are seen clearly in the problem of extracting the maximum amount of information, for example on plasma profiles, starting from only a limited and noisy data set. Used in this way, the method responds flexibly to the demands of the data and does not suppress any significant features.
The Measurement of Motion Using Spin Echoes
Authors: Callaghan Paul T
Published: November 2023

In Chapter 5 the concept of image contrast was introduced. The nuclear magnetic resonance spectrum is rich in details which reveal the molecular environment of the nucleus. Chemical shift contrast and other more sophisticated methods of spectral editing can provide molecularly selective images while other schemes take advantage of the various characteristic time-scales in NMR, giving effects which are highly sensitive to the motion of the surrounding molecule. For example, the use of relaxation time contrast can differentiate molecules via their characteristic rotational motions. The suggestion that nuclear magnetic resonance could be used to measure molecular translational motion dates from the earliest days of this field of research.
Pulsed NMR in solids-then and now
Authors: Slichter C P , Barrett S E , Becerra L , Durand D J , Klug C A , Martindale A , Pennington C H , Ross J H , Shore S , Wang Z , Zax D B
Published: November 2023

This volume celebrates the scientific career of Erwin Hahn. As a graduate student, he initiated pulsed NMR [1] . Immediately thereafter he discovered spin echoes [2]. I am one of the few practitioners of magnetic resonance still active who knew Erwin even before he made his celebrated discovery of spin echoes. The intervening years have seen a nearly complete transformation of magnetic resonance from steady state techniques to pulse methods. Pulse methods were employed heavily by physicists from the time of their discovery by Erwin, as is chronicled partially below. For the first 20 years of magnetic resonance, high resolution NMR as practised in chemistry labs employed steady state techniques. Indeed, a commercial pulsed NMR apparatus was not available. The discovery by Ernst and Anderson [3] that pulsed NMR could give high resolution results via Fourier transforms changed things, giving strong impetus to the use of pulse methods in chemistry. The final impetus was the discovery of the power of two-dimensional Fourier transforms to simplify spectra.
New angles in motional averaging
Authors: Samoson A , Sun B Q , Pines A
Published: November 2023

It is the dispersion of local magnetic fields-the spread of resonant frequencies inherent even in the simplest systems-that determines selectivity and resolution in NMR. The local fields among a group of coupled nuclei, for example, may be rendered non-stationary owing to spin flip-flops, or spin diffusion, and the associated resonance can acquire a certain width as a result. Another source of frequency dispersion arises from the dependence of most spin interactions on the orientation of the external magnetic field relative to each nucleus. Thus both the spin and spatial dependence of the magnetic interactions must be addressed if one is to realize full spectroscopic control in NMR. random molecular reorientation, spatial anisotropy is averaged largely to zero. For sufficiently rapid tumbling, only the isotropic components of the spin interactions remain and so it becomes possible to achieve truly high resolution. In solids, however, restrictions on molecular motion prevent the spins from sampling a spherically symmetric set of orientations. Here, there are two general solutions: either remove the field altogether, and by so doing eliminate the very notion of directionality, as in zero-field NMR (this eliminates also the distinct isotropic chemical shifts of different nuclei), or, alternatively, one can impose an artificial motion on the spins to create the equivalent of a spherically symmetric environment. This latter option, that of supplying the motion externally, was inherent in the spin echo experiment [1] and its generalizations [2] in which the spin angular momenta are perturbed while leaving the molecules in place; and in the sample-spinning experiments of Anderson [3] , in which the sample is rotated. Averaging in spin space has progressed from simple spin echoes to the prolonged trains introduced by Waugh and later workers for solids [4].
Spin echoes and thermodynamics
Authors: Waugh J S
Published: November 2023

The spin echo [1] is still striking to those who see it for the first time, as it probably was to Hahn. A nuclear magnetization, having disappeared in a free induction decay (FID), spontaneously reappears as a giant fluctuation. While the phenomenon is easily understood from a mechanical point of view, it seems to verge on a violation of the second law of thermodynamics. It is this problem, about which Hahn [2] and others [3] have written, that we approach here again from what is at least partly a fresh perspective. Our point of view will be that echoesdo violate the second law. After having defended this case we will discuss briefly how the problem can be avoided by appropriate statement of purely macroscopic thermodynamic principles.
Spin choreography
Authors: Freeman R
Published: November 2023

Very soon after the initial discovery of nuclear magnetic resonance, E. L. Hahn performed an experiment that, in conceptual originality and elegance, transcended all that had preceded it-the spin echo experiment [1]. Here was an idea to inspire the young scientists reading about NMR for the first time. Not only could oneworkwith these strange new entities called spins, but alsomanipulatethem like a conjuror with a pack of cards. In its original form, experiment was conceptually easier to follow, resembling the opening and closing of a ‘fan’ of vectors confined to the transverse(x-y)plane of the rotating frame. Note that the description of the conventional continuous wave NMR experiments of the time scarcely required this level of sophistication, relying on the steady state solutions of the Bloch equations. To understand spin echoes, one was forced to come to grips with homogeneous and inhomogeneous line broadening, transformation into the rotating frame of reference, and the concept of ‘spin isochromats’. This was a term coined by Abragam [3]. The sample is considered to be made up of a mosaic of volume elements, each small enough that the variation of the applied field intensity across that element could be neglected, but with neighbouring elements in slightly different applied fields due to the spatial inhomogeneity. Each element has a nuclear magnetization with a characteristic precession frequency; this is an isochromat. The total sample magnetization is the resultant of all these isochromatic magnetization vectors. Because the isochromats have different intrinsic frequencies this resultant can change as individual isochromats fan out or come back into alignment. This has proved a valuable idea for describing spin echo experiments.
Deuteron multiple echoes
Authors: Conradi M S , Fedders P A , Norberg R E
Published: November 2023

Deuteron multiple echoes have been observed for HD and o - D2molecules trapped in the presence of large static electric field gradients. The multiple echoes are of the variety described by Solomon [ 1], Butterworth [2], Mehring and Kanert [ 3] , and Boden [4,5] and are resolved from the 2r solid echo because of the presence of a relatively large intramolecular dipolar interaction colinear with the intramolecular quadrupole coupling. The deuteron multiple echoes are uniquely molecule-specific and have been observed for HD and o - D2molecules trapped in amorphous silicon [5-10] and germanium [ 11] as well as adsorbed on MgO surfaces [12] . The occurrence of the multiple echoes, and their manipulation by proton double resonance, provides a nice example of spin dynamics in exceedingly simple systems and a unique opportunity to measure the average field gradient at a surface.
Imaging by nuclear magnetic resonance*
Authors: Mansfield P
Published: November 2023

The subject of nuclear magnetic resonance (NMR) is well known to physicists, and especially chemists and biologists, as an analytical technique for the study of inter- and intra-molecular interactions [1,2]. For those unfamiliar with recent developments, therefore, it is perhaps surprising to learn that NMR techniques have over the last 10 years or so been adapted and refined by a number of groups, thus making possible, through the study of externally imposed macroscopic spin interactions, the observation and measurement of morphology of macroscopic objects. The aim in traditional NMR experiments is to observe the specimen in as uniform a magnetic field as possible (high resolution). In this case all magnetically active spins within the sample resonate at approximately the same Larmor resonance angular frequencyw,given byw=‘YB,where‘Yis a constant for a particular spin species and is called the gyromagnetic ratio, andB is the magnitude of the applied static magnetic field B. The small deviations in frequency measured in such high resolution experiments are minor perturbations of the spin energy levels which come about through electronic screening of the nucleus (chemical shift), and/or indirect nuclear (hyperfine) interactions via the overlap of electronic shells of neighbouring nuclei. In a solid there is additionally the nuclear dipole-dipole interaction which usually dominates in size over the previously mentioned interactions by an order of magnitude or so. For protons, the chemical shift and hyperfine interactions are usually very small indeed. In a medium resolution magnet, therefore, the proton resonance absorption line shape for many common materials is broadened or smeared into a symmetric structureless line which completely masks the smaller interactions. This is the case for most of the mobile protons in biological tissue. However, at high enough fields, there is a measurable chemical shift difference between water and fat.
Clinical imaging
Authors: Crooks L E , Rothschild P
Published: November 2023

The advent of diagnostic magnetic resonance imaging (MRI) appears to have occurred in a startlingly short time, but what was actually abrupt is only the perception by physicians of this technology’s impact on the way diagnoses are performed. The theoretical basis and demonstration of NMR is a development of the late 1940s and, in condensed matter, resulted in the 1952 Noble prize for physics to Edward Purcell and Felix Bloch. The understanding of the nucleus (which led to the conception of NMR), discovery of superconductivity (an important component of magnets used for MRI), and basic work leading to present computers were all developments of the early 1900s incorporated together in the 1960s. Then NMR systems combined these three items for spectroscopy investigations with ever improving performance. Clinical MRI also owes much to the development of computed tomography (CT): first, it established the precedent that an expensive device could have a place in routine diagnosis; second, most, if not all, of the companies that build CT scanners found themselves with unused plant and personnel capacity when regulation slowed the growth of CT below their expectations. With the advent of MRI, some companies saw a natural outlet for their excess capacity. In addition, the companies that fared poorly in CT hoped for a chance to make up their losses by aggressively pursuing MR, while successful CT manufacturers felt the need to go into MR to protect their market positions. These factors resulted in unprecedented expenditures for an untested product by traditionally conservative companies that typically allow the marketplace to be tested by small entrants, which they then try to buy or displace.
Quantum beat echoes
Authors: Hashi T , Fukuda Y , Tanigawa M
Published: November 2023

The spin echo [1 ] discovered by Erwin Hahn in 1950 is one of the most sophisticated phenomena in physics. It demonstrates the fact that the decay of coherence due to the inhomogeneous broadening can be recovered by an ingenious ‘effective time reversal’ technique. Since then, the research on coherent transients has been developed in the field of pulsed magnetic resonance [2]. The advent of the laser stimulated the studies in the optical region. Optical analogues of most of the coherent transients in magnetic resonance have been realized [ 3] except for those in solids, whose mechanisms are based on the spin temperature hypothesis [4] . Thus coherent interactions between radiation and atoms have been extensively studied and the techniques developed have been effectively used in a variety of fields. In the studies of so-called two-level problems the coherence is generated by a direct excitation of the relevant transitions by radiofrequency (r.f.), microwave, or laser fields.
General constraints on naked singularity formation
Authors: Joshi Pankaj S
Published: November 2023

In the previous chapter, we showed that strong curvature naked singularities arise in a variety of situations involving dust, perfect fluid, and radiation collapse for self-similar as well as non-self-similar space-times. These are dynamical situations representing a gravitational collapse scenario and the matter content of the space-time is reasonable in that the energy conditions implying the positivity of energy are satisfied and widely used equations of state arc obeyed. Hence, these collapse scenarios must be taken into account for any possible formulation of the cosmic censorship hypothesis. In fact, in order to arrive at any provable formulation of the censorship hypothesis, or otherwise to assess the reasonability of these examples, it appears necessary to examine possible constraints which must be obeyed by naked singularities occurring in the general theory of relativity.
Global upper limits in cosmology
Authors: Joshi Pankaj S
Published: November 2023

In this chapter, we apply the global concepts developed in Chapters 4 and 5 to deduce certain general upper limits in cosmology. Specifically, our aim is to allow for perturbations from the assumed homogeneity of the universe and to deduce in this general scenario the upper bounds on the age of the universe as well as limits on the elementary particle masses which were produced copiously during the early phases of the universe and which may be filling the universe today.
phase transitions and criticality
Authors: Dixon J M , Tuszynski J A , Clarkson P A
Published: November 2023

I would claim that the most important advances in this area (condensed matter physics) come about by the emergence of qualitatively new concepts at the intermediate or macroscopic levels-concepts which, one hopes, will be compatible with one’s information about the microscopic constituents, but which are in no sense logically dependent on it. These new concepts . . . have in common. . . that they provide a new way of classifying a seemingly intractable mass of information of selecting the important variables from the innumerable possible variables which one can identify in a macroscopic system.
The method of coherent structures (MCS)
Authors: Dixon J M , Tuszynski J A , Clarkson P A
Published: November 2023

I disagree with most physicists at the present time just on this point [of removing divergent diagrams). I cannot tolerate departing from the standard rules of mathematics. Of course, the proper inference from this work is that the basic equations are not right. There must be some drastic change introduced into them so that no infinities occur in the theory at all and so that we can carry out the solution of the equations sensibly, according to ordinary rules and without being bothered by difficulties. This requirement will necessitate some really drastic changes: simple changes will not do, just because the Heisenberg equations of motion in the present theory are all so satisfactory. I feel that the change required will be just about as drastic as the passage from the Bohr orbit theory to the quantum mechanics.
Chaos and one-dimensional maps
Authors: Holton David , May* Robert M
Published: November 2023

In our everyday experience we frequently encounter processes which exhibit chaotic or apparently random behaviour: the constantly changing weather pattern, the flow of a turbulent stream, or the fluctuations in the population of a species. These are dramatic examples of systems which display complicated and seemingly indeterminate behaviour. However, these are precisely the kinds of systems which hold most fascination and which we wish most to be able to rationalize, to model, and, using estimates based on the model, to predict future behaviour. The traditional view of the complexity of nature is that there is little hope of unravelling the underlying reasons for randomness. The elements of cause and effect are believed to be so intricate and the interactions so complicated, appearing on so many spatial and temporal scales, that the net result is that the many influences act incoherently and statistically, to yield an unfathomable mess.
Models of chaos from natural selection
Authors: Holton David , May Robert M
Published: November 2023

In experimental philosophy we are able to look upon propositions obtained by general induction from phenomena as accurately or very nearly true ... till such time as other phenomena occur, by which time they may be accurate or liable to exceptions. The principles of general induction upon which Newton formulated the celestial mechanical equations of motion began the interpretation of dynamics in terms of mathematics. This early development spawned infinitesimal mathematics or calculus. A complete understanding of the solutions of these equations of motion, however, has remained out of reach.
Distinguishing chaos from noise
Authors: Holton David , May Robert M
Published: November 2023

A central theme to dynamical systems is the recognition that simple deterministic mechanisms can generate random-looking data. However, can random-looking data, derived from an experiment, be attributable to a simple deterministic mechanism? There are several sources of difficulty in attributing a random time series from a natural system to a deterministic source. The randomness may be a result of errors inherent in making the measurement, for example, in sampling errors in estimating sizes. Also, there may be fluctuations derived from unpredictable environmental changes; this is perhaps most insidious, since it suggests the system is strongly coupled to the environment and hence inherently of high dimension. Another difficulty could be that the system is intrinsically of high or infinite dimension with interactions on many temporal and spatial scales. This being the case, we can no longer hope for a low-dimensional dynamical description.
Ion Traps
Authors: Ghosh Pradip K
Published: November 2023

The author provides, in nine chapters, a compact and up-to-date coverage of the entire range of applications of the two most important ion traps: the Paul('radiofrequency') trap and the Penning('dc) trap. The book begins with full details of the ion confinement principles of both these traps; this is followed by a presentation of the basic experimental techniques, including details of a few actual traps. There is then a chapter on the methods of ion cooling, now an essential integral part of all trap-based experiments. The next four chapters provide a comprehensive coverage of applications in four major areas, broadly classified as: atomic physics, frequency standards, collision studies, and analytical mass spectrometry. The text is appended by a set of more than 600 fully titled chronologically arranged references which mirror the growth of the field as well as providing a comprehensive guide to original research papers. The text should be useful to students both at the senior undergraduate and beginning graduate level as a general reader for professionals in atomic physics, chemical physics, mass spectometry and related fields.
Ion Traps In Atomic Physics
Authors: Ghosh Pradip K
Published: November 2023

In this chapter we present applications of ion traps to: (i) determination of the g-value of an electron from electron spin resonance experiments on a single electron, (ii) observation of quantum jumps in a single trapped ion, (iii) an experimental test of the quantum Zeno effect, (iv) a precision test of the linearity of quantum mechanics, (v) a range of studies on one-component microplasmas, (vi) optical spectroscopy of molecular ions, (vii) precision mass measurement of stable isotopes, (viii) precision mass measurement of radioactive isotopes, (ix) trapping and precision mass measurement of antimatter, specifically of antiprotons, (x) lifetime measurement of neutron undergoing beta decay, and (xi) atomic physics of highly charged ions.
Biology
Authors: Kimsey Lynn S , Bohart Richard M
Published: November 2023

The biology of only a small percentage of chrysidid species has been investigated, and even these cases deal mostly with the identity of the host. All known chrysidids are parasites and their presence nearly always results in the death of the host. Therefore they fall into the categories of parasitoids or cleptoparasites. The latter name is appropriate when provisions by the adult host for its larva are ‘stolen’ and consumed. Bethylids, the sister-group of the chrysidids, are parasitic on moth and beetle larvae. Chrysidids may feed on both of these, but only in a secondary way.
Subfamily Amiseginae
Authors: Kimsey Lynn S , Bohart Richard M
Published: November 2023

The Amiseginae are small cryptic wasps, found low in vegetation or in leaf litter. They can be recognized by the five external abdominal segments in males and four in females, as well as the flat or concave face, slender mandibles, and needle-like ovipositor. These wasps are infrequently collected but this is more a reflection of collecting techniques than of actual abundance. The highest species diversity occurs between latitudes 30° north and 30° south. Amisegines are parasites of phasmatid walking stick eggs.
Subfamily Loboscelidiinae
Authors: Kimsey Lynn S , Bohart Richard M
Published: November 2023

These unusual and aberrant looking wasps are rarely collected and as a consequence are not well known. They can be recognized immediately by the oddly shaped head, antennae inserted high on the face, large tegulae, and abdomen with five external segments in males and four in females. Loboscelidiines occur in the Indoaustralian Region. The structure of the mandibles and ovipositor suggests that these wasps are also parasites of walking stick eggs.
Re-introducing birds: lessons to be learned for mammals
Authors: Ounsted M L
Published: November 2023

The criteria for bird re-introductions are likely to be similar to those for mammals. To date, though some bird re-introductions are considerd a useful conservation tool in the broadest sense, bird re-introduction has rarely been shown to have achieved its primary aim of re-establishing a self-sustaining population in the wild. With birds, the behavioural and anatomical implications of flight severely restrict the control and monitoring of individual re-introduced birds. The behavioural characteristics of species even within one taxonomic group vary greatly and limit the suitability of species for re-introduction. Eggs facilitate the artificial propagation of many species. Since eggs are easy to transport, hatched chicks may more easily acclimatize to new environments and the likelihood of disease transfer can be reduced.
Veterinary considerations in re-introduction and translocation projects
Authors: Woodford M H , Kock R A
Published: November 2023

Wildlife management is a rapidly developing science and relocation of wild species for reinforcement of a population or re-introduction is becoming a popular conservation technique. However, when wild animals are moved from one place to another, inherent disease risks are evident. These risks can be assessed in advance and minimized if appropriate and timely veterinary precautions are taken.
Training for life after release: simian primates as examples
Authors: BOX Hilary O
Published: November 2023

Using simian primates as an example, the paper outlines the variety of skills required to adjust adequately to a natural environment after release from captive conditions. Specific examples are given from wild-born individuals which have been rehabilitated by release programmes after periods in captivity. Examples are also taken from programmes of environmental enrichment in captivity which encourage natural behaviour in various species of primates that have been bred in captivity, and thus maximize the chances that their subsequent re-introduction into the wild will succeed. In addition, a number of issues are raised with reference to differences among species in their behavioural and physiological responsiveness to changes in their environments. It is argued that these issues are an important source of hypotheses in the development of training programmes for species with different predispositions, as in their social organization.
Costs of a re-introduction and criteria for success: accounting and accountability in the Golden Lion Tamarin Conservation Program
Authors: Kleiman Devra G , Beck Benjamin B , Dietz James M , Dietz Lou Ann
Published: November 2023

In this paper, we review the separate components of the Golden Lion Tamarin Conservation Program, including field studies, education, habitat preservation and restoration and re-introduction. We summarize the history of the captive population and provide an estimate of the annual cost of maintaining the captive population at 550 animals in 100 institutions. We then develop estimates of the ‘costs’ of the re¬ introduction programme, including salaries of Brazilian and US personnel, construction costs, animal and human facilities, vehicles and transportation and supplies and equipment. By considering the number of tamarins surviving as a result of the re¬ introduction and the total costs, we estimate that one surviving re-introduced golden lion tamarin has cost approximately $22,000 to date.

We then evaluate the other benefits of the programme, including the effects of the re-introduction on habitat preservation and augmentation as well as education in conservation, ecology and wildlife management, locally, nationally and inter¬ nationally.
Viable population strategies for re introduction programmes
Authors: Foose Thomas J
Published: November 2023

Re-introduction programmes should be based on viable population strategies because of stochastic risks to the small population that will characterize most taxa for which re-introduction is attempted. These strategies will entail metapopulations incorporating both captive and wild subpopulations which will need to be interactively managed for mutual support and survival. Even when re-introductions have to be opportunistic, they should occur within the strategic framework of a metapopulation survival masterplan.