bluuebunny/crossref_metadata_2025 huggingface dataset:
Superfluid 3He and unconventional superconductivity
Authors: Annett James F
Published: November 2023

By about 1970 the Bardeen Cooper and Schrieffer (BCS) theory of superconductivity was well established, and had led to major new discoveries, such as the Josephson effect. The theory of superfluidity in He was also clear in the outline, although the numerical problems of calculating observable quantities for a dense and strongly interacting Bose liquid were considerable with the computational tools available at that time. So, for many scientists the FB01eld of low temperature physics seemed to be nearing its completion.
Naturalized Reptiles and Amphibians of the World
Authors: Lever Christopher
Published: November 2023

This book describes how the various alien reptiles and amphibians now living in the wild throughout the world were first introduced, how they subsequently became naturalized, their present distribution and status in those countries to which they were introduced, and their ecological and socio-economic impact (if any) on the native biota and local economies. Many species have had a more or less neutral impact, being neither beneficial nor harmful. However, several have had a positive ecological or socio-economic impact, while some such as the cane toad, have had an extremely destructive effect.The criteria for inclusion of a species are that it should have been imported from its natural range to a new country by human agency (either accidentally or deliberately) and that it should currently be established in the wild in self-maintaining and self-perpetuating populations unsupported by, and independent of, mankind.
Introduction
Authors: Lever Christopher
Published: November 2023

Animals have been deliberately introduced by humans outside their natural range with a variety of motives: as an aesthetic amenity; as an additional source of food; as fur-bearers; as scavengers; as a means of conservation of an endangered species; for sporting purposes; for sentimental or nostalgic reasons by homesick colonists; out of simple curiosity as to the outcome—a particularly irresponsible reason; and as a form of biological control of a (frequently alien) pest species.
Surface Temperature of Rubbing Solids
Authors: Bowden F P , Tabor D
Published: November 2023

When one solid body slides over another most of the work done against the frictional force opposing the motion will be liberated as heat between the surfaces. This heat will be carried away from the surfaces by conduction and radiation, but quite primitive calculations indicate that even under moderate conditions of speed and load the surface temperatures may reach very high values. It is of course difficult to measure these temperatures by ordinary methods. If we embed thermometers or thermocouples in the solids near the rubbing surfaces, we find that the temperature rise is very small. This is partly because of the relatively large heat capacity of the thermometer (or thermocouple), but is mainly due to the fact that the temperature falls off very rapidly as we move away from the actual rubbing interface. We may, however, measure the surface temperatures directly by using the surfaces themselves as a thermometer.
Friction of Non-Metals
Authors: Bowden F P , Tabor D
Published: November 2023

It is interesting to consider the friction of non-meta.ls and to compare their behaviour with that of metals. As we saw earlier, the characteristic frictional properties of metals are due largely to their ability to flow plastically and to weld together under load. The welded junctions so formed are sheared during the sliding process. With many non-metals, such as glass and certain plastics, flow and welding may occur as with metals. With other materials, particularly those which are markedly crystalline in structure, it is difficult to envisage plastic flow and subsequent welding. Nevertheless many non-metals, even of a crystalline nature, have frictional properties similar to those of metals and it is possible that other mechanisms analogous to the welding process are responsible for the frictional behaviour observed. In other cases, as we shall see, the friction is very different from that of metals.
Breakdown of Lubricant Films [A]
Authors: Bowden F P , Tabor D
Published: November 2023

As we have already seen, when surfaces slide under ideal hydrodynamic conditions there is no wear of the moving parts. In many mechanisms, however, it is not always possible to maintain completely hydrodynamic conditions and there may be a considerable amount of boundary lubrication during which wear of the surfaces may occur. For this reason it is important to be able to estimate the amount of non-hydrodynamic lubrication since this determines the life of the running parts. In practical tests the effectiveness of the lubrication in any particular mechanism is usually determined by measuring the amount of wear which occurs under given conditions, or the critical load and speed at which a-marked increase of wear and seizure takes place. This method often provides useful empirical information, but it may shed little light on the detailed processes occurring during sliding.
Adhesion Between Solid Surfaces: The Influence of Liquid Films
Authors: Bowden F P , Tabor D
Published: November 2023

Earlier chapters have shown that the friction between metal surfaces is due to the shearing of metallic junctions formed by adhesion or welding at the points of intimate contact. We might, at first thought, expect that when the load is removed these junctions would still remain and an appreciable normal force would be needed to separate the surfaces. It is therefore of interest to e amine the normal adhesion between solids and to determine the effect of interposed liquid films on the adhesion. Earlier work by Holm (1946), Shaw and Leavey (1930), and Jacob (1912) has shown that strong adhesion may .occur between surfaces which have been cleaned and freed of adsorbed surface films, but if the surfaces are exposed to air no adhesion is observed. The work of McBain (1931) and Hardy (1936) has dealt more specifically with the strength of adhesives between solid surfaces. Similarly Budgett (1911), Stone ·(1930), and other workers have shown that marked adhesion between solid surfaces can occur in the presence of water or other liquid films.
Chemical Reaction Produced By Friction and Impact [A]
Authors: Bowden F P , Tabor D
Published: November 2023

It is well known that chemical reaction may be brought about by friction and by: impact. Early work was concerned with the decomposition of solids by high pressure and by grinding in a mortar with a pestle, where the solid is subjected to both pressure and shear.
Introduction
Authors: Berthold Peter
Published: November 2023

The environmental conditions for most living beings on our planet are characterized by the continuous influence of two geophysical cycles: diurnal and annual periodicity. These are caused by the earth’s rotation around its axis and the seasonally changing altitude of the sun’s position. The resulting diurnal patterns and the four seasons, with their characteristic features, bring with them constant changes in environmental conditions to which animals must adapt if they are to survive and reproduce.
Evolution, genetic basis, and extent of bird migration
Authors: Berthold Peter
Published: November 2023

We do not know whether the fossil bird Archaeopteryx, which was found in the Jurassic chalk layers near Eichstätt in Bavaria, and which lived 140 million years ago, or the Chinese fossil bird Confuciusornis of the late Jurassic (about 120 million years ago) showed some modest migratory movements even then.
Threats and the conservation and future of migrants
Authors: Berthold Peter
Published: November 2023

Under normal environmental conditions that have not been adversely affected by humans, migrants are generally no more exposed to threats than residents-at least no more than those birds resident at higher geographical latitudes. On the contrary, many residents have to raise several broods per year in order to keep their population levels constant, whereas many long-distance migrants essentially get by (or have until now got by) on only one brood annually and relatively few offspring (5.31).
Into the limelight
Authors: Gregory Jane
Published: November 2023

A new cosmology; postwar gloom; steady-state theory in the spotlight; The Nature of the Universe; the Massey conference; confronting Rylene evening in 1946, Hoyle, Bondi and Gold strolled across Cam- bridge to the cinema. The film they were going to see was Dead of Night, the first post-war release from the famous Ealing Studios
Under fire
Authors: Gregory Jane
Published: November 2023

A Caltech, Willy Fowler had been impressed by Hoyle, and, inspired by the carbon-12 work to think further about the evolution of stars, he had arranged to spend the academic year 1954–55 in Cambridge on a Fulbright scholarship. It was his first trip to Cambridge, and in order to explore more widely he bought a car – a convertible Hillman 10, like Tommy Gold ‘s but without all the mechanical problems.
Evolution on trial
Authors: Gregory Jane
Published: November 2023

While some of Hoyle and Wickramasinghe ‘s earlier work had claimed kinship with Darwin, who, like them, had struggled against the disapproval of his peers, by 1980 Darwinian evolutionhad become their target. In December 1981, in the wake of the publication of Evolution from Space, when they took part in a legal battle in Little Rock, Arkansas, where a law had been passed requiring that Creationism – the idea that God created the universe and its creatures as described in the Bible
Energy Minimization
Authors: Aharoni Amikam
Published: November 2023

The most popular case of minimizing all three energy terms (namely, the exchange, the anisotropy and the magnetostatic energies) is the study of the structure and energy of the wall between antiparallel domains in thin films. The Landau and Lifshitz solution described in section 7.2 assumes an infinite crystal, in which it is possible to get away with no magnetostatic energy contribution.
Analytic Micromagnetics
Authors: Aharoni Amikam
Published: November 2023

In this chapter and the next one, various topics in micromagnetics, outside the nucleation problem, will be described. The subdivision into analytic and numerical studies in the two chapters is rather artificial and quite arbitrary. In most cases there is no real distinction between analytic solutions and numerical ones, and many physical problems use a mixture of both. Nevertheless, it seems desirable from a didactic point of view to keep them as separate chapters.
Hormonal control of incubation behaviour
Authors: Vleck C M
Published: November 2023

Contact incubation is displayed by nearly all birds to maintain egg temperature within acceptable limits for embryonic development. The behaviours involved have been studied in exquisite detail in a few species such as herring gulls(Larus argentatus; Baerends and Drent 1970). This work analysed nest building activity, incubation, retrieval of eggs, and re-settling behaviour of adult gulls, and how the tendency to sit quietly on the eggs varied over both the reproductive season and over a single bout of incubation. Changes in behaviour were attributed to changes in tendency to incubate, but without a clear understanding of the underlying factors influencing behaviour.
The brood patch
Authors: Lea R W , H. Klandorf
Published: November 2023

The vast majority of birds achieve successful incubation of eggs through the transfer of heat between parts of their body, usually but not always their ventral surface, and the clutch of eggs. That region of the incubating bird making contact with the egg is commonly termed the incubation or ‘brood patch’.

Although the evolution of this structure is open to conjecture, an attractive possibility is that the appearance of a brood patch was a definitive step in the development of birds from reptiles and it has been thus suggested to share a common ancestry with the mammalian mammary gland (Long 1969). The nature, formation and structure of this patch vary enormously between species, reflecting the diverse mechanisms and methods adopted by different species in the incubation of eggs. In some birds, such as the domestic pigeon (Columba livia) and ring dove(Streptopelia risoria), there is a form of pocket or ‘apterium’ on the ventral surface of both sexes, which is devoid of feathers throughout adult life. In other species, patch formation occurs periodically and closely related to the period of egg laying and incubation. Furthermore, though both genders may have the potential to develop a brood patch, it is a general observation that it only occurs in the gender actually involved in incubation.
Energetics of incubation
Authors: Tinbergen J M , Williams J B
Published: November 2023

All birds lay eggs which must be maintained at suitable temperatures for proper embryological development to occur (Lundy 1969; Anderson etal. 1987). Contact incubation, the act of applying heat to eggs, has captured the imagination of investigators for decades, but the constraints imposed by the incubation period on life-history evolution have only begun to be appreciated (Huggins 1941; Kendeigh 1952; Drent 1975; Williams 1996; Bryan and Bryant 1998).
Paramagnets and Oscillators
Authors: Wark J S , Glazer A M
Published: November 2023

Up until now everything has been quite general, and no doubt you are starting to question the relevance to the price of sugar of all these pages of formulae. So, before you get lost in the abstraction of it all, let us start to apply them to some relatively simple physical systems. We have picked two: a paramagnetic solid and an array of simple harmonic oscillators. We choose these examples as not only are they perhaps the simplest to deal with from a mathematical point of view, but they are also of considerable physical interest.
Mangrove Forests
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

Mangrove forests are sometimes regarded as a very distinct ecosystem virtually requiring a separate discipline of science. In fact, they are just one of the many types of forest in Sumatra having a closed, even canopy made up of tree species which are predominantly evergreen. The environmental conditions in which they grow are extreme, however, because they are subject to soil-water salinity and waterlogging. Mangrove forests have important environmental roles concerned with land, wildlife and fisheries management (table 2.1) and have been exploited by man for numerous natural products (table 2.2). This exploitation by man has had important effects on the ecosystem.
Other Coastal Ecosystems
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

In addition to mangrove forests, five other types of ecosystems are found around the coasts of Sumatra. These are: beach vegetation on accreting coasts (pes-caprae formation), beach vegetation on abrading coasts (Barringtonia formation:), brackishwater forests, rocky shores and coral reefs. The last of these is not strictly within the scope of this book as it is a marine ecosystem, but it is included as background material for the reader who may wish to pursue studies on coral reefs.
Rivers and Lakes
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

Sumatran lakes (together with those in Java and Bali) have the distinction of being the first tropical lakes to be studied in great detail. In contrast to many other aspect of Sumatran biology, an enormous amount has been written about a number of Sumatra’s lakes. Between 1928 and 1929 a German expedition spent 10 months conducting thorough studies of lakes (and to a lesser extent rivers) in Java, Sumatra and Bali. The results, written by over 100 experts, total an amazing 7,920 text pages with 3,055 tables and figures and were published in Archiv fur Hydrobiologie (Supplement) between 1931 and 1958. Most of the papers are taxonomic (over 1,100 new species were described), and this gives a wonderful base for freshwater ecology studies. Very little work has been conducted on Sumatran rivers and lakes since that expedition, except for the work by the National Biological Institute on the River Alas (LBN 1980) and by the Bogar Agricultural Institute on the largely brackish Upang-Banyuasin delta (IPB 1975).
Uncommon Lowland Forests
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

Lowland forests vary quite considerably in composition (p. 198) and three types are discussed individually below because they are so strikingly different. They are: heath forest/padang vegetation, ironwood forest and forest on limestone. The first two types were investigated by a team from CRES and are discussed in detail below.
Effects of Disturbance
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

Natural ecosystems are not static. The plants and animals within them die and others are born to replace them. Energy and nutrients pass through the organisms and are removed from the system in water, by emigration or by ‘visitors’. If part of an ecosystem is destroyed in some way, the biotic community and the physical features of the soil will generally be rebuilt. This can take decades or even a thousand years depending on the ecosystem and the extent of the disturbance. The disturbed area is colonised by pioneer species which are gradually replaced by others until an ecosystem closely resembling the original is formed which is itself subject to disturbance. This sequence of changes is called succession. In areas where repeated disturbance occurs or where the process of succession is halted, an ecosystem may never have a chance to recover.
Deactivation of Feedforward and Feedback Pathways in the Visual Cortex of the Monkey
Authors: Girard Pascal , Bullier Jean
Published: November 2023

In this chapter we present an overview over our group’s long-standing experience with different inactivation methods to investigate the function of corticocortical visual pathways in the macaque monkey. Our studies are mainly centered on the role of feedforward and feedback pathways. Both of these pathways were originally defined on purely anatomical grounds (Van Essen and Maunsell 1983) and a speculative hierarchy of visual areas was derived from this anatomical work. For the past fifteen years we have been examining the functional aspects of this hierarchy with the help of reversible inactivation methods. The advantages and limitations of these methods are provided in the comprehensive overview of Lomber (1999). Many of these points will also be considered in this chapter.
Case Studies in Virtual Neuropsychology: Reversible Lesions and Magnetic Brain Stimulation
Authors: Walsh Vincent , Pascual-Leone Alvaro
Published: November 2023

Transcranial Magnetic Stimulation (TMS) is now an established technique in cognitive neuroscience. The utility of the technique can be stated simply: the temporary disruption of normal cortical functioning, within a prescribed brain region and/or period of processing, can be used to study the effects of lesions in real time, without the masking effects of the “specter of compensation.” These virtual lesion patients produced by TMS can be used as their own controls, unlike real neuropsychological patients and, again unlike in real patients, the temporal resolution of TMS makes a chronometric analysis of the virtual lesion effects possible.
Excitability of Human Visual Cortex Examined with Transcranial Magnetic Stimulation
Authors: Boroojerdi Babak , Cohen Leonardo G
Published: November 2023

In the last 15 years, transcranial magnetic stimulation (TMS) has become a valuable method of study of the physiology and cognitive functions of the human brain. Using this technique, it is possible to stimulate the human cerebral cortex in a noninvasive and painless way (Barker et al. 1985). TMS elicits a magnetic field that passes virtually unaffected through the skin, skull and scalp (in simple terms, it elicits an electric field oriented perpendicular to the magnetic field). Induced currents in the tissue flow in a direction parallel to the coil (Maccabee et al. 1991b; Roth et al. 1991; Roth 1994). This method has an overall temporal resolution in the range of milliseconds, and a spatial resolution depending on the magnetic coils utilized, approximately down to a square centimeter. Examples of responses elicited by TMS include motor evoked potentials (MEP) elicited after stimulating the contralateral motor cortex. On the other hand, TMS can also cause a brief disruption of the cortical activity under the magnetic coil.
The Emergence and Co-Evolution of Human Pathogens
Authors: Baum Jake , Bar-Gal Gila Kahila
Published: November 2023

The great diversity of life that we see today has evolved through a complex history of selective inter actions between organisms competing with each other for limited resources and striving to survive changes in the environment. Whilst our vision of this diversity is dominated by what we see with the naked eye, we should not forget the microscopic pathogens that plague everything from the single celled prokaryote to multicellular plants and animals. As a group they are unsurpassed in the breadth of their life strategies and the biological niches that they occupy. Indeed even if we restrict our discussion to human pathogens, the consortium is still impressive, comprising a heterogeneous array of viruses, bacteria, fungi, protozoa, and metozoa, all living temporarily or permanently within our bodies, on our outer surfaces, in our body fluids, in our tissues, and cells and even in our genomes.
Smart-tourist guide to a synchrotron light facility
Authors: Margaritondo Giorgio
Published: November 2023

A person visiting a synchrotron laboratory for the first time is confronted with a rather confusing picture: a huge room cluttered with metal tubes, aluminum foil and mysterious electronic equipment, where scientists and technicians are engaged in a variety of tasks. Gradually, a coherent structure becomes evident (Fig. 1.1): in the center of everything, there is a closed-loop tube. Several straight tubes depart from it in tangential directions; each one passes through complicated devices and ends with a formidable-looking piece of equipment. This is where most of the scientists and technicians are gathered.
The facility
Authors: Margaritondo Giorgio
Published: November 2023

The storage ring and its many sources of synchrotron light—undulators, wigglers and bending magnets--constitutes the core of a synchrotron facility. Such sources, however, would be useless without additional equipment. Quite often, for example, optical devices are needed to modify the spectral and geometrical characteristics of the emitted light beam and meet the requirements of specific applications. The back-end of each beamline must be equipped with an experimental chamber that includes different instruments, and interfaced with computers for controlling the experimental parameters and taking, processing, storing and exporting the data. The many different applications of synchrotron light require a wide variety of instruments. A complete and detailed description of such instruments is well beyond our scope, and so we will limit the discussion to general issues and a to some examples of specific relevance to the audience of this book.
Future directions
Authors: Margaritondo Giorgio
Published: November 2023

Synchrotron-based activities have expanded for more than three decades. This evolution is not slowing down but accelerating. We have already discussed several important aspects of the expansion such as the shift from physics to the life sciences and the progress towards X-FELs. There are many other important aspects. In this chapter we discuss some of them, in three general areas: new sources, new applications and new management approaches.
Continuum Theory Of Crystalline Solids
Authors: Bhattacharya Kaushik
Published: November 2023

In this chapter, we develop a continuum theory of crystalline solids. We begin with a review of lattices and the symmetry of lattices. A reader who finds this review insufficient is referred to introductory books on solid state physics like that by Ashcroft and Mermin (1976). We then link the lattice to the continuum using the Cauchy–Born hypothesis and describe the consequences of this linkage on the resulting continuum theory. This presentation draws heavily from the ideas of Ericksen (1978; 1979; 1980; 1984) and the work of Pitteri and Zanzotto (1984; 1985; 2003).
The Shape-Memory Effect
Authors: Bhattacharya Kaushik
Published: November 2023

We are now in a position to discuss the shape-memory effect. Recall from the introduction that this is the ability of certain materials to recover, on heating, apparently plastic deformation sustained below a critical temperature. We begin in this chapter to address the question as to what makes shape-memory alloys special amongst martensites.
The problems of the Standard Model
Authors: Binétruy P
Published: November 2023

The Standard Model is a very satisfying theory of fundamental interactions: it has been superbly confirmed by experimental data, especially precision tests at the LEP collider. But it does not answer all the questions that one may raise about fundamental interactions. It is therefore believed to be the low energy limit of some deeper theory. It is the purpose of this chapter to make this statement more explicit. We will see that most of the questions which remain to be answered require new physics at much larger mass scales than the typical Standard Model scale.
The singular rôle of Supersymmetry
Authors: Binétruy P
Published: November 2023

This chapter presents basic notions about super symmetry and super symmetry breaking. In particular, it underlines the way super symmetry is a unique symmetry among space time symmetries. 2.1 Why supersymmetry? Super symmetry is a symmetry between boson and fermion fields. Why should we try to search for such a symmetry? One very fundamental reason is the following. Bosons are the mediators of interaction: their statistics allows for a coherent superposition and thus for a macroscopic force, such as the Coulomb force. On the other hand, fermions are the constituents of matter: their statistics is translated at the macroscopic level into the additive character of matter. It is certainly a very fundamental question to ask whether there exists a symmetry which unifies matter and radiation. The educated reader already knows that the present models of super symmetry applied to particle physics do not fulﬁll this goal. Should this be taken as an indication that they are not yet complete? But let us put this aside and try to identify the general properties of a symmetry between bosons and fermions.
Supersymmetric grand unification
Authors: Binétruy P
Published: November 2023

With all its successes, the Standard Model does not really achieve complete unification. Indeed, it trades the two couplings αe.m. and GF describing respectively electromagnetic and weak interactions for the two gauge couplings g and gt. More-over, even if one disregards gravitational interactions which are so much weaker, one should at some point take into account the remaining fundamental gauge interaction, namely quantum chromo dynamics (QCD), which describes strong interactions. Indeed, as one goes to higher energies, the QCD running coupling becomes weaker, and thus closer in magnitude to the electroweak couplings. Earlier work on quark–lepton unification [302] helped to bridge the gap towards a real unification of all known gauge interactions and in 1973 Georgi and Glashow proposed the first such grand unified model based on the gauge group SU (5) [181].
Mixed III-V-N semiconductors: a challenge for tomorrow?
Authors: Tournie Eric , Gil Bernard
Published: November 2023

The first investigations on mixed III-V-N semiconductors date back almost 40 years [1-4]. III-V-N samples, however, have long been prepared by near equilibrium crystal-growth techniques such as bulk growth or liquid and vapour phase epitaxy. The nitrogen content is then governed by thermodynamic considerations which predict an exceedingly low solubility of N in III-V compounds (e.g. < 1014 cm-3 in GaAs at 650 °C) under equilibrium conditions [5-7]. The nitrogen concentration in early III-V-N samples was thus limited to doping amounts. The problem had thus been entered from its fundamental aspect, by considering N as an isoelectronic impurity in III-V compounds.
Experimental examples of structural studies
Authors: Higgins Julia S , BenoÎt Hendri C
Published: November 2023

In the earlier chapters of this book we introduced the experimental methods of small angle scattering, and explained how the raw data can be reduced to the point where the quantity remaining is the scattering law, S ( q). Sub sequent chapters have been devoted to deriving the mathematical forms for S(q) for various models. We now want to demonstrate by using some examples from the literature how these models can be used to extract useful physical parameters from the data. This is in no way to be interpreted as a review of the literature, which is both extensive and growing rapidly.
Physics Of Solid Helium
Authors: Glyde Henry R
Published: November 2023

Natural helium was first solidified in the famous Kamerlingh Onnes Laboratory in Lieden by Keesom in 1926 (Keesom 1942). The much rarer isotope, 3He, was first solidified in 1951 at Los Alamos National Laboratory by Osborne, Abraham, and Weinstock (1951). Under its own saturated vapour pressure (SVP) helium remains a liquid at the lowest temperatures. Owing to its light mass, the de Broglie wavelength of 4He is long (e.g. thermal wavelength λT- = (h  2/2 π mk;T)1/2 is λT ∼ 5 Å at T = 4.2 K). The attractive potential between helium atoms is weak (Aziz 1984; Aziz et al. 1987). Thus helium atoms can be localized enough to form a solid only under pressure. At p ≃ 25 bars, 4He solidifies into a bcc or an hep phase, depending on the temperature (see Fig. 3.1) (Keller 1969; Wilks 1967). At p ≈ 30 bars, 3He solidifies into the bcc phase, a highly expanded solid of molar volume V ≃ 24.5 cm3 mol-1and interatomic separation R ≃ 3.75 Å.
Introduction To Liquid 4HE
Authors: Glyde Henry R
Published: November 2023

In this chapter we introduce some basic concepts of superfluid 4He that we will draw on in Chapters 8-12. Liquid 4 He has a long and rich history and there are many concepts that are implicit in the field today. We begin with a sketch of the unique mass and heat flow character of superfluid 4He. The assumptions of the two-fluid model used successfully to describe these properties are noted in §7.1. We introduce Bose-Einstein condensation in a Bose gas and the extension of this to interacting superfluid 4 He in §7.2. This leads naturally to the one-body density matrix which is the intermediate scattering function in the impulse approximation,We introduce a number of basic properties such as the static structure factor, the pair correlation function, and the momentum distribution which can be calculated from first principles using Monte Carlo and path integral Monte Carlo (PIMC) methods. We conclude by noting the two current descriptions of the characteristic excitation in superfluid 4He. The first is a density excitation, based on the Landau and Feynman view, with suitable modifications at higher Q to take account of correlations among atoms. In the second, the density excitation is separated into a part due to the excitation of single particles out of the condensate to states above the condensate and a part due to regular density excitations involving only states above the condensate. In the latter picture the condensate appears explicitly in S(Q, ω).
Historical Development Of Ideas
Authors: Glyde Henry R
Published: November 2023

In this chapter, we note the highlights in the historical development of our understanding of excitations in normal and superfluid 4He. The aim is to provide a background to the experimental data and theory presented in Chapters 10 and Chapter 11, respectively. This will also help to clarify the origin and meaning of terms commonly used to describe the excitations: terms such as phonon, roton, quasiparticle, and so on.
Interactions
Authors: Hicks Trevor J
Published: November 2023

The magnetic properties of disordered solids are rich and varied and no one technique is sufficient to probe the whole range of behaviour. Nevertheless, neutron scattering comes closest to universal applicability. Spatial inhomogeneity is an important aspect of disordered materials. For some techniques spatial information can only be inferred indirectly from the data, for instance by assuming that the largest effects are most probably from first neighbour atoms. Spatial information is built directly into neutron scattering experiments because of the neutron wavelength. The accessible length scale is from atomic dimensions to distances of hundreds of Ångstroms; a very useful range for disorder at the atomic level.
Spin glasses
Authors: Hicks Trevor J
Published: November 2023

Spin glasses are spatially magnetically disordered materials which are frozen at least on the time scale of ordinary laboratory measurements. This means that the magnetic fluctuations of these materials in the frozen state are definitely much slower than can be detected with neutrons. However, the static configuration of magnetic moments gives rise to magnetic diffuse scattering of neutrons which can be isolated by the same polarization analysis techniques outlined at the beginning of Chapter 4 on antiferromagnets. Even above the freezing temperature, measured at laboratory times by, say, the acquisition of susceptibility data as a function of temperature, the magnetic fluctuations are so slow that quasielastic approximations for the neutron scattering can be used and a picture of the magnetic moment correlations can be obtained which if not static on laboratory time scales are static on neutron scattering time scales.
Electron Dynamics by Inelastic X-ray Scattering
Authors: Schülke Winfried
Published: November 2023

Knowledge of the dynamics of many-electron systems is of fundamental importance to all disciplines of condensed matter physics. A very effective access to electron dynamics is offered by inelastic X-ray scattering (IXS) spectroscopy. The double differential scattering cross section for IXS is directly related to the time-dependent two-particle density correlation function, and, for large momentum and energy transfer (Compton limit) to the electron momentum distribution. Moreover, resonant inelastic X-ray scattering (RIXS) enables the study of electron dynamics via electronic excitations in a very selective manner (e.g. selectively spin, crystal momentum, or symmetry), so that other methods are efficaciously complemented. The progress of IXS spectroscopy is intimately related to the growing range of applications of synchrotron radiation. The aim of the book is to provide the growing community of researchers with accounts of experimental methods, instrumentation, and data analysis of IXS, with representative examples of successful applications, and with the theoretical framework for interpretations of the measurements.
Resonant inelastic X-ray scattering (RIXS)
Authors: Schülke Winfried
Published: November 2023

When Sparks jr. (1974), still using conventional X-ray sources, started to investigate resonant emission of X-rays, and Eisenberger et al. (1976a,b), using for the first time synchrotron radiation for inelastic X-ray scattering studies, detected the so-called Raman shift and the anomalous width of the resonant emission, nobody would believe that it was just RIXS, which became the most important field of inelastic X-ray scattering, at least for investigating actual materials of high practical importance.
Artificial Ethology
Authors: Holland Owen , McFarland David
Published: November 2023

Artificial ethology is an exciting new field of research that explores the ways that we can use robots and robotics to enhance our understanding of how real animals behave. Modelling and computer simulations combined with empirical research are the traditional tools of animal behaviour. This new text sets out to show how experimentation with animal-like robots can add a new dimension to our understanding of behavioural questions. Introductory chapters explain the history of the use of models in animal behaviour, and describe how animal like mobile robots 'evolved' during the development of the discipline. Then thematic chapters scrutinise sensory processes and orientation, motor co-ordination, and motivation and learning in turn. Each thematic exploration is exemplified by a series of case studies, written by some of the leading researchers in artificial ethology. From robotic lobsters to robot crickets and robot 'sheepdogs', each of these case studies give a detailed description of a particular problem, research approach, and robot application. The examples bring the text to life, and will enable students to get an in- depth picture of the potential and the practicalities of this research. The text concludes with a discussion of general points arising from the use of robots in biological research, and the rationale for using real robots as opposed to simulation. Aimed at advanced students taking courses in animal behaviour, the text should also be of interest to computer scientists and engineers interested in robotics, artificial intelligence, and the study of biological systems.
History of models in ethology
Authors: Holland Owen , McFarland David
Published: November 2023

Models and analogies have been a feature of ethology since its early days. Konrad Lorenz (1950) likened the motivational system of an animal to the simple hydraulic system illustrated in Figure 1.1. In this model, motivational ‘energy’, represented by the liquid in the reservoir, builds up in the absence of an opportunity to perform the relevant behaviour, and ‘discharges’ when the relevant external stimuli (represented by the weight on the pan) ‘release’ the behaviour. Apart from the inappropriateness of the concept of energy (Hinde 1960; McFarland 1971) this model offers a good analogy, at a general level, of the interaction of internal and external factors in animal motivation. However, ethological modelling of a much more precise nature considerably predates Lorenz’s attempts
Tensors and Manifolds
Authors: Wasserman Robert H
Published: November 2023

This book is a new edition of “Tensors and Manifolds: With Applications to Mechanics and Relativity” which was published in 1992. It is based on courses taken by advanced undergraduate and beginning graduate students in mathematics and physics, giving an introduction to the expanse of modern mathematics and its application in modern physics. It aims to fill the gap between the basic courses and the highly technical and specialised courses which both mathematics and physics students require in their advanced training, while simultaneously trying to promote, at an early stage, a better appreciation and understanding of each other’s discipline. The book sets forth the basic principles of tensors and manifolds, describing how the mathematics underlies elegant geometrical models of classical mechanics, relativity and elementary particle physics. The existing material from the first edition has been reworked and extended in some sections to provide extra clarity, as well as additional problems. Four new chapters on Lie groups and fibre bundles have been included, leading to an exposition of gauge theory and the standard model of elementary particle physics. Mathematical rigour combined with an informal style makes this a very accessible book and will provide the reader with an enjoyable panorama of interesting mathematics and physics.
Exterior (Grassmann) Algebra
Authors: Wasserman Robert H
Published: November 2023

We will imbed collections of the spaces Vs  r into larger structures containing them. We will then focus primarily on the exterior, or Grassmann, algebras, ΛV, and ΛV*.
Topological Spaces
Authors: Wasserman Robert H
Published: November 2023

Chapter 1 was supposed to serve to recall some linear algebra needed for the following exposition of tensor algebra. This chapter is supposed to serve a similar purpose, to recall some topology which we will need to discuss differentiable manifolds.
Submanifolds
Authors: Wasserman Robert H
Published: November 2023

The prototypical submanifold is a surface in ordinary space. There are various ways of describing surfaces in ordinary space.
Vector Fields, 1-Forms, and Other Tensor Fields
Authors: Wasserman Robert H
Published: November 2023

Our discussion of vector fields will include their interpretation as derivations, construction of the tangent manifold, C∞ vector fields, and the Lie bracket of two vector fields. Comments on 1-forms will be focused on analogies with vector fields. Finally, under mappings of tensor fields, we discuss interior multiplication of forms, the pull-back of (0, s) tensor fields, and ¢-related (r, 0) tensor fields.
The Flow and the Lie Derivative of a Vector Field
Authors: Wasserman Robert H
Published: November 2023

The concept of a vector field on a manifold, M (or, on an open subset, U, of M), has a simple intuitive definition, but also has broad and deep ramifications. In particular, we want to look at vector fields from two rather different and important points of view. Roughly, (1) a vector field can be thought of as determining, or being determined by, a family of curves, and (2) a vector field can be thought of as determining, or being determined by, a certain derivation on tensor fields on M (or U).
Nonempty Spacetimes
Authors: Wasserman Robert H
Published: November 2023

We will obtain two types of solutions of Einstein’s equation, (22.27); a model of the interior of a star, and a class of models of the universe as a whole, a class of cosmologies.
Connections on Fiber Bundles
Authors: Wasserman Robert H
Published: November 2023

In Section 17.1, we noted that in general there is no a priori relation between the fibers of the tangent bundle of a manifold, and that an additional structure “a connection” provides such a relation. The same is true for fiber bundles generally. We will now introduce an additional structure on fiber bundles which relates the fibers in the sense that to each given curve in M and point in E, there is a unique curve in E along which we say a point is parallelly propagated (translated, transported, or displaced). Once we have a connection, we can define the curvature of the connection.
Electron excitation: electron energy loss spectroscopy (ELS), core electron energy loss spectroscopy (CEELS), and high resolution electron energy loss spectroscopy (HREELS)
Authors: Riviere J C
Published: November 2023

In none of these loss spectroscopies is spatial resolution required, but they do require electron sources capable of variable primary energy down to very low energies, with good stability. The need in HREELS for careful screening of the whole analytical system of source and analyser from strong magnetic fields has already been emphasized, as has the practice of minimizing currents of unwanted secondary electrons by coating internal surfaces with a low secondary emitter such as carbon.
Electron excitation: soft X-ray appearance potential spectroscopy (SXAPS), Auger electron appearance potential spectroscopy (AEAPS), and dis-appearance potential spectroscopy (DAPS)
Authors: Riviere J C
Published: November 2023

Many different experimental geometries have been used for SXAPS, probably as many as there are experimenters in the field, but the basic configuration is common to all, and is summarized in the simplified diagram of Fig. 6.1, from Harte et al. Electrons from a filament F are accelerated through a ramped accelerating potential on to the surface of the material under investigation, which forms the target T. Soft X-rays produced in T pass through a screen S, designed to block passage of electrons, and impinge on a photosensitive.
Ion excitation: ion-excited Auger electron spectroscopy (IAES) and proton-excited Auger electron spectroscopy (PAES)
Authors: Riviere J C
Published: November 2023

For operation in the low energy region, ions are usually produced in a conventional gun of the type also used for sputter cleaning and depth profiling, such as the duoplasmatron described under Section 3.2.3 and show in Fig. 3.13. The general experimental arrangement would be very similar to that used for electron-excited AES, as seen in Fig. 13.1 from the work of Kempf and Kaus. With such an arrangement the techniques of AES, IAES, SSIMS, and ISS could all be performed, although the conditions for the two latter would not be ideal. For electron energy analysis a cylindrical mirror analyser (CMA) is commonly used, since high energy resolution is not normally required.
Ion excitation: ion neutralization spectroscopy (INS) and metastable quenching spectroscopy (MQS)
Authors: Riviere J C
Published: November 2023

Strictly speaking INS should be included with IAES in the previous chapter, but it is treated separately here for several reasons. Firstly, the incident ion energies are very much lower (5-10 eV) than any discussed previously, and the production and transport of the ions therefore require special experimental design. Secondly, for reasons that will become apparent, the only ion type used is helium. Thirdly, the processing of the experimental data leads necessarily into complex but fascinating mathematical manipulations involving, principally, deconvolution. And fourthly, it is still almost a one-man technique; nearly all the published work on INS has come from Hagstrum (and co-workers), who was both the originator and the developer of the technique. What follows, therefore, is taken almost entirely from his publications. The experimental chamber is a three-dimensional symmetric cross, with the experimental facilities on the four horizontal ports, specimen manipulator on the top port, and pumping on the bottom port.
Ion excitation: static secondary ion mass spectrometry (SSIMS)
Authors: Riviere J C
Published: November 2023

SSIMS ranks with XPS and AES as one of the three principal techniques currently used in surface analysis, although judging from the published applications its usage is still probably less widespread than that of the other two. Since its origination by Benninghoven in 1969 coincided roughly with that of AES, it must be regarded as a mature technique, although as will be seen below there are even now some considerable problems in its interpretation. As remarked earlier (Section 2.3.5), ‘static’ SIMS is at one end of the spectrum of SIMS-type techniques, while ‘dynamic’ SIMS is at the other, and the two should not be confused.
High field excitation: scanning tunnelling microscopy and spectroscopy (STM and STS)
Authors: Riviere J C
Published: November 2023

Just as APFIM (see previous chapter) arose out of its parent technique FIM, so Scanning Tunnelling Spectroscopy (STS) has arisen out of Scanning Tunnelling Microscopy (STM). The similarities in origin go further, because while both FIM and STM are surface topographical imaging techniques, i.e. are concerned principally with effects due to surface structure, APFIM and STS provide information about the chemical nature of the surface, either by atomic compositional analysis or by surface state spectroscopic analysis. Again, in the same way that it was necessary in Chapter 21 to describe FIM in order to describe APFIM, so here it will be necessary to go into the details of the STM technique in order to be clear about the associated spectroscopic technique. There the similarities end, however, because although APFIM is now a well established technique, both STM and STS, the latter in particular, are relatively new. The inventors of STM were Binnig and Rohrer,1 who received the Nobel Prize for their contribution to physics.
Introduction
Authors: Dobbs E R
Published: November 2023

Helium exists as two stable isotopes of masses 3 and 4. Ordinary helium gas, with atoms of mass 4, is a rare element, which was only discovered by Ramsay in 1895. Helium 3 is much rarer still, for only about 1 atom in 104 of helium gas is of mass 3. Fortunately, one of the useful by products of nuclear reactors is their ability to convert the isotope lithium 6 by neutron bombardment into helium 3.