bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution and peculiarities of the harriers
Authors: Simmons Robert E
Published: November 2023

Harriers occur on every continent bar Antarctica and are relatively evenly spaced around the globe. Four occur in Europe, four in Africa, two each in Asia, Australasia, and South America and one in North America. However, recent work on the genetics of this group has revealed 2 new species and the interrelationships between all 16. In this chapter we will look at these relationships and discuss the peculiarities that distinguish harriers from other raptors.
Aerial displays: mate choice and reversed dimorphism
Authors: Simmons Robert E
Published: November 2023

The father of systematic biology, Carl von Linnaeus, mistakenly lumped the harriers in with falcons when he named the first two harriers Falco aeruginosus and Falco pygargus, in 1758. It took Frenchman Lacepede to realise their differences in 1799, and he was presumably impressed enough with the display behaviour of the harriers to rename the genus Circus-the hawk that circles. The name captures one trait that distinguishes harriers from the falcons-their astounding acrobatic nature and uncontrolled abandon during aerial displays before and during breeding. In this chapter I will explore the different types of display, the reasons why harriers expend a great deal of energy displaying, what they communicate to other birds, and whether females can and do use the displays as a guide to male fitness.
Clutch size and latitude
Authors: Simmons Robert E
Published: November 2023

One of the most widespread ecological phenomena for which there is yet to be a single satisfying explanation is why the number of eggs in a clutch declines with latitude. This is one area where research on raptorial birds can make an impact because several studies have now compared food resources between northern temperate and southern subtropical regions and arrived at similar conclusions. These global trends in avian reproduction are well known and were first analysed by Moreau (1944) and Lack (1947); they found that avian reproductive output, particularly clutch size, decreases progressively towards the equator for both passerines and non-passerines. This has been confirmed many times for both passerines (e.g. Klomp 1970; Kulesza 1990) and falconiforms (Donazar 1990; Jenkins 1991}, yet the selection pressures on small clutches in the tropics are still widely debated (Skutch l 949; Lack l 954; Ashmole l 963; Hussell l 985; Murray 1985; Kulesza 1990; Martin 1996).
Farmland
Authors: Gilbert Oliver L , Anderson Penny
Published: November 2023

The 1945 Agriculture Act, driven by a perceived need for agricultural selfsufficiency in the wake of the Second World War, set the scene for agricultural intensification and marked a watershed for farmland as a habitat for wildlife (Dodds et al. 1995; Stoate 1996).With subsidies available, huge areas of unimproved grassland were replaced either with arable or carefully managed swards composed of cultivated varieties of rye-grass (Lolium perenne) and white clover (Trifolium repens). This grassland took the form of short-term leys within a rotation, and longer-term grazed pastures. These productive alternatives meant that it was no longer economic to manage water meadows, and most old unimproved pastures were ploughed out or, with the help of large amounts of inorganic nitrogenous fertilizer, converted to productive, species-poor swards.
The littorina saxatilis species complex — interpretation using random amplified Polymorphic DNAs
Authors: Crossland Susan , Coates David , Grahame John , Mill Peter J
Published: November 2023

The Littorina saxatilis species complex comprises four recognised species. Littorina saxatilis (Olivi), L. arcana Hannaford Ellis and L. nigrolineata Gray are generally recognised as ‘good’ species by most workers since Hannaford Ellis (1978) described L. arcana as a separate species. The status of L. neglecta Bean has, however, been called into question by several workers (B. Johannesson and K. Johannesson, 1990; K. Johannesson and B. Johannesson; 1990, Reid, 1993), who have suggested that L. neglecta represents an extreme ecomorph of L. saxatilis. Previous work on the species complex has been ambiguous in separating Littorina saxatilis and L. arcana into genetically distinct groups (e.g. Knight, Hughes and Ward, 1987; Mill and Grahame, 1988; Knight and Ward, 1991). However, their different reproductive modes, for example, provide clear evidence for separation at the species level. Morphometric analysis is confounded by ecological variance, with exposed shore morphs differing from sheltered shore morphs.
Evolutionary radiations in the cypraeidae
Authors: Kay E Alison
Published: November 2023

J.E. Gray (1824-1828) listed 101 species of cowries in his newly proposed family Cypraeidae (excluding members of the Triviidae). An estimated 200 Recent species and another 500 extinct species are recognized today, but Gray’s challenge remains despite the high visibility of cowries as collectors’ items, a respectable fossil record, and the enormous contributions to the systematics of the cypraeids by Franz Schilder, who with his wife, Maria, for fifty years devoted his life attempting to order the cowries in “natural genera.” Schilder’s vision of the characters necessary for a phylogeny was extraordinarily perceptive and anticipates many aspects of character definition now employed in modem cladistics (see, for example, Schilder, 1936). However, his system is marred by inconsistencies in shell characters and anatomy within tribes and between genera (Kay, 1960,1963; Dolin and Bouchet, 1986), perhaps because he painted with too broad a brush, utilizing tribes (groups of genera) as his standard for the history of characters.
Feeding ecology
Authors: Kushlan James A , Hancock James A
Published: November 2023

Herons are, fundamentally, birds that wade in the water to capture aquatic prey with their bills. Many of the biological characteristics, described in Chapter 1, influence and reflect the way they feed. Specifically, the archetypical heron is a medium-sized bird, relative to the range of all birds, with long legs, long neck, and long bill. It uses its long legs to wade and stand in shallow water where it strikes at fish with its long neck, and bill. It feeds alone and also at times joins others aggregating in shallow water habitats having a supply of fish.
Herons and people
Authors: Kushlan James A , Hancock James A
Published: November 2023

When despair for the world grows in me and I wake in the night at the least sound in fear of what my life and my children’s life may be, I go and lie down where the wood drake rests in his beauty on the water, and the great heron feeds I come into the peace of wild things who do not tax their lives with forethought of grief. I come into the presence of still water. And I feel above me the day-blind stars waiting with their lights. For a time I rest in the grace of the world, and am free. from Wendell Berry, Collected Poems: 1957–1982. Copyright 1985. North Point Press, a division of Farrar, Straus and Giroux, LLC.
Grey Heron Ardea cinerea
Authors: Kushlan James A , Hancock James A
Published: November 2023

Other names: The Heron in English; Garza Real in Spanish; Héron cendré in French; Graureiher, Fischreiher in German; Blauwe Reiger in Dutch; E,D”b B”Bjzb in Russian; Gråhäger in Swedish; Cangak abu in Indonesian; Ao-sagi in Japanese; Cang lu in Chinese. Ardea Linnaeus, 1758. Syst. Nat. ed. 10, 1, 141. Type by subsequent designation Ardea cinerea Linnaeus (Gray, 1840, List Gen. Birds, p. 66). Ardea cinerea Linnaeus, 1758. Syst. Nat. 10(1), 143: Sweden.
Cocoi Heron Ardea cocoi
Authors: Kushlan James A , Hancock James A
Published: November 2023

Other names: White-necked Heron in English: Garza Cuca, Garza Morena, Garza Gris, Garza Mora, Garza Real, Garza Cenicienta, Garzón in Spanish; Socó-grande, João-grande, Maguari, Baguari in Portugese; Héron cocoi in French; Cocoireiher in German. Ardea cocoi Linnaeus, 1766. Syst. Nat. ed. 12(1), p. 237: Cayenne. The Cocoi Heron is a large grey heron with white neck and black cap.
Squacco Heron Ardeola ralloides
Authors: Kushlan James A , Hancock James A
Published: November 2023

Loss of mangroves in Australia and Seychelles and elsewhere in its range is creating cause for concern. This is a polymorphic species with many island forms. Each of these forms has its own set of conservation issues that need to be addressed. Conservation of each genetic population is crucial. There is surprising little known about the biology, especially the behaviour of this species.
Indian Pond-Heron Ardeola grayii
Authors: Kushlan James A , Hancock James A
Published: November 2023

The Squacco Heron is a brownish-buff bird that blends completely into its surroundings. It typically is a lone feeder, standing, crouched low and still, watching for prey in the water below. It is bird of dense marshes and rice fields. The alarm and flight call is highly recognizable, giving the bird its name. Populations fluctuate, the causes not being clear; hunting, habitat change, and perhaps climate have all been advocated. The increase in rice fields are a likely cause of its recent population growth.
Agami Heron Agamia agami
Authors: Kushlan James A , Hancock James A
Published: November 2023

biology, particularly clutch size, success, and nesting cycles, need to be further examined. It is likely to reveal interesting twists in heron biology which may in turn reveal basic understanding of the biology of forest herons. Observations and surveys need to continue to locate concentrations that can be identified as important areas for conservation. Per- haps touring associations and lodges can adopt this species as one to be sought after, recorded, monitored, and reported upon.
Melanism in conspicuous Lepidoptera
Authors: Majerus Michael E N
Published: November 2023

In the previous three chapters, the majority of Lepidoptera discussed have relied on some form of camouflage to avoid predation, and the melanic forms that they exhibit have often evolved to maximise predator avoidance, either when at rest, or, in some instances, when in flight. However, many organisms have evolved conenrty; to mimic thus protected species; or to attract mates or deter rivals. Melanism in conspicuous species occurs in a wide range of taxa, some of which have already been discussed in Chapter 2. However, in this chapter I will again confine myself to the Lepidoptera, for the main principles involved in the evolution of melanism in brightly coloured species can all be related using examples from this order. I will continue this theme in Chapter 9, in which I will discuss melanism in a brightly coloured family of beetles, the ladybirds, in which warning coloration, mimicry, sexual selection, and other factors, such as thermal melanism, may all have an effect on the evolution and maintenance of melanism, sometimes within a single species.
What this book is about
Authors: Harvey Paul H , Sean Nee
Published: November 2023

From time to time scientists working in quite different areas find themselves united by common knowledge, methods, or theories. This volume shows how biologists working on a set of seemingly different problems are entering such a time. The revolution in gene sequencing technology is resulting in the production of more accurate phylogenies or gene genealogies which can be used to help understand biological processes occurring at many different levels of life’s hierarchy. As different chapters demonstrate, genetics, development, behaviour, epidemiology, ecology, conservation biology, and evolution arc examples of fields that can be illuminated by such information.
The NMR parameters
Authors: Gadian David G
Published: November 2023

Detailed interpretation of magnetic resonance images and spectra requires an understanding of the various factors that influence the characteristics of NMR signals. In previous chapters, it was noted that the nature of NMR signals depends on a wide range of physical and chemical effects, and the purpose of this chapter is to explain the basis of these effects, and to indicate how they can be quantified. We shall consider in turn the chemical shift, spin-spin coupling, and relaxation, and then discuss the ways in which these properties of NMR signals can be influenced by magnetization transfer effects and by paramagnetic species.
The importance of accurate structure determination in inorganic chemistry
Authors: Burdett Jeremy K
Published: November 2023

Inorganic chemistry involves the study of virtually all of the periodic table, and as such exhibits a tremendously diverse structural chemistry. It is a truism to say that today the characterization of a new inorganic or organometallic species is not complete without an X-ray structure determination. Organic chemists, on the other hand, are often quite happy with an NMR or other spectroscopic study. In fact a comparison between the material in this chapter and that of Chapter 16 on organic chemistry will show some very important differences between the two fields. At the present time organic chemistry is a much more mature subject than its inorganic counterpart. As a result we find a considerably smaller number of new organic structural types compared with new modes of coordination or geometry in the inorganic and organometallic areas. Even in its immature state, structural inorganic chemistry is a much richer field than its organic analog. Inorganic and organic chemists, as a result, use accurate structural results in rather different ways. While the organic chemist may be interested in rather small changes in molecular dimensions as the result of a substitution of one or more of the atoms in a parent molecule, the inorganic chemist determines bond lengths and angles which show much wider system-to-system variations than corresponding parameters in organic chemistry. Molecular orbital models to account for this wide spectrum of observations are well developed in the inorganic area and many experiments are, in fact, devised to test existing theories.
Pulsed radiation techniques: flash photolysis and pulse radiolysis
Authors: Bensasson R v. , Land E J , Truscott T G
Published: November 2023

The technique of flash photolysis was introduced in 1949 (Norrish and Porter 1949; Porter 1950). It is a powerful method for studying, as a function of time, transient species (mainly excited states and radicals) produced via electronic excitation of molecules by short pulses of UV or visible radiation. About a decade later pulse radiolysis, using the same principle, was applied to the study of similar species produced by pulses of high energy radiation (Boag and Steel 1960; Keene 1960; M.S. Matheson and Dorfman 1960; McCarthy and MacLachlan 1960).
Pyrimidines, purines, and nucleic acids
Authors: Bensasson R v. , Land E J , Truscott T G
Published: November 2023

All cells contain both deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Most of the DNA is located in the nucleus and in the mitochondria, whereas most of the RNA is in the cytoplasm, and more precisely in subcellular organelles involved in protein synthesis. DNA contains purine bases, adenine (A) and guanine (G), and pyrimidine bases, thymine (T) and cytosine (C). The RNA structure differs from that of DNA by two features: the sugar unit is ribose and not deoxyribose and thymine is replaced by uracil (U). DNA stores genetic information in all prokaryotic and eukaryotic cells using a code in which the ‘letters’ are the four bases of DNA.
Principle of diffraction experiment
Authors: Aslanov L A , Fetisov G V
Published: November 2023

In order to answer the question ‘How does one measure Bragg reflections from crystals?’ it is helpful first to introduce the concept of the Ewald construction, based upon which it is easy to consider experimental geometries. The concept of the Ewald’s construction permits one to visualize diffraction effects in reciprocal space, helps to understand better the effects and is often helpful in calculations related to geometrical features of diffraction measurements. Since we will use this concept widely in our further Due to the three-dimensional periodicity of a crystal lattice, X-rays are scattered by crystals and form a corresponding three-dimensional set of diffracted intensities, which are observed at specific angles 20 between directions of the incident and reflected X-rays. W.L. Bragg described this fact at the beginning of this century by the formula.
Fundamental techniques for X-ray diffractometry
Authors: Aslanov L A , Fetisov G V
Published: November 2023

Two main types of equipment are used now to obtain X-rays for crystallographic applications. They are X-ray generators with X-ray tubes and synchrotrons. The generation of X-rays requires a source of electrons (either ions or some other charged particles) with sufficiently high energy. The simplest solution therefore used in X-ray crystallography is employment of a high voltage to accelerate electrons in vacuum. The mechanism of X-ray generation is schematically shown in Fig. 3.1. The electrons are driven at high speed into a metallic target. Their collision against the target reduces the speed of the electrons, gives energy to the atoms composing the target and excites them. A continuous spectrum of white radiation and characteristic radiation are emitted in this process. Thus, for X-ray generation one needs first of all a high voltage generator. An electron-vacuum unit including a cathode emitting electrons, a system for electron beam formation, a metallic target (anode) for deceleration of electrons and windows for transmission of X-rays generated in the anode to the outside of the unit must be attached to the high-voltage generator. This unit is called an X-ray tube.
Single-crystal X-ray diffractometry
Authors: Aslanov L A , Fetisov G V
Published: November 2023

This chapter is devoted to experimental conditions and techniques for crystal structure data collection. First of all let us determine the type of task which should be carried out by the experimenter. What is an experiment in general? An experiment is a scientific test which is done in order to prove or discover what happens to something under particular conditions. At the same time a measurement can be defined as a sequence of experimental and ca1cu1ating operations carried out in order to determine the value of a physical quantity characterizing a certain object or phenomenon. The “measurement’ result is the degree of approach to the true value of the quantity and therefore must contain the determined value and an estimate of its deviation from the true meaning of the quantity, that is the ‘measurement’ error. The main difference between experiment and measurement consists in the fact that the experiment is done once, or just a few times and may include many types of measurements and calculations, while the measurements represent nearly identical operations which are carried out routinely over and over again on series of substances to determine their properties. The measurements may be either direct, when the result is obtained immediately as the measured quantity, or indirect, when the value is found on the basis of its known dependence on the directly measured quantities. Indirect measurements are used when there is no possibility of obtaining the value directly or the precision of direct measurement is insufficient.
Single-crystal diffraction data collection and primary processing
Authors: Aslanov L A , Fetisov G V
Published: November 2023

Figure 5.1 represents a simplified flow diagram for the evaluation of structure factors |F<H)|2 from the very beginning of the instrumental work. The beginning of the instrumental stage of the analysis has been considered in detail in Chapter 4, so this chapter is devoted to the most important stage of X-ray crystal structure analysis-experimental data acquisition. When the diffractometer is ready for measurements and the selected and prepared specimen placed on the goniometer it is necessary, first of all, to determine the orientation of the crystal lattice relative to the goniometer reference system. For a unique correspondence between these two coordinate systems it is necessary to know the coordinates of at least three non-coplanar crystallographic directions in the reference system of the diffractometer. The first task in this problem is to find Bragg reflections corresponding to such a crystallographic direction. Such reflections are found by systematic investigation of reciprocal space and determination of the angles <p, X, w and 20 in the four-circ1e diffractometer reference system.
Primary data reduction and error correction in single-crystal diffractometry
Authors: Aslanov L A , Fetisov G V
Published: November 2023

X-ray structure analysis enables crystallographers to solve problems both for determination of the positions of atoms in a crystal unit cell (routine structure analysis), and revealing the electron density distributions and the parameters of thermal vibrations in a unit cell (precision analysis). Both problems require accurate experimental measurements and correct data processing. Certainly, the requirements of the experiment are more severe in precision structure analysis, where any possible experimental artefacts and errors of data processing should be excluded. The task of instrumental methods is to obtain correct values of the modulus of structure amplitudes IFI.
Introduction
Authors: Whalley P B
Published: November 2023

Two-phase flows are commonly found in industrial processes and in ordinary life. The phases may of course be solid, liquid, or gas. Gas-liquid flow occurs in boiling and condensation operations, and inside many pipelines which nominally carry oil or gas alone, but which actually carry a mixture of oil and gas.
Two-Phase Flow Patterns and Flow Pattern Maps
Authors: Whalley P B
Published: November 2023

In gas-liquid flow the two phases can adopt various geometric configurations: these are known as flow patterns or flow regimes. Important physical parameters in determining the flow pattern are:
Critical Two-Phase Flow
Authors: Whalley P B
Published: November 2023

As an introduction, critical (or choked) single-phase flow is first reviewed briefly. Then, in subsequent sections two-phase flow is treated in an analogous manner. Critical two-phase flow is here only considered for a one-component flow, that is for a liquid and its vapour (for example a steam-water flow). From Chapter 5 eqn (5.8) gives(8.1)−dpdz=4τd + ρg sinθ + G2ddz(1ρ).
Rewetting of Hot Surfaces
Authors: Whalley P B
Published: November 2023

Since min = 27kW/m2, then ATmin = 80°C. This is a rather low value, giving a minimum film boiling temperature of 180 °C. In practice, effects such as liquid and surface contamination and the presence of an oxide layer on the surface all tend to increase the minimum film boiling temperature, another term for the Leiden frost temperature (see Bergles and Thompson 1970), and so the value of min is also increased. Indeed, it seems probable that there is, in general, no well-defined minimum film-boiling heat flux and, correspondingly, no well-defined minimum film-boiling temperature. Nevertheless these quantities are calculated in Example 7 in Chaper 25 as part of the pool-boiling curve calculation. Typical values for the minimum film-boiling temperature for water at 1 bar are around 290 °C
Process Industry Reboilers
Authors: Whalley P B
Published: November 2023

Some of the more practical aspects of boiling are considered here. The examples are taken from the process industry. Of the boiling operations in the process industry, one of the most common is that to provide the vapour for a distillation column. In a distillation column vapour moves up the column and is brought into contact with liquid which moves down. The vapour is provided by a reboiler which vaporizes most the liquid which arrives at the bottom of the column.
Practical Calculation Methods
Authors: Whalley P B
Published: November 2023

This chapter contains full details of a number of the calculation methods described in the text which are likely to be of direct, practical interest. The calculation methods which are included are listed below. For each the relevant section, equation, and figure numbers are given. The relevant text should be read carefully before the method is used to check, for example, the range of applicability. Four of the more complicated methods have been detailed separately in appendices.
Questions
Authors: Whalley P B
Published: November 2023

These questions are arranged in rough chapter order. References to equations and figures in the main text are given. It should be noted that the text is not sufficient to answer all the questions: for some, additional reading and thought are necessary. General references which are useful for the examples are Collier (1981), Hetsroni (1982), and Wallis (1969). These references, and others used in the questions, are given after the questions. Most of the necessary data on physical properties are given in the question or in the main text.
Linear Dependence: Reciprocity of Screws: Linear and Non-Linear Screw Systems
Authors: Davidson Joseph K , Hunt Kenneth H
Published: November 2023

The join of any two given points A  1  (x  1  , y  1  , z  1  , w  1  ) and A  2  (x  2  , y  2  , z  2  , w  2  ) is a line (see §3.3). Any point on this line is linearly dependent on A  1 and A  2; indeed every point on the line is linearly dependent on any two distinct points on it.
Spectral Field Calculations in a Mul Tila Yered Medium
Authors: FachÉ Niels , Olyslager Frank , De Zutter Daniël
Published: November 2023

The transmission line structures analysed in Chapters 7 – 9 consist of conductors embedded in a multilayered medium. We distinguish three types of media of which the cross-sections are shown in Fig. 6.1: a closed type (Fig. 6.l(a)), a semi-open type (Fig. 6.l(b)), and an open type (Fig. 6.l(c)). In the dosed type the layers are sandwiched between two ground planes. In the semi-open type the medium is placed on top of a ground plane and the top layer is semi-infinite. In the open type both outermost layers are semi-infinite.
Lossless Wire Transmission Line Structures
Authors: FachÉ Niels , Olyslager Frank , De Zutter Daniël
Published: November 2023

Wire transmission line structures are the second type of interconnection structures handled in this book. This type of transmission line, like the strip transmission line structures, allows a special treatment. Wire transmission line structures are gaining more and more practical importance in, for example, the Multiwire®, Microwire®, and Microdot® technologies.
Arbitrarily-Shaped Polygon Al Transmission Line Structures with Finite Conductivity
Authors: FachÉ Niels , Olyslager Frank , De Zutter Daniël
Published: November 2023

As a third and most general transmission line structure, we handle transmission lines consisting of conductors with polygonal cross-section and finite conductivity. This kind of structure can for example be used for studying the influence of the thickness of strip transmission lines or to analyse transmission lines with trapezoidal cross-section due to under-etching. A conductor with a regular polygonal cross-section can serve as a model for a wire. The theory developed below also enables us to study the skin effect

The waveguide structures analysed in this chapter consist of polygonal inhomogeneities in a multilayered medium. Though the theory elaborated in this chapter is valid for situations ranging from pure dielectric to perfectly conducting inhomogeneities, we will restrict ourselves to conductors. These conductors can be either perfectly conducting or have a finite conductivity.
Model-Based Adaptive Control
Authors: Arimoto Suguru
Published: November 2023

Trajectory tracking control problems for a given desired trajectory q/t) in joint space are treated on the basis of passivity analysis of residual error robot dynamics. Owing to the physical property that dynamic parameters appear linearly in Lagrange’s equation, a concept named a ‘regressor’ is introduced, which renders the system description more flexible. Model-based adaptive control for trajectory tracking is then devised by defining an update law of parameter estimation. This method is extended to cope with adaptive hybrid trajectory tracking control for dynamics under holonomic constraint. The effectiveness of this adaptive scheme is finally verified by experimental data.
Advanced Control for Electromechanical Systems
Authors: Arimoto Suguru
Published: November 2023

We discuss advanced techniques for analysing mechatronic systems in various situations and designing controllers from various practical viewpoints. These are (1) control problems in task coordinates, (2) generalization of impedance control to cope with non-linear dynamics with passivity, (3) coordination control of multiple arms, (4) control problems for mechatronic systems with actuator dynamics, (5) H  ∞-tuning problems for robot control, (6) adaptive sliding mode control, and (7) friction compensation. In particular, a necessary and sufficient condition without invoking Riccati’s equation for the establishment of H  ∞-tuning is presented, which explores a new physical characterization of non-linear mechanical systems. Almost all of the techniques, except in Section 7.3, involve more or less the ideas of developing corresponding non-linear position-dependent circuits and their passivity analysis. In fact, it was helpful at first to visualize these dynamics as being depicted in their corresponding circuits and then to interpret their physical properties in mathematical terminology.
Survey Papers
Authors: Clarke D W
Published: November 2023

There has been significant recent progress in our understanding of the design and use of ModelBased Predictive Control. Rather than imposing a specific model structure, different forms are used to suit individual application areas. The two-degree-of-freedom solution of many MBPC algorithms enables optimal behaviour in set-point response and for rejection of known disturbance patterns, gives enhanced robustness against model/plant mismatch, or provides a compromise - a trade-off - between these objectives. The original lack of a comprehensive theory of stability has now been overcome by adapting earlier work on terminal constraints in receding-horizon control. This has been accompanied by a growing awareness of how best to choose ‘design knobs’ for typical heuristic closed-loop performance criteria. The finite-horizon methodology readily enables the addition of practical actuator, output, or state constraints for which stability theories are emerging. Further extensions are to plants with inherent non-linear structure: here MBPC is one of the leading design approaches.
Applications of MBPC
Authors: Linkens D A , Mahfouf M
Published: November 2023

The development and evaluation of Generalised Predictive Control (GPC) for on-line administration of muscle relaxant drugs in operating theatre is described. The necessary software was transferred into the operating theatre at two sites where successful trials were performed. Excellent regulation has been achieved, and the GPC algorithm displayed good robustness properties against disturbances such as surgical diathermy. The work was extended later to the multivariable case involving simultaneous control of muscle relaxation, and unconsciousness using blood pressure monitoring. A fault detection isolation and accommodation (FDIA) layer has been superimposed on top of the multivariable GPC strategy and the performance of the overall supervisory control scheme has been evaluated in a series of simulation runs on a workstation. The algorithm has proved very effective in detecting, diagnosing and eventually compensating for various simulated faults normally encountered in the operating theatre.
Conversion factors
Authors: Cook James L
Published: November 2023

The density of water is frequently quoted as 1000 kg/ cubic metre or I gram/cubic centimetre with no reference to the conditions at which this density is valid. The calculation of an ‘ideal’ pressure column of water is given in BS 350, referring only to the ‘standard gravity’ of9.80665 metres/second squared. For most practical purposes, water may be assumed incompressible but the temperature will have some effect on its density and for critical work should always be considered.
Skeletal elements
Authors: Mohr G A
Published: November 2023

After some preliminary discussion of the finite element method, discrete one-dimensional finite elements of skeletal engineering systems are considered as an introduction to finite element analysis. The matrices for these elements can be derived without recourse to finite element theory, but once these are derived their application to build a complete mathematical model of a system follows the same general lines as with all other finite elements.
Energy principles and applications
Authors: Mohr G A
Published: November 2023

The energy basis used in the development of displacement finite elements is demonstrated and the displacement method is then used to establish again the matrices for the spar and beam elements discussed in Chapter 1. The displacement method is then generalized to include initial strains and boundary terms and the chapter closes with a discussion of alternative variational approaches to finite element formulation.
Interpolation functions and numerical integration
Authors: Mohr G A
Published: November 2023

In this chapter interpolation functions for two and three dimensions are discussed. First Cartesian displacement functions are considered and examples of these are used to demonstrate some of the constraints which should be considered in choosing interpolations for a finite element formulation. Particular emphasis is then given to the definition of suitable dimensionless coordinates for rectangular and triangular regions and the derivation of interpolation functions for such regions. As we saw in Chapter 3 finite element stiffness matrices are then obtained by differentiating these interpolation functions to obtain a strain-interpolation matrix Band then integrating the product B’ DB over the element volume. In simple cases analytical integration can be used to obtain explicit matrices but in general numerical integration is used. The chapter closes with a discussion of numerical integration techniques for finite elements.
Thick plate elements
Authors: Mohr G A
Published: November 2023

The analysis of thick plates must allow for the additional deformations of the plate caused by transverse shearing, and appropriate equations for this were discussed in Section 2.7. These equations have been implemented in a variety of ways for rectangular finite elements but may meet with difficulties in triangular elements. These difficulties are reduced by the use of the natural strain technique of Argyris and Scharpf.1 Such elements may still be used to analyse thin plates with the use of penalty factors to enforce the Kirchhoff constraints.
Non-linear materials and large displacements
Authors: Mohr G A
Published: November 2023

The present chapter provides a brief introduction to techniques for the solution of non-linear finite element problems. The two main types of nonlinear problem are those where the magnitudes of the stresses, displacements velocities, and so on, are sufficient to alter the nature of the constitutive relationships or to make non-linear terms in the governing straindisplacement relationships or differential equations significant. In the mechanics of solids we call these non-linear material and large displacement problems respectively, and both types of problem are discussed in this chapter.
Eigenvalue analysis of vibration and stability
Authors: Mohr G A
Published: November 2023

Many physical systems possess eigenvalues, that is, values of some important parameter at which the system falls into characteristic states of behaviour. Each of these states is described by an eigenvector which is associated with one of the eigenvalues. The eigenvalue problems most frequently encountered in the mechanics of solids are those of vibration and buckling and both of these are discussed in the present chapter. Techniques for solving linear eigenvalue problems are then discussed and these can also be applied to the eigenvalue problems of electromagnetic vibration and seiche motion which we shall encounter in Chapters 18 and 20.
Time stepping analysis of vibration and creep
Authors: Mohr G A
Published: November 2023

Time-dependent propagation problems for which finite element methods are much used include those of structural vibrations, creep problems, and transient field problems such as those of seepage through porous media and heat conduction. The linear eigenvalue problem of dynamics has already been discussed in Chapter 13 and any dynamical analysis can be made by mode superposition once the eigenvectors have been determined. In this chapter we shall restrict attention to the application of time stepping techniques to analyse the creep and vibration of solids. Heat and fluid flow problems are deferred until Chapters 18, 19, and 20 following the introduction of the governing equations and weighted residual methods needed to deal with these.
Basic differential equations in continua
Authors: Mohr G A
Published: November 2023

Previous chapters concentrated upon formulation of finite element models based upon energy or equivalent virtual work arguments and applied these to a wide range of problems in the mechanics of solids. In the mechanics of fluids and many other field problems, however, energy arguments are more difficult to construct; instead a governing differential equation is usually used as the starting point for the analysis. The present chapter introduces some of the basic differential equations that govern the behaviour of physical systems as a prelude to Chapter 17 in which techniques for attacking these are introduced. Later chapters apply these techniques to a wide range of fluid and field problems.
Fluid flow examples and programs
Authors: Mohr G A
Published: November 2023

As an example of two-dimensional potential flow consider the problem of ducted flow with unit free stream velocity around an infinitely long cylinder of unit radius. Figure 20.l(a) shows the boundary conditions for analysis of a quadrant of the domain using five bilinear elements and the stream function formulation described in Section 19.2.
Introduction
Authors: Zhong Zhi-Hua
Published: November 2023

Any mechanical load results from an interaction between two mechanical components (or two parts of a single component) which come into contact with each other. It is therefore not surprising that contact interactions exist in virtually all structural and mechanical systems. In engineering, contact interactions are usually intentional such that a structure, like a bridge, can sustain loads or that a mechanical system, like a forging press, can perform an assigned task. There are, however, situations where contact interactions are not intended, as in a vehicle crash. It is obvious that contact interactions may have a significant influence on the behaviour of the structure or the mechanical system. To increase efficiency in intentional contact interactions and to decrease adverse effects in non-intentional contact interactions, it is desirable to gain an insight into the process of the interactions.
Numerical Solution Procedures
Authors: Zhong Zhi-Hua
Published: November 2023

There are several types of difficulties in finding a solution to the general contact-impact problem formulated in the preceding chapter. The difficulties come from the inherent non-linearity of the contact-impact problem itself and other possible non-linearities. First of all, the equilibrium (or fictitious ‘dynamic equilibrium’) of the contact system is expressed in the configuration at time t, which is not yet known. This is one source of non-linearity, the geometry non-linearity, which presents difficulties in calculating such quantities as stresses. It is not possible either to directly carry out the volume integrations and the surface integrations presented in the equilibrium equation. Secondly, it can happen that the stresses at the current configuration cannot be determined by only knowing the current configuration. Specifically, the complete deformation history of the contact system may be required for stress calculations. This is a kind of material non-linearity. Furthermore, the solution must satisfy the contact conditions over the contacting boundaries, which are also not known prior to the solution of the problem. This will be referred to as the contact non-linearity in our study.
Explicit Solution Procedures with the Lagrange Multiplier Method
Authors: Zhong Zhi-Hua
Published: November 2023

In the preceding chapters, the penalty method has always been used as a contact constraint method in the explicit solution procedure. While the penalty method works properly with a properly chosen penalty parameter for many applications, it can fail or behave badly for other applications as discussed in Chapter 4.
Elementary Kinetic Theory
Authors: Woods L C
Published: November 2023

Calculating the transport of fluid momentum and energy by what Maxwell termed ‘molecular agitation’ has been a central problem in macroscopic physics for more than a century. And while its solution for neutral gases was largely completed by the early part of this century, it is only recently that progress has been made for magnetoplasmas. There are two distinct methods of determining transport, both of which are due to Maxwell. The first is non-local and depends on the displacement of molecules between collisions; the particle agitation tends to equalize conditions-temperature, fluid velocity, etc. —at the two ends of each free path by transporting properties from one end to the other. The second is a local theory, based on a differential equation similar to (1.38), involving the velocity distribution function f(r, w, t), and expressing the conservation of molecular properties. In Boltzmann’s extension of the local theory the property is taken to be f itself. Once f is known, the required transport laws for q and p follow from (2.5), (2.6), and (2.7). Maxwell avoided determining f, aiming instead directly at the required velocity moments.
Particle Diffusion
Authors: Woods L C
Published: November 2023

In §1.7.1, diffusion was defined as being a transport process due to the purely random component of molecular motion, frame indifference being identified as an essential property of the phenomenon. In the preceding chapter we studied the diffusion of momentum and energy. It remains to consider the diffusion of particle mass, or equivalently, the diffusion of particle numbers. In a gas comprising a single species, unless particles can be differentiated, the diffusion of particle number density is a meaningless concept. The property of being a particular type of particle is universal, so its migration cannot be distinguished. However, if we could label some of the particles, for example by using radioactive isotopes of some of the original species, and could trace the relative motions of such isotopes, we would have a good approximation to what is termed ‘self-diffusion’.
Theory And Experiments On The Wedge-Type Motor
Authors: Sashida Toshiiku , Kenjo Takashi
Published: November 2023

In this chapter, we develop the theory of the wedge-type ultrasonic motor and present some experimental results. The high efficiency of the wedge-type motor was theoretically explained and experimentally demonstrated as early as 19821. Yet to this day its significance has not been generally recognized. The wedge-type motor played an important role as a stepping stone to the development of the travelling-wave motor. Hence, if one is to understand the structure of the new motor and hope to improve on it, one must first gain a thorough grasp of the structure and theory of the original wedge-type motor.
Transition-In-Shear-Layers State
Authors: Zdravkovich M M
Published: November 2023

The near-wake in the TrSL state of flow is surrounded by initially laminar free shear layers. The free shear layers become turbulent, however, before rolling up into turbulent eddies. The old termsubcritical state refers to boundary layers that remain laminar up to and beyond separation. The more precise term is adopted in this book and refers to thetransition in the free shear layers orTrSL state. Roshko (1954P) called it the ‘irregular state’ because the alternate turbulent eddies became rapidly disarranged and dissipated downstream.
Free Streamline Models
Authors: Zdravkovich M M
Published: November 2023

The concept of hypothetical ideal fluid is related to an inviscid, irrotational and potential flow. The potential theory predicts zero resistance exerted on a body submerged in ideal fluid. This is known asd’Alembert’s paradox. It is in obvious disagreement with observation because large forces are exerted on bluff bodies even in fluids of a very small viscosity.
Vortex Sheet Models
Authors: Zdravkovich M M
Published: November 2023

Helmholtz (1868J) was the first to remark on the instability of those ‘liquid surfaces’ which separate layers of fluid with different velocities. Kelvin (1871J) investigated the influence of wind on water waves and discussed the conditions under which a plane surface of water became unstable. Adopting Kelvin’s method, Rayleigh (1880J) investigated further the instability of a surfaceof discontinuity.
Miscellaneous Models
Authors: Zdravkovich M M
Published: November 2023

Mathematicall modelling of flow past circular cylinders has conveniently been classified in Chapters 8-12 in three main groups based on (i) the Navier-Stokes equation, Chapter 8; (ii) Prandtl’s boundary layer equations, Chapter 9; (iii) heuristic arguments to guide empirical research but unproved or in- capable of proof, Chapters 10-12.Solutions of the Navier-Stokes equations are limited at present to twodimensional laminar flows. Prandtl’s approximations of the Navier-Stokes equations to boundary layers deal successfully with all flows, three-dimensional and turbulent. The theory is now in a mature state.
Aerodynamic Sound
Authors: Zdravkovich M M
Published: November 2023

The fascinating hiss of sticks and cords in wind attracted the attention of the ancients. There are various vague references to ‘harps’ constructed to sound in wind and called Aeo1ian harps. The history of the Aeolian harp goes presumably back even further into the remote past. The Chinese had from time immemorial their ‘music’ in the air produced either by long bows with a thin bamboo strip or a ribbon for the chord and attached across a small frame and hung on the string.
Introduction
Authors: Olyslager Frank
Published: November 2023

As early as 1747, none other than Sir William Watson showed that it was possible to send an electric current through a wire using the Earth as return conductor. The first electrical transmission line was born. Already, in 1753, it was suggested that this idea could be used to construct a telegraph. It still took almost another century to fully develop overland telegraphy. The most often used transmission lines were just open-wire pole-line constructions.
Fields Incident On Transmission Lines
Authors: Olyslager Frank
Published: November 2023

The previous chapters have investigated the propagation of eigenmodes in wave guides and their transmission line representation without considering the excitation of these eigenmodes.45 In this chapter, the excitation of eigenmodes will be studied in detail. The analysis starts with the determination of the eigenmodes excited in a waveguide by external electric and magnetic current densities. This is a generic excitation problem that can be used in many practical situations. The fields generated by these sources will also illuminate junctions of waveguides. This will result in the excitation of eigenmodes in the waveguides connected to these junctions.