bluuebunny/crossref_metadata_2025 huggingface dataset:
Apparatus and Procedures for Laboratory Tests
Authors: Ishihara Kenji
Published: November 2023

The triaxial test apparatus has been widely in use for testing cohesionless soils in the laboratory under both monotonic and cyclic loading conditions. While there are several models with some variations in details, the basic design is the same as the conventional triaxial apparatus used for testing cohesive soils. In the conventional type developed in the UK, the rods or columns to support the top cap and piston are posted outside the triaxial cell. In this type, after the cap is mounted on top of the specimen, the cell, the top cap and the columns are assembled together and then the top cap is fastened to the column.
Settlement in Sand Deposits Following Liquefaction
Authors: Ishihara Kenji
Published: November 2023

When saturated sand deposits are subjected to shaking during an earthquake, pore water pressure is known to build up leading to liquefaction or loss of strength. The pore water pressure then starts to dissipate mainly towards the ground surface, accompanied by some volume change of the sand deposits which is manifested on the ground surface as settlement.
Flow and Non-Flow Conditions and Residual Strength
Authors: Ishihara Kenji
Published: November 2023

Flow-type failure has been known to occur in loose deposits of sandy soils when they are put into a steady state of deformation following the onset of liquefaction due to seismic shaking. For the flow-type failure to occur, it is necessary therefore, that the sand be loose enough to exhibit contractive behaviour during shear stress application. Under the usual range of overburden pressures around 100 kPa, there appears to be an upper limit in relative density above which there is practically no possibility for sand to become contractive and hence to be put in a steady state with a reduction in shear resistance. Conversely, if the sand exists with a relative density below this limit, the likelihood would be high for developing steady-state deformation and hence a flow-type failure. Such a limit may be properly expressed in term of any of the density parameters such as relative density. If these parameters are correlated with the penetration resistance of any sounding tests in the field such as the SPT or CPT, the limiting condition may be expressed alternatively in terms of a threshold value of the penetration resistance. In compliance with the limiting conditions or threshold values as above, there would also be an upper limit in the normalized residual strength. This aspect of the problem will be addressed in the following.
Mixing And Coalescence Phenomena In Liquid-Liquid Systems
Authors: Davies G A
Published: November 2023

The process of liquid-liquid extraction involves the contact of two partially miscible liquid solutions. These are not at chemical equilibrium so that one more component, solute(s) will transfer from one phase, the raffinate to the second phase, the extract. The maximum extraction of the solute will be achieved at a particular temperature if the two phases are allowed to come to chemical equilibrium.
Liquid-Liquid Partition in the Pharmaceutical Industry
Authors: Verrall Michaels.
Published: November 2023

Liquid-liquid partition is used by the pharmaceutical industry in a number of ways, some of which are entirely conventional while others have distinctive features. The former-for example the use of solvents to work up reaction mixtures-will not be discussed. This chapter will instead deal with the use of solvents in the isolation of products of biological origin, small scale biochemical applications which have interesting partition systems and selected chemically assisted extractions.
The Simple, Tubular Thermosyphon
Authors: Lock G S H
Published: November 2023

Newton’s law of cooling, in which the rate of cooling of a body is taken to be proportional to its temperature measured relative to that of the environment, is the first quantitative statement ever made about natural convection. Implicit within this law is the requirement that the heat transfer coefficient at the body surface be constant. Today, not only is it known that the heat transfer coefficient h is a function of the temperature difference θ, but it is also understood that the natural convective system established around the body is governed directly by this temperature difference. It is a commonplace observation that h∝ θn where n is a small positive fraction. Over a small temperature difference range this power law relation may be approximated by a constant.
The Rotating, Tubular Thermosyphon
Authors: Lock G S H
Published: November 2023

At first glance, it may seem that the replacement of gravitational acceleration by centrifugal acceleration is a minor change, and indeed it is often assumed that heat and mass transfer relations in a rotating field may be obtained from those in a uniform gravitational field by this simple substitution. As first-order approximations, the results are often useful but they cannot be expected to reflect with great accuracy the consequences of spatially varying centrifugal and Coriolis accelerations. In particular, it is often found that the Coriolis effect in a rotating thermosyphon plays an important role in the overall circulation pattern and heat transfer rate. In general, the vector addition of the centrifugal and gravitational accelerations produces a flow field which, at best, is steady but complex; at worst, it is transient, complex, and subject to instability.
Related Devices
Authors: Lock G S H
Published: November 2023

It is evident from the material covered thus far that the tubular thermosyphon may be used in a wide variety of circumstances. Hopefully, the coverage will have led to an understanding of the device which is sufficiently basic and general to enable the reader to envisage other uses and other circumstances. Frequently, these will entail simple adaptation; no new ideas or principles will arise. Occasionally, however, the circumstances may be sufficiently unconventional to require modifications to the operating principles. This chapter is devoted to the main forms of modification, their physical basis, and the performance alterations which they introduce. A different operating principle, acting alone, implies a different device, and indeed the systems considered below are often regarded in that light. Clearly, the treatment of other devices in any depth is beyond the scope of this book, and the reader seeking a more detailed discussion of these must consult the appropriate references listed in the Bibliography. The following constitutes only an introduction devoted specifically to those devices which are related in application to the thermosyphon.
Thermal Properties And Thermal Failure
Authors: Lawton B , Klingenberg G
Published: November 2023

In scientific work, transient temperatures and heat flows are measured because they may help to confirm or enlighten our understanding of the process being investigated. The is also true in engineering. However, engineers have an additional need for such data because they may have to ensure that the components they are designing are capable of withstanding high temperatures and heat flows. It is, in fact, the temperature and heat flux that often limit the performance of engineering equipment. For example, the boost pressure, and hence the power output, of turbocharged diesel engines could be increased to values three or more times higher than at present. However, if this were done the pistons, valves, and other combustion chamber components would certainly overheat and fail. Thus progress in developing more powerful engines is controlled by the rate at which the thermal design of such components develops. Similar comments might be applied to aircraft gas turbines, rockets and satellites, steam power plant, refrigeration, X-ray machines, and many other devices.
Raman Scattering
Authors: Eremets M I
Published: November 2023

It is difficult to provide an overview from the physical standpoint of the enormous number of Raman scattering studies performed under pressure. On the other hand, the experimental aspect seems too simple: only a slight modification of the optical scheme is needed to replace a sample by a high-pressure cell, especially by a small DAC. From this point of view Raman spectroscopy is one of the easiest high-pressure methods. However, there are many specific problems with weak scatterers and with studies in the megabar region.
Nano-forming or three-dimensional shaping systems and surface finishing systems
Authors: Taniguchi Norio
Published: November 2023

High-precision machining using diamond cutting tools has been used in finishing of soft metals such as copper and aluminium, for which it is difficult to perform such machining by grinding, lapping and polishing. This diamond turning technique is finding wide application in the finishing of parts used in precision machines and optics such as information equipment, laser machining equipment, and space equipment. Ultra-precision machines have been developed for mirror-like surface finishing of precision parts and optics by the use of these diamond tools.
The Dynamics Of Heterogeneous Fluids
Authors: LOCK G S H
Published: November 2023

This chapter is devoted to the dynamics of heterogeneous fluid media under steady or quasi-steady conditions. It provides an exploration and, to some extent, a review of the various hydrodynamic phenomena which accompany phase change. The organization is based largely on observations commonly made during condensation and evaporation. While the accompanying fluid dynamic phenomena take many forms, they may be subdivided into two general categories: bipartitioned and dispersed. In the first of these, two continuous and homogeneous phases are separated by an extensive and continuous interface; this is typified by film condensation. In the second, one phase is continuous but the other is dispersed through it in numerous small pockets; a good example is provided by vapor bubbles during boiling. It is reasonable to expect that bipartitioned and dispersed systems will behave very differently. Sections 3.1, 3.2, and 3.3 deal with the former while Sections 3.4 and 3.5 deal with the latter. Section 3.6 explores systems which combine the characteristics of both.
Condensation
Authors: LOCK G S H
Published: November 2023

We now enter the first of two chapters dealing exclusively with vapourliquid transformations: condensation and evaporation. In an engineering context, condensation frequently occurs in the form of a liquid film, and consequently most of the discussion below is devoted to the dynamic behaviour of this film and its influence on condensation rates. Once a basic heat transfer model has been developed in Sections 5.1 and 5.2, the treatment is extended to include the important effects of surface geometry, vapour composition, and vapour motion, all referring to film condensation on an external surface in typical circumstances. Condensation inside tubes, which makes full use of the discussion of two-phase flow in Chapter 3, is treated separately. However, before attempting to discuss any of these situations, it is first necessary to explain the circumstances which lead to the creation of drops and films.
Physical basis of the plasma etching process
Authors: Sugawara M
Published: November 2023

Process engineers and scientists have used a confusing variety of terms to refer to processing at various working pressures. A brief commentary on these terms is appropriate at this point. Plasma etching is the practice of etching or gasifying substrate material in a plasma. Sometimes the phrase has been colloquially used to define etching at higher pressures, for example, at 13.3 Pa, where ion energies are often low. There is an innuendo that etching in this pressure range is done by neutrals, while etching at lower pressure is done by ions. This concept and usage is not right: because ions are rarely etchant, neutrals are responsible for almost all etching at pressures above about 0.13 0.66 Pa, and etching is done in a plasma over the entire pressure range.
Magnetic field coupled etchers
Authors: Fujita K
Published: November 2023

In the present rapid growth of plasma processing techniques, the development of plasma sources is required, providing not only a large area plasma with high and homogeneous density at a low gas pressure but also plasma modified in its geometry to fit the shape of’ any particular substrate. Thus, the magnetic field plays an important role in achieving the plasma processing technique, unless the field is not considered to affect the quality of the film prepared.
ECR plasma etchers
Authors: Watanabe S
Published: November 2023

The density of VLSI (very large scale integration) has increased four-fold over the last three years. Drams (dynamic random access memory) are representative semiconductor devices; 64 Mbit Drams are mass produced, their minimum feature length being 0.35 μm. VLSI have a multilayered structure and their minimum feature length shrinks with high integration. Dry etching enables microfabrication with high accuracy to be performed and etching under low-pressure conditions can further aid this demand for accuracy. On the other hand, the diameter of Si wafers is becoming larger (advantageous from the viewpoint of production costs) and although 8-inch diameter wafers are generally used now, 12-inch diameter wafers will be used in the near future. In order to process the large wafer uniformly, dry etching apparatus has evolved from the batch type, which processes multiple wafers at the same time, to leaf type, which processes one wafer at a time. However, a high etching rate is essential to keep the throughput constant. Thus it has become one of the important technological challenges to generate high-density plasmas.
Introduction
Authors: Bruun H H
Published: November 2023

The primary objective in writing this book on practical Hot-Wire Anemometry (HWA) was to provide a reference textbook for the selection and use of the most appropriate hot-wire/film anemometry technique for different turbulent flow studies. This book has a logical framework, with simple principles and single-wire techniques preceding more advanced multi-sensor methods. It includes a relatively detailed discussion of the more common hot-wire/film probes and the related signal-analysis techniques, while shorter descriptions are given of more specialized HWA applications. A historical review of HWA has not been included since one has been written by Freymuth (1983a).
One-Component Velocity Measurements
Authors: Bruun H H
Published: November 2023

This chapter is concerned with the use of a single normal (SN) hot-wire or hot-film probe for measurements of the velocity component in the mean flow direction. The presentation will follow the step-by-step procedure out lined in Chapter 3, but in the case of an SN-probe some of the options are predetermined. For an SN-probe, the wire-fixed (x ‘, y ‘, z ‘) and the probe stem (X8, Ys, Zs) coordinate systems are often the same. If the probe-stem is aligned with the mean-flow direction, see Fig. 4.1, and if this orientation is selected as the space-fixed coordinate system then the analysis can be carried out directly in terms of the velocity components (U, V, W) in the selected space-fixed system. This probe-stem orientation and analysis pro cedure will be used below unless otherwise stated.
Temperature Effects: Correction Methods For Drift In The Fluid Temperature; Measurements Of Fluid Temperature Fluctuations
Authors: Bruun H H
Published: November 2023

In many fluid flows the temperature of the fluid, Ta, may vary with time. This change may take the form of either a slow drift caused by, for example, electrical heat from the fan motor in a closed-loop wind-tunnel or as temperature fluctuations in a nonisothermal flow. In both cases the output voltage from a hot-wire placed in the flow will be modified by the variation in Ta. This chapter deals with (i) correction procedures for CT anemometer signals caused by drift in the ambient-fluid temperature, and (ii) measurements of the fluctuating ambient-fluid temperature,
Conditional Sampling Techniques
Authors: Bruun H H
Published: November 2023

Distinct flow events are found in many types of turbulent flows, and they can often be identified by a HWA sensor placed in the flow field. In some fluid machinery, these events will occur periodically, and a phase-locked ensemble-averaging technique can be used to extract the periodic signal component from the fluctuating signal; this is discussed in Section 11.1. Coherent flow structures have also been observed in many turbulent flows, but their developments are often random in both space and time. To identify these large-scale structures, special signal-analysis procedures have been developed and applied to hot-wire probes; this is described in Section 11.2.
Fundamentals of intensity-dependent phase phenomena for CW operations in waveguide circuits
Authors: Shvartsburg A B
Published: November 2023

The theoretical analysis of non-linear integrated and waveguide optics is based on the solution of Maxwell’s equations for spatially localized fields. Realization of series of non-linear index-related effects is implemented by high intensity of the wave fields, achieved due to the localization of wave energy flow in guided systems. However, we may discuss the essential physics of some of these phenomena using the simple model of powerful plane waves in an unbounded homogeneous non-linear medium. Thus, the basic non-linear phase effects are described by means of this model. The task of this section consists in evaluation of energetic parameters and spatial scales of intensity-dependent phase phenomena within the scope of such a simplified approach.
Introduction
Authors: Kanatani Kenichi
Published: November 2023

This chapter describes the aim, scope, organization, and style of this book. First, the historical background of machine vision research is briefly summarized, contrasting the emphasis of this book to traditional treatments. Then, the content of each chapter is summarized-computational projective geometry, translational motion, stereo, 3-D rotation, 3-D motion analysis, analysis of optical flow, analysis of conics, and statistical analysis of geometric computation. Finally, a short bibliography of general references is given.
Computational Projective Geometry, 2
Authors: Kanatani Kenichi
Published: November 2023

Projective geometry in the form described in Chapter 2 does not involve any metrics (e.g., lengths and angles). It certainly suits the description of “parallelism” in 3-D scenes in terms of vanishing points and vanishing lines. However, “orthogonality” is also an important characteristic of 3-D scenes, since many man-made objects have rectangular shapes and orthogonal edges. In this chapter, we show that orthogonality in 3-D scenes can be described in terms of projective geometry if we introduce a special “conic” called the absolute conic. It is shown that the camera rotation transformation introduced in Section 2.3.1 is characterized as a collineation that preserves the absolute conic. It is also shown that the conjugacy with respect to the absolute conic can be interpreted as orthogonality in 3-D scenes. We then discuss two machine vision applications: camera calibration and 3-D road shape reconstruction, the latter being an important component of autonomously navigating land vehicles.
Torque control of switched reluctance motors
Authors: Vas Peter
Published: November 2023

In the present chapter, first the fundamentals of switched reluctance motor drives are discussed. This is then followed by a description of various position estimators which can be used in position-sensor less switched reluctance motor drives. Finally the two main possibilities for instantaneous torque-controlled switched reluctance motor drives are discussed. The first solution uses profiled stator currents, and thus the drive contains a current controller, but the second solution uses profiled stator flux linkages, and the drive scheme contains a stator flux-linkage controller. It is shown that the second scheme is simpler to implement. Both schemes can operate in a wide speed range and offer the potential of using switched reluctance motors in many applications, where so far only other types of motors have been used.
Introduction
Authors: Dote Yasuhiko , Hoft Richard G
Published: November 2023

In the field of computer integrated manufacturing (CIM), equipment such as computer numerically controlled (CNC) machine tools, industrial robots, etc., is being widely used to save energy, to implement automation, and to increase both production and the quality of products. This equipment which is used in common societal and industrial applications such as energy, environment, food, housing, and transportation, etc., is becoming more sophisticated day by day with the application of intelligent control techniques. Self-controlled AC drives and UPS systems which are typical products of power electronic systems are being employed as supporting tools to fulfill the above requirements.
Inverters
Authors: Dote Yasuhiko , Hoft Richard G
Published: November 2023

The semiconductor age began with the announcement by Bell Laboratories of the invention of the transistor in 1948 (the year that the second author earned his BSEE degree from Iowa State University in the USA). Bardeen, Brattain, and Shockley received the Nobel Prize for this most significant discovery. Silicon diodes soon became available to replace selenium and germanium diodes. General Electric in the USA introduced the silicon controlled rectifier (SCR) in 1957 and this gave great impetus to the development of semiconductor inverter and converter circuits. Reference [l] published in 1964 was the first modern book on inverters. Reference [2] is believed to be the first textbook written for use in senior and graduate level courses on power electronics, and [3] is a slightly updated version of [2]. Thyristor inverters are used widely in large motor drives, high-voltage DC systems, and in large battery storage systems to supply peak loads on utility systems.
Robust AC drive control
Authors: Dote Yasuhiko , Hoft Richard G
Published: November 2023

This chapter describes a simple gain scheduling robust controller whose parameters are continuously changed by fuzzy logic such that the controller makes the system respond quickly if the error e is large (SIN is large) and vice versa in order to obtain a robust controller which is insensitive to both plant noise and observation noise. Then, the controller is applied to speed control of an induction drive without a tachometer (sensor). Experiments show that the proposed controller is superior to both a sliding mode controller and a PID controller. This chapter also includes the stability analysis of the overall system.
The Materials Equations
Authors: Solymar L , Webb D J , Grunnet-Jepsen A
Published: November 2023

We have already discussed a simple model of charge transport in Section 1.3 and two somewhat more complicated models in Section 2.11 where we considered both electrons and holes. Our aim is now to present further models which were used at some time or other in the literature. The complications that come are quantitative rather than qualitative. One may have more species of impurities (or traps as they are often called) and more transitions between them, but each process can still be understood by a modest amount of solid state theory.
Multi-Wave Mixing
Authors: Solymar L , Webb D J , Grunnet-Jepsen A
Published: November 2023

In the preceding chapters we have seen that the interaction of two beams within a photorefractive medium involves a great deal of interesting physics and can result in optical amplification. As might be expected, the interaction of three or more waves in such a medium leads to additional surprising effects, perhaps the most remarkable of which is phase conjugation.
Spurious Beams
Authors: Solymar L , Webb D J , Grunnet-Jepsen A
Published: November 2023

A spurious beam may be defined as a beam which by certain simple considerations should not be there. For example, if we have one or more beams incident upon a piece of ordinary optical material (say, a window pane) the expectation is that apart from a small attenuation the beams will be unchanged. When it comes to photorefractive materials we know that the various beams may interact with each other and consequently their relative output intensities may change. But can the beams wander away from their original paths or, even worse, can new beams arise out of nothing? Yes, we have discussed such phenomena a number of times in this book: higher diffraction orders in Section 3.8, ring resonators in Section 3.11, the double phase conjugate mirror in Section 3.12, and a string of phase conjugate resonators in Section 7.6. And of course self-phase-conjugation of the types shown in Figs 7.15 and 7.18 are prime examples of beams appearing rather unexpectedly and following rather unconventional paths. So why do we need an extra chapter on spurious beams? The reason is that apart from the examples quoted, there are still plenty of configurations in a number of photorefractive materials which lead to the appearance of new beams and for which some classification is desirable.
General Introduction
Authors: Solymar L , Webb D J , Grunnet-Jepsen A
Published: November 2023

In this third section of the book, we address as best we can in the space available the enormous range of applications that have been proposed for photorefractive materials. We should start by saying exactly what we mean by applications. At the time of writing, whilst a few prototype devices have been produced that make use of some form of photorefractive signal processing element, these have almost all been constructed as technology demonstrators, and there is to our knowledge only one commercial product on the market (Rakuljic and Leyva 1993). Nevertheless, there is hope that with the rapid progress being made in photorefractive materials research it will not be long before other photorefractive devices do achieve commercial success.
Correlation And Associative Memories
Authors: Solymar L , Webb D J , Grunnet-Jepsen A
Published: November 2023

As we have already discussed, one of the main advantages of signal processing using non-linear optics as opposed to digital electronics is the ability to handle potentially large quantities of information in parallel. Image processing is an area that lends itself naturally to optical techniques, and in this field two of the most important operations that must be performed are those of convolution and especially correlation. In this chapter we shall see how these operations may be performed using non-linear optics and how the process of correlation may be used to realize an associative memory.
Performance prediction for switched reluctance motors (two-and three-dimensional)
Authors: Reece A B J , Preston T W
Published: November 2023

A common procedure is to neglect coupling between phases and to predict flux linkages with an excited phase as a function of angle and current. Circuit equations, which include a model of the converter, are then used to calculate the phase current and flux linkages as a function of time, assuming speed to be constant. The torque produced can be derived from rate of change of coenergy as described by Stephenson and Corda (1979).
Future developments
Authors: Reece A B J , Preston T W
Published: November 2023

Perhaps this account of the principles of finite clement modelling and the examples of its application in electrical power engineering suggests that the subject has reached a plateau in its ability to contribute to good design. There is no doubt that the technique is well established, but there is much development still going on, and new techniques are also pushing their way into engineering applications. Thus an attempt to look into the future seems justified, as a conclusion to this book. First however it may be of interest and value to review briefly the present situation and recall how this has been reached. This review will be very much a personal view, based on the authors’ involvement over some 30 years.
Soliton Transmission Experiments
Authors: Hasegawa Akira , Kodama Yuji
Published: November 2023

This chapter summarizes experimental results of soliton transmission in fibres starting from the first verification of soliton phenomena to the most recent ultra-high bit-rate transmission in a single channel as well in wavelength or polarization division multiplexing.
Time-domain Optics of Ultrashort Waveforms
Authors: Shyartsburg A B
Published: November 2023

Time domain transient electrodynamics of dispersive and glossy media form the subject of this book. This topic is associated with the unusual interactions between ultra-short transient signals and these media. Techniques based on such interactions find use in materials analysis, fractal communication, and energy transfer through dispersive and absorbing media, Traditional analytical techniques (Fourier based) break down in the extreme conditions encountered in these situations; Shvartsburg gives here other successful techniques and methods to allow scientists to analyse and model this behaviour.
Segmentation and Grouping
Authors: Rothwell Charles A
Published: November 2023

Segmentation is important because it provides the features required for shape description; these have to be localized and then represented in a suitable manner. This chapter describes the segmentation and grouping algorithms that are used by the two planar recognition systems described in the previous chapters that use the LEWIS architecture. All of the algorithms that will be described can be substituted directly into the architecture.
A horologist in the making
Authors: Woodward Philip
Published: November 2023

The detour through the arboretum gave us time to collect a fresh supply of conkers, but we had to judge things carefully if we were not to be late for school. An old gentleman taking his morning walk in the park might possess the time, but he could prove grumpy when accosted by a couple of seven-year-olds in caps. We would put on our humblest expressions and ask for ‘the right time, please’, a manoeuvre that could be self-defeating as it would take him an age to reach into his pocket, extract the watch and open it up. Gold hunters on chains were the watches we preferred, though it soon became obvious that the time we were given was unlikely to tally with the school clock. Indeed, watches never agreed with one another, and I was becoming obsessed with the desire to have my own ‘right time’, accurate to a minute. My father had said it could always be obtained at the Post Office, an observation firmly grounded in history but one that seemed to have little relevance to my immediate needs.
Silence for a cellist
Authors: Woodward Philip
Published: November 2023

The quiet clock I needed for the music room would be my first essay in purely mechanical clockwork, not counting the early Meccano effort, and for obvious reasons I wished to sidestep as many gears as I could. If an escapement could be designed in such a way that the escape wheel would turn in an hour instead of the more usual minute, it should be possible to make an eight-day clock with only a single gear mesh. The need for silence made me abandon the idea of a gravity escapement, and I began to think of Harrison’s grasshopper. Perhaps some similar principle could be used for intermittent impulsing.
The Shortt free pendulum
Authors: Woodward Philip
Published: November 2023

There is no such thing as a free pendulum, because a pendulum can never be totally isolated from its environment. If it could, its Q would be infinite and we would have perpetual motion. Freedom has always been an unattainable ideal, but the degree to which it has been approached is truly remarkable, so much so that the term free pendulum need hardly be regarded as a contradiction in terms. An earlier concept was that of detachment, which is more easily defined.
The Equatorial Ionosphere And Radio Communications
Authors: Reddy B Madhava
Published: November 2023

The primary objective of the international union of Radio Science (URSI) has always been stimulating research on radio and telecommunications. The physics and propagation aspects of ionosphere were kept integrated until the fifties largely by stalwarts like Appleton. But with the considerable expansion in ionospheric research, especially after the International Geophysical year (1957-58), it tended to split distinctly as the propagation and physical aspects diverged [Rishbeth, 1994].
Personal communication services - technology and health concerns: is there a common solution?
Authors: Smchly Maria A
Published: November 2023

With the expansion of current use and anticipated further increases in the use of cellular telephones and other personal communication services (PCS), there have been an interest and considerable research effort devoted co interactions between antennas on hand-sets and the human body. The motivation for research in this area is due to two factors. From the technology point of view, as many of the PCS devices are used close co the human body, the latter results in a deterioration of the antenna performance and may therefore either require operation with increased power or other means chat prevent the deterioration of communication. From the health point of view, concern arc expressed that the deposition of microwave power in some locations may be excessive and therefore lead to detrimental health effects.
Why use steam?
Authors: Semmens P W B , Goldfinch A J
Published: November 2023

Although every enthusiast knows what a steam locomotive is like, to be able to understand how it works in detail we must first look at its fundamental characteristics and the physical, chemical and engineering laws under which it operates.

A steam locomotive is a ‘heat engine’, which converts the chemical energy of the fuel it burns into useful work hauling trains. It does this by turning water into steam, which it uses as a working fluid to drive the pistons and coupled wheels. The important thing about the efficiency of this process is not the boiler pressure, of itself, but the temperature range over which this working fluid operates. Nor is the water/steam system the only one that could be used-indeed, because the steam in a locomotive’s cylinders is only slightly above its condensing temperature, the mean pressure as it expands is not as great as it would be with other working fluids.
Burning the fuel
Authors: Semmens P W B , Goldfinch A J
Published: November 2023

The steam locomotive was originally developed for the private railways in the coalfields of Britain, and, not surprisingly, coal was used as the source of heat. Almost immediately after public railways had subsequently started to spread across the country, legislation, in response to public opinion, required locomotives ‘to consume their own smoke’. Initially this was not easy to achieve with coal, and there was a wholesale switch to coke as a fuel. Coke had first been a byproduct of William Murdock’s process to produce gas for illumination purposes, which he had made by heating coal in a closed retort some three decades before the first practical steam locomotive appeared. The techniques were well developed by the time railways had to conform to the new legislation, and coke manufacture took place at numerous locomotive depots around the country.
Raising steam
Authors: Semmens P W B , Goldfinch A J
Published: November 2023

The boiler, usually constructed integrally with the firebox, is the largest single component of a steam locomotive, and dominates its appearance. However, it contains few moving parts, and from an engineering point of view is a relatively simple unit. It nevertheless requires conscientious servicing and maintenance, and a good grasp of its technology is vital for anyone wanting to understand all the workings of the steam locomotive. Diagrams showing longitudinal- and cross-sections of small and large locomotive boilers appear in Figs 3.1 and 3.2.
The locomotive as a vehicle
Authors: Semmens P W B , Goldfinch A J
Published: November 2023

To understand the problems of stability with steam locomotives, we must go back nearly 150 years before the construction of Rocket, to when Isaac Newton formulated his three ‘Laws of Motion’. Some of their implications have already been touched on earlier in this book, but it is now worth stating them formally, as follows:

Law 1 Every body continues in its state of rest or uniform motion in a straight line, unless impressed forces act upon it.

Law 2 The change in momentum per unit time is proportional to the impressed force, and takes place in the direction of the straight line along which the force acts.
The steam locomotive at work
Authors: Semmens P W B , Goldfinch A J
Published: November 2023

During the Grouping and early BR years, for operational purposes most steam-hauled trains were classified into ten categories, as shown in Fig. 7.1, each of which was identified by the position of one or two lamps.
Mining and milling uranium ore
Authors: Ritcey G M
Published: November 2023

Whole books have been written about every aspect of uranium mining and milling, so this chapter presents a selection of material particularly related to the author’s experience, largely in milling. Much of it is drawn from his own and other contributions to the comprehensive ‘Uranium Extraction Technology’ published by the IAEA, Vienna.
Fuel fabrication
Authors: Marsh G , Eccles H
Published: November 2023

The two principal types of fuel in current use are based respectively on uranium metal and uranium oxide. (Thorium oxide can also be used but is not widely adopted, despite considerable interest on the part of the Indian nuclear industry where relative abundance and a desire for technological independence tend to counterbalance its disadvantages.) Metal can be used in the form of massive rods, which are conveniently handled individually. The oxide has a much lower conductivity; it is therefore formed into thinner rods or pinsand to avoid unnecessary handling operations within the reactor these are built up into clusters, assemblies, bundles, elements or sub-assemblies (the terminology varies according to the type of reactor, but with much the same meaning) which may each contain several hundred.
Power reactors
Authors: Hesketh K W
Published: November 2023

The nuclear fission reactor is the central element of the fuel cycle, generating the energy that is the primary aim of the industry. It is also the source of fission and transmutation products presenting opportunities and problems in succeeding stages. Various designs have been developed for central power generation and for more specialised applications; the purpose of this chapter is to describe the principles and main practical features of the more important types.
Transport and storage of irradiated fuel
Authors: Haslett D E
Published: November 2023

The storage and transport of irradiated nuclear fuel, although not strictly process stages in the cycle, are nevertheless essential links between those stages. As finally discharged from the reactor, fuel represents to the operating utility a liability requiring disposal, whether directly or through a reprocessing plant that can recover materials for re-use. Meanwhile it must be kept under conditions protecting public and work-force from its radioactivity, while preserving the integrity of its structure. The world stock of stored irradiated fuel in 1993 is estimated to have been 95 000 metric tons of heavy metal (MTHM), that is the amount of uranium plus plutonium.
Decommissioning nuclear facilities
Authors: Buck S
Published: November 2023

Nuclear facilities at the end of their useful lives cannot merely be abandoned. The site may be needed for other purposes, amenity must be preserved, and above all else, the public must be protected from any remaining hazards. Decommissioning is a major world-wide task: the IAEA has estimated that some 50 nuclear power plants and over 220 research reactors are already shut down, by the year 2000 a further 40 and 230 respectively will be at least 30 years old,la and supporting facilities, such as the successive British Magnox reprocessing plants, must eventually be included.
Inverse Problems Related To Fields From Localized Sources Over A Stratified Half-Space
Authors: He Sailing , Strom Staffan , Weston Vaughan H
Published: November 2023

Inverse problems involving a localized source over a stratified half-space are relevant in many different contexts, such as non-invasive investigations of subsurface physical properties by means of acoustic, electromagnetic or elastodynamic waves. In the present chapter the previous treatment is generalized inasmuch as instead of normally or obliquely incident plane waves, we now consider more general incident fields generated within a bounded region. The main assumption about the half-space to be investigated is the same as before, i.e., it is assumed to be plane-stratified. For these more general incident fields it is shown how the use of suitably defined moments of the fields and the reflection kernel can be used to solve inverse problems. In particular it is shown how the use of the zeroth, second and fourth moments of the three-dimensional fields reduce the inverse problem to a set of one-dimensional problems. When one has additional symmetry properties of the incident field, such as axial symmetry, it is shown how the inverse problem is reduced to a one-dimensional problem through the use of a Hankel transform. In this case an explicit form of the wave-splitting operator is found in the Hankel transformed space. The Green’s function formalism for this case is developed. The explicit form of the wave-splitting is also used to treat wave propagation in homogeneous plasmas, dispersive media and waveguides.
The spectral properties of equilibrium fluctuations
Authors: Scaife B K P
Published: November 2023

In our discussion of multipolar fluctuations in the previous chapter we were primarily concerned with ensemble averages of fluctuating quantities since we were interested in the magnitude of the fluctuations without any need to advert directly to their temporal behaviour. Here we shall examine the evolution in time of multipolar fluctuations by means of the autocorrelation function and the spectral density. The latter concept enables us to discuss some of the topics dealt with in the previous chapter from a different point of view.
Acquisition of knowledge
Authors: Videler John J
Published: November 2023

It would be unwise to start thinking about any scientific problem without knowing what previous generations discovered. Bird flight has a long history of widespread interest witnessed by prehistoric cave drawings. A great deal of that interest arose from the desire to fly like birds.
The flight apparatus
Authors: Videler John J
Published: November 2023

Birds are unique because they use feathered front legs as wings. The basic quadruped organization is modified to accommodate the needs required by the special function. Natural selection sacrificedother functions of the arms and hands during the evolutionary process.
Aerodynamics
Authors: Videler John J
Published: November 2023

A flying bird generates lift forces to counteract gravity and thrust forces to overcome drag. The magnitude of these forces can be crudely approximated using elementary physical principles. Steady flight in still air at a uniform speed and at one altitude is the simplest case.
Comparing the metabolic costs of flight
Authors: Videler John J
Published: November 2023

The data set accumulated in Chapter 8 represents the tremendous amount of effort of many investigators to measure flight costs directly. This deserves further exploitation. Comparison of the best measurements available over a wide range of species should reveal general trends in bird flight costs if there are any.
Down the Slope
Authors: Frova Andrea , Marenzana Mariapiera , Mcmanus Jim
Published: November 2023

Described here is the famous experiment of a ball which rolls down an inclined plane, devised to demonstrate that in uniformly accelerated motion distance covered is proportional to the square of the time elapsed. The experiment was intended as support for the hypothesis that speed increases in proportion to time, not to distance covered, as many of Galileo’s contemporaries held—and as did Galileo too, somewhat inexplicably, during the first phase of his studies. Although he was later to change his mind on this, the conceptual mistake he made when attempting to prove the impossibility of the proportionality of distance to time using logic alone, was substantial. Before coming to the inclined plane experiment (but did Galileo actually perform it?) the three friends Salviati, Sagredo, and Simplicio discuss the matter from various viewpoints, touching upon subtle concepts which are the prelude to differential calculus, such as the relationship between infinitesimal, finite and infinite.
Phonons; Coupling to Electrons
Authors: Bruus Henrik , Flensberg Karsten
Published: November 2023

In this chapter we study the basic properties of ionic vibrations. These vibrations are well described by harmonic oscillators and, therefore, we can employ the results from Section 1.4.1 to achieve the second-quantized form of the corresponding Hamiltonian. The quantized vibrations are denoted phonons, a name pointing to the connection between sound waves and lattice vibrations. Phonons play a fundamental role in our understanding of sound, specific heat, elasticity, and electrical resistivity of solids. More surprising may be the fact that the electron-phonon coupling is the cause of conventional superconductivity. In the following sections we shall study the three types of matter oscillation sketched in Fig. 3.1. The ions will be treated using two models: the jellium model, where the ions are represented by a smeared-out continuous positive background, and the lattice model, where the ions oscillate around their equilibrium positions forming a regular crystal lattice.
Mean-Field Theory
Authors: Bruus Henrik , Flensberg Karsten
Published: November 2023

The physics of interacting particles is often very complicated because the motions of the individual particles depend on the position of all the others, or in other words the particles motions become correlated. This is clearly the case for a system of charged particles interacting by Coulomb forces, such as e.g., the electron gas. There we expect the probability to find two electrons in close proximity to be small due to the strong repulsive interaction.
Time Dependence in Quantum Theory
Authors: Bruus Henrik , Flensberg Karsten
Published: November 2023

Using the second quantization procedure, we have so far only treated energy eigenstates with a trivial time dependence e−iωt, instant processes at a single time, and systems where interactions are approximated by time-independent mean-field theory. But how does one then treat the general case of time dependence in second quantization? That question will be addressed in this chapter, where the formal theory of time evolution is discussed using three representations, or “pictures:” the Schrödinger picture, the Heisenberg picture, and the interaction picture.