bluuebunny/crossref_metadata_2025 huggingface dataset:
Atmospheres in Radiative Equilibrium
Authors: Goody R. M. , Yung Y. L.
Published: November 2020

In this chapter we discuss radiative equilibrium models of the earth’s atmosphere and the closely related radiative—convective models, for which small-scale convection is included in a highly parameterized form. In both cases, heat transports by planetary-scale motions are neglected. Despite their limitations, radiative equilibrium and radiativeconvective studies have provided stimuli for many of the fundamental ideas discussed in this book. Their value is principally heuristic. The radiative equilibrium state is one conceivable state of a planetary atmosphere that may be analyzed so that the implications of parameteric changes can be understood in simple terms (e.g., changes in atmospheric composition, earth orbital elements, solar emission, etc.). The same cannot yet be said of any dynamic model. While numerical solutions are available from general circulation models, their behavior is often no easier to interpret than that of the atmosphere itself. For studies that are not based on the existence of day-to-day observations, radiative equilibrium considerations provide the irreplaceable first step in a number of fields: the atmospheres of other planets, stellar atmospheres, the earth’s primitive atmosphere; and much of the progress in studies of climate change has been based on the simplest energy balance models. In addition to their value in examining general principles, there is a recurrent, although disputed theme that radiative equilibrium has direct relevance to the observed atmospheric structure. This proposition embraces a number of instructive ideas but, before examining them, we consider some of the observational evidence that motivates them. From the earliest days following the discovery of the stratosphere, theoretical workers assumed that the stratosphere, unlike the troposphere, was in radiative equilibrium. The reasoning was that no forms of heat transport, other than radiative, could be important in a highly stable atmosphere. Since nothing was known about planetary-scale motions at that time, this conclusion was premature. If we turn to modern data, Fig. 9.1a presents the observed climatological temperatures in the middle atmosphere, to be compared with radiative equilibrium calculations shown in Fig. 9.1b. Agreement between theory and observation is fairly good except in the region of the polar winter.
The Literatures of America—A Comparative Discipline
Authors: Lauter Paul
Published: November 2020

An image has long haunted the study of American culture. It limits our thought, shapes our values. We speak of the “mainstream,” and we imply by that term the existence of other work, minor rills and branches. In prose, the writing of men like Franklin, Emerson, Thoreau, Hawthorne, Melville, James, Eliot, Hemingway, Faulkner, Bellow—to name some of the central figures—constituted the “mainstream.” Others—writers of color, most women writers, “regional” or “ethnic” male and female authors—might, we said, be assimilated into the mainstream, though probably they would continue to constitute tributaries, interesting and often sparkling, but finally of less importance. They would, we tacitly assumed, be judged by the standards and aesthetic categories we had developed for the canonical writers. At best, we acknowledged that including in the canon writers like Wharton, Cather, Chopin, and Ellison might change somewhat our definition of the mainstream, but the intellectual model imposed by that mainstream image, this Great River theory of American letters, has persisted even among mildly revisionist critics. Such critics have continued to focus on a severely limited canon of “major” writers based on historical and aesthetic categories from this slightly augmented mainstream. The problem we face is that the model itself is fundamentally misleading. The United States is a heterogeneous society whose cultures, while they overlap in significant respects, also differ in critical ways. A normative model presents those variations from the mainstream as abnormal, deviant, lesser, perhaps ultimately unimportant. That kind of standard is no more helpful in the study of culture than is a model, in the study of gender differences, in which the male is considered the norm, or than are paradigms, in the study of minority or ethnic social organization and behavior based on Anglo-American society. What we need, rather, is to pose a comparativist model for the study of American literature. It is true that few branches of academe in the United States have been so self-consciously indifferent to comparative study as has been the field we call “American literature.”
A Scandalous Misuse of Faculty—Adjuncts
Authors: Lauter Paul
Published: November 2020

While increasing attention began to be focused a decade ago on the scandalous misuse of part-time or “adjunct” faculty in colleges, their use has persistently spread. In fact, new varieties of “temporary” positions continue to be invented by college managers. “Part-time” faculty now include some who teach what amounts to a full load, but who are paid on a credit hour or per course basis, others who scramble for one or two courses each term and are paid flat rates, as well as a few whose salaries and benefits are prorated fractions of those of a full-timer. But there are now many “off-tenure” full-time appointments as well: “lecturers,” whose contracts are renewed every year or two but who may remain in their positions, without tenure, indefinitely; “nontenure-track” instructors and assistant professors, who may stay at an institution for four, six or more years but who, at the point of a tenure decision, must move on; “replacement” appointments, who fill lines for a year or two and then migrate to similar positions elsewhere. I shall use the term “adjunct faculty” or “adjuncts” to describe this quite varied group of individuals, for while the word is not precisely appropriate in all cases, its dictionary definition calls attention to the fact that such faculty, while “joined or added” to the institution, are in critical ways “not essentially a part of it.” Handwringing over the plight of adjuncts has brought no relief, and even most union contracts have so far been marginally helpful. That should be no surprise, for the exploitation of adjuncts serves a number of crucial interests of college managers and of those to whom they report. It is important to identify these interests more clearly if the abuse of this large number of our colleagues is ever to be brought under control, much less halted. For the exploitation of adjuncts is not a function of managerial nastiness, nor is it—any more than was the War on Vietnam—an unfortunate product of historical “accidents.” Rather, it is rooted in a particular conception of college management designed to serve historically distinctive social and political interests.
Redox Thermodynamics for Oxygen Species (O3, O2, HOO·, O2-, HOOH, HOO-, O, O-, and HO-); Effects of Media and pH
Authors: Sawyer Donald T. , Williams R. J. P.
Published: November 2020

Biological systems activate ground-state dioxygen (3O2) for controlled energy transduction and chemical syntheses via electron-transfer and hydrogen-atomtransfer reduction to O2-, HOO·, and HOOH. These reduction products are further activated with metalloproteins to accomplish oxygen atom-transfer chemistry. Conversely, green plants via photosystem II facilitate the oxidation of chemistry.
Physical Probability
Authors: Pollock John L.
Published: November 2020

Probability theorists divide into two camps-the proponents of subjective probability and the proponents of objective probability. Opinion has it that subjective probability has carried the day, but I think that such a judgment is premature. I have argued elsewhere that there are deep incoherencies in the notion of subjective probability. Accordingly, I find myself in the camp of objective probability. The consensus is, however, that the armies of objective probability are in even worse disarray. The purpose of this book is to construct a theory of objective probability that rectifies that. Such a theory must explain the meaning of objective probability, show how we can discover the values of objective probabilities, clarify their use in decision theory, and demonstrate how they can be used for epistemological purposes. The theory of nomic probability aims to do all that. This book has two main objectives. First, it will propose a general theory of objective probability. Second, it will, in a sense to be explained, propose a solution to the problem of induction. These two goals are intimately connected. I will argue that a solution to the problem of induction is forthcoming, ultimately, from an analysis of probabilistic reasoning. Under some circumstances, probabilistic reasoning justifies us in drawing non-probabilistic conclusions, and this kind of reasoning underlies induction. Conversely, an essential part of understanding probability consists of providing an account of how we can ascertain the values of probabilities, and the most fundamental way of doing that is by using a species of induction. In statistical induction we observe the relative frequency (the proportion) of A's in a limited sample of B's, and then infer that the probability of a B being an A is approximately the same as that relative frequency. To provide philosophical foundations for probability we must, among other things, explain precisely how statistical induction works and what justifies it. Probability is important both in and out of philosophy. Much of the reasoning of everyday life is probabilistic. We look at the clouds and judge whether it is going to rain by considering how often clouds like that have spawned rain in the past.
Advanced Topics: Acceptance Rules
Authors: Pollock John L.
Published: November 2020

There once was a man who wrote a book. He was very careful in his reasoning, and was confident of each claim that he made. With some display of pride, he showed the book to a friend (who happened to be a probability theorist). He was dismayed when the friend observed that any book that long and that interesting was almost certain to contain at least one falsehood. Thus it was not reasonable to believe that all of the claims made in the book were true. If it were reasonable to believe each claim then it would be reasonable to believe that the book contained no falsehoods, so it could not be reasonable to believe each claim. Furthermore, because there was no way to pick out some of the claims as being more problematic than others, there could be no reasonable way of withholding assent to some but not others. “Therefore,” concluded his friend, “you are not justified in believing anything you asserted in the book.” This is the paradox of the preface (so named because in the original version the author confesses in the preface that his book probably contains a falsehood). The paradox of the preface is more than a curiosity. It has been used by some philosophers to argue that the set of one's warranted beliefs need not be deductively consistent, and by others to argue that you should not befriend probability theorists. If (Al) is to be a correct acceptance rule it must be capable of explaining what is involved in the paradox of the preface. The lottery paradox and the paradox of the preface seem superficially similar, so it might be supposed that a resolution of one will automatically generate a resolution of the other in some trivial manner. But in fact, the opposite is true. It is the principle of collective defeat that makes possible the resolution of the lottery paradox, but it is the principle of collective defeat that is responsible for the creation of the paradox of the preface.
Tactics for Individual Productivity
Authors: Kim Steven
Published: November 2020

The resolution of a difficult task often follows a series of identifiable steps. Students of creativity have often characterized the process as a four-stage phenomenon: • Preparation: Orientation to the problem and definition of the task. • Incubation: A period of aridity or immersion in unrelated activities. • Illumination: A sudden spark of insight and the recognition of a candidate solution. • Resolution: Assessment of the candidate solution and its implementation. The preparatory phase of a difficult task involves a careful consideration of the underlying problem and a clear specification of the goals. Too often we tackle tasks without an adequate definition of the true problem, and discover too late that the solution resolves an irrelevant problem. A distinguishing feature of challenging tasks lies in their resistance to attack, and solutions do not always spring from a single session of wrestling with the problem. Often difficult issues are resolved, whether gradually or suddenly, over spaced efforts interrupted by unrelated activities. Some students of creativity take the view that incubation is a period of “intermission” in which the problem submerges into the subconscious. The lack of strict conventions in this netherworld allows for the juxtaposition of new objects in novel and even bizarre combinations. The resulting ideas possess the novelty that is an essential ingredient of a creative solution. Other writers take the view that incubation is nothing more than a period of relaxation or recuperation in which a tired mind regains its energies. Still others would claim that the incubation phase is merely a stretch of time that allows the mind to assimilate other stimuli from the environment, whether at the conscious or subconscious level. Whatever the true role of incubation, the fact remains that many of our difficult problems are resolved only after several sessions of conscious effort separated by seemingly unrelated activities. A candidate solution to a difficult problem often occurs suddenly, just like the elementary ideas that constitute them. Such preliminary solutions or “insights,” however, can be misleading or even incorrect. For this reason, the ideas must be properly evaluated.
Consonants
Authors: Treiman Rebecca
Published: November 2020

Learning to spell involves learning about the relations between the phonemes of the spoken language and the graphemes of the printed language. In Chapter 4, I asked how children learn these relations for vowels. The results showed that a number of factors affect children’s learning, including their exposure to printed words, their knowledge of letter names, and their phonological systems. In this chapter, I turn to consonants. I ask whether these same factors affect children’s spelling of consonants. This chapter focuses on substitution errors and, to a lesser extent, correct spellings. Consonant omission errors will be considered in detail in Chapter 8. Sometimes, the first graders’ most common spellings of consonant phonemes were those spellings that are most frequent in the conventional English system. However, the children’s spellings did not always mirror those of conventional English. The children sometimes used a grapheme that never represents the phoneme in the standard system; that is, an illegal spelling. As in Chapter 4, I focus on illegal spellings that occurred at rates of 2.5% or more. I ask why the children selected that particular grapheme to represent the phoneme. In other cases, the students used a legal spelling significantly more often than expected given its frequency in the conventional system. Again, factors other than exposure to the relations between phonemes and graphemes in English words must be responsible for the error. I ask what these factors are. As in Chapter 4, I use binomial tests to compare the frequencies of correspondences in children’s spelling to the frequencies of the correspondences in the conventional spellings of the same words. In this section, the children’s spellings of various consonant phonemes are discussed. The reader may find it helpful to refer to the consonant chart of Figure 1.5 when reading this section. The stop consonants of English are /p/, /t/, /k/, /b/, /d/, and /g/. In discussing how the children spelled these consonants, I will first consider the children’s spellings without regard to the contexts in which the consonants occurred. Next, I will discuss some errors that occurred for stop consonants in particular contexts.
Atmospheric Boundary Layer Flows
Authors: Kaimal J. C. , Finnigan J. J.
Published: November 2020

Boundary layer meteorology is the study of the physical processes that take place in the layer of air that is most influenced by the earth's underlying surface. This text/reference gives an uncomplicated view of the structure of the boundary layer, the instruments available for measuring its mean and turbulent properties, how best to make the measurements, and ways to process and analyze the data. The main applications of the book are in atmospheric modelling, wind engineering, air pollution, and agricultural meteorology. The authors have pioneered research on atmospheric turbulence and flow, and are noted for their contributions to the study of the boundary layer. This important work will interest atmospheric scientists, meteorologists, and students and faculty in these fields.
Flow Over Flat Uniform Terrain
Authors: Kaimal J. C. , Finnigan J. J.
Published: November 2020

We start with the simplest of boundary layers, that over an infinite flat surface. Here we can assume the flow to be horizontally homogeneous. Its statistical properties are independent of horizontal position; they vary only with height and time. This assumption of horizontal homogeneity is essential in a first approach to understanding a process already complicated by such factors as the earth's rotation, diurnal and spatial variations in surface heating, changing weather conditions, and the coexistence of convective and shear-generated turbulence. It allows us to ignore partial derivatives of mean quantities along the horizontal axes (the advection terms) in the governing equations. Only ocean surfaces come close to the idealized infinite surface. Over land we settle for surfaces that are locally homogeneous, flat plains with short uniform vegetation, where the advection terms are small enough to be negligible. If, in addition to horizontal homogeneity, we can assume stationarity, that the statistical properties of the flow do not change with time, the time derivatives in the governing equations vanish as well. This condition cannot be realized in its strict sense because of the long-term variabilities in the atmosphere. But for most applications we can treat the process as a sequence of steady states. The major simplification it permits is the introduction of time averages that represent the properties of the process and not those of the averaging time. These two conditions clear the way for us to apply fluid dynamical theories and empirical laws developed from wind tunnel studies to the atmosphere's boundary layer. We can see why micrometeorologists in the 1950s and 1960s scoured the countryside for flat uniform sites. The experiments over the plains of Nebraska, Kansas, and Minnesota (USA), Kerang and Hay (Australia), and Tsimliansk (USSR) gave us the first inklings of universal behavior in boundary layer turbulence. Our concept of the atmospheric boundary layer (ABL) and its vertical extent has changed significantly over the last few decades.
Flow Over Changing Terrain
Authors: Kaimal J. C. , Finnigan J. J.
Published: November 2020

The micrometeorologist setting out to find a field site that satisfies the requirements of horizontal homogeneity will soon be reminded that most of the earth’s surface is not flat and that most of the flat bits are inconveniently heterogeneous. This is what forced the location of early pioneering experiments to remote sites such as Kansas, Minnesota, or Hay (Chapter 1), where the elusive conditions could be realized. Vital as these experiments were to the development of our understanding, they are merely the point of departure for applications to arbitrary terrain. The components of arbitrariness are two: changes in the land surface and hills. In this chapter we discuss the first of these, flow over changing surface conditions; in Chapter 5 we look at flow over hills. In the real world, the two conditions often occur together — in farmland it is the hills too steep to plow that are left covered with trees — but we separate them here to clarify the explication of phenomena and because treating them in combination would exceed the state of the art. We simplify the problem of horizontal heterogeneity still further and discuss mainly single changes in surface conditions from one extensive uniform surface to another. Furthermore, the change will typically be at right angles to the wind direction so the resulting flow field is two-dimensional. Although multiple changes are now receiving theoretical attention (Belcher et al., 1990; Claussen, 1991), there exist as yet no experimental data for comparison. Two types of surface change may be distinguished at the outset: change in surface roughness, which produces a change in surface momentum flux with a direct effect upon the wind field, and change in the surface availability of some scalar. Those of most interest are the active scalars, heat and moisture. (These are called active because their fluxes and concentrations affect stability and thereby turbulent mixing and momentum transfer, as we saw in Chapters 1 and 3.) We shall discover significant differences in flow behavior according to whether the wind blows from a smooth to a rough surface or a rough to a smooth surface.
Sensors and Techniques for Observing the Boundary Layer
Authors: Kaimal J. C. , Finnigan J. J.
Published: November 2020

Sensors used for boundary layer measurements fall into two broad categories: in situ sensors that can be mounted on the ground, on masts, towers, tethered balloons, free balloons, or aircraft; and remote sensors, ground-based or aircraft-mounted, that infer atmospheric properties through their effects on acoustic, microwave, and optical signals propagating through the air. In situ sensors are the traditional instruments of choice for surface and lower boundary layer studies, being the only ones capable of the accuracy and resolution needed for quantitative work. A major portion of this chapter will therefore be devoted to discussions of their characteristics. Remote sensors have the advantage of increased range and spatial scanning capability, but the constraints on minimum range and spatial resolution limit their usefulness for surface layer measurements. Used in combination, however, the two types of sensors provide a more complete description of the flow field being studied than either of the two can provide separately. New remote sensors with shorter minimum ranges and finer range resolutions are now becoming available for boundary layer applications. A brief discussion of such devices is also included in this chapter. The variables of greatest interest to boundary layer meteorologists are wind speed, temperature, humidity, and the fluxes of momentum, heat, mass, and radiant energy. Given suitable fast-response measurements of wind velocity and scalar fluctuations, we can calculate the eddy fluxes directly from the products of their fluctuating components as explained in Chapter 1. If only the gradients of their means are available, however, then over a flat homogeneous surface the fluxes may be inferred from the Monin-Obukhov relationships of Chapters 1 and 3. Practical methods for doing that are described in many texts; see, for example, Monteith (1975, 1976). (Those simple relationships do not hold, as we know, under advective conditions, in plant canopies, and over hills.) There are also sensors in use that measure surface and near-surface fluxes directly, such as the drag plate (surface stress), the lysimeter (latent heat flux), flux plates (soil heat flux), and radiometers (radiant heat flux). We will discuss these and a few other types as well because of their application to studies of plant canopies.
An Uncertain Enterprise: Learning to Heal in the Enlightenment
Authors: Bonner Thomas Neville
Published: November 2020

There was no more turbulent yet creative time in the history of medical study than the latter years of the eighteenth century. During this troubled era, familiar landmarks in medicine were fast disappearing; new ideas about medical training were gaining favor; the sites of medical education were rapidly expanding; and the variety of healers was growing in every country. Student populations, too, were undergoing important changes; governments were shifting their role in medicine, especially in the continental nations; and national differences in educating doctors were becoming more pronounced. These transformations are the subject of the opening chapters of this book. These changes in medical education were a reflection of the general transformation of European society, education, and politics. By the century’s end, the whole transatlantic world was in the grip of profound social and political movement. Like other institutions, universities and medical schools were caught up in a “period of major institutional restructuring” as new expectations were placed on teachers and students. Contemporaries spoke of an apocalyptic sense of an older order falling and new institutions fighting for birth, and inevitably the practice of healing was also affected. From the middle of the century, the nations of Europe and their New World offspring had undergone a quickening transformation in their economic activity, educational ideas, and political outlook. By 1800, in the island kingdom of Great Britain, the unprecedented advance of agricultural and industrial change had pushed that nation into world leadership in manufacturing, agricultural productivity, trade, and shipping. Its population growth exceeded that of any continental state, and in addition, nearly three-fourths of all new urban growth in Europe was occurring in the British Isles. The effects on higher education were to create a demand for more practical subjects, modern languages, and increased attention to the needs of the thriving middle classes. Although Oxford and Cambridge, the only universities in England, were largely untouched by the currents of change, the Scottish universities, by contrast, were beginning to teach modern subjects, to bring practical experience into the medical curriculum, and to open their doors to a wider spectrum of students.
The Laboratory Versus the Clinic: The Fight for the Curriculum, 1870-1890
Authors: Bonner Thomas Neville
Published: November 2020

What was most compelling in the case for science in medicine after 1870 were the stunning achievements in laboratory medicine by that time. During the preceding decades, the work of laboratory scientists, especially in France and Germany, had brought a far more sophisticated understanding of the physical and chemical makeup and functioning of the human body and had produced a host of new tests, instruments, and techniques that were being increasingly used to study the sick patient. The role of bacteria in fermentation and then in wound pus had been demonstrated in the years preceding 1870, and they were now claimed to be responsible for a number of specific diseases. These discoveries, in turn, stimulated a great burst of energy in surgery, eventually gave a new and more certain basis to public health work, infused new optimism into the search for pharmacological remedies, and opened up new possibilities of protection against illness through deliberate immunization. Virtually no subject in the medical curriculum was untouched by the changes in medical knowledge, as dozens of new courses were created to teach the new viewpoints in disease. The new viewpoints were deemed necessary for students to master, even though they had as yet little impact on therapy. Contrary to some later critics, medicine has always been more than the simple application of “cures” to human ailments. For thousands of years as well as in our own time, the understanding of disease, its origins and causes, its transmission, and its prevention, prognosis, and palliation have been principal reasons for consulting a physician. In the years around 1870, in particular, science made enormous gains in understanding ancient afflictions and was gaining in ways to control, alleviate, and, in a few cases, to cure them. Was science important to medicine in these years, despite the slow pace of therapeutic change? Indeed it was, even if much of ordinary medical practice, especially the healing of many illnesses, was not immediately affected by what students learned. The rapid-fire developments of these years created a vision of an experimentally based, irresistible medical science that would soon sweep all doubts before it.
Thermodynamics—A Model Subject
Authors: Anderson Greg M. , Crerar David A.
Published: November 2020

The teaching of thermodynamics, not to mention the writing of a book on thermodynamics, presents a great challenge for anyone foolhardy enough to undertake it. How to present the subject?—historical or postulational; classical or statistical; macroscopic or microscopic; mathematical or non-mathematical; rigorous or close enough; applications or fundamentals; and so on. Then there is the uncomfortable fact that, as Reiss (1965) points out, one very probably doesn't completely understand the subject. But if teaching thermodynamics presents difficulties, what of the poor student who is subjected to an almost insuperable series of obstacles; everything seems to depend on infinitesimals, on the most unusual and unlikely hypothetical systems, on differentials which may or may not be integrable, and especially on reversible processes which are completely unimaginable and seem to be the key to everything. Somehow out of this mess come concepts and relationships which are very useful in the real world, and it can be argued that in introductory courses the goal should be an ability to use these relationships, not to understand them. At the same time the subject is so profound and esthetically pleasing to scientists that many feel the urge to rhapsodize on it. Lewis and Randall (1923), who wrote one of the more significant books on the subject after Gibbs, likened thermodynamics to a cathedral inspiring solemnity and awe; Einstein wrote that it was the only physical theory of universal content that he was sure would never be overthrown. The profundity of the subject comes from the seemingly universal applicability of its premises and conclusions to some of the most fundamental questions of science, and the elegance from the simplicity and symmetry of its mathematical operations. For example, it is quite amazing to realize that essentially all the geochemical applications discussed in this book involve a single equation, along with a few direct descendants, derived directly from the first and second laws of thermodynamics. It is a considerable challenge to show the meaning of this equation and how to use it. In this text we present the subject as we would have liked to have had it presented to us—with a careful and complete explanation of some fundamental points, a partial or complete neglect of others, a combination of historical, postulational, and statistical approaches as seems appropriate at the moment, and a smattering of applications in geochemistry.
Ideal Solutions
Authors: Anderson Greg M. , Crerar David A.
Published: November 2020

The chemical constituents of a solution can be varied — added, subtracted and interchanged or substituted for each other — within limits ranging from complete (e.g., gases) to highly restricted (trace components in quartz). Adding or subtracting chemical constituents to or from a phase involves changes in energy, which will be discussed in the following sections. For example, if two components A and B are mixed together, the Gibbs energy of a solution of the two mixed must be less than the sum of the Gibbs energies of the two separately for the spontaneous reaction to take place. That is, if we mix nA moles of component A and nA moles of component B, their combined total G is (nAGA + nBGB) where GA and GB are the molar free energies of A and B. If G(A,B) is the total free energy of the resulting solution, then necessarily if the solution took place spontaneously. Alternatively, dividing through by nA + nB, where XA and XB are the mole fractions. Thus if A is albite and B is anorthite, then (A,B) is plagioclase, and we say that the plagioclase solid solution is more stable than a "mechanical mixture" of grains of albite and anorthite. On the other hand if A is diopside and B is anorthite, little or no mutual solution takes place because in this case so that no spontaneous solution reaction takes place. The term "mechanical mixture" in this context nicely conveys the idea of quantities of mineral grains mixed together and not reacting, but does not work quite so well if A and B are other things such as water and halite, or water and alcohol. Nevertheless, the term is traditionally used no matter what the nature of the solution constituents, and no harm is done as long as we remember that "mechanical mixture" means that the constituents considered do not react with each other, whatever their physical nature.
Atmosphere-Ocean Interaction
Authors: Kraus Eric B. , Businger Joost A.
Published: November 2020

With both the growing importance of integrating studies of air-sea interaction and the interest in the general problem of global warming, the appearance of the second edition of this popular text is especially welcome. Thoroughly updated and revised, the authors have retained the accessible, comprehensive expository style that distinguished the earlier edition. Topics include the state of matter near the interface, radiation, surface wind waves, turbulent transfer near the interface, the planetary boundary layer, atmospherically-forced perturbations in the oceans, and large-scale forcing by sea surface buoyancy fluxes. This book will be welcomed by students and professionals in meteorology, physical oceanography, physics and ocean engineering.
Chemical Change in Deforming Materials
Authors: Bayly Brian
Published: November 2020

This book is the first to detail the chemical changes that occur in deforming materials subjected to unequal compressions. While thermodynamics provides, at the macroscopic level, an excellent means of understanding and predicting the behavior of materials in equilibrium and non-equilibrium states, much less is understood about nonhydrostatic stress and interdiffusion at the chemical level. Little is known, for example, about the chemistry of a state resulting from a cylinder of deforming material being more strongly compressed along its length than radially, a state of non-equilibrium that remains no matter how ideal the cylinder's condition in other respects. M. Brian Bayly here provides the outline of a comprehensive approach to gaining a simplified and unified understanding of such phenomena. The author's perspective differs from those commonly found in the technical literature in that he emphasizes two little-used equations that allow for a description and clarification of viscous deformation at the chemical level. Written at a level that will be accessible to many non-specialists, this book requires only a fundamental understanding of elementary mathematics, the nonhydrostatic stress state, and chemical potential. Geochemists, petrologists, structural geologists, and materials scientists will find Chemical Change in Deforming Materials interesting and useful.
Disequilibrium 1: Potential Gradients and Flows
Authors: Bayly Brian
Published: November 2020

As in Chapter 2, so again here the intention is to review ideas that are already familiar, rather than to introduce the unfamiliar; to build a springboard, but not yet to leap off into space. The familiar idea is of flow down a gradient—water running downhill. Parallels are electric current in a wire, salt diffusing inland from the sea, heat flowing from the fevered brow into the cool windowpane, and helium diffusing through the membrane of a helium balloon. For any of these, we can imagine a linear relation: . . . Flow rate across a unit area = (conductivity) x (driving gradient) . . . where the conductivity retains a constant value, and if the other two quantities change, they do so in a strictly proportional way. Real life is not always so simple, but this relation serves to introduce the right quantities, some suitable units and some orders of magnitude. For present purposes, the second and fourth of the examples listed are the most relevant. To make comparison easier we imagine a barrier through which salt can diffuse and through which water can percolate, but we imagine circumstances such that only one process occurs at a time. Specifically, imagine a lagoon separated from the ocean by a manmade dike of gravel and sand 4 m thick, as in Figure 3.1. If the lagoon is full of seawater but the water levels on the two sides of the dike are unequal, water will percolate through the dike, whereas if the levels are the same and the dike is saturated but the lagoon is fresh water, salt will diffuse through but there will be no bulk flow of water. (More correctly, because seawater and fresh water have different densities, and because of other complications, the condition of no net water flow would be achieved in circumstances a little different from what was just stated. For present purposes all we need is the idea that conditions exist where water does not percolate but salt does diffuse.) For flow of water driven by a pressure gradient, suitable units are shown in the upper part of Table 3.1 and for diffusion of salt driven by a concentration gradient, suitable units are shown in the lower part.
Change of Shape and Change of Volume
Authors: Bayly Brian
Published: November 2020

In earlier chapters we first defined a material's chemical potential, and then went on to enquire how the material responds. And similarly with a state of nonhydrostatic stress: having reviewed what it is, we consider how a material might respond. For the sake of simplicity, we imagine an extensive sample, such as a cubic meter, and suppose that the stress state is the same in every cubic centimeter; that is to say, there are no gradients in stress from point to point. Thus we do not enquire yet how a material responds to a spatial stress gradient; that comes later. We first enquire how it responds to a homogeneous but nonhydrostatic stress. Inside the material, close to the point of interest, we define a small length l by means of the material particles at its two ends. If, at a later moment, we find the distance between the particles to be l — δl, then we envisage the limit of the ratio δl/l as l goes to zero, give the limit the symbol ε, and name it the linear strain at the point of interest in the direction of l, positive when δl is positive, i.e., for a shortening and negative for an elongation. Another mental operation that can be performed in the neighborhood of the point of interest is to define a small sphere by means of the material particles that form its surface. At a later moment the particles will form the surface of an ellipsoid. (For a large sphere and an inhomogeneous situation, the new shape can be something more complicated; but as the imagined original sphere approaches zero diameter, the shape of its deformed counter-part can only approach an ellipsoid). The axes of the ellipsoid are principal directions of strain, and the magnitudes of the strains along them are named ε1, ε2, and ε3, with ε1 the largest. In an isotropic material, the principal axes of stress and strain coincide, with ε1 lying along the direction of σ1 and correspondingly; see Figure 7.la. As with stresses, the three values of ε themselves define an ellipsoid if they are all positive—see Figure 7.1b.
Two Phases and One Component
Authors: Bayly Brian
Published: November 2020

It is at interfaces that the links between deformation and diffusive transfer are most noticeable. In general, stresses in a material vary only gradually from point to point, but at an interface—that is, a phase boundary—the variation can be abrupt. Figure 13.1 shows two stress profiles: if we take the interface as the yz plane of a coordinate system, the normal stress σxx is necessarily the same on both sides; but the normal stress on an xy plane, for example, namely σzz, is not necessarily the same. In fact the two magnitudes σzz1 and σzz2 are apt to be noticeably different. Assume for the moment that the interface is coherent, i.e., the two phases adhere so that any change of dimension on side 1 is exactly matched by an equal change on side 2. Then if one material is ten times stiffer than the other, either in elastic modulus or viscosity, we need . . . σzz1 – σxx = 10(σzz2 – σxx) . . . Magnitudes might be σxx = 0.1, σzz2 = 1.1, σzz1 = 10.1 MPa, for example. For the purpose of designing machine parts, one can imagine a simple stress profile as in Figure 13.1b, with a vertical step or infinite gradient ∂σzz /∂x; but if one is interested in chemical details at the interface, it is prudent to consider the possibility that the profile may actually be as in Figure 13.1c — with a strong but not infinite gradient. As will be shown later in this chapter, the width over which the main stress-drop extends is measured in nanometers or perhaps micrometers. As in Figure 13.1a, the interface is taken as the yz plane. The material on the left, material 1, has properties N1, K1, R1 (viscosity, diffusivity, and characteristic length, as in Chapter 12) and material 2 similarly. To be realistic one would assign the materials different unit volumes V1 and V2, but the effects of interest can be explored more directly if we assume initially that V1 = V2.
Two Phases and Two Components
Authors: Bayly Brian
Published: November 2020

The overall plan of Chapters 13 through 16 is shown in the introductory figure of Part III. As the figure suggests, the objective of this chapter can be stated in three ways: (i) to extend ideas from Chapter 15 to a situation where an interface is present, or (ii) to extend ideas from Chapter 13 to a situation where the material envisaged is of variable composition, or (iii) to combine the main ideas from Chapter 14 and 15 with the main ideas from Chapter 13. The program of the present chapter is to do a little of (i) and then a little of (ii), before attempting a total union. By way of preview, it is to be noted that an interface may move with respect to the material on either side or, in other words, material may change phase, crossing the interface as it does so. Situations with a moving interface are more complicated than situations where the interface is stationary. In both part (i) and part (ii) of this chapter, the fact that the interface moves is recognized but disregarded. The reason is that in part (iii), a particular combination of circumstances is examined that leads to no movement of the interface. Such a combination is highly special and not likely to be met in the real world, but it shows particularly clearly how chemical change and a material's deformation interact. The overall program then is to lead up to discussion of this stationary-interface state. Chapters 14 and 15 emphasize spatial variations of a harmonic kind, continuing through space at constant amplitude to an unlimited extent. The essential difference in this chapter is that here we treat effects that have maximum intensity at or close to an interface, and die away to insignificance in the remote interiors of the two touching phases. Exponential functions were found useful to describe an effect of this type in Chapter 13, and it is natural to seek a physical situation where they can be used again; the first step is to distinguish the two types of behavior in Figure 16.1.
Measurements of Phytoplankton Absorption Other Than Per Unit of Chlorophyll a
Authors: Perry Mary Jane
Published: November 2020

Phytoplankton plays a critical role in determining light fields of the world’s oceans, primarily through absorption of light by photosynthetic pigments (see Chapters 1 to 5). Consequently there has been considerable interest from optical researchers in determining phytoplankton absorption. Conversely, from the biological point of view, this absorption assumes paramount importance because it is the sole source of energy for photosynthesis and thus should be central to direct estimates of primary production. There are two logical parts in determining this effect of phytoplankton and in estimating primary production. One is the estimation of abundance, and the other is estimation of specific effect or specific production rate. The earliest estimates of phytoplankton abundance were based on cell counts. From the time of Francis A. Richards’ Ph.D. dissertation, however, measurement of chlorophyll a concentration per unit of water volume, because of its relative ease, has assumed a central role in abundance estimation. Physiological studies and technological advances in optical instrumentation over the last decade lead me to question whether the continued use of chlorophyll a concentration to estimate phytoplankton abundance was wise either from the viewpoint of narrowing confidence intervals on estimates of absorption and production or from the viewpoint of mechanistic understanding of the processes involved. The measurement of chlorophyll a has become such a routine tool of biological oceanography, however, that the reasons for my heresy require elaboration. Some of the reasons are not too subtle. Chlorophyll a exists with other photosynthetic pigments in organized arrays associated with photosynthetic membranes. The function of these arrays is to harvest photons and transfer their energy to the specialized reaction center complexes that mediate photochemistry (see Chapter 9). The size of the arrays or packages and the ratio of chlorophyll a molecules to other light-harvesting pigments within the packages vary with phytoplankton cell size, total irradiance and its spectral distribution, as well as with other environmental parameters. It is well known that dark-adapted (= light-limited) cells increase their complements of photopigments. This plasticity in pigment packaging is evidenced in the variability of chlorophyll a-specific absorption coefficients. Simple optical models based only on chlorophyll a concentrations cannot be accurate or precise unless the effects of pigment packaging are considered.
Raman Scattering and Optical Properties of Pure Water
Authors: Smith Raymond C. , Marshall Bruce R.
Published: November 2020

There are numerous observations of the spectral attenuation, absorption, and scattering of distilled water and seawater. Morel (1974) reviewed the literature with respect to the attenuation coefficient as a function of wavelength and published his seawater and distilled water scattering coefficients. Smith and Baker (1978b) critically reviewed measurements made by many investigators to estimate the relative accuracies in the published values for the total absorption coefficient and the diffuse attenuation coefficient, and found a large range. Early workers frequently did not make a careful distinction between the absorption coefficient, the diffuse attenuation coefficient, and the total beam attenuation coefficient. Preisendorfer (1976) derived a set of inequalities linking the total beam attenuation coefficient, the diffuse attenuation coefficient, the forward scattering coefficient, the average cosine, the backscattering coefficient, and the absorption coefficient. This treatment allows us to define the theoretical bounds for the inherent and apparent optical properties of optically pure water. Morel (1974) defined optically pure water as a medium devoid of dissolved and suspended material. Thus, optically pure water is a medium for which particle backscattering, particle absorption, and the absorption due to dissolved organic material are zero, so the attenuation due to the water is the absorption due to water plus molecular scattering; that is, . . . cw = aw+bm (12.1) . . . Using the relationship (Preisendorfer, 1976) one can derive an inequality for the fresh water diffuse attenuation coefficient, establishing the following limitation (in the absence of transpectral scattering): where one-half the molecular scattering is included since molecular scattering is isotropic.