bluuebunny/crossref_metadata_2025 huggingface dataset:
Thoughts on the History of Greek Urbanization
Authors: Crouch Dora P.
Published: November 2020

Today we are facing constraints on the use of water. Some cities have astronomically high densities or unusually low access to fresh water while still others may have only enough water that is not contaminated with heavy metals or pesticides to cover the 6 percent allocated for drinking but not enough of that highest quality for the rest of domestic use. In all of these cases, modern hydraulic engineers are experimenting—though often without realizing it—with a set of solutions that are at least 2500 years old. These solutions were appropriate quality of water for each use, plus reuse to the extent feasible. Both solutions were determined then and are implemented now on a cost-benefit basis. Those who understand the lessons of history of water management can repeat them more quickly and efficiently than those who, for instance, have to re-invent a three-tiered water system from scratch. This is where the urban historian can play the role of interpreter, to help us understand in a way that the recital of disconnected facts never can. The historian recovers the plan of the past—both the physical form and the social intention. From the point of view of the development of architectural and urban history and theory, this approach to the data involves humble acknowledgment of ignorance, careful amassing of facts, meditation on the facts to see what principles they suggest, and utilization of both data and methodology from many different disciplines. Then the principles derived from one site can be tried to facilitate the understanding of another site, and a body of theory develops strongly bolstered by facts as well as principles and insights. From the site-specific facts about water management in the ancient Greek world, I have provisionally arrived at the following elements for a theoretical position about the role of water in the formation of traditional settlements: 1. Founders of these settlements used traditional knowledge to find and develop water resources. 2. Their methods were positive for long-term water resource management. 3. Water of several qualities was allocated to its best use. 4. House design and city form reveal the society's means of collecting and using water, as well as constraining that use.
Anisotropic Media with a Crack or a Rigid Line Inclusion,
Authors: Ting T. T. C.
Published: November 2020

A crack, or cracks, in a material is perhaps one of the most studied problems in solid mechanics. This is due to the fact that many structural failures are related to the presence of a crack in the material. The knowledge of stress distribution near a crack tip is indispensable in a fracture mechanics analysis (Rice, 1968; Sih and Liebowitz, 1968; Sih and Chen, 1981; Kanninen and Popelar, 1985; K. C. Wu, 1989a). A crack is represented by a slit cut whose surfaces are assumed traction-free. This is a mathematical idealization. For a composite material that consists of stiff short fibers or whiskers in the matrix, we have rigid line inclusions. A rigid line inclusion is the counterpart of a crack. It is sometimes called an anticrack. The displacement at a rigid line inclusion either vanishes or has a rigid body translation and rotation. One of the puzzling problems for a crack is the one when it is located on the x1-axis that is an interface between two dissimilar materials. The displacement of the crack surfaces near the crack tips may oscillate, creating a physically unacceptable phenomenon of interpenetration of two materials. The bimaterial tensor Š introduced in Section 8.8 plays a key role in the analysis. If Š vanishes identically, there is no oscillation. If Š is nonzero, we may decompose the tractions applied on the crack surfaces into two components, one along the right null vector of Š denoted by to and the other on the right eigenplane of Š denoted by tγ . The solution associated with to is not oscillatory. It has the property that the traction on the interface x2=0 is polarized along the right null vector of Š while the crack opening displacement is polarized along the left null vector of Š. The solution associated with tγ is oscillatory. It has the property that the traction on the interface x2=0 is polarized on the right eigenplane of Š while the crack opening displacement is polarized on the left eigenplane of Š.
Applications and Extensions of Statistical Theories
Authors: Baer Tomas , Hase William L.
Published: November 2020

The RRKM rate constant as given by equation (6.73) in the previous chapter is expressed as a ratio of the sum of states in the transition state and the density of states in the reactant molecule. An accurate calculation of this rate constant requires that all vibrational anharmonicity and vibrational/rotational coupling be included in calculating the sum and density.
Dynamical Approaches to Unimolecular Rates
Authors: Baer Tomas , Hase William L.
Published: November 2020

In the previous chapters theories were discussed for calculating the unimolecular rate constant as a function of energy and angular momentum. The assumption inherent in these theories is that a microcanonical ensemble is maintained during the unimolecular reaction and that every state in the energy interval E → E + dE has an equal probability of decomposing. Such theories are viewed as statistical since the unimolecular rate constant is found from a statistical counting of states in the microcanonical ensemble. A dynamical description of unimolecular decomposition is concerned with properties of individual states of the energized molecule. Of interest are the decomposition probabilities for the states as well as the rate of transitions between the states. Dynamical theories of unimolecular decomposition deal with the properties of vibrational/rotational energy levels, state preparation and intramolecular vibrational energy redistribution (IVR). Thus, the presentation in this chapter draws extensively on the previous chapters 2 and 4. Unimolecular decomposition dynamics can be treated using quantum and classical mechanics, and both perspectives are considered here. The role of nonadiabatic electronic transitions in unimolecular dynamics is also discussed. A molecule which can dissociate does not, strictly speaking, have a discrete energy spectrum. The relative motion of the product fragments is unbounded and, in this sense the motion of the unimolecular system is infinite, and hence the energy spectrum is continuous. However, it may happen that the dissociation probability of the molecule is sufficiently small that one can introduce the concept of quasi-stationary states. Such states are commonly referred to as resonances since the energy of the unimolecular fragments in the continuum is in resonance with (i.e., matches) the energy of a vibrational/rotational level of the unimolecular reactant. For unimolecular reactions there are two types of resonance states. The simplest type, a shape resonance, occurs when a molecule is temporarily trapped by a fairly high and wide potential energy barrier. The second type of resonance, called a Feshbach or compound-state resonance, occurs when energy is initially distributed between vibrational/rotational degrees of freedom of the molecule which are not strongly coupled to the fragment relative motion, so that there is a time lag for unimolecular dissociation.
Syntax and Semantics
Authors: Ashcroft E. A. , Faustini A. A. , Jaggannathan R. , Wadge W. W.
Published: November 2020

In this chapter, the syntax of Lucid will be formally specified. Also, the denotational semantics of Lucid will be outlined. The example programs in Chapter 1, surprisingly perhaps, informally introduced all the syntax of Lucid. There, we saw where clauses, definitions, terms, dimension names variables, functions, constants, and operations. Now, we will see how these syntactic entities are formalized, and the examples in the previous chapter will be looked at again, this time to see which of the syntactic entities are being used, and how. Lucid is an expression-based language: every Lucid program is a term, which might be a where clause of size 1. A where clause of size n is an n-tuple of terms together with declarations of new dimensions and subsidiary definitions (that follow the keyword where). The definitions in a where clause have right-hand sides that may be where clauses. Thus, Lucid programs are naturally recursively structured, to arbitrary depth. We will say that Lucid is where clause structured, where we intend that expression to convey all that the expression block structured conveys about scoping in, say, Algol, Pascal, or Ada. After that very cursory top-down view of Lucid, we now immediately look at the basic entities from which terms are formed: variables, functions, constants, and operations. These four basic types of entities we will call atoms. Syntactically, variables and functions are represented by identifiers, which are alphanumeric strings that start with a letter. Constants and operations, on the other hand, are usually represented by characters other than letters, such as + and 3 and #. Some operations and constants are represented by alphanumeric strings, such as fby, true, and div. (Also, the ternary conditional operation is represented by four such strings: if, then, else, and fi.) We will say that these strings are not identifiers—they are special reserved keywords—and we will not allow them to be used to represent variables or functions. (This is standard practice for many languages.) All atoms have two arities, which we will call the Roman and the Greek arities.
Housing and Residential Communities
Authors: Thrall Grant Ian
Published: November 2020

Housing occupies about 70 percent of the land area of a typical city. That land area is not randomly distributed, but instead follows regular spatial patterns; these patterns are sectorial and radial (see Hoyt 1939; chapter 2). These geographic patterns form housing submarkets. Specific demographic groups are attracted to housing in those submarkets. As there are many kinds of demographic characteristics of households, there are also many types of housing, and many housing submarkets. Housing submarkets include downtowns, middle-burbs, suburbs; high income; middle income, and low income; new development, mixed use, older development, and mixed new infill with older development; apartments, condominiums; townhouses, high rises, and single-family dwellings. The market analyst makes recommendations on which type of development will be most successful in which submarket and on which submarket would be appropriate for a particular type of development (see Sumichrast and Seldin 1977). Few people today choose to live without the benefit of some type of housing. The choice and availability of what type of housing to live in depends on a complex interaction of many factors, including culture, the natural and built environment, technological scale of society, government, income, stage of life cycle, economics of building construction, and knowledge and imagination of those building the housing. This chapter presents a broad overview of housing market analysis. In the overview, the determinants to demand and supply of housing are presented (See also Harvey, 1992). There is a broad overview of forecasting procedures and methodologies, the methods for projecting absorption rate, housing demand, and competitive supply, and how sales prices and rental prices might be determined. In the last quarter of the nineteenth century, upper-middle-income urban households in the United States and Canada often lived in what are today commonly referred to as Victorian houses. These houses were designed for multigenerational living, including grandparents as the head of household, their children, and their grandchildren. Aunts, uncles, and cousins might have lived in the same dwelling. All the family subunits contributed to the finances of maintaining the house. This provided social security to the elder members of the household, and inexpensive yet high-quality living conditions for the other family members.
Mixed Use
Authors: Thrall Grant Ian
Published: November 2020

With perhaps the exception of building a new town, mixed-use (MXD) development requires the most complex real estate market analysis. As with the structural organization of the preceding chapters on real estate products in this book, this chapter will begin with a background of the real estate product type. A background of MXDs is necessary to understand those developments that are already in place across the North American landscape. Some MXDs have been successful and others have been dismal failures. A goal of this chapter is to describe and explain the instruments hypothesized to make an MXD successful. Some MXDs are approaching their functional age of obsolescence—25 or 50 years old. They may require new real estate market analysis to guide their redevelopment and that redevelopment must be executed in the context of how they originated. The background coverage, contemporary notions of trade areas, demand, supply, and report, for MXDs are presented. What Is a Mixed-Use Development? To be defined as an MXD, the real estate project must have three components (Schwanke 1987): . . . Three or more significant revenue-producing uses (such as retail, office, residential, hotel, and/or entertainment/cultural/recreation), which in well-planned projects are mutually supporting Significant physical and functional integration of project components (and thus a relatively close-knit and intensive use of land), including uninterrupted pedestrian connections Development in conformance with a coherent plan, which frequently stipulates the type and scale of uses, permitted densities, and related items. . . . Each of the above concepts is discussed below. Three or More Significant Revenue-Producing Uses Many real estate projects have multiple uses. However, MXDs as denned and discussed here must have at least three major revenue-producing uses. These uses should be nontrivial. In other words, if retail space is one of the mixed uses, then that retail space should have a trade area beyond the mere project site. In most contemporary mixed-use projects, retail, office, residential, and/or hotel facilities are the primary revenue-producing uses. Other revenue-producing uses of MXDs might include sports arenas and convention centers, performing arts facilities, and museums.
Equilibrium Thermodynamics
Authors: Beris Antony N. , Edwards Brian J.
Published: November 2020

The ideas which we shall present in the remainder of this book are intimately connected with thermodynamics. In order to describe the various transport processes in structured continua, one must first build a solid foundation of equilibrium thermodynamics upon which to base further development. In approaching transport phenomena from an energetic viewpoint, one must first define what is meant by various thermodynamic variables as, for example, the temperature and pressure, in terms of the primitive variables used to characterize the system under investigation. In this chapter, we present a brief overview of equilibrium thermodynamics tailored to the needs of this book. Specifically, we want to define explicitly the thermodynamic quantities which are used in subsequent chapters. For clarity and completeness, we shall re-derive, rather than merely state, some of the standard thermodynamic relationships. Of course, the experienced reader may proceed directly to the next chapter and use this chapter as a reference to notation as the need arises. The starting point for our discussion of equilibrium thermodynamics is the axiomatic foundation of the description of macroscopic equilibria on certain fundamental principles. First, the macroscopic equilibrium of a closed system is completely described through the specification of a number of extensive (i.e., proportional to the total mass or volume of the system, and additive between systems) or intensive (i.e., independent of the total mass or volume of the system) parameters. This is a very important point which is usually overlooked in the traditional thermodynamic development. The extensive nature of the primary variables of the system introduces an additional relationship which acts on the allowed variations of the differentials, which, as we shall see, is tantamount to the Gibbs/Duhem relation. This implies, as we shall demonstrate in §4.3, that the density formalism, where every extensive quantity is reported on a unit volume basis, is a much more natural framework for describing the system in that it avoids a number of pitfalls of the traditional formalism.
Poisson Brackets in Continuous Media
Authors: Beris Antony N. , Edwards Brian J.
Published: November 2020

Now that we have defined the necessary thermodynamic quantities in chapter 4, we can turn back to the consideration of the dynamics of various physical systems. In order to apply a Poisson bracket to macroscopic transport phenomena, it is first necessary to rewrite the bracket (3.3-3) in a form which is suitable for continuum-mechanical considerations. As the number of particles increases to infinity, the transition is made from the specification of a very large number of discrete particle trajectories, xi(t), i=1,2,...,N, N→∞, to the determination of a single, continuous, vector function, Y(r,t), indicating the position of a fluid particle at time t which at a reference time t=0 was at position r, i.e., Y(r,0)=r. This is called a Lagrangian or material description. Alternatively, an Eulerian or spatial description can be used according to which the flow kinematics are completely specified through the determination of the velocity vector field, v(x,t), indicating the velocity of a fluid particle at a fixed spatial position, x, and time, t. (Truesdell [1966, p. 17] notes that the Lagrangian/Eulerian terminology is erroneous, however.) In this chapter, we shall use both descriptions to tackle the problem of ideal (inviscid) fluid flow and to arrive at a Poisson bracket for each case. The dissipative system will be considered in chapter 7. Once again, the concept of time and length scales is very important in determining when the experimenter views the system in consideration as a continuum entity. In chapter 3, we studied the dynamics of a system of discrete particles bouncing around with our time scale implicitly set on the order of the mean free time of the particles between collisions, ζ, and the length scale on the order of the mean free path, λ. As the number of particles approaches infinity, however, we note that certain averages, such as the velocity and the energy of the system, are practically constant on such a small time scale. Since the number of particles is so large, it is almost impossible to get any detailed information about the system as a whole by looking at individual particles because the number of the degrees of freedom is horrendous.
Fluids and Porous Media as Continua
Authors: Furbish David Jon
Published: November 2020

Let us anticipate that we wish to treat fluids as continuous substances at a microscopic scale. To see the motivation for this, it is instructive to consider the possibility of describing fluid behavior at a molecular scale by making use of Lagrangian mechanics to track the behavior of each molecule, just as we would describe the ballistics of a moving, rigid body. Consider describing the state of a simple diatomic molecule at some instant; to do this, we must decide what minimum set of coordinates completely specifies the position and configuration of the molecule. For example, we must specify its position within an inertial reference frame, which requires the three Cartesian coordinates x, y, and z. We also must specify its velocity with respect to this coordinate system, which requires the three corresponding components of velocity um, vm, and wm. The molecule may be spinning; to describe this, we must assign to the molecule three local coordinate axes to specify three angular coordinates that give its orientation within the inertial reference frame. Because the axis of rotation may not coincide with one of the local axes, we also must specify two angular coordinates that give the orientation of the axis of rotation within the local coordinate system. Finally, we must specify the angular velocity about this axis of rotation. Thus, in addition to specifying the mass of a molecule, we need twelve variables or generalized coordinates to specify its state. Moreover, we must know initial values of these twelve coordinates, just as we need to know the initial position and velocity of a ballistic body to track its course. To track the behavior of N molecules, we therefore must know N masses plus 12N initial position, velocity, and orientation coordinates. It becomes clear that to adopt this approach to describe the behavior of a fluid constitutes a formidable task! One has no choice but to abandon a molecular scale treatment and adopt a view involving the microscopic scale, where behaviors of individual molecules are ignored, and instead, the collective behavior of a suitably defined ensemble of molecules is treated in a statistical (average) sense in terms of bulk properties such as fluid density, temperature, and viscosity.
Thermodynamic Properties of Fluids
Authors: Furbish David Jon
Published: November 2020

Fluid behavior in many geological problems is strongly influenced by extant thermal conditions and flow of heat. Recall, for example, that the coefficient A in Glen’s law for ice (3.40) varies over three orders of magnitude with a change in temperature of 50 °C. The effect of this is to strongly modulate the rate of ice deformation for a given level of stress. Recall further that we introduced several fluid properties—fluid compressibility, for example—where we asserted that our purely mechanical developments were incomplete inasmuch as they did not treat effects of varying temperature. The reasons for this will become clear in this chapter, including why it is difficult to maintain isothermal conditions when the pressure of a fluid is changing. In addition, many geological problems involve fluid flows that are induced by effects of variations in thermal conditions over time and space. These include buoyancy-driven convective motions that arise from variations in fluid density associated with variations in temperature (Chapter 16). Specific examples include convective overturning in a magma chamber, which can significantly influence how crystallizing minerals are distributed; convective circulations of water and chemical solutions in a sedimentary basin, which can influence where rock materials are dissolved and where they are precipitated as cements within pores; and convective circulation of water within the active layer above seasonally frozen ground, which may influence where patterned ground develops in periglacial environments. These processes, and viscous flows in general, invariably involve conversions of mechanical energy to heat, or vice versa. So in considering problems involving heat energy, we should recall from introductory chemistry and physics that such conversions can involve work performed on the fluid or its surroundings, and anticipate that the effects of this ought be manifest in fluid behavior. This chapter, then, is concerned with fluid pressure, temperature, and density, and how these variables are related to heat, mechanical energy, and work. We will note in digressions how these macroscopic concepts, like fluid viscosity, often have clear interpretations at a molecular scale based on kinetic theory of matter.
Dimensional Analysis and Similitude
Authors: Furbish David Jon
Published: November 2020

Some fluid flow problems are sufficiently simple that they can be treated mathematically in a straightforward way, making use of definitions of physical quantities, and taking into account initial and boundary conditions. For example, our derivation of the average velocity in a conduit with parallel walls (Example Problem 3.7.1) was obtained in a straightforward way once we specified the geometry of the problem, then made use of the definition of a Newtonian fluid and the no-slip condition. Whereas this type of analysis may work for some problems, it would be misleading to think that such direct approaches to solving problems are, in principle, always possible, hinging only on one’s mathematical skills and adeptness in specifying the geometry of a problem. Herein arise two noteworthy points. First, when initially examining a problem, one can sometimes obtain a clear idea of the desired solution before attempting a formal mathematical analysis. The means to do this, as we shall see below, is supplied by dimensional analysis, and it is a strategy that ought to be adopted in many circumstances. In fact, it is worth noting that dimensional analysis underlies many of the problems presented in this text. The advantage of knowing the form of a desired solution, of course, is that one has a clear target to guide the subsequent mathematical analysis. Indeed, this is the vantage point from which many classic problems, for example Stokes’s law for settling spheres, were initially examined. Second, a complete mathematical formulation of a problem may not be possible, due to the complexity of the problem, or due to absence of information required to constrain the mathematics of the problem. As a simple example, suppose that we were unaware of the no-slip condition in our analysis of the conduit-flow problem (Example Problem 3.7.1). Our analysis in this case would have essentially ended with (3.70), with the constant of integration C undetermined. Nevertheless, we could get close to our result (3.75) for the average velocity by another way.
Inviscid Flows
Authors: Furbish David Jon
Published: November 2020

This chapter covers an important step toward our development of dynamical equations of fluid motion. Herein we will develop explicit expressions for the forces that produce the fluid accelerations that we described kinematically in Chapter 7. In particular, we will consider the behavior of inviscid fluids. Viscous forces therefore are not involved; accelerations are wholly due to body forces and normal surface forces associated with fluid pressure. The results of our development are Euler’s equations, or the momentum equations for inviscid flow. One consequence of the inviscid assumption is that slip flow may occur at real boundaries, in contrast to the no-slip condition that occurs with real fluids. This is unrealistic for the viscous flows of interest in many geological problems. Nonetheless, situations exist in which viscous fluids can be treated as inviscid. Examples include fluids having small viscosity, and flows far from boundaries. The study of inviscid flow therefore is justified in its own right. A particularly important example involves the consideration of how velocity and pressure vary along a streamline, which leads to Bernoulli’s equation. Consider a rectangular control volume with edges of length dx, dy, and dz embedded within a local Cartesian coordinate system. This local system has an arbitrary orientation with respect to the Earth coordinate system; the x-axis is inclined at an angle α measured from the horizontal. Acceleration due to gravity g acts vertically, and the centroid of the control volume is at height h above a horizontal datum. The height h provides a measure of the position of the fluid within the gravitational field. Consider, now, forces acting on the control volume parallel to the x-axis. The weight W of fluid within the control volume possesses a component Wx parallel to the x-axis: . . . Wx = −ρg sin α dx dy dz . . . . . . (10.2) . . . where ρ is the fluid density, and the negative sign indicates that Wx acts in the direction of negative x.
Vorticity and Fluid Strain
Authors: Furbish David Jon
Published: November 2020

Many flows involve a sense of rotation. Clear examples include cyclones, whirlpools, and eddies. Less apparent, perhaps, is the interesting result that a one-dimensional shearing flow—for example, Couette flow—possesses a rotational component. As we will see below, the idea of fluid vorticity provides a way to characterize the rotational qualities of such flows. In addition, our treatment of vorticity will provide a way to distinguish between simple shear and pure shear of a fluid. Because shearing motions involve viscous dissipation of energy in real fluids, our descriptions of vorticity and shear will form an important part of the development of dynamical equations for flows that involve viscous forces (Chapter 12). The idea of vorticity also is useful in visualizing the onset of flow separation (Example Problem 11.4.2), very viscous flow behavior (Example Problem 12.6.5), and certain aspects of turbulence (Chapters 14 and 15). Beyond this, our treatment of vorticity is not emphasized. Let us envision a vorticity meter made of two small orthogonal vanes, with the end of one vane marked for easy identification. (Such meters can readily be constructed and used as described next.) Consider placing this meter at some position within a fluid that is rotating like a rigid body. The vorticity meter in this case rotates with the fluid in such a way that its orientation relative to the axis of rotation of the fluid remains fixed. As we will see below, the fluid possesses a definite vorticity that is reflected in the observation that the vorticity meter rotates with respect to its own axis. In this regard, we also may observe that the angular velocity of this local rotation of the meter is the same regardless of its distance from the fluid axis. Now consider a one-dimensional (Couette) shear flow. A vorticity meter placed at any position within this flow also rotates about its center due to the streamwise velocity differential over the span of the meter. Judging from the behavior of the meter, this flow also possesses a definite vorticity. We also may envision that the rate of rotation varies directly with the velocity gradient du/dy.
What Malthus Missed
Authors: Hardin Garrett
Published: November 2020

Though John Maynard Keynes had the highest opinion of his contributions to economics, Malthus continues to be bad-mouthed by many of today's sociologists and economists. The passion displayed by some of his detractors is grossly disproportionate to the magnitude of his errors. A conscientious listing of the explicit statements made by Malthus would, I am sure, show that far more than 95 percent of them are correct. But for any writer who becomes notorious for voicing unwelcome "home truths," a correctness score of 95 percent is not enough. Envy, an all-toohuman failing, is not unknown among critics. Envy sharpens the critical faculties but dulls the sense of proportion. The potentially unlimited growth of debt through the exponential growth of usury is counterbalanced, as we have seen, by such factors as bankruptcy, repudiation of debts, and inflation. Potentially exponential biological reproduction is also kept in check by counterbalancing forces. Every species "seeks" to convert the matter of its surroundings ("the environment") into more of its own kind, without limit. But since the amount and quality of convertible matter does have limits, so also must the growth of every population be limited. What in fact does limit the growth of populations? Malthus was concerned only with the human species. Having found a mathematical expression for reproduction he then sought another mathematical expression for the limitation to human fertility. No one thinks he was successful in this second endeavor. We note that as a student at Cambridge he was graduated as Ninth Wrangler. The quaint term "wrangler" is awarded by the English to someone who takes honors in mathematics. Since Malthus placed ninth in his class we may assume that he was only modestly endowed with mathematical ability. We should not be surprised to learn that he made a serious mistake in applying mathematics to the problem of the factors limiting human populations. (Look again at Box 9-1 on page 88.)
Discriminating Altruisms
Authors: Hardin Garrett
Published: November 2020

Sooner or later discussions of population problems raise the issue of altruism. Why should I refrain from exploiting the environment because posterity may some day wish that I had? Or because today's poor want a larger share of the world's wealth? Is altruism natural? Is it safe? Altruism, like "will," may be one of those topics on which universal agreement is impossible. In both cases opposing arguments seem quite convincing—until you listen to the other side! In general, having names for things makes for clarity in discussion; but one wonders if that is so in this instance. For thousands of years people worried about the best balance between self-considering actions and actions that focus on the interests of others, but the disputes may have become more acute since neat names were coined. The earliest use of the word "egoism" recorded in the Oxford English Dictionary is 1722, with "altruism" appearing in 1853. Often the creation of a noun ("substantive") seems to presume the presence of a substance, a physical thing. Students of mental functions used to waste a great deal of time looking for the "faculties" of the mind; ultimately psychologists abandoned that substantive. Should "egoism" and "altruism" also be jettisoned? Perhaps not yet: but many arguments can be curtailed if we note two different referents of the word altruism. Sometimes the reference is to the motives inside the mind of the altruist; at other times we are interested in the consequences of the action. Philosophical and religious writers are more concerned with the former; students of politics and bioethics with the latter. Religions are interested in promoting virtuous thought, but all assertions about motives suffer from the "egocentric predicament," the inability of each of us to really know what is going on inside any other mind. (Assertions made by the other do not help because how can I know he is telling the truth?) Determinations of consequences do not have this shortcoming since consequences lie outside the brain of the actor. Bioethicists adopt a consequential approach to altruism. This is the path followed here.
Undecidability and Recursive Inseparability
Authors: Smullyan Raymond M
Published: November 2020

§1. Some Preliminary Theorems. we continue to let S be an arbitrary system, P be the set of Gödel numbers of the provable formulas of S and R be the set of Gödel numbers of the refutable formulas of S. Theorem 1. The set P̃* is not representable in S. Proof. This is the diagonal argument all over again. If H(v1) represents P̃* and h is the Gödel number of H(v1), the H[h̅] is provable in S iff h Ï p* iff d(h) ÏP iff H[h̅] is not provable in S, which is a contradiction. Theorem 1.1. If S is consistent, then P* is not definable in S. Proof. Suppose P* is definable in S. If S were consistent, then P* would be completely representable in S (cf. §3.1, Ch. 0). Hence P̃* would be representable in S, contrary to Theorem 1. Therefore, if S is consistent, then P* is not definable in S. Theorem 1.2. If the diagonal function d(x) is strongly definable in S and S is consistent, then P is not definable in S. Proof. Suppose d(x) is strongly definable in S. Since P* = d -1(P), then if P were definable in S, P* would be definable in S (by Th. 11.2, Ch. 0). Hence S would be inconsistent by Theorem 1.1. Exercise 1. Show that if S is consistent, then R* is not definable in S. Exercise 2. Show that if S is consistent, then no superset of R* disjoint from P* is definable in S, and no superset of P* disjoint from R* is definable in S. Exercise 3. Prove that if S is consistent and if the diagonal function is strongly definable in S, then no superset of P disjoint from R is definable in S. [This is stronger than Theorem 1.2.] §2. Undecidable Systems. A system S is said to be decidable (or to admit of a decision procedure) if the set P of Gödel numbers of the provable formulas of S is a recursive set. It is undecidable if P is not recursive. This meaning of ‘undecidable’ should not be confused with the meaning of ‘undecidable’ when applied to a particular formula (as being undecidable in a given system S).
Calculations and Simulations
Authors: Erman Burak , Mark James E.
Published: November 2020

The classical theories of rubber elasticity are based on the Gaussian chain model. The only molecular parameter that enters these theories is the mean-square end-to-end separation of the chains constituting the network. However, there are various areas of interest that require characterization of molecular quantities beyond the Gaussian description. Examples are segmental orientation, birefringence, rotational isomerization, and finite extensibility, and we will address these properties in the following chapters. One often needs a more realistic distribution function for the end-to-end vector, as well as for averages of the products of several vectorial quantities, as will be evident in these chapters. The foundations for such characterizations, and several examples of their applications, are given in this chapter. Several aspects of rubber elasticity (such as the dependence of the elastic free energy on network topology, number of effective junctions, and contributions from entanglements) are successfully explained by theories based on the freely jointed chain and the Gaussian approximation. Details of the real chemical structure are not required at the length scales describing these phenomena. On the other hand, studies of birefringence, thermoelasticity, rotational isomerization upon stretching, strain dichroism, local segmental orientation and mobility, and characterization of networks with short chains require the use of more realistic network chain models. In this section, properties of rotational isomeric state models for the chains are discussed. The notation is based largely on the Flory book, Statistical Mechanics of Chain Molecules. More recent information is readily found in the literature. Due to the simplicity of its structure, a polyethylene-like chain serves as a convenient model for discussing the statistical properties of real chains. This simplicity can be seen in figure 8.1, which shows the planar form of a small portion of a polyethylene chain. Bond lengths and bond angles may be regarded as fixed in the study of rubber elasticity because their rapid fluctuations are usually in the range of only ±0.05 A and ±5°, respectively. The chain changes its configuration only through torsional rotations about the backbone bonds, shown, for example, by the angle for the ith bond in figure 8.1.
General Conclusions
Authors: Crouch Dora P.
Published: November 2020

When we began this study, we hypothesized the following: (1) similar geology fosters similar urban development, but not every urban difference has a geological basis; (2) geological differences are likely to result in developmental differences; and (3) geology forms an active backdrop to human actions. We assumed that (1) the growth of classical cities was in response to the setting with which the inhabitants interact, (2) tectonic, sedimentary, structural, and engineering aspects of the geology affect how the city developed and its durability, and (3) hydrogeology defines the nature, amount, and location of water resources. At the end of the study, we have verified that implacable geological forces affected each city. Specific interactions between the local terrane and the residents of these ten sites during the Greco-Roman period can be documented. We have struggled with problems of scale and interpretation, and with which methodologies to use in weighing evidence. We have wondered which links between phenomena and process are the crucial ones. In our research, we have used both the optimism and the informed skepticism that Dincauze (1987) called for in her parallel work of reconstructing paleoenvironments. Temptations in research can be subtle, such as “equating what is observable with what is significant” (Snodgrass 1987). We do not claim to be exempt from these problems. New information does not of itself produce better science or better human history. The contributions of oversimplification to the scientific discourse continued unabated in the last half of the twentieth century, with Wittvogel’s Oriental Despotism (1957), which based urban development and the growth of the state on irrigation, or Vita-Finzi’s concept (1969) of one period of sedimentation for the whole Mediterranean area. The attentive reader may have noticed similar examples of arguing ahead of the data in this present work, in spite of our efforts to be moderate and truthful. We apply scientific and engineering data to the sites in question, and we offer the results as models for investigation rather than exhaustive studies.
Physical and Intellectual Issues
Authors: Crouch Dora P.
Published: November 2020

The issues associated with this study are both physical and intellectual, as are the factors in urban development. The correlation of known data from inscriptions (epigraphy), literary references (ancient history and more recent government and church documents), evidence from destroyed and rebuilt buildings (archaeology), and modern scientific and technical findings (several kinds of engineering and subfields of geology such as seismology and sedimentology) can give a more complete picture of each city’s development than does one kind of information alone. Most of the necessary site-specific studies, however, have not been done. Our problem parallels the study of global warming, where precise records of weather events have been kept for less than 200 years. Urban elements must be studied by experts in that building type and in social expression. Ramparts need more study by historians of warfare, theaters by scholars of drama and literature, stadia by those who study the history of sports, plumbing by hydraulic, civil, and fluids engineers, and temples by historians of comparative religion. Insights into institutional and political aspects of ancient studies and the historiography of all the disciplines involved in ancient studies would be both useful and fascinating (Kardulias 1994). The benefits and difficulties of interdisciplinary research are clearer now to us than when we started. In considering the physical setting and geological processes in the Mediterranean area, is description sufficient or should scholars strive for explanation, even if this involves theory building? “In much of art history and classical archaeology traditional practices have continued without explicit theoretical support” (McNally 1985; but cf. Preziosi 1989). The theorists of archaeology and urban history desire comprehensive and precise theories—even in the absence of enough data to make that possible. Some data may be rescued by followers of one discipline after being ignored or thrown out by followers of another. The awareness of theoretical difficulty is part of the increase in consciousness typical of the second half of the twentieth century when we began to question the nature of both knowledge and culture.
Banking and a Tale of Two Systems
Authors: Salzman Harold , Rosenthal Stephen R.
Published: November 2020

The 1980s were the worst of times for many in the banking industry. Following the deregulation of the early 1980s, the industry nearly went into shock as more than 2,000 banks and savings and loans failed. Banking could no longer be characterized as a staid enterprise of blue pin-striped suits and “banker’s hours.” Deregulation and competition made traditional ways of doing business obsolete and, in many cases, disastrous for banks that failed to adapt. A record number of banks were unable to make the transition successfully and, among those that survived, it was a difficult period that required them to reassess their operations. Software developed for the banking industry during this period reflected the contradictions of an industry in transition. Some banks tried to maintain their traditional values and operating procedures in their system design requirements. However, some software developers found that changes in the banking environment and their own software market required them to consider different values and methods of service delivery in their designs for new systems. A brief account of the industry’s evolution with computer systems sets the stage for the cases presented in this chapter. Banks are large users of computer systems and were among the first large commercial institutions to use computers. Design of banking systems has been affected by changes in technology, external regulation, competition, and the labor market. These changes have combined to define the operational objectives of new computer system designs. During the 1950s and 1960s, banks installed large mainframe systems for back office transaction processing, such as account updating, on a batch system mode. By the 1970s large banks had invested extensively in mainframe computer systems and smaller banks were beginning to adopt computer systems as prices dropped and smaller computers became more powerful. In both large and small banks, computer applications were increasingly introduced to support front office transactions of tellers and customer service representatives in branch offices. Because these systems make data instantly available for a variety of steps in processing transactions, they integrate people throughout the banking organization.
Bursty Magnetopause Reconnection and its Consequences
Authors: Kennel Charles F.
Published: November 2020

There is at least one way in which the reconnection model of substorms is unrealistic. Rarely if ever will the interplanetary field rotate southward, stay southward, and remain constant. Even on those infrequent occasions when it does do so, steady reconnection may not be established on the dayside: We will see that dayside reconnection proceeds in bursts even then. How likely is it then that steady convection will be established on the nightside? In the next two chapters, we will fit together observations of bursty convection at the magnetopause, in the polar cap and auroral ionosphere, at various distances downtail in the plasma sheet, and beyond the average position of the neutral line in the deep tail. In this chapter, we deal with unsteady magnetopause reconnection. We start with one simple observation: The magnetopause is a source of escaping particles with energies higher than can be generated by the average convection potential across the ionosphere (Section 8.2). This, together with the fact that high-speed magnetopause flows can turn on and off between successive magnetopause crossings only minutes apart, suggests that the rate of reconnection is high for short periods of time and low for longer intervals. When the reconnection events are shorter than or comparable to MHD wave propagation times to the ionosphere, we call the reconnection “bursty.” We then let observation define the properties of bursty magnetopause reconnection. First, we discuss “flux transfer events” (FTEs), the traveling magnetic perturbations near the magnetopause (Section 8.3) that are signatures of bursty reconnection elsewhere on the magnetopause (Section 8.4). The magnitudes of the fluxes reconnected in FTEs are estimated in Section 8.5. Next, we discuss some of the ionospheric signatures of flux transfer events that might be expected on general theoretical grounds (Section 8.6). Variable dayside reconnection could be responsible for ULF magnetic activity in the polar cusp region (Section 8.7). We expect sudden magnetopause reconnection events to send Alfven waves (Section 8.8) and velocity-dispersed ions along field lines towards the polar cusp ionosphere (Section 8.9).