bluuebunny/crossref_metadata_2025 huggingface dataset:
Aluminum Oxides: Alumina and Aluminosilicates
Authors: Jolivet Jean-Pierre
Published: November 2020

Aluminum is the third most abundant element in Earth’s crust (8.3% in mass), behind oxygen (45.5%) and silicon (27.2%). It forms in nature various oxygenated mineral phases: hydroxides Al(OH)3, oxyhydroxides AlOOH, of which bauxite is the main ore, and oxides, Al2O3, alumina. Corundum, α- Al2O3, is the component of many gems: sapphire (pure Al2O3, perfectly colorless), ruby (red colored due to the presence of Cr3+ ions), and blue sapphire (blue colored by the presence of Ti4+ and Fe2+ ions), among many others. The content of foreign elements substituted for Al3+ ions in these phases accounts for only a small percentage of the total. Aluminum also forms many natural phases in combination with various elements, especially silicon in aluminosilicates, such as feldspars, clays, zeolites, allophanes, and imogolites. The biochemical cycling of the elements involves many soluble complexes of aluminum in natural waters [1, 2]. Aluminum oxides and oxy(hydroxi)des are important materials and nanomaterials used in many fields: for instance, as active phase for adsorption in water treatment; as inert support and active phase in catalysis; as active phase in flame-retardant polymers; as refractory material for laboratory tools and in the ceramics industry; and as abrasives [3, 4]. Alumina Al2O3 is produced in various forms (tubes, balls, fibers, and powders) for numerous industrial uses (laboratory tools, filtration membranes, ball bearings, fine powders as catalysis supports, etc.). The structural chemistry of aluminum oxy(hydroxi)des is rich. There are various hydroxides, Al(OH)3 (gibbsite, also named hydrargillite, bayerite, and some other polytypes such as nordstrandite and doyleite), oxyhydroxides, AlOOH (boehmite and diaspore), and a series of oxides, Al2O3, so-called transition aluminas. These last phases have different degrees of hydration and different degrees of order of the Al3+ cations within the cubic close packing of oxygen atoms according to the temperature at which they have been submitted. They belong to various structural types (γ, δ, θ, η, κ, etc.). These aluminas of huge specific surface areas are usually used in catalysis, especially γ-alumina of spinel crystal structure.
February: About Beavers
Authors: Wohl Ellen
Published: November 2020

February: when I first notice the days begin to stretch out after the tight curl of December and January. February: the month for creating new beavers. Somewhere sheltered from the cold light of sun reflecting off snow, in a bank den or a lodge, perhaps even in the water, the beavers are mating. The North St. Vrain beaver meadow is good habitat, and the adult pair will create another litter of two to four kits, allowing the current kits to become yearlings, and pushing the current yearlings out of the colony to find new homes and their own mates. I enter the meadow from the northern side on a mild day when a steady breeze seems to keep pace with the scattered clouds moving overhead. Just as I start to descend the slope into the meadow, I flush a moose resting beneath a big spruce. I am close enough to see the coarse, thick fur along the moose’s spine bristle with alarm and to note the scars where the animal dropped its antlers after the autumn rut. The alarm is only momentary. The moose ambles down the slope and into the meadow, steadily browsing willow stems as it moves. The stems have a hue of burnt yellow, and each bud is clearly visible, although not yet swollen. The past few days have been mild, and patches of bare ground show along the south-facing slopes and under the big conifers that border the beaver meadow. In the meadow itself the snow remains sufficiently deep to keep navigation easier by filling the pitfalls of the meadow—the winding canals, one beaver wide, and the steep-sided holes that the beavers dig to create air exchange near their dens. The snow bears abundant witness to the activity of the meadow. The widely spaced leaps of snowshoe hare tracks create diagonals between the creek and the conifer forests adjacent to the meadow. The single, precise line left by a fox has melted in the warmth of midday and refrozen into ice casts.
Lead murders
Authors: Emsley John
Published: November 2020

Criminal poisonings with lead compounds are noteworthy because of their rarity. Indeed a person intent on poisoning someone would be unlikely to choose lead because of its uncertainty of action. Nevertheless there were murders in which it was used, such as the killing of Thomas Taylor in September 1858, when white lead was the poison, and the murder of Mary Ann Tregillis in 1882, when lead acetate was used. This salt was also the agent in the attempted murder of Honora Turner also in 1858. The lead compound that killed Pope Clement II in 1047 can only be speculated on. The inquest into the death of Thomas Taylor, which was held by the coroner for Gloucestershire on 27 September 1858, was reported in the November issue of the Pharmaceutical Journal because it was an unusual case of death by poisoning with lead carbonate. Thomas lived in Gloucestershire with his wife, Ann, and the child that he had fathered by another woman. He also had a brother, Charles, who had recently been released from prison and who had gone to live with the Taylors. It was not long before quarrels broke out between Thomas and his wife, whom he accused of being too affectionate towards Charles. In fact Ann was more than affectionate; she openly stated that she preferred brother Charles and wished her husband was dead. Her wish was to be granted. In August 1858 Thomas was seized with violent pains in his stomach which lasted for several days and for which he sought medical treatment. The doctor gave him some opium pills to kill the pain and senna water to act as a laxative. When these failed to cure him his doctor prescribed larger doses which he said could be obtained from his surgery. However, the doctor noticed that when his wife Ann went to collect more senna water she brought along a bottle that had contained the original medicine and that the dregs of the first dose were now a different colour and it tasted odd. Thomas died on 4 September, but the doctor was sufficiently suspicious of the cause of death that he refused to issue a death certificate until he and a surgeon friend of his had carried out a post-mortem.
Introduction to David Harvey
Authors: Swyngedouw Erik , Harvey David
Published: November 2020

David Harvey is one of the few global public intellectuals whose lifelong political and academic mission is the search for a more genuinely humanizing geography of everyday urban life. His relentless and thought-provoking engagement with the realities and contradictions of contemporary capitalist urbanization has long inspired those seeking to fight for an urban life free from the practices of social, political, and racial exclusion and the divisions that have been the hallmark of modern urbanization throughout the world. Harvey is one of the urban geographers whose intellectual influence has reached most widely across disciplines. With a Ph.D. in Geography from Cambridge University, he embarked on a lifelong intellectual and political trajectory that has transformed the ways in which urban theorists approach the capitalist city and in which activists seek urban, social, and political change. Already noted for the landmark publication in 1969 of Explanation in Geography, his epistemological and political attention soon turned to a more radical and Marxist understanding of the urban. This epistemological shift coincided with his transatlantic migration to the Johns Hopkins University, where he taught Marxist urban theory for the next fifteen years or so. The deep injustices that had just come to the boil in rioting US cities, combined with a rediscovery of the power of historical materialist Marxist analysis, resulted in the publication of Social Justice and the City (1973). Harvey’s theorization of the city, deeply embedded in the original writings of Marx, also draws on the radical urban theories and politics pioneered by Henri Lefebvre. For Harvey, cities are—and have always been—highly differentiated spaces of activity, excitement, and pleasure. They are arenas for the pursuit of unoppressed activities and desires, but also ones replete with systematic power, danger, oppression, domination, and exclusion. Exploring the tensions between this dialectical twin of emancipation and disempowerment has been at the centre of Harvey’s theoretical and political concerns. Questions of justice cannot be seen independently from the urban condition, not only because most of the world’s population now lives in cities, but above all because the city condenses the manifold tensions and contradictions that infuse modern life.
How Colossus was Built and Operated—One of its Engineers Reveals its Secrets
Authors: Fensom Harry
Published: November 2020

Flowers’ team, which included me, became involved with the design of the logic units of Newman’s proposed machine after Morrell’s Telegraph Group, which had been assigned the job, got into difficulties. For modulo-2 addition (‘exclusive-or’, or XOR) Morrell was proposing to use a type of frequency-modulator employed for voice-frequency telegraph signals. This might have been all right for adding only two signals, but it was useless for adding many signals, because the device was analogue in nature (i.e. not digital or discrete, but using continuously variable voltages). The small variations added up, with the result that the device often produced a wrong answer. After some clever work by Gil Hayward, it just about worked for the number of additions that were required. The Heath Robinson’s ‘bedstead’, containing the tape drive and the photoelectric tape-reader, was designed and built at Dollis Hill. Our people Eric Speight and Arnold Lynch had very recently used photoelectric cells to do what was required. Fighter Command had asked Dollis Hill for a fast means of recording the telegraphic signals from their aircraft observers. Speight and Lynch, working together with Morrell’s group, had designed some photoelectric equipment that would record these signals directly from the telegraphic punched tape. The device they built, called the ‘Auto-Teller’, was never in fact used, but this photoelectric technology formed the basis for the bedstead. When we finished our part of Newman’s machine at Dollis Hill I moved to Bletchley Park, and Alan Bruce from TRE accompanied their part of the machine, the counter and display rack. The Heath Robinson was installed in the wooden Hut 11—the Newmanry. I was privileged to be one of those present at the Heath’s inauguration before the VIPs—and I can confirm that smoke did rise from it at switch-on. I was able to deal with this. A large resistor had overloaded, which I bypassed, and we carried on. (The machine never did catch fire, on this or any other occasion, but as mentioned in Chapter 13, we had a benzene fire in our workshop, at a much later date, and this may have contributed to the erroneous stories of Heath Robinson catching fire.)
Reforming the High Schools
Authors: Nasaw David
Published: November 2020

The reformed boards, their superintendents, and their professional staffs had their work cut out for them. As we have seen, the city and some rural school systems had never been able to catch up with the expanding school-age population. Overcrowding was particularly a problem in the urban areas of the Northeast and the Midwest. In New York City alone, “at the turn of the century 1,100 willing children were refused admission to any school for lack of space.” The situation was as bad in other city school systems. The overcrowding was no doubt contributory to the high rate of failure and growing percentage of overage students in the city schools—over 40 percent of the total in the Boston, Chicago, Detroit, Philadelphia, Pittsburgh, New York, and Minneapolis systems, according to Colin Greer. One might have expected that the major thrust of reform at the turn of the century would be these urban schools. But this was not the case. As the nineteenth century gave way to the twentieth, the major concern of the public school reformers was not the overcrowded elementary schools, but the relatively underattended high schools. Though the elementary schools were not doing their job as well as might be hoped, they were at least keeping upwards of 70 percent of the school-age population off the streets and under proper supervision through their most tender years. The same could not be said of the secondary schools. As late as 1890, more than 90 percent of the fourteen-to-seventeen-year-olds (those potentially dangerous adolescents) were free of any institutional supervision. Here was a potential “social problem” much more dangerous than overcrowding and failure in the elementary grades. The progressive reformers and their colleagues had succeeded through the closing decades of the nineteenth century in drawing attention to the “youth” and “class” problems. The problems, as they themselves had pointed out, were interconnected. Problem adolescents were not going to become model wageworkers; they were much more likely to become problem workers. The solution proposed to the youth and class problems was an institutional one.
To Bus or Not to Bus
Authors: Wilkinson J. Harvie
Published: November 2020

The Supreme Court in Swann drove the yellow school bus down the road of racial reform. And a bumpy journey it would prove to be. Why, one wonders, did the Court choose busing among all the alternatives available? Why, moreover, was that choice unanimous? Why, lastly, had several justices even swallowed their personal misgivings to join the opinion? For the Court’s commitment to this fateful step, there exist various explanations. One is that the Court never anticipated just how much opposition compulsory busing would provoke. Northern sentiment had not yet been aroused at the time of Swann; South Boston was but a speck on the racial horizon. The justices might still have believed opposition to busing just another eruption of the same southern temper that had produced Little Rock, Prince Edward, and the ugly happenings at Lamar. By 1970, moreover, the Court was most impatient with the South and more than a little embarrassed that sixteen years after Brown the task of southern integration remained incomplete. Thus Swann seemed the final step in the South’s subjugation. That busing would soon become the hottest issue of national domestic politics, the justices had not as yet fully foreseen. There was more to the Court’s approval of busing than integrating the South. Green had whetted the Court’s appetite for numbers. Black-white percentages at last gave the Court a concrete measuring rod, an objective determinant of a school board’s good faith. If one’s goal for schools was statistical racial balance, busing seemed the most direct way to achieve it. In fact, busing seemed the only way to achieve it in the urban metropolis where the races lived largely apart. But something more profound motivated the Court’s probusing stance in 1971: a mystical force in the catacombs of the Supreme Court known as the spirit of Brown. Brown’s legacy was a special race consciousness, an understanding among justices that blacks were henceforth to enjoy constitutional priority.
Writing, High School
Authors: lebovitz Richard
Published: November 2020

While riding down the beach one day, my friend and I ran across some trails which led back into the dunes. That same night we went down the trails in a truck. Back in the dunes near the surf was a hill about 35 or 40 feet high. We drove up the trail and parked the truck. While getting out we noticed that the roar of the ocean was very loud and very clear. We went back to the truck and got a flashlight and started walking back towards the sound of the surf. My friend was carrying the flashlight and was about 10 or 12 feet to my left. As the light shone over the top of the hill, the other side seemed to disappear as if it were cut straight off. But before the thought crossed my mind, I fell—about 25 feet straight off the side of a dune! After making my landing I looked, and there, about a foot in front of me, lay the great Atlantic.—Richard Quidley Another testament to the water came in the form of a story by Terri Midgett. Its matter-of-fact voice reveals his closeness to the practice of rescuing, which has dominated the history of his family for generations. It was in the winter of ‘76. The Sound had had a layer of ice on it for at least a week. Now it was slowly beginning to melt. I went to the edge of the creek. As I walked on the ice my boots seemed to want to slip out from under me. I slowed down just enough to where I thought I wouldn’t fall, and about, that time, BAM! I’d slipped, falling hard on the ice, its wetness cold to my face. I stood up, my face numbed from the cold. Looking ahead, I saw three figures waving at me. It looked as though they needed help. I ran toward them, falling several times before reaching them. One of the boys had fallen through the ice. He was wet and cold and wanted to lie down, but I knew if he did, it would only be a matter of minutes before he’d die.
The Structure and Content of the Modern Synthesis
Authors: Eldredge Niles
Published: November 2020

When taken together, the four books of Dobzhansky, Mayr, and Simpson, written as they were so closely together in time (and space—Columbia University and the American Museum of Natural History are within forty blocks of each other in New York City) reveal a relatively minor amount of disarray, a slight lack of cohesion in the early stages of the synthesis. That some of these discrepancies were later removed—most notably through a more universal acceptance of the dominant role of natural selection in effecting adaptive change (Gould 1980b)—is important, if only because it established more of a semblance of agreement and consensus. The acceptance that Mayr (1982, pp. 568-69) reports among nearly all participants at the Princeton conference held in 1947 seems real enough; by the late 1940s the final, polished version of the synthesis apparently had begun to emerge. But we must ask if there were any important additions to evolutionary theory after these four books appeared. Changes in emphasis—for example, on selection, but also in such issues as Mayr’s later (especially 1963) views on the role that species play in evolution—certainly did occur. And, of course, beyond the conceptual lies the straightforward discovery of new phenomena, such as the myriad wonders of the molecular biology of the gene, begun in earnest in the early 1950s and still being announced daily. What concerns me here is more the structure of evolutionary theory than its precise content. Have either new ideas or new data since the publication of these four books materially modified the way we think about evolution? The answer, for the most part, is no; the theory presented in the better recent college textbooks (e.g., Dobzhansky et al. 1977; Futuyma 1979) is substantially the same as the amalgam that arose from the four books analyzed here, with the rough edges sanded and recent discoveries—nearly all concerning the molecular structure of the gene—duly incorporated. But there were some particularly important innovations and shifts of emphasis within the purview of the synthesis.
Federal Policies for Private Schools
Authors: Kutner Mark A. , Sherman Joel D.
Published: November 2020

The appropriate governmental relationship with private education has been the subject of controversy for many years. Some argue that parents should be able to choose private or public schools for their children without financial sacrifice and that the limitations on public financial support for private schools should be eliminated. Others maintain that financial support for private education is an improper use of public funds, that aiding private schools is unconstitutional, and that aid to private schools could have undesirable social consequences. Even among those who endorse some private school support, there are major disagreements over what the limits should be, what forms of aid are desirable, and what should be expected of private schools that receive public support. The policy debate concerning federal aid for private schools has shifted during recent years. Where once it focused on including requirements for program services to private school students in federal education legislation, most of the current debate centers around new types of aid arrangements which would enhance educational choice. The impetus behind this refocused policy debate is threefold. First, the federal government is funding limited services to children attending private schools. The major federal elementary and secondary education programs include provisions requiring the equitable provision of services to eligible students attending private schools. As a result, there is now an established relationship between the federal government and private schools. Second, over the past few years there has been a significant increase in concern about the quality of American public education and the effect that a virtual public monopoly over education has on educational achievement. Third, the concern that without federal assistance private schools would disappear has subsided. As shown in the Erickson contribution to this volume, the latest available figures indicate that enrollments in private schools as a percentage of total elementary and secondary school enrollments have stabilized. This paper traces the evolution of the federal role in the area of private elementary and secondary education finance and examines critical issues that relate to the possible expansion of federal funding for private education.
Comparisons of Private and Public Schools: The Critical Role of Regulations
Authors: Murnane Richard J.
Published: November 2020

The rising cost of publicly provided social services had led many analysts to conclude that government agencies are inefficient suppliers of services, both because they do not maximize output from existing resources and because they respond only very sluggishly to changes in the level and composition of demand. These analysts often couple this diagnosis with the prescription that private nonprofit organizations should play a larger role in delivering many social services. In debates over the wisdom of this type of reform, advocates often introduce statistical evidence on the comparative performance of public and private organizations, concluding as a rule that the performance of the private providers is superior. The central theme of this chapter is that much of the performance differences between public and private providers of social services stems from differences in the regulations they face, and the resulting differences in the characteristics of the clients they serve. The evidence in support of that conclusion presented here focuses on one social service, education. The reasons are twofold: The data on the determinants of performance in that sector are of relatively high quality and the issue of governmental policy toward private sector providers of educational services is currently a topic of much public interest. But, as I intend to show, the themes developed in the context of the education sector have relevance in other sectors as well, especially as one confronts the problem of designing an appropriate set of regulatory policies. A recent, highly publicized study reported that the education offered in private high schools is of higher average quality than the education offered in public high schools. The analysis in this section demonstrates that a large part of the observed quality difference is due to differences in the composition of student bodies, and that these differences stem to a significant extent from differences in the regulations pertaining to public and private schools.
Cross-Subsidization in Higher Education: Does it Pervert Private Choice and Public Policy?
Authors: James Estelle
Published: November 2020

During the 1950s and 1960s American higher education underwent a major change in size and structure, with a vast expansion in enrollments and increased emphasis on graduate training and research, relative to undergraduate teaching. This chapter explores the implications of this changing product mix for our understanding of costs, subsidies, financing methods, and decision-making structures in higher education. We ask the following questions: . . . 1. How did universities finance their production of graduate training and research (G and R), which usually do not bring in enough revenues to cover their costs? 2. What differences, if any, were there in the behavior of public and private universities regarding the shift toward G and R? 3. How did this change in product mix affect relative costs in universities versus two- and four-year colleges, which still specialize in undergraduate teaching? 4. What are the implications of this analysis for our understanding of the costs and benefits of education and for future public policy? For example, to what degree do state legislators and private donors control the product mix in higher education and who ultimately gains from the resources they provide?. . . Specifically, I characterize universities as multiproduct nonprofit organizations (NPOs) engaging in the teaching of undergraduates as a profitable activity, in order to subsidize graduate training and research, which are loss-making but yield direct utility to them. Cross-subsidization by NPOs, then, is an alternative to direct government funding of socially beneficial goods such as research, under certain circumstances. With certain differences that we shall note, this characterization applies to public and private institutions, and the term NPO is used for both in this chapter. At private universities, during the 1950s and 1960s, profits were generated mainly by huge tuition increases, made possible by rapidly rising demand, as we shall see below. State universities, too, engaged in cross-subsidization to finance G and R. However, since state universities often do not control or retain tuition revenue, their main device was a decrease in teaching cost per student.
Hospitals and Health Care
Authors: Rothstein William G.
Published: November 2020

The use of hospitals for medical care became more varied after 1950. More patients were admitted for a wide variety of conditions and more different types of treatments were provided. Many new technologies were adopted that have raised costs considerably. Hospitals employed more residents, foreign medical graduates, and nurses. Between 1946 and 1983, hospitals grew both in size and importance in the health care system. The number of short-term nonfederal hospitals increased by only one-third, but the number of beds and the average daily census doubled and the number of admissions increased 2.6 times, while the U.S. population grew by only two-thirds. Much of the additional use was for nonsurgical care. During the 1928–1943 period, 74 percent of all hospital admissions were surgical. This declined to 60 percent between 1956 and 1968 and to 50 percent between 1975 and 1981. Outpatient care grew even more rapidly than inpatient care, with the number of hospital outpatients doubling between 1965 and 1983. The hospital system has become dominated by large hospitals, practically all of which have affiliated with medical schools. In 1983, the 18 percent of nonfederal short-term hospitals that had 300 or more beds admitted 50 percent of the patients, carried out 59 percent of the surgery, and had 55 percent of the outpatient visits and 61 percent of the births. They employed 72 percent of all physicians and dentists employed in hospitals and 90 percent of all medical and dental residents. At least 60 percent of them had nurseries for premature infants, hemodialysis units, radiation therapy or isotype facilities, computerized tomograhy (CT) scanners, and cardiac catheterization facilities, and almost one-half had open-heart surgery facilities. Most also offered types of care not traditionally associated with hospitals. Practically all of them provided social work services and physical therapy, at least 75 percent provided occupational and speech therapy, and 40 percent provided outpatient psychiatric care. On the other hand, fewer than one-third provided family planning, home care, or hospice services, or partial hospitalization for psychiatric patients. The expanding services of nonfederal short-term general hospitals has led to the employment of larger numbers of workers.
Metal-Forming Processes
Authors: Kobayashi Shiro , Oh Soo-Ik , Altan Taylan
Published: November 2020

In metal forming, an initially simple part—a billet or sheet blank, for example—is plastically deformed between tools (or dies) to obtain the desired final configuration. Thus, a simple part geometry is transformed into a complex one, in a process whereby the tools “store” the desired geometry and impart pressure on the deforming material through the tool-material interface. The physical phenomena constituting a forming operation are difficult to express with quantitative relationships. The metal flow, the friction at the tool-material interface, the heat generation and transfer during plastic flow, and the relationships between microstructure/properties and process conditions are difficult to predict and analyze. Often, in producing discrete parts, several forming operations (preforming) are required to transform the initial “simple” geometry into a “complex” geometry, without causing material failure or degrading material properties. Consequently, the most significant objective of any method of analysis is to assist the forming engineer in the design of forming and/or preforming sequences. For a given operation (preforming or finish-forming), such design essentially consists of (1) establishing the kinematic relationships (shape, velocities, strain-rates, strains) between the deformed and undeformed part, i.e., predicting metal flow; (2) establishing the limits of formability or producibility, i.e., determining whether it is possible to form the part without surface or internal defects; and (3) predicting the forces and stresses necessary to execute the forming operation so that tooling and equipment can be designed or selected. For the understanding and quantitative design and optimization of metal-forming operations it is useful (a) to consider a metal forming process as a system and (b) to classify these processes in a systematic way. A metal-forming system comprises all the input variables relating the billet or blank (geometry and material), the tooling (geometry and material), the conditions at the tool-material interface, the mechanics of plastic deformation, the equipment used, the characteristics of the final product, and finally the plant environment in which the process is being conducted. Such a system is illustrated in Fig. 2.1, using impression die forging as an example.
Thermo-Viscoplastic Analysis
Authors: Kobayashi Shiro , Oh Soo-Ik , Altan Taylan
Published: November 2020

The main concern here is the analysis of plastic deformation processes in the warm and hot forming regimes. When deformation takes place at high temperatures, material properties can vary considerably with temperature. Heat is generated during a metal-forming process, and if dies are at a considerably lower temperature than the workpiece, the heat loss by conduction to the dies and by radiation and convection to the environment can result in severe temperature gradients within the workpiece. Thus, the consideration of temperature effects in the analysis of metal-forming problems is very important. Furthermore, at elevated temperatures, plastic deformation can induce phase transformations and alterations in grain structures that, in turn, can modify the flow stress of the workpiece material as well as other mechanical properties. Since materials at elevated temperatures are usually rate-sensitive, a complete analysis of hot forming requires two considerations—the effect of the rate-sensitivity of materials and the coupling of the metal flow and heat transfer analyses. A material behavior that exhibits rate sensitivity is called viscoplastic. A theory that deals with viscoplasticity was described in Chap. 4. It was shown that the governing equations for deformation of viscoplastic materials are formally identical to those of plastic materials, except that the effective stress is a function of strain, strain-rate, and temperature. The application of the finite-element method to the analysis of metal-forming processes using rigid-plastic materials leads to a simple extension of the method to rigid-viscoplastic materials. The importance of temperature calculations during a metal-forming process has been recognized for a long time. Until recently, the majority of the work had been based on procedures that uncouple the problem of heat transfer from the metal deformation problem. Several researchers have used the following approach. They determined the flow velocity fields in the problem either experimentally or by calculations, and they then used these fields to calculate heat generation. Examples of this approach are the works of Johnson and Kudo on extrusion, and of Tay et al. on machining. Another approach uses Bishop’s numerical method in which heat generation and transportation are considered to occur instantaneously for each time-step with conduction taking place during the time-step.
Definability and Diagonalization
Authors: Smullyan Raymond M.
Published: November 2020

In this chapter we establish some basic facts about Σ1-relations and functions that will be needed for the rest of this study. We also introduce the notion of fixed-points of formulas and prove a fundamental fact about them which is crucial for Gödel’s second incompleteness theorem and related results of the next chapter. A formula F(v1,...,vn) is said to define a relation R(x1,..., xn) in a system S if for all numbers a1,...,an, the two following conditions hold. (1) R(a1,... ,an) ⇒ F(ā1,... , ā n) is provable in S. (2) R̃(a1,...,an) ⇒ F(ā1,... , ā n) is refutable in S. We say that F(v1,...,vn) completely represents R(x1, . . . ,xn ) in S iff F represents R and ~ F represents the complement R of R in S—in other words, if (1) and (2) above hold with “⇒” replaced by “↔”. If F defines R in S and S is consistent, then F completely represents R in S. Proof. Assume hypothesis. We must show that the converses of (1) and (2) above must hold. Suppose F(ā1,... , ān) is provable in S. Then F(ā1,..., ān) is not refutable in S (by the assumption of consistency). Therefore by (2), R̃ (a1,...,an) cannot hold. Hence R(a1,...,an) holds. Similarly, if F(ā1,..., ān) is refutable, then it is not provable. Hence by (1), R(a1,..., an) cannot hold and hence R̃ (a1,...,an). By a recursive set or relation, we mean one such that it and its complement are both Σ1. [There are many different, but equivalent, definitions in the literature of recursive relations. We will consider some others in the sequel to this volume.] It is obvious that a formula F defines a relation R in S iff F separates R from R̃ in S. Suppose now S is a Rosser system and that R is a recursive relation. Then R and R̃ are both Σ1. Hence R is separable from R̃ in S, which means that R is definable in S. And so we have: 1. If S is a Rosser system, then all recursive relations are definable in S. 2. If S is a consistent Rosser system, then all recursive relations are completely representable in S.
Designs for Comprehensive Community Colleges: 1958-1970
Authors: Brint Steven , Karabel Jerome
Published: November 2020

No analysis of the history of the community college movement in Massachusetts can begin without a discussion of some of the peculiar features of higher education in that state. Indeed, the development of all public colleges in Massachusetts was, for many years, inhibited by the strength of the state’s private institutions (Lustberg 1979, Murphy 1974, Stafford 1980). The Protestant establishment had strong traditional ties to elite colleges—such as Harvard, Massachusetts Institute of Technology, Williams, and Amherst—and the Catholic middle class felt equally strong bonds to the two Jesuit institutions in the state: Boston College and Holy Cross (Jencks and Riesman 1968, p. 263). If they had gone to college at all, most of Massachusetts’s state legislators had done so in the private system. Private college loyalties were not the only reasons for opposition to public higher education. Increased state spending for any purpose was often an anathema to many Republican legislators, and even most urban “machine” Democrats were unwilling to spend state dollars where the private sector appeared to work well enough (Stafford and Lustberg 1978). As late as 1950, the commonwealth’s public higher education sector served fewer than ten thousand students, just over 10 percent of total state enrollments in higher education. In 1960, public enrollment had grown to only 16 percent of the total, at a time when 59 percent of college students nationwide were enrolled in public institutions (Stafford and Lustberg 1978, p. 12). Indeed, the public sector did not reach parity with the private sector until the 1980s. Of the 15,945 students enrolled in Massachusetts public higher education in 1960, well over 95 percent were in-state students. The private schools, by contrast, cast a broader net: of the nearly 83,000 students enrolled in the private schools, more than 40 percent were from out of state (Organization for Social and Technical Innovation 1973). The opposition to public higher education began to recede in the late 1950s. Already by mid-decade, a large number of urban liberals had become members of the state legislature, and a new governor, Foster Furcolo, had been elected in 1956 on an activist platform.
On Biomineralization
Authors: Lowenstam Heinz A. , Weiner Stephen
Published: November 2020

Focusing on the basic principles of mineral formation by organisms, this comprehensive volume explores questions that relate to a wide variety of fields, from biology and biochemistry, to paleontology, geology, and medical research. Preserved fossils are used to date geological deposits and archaeological artifacts. Materials scientists investigate mineralized tissues to determine the design principles used by organisms to form strong materials. Many medical problems are also associated with normal and pathological mineralization. Lowenstam, the pioneer researcher in biomineralization, and Weiner discuss the basic principles of mineral formation by organisms and compare various mineralization processes. Reference tables listing all known cases in which organisms form minerals are included.
Cnidaria
Authors: Lowenstam Heinz A. , Weiner Stephen
Published: November 2020

The phylum Cnidaria or Coelenterates includes sea anemones, jellyfish, hydras, sea fans, and, of course, the corals. With few exceptions they are all marine organisms and most are inhabitants of shallow water. In spite of the great variation in shape, size, and mode of life, they all possess the same basic metazoan structural features: an internal space for digestion (gastrovascular cavity or coelenteran), a mouth, and a circle of tentacles, which are really just an extension of the body wall. The body wall in turn is composed of three layers: an outer layer of epidermis, an inner layer of cells lining the gastrovascular cavity, and, sandwiched between them, a so-called mesoglea (Barnes 1980). All these features are present in both of the basic structural types: the sessile polyp and the free-swiming medusa. During their life cycle, some cnidarians exhibit one or the other structural type whereas others pass through both. Most Cnidaria have no mineralized deposits. The ones that, to date, are known to have mineralized deposits are listed in Table 5.1. They are found in both the free-swimming medusae and the sessile polyps. Not surprisingly, these have very different types of mineralized deposits. In the medusae they are located exclusively within the statocyst where they constitute an important part of the organism’s gravity perception apparatus. Interestingly the statoconia of the Hydrozoa, examined to date for their major elemental compositions only, are all composed of amorphous Mg-Ca-phosphate, whereas those of the Scyphozoa and Cubozoa are composed of calcium sulfate. Calcium sulfate minerals (presumably gypsum) are not commonly formed by organisms and the only other known occurrence is in the Gamophyta among the Protoctista. Spangenberg (1976) and her colleagues have expertly documented this phenomenon in the Cnidaria. (For a more detailed discussion of mineralization and gravity perception see Chapter 11.) The predominant mineralized hard part associated with the sessile polyps is skeletal. These can take the form of skeletons composed of individual spicules, spicule aggregates, or massive skeletons. They are composed of aragonite, calcite, or both.
Atmospheric Radiation
Authors: Goody R. M. , Yung Y. L.
Published: November 2020

A complete revision of Goody's classic 1964 work, this volume offers a systematic discussion of atmospheric radiation processes that today are at the center of worldwide study and concern. It deals with the ways in which incident solar radiation is transformed into scattered and thermal radiation, and the thermodynamic consequences for the Earth's gaseous envelope, identifying aspects of the interaction between radiation and atmospheric motions as the central theme for atmospheric radiation studies. As a complete treatment of physical and mathematical foundations, the text assumes no prior knowledge of atmospheric physics. The theoretical discussion is systematic, and can therefore be applied with minor extension to any planetary atmosphere.
From State College to University System: The University of Massachusetts, 1945–1973
Authors: Freeland Richard M.
Published: November 2020

The conditions of the golden age liberated Massachusetts State College from the forces that had restricted its development since the nineteenth century. In spurts of growth linked to demographic and political cycles, M.S.C. mushroomed from a limited-purpose college into a comprehensive university and from a single campus in Amherst into a multicampus system, with units in Worcester and Boston and a statewide president’s office. By the end of the period, UMass seemed finally to have joined its counterparts in western states as a full-fledged public university in the land grant tradition, with strong programs of graduate education and research built on a large undergraduate base and linked to public service activities of applied research and nondegree instruction. The evolutionary process remained incomplete, however, and Massachusetts was still Massachusetts. The state’s nonelite private institutions watched the public expansion nervously and organized to protect their interests. Other components of the public system, including the state colleges and a new network of community colleges, vied for support from an intensely politicized government still unsure of its role in higher education. Though the effort during the 1930s to transform Massachusetts State College into a full public university had ended in failure when the General Court shelved the enabling legislation, the university movement had gained important ground. In particular, by the end of the prewar decade, the loose coalition of students, alumni/ae, and organized labor that had kept the movement alive had stirred public interest and won support from the college’s trustees as well as its president, Hugh Potter Baker. Baker himself, with his roots in the scientific-technical traditions of land grant education, had been slow to endorse a broadened conception of his institution but once converted had become an eloquent and persistent advocate. Believing, despite his disappointment over the legislature’s inaction, that World War II would foster increased interest in higher education and create new opportunities for M.S.C., Baker used his annual reports during the war to reiterate the central arguments of the university movement: that, in comparison with other states, Massachusetts was not providing adequate support for public higher education; that demand for places at the college far exceeded enrollment capacity; that the region’s private institutions were not prepared to respond to the need; and that large numbers of Massachusetts residents were being forced to attend public universities in other states.
The Two Criticisms—or, Structure, Lingo, and Power in the Discourse of Academic Humanists
Authors: Lauter Paul
Published: November 2020

In October of 1966 the Johns Hopkins Humanities Center was the site of an international symposium on “The Languages of Criticism and the Sciences of Man.” The name of the symposium expresses part of its ambition: to model literary criticism on certain “scientific” paradigms. In particular, the meeting was designed to explore the implications of structuralist thinking—and especially that of continental scholars—on “critical methods in humanistic and social sciences.” Whatever the organizers may have meant by “humanistic . . . sciences,” and whatever the value of the conference in examining structuralist thought, as it turned out the symposium will be remembered historically, if at all, as a beginning of poststructuralist analysis in the United States. For at the conference Jacques Derrida made his American debut, delivering a critique of structuralism whose title, “Structure, Sign, and Play in the Discourse of the Human Sciences,” embodied many of the terms and concepts that have since characterized academic criticism in this country. In the two decades after that Baltimore conference, some version of Derridean analysis— call it deconstructionist, speculative, formalist, or, my preference, “ludic”—has come to be increasingly central to the practice of literary study ... at least as it is carried out in the influential academic towers of New Haven and its suburbs across the land. A few months before this event in 1966, and I dare say unnoted at that conference, Stokely Carmichael had posed a new slogan for what had been thought about up to that time as the “civil rights movement.” Carmichael had been arrested by Greenwood, Mississippi police when, on June 16, participants in the march named after James Meredith had attempted to erect their tents at a local black school. During that evening’s rally, Carmichael angrily asserted that blacks had obtained nothing in years of asking for freedom; “what we gonna start saying now,” he insisted, is “‘black power.’” The crowd responded immediately to those words, chanting its “black power” response to Carmichael’s call.
Reactivity of superoxide ion
Authors: Sawyer Donald T. , Williams R. J. P.
Published: November 2020

Reduction of dioxygen by electron transfer yields superoxide ion (O2-.), which has its negative charge and electronic spin density delocalized between the two oxygens. As such it has limited radical character [H-OO bond energy ΔGBF, 72 kcal]2 and is a weak Bransted base in water . . . HOO· → H+ + O2-. Kdiss, 2.0 × 10-5 (7.1) . . . The dynamics for the hydrolysis and disproportionation of O2-. in aqueous solutions have been characterized by pulse radiolysis. For all conditions the rate-limiting step is second order in O2-. concentration, and the maximum rate occurs at a pH that is equivalent to the pKa for HOO· (it decreases monotonically with further decreases in the hydrogen ion concentration).