bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Nitrogen in Plant Composts and Native Humic Material by Natural-Abundance 15N CPMAS and Solution NMR Spectra
Authors: Knicker Heike , Fründ Rüdiger
Published: November 2020

Soil organic matter (SOM) provides one of the major deposits for carbon and nitrogen on the surface of the Earth. It is continuously produced, mainly from dead plant material, by composting and humification processes. During these processes microorganisms thoroughly convert the starting material, which consists mostly of insoluble lignocelluloses. The end products of these processes in average middle-European soils, that contain typically 1 to 5% w/w of organic material, are clay–SOM complexes which are insoluble in all the usual organic and inorganic solvents. The standard aqueous sodium hydroxide extraction procedure dissolves at most 40% of the total organic carbon in all the soils tested by our group. The insoluble majority, the humin fraction, remains as poorly defined aluminosilicate- SOM complexes. During the decomposition and conversion processes the carbon to nitrogen ratio–decreases. Compared to the starting material, SOM is enriched in nitrogen. Under natural conditions, i.e., without the artificial addition of nitrogen in the form of manure or fertilizer, SOM provides the major part of the nitrogen available for plant growth. The chemical characterization of this ubiquitous but ill-defined material has only been partly successful until now. For characterization of the organic carbon in complete soils and extracts, nuclear magnetic resonance (NMR) methods appear to be most promising, especially since the application of high-resolution solid-state methods has become almost a laboratory routine. The combination of proton–carbon cross polarization with high-speed magic angle rotation (the CPMAS technique) permits the study of complete native soils, and thus provides detailed information about the gross chemical structure of the total SOM, without introducing any of the chemical modifications that could result from aggressive chemical extraction procedures. It has been shown by 13C CPMAS and high-resolution (HR) solution 13C NMR studies of a series of typical European soils, in which the concentration of paramagnetic metal ions was fairly low and which contained humic material with an aromatic carbon content ≤20%, that the carbon could be quantitatively assigned. The measurement of the 13C CPMAS spectra of complete native soils with a carbon content in the region of 1 % w/w is rather instrument-time consuming, and appeared to be at the limit of sensitivity.
Respect from Respect
Authors: Magarian Valerie
Published: November 2020

Because the adults and kids respected each other, I was excited about learning and felt appreciated in the OC. Teachers treat kids with respect, and parents learn to respect kids’ ideas by observing the kids and teachers in the classroom. Lots of people might wonder why co-opers need to learn, since it’s the kid who’s going to school. If the parent has never been in the classroom and the kid says, “We’re doing kid co-oping, and we’re making marshmallow houses,” a parent might say, “What does that have to do with school? Are you learning anything from making marshmallow houses?” The parent might not notice that their kid is learning about angles, architecture, how to make a structure that stands, and being creative. But when they see what their kid and other kids do around the classroom, they get more confident, and they respect the kid more and learn to respect the kids’ ways of learning. Adults learn to respect kids’ ideas even if they don’t agree with them. They can respect a kid’s idea and express their opinion and what most people think about it and why—rather than saying, “You’re wrong.” An outsider who comes into the classroom and sees kids discussing history might think, “There’s only one right answer, and that’s the teacher’s, so don’t debate about it because it wastes time.” It’s important for kids to be allowed to express their ideas and opinions, because that makes them really think about the topic and makes them more comfortable taking a different stance on something. They can learn about subjects by listening to other people’s opinions, too. In the OC, the teachers trust people to help each other. They know you can learn a lot from each other and from teaching others. The kids learn to understand and respect the adults who help them by leading activities in kid co-oping. Kid co-oping teaches them what it’s like to be in the co-oper’s place and how hard it is to organize a group and keep people interested. Then the kids treat the adults better because they have learned what the adults go through.
"What about Sharing?"
Authors: Bradshaw Pamela
Published: November 2020

I looked down at six-year-old Patrick, who stood at my elbow, while I scanned the crowd near the exit gate of Salt Lake’s Hogle Zoo. “What about sharing?” he asked. It was a bright May morning; hundreds of children with name tags streamed by our kindergarten group as we gathered on a small patch of lawn. As the teacher in charge of this group, I was to meet the co-opers at this spot with their smaller groups so that we could count noses before heading back to school. With only four mornings a week for kindergarten, time was always tight, and using one morning for a zoo trip was like trying to make a shoebox into a garage for an elephant. Patrick wanted to share?—surely he could see that there was no way. He just had to be kidding. I shaded my eyes to better see through the crowd for the missing zoo-explorers. Patrick asked again; his eyebrows pinched a crease on his forehead as I began to realize how serious he was. He waited patiently, tenaciously as only a six-year-old could, for my reply. If time was normally limited, and tremendously limited for a trip to the zoo, on this particular day it was impossibly limited. Already Mary’s dad held out a Tupperware container that held precious birthday cupcakes Mary had waited all day—all year—to present. I called Mary to me, positioning her before the handful of gathered children for her Happy Birthday song. If the children were ready to sing, we might still have just enough time to buckle seat belts and drive across the valley. We would pull up to the curb at school just in time for the children to meet their rides home, but certainly not with enough time to regroup in the classroom for what we knew as a sharing circle. Sharing circle was a much anticipated time every day when four or five children would present something they chose to show us. At this show-and-tell time, their classmates could admire and ask questions about the object of choice.
Becoming an Adult Member in a Community of Learners
Authors: Matusov Eugene
Published: November 2020

I thought it would be relatively easy for me, with my six-year background of high school teaching and tutoring of math and physics, to co-op in the OC classroom with my first-grade son. I was both right and wrong. Indeed, my teaching experience and professional knowledge as a graduate student in child psychology helped me design activities suitable for first- and second-grade children. However, in terms of philosophy of teaching and organization of learning activities, my experience with traditional schooling was more harmful than helpful. My previous experience prepared me for delivering a lesson to a whole class or an individual. I was used to controlling children’s talk, which was supposed to be addressed only to me, and my students had learned early on in their schooling that they could talk legitimately only to the teacher and only when it was allowed by the teacher. The teacher was supposed to be the director, conductor, and main participant in classroom interaction. In the OC, I was shocked to discover that this traditional format of instruction was actively discouraged by teachers, co-opers, and children. This kind of teaching was not supported by the children in their interactions or by the classroom structure, with its small-group organization, children’s choice of groups, and nonsimultaneous rotation of the children from group to group. However, I did not know how to teach any other way. At the beginning of the school year I planned an activity that I called Magic Computer. It was designed to teach the reversibility of addition and subtraction as well as reading and computational skills, and it had worked beautifully with first- and second-graders in the past. The activity involved moving a paper strip that carried “computer commands” (“Think of a number. Add five to it. Take two away from it,” and so on) through an envelope with a window, to see one command at a time. The commands were designed so that addition and subtraction compensated for each other; therefore, the last message was “You have got your initial number!” The children’s job was to discover addition and subtraction combinations that cancel each other out and write them down on the paper strip, line by line.
Teachers Learning Together in Forming a Learning Community
Authors: Cryns Theresa , Johnston Marilyn
Published: November 2020

The three of us, teachers from the early years of the OC, have yet to find professional situations where both the challenges and the support are as strong as in the OC. (Marcy went on to start her own business boarding and training horses; Theresa is now principal of a private school; Marilyn became a university professor.) Perhaps the combination of challenges and support was the key to why this was such a powerful context for our growth and development—and for the development of this learning community. We trace a significant strand of our intellectual growth and development to our participation in the early years of the OC (and, before it, the Thoreau School). Its influence has followed us into our subsequent personal and professional lives, permeating the crevices of our minds and feelings in ways that we have only recently come to appreciate. Our recollections of being teachers in the OC are filled with sharp images and memorable experiences; it was a time of challenge, exhilaration, and exhaustion. We have likely romanticized some of these memories, yet the pains are also vivid. What is most evident is that it was a time of immeasurable learning, for us as individuals as well as for the development of the program as a whole. Many aspects of our participation in the OC prompted this learning. The inherent ambiguity of our loosely defined roles and the changing nature of the program created a challenging environment for us as teachers. Our roles and responsibilities as teachers were ill-defined, collaborative decision making was an unfamiliar way to make educational decisions, and the curriculum was open-ended and required the integration of student and parent interests. As a consequence, we developed a strong, mutual support system, which in turn encouraged the risk taking that nurtured our further development as teachers. The intense support and challenges are the basis of the initial and continuing development of the curriculum and philosophical principles of this community.
Decision Making in a Learning Community
Authors: Lubomudrov Carol
Published: November 2020

As a principal, I know that it is never easy to bring together a diverse group of people of different ages, backgrounds, and philosophies to make decisions, even about the most mundane issues. When parents, teachers, and administrators join together to make decisions about the education of their children, it takes commitment, patience, flexibility, perseverance, and a basic belief in the strength of collaborative decision making for the learning community to function smoothly. This basic belief in the strength of collaborative decision making forms the essence of the OC as a learning community. Before becoming principal of Washington Elementary School, which houses both the OC program and the traditional school for neighborhood children, I had taught for 13 years and been an administrator for 8 years in a variety of settings. I viewed myself as a believer in and practitioner of collaborative decision making. I had a fair amount of experience working with diverse groups, including students, parents, and boards of trustees. Never, however, had I encountered a group of parents and teachers who had a stronger sense of “community” or deeper implicit beliefs as to how their program should function. This may sound as if decision making in the OC was rigid—which was not the case. It was only that over the program’s 13 years, many of its beliefs and processes had become so intuitive that as a newcomer I sometimes had a difficult time understanding how decisions were made and who the ultimate authority was. I was principal of the OC for four years and never discovered “the ultimate authority.” During that time, I did discover that common understandings regarding the importance and value of dialogue, communication, and participation served as threads that formed the fabric of the program. Here I discuss some issues that arose regarding decision making and how they were handled by the community. Notice that I did not say “how they were resolved,” since one of the things I learned while working with the OC is that often simply processing or dialoguing about the particular issues brought about closure.
The Importance of Mission
Authors: Pierce Susan Resneck
Published: November 2020

In fall 1993 the University of Puget Sound Board of Trustees accepted an offer from Seattle University to assume sponsorship of the Puget Sound School of Law. Although we had not been seeking an alternative home for the law school, we board members responded to Seattle University's initiative as we did because we believed that transferring the law school would clarify to all our constituents the University of Puget Sound's mission as a national liberal arts college. We were also convinced that the law school— which had been established in 1971 and was located in a renovated department store in downtown Tacoma, a ten-minute drive from Puget Sound's main campus—would be better served by becoming part of an institution firmly committed to professional and graduate education. The action illustrates how two very different universities can work together to ensure that each offers those programs that best fit its mission. For Puget Sound, the decision further exemplifies our determination to focus our resources, financial and human, on what we do best—a determination that grew out of the awareness that we cannot (and should not) try to do and be everything. The aftermath of the decision, however, dramatizes something very different: that even though the rhetoric of higher education in the 1990s is characterized by calls for institutional focus and for funding only the endeavors that are central to that focus, the pressure from multiple constituencies makes it very difficult for colleges and universities to move beyond talk to action. Furthermore, although most universities are not likely to face the directly comparable choice of transferring a program, this situation demonstrates instructive principles to all institutions: it is essential that their governing boards be absolutely clear about institutional mission and ensure that resources are allocated accordingly,- it is equally important that institutional mission grows out of institutional strengths; and it is crucial that boards select and support presidents whose vision is consistent with their own. Puget Sound has deliberately been true to these principles for some time.
The Student as Scholar
Authors: Boyer Ernest L.
Published: November 2020

While I thought about this conference, my mind drifted back to fall 1956, when I became academic dean at one of the world's smallest higher learning institutions, a tiny college of arts and sciences in southern California. During my first month on the job, the faculty curriculum committee met to review the college's requirements for graduation. In an act of unrestrained innocence, I asked why we had a "distribution requirement" for all students. A senior professor replied, "We borrowed it from Pomona College" (our prestigious neighbor down the road). I then asked where Pomona got it and was told, "From Harvard"—which gave me a basic lesson about higher education policymaking that's stood me in good stead for almost forty years. Liberal education is one of the most enduring and widely shared visions in American higher learning. Almost everyone agrees that beyond acquiring competence in a special field, undergraduates must be broadly informed, discover relationships across the disciplines, form values, and advance the common good. It's also true, however, that this inspired vision of liberal learning, which is powerfully reaffirmed in almost all college mission statements, is under siege on many fronts. The decline in the quality of the nation's schools surely has weakened liberal education, as has the growing emphasis on careerism and credentials. Also, the cultural fragmentation in America today makes it especially difficult for academics to bring to undergraduate education a sense of coherence and shared purpose. In 1920 Archibald MacLeish diagnosed the problem this way: 'There can be no educational postulates so long as there are no generally accepted postulates of life itself." Beyond all of these impediments, it is my own impression that the most serious challenge to liberal education on most campuses is the system of faculty rewards. And I remain convinced that liberal learning will be renewed only as faculty members who teach undergraduates and spend time with incoming students are rewarded for such efforts. But before considering how this ambitious goal might be accomplished, I would like to take a backward glance and reflect on how priorities of the professoriate have changed through the years.
A New Beginning: Catholic Colleges, 1900-1930
Authors: Gleason Philip
Published: November 2020

The changes we have been discussing naturally affected individual institutions in different ways. In this chapter we shall look more closely at some examples that illustrate the the general trends and at the same time shed light on other matters not previously discussed or touched on only in passing—for example, the rapid growth of professional and vocationally oriented programs and the equally rapid expansion of Catholic colleges for women. By way of background, we begin with some statistics on the overall growth of Catholic higher education in the first quarter of the twentieth century. Detailed surveys made by the Catholic Educational Association in 1916 and 1926 provide useful base points for analyzing changes in the latter part of the period, but information for the earlier part is much less satisfactory. Indeed, the figures for 1899 in the following table must be regarded as mere approximations. But these are the best figures we have, and Table 1 may be taken as a reliable indicator of the direction and overall scale of change in enrollments. These figures show that although secondary-level students accounted for approximately 60 percent of the enrollment in catholic colleges at the turn of the century, and about half in 1916, they were no longer considered part of the same student population in the mid-twenties. Undergraduate enrollment for 1916 is understated by perhaps as much as 1000 because the survey did not include the Catholic colleges for women that had come on the scene since 1899. Failure to include them stemmed not only from the traditional sexist bias of Catholic “college men,” but also from the fact that women’s colleges were only beginning to make their presence felt.
Ab Initio Calculations
Authors: Sapse Anne-Marie
Published: November 2020

Various difficulties of classical physics, including inadequate description of atoms and molecules, led to new ways of visualizing physical realities, ways which are embodied in the methods of quantum mechanics. Quantum mechanics is based on the description of particle motion by a wave function, satisfying the Schrodinger equation, which in its “time-independent” form is: ((−h2/8mπ2)⛛2+V)Ψ=E Ψ or, for short: HΨ = EΨ In this equation, H, the Hamiltonian operator, is defined by H = − ((h2/8mπ2)⛛2+V, where h is Planck’s constant (6.6 10−34 Joules), m is the particle’s mass, ⛛2 is the sum of the partial second derivative with x,y, and z, and V is the potential energy of the system. As such, the Hamiltonian operator is the sum of the kinetic energy operator and the potential energy operator. (Recall that an operator is a mathematical expression which manipulates the function that follows it in a certain way. For example, the operator d/dx placed before a function differentiates that function with respect to x.) E represents the total energy of the system and is a number, not an operator. It contains all the information within the limits of the Heisenberg uncertainty principle, which states that the exact position and velocity of a microscopic particle cannot be determined simultaneously. Therefore, the information provided by Ψ(nit) is in terms of probability: Ψ2(x,t) is the probability of finding the particle between x and x + dx, at time t. The Schrödinger equation applied to atoms will thus describe the motion of each electron in the electrostatic field created by the positive nucleus and by the other electrons. When the equation is applied to molecules, due to the much larger mass of nuclei, their relative motion is considered negligible as compared to that of the electrons (Born-Oppenheimer approximation). Accordingly, the electronic distribution in a molecule depends on the position of the nuclei and not on their motion. The kinetic energy operator for the nuclei is considered to be zero. For a many-electron molecule, the Hamiltonian operator can thus be written as the sum of the electrons’ kinetic energy term, which in turn is the sum of individual electrons’ kinetic energies and the electronic and nuclear potential energy terms.
Similarity and Homology
Authors: States David J. , Boguski Mark S.
Published: November 2020

Properly approached, molecular sequence data is a rich source of knowledge capable of teaching us much about the structure, function, and evolution of biological macromolecules. To effectively realize this potential, however, some understanding of the process of and theoretical basis for sequence comparison is needed as well as a variety of practical tools to access and manipulate the data. The volume of molecular sequence data has long since surpassed human information processing capacity for even simple tasks such as searching for related sequences, and with the ever increasing rate at which new sequences are being produced, the need for computer-assisted analysis becomes more and more acute. Automated tools can extend human capabilities by orders of magnitude in both speed and accuracy. The educated application of these automated tools is an essential part of modern molecular biology research. This chapter considers the theory and practice of analyzing sequence similarity as it applies to database searching and sequence alignment. Five major areas will be examined. First, we describe the use of dot matrix plots to elucidate the structures and features relating a sequence pair. Secondly, we discuss optimal pairwise alignment of sequences using dynamic programming algorithms. Thirdly, we examine fast, approximate techniques for detecting local similarities. Fourthly, the uses of and techniques for multiple sequence alignment are described. Finally, the statistical significance of sequence similarity is considered. In the analysis of molecular sequences, the terms similarity andhomology are often used without a clear understanding of their distinct implications. Similarity is a descriptive term which only implies that two sequences, by some criterion, resemble each other and carries no suggestion as to their origins or ancestry. Homology refers specifically to similarity due to descent from a common ancestor (Patterson, 1988;Reeck etal., 1987). On the basis of similarity relationships among a group of sequences, it may be possible to infer homology, but outside of an explicit laboratory model system, descent from a common ancestor remains hypothetical. There are philosophical issues in the inference of homology as well as practical ones. In classical morphology, conjunction (the occurrence of two traits in a single individual) is considered evidence that they are not homologous (Patterson, 1982).
Practical Aspects: Analysis of Notch
Authors: Caballero Lisa
Published: November 2020

The Notch sequence from Drosophila is used as the sample data. Notch is thought to control cell fate decisions in development It encodes a large, transmembrane protein which may function through cell adhesion, and it was cloned and sequenced in 1985(WhartonetaI., 1985a&b; Kidd et al., 1986). Notch is an ideal sequence to analyze because it contains many features that computers are good at finding. Figure 1 shows a schematic of the Notch protein and its major features. The Notch sequence is available in the Genbank and EMBL sequence database under accession numbers M16153, M16149, M16150, M16151 and M16152 (see Appendix VIS). The most successful way to approach this chapter is to reproduce the analyses. This will familiarize one with a specific software package, and offers a more accurate picture of the volume of output data produced by many programs than could be allowed in the figures in this chapter. Programs for most of the analyses used in this chapter are widely available on IBM PCs, Macintoshes and mainframe computers. The examples have intentionally been kept generic, but programs from the following sources were used: Genetics Computer Group Sequence Analysis Software (Devereux et al., 1984; Genetics Computer Group Inc., Madison, WI),Genbank Online Services (Benton,1990),NationalLibrary of Medicine Services (Benson et al., 1990), and PC Gene (A. Bairoch, University of Geneva; ™ Intelligenetics Inc., Mountain View, CA and Genofit SA). Unless a researcher is studying nontranslatable segments of DNA, the immediate goal upon the isolation of a new gene is usually to deduce the amino acid sequence of its product. The laboratory approach might go from isolating a cDNA clone, determining its nucleotide sequence, locating alarge open reading frame, and translating the sequence into a putative protein. In this case priority is usually given to analyzing the putative protein, with promoter regions introns being sequenced later to elucidate gene regulation. The organization of the following example analysis of Notch reflects these laboratory priorities by beginning with cDNA analysis, moving to protein analysis, and then returning to DNA analysis for the genomic sequence.
Administration and Organization of the Market
Authors: Sperber Daniel
Published: November 2020

To operate a market, or fair, individuals and communities needed the sanction of the Roman senate or the emperor. We are told that the Emperor Claudius held markets on his estates. Pliny mentions in one of his Letters that “Sollers, a man of praetorian rank, petitioned the Senate to be allowed to establish a market on his estate. His petition was opposed by envoys from Vicetia—no doubt because there was a market in that town which stood to lose from Sollers’ competition.” An inscription from 138 C.E. describes how a new market was established at Casae in the Roman province of Africa Proconsularis. The founding of this market required a specific vote of the Senate at Rome and granted Lucilius Africanus, a senator, permission to hold a market twice a month on a regular basis. The official decision of the Senate was formulated as follows: . . .Concerning this matter the senate decreed as follows: that Lucilius Africanus, vir clarissimus, be permitted to establish and maintain a market at Casae in the province of Africa, Beguensian district, territory of the Musulamians, on November 2 and 20 and every month there in the fourth day before the Nones and the twelfth day before the Kalends, and that people from the neighbourhood be permitted to gather and assemble there for the convenience of attending market only, without harm or inconvenience to anyone. . . . . . . But what was the real effect of the decision of the Roman Senate? John E. Stanbaugh gives us a hint in his book The Ancient Roman City: “Lurking clearly between the lines of the inscription are the prospect of big profits for Lucilius and the desire of the authorities that the market not become the focus of any political activity.” Normally, after receiving permission to establish a market, it became subject to the authority of the city prefect. Cicero writes that “there will be aediles who will oversee the city’s markets, merchandise, and food supplies. . . .”, while from the Digesta we learn that “It is his job to see that meat is offered for sale at a fair price, and for this reason the swine market is . . . under his supervision. Similarly other livestock which are used to provide meat are within his jurisdiction.”
On the Bathhouse
Authors: Sperber Daniel
Published: November 2020

We will now move away from the market and forum area to that other central institution of the Roman city, the bathhouse. We have already mentioned in passing (see chapter 1) that the bathhouse was usually near the market, as indicated in the passage from Apuleius, and as is evident from numerous excavations, including those of Tiberias and Beit Shean. This may further be seen in a passage in Exodus Rabba 15.22: . . . . . . Like unto a servant whose master said to him, “Wait for me in the marketplace.” But he did not tell him where [exactly] he should wait . . ., near the basilica or near the bathhouse . . . or near the theatre. . . . [His master] said to him: I sent you [to wait for me] near the entrance to the palace of the eparchos. . . . There is a wealth of archeological evidence from the Roman world in general and from Roman Palestine in particular on almost all aspects of the bathhouse and its activities. Nonetheless, a number of issues remain unclear, and Rabbinic sources can further clarify to them. Likewise, points of halachic obscurity may be solved by reference to contemporary literary sources and archeological findings. Apparently, the bathhouse was one of the landmarks in the market area, and the larger the city, the more bathhouses there were. We shall now take as our point of departure a brief passage in B. Shabbat 41 a (= B. Baba Batra 53b), which reads as follows: . . .If he bathed and did not annoint [himself] this is like water in a barrel (and not in it, i.e., the water is wasted and so too the bathing is purposeless). . . . A plain reading of this aphorism would seem to indicate that the process of annointing comes after bathing, and indeed the Tosafists (ad loc.) remark that “throughout the Talmud bathing precedes annointing.” So likewise in M. Sanhedrin 7.6 (in a description of idolatrous practices) we find the order: “bathes, annoints, clothes, and puts on his shoes.”
An Experiment in Meta-Evolution
Authors: Bäck Thomas
Published: November 2020

So far, the basic knowledge about setting up the parameters of Evolutionary Algorithms stems from a lot of empirical work and few theoretical results. The standard guidelines for parameters such as crossover rate, mutation probability, and population size as well as the standard settings of the recombination operator and selection mechanism were presented in chapter 2 for the Evolutionary Algorithms. In the case of Evolution Strategies and Evolutionary Programming, the self-adaptation mechanism for strategy parameters solves this parameterization problem in an elegant way, while for Genetic Algorithms no such technique is employed. Chapter 6 served to identify a reasonable choice of the mutation rate, but no theoretically confirmed knowledge about the choice of the crossover rate and the crossover operator is available. With respect to the optimal population size for Genetic Algorithms, Goldberg presented some theoretical arguments based on maximizing the number of schemata processed by the algorithm within fixed time, arriving at an optimal size λ* = 3 for serial implementations and extremely small string length [Gol89b]. However, as indicated in section 2.3.7 and chapter 6, it is by no means clear whether the schema processing point of view is appropriately preferred to the convergence velocity investigations presented in section 2.1.7 and chapter 6. As pointed out several times, we prefer the point of view which concentrates on a convergence velocity analysis. Consequently, the search for useful parameter settings of a Genetic Algorithm constitutes an optimization problem by itself, leading to the idea of using an Evolutionary Algorithm on a higher level to evolve optimal parameter settings of Genetic Algorithms. Due to the existence of two logically different levels in such an approach, it is reasonable to call it a meta-evolutionary algorithm. By concentrating on meta-evolution in this chapter, we will radically deviate from the biological model, where no two-level evolution process is to be observed but the self-adaptation principle can well be identified (as argued in chapter 2). However, there are several reasons why meta-evolution promises to yield some helpful insight into the working principles of Evolutionary Algorithms: First, meta-evolution provides the possibility to test whether the basic heuristic and the theoretical knowledge about parameterizations of Genetic Algorithms is also evolvable by the experimental approach, thus allowing us to confirm the heuristics or to point at alternatives.
Introduction
Authors: Floudas Christodoulos A.
Published: November 2020

This chapter introduces the reader to elementary concepts of modeling, generic formulations for nonlinear and mixed integer optimization models, and provides some illustrative applications. Section 1.1 presents the definition and key elements of mathematical models and discusses the characteristics of optimization models. Section 1.2 outlines the mathematical structure of nonlinear and mixed integer optimization problems which represent the primary focus in this book. Section 1.3 illustrates applications of nonlinear and mixed integer optimization that arise in chemical process design of separation systems, batch process operations, and facility location/allocation problems of operations research. Finally, section 1.4 provides an outline of the three main parts of this book. A plethora of applications in all areas of science and engineering employ mathematical models. A mathematical model of a system is a set of mathematical relationships (e.g., equalities, inequalities, logical conditions) which represent an abstraction of the real world system under consideration. Mathematical models can be developed using (i) fundamental approaches, (ii) empirical methods, and (iii) methods based on analogy. In (i), accepted theories of sciences are used to derive the equations (e.g., Newton’s Law). In (ii), input-output data are employed in tandem with statistical analysis principles so as to generate empirical or “black box” models. In (iii), analogy is employed in determining the essential features of the system of interest by studying a similar, well understood system. The variables can take different values and their specifications define different states of the system. They can be continuous, integer, or a mixed set of continuous and integer. The parameters are fixed to one or multiple specific values, and each fixation defines a different model. The constants are fixed quantities by the model statement. The mathematical model relations can be classified as equalities, inequalities, and logical conditions. The model equalities are usually composed of mass balances, energy balances, equilibrium relations, physical property calculations, and engineering design relations which describe the physical phenomena of the system. The model inequalities often consist of allowable operating regimes, specifications on qualities, feasibility of heat and mass transfer, performance requirements, and bounds on availabilities and demands. The logical conditions provide the connection between the continuous and integer variables.
Convex Analysis
Authors: Floudas Christodoulos A.
Published: November 2020

This chapter discusses the elements of convex analysis which are very important in the study of optimization problems. In section 2.1 the fundamentals of convex sets are discussed. In section 2.2 the subject of convex and concave functions is presented, while in section 2.3 generalizations of convex and concave functions are outlined. This section introduces the fundamental concept of convex sets, describes their basic properties, and presents theoretical results on the separation and support of convex sets.
Process Synthesis
Authors: Floudas Christodoulos A.
Published: November 2020

This chapter provides an introduction to Process Synthesis. Sections 7.1 and 7.2 discuss the components of a chemical process system and define the process synthesis problem. Section 7.3 presents the different approaches in the area of process synthesis. Section 7.4 focuses on the optimization approach and discusses modeling issues. Finally, Section 7.5 outlines application areas which are the subject of discussion in chapters 8, 9 and 10. Process Synthesis, an important research area within chemical process design, has triggered during the last three decades a significant amount of academic research work and industrial interest. Extensive reviews exist for the process synthesis area as well as for special classes of problems (e.g., separation systems, heat recovery systems) and for particular approaches (e.g., insights-based approach, optimization approach) applied to process synthesis problems. These are summarized in the following: Overall Process Synthesis: Hendry et al. (1973) Hlavacek(1978) Westerberg (1980) Stephanopoulos (1981) Nishida et al. (1981) Westerberg (1989) Gundersen(1991) Heat Exchanger Network Synthesis: Gundersen and Naess (1988) Separation System Synthesis: Westerberg (1985) Smith and Linnhoff( 1988) Optimization in Process Synthesis: Grossmann (1985), (1989), (1990) Floquet et al. (1988) Grossmann et al. (1987) Floudas and Grossmann (1994) Prior to providing the definition of the process synthesis problem we will describe first the overall process system and its important subsystems. This description can be addressed to the overall process system or individual subsystems and will be discussed in the subsequent sections. An overall process system can be represented as an integrated system that consists of three main interactive components : (i) Chemical plant, (ii) Heat recovery system, (iii) Utility system. In the chemical plant, the transformation of the feed streams (e.g., raw materials) into desired products and possible by-products takes place. In the heat recovery system, the hot and cold process streams of the chemical plant exchange heat so as to reduce the hot and cold utility requirements. In the utility plant, the required utilities (e.g., electricity and power to drive process units) are provided to the chemical plant while hot utilities (e.g., steam at different pressure levels) are provided to the heat recovery system.
Heat Exchanger Network Synthesis
Authors: Floudas Christodoulos A.
Published: November 2020

This chapter focuses on heat exchanger network synthesis approaches based on optimization methods. Sections 8.1 and 8.2 provide the motivation and problem definition of the HEN synthesis problem. Section 8.3 discusses the targets of minimum utility cost and minimum number of matches. Section 8.4 presents synthesis approaches based on decomposition, while section 8.5 discusses simultaneous approaches. Heat exchanger network HEN synthesis is one of the most studied synthesis/design problems in chemical engineering. This is attributed to the importance of determining energy costs and improving the energy recovery in chemical processes. The comprehensive review of Gundersen and Naess (1988) cited over 200 publications while a substantial annual volume of studies has been performed in the last few years. The HEN synthesis problem, in addition to its great economic importance features a number of key difficulties that are associated with handling: (i) The potentially explosive combinatorial problem for identifying the best pairs of hot and cold streams (i.e., matches) so as to enhance energy recovery; (ii) Forbidden, required, and restricted matches; (iii) The optimal selection of the HEN structure; (iv) Fixed and variable target temperatures; (v) Temperature dependent physical and transport properties; (vi) Different types of streams (e.g., liquid, vapor, and liquid-vapor); and (vii) Different types of heat exchangers (e.g., counter-current, noncounter-current, multistream), mixed materials of construction, and different pressure ratings. It is interesting to note that the extensive research efforts during the last three decades toward addressing these aforementioned difficulties/issues exhibit variations in their objectives and types of approaches which are apparently cyclical. The first approaches during the 1960s and early 1970s treated the HEN synthesis problem as a single task (i.e., no decomposition into sub-tasks). The work of Hwa (1965) who proposed a simplified superstructure which he denoted as composite configuration that was subsequently optimized via separable programming was a key contribution in the early studies, as well as the tree searching algorithms of Pho and Lapidus (1973). Limitations on the theoretical and algorithmic aspects of optimization techniques were, however, the bottleneck in expanding the applicability of the mathematical approaches at that time.
Synthesis of Reactor Networks and Reactor-Separator-Recycle Systems
Authors: Floudas Christodoulos A.
Published: November 2020

This chapter discusses the application of MINLP methods in the synthesis of reactor networks with complex reactions and in the synthesis of reactor-separator-recycle systems. Despite the importance of reactor systems in chemical engineering processes, very few systematic procedures for the optimal synthesis of reactor networks have been proposed. The main reason for the scarcity of optimization strategies for reactor networks is the difficulty of the problem itself. The large number of alternatives along with the highly nonlinear equations that describe these systems have led to the development of a series of heuristic and intuitive rules that provide solutions only for simple cases of reaction mechanisms. Most of the studies considered single reactors with a specified mixing pattern and focused on investigating the effect of temperature distribution, residence time distribution, or catalyst dilution profile on its performance. In the sequel, we will briefly review the approaches developed based on their classification: (i) isothermal operation and (ii) nonisothermal operation. Trambouze and Piret (1959) proposed graphical and analytical criteria for selecting the type of reactor. Levenspiel (1962) reported heuristic rules for optimal yield and selectivity in stirred tank and tubular reactors. Aris (1964, 1969) applied dynamic programming to determine the optimal amounts of by-passes and cold streams in a multistage reaction system within a fixed structure. Gillespie and Carberry (1966) studied the Van der Vusse reaction with an intermediate level of mixing and demonstrated the potential advantages of recycle reactors for such a complex reaction. Horn and Tsai (1967) studied the effects of global and local mixing using the adjoint variables of optimization theory. Jackson (1968) proposed an algebraic structure for the reactor representation consisting of parallel ideal tubular reactors that were interconnected with side streams at various sink and source points. Different flow configurations and mixing patterns could be obtained by varying the number and the positions of the sink and source points, as well as the levels of the sidestreams. By deliberate manipulation of the flow configuration, potential improvements in the reactor performance coul be investigated. Ravimohan (1971) modified Jackson's model so as to handle cases of local mixing.
The Aftermath
Authors: Verschuur Gerrit L.
Published: November 2020

After all the hoopla associated with Jupiter’s publicity stunt died down, planetary scientists got down to the business of analyzing their data. Simulations of the aftermath of a comet or asteroid impact had been available for years and in July 1994 many of the predictions were confirmed, albeit some more dramatically than expected. The timing of the event was almost as if to remind us to take more seriously what we have been thinking and talking about for some time. Putting aside for a moment the implications for life on earth had something similar happened here, let’s look at some of the things that were learned. Argument continues as to what actually hit Jupiter, a comet or asteroid. When the Space Telescope Science Institute sent out a press release on September 29, 1994, entitled “Hubble Observations Shed New Light on Jupiter Collision,” we were led to expect an answer. The introduction gave us further hope: “Was it a comet or an asteroid?” But the institute didn’t have the answer. Its observations slightly favored a cometary origin, but the asteroid possibility still could not be ruled out. Comets are mostly icy, or so we like to think, and asteroids are mostly rocky or metallic, or so we like to think. When you really get down to it, this business of the difference between comets and asteroids has launched a new cottage industry within astronomical circles. A more recent hint that a comet was involved came from observations made from on board the Kuiper Airborne Observatory, an airplane that carries a beautiful infrared telescope high above most of the water vapor in the atmosphere where it can then see more clearly. Ann Sprague and Donald Huntern from the University of Arizona and their colleagues found evidence for water minutes after two of the fragments smashed into Jupiter. The water signature, a spectral line, indicated it was at a temperature of 500 kelvins (degrees above absolute zero, or about 230 Celcius), much hotter than Jupiter’s usual 200 kelvins (-73 Celcius). Although they could not rule out that the water originated deep in Jupiter’s clouds, the way it came and went over a period of 20 minutes suggested that it was liberated by the impact and was part of a cometlike object.