bluuebunny/crossref_metadata_2025 huggingface dataset:
Retreat from Progress
Authors: Gordon Robert B.
Published: November 2020

Salisbury ironmakers throve by selling wrought iron rather then cast iron through the first half of the nineteenth century. Their finery forges and puddling works converted nearly all of the pig produced by the district’s furnaces to bar iron or forged products. However, by the 1860s, when the district’s ironmasters were smelting up to 11,800 tons of pig iron per year, they converted little of it to wrought iron. The demise of the forges left just one principal product, cast iron used mainly for railroad car wheels. Milo Barnum and Leonard Richardson had started making railroad castings in 1840. When Milo Barnum retired in 1852, his son W. H. Barnum took his place in the partnership with Richardson. The partners expanded the business by acquiring the Beckley and Forbes furnaces in 1858 and 1862, respectively, from the Adam family in East Canaan. Upon Leonard Richardson’s death, Barnum and the Richardson heirs reconstituted the business as the Barnum-Richardson Company, the firm that gradually gained control of all mines and blast furnaces in the northwest, except for the Kent furnace. A new railway facilitated the Barnum-Richardson operations. Dedicated residents of the northwest, in the face of much skepticism, raised the capital needed to build the Connecticut Western Railroad from Hartford to State Line, where it joined with the Dutchess & Columbia line running to Beacon, New York. Salisbury residents eagerly awaited its 1871 completion: they wanted to be rid of the heavy ore wagons that kept their roads a rness passing from Ore Hill to the furnaces in East Canaan. The Connecticut Western passed through Winsted, traversed difficult terrain in Norfolk, and crossed the Housatonic Railroad at Canaan, where the two companies built a handsome union station . Railroad enthusiasm also led residents in the northwest to propose impractical schemes. The Shepaug Railroad had been completed in 1872 from Danbury to Litchfield. A correspondent writing to the Connecticut Western News that year proposed extension into the Salisbury district.
GICs and Batteries
Authors: Enoki Toshiaki , Endo Morinobu , Suzuki Masatsugu
Published: November 2020

Intercalation can be defined as the process of inserting atoms or molecules (guest chemical species) between layers in a host material with layered structure such as graphite. Intercalation can be achieved using a solid, liquid, or gaseous intercalate reagent, as discussed in Chapter 2. However, preparation from the vapor is the most common. When graphite is used as a host material, a high degree of three-dimensional (3D) structural ordering is generally desired. The intercalation rate and the resulting intercalate concentration are strongly dependent on the intercalation conditions, such as pressure, temperature difference between the host graphite material and the intercalate, the physical dimensions of the sample, the degree of crystalline order, and the defect density within the host graphite material. The most important factors for controlling the physicochemical properties of GICs are the host material and the types of intercalate. Compared with other host materials, fibrous materials, including vapor-grown carbon fibers (VGCFs) (Dresselhaus et al., 1988), have shown particular suitability for GIC from the viewpoint of practical applications. Fiber hosts are normally intercalated using techniques similar to those considered for HOPG-based GICs, though the specific intercalation conditions may be different with regard to intercalation temperature, time, and other conditions. It is noteworthy that the intercalation of chemical species within fiber hosts is successful at lower temperature ranges than for bulk graphite or HOPG host materials (Meschi, 1988; Meschi et al., 1986). Because of the small size of the fibrous hosts, with diameter around 10 μm , the intercalation time tends to be shorter. With regard to the kinetics, the intercalation of fibers is initiated at the free edges of the fibers and then proceeds along the fiber length, thus depending on the macroscopic structure or morphology of the host fibers (Shioya et al., 1986). Fibers prepared from polymeric precursors can be intercalated in the radial direction (Goldberg and Kalnin, 1981). However, for the case of low crystalline fibrous carbon such as PAN-based carbon fiber, it is very difficult to fully form intercalated materials. On the other hand, covalent GICs such as fluorinated graphite and graphite oxide can be synthesized (see Sections 2.3.4 and 9.1.8).
Exfoliated Graphite Formed by Intercalation
Authors: Enoki Toshiaki , Endo Morinobu , Suzuki Masatsugu
Published: November 2020

When a graphite intercalation compound (GIC) is heated, a thermal expansion, large (~3.5 × 10−5/K) compared with most materials, occurs along the c-axis, while the in-plane lattice constant remains almost unchanged. This anisotropic thermal expansion behavior is reversible and can be modeled in terms of a superposition of the c-axis thermal expansion coefficients of the constituent layers (Salamanca-Riba and Dresselhaus, 1986). However, when a GIC is heated above a specific critical temperature, a gigantic c-axis expansion can occur, with sample elongations (ΔLS/LS) of a factor of 300 (Inagaki et al., 1983). This extremely large elongation, also called “exfoliation,” is generally irreversible, and leads to a spongy, foamy, low-density, high-surface-area carbon material of about 85 m2/g (Thomy and Duval, 1969). This exfoliation effect alters the structural integrity of the GIC material and therefore is undesirable for structural applications of GICs. However, this spongy, foam-like material is advantageous for some applications, such as gas adsorption. The commercial version of the exfoliated wormy-like material is called vermicular graphite from its appearance, and is used for high-surface-area applications. Furthermore, when pressed into sheets, it is called grafoil and is widely used as a high-temperature gasket or packing material because of its flexibility, chemical inertness, low transverse thermal conductivity, and ability to withstand high temperatures. Grafoil-type products can also be used to contain molten corrosive liquid metals at high temperatures and to extinguish metal fires (Anderson and Chung, 1984). These products have been expected to be useful for oil adsorption (Toyoda et al., 1998a, 1998b, 1999). In this chapter, the preparation and conventional as well as advanced applications of exfoliated graphite with unique properties, obtained from QIC-based materials, is demonstrated.
Archiving Odors
Authors: Morton Thomas Hellman
Published: November 2020

In an ode addressed to his friend Fabullus, the Roman poet Catullus speaks of a fragrance so pleasing that “when you smell it you will beg the gods to make you all nose.” Would that the recipe for such a scent had been transmitted through the ages! Even today, however, it is not possible to document chemical composition with adequate fidelity to reconstruct an odor perfectly. Catullus writes that the gods of love gave the perfume to his girlfriend. Suppose such gods existed and could list the ingredients of its aroma. The list would contain hundreds—perhaps thousands—of chemical structures and their relative proportions. Very likely, many of the structures would stand for compounds that are currently unknown, but they could be synthesized in the laboratory. Would that knowledge permit me to reproduce the odor? This chapter argues that the answer remains uncertain. The current state of chemical knowledge can neither account for why an odor smells the way it does nor what determines its intensity. The recipe for replicating a sensory experience—what is essential and what is superfluous—remains obscure. The sense of smell challenges chemical understanding. On the one hand, given the structure of a new molecule a chemist can predict its spectroscopic properties over a wide domain of electromagnetic frequencies. A mixture ordinarily displays a spectrum that superimposes the spectra of its individual components, unless they physically interact with each other. In the chemical senses, on the other hand, perceptions of mixtures often cannot be inferred from their constituents, even though the components do not interact at the molecular level. Moreover, no one can reliably predict the organoleptic properties (taste or smell) of a new molecule from its structure. Even if that were possible, the English language does not offer a vocabulary with which to describe new smells, except by analogy to odors that are already familiar. The poverty of descriptors means that, in talking about olfactory stimuli, many people allude to direct experiences. These allusions call on memories of characteristic odors of familiar objects, which represent “unitary percepts.”
The All-Powerful NIMBY
Authors: Tammemagi Hans
Published: November 2020

Our society has reached a frustrating impasse: everyone wants consumer goods, but nobody wants the associated waste. In all levels of society from the grass-roots to the highest level of politics, enormous public opposition has developed to siting landfills, incinerators, or transfer stations. With complex judicial and political systems that promote empowerment of the people, it has become common for opposition groups to delay or halt altogether the introduction of new waste management facilities. The NIMBY—Not In My Back Yard—syndrome has become a powerful force. This chapter explores the process by which the sites for landfills and related waste facilities are selected. This fascinating topic goes far beyond technical issues: it provides insight into human behavior and the ways political decisions are made. An understanding of the NIMBY phenomenon is essential for anyone who wishes to pursue a career in waste management. In some regions there is already a crisis. In New Jersey, for example, the number of landfills has dropped from more than 300 to about a dozen in the past two decades. As a result, more than half of New Jersey’s municipal solid waste must be exported to other states. In New York state, 298 landfills were closed and only 6 new ones opened in the decade since 1982. The same story is unfolding in almost all jurisdictions in North America; the number of landfills in the United States dwindled from 20,000 in 1979 to about 5,300 in 1993 (Miller, 1997). There is a very strong trend toward fewer—but much bigger—landfills. In the United States it is estimated that 8% of the existing landfills handle 75% of the country’s garbage. As the number of landfills decreases, their heights grow, casting dark shadows across the land. There is no doubt that new landfills are safer than old ones: they are generally better sited and incorporate better engineering and modern technology such as liners, covers, and leachate and gas extraction systems. However, people still do not want them next door. Thus, the few new landfills that are being developed are getting larger and larger; the megadump is the trend of the future.
Dynamic Processes in Cirrus Clouds: Concepts and Models
Authors: Starr David O’C. , Quante Markus
Published: November 2020

Advancement in the understanding of cirrus clouds and their life cycle comes through symbiotic use of models, observations, and related concepts (fig. 18.1). Models of cirrus clouds represent an integration of our knowledge of cirrus cloud properties and processes. They provide a capacity to extend knowledge and enhance understanding in ways that complement existing observational capabilities. Models can be used to develop new theories, such as parameterizations, and focus science issues and observational requirements and developments. For example, early model results of Starr and Cox (1985a) and Starr (1987b) predicted that fine cellular structure (~lkm or less) would be found in the upper part of extended stratiform cirrus clouds. This prediction was confirmed when high-frequency sensors were deployed both for active remote sensing (Sassen et al. 1990a, 1995) and later for in-situ measurements (Quante and Brown 1992; Gultepe et al. 1995; Quante et al. 1996). Sampling rates of 10Hz, or better, are now accepted as a minimum requirement for resolving cirrus cloud internal structure and circulation where 1-Hz or coarser measurements were previously used. Similarly, discrepancies between observed cloud radiative properties and calculations (theory) based on corresponding in-situ observations of cloud microphysical properties (Sassen et al. 1990b) led to the development of improved observing capabilities for small ice crystals (Arnott et al. 1994; Miloshevich and Heymsfield 1997; Lawson et al. 1998). Such sensors are now regarded as part of the standard complement when doing in-situ microphysical measurements in cirrus. At the same time, observations are absolutely essential in developing and evaluating cloud models. No cloud modeler wants to apply a model or theory too far beyond the limits of what can be observationally confirmed, at least in gross terms. The third aspect of this triad is concepts. Although models and observations can lead to predictions or diagnosis of unexpected relationships, they are each limited by the concepts that were used in their design and/or implementation. In the end, new concepts arising from analogy to other phenomena and/or from synergistic integration of existing knowledge can lead to new understanding, new models, new instruments, and new sampling strategies (fig. 18.1). Chapter 17 focuses on observations of internal cloud circulation and structure.
Microphysical Processes in Cirrus and Their Impact on Radiation: A Mesoscale Modeling Perspective
Authors: Khvorostyanov Vitaly I. , Sassen Kenneth
Published: November 2020

The impact of cloudiness on the global radiative budget and its climatic consequences have been widely discussed during the last three decades. It was gradually recognized that the climatic effect of cloudiness depends on its height: low- and middle-level cloudiness have a total cooling effect on the Earth climatic system, while the upper-level clouds, cirrus, may have mostly a warming effect (IPCC 1995). The net effect of cirrus (i.e., warming or cooling), is much less clear because neither their microphysical and optical properties, nor the processes that govern their formation, are well understood and parameterized in climate models. These uncertainties have stimulated several major field projects performed within the International Satellite Cloud Climatology Project (ISCCP; Rossow and Schiffer 1991) with subsequent data analysis reports [e.g., FIRE IFO-I (1990), FIRE IFO-II (1995), and EUCREX (Raschke et al. 1996)]. The relevant theoretical works, and even the simplest climate models, indicate that the climatic impact of cirrus depends on their microstructure: clouds composed of small crystals with effective radii less than about 16 μm have a total cooling effect, but clouds of larger crystals have a warming effect (Stephens et al. 1990). It was shown that the total cloud forcing at the top of the atmosphere (TOA) is positive from a few to a few tens of watts per square meter for the large crystals and decreases with decreasing crystal radius (Fu and Liou 1993). Most of the previous theoretical studies of cirrus radiative properties, after choosing some model of microphysics and some values for the mass extinction and absorption coefficients, then prescribed them to the whole cloud, neglecting any vertical variations. Simulations with general circulation models (GCMs) showed that cirrus clouds with their optical properties parameterized in such a way (i.e., constant with height) have a total warming effect and positive feedbacks with respect to greenhouse gas-induced global warming (e.g., Ramanathan et al. 1983; Wetherald and Manabe 1988). Today, the estimation of the warming/cooling effect of cirrus has become even more complicated due to two factors. First, for many years the usual in situ probes allowed the measurement of ice crystals with radii only larger than 25-50 μm, so the smallest and most optically and radiatively active crystals were unresolved.
Parasite-Host Interactions
Authors: Lively Curtis M.
Published: November 2020

The diversity of known strategies for parasitic lifestyles is truly astonishing. Many species of parasitic worms, for example, utilize only one host species, while others cycle between two or more (as many as four) different species of hosts. Some parasites are highly virulent, seriously debilitating or even killing their hosts, while others cause only minor damage. Some parasites (such as viruses) are very small relative to their hosts and have the capacity for explosive reproduction. Others are almost as large as their hosts, and have relatively slow generation times. Therefore, parasites are difficult to categorize. Here, I use parasite to refer to organisms that have an obligate association with, and a negative effect on, another organism (the host). Host strategies for dealing with parasites are equally complex. Vertebrates have highly specialized immune systems that can rapidly respond to infection and then store information that can be used to mount future responses to the same type of infection. Invertebrates lack the memory cells of true immune systems, but they do have complex self-nonself recognition systems for recognizing and killing foreign tissues. Plants also have highly specialized defenses against pathogens, and the genetic basis of these defenses is especially well known due to the work of plant pathologists on crop plants. The myriad of details involved in the interactions between hosts and their parasites is overwhelming, but there are some shared, general aspects of these interactions that are of particular interest to evolutionary ecologists. First, parasites may attack in a frequency-dependent way. In other words, the probability of infection for a particular host genotype is expected to be, at least in part, a function of the frequency of that host genotype. This expectation has implications for sexual selection and the evolutionary maintenance of cross-fertilization (Sakai, this volume; Savalli, this volume). Second, parasites may affect the population density of their hosts, and host density may feed back to affect the numerical dynamics of the parasite. Host density may also affect natural selection on the reproductive rates of parasites, which in turn is likely to affect host fitness and host dynamics.
Ant Foraging Behavior, Combinatorial Optimization, and Routing in Communications Networks
Authors: Bonabeau Eric , Dorigo Marco , Theraulaz Guy
Published: November 2020

This chapter is dedicated to the description of the collective foraging behavior of ants and to the discussion of several computational models inspired by that behavior—ant-based algorithms or ant colony optimization (AGO) algorithms. In the first part of the chapter, several examples of cooperative foraging in ants are described and modeled. In particular, in some species a colony self-organizes to find and exploit the food source that is closest to the nest. A set of conveniently defined artificial ants, the behavior of which is designed after that of their real counterparts, can be used to solve combinatorial optimization problems. A detailed introduction to ant-based algorithms is given by using the traveling salesman problem (TSP) as an application problem. Ant-based algorithms have been applied to other combinatorial optimization problems such as the quadratic assignment problem, graph coloring, job-shop scheduling, sequential ordering, and vehicle routing. Results obtained with ant-based algorithms are often as good as those obtained with other general-purpose heuristics. Application to the quadratic assignment problem is described in detail. Coupling ant-based algorithms with local optimizers obtains, in some cases, world-class results. Parallels are drawn between ant-based optimization algorithms and other nature-inspired optimization techniques, such as neural nets and evolutionary computation. All the combinatorial problems mentioned above are static, that is, their characteristics do not change over time. In the last part of the chapter, the application of ant-based algorithms to a class of stochastic time-varying problems is investigated: routing in telecommunications networks. Given the adaptive capabilities built into the ant-based algorithms, they may be more competitive in stochastic time-varying domains, in which solutions must be adapted online to changing conditions, than in static problems. The performance of AntNet, an ant-based algorithm designed to adaptively build routing tables in packet-switching communications networks, is the best of a number of state-of-the-art algorithms compared on an extensive set of experimental conditions. Many ant species have trail-laying trail-following behavior when foraging: individual ants deposit a chemical substance called pheromone as they move from a food source to their nest, and foragers follow such pheromone trails.
Nonlinear and Synthetic Models for Primate Societies
Authors: te Boekhorst Irenaeus J. A. , Hemelrijk Charlotte K.
Published: November 2020

We explore some unorthodox models for studying primate societies as self-organized and, hence, nonlinear complex systems. The incentive is that the conventional rationalist-analytic approach often leads to superfluous and contrived explanations. This is due to the habit of seeking separate explanations for each observed phenomenon, the tendency to ascribe social patterns solely to cognitive or genetic qualities of individuals, and the use of a short-sighted logic that yields naive predictions. These practices stem from the desire to produce testable predictions derived from a normative perspective, leading to a disregard of real world properties like nonlinear dynamics, the effects of numerous parallel interactions, and the importance of local spatial configurations. We illustrate how dynamical systems and individualoriented models explicitly include these features by starting from a synthetic perspective. As a result, they generate versatile, and often counterintuitive, insights into primate social behavior. The hypotheses derived in this way are parsimonious in the sense that a multitude of patterns can be traced back to one and the same minimal set of interactive dynamics. This type of model therefore leads to more integrating and comprehensive explanations than the purely function- alistic top-down approaches of cognitive science and neo-Darwinian evolutionary theory. We suggest that building autonomous robots and studying their performance might yield additional understanding of self-organized collective behavior in the real world. As mechanistic implementations of principles discovered in silica, robots form an interesting extension to individual-oriented models because they confront us with important real world conditions and physical constraints that are hard to program or would go otherwise unnoticed. In this chapter we use examples from primatology to tackle problems in the study of (small-scale) human societies. In contrast to the usual rationale, our objective is not to learn about our own kind by regarding monkeys and apes as simplified versions of humans. Instead, we argue that certain features of both human and nonhuman social behavior rest on common principles of selfstructuring and that studying these may shed light on general issues of social organization.
Since 1945: New Amenities, New Hazards
Authors: Meyer William B.
Published: November 2020

If the average citizen's surroundings defined the national climate, then the United States grew markedly warmer and drier in the postwar decades. Migration continued to carry the center of population west and began pulling it southward as well. The growth of what came to be called the Sunbelt at the "Snowbelt's" expense passed a landmark in the early 1960s when California replaced New York as the most populous state. Another landmark was established in the early 1990s when Texas moved ahead of New York. In popular discussion, it was taken for granted that finding a change of climate was one of the motives for relocating as well as one of the results. It was not until 1954, though, that an American social scientist first seriously considered the possibility. The twentieth-century flow of Americans to the West Coast, the geographer Edward L. Ullman observed in that year, had no precedent in world history. It could not be explained by the theories of settlement that had worked well in the past, for a substantial share of it represented something entirely new, "the first large-scale in-migration to be drawn by the lure of a pleasant climate." If it was the first of its kind, it was unlikely to be the last. For a set of changes in American society, Ullman suggested, had transformed the economic role of climate. The key changes included a growth in the numbers of pensioned retirees; an increase in trade and service employment, much more "footloose" than agriculture or manufacturing was; developments in technology making manufacturing itself more footloose; and a great increase in mobility brought about by the automobile and the highway. All in one way or another had weakened the bonds of place and made Americans far freer than before to choose where to live. Whatever qualities made life in any spot particularly pleasant thus attracted migration more than in the past. Ullman grouped such qualities together as "amenities." They ranged from mountains to beaches to cultural attractions, but climate appeared to be the most important, not least because it was key to the enjoyment of many of the rest. Ullman did not suppose that all Americans desired the same climate. For most people, in this as in other respects, "where one was born and lives is the best place in the world, no matter how forsaken a hole it may appear to an outsider."
The Cast of Characters
Authors: Lewis William M.
Published: November 2020

Through the inexorable workings of natural selection, wetlands have come to support a group of species that are especially well adapted to the physical and chemical peculiarities of saturated substrates and shallow water. These species give wetlands their distinctive biological signature and sustain the biotic functions of wetlands (Tiner 1998). The species that occupy wetlands show varying degrees of specialization. Some are so highly specialized that they can live or reproduce only in wetlands; these are called obligate wetland species. A second group contains organisms that are adapted for life in wetlands but are not restricted to wetlands; these are called facultative wetland species. Facultative wetland species show every conceivable shade of association with wetlands: they range from almost obligate to barely facultative. The distribution of obligate wetland species coincides closely with the distribution of wetlands. Thus, one could be tempted to rely heavily on obligate wetland species to find and map wetlands. Inference from obligate wetland species, however, must be tempered with caution. First, the absence of obligate wetland species does not necessarily mean absence of wetland, given that a wetland can be mostly or even entirely occupied by facultative wetland species. In addition, the degree to which a given species is a wetland obligate may not be known with absolute certainty. Where a genetic variant or an unusual set of physical conditions prevails, a species that seemed to be obligate in other situations may prove to be merely facultative and thus not diagnostic proof of the presence of wetland. The perils of absolute reliance on obligate wetland species have turned the attention of wetland mappers to the analysis of entire communities. Although community analysis can be done in a number of ways, the central idea is to score a community according to the proportionate representation of species that show a known facultative or obligate affinity with wetland conditions. The analysis of communities for the purpose of mapping and identifying wetlands has been focused almost entirely on vascular plants (grasses, forbs, shrubs, and trees). Two good reasons for this are the relative ease with which plant communities can be analyzed and the immobility of plants.
Air Masses and Fronts
Authors: Whiteman C. David
Published: November 2020

An air mass is a regional-scale volume of air with horizontal layers of uniform temperature and humidity. Air masses form during episodes of high pressure when weak winds allow air to remain for several days over a flat area with uniform surface characteristics. The characteristics of the underlying surface determine the characteristics of the air mass, which is given a two-letter identifier. Air masses are identified by their locations of origin (maritime “m” or continental “c”) and by their characteristics (tropical “T” or polar “P”). Tropical air masses form in high pressure areas in warm, tropical regions. When a tropical air mass is formed over oceans (mT), it is warm, moist, and usually unstable. When formed over land (cT), it is hot and dry, with unstable air near the surface and stable air aloft. Polar air masses form in high pressure areas in the polar and subpolar regions. A polar air mass that forms over water (mP) is cool, moist, and unstable. A polar air mass that forms over land (cP) is cold, dry, and stable. An extremely cold polar air mass that forms in winter over arctic ice and snow surfaces is called an arctic air mass (cA). The distinction between arctic and polar air masses is not always clear because an arctic air mass that travels over a warm surface may be warmer near the surface than a polar air mass, although it is still colder aloft. Source regions for air masses and typical trajectories affecting North America are shown in figure 6.1. Polar air masses that originate over the flat, ice- and snow-covered regions east of the Rocky Mountains in northern and central Canada and Alaska, and arctic air masses that originate over the ice-covered Arctic Ocean influence winter weather. The midlatitudes are not a good air mass source region. The exposure to traveling weather systems is too great, the range of temperature and humidity too wide, and, in the United States, the topography is too varied. Instead, the midlatitudes are a region where clashing air masses meet. Cold air masses are usually driven southward from the subpolar regions, whereas warm air is forced northward from tropical regions.
Weather Maps, Forecasts, and Data
Authors: Whiteman C. David
Published: November 2020

Weather maps prepared by the National Weather Service summarize and synthesize weather data to provide a comprehensive picture of weather conditions at a given time. They are the basis of weather maps used on television to show precipitation, high and low pressure centers, and fronts. Weather maps are produced using both surface data and data from specified pressure levels. Data are plotted and contoured by computer, and analysts use satellite photos, satellite video loops, weather forecast models, and extrapolations from previous frontal and pressure system analyses to locate fronts and pressure centers. An example of a surface weather chart is presented in figure 9.1. A 500-mb chart for the same date and time was presented in figure 5.1. Symbols are used on weather maps to indicate synoptic-scale features. High and low pressure weather systems (highs and lows) are indicated by the letters H and L, with isobars labeled in millibars. Lines indicating frontal positions (section 6.2) represent the position on the ground of boundaries between air masses. Additional meteorological variables, such as temperature, are often analyzed on the same map using dashed or colored lines. Pressure, temperature, and other data from the reporting stations are plotted in coded form at the station locations. A station model specifies the positions in which different types of data are plotted relative to the station location. Figure 9.1 used an abbreviated station model. A complete station model is shown in figure 9.2. Figures 9.3 — 9.7 show additional symbols used in station models to indicate total sky cover, winds, pressure tendency, cloud types, and present weather types, respectively. A surface weather chart, with the symbols indicating fronts and high and low pressure centers and the information included in the station model, provides a snapshot of synoptic-scale conditions at ground level. By overlaying charts for several pressure levels (section 5.1.3), changes with altitude can be identified and the three-dimensional structure of the atmosphere at a given point in time can be visualized. By comparing consecutive charts, the rate of movement of fronts and the rates of development of high and low pressure centers can be determined.
Molecular Energetics
Authors: Martinho Simões José A. , da Piedade Manuel Minas
Published: November 2020

This book offers a broad discussion of the concepts required to understand the thermodynamic stability of molecules and bonds and a description of the most important condensed-phase techniques that have been used to obtain that information. Above all, this book attempts to provide useful guidelines on how to choose the "best" data and how to use it to understand chemistry. Although the book assumes some basic knowledge on physical-chemistry, it has been written in a "textbook" style and most topics are addressed in a way that is accessible to advanced undergraduate students. Many examples are given throughout the text, involving a variety of molecules. This text will provide a good starting point for those who wish to initiate in the field or simply to understand how to assess, to estimate, and to use thermochemical data. It will therefore appeal to a broad range of practicing chemists and particularly to those interested in energetics-structure-reactivity relationships.
Isoperibol Reaction-Solution Calorimetry
Authors: Martinho Simões José A. , da Piedade Manuel Minas
Published: November 2020

The determination of enthalpies of reaction in solution, using isoperibol reaction-solution calorimetry, is often the easiest and most accurate method of determining enthalpies of formation of compounds that cannot be studied by combustion calorimetry. The technique was pioneered by Thomsen who, between 1882 and 1886, performed thermochemical measurements involving the solution of various substances in liquids (e.g., diluted acids). Many types of isoperibol reaction-solution calorimeters have been developed since then. The designs vary according to the nature of the reactions of interest. One of the most widely used consists of a vessel, such as the one shown in figure 8.1, immersed in a thermostatic water bath. The sample is sealed inside a thin-walled glass ampule A, fixed to an ampule breaking system B in the calorimeter head C. The calorimeter head also supports the temperature sensor D, the stirrer E, and an electrical resistance F, used for calibration of the apparatus. The Dewar vessel G, containing the solution to be reacted with the sample, is adjusted to C. The assembled calorimetric vessel is transferred to the thermostatic bath, and from then on, the experimental procedure closely follows that already described in section 7.1 for isoperibol static-bomb combustion calorimetry. The reaction is initiated at the end of the fore period by pushing down the plunger H and breaking the ampule against a pin situated at the bottom of the ampule breaking system B. As a result of the calorimetric experiment, a temperature-time curve such as the one in figure 7.2 is obtained. Note that figure 7.2 is typical of an exothermic process. In the case of an endothermic process, a decrease of the temperature of the calorimetric system is observed during the reaction period. The experiments are usually carried out at atmospheric pressure and the initial goal is the determination of the enthalpy change associated with the calorimetric process under isothermal conditions, ΔHICP, usually at the reference temperature of 298.15 K. This involves the determination of the corresponding adiabatic temperature change, ΔTad, from the temperature-time curve just mentioned, by using one of the methods discussed in section 7.1; the determination of the energy equivalent of the calorimeter in a separate experiment.
Photoacoustic Calorimetry
Authors: Martinho Simões José A. , da Piedade Manuel Minas
Published: November 2020

“Any chemical species, which under ambient conditions (i.e., a temperature around 25°C, and a pressure close to 1 atm) will, for a combination of kinetic and thermodynamic reasons, decay on a timescale ranging from microseconds, or even nanoseconds, to a few minutes” can be classified as a short-lived compound. According to this definition, suggested by Almond, it is clear that the experimental methods described in previous chapters can only be used to study the thermochemistry of long-lived substances. The technique that we address here, known as photoacoustic calorimetry (PAC) or laser-induced optoacoustic calorimetry (LIOAC), is suitable for investigating the energetics of molecules with lifetimes smaller than about 1μs. It relies on the photoacoustic effect, which was discovered by Bell more than 100 years ago. With the assistance of Tainter, he was able to “devise a method of producing sounds by the action of an intermittent beam of light” and conclude that the method “can be adapted to solids, liquids, and gases”. Figure 13.1 shows a photophone, “an apparatus for the production of sound by light,” used by Bell to investigate the photoacoustic effect. The controversy around the origin of this phenomenon was settled by Bell himself and by Lord Rayleigh; their views were rather close to our present understanding: When a light pulse is absorbed by a substance, a given amount of heat is deposited, producing a local thermal expansion; this thermal expansion propagates through the medium, generating sound waves. The basic theory of the photoacoustic effect was described by Tam and Patel and some of its applications were presented in a review by Braslavsky and Heibel. The first use of PAC to determine enthalpies of chemical reactions was reported by the groups of Peters and Braslavsky. The same groups have also played an important role in developing the methodologies to extract those thermodynamic data from the experimentally measured quantities. In the ensuing discussion, we closely follow a publication where the use of the photoacoustic calorimety technique as a thermochemical tool was examined. Consider the elementary design of a photoacoustic calorimeter, shown in figure 13.3. The cell contains the sample, which is, for instance, a dilute solution of a photoreactive species.
Lakes as Archives of Earth History
Authors: Cohen Andrew S.
Published: November 2020

For several months each year I work in central Africa collecting sediment cores and fossils from a large rift lake, Lake Tanganyika. Periodically my nonscientist friends ask me why I do this. They usually mean both ‘‘why would someone collect mud from the bottom of a lake’’? and perhaps as an even greater challenge to my sanity, ‘‘why would one travel halfway around the world to do this’’? The answer to these questions (and the theme of this book) is deceptively simple. Paleolimnologists study lake deposits because they provide science with archives of earth and ecosystem history that are both highly resolved in time and of long duration. In the particular case of Lake Tanganyika, this combination, in principle, permits us to study events as closely spaced in time as annual events over the lake’s 10-million-year history. Few other records of earth history beyond those found in lake muds provide this combination of duration and resolution. The range of questions that can be examined with these archives is enormous. Paleolimnologists provide constraints on the timing of past climate change, determine rates of evolutionary change in species, and investigate the timing of pollutant introduction into watersheds. One might reasonably ask what good could come from trying to synthesize these disparate questions. I believe that the unifying factor behind all of these fields of study lies in the character of lake sediment archives. Lakes are attractive targets for study by such different fields of investigation because of the special nature of their depositional environment. Considering the contents of lake archives and their characteristics is the best place to start thinking about what makes paleolimnology a distinctive discipline. . . . What Are Lake Archives? . . . An archive is a singularly appropriate term to describe the foundations of paleolimnological research. The term archive can refer both to a historical record, its content, and to the place where such records are housed, its container.
Thermometry
Authors: Brock Fred V. , Richardson Scott J.
Published: November 2020

Air temperature is one of the most fundamental of all meteorological measurements and directly effects our everyday lives. It has been measured for centuries, using countless different techniques. One might assume that accurate air temperature measurements are readily made. Indeed, it is possible to make very accurate air temperature measurements but it can be a remarkably hard task, especially when limitations such as power consumption, reliability, and cost are involved. Errors in the measurement of air temperature in excess of 2 to 3°C are not uncommon in many networks. Errors of this magnitude are generally acceptable for the general public who is most interested in what clothes to wear for the day. However, numerical models at all scales of motion (mesoscale, synoptic scale, or climate models) are greatly affected by errors even as large as 1°C. Errors of just 1°C in a mesoscale model have been shown to be the deciding factor between no storms initiated and intense storms (Crook, 1996). In addition, errors as small as 0.2°C can change the prediction of a global climate model, depending on its dependency on initial conditions (DeFelice, 1998). Measurement of air temperature near the surface of the earth is facilitated by the vast array of temperature sensors and supporting electronic modules that are readily available. Accuracy is limited not by technology but by our ability to use it and by our ability to avoid exposure error, that is, to provide adequate coupling with the atmosphere. The preferred temperature scales are Celsius and Kelvin. These scales can be used almost interchangeably (except when absolute temperature is required) because a temperature difference of 1 K is equal to a temperature difference of 1°C. The Fahrenheit scale is still in general use by the U.S. public. Some common temperature reference points are shown in table 4-1. The triple point of water is the temperature and pressure where all three phases, gas, liquid, and solid, can coexist. Temperature sensors can be categorized according to the physical principle that they use: thermal expansion, thermoelectric, electrical resistance, electrical capacitance and some other effects.
Dynamic Performance Characteristics, Part 1
Authors: Brock Fred V. , Richardson Scott J.
Published: November 2020

When the input to a sensor is changing rapidly, we observe performance characteristics that are due to the change in input and are not related to static performance characteristics. In this chapter we will assume that a static calibration has been applied so that we can consider dynamic performance independently of static characteristics. The terms “linear” and “nonlinear” have been used in chap. 3 in the static sense. Now they are being used in the dynamic sense where “linear” connotes the applicability of the superposition property. A given sensor could be nonlinear in the static sense (e.g., a PRT is nonlinear in that is static sensitivity is not constant over the range) but could be linear in the dynamic sense (modeled by a linear differential equation). We use differential equations to model this dynamic performance while realizing the models can never be exact. If the dynamic behavior of physical systems can be described by linear differential equations with constant coefficients, the analysis is relatively easy because the solutions are well known. Such equations are always approximations to the actual performance of physical systems that are often nonlinear, vary with time, and have distributed parameters. The justification for the use of simple, readily solved models must be the quality of the fit of the solution to the actual system output and the usefulness of the resulting analysis. Dynamic performance characteristics define the way instruments react to measurand fluctuations. When a temperature sensor is mounted on an airplane these characteristics will indicate what the sensor “sees.” If the airplane flies through a cloud with a slow sensor (where time constant is large) it may not register change of temperature or humidity. That would not be tolerable if we wanted to measure the cloud. Similarly, if the airplane flies through turbulence we would like to measure changes in air speed. Variations in temperature and humidity would be vital in the flight of a radiosonde, so again the time constant of the sensors would be considered. Fluxes of heat, water vapor, and momentum near the ground require fast sensors (with small time constants).
Effects of Grazing on Abundance and Distribution of Shortgrass Steppe Consumers
Authors: Milchunas Daniel G. , Lauenroth William K.
Published: November 2020

Although livestock are the most obvious consumers on the shortgrass steppe, they are certainly not the only consumers. However, livestock may influence the other consumers in a number of different ways. They may directly compete for food resources with other aboveground herbivores. There is behavioral interference between livestock and some species of wildlife (Roberts and Becker, 1982), but not others (Austin and Urness, 1986). The removal of biomass by livestock alters canopy structure (physiognomy) and influences microclimate. Bird, small-mammal, and insect species can be variously sensitive to these structural alterations (Brown, 1973; Cody, 1985; MacArthur, 1965; Morris, 1973; Rosenzweig et al., 1975; Wiens, 1969). There are both short- and long-term effects of grazing on plant community species composition, primary production, and plant tissue quality. Belowground consumers can also be affected by the effects of grazing on soil water infiltration, nutrient cycling, carbon allocation patterns of plants, litter accumulation, and soil temperature. The overall effects of livestock on a particular component of the native fauna can be negative or can be positive through facilitative relationships (Gordon, 1988). In this chapter we assess the effects of cattle grazing on other above- and belowground consumers, on the diversity and relative sensitivity of these groups of organisms, and on their trophic structure. We first present some brief background information on plant communities of the shortgrass steppe and on the long-term grazing treatments in which many of the studies reported herein were conducted. Details on the plant communities are presented by Lauenroth in chapter 5 (this volume), grazing effects on plant communities by Milchunas et al. in chapter 16 (this volume); and grazing effects on nutrient distributions and cycling by Burke et al. in chapter 13 (this volume). The physiognomy of the shortgrass steppe is indicated in its name. The dominant grasses (Bouteloua gracilis and Buchloë dactyloides), forb (Sphaeralcea coccinea), and carex (Carex eleocharis) have the majority of their leaf biomass within 10 cm of the ground surface. A number of less abundant midheight grasses and dwarf shrubs are sparsely interspersed among the short vegetation, but usually much of their biomass is within 25 cm of the g round. Basal cover of vegetation typically totals 25% to 35%, and is greater in long-term grazed than in ungrazed grassland. Bare ground (more frequent on grazed sites) and litter-covered ground (more frequent on ungrazed sites) comprise the remainder of the soil surface (Milchunas et al., 1989).