Ted Janssen, Gervais Chapuis, and Marc de Boissieu
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780198567776
- eISBN:
- 9780191718335
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567776.001.0001
- Subject:
- Physics, Crystallography
Until the 1970s, all materials studied consisted of periodic arrays of unit cells, or were amorphous. In the last decades a new class of solid state matter, called aperiodic crystals, has been found. ...
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Until the 1970s, all materials studied consisted of periodic arrays of unit cells, or were amorphous. In the last decades a new class of solid state matter, called aperiodic crystals, has been found. It is a long range ordered structure, but without lattice periodicity. It is found in a wide range of materials: organic and anorganic compounds, minerals (including a substantial portion of the earths crust), and metallic alloys, under various pressures and temperatures. Because of the lack of periodicity, the usual techniques for the study of structure and physical properties no longer work, and new techniques have to be developed. This book deals with the characterization of the structure, the structure determination, and the study of the physical properties, especially dynamical and electronic properties of aperiodic crystals. The treatment is based on a description in a space with more dimensions than three, the so-called superspace. This allows us to generalise the standard crystallography and to look differently at the dynamics. The three main classes of aperiodic crystals, modulated phases, incommensurate composites, and quasicrystals are treated from a unified point of view, which stresses the similarities of the various systems.Less
Until the 1970s, all materials studied consisted of periodic arrays of unit cells, or were amorphous. In the last decades a new class of solid state matter, called aperiodic crystals, has been found. It is a long range ordered structure, but without lattice periodicity. It is found in a wide range of materials: organic and anorganic compounds, minerals (including a substantial portion of the earths crust), and metallic alloys, under various pressures and temperatures. Because of the lack of periodicity, the usual techniques for the study of structure and physical properties no longer work, and new techniques have to be developed. This book deals with the characterization of the structure, the structure determination, and the study of the physical properties, especially dynamical and electronic properties of aperiodic crystals. The treatment is based on a description in a space with more dimensions than three, the so-called superspace. This allows us to generalise the standard crystallography and to look differently at the dynamics. The three main classes of aperiodic crystals, modulated phases, incommensurate composites, and quasicrystals are treated from a unified point of view, which stresses the similarities of the various systems.
KENNETH P. CANTOR, MARY H. WARD, LEE E. MOORE, and JAY H LUBIN
- Published in print:
- 2006
- Published Online:
- September 2009
- ISBN:
- 9780195149616
- eISBN:
- 9780199865062
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195149616.003.0020
- Subject:
- Public Health and Epidemiology, Public Health, Epidemiology
This chapter discusses water contaminants that may contribute to the human cancer burden. Specifically, it addresses the epidemiologic evidence for several contaminants and includes information on ...
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This chapter discusses water contaminants that may contribute to the human cancer burden. Specifically, it addresses the epidemiologic evidence for several contaminants and includes information on their levels and environmental distribution, as well as individual susceptibility, where data exist. The three categories of drinking water contaminants that may be carcinogenic and that have been studied most systematically are arsenic, disinfection by-products, and nitrate. In addition, radionuclides, microbiological agents, organic compounds from human commerce, and asbestiform particles have been reported to cause cancer, either as they occur in drinking water or in other media, giving rise to suspicion about their carcinogenicity when ingested. Future research priorities and prevention strategies are discussed.Less
This chapter discusses water contaminants that may contribute to the human cancer burden. Specifically, it addresses the epidemiologic evidence for several contaminants and includes information on their levels and environmental distribution, as well as individual susceptibility, where data exist. The three categories of drinking water contaminants that may be carcinogenic and that have been studied most systematically are arsenic, disinfection by-products, and nitrate. In addition, radionuclides, microbiological agents, organic compounds from human commerce, and asbestiform particles have been reported to cause cancer, either as they occur in drinking water or in other media, giving rise to suspicion about their carcinogenicity when ingested. Future research priorities and prevention strategies are discussed.
Angelo Gavezzotti
- Published in print:
- 2006
- Published Online:
- January 2010
- ISBN:
- 9780198570806
- eISBN:
- 9780191718779
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198570806.001.0001
- Subject:
- Physics, Atomic, Laser, and Optical Physics
Intermolecular interactions stem from the electric properties of atoms. Being the cause of molecular aggregation, intermolecular forces are at the roots of chemistry and are the fabric of the world. ...
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Intermolecular interactions stem from the electric properties of atoms. Being the cause of molecular aggregation, intermolecular forces are at the roots of chemistry and are the fabric of the world. They are responsible for the structure and properties of all condensed bodies — the human body, the food we eat, the clothes we wear, the drugs we take, the paper on which this book is printed. In the last forty years or so, theoretical and experimental research in this area has struggled to establish correlations between the structure of the constituent molecules, the structure of the resulting condensed phase, and the observable properties of any material. As in all scientific enterprise, the steps to follow are analysis, classification, and prediction, while the final goal is control; which in this case means the deliberate design of materials with specified properties. This last step requires a synthesis and substantial command of the three preceding steps. This book provides a brief but accurate summary of all the basic ideas, theories, methods, and conspicuous results of structure analysis and molecular modelling of the condensed phases of organic compounds: quantum chemistry, the intermolecular potential, force field and molecular dynamics methods, structural correlation, and thermodynamics. The book also exposes the present status of studies in the analysis, categorisation, prediction, and control, at a molecular level, of intermolecular interactions in liquids, solutions, mesophases, and crystals. The main focus here is on the links between energies, structures, and chemical or physical properties.Less
Intermolecular interactions stem from the electric properties of atoms. Being the cause of molecular aggregation, intermolecular forces are at the roots of chemistry and are the fabric of the world. They are responsible for the structure and properties of all condensed bodies — the human body, the food we eat, the clothes we wear, the drugs we take, the paper on which this book is printed. In the last forty years or so, theoretical and experimental research in this area has struggled to establish correlations between the structure of the constituent molecules, the structure of the resulting condensed phase, and the observable properties of any material. As in all scientific enterprise, the steps to follow are analysis, classification, and prediction, while the final goal is control; which in this case means the deliberate design of materials with specified properties. This last step requires a synthesis and substantial command of the three preceding steps. This book provides a brief but accurate summary of all the basic ideas, theories, methods, and conspicuous results of structure analysis and molecular modelling of the condensed phases of organic compounds: quantum chemistry, the intermolecular potential, force field and molecular dynamics methods, structural correlation, and thermodynamics. The book also exposes the present status of studies in the analysis, categorisation, prediction, and control, at a molecular level, of intermolecular interactions in liquids, solutions, mesophases, and crystals. The main focus here is on the links between energies, structures, and chemical or physical properties.
- Published in print:
- 2010
- Published Online:
- March 2013
- ISBN:
- 9780226723327
- eISBN:
- 9780226723358
- Item type:
- chapter
- Publisher:
- University of Chicago Press
- DOI:
- 10.7208/chicago/9780226723358.003.0001
- Subject:
- History, History of Science, Technology, and Medicine
A paper by Alexander Williamson, read at the annual meeting of the British Association for the Advancement of Science in Edinburgh on August 3, 1850, was groundbreaking in a lot of ways. As the first ...
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A paper by Alexander Williamson, read at the annual meeting of the British Association for the Advancement of Science in Edinburgh on August 3, 1850, was groundbreaking in a lot of ways. As the first of an important series of papers on the formation of ethers, the constitutions of molecules, and reaction dynamics, Williamson's work would radically alter chemical theory. Whether consciously or only instinctively, Williamson understood the importance of using vivid mental images to comprehend and explore molecular reality in scientific fashion. His intellectual formation was influenced in part by the British chemist Thomas Graham, who in 1833 announced his discovery of the law of gaseous diffusion. Williamson discovered that he could form ether by reacting “ethylate of potash” (potassium ethoxide) with ethyl iodide. After his experiments on etherification, he published three papers charting the early stages of an investigative route toward the systematic conceptual dissection of organic compounds, offering the promise of a secure pathway into organic chemistry.Less
A paper by Alexander Williamson, read at the annual meeting of the British Association for the Advancement of Science in Edinburgh on August 3, 1850, was groundbreaking in a lot of ways. As the first of an important series of papers on the formation of ethers, the constitutions of molecules, and reaction dynamics, Williamson's work would radically alter chemical theory. Whether consciously or only instinctively, Williamson understood the importance of using vivid mental images to comprehend and explore molecular reality in scientific fashion. His intellectual formation was influenced in part by the British chemist Thomas Graham, who in 1833 announced his discovery of the law of gaseous diffusion. Williamson discovered that he could form ether by reacting “ethylate of potash” (potassium ethoxide) with ethyl iodide. After his experiments on etherification, he published three papers charting the early stages of an investigative route toward the systematic conceptual dissection of organic compounds, offering the promise of a secure pathway into organic chemistry.
Phoebe N. Okowa
- Published in print:
- 2000
- Published Online:
- March 2012
- ISBN:
- 9780198260974
- eISBN:
- 9780191682186
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198260974.003.0001
- Subject:
- Law, Public International Law
This introductory chapter first sets out the purpose of the book, which is to examine what states claim in the context of disputes involving transboundary air pollution and what they protest to as ...
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This introductory chapter first sets out the purpose of the book, which is to examine what states claim in the context of disputes involving transboundary air pollution and what they protest to as part of the evaluation of the content of the applicable legal regime. The study focuses on three principal sources of pollutants, namely pollution from industrial activities (in particular acid deposition from sulphur and nitrogen emissions, as well as volatile organic compounds), atmospheric nuclear tests, and accidental radioactive contamination from the civil uses of nuclear energy. An overview of the subsequent chapters is also presented.Less
This introductory chapter first sets out the purpose of the book, which is to examine what states claim in the context of disputes involving transboundary air pollution and what they protest to as part of the evaluation of the content of the applicable legal regime. The study focuses on three principal sources of pollutants, namely pollution from industrial activities (in particular acid deposition from sulphur and nitrogen emissions, as well as volatile organic compounds), atmospheric nuclear tests, and accidental radioactive contamination from the civil uses of nuclear energy. An overview of the subsequent chapters is also presented.
Andrea Hricko
- Published in print:
- 2006
- Published Online:
- September 2009
- ISBN:
- 9780195179477
- eISBN:
- 9780199864638
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195179477.003.0012
- Subject:
- Public Health and Epidemiology, Public Health, Epidemiology
This chapter discusses outdoor air pollution in school environments. Outdoor (ambient) air pollution presents a number of issues in the school environment, including exposure of children to diesel ...
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This chapter discusses outdoor air pollution in school environments. Outdoor (ambient) air pollution presents a number of issues in the school environment, including exposure of children to diesel exhaust from older buses, potential risks for students who play or exercise outdoors on smoggy days, and exposure to emissions from nearby traffic and industrial facilities. There are steps that school administrators can take to protect children and address pollution. These include limiting outdoor activities on high ozone days, keeping students indoors for recess and practices, and contacting the air pollution control authority with any concerns about sources of pollution very close to the school, and discuss the record of the polluting facility.Less
This chapter discusses outdoor air pollution in school environments. Outdoor (ambient) air pollution presents a number of issues in the school environment, including exposure of children to diesel exhaust from older buses, potential risks for students who play or exercise outdoors on smoggy days, and exposure to emissions from nearby traffic and industrial facilities. There are steps that school administrators can take to protect children and address pollution. These include limiting outdoor activities on high ozone days, keeping students indoors for recess and practices, and contacting the air pollution control authority with any concerns about sources of pollution very close to the school, and discuss the record of the polluting facility.
Randy A. Becker and J. Vernon Henderson
- Published in print:
- 2000
- Published Online:
- February 2013
- ISBN:
- 9780226094816
- eISBN:
- 9780226094809
- Item type:
- chapter
- Publisher:
- University of Chicago Press
- DOI:
- 10.7208/chicago/9780226094809.003.0006
- Subject:
- Economics and Finance, Development, Growth, and Environmental
An ongoing debate in the United States concerns the costs imposed by environmental regulations on industry. This chapter explores some of the costs associated with air quality regulation, focusing on ...
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An ongoing debate in the United States concerns the costs imposed by environmental regulations on industry. This chapter explores some of the costs associated with air quality regulation, focusing on regulation pertaining to ground-level ozone and its effects on two industries sensitive to such regulation: industrial organic chemicals and miscellaneous plastic products. Both of these industries are major emitters of volatile organic compounds and nitrogen oxides, the chemical precursors to ozone. Using plant-level data from the U.S. Census Bureau's Longitudinal Research Database (LRD), the chapter analyzes the effects this type of regulation has had on the timing and magnitudes of investments by firms in these industries and on their operating costs. As an alternative way to assess costs, it also employs plant-level data from the U.S. Census Bureau's Pollution Abatement Costs and Expenditures survey.Less
An ongoing debate in the United States concerns the costs imposed by environmental regulations on industry. This chapter explores some of the costs associated with air quality regulation, focusing on regulation pertaining to ground-level ozone and its effects on two industries sensitive to such regulation: industrial organic chemicals and miscellaneous plastic products. Both of these industries are major emitters of volatile organic compounds and nitrogen oxides, the chemical precursors to ozone. Using plant-level data from the U.S. Census Bureau's Longitudinal Research Database (LRD), the chapter analyzes the effects this type of regulation has had on the timing and magnitudes of investments by firms in these industries and on their operating costs. As an alternative way to assess costs, it also employs plant-level data from the U.S. Census Bureau's Pollution Abatement Costs and Expenditures survey.
John Raven
- Published in print:
- 2017
- Published Online:
- October 2017
- ISBN:
- 9780199233267
- eISBN:
- 9780191835698
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780199233267.003.0003
- Subject:
- Biology, Aquatic Biology, Ecology
This chapter describes the productivity of phytoplankton, from the initial energy and chemical requirements for photosynthesis to the rate of production of heterotrophic organisms. Phytoplankton are ...
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This chapter describes the productivity of phytoplankton, from the initial energy and chemical requirements for photosynthesis to the rate of production of heterotrophic organisms. Phytoplankton are the planktonic organisms which account for most of the primary production in the ocean. Their characteristic trophic mode is the production of organic compounds using energy from light and chemical elements from inorganic compounds, known as phototrophy, or more strictly photolithotrophy. This process uses water as the electron donor and the reduction of inorganic carbon producing sugars, from which all other cell components are made using inorganic forms of nitrogen, phosphorus, and all the other chemical elements needed to produce cells.Less
This chapter describes the productivity of phytoplankton, from the initial energy and chemical requirements for photosynthesis to the rate of production of heterotrophic organisms. Phytoplankton are the planktonic organisms which account for most of the primary production in the ocean. Their characteristic trophic mode is the production of organic compounds using energy from light and chemical elements from inorganic compounds, known as phototrophy, or more strictly photolithotrophy. This process uses water as the electron donor and the reduction of inorganic carbon producing sugars, from which all other cell components are made using inorganic forms of nitrogen, phosphorus, and all the other chemical elements needed to produce cells.
William G. Wilson
- Published in print:
- 2011
- Published Online:
- February 2013
- ISBN:
- 9780226901459
- eISBN:
- 9780226901473
- Item type:
- chapter
- Publisher:
- University of Chicago Press
- DOI:
- 10.7208/chicago/9780226901473.003.0004
- Subject:
- Biology, Biodiversity / Conservation Biology
This chapter looks at the issues involving air, covering the causes and consequences of contributions from both human and nonhuman organisms. Humans dominate emissions in urban areas. Air quality ...
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This chapter looks at the issues involving air, covering the causes and consequences of contributions from both human and nonhuman organisms. Humans dominate emissions in urban areas. Air quality studies categorize emission sources as either point or nonpoint, roughly corresponding to fixed or moving, respectively. Both types of emissions roughly match maps of population density, at least in the United States. Vegetation and soils also emit chemicals, often as a by-product of evolution in the face of herbivory, competition, and environmental stresses that yielded chemical responses and defenses. These emissions can reduce air quality in urban areas, with some tree species being worse “violators” than others. These emissions feed into, among other pollutants, ozone formation in the hot summer months. For a more complete understanding of urban pollution, the chapter provides an overview of the chemical reactions that link volatile organic compounds (VOCs), reactive nitrogen, sunshine, ozone, and eye-stinging pollutants.Less
This chapter looks at the issues involving air, covering the causes and consequences of contributions from both human and nonhuman organisms. Humans dominate emissions in urban areas. Air quality studies categorize emission sources as either point or nonpoint, roughly corresponding to fixed or moving, respectively. Both types of emissions roughly match maps of population density, at least in the United States. Vegetation and soils also emit chemicals, often as a by-product of evolution in the face of herbivory, competition, and environmental stresses that yielded chemical responses and defenses. These emissions can reduce air quality in urban areas, with some tree species being worse “violators” than others. These emissions feed into, among other pollutants, ozone formation in the hot summer months. For a more complete understanding of urban pollution, the chapter provides an overview of the chemical reactions that link volatile organic compounds (VOCs), reactive nitrogen, sunshine, ozone, and eye-stinging pollutants.
Edward E. Farmer
- Published in print:
- 2014
- Published Online:
- May 2014
- ISBN:
- 9780199671441
- eISBN:
- 9780191779626
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199671441.003.0006
- Subject:
- Biology, Plant Sciences and Forestry
Plant populations are remodelled after carnivore removal, and the animals that eat herbivores can play critical roles in the biology of the leaf. Of particular interest is the fact that plants often ...
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Plant populations are remodelled after carnivore removal, and the animals that eat herbivores can play critical roles in the biology of the leaf. Of particular interest is the fact that plants often facilitate the task of the carnivore in its quest to find food, either by providing information to predators or by housing them. The chapter examines several interactions between bottom-up and top-down defence and uses an example to illustrate a mechanism that helps to maintain chemical polymorphism. Ant–plant interactions, extrafloral nectaries and food bodies are discussed with reference to ant vachellias from the neotropics. Examples of mite domatia are also given. The chapter then moves on to an examination of predator and parasitoid attraction by volatile organic compounds released by plants and uses examples from maize and other plants to illustrate the important role of oral secretions in the elicitation of volatile production. The use of plant volatiles to attract predators may be more far-ranging than is often thought. Finally, to demonstrate that some of the literature on plant volatiles needs to be read with caution, a potentially misleading report on acacias that were damaged by kudus is examined.Less
Plant populations are remodelled after carnivore removal, and the animals that eat herbivores can play critical roles in the biology of the leaf. Of particular interest is the fact that plants often facilitate the task of the carnivore in its quest to find food, either by providing information to predators or by housing them. The chapter examines several interactions between bottom-up and top-down defence and uses an example to illustrate a mechanism that helps to maintain chemical polymorphism. Ant–plant interactions, extrafloral nectaries and food bodies are discussed with reference to ant vachellias from the neotropics. Examples of mite domatia are also given. The chapter then moves on to an examination of predator and parasitoid attraction by volatile organic compounds released by plants and uses examples from maize and other plants to illustrate the important role of oral secretions in the elicitation of volatile production. The use of plant volatiles to attract predators may be more far-ranging than is often thought. Finally, to demonstrate that some of the literature on plant volatiles needs to be read with caution, a potentially misleading report on acacias that were damaged by kudus is examined.
Alan H. Lockwood
- Published in print:
- 2016
- Published Online:
- May 2017
- ISBN:
- 9780262034876
- eISBN:
- 9780262335737
- Item type:
- chapter
- Publisher:
- The MIT Press
- DOI:
- 10.7551/mitpress/9780262034876.003.0007
- Subject:
- Public Health and Epidemiology, Public Health
The effects of climate change on air quality are difficult to model due to the large number of unpredictable variables. Hotter temperatures favor ozone production. Higher atmospheric water content ...
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The effects of climate change on air quality are difficult to model due to the large number of unpredictable variables. Hotter temperatures favor ozone production. Higher atmospheric water content may blunt this effect in some regions. Higher levels of natural volatile organic compounds (VOCs), such as terpenes from plants, are likely to act synergistically with anthropogenic VOCs to favor ozone production. Droughts increase wildfire risks that produce particulate pollution and carbon monoxide, a VOC involved in ozone production. Some models predict increased ozone concentrations in many urban settings. Future revisions of National Ambient Air Quality Standards, a process driven by politics and science, should consider these effects.Less
The effects of climate change on air quality are difficult to model due to the large number of unpredictable variables. Hotter temperatures favor ozone production. Higher atmospheric water content may blunt this effect in some regions. Higher levels of natural volatile organic compounds (VOCs), such as terpenes from plants, are likely to act synergistically with anthropogenic VOCs to favor ozone production. Droughts increase wildfire risks that produce particulate pollution and carbon monoxide, a VOC involved in ozone production. Some models predict increased ozone concentrations in many urban settings. Future revisions of National Ambient Air Quality Standards, a process driven by politics and science, should consider these effects.
