ALBERT

Description / Table of Contents: "Examines issues faced by disabled library workers, through the lens of critical disability theory"

Description / Table of Contents: This book provides a comprehensive, up-to-date assessment of the key terrestrial components of the Arctic system, i.e., its hydrology, permafrost, and ecology, drawing on the latest research results from across the circumpolar regions. The Arctic is an integrated system, the elements of which are closely linked by the atmosphere, ocean, and land. Using an integrated system approach, the book’s 30 chapters, written by a diverse team of leading scholars, carefully examine Arctic climate variability/change, large river hydrology, lakes and wetlands, snow cover and ice processes, permafrost characteristics, vegetation/landscape changes, and the future trajectory of Arctic system evolution. The discussions cover the fundamental features of and processes in the Arctic system, with a special focus on critical knowledge gaps, i.e., the interactions and feedbacks between water, permafrost, and ecosystem, such as snow pack and permafrost changes and their impacts on basin hydrology and ecology, river flow, geochemistry, and energy fluxes to the Arctic Ocean, and the structure and function of the Arctic ecosystem in response to past/future changes in climate, hydrology, and permafrost conditions. Given its scope, the book offers a valuable resource for researchers, graduate students, environmentalists, managers, and administrators who are concerned with the northern environment and resources.

Description / Table of Contents: This book provides in-depth information about the sea ice in the Arctic at scales from paleoenvironmental variability to more contemporary changes during the past and present centuries. The book is based on several decades of research related to sea ice in the Arctic and its variability, sea ice process studies as well as implications of the sea ice variability on human activities. The chapters provide an extensive overview of the research results related to sea ice in the Arctic at paleo-scales to more resent scales of variations as well as projections for changes during the 21st century. The authors have pioneered the satellite remote sensing monitoring of sea ice and used other monitoring data in order to study, monitor and model sea ice and its processes

Description / Table of Contents: Seaweeds (macroalgae) represent the most striking living components in the Antarctic’s near-shore ecosystems, especially across the West Antarctic Peninsula and adjacent islands. Due to their abundance, their central roles as primary producers and foundation organisms, and as sources of diverse metabolically active products, seaweed assemblages are fundamental to biogeochemical cycles in Antarctic coastal systems. In recent years, the imminence of climate change and the direct impacts of human beings, which are affecting vast regions of the Antarctic, have highlighted the importance of seaweed processes in connection with biodiversity, adaptation and interactions in the benthic network. Various research groups have been actively involved in the investigation of these topics. Many of these research efforts have a long tradition, while some “newcomers” have also recently contributed important new approaches to the study of these organisms, benefiting polar science as a whole. This book provides an overview of recent advances and insights gleaned over the past several years. Focusing on a timely topic and extremely valuable resource, it assesses the challenges and outlines future directions in the study of Antarctic seaweeds.

Description / Table of Contents: This book provides a comprehensive summary of research to date in the field of stable iron isotope geochemistry. Since research began in this field 20 years ago, the field has grown to become one of the major research fields in "non-traditional" stable isotope geochemistry. This book reviews all aspects of the field, from low-temperature to high-temperature processes, biological processes, and cosmochemical processes. It provides a detailed history and state-of-the art summary about analytical methods to determine Fe-isotope ratios and discusses analytical and sample prospects.

Description / Table of Contents: 'Seawater' has been substantially updated in this second edition to take account of recent developments in marine science. Sections dealing with difficult physical and chemical concepts have been developed on the basis of feedback from the first edition, making this an ideal learning tool for oceanography students.Chapter 1 summarizes the special properties of water and the role of the oceans in the hydraulic cycle. The distribution of temperature and salinity in the oceans and how they influence water density and movements is then discussed. Light and sound in seawater are considered next, al

Description / Table of Contents: Senior managers and Heads of Geological Survey Organizations (GSOs) from around the world have contributed a collection of papers to provide a benchmark on how GSOs are responding to national and international needs in a rapidly changing world. GSOs continue to provide key scientific information about Earth systems, natural hazards and climate change. As countries adopt sustainable development principles and the public increasingly turns to social media to find information about resource and environmental issues, the generation and communication of Earth science knowledge become increasingly important. This volume provides a snapshot of how GSOs are adapting their activities to this changing world. The different national perspectives presented converge around several common themes related to resources, environment and big data. Climate change and the UN's Sustainable Development Goals provide an increased incentive for GSOs of the world to work in harmony, to generate knowledge of Earth systems and to provide solutions for sustainable management of the planet.

Description / Table of Contents: Eine Medien- und Wissensgeschichte von Biologie und Ozeanographie im Kielwasser der Walfänger. Immer wieder entzieht sich der Wal wissenschaftlicher Klassifikation und Darstellbarkeit. Wale sind buchstäblich nicht zu fassen - als sich die neuen biologischen Wissenschaften im 19. Jahrhundert daran machten, »das Leben« zu erklären, blieb das der Wale ein Problem. Doch Walfänger durchkreuzten auf ihren Spuren im 19. Jahrhundert die Meere der Welt. Kartographen erschlossen auf den Spuren dieser Walfänger die Nordwestpassage und den pazifischen Ozean, während Naturhistoriker und Zoologen sie in die Lebensräume der Wale begleiten. Felix Lüttge erzählt die Geschichte der Walfänger, die den Walen, und der Wissenschaftler, die wiederum den Walfängern folgten.Es ist eine Medien- und Wissensgeschichte des Wals wie auch der Meere, die auf seinen Spuren durchfahren und vermessen wurden. Felix Lüttge beschreibt die komplexen Austauschprozesse, mit denen Walfänger und Wissenschaftler ökonomisches, ozeanographisches, zoologisches und geographisches Wissen hervorbrachten.

Description / Table of Contents: Until recently, the prevailing view of marine life at high latitudes has been that organisms enter a general resting state during the dark Polar Night and that the system only awakens with the return of the sun. Recent research, however, with coordinated, multidisciplinary field campaigns based on the high Arctic Archipelago of Svalbard, have provided a radical new perspective. Instead of a system in dormancy, a new perspective of a system in full operation and with high levels of activity across all major phyla is emerging. Examples of such activities and processes include: Active marine organisms at sea surface, water column and the sea-floor. At surface we find active foraging in seabirds and fish, in the water column we find a high biodiversity and activity of zooplankton and larvae such as active light induced synchronized diurnal vertical migration, and at seafloor there is a high biodiversity in benthic animals and macroalgae. The Polar Night is a period for reproduction in many benthic and pelagic taxa, mass occurrence of ghost shrimps (Caprellides), high abundance of Ctenophores, physiological evidence of micro- and macroalgal cells that are ready to utilize the first rays of light when they appear, deep water fishes found at water surface in the Polar night, and continuous growth of bivalves throughout the winter. These findings not only begin to shape a new paradigm for marine winter ecology in the high Arctic, but also provide conclusive evidence for a top-down controlled system in which primary production levels are close to zero. In an era of environmental change that is accelerated at high latitudes, we believe that this new insight is likely to strongly impact how the scientific community views the high latitude marine ecosystem. Despite the overwhelming darkness, the main environmental variable affecting marine organisms in the Polar Night is in fact light. The light regime during the Polar Night is unique with respect to light intensity, spectral composition of light and photoperiod. .

Description / Table of Contents: This book provides a comprehensive overview of recent novel coronavirus (SARS-CoV-2) infection, their biology and associated challenges for their treatment and prevention of novel Coronavirus Disease 2019 (COVID-19). Discussing various aspects of COVID-19 infection, including global epidemiology, genome organization, immunopathogenesis, transmission cycle, diagnosis, treatment, prevention, and control strategies, it highlights host-pathogen interactions, host immune response, and pathogen immune invasion strategies toward developing an immune intervention or preventive vaccine for COVID-19. An understanding of the topics covered in the book is imperative in the context of designing strategies to protect the human race from further losses and harm due to SARS-CoV-2 infection causing COVID-19.

Description / Table of Contents: Dedication -- Preface -- Chapter 1: Introduction -- Chapter 2: Introduction to Spherical Elementary Current Systems -- Chapter 3: Spherical Elementary Current Systems applied to Swarm data -- Chapter 4: Local least squares analysis of auroral current structures in multi-spacecraft data -- Chapter 5: Multi-spacecraft current estimates at Swarm -- Chapter 6: Applying the dual-spacecraft approach to the Swarm constellation for deriving radial current density. Chapter 7: Science data products for AMPERE -- Chapter 8: ESA Field Aligned Currents - Methodology Inter-Comparison Exercise -- Chapter 9: Spherical Cap Harmonic Analysis techniques for mapping high-latitude ionospheric plasma flow - Application to the Swarm satellite mission -- Chapter 10: Recent Progress on Inverse and Data Assimilation Procedure for High-Latitude Ionospheric Electrodynamics -- Chapter 11: Estimating currents and electric fields at low-latitudes from satellite magnetic measurements -- Chapter 12. Models of the main geomagnetic field based on multi-satellite magnetic data and gradients – Techniques and latest results from the Swarm mission -- Index

Description / Table of Contents: This open access book provides a comprehensive toolbox of analysis techniques for ionospheric multi-satellite missions. The immediate need for this volume was motivated by the ongoing ESA Swarm satellite mission, but the tools that are described are general and can be used for any future ionospheric multi-satellite mission with comparable instrumentation. In addition to researching the immediate plasma environment and its coupling to other regions, such a mission aims to study the Earth’s main magnetic field and its anomalies caused by core, mantle, or crustal sources. The parameters for carrying out this kind of work are examined in these chapters. Besides currents, electric fields, and plasma convection, these parameters include ionospheric conductance, Joule heating, neutral gas densities, and neutral winds

Description / Table of Contents: This book presents current knowledge on chemistry and physics of Arctic atmosphere. Special attention is given to studies of the Arctic haze phenomenon, Arctic tropospheric clouds, Arctic fog, polar stratospheric and mesospheric clouds, atmospheric dynamics, thermodynamics and radiative transfer as related to the polar environment. The atmosphere-cryosphere feedbacks and atmospheric remote sensing techniques are presented in detail. The problems of climate change in the Arctic are also addressed.

Description / Table of Contents: The collection of papers in this volume records the development of hydrogeology in Britain over the last 200 years. Following the application, by William smith, of stratigraphic principles to the sinking of wells, Victorian engineers and scientists established groundwater as a major contributor to public water supplies. In the twentieth century, the development of groundwater continued rapidly, controlled by an ever-changing regulatory regime. The 25 papers in this volume review the progrss which has been made, and the lives and work of some of those who were intimately involved.

Description / Table of Contents: Faults commonly trap fluids such as hydrocarbons and water and therefore are of economic significance. During hydrocarbon field development, smaller faults can provide baffles and/or conduits to flow. There are relatively simple, well established workflows to carry out a fault seal analysis for siliciclastic rocks based primarily on clay content. There are, however, outstanding challenges related to other rock types, to calibrating fault seal models (with static and dynamic data) and to handling uncertainty. The variety of studies presented here demonstrate the types of data required and workflows followed in today's environment in order to understand the uncertainties, risks and upsides associated with fault-related fluid flow. These studies span all parts of the hydrocarbon value chain from exploration to production but are also of relevance for other industries such as radioactive waste and CO2 containment.

Description / Table of Contents: The Eastern Mediterranean is an excellent ‘field laboratory’ for the study of fundamental processes of continental rifting, passive margin development, ophiolite generation and emplacement and the tectonic, magmatic and sedimentary effects of continental collision. Since its publication in 1984, The Geological Evolution of the Eastern Mediterranean has proved to be an invaluable aid to research in this important region. Many of the papers are classics that report basic data and tectonic interpretations that still remain valid today. The individual papers summarize a large amount of international research that was carried out in the Eastern Mediterranean region during the previous decade. This volume was the first integrated overview of one of the world’s most complex orogenic areas. The editors have added an outline of the main research developments since 1984 and key references to the more recent literature; several figures have been redrawn and the volume is now fully indexed.

Description / Table of Contents: This book provides a cross-disciplinary overview of permafrost and the carbon cycle by providing an introduction into the geographical distribution of permafrost, with a focus on the distribution of permafrost and its soil carbon reservoirs. The chapters explain the basic physical properties and processes of permafrost soils: ice, mineral and organic components, and how these interact with climate, vegetation and geomorphological processes. In particular, the book covers the role of the large quantities of ice in many permafrost soils which are crucial to understanding carbon cycle processes. An explanation is given on how permafrost becomes loaded with ice and carbon. Gas hydrates are also introduced. Structures and processes formed by the intense freeze-thaw action in the active layer are considered (e.g. ice wedging, cryoturbation), and the processes that occur as the permafrost thaws, (pond and lake formation, erosion). The book introduces soil carbon accumulation and decomposition mechanisms and how these are modified in a permafrost environment. A separate chapter deals with deep permafrost carbon, gas reservoirs and recently discovered methane emission phenomena from regions such as Northwest Siberia and the Siberian yedoma permafrost.

Description / Table of Contents: High-resolution images of phytoplankton cells such as diatoms or desmids, which are useful for monitoring water quality, can now be provided by digital microscopes, facilitating the automated analysis and identification of specimens. Conventional approaches are based on optical microscopy; however, manual image analysis is impractical due to the huge diversity of this group of microalgae and its great morphological plasticity. As such, there is a need for automated recognition techniques for diagnostic tools (e.g. environmental monitoring networks, early warning systems) to improve the management of water resources and decision-making processes. Describing the entire workflow of a bioindicator system, from capture, analysis and identification to the determination of quality indices, this book provides insights into the current state-of-the-art in automatic identification systems in microscopy. .

Description / Table of Contents: This book addresses a broad range of issues concerning microplastic pollution, including microplastic pollution in various environments (freshwater, marine, air and soil); the sources, fate and effects of microplastics; detection systems for microplastic pollution monitoring; green approaches for the synthesis of environmentally friendly polymers; recovery and recycling of marine plastics; wastewater treatment plants as a microplastic entrance route; nanoplastics as emerging pollutants; degradation of plastics in the marine environment; impacts of microplastics on marine life; microplastics: from marine pollution to the human food chain; mitigation of microplastic impacts and innovative solutions; sampling, extraction, purification and identification approaches for microplastics; adsorption and transport of pollutants on and in microplastics; and lastly, the socio-economic and environmental impacts: assessment and risk analysis. In addition to presenting cutting-edge information and highlighting current trends and issues, the book proposes concrete solutions to help face this significant environmental threat. It is chiefly intended for researchers and industry decision-makers; international, national and local institutions; and NGOs, providing them with comprehensive information on the origin of the problem; its effects on marine environments, with a particular focus on the Mediterranean Sea and coasts; and recent and ongoing research activities and projects aimed at finding technical solutions to mitigate the phenomenon. .

Description / Table of Contents: Wissenschaftliche Wahrnehmung von Forschungsinstituten und Wissenschaftlern in aller Welt wird oft anhand ihrer Publikationen gemessen. Dazu werden bibliometrische Indikatoren, etwa die Anzahl der Veröffentlichungen und ihre Zitate, zu Rate gezogen. Mit bibliometrischen Analysen kann der Erfolg von wissenschaftlichen Arbeiten messbar dokumentiert werden. Dies ist ein wichtiger Aspekt gegenüber Entscheidungsträgern und Geldgebern, denn Forschungs- gelder sind knapp und immer lauter wird die Frage, nach welchen Kriterien sie gerecht vergeben werden können. Hier sind bibliometrische Methoden zukünftig stärker gefragt. Bücher zu bibliometrischen Analysen gibt es aber nicht viele. Gut lesbare noch weniger und eigentlich gar keine für Menschen, die nicht Statistiker oder Bibliometriker sind. Alle, die sich mit dieser Art der wissenschaftlichen Bewertung auseinandersetzen möchten oder müssen, vermissen eine knappe und gut lesbare Übersicht über Methoden, Anwendungen aber auch Grenzen bibliometrischer Analysen. Diesen Missstand behebt das vorliegende Buch.

Description / Table of Contents: This book presents current knowledge on chemistry and physics of Arctic atmosphere. Special attention is given to studies of the Arctic haze phenomenon, Arctic tropospheric clouds, Arctic fog, polar stratospheric and mesospheric clouds, atmospheric dynamics, thermodynamics and radiative transfer as related to the polar environment. The atmosphere-cryosphere feedbacks and atmospheric remote sensing techniques are presented in detail. The problems of climate change in the Arctic are also addressed.

Description / Table of Contents: In an increasingly globalized world, an understanding of the role of international trade is central to the study of agricultural economics and agribusiness. This text interweaves these two elements, explaining the theories and practices relevant to agricultural trade. Using real-life examples to explain theories and models, the text prepares readers to critically examine agricultural trade issues. In addition to its comprehensive coverage, each chapter features chapter overviews and summaries, key concepts, questions for review, and suggested readings.Explains the theories and practices releva

Description / Table of Contents: PREFACE The four-year period of activity of the Groupement de Recherche 942 (GDR) of the Centre National de la Recherche Scientifique (CNRS) came to an end in December 1993. This GDR was a scientific association grouping research teams from the academic sphere -- i.e. the Unités de Recherches Associées 723 & 724 of the CNRS as well as the Universities of Orléans and Paris-Sud -- and from the industrial world: Elf-Aquitaine Production, TOTAL and the Institut Français du Pétrole (IFP). The aim of the GDR was to understand the processes and the causes of organic carbon fossilization in sediments, especially when they can be modified by environmental conditions such as climate, eustatism, productivity etc., factors which can alko interact. This goal implies the simultaneous study of ancient geological formations (hydrocarbon source rocks from the famous Kimmeridge Clay Formation) and recent Quaternary sediments (the Lac du Bouchet or lake Bouchet maar, Massif Central, France). In the latter case, we benefit from a fine-scale stratigraphical framework as well as a reliable reconstruction of the local and regional environment. This volume is a collection of papers representing oral presentations given on December 7, 1993, at the Société Géologique de France in Paris, during the final meeting of the GDR. These articles thus report the latest developments of the studies carried out under the GDR. However, this is not the first publication of our results, which can be found in the papers referred to in each article. The Kimmeridge Clay Formation was previously studied in 1987, by the Yorkim Group from IFP, Elf-Aquitaine and the British Geological Survey, on the basis of a series of wells drilled across the Cleveland Basin of Yorkshire. In each well, the distribution with depth of the total organic content is cyclic. We have compared some of the organic cycles from two wells (Matron and Ebberston) based on mineralogy, organic and inorganic geochemistry and petrography, at a high resolution scale (centimetric). The main conclusion of this work is that the driving force for organic matter accumulation in the studied cycles was organic phytoplankton productivity. Oxygenation conditions seem to have played a secondary role as a positive feedback action enhancing organic matter storage. Lac du Bouchet is located on the Devès volcanic plateau, 15 km SW of Le Puy en Velay, at an altitude of 1205 m. The depth of the water column is 28 m. The lake has a subcircular shape (1 km in diameter) and a very restricted watershed. This site is exceptionally suitable for research on climate variations and palaeomagnetic field modifications (Euromaars EC Program). The GDR focused on sedimentary organic matter and its relationship to inorganic phases. An important result is that organic matter appears to be a good indicator of palaeoenvironmental reconstructions for over 350 000 years. In addition, the study of early diagenetic reactions in surficial sediments (porewater and solid phase) allows the specification of the processes of organic matter degradation and storage in such an oligothrophic lake.

Description / Table of Contents: PREFACE In recent years, there has been increasing interest from geoscientists in potassic igneous rocks. Academic geoscientists have been interested in their petrogenesis and their potential value in defining the tectonic setting of the terranes into which they were intruded, and exploration geoscientists have become increasingly interested in the association of these rocks with major epithermal gold and porphyry gold-copper deposits. Despite this current interest, there is no comprehensive textbook that deals with these aspects of potassic igneous rocks. This book redresses this situation by elucidating the characteristic features of potassic (high-K) igneous rocks, erecting a hierarchical scheme that allows interpretation of their tectonic setting using whole-rock geochemistry, and investigating their associations with a variety of gold and copper-gold deposits, worldwide. About twothirds of the book is based on a PhD thesis by Dr Daniel MOiler which was produced at the Key Centre for Strategic Mineral Deposits within the Department of Geology and Geophysics at The University of Western Australia under the supervision of Professor David Groves, the late Dr Nick Rock, Professor Eugen Stumpfl, Dr Wayne Taylor, and Dr Brendon Griffin. The remainder of the book was compiled from the literature using the collective experience of the two authors. The book is dedicated to the memory of Dr Rock who initiated the research project but died before its completion...

Description / Table of Contents: PREFACE The sedimentology of Chalk describes processes that caused the rhythmic vertical variation in grain size, structures and authigenic mineral concentrations in Late Cretaceous and Early Tertiary, subtropical, shallow marine, fine-grained, detrital bioclastic carbonates of northwest Europe. In particular, attention is paid to the sedimentology of the Tuffaceous Chalk of Maaslricht (The Netherlands), a coarsegrained variety of Chalk that resembles the Chalk (coccolithic mudstones) as well as modern shallow marine carbonate sands. Numerical models are presented that enable the simulation of the genesis of flint nodule layers, hardgrounds and complex wavy bedded sequences, such as the K/T boundary sequence of Stevns Klint (Denmark). The aim of this book is to show how depositional and early diagenetic features, which are observed in small-scale Chalk outcrops, can be used to reconstruct the large-scale dynamics of the northwest European continent during the Late Cretaceous and Early Tertiary...

Description / Table of Contents: PREFACE Seismic imaging is the process through which seismograms recorded on the Earth's surface are mapped into representations of its interior properties. Imaging methods are nowadays applied to a broad range of seismic observations: from nearsurface environmental studies, to oil and gas exploration, even to long-period earthquake seismology. The characteristic length scales of the features imaged by these techniques range over many orders of magnitude. Yet there is a common body of physical theory and mathematical techniques which underlies all these methods. The focus of this book is the imaging of reflection seismic data from controlled sources. At the frequencies typical of such experiments, the Earth is, to a first approximation, a vertically stratified medium. These stratifications have resulted from the slow, constant deposition of sediments, sands, ash, and so on. Due to compaction, erosion, change of sea level, and many other factors, the geologic, and hence elastic, character of these layers varies with depth and age. One has only to look at an exposed sedimentary cross section to be impressed by the fact that these changes can occur over such short distances that the properties themselves are effectively discontinuous relative to the seismic wavelength. These layers can vary in thickness from less than a meter to many hundreds of meters. As a result, when the Earth's surface is excited with some source of seismic energy and the response recorded on seismometers, we will see a complicated zoo of elastic wave types: reflections from the discontinuities in material properties, multiple reflections within the layers, guided waves, interface waves which propagate along the boundary between two different layers, surface waves which are exponentially attenuated with depth, waves which are refracted by continuous changes in material properties, and others. The character of these seismic waves allows seismologists to make inferences about the nature of the subsurface geology. Because of tectonic and other dynamic forces at work in the Earth, this first-order view of the subsurface geology as a layer cake must often be modified to take into account bent and fractured strata. Extreme deformations can occur in processes such as mountain building. Under the influence of great heat and stress, some rocks exhibit a taffy-like consistency and can be bent into exotic shapes without breaking, while others become severely fractured. In marine environments, less dense salt can be overlain by more dense sediments; as the salt rises under its own buoyancy, it pushes the overburden out of the way, severely deforming originally flat layers. Further, even on the relatively localized scale of exploration seismology, there may be significant lateral variations in material properties. For example, if we look at the sediments carried downstream by a river, it isclear that lighter particles will be carried further, while bigger ones will be deposited first; flows near the center of the channel will be faster than the flow on the verge. This gives rise to significant variation is the density and porosity of a given sedimentary formation as a function of just how the sediments were deposited. Taking all these effects into account, seismic waves propagating in the Earth will be refracted, reflected and diffracted. In order to be able to image the Earth, to see through the complicated distorting lens that its heterogeneous subsurface presents to us, in other words, to be able to solve the inverse scattering problem, we need to be able to undo all of these wave propagation effects. In a nutshell, that is the goal of imaging: to transform a suite of seismograms recorded at the surface of the Earth into a depth section, i.e., a spatial image of some property of the Earth (usually wave speed or impedance). There are two main types of spatial variations of the Earth's properties. There are the smooth changes (smooth meaning possessing spatial wavelengths which are long compared to seismic wavelengths) associated with processes such as compaction. These gradual variations cause ray paths to be gently turned or refracted. On the other hand, there are the sharp changes (short spatial wavelength), mostly in the vertical direction, which we associate with changes in lithology and, to a lesser extent, fracturing. These short wavelength features give rise to the reflections and diffractions we see on seismic sections. If the Earth were only smoothly varying, with no discontinuities, then we would not see any events at all in exploration seismology because the distances between the sources and receivers are not often large enough for rays to turn upward and be recorded. This means that to first order, reflection seismology is sensitive primarily to the short spatial wavelength features in the velocity model. We usually assume that we know the smoothly varying part of the velocity model (somehow) and use an imaging algorithm to find the discontinuities. The earliest forms of imaging involved moving, literally migrating, events around seismic time sections by manual or mechanical means. Later, these manual migration methods were replaced by computer-oriented methods which took into account, to varying degrees, the physics of wave propagation and scattering. It is now apparent that all accurate imaging methods can be viewed essentially as linearized inversions of the wave equation, whether in terms of Fourier integral operators or direct gradient-based optimization of a waveform misfit function. The implicit caveat hanging on the word "essentially" in the last sentence is this: people in the exploration community who practice migration are usually not able to obtain or preserve the true amplitudes of the data. As a result, attempts to interpret subtle changes in reflector strength, as opposed to reflector position, usually run afoul of one or more approximations made in the sequence of processing steps that makes up a migration (trace equalization, gaining, deconvolution, etc.) On the other hand, if we had true amplitude data, that is, if the samples recorded on the seismogram really were proportional to the velocity of the piece of Earth to which the geophone were attached, then we could make quantitative statements about how spatial variations in reflector strength are related to changes in geological properties. The distinction here is the distinction between imaging reflectors, on the one hand, and doing a true inverse problem for the subsurface properties on the other. Until quite recently the exploration community was exclusively concerned with the former, and today the word "migration" almost always refers to the imaging problem. The more sophisticated view of imaging as an inverse problem is gradually making its way into the production software of oil and gas exploration companies, since careful treatment of amplitudes is often crucial in making decisions on subtle lithologic plays (amplitude versus offset or AVO) and in resolving the chaotic wave propagation effects of complex structures. When studying migration methods, the student is faced with a bewildering assortment of algorithms, based upon diverse physical approximations. What sort of velocity model can be used: constant wave speed v? v(x), v(x, z), v(x, y, z)? Gentle dips? Steep dips? Shall we attempt to use turning or refracted rays? Take into account mode converted arrivals? 2D (two dimensions)? 3D? Prestack? Poststack? If poststack, how does one effect one-way wave propagation, given that stacking attenuates multiple reflections? What domain shall we use? Time-space? Time-wave number? Frequency-space? Frequency-wave number? Do we want to image the entire dataset or just some part of it? Are we just trying to refine a crude velocity model or are we attempting to resolve an important feature with high resolution? It is possible to imagine imaging algorithms that would work under the most demanding of these assumptions, but they would be highly inefficient when one of the simpler physical models pertains. And since all of these situations arise at one time or another, it is necessary to look at a variety of migration algorithms in daily use. Given the hundreds of papers that have been published in the past 15 years, to do a reasonably comprehensive job of presenting all the different imaging algorithms would require a book many times the length of this one. This was not my goal in any case. I have tried to emphasize the fundamental physical and mathematical ideas of imaging rather than the details of particular applications. I hope that rather than appearing as a disparate bag of tricks, seismic imaging will be seen as a coherent body of knowledge, much as optics is...

Description / Table of Contents: Pages 1-3: Introduction --- Pages 4-11: Euler equations --- Pages 12-32: Vortex model --- Pages 33-52: An existence theorem for Euler equations --- Pages 53-66: Further considerations on vortex model --- Pages 67-79: A mean field limit --- Pages 80-86: Navier-Stokes equations --- Pages 87-98: Diffusion process and Navier-Stokes equations --- Pages 99-115: Mean field limit and propagation of chaos for Navier-Stokes equations --- Pages 116-129: The problem of boundary conditions, chorin method and concluding remarks

Description / Table of Contents: In den ersten zehn Kapiteln des Buches erfahren Sie alles, was Sie zur Shell-Programmierung wissen müssen. Weitere Kapitel gehen auf die unverzichtbaren Tools grep, sed und awk ein, die in Kombination (oder auch allein) mit der Shellscript-Programmierung zu wertvollen Helfern werden können.

Description / Table of Contents: Wer PHP effizient einsetzen will, sollte die umfangreichen Erweiterungen von PEAR nutzen. Dabei ist PEAR mehr als nur eine einfache Bibliothek. Vergleichbar dem CPAN-Projekt für Perl bietet PEAR zahlreiche Bibliotheken und nützliche Hilfsmittel für PHP-Entwickler, die sich dank des PEAR-Installers auf einfache Weise in bestehende PHP-Installationen integrieren lassen. So lassen sich Entwicklungprozesse erheblich verkürzen. Ein Hindernis stellten bisher lediglich die unzureichnenden Dokumentationen dar. Das Buch von Carsten Möhrke schafft Abhilfe. Es führt in die Nutzung ein, beschreibt ausführlich die Installation und alle wichtigen PEAR- und PECL-Pakete. Auch die Entwicklung eigener Pakete für das Archiv wird beschrieben.

Description / Table of Contents: PREFACE There can be little doubt that estuarine, coastal and shelf circulation modeling will assume increasing importance in the immediate future, as we work through the implications of industrialization for oceanic systems. These issues will place new and serious operational demands on available models, and the rapid increase in computational power we now enjoy makes it possible to respond with detailed simulations in many categories. As a result, we are witnessing an explosive growth in the quantity of model-generated information. Lacking, however, is a concomitant increase in its quality or even in quality control procedures. A single simulation exercise is easily capable of generating gigabytes of output in a matter of hours. Most of the data will necessarily go unexamined by its progenitors. Yet it is highly likely that disks full of simulation output will be used extensively as learning tools for students and researchers, as criteria for engineering design, as a basis for operational decision-making, and in the formulation of public policy. The purpose of this volume is to assemble and present what is known about the intrinsic quality of simulation output: its "correctness" for various purposes. We have operated on the twin premises that (1) every simulation has some intrinsic value and (2) every simulation has serious drawbacks. Between these two extremes lies a vast gulf of uncertainty and potential error, which must be bridged in a professional way if modeling is to achieve its potential in the coastal ocean. This is the basic challenge put to the authors of this volume. Essentially we seek to describe and consolidate approaches, theories, and practices for extracting information from models, and to understand the limits of their proper use. We have focused on quantitative approaches to the problem, from diverse physical and mathematical perspectives. Rather than pursuing abstract, philosophical analyses, we have sought contributions reflecting contemporary practice in government, academic, engineering, and research units where frontier model development is taking place. In a similar spirit, we have avoided imposing linguistic norms among authors, which we view as unproductive at this time. Instead, we have let the authors describe their approaches to this multi-faceted problem in their own terms, subject only to standards of clarity of expression. We are especially pleased to have balanced representation from European and North American authors. This volume was initially conceived at an informal workshop in Brussels, convened by our great friend and colleague, the late Bruno M. Jamart. That event first brought several of the contributing authors together over the skill assessment theme, and seeded a mutual vision of the present work. Bruno's energy, insight, integrity, collegiality, and boundless spirit has been an inspiration to all who knew and worked with him. His untimely death in 1990 represents a great loss which is deeply and widely felt. In his memory we dedicate this volume, a humble memorial to a great spirit and friend.

Description / Table of Contents: Weather and climate are of concern to virtually all countries worldwide. For many countries the economy depends largely on agriculture, which is significantly affected by variations in weather and climate. This volume contains many original findings on weather and climate related to atmospheric and oceanic processes through mathematical modeling, numerical simulations, and field experiments and it will be useful as a reading material in graduate level courses dealing with weather, climate, boundary layer and air quality. The scientific community at large, especially younger scientists, will find this book a useful addition to their personal and institutional libraries.

Description / Table of Contents: Weather and climate are of concern to virtually all countries worldwide. For many countries the economy depends largely on agriculture, which is significantly affected by variations in weather and climate. This volume contains many original findings on weather and climate related to atmospheric and oceanic processes through mathematical modeling, numerical simulations, and field experiments and it will be useful as a reading material in graduate level courses dealing with weather, climate, boundary layer and air quality. The scientific community at large, especially younger scientists, will find this book a useful addition to their personal and institutional libraries.