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  • 1
    Unknown
    Washington, D.C. : American Geophysical Union
    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.
    Pages: Online-Ressource (510 Seiten)
    ISBN: 0875902618
    Language: English
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  • 2
    Publication Date: 2020-05-14
    Description: Large increases in the generation of electricity using marine renewable energy (MRE) are planned, and assessment of the environmental impacts of novel MRE devices, such as kites, are urgently needed. A first step in this assessment is to quantify overlap in space and time between MRE devices and prey species of top predators such as small pelagic fish. Here, we quantify how the distribution of fish schools overlaps with the operational depth (20–60 m) and tidal current speeds (≥1.2–2.4 m/s) used by tidal kites, and the physical processes driving overlap. Fish schools undertake diel vertical migrations driven by the depth of light penetration into the water column, controlled by the supply of solar radiation and water column light absorption and scattering, which in turn depends on the cross‐sectional area of suspended particulate matter (SPM). Fish schools were found shallower in the morning and evening and deeper in the middle of the day when solar radiation is greatest, with the deepest depths reached during predictable bimonthly periods of lower current speeds and lower cross‐sectional area of SPM. Potential kite operations overlap with fish schools for a mean of 5% of the time that schools are present (maximum for a day is 36%). This represents a mean of 6% of the potential kite operating time (maximum for a day is 44%). These were both highest during a new moon spring tide and transitions between neap and spring tides. Synthesis and applications. Overlap of fish school depth distribution with tidal kite operation is reasonably predictable, and so the timing of operations could be adapted to avoid potential negative interactions. If all interaction between fish schools was to be avoided, the loss of operational time for tidal kites would be 6%. This information could also be used in planning the operating depths of marine renewable energy (MRE) devices to avoid or minimize overlap with fish schools and their predators by developers, and for environmental licencing and management authorities to gauge potential ecological impacts of different MRE device designs and operating characteristics.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
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  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of medicinal chemistry 15 (1972), S. 65-68 
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1520-510X
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 170 (1952), S. 849-849 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The range in a series of thirty-nine affected birds submitted for diagnosis from farms in different parts of England was 0-126 i.u. vitamin A/gm., with a mean value of 6-9 i.u./gm. The birds in question were of varying ages and breeds and were from farms on which widely different systems of ...
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Fire technology 23 (1987), S. 95-114 
    ISSN: 1572-8099
    Keywords: Error components ; fire models ; graphical methods ; model validation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Abstract General ideas are offered for describing fire model validity prior to starting product design. Validation of independent test results is part of this phase. Differences between comparable results, graphical methods, and distinctions between random and systematic errors are discussed.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Ocean dynamics 33 (1980), S. 19-37 
    ISSN: 1616-7228
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Zusammenfassung Eine Methode für die dynamische Kopplung zweidimensionaler und dreidimensionaler numerischer Meeresmodelle wird vorgestellt. Um die Methode zu testen, werden Strömungen berechnet in einem inneren Teilgebiet eines geschlossenen rechtwinkligen Beckens mit Hilfe eines inneren dreidimensionalen Systems (das dieses Teilgebiet bedeckt), das in Verbindung steht mit einem äußeren zweidimensionalen System (welches das übrige äußere Gebiet des Beckens bedeckt). Das so gebildete Hybrid-System wird Modell 2D/3D genannt. Die vom dreidimensionalen Teil dieses Modells abgeleiteten Strömungen werden mit den mit Hilfe eines dreidimensionalen Modells des gesamten Beckens (im folgenden Modell 3D genannt) entsprechenden berechneten Strömungen verglichen. Die Vergleiche veranschaulichen die Bedeutung des Ansatzes der Bodenreibung im 2D-Bereich des Modells 2D/3D bei der Bestimmung der Größe des Transports im 3D-Bereich dieses Modells. Bei einem Ansatz für die Bodenreibung, der auch den Windschub an der Oberfläche mit einschließt, ergibt sich eine Übereinstimmung bis auf 4 cm/s für die mit dem Modell 2D/3D berechnete Änderung der horizontalen Strömung mit der mit Hilfe des gesamten Modells berechneten.
    Abstract: Résumé On présente une méthode pour raccorder dynamiquement des modèles numériques de la mer à deux et trois dimensions. Pour tester la méthode, on calcule les courants dans une zone intérieure à un bassin fermé rectangulaire, à l'aide d'un modèle tridimensionnel (couvrant cette zone), raccordé à un modèle bidimensionnel (couvrant le reste du bassin). Le système hybride ainsi réalisé est appelé un modèle 2D/3D. Les courants obtenus à l'aide de la partie à 3 dimensions sont comparés avec les courants correspondants calculés à l'aide d'un modèle à 3 dimensions du bassin entier (appelé ci-après le modèle 3D). Cette comparaison met en lumière l'importance de la loi de frottement sur le fond dans la région 2D du modèle 2D/3D pour une bonne détermination de la valeur du flux dans la région 3D de ce modèle. En utilisant une loi de frottement sur le fond qui tient compte de la force d'entraînement du vent en surface, la vitesse du courant horizontal en fonction de la profondeur, calculée sur le modèle 2D/3D, est en accord à 4 cm/s près avec celle calculée sur le modèle 3D complet.
    Notes: Summary A method is presented for dynamically connecting two-dimensional and three-dimensional numerical sea models. To test the method, currents are computed in an interior sub-area of a closed rectangular basin, using an inner three-dimensional system (covering that sub-area) connected to an outer two-dimensional system (covering the remaining outer area of the basin). The hybrid scheme thus formed is called a 2D/3D model. The currents derived from the three-dimensional part of it are compared with the corresponding currents calculated using a three-dimensional model of the whole basin (henceforth known as the 3D model). The comparisons illustrate the importance of the formulation of bottom friction in the 2D region of the 2D/3D model in determining the magnitude of the transport in the 3D region of this model. By using a formulation of bottom friction which includes the surface wind stress, the variation of horizontal current with depth computed with the 2D/3D model agrees to within 4 cm/s with that computed with the full 3D model.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 5 (1985), S. 405-425 
    ISSN: 0271-2091
    Keywords: DuFort-Frankel ; Saul'ev ; Instability ; Sea Model ; Hydrodynamic ; Three-dimensional Time-splitting ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A three dimensional hydrodynamic sea model of an arbitrary sea area is formulated using sigma co-ordinates in the vertical. The solution of the equations using finite difference grids in the horizontal and the vertical is described.Discretization of the vertical viscosity term in the hydrodynamic equations using the DuFort-Frankel and Saul'ev methods is developed. Some numerical instabilities occur with the DuFort-Frankel method which can be overcome by splitting the hydrodynamic equations into equations describing the mean flow and equations describing the deviations from it. The computational advantages of solving these equations with different time steps are discussed.The accuracy and stability of the various methods is demonstrated for wind induced flow in a simple rectangular basin having dimensions representing the North Sea.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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