ALBERT

Beschreibung / Inhaltsverzeichnis: Contents: Processing of Contact. Interaction in the Combined Finite-Discrete Element Method. Contact Detection. Deformability of Discrete Elements. Temporal Discretisation. Sensitivity to Initial Conditions in Combined Finite-Discrete Element Simulation. Transition from Continua to Discontinua. Fluid Coupling in the Combined Finite-Discrete Element Method.Computational Aspects of Combined Finite-Discrete Element Simulations. Implementation of Some of the Core CombinedFinite-Discrete Element Algorithms.

Beschreibung / Inhaltsverzeichnis: Contents: Section I. Introduction and Overview. - Emerging Issues in Fractured-Rock Flow and Transport Investigations: Introduction and Overview / Boris Faybishenko, Paul A. Witherspoon, Gudmundur S. Bodvarsson, and John Gale. - Section II. Models and Modeling of Flow and Transport in Fractured Rock. - Do Heterogeneous Sediment Properties and Turbulent Velocity Fluctuations Have Something in Common? Some History and a New Stochastic Process / Fred J. Molz, Mark M. Meerschaert, Tom J. Kozubowski, and Paul D. Hyden . - Quantification of Non-Fickian Transport in Fractured Formations / Brian Berkowitz and Harvey Scher . - Study of Single and Multiphase Flow in Fractured Porous Media, Using a Percolation Approach / P.M. Adler, V.V. Mourzenko, J.-F. Thovert, and I. Bogdanov . - Percolation-Continuum Model of Evaporative Drying: Homogeneous or Patchy Saturation? / H. F. Wang, T. E. Strand, and J. G. Berryman . - Navier-Stokes Simulations of Fluid Flow Through a Rock Fracture / Azzan H. Al-Yaarubi, Chris C. Pain, Carlos A. Grattoni, and Robert W. Zimmerman . - Theoretical and Numerical Study of Flow at the Interface of Porous Media / Ravid Rosenzweig and Uri Shavit . - Numerical Simulations Show Potential for Strong Nonisothermal Effects During Fluid Leakage from a Geologic Disposal Reservoir for CO 2 / Karsten Pruess . - Uncertainty in Groundwater Flow Simulations Caused by Multiple Modeling Approaches, at the Mizunami Underground Research Laboratory, Japan / Atsushi Sawada, Hiromitsu Saegusa, andYuji Ijiri . - Section III: Case Studies from Laboratory and Field Investigations . - III.1. Multi-Scale Investigations and Underground Facilities . - Predicting Fractured Zones in the Culebra Dolomite / Robert M. Holt, Richard L. Beauheim, and Dennis W. Powers . - Assessment of Retention Processes for Transport in a Fractured System at Äspö (Sweden) Granitic Site: From Short-Time Experiments to Long-Time Predictive Models / Christophe Grenier, André Fourno, Emmanuel Mouche, Frédérick Delay, and Hakim Benabderrahmane. - Simulation of Hydraulic Disturbances Caused by the Underground Rock Characterization Facility in Olkiluoto, Finland / Jari Löfman and Ferenc Mészáros . - III.2. Coupled Processes of Solute Transport and Chemical Processes. - Evaporation from Fractures Exposed at Land Surface: Impact of Gas-Phase Convection on Salt Accumulation / Noam Weisbrod, Modi Pillersdorf, Maria Dragila, Chris Graham, James Cassidy, and Clay A. Cooper . - Dissolved Chemical Discharge from Fractured Clay Aquitards Contaminated by DNAPLs / Ronald W. Falta . - III.3. Geothermal Reservoirs . - Dry-Steam Wellhead Discharges From Liquid-Dominated Geothermal Reservoirs: A Result of Coupled Nonequilibrium Multiphase Fluid and Heat Flow Through Fractured Rock / John W. Pritchett . - III.4. Microbial Transport . - Microbial Processes in Fractured Rock Environments / Nancy E. Kinner, T. Taylor Eighmy, M. Mills, J. Coulburn, and L. Tisa . - The Effect of Microbial Activity on Biodegradation of 2,4,6-Tribromophenol and Flow in Naturally Fractured Chalk Cores / Shai Arnon, Eilon Adar, Zeev Ronen, Alexander Yakirevich, and Ronit Nativ .

Beschreibung / Inhaltsverzeichnis: This volume of Reviews in Mineralogy attempts to synthesize our present understanding of certain aspects of the mineralogy and chemistry of the rock-forming carbonates. Hopefully, it reflects the presently more active areas of research. This review follows, by ten years, a major assessment of (sedimentary) carbonate minerals by Lippmann (1973). There is only minor overlap of subject material, and I hope that this difference reflects fairly how this field has developed. In some respects carbonates are unique, for they are one of the few mineral groups providing an abundant record of biological, physical, and chemical processes throughout much of geologic time. Because of their relative importance in sedimentary rocks, lowtemperature examples are given more emphasis here. Moreover, the obvious correlation with energy resources has been a significant factor contributing to the current resurgence of interest in this area. However, the broader interest in carbonates is also a reflection of their widespread occurrence in vastly different geologic environments, including metamorphic and igneous settings, as well as an appreciation of their role in both atmospheric and oceanic chemistry, both past and present. In this volume, some of the papers are general (i.e., those addressing crystal chemistry and phase relations), and they provide overviews of a fundamental nature and are of interest to many. Others are more specialized in coverage and generally reflect the different approaches used in carbonate geochemistry. The final chapter introduces transmission electron microscopy, a relatively new and powerful technique for mineralogical research that has great potential in carbonate research. Owing to the short time interval between the completion of manuscripts and publication, much of the newer material in this volume is still "fresh." The various reviewers, all gratefully acknowledged, were expeditious in their efforts. A hurried schedule, however, allows for unnoticed errors to persist; these should be brought to my attention.

Beschreibung / Inhaltsverzeichnis: This book treats the subject of satellite orbits, showing how the wide range of available orbits can be put to use to satisfy the needs of fields as varied as communications, positioning, remote-sensing, meteorology, and astronomy. The satellite is first discussed in the context of the laws of space mechanics. The various categories of orbit (circular, elliptical, high, low, geostationary, and sun-synchronous) are then presented, together with the problem of sampling (when and how the satellite views its target). There is then a study of specific cases, in particular, applying all the ideas encountered for earth-orbiting satellites to the case of a satellite in orbit around Mars.

Beschreibung / Inhaltsverzeichnis: Geochemistry is a science that is based on an understanding of chemical processes in the earth. One of the principal tools available to the chemist for understanding systems at equilibrium is thermodynamics. The awareness and application of thermodynamic techniques has increased at a very fast pace in geosciences; in fact, one may be so bold as to say that thermodynamics in geology has reached the "mature" stage, although much future thermodynamic research is certainly needed. However, the natural processes in the earth are often sluggish enough that a particular system may not reach equilibrium. This observation is being supported constantly by new experimental and field data available to the geochemist e.g. the non-applicability of the phase rule in some assemblages, the compositional inhomogeneities of mineral grains, the partial reaction rims surrounding original minerals, the lack of isotopic equilibration or the absence of minerals (e.g. dolomite), which should be present according to thermodynamics. The need to apply kinetics has produced a large number of papers dealing with kinetics in geochemistry. As an initial response to this growing field, a conference on geochemical transport and kinetics was conducted at Airlie House, VA, in 1973, sponsored by the Carnegie Institution of Washington. The papers there dealt with several kinetic topics including diffusion, exsolution, metasomatism and metamorphic layering. Since 1973 the number of kinetic papers has continued to increase greatly. Therefore, the time is ripe for a Short Course in Kinetics, which brings together the fundamentals needed to explain field observations using kinetic data. It is hoped that this book may serve, not only as a reference for researchers dealing with the rates of geochemical processes, but also as a text in courses on geochemical kinetics. One of us has found this need of a text in teaching a graduate course on geochemical kinetics at Harvard and at Penn State during the past several years. Finally, it is our hope that the book may itself further even more research into the rates of geochemical processes and into the quantification of geochemical observations. The book is organized with a rough temperature gradient in mind, i.e. low temperature kinetics at the beginning and igneous kinetics at the end (no prejudices are intended with this scheme!). However, the topics in each chapter are general enough that they can be applied often to any geochemical domain: sedimentary, metamorphic or igneous. The theory of kinetics operates at two complementary levels: the phenomenological and the atomistic. The former relies on macroscopic variables (e.g. temperature or concentrations) to describe the rates of reactions or the rates of transport; the latter relates the rates to the basic forces operating between the particular atomic or molecular species of any system. This book deals with both descriptions of the kinetics of geochemical processes. Chapter one sets the framework for the phenomenological theory of reaction rates. If any geochemical reaction is to be described quantitatively, the rate law must be experimentally obtained in a kinetically sound manner and the reaction mechanism must be understood. This applies to heterogeneous fluid-rock reactions such as those occurring during metamorphism, hydrothermal alteration or weathering as well as to homogeneous reactions. Chapter 2 extends the theory to the global kinetics of geochemical cycles. This enables the kinetic concepts of stability and feedback to be applied to the cycling of elements in the many reservoirs of the earth. Chapter 3 applies the phenomenological treatment of chapter 1 to diagenesis and weathering. The rate of dissolution of minerals as well as the chemical evolution of pore waters are discussed. The atomistic basis of rates of reaction, transition state theory, is introduced in Chapter 4. Transition state theory can be applied to relate the rate constants of geochemical reactions to the atomic processes taking place. This includes not only homogeneous reactions but also reactions that occur at the surface of minerals. Chapter 5 discusses the theory of irreversible thermodynamics and its application to petrology. The use of the second law of thermodynamics along with the expressions for the rate of entropy production in a system have been used successfully since 1935 to describe kinetic phenomena. The chapter applies the concepts to the growth of minerals during metamorphism as well as to the formation of differentiated layers (banding) in petrology. Chapter 6 describes the phenomenological theory of diffusion both in aqueous solutions and in minerals. In particular, the multicomponent nature of diffusion and its consequence in natural systems is elaborated. Chapter 7 provides the atomistic basis for the rates of reactions in minerals. Understanding of the rates of diffusion, conduction, order-disorder reactions or exsolution in minerals depends on proper description of the defects in the various mineral structures. Chapter 8 provides the kinetic theory of crystal nucleation and growth. While many of the concepts in the chapter can be applied to aqueous systems, the emphasis is on igneous processes occurring during crystallization of a melt. To fully understand both the mineral composition as well as the texture of igneous rocks, the processes whereby new crystals form and grow must be quantified by using kinetic theory. Due to space and time limitations (kinetics!) some topics have not been covered in detail. In particular, the mathematical solution of diffusion or conduction equations is discussed very well by Crank in his book, Mathematics of Diffusion, and so is not covered to a great extent here. The treatment of fluid flow (e.g. convection) is also not covered in the text.

Beschreibung / Inhaltsverzeichnis: An Airborne Mobile Aerosol Lidar (AMALi) was constructed and built at Alfred-Wegener-Institute for Polar and Marine Research (AWI) in Potsdam, Germany for the lower tropospheric aerosol and cloud research under tough arctic conditions. The system was successfully used during two AWI airborne field campaigns, ASTAR 2004 and SVALEX 2005, performed in vicinity of Spitsbergen in the Arctic. The novel evaluation schemes, the Two-Stream Inversion and the Iterative Airborne Inversion, were applied to the obtained lidar data. Thereby, calculation of the particle extinction and backscatter coefficient profiles with corresponding lidar ratio profiles characteristic for the arctic air was possible. The comparison of these lidar results with the results of other in-situ and remote instrumentation (ground based Koldewey Aerosol Raman Lidar (KARL), sunphotometer, radiosounding, satellite imagery) allowed to provided clean contra polluted (Arctic Haze) characteristics of the arctic aerosols. Moreover, the data interpretation by means of the ECMWF Operational Analyses and small-scale dispersion model EULAG allowed studying the effects of the Spitsbergens orography on the aerosol load in the Planetary Boundary Layer. With respect to the cloud studies a new methodology of alternated remote AMALi measurements with the airborne in-situ cloud optical and microphysical parameters measurements was proved feasible for the low density mixed-phase cloud studies. An example of such approach during observation of the natural cloud seeding (feeder-seeder phenomenon) with ice crystals precipitating into the lower supercooled stratocumulus deck were discussed in terms of the lidar signal intensity profiles and corresponding depolarisation ratio profiles. For parts of the cloud system characterised by almost negligible multiple scattering the calculation of the particle backscatter coefficient profiles was possible using the lidar ratio information obtained from the in-situ measurements in ice-crystal cloud and water cloud.

Beschreibung / Inhaltsverzeichnis: Currently, a first generation of dedicated satellite missions for the precise mapping of the Earth's gravity field is in orbit (CHAMP, GRACE, and soon GOCE). The gravity data from these satellite missions provide us with very new information on the dynamics of planet Earth. In particular, on the mass distribution in the Earths interior, the entire water cycle (ocean circulation, ice mass balance, continental water masses, and atmosphere), and on changes in the mass distribution.The results are fascinating, but still rough with respect to spatial and temporal resolution. Technical progress in satellite-to-satellite tracking and in gravity gradiometry will allow more detailed results in the future. In this special issue, Earth scientists develop visions of future applications based on follow-on high-precision satellite gravimetry missions.