Download or read book Multiscale Modeling of Clay water Systems written by Davoud Ebrahimi and published by . This book was released on 2014 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: The engineering properties of soils are highly affected by clay content and clay-water interactions. However, existing macro-scale continuum models have no length scale to describe the evolution of the clay microstructure and its role in affecting macroscopic properties. This research proposes a bottom-up multiscale modeling approach to understand the physics underlying macroscopic clay behavior. Atomistic models are developed to understand clay-water interactions using the ClayFF force field. We simulate water adsorption between clay layers for a reference mineral, Wyoming montmorillonite (Na-smectite) using molecular dynamics simulations. The elastic properties of the system are found to vary with the hydration state (amount of interlayer water) and can be well-approximated using cross-anisotropic symmetries. The simulated adsorption isotherm and stiffness are compared with available experimental measurements. We develop a perturbation approach to investigate the free energy associated with relative positions of two clay platelets in water. The free energy functions for edge-edge and faceface particle associations are used to calibrate the Gay-Berne (GB) potential that represents each platelet as a single-site ellipsoidal body. A coarse-graining upscaling approach then uses the GB potentials and molecular dynamics to represent the meso-scale aggregation of clay platelets (at submicron length scale). Results from meso-scale simulations obtain the equilibrium/ jamming configurations for mono-disperse clay platelets. The results show aggregation for a range of clay platelets dimensions and pressures with mean stack size ranging from 3-8 platelets. The particle assemblies become more ordered and exhibit more pronounced elastic anisotropy at higher confining pressures. The results are in good agreement with previously measured nanoindentation moduli over a wide range of clay packing densities. The current research represents an important step forward towards multiscale modeling of soils and can be used to study any system composed of platy constituents.

Download or read book Modelling of Chemical Process Systems written by Syed Ahmad Imtiaz and published by Elsevier. This book was released on 2023-07-25 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Models and simulations are widely being used for design, optimization, fault detection and diagnosis, and various other decision-making purposes. Increasingly, models are developed at different scales and levels, all the way from molecular level to the large-scale process systems scale. Modelling of Chemical Process Systems gives readers a feel for the multiscale modelling. As models have been developed for various applications, a general systematic method for building model has emerged. This book starts with the history of modelling and its usefulness, describing modelling steps in detail. Examples have been chosen carefully from both conventional chemical process systems to contemporary systems, including fuel cell and bioprocesses. Modelling theories are complemented with case studies that explain step-by-step modelling methodologies. This book also introduces the application of machine learning techniques to model chemical process systems. This makes the book an indispensable reference for academics and professionals working in modelling and simulation. - Includes case studies that explain step-by-step modelling methodologies - Covers detailed multiscale modelling of chemical processes, providing examples from traditional and novel areas - Provides modelling insight at micro and macro-scale levels, including machine learning techniques

Download or read book Multiscale Modeling of Thixotropy in Soft Clays written by Peyman Aminpour and published by . This book was released on 2019 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thixotropy is a material property that describes how a substance can 'soften' upon continues deformation and heal back to the 'thicker' state over time when left to rest. It is also a fundamental soil behavior mechanism that governs multiple time-dependent engineering properties of soft clays (e.g., the evolution of stiffness, strength, and sensitivity over time).While significant understanding of thixotropy of colloid systems has been achieved since the initiation of the field of thixotropy in the early 1920s, current knowledge on soil thixotropy is still based primarily on some pioneering work performed in and prior to the 1960s and, since then, new developments have been scarce and fragmental. Such a paucity of new findings and the disparity in thixotropy research and advancement between colloid science and soil mechanics provide an impetus to this research. Therefore, this project that integrates multiscale computational and experimental efforts is to study soft clay thixotropy. The work done in this study aims to examine and simulate the clay particle-scale development of thixotropy under various environmental conditions (time, water chemistry, and temperature) and at different size scales. This innovative bottom-up multiscale modeling approach serves to understand the physics underlying macroscopic soft clay thixotropic behavior. The overall goal of the project is to create the enabling knowledge on the macroscale mechanical and microscale structural mechanisms of soft clay thixotropy and hence to append some new time-dependent soil behavior to the geotechnical knowledge base. It is to develop an understanding of the micro- to macro-linkage of soft clay thixotropy through the development of a versatile molecular dynamics (MD) simulation tool to accurately duplicate the time-dependent interactions between clay particles and to provide a framework for the study of the three-dimensional mechanical behavior of soft clays. The value of this project stems from three aspects: (1) the geotechnical knowledge base on soil thixotropy will be expanded with new understanding, particularly the effects of physico-chemical factors such as temperature and porewater chemistry; (2) both the macroscale mechanical and microscale structural mechanisms of thixotropic hardening of soft clays will be uncovered via multiscale computational research; and (3) the linkage between quantitative time-dependent clay fabric evolution and macroscale thixotropic processes will be developed. Because soil thixotropy plays an important role in many engineering problems, the project also can generate significant practical impacts to geotechnical engineering, particularly the design and construction of engineering systems involving soft clays. Examples include evaluation of pile and suction caisson setup, design of wind farm foundations, and disposal of dredged materials, among others. Moreover, the multiscale investigation methodology developed through this project can be generalized to other more complex soil research topics and can also serve as a generic approach for other basic research queries.

Download or read book Multiscale Modeling written by Pedro Derosa and published by CRC Press. This book was released on 2010-12-09 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: While the relevant features and properties of nanosystems necessarily depend on nanoscopic details, their performance resides in the macroscopic world. To rationally develop and accurately predict performance of these systems we must tackle problems where multiple length and time scales are coupled. Rather than forcing a single modeling approach to

Download or read book Multiscale and Multiphysics Processes in Geomechanics written by Ronaldo I. Borja and published by Springer Science & Business Media. This book was released on 2011-05-10 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt: This state-of-the-art book contains all results and papers of the International Workshop on Multiscale and Multiphysics Processes in Geomechanics at Stanford University Campus, June 23–25, 2010.

Download or read book Multiscale and Multiphysics Modeling of Soil Water Systems written by Yuan Guo and published by . This book was released on 2018 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many geotechnical problems involve the interactions between soil skeleton and different multiphysics, e.g., frost heave of foundation, underground hazardous substance transport, geothermal heat transfer, and soil erosion under surface flow. The associated physical and mechanical behaviors of natural soils are highly determined by their microscale structural attribute. This study discussed the multiscale and multiphysics nature of granular materials focusing on three major areas, i.e., surface erosion behavior, desiccation cracking, and clay particle interaction. A coupled CFD-DEM model has been built to study the erosion behavior of granular soils under surface flow. The model was first verified by two benchmark examples, i.e., free settling of a single sphere in water and formation of repose angle of sand piles in water. Surface erosion of sand grains has been simulated considering different influencing factors, including particle size, particle bonding strength, flow turbulence, and particle angularity. It is shown erosion resistance increases linearly with particle size, and angular particles have a higher erosion resistance than spherical particles. An aggregate-scale DEM model was also built to simulate the formation and propagation of desiccation cracks of a thin clay layer. Model parameters have been calibrated by a customized experimental system monitoring the volumetric shrinkage of clay while drying. It is shown this aggregate-scale model replicates the formation and final cracking polygons very well. Sample thickness and bottom constraint have a significant influence on the cracking formation. A particle-scale DEM clay model was developed subsequently to study the mechanical interaction between clay particles with implementation of complicated inter-particle forces, e.g., long-range electrostatic force, short-range van der Waals force. The double-layer repulsion has been calibrated by AFM force measurement on kaolinite particles in 1.0 mM NaCl electrolyte. The model has been verified by comparing the equilibrium void ratio of kaolinite suspension under different centrifugal accelerations. Compressibility and shear strength of bulk clay particles have been simulated and compared with experimental observations. It is shown this microscale model holistically simulates the macroscale characteristics of clay under compression and shearing.

Download or read book Multiscale Experimental and Numerical Study of the Structure and the Dynamics of Water Confined in Clay Minerals written by Emmanuel Guillaud and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clay are complex minerals with a multiscale porosity and a remarkable ability to swell under humid atmosphere. These materials have many applications in catalysis, waste management, construction industry... However, the properties of confined water are still not fully understood, due in particular to the complexity of water itself. The aim of this work is, using mainly molecular simulations and vibrational spectroscopy, to understand the structure and the dynamics of water confined in clay minerals. To evaluate the accuracy of numerical models to describe water confined in clay minerals, and to understand the origin of its structural and dynamical properties, a large part of the work was devoted to the building blocks of clays: pure bulk water, water at the surface of a solid, and salt water. To this extent, the viscoelastic properties of water from the deeply supercooled regime to the boiling temperature were investigated using classical molecular dynamics. The evolution of the friction properties of water on a prototypical solid surface was also analyzed, and the accuracy of ab initio approaches and empirical salt models was studied.In a second part, those results were confronted to the properties of water confined in clay minerals at low and room temperature, studied both experimentally and numerically. Experimental work consisted mostly in extensive far- and -mid infrared absorption spectrometry measurements, whereas numerical work mainly consisted in empirical molecular dynamics simulations. Especially, the existence of confinement- or temperature-induced phase transitions of confined water was investigated.

Download or read book Clay water Systems written by Willis Grant Lawrence and published by . This book was released on 1965 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Clay Polymer Nanocomposites written by Khouloud Jlassi and published by Elsevier. This book was released on 2017-07-26 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clay–Polymer Nanocomposites is a complete summary of the existing knowledge on this topic, from the basic concepts of synthesis and design to their applications in timely topics such as high-performance composites, environment, and energy issues. This book covers many aspects of synthesis such as in- situ polymerization within the interlamellar spacing of the clays or by reaction of pristine or pre-modified clays with reactive polymers and prepolymers. Indeed, nanocomposites can be prepared at industrial scale by melt mixing. Regardless the synthesis method, much is said in this book about the importance of theclay pre-modification step, which is demonstrated to be effective, on many occasions, in obtaining exfoliated nanocomposites. Clay–Polymer Nanocomposites reports the background to numerous characterization methods including solid state NMR, neutron scattering, diffraction and vibrational techniques as well as surface analytical methods, namely XPS, inverse gas chromatography and nitrogen adsorption to probe surface composition, wetting and textural/structural properties. Although not described in dedicated chapters, numerous X-ray diffraction patterns of clay–polymer nanocomposites and reference materials are displayed to account for the effects of intercalation and exfoliations of layered aluminosilicates. Finally, multiscale molecular simulation protocols are presenting for predicting morphologies and properties of nanostructured polymer systems with industrial relevance. As far as applications are concerned, Clay–Polymer Nanocomposites examines structural composites such as clay–epoxy and clay–biopolymers, the use of clay–polymer nanocomposites as reactive nanocomposite fillers, catalytic clay-(conductive) polymers and similar nanocomposites for the uptake of hazardous compounds or for controlled drug release, antibacterial applications, energy storage, and more. - The most comprehensive coverage of the state of the art in clay–polymer nanocomposites, from synthesis and design to opportunities and applications - Covers the various methods of characterization of clay–polymer nanocomposites - including spectroscopy, thermal analyses, and X-ray diffraction - Includes a discussion of a range of application areas, including biomedicine, energy storage, biofouling resistance, and more

Download or read book Low temperature Phases of Interfacial Water in Clay water Systems written by Duwayne Marlo Anderson and published by . This book was released on 1970 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low temperature differential thermal analyses of selected clay-water systems were made to locate important phase change temperatures and to define fruitful temperature-pressure fields for precise calorimetric investigation. In addition to an exotherm corresponding to initial freezing, one, two or three exotherms were observed between -35C and -60C. The low temperature exotherms do not depend critically upon water content, but clearly they are related to clay mineral and exchangeable cation type. The evolution of heat in this temperature range probably corresponds to a phase change in the interfacial water. (Author).

Download or read book Changes in the Clay water System with Depth Temperature and Time written by Charles Edward Weaver and published by . This book was released on 1969 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface and Interface Chemistry of Clay Minerals written by Robert Schoonheydt and published by Elsevier. This book was released on 2018-11-05 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface and Interface Chemistry of Clay Minerals, Volume 9, delivers a fundamental understanding of the surface and interface chemistry of clay minerals, thus serving as a valuable resource for researchers active in the fields of materials chemistry and sustainable chemistry. Clay minerals, with surfaces ranging from hydrophilic, to hydrophobic, are widely studied and used as adsorbents. Adsorption can occur at the edges and surfaces of clay mineral layers and particles, and in the interlayer region. This diversity in properties and the possibility to tune the surface properties of clay minerals to match the properties of adsorbed molecules is the basis for study. This book requires a fundamental understanding of the surface and interface chemistry of clay minerals, and of the interaction between adsorbate and adsorbent. It is an essential resource for clay scientists, geologists, chemists, physicists, material scientists, researchers, and students. - Presents scientists and engineers with a resource they can rely on for their own research and work involving clay minerals - Includes an in-depth look at ion exchange, adsorption of inorganic and organic molecules, including polymers and proteins, and catalysis occurring at the surfaces of clay minerals - Includes materials chemistry of clay minerals with chiral clay minerals, optical materials and functional films

Download or read book Reactive Transport in Natural and Engineered Systems written by Jennifer Druhan and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-03-04 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Open system behavior is predicated on a fundamental relationship between the timescale over which mass is transported and the timescale over which it is chemically transformed. This relationship describes the basis for the multidisciplinary field of reactive transport (RT). In the 20 years since publication of Review in Mineralogy and Geochemistry volume 34: Reactive Transport in Porous Media, RT principles have expanded beyond early applications largely based in contaminant hydrology to become broadly utilized throughout the Earth Sciences. RT is now employed to address a wide variety of natural and engineered systems across diverse spatial and temporal scales, in tandem with advances in computational capability, quantitative imaging and reactive interface characterization techniques. The present volume reviews the diversity of reactive transport applications developed over the past 20 years, ranging from the understanding of basic processes at the nano- to micrometer scale to the prediction of Earth global cycling processes at the watershed scale. Key areas of RT development are highlighted to continue advancing our capabilities to predict mass and energy transfer in natural and engineered systems.

Download or read book The Future of Geological Modelling in Hydrocarbon Development written by Adam Robinson and published by Geological Society of London. This book was released on 2008 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 3D geological model is still regarded as one of the newest and most innovative tools for reservoir management purposes. The computer modelling of structures, rock properties and fluid flow in hydrocarbon reservoirs has evolved from a specialist activity to part of the standard desktop toolkit. The application of these techniques has allowed all disciplines of the subsurface team to collaborate in a common workspace. In today's asset teams, the role of the geological model in hydrocarbon development planning is key and will be for some time ahead. The challenges that face the geologists and engineers will be to provide more seamless interaction between static and dynamic models. This interaction requires the development of conventional and unconventional modelling algorithms and methodologies in order to provide more risk-assessed scenarios, thus enabling geologists and engineers to better understand and capture inherent uncertainties at each aspect of the geological model's life.

Download or read book Model Studies of Clay water Systems written by L. K. Walker and published by . This book was released on 1964 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Groundwater in Geologic Processes written by Steven E. Ingebritsen and published by Cambridge University Press. This book was released on 2006-05-04 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: An extensively revised 2006 second edition of the well received and widely adopted textbook on groundwater.

Download or read book Modeling and Prediction of Polymer Nanocomposite Properties written by Vikas Mittal and published by John Wiley & Sons. This book was released on 2012-12-07 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book series 'Polymer Nano-, Micro- and Macrocomposites' provides complete and comprehensive information on all important aspects of polymer composite research and development, including, but not limited to synthesis, filler modification, modeling, characterization as well as application and commercialization issues. Each book focuses on a particular topic and gives a balanced in-depth overview of the respective subfi eld of polymer composite science and its relation to industrial applications. With the books the readers obtain dedicated resources with information relevant to their research, thereby helping to save time and money. This book lays the theoretical foundations and emphasizes the close connection between theory and experiment to optimize models and real-life procedures for the various stages of polymer composite development. As such, it covers quantum-mechanical approaches to understand the chemical processes on an atomistic level, molecular mechanics simulations to predict the filler surface dynamics, finite element methods to investigate the macro-mechanical behavior, and thermodynamic models to assess the temperature stability. The whole is rounded off by a look at multiscale models that can simulate properties at various length and time scales in one go - and with predictive accuracy.