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  • Journal article
    Neethling SJ, 2008,

    Simple approximations for estimating froth recovery

    , INTERNATIONAL JOURNAL OF MINERAL PROCESSING, Vol: 89, Pages: 44-52, ISSN: 0301-7516
  • Journal article
    Neethling SJ, Cilliers JJ, 2008,

    Predicting and correcting grade-recovery curves: Theoretical aspects

    , INTERNATIONAL JOURNAL OF MINERAL PROCESSING, Vol: 89, Pages: 17-22, ISSN: 0301-7516
  • Journal article
    Xie Z, Lin J, Zhou J, 2008,

    A new unconditionally stable explicit scheme for the convection-diffusion equation with Robin boundary conditions

    , International Journal of Computer Mathematics, Vol: 85, Pages: 1833-1847, ISSN: 0020-7160

    An alternating direction explicit (ADE) scheme to solve the unsteady convection-diffusion equation with Robin boundary conditions is presented and discussed in this paper. It was derived based on the local series expansion method and proved unconditionally stable by von Neumann stability analysis. Thereafter, the ADE scheme is compared with the conventional schemes, and a comparison between the amplification factor of all schemes and the exact one shows that the proposed scheme can simulate well both convection- and diffusion-dominated problems. Finally, the proposed method was validated by a numerical experiment which indicates that, for large cell Reynolds numbers, the proposed scheme, which has unconditional stability, is more accurate than implicit schemes and most explicit schemes. It is also shown that the proposed scheme is simple to implement, economical to use, effective for dealing with Robin boundary conditions and easy to apply to multidimensional problems.

  • Journal article
    Latham J-P, Munjiza A, Mindel J, Xiang J, Guises R, Garcia X, Pain C, Gorman G, Piggott Met al., 2008,

    Modelling of massive particulates for breakwater engineering using coupled FEMDEM and CFD

    , PARTICUOLOGY, Vol: 6, Pages: 572-583, ISSN: 1674-2001
  • Journal article
    Paul CRC, Allison PA, Brett CE, 2008,

    The occurrence and preservation of ammonites in the Blue Lias Formation (Lower Jurassic) of Devon and Dorset, England and their palaeoecological, sedimentological and diagenetic significance

    , Palaeogeography, Palaeoclimatology, Palaeoecology, Vol: 270, Pages: 258-272, ISSN: 0031-0182
  • Journal article
    Gorman GJ, Piggott MD, Wells MR, Pain CC, Allison PAet al., 2008,

    A systematic approach to unstructured mesh generation for ocean modelling using GMT and Terreno

    , Computers & Geosciences, Vol: 34, Pages: 1721-1731, ISSN: 0098-3004

    A systematic approach to unstructured mesh generation for ocean modelling is presented. The method optimises unstructured meshes to approximate bathymetry to a user specified accuracy which may be defined as a function of longitude, latitude and bathymetry. GMT (Generic Mapping Tools) is used to perform the initial griding of the bathymetric data. Subsequently, the Terreno meshing package combines automated shoreline approximation, mesh gradation and optimisation methods to generate high-quality bathymetric meshes. The operation of Terreno is based upon clearly defined error measures and this facilitates the automation of unstructured mesh generation while minimising user intervention and the subjectivity that this can introduce.

  • Journal article
    Bosence DWJ, Allison PA, 2008,

    Biotic – Sediment Interactions; an introduction

    , Palaeogeography, Palaeoclimatology, Palaeoecology, Vol: 270, Pages: 217-219, ISSN: 0031-0182
  • Journal article
    Allison PA, Hesselbo SP, Brett CE, 2008,

    Methane seeps on an Early Jurassic dysoxic seafloor

    , Palaeogeography, Palaeoclimatology, Palaeoecology, Vol: 270, Pages: 230-238, ISSN: 0031-0182
  • Journal article
    Morris G, Pursell MR, Neethling SJ, Cilliers JJet al., 2008,

    The effect of particle hydrophobicity, separation distance and packing patterns on the stability of a thin film

    , JOURNAL OF COLLOID AND INTERFACE SCIENCE, Vol: 327, Pages: 138-144, ISSN: 0021-9797
  • Journal article
    Neethling SJ, Cilliers JJ, 2008,

    Predicting air recovery in flotation cells

    , MINERALS ENGINEERING, Vol: 21, Pages: 937-943, ISSN: 0892-6875
  • Journal article
    Smith C, Neethling S, Cilliers JJ, 2008,

    Air-rate profile optimisation: From simulation to bank improvement

    , MINERALS ENGINEERING, Vol: 21, Pages: 973-981, ISSN: 0892-6875
  • Journal article
    Wells MR, Allison PA, Hampson GJ, Piggott MD, Pain CC, Dodman Aet al., 2008,

    Investigating tides in the Early Pennsylvanian Seaway of NW Eurasia using the Imperial College Ocean Model

    , Geological Association of Canada Special Paper, Vol: 48, Pages: 363-387, ISSN: 0072-1042
  • Software
    Ham D, Farrell P, Gorman G, Maddison Jet al., 2008,

    Spud

    Spud is a generic system for defining, writing and processing options files for scientific computer models.The interfaces to scientific computer models are frequently primitive, under-documented and ad-hoc text files. This makes using and developing the model in question difficult and error-prone.With Spud, the model developer need only write a rules file (schema) which defines the options which the model takes and the relationship between them. The Spud component Diamond then provides an automatically generated graphical user interface which guides the user and validates the user's input against the schema. Diamond writes out an xml options file for use in Spud.The developer then uses libspud to read the options file into the model. Libspud can read any valid options file without further code modifications and makes the options available at any point in the model code at which they are required.Spud further provides the facility for the schema to be self-documenting and Diamond presents this documentation to the model user in a context-sensitive manner.

  • Journal article
    Merton SR, Pain CC, Smedley-Stevenson RP, Buchan AG, Eaton MDet al., 2008,

    Optimal discontinuous finite element methods for the Boltzmann transport equation with arbitrary discretisation in angle

    , ANNALS OF NUCLEAR ENERGY, Vol: 35, Pages: 1741-1759, ISSN: 0306-4549
  • Conference paper
    Percival JR, Cotter CJ, Holm DD, 2008,

    A Euler–Poincaré framework for the multilayer Green–Nagdhi equations

    , Meeting held in Honor of Darryl D Holms on Geometry and Analysis in Physical Systems, Publisher: IOP Publishing, Pages: 344018-344031, ISSN: 1751-8113

    The Green–Nagdhi equations are frequently used as a model of the wave-like behaviour of the free surface of a fluid, or the interface between two homogeneous fluids of differing densities. Here we show that their multilayer extension arises naturally from a framework based on the Euler–Poincaré theory under an ansatz of columnar motion. The framework also extends to the travelling wave solutions of the equations. We present numerical solutions of the travelling wave problem in a number of flow regimes. We find that the free surface and multilayer waves can exhibit intriguing differences compared to the results of single layer or rigid lid models.

  • Journal article
    Lin JG, Xie ZH, Yu D, Zhou JTet al., 2008,

    A three-point explicit compact difference scheme with arbitrary order of accuracy for the two dimensional pollutant diffusion equation

    , Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics, Vol: 25, Pages: 511-516, ISSN: 1007-4708

    Based on the successive iterative approach in the Taylor series expansion method, a three-point explicit compact formula with arbitrary order of accuracy for the spatial second order derivative is derived in this paper. With the transformation of the temporal derivative to spatial derivative from the original diffusion equation, a three-point explicit compact difference scheme for the diffusion equation is proposed and it can achieve arbitrary order of accuracy in both space and time. From the numerical test, it is found that the proposed compact scheme is not only simple to implement and economical to use, but also is effective to apply to many theoretical and engineering problems.

  • Journal article
    Collins GS, Morgan J, Barton P, Christeson GL, Gulick S, Urrutia J, Warner M, Wunnemann Ket al., 2008,

    Dynamic modeling suggests terrace zone asymmetry in the Chicxulub crater is caused by target heterogeneity

    , EARTH PLANET SC LETT, Vol: 270, Pages: 221-230, ISSN: 0012-821X
  • Journal article
    Buchan AG, Pain CC, Eaton MD, Goddard AJHet al., 2008,

    Linear and quadratic hexahedral wavelets on the sphere for angular discretizations of the Boltzmann transport equation

    , NUCLEAR SCIENCE AND ENGINEERING, Vol: 159, Pages: 127-152, ISSN: 0029-5639
  • Journal article
    Buchan AG, Pain CC, Eaton MD, Smedley-Stevenson RP, Goddard AJHet al., 2008,

    Chebyshev spectral hexahedral wavelets on the sphere for angular discretisations of the Boltzmann transport equation

    , ANNALS OF NUCLEAR ENERGY, Vol: 35, Pages: 1098-1108, ISSN: 0306-4549
  • Journal article
    Jackson MD, 2008,

    Characterization of multiphase electrokinetic coupling using a bundle of capillary tubes model

    , JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, Vol: 113, ISSN: 2169-9313
  • Journal article
    Collins GS, Artemieva N, Wuennemann K, Bland PA, Reimold WU, Koeberl Cet al., 2008,

    Evidence that Lake Cheko is not an impact crater

    , TERRA NOVA, Vol: 20, Pages: 165-168, ISSN: 0954-4879
  • Conference paper
    Piggott MD, Gorman GJ, Pain CC, Allison PA, Candy AS, Martin BT, Wells MRet al., 2008,

    A new computational framework for multi-scale ocean modelling based on adapting unstructured meshes

    , 9th ICFD Conference on Numerical Methods for Fluid Dynamics, Pages: 1003-1015

    A new modelling framework is presented for application to a range of three-dimensional (3D) multi-scale oceanographic problems. The approach is based upon a finite element discretization on an unstructured tetrahedral mesh which is optimized to represent highly complex geometries. Throughout a simulation the mesh is dynamically adapted in 3D to optimize the representation of evolving solution structures. The adaptive algorithm makes use of anisotropic measures of solution complexity and a load-balanced parallel mesh optimization algorithm to vary resolution and allow long, thin elements to align with features such as boundary layers. The modelling framework presented is quite different from the majority of ocean models in use today, which are typically based on static-structured grids. Finite element (and volume) methods on unstructured meshes are, however, gaining popularity in the oceanographic community. The model presented here is novel in its use of unstructured meshes and anisotropic adaptivity in 3D, its ability to represent a range of coupled multi-scale solution structures and to simulate non-hydrostatic dynamics. Copyright (C) 2007 John Wiley & Sons, Ltd.

  • Journal article
    Piggott MD, Gorman GJ, Pain CC, Allison PA, Candy AS, Martin BT, Wells MRet al., 2008,

    A new computational framework for multi-scale ocean modelling based on adapting unstructured meshes

    , International Journal for Numerical Methods in Fluids, Vol: 56, Pages: 1003-1015
  • Journal article
    Shaw B, Ambraseys NN, England PC, Floyd MA, Gorman GJ, Higham TFG, Jackson JA, Nocquet J-M, Pain CC, Piggott MDet al., 2008,

    Eastern Mediterranean tectonics and tsunami hazard inferred from the AD 365 earthquake

    , Nature Geoscience, Vol: 1, Pages: 268-276
  • Journal article
    Buchan AG, Pain CC, Eaton MD, Smedley-Stevenson RP, Goddard AJHet al., 2008,

    Self-adaptive spherical wavelets for angular discretizations of the Boltzmann transport equation

    , NUCLEAR SCIENCE AND ENGINEERING, Vol: 158, Pages: 244-263, ISSN: 0029-5639

    A new method for applying anisotropic resolution in the angular domain of the Boltzmann transport equation is presented. The method builds on our previous work in which two spherical wavelet bases were developed for representing the direction of neutral particle travel. The method proposed here enables these wavelet bases to vary their angular approximations so that fine resolution may be applied only to the areas of the unit sphere (representing the direction of particle travel) that are important. We develop an error measure that operates in conjunction with the wavelet bases to determine this importance. A procedure by which the angular resolution is gradually refined for steady-state problems is also given.The adaptive wavelets are applied to three test problems that demonstrate the ability of the wavelets to resolve complex fluxes with relatively few functions, and to achieve this a particular emphasis is placed on their ability to approximate particle streaming through ducts with voids. It is shown that the wavelets are capable of applying the appropriate resolution (as dictated by the error measure) to the directional component of the angular flux at all spatial positions. This method therefore offers a new and highly efficient adaptive angular approximation method.

  • Journal article
    Jonoud S, Jackson MD, 2008,

    New criteria for the validity of steady-state upscaling

    , TRANSPORT IN POROUS MEDIA, Vol: 71, Pages: 53-73, ISSN: 0169-3913
  • Conference paper
    Jiang S, Pain CC, Carter JN, Ziver AK, Eaton MD, Goddard AJH, Franklin SJ, Phillips HJet al., 2008,

    Nuclear Reactor Reactivity Prediction Using Feed Forward Artificial Neural Networks

    , 5th International Symposium on Neural Networks, Publisher: SPRINGER-VERLAG BERLIN, Pages: 400-+, ISSN: 0302-9743
  • Journal article
    Carmine L, Aristodemou E, Pain C, Muggeridge Aet al., 2008,

    Inversion of time-dependent nuclear well-logging data using neural networks

    , Geophysical Prospecting, Vol: 56, Pages: 115-140, ISSN: 0016-8025

    The purpose of this work was to investigate a new and fast inversion methodology for the prediction of subsurface formation properties such as porosity, salinity and oil saturation, using time-dependent nuclear well logging data. Although the ultimate aim is to apply the technique to real-field data, an initial investigation as described in this paper, was first required; this has been carried out using simulation results from the time-dependent radiation transport problem within a borehole. Simulated neutron and gamma-ray fluxes at two sodium iodide (NaI) detectors, one near and one far from a pulsed neutron source emitting at similar to 14 MeV, were used for the investigation. A total of 67 energy groups from the BUGLE96 cross section library together with 567 property combinations were employed for the original flux response generation, achieved by solving numerically the time-dependent Boltzmann radiation transport equation in its even parity form. Material property combinations (scenarios) and their correspondent teaching outputs (flux response at detectors) are used to train the Artificial Neural Networks (ANNs) and test data is used to assess the accuracy of the ANNs. The trained networks are then used to produce a surrogate model of the expensive, in terms of computational time and resources, forward model with which a simple inversion method is applied to calculate material properties from the time evolution of flux responses at the two detectors. The inversion technique uses a fast surrogate model comprising 8026 artificial neural networks, which consist of an input layer with three input units (neurons) for porosity, salinity and oil saturation; and two hidden layers and one output neuron representing the scalar photon or neutron flux prediction at the detector. This is the first time this technique has been applied to invert pulsed neutron logging tool information and the results produced are very promising. The next step in the procedure is to apply th

  • Journal article
    C J Cotter, G Gorman, 2008,

    Diagnostic tools for 3D unstructured oceanographic data

    , Ocean Modelling, Vol: 20, Pages: 170-182
  • Book
    Bosence DWJ, Allison PA, 2008,

    Biotic sediment interactions: Selected papers from: Organism sediment relations and preservational windows; A tribute to the scientific career of Roland Goldring. Published in Palaeogeography, Palaeoclimatology, Palaeoecology

    , Publisher: Elsevier Science Ltd.
  • Conference paper
    Xiang J, Latham JP, Munjiza A, Mindel Jet al., 2008,

    Applications of the combined finite-discrete element method

    , Discrete Element Methods and Numerical Modelling of Discontinuum Mechanics, Pages: 223-231
  • Book chapter
    Piggott MD, Pain CC, Gorman GJ, 2008,

    Unstructured adaptive meshes for ocean modeling

    , Ocean modeling in an eddying regime, Editors: Hecht, Hasumi, Hecht, Hasumi, Publisher: Amer Geophysical Union, Pages: 383-408, ISBN: 9780875904429
  • Journal article
    Gomes JLMA, Pain CC, Eaton MD, Piggott MD, Goddard AJH, Ziver AK, Yamane Y, de Oliveira CREet al., 2008,

    Investigation of nuclear criticality within a powder using coupled neutronics and thermofluids

    , Annals of Nuclear Engineering, Vol: 35, Pages: 2073-2093
  • Conference paper
    Garcia X, Latham JP, Xiang J, Munjiza Aet al., 2008,

    Modelling of the forming processes of sandstones with irregular particles

    , Discrete Element Methods and Numerical Modelling of Discontinuum Mechanics, DEM'08, Pages: 232-241
  • Conference paper
    Schiava D'Albano GG, Munjiza A, Rougier E, Latham JP, John NWMet al., 2008,

    Fluid driven fracture processes in FEM/DEM analysis

    , Discrete Element Methods and Numerical Modelling of Discontinuum Mechanics, DEM'08, Pages: 242-248
  • Journal article
    Allison PA, Maeda H, TuZino T, Maeda Yet al., 2008,

    Exceptional preservation within Pleistocene lacustrine sediments of Shiobara, Japan

    , Palaois, Vol: 23, Pages: 260-266
  • Journal article
    Jonoud S, Jackson MD, 2008,

    Validity of Steady-State Upscaling Techniques

    , SPE Reservoir Evaluation and Engineering, Vol: April, Pages: 405-416
  • Journal article
    Latham J-P, Munjiza A, Garcia X, Xiang J, Guises Ret al., 2008,

    Three-dimensional particle shape acquisition and use of shape library for DEM and FEM/DEM simulation

    , Minerals Engineering, Vol: 21, Pages: 797-805
  • Journal article
    saunders J, jackson M, pain C, 2008,

    Fluid flow monitoring in oilfields using downhole measurements of electrokinetic potential

    , Geophysics, Vol: 73, Pages: E165-E180

    Downhole measurements of electrokinetic potential are a promising new technology for hydrocarbon reservoir monitoring. Using a 3Dfinite-element model combining both multiphase flow and electrokinetic components, we investigated the behavior of electrokinetic (streaming) potential during oil production in a range of reservoir environments. We found that streaming-potential signals originate at fluid fronts and at geologic boundaries where fluid saturation changes. As water encroaches on an oil production well, the streaming-potential signal associated with the water front encompasses the well even when the front is up to 100 m away, so the potential measured at the well starts to change significantly relative to a distant reference electrode. Variations in the geometry of the encroaching water front can be characterized using an array of electrodes positioned along the well, but a good understanding of the local reservoir geology is required to identify signals caused by the front. The streaming potential measured at a well is maximized in low-permeability reservoirs produced at a high rate and in thick reservoirs with low shale content. However, considerable uncertainties remain, particularly relating to the nature of electrokinetic coupling at high salinity and during multiphase flow. Our results suggest that the streaming potential at low salinity (10^-3–10^-4 mol/L) is large (100–1000 mV) but might become too small to resolve (<0.1) mV at high salinity (0.5–2 mol/L), depending on how the available data for the electrokinetic coupling at low salinity are extrapolated into the high-salinity domain. More work remains to determine the behavior of electrokinetic coupling and therefore the utility of this technique at high salinity.

  • Conference paper
    Latham JP, Mindel J, Xiang J, Garcia X, Pain C, Gorman G, Munjiza Aet al., 2008,

    Development of a modelling approach for large granular media used in coastal applications

    , Discrete Element Methods and Numerical Modelling of Discontinuum Mechanics, Pages: 122-130
  • Journal article
    Rushmer T, Jackson MD, 2008,

    Impact of melt segregation on tonalite–trondhjemite–granodiorite (TTG) petrogenesis

    , Trans. Royal Society of Edinburgh: Earth Science, Vol: 79, Pages: 325-336
  • Conference paper
    Addiego-Guevara EA, Jackson MD, Giddens MA, 2008,

    Insurance value of intelligent well technology against reservoir uncertainty

    , SPE/DOE Improved Oil Recovery Symposium
  • Conference paper
    Munjiza A, Xiang J, Garcia X, Latham JP, Schiava D'Albano G, John NMWet al., 2008,

    The Virtual Geoscience Workbench, VGW: Open source tools for discontinuous systems

    , Discrete Element Methods and Numerical Modelling of Discontinuum Mechanics, Pages: 113-121
  • Conference paper
    Pavlidis D, Aristodemou E, Gorman GJ, Gomes JLMA, ApSimon Het al., 2008,

    Numerical Simulation of Air Flows in Street Canyons using Mesh-Adaptive LES

    , Trieste, Italy, ERCOFTAC Workshop: Direct and Large-Eddy Simulations 7 (DLES7)
  • Journal article
    Hopcroft PO, Gallagher K, Pain CC, 2007,

    Inference of past climate from borehole temperature data using bayesian reversible jump markov chain monte carlo

    , GEOPHYSICAL JOURNAL INTERNATIONAL, Vol: 171, Pages: 1430-1439, ISSN: 0956-540X
  • Journal article
    Lin JG, Xie ZH, Zhou JT, 2007,

    High-order compact scheme and its stability analysis for the pollutant diffusion equation

    , Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics, Vol: 24, Pages: 790-794, ISSN: 1007-4708

    An explicit numerical method which has arbitrary order of accuracy in time was derived in this paper, including the analysis of the stability and the accuracy of the pollutant diffusion equation. The conventional explicit Forward Time Central Space scheme (FTCS) is the specific form with first order accuracy of the proposed method. The theoretical analysis demonstrated that the stable region would expand along with the increase of the order of accuracy and the proposed explicit method was unconditionally stable when remaining the infinite order of accuracy. Finally, the validity of the proposed method was tested by a numerical example and it is shown that the numerical results agree quite well with the anterior theoretical analysis. And it also reveals the relationship between the stability and the accuracy, and provides the advisory principle for the development of the high-performance computational schemes.

  • Journal article
    Meloy JR, Neethling SJ, Cilliers JJ, 2007,

    Geometric dispersion of unattached particles in foams

    , COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, Vol: 309, Pages: 246-253, ISSN: 0927-7757
  • Conference paper
    Farrell PE, Gorman GJ, Piggott MD, Pain CCet al., 2007,

    Some problems with quadratic fitting algorithm for Hessian recovery in the context of anisotropic mesh optimisation

    , International Conference on Adaptive Modeling and Simulation (ADMOS)
  • Journal article
    Meloy JR, Neethling SJ, Cilliers JJ, 2007,

    Modelling the axial dispersion of particles in froths

    , INTERNATIONAL JOURNAL OF MINERAL PROCESSING, Vol: 84, Pages: 185-191, ISSN: 0301-7516
  • Journal article
    Zhou JT, Lin JG, Xie ZH, 2007,

    Compact explicit difference scheme of high accuracy for extended boussinesq equations

    , China Ocean Engineering, Vol: 21, Pages: 507-514, ISSN: 0890-5487

    Presented here is a compact explicit difference scheme of high accuracy for solving the extended Boussinesq equations. For time discretization, a three-stage explicit Runge-Kutta method with TVD property is used at predicting stage, a cubic spline function is adopted at correcting stage, which made the time discretization accuracy up to fourth order; For spatial discretization, a three-point explicit compact difference scheme with arbitrary order accuracy is employed. The extended Boussinesq equations derived by Beji and Nadaoka are solved by the proposed scheme. The numerical results agree well with the experimental data. At the same time, the comparisons of the two numerical results between the present scheme and low accuracy difference method are made, which further show the necessity of using high accuracy scheme to solve the extended Boussinesq equations. As a valid sample, the wave propagation on the rectangular step is formulated by the present scheme, the modelled results are in better agreement with the experimental data than those of Kittitanasuan.

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