A5025579578- Lattice Boltzmann Simulation Studies
- Liquid Crystal Research Advancements
- Pickering emulsions and particle stabilization
- Micro and Nano Robotics
- Material Dynamics and Properties
- Advanced Data Storage Technologies
- Distributed and Parallel Computing Systems
- Microfluidic and Bio-sensing Technologies
- Oceanographic and Atmospheric Processes
- Parallel Computing and Optimization Techniques
- Characterization and Applications of Magnetic Nanoparticles
- Aerosol Filtration and Electrostatic Precipitation
- Surfactants and Colloidal Systems
- Nonlinear Dynamics and Pattern Formation
- Fluid Dynamics and Turbulent Flows
- Generative Adversarial Networks and Image Synthesis
- Blood properties and coagulation
- Marine and coastal ecosystems
- Advanced Materials and Mechanics
- Quantum and electron transport phenomena
- Enhanced Oil Recovery Techniques
- Scientific Computing and Data Management
- Phase Equilibria and Thermodynamics
- Scientific Research and Discoveries
- Heat and Mass Transfer in Porous Media
University of Edinburgh
2013-2024
El Paso Community College
2009-2023
Engineering and Physical Sciences Research Council
2019
Guthrie Foundation
2019
Scottish Universities Physics Alliance
2016
Institute of Mathematical Sciences
2008
Universitat de Barcelona
2005
Irish Centre for High-End Computing
2005
University of Liverpool
1998-1999
University of Leicester
1993
Colloidal particles or nanoparticles, with equal affinity for two fluids, are known to adsorb irreversibly the fluid-fluid interface. We present large-scale computer simulations of demixing a binary solvent containing such particles. The newly formed interface sequesters colloidal particles; as coarsens, forced into close contact by interfacial tension. Coarsening is dramatically curtailed, and jammed layer seemingly enters glassy state, creating multiply connected, solid-like film in three...
The lattice Boltzmann algorithm efficiently simulates the Navier Stokes equation of isothermal fluid flow, but ignores thermal fluctuations fluid, important in mesoscopic flows. We show how to adapt include noise, satisfying a fluctuation-dissipation theorem (FDT) directly at level: this gives correct for mass and momentum densities, stresses, all wavevectors $k$. Unlike previous work, which recovers FDT only as $k\to 0$, our offers full statistical mechanical consistency mesoscale...
We report large scale simulations of the blue phases cholesteric liquid crystals. Our results suggest a structure for phase III, fog, which has been subject long debate in crystal physics. propose that III is an amorphous network disclination lines, thermodynamically and kinetically stabilised over crystalline at intermediate chiralities}. This becomes ordered under applied electric field, as seen experiments.
Lattice Boltzmann simulations have become the method of choice to solve hydrodynamic equations motion a number complex fluids. Here we review some recent applications lattice study hydrodynamics liquid crystalline materials. In particular, focus on (a) exotic blue phases cholesteric crystals, and (b) active gels—a model system for actin plus myosin solutions or bacterial suspensions. both cases studies proved useful provide new insights into these
We present a lattice Boltzmann study of the hydrodynamics fully resolved squirmer, confined in slab fluid between two no-slip walls.
The wave-of-advance model was introduced to describe the spread of advantageous genes in a population. It can be adapted uptake any technology through population, such as arrival neolithic farmers Europe, domestication horse, and development wheel, iron tools, political organization, or advanced weaponry. Any trait that preexists alongside one could carried along with it, genetics language, regardless intrinsic superiority. Decoupling from other “hitchhiking” traits depends on its adoption...
We simulate a colloidal particle (radius R) in cholesteric liquid crystal (pitch p) with tangential order parameter alignment at the surface. The local defect structure evolves from dipolar pair of surface defects (boojums) small R/p to twisted disclination lines wrapping around larger values. On dragging colloid velocity v through medium along helix axis (an active microrheology measurement), we find hydrodynamic drag force that scales linearly but superlinearly R-in striking violation...
We propose a hybrid lattice Boltzmann algorithm to simulate the hydrodynamics of colloidal particles inside liquid crystalline host. To validate our algorithm, we study static and microrheology colloid in nematic, with tangential anchoring director field at particle surface, confirm theories experiments showing that drag force nematic is markedly anisotropic. then apply method consider case cholesteric, normal surface. show by tuning ratio between size cholesteric pitch it possible control...
Our understanding of the complex, transcriptional feedback loops in circadian clock mechanism has depended upon quantitative, timeseries data from disparate sources. We measure gene RNA profiles Arabidopsis thaliana seedlings, grown with or without exogenous sucrose, soil-grown plants and wild-type mutant backgrounds. The were strikingly robust across experimental conditions, so current mathematical models are likely to be broadly applicable leaf tissue. In addition providing reference data,...
Bicontinuous Pickering emulsions (bijels) are a physically interesting class of soft materials with many potential applications including catalysis, microfluidics and tissue engineering.
DL_MONTE is an open-source, general-purpose software package for performing Monte Carlo (MC) simulations. It includes a wide variety of force fields and MC techniques, thus applicable to broad range problems in molecular simulation. Here we provide overview DL_MONTE, focussing on key features recently added the package. These include ability treat systems confined planar pore (i.e. 'slit' or 'slab' boundary conditions); lattice-switch (LSMC) method evaluating precise free energy differences...
Abstract Discrete element modeling (DEM) of polydisperse granular materials is significantly more computationally expensive than monodisperse as a larger number particles are required to obtain representative elementary volume, and standard contact detection algorithms become progressively less efficient with polydispersity. This paper presents modified inter-processor communication schemes implemented in LAMMPS which account for different sizes separately, greatly improving efficiency. new...
The role of the thermohaline circulation in controlling export production, oxygenation deep waters, and hence possible sapropel formation eastern Mediterranean is examined using a simple nutrient‐cycling model. model driven by velocity fields from general receives fluxes nutrient river run‐off atmospheric deposition. used to study three scenarios: strong anti‐estuarine circulation, weakened weak estuarine circulation. Nutrient transports, ventilation oxygen, deposition organic matter are...
We present a progress report on our work lattice Boltzmann methods for colloidal suspensions. focus the treatment of particles in binary solvents and inclusion thermal noise. For benchmark problem colloids sedimenting becoming trapped by capillary forces at horizontal interface between two fluids, we discuss criteria parameter selection, address inevitable compromise computational resources simulation accuracy.
The cubic blue phases of liquid crystals are fascinating and technologically promising examples hierarchically structured soft materials, comprising ordered networks defect lines (disclinations) within a crystalline matrix. We present the first large-scale simulations their domain growth, starting from phase nucleus supercooled isotropic or cholesteric background. nucleated is thermodynamically stable; one expects its slow orderly creating bulk cubic. Instead, we find that strong propensity...
We present a study of the hydrodynamics an active particle, model squirmer, in envi- ronment with broken rotational symmetry: nematic liquid crystal. By combining simulations analytic calculations, we show that hydrodynamic coupling between squirmer flow field and crystalline director can lead to re-orientation swimmers. The preferred orientation depends on exact details field. In steady state, pushers are shown swim parallel while pullers perpendicular director. This behaviour arises solely...
We use lattice Boltzmann simulations to investigate the formation of arrested structures upon demixing a binary solvent containing neutrally wetting colloidal particles. Previous for symmetric fluid quenches pointed "bijels": bicontinuous interfacially jammed emulsion gels. These should be created when glassy monolayer particles forms at fluid−fluid interface, arresting further and rigidifying structure. Experimental work has broadly confirmed this scenario, but it shows that bijels can also...
Bicontinuous, interfacially jammed emulsion gels (bijels) represent a class of soft solid materials in which interpenetrating domains two immiscible fluids are stabilized by an interfacial colloidal monolayer. Such structures can be formed arrested spinodal decomposition from initially single-phase suspension. Here, we explore lattice Boltzmann simulation the possible effects using magnetic colloids bijels. This may allow additional control over structure, during or after formation,...
We simulate an experiment in which a colloidal probe is pulled through active nematic fluid. find that the drag on particle non-stokesian (not proportional to its radius). Strikingly, large enough contractile fluid (such as actomyosin gel) can show negative viscous steady state: moves opposite direction externally applied force. explain this, and qualitative trends seen our simulations, terms of disruption orientational order around resulting modifications stress.