A5076651454- Membrane Separation Technologies
- Lattice Boltzmann Simulation Studies
- Surfactants and Colloidal Systems
- Characterization and Applications of Magnetic Nanoparticles
- Fluid Dynamics and Thin Films
- Advanced Mathematical Modeling in Engineering
- Pickering emulsions and particle stabilization
- Advanced Sensor and Energy Harvesting Materials
- Surface Modification and Superhydrophobicity
- Nanopore and Nanochannel Transport Studies
- Liquid Crystal Research Advancements
- Heat and Mass Transfer in Porous Media
- Fluid Dynamics and Heat Transfer
- Micro and Nano Robotics
- Aerosol Filtration and Electrostatic Precipitation
- Composite Material Mechanics
- Advanced Materials and Mechanics
- Minerals Flotation and Separation Techniques
- Adhesion, Friction, and Surface Interactions
- Membrane-based Ion Separation Techniques
- Rheology and Fluid Dynamics Studies
- Electrospun Nanofibers in Biomedical Applications
- Water Systems and Optimization
- Microfluidic and Bio-sensing Technologies
- Electrowetting and Microfluidic Technologies
University of Oxford
2016-2025
Mathematical Institute of the Slovak Academy of Sciences
2015-2025
Decision Research
2023
Science Oxford
2011-2021
Google (United States)
2015-2017
Princeton University
2011-2015
Applied Mathematics (United States)
2013
Surfactant distribution heterogeneities at a fluid-fluid interface trigger the Marangoni effect, i.e., bulk flow due to surface tension gradient. The influence of surfactant solubility in on these flows remains incompletely characterized. Here we study sustained by injection hydrosoluble surfactants air-water interface. We show that have finite size increases with decrease critical micelle concentration surfactants. document universality velocity field and predict scaling laws based...
Filters whose porosity decreases with depth are often more efficient at removing solute from a fluid than filters uniform porosity. We investigate this phenomenon via an extension of homogenization theory that accounts for macroscale variation in microstructure. In the first stage paper, we homogenize problems flow through filter near-periodic microstructure and transport due to advection, diffusion, adsorption. second stage, use computationally homogenized equations quantify why gradients...
Robust, simple, and scalable touch- brush-spinning methods for the drawing of nanofibers, core–shell their aligned 2D 3D meshes using polymer solutions melts are discussed. As a service to our authors readers, this journal provides supporting information supplied by authors. Such materials peer reviewed may be re-organized online delivery, but not copy-edited or typeset. Technical support issues arising from (other than missing files) should addressed Please note: The publisher is...
We develop a spatially dependent generalization to the Wells–Riley model, which determines infection risk due airborne transmission of viruses. assume that infectious aerosol concentration is governed by an advection–diffusion–reaction equation with aerosols advected airflow, diffused turbulence, emitted infected people, and removed ventilation, inactivation virus gravitational settling. consider one asymptomatic or presymptomatic person breathing talking, without mask, model...
Liquid–liquid interfaces play a pivotal role in various microfluidic processes involving microparticles, including coating, dissolution, controlled release of polyelectrolytes or drugs, and self-assembly processes. In all these cases, noninvasive techniques to manipulate the microparticle transport are essential. Magnetic manipulation offers an accessible straightforward means controlling motion magnetic particles within devices. microparticles commonly used for conformal polyelectrolyte...
We derive leading-order governing equations and boundary conditions for a sheet of viscous fluid retracting freely under surface tension. show that small thickness perturbations about flat base state can lead to regions compression, where one or both the principal tensions in becomes negative, thus drive transient buckling centre-surface. The general theory is applied simple model problem disc with axisymmetric variations. Transient growth centre-surface found be possible generically,...
We consider the propagation of a bubble in non-uniform Hele-Shaw flow. focus on distinguished limit which is approximately circular plan view and its velocity determined by net force balance incorporating viscous pressure drag due to thin films separating from cell walls. find that instantaneous same as for uniform flow given background fluid evaluated at centre. apply model common microfluidic components, such T-junction injection sources sinks. Using methodology, we derive approximate...
To date, there has been limited reporting on the fabrication and properties of macroscopic sheet assemblies (specifically buckypapers) composed carbon/boron nitride core-shell heteronanotubes (MWCNT@BNNT) or boron nanotubes (BNNTs). Herein we report synthesis MWCNT@BNNTs via a facile method involving Atmospheric Pressure Chemical Vapor Deposition (APCVD) safe h-BN precursor ammonia borane. These were used as sacrificial templates for BNNT by thermal oxidation core carbon. Buckypaper was...
Predicting the distribution of solutes or particles in flows within porous-walled tubes is essential to inform design devices that rely on cross-flow filtration, such as those used water purification, irrigation devices, field-flow fractionation, and hollow-fibre bioreactors for tissue-engineering applications. Motivated by these applications, a radially averaged model fluid solute transport tube with thin porous walls derived developing classical ideas Taylor dispersion. The includes...
We describe a microfluidic system that uses magnetic field to sort paramagnetic beads by deflecting them in the direction normal flow. In experiments we systematically study dependence of beads' deflection on bead size and susceptibility, magnet strength, fluid speed viscosity, device geometry. also develop design parameter can aid devices for immunomagnetic multi-target sorting.
Magnetospinning is a new method for spinning of continuous micro- and nano-fibers using permanent revolving magnet. The utilizes magnetic forces the hydrodynamic features stretched threads to produce highly loaded, fine nanofibers. magnetospinning process independent solution dielectric properties requires no high voltages, in contrast more-traditional electrospinning technique.
This paper concerns the manufacture of non-axisymmetric capillary tubing via Vello process, in which molten glass is fed through a die and drawn off vertically. The shape cross-section evolves under surface tension as it flows downstream. aim to achieve given desired final shape, typically square or rectangular, our goal determine required shape. We use result that, provided tube slowly varying axial direction, each like two-dimensional Stokes flow when expressed suitably scaled Lagrangian...
The familiar example of Taylor dispersion molecular solutes is extended to describe colloidal suspensions, where the fluctuations that contribute arise from hydrodynamic interactions. generic scheme illustrated for a suspension particles in pressure-driven pipe flow, with concentration-dependent diffusivity captures both shear-induced and Brownian contributions. effect cross-stream migration via diffusion shown dramatically reduce axial predicted by classical solute. Analytic numerical...
The ITER project is considering the inclusion of two sets in-vessel coils, one to mitigate effect Edge Localized Modes (ELMs) and another provide vertical stabilization (VS). location (behind blanket shield modules, mounted vacuum vessel inner wall) presents special challenges in terms nuclear radiation (˜3000 MGy) temperature (100 °C during operations, 200 bakeout). Mineral insulated conductors are well suited this environment but not commercially available large cross section required. An...
Abstract Understanding the behaviour of particles entrained in a fluid flow upon changes direction is crucial problems where particle inertia important, such as erosion process pipe bends. We present results on impact T-shaped channel laminar–turbulent transitional regime. The impacting event for given system described terms Reynolds number and Stokes number. Experimental are compared with trajectories predicted by theoretical particle-tracing models range configurations to determine role...
Filters that act by adsorbing contaminant onto their pore walls will experience a decrease in porosity over time, and may eventually block. As adsorption generally be larger towards the entrance of filter, where concentration particles is higher, these effects can also result spatially varying porosity. We investigate this dynamic process using an extension homogenization theory accounts for macroscale variation microstructure. formulate homogenize coupled problems flow through filter with...
We consider the evolution of an annular two-dimensional region occupied by viscous fluid driven surface tension and applied pressure at free surfaces. assume that thickness domain is small compared with its circumference, so it may be described as a thin sheet whose ends are joined to form closed loop. Analytical numerical solutions resulting model obtained we show well posed whether run forwards or backwards in time. This enables us determine, many cases explicitly, which initial shapes...
ITER will incorporate In Vessel Coils (IVCs) as a method of stabilizing "Edge Localized Modes" (ELM) and providing "Vertical Stabilization" (VS). To meet the ELM VS Coil requirements strong coupling with plasma is required so that it necessary for coils to be installed in vessel just behind blanket shield modules. Due this close proximity radiation temperature environment severe conventional electrical insulation materials processes cannot used. The development mineral insulated conductor...
The kinetics of re-equilibration the anionic surfactant sodium dodecylbenzene sulfonate at air-solution interface have been studied using neutron reflectivity. experimental arrangement incorporates a novel flow cell in which subphase can be exchanged (diluted) laminar while surface region remains unaltered. rate is relatively slow and occurs over many tens minutes, comparable with dilution time scale approximately 10-30 min. A detailed mathematical model, desorption determined by transport...
Cell proliferation within a fluid-filled porous tissue-engineering scaffold depends on sensitive choice of pore geometry and flow rates: regions high curvature encourage cell proliferation, while critical rate is required to promote growth for certain types. When the too slow, nutrient supply limited; when it fast, cells may be damaged by fluid shear stress. As result, determining appropriate tissue-engineering-construct geometries operating regimes poses significant challenge that cannot...