@article { ISI:000239375900008, title = {Eulerian-lagrangian simulations of unsteady gas-liquid flows in bubble columns}, journal = {International Journal of Multiphase Flow }, volume = {32}, number = {7}, year = {2006}, month = {JUL}, pages = {864-885}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

We studied the dynamics of gas-liquid flows in a rectangular bubble column using Eulerian-Lagrangian simulations. Three-dimensional, unsteady simulations were performed to simulate the dynamic characteristics of the oscillating bubble plume. The effect of superficial gas velocity and aerated liquid height-to-column width (HI K) ratio on the dynamic and time-averaged flow properties was studied and the simulated results were validated using wall pressure and voidage fluctuation measurements. The effect of lift force and numerical diffusion on the dynamic and time-averaged properties is discussed in detail. Further, the results obtained using the Eulerian-Lagrangian simulations were compared with the Eulerian-Eulerian simulations. The bubble scale information, which is otherwise lost in the Eulerian-Eulerian simulations, was validated using the voidage fluctuation measurements. Such experimentally validated Eulerian-Lagrangian models will be useful for the simulation of mass transfer and reactions in bubble columns. (c) 2006 Elsevier Ltd. All rights reserved.

}, keywords = {Bubble column, CFD, Dynamics, Eulerian-Eulerian simulations, Eulerian-Lagrangian simulations, gas-liquid flow}, issn = {0301-9322}, doi = {10.1016/j.ijmultiphaseflow.2006.02.017}, author = {Buwa, Vivek V. and Deo, Dhanannjay S. and Ranade, Vivek V.} } @article { ISI:000287056000001, title = {Structure determination and dynamics of protein-RNA complexes by NMR spectroscopy}, journal = {Progress in Nuclear Magnetic Resonance Spectroscopy}, volume = {58}, number = {1-2}, year = {2011}, month = {FEB}, pages = {1-61}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, keywords = {Dynamics, NMR spectroscopy, Protein-RNA complex, Structure determination}, issn = {0079-6565}, doi = {10.1016/j.pnmrs.2010.10.001}, author = {Dominguez, Cyril and Schubert, Mario and Duss, Olivier and Ravindranathan, Sapna and Allain, Frederic H. T.} } @article {43871, title = {Capillary uptake in macroporous compressible sponges}, journal = {Soft Matter}, volume = {13}, year = {2017}, month = {SEP}, chapter = { 5731-5740}, abstract = {

The capillarity-driven uptake of liquid in swellable, highly porous sponges is of significant industrial importance. Sponges prepared using polymers and their composites with carbon nanotubes and graphene have been reported, with extraordinary solvent uptake capacities and with the ability to separate oil from water. However, the effect of systematic variation of sponge characteristics on solvent uptake has not been investigated. Here, we report experiments that study capillary uptake in a variety of flexible, centimetre-sized macroporous cylindrical sponges. We used ice-templating to prepare a series of model macroporous sponges in which the porosity, modulus and composition were systematically varied. We investigated two kinds of sponge: (a) those composed purely of cross-linked polymers and (b) those prepared as composites of inorganic particles and polymers. Both kinds of sponge are flexible and exhibit elastic recovery after large compressive deformation. All sponges were characterized thoroughly with respect to their pore microstructure and elastic modulus. When one end of a sponge is plunged into a large reservoir, water rises through capillary action against gravity. We observed a transition from an inertial capillary regime, where the liquid column height rose linearly with time, t, to a viscous capillary regime, where the liquid height rose with time t(0.5). We showed that these results can be rationalized using analyses developed for rigid sponges. We combined differential momentum balance equations for uptake in rigid capillaries with the phenomenological Ergun-Forchheimer relations to account for the effect of the sponge microstructure. This approach works remarkably well in the viscous capillary regime and shows that capillary uptake is governed primarily by the total porosity and pore dimensions of soft sponges.

}, keywords = {aerogels, Building blocks, Catalyst Supports, Contact-angels, Dynamics, flow, Organic Liquids, Porous-Media, Rise}, issn = {1744-683X}, doi = {10.1039/c7sm00826k}, author = {Chatterjee, Soumyajyoti and Doshi, Pankaj and Kumaraswamy, Guruswamy} } @article {43773, title = {Studies on the role of unsaturation in the fatty acid surfactant molecule on the thermal conductivity of magnetite nanofluids}, journal = {Journal of colloid and interface science }, volume = {506}, year = {2017}, month = {NOV}, chapter = {162-168}, abstract = {

To study the role of unsaturation in the surfactant molecule on the thermal conductivity of magnetite nanofluids, four different fatty acid (stearic, oleic, linoleic, and linolenic acids with different degree of unsaturation) coated magnetite nanoparticles of comparable size are prepared and dispersed in toluene. It is found that the nanofluid with the saturated fatty acid coated nanoparticles show larger viscosity than the fluid with the unsaturated fatty acid coated particles at all concentrations. Thermal conductivity studies show enhancement only above a critical concentration for all fluids. The critical concentration for thermal conductivity enhancement varies with the surfactant, possibly due to the difference in the degree of aggregation of the nanoparticles in the fluid, because of the difference in the conformation of the surfactant molecules on the nanoparticle{\textquoteright}s surface. The experimental thermal conductivity follows the Maxwell model at higher concentrations. From the overall studies, it is observed that the thermal conductivity of the fluids with aggregated or assembled nanoparticles shows slightly larger enhancement than that of the fluids with isolated particles. However, in the presence of a magnetic field, the fluids with isolated nanoparticles showed relatively larger enhancement, possibly due to the easy response of the isolated magnetite nanoparticles to the applied field. (C) 2017 Elsevier Inc. All rights reserved.

}, keywords = {Chains, Dynamics, Enhancement, Fields, Fluids, Forces, gold nanoparticles, Magnetic fluid; Nanofluid; Surfactant; Unsaturation; Conformation; Thermal conductivity; Viscosity, Self-assembled Monolayers}, issn = {0021-9797}, doi = {10.1016/j.jcis.2017.07.038}, author = {Lenin, Ramanujam and Joy, Pattayil Alias} }