Kevin Gleason

Bio: Kevin Gleason is an academic researcher from Yale University. The author has contributed to research in topics: Soot & Evaporation. The author has an hindex of 7, co-authored 13 publications receiving 163 citations. Previous affiliations of Kevin Gleason include University of Central Florida.

Microdroplet evaporation with a forced pinned contact line.

Abstract: Experimental and numerical investigations of water microdroplet evaporation on heated, laser patterned polymer substrates are reported. The study is focused on both (i) controlling a droplet’s contact line dynamics during evaporation to identifying how the contact line influences evaporative heat transfer and (ii) validating numerical simulations with experimental data. Droplets are formed on the polymer surface using a bottom-up methodology, where a computer-controlled syringe pump feeds water through a 200 μm diameter fluid channel within the heated polymer substrate. This methodology facilitates precise control of the droplet’s growth rate, size, and inlet temperature. In addition to this microchannel supply line, the substrate surfaces are laser patterned with a moatlike trench around the fluid-channel outlet, adding additional control of the droplet’s contact line motion, area, and contact angle. In comparison to evaporation on a nonpatterned polymer surface, the laser patterned trench increases cont...

Pressure effects on incipiently sooting partially premixed counterflow flames of ethylene

Abstract: We studied the effect of pressure on the flame structure of incipiently sooting partially premixed counterflow ethylene flames. Oxygen was added to the fuel stream of a purely diffusion flame and removed from the oxidizer side to lower the overall equivalence ratio at constant stoichiometric value of the mixture fraction. These rich conditions lead to a two-stage combustion mode, with substantial amounts of CO and H2 in the post-premixed flame region burning in the diffusion flame part. Soot was formed in the region straddling the gas stagnation plane and sandwiched between the two flame components. We quantified profiles of species as large as 3-ring aromatics. Using C6H6 as a qualitative marker of the flame soot load, we observed that under partially premixing an eightfold pressure increase lead to a substantial increase in the concentration of C6H6 despite the fact that the flame peak temperature was deliberately decreased by hundreds of degrees to preserve conditions of incipient sooting compatible with gas microsampling. Part of the increased soot load with pressure was attributed to a diminished back diffusion of oxidizing radicals like OH from the diffusion flame side towards the gas stagnation region where the soot was formed. Benzene mole fraction and visible soot luminosity increased with the lowering of the equivalence ratio regardless of the pressure because of an increase in temperature in the region between the two flame components of the double flame structure, with attending enhancement of pyrolytic growth reactions. A comparison of the experimental results with one-dimensional modeling of the flames, revealed good agreement for major species, some key intermediates and benzene, in the latter case for just one of the two tested chemical kinetic mechanisms. Reaction path analysis revealed an increased role of the C2/C4 path in the formation of C6H6 as the pressure increased.

Thermal conductivity of nanoparticle suspensions

Abstract: We describe an optical beam deflection technique for measurements of the thermal diffusivity of fluid mixtures and suspensions of nanoparticles with a precision of better than 1%. Our approach is tested using the thermal conductivity of ethanol-water mixtures; in nearly pure ethanol, the increase in thermal conductivity with water concentration is a factor of 2 larger than predicted by effective medium theory. Solutions of C60–C70 fullerenes in toluene and suspensions of alkanethiolate-protected Au nanoparticles were measured to maximum volume fractions of 0.6% and 0.35vol%, respectively. We do not observe anomalous enhancements of the thermal conductivity that have been reported in previous studies of nanofluids; the largest increase in thermal conductivity we have observed is 1.3%±0.8% for 4nm diam Au particles suspended in ethanol.

The Scientific Papers of James Clerk Maxwell

Abstract: IT is not often that a reissue of the collected papers of an outstanding scientific man has been called for. Some of the papers cannot fail to have historical value because of the part which their original publication played in the development of science; but that value alone would not be sufficient to secure the demand. The work involved must be of present-day importance. Therefore its consequences must still be in process of development; and it follows that if, as in the present case, the republication follows the first publication after an interval of half a century, the main papers involved must have been of very epoch-making type. The condition of present value is a sufficient test; but the most essential condition is that of permanent value. Present value persisting after the lapse of fifty years suggests permanence, and at least points to some enduring quality—the direct impress of the distinctive personality of the man. The Scientific Papers of James Clerk Maxwell. Edited By W. D. Niven. (Photographic Reprint by arrangement with the Cambridge University Press.) Vol. 1. Pp. xxxii + 607. Vol. 2. Pp. viii + 806. (Paris: J. Hermann, 1927.) 3 livres 6.

Water-Repellent Properties of Superhydrophobic and Lubricant-Infused “Slippery” Surfaces: A Brief Study on the Functions and Applications

Abstract: Bioinspired water-repellent materials offer a wealth of opportunities to solve scientific and technological issues. Lotus-leaf and pitcher plants represent two types of antiwetting surfaces, i.e., superhydrophobic and lubricant-infused “slippery” surfaces. Here we investigate the functions and applications of those two types of interfacial materials. The superhydrophobic surface was fabricated on the basis of a hydrophobic fumed silica nanoparticle/poly(dimethylsiloxane) composite layer, and the lubricant-infused “slippery” surface was prepared on the basis of silicone oil infusion. The fabrication, characteristics, and functions of both substrates were studied, including the wettability, transparency, adhesive force, dynamic droplet impact, antifogging, self-cleaning ability, etc. The advantages and disadvantages of the surfaces were briefly discussed, indicating the most suitable applications of the antiwetting materials. This contribution is aimed at providing meaningful information on how to select wa...