Publications by Year: 2014

E. Ortega, Torres-Verdín, C., Preeg, W. E., and Miles, J., “1D radial inversion of multi-detector logging-while-drilling Sigma measurements,” Geophysics, vol. 79, no. 5, pp. D363-D384, 2014.
E. Ortega, Torres-Verdín, C., Preeg, W. E., and Miles, J., “1D radial inversion of multi-detector logging-while-drilling Sigma measurements,” Geophysics, vol. 79, no. 5, pp. D363-D384, 2014.
R. Fievet, Tinney, C. E., Baars, W. J., and Hamilton, M. F., “Acoustic waveforms produced by a laboratory scale supersonic jet,” 20th AIAA/CEAS Aeroacoustics Conference, AIAA Paper 2014-2906. Atlanta, Georgia. USA, 2014.Abstract
The spatial evolution of acoustic waveforms produced by a Mach 3 jet are investigated using both 1/4 inch and 1/8 inch pressure field microphones located along rays emanating from the post potential core where the peak sound emission is found to occur. The measurements are acquired in a fully anechoic chamber where ground, or other large surface reflections are minimal. The calculation of the OASPL along an arc located at 95 jet diameters using 120 planar grid measurements are shown to collapse remarkably well when the arc array is centered on the post potential core region. Various statistical metrics, including the quadrature spectral density, number of zero crossings, the skewness of the pressure time derivative and the integral of the negative part of the quadrature spectral density, are exercised along the peak emission path. These metrics are shown to undergo rapid changes within 2 meters from the source regions of this laboratory scale jet. The sensitivity of these findings to both transducer size and humidity effects are discussed. A visual extrapolation of these nonlinear metrics toward the jet shear layer suggests that these waveforms are initially skewed at the source. An experimentally validated wave packet model is used to confirm the location where the pressure decay law transition from cylindrical to spherical. It is then used to estimate the source intensity which is required to predict the effective Gol’dberg number. 1
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M. Fitzmaurice, Pogue, B. W., Tearney, G. J., Tunnell, J. W., and Yang, C., “Advances in optics for biotechnology, medicine and surgery.,” Biomed Opt Express, vol. 5, no. 2, pp. 560-1, 2014.Abstract
The guest editors introduce a Biomedical Optics Express feature issue that includes contributions from participants at the 2013 conference on Advances in Optics for Biotechnology, Medicine and Surgery XIII.
T. Bui-Thanh and Ghattas, O., “An Analysis of Infinite Dimensional Bayesian Inverse Shape Acoustic Scattering and its Numerical Approximation,” SIAM Journal on Uncertainty Quantification, no. 2, pp. 203--222, 2014.
T. J. Mefford, Hardin, W. G., Dai, S., Johnston, K. P., and Stevenson, K. J., “Anion charge storage through oxygen intercalation in LaMnO3 perovskite pseudocapacitor electrodes,” Nature materials, vol. 13, no. 7, pp. 726-732, 2014. Publisher's VersionAbstract
Perovskite oxides have attracted significant attention as energy conversion materials for metal–air battery and solid-oxide fuel-cell electrodes owing to their unique physical and electronic properties. Amongst these unique properties is the structural stability of the cation array in perovskites that can accommodate mobile oxygen ions under electrical polarization. Despite oxygen ion mobility and vacancies having been shown to play an important role in catalysis, their role in charge storage has yet to be explored. Herein we investigate the mechanism of oxygen-vacancy-mediated redox pseudocapacitance for a nanostructured lanthanum-based perovskite, LaMnO3. This is the first example of anion-based intercalation pseudocapacitance as well as the first time oxygen intercalation has been exploited for fast energy storage. Whereas previous pseudocapacitor and rechargeable battery charge storage studies have focused on cation intercalation, the anion-based mechanism presented here offers a new paradigm for electrochemical energy storage
H. Shen, Li, Y., Ren, P., Zhang, D., and Li, G., “An Anisotropic Coarse-Grained Model for Proteins Based On Gay-Berne and Electric Multipole Potentials,” Journal of Chemical Theory and Computation, vol. 10, pp. 731–750, 2014.
H. Shen, Li, Y., Ren, P., Zhang, D., and Li, G., “Anisotropic coarse-grained model for proteins based on Gay–Berne and electric multipole potentials,” Journal of chemical theory and computation, vol. 10, pp. 731–750, 2014.
H. Yoon, Leibeling, S., Zhang, C., Mueller, R. H., Werth, C. J., and Zilles, J., “Aptation of Delftia acidovorans for degradation of 2, 4-dichlorophenoxyacetate in a microfluidic porous medium,” Biodegradation, vol. 25, pp. 595–604, 2014.
T. M. Truskett, Johnston, K. P., Maynard, J. A., Borwankar, A. U., Murthy, A. K., Stover, R. J., Wilson, B. K., Dinin, A. K., Laber, J. R., and Gourisankar, S., “Assembling nanoclusters in water for therapy or imaging,” ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, vol. 247. AMER CHEMICAL SOC 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2014.
I. Jo, Pettes, M. T., Ou, E., Wu, W., and Shi, L., “Basal-plane thermal conductivity of few-layer molybdenum disulfide,” Applied Physics Letters, vol. 104, pp. 201902, 2014. Publisher's Version
M. Nole, Daigle, H., and Mohanty, K. K., “Basin-Scale Modeling of Methane Hydrate Accumulations in the Gulf of Mexico,” AGU Fall Meeting Abstracts, vol. 1. pp. 1110, 2014.
K. M. Eckes, Mu, X., Ruehle, M. A., Ren, P., and Suggs, L. J., “$\beta$ Sheets not required: Combined experimental and computational studies of self-assembly and gelation of the ester-containing analogue of an Fmoc-dipeptide hydrogelator,” Langmuir, vol. 30, pp. 5287–5296, 2014.
J. R. Laber, Borwankar, A. U., Maynard, J. A., Truskett, T. M., and Johnston, K. P., “Biochemical characterization of the low viscosity reversible protein nanocluster platform,” ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, vol. 247. AMER CHEMICAL SOC 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2014.
R. I. Stover, Murthy, A., Gourisankar, S., Ne, G., Martinez, M., Truskett, T., Sokolov, K., and Johnston, K., “Biodegradable gold nanoclusters which exhibit high-NIR absorbance for biomedical imaging,” ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, vol. 247. AMER CHEMICAL SOC 1155 16TH ST, NW, WASHINGTON, DC 20036 USA, 2014.
J. Brunner, Bard, J. F., and Köhler, J. M., Bounded Flexibility in Days-on and Days-Off Scheduling, To appear in Naval Research Logistics. 2014.
Y. Qu and Bard, J. F., A Branch-and-Price-and-Cut Algorithm for Heterogeneous Pickup and Delivery Problems with Configurable Vehicle Capacity. To appear in Transportation Science, 2014.
G. Yu, Dong, J., Foster, L. M., Metaxas, A. E., Truskett, T. M., and Johnston, K. P., “Breakup of oil jets into droplets in seawater with environmentally benign nanoparticle and surfactant dispersants,” Industrial & Engineering Chemistry Research, vol. 54, no. 16, pp. 4243-4251, 2014. Publisher's VersionAbstract
During deep-sea oil leaks, dispersants may be used to break up the oil into droplets smaller than about 70 μm, which may then be bioremediated by bacteria before they reach the ocean surface. To investigate the mechanism of droplet formation as a function of dispersant type, concentration, and jet velocity, a flowing oleophilic stream containing amphiphiles was mixed with flowing dodecane and then atomized through a 0.25 mm circular nozzle. The minimum droplet diameters were 2.2, 4.5, and 24 μm for only 5 w:v % amphiphile in the oil phase for Corexit 9500A, Tergitol 15-S-7 (C12H25CH(OCH2CH2)7OH), and a silica nanoparticle/Span 20 mixture, respectively. For Tergitol 15-S-7, the droplet size exhibited the expected scaling with Weber number (We) at low viscosity numbers (Vi < 50), where inertial forces overcome interfacial forces, and Reynolds number (Re) at high Vi numbers (Vi > 50), where inertial forces overcome viscous forces. However, in the case of the silica nanoparticle/Span 20 mixture, the magnitude of the exponent of We scaling was found to be smaller than −3/5. A better understanding of how low concentrations of dispersants (with relatively high oil–water interfacial tensions) may be used to provide a sufficient We with high inertial forces (high Re) in jets to form small oil droplets, which is of interest for advancing environmental protection in the undesired event of a deep-sea oil leak
A. J. Worthen, Parikh, P. S., Chen, Y., Bryant, S. L., Huh, C., and Johnston, K. P., “Carbon Dioxide-in-Water Foams Stabilized with a Mixture of Nanoparticles and Surfactant for CO2 Storage and Utilization Applications,” Energy Procedia, vol. 63, pp. 7929-7938, 2014. Publisher's VersionAbstract
Synergistic interactions between appropriately designed surface-modified nanoparticles and surfactants are shown to stabilize foams of CO2 bubbles/droplets dispersed in water at elevated temperature and pressure typical of subsurface formations for enhanced oil recovery or geologic storage of CO2. The foams are sufficiently viscous to mitigate or eliminate the instability associated with CO2 displacement of fluids resident in the oil reservoir or brine aquifer. This technology therefore has the potential to increase the efficiency of oil recovery and the efficiency of pore space utilization for storage.
W. J. Baars, Tinney, C. E., and Hamilton, M. F., “Challenges associated with studying nonlinear distortion of acoustic waveforms emitted by high-speed jets,” 43rd International Congress on Noise Control Engineering. Australian Acoustical Society, Melbourne, Australia, 2014.Abstract
Discrepancies between linear predictions and direct measurements of the far-field sound produced by high speed jet flows are typically ascribed to nonlinear distortion. Here we employ an effective Gol’dberg number to investigate the likelihood of nonlinear distortion in the noise fields of supersonic jets. This simplified approach relies on an isolated view of a ray tube along the Mach wave angle. It is known that the acoustic pressure obeys by cylindrical spreading in close vicinity to the jet before advancing to a spherical decay in the far-field. Therefore, a ‘piecewise-spreading regime’ model is employed in order to compute effective Gol’dberg numbers for these jet flows. Our first-principal approach suggests that cumulative nonlinear distortion can only be present within 20 jet exit diameters along the Mach wave angle when laboratory-scale jets are being considered. Effective Gol’dberg numbers for full-scale jet noise scenarios reveal that a high-degree of cumulative distortion can likewise be present in the spherical decay regime. Hence, full-scale jet noise fields are more affected by cumulative distortion.
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