Publications

2016
J. D. Escobar, Torres-Verdín, C., Proett, M., and Ma, S. M., “Improving the interpretation of formation-tester measurements with expedient and detailed numerical simulations (Expanded Abstract),” Society of Petrophysicists and Well Log Analysts (SPWLA) 57th Ann. Logging Symposium. Reykjavik, Iceland, June 25-29, 2016.
A. Frooqnia, Torres-Verdín, C., and Sepehrnoori, K., “Inference of rock pressure-production properties from gas-oil production logs.,” Journal of Natural Gas and Engineering, vol. 36, Part A, no. November, pp. 124-143, 2016.
A. Frooqnia, Torres-Verdín, C., and Sepehrnoori, K., “Inference of rock pressure-production properties from gas-oil production logs.,” Journal of Natural Gas and Engineering, vol. 36, Part A, no. November, pp. 124-143, 2016.
S. Misra, Torres-Verdín, C., Revil, A., Rasmus, J., and Homan, D., “Interfacial polarization of disseminated conductive minerals in absence of redox-active species, Part 2: Effective electrical conductivity and dielectric permittivity,” Geophysics, vol. 81, no. 2, pp. E159-E176, 2016.
S. Misra, Torres-Verdín, C., Revil, A., Rasmus, J., and Homan, D., “Interfacial polarization of disseminated conductive minerals in absence of redox-active species. Part 1: Mechanistic model and validation,” Geophysics, vol. 81, no. 2, pp. E139-E157, 2016.
S. Misra, Torres-Verdín, C., Revil, A., Rasmus, J., and Homan, D., “Interfacial polarization of disseminated conductive minerals in absence of redox-active species. Part 1: Mechanistic model and validation,” Geophysics, vol. 81, no. 2, pp. E139-E157, 2016.
S. Misra, Torres-Verdín, C., Revil, A., Rasmus, J., and Homan, D., “Interfacial polarization of disseminated conductive minerals in absence of redox-active species, Part 2: Effective electrical conductivity and dielectric permittivity,” Geophysics, vol. 81, no. 2, pp. E159-E176, 2016.
V. Puzyrev and Torres-Verdín, C., “Inversion-based interpretation of 3D borehole directional resistivity measurements acquired in high-angle and horizontal wells (Expanded Abstract).,” Society of Exploration Geophysicists (SEG) 86th Ann. Internat. Mtg. Dallas, TX, October 16-21., 2016.
V. Puzyrev and Torres-Verdín, C., “Inversion-based interpretation of 3D borehole directional resistivity measurements acquired in high-angle and horizontal wells (Expanded Abstract),” Society of Exploration Geophysicists (SEG) 86th Ann. Internat. Mtg. Dallas, TX, October 16-21, 2016.
S. Huang and Torres-Verdín, C., “Inversion-based interpretation of borehole sonic measurements using semi-analytical spatial sensitivity functions,” Geophysics, vol. 81, no. 2, pp. D111-D124, 2016.
S. Huang and Torres-Verdín, C., “Inversion-based interpretation of borehole sonic measurements using semi-analytical spatial sensitivity functions,” Geophysics, vol. 81, no. 2, pp. D111-D124, 2016.
S. Huang and Torres-Verdín, C., “Inversion-based interpretation of borehole sonic measurements using semi-analytical spatial sensitivity functions,” Geophysics, vol. 81, no. 2, pp. D111-D124, 2016.
O. Ajayi, Torres-Verdín, C., and Preeg, W. E., “Inversion-based interpretation of logging-while-drilling gamma-ray spectroscopy measurements.,” Geophysics, vol. 81, no. 1, pp. D9-D34, 2016.
O. Ajayi, Torres-Verdín, C., and Preeg, W. E., “Inversion-based interpretation of logging-while-drilling gamma-ray spectroscopy measurements,” Geophysics, vol. 81, no. 1, pp. D9-D34, 2016.
M. J. Ramos, Espinoza, D. N., Torres-Verdín, C., Shovkun, I., and Grover, T., “Laboratory characterization and detection of fractures through combined ultrasonic and triaxial-stress testing (Extended Abstract).,” American Rock Mechanics Association (ARMA) 50th US Rock Mechanics/Geomechanics Symposium. Houston, Texas, June 26-29, 2016.
M. J. Ramos, Espinoza, D. N., Torres-Verdín, C., Shovkun, I., and Grover, T., “Laboratory characterization and detection of fractures through combined ultrasonic and triaxial-stress testing (Extended Abstract),” American Rock Mechanics Association (ARMA) 50th US Rock Mechanics/Geomechanics Symposium. Houston, Texas, June 26-29, 2016.
L. Zhang, Xiao, P., Shi, L., Henkelman, G., Goodenough, J. B., and Zhou, J., “Localized Mg-vacancy states in the thermoelectric material Mg2−δSi0.4Sn0.6,” Journal of Applied Physics, vol. 119, pp. 085104, 2016. Publisher's Version
E. E. Ureña-Benavides, Lin, E. L., Foster, E. L., Xue, Z., Ortiz, M., Fei, Y., Larsen, E. S., Kmetz II, A. A., Lyon, B. A., and Bielawski, C. W., “Low Adsorption of Magnetite Nanoparticles with Uniform Polyelectrolyte Coatings in Concentrated Brine on Model Silica and Sandstone,” Industrial & Engineering Chemistry Research, 2016. Publisher's VersionAbstract
In subsurface imaging and oil recovery where temperatures and salinities are high, it is challenging to design polymer-coated nanoparticles with low retention (high mobility) in porous rock. Herein, the grafting of poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co-acrylic acid) (poly(AMPS-co-AA)) on magnetic iron oxide nanoparticles was sufficiently uniform to achieve low adsorption on model colloidal silica and crushed Berea sandstone in highly concentrated API brine (8% NaCl and 2% CaCl2 by weight). The polymer shell was grafted via amide bonds to an aminosilica layer, which was grown on silica-coated magnetite nanoparticles. The particles were found to be stable against aggregation in American Petroleum Institute (API) brine at 90 °C for 24 h. For IO nanoparticles with ∼23% polymer content, Langmuir adsorption capacities on colloidal silica and crushed Berea Sandstone in batch experiments were extremely low at only 0.07 and 0.09 mg of IO/m2, respectively. Furthermore, upon injection of a 2.5 mg/mL IO suspension in API brine in a column packed with crushed Berea sandstone, the dynamic adsorption of IO nanoparticles was only 0.05 ± 0.01 mg/m2, which is consistent with the batch experiment results. The uniformity and high concentration of solvated poly(AMPS-co-AA) chains on the IO surfaces provided electrosteric stabilization of the nanoparticle dispersions and also weakened the interactions of the nanoparticles with negatively charged silica and sandstone surfaces despite the very large salinities.
Z. Wang, Xu, X., Fan, D., Wang, Y., and Chen, R., “Low-loss Subwavelength Grating Waveguide Bends Based on Index Engineering,” in CLEO: Science and Innovations 2016, San Jose, California, United States, 2016. Publisher's VersionAbstract
We report the design, simulation and experimental demonstration of low loss subwavelength grating waveguide (SWG) bends. With trapezoidal shape silicon pillars, the average insertion loss of a 5μm SWG waveguide bend is reduced drastically from 5.43dB to 1.10dB per 90°bend for quasi-TE polarization.
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L. A. Jauregui, Pettes, M. T., Rokhinson, L. P., Shi, L., and Chen, Y. P., “Magnetic field-induced helical mode and topological transitions in a topological insulator nanoribbon,” Nature Nanotechnology, vol. 11, pp. 345–351, 2016. Publisher's VersionAbstract
The spin-helical Dirac fermion topological surface states in a topological insulator nanowire or nanoribbon promise novel topological devices and exotic physics such as Majorana fermions. Here, we report local and non-local transport measurements in Bi2Te3 topological insulator nanoribbons that exhibit quasi-ballistic transport over ∼2 μm. The conductance versus axial magnetic flux Φ exhibits Aharonov–Bohm oscillations with maxima occurring alternately at half-integer or integer flux quanta (Φ0 = h/e, where h is Planck's constant and e is the electron charge) depending periodically on the gate-tuned Fermi wavevector (kF) with period 2π/C (where C is the nanoribbon circumference). The conductance versus gate voltage also exhibits kF-periodic oscillations, anti-correlated between Φ = 0 and Φ0/2. These oscillations enable us to probe the Bi2Te3 band structure, and are consistent with the circumferentially quantized topological surface states forming a series of one-dimensional subbands, which undergo periodic magnetic field-induced topological transitions with the disappearance/appearance of the gapless Dirac point with a one-dimensional spin helical mode.

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