Browsing by Author/Contributor "Wexler, Carlos, 1966-"
Now showing items 1-20 of 22
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Behavior of hexane on graphite at near-monolayer densities: Molecular dynamics study
Pint, Cary L.; Roth, M. W.; Wexler, Carlos, 1966- (American Physical Society, 2006)We present the results of molecular-dynamics studies of hexane physisorbed onto graphite for eight coverages in the range 0.875⩽ρ⩽1.05 (in units of monolayers). At low temperatures, the adsorbate molecules form a uniaxially ... -
Collective excitations in quantum Hall liquid crystals: Single-mode approximation calculations
Lapilli, Cintia Mariela, 1980-; Wexler, Carlos, 1966- (American Physical Society, 2006)A variety of recent experiments probing the low-temperature transport properties of quantum Hall systems have suggested an interpretation in terms of liquid crystalline mesophases dubbed quantum Hall liquid crystals. The ... -
Computational studies of methane adsorption in nanoporous carbon
Ortiz, Lindsey (University of Missouri--Columbia, 2012)In this thesis we have completed computational studies using Grand Canonical Monte Carlo on the adsorption of methane into a graphitic nanoporous adsorbent with slit-shaped pores. Simulations were done at a temperature of ... -
Cross-over mechanism of the melting transition in monolayers of alkanes adsorbed on graphite and the universality of energy scaling
Firlej, Lucyna; Kuchta, Bogdan; Roth, M. W.; Wexler, Carlos, 1966- (arXiv, 2009)The interplay between the torsional potential energy and the scaling of the 1-4 van der Waals and Coulomb interactions determines the stiffness of flexible molecules. In molecular simulations often ad-hoc values for the ... -
Disclination unbinding transition in quantum Hall liquid crystals
Dorsey, Alan T.; Wexler, Carlos, 1966- (American Physical Society, 2001)We derive the long-wavelength elastic theory for the quantum Hall smectic state starting from the Hartree-Fock approximation. Dislocations in this state lead to an effective nematic model for T>0, which undergoes a ... -
Enhanced hydrogen adsorption in boron substituted carbon nanospaces
Firlej, Lucyna; Roszak, Sz.; Kuchta, Bogdan; Pfeifer, Peter; Wexler, Carlos, 1966- (American Institute of Physics, 2009)Activated carbons are one of promising groups of materials for reversible storage of hydrogen by physisorption. However, the heat of hydrogen adsorption in such materials is relatively low, in the range of about 4-8 kJ/mol, ... -
Fermi hypernetted-chain study of half-filled Landau levels with broken rotational symmetry
Ciftja, Orion; Wexler, Carlos, 1966- (American Physical Society, 2002)We investigate broken rotational symmetry (BRS) states at half-filling of the valence Landau level (LL). We generalize Rezayi and Read's (RR) trial wave function, a special case of Jain's composite fermion (CF) wave ... -
Hydrogen storage in engineered carbon nanospaces
Burress, Jacob W., 1983-; Kraus, Michael A., 1978-; Beckner, Matt; Cepel, Raina; Suppes, Galen J.; Pfeifer, Peter; Wexler, Carlos, 1966- (Institute of Physics, 2009)It is shown how appropriately engineered nanoporous carbons provide materials for reversible hydrogen storage, based on physisorption, with exceptional storage capacities (~80 g H2/kg carbon, ~50 g H2/liter carbon, at 50 ... -
Hypernetted-chain study of broken rotational symmetry states for the ν=1/3 fractional quantum Hall effect and other fractionally filled Landau levels
Ciftja, Orion; Wexler, Carlos, 1966- (American Physical Society, 2001)We investigate broken rotational symmetry (BRS) states for the fractional quantum Hall effect (FQHE) at 1/3 filling of the valence Landau level (LL). Recent Monte Carlo calculations by Musaelian and Joynt [J. Phys.: Condens. ... -
Investigations of novel hydrogen adsorption phenomena
Olsen, Raina J. (University of Missouri--Columbia, 2011)For convenient use of energy, it is common to use chemical potential energy stored in a fuel. To reduce pollution, a desirable fuel is molecular hydrogen, whose only byproduct is water vapor. However, there are still many ... -
Liquid crystalline states for two-dimensional electrons in strong magnetic fields
Ciftja, Orion; Lapilli, Cintia Mariela, 1980-; Wexler, Carlos, 1966- (American Physical Society, 2004)Based on the Kosterlitz-Thouless-Halperin-Nelson-Young theory of two-dimensional melting and the analogy between Laughlin states and the two-dimensional one-component plasma, we investigate the possibility of liquid ... -
Melting of hexane monolayers adsorbed on graphite: the role of domains and defect formation
Firlej, Lucyna; Kuchta, Bogdan; Roth, M. W.; Wexler, Carlos, 1966- (arXiv, 2009)We present the first large-scale molecular dynamics simulations of hexane on graphite that completely reproduces all experimental features of the melting transition. The canonical ensemble simulations required and used the ... -
Monte Carlo simulation method for Laughlin-like states in a disk geometry
Ciftja, Orion; Wexler, Carlos, 1966- (American Physical Society, 2003)We discuss an alternative accurate Monte Carlo method to calculate the ground-state energy and related quantities for Laughlin states of the fractional quantum Hall effect in a disk geometry. This alternative approach ... -
Phase transitions in hexane monolayers physisorbed onto graphite
Roth, M. W.; Pint, Cary L.; Wexler, Carlos, 1966- (American Physical Society, 2005)We report the results of molecular dynamics simulations of a complete monolayer of hexane physisorbed onto the basal plane of graphite. At low temperatures the system forms a herringbone solid. With increasing temperature, ... -
Properties of low-dimensional systems
Lapilli, Cintia Mariela, 1980- (University of Missouri--Columbia, 2006)[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] In this work we study the equilibrium properties of systems in two-dimensions, and the effects that discrete symmetry, space dimensionality, character ... -
Quantum energy levels of hydrogen adsorbed on nanoporous carbons: an intrinsic probe for pore structure, and improving Monte Carlo simulations of adsorption [abstract]
Cepel, Raina; Wexler, Carlos, 1966-; Pfeifer, Peter; Kuchta, Bogdan; Firlej, Lucyna (2009)Hydrogen is the lightest molecule in nature, making both rotational and translational degrees of freedom eminently quantum mechanical (especially at low temperatures). For isolated molecules the first excited (degenerate) ... -
The reversibility of the adsorption of methane-methyl mercaptan mixtures in nanoporous carbon
Golebiowska, Monika R. (University of Missouri--Columbia, 2011)Methane is the main constituent of natural gas (NG). As fuel for vehicular applications NG requires sorbents that allow efficient, reversible and safe storage at room temperature and moderate pressure. To enable easy human ... -
Structural and chemical characterization of modified graphenes for hydrogen storage
Schaeperkoetter, Joseph (University of Missouri--Columbia, 2018)The automotive industry is already showing signs of moving beyond a century long dependence on petroleum. The tens of billions of dollars in the electric vehicle (EV) consumer market are a powerful demonstration of this ... -
Structural and energetic factors in designing a perfect nano-porous sorbent for hydrogen storage [abstract]
Kuchta, Bogdan; Firlej, Lucyna; Wexler, Carlos, 1966-; Pfeifer, Peter; Cepel, Raina (2009)Carbons are one of several promising groups of materials for hydrogen storage by adsorption. However, the heat of hydrogen physisorption in such materials is low, in the range of about 4-8 kJ/mol which limits the total ... -
Structural and phase properties of tetracosane (C24H50) monolayers adsorbed on graphite. Explicit Hydrogen Molecular Dynamics study
Firlej, Lucyna; Kuchta, Bogdan; Roth, M. W.; Connolly, M. J.; Wexler, Carlos, 1966- (arXiv, 2008)We discuss Molecular Dynamics (MD) computer simulations of a tetracosane (C24H50) monolayer physisorbed onto the basal plane of graphite. The adlayer molecules are simulated with explicit hydrogens, and the graphite ...