Browsing by Author "Kusalik, Peter G."
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- ItemOpen AccessApplications of Integral Equation Calculations to High-Temperature Solvation Phenomena(Springer, 2000) Kusalik, Peter G.; Chialvo, A. A.; Kalyuzhnyi, Yu. V.; Cummings, P. T.
- ItemOpen AccessCalculation of the third virial coefficient for water(American Institute of Physics, 1995) Kusalik, Peter G.; Liden, F.; Svishchev, I. M.
- ItemOpen AccessA comparison between computer simulation and theoretical results for fluids of dipolar soft spheres(Taylor & Francis, 1989) Kusalik, Peter G.
- ItemOpen AccessA comparison between computer simulation and theoretical results for ionic solutions(Taylor & Francis, 1987) Kusalik, Peter G.; Caillol, J. M.; Levesque, D.; Weis, J. J.; Patey, G. N.
- ItemOpen AccessComputer simulation and theoretical results for a polar-polarizable fluid(Taylor & Francis, 1985) Kusalik, Peter G.; Caillol, J. M.; Levesque, D.; Weis, J. J.; Patey, G. N.
- ItemOpen AccessComputer simulation results for the dielectric properties of highly polar fluid(American Institute of Physics, 1990) Kusalik, Peter G.
- ItemOpen AccessComputer simulation study of a highly polar fluid under the influence of static electric fields(Taylor & Francis, 1994) Kusalik, Peter G.
- ItemOpen AccessComputer simulations of heterogeneous crystal growth of atomic systems(Taylor & Francis, 2005) Kusalik, Peter G.; Gulam Razul, M. S.; Tam, E. V.; Lam, M. E.; Linden, P.
- ItemEmbargoConfirmation and Quantification of Nanobubbles in Water Produced from a Batch Generator Driven by Electric Fields(2023-08) Andrews, Jeas Grejoy; Kimura-Hara, Susana Y.; Kusalik, Peter G.; Marriott, Robert A.; Thurbide, Kevin B.Nanobubbles, also known as ultrafine bubbles, are spherical gas pockets suspended in a liquid or attached to a solid substrate. The former is referred to as bulk nanobubbles, and the latter is termed as surface nanobubbles. Bulk nanobubbles are the focus of this study. Due to their smaller size, and large surface-to-volume ratio, they are remarkable in maintaining neutral buoyancy, and high mass transfer efficiencies. In this study, oxygen nanobubbles are created in water using a self-developed batch generator with the application of an electric field. Preliminary investigations of critical factors with this generator influencing nanobubble generation, such as wire arrangements, low-pressure headspace gas provision, and electric field intensities, are studied. Another focus of this study is to confirm the nanobubble existence using a sensitive speed of sound measurement, vibrating tube density (VTD) meter, and other sizing and counting techniques such as dynamic light scattering (DLS), nanoparticle tracking analyzer (NTA), and cryogenic scanning electron microscopy (Cryo-SEM).
- ItemOpen AccessCrystallization of Liquid Water in a Molecular Dynamics Simulation(American Physical Society, 1994) Kusalik, Peter G.; Svishchev, Igor M.
- ItemOpen AccessCrystallization of Molecular Liquids in Computer Simulations: Carbon Dioxide(American Physical Society, 1995) Kusalik, Peter G.; Svishchev, Igor M.
- ItemOpen AccessDetermination of the transient polarization response of a dipolar fluid(Taylor & Francis, 1992) Kusalik, Peter G.
- ItemOpen AccessThe dielectric constant of polar fluids and the distribution of the total dipole moment(American Institute of Physics, 1994) Kusalik, Peter G.; Mandy, M. E.; Svishchev, I. M.
- ItemOpen AccessThe distribution of fluctuations of the total dipole moment in polar liquids(Taylor & Francis, 1993) Kusalik, Peter G.
- ItemOpen AccessDynamical properties of Coulombic systems at low densities: computer simulation results(Elsevier, 1993) Kusalik, Peter G.; Svishchev, I.M.
- ItemOpen AccessHard discs with embedded three dimensional quadrupoles(Taylor & Francis, 1983) Kusalik, Peter G.; O'Shea, Seamus F.
- ItemOpen AccessHeterogeneous Catalytic H2S Oxidation within Supercritical CO2 for a New Sulfur Recovery Process(2021-01-25) Lee, Seungwook; Marriott, Robert A.; Birss, Viola I.; Kusalik, Peter G.; Trudel, Simon; Versteeg, Geert F.Many natural gas sources can have small amounts of acid gases (H2S and CO2). These acid gases are removed from the natural gas for the consumers due to toxicity and low heating value. Conventionally, acid gas is removed by absorption into aqueous amine solutions. This separated acid gas can then be injected into reservoirs for sequestration or can be further processed to convert the H2S to S8 by sulfur recovery. For low-quality acid gases (< 1% H2S in CO2), available methods to remove H2S results in waste rather than marketable sulfur. The remaining CO2 is at near atmospheric pressure, often being released to the environment due to high recompression costs. In this thesis, an alternative sulfur recovery process is investigated to produce marketable sulfur and high-pressure CO2 using post cryogenic separation of low-quality acid gases. Cryogenic distillation for acid gas separation is beneficial, resulting in a high-pressure liquid form of acid gas that does not require recompression. However, currently available low-pressure methods to convert H2S to S8 do not take the advantage of this high-pressure. Heterogeneous catalysis was utilized to convert H2S to S8 within the high-pressure CO2 in this thesis. For the high-pressure sulfur recovery process to be viable, several studies were completed in order to provide the best conditions to carry out the heterogeneous catalysis in high-pressure CO2. Sulfur solubility within high-pressure CO2 was initially studied to define the process conditions to maintain a single-phase product and subsequent separation of produced sulfur and CO2. The sulfur solubility study also allowed for the modelling of the sulfur fugacity coefficient within high-pressure CO2, which was utilized in a high-pressure Gibbs Free Energy Minimization routine to calculate the theoretical equilibrium conversion limit of H2S to S8. Heterogeneous H2S oxidation catalyses were experimentally carried out to verify calculated high-pressure thermodynamic conversion limits by the Gibbs Free Energy Minimization routine. Kinetic limitations were found at lower temperatures and higher pressures in pursuit of improving the thermodynamic conversion limit. The kinetics of the high-pressure heterogeneous H2S oxidation catalysis were studied to model the kinetic limitations of the reaction within the high-pressure CO2. The three models developed allow for high-pressure calculations of S8/CO2 solubility conditions, thermodynamic H2S equilibrium conversion limits, and minimum residence times required for the equilibrium conversion limits to establish. These models therefore enable practical industrial condition optimization to carry out the heterogeneous catalytic oxidation of H2S within high-pressure CO2.
- ItemOpen AccessIce growth phenomenology in the presence of non-electrolytes: from small molecules to antifreeze proteins(2012-08-16) Pirzadeh, Payman; Kusalik, Peter G.Ice is a well known material, and is found in a variety of shapes on earth and its atmosphere. Despite all the investigations on ice, the molecular details of its growth from a liquid phase have yet to be resolved. Molecular-level understanding of ice growth helps better controlling and engineering ice formation in cryopreservation, cryosurgery and the food industry. In this thesis, the growth of ice from pure melt and solution is investigated using a molecular dynamics approach. The formation and evolution of water rings have been the focus of this work in the case of ice growth from pure water as well as the influence of non-electrolyte solutes and gas hydrates. In the case of growth from pure water, the key single and coupled ring features participating in the transition of water to ice have been identified. While the presence of non-electrolyte solutes typically suppresses the populations of these rings, it can enhance formation of a special feature on the surface of ice, identified as the coupled 5-8 ring defect, which can play an essential role in promoting stacking faults within the ice crystal. The coupled 5-8 ring defects can initiate structural fluctuations promoting occurrence of 5-member rings in the case of a supersaturated methane solution, elevating the local density of methane molecules and ultimately nucleating an amorphous phase of methane clathrate hydrate. Furthermore, the coupled 5-8 ring defects appear to serve as grain boundaries, and potentially inhibit recrystallization of ice crystals, particularly in the presence of antifreeze proteins (AFPs). The relative structural flexibility of AFPs, their ability to retain the hydration shell upon crystallization of bulk water and the hydrophobic nature of their ice binding site apparently enable them to induce these defects when they interact with the pyramidal faces of hexagonal ice. In addition to the structural descriptions of the ice-water interface, thermodynamic properties such as energy, entropy, and free energy across the ice-water interface have been estimated. Furthermore, a stepwise evolution of order is observed during the growth of ice using the populations of single and coupled rings as order parameters. A crystallization funnel is suggested which captures the structural and thermodynamic evolution of water molecules towards the crystalline state. In addition to the molecular-level insights into the ice growth, this thesis also provides suggestions for future explorations.
- ItemOpen AccessThe local structure in liquid methylamine and methylamine–water mixtures(American Institute of Physics, 2000) Kusalik, Peter G.; Bergman, Dan; Laaksonen, Aatto
- ItemOpen AccessMachine Learning Assisted Study of Early-Stage MOF Self-Assembly: Structural Characterization and Multi-Scale Modeling(2024-01-25) Shukla, Rishabh; Kusalik, Peter G.; Kusalik, Peter G.; MacCallum, Justin Laine; Shimizu, George Kisa Hayashi; Salahub, Dennis R.; Woo, Tom K.Metal-Organic Frameworks (MOFs) are an important class of materials with a broad range of applications (e.g., gas storage and catalysis). While a great number of MOF compounds are reported in the literature, where these studies have described a multitude of ways of synthesizing MOFs, there have been few studies probing the self-assembly process. Mechanisms of MOF self-assembly are amenable to Molecular Dynamic (MD) simulations, although there have been very few such studies to date, and even they suffer from unreasonable assumptions or fall short due to the limited timescales available to all-atom simulations. To allow simulations to reach much longer timescales, this thesis project looks to find an optimal way to develop effective potentials. The all-atom molecular interactions have been redefined so that the explicit solvent molecules could be omitted from the system without losing the solvent effect on the self-assembly processes. Since a large majority of atoms in the explicit system are the solvent molecules, we expect the effective potentials would result in a dramatic acceleration of the simulations. The complexity of the potential space makes the optimization slow and sensitive to small perturbations. We have explored the challenges associated with the iterative optimization of effective potentials and worked especially on the transferability of these potentials from a small MOF-like system to an ever-evolving environment in MOF self-assembly. Another important aspect of the project is to characterize the structures seen in the self-assembly process and to quantify the structural order, which can be further used to bias the simulations and further speed up the sampling, thus bridging the gap between experimental and computational studies.