A5030711255- Coagulation and Flocculation Studies
- Dust and Plasma Wave Phenomena
- Particle Dynamics in Fluid Flows
- Aerosol Filtration and Electrostatic Precipitation
- nanoparticles nucleation surface interactions
- Ionosphere and magnetosphere dynamics
- Electrostatics and Colloid Interactions
- Earthquake Detection and Analysis
- Advanced Chemical Physics Studies
- Atomic and Molecular Physics
- Cold Atom Physics and Bose-Einstein Condensates
- Atmospheric chemistry and aerosols
- High-Energy Particle Collisions Research
- Molecular Junctions and Nanostructures
- Electrohydrodynamics and Fluid Dynamics
- Quantum Electrodynamics and Casimir Effect
- Advanced Thermodynamics and Statistical Mechanics
- Quantum, superfluid, helium dynamics
- Plasma Diagnostics and Applications
- Catalytic Processes in Materials Science
- Toxic Organic Pollutants Impact
- Spectroscopy and Quantum Chemical Studies
- Advanced Aircraft Design and Technologies
- Microfluidic and Bio-sensing Technologies
- Atmospheric aerosols and clouds
University of Memphis
2018-2025
University of Iowa
2018
University of Minnesota
2011-2015
Dusty plasmas are electrically quasi-neutral media that, along with electrons, ions, neutral gas, radiation, and electric and/or magnetic fields, also contain solid or liquid particles sizes ranging from a few nanometers to micrometers. These can be found in many natural environments as well various laboratory setups industrial applications. As separate branch of plasma physics, the field dusty physics was born beginning 1990s at intersection interests communities investigating astrophysical...
We examine theoretically and numerically collisions of arbitrarily shaped particles in the mass transfer transition regime, where ambiguities remain regarding collision rate coefficient (collision kernel). Specifically, we show that dimensionless kernel for particles, H, depends solely on a correctly defined diffusive Knudsen number (KnD , contrast with traditional number), to determine number, it is necessary calculate two combined size parameters colliding particles: Smoluchowski radius,...
Aerosol particle reactions with vapor molecules and molecular clusters are often collision rate limited, hence determination of particle-vapor molecule particle-molecular cluster rates fundamental importance. These collisions typically occur in the mass transfer transition regime, wherein kernel (collision coefficient) is dependent upon diffusive Knudsen number, Kn(D). While this alone prohibits analytical kernel, aerosol particle- further complicated when particles non-spherical, as case...
Particle–vapor molecule (condensation) and particle–particle (coagulation) collision kernels are critically important parameters for the description of particle size distribution evolution in aerosols. We use mean first passage time calculations to find a dimensionless form kernel that applies limit where ratio masses colliding entities (aerosol particles or vapor molecules) gas mass, Z, approaches infinity, dilute concentration. In these calculations, motion is monitored with Langevin...
Collisional growth and ionization is commonplace for gas phase nanoparticles (i.e., in aerosols). Nanoparticle collisions atmospheric pressure environments occur the mass transfer transition regime, further attractive singular contact potentials (which arise when modeling as condensed matter which potential energy approaches -∞ two entities contact) often have a non-negligible influence on collision processes. For these reasons rate calculations are not straightforward. We use mean first...
In aerosol and dusty plasma systems, the behavior of suspended particles (grains) is often strongly influenced by collisions occurring between ions particles, as well themselves. determining collision kernel or rate coefficient for such charged entities, complications arise in that process can be completely described neither continuum transport mechanics nor free molecular (ballistic) mechanics; is, are transition regime processes. Further, both thermal energy potential colliding entities...
In this computational study, we self-consistently calculate the rate constants of mutual neutralization reactions by incorporating electron transfer probability, using Landau–Zener state transition theory with inputs derived from ab initio quantum chemistry calculations, into classical trajectory simulations. Electronic structure calculations are done correlation consistent basis sets multi-reference configuration interaction to map all molecular electronic states below ion-dissociation...
Abstract Particle charging in the afterglows of non-thermal plasmas typically take place a non-neutral space charge environment. We model same by incorporating particle–ion collision rate constant models, developed prior work analyzing trajectories calculated using Langevin Dynamics (LD) simulations, into species transport equations for ions, electrons and charged particles afterglow. A scaling analysis particle additional LD calculations are presented to extend range applicability ion...
Determination of the particle charge in aerosols and dusty plasmas requires an accurate calculation particle-ion collision kernel taking into account Coulombic coupling ion-neutral gas molecule collisions. While effect interactions any strength is described accurately continuum limit free molecular limit, physical description at intermediate collisional regimes remains elusive. Specifically, Coulomb influenced collisions between oppositely charged particles ions have evaded theoretical past....
We report a Bidirectional Electrode Control Arm Assembly (BECAA) for precisely manipulating dust clouds levitated above the powered electrode in RF plasmas. The reported techniques allow creation of perfectly 2D layers by eliminating off-plane particles moving from outside plasma chamber without altering conditions. tilting and electrodes using BECAA also allows precise repeatable elimination one to achieve any desired number grains N trial error. Simultaneously acquired top side view images...
In this computational study, we describe a self-consistent trajectory simulation approach to capture the effect of neutral gas pressure on ion–ion mutual neutralization (MN) reactions. The electron transfer probability estimated using Landau–Zener (LZ) transition state theory is incorporated into classical simulations elicit predictions MN cross sections in vacuum and rate constants at finite pressures. Electronic structure calculations with multireference configuration interaction large...
The dispersion of dry, cohesive micro- and nanosized powders has wide applications ranging from medical environmental science to manufacturing technology. Being able disperse the dry powder at a stable concentration over periods time (∼hour several hours) is challenging achieve, which we attempt address with novel A portable, cost effective simple device that uses ultrasonic energy for continuous feeding aerosol particles de-agglomeration developed tested commercially available powders....
The shape of an aerosol particle strongly influences its mass and momentum transfer cross-sections, charging properties, other physical properties. We present explicit time-stepping procedure to simulate the rotational Brownian motion arbitrary shaped particles by solving Euler's equation rotation. A Langevin formulation rotation equations is used, wherein due thermal collisions between a background gas molecules represented using stochastic fluctuating torque fluid resistance included as...