Open Access. Powered by Scholars. Published by Universities.^{®}
Nanoscience and Nanotechnology Commons^{™}
Open Access. Powered by Scholars. Published by Universities.^{®}
 Institution
 Keyword

 Selected recent publications (15)
 Dewetting (4)
 Presentations (4)
 Mathematical Modeling (3)
 Selfassembly (3)

 Theory and models of film growth (3)
 Morphology of films (3)
 Pulsed laser irradiation (2)
 Thermocapillary convection (2)
 Selforganization (2)
 Stability analysis (2)
 PDE model (2)
 Liquid bilayer films (2)
 Interfacial stabil ity (2)
 Nanopatterning (2)
 Ultrathin metal lms (2)
 Density (1)
 Fluids (1)
 Centrality (1)
 Focus Localization (1)
 Beaded fiber (1)
 Applied sciences (1)
 Brain Connectivity (1)
 Electrolyte solutions (1)
 Bubble electrospinning (1)
 Bubbfil spinning (1)
 Air permeability (1)
 Epilepsy (1)
 Biological sciences (1)
 Dynamics (1)
 Publication Year
 Publication
 Publication Type
 File Type
Articles 1  30 of 41
FullText Articles in Nanoscience and Nanotechnology
Swelling As A Stabilizing Mechanism During Ion Bombardment Of Thin Films: An Analytical And Numerical Study, Jennifer M. Swenson
Swelling As A Stabilizing Mechanism During Ion Bombardment Of Thin Films: An Analytical And Numerical Study, Jennifer M. Swenson
Mathematics Theses and Dissertations
Irradiation of semiconductor surfaces often leads to the spontaneous formation of rippled structures at certain irradiation angles. However, at high enough energies, these structures are observed to vanish for all angles, despite the absence of any identified, universallystabilizing physical mechanisms in operation. Here, we examine the effect on pattern formation of radiationinduced swelling, which has been excluded from prior treatments of stress in irradiated films. After developing a suitable continuum model, we perform a linear stability analysis to determine its effect on stability. Under appropriate simplifying assumptions, we find swelling indeed to be stabilizing at wavenumbers typical of experimental observations ...
Interplay Of Quantum Size Effect, Anisotropy And Surface Stress Shapes The Instability Of Thin Metal Films, Mikhail Khenner
Interplay Of Quantum Size Effect, Anisotropy And Surface Stress Shapes The Instability Of Thin Metal Films, Mikhail Khenner
Mathematics Faculty Publications
Morphological instability of a planar surface ([111], [011], or [001]) of an ultrathin metal film is studied in a parameter space formed by three major effects (the quantum size effect, the surface energy anisotropy and the surface stress) that influence a film dewetting. The analysis is based on the extended Mullins equation, where the effects are cast as functions of the film thickness. The formulation of the quantum size effect (Z. Zhang et al., PRL 80, 5381 (1998)) includes the oscillation of the surface energy with thickness caused by electrons confinement. By systematically comparing the effects, their contributions into the ...
Interplay Of Quantum Size Effect, Anisotropy And Surface Stress Shapes The Instability Of Thin Metal Films, Mikhail Khenner
Interplay Of Quantum Size Effect, Anisotropy And Surface Stress Shapes The Instability Of Thin Metal Films, Mikhail Khenner
Mikhail Khenner
Generalized Partial Directed Coherence And Centrality Measures In Brain Networks For Epileptogenic Focus Localization, Joshua Aaron Adkinson
Generalized Partial Directed Coherence And Centrality Measures In Brain Networks For Epileptogenic Focus Localization, Joshua Aaron Adkinson
Doctoral Dissertations
Accurate epileptogenic focus localization is required prior to surgical resection of brain tissue for treatment of patients with intractable temporal lobe epilepsy, a clinical need that is partially fulfilled to date through a subjective, and at times inconclusive, evaluation of the recorded electroencephalogram (EEG). Using brain connectivity analysis, patterns of causal interactions between brain regions were derived from multichannel EEG of 127 seizures in nine patients with focal, temporal lobe epilepsy (TLE). The statistically significant directed interactions in the reconstructed brain networks were estimated from three second intracranial multielectrode EEG segments using the Generalized Partial Directed Coherence (GPDC) and validated ...
Model For Computing Kinetics Of The Graphene Edge Epitaxial Growth On Copper, Mikhail Khenner
Model For Computing Kinetics Of The Graphene Edge Epitaxial Growth On Copper, Mikhail Khenner
Mathematics Faculty Publications
A basic kinetic model that incorporates a coupled dynamics of the carbon atoms and dimers ona copper surface is used to compute growth of a singlelayer graphene island. The speed of theisland's edge advancement on Cu[111] and Cu[100] surfaces is computed as a function of the growthtemperature and pressure. Spatially resolved concentration pro les of the atoms and dimers aredetermined, and the contributions provided by these species to the growth speed are discussed.Island growth in the conditions of a thermal cycling is studied.
Model For Computing Kinetics Of The Graphene Edge Epitaxial Growth On Copper, Mikhail Khenner
Model For Computing Kinetics Of The Graphene Edge Epitaxial Growth On Copper, Mikhail Khenner
Mikhail Khenner
Criterion For An Oscillatory Charged Jet During The Bubble Spinning Process, JiHuan He, H.Y. Kong
Criterion For An Oscillatory Charged Jet During The Bubble Spinning Process, JiHuan He, H.Y. Kong
JiHuan He
The oscillatory diameter of the charged jet during the bubble electrospinning results in beads on the obtained nanofibers. We demonstrate that the applied voltage and the initial flow rate of the jet are the crucial parameters that are necessary to control morphology of the nanofibers. We also find that there is a criterion for production of smooth nanofibers without beads. The theory developed in this paper can be extended to the classical electrospinning and the blown bubblespinning.
Fractional Calculus For Nanoscale Flow And Heat Transfer, HongYan Liu, JiHuan He, ZhengBiao Li
Fractional Calculus For Nanoscale Flow And Heat Transfer, HongYan Liu, JiHuan He, ZhengBiao Li
JiHuan He
Purpose – Academic and industrial researches on nanoscale flows and heat transfers are an area of increasing global interest, where fascinating phenomena are always observed, e.g. admirable water or air permeation and remarkable thermal conductivity. The purpose of this paper is to reveal the phenomena by the fractional calculus. Design/methodology/approach – This paper begins with the continuum assumption in conventional theories, and then the fractional Gauss’ divergence theorems are used to derive fractional differential equations in fractal media. Fractional derivatives are introduced heuristically by the variational iteration method, and fractal derivatives are explained geometrically. Some effective analytical approaches to ...
Controlling Nanoparticles Formation In Molten Metallic Bilayers By PulsedLaser Interference Heating, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Controlling Nanoparticles Formation In Molten Metallic Bilayers By PulsedLaser Interference Heating, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Mathematics Faculty Publications
The impacts of the twobeam interference heating on the number of coreshell and embedded nanoparticles and on nanostructure coarsening are studied numerically based on the nonlinear dynamical model for dewetting of the pulsedlaser irradiated, thin (< 20 nm) metallic bilayers. The model incorporates thermocapillary forces and disjoining pressures, and assumes dewetting from the optically transparent substrate atop of the reflective support layer, which results in the complicated dependence of light reflectivity and absorption on the thicknesses of the layers. Stabilizing thermocapillary effect is due to the local thicknessdependent, steady state temperature profile in the liquid, which is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Linear stability analysis of the model equations set for Ag/Co bilayer predicts the dewetting length scales in the qualitative agreement with experiment.
Controlling Nanoparticles Formation In Molten Metallic Bilayers By PulsedLaser Interference Heating, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Controlling Nanoparticles Formation In Molten Metallic Bilayers By PulsedLaser Interference Heating, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Mikhail Khenner
The impacts of the twobeam interference heating on the number of coreshell and embedded nanoparticles and on nanostructure coarsening are studied numerically based on the nonlinear dynamical model for dewetting of the pulsedlaser irradiated, thin (< 20 nm) metallic bilayers. The model incorporates thermocapillary forces and disjoining pressures, and assumes dewetting from the optically transparent substrate atop of the reflective support layer, which results in the complicated dependence of light reflectivity and absorption on the thicknesses of the layers. Stabilizing thermocapillary effect is due to the local thicknessdependent, steady state temperature profile in the liquid, which is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Linear stability analysis of the model equations set for Ag/Co bilayer predicts the dewetting length scales in the qualitative agreement with experiment.
Formation Of Organized Nanostructures From Unstable Bilayers Of Thin Metallic Liquids, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Formation Of Organized Nanostructures From Unstable Bilayers Of Thin Metallic Liquids, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Mathematics Faculty Publications
Dewetting of pulsedlaser irradiated, thin (< 20 nm), optically reflective metallic bilayers on an optically transparent substrate with a reflective support layer is studied within the lubrication equations model. A steadystate bilayer film thickness (h) dependent temperature profile is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Large thermocapillary forces are observed along the plane of the liquidliquid and liquidgas interfaces due to this hdependent temperature, which, in turn, is strongly influenced by the hdependent laser light reflection and absorption. Consequently the dewetting is a result of the competition between thermocapillary and intermolecular forces. A linear analysis of the dewetting length scales established that the nonisothermal calculations better predict the experimental results as compared to the isothermal case within the bounding Hamaker coefficients. Subsequently, a computational nonlinear dynamics study of the dewetting pathway was performed for Ag/Co and Co/Ag bilayer systems to predict the morphology evolution. We found that the systems evolve towards formation of different morphologies, including coreshell, embedded, or stacked nanostructure morphologies.
Formation Of Organized Nanostructures From Unstable Bilayers Of Thin Metallic Liquids, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Formation Of Organized Nanostructures From Unstable Bilayers Of Thin Metallic Liquids, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman
Mikhail Khenner
Dewetting of pulsedlaser irradiated, thin (< 20 nm), optically reflective metallic bilayers on an optically transparent substrate with a reflective support layer is studied within the lubrication equations model. A steadystate bilayer film thickness (h) dependent temperature profile is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Large thermocapillary forces are observed along the plane of the liquidliquid and liquidgas interfaces due to this hdependent temperature, which, in turn, is strongly influenced by the hdependent laser light reflection and absorption. Consequently the dewetting is a result of the competition between thermocapillary and intermolecular forces. A linear analysis of the dewetting length scales established that the nonisothermal calculations better predict the experimental results as compared to the isothermal case within the bounding Hamaker coefficients. Subsequently, a computational nonlinear dynamics study of the dewetting pathway was performed for Ag/Co and Co/Ag bilayer systems to predict the morphology evolution. We found that the systems evolve towards formation of different morphologies, including coreshell, embedded, or stacked nanostructure morphologies.
Stability Of A Strongly Anisotropic Thin Epitaxial Film In A Wetting Interaction With Elastic Substrate, Mikhail Khenner, Wondimu Tekalign, Margo Levine
Stability Of A Strongly Anisotropic Thin Epitaxial Film In A Wetting Interaction With Elastic Substrate, Mikhail Khenner, Wondimu Tekalign, Margo Levine
Mathematics Faculty Publications
The linear dispersion relation for longwave surface perturbations, as derived by Levine et al. Phys. Rev. B 75, 205312 (2007) is extended to include a smooth surface energy anisotropy function with a variable anisotropy strength (from weak to strong, such that sharp corners and slightly curved facets occur on the corresponding Wulff shape). Through detailed parametric studies it is shown that a combination of a wetting interaction and strong anisotropy, and even a wetting interaction alone results in complicated linear stability characteristics of strained and unstrained films.
Modeling Diverse Physics Of Nanoparticle SelfAssembly In Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Modeling Diverse Physics Of Nanoparticle SelfAssembly In Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Mathematics Faculty Publications
Presents physics behind dewetting of thin liquid films and mathematical/computational modeling tools (Educational/Research presentation for senior physics majors).
Stability Of A Strongly Anisotropic Thin Epitaxial Film In A Wetting Interaction With Elastic Substrate, Mikhail Khenner, Wondimu T. Tekalign, Margo S. Levine
Stability Of A Strongly Anisotropic Thin Epitaxial Film In A Wetting Interaction With Elastic Substrate, Mikhail Khenner, Wondimu T. Tekalign, Margo S. Levine
Mathematics Faculty Publications
The linear dispersion relation for longwave surface perturbations, as derived by Levine et al. Phys. Rev. B 75, 205312 (2007) is extended to include a smooth surface energy anisotropy function with a variable anisotropy strength (from weak to strong, such that sharp corners and slightly curved facets occur on the corresponding Wulff shape). Through detailed parametric studies it is shown that a combination of a wetting interaction and strong anisotropy, and even a wetting interaction alone results in complicated linear stability characteristics of strained and unstrained films.
Stability Of A Strongly Anisotropic Thin Epitaxial Film In A Wetting Interaction With Elastic Substrate, Mikhail Khenner, Wondimu T. Tekalign, Margo S. Levine
Stability Of A Strongly Anisotropic Thin Epitaxial Film In A Wetting Interaction With Elastic Substrate, Mikhail Khenner, Wondimu T. Tekalign, Margo S. Levine
Mikhail Khenner
The linear dispersion relation for longwave surface perturbations, as derived by Levine et al. Phys. Rev. B 75, 205312 (2007) is extended to include a smooth surface energy anisotropy function with a variable anisotropy strength (from weak to strong, such that sharp corners and slightly curved facets occur on the corresponding Wulff shape). Through detailed parametric studies it is shown that a combination of a wetting interaction and strong anisotropy, and even a wetting interaction alone results in complicated linear stability characteristics of strained and unstrained films.
Modeling Diverse Physics Of Nanoparticle SelfAssembly In Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Modeling Diverse Physics Of Nanoparticle SelfAssembly In Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Mikhail Khenner
Presents physics behind dewetting of thin liquid films and mathematical/computational modeling tools (Educational/Research presentation for senior physics majors).
Morphological Evolution Of SingleCrystal Ultrathin Solid Films, Mikhail Khenner
Morphological Evolution Of SingleCrystal Ultrathin Solid Films, Mikhail Khenner
Mathematics Faculty Publications
An introduction to mathematical modeling of ultrathin solid films and the role of such modeling in nanotechnologies: Educational/Research presentation for senior physics majors
Morphological Evolution Of SingleCrystal Ultrathin Solid Films, Mikhail Khenner
Morphological Evolution Of SingleCrystal Ultrathin Solid Films, Mikhail Khenner
Mathematics Faculty Publications
An introduction to mathematical modeling of ultrathin solid films and the role of such modeling in nanotechnologies: Educational presentation for senior physics majors
Morphological Evolution Of SingleCrystal Ultrathin Solid Films, Mikhail Khenner
Morphological Evolution Of SingleCrystal Ultrathin Solid Films, Mikhail Khenner
Mikhail Khenner
An introduction to mathematical modeling of ultrathin solid films and the role of such modeling in nanotechnologies: Educational/Research presentation for senior physics majors
Oscillatory And Monotonic Modes Of LongWave Marangoni Convection In A Thin Film, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Oscillatory And Monotonic Modes Of LongWave Marangoni Convection In A Thin Film, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Mathematics Faculty Publications
We study longwave Marangoni convection in a layer heated from below. Using the scaling k=O Bi, where k is the wave number and Bi is the Biot number, we derive a set of amplitude equations. Analysis of this set shows presence of monotonic and oscillatory modes of instability. Oscillatory mode has not been previously found for such direction of heating. Studies of weakly nonlinear dynamics demonstrate that stable steady and oscillatory patterns can be found near the stability threshold.
Oscillatory And Monotonic Modes Of LongWave Marangoni Convection In A Thin Film, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Oscillatory And Monotonic Modes Of LongWave Marangoni Convection In A Thin Film, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Mathematics Faculty Publications
We study longwave Marangoni convection in a layer heated from below. Using the scaling k=O Bi, where k is the wave number and Bi is the Biot number, we derive a set of amplitude equations. Analysis of this set shows presence of monotonic and oscillatory modes of instability. Oscillatory mode has not been previously found for such direction of heating. Studies of weakly nonlinear dynamics demonstrate that stable steady and oscillatory patterns can be found near the stability threshold.
A TangentPlane, MarkerParticle Method For The Computation Of ThreeDimensional Solid Surfaces Evolving By Surface Diffusion On A Substrate, Ping Du, Mikhail Khenner, Harris Wong
A TangentPlane, MarkerParticle Method For The Computation Of ThreeDimensional Solid Surfaces Evolving By Surface Diffusion On A Substrate, Ping Du, Mikhail Khenner, Harris Wong
Mikhail Khenner
We introduce a markerparticle method for the computation of threedimensional solid surface morphologies evolving by surface diffusion. The method does not use gridding of surfaces or numerical differentiation, and applies to surfaces with finite slopes and overhangs. We demonstrate the method by computing the evolution of perturbed cylindrical wires on a substrate. We show that computed growth rates at early times agree with those predicted by the linear stability analysis. Furthermore, when the marker particles are redistributed periodically to maintain even spacing, the method can follow breakup of the wire.
Oscillatory And Monotonic Modes Of LongWave Marangoni Convection In A Thin Film, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Oscillatory And Monotonic Modes Of LongWave Marangoni Convection In A Thin Film, Sergey Shklyaev, Mikhail Khenner, Alexei Alabuzhev
Mikhail Khenner
We study longwave Marangoni convection in a layer heated from below. Using the scaling k=O#1;#3;Bi#2;, where k is the wave number and Bi is the Biot number, we derive a set of amplitude equations. Analysis of this set shows presence of monotonic and oscillatory modes of instability. Oscillatory mode has not been previously found for such direction of heating. Studies of weakly nonlinear dynamics demonstrate that stable steady and oscillatory patterns can be found near the stability threshold.
ThicknessDependent Spontaneous Dewetting Morphology Of Ultrathin Ag Films, H Krishna, R Sachan, J Strader, C Favazza, Mikhail Khenner, Ramki Kalyanaraman
ThicknessDependent Spontaneous Dewetting Morphology Of Ultrathin Ag Films, H Krishna, R Sachan, J Strader, C Favazza, Mikhail Khenner, Ramki Kalyanaraman
Mikhail Khenner
We show here that the morphological pathway of spontaneous dewetting of ultrathin Ag films on SiO2 under nanosecond laser melting is found to be film thickness dependent. For films with thickness h between 2<=h<=9.5 nm, the intermediate stages of the morphology consisted of bicontinuous structures. For films 11.5<=h<=20 nm, the intermediate stages consisted of regularlysized holes. Measurement of the characteristic length scales for different stages of dewetting as a function of film thickness showed a systematic increase, which is consistent with the spinodal dewetting instability over the entire thickness range investigated. This change in morphology with thickness is consistent with observations made previously for polymer films [A. Shama et al, Phys. Rev. Lett., v81, pp3463 (1998); R. Seemann et al, J. Phys. Cond. Matt., v13, pp4925, (2001)]. Based on the behavior of free energy curvature that incorporates intermolecular forces, we have estimated the morphological transition thickness for Ag on SiO2. The theory predictions agree well with observations for Ag. These results show that it is possible to form a variety of complex Ag nanomorphologies in a consistent manner, which could be useful in optical applications of Ag surfaces, such as in surface enhanced Raman sensing.
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Mathematics Faculty Publications
A mathematical model for the evolution of pulsed laserirradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D longwave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam ...
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Mathematics Faculty Publications
A mathematical model for the evolution of pulsed laserirradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D longwave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam ...
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Mathematics Faculty Publications
A mathematical model for the evolution of pulsed laserirradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D longwave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam ...
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Mikhail Khenner
Mikhail Khenner
A mathematical model for the evolution of pulsed laserirradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D longwave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam ...
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Agegnehu Atena, Mikhail Khenner
Thermocapillary Effects In Driven Dewetting And SelfAssembly Of Pulsed LaserIrradiated Metallic Films, Agegnehu Atena, Mikhail Khenner
Mathematics Faculty Publications
In this paper the lubricationtype dynamical model is developed of a molten, pulsed laserirradiated metallic film. The heat transfer problem that incorporates the absorbed heat from a single beam or interfering beams is solved analytically. Using this temperature field, we derive the 3D longwave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the peak laser beam intensity, the film optical thickness, the Biot and ...