Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 14 of 14

Full-Text Articles in Physics

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner Dec 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, 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 long-wave 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 Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner Dec 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, 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 long-wave 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 Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner Dec 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, 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 long-wave 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 Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner Dec 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mikhail Khenner

A mathematical model for the evolution of pulsed laser-irradiated, 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 long-wave 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 …


Absolute Nitrogen Atom Density Measurements By Two-Photon Laser-Induced Fluorescence Spectroscopy In Atmospheric Pressure Dielectric Barrier Discharges Of Pure Nitrogen, Et-Touhami Es-Sebbar, Christian Sarra-Bournet, Nicolas Naudé, Françoise Massines, Nicolas Gherardi Oct 2009

Absolute Nitrogen Atom Density Measurements By Two-Photon Laser-Induced Fluorescence Spectroscopy In Atmospheric Pressure Dielectric Barrier Discharges Of Pure Nitrogen, Et-Touhami Es-Sebbar, Christian Sarra-Bournet, Nicolas Naudé, Françoise Massines, Nicolas Gherardi

Dr. Et-touhami Es-sebbar

In this paper, two-photon absorption laser induced fluorescence spectroscopy is used to follow the nitrogen atom density in flowing dielectric barrier discharges fed with pure nitrogen and operating at atmospheric pressure. Two different dielectric barrier discharge regimes are investigated: the Townsend regime, which is homogeneous although operating at atmospheric pressure, and the more common filamentary regime. In both regimes, densities as high as 3x1014 /cm3 are detected. However, the N atoms kinetic formation depends on the discharge regime. The saturation level is reached more rapidly with a filamentary discharge. For a given discharge regime, the N atom density depends strongly …


Contributions To The Development Of The S.E.T.U.P. (Experimental And Theoretical Simulations Useful For Planetology) Project, E. Arzoumanian, C. Romanzin, M-C. Gazeau, Et. Es-Sebbar, A. Jolly, S. Perrier, Y. Benilan Oct 2009

Contributions To The Development Of The S.E.T.U.P. (Experimental And Theoretical Simulations Useful For Planetology) Project, E. Arzoumanian, C. Romanzin, M-C. Gazeau, Et. Es-Sebbar, A. Jolly, S. Perrier, Y. Benilan

Dr. Et-touhami Es-sebbar

No abstract provided.


Multiwavelength Studies For Titan's Atmospheric Composition Analysis, Y. Benilan, Et. Es-Sebbar, N. Fray, M-C. Gazeau, A. Jolly, M. Schwell, J. Guillemin Oct 2009

Multiwavelength Studies For Titan's Atmospheric Composition Analysis, Y. Benilan, Et. Es-Sebbar, N. Fray, M-C. Gazeau, A. Jolly, M. Schwell, J. Guillemin

Dr. Et-touhami Es-sebbar

Titan's atmosphere mainly made of nitrogen and methane is rich in organic molecules. Hydrocarbons are formed from the photolytic dissociation of CH4 and nitriles are created by dissociation of N2 followed by reactions with hydrocarbons. In order to understand the physicochemical mechanisms responsible for the evolution of Titan's atmosphere, photochemical models are built. The latter need constrains for vertical profiles of organic compounds from the high thermosphere down to the low stratosphere as well as photodissociation rates. Those profiles over the entire atmosphere can be retrieved from Cassini observations, in particular by limb sounding, coupling infrared and ultraviolet spectroscopy. However, …


Vuv Photostability Of Prebiotic Species, M. Schwell, Y. Bénilan, M.-C. Gazeau, N. Fray, A. Jolly, Et. Es-Sebbar, N. Champion, S. Leach, H. W Jochims, H. Baumgärtel, E. Rühl Sep 2009

Vuv Photostability Of Prebiotic Species, M. Schwell, Y. Bénilan, M.-C. Gazeau, N. Fray, A. Jolly, Et. Es-Sebbar, N. Champion, S. Leach, H. W Jochims, H. Baumgärtel, E. Rühl

Dr. Et-touhami Es-sebbar

No abstract provided.


S.E.T.U.P. Experimental And Theoretical Simulations Useful For Planetology- Related Studies In The Frame Of A Program Of Titan’S Atmosphere Laboratory Simulations, M.-C. Gazeau, Et. Es-Sebbar, E. Arzoumanian, C. Romanzin, A. Jolly, S. Perrier, Y. Bénilan Sep 2009

S.E.T.U.P. Experimental And Theoretical Simulations Useful For Planetology- Related Studies In The Frame Of A Program Of Titan’S Atmosphere Laboratory Simulations, M.-C. Gazeau, Et. Es-Sebbar, E. Arzoumanian, C. Romanzin, A. Jolly, S. Perrier, Y. Bénilan

Dr. Et-touhami Es-sebbar

No abstract provided.


Characterization Of An N2 Flowing Microwave Post-Discharge By Oes Spectroscopy And Determination Of Absolute Ground-State Nitrogen Atom Densities By Talif, Et. Es-Sebbar, Y. Benilan, A. Jolly, M-C. Gazeau Jun 2009

Characterization Of An N2 Flowing Microwave Post-Discharge By Oes Spectroscopy And Determination Of Absolute Ground-State Nitrogen Atom Densities By Talif, Et. Es-Sebbar, Y. Benilan, A. Jolly, M-C. Gazeau

Dr. Et-touhami Es-sebbar

A flowing microwave post-discharge source sustained at 2.45 GHz in pure nitrogen has been investigated by optical emission spectroscopy (OES) and two-photon absorption laser-induced fluorescence (TALIF) spectroscopy. Variations of the optical emission along the post-discharge (near, pink and late afterglow) have been studied and the gas temperature has been determined. TALIF spectroscopy has been used in the late afterglow to determine the absolute ground-state nitrogen atomic densities using krypton as a reference gas. Measurements show that the microwave flowing post-discharge is an efficient source of N (4S) atoms in late afterglow. In our experimental conditions, the maximum N (4S) density …


Drag Reduction In Turbulent Flows Over Micropatterned Superhydrophobic Surfaces, Robert J. Daniello Jan 2009

Drag Reduction In Turbulent Flows Over Micropatterned Superhydrophobic Surfaces, Robert J. Daniello

Masters Theses 1911 - February 2014

Periodic, micropatterned superhydrophobic surfaces, previously noted for their ability to provide drag reduction in the laminar flow regime, have been demonstrated capable of reducing drag in the turbulent flow regime as well. Superhydrophobic surfaces contain micro or nanoscale hydrophobic features which can support a shear-free air-water interface between peaks in the surface topology. Particle image velocimetry and pressure drop measurements were used to observe significant slip velocities, shear stress, and pressure drop reductions corresponding to skin friction drag reductions approaching 50%. At a given Reynolds number, drag reduction was found to increase with increasing feature size and spacing, as in …


Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner Jan 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner

Mathematics Faculty Publications

In this paper the lubrication-type dynamical model is developed of a molten, pulsed laser-irradiated 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 long-wave 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 …


Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner Jan 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner

Mathematics Faculty Publications

In this paper the lubrication-type dynamical model is developed of a molten, pulsed laser-irradiated 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 long-wave 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 …


Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner Jan 2009

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner

Mikhail Khenner

In this paper the lubrication-type dynamical model is developed of a molten, pulsed laser-irradiated 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 long-wave 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 …