Engineering Commons^™

Should Tortuosity Still Be Used In Upscaling?, Francisco J. Valdes-Parada, Mark L. Porter, Brian D. Wood

Francisco J. Valdes-Parada

The concept of tortuosity is an integral part of models that describe trans- port in multiscale systems. Traditionally, tortuosity is de#12;ned as the ratio of an e#11;ective path length to the shortest path length in a representative sample of the porous medium microstructure. While the latter can be unambiguously speci#12;ed, the same is not true for the e#11;ective path length, since it changes from one type of transport to another. Consequently, it is possible to have di#11;erent tortuosity values for di#11;erent transport processes taking place in the same system. In order to avoid running into unclear interpretations, we pro- pose …

Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies And Vapor Pressures Of Polyaromatic Heterocycles And Related Compounds

James Chickos

No abstract provided.

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

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

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, …

Main Speaker, Kevin Cavicchi

Kevin Cavicchi

No abstract provided.

Theory And Computation Of Photopolymerization Induced Phase Transition And Morphology Development In Blends Of Crystalline Polymer And Photoreactive Monomer, Thein Kyu

Thein Kyu

A hypothetical phase diagram of a crystalline polymer/photoreactive monomer mixture has been calculated on the basis of phase field (PF) free energy of crystal solidification in conjunction with Flory-Huggins (FH) free energy of liquid-liquid demixing to guide the morphology development during photopolymerization of poly(ethylene oxide)/triacrylate blend. The self-consistent solution of the combined PF-FH theory exhibits a crystalline-amorphous phase diagram showing the coexistence of solid+liquid gap bound by the liquidus and solidus lines, followed by an upper critical solution temperature at a lower temperature. When photopolymerization was triggered in the isotropic region, i.e., slightly above the crystal melting transition temperatures, the …

Mineralization Of Phenol In An Improved Photocatalytic Process Assisted With Ferric Ions: Reaction Network And Kinetic Modeling, Jesus Moreira Del Rio

Jesus Moreira del Rio

No abstract provided.

Polymer , Yu Zhu

Yu Zhu

No abstract provided.

Chemistry Of Materials , Yu Zhu

Yu Zhu

No abstract provided.

Ultrasensitive Polymer Photodetectors, Xiong Gong

Xiong Gong

No abstract provided.

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

Dr. Et-touhami Es-sebbar

No abstract provided.

Photocatalytic Reactor Efficiency Factor For The Complete Spam Of Reaction Times, Benito Serrano Rosales, Jesus Moreira Del Rio, Hugo De Lasa

Jesus Moreira del Rio

No abstract provided.

Modelling Of Radiation Transfer And Adsorption In Photocatalytic Reactors, Jesus Moreira Del Rio

Jesus Moreira del Rio

No abstract provided.

Polymer Photodetector, Xiong Gong

Xiong Gong

No abstract provided.

A Preliminary Study On The Effectiveness Of Inquiry-Based Activities For Addressing Misconceptions Of Undergraduate Engineering Students, Michael Prince, M. Vigeant, K. Nottis

Michael J. Prince

No abstract provided.

Electrospinning Route For The Fabrication Of Pn Junction Using Nanofiber Yarns, Darrell Reneker

Darrell Hyson Reneker

Electrospinning is a simple, versatile, and cost effective method for generating nanoscale fibers, wires, and tubes. Nanowires and nanotubes could be important building blocks for nanoscale electronics, optoelectronics, and sensors as they can function as miniaturized devices as well as electrical interconnects. We report on a simple method to fabricate free standing ceramic nanofiber heterostructures, which exhibit rectifying behavior of a p-n junction

Production Of Meso-And Giga-Porous Zirconia Particles—An Improved Multi-Step Particle Aggregation Process, Abhinandan Pattanayak

Abhinandan Pattanayak

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

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 …

Design And Cfd Analysis Of Mass Transfer And Shear Stresses Distributions In Airlift Reactor, Rachid Bannari, Brahim Selma, Abdelfettah Bannari, Pierre Proulx

Rachid BANNARI

The design, scale-up and performance evaluation of biological reactors require accurate information about the gas-liquid flow dynamics. In this study, we use CFD techniques to investigate important parameters of the multiphase flow dynamics on an initial airlift bioreactor in order to improve its design. Such parameters are distributions of shear stresses and mass transfer. Our initial proposed design of the airlift bioreactor was used for biomass growing. Specifically to produce cellulase enzyme using the fungus Trichoderma Reesei. However, the morphology of the microorganism obtained in this bioreactor was not appropriated to produce cellulase. Since the microorganism morphology presented a small …

Saw Dust And Neem Bark As Low-Cost Natural Biosorbent For Adsorptive Removal Of Zn (Ii) And Cd (Ii) Ions From Aqueous Solutions, Tarun Naiya, Pankaj Chowdhury, Ashim Bhattacharya, Sudip Das

PC

The ability of saw dust and neem bark as low-cost natural adsorbents were investigated for adsorptive removal of Zn(II) and Cd(II) ions from aqueous solutions. Various physico-chemical parameters such as pH, initial metal ion concentration, and adsorbent dosage level and equilibrium contact time were studied. The optimum pH for adsorption was found to be 5 for Zn(II) and 6 for Cd(II). Kinetics data were best described by pseudo-second-order model. Mass transfer coefficients were also determined for individual adsorbents for removal of Zn(II) and Cd(II) ions from aqueous solutions. The equilibrium adsorption data were fitted to Langmuir and Freundlich isotherm models …

Solution-Processed Ultrasensitive Polymer Photodetectors, Xiong Gong

Xiong Gong

No abstract provided.

Density Of Jatropha Curcas Seed Oil And Its Methyl Esters: Measurement And Estimations, Abdul Aziz Abdul Raman

Abdul Aziz Abdul Raman

Density data as a function of temperature have been measured for Jatropha curcas seed oil, as well as biodiesel jatropha methyl esters at temperatures from above their melting points to 90 ° C. The data obtained were used to validate the method proposed by Spencer and Danner using a modified Rackett equation. The experimental and estimated density values using the modified Rackett equation gave almost identical values with average absolute percent deviations less than 0.03% for the jatropha oil and 0.04% for the jatropha methyl esters. The Janarthanan empirical equation was also employed to predict jatropha biodiesel densities. This equation …

Researches On Copper. History & Metallurgy, Fathi Habashi

Fathi Habashi

Gold. History, Metallurgy, Culture, Fathi Habashi

Fathi Habashi

The Natural Transparency And Piezoelectric Response Of The Greta Oto Butterfly Wing, Valerie R. Binetti, Jessica D. Schiffman, Oren D. Leaffer, Jonathan E. Spanier, Caroline L. Schauer

Jessica D. Schiffman

The Greta oto, or the ‘‘glasswing butterfly’’, is a member of the Ithomiini tribe. Although rare among lepidopteran, the G. oto’s wings are naturally transparent. To understand the material properties of natural transparency, the various structures on the surface of the wings, both the transparent and brown ‘‘veins’’ and wing parameter regions were studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), reflectance spectrometry, transmission spectrometry and scanning probe microscopy (SPM) in order to investigate their local structure, periodic character, and electromechanical response. Nanosized protuberances in a highly ordered array were found on the surface of the transparent part …

Energy Efficiency In Photocatalytic Reactors For The Full Span Of Reaction Times, Jesus Moreira Del Rio, Benito Serrano Rosales, Aaron Ortiz Gomez, Hugo De Lasa

Jesus Moreira del Rio

No abstract provided.

Interfacial Fluctuations In An Ideal Block Copolymer Resist, August Bosse, Eric Lin, Ronald Jones, Alamgit Karim

Alamgir Karim

We use field-theoretic computer simulations to show that intrinsic interfacial fluctuations may place limits on the use of block copolymer materials as resists for the nanofabrication of next-generation electronics devices. Even for an ideal system, our simulations demonstrate that the magnitude of the interfacial fluctuations is of the same order as the maximum interfacial roughness requirements noted in the International Technology Roadmap for Semiconductors. Furthermore, we show that the interfacial fluctuations exhibit an inverse power law dependence on the copolymer molecular mass, and we identify a peak in the interfacial fluctuation spectrum indicative of fluctuations with a wavelength of order …

Soot Oxidation, J. S. Lighty, V. Romano, A. F. Sarofim

JoAnn S. Lighty