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Selected Works

2005

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Full-Text Articles in Chemical Engineering

Quantitative Elucidation Of A Distinct Spatial Gradient-Sensing Mechanism In Fibroblasts, Ian C. Schneider, Jason M. Haugh Dec 2005

Quantitative Elucidation Of A Distinct Spatial Gradient-Sensing Mechanism In Fibroblasts, Ian C. Schneider, Jason M. Haugh

Ian C. Schneider

Migration of eukaryotic cells toward a chemoattractant often relies on their ability to distinguish receptor-mediated signaling at different subcellular locations, a phenomenon known as spatial sensing. A prominent example that is seen during wound healing is fibroblast migration in platelet-derived growth factor (PDGF) gradients. As in the well-characterized chemotactic cells Dictyostelium discoideum and neutrophils, signaling to the cytoskeleton via the phosphoinositide 3-kinase pathway in fibroblasts is spatially polarized by a PDGF gradient; however, the sensitivity of this process and how it is regulated are unknown. Through a quantitative analysis of mathematical models and live cell total internal reflection fluorescence microscopy …


54th Spsj Annual Meeting Yokohama, Japan, May 25-27, 2005, Jane C. Vogl, Hiroyuki Ohno Dec 2005

54th Spsj Annual Meeting Yokohama, Japan, May 25-27, 2005, Jane C. Vogl, Hiroyuki Ohno

Otto Vogl

No abstract provided.


Macromolecules In Graz, Austria, December 3, 2004, Otto Vogl, Volker Ribitsch Nov 2005

Macromolecules In Graz, Austria, December 3, 2004, Otto Vogl, Volker Ribitsch

Otto Vogl

No abstract provided.


Forwarding Green Chemical Engineering Education And Research Through A Student Run Organization: The Society Of Environmental Engineers And Scientists, Samuel Morton Oct 2005

Forwarding Green Chemical Engineering Education And Research Through A Student Run Organization: The Society Of Environmental Engineers And Scientists, Samuel Morton

Samuel A Morton

No abstract provided.


Looking To The Unit Operations Laboratory As A Source Of Chemical Engineering Design Projects, Samuel Morton Oct 2005

Looking To The Unit Operations Laboratory As A Source Of Chemical Engineering Design Projects, Samuel Morton

Samuel A Morton

No abstract provided.


Branching In Electrospinning Of Nanofibers, Darrell Reneker Sep 2005

Branching In Electrospinning Of Nanofibers, Darrell Reneker

Darrell Hyson Reneker

Electrospinning of polymer nanofibers often begins with a single, straight, elongating, and electrified fluid jet that emanates from a droplet tip when the electric field at the surface is high enough. After some distance an electrically driven bending instability of the elongating jet occurs. For a polymer solution suitable for electrospinning, capillary instability does not cause the jet to become a spray of droplets. Under some conditions, a sequence of secondary jet branches emanates from the primary jet. This paper describes an experiment in which many closely spaced branches along the jet were observed during the electrospinning of a polycaprolactone …


Correlation Of Free Radical Copolymerization Behavior And Copolymer Properties With The Strength Of Pi-Pi Stacking Interactions Between Aromatic Fluorocarbons And Aromatic Hydrocarbons: Comparison Of The Copolymerization Behavior Of 2, 3, 4, 5, 6-Pentafluorostyrene With Styrene, 1-Vinylnaphthalene And 2-Vinylnaphthalene, Coleen Pugh Sep 2005

Correlation Of Free Radical Copolymerization Behavior And Copolymer Properties With The Strength Of Pi-Pi Stacking Interactions Between Aromatic Fluorocarbons And Aromatic Hydrocarbons: Comparison Of The Copolymerization Behavior Of 2, 3, 4, 5, 6-Pentafluorostyrene With Styrene, 1-Vinylnaphthalene And 2-Vinylnaphthalene, Coleen Pugh

Coleen Pugh

No abstract provided.


White Pleds, Xiong Gong Sep 2005

White Pleds, Xiong Gong

Xiong Gong

No abstract provided.


Rupture Of Two-Dimensional Alkane Crystal, Ali Dhinojwala Sep 2005

Rupture Of Two-Dimensional Alkane Crystal, Ali Dhinojwala

Ali Dhinojwala

We have studied the breaking of a two-dimensional alkane crystal above the disordered melt using an oscillating bubble rheometer. Surface tension changes abruptly during the expansion and contraction cycle. We postulate that this is due to rupture of the 2D crystal at grain boundaries. The magnitude of the abrupt change in surface tension decreases with a decrease in the rate of change of bubble surface area with a power law exponent of 0.8. The interfacial area formed after rupture decreases with a decrease in rate. These results provide new insights in understanding defect-mediated rupture in confined geometry.


Template-Induced Enhanced Ordering Under Confinement, Mesfin Tsige Sep 2005

Template-Induced Enhanced Ordering Under Confinement, Mesfin Tsige

Mesfin Tsige

We report a surprisingly strong ordering of Si-(CH(3))(2) groups upon confinement between two surfaces, an oxidized poly(dimethyl siloxane) (PDMS(ox)) elastomer and a methyl-terminated self-assembled monolayer (octadecyltrichlorosilane (OTS)) on sapphire substrates. This enhanced ordering is induced by the template of ordered methyl groups of OTS and is not observed for other surfaces (fluorinated monolayers and sapphire substrates). This strong ordering is reminiscent of layering observed for confined symmetric molecules between two mica surfaces but was expected to vanish between rough macroscopic surfaces. These results provide new insights on confined structure at the interface between two solids and are important in the …


Confinement-Induced Ordering Of Alkanes Between An Elastomer And A Solid Surface, Ali Dhinojwala Sep 2005

Confinement-Induced Ordering Of Alkanes Between An Elastomer And A Solid Surface, Ali Dhinojwala

Ali Dhinojwala

We have studied the molecular structure of liquid alkanes confined between a flexible elastomeric poly(dimethyl siloxane) lens and a rigid sapphire substrate using surface-sensitive infrared-visible sum frequency generation spectroscopy. The reduction in the gauche defects suggests ordering of liquid alkanes under confinement. The cooling of confined liquid below the freezing temperature leads to crystallization with alkane molecules lying on the substrate with the symmetry axis parallel to the surface normal. This structure is very different from the bulk alkane crystals next to sapphire or air interfaces.


White Electrophosphorescence From Semiconducting Polymer Blends. U.S. Pat. Appl. Publ, Xiong Gong Sep 2005

White Electrophosphorescence From Semiconducting Polymer Blends. U.S. Pat. Appl. Publ, Xiong Gong

Xiong Gong

No abstract provided.


Controllability Of Lumped Parameter Chemical Reactors, Rafael Maya-Yescas Sep 2005

Controllability Of Lumped Parameter Chemical Reactors, Rafael Maya-Yescas

Rafael Maya-Yescas

Although there have been several attempts to develop systematic evaluation of control schemes, the choosing and pairing of control variables in chemical reactors is not an easy task. Intrinsic nonlinearities of this kind of systems provoke dynamic responses that are difficult to predict. In this paper, a simple proposition for the evaluation of pairs of control and manipulated variables is developed for nonlinear control affine systems. It compliments the RGA analysis for nonlinear systems because is based on the relationship between zero dynamics and control stability. The resulting strategy is simple, easy to understand and easy to apply for the …


Co-Generation Of C2 Hydrocarbons And Synthesis Gases From Methane And Carbon Dioxide: A Thermodynamic Analysis, Istadi Istadi, Nor Aishah Saidina Amin Aug 2005

Co-Generation Of C2 Hydrocarbons And Synthesis Gases From Methane And Carbon Dioxide: A Thermodynamic Analysis, Istadi Istadi, Nor Aishah Saidina Amin

Istadi

This paper deals with thermodynamic chemical equilibrium analysis using the method of direct minimization of Gibbs free energy for all possible CH4 and CO2 reactions. The effects of CO2/CH4 feed ratio, reaction temperature, and system pressure on equilibrium composition, conversion, selectivity and yield were studied. In addition, carbon and no carbon formation regions were also considered at various reaction temperatures and CO2/CH4 feed ratios in the reaction system at equilibrium. It was found that the reaction temperature above 1100 K and CO2/CH4 ratio=1 were favourable for synthesis gas production with H2/CO ratio unity, while carbon dioxide oxidative coupling of methane …


A Hybrid Numerical Approach For Multi-Responses Optimization Of Process Parameters And Catalyst Compositions In Co2 Ocm Process Over Cao-Mno/Ceo2 Catalyst, Istadi Istadi Aug 2005

A Hybrid Numerical Approach For Multi-Responses Optimization Of Process Parameters And Catalyst Compositions In Co2 Ocm Process Over Cao-Mno/Ceo2 Catalyst, Istadi Istadi

Istadi

A new hybrid numerical approach, using Weighted Sum of Squared Objective Functions (WSSOF) algorithm, was developed for multiresponses optimization of carbon dioxide oxidative coupling of methane (CO2 OCM). The optimization was aimed to obtain optimal process parameters and catalyst compositions with high catalytic performances. The hybrid numerical approach combined the single-response modeling and optimization using Response Surface Methodology (RSM) and WSSOF technique of multi-responses optimization. The hybrid algorithm resulted in Pareto-optimal solutions and an additional criterion was proposed over the solutions to obtain a final unique optimal solution. The simultaneous maximum responses of C2 selectivity and yield were obtained at …


Synthesis And Characterization Of Highly Amine Functionalized Mesoporous Organosilicas By An “All-In-One” Approach, Rebecca Voss, Arne Thomas, Markus Antonietti, Geoffrey A. Ozin Aug 2005

Synthesis And Characterization Of Highly Amine Functionalized Mesoporous Organosilicas By An “All-In-One” Approach, Rebecca Voss, Arne Thomas, Markus Antonietti, Geoffrey A. Ozin

Rebecca Cademartiri

Mesoporous organosilicas (MOs) represent a promising class of organic–inorganic nanocomposites for a broad range of applications like catalysis, sensing, separation, or microelectronics. Their distinct feature is the presence of organic groups incorporated into the channel walls of a mesoporous structure. Here, we present a convenient “all-in-one” approach using silsesquioxane surfactant precursors for the functionalization of the channel walls with primary amine groups. The monomer is made by a hydroboration/aminolysis sequence on the base of a commercial monomer, with the template bound to the functionalization site by hydroboration and released after silica condensation and aminolysis. This combination ensures both the placement …


Spatial Analysis Of 3′ Phosphoinositide Signaling In Living Fibroblasts, Iii: Influence Of Cell Morphology And Morphological Polarity, Ian C. Schneider, Elizabeth M. Parrish, Jason M. Haugh Aug 2005

Spatial Analysis Of 3′ Phosphoinositide Signaling In Living Fibroblasts, Iii: Influence Of Cell Morphology And Morphological Polarity, Ian C. Schneider, Elizabeth M. Parrish, Jason M. Haugh

Ian C. Schneider

Activation of phosphoinositide (PI) 3-kinase is a required signaling pathway in fibroblast migration directed by platelet-derived growth factor. The pattern of 3′ PI lipids in the plasma membrane, integrating local Pl 3-kinase activity as well as 3′ PI diffusion and turnover, influences the spatiotemporal regulation of the cytoskeleton. In fibroblasts stimulated uniformly with platelet-derived growth factor, visualized using total internal reflection fluorescence microscopy, we consistently observed localized regions with significantly higher or lower 3′ PI levels than adjacent regions (hot and cold spots, respectively). A typical cell contained multiple hot spots, coinciding with apparent leading edge structures, and at most …


Elastic Waves Push Organic Fluids From Reservoir Rock, Igor A. Beresnev, R. Dennis Vigil, Wenqing Li, Wayne D. Pennington, Roger M. Turpening, Pavel P. Iassonov, Robert P. Ewing Jul 2005

Elastic Waves Push Organic Fluids From Reservoir Rock, Igor A. Beresnev, R. Dennis Vigil, Wenqing Li, Wayne D. Pennington, Roger M. Turpening, Pavel P. Iassonov, Robert P. Ewing

R. Dennis Vigil

Elastic waves have been observed to increase productivity of oil wells, although the reason for the vibratory mobilization of the residual organic fluids has remained unclear. Residual oil is entrapped as ganglia in pore constrictions because of resisting capillary forces. An external pressure gradient exceeding an ‘‘unplugging’’ threshold is needed to carry the ganglia through. The vibrations help overcome this resistance by adding an oscillatory inertial forcing to the external gradient; when the vibratory forcing acts along the gradient and the threshold is exceeded, instant ‘‘unplugging’’ occurs. The mobilization effect is proportional to the amplitude and inversely proportional to the …


Temperature Dependence Of Order, Disorder, And Defects In Laterally Confined Diblock Copolymer Cylinder Monolayers, Matthew R. Hammond, Eric W. Cochran, Glenn H. Fredrickson, Edward J. Kramer Jul 2005

Temperature Dependence Of Order, Disorder, And Defects In Laterally Confined Diblock Copolymer Cylinder Monolayers, Matthew R. Hammond, Eric W. Cochran, Glenn H. Fredrickson, Edward J. Kramer

Eric W. Cochran

Monolayer arrays of polystyrene-poly(2-vinylpyridine) diblock copolymer cylinders with excellent orientational order and a very low density of dislocations are prepared by cooling slowly from above the bulk order - disorder temperature (ODT) ∼212°C within silicon oxide channels one cylinder spacing a in depth and 2 μm in width. The translational order of this array, however, is short range with a correlation length of ∼12a. If such an array is heated to a temperature above the glass transition temperature of the block copolymer (100°C) but well below the ODT, a finite density of thermally generated dislocations is observed, which leads to …


Making Scotch: Its Engineering, Chemistry, And Education, J. Collier, Samuel Morton, T. Rogers, J. Mcewan, M. Reynier Jun 2005

Making Scotch: Its Engineering, Chemistry, And Education, J. Collier, Samuel Morton, T. Rogers, J. Mcewan, M. Reynier

Samuel A Morton

No abstract provided.


Developing A Student Lead Undergraduate Environmental Research Organization: The Society Of Environmental Engineers And Scientists, P. Dimick, A. Baker, L. Vanzler, A. Kney, Samuel Morton, S. Mylon May 2005

Developing A Student Lead Undergraduate Environmental Research Organization: The Society Of Environmental Engineers And Scientists, P. Dimick, A. Baker, L. Vanzler, A. Kney, Samuel Morton, S. Mylon

Samuel A Morton

No abstract provided.


Integrating The Principles Of Green Engineering In The Project Based Process Synthesis Curriculum, Samuel Morton, R. Counce May 2005

Integrating The Principles Of Green Engineering In The Project Based Process Synthesis Curriculum, Samuel Morton, R. Counce

Samuel A Morton

No abstract provided.


Inverse Density Functional Theory As An Interpretive Tool For Measuring Colloid-Surface Interactions In Dense Systems, David M. Ford, Mingqing Lu, Michael A. Bevan Apr 2005

Inverse Density Functional Theory As An Interpretive Tool For Measuring Colloid-Surface Interactions In Dense Systems, David M. Ford, Mingqing Lu, Michael A. Bevan

David M Ford

Recent advances in optical microscopy, such as total internal reflection and confocal scanning laser techniques, now permit the direct three-dimensional tracking of large numbers of colloidal particles both near and far from interfaces. A novel application of this technology, currently being developed by one of the authors under the name of diffusing colloidal probe microscopy (DCPM), is to use colloidal particles as probes of the energetic characteristics of a surface. A major theoretical challenge in implementing DCPM is to obtain the potential energy of a single particle in the external field created by the surface, from the measured particle trajectories …


A Minimal Model For The Helix-Coil Transition Of Worm-Like Polymers, Gustavo Carri Mar 2005

A Minimal Model For The Helix-Coil Transition Of Worm-Like Polymers, Gustavo Carri

Gustavo A. Carri

We present a geometric approach to the simulation of the Helix-Coil transition in wormlike polymers. In our model, the polymer is treated as a Freely Rotating Chain with hard-core repulsion between beads. The conformational state (helix or coil) of each bead is determined by the value of its torsion. If the difference between the torsion of a bead and the one of the perfect helix is less than a cutoff value, then the bead is part of a helical domain and carries a negative energy, otherwise it is part of a random coil. We have simulated these concepts using the …


Ethane Oxidation And Pyrolysis From 5 Bar To 1000 Bar: Experiments And Simulation, Abdul Aziz Abdul Raman Mar 2005

Ethane Oxidation And Pyrolysis From 5 Bar To 1000 Bar: Experiments And Simulation, Abdul Aziz Abdul Raman

Abdul Aziz Abdul Raman

An extensive experimental study of ethane oxidation and pyrolysis has been conducted in the high pressure shock tube at UIC covering reflected shock pressures from 5-1000 bar, reaction temperatures up to 1550 K and stoichiometric (Φ = 1 ), fuel rich (Φ = 5), and pyrolytic mixtures. The experimental data has been used to develop a single model that can simulate the whole dataset very well and is the first ethane model capable of simulating experimental results over such an extensive range of pressure, temperature, and stoichiometry. © 2005 Wiley Periodicals, Inc.


Jump Condition At The Boundary Between A Porous Catalyst And A Homogeneous Fluid, Francisco J. Valdes-Parada, J. Alberto Ochoa-Tapia Jan 2005

Jump Condition At The Boundary Between A Porous Catalyst And A Homogeneous Fluid, Francisco J. Valdes-Parada, J. Alberto Ochoa-Tapia

Francisco J. Valdes-Parada

The method of volume averaging (Whitaker, 1999) is used to derive the jump conditions between a porous catalyst and a homogeneous fluid. To simplify the analysis a first order kinetics is used and the convective transport is neglected. The statement for the derivation is in terms of the spatially smoothed equations obtained by Wood et al. (2000). We have followed a similar procedure to the one used by those authors to derive, besides a jump boundary condition that couples the two media transport, a closure problem to predict the effective reaction rate coefficient at the interregion dividing surface as a …


Aplicación Del Método De Optimización De Recocido Simulado En La Regresión De Isotermas De Adsorción, Adrian Bonilla-Petriciolet, María Guadalupe Lira-Padilla, Carlos A. Soto-Becerra Jan 2005

Aplicación Del Método De Optimización De Recocido Simulado En La Regresión De Isotermas De Adsorción, Adrian Bonilla-Petriciolet, María Guadalupe Lira-Padilla, Carlos A. Soto-Becerra

Adrian Bonilla-Petriciolet

The nonlinear parameter estimation of thermodynamic models, including the adsorption isotherms, is a multivariable and nonlinear problem that can present several local optimums. The conventional optimization methods used in the parameter estimation of adsorption isotherms are efficient but they are not reliable to solve such problem. In this paper, we describe the application of the stochastic global optimization method simulated annealing in the nonlinear regression of adsorption isotherms. This method has been applied with Toth and Sips models. Our results indicate that this method is a reliable optimization strategy for parameter estimation in adsorption isotherms.


Efficiency Of Heat Recovery Versus Maximum Catalyst Temperature In A Reverse-Flow Combustion Of Methane, Krzysztof Gosiewski Jan 2005

Efficiency Of Heat Recovery Versus Maximum Catalyst Temperature In A Reverse-Flow Combustion Of Methane, Krzysztof Gosiewski

Krzysztof Gosiewski

Results of simulations are presented concerning a reverse-flow reactor for the catalytic combustion of methane that occurs in coal-mine ventilation air. The simulations were performed for two types of catalyst: 12% MnO2/-Al2O3 and 0.5% Pd/-Al2O3. A special attention is given to maximum temperature of the catalyst bed in order to minimize occurrence of homogeneous combustion. The simulations revealed that there is a visible contradiction between efficiency of heat recovery aimed to high-pressure steam production and efforts to constraint maximum temperature in the bed.


Avoid Sulfuric Acid Corrosion In Metallic Stacks, João F. Gomes Jan 2005

Avoid Sulfuric Acid Corrosion In Metallic Stacks, João F. Gomes

João F Gomes

Acidic gaseous effluents frequently cause corrosion on metallic stacks. This paper presents a method for prevision of probability of corrosion occurrence caused by gaseous effluents containing sulphur oxides which is based on the sulphur trioxide and moisture content measured in stack


Emissions Of Dioxin And Dibenzofuran From Electric Arc Furnaces, João F. Gomes Jan 2005

Emissions Of Dioxin And Dibenzofuran From Electric Arc Furnaces, João F. Gomes

João F Gomes

This paper describes work done in order to clarify the formation mechanism of highly toxic micropollutants, such as dioxins and dibenzofurans, from electric arc furnaces used in the production of carbon steel from scrap. The study is allowing to derive relationships between the levels of airborne micropollutants and the operational parameters of the production process so that an abatement of pollution could be achieved. By using the European standard method CEN 1948 for dioxin like compounds sampling and measurement, it was possible to determine the characteristic fingerprint of micropollutants emitted by this particular stationary source.