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270 full-text articles. Page 3 of 10.

Reductive Decomposition Of Gypsum By Carbon Monoxide, Thomas D. Wheelock, D.R. Boylan 2016 Iowa State University

Reductive Decomposition Of Gypsum By Carbon Monoxide, Thomas D. Wheelock, D.R. Boylan

Thomas D. Wheelock

Tremendous domestic reserves of gypsum and anhydrite constitute a potential source of raw material f i x sulfur-based chemicals. As in Europe today, calcium sulfate may become one of our principal raw materials for sulfuric acid. Several European acid plants are based on a process in which sulfur dioxide is freed from anhydrite by heating the latter with coke and shale to a sintering temperature (4). The sulfur dioxide is converted into acid and the clinker is used for portland cement.


Production Of Hydrogen From Coal Char In An Electrofluid Reactor, A.H. Pulsifer, Thomas D. Wheelock 2016 Iowa State University

Production Of Hydrogen From Coal Char In An Electrofluid Reactor, A.H. Pulsifer, Thomas D. Wheelock

Thomas D. Wheelock

A potential industrial process for producing a hydrogen-rich synthesis gas by reacting coal char and steam in an electrofluid reactor is described. The characteristics of this type of reactor are reviewed, and a reaction model which appears to fit experimental results is proposed. Product gas compositions and energy requirements predicted by the model for the gasification process are presented for various possible operating conditions. The present state of development of the reaction system and foreseeable problems which must be worked out are reviewed. In addition, the adaptation of the process to the production of various products such as hydrogen, methane ...


Hydrogen From Coal Char In A Continuous Electrofluid Reactor, Justin L. Beeson, Allen H. Pulsifer, Thomas D. Wheelock 2016 Iowa State University

Hydrogen From Coal Char In A Continuous Electrofluid Reactor, Justin L. Beeson, Allen H. Pulsifer, Thomas D. Wheelock

Thomas D. Wheelock

The production of a hydrogen-rich synthesis gas from coal char and steam was investigated in a 12-in. diameter, continuous electrofluid reactor. The reactor has been operated at temperatures approaching 2000°F and using both single and three-phase ac power. Data on the gasification rate and the electrical characteristics of the system were taken and several different electrode materials were tested. A large part of the interelectrode resistance seemed to be due to contact resistance. Electrode life remains a problem.


Chemical Cleaning Of Coal With Hot Alkaline Solutions, C.Y. Chi, C.W. Fan, Richard Markuszewski, Thomas D. Wheelock 2016 Iowa State University

Chemical Cleaning Of Coal With Hot Alkaline Solutions, C.Y. Chi, C.W. Fan, Richard Markuszewski, Thomas D. Wheelock

Thomas D. Wheelock

Various bituminous coals were demineralized by an experimental two-step leaching process in which the ballmilled coals were first treated with a hot alkaline solution and then with a dilute mineral acid. Different alkalis and acids were studied to determine their relative effectiveness. In addition, the effects of alkali concentration, treatment temperature, and treatment time were evaluated. Under the best conditions, the process reduced the ash content of the coals by 85-90% and the total sulfur content by 70-90%. As the temperature of the alkaline treatment was raised from 150 to 345°C, the removal of sulfur increased greatly whereas the ...


Desulfurizing Coal With Alkaline Solutions Containing Dissolved Oxygen, C.Y. Tai, G.V. Graves, Thomas D. Wheelock 2016 Iowa State University

Desulfurizing Coal With Alkaline Solutions Containing Dissolved Oxygen, C.Y. Tai, G.V. Graves, Thomas D. Wheelock

Thomas D. Wheelock

The extraction of pyritic sulfur from coal by leaching the comminuted material with hot aqueous solutions containing dissolved oxygen has been demonstrated in numerous laboratory experiments (1-6). Although acidic solutions have generally been used for such experiments, basic solutions appear to offer several important advantages. Thus Majima and Peters (7) showed that the rate of extraction of sulfur from relatively pure pyrite is much greater in basic solutions containing dissolved oxygen than in neutral solutions. Moreover it has been shown recently that basic solutions containing ammonium hydroxide and oxygen can extract a significant portion of the organic sulfur as well ...


Coal Char Gasification In A Continuous Electrofluid Reactor, Justin L. Beeson, Allen H. Pulsifer, Thomas D. Wheelock 2016 Iowa State University

Coal Char Gasification In A Continuous Electrofluid Reactor, Justin L. Beeson, Allen H. Pulsifer, Thomas D. Wheelock

Thomas D. Wheelock

A 12-inch-diameter, continuous electrofluid reactor was built to investigate the production of synthesis gas from coal char and steam. Some initial runs were made. The system has operated reasonably well and the results of gasification have been similar to those obtained with other systems. However, further investigation is needed, particularly concerning the electrical properties of the system.


Kinetics Of A Moving Boundary Ion-Exchange Process, Paul R. Dana, Thomas D. Wheelock 2016 Iowa State University

Kinetics Of A Moving Boundary Ion-Exchange Process, Paul R. Dana, Thomas D. Wheelock

Thomas D. Wheelock

The acid elution of the dark blue cupric ammine complex from a cation-exchange resin produced a sharply defined moving boundary within each bead, which was photographed and measured to provide rate data. 'Analysis of the data by means of a theoretical model indicated that the overall elution process was controlled by a combination of internal and external mass transfer when acid concentrations less than 1.0 N were employed. At these acid concent1'ations the interdiffusion coefficient for the resin phase was found to be 3 X 10-6 cm2/sec, independent of acid concentration but somewhat dependent on particle size ...


Decomposition Of Calcium Sulfate In A Two-Zone Reactor, William M. Swift, Thomas D. Wheelock 2016 Iowa State University

Decomposition Of Calcium Sulfate In A Two-Zone Reactor, William M. Swift, Thomas D. Wheelock

Thomas D. Wheelock

A new method of decomposing calcium sulfate has been demonstrated with a bench-scale fluidized bed reactor in which two reaction zones were established. A reducing zone was set up in the lower part of the reactor by partial combustion of natural gas and an oxiding zone in the upper part by the addition of secondary air. Through natural circulation in such a system. the solids were alternately reduced and oxidized. Both gypsum and anhydrite were decomposed in a continuous manner at temperatures ranging from 1910 to 2230°F. With temperatures of 2100°F and higher, the solids were 98 to ...


A Comparison Of Coal Beneficiation Methods, Seongwoo Min, Thomas D. Wheelock 2016 Iowa State University

A Comparison Of Coal Beneficiation Methods, Seongwoo Min, Thomas D. Wheelock

Thomas D. Wheelock

Although iron pyrites and other minerals are removed from coal on an industrial scale almost exclusively by gravity separation methods at the present time, other beneficiation methods are coming into use. Among the developing methods, froth flotation (1,2,3) is the foremost, although the oil agglomeration method (4,5,6) is also promising. Both of these methods take advantage of the difference in surface properties of coal and inorganic mineral particles suspended in water to effect a separation. In the first method the hydrophobic coal particles are removed from the hydrophilic mineral particles by selective attachment to a mass ...


Coal Char Gasification In An Electrofluid Reactor, Allen H. Pulsifer, Ted M. Knowlton, Thomas D. Wheelock 2016 Iowa State University

Coal Char Gasification In An Electrofluid Reactor, Allen H. Pulsifer, Ted M. Knowlton, Thomas D. Wheelock

Thomas D. Wheelock

The use of an electrofluid reactor for the production of synthesis gas from coal char and steam is being investigated. Preliminary experiments have been carried out in a 4-inch-diameter batch reactor using two coal chars, both reactive over the temperature studied (1500' to 1960' F.). The gasification rate increased with temperature, steam flow rate, and carbon burnoff. The reaction rate was not significantly affected by the passage of current through the bed. Fifty to 60% of the off-gas from the reactor was hydrogen, the rest predominantly carbon monoxide and carbon dioxide. The resistance of the fluidized bed remained constant early ...


Microstructure And Rheology Of Carbon Nanotubes At Air-Water Interfaces, Charles D. Young 2016 University of Connecticut - Storrs

Microstructure And Rheology Of Carbon Nanotubes At Air-Water Interfaces, Charles D. Young

Honors Scholar Theses

This work characterizes the material properties of carbon nanotubes at air-water interfaces for potential use in creating stable emulsions. Properties such as length, aspect ratio, contact angle, microstructural ordering, surface pressure, compression and shear elastic moduli, stresses, surface viscosities and non-linearity are explored. Challenges such as deviation from a classical analysis of monolayers are encountered in the form of aggregation, mechanical contributions, and interface relaxation. These factors are taken into account to explain experimental measurements and trends. Ultimately, existing models for more homogeneous systems are resolved with observations to offer insight and areas of promise moving forward.


Particle Image Velocimetry Design & Installation, Zach Ritchie 2016 University of Arkansas, Fayetteville

Particle Image Velocimetry Design & Installation, Zach Ritchie

Mechanical Engineering Undergraduate Honors Theses

This work will mainly focus on the design, construction, and installation of the Particle Image Velocimetry (PIV) system in the Chemical Hazards Research Center wind tunnel. The PIV system utilizes a Class IV (double pulsed) laser, optics to produce a light sheet, timing circuitry, and a high-resolution camera (with buffered output) to measure a system’s velocity (two-dimensional) field by determining the displacement of particles over the time between laser pulses. For maximum mobility and functionality, the PIV system was installed in the center of the tunnel on a moveable cart with the laser and camera mounted to an adjustable ...


Biomolecular Interactions Control The Shape Of Stains From Drying Droplets Of Complex Fluids, Cedric Hurth, Ranjeesh Bhardwaj, Sahar Andalib, Christophe Frankiewicz, Andrew Dobos, Daniel Attinger, Frederic Zenhausern 2016 University of Arizona

Biomolecular Interactions Control The Shape Of Stains From Drying Droplets Of Complex Fluids, Cedric Hurth, Ranjeesh Bhardwaj, Sahar Andalib, Christophe Frankiewicz, Andrew Dobos, Daniel Attinger, Frederic Zenhausern

Daniel Attinger

When a sessile droplet of a complex fluid dries, a stain forms on the solid surface. The structure and pattern of the stain can be used to detect the presence of a specific chemical compound in the sessile droplet. In the present work, we investigate what parameters of the stain or its formation can be used to characterize the specific interaction between an aqueous dispersion of beads and its receptor immobilized on the surface. We use the biotin-streptavidin system as an experimental model. Clear dissimilarities were observed in the drying sequences on streptavidin-coated substrates of droplets of aqueous solutions containing ...


Texture And Wettability Of Metallic Lotus Leaves, Christophe Frankiewicz, Daniel Attinger 2016 Iowa State University

Texture And Wettability Of Metallic Lotus Leaves, Christophe Frankiewicz, Daniel Attinger

Daniel Attinger

Superhydrophobic surfaces with the self-cleaning behavior of lotus leaves are sought for drag reduction and phase change heat transfer applications. These superrepellent surfaces have traditionally been fabricated by random or deterministic texturing of a hydrophobic material. Recently, superrepellent surfaces have also been made from hydrophilic materials, by deterministic texturing using photolithography, without low-surface energy coating. Here, we show that hydrophilic materials can also be made superrepellent to water by chemical texturing, a stochastic rather than deterministic process. These metallic surfaces are the first analog of lotus leaves, in terms of wettability, texture and repellency. A mechanistic model is also proposed ...


On Brownian Dynamics Simulation Of Nanoparticle Aggregation, Sergiy Markutsya, Shankar Subramaniam, R. Dennis Vigil, Rodney O. Fox 2016 Iowa State University

On Brownian Dynamics Simulation Of Nanoparticle Aggregation, Sergiy Markutsya, Shankar Subramaniam, R. Dennis Vigil, Rodney O. Fox

R. Dennis Vigil

Accurate simulation and control of nanoparticle aggregation in chemical reactors requires that population balance equations be solved by using realistic expressions for aggregation and breakage rate kernels. Obtaining such expressions requires that atomistic simulation approaches that can account for microscopic details of particle collisions be used. In principle, molecular dynamics simulations can provide the needed microscopic information, but because of the separation in length scales between the aggregates and solvent molecules, such simulations are too costly. Brownian dynamics simulations provide an alternative to the molecular dynamics approach for simulation of particle aggregation, but there has been no systematic attempt to ...


Investigation And Modeling Of Dip-Coating Process For Dispersions, Mahyar Javidi Soufiani 2016 The University of Western Ontario

Investigation And Modeling Of Dip-Coating Process For Dispersions, Mahyar Javidi Soufiani

Electronic Thesis and Dissertation Repository

Dip coating of liquid film deposition on cylindrical substrates is studied using mathematical modeling, numerical simulation and experimental investigation. A mathematical model based on the Landau-Levich approach for dip coating has been developed using the Ellis constitutive equation, for cylindrical geometries, to analyze the effects on the coating thickness of the substrate radius and hydrodynamic behavior for a non-Newtonian fluid. The influence of the viscosity at low shear rates near the surface of the withdrawal film is included in the Ellis model and coating thickness results for Ellis, power law and Newtonian models are compared with experimental data. Good agreement ...


Procesy Cieplne I Aparaty (Lab), Wojciech M. Budzianowski 2016 Wroclaw University of Technology

Procesy Cieplne I Aparaty (Lab), Wojciech M. Budzianowski

Wojciech Budzianowski

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Texture And Wettability Of Metallic Lotus Leaves, Christophe Frankiewicz, Daniel Attinger 2016 Iowa State University

Texture And Wettability Of Metallic Lotus Leaves, Christophe Frankiewicz, Daniel Attinger

Mechanical Engineering Publications

Superhydrophobic surfaces with the self-cleaning behavior of lotus leaves are sought for drag reduction and phase change heat transfer applications. These superrepellent surfaces have traditionally been fabricated by random or deterministic texturing of a hydrophobic material. Recently, superrepellent surfaces have also been made from hydrophilic materials, by deterministic texturing using photolithography, without low-surface energy coating. Here, we show that hydrophilic materials can also be made superrepellent to water by chemical texturing, a stochastic rather than deterministic process. These metallic surfaces are the first analog of lotus leaves, in terms of wettability, texture and repellency. A mechanistic model is also proposed ...


Inżynieria Chemiczna Lab., Wojciech M. Budzianowski 2016 Wroclaw University of Technology

Inżynieria Chemiczna Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

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Proceedings Of The 1st Resrb 2016 Conference, June 22-24, 2016, Wrocław, Poland, Wojciech M. Budzianowski 2016 Wojciech Budzianowski Consulting Services

Proceedings Of The 1st Resrb 2016 Conference, June 22-24, 2016, Wrocław, Poland, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


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