Engineering Commons^™

Development Of Novel Method For Preparation Of Pemfc Electrodes, Hansung Kim, Branko N. Popov

Faculty Publications

A method based on pulse electrodeposition technique was developed for preparation of membrane electrode assemblies (MEAs). In this approach, platinum is deposited directly on the surface of the carbon electrode. The method ensures most of the platinum to be in close contact with the membrane. Using this method it is possible to increase the Pt/C ratio up to 75 wt % near the surface of the electrode resulting in a 5 µm thick catalyst layer. The MEA prepared by pulse electrodeposition exhibits a current density of 0.33 A/cm² at 0.8 V with platinum loading of 0.25 mg of Pt/cm …

Modeling Of Cane Sugar Colorant Removal In Packed-Bed Ion Exchange Columns And An Investigation Into Pretreatment Methods, Bruce Malcolm Ellis

LSU Master's Theses

Cane sugar colorants have been extensively researched but still little is known about their exact compositions. Rather than distinct compounds, they are a mixture of many compounds. Some it is assumed can be classified into the pseudo components that have been defined using gel permeation chromatography, based on molecular weight. The defining of these components has allowed the colorants to be modeled independently, instead of as one lumped color parameter. The measured colored components were modeled using a linear driving force adsorption model, which could be applied in the design process for optimizing the decolorizing capacity of the resins. The …

Design And Technologies For A Smart Composite Bridge, K. Chandrashekhara, Prakash Kumar, Steve Eugene Watkins, Antonio Nanni

Mechanical and Aerospace Engineering Faculty Research & Creative Works

An all-composite, smart bridge design for shortspan applications is described. The bridge dimensions are 9.14-m (30-ft.) long and 2.74-m (9-ft.) wide. A modular construction based on assemblies of pultruded fiber-reinforced-polymer (FRP) composite tubes is used to meet American Association of State Highway and Transportation Officials (AASHTO) H20 highway load ratings. The hollow tubes are 76 mm (3 in.) square and are made of carbon/vinyl-ester and glass/vinyl-ester. An extensive experimental study was carried out to obtain and compare properties (stiffness, strength, and failure modes) for a quarter portion of the full-sized bridge. The bridge response was measured for design loading, two-million-cycle …

Continuation Of Research To Determine The Effectiveness Of Its On Borman Expressway, Robert Bertram Jacko, William H. Schneider, Ahmed S. Soliman, Barry K. Partridge

JTRP Technical Reports

This study is a continuation and the final phase of the SPR-2338 project that involves monitoring the ambient air quality levels adjacent to the Borman Expressway. The purpose of this phase was to classify the traffic conditions along the Borman Expressway in terms of ambient air quality levels. The duration of the phase was from April 1, 2002 to April 30, 2004. The study has shown that, in a close proximity to the Borman Expressway, air quality levels mirror the dynamic nature of traffic along the Borman, despite being surrounded by major industrial stationary sources. Therefore, a descriptive model was …

Polymethylmethacrylate Augmented With Carbon Nanotubes, David A. Pienkowski, Rodney J. Andrews

Center for Applied Energy Research Faculty Patents

An augmented synthetic resin is provided. That resin includes carbon nanotubes dispersed in a polymethylmethacrylate matrix. The method of preparing this synthetic resin includes the mixing and disaggregating of the carbon nanotubes.

Delta-Ferrite Recovery Structures In Low-Carbon Steels, Rian Dippenaar, Dominic Phelan

Faculty of Engineering and Information Sciences - Papers: Part A

The development of delta-ferrite recovery substructures in low-carbon steels has been observed in-situ utilizing laser scanning confocal microscopy (LSCM). Well-developed sub-boundaries with interfacial energies much smaller than that of delta-ferrite grain boundaries formed following transformation from austenite to delta-ferrite on heating. It is proposed that transformation stresses associated with the austenite to delta-ferrite phase transformation generate dislocations that subsequently recover into sub-boundaries by a process of polygonization. Experimental evidence in support of this proposal was found in a ferritic stainless steel. Thermal cycling through the high-temperature delta-ferrite/austenite/delta-ferrite phase transformation leads to the development of a well-defined recovery substructure, which, in …

Detection Of Carbon Monoxide Within The Magellanic Bridge, E Muller, L Staveley-Smith, William Zealey

Faculty of Engineering and Information Sciences - Papers: Part A

The Mopra 22-m and SEST 15-m telescopes have been used to detect and partially map a region of ¹²CO(1-0) line emission within the Magellanic Bridge, a region lying between the Large and Small Magellanic Clouds (LMC and SMC, respectively). The emission appears to be embedded in a cloud of neutral hydrogen, and is in the vicinity of an IRAS source. The CO emission region is found to have a 60 μm/100 μm flux density ratio typical for ¹²CO(1-0) detections within the SMC, although it has a significantly lower ¹²CO brightness and velocity width. These suggest that the …

Improving The Mechanical Properties Of Single-Walled Carbon Nanotube Sheets By Intercalation Of Polymeric Adhesives, Jonathan N. Coleman, Werner J. Blau, Alan B. Dalton, Edgar Munoz, Steve Collins, Bog G. Kim, Joselito M. Razal, Miles Selvidge, Guillermo Vieiro, Ray Baughman

Australian Institute for Innovative Materials - Papers

Organic polymers, such as poly(vinyl alcohol), poly(vinyl pyrrolidone), and poly(styrene), were intercalated into single-walled carbon nanotube sheets by soaking the sheets in polymer solutions. Even for short soak times, significant polymer intercalation into existing free volume was observed. Tensile tests on intercalated sheets showed that the Young's modulus, strength, and toughness increased by factors of 3, 9, and 28, respectively, indicating that the intercalated polymer enhances load transmission between nanotubes.

A Mathematical Model Of Oxide/Carbon Composite Electrode For Supercapacitors, Hansung Kim, Branko N. Popov

Faculty Publications

A pseudo two-dimensional model is developed for the general application of supercapacitors consisting of an oxide/carbon composite electrode. The model takes into account the diffusion of protons in the oxide particle by employing the method of superposition. RuO₂/carbon system is modeled as a specific example. From the simulation data, it is found that the oxide particle size and proton diffusion coefficient have an enormous effect on the performance at high discharge rate due to the limitation of proton transport into RuO₂ particles. With increasing carbon ratio, the porosity of electrode increases, which causes the potential drop in …

Nanofatigue Studies Of Ultrathin Hard Carbon Overcoats Used In Magnetic Storage Devices, Xiaodong Li, Bharat Bhushan

Faculty Publications

A technique to perform nanofatigue experiments was developed. This technique utilizes a depth-sensing nanoindenter with harmonic force. The nanofatigue behavior of 20 nm thick amorphous carbon coatings was studied. The contact stiffness was monitored continuously throughout the test. The abrupt decrease in the contact stiffness indicates fatigue damage has occurred. The critical load amplitude, below which no fatigue damage occurs, was identified. It was found that the filtered cathodic arc coating exhibits longer fatigue life than a direct ion beam coating. Failure mechanisms of the coatings during fatigue are also discussed in conjunction with the hardness,elastic modulus, and fracture toughness, …

Delta-Ferrite Recovery Structures In Low Carbon Steels, Rian J. Dippenaar, Dominic J. Phelan

Faculty of Engineering - Papers (Archive)

The development of delta-ferrite recovery sub-structures in low carbon steels has been observed in-situ utlhsing laser scanniJlg confocal microscopy (LSCM). Well developed subboundaries with interfaCial' energies much smaller than that of delta-fen'ite grain boundaries fOfmed following transformation from austenite to delta-fen'ite on heating. Transfonnatioll stresses associated with the austenite to delta-fenite phase transt'onnation generate dislocations that subsequently recover into sub-boundaries by a process of polygonisation. Experimental evidence in suppol1 of this proposal was found in a ferritic stainless steel. Thermal cycling through the high temperature delta-ferrite/austenite/delta-fel1'ite phase b'ansformation leads to the development of a strong recovery substructure, wh.ich in turn. …

Modeling The Effects Of Electrode Composition And Pore Structure On The Performance Of Electrochemical Capacitors, Changqing Lin, Branko N. Popov, Harry J. Ploehn

Faculty Publications

This work presents a mathematical model for charge/discharge of electrochemical capacitors that explicitly accounts for particle-packing effects in a composite electrochemical capacitor consisting of hydrous RuO₂ nanoparticles dispersed within porous activated carbon. The model is also used to investigate the effect of nonuniform distributions of salt in the electrolyte phase of the electrode in the context of dilute solution theory. We use the model to compare the performance of capacitors with electrodes made from different activated carbons and to investigate the effects of varying carbon content and discharge current density. Even at low discharge current density, concentration polarization in …

Modeling The Effects Of Electrode Composition And Pore Structure On The Performance Of Electrochemical Capacitors, Changqing Lin, Branko N. Popov, Harry J. Ploehn

Faculty Publications

This work presents a mathematical model for charge/discharge of electrochemical capacitors that explicitly accounts for particle-packing effects in a composite electrochemical capacitor consisting of hydrous RuO₂ nanoparticles dispersed within porous activated carbon. The model is also used to investigate the effect of nonuniform distributions of salt in the electrolyte phase of the electrode in the context of dilute solution theory. We use the model to compare the performance of capacitors with electrodes made from different activated carbons and to investigate the effects of varying carbon content and discharge current density. Even at low discharge current density, concentration polarization in …

Effectiveness Of The Borman Expressway Its Program On Local Air Quality, Timothy M. Labreche, Robert Bertram Jacko, Barry K. Partridge, William H. Schneider, Ahmed S. Soliman

JTRP Technical Reports

Particulate Matter less than 2.5 μm in diameter (PM2.5), carbon monoxide (CO), and meteorological parameters were monitored at 10 second averaging intervals adjacent the Borman Expressway in Northwestern Indiana before and during the implementation of an Intelligent Transportation System. Traffic data was collected from sensors on the expressway. The high-resolution data permitted the expressway contribution to local air quality to be separated from background components of local air quality and significant correlations were made between pollutant flux and traffic flow and pollutant flux and highway occupancy. Traffic incidents (accidents / congestion) were shown to have a rapid impact on local …

Synthesis And Characterization Of Hydrous Ruthenium Oxide-Carbon Supercapacitors, Manikandan Ramani, Bala S. Haran, Ralph E. White, Branko N. Popov

Faculty Publications

It is shown that composite Ru oxide-carbon based supercapacitors possess superior energy and power densities as compared to bare carbon. An electroless deposition process was used to synthesize the ruthenium oxide-carbon composites. Ru is dispersed on the carbon matrix as small particles. The effect of electrochemical oxidation and temperature treatment on the material performance has been studied extensively. Increasing the oxidation temperature reduces the proton transport rate and also increases the degree of crystallinity of the deposits. This adversely affects the performance of the composite. Loading a small amount of Ru oxide (9 wt %) on carbon increases the capacitance …

Modeling Lithium Intercalation In A Porous Carbon Electrode, Gerardine G. Botte, Ralph E. White

Faculty Publications

No abstract provided.

The Effects Of Patch Properties On The Debonding Behavior Of Patched Beam-Plates, Anette M. Karlsson

Mechanical Engineering Faculty Publications

The debonding characteristics of patched structures are investigated in this study by means of an analytical model. In particular, the effects the lay-up sequence and edge tapering of a carbon-reinforced epoxy patch, as well as the beveling of an aluminum patch, have on the initiation, stability, and extent of the debonding are considered. The results presented show that both the degree of edge-tapering and the patch properties must be carefully selected in order to optimize the patched structure. It is also shown that when designing a patched system, it is important to model the correct boundary and load conditions to …

Activated Carbon And Process For Making Same, Francis John Derbyshire, Marit Jagtoyen

Chemical and Materials Engineering Faculty Patents

A process is described for the manufacture of activated carbon in the form of a powder, as granules or as extrudates. The process includes treating a biomass feedstock, such as woods, coconut shells, fruit pits, peats, lignites and all ranks of coal with a processing agent and an activation agent. The processing agent may be a natural or synthetic monomer, oligomer, polymer or mixtures thereof capable of interacting or co-polymerizing with the biomass feedstock. The activation agent may be, for example, phosphoric acid, zinc chloride or mixtures thereof. A high surface area, high hardness extruded activated carbon may be produced …

Kinetics Of Laser Chemical Vapor Deposition Of Carbon And Refractory Metals, Feng Gao

Doctoral Dissertations

Three-dimensional laser chemical vapor deposition (3D-LCVD) has been used to grow rods of carbon, tungsten, titanium, and hafnium from a variety of hydrocarbons and metal halide-based precursors. A novel computerized 3D-LCVD system was designed and successfully used in the experiments. A focused Nd:Yag laser beam (λ = 1.06 μm) was utilized to locally heat up a substrate to deposition temperature. The rods, which grew along the axis of the laser beam, had a typical diameter of 30–80 μm and a length of about 1 mm. The precursors for carbon deposition were the alkynes: propyne, butyne, pentyne, hexyne, and octyne. Propyne …

Method Of Removing Carbon From Fly Ash, John Groppo, Steven M. Brooks

Center for Applied Energy Research Faculty Patents

An improved froth flotation method is provided for the removal and recovery of an ultra-fine constituent such as carbon from tailings such as fly ash. A flotation apparatus is utilized that preferably includes a slurry conditioning tank and a flotation cell. The method of the present invention comprises the improvement of utilizing a flotation reagent formulation comprising a mixture of fuel oil and petroleum sulfonate. The method broadly includes the steps of (1) producing a slurry, or solid suspension, of the material containing the constituent to be recovered by adding a preselected amount of water or other slurrying liquid; (2) …

Effect Of Inorganic Salts On Adsorption Process, Pai-Yuan Horng

Dissertations

`Small amounts (0.0 M-0.01 M) of inorganic salts (sodium chloride, calcium chloride, and aluminum chloride) added to bituminous coal fly ash and granular activated carbon in batch adsorption treatment experiments indicates the possibility of enhancing the extent and rate of adsorption process.

Experiments were conducted on aqueous solutions of highly toxic and hazardous chemicals, those include : phenol, benzene, toluene, isopropyl alcohol, and methyl-isobutyl ketone. Single and multiple solute systems were examined separately. Removal of organic pollutants was measured using a Flame Ionization Detector Gas Chromatograph.

This study investigated the role of inorganic salts during the sorption process. The results …

The Effect Of Grinding On The Sorption Capacity Of Activated Carbon, John Garrett Dempsey

Civil & Environmental Engineering Theses & Dissertations

The current procedure employed to design full scale activated carbon contacting systems is presented in detail and followed by a review of the more important process controls and operating parameters. Inherent limitations of the design procedure are identified, with the need to be able to accurately predict carbon sorption capacity from bench scale analysis determined to be the most important. Some of the more recent models developed to predict activated carbon sorption capacity were analyzed leading to the realization that even the most sophisticated dynamic models were based upon sorption capacities determined from classical isotherm procedures. The validity of the …

Granular Activated Carbon Pilot Plant For The Removal Of Color, Toc, And Thmfp, Jeffrey L. Herr

Retrospective Theses and Dissertations

As part of an Environmental Protection Agency grant to reduce the trihalomethane concentration in the Melbourne, Florida drinking water, a granular activated carbon (GAC) plant was operated for approximately 1 year. Four GAC pilot plant systems were operated in parallel each treating a different influent. Raw water, coagulated, settled and filtered water, filtered water with ozone pretreatment, and filtered water with chlorine dioxide pretreatment were pumped through the individual systems. Influent and effluent concentrations of various pollutants were monitored regularly throughout the study. The raw water GAC system showed rapid breakthrough for color, total organic carbon (TOC) and trihalomethanes (THM's). …

An Isothermal Study Of An S.A.E. 6150 Steel, Tom Liss, C. Arentzen

Bachelors Theses and Reports, 1928 - 1970

The purpose of this thesis is to set forth the method followed, the laboratory procedure practiced, the results obtained, the conclu­sions drawn, and the recommendations proposed as a consequence of a metallographic study of the isothermal transformation of an S.A.E. 6150 steel.

The Casting Of Anodes For The Series System Of Electrolytic Copper Refining, Robert R. Kupfer

Bachelors Theses and Reports, 1928 - 1970

The electrolytic refining process, while usually considered an auxiliary process used in conjunction with pyrometallurgical extraction, deserves a special niche in the complex metallurgy of copper. The development of electrolytic copper refining, for example, is largely responsible for the prominence of the electrical industry. Conversely, it could be stated that the electrical industry played an important part in the development of the copper industry.

Chromizing Of Steels, Edward Buchanan

Bachelors Theses and Reports, 1928 - 1970

In recent years, considerable thought and study have been given to the use of chromized articles in place of chromium stainless steel articles. The present extensive application of chromizing, indeed, helps greatly to conserve this valuable metal.

An Investigation Of A Particular Weldment Failure, Byron Clow

Bachelors Theses and Reports, 1928 - 1970

Two sets of weld-test coupons, supposedly made under identical conditions, were submitted to this institution last year for approval and certification under the A.S.M.E. Welder's Qualification Code. The first set of coupons was unsatisfactory. The second set, made by the same operators one month later, was satisfactory.

The Leaching Of Electrodeposition Of Iron, Emmett G. Simmons

Bachelors Theses and Reports, 1928 - 1970

Electrolytic iron as deposited is brittle and therefore must be annealed. After annealing, the material is ductile and closely resembles copper in its behavior under work. It is claimed to be more resistant to corrosion than dead soft iron. It also has the advantage of corroding uniformly ( or­dinary soft iron develops pin holes which shorten its life considerably).

The extreme purity of electrolytic iron namely makes it very suitable as a base metal for alloys. Its ductility opens up a field for use in the manufacture of cold rolled strip, seamless tubes, and wire.