Chemical Engineering Commons^™

Foundational Work In Bioelectrochemical Anaerobic Reactor Design With Electron Mediators, Christopher D. Hoeger

Theses and Dissertations

Bioelectrical reactors (BER) have potential to be utilized in a wide variety of industrial applications. This work explores the kinetics involved with reduction of electron mediators (anthraquinone disulfonate and methyl viologen) in bioelectrical reactors. It also discusses on possible application of BER technology to produce ethanol from CO2 and electricity. It is established that Clostridium ragdahlei is capable of sustaining life and product formation with CO2 as the only carbon source. This means it is theoretically possible to utilize CO2 as he source of carbon and electricity as the source of reducing equivalents for bacterial growth and product formation. A …

Immobilized Viologen Polymer For Use In Direct Carbohydrate Fuel Cells, Yining Pan

Theses and Dissertations

Glucose and other carbohydrates are some of the most abundant renewable energy sources in the world. The oxidation of carbohydrates in a fuel cell allows their chemical energy to be converted directly into electrical energy. Viologen has been indentified and shows promising ability as an electron-transfer catalyst or mediator for carbohydrate oxidation in an alkaline carbohydrate fuel cell. Building on the previous results, the objective of this work was to develop an immobilization chemistry of viologen onto an electrode and to investigate the catalytic activity for carbohydrate oxidation in direct carbohydrate fuel cells.The immobilization was achieved by electropolymerizing a novel …

Application Of Fuel Element Combustion Properties To A Semi-Empirical Flame Propagation Model For Live Wildland Utah Shrubs, Chen Shen

Theses and Dissertations

Current field models for wildfire prediction are mostly based on dry or low-moisture fuel combustion research. To better study live fuel combustion behavior and develop the current semi-empirical bush combustion model, a laminar flow flat-flame burner was used to provide a convection heating source to ignite individual live fuel samples. In this research project, four Utah species were studied: Gambel oak (Quercus gambelii), canyon maple (Acer grandidentatum), big sagebrush (Artemisia tridentata) and Utah juniper (Juniperus osteosperma). Leaf geometrical parameters and time-dependent combustion behavior were recorded. Qualitative results included various combustion phenomena like bursting, brand formation and bending. Quantitative results included …

Protein-Surface Interactions With Coarse-Grain Simulation Methods, Shuai Wei

Theses and Dissertations

The interaction of proteins with surfaces is a major process involved in protein microarrays. Understanding protein-surface interactions is key to improving the performance of protein microarrays, but current understanding of the behavior of proteins on surfaces is lacking. Prevailing theories on the subject, which suggest that proteins should be stabilized when tethered to surfaces, do not explain the experimentally observed fact that proteins are often denatured on surfaces. This document outlines several studies done to develop a model which is capable of predicting the stabilization and destabilization of proteins tethered to surfaces. As the start point of the research, part …

Effect Of Cd44 Binding Peptide Conjugated To An Engineered Inert Matrix On Maintenance Of Breast Cancer Stem Cells And Tumorsphere Formation, Xiaoming Yang, Samaneh Kamali Sarvestani, Seyedsina Moeinzadeh, Xuezhong He, Esmaiel Jabbari

Faculty Publications

Introduction: As cancer cells are affected by many factors in their microenvironment, a major challenge is to isolate the effect of a specific factor on cancer stem cells (CSCs) while keeping other factors unchanged. We have developed a synthetic inert 3D polyethylene glycol diacrylate (PEGDA) gel culture system as a unique tool to study the effect of microenvironmental factors on CSCs response. We have reported that CSCs formed in the inert PEGDA gel by encapsulation of breast cancer cells maintain their stemness within a certain range of gel stiffness. The objective was to investigate the effect of CD44 binding peptide …

Method Of Purifying Crude Noscapine, Benjamin M. Marshall, Keith Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

The invention provides a method for separating noscapine from an opium source without substantially changing the color of the noscapine.

Self-Assembling Biomimetic Hydrogels With Bioadhesive Properties For Tissue Engineering Applications, Craig Wiltsey

Theses and Dissertations

Tissue engineering is a multidisciplinary field that aims to repair or regenerate lost or damaged tissues and organs in the body. For the repair of certain load-bearing parts of the body, success of a tissue regeneration strategy can be dependent on scaffold adhesion or integration with the surrounding host tissue to prevent dislocation. One such area is the regeneration of the intervertebral disc (IVD). The objective of this work is to generate a bioadhesive polymer that, in addition to bonding with tissue, can support encapsulated cell survival post-adhesion. Thermosensitive poly(N-isopropylacrylamide) (PNIPAAm) was grafted with chondroitin sulfate (CS) (PNIPAAm-g-CS) and blended …

A Framework For Oil Price Benchmark Determination: Lessons For Nigeria, Taiwo H. Sanni, Bassey D. Akpan

Bullion

The main thrust of this paper is to draw lessons of experience from other selected oil producing countries. the outcome of the study is expected to help in strengthening Nigeria's oil price framework in line with international best practice. Section 2 dwells on the theoretical and literature review on oil based fiscal rule, while section 3 presents the framework for oil price benchmark determination and section 4 examines those factors capable of stimulating determination of oil price benchmark, lastly section 5 discusses some lessons of experience from Nigeria and then the conclusion.

Fuel Subsidy And Other Unproductive Public Expenditures Removal: A Pragmatic Approach To Restructure And Transform The Nigerian Economy, Lawrence O. Akinboyo

Bullion

While the short term measures to reduce recurrent expenditure are necessary conditions for fiscal sustainability, the long term imperative is to increase revenue. Thus, efforts should be made by the fiscal authorities in Nigeria to pursue the policy of balancing of expenditure with revenue improvements. The issues of the underperformance of the capital budget should be reversed before savings from cuts in recurrent expenditure can be diverted to the financing of capital expenditure. From the analysis, we say that removal of fuel subsidy would no doubt have some social and economic hardship on the people in the short run, However, …

A Steady-State Detection (Ssd) Algorithm To Detect Non-Stationary Drifts In Processes, Jeff Kelly, John Hedengren

Faculty Publications

Detecting windows or intervals of when a continuous process is operating in a state of steadiness is useful especially when steady-state models are being used to optimize the process or plant on-line or in real-time. The term steady-state implies that the process is operating around some stable point or within some stationary region where it must be assumed that the accumulation or rate-of-change of material, energy and momentum is statistically insignificant or negligible. This new approach is to assume the null-hypothesis that the process is stationary about its mean subject to independent and identically distributed random error or shocks (white-noise) …

Study Of An Alternative Process For Oxidizing Vapor Grown Carbon Nanofibers Using Electron Beam Accelerators, Maria Cecília Evora, Donald A. Klosterman, Khalid Lafdi, Lingchuan Li, L.G.A. Silva

Chemical and Materials Engineering Faculty Publications

The use of a high-energy electron beam was explored in this study as an alternative technique for oxidizing vapor grown carbon nanofiber surfaces. The radiation exposures were carried out at three different electron beam facilities with beam energies of 1.5, 3.0 and 4.5 MeV and radiation doses ranging from 1000 to 3500 kGy. XPS analysis showed that oxygen was readily incorporated on the surface: the ratio O1s/C1s increased approximately by a factor of 4 when the carbon nanofibers were irradiated at 3500 kGy. The oxidized nanofibers exhibited better dispersion in a water/methanol solution (50% v/v) than as-received nanofibers. Raman spectroscopy …

Note: A Simple Thermal Gradient Annealing Unit For The Treatment Of Thin Films, C. J. Metting, Johnathan K. Bunn, Ellen A. Underwood, Yihao Zhu, G. Koley, T. Crawford, Jason R. Hattrick-Simpers

Faculty Publications

A gradient annealing cell has been developed for the high-throughput study of thermalannealing effects on thin-film libraries in different environments. The inexpensive gradientannealing unit permits temperature gradients as large as 28 °C/mm and can accommodate samples ranging in length from 13 mm to 51 mm. The system was validated by investigating the effects of annealing temperature on the crystallinity, resistivity, and transparency of tin-doped indium oxide deposited on a glass substrate by magnetron sputtering. The unit developed in this work will permit the rapid optimization of materials properties such as crystallinity, homogeneity, and conductivity across a variety of applications.

Three-Dimensional Engineered Matrix To Study Cancer Stem Cells And Tumorsphere Formation: Effect Of Matrix Modulus, Xiaoming Yang, Samaneh Kamali Sarvestani, Seyedsina Moeinzadeh, Xuezhong He, Esmaiel Jabbari

Faculty Publications

Maintenance of cancer stem cells (CSCs) is regulated by the tumor microenvironment. Synthetic hydrogels provide the flexibility to design three-dimensional (3D) matrices to isolate and study individual factors in the tumor microenvironment. The objective of this work was to investigate the effect of matrix modulus on tumorsphere formation by breast cancer cells and maintenance of CSCs in an inert microenvironment without the interference of other factors. In that regard, 4T1 mouse breast cancer cells were encapsulated in inert polyethylene glycol diacrylate hydrogels and the effect of matrix modulus on tumorsphere formation and expression of CSC markers was investigated. The gel …

Single-Cell Measurements Of Ige-Mediated Fcεri Signaling Using An Integrated Microfluidic Platform, Yanli Liu, Dipak Barua, Peng Liu, Bridget S. Wilson, Janet M. Oliver, William S. Hlavacek, Anup K. Singh

Chemical and Biochemical Engineering Faculty Research & Creative Works

Heterogeneity in responses of cells to a stimulus, such as a pathogen or allergen, can potentially play an important role in deciding the fate of the responding cell population and the overall systemic response. Measuring heterogeneous responses requires tools capable of interrogating individual cells. Cell signaling studies commonly do not have single-cell resolution because of the limitations of techniques used such as Westerns, ELISAs, mass spectrometry, and DNA microarrays. Microfluidics devices are increasingly being used to overcome these limitations. Here, we report on a microfluidic platform for cell signaling analysis that combines two orthogonal single-cell measurement technologies: on-chip flow cytometry …

Entropic Depletion Of Dna In Triangular Nanochannels, Wesley F. Reinhart, Douglas R. Tree, Kevin D. Dorfman

Faculty Publications

Using Monte Carlo simulations of a touching-bead model of double-stranded DNA, we show that DNA extension is enhanced in isosceles triangular nanochannels (relative to a circular nanochannel of the same effective size) due to entropic depletion in the channel corners. The extent of the enhanced extension depends non-monotonically on both the accessible area of the nanochannel and the apex angle of the triangle. We also develop a metric to quantify the extent of entropic depletion, thereby collapsing the extension data for circular, square, and various triangular nanochannels onto a single master curve for channel sizes in the transition between the …

An In Situ Ftir Spectroelectrochemical Study On Methanol Oxidation At Pt-Mo2C/Gc Catalyst, Hai-Ping Huang, Xi-Yu Yao, Pei-Kang Shen

Journal of Electrochemistry

A 40% Pt on Mo₂C/GC catalyst has been prepared by ion exchange method. The mechanism of methanol electrooxidation on Pt-Mo₂C/GC and commercial Pt/C catalysts in acidic media was studied by cyclic voltammetry, XRD measurements and in-situ Fourier transform infrared spectroelectrochemistry. The results revealed that the Pt nanoparticles were uniformly dispersed on Mo₂C/GC with an average particle size of 3 nm. The cyclic voltammetric and chronopotentiometric experiments indicated that Pt-Mo₂C/GC catalyst exhibited a better performance for methanol oxidation than that of Pt/C in acid solution. A negative shift over 90 mV of the …

Oxygen Reduction Reaction On Glycin Modified Pt(111) Electrode, Ming-Fang Li, Jing Kang, Ling-Wen Liao, Yan-Xia Chen, Shen Ye

Journal of Electrochemistry

O

xygen reduction reaction (ORR) on glycin (NH₂CH₂COOH) modified Pt(111) electrode has been investigated using hanging meniscus rotating disk electrode system (HMRD) in 0.05 mol•L^-1 H₂SO₄ and 0.1 mol•L^-1 HClO₄ solutions, respectively. Cyclic voltammograms of the glycin modified Pt (111) electrode measured in 0.05 mol•L^-1 H₂SO₄ solution similar to that of CN^- modified Pt(111) electrodes, demonstrating that sulfate adsorption is strongly inhibited at the glycin modified Pt(111). From the polarization curve of ORR recorded in 0.05 mol•L^-1 H₂SO₄ solution, it is …

Effect Of Ti/Pbo2 Electrodes Doped With Different Elements On Electrocatalytic Oxidation Characteristics Of Phenol, Xiao-Lei Liu, Yuan-Yuan Dan, Hai-Yan Lu, Hai-Bo Lin, Ming-Li Ouyang, Chuan-Jun Yun

Journal of Electrochemistry

Three types of electrodes, namely, Ti/PbO₂, F-doped PbO₂ (Ti/PbO₂-F) and nano-Co₃O₄-doped PbO₂ (Ti/PbO₂+Nano-Co₃O₄) electrodes, were prepared by electro-deposition method on the Ti substrate with the interlayer of SnO₂-Sb₂O₅. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to study the compositions, structures and film morphologies of the electrodes. Electrocatalytic oxidation characteristics to phenol on the prepared electrodes were investigated by electrochemical method. The experimental results showed that compared with the Ti/PbO₂ electrode, the potentials of oxygen …

A Dft Calculation Screening Of Pt-Based Bimetallic Catalysts For Oxygen Reduction, Li-Hui Ou, Sheng-Li Chen

Journal of Electrochemistry

Developing Pt-lean catalysts for oxygen reduction reaction (ORR) is the key for large-scale application of proton exchange membrane fuel cell (PEMFC). In this paper, we have proposed a multiple-descriptor strategy for screening efficient and durable ORR alloy catalysts of low Pt content. We argue that an ideal Pt-based bimetallic alloy catalyst for ORR should possess simultaneously negative alloy formation energy, negative surface segregation energy of Pt and a lower oxygen binding ability than pure Pt. By performing detailed DFT calculations on the thermodynamics, surface chemistry and electronic properties of various Pt-M alloys (M refers to non-precious transition metals in the …

Advances In The Synthesis Of Zno Nanomaterials For Varistor Devices, Suresh Pillai, John M. Kelly, Raghavendra Ramesh, Declan Mccormack

Articles

ZnO based varistors are widely used for overvoltage protection in many electrical and electronic circuits, at voltages ranging from a few to over a million volts. By careful control of the microstructure, through nanostructuring by chemical routes, it should be possible to produce varistors with high breakdown voltage (Vc), as this is proportional to the number of active grain boundaries in the sintered body. This property is particularly important for the production of the small-sized varistors needed for modern electronic instruments such as tablet computers and mobile phones. The current review will outline the recent advances in the chemical processing …