Chemical Engineering Commons^™

Design Of Advanced Ion-Exchange Membranes And Their Performance Assessment For Downstream Chromatographic Bioseparations, Bharatkumar Bhut

All Dissertations

This doctoral research focuses on the design, development and characterization of advanced ion-exchange membranes and their performance evaluation as process chromatography media for downstream bioseparations. Chromatography is a widely used unit operation in the biopharmaceutical industry for the downstream purification of protein therapeutics. The rapid developments in biotechnology and the pharmaceutical potential of biomolecules have increased the worldwide demand for protein therapeutics dramatically. Considering that 50−90% of the total cost of bioprocesses is due to the downstream recovery and purification, high-productivity and high-resolution separation techniques that will enable cost-effective production are essential to the biopharmaceutical industry. In recent years, membrane …

A Spectroscopic Investigation Into The Setting And Mechanical Properties Of Titanium Containing Glass Polyalkenoate Cements, A. W. Wren, A. Kidari, N. M. Cummins, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Titanium (Ti) implants are extensively used in a number of biomedical and dental applications. This work introduces Ti into the glass phase of a zinc-based glass polyalkenoate cement (GPC) and investigates changes in handling and mechanical properties considering two molecular weight polyacrylic acids (PAA), E9 and E11. Considering the handling properties, the working time (T_w) increased from 50 s_E9, 32 s_E11 (BT 101, Ti-free) to 169 s_E9, 74 s_E11 with TW-Z (highest Ti content), respectively. The setting time (T_s) increased from 76 s_E9, 47 s_E11 (BT 101) …

A Genome-Wide Analysis Reveals No Nuclear Dobzhansky-Muller Pairs Of Speciation Genes Between S. Cerevisiae And S. Paradoxus, But Suggests More Complex Incompatibilities, Katy Kao, Katja Schwartz, Gavin Sherlock

Faculty Publications

The Dobzhansky-Muller (D-M) model of speciation by genic incompatibility is widely accepted as the primary cause of interspecific postzygotic isolation. Since the introduction of this model, there have been theoretical and experimental data supporting the existence of such incompatibilities. However, speciation genes have been largely elusive, with only a handful of candidate genes identified in a few organisms. The Saccharomyces sensu stricto yeasts, which have small genomes and can mate interspecifically to produce sterile hybrids, are thus an ideal model for studying postzygotic isolation. Among them, only a single D-M pair, comprising a mitochondrially targeted product of a nuclear gene …

Investigation Of Buildup Dose For Therapeutic Intensity Modulated Photon Beams In Radiation Therapy, Khosrow Javedan

USF Tampa Graduate Theses and Dissertations

Buildup dose of Mega Voltage (MV) photon beams can be a limiting factor in intensitymodulated radiation therapy (IMRT) treatments. Excessive doses can cause patient discomfort and treatment interruptions, while underdosing may lead to local failure.

Many factors which contribute to buildup dose, including the photon beam energy spectrum, scattered or contaminant radiation and their angular distribution, are not modeled well in commercial treatment planning systems. The accurate Monte Carlo method was employed in the studies to estimate the doses.

Buildup dose of 6MV photon beams was investigated for three fundamentally different IMRT modalities: between Helical TomoTherapy and traditional opposed tangential …

Crystallization Method For Benzphetamine, Dennis J. Kalota, Keith Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

There is disclosed a method for the crystallization of benzphetamine hydrochloride from an organic medium by the steps of removing water from the system to a very low level and then reducing the temperature of the organic medium to provide crystallization of the acid salt. In the event that crystallization does not occur upon lowering the temperature of the medium, it has been discovered that gentle heating of the organic medium results in crystallization of the acid salt. It has also been discovered that higher temperature crystallization has been provided by removal of methamphetamine from the composition. The crystalline benzphetamine …

2,4,6-Tri­Phenyl­Aniline, Onome Ugono, Stephanie Cowin, Alicia M. Beatty

Educator Preparation & Leadership Faculty Works

No abstract provided.

Recombinant Factors For Hemostasis, Jennifer Calcaterra

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Trauma deaths are a result of hemorrhage in 37% of civilians and 47% military personnel and are the primary cause of death for individuals under 44 years of age. Current techniques used to treat hemorrhage are inadequate for severe bleeding. Preliminary research indicates that fibrin sealants (FS) alone or in combination with a dressing may be more effective; however, it has not been economically feasible for widespread use because of prohibitive costs related to procuring the proteins. To meet future demands for hemostatic therapies, FS will likely include recombinant human fibrinogen (rFI) and recombinant human Factor XIII (rFXIII). The underlying …

The Effect Of Adding Organic Polymers On The Handling Properties, Strengths And Bioactivity Of A Ca-Sr-Zn-Si Glass Polyalkenoate Cement, A. W. Wren, N. M. Cummins, A. Coughlan, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This work demonstrates the addition of a number of naturally occurring proteins/polymers to a zinc-based glass polyalkenoate cements (GPCs). Chitin (Chi.), collagen (Col.), cysteine (Cys.) and keratin (Ker.) were added with the intention of improving the bioactivity of this cement. Initial testing involved characterization of the glass with X-ray diffraction (XRD) and differential thermal analysis (DTA) before and after sterilization with γ-irradiation. No significant changes occurred as a result of sterilization. Handling properties of the modified cements were not significantly different from those of the control, BT 101 (Working T_w-36_s, and setting time T_s-70 …

Development Of Pilot Plant For Bio-Ethanol Processing, Emrod Elisante

Tanzania Journal of Engineering and Technology (TJET)

The paper outlines achievements obtained in developing a pilot bio-ethanol plant at the Department of Chemical and Mining Engineering (CME), University of Dar es Salaam. The pilot plant consists of: 30 L inoculums tank; 1,700 L fermenter; 1,500 L/day distillation column; and ancillary equipment. The prototype is a platform intended to be used for technology demonstration and research by graduate and undergraduate students studying the production of bio-ethanol using traditional and non-traditional raw materials like coffee mash, cashew fruit, and sisal inulin. The equipment has been developed using locally available engineering resources and the distillation column with 18 sieve tray …

The Structure And Stability Of Alpha-Helical, Orthogonal-Bundle Proteins On Surfaces, Shuai Wei

Theses and Dissertations

The interaction of proteins with surfaces is a major problem 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. In an attempt to develop some predictive capabilities with respect to protein/surface interactions, it was asked in previous works if the stabilization/destabilization of proteins on surfaces could be correlated to secondary structure …

Synthesis, Characterization, And Self-Assembly Of Gold Nanorods And Nanoprisms, Kristina L. Tran

USF Tampa Graduate Theses and Dissertations

The unique properties of gold nanoparticles make them excellent candidates for applications in electronics, sensing, imaging, and photothermal therapy. Though abundant literature exists for isotropic gold nanoparticles, work on nanoparticles of different shapes has been gaining interest recently. Anisotropic gold nanoparticles, such as nanorods and nanoprisms, have tunable optical properties in the visible and near-infrared regions. Through synthesis and surface modification, the production of various shapes of these gold nanoparticles can be controlled to meet different applications.

Two different types of gold nanorods were used in this thesis. The first type was stabilized with cetyltrimethylammonium bromide (CTAB) and had aspect …

Atomic-Level Investigation Of Surface Processes Governing Sige Wetting Layer Formation Using Stm/Sts, Kyle J. Solis

Chemical and Biological Engineering ETDs

Upon sub-monolayer Ge deposition on the 2xn reconstructed SiGe alloy wetting layer at room temperature, the predominant adspecies observed are so-called addimer chain structures (ADCSs). Polarity-switching scanning tunneling microscopy (STM) is used to study ADCSs, as they only appear in empty-state images. ADCSs are dilute structures comprising type-C addimers that reside in neighboring troughs and extend along all equivalent < 130> directions of the surface, giving rise to a zigzagged morphology. ADCSs exhibit localized movements, wherein their rearrangements are strongly coupled with the structure of the underlying substrate dimers. At elevated temperatures, ADCSs are observed to transition to compact epitaxial segments of …

The Sintering And Stability Of Catalytic Nano-Particles, Andrew Delariva

Chemical and Biological Engineering ETDs

Studies were performed on three different catalysts in order to determine their stability and sintering behavior. Pd deposited on a flat single crystal substrate made of Al2O3 was characterized to determine if the mechanism of Ostwald ripening was solely dominated by vapor phase transport of metal atoms. The atoms emitted could be determined by the rate of evaporation and an attempt was then made in order to relate the rates of emission to sintering (instability of nanoparticles). It was found that the rates of emission did not fully reflect vapor phase transport (direct evaporation). The particle-support interaction was increasing the …

Long-Term Desorption Behavior Of Uranium And Neptunium In Heterogeneous Volcanic Tuff Materials, Dean Cynthia

Chemical and Biological Engineering ETDs

Uranium and neptunium desorption were studied in long-term laboratory experiments using four well-characterized volcanic tuff cores collected from southeast of Yucca Mountain, Nevada. The objectives of the experiments were to 1. Demonstrate a methodology aimed at characterizing distributions of sorption parameters (attributes of multiple sorption sites) that can be applied to moderately-sorbing species in heterogeneous systems to provide more realistic reactive transport parameters and a more realistic approach to modeling transport in heterogeneous systems. 2. Focus on uranium and neptunium because of their high solubility, relatively weak sorption, and high contributions to predicted dose in Yucca Mountain performance assessments. Also, …

Flammability Limits, Flash Points, And Their Consanguinity: Critical Analysis, Experimental Exploration, And Prediction, Jeffrey R. Rowley

Theses and Dissertations

Accurate flash point and flammability limit data are needed to design safe chemical processes. Unfortunately, improper data storage and reporting policies that disregard the temperature dependence of the flammability limit and the fundamental relationship between the flash point and the lower flammability limit have resulted in compilations filled with erroneous values. To establish a database of consistent flammability data, critical analysis of reported data, experimental investigation of the temperature dependence of the lower flammability limit, and theoretical and empirical exploration of the relationship between flash points and temperature limits are undertaken. Lower flammability limit measurements in a 12-L ASHRAE style …

Bioadhesion To Model Thermally Responsive Surfaces, Brett J. Andrzejewski

Chemical and Biological Engineering ETDs

This dissertation focuses on the characterization of two surfaces: mixed self-assembled monolayers (SAMs) of hexa(ethylene glycol) and alkyl thiolates (mixed SAM) and poly(N-isopropylacrylamide) (PNIPAAm). The synthesis of hexa(ethylene gylcol) alkyl thiol (C11EG6OH) is presented along with the mass spectrometry and nuclear magnetic resonance results. The mixed SAM surface was confirmed to be thermally responsive by contact angle goniometry, 35° at 28 °C and 55° at 40 °C. In addition, the mixed SAM surfaces were confirmed to be thermally responsive for various aqueous mediums by tensiometry. Factors such as oxygen, age, and surface mole fraction and how they affect the thermal …

Results And Analysis Of A Required Senior Exam To Assess Learning Of Course Competencies, Randy Lewis, Thomas Knotts, W. Vincent Wilding, William G. Pitt, Morris D. Argyle

Faculty Publications

As part of the ABET Accreditation Criterion, Program Outcomes refer to the outcomes that chemical engineering students should possess when they leave the university and enter the workforce. In 1999, as a response to ABET’s EC2000 criterion, a list of specific competencies was defined in the Chemical Engineering Program at Brigham Young University that, when taken together, constituted each Program Outcome. When the competencies were first developed, it became clear that the level of mastery expected from students varied from competency to competency. Exposure to the material was all that was required for some competencies. For others, it was our …

Results And Analysis Of A Required Senior Exam To Assess Learning Of Course Competencies, Randy Lewis, Thomas Knotts, W Vincent Wilding, William Pitt, Morris Argyle

Faculty Publications

As part of the ABET Accreditation Criterion, Program Outcomes refer to the outcomes that chemical engineering students should possess when they leave the university and enter the workforce. In 1999, as a response to ABET’s EC2000 criterion, a list of specific competencies was defined in the Chemical Engineering Program at Brigham Young University that, when taken together, constituted each Program Outcome. When the competencies were first developed, it became clear that the level of mastery expected from students varied from competency to competency. Exposure to the material was all that was required for some competencies. For others, it was our …

Computer Simulation Of A Biomass Gasification-Solid Oxide Fuel Cell Power System Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

The operation and performance of a solid oxide fuel cell (SOFC) stack on biomass syn-gas from a biomass gasification combined heat and power (CHP) plant is investigated. The objective of this work is to develop a model of a biomass-SOFC system capable of predicting performance under diverse operating conditions. The tubular SOFC technology is selected. The SOFC stack model, equilibrium type based on Gibbs free energy minimisation, is developed using Aspen Plus. The model performs heat and mass balances and considers ohmic, activation and concentration losses for the voltage calculation. The model is validated against data available in the literature …

A Multi-Objective Evaluation Of Pc Plants With Aqueous Amine Carbon Capture Systems, John Eslick

CO2 Summit: Technology and Opportunity

No abstract provided.