Engineering Commons^™

Computational And Experimental Determination Of The Mixing Efficiency Of A Microfluidic Serpentine Micromixer, Siril Arockiam

Theses

In microfluidics, efficiency and mixing time are the greatest disadvantages. These parameters hinder the application of microfluidic devices for biochemical and immunological assays. However, once these disadvantages have been overcome by optimizing the parameters of the microfluidic device, it becomes the important analytical tool. In this experiment, various designs of microfluidic devices have been both simulated using COMSOL software, and experimentally verified to obtain the optimized parameter such as depth and velocity for better mixing efficiency. The COMSOL model has been validated by comparing the results with fluorescent images data of the experiment. The microfluidic device is built with Adhesive …

The Role Of Catalytic Residue PKA On The Hydrolysis/Transglycosylation Partition In Family 3 Β-Glucosidases, Inacrist Geronimo, Christina M. Payne, Mats Sandgren

Chemical and Materials Engineering Faculty Publications

β-Glucosidases (βgls) primarily catalyze the hydrolysis of the terminal glycosidic bond at the non-reducing end of β-glucosides, although glycosidic bond synthesis (called transglycosylation) can also occur in the presence of another acceptor. In the final reaction step, the glucose product or another substrate competes with water for transfer to the glycosyl-enzyme intermediate. The factors governing the balance between the two pathways are not fully known; however, the involvement of ionizable residues in binding and catalysis suggests that their pK_a may play a role. Through constant pH molecular dynamics simulations of a glycoside hydrolase Family 3 (GH3) βgl, we …

Production Of Bio-Oil With Different Oxygen Content And Characterization Of Catalytic Upgrading To Transportation Fuel, Mubarak Mohammed Khlewee

Electronic Theses and Dissertations

The world’s increasing population requires an increase in transportation fuel production. The lack of production of transportation fuels due to the shortage of fossil fuel resources combined with concerns about global emissions of carbon dioxide from fossil fuel combustion are the two major issues that have driven researchers to actively pursue alternative sources for oil production. Biomass is being considered as an alternative feedstock to produce fuel and chemicals due to its abundance and renewability. It has many features that make it suitable as a source of transportation fuel production. However, the bio-oil produced by the fast pyrolysis process has …

Reducing Biomass Recalcitrance By Heterologous Expression Of A Bacterial Peroxidase In Tobacco (Nicotiana Benthamiana), Ayalew Ligaba-Osena, Bertrand Hankoua, Kay Dimarco, Robert Pace, Mark Crocker, Jesse Mcatee, Nivedita Nagachar, Ming Tien, Tom L. Richard

Center for Applied Energy Research Faculty and Staff Publications

Commercial scale production of biofuels from lignocellulosic feed stocks has been hampered by the resistance of plant cell walls to enzymatic conversion, primarily owing to lignin. This study investigated whether DypB, the lignin-degrading peroxidase from Rodococcus jostii, depolymerizes lignin and reduces recalcitrance in transgenic tobacco (Nicotiana benthamiana). The protein was targeted to the cytosol or the ER using ER-targeting and retention signal peptides. For each construct, five independent transgenic lines were characterized phenotypically and genotypically. Our findings reveal that expression of DypB in the cytosol and ER does not affect plant development. ER-targeting increased protein accumulation, and …

Nanoparticle-Based Plasmonic Transduction For Modulation Of Electrically Excitable Cells, Parveen Bazard, Robert D. Frisina, Joseph P. Walton, Venkat R. Bhethanabotla

Chemical and Biochemical Engineering Faculty Research & Creative Works

There is a compelling need for the development of new sensory and neural prosthetic devices which are capable of more precise point stimulation. Current prosthetic devices suffer from the limitation of low spatial resolution due to the non-specific stimulation characteristics of electrical stimulation, i.e., the spread of electric fields generated. We present a visible light stimulation method for modulating the firing patterns of electrically excitable cells using surface plasmon resonance phenomena. In in-vitro studies using gold (Au) nanoparticle-coated nanoelectrodes, we show that this method (substrate coated with nanoparticles) has the potential for incorporating this new technology into neural stimulation prosthetics, …

Peptoid-Modified Bicelles As Surrogate Cell Membranes For Membrane Protein Sensors And Analytics, Helya Najafi

Graduate Theses and Dissertations

Membrane-affiliated interactions are significant in understanding cell function, detecting biomarkers to diagnose disease, and in testing the efficiency of new therapeutic targets. Model membrane systems have been developed to study membrane proteins, allowing for stable protein structure and maintaining native activity. Bicelles, disc-shaped lipid bilayers created by combining long- and short-chain phospholipids, are the model membrane system of focus in this study. Bicelles are accessible from both sides and have a wide size range, which make them attractive for studying membrane proteins without affecting function. In this work, bicelles were functionalized with two peptoids to alter the edge and face …

High-Throughput Droplet Barcoding And Automated Image Analysis In Microfluidic Droplet Trapping Array, Manibarathi Vaithiyanathan

LSU Master's Theses

Molecularly-targeted therapeutics and personalized medicine have dramatically increased the median survival rate of patients suffering from cancer. However, cellular heterogeneity and the personalized nature of cancer have resulted in the limited success of single drug treatments which has led to the use of multiple therapeutic combinations. This has required the development of new analytical methods capable of multiplexed high-throughput screening (HTS) technologies necessary to identify is single or multi-agent therapies are effective in ex vivo samples like liquid biopsies. Droplet microfluidic devices have garnered significant interest to facilitate high-throughput, single cell analysis of heterogeneous populations. However, these devices are still …

Titanium Addition Influences Antibacterial Activity Of Bioactive Glass Coatings On Metallic Implants, Omar Rodriguez, Wendy Stone, Emil H. Schemitsch, Paul Zalzal, Stephen Waldman, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

In an attempt to combat the possibility of bacterial infection and insufficient bone growth around metallic, surgical implants, bioactive glasses may be employed as coatings. In this work, silica-based and borate-based glass series were synthesized for this purpose and subsequently characterized in terms of antibacterial behavior, solubility and cytotoxicity. Borate-based glasses were found to exhibit significantly superior antibacterial properties and increased solubility compared to their silica-based counterparts, with BRT0 and BRT3 (borate-based glasses with 0 and 15 mol% of titanium dioxide incorporated, respectively) outperforming the remainder of the glasses, both borate and silicate based, in these respects. Atomic Absorption Spectroscopy …

Potency And Cytotoxicity Of A Novel Gallium-Containing Mesoporous Bioactive Glass/Chitosan Composite Scaffold As Hemostatic Agents, Sara Pourshahrestani, Ehsan Zeimaran, Nahrizul Adib Kadri, Nicola Gargiulo, Hassan Mahmood Jindal, Sangeetha Vasudevaraj Naveen, Shamala Devi Sekaran, Tunku Kamarul, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Chitosan-based hemostats are promising candidates for immediate hemorrhage control. However, they have some disadvantages and require further improvement to achieve the desired hemostatic efficiency. Here, a series of 1% Ga2O3-containing mesoporous bioactive glass-chitosan composite scaffolds (Ga-MBG/CHT) were constructed by the lyophilization process and the effect of various concentrations of Ga-MBG (10, 30, and 50 wt %) on the hemostatic function of the CHT scaffold was assessed as compared to that of Celox Rapid gauze (CXR), a current commercially available chitosan-coated hemostatic gauze. The prepared scaffolds exhibited >79% porosity and showed increased water uptake compared to that in CXR. The results …

Advancement Of Oxygen Biosensor In Escherichia Coli, Caitlyn Meiser

Rose-Hulman Undergraduate Research Publications

Microbial biosensors can be used to provide information about the cells’ environment in large-scale fermentations. In this project an oxygen sensitive biosensor is being developed in Escherichia coli to determine what kind of conditions cells are growing in: aerobic or anaerobic. This project specifically studies expression from the fumarate and nitrate reductase (FNR) promoter (P_FNR) under aerobic and anaerobic conditions. In fluorescence experiments, the expression levels of green fluorescent protein (GFP) were used to quantify the effectiveness of the P_FNR in the DH5α, MG1655 and BL21 strains of E. coli. The negative control of the experiments, …

Bacterial Cellulose Nanocrystals: Production And Application, Isabela Reiniati

Electronic Thesis and Dissertation Repository

The aims of this study were to investigate the effect of culture conditions on the production of bacterial cellulose (BC) by Komagataeibacter xylinus (K. xylinus), to assess the feasibility of tailoring the surface properties of bacterial cellulose nanocrystals (BCNs) through the culture conditions, and to use the BCNs in an aqueous system for drug adsorption application. BC fibers production improved with increased agitation rates in a stirred tank bioreactor resulting in yields of 0.54 and 1.13 g of BC per litre at agitation rates of 500 rpm and 700 rpm, respectively. Separation and purification of bacterial cellulose were achieved …

Identification Of Developmental Stage And Anatomical Fraction Contributions To Cell Wall Recalcitrance In Switchgrass, Jacob D. Crowe, Nicholas Feringa, Sivakumar Pattathil, Brian Merritt, Cliff Foster, Dayna Dines, Rebecca G. Ong, David B. Hodge

Rebecca Ong

Background Heterogeneity within herbaceous biomass can present important challenges for processing feedstocks to cellulosic biofuels. Alterations to cell wall composition and organization during plant growth represent major contributions to heterogeneity within a single species or cultivar. To address this challenge, the focus of this study was to characterize the relationship between composition and properties of the plant cell wall and cell wall response to deconstruction by NaOH pretreatment and enzymatic hydrolysis for anatomical fractions (stem internodes, leaf sheaths, and leaf blades) within switchgrass at various tissue maturities as assessed by differing internode. Results Substantial differences in both cell wall composition …

Bubble-Induced Inverse Gas-Liquid-Solid Fluidized Bed, Xiliang Sun

Electronic Thesis and Dissertation Repository

Gas-liquid-solid fluidized beds have been widely applied in wastewater treatment, however, the current method of wastewater process has several limitations. Hence, an improved method is in demand. A 3.5 height and 0.1534m inner diameter column was used to study the hydrodynamic characteristics of a bubble-induced three-phase inverse fluidized bed. Air, water and three types of low-density particles were employed as gas, liquid and solid phases.

The hydrodynamic properties in the bubble-induced three-phase fluidized bed were investigated to provide the basic information for the industrial process, such as flow regime, bed expansion ratio and phase holdups. A flow regime map containing …

Fabrication And Characterization Of Hybrid Nanocomposites By Matrix Assisted Pulsed Laser Evaporation, Songlin Yang

Electronic Thesis and Dissertation Repository

Different methods have been applied to deposit hybrid nanocomposites which can be applied in various fields due to their light weight and multifunctional properties. Here, matrix assisted pulsed laser evaporation (MAPLE) equipment with 532 nm Nd:YAG laser is applied to fabricate three types of hybrid nanocomposites on different substrates.

Chemical synthesized FeCo nanoparticles were deposited on graphene sheets by MAPLE technique (laser fluence: 300 mJ/cm²). The effects of deposition time (t) on particle amount, shape and size have been investigated. Yttrium barium copper oxide (YBCO) materials are one type of high-temperature superconductive materials and …

Nanostructured Biosensor For Tear Glucose Detection Based On Bioluminescence Resonance Energy Transfer (Bret) Mechanism., Denghuang Zhan

Electronic Thesis and Dissertation Repository

Bioluminescence Resonance Energy Transfer (BRET), a sensitive, non-destructive and self-illuminated method, has been now commonly used to test protein interactions. Here, we describe a BRET sensor for non-invasively detecting glucose molecules. The sensor is made by the bioconjugation of quantum dots and recombinant protein. The recombinant protein contains the bacterial glucose binding protein (GBP) and a bioluminescent protein, Renilla luciferase (Rluc), used as the donor with the emission peak at 470 nm, which is able to excite the acceptor of BRET sensor made of cadmium tellurium quantum dots ( CdTe QDs) with the emission peak at 570 nm. The distance …

Simulating Microbial Electrolysis For Renewable Hydrogen Production Integrated With Separation In Biorefinery, Christian James Wilson

Masters Theses

Biomass conversion to hydrocarbon fuels requires significant amounts of hydrogen. Fossil resources typically supply hydrogen via steam reforming. A new technology called microbial electrolysis cells (MECs) has emerged which can generate hydrogen from organic sources and biomass. The thermochemical route to fuels via pyrolysis generates bio-oil aqueous phase (BOAP) which can be used to make hydrogen. A process engineering and economic analysis of this technology was conducted for application in biorefineries of the future. Steam methane reforming, bio-oil separation and microbial electrolysis unit operations were simulated in Aspen Plus to derive the mass and energy balance for conversion of biomass. …

Peptoid-Based Microsphere Coatings For Use As Tunable Biocompatible Interfaces, German Raul Perez Bakovic

Graduate Theses and Dissertations

The pursuit of sensitive, non-invasive, and cost efficient diagnostic tools for early stage disease detection have led to the development of sophisticated biosensor technologies for proteomic studies. As these markers increase in complexity, the role of support substrates grows increasingly important. Limitations in existing support substrates include the potential for increased sensitivity, binding specificity, and bio-stability. Ideal support substrates need to provide biocompatible and bioresistant surfaces, that offer high surface areas for binding, and enables the incorporation of diverse chemistries. The use of peptoids as the basis for the deposition of uniform microsphere coatings offers a mean to the attainment …

Effects Of Filtration Conditions On Clearance Of Bacteriophage, Rigen Te

Graduate Theses and Dissertations

Virus Clearance is one of the major challenges in biopharmaceutical industry, especially in the manufacturing of drugs. U.S. Food and Drug Administration (FDA) recommends using several model bacteriophages as surrogates of pathogenic mammalian virus for process validation. In this work, two bacteriophages were tested against 30 kDa, 100 kDa, 300 kDa polyethersulfone (PES) membranes to investigate the effects of pore size on virus clearance. Virus particles were spiked into the protein feed solutions containing bovine serum albumin (BSA) or lysozyme at different concentrations. Besides protein concentration, the effects of feed pH on the filtration performance and virus rejection were also …

Genetic Engineering Studies Of Escherichia Coli And Microalgae For Expression Of Hydrolytic Enzymes And Development Of High Throughput Screening Technique, Shreyas S. Yedahalli

Electronic Thesis and Dissertation Repository

The field of biochemical engineering has made substantial progress through major advances in genetic and metabolic engineering with applications in various sectors such as energy, food science, pharmaceuticals, etc. The hosts used for this work are constantly broadening. A host particularly important for energy applications are microalgae. The potential to enhance microalgae genetically for energy applications is not well explored and was therefore investigated in this thesis. Non-photosynthetic micro-organisms and photosynthetic microalgae offer a potential approach to enhance sustainable biochemical production. In this study expression vectors for Escherichia coli (E. coli) and Chlorella vulgaris (C. vulgaris) …

Identification Of Developmental Stage And Anatomical Fraction Contributions To Cell Wall Recalcitrance In Switchgrass, Jacob D. Crowe, Nicholas Feringa, Sivakumar Pattathil, Brian Merritt, Cliff Foster, Dayna Dines, Rebecca Ong, David B. Hodge

Department of Chemical Engineering Publications

Background

Heterogeneity within herbaceous biomass can present important challenges for processing feedstocks to cellulosic biofuels. Alterations to cell wall composition and organization during plant growth represent major contributions to heterogeneity within a single species or cultivar. To address this challenge, the focus of this study was to characterize the relationship between composition and properties of the plant cell wall and cell wall response to deconstruction by NaOH pretreatment and enzymatic hydrolysis for anatomical fractions (stem internodes, leaf sheaths, and leaf blades) within switchgrass at various tissue maturities as assessed by differing internode.

Results

Substantial differences in both cell wall composition …

Investigation Of Lutein Production And Recovery From Chlorella Vulgaris Using Phototrophic Cultivation, Mengyue Gong

Electronic Thesis and Dissertation Repository

Microalgae have been recognized as a natural reservoir of the valuable commercial carotenoid lutein due to its high lutein content and fast growth cycle. However, the production of lutein from microalgal sources is not yet sufficiently cost-effective to compete with traditional marigold flower-based processing (Park et al., 2015). This thesis aims to investigate the factors affecting lutein production and recovery from microalgae using a phototrophic cultivation mode.

The closed photobioreactors can offer controlled conditions for faster microalgae growth. A coiled tubular tree photobioreactor (CTPBR) design was first investigated for cultivating the cold tolerant microalgae, Chlorella vulgaris UTEX 265, under various …

Bioethanol Production Using Saccharomyces Cerevisae Cultivated In Sugarcorn Juice, Thirumalai Nambi Thiruvengadathan

Electronic Thesis and Dissertation Repository

For the first time, juice extracted from sugarcorn, a new Canadian energy crop, was used for bioethanol production. Physical and chemical characteristics of sugarcorn juice (SCJ) were determined. SCJ contained a maximum of 145 g/L of carbohydrates, with sucrose, glucose and fructose together contributing 80%. Effect of autoclaving and carbon filtration on juice sugars were investigated.

Shake flask fermentations using Saccharomyces cerevisiae grown in yeast extract supplemented SCJ produced a maximum of 45.6 g/L ethanol in 72 h. Bioreactor studies using un-supplemented SCJ achieved 40 g/L ethanol in 26 h, yielding a maximum of 0.46 g ethanol/g fermentable sugars, representing …

Magnetic Stimulation On The Growth Of The Microalga Nannochloropsis Oculata, Manuella Oliveira

Electronic Thesis and Dissertation Repository

Fossil fuels, our principal sources of energy supply, are non-renewable and research is needed on alternatives that are renewable and potentially more environmentally friendly. Microalgae have been investigated as a future feedstock alternative to petroleum but the technology is still expensive and improvements are needed. Reduction in costs might be achieved by increasing algal biomass and lipid productivity. The lipids can be used to produce biofuels such as biodiesel and biojet fuel. The marine microalga Nannochloropsis oculata grows well and can accumulate high lipid content. In this study, the effects of static magnetic field stimulation (SMF) of 0 (control), 5, …

Raman Spectral Variation For Human Fingernails Of Postmenopausal Women Is Dependent On Fracture Risk And Osteoporosis Status, J. R. Beattie, M. C. Caraher, N. M. Cummins, O. M. O'Driscoll, R. Eastell, S. H. Ralston, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Patients diagnosed with osteoporosis have reported loss of fingernail resilience as the disease progresses. Keratin is the predominant protein in human nail tissue, and its structure has been postulated to be different in fingernails clipped from subjects who have sustained fragility fractures and those who have not, which may offer a window into the donor's bone health. This study was designed to qualify these differences, which may lead to the development of a novel screening tool for fracture risk. Raman spectroscopy was used to measure the fingernails of 633 postmenopausal women who presented at six fracture clinics located across the …

Morphological And Photoelectrochemical Characterization Of Membrane Reconstituted Photosystem I (Psi), Seyedeh Hanieh Niroomand

Doctoral Dissertations

The robust structural and photoactive electrochemical properties of Photosystem I (PSI), a transmembrane photosynthetic protein complex, make it an ideal candidate for incorporation into solid state bioelectronic or hybrid photovoltaic devices. However, the first step towards the successful fabrication of such devices requires systematic assembly of oriented and functional PSI onto desired bio-abio interfaces via suitable protein scaffoldings. Hence, this dissertation focuses on utilizing the cyanobacterial PSI for integration into organic/inorganic interfaces that mediate photo-electrochemical energy conversions for electricity and/or solar fuel production. To this end, in this study the effect of systematic incorporation of PSI complexes into synthetic membrane-bound …

Common Treatments And Procedures Used For Fractures Of The Distal Radius And Scaphoid: A Review, Basel A. Khader, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The distal radius and the scaphoid are the most commonly injured carpal bones among both active adults and the osteoporotic elderly. The purpose of surgical treatment is to restore form and function to the wrist. Depending on the nature of the fracture, either topical procedures or invasive surgery can be applied. This article critiques the treatments currently used for fixation of wrist fractures in order to drive the development of new materials to improve patient outcomes.

A Bug’S Life: Integration Of Anaerobic Digestion And Bioelectrochemical Systems For Enhanced Energy Recovery From Wastewater Solids And Other Waste Substrates, Jeff Ryan Beegle

Masters Theses

Organic waste streams, like domestic wastewater and municipal solid waste, have the potential to be used as feedstocks for biotechnology processes to produce high value products and energy. This thesis investigated the technological, economical, and environmental potential for integrated anaerobic digestion (AD) and bioelectrochemical system (BES) platforms as they were theoretically and physically evaluated for energy recovery from domestic wastewater. The first chapter of this thesis compared the theoretical energy efficiencies of converting waste directly into electricity, using AD and BES alone and in various combinations. This chapter reviewed the experimentally demonstrated energy efficiencies reported in the literature with comparisons …

The Effects Of Adaptogens On The Physical And Psychological Symptoms Of Chronic Stress, Tosin Ajala

Georgia State Undergraduate Research Conference

No abstract provided.

Genetic Code Expansion In Biochemical Investigations And Biomedical Applications, Nanxi Wang

Department of Chemistry: Dissertations, Theses, and Student Research

Genetic code expansion provides a powerful tool for site-specific incorporation of unnatural amino acids (unAAs) with novel biochemical and physiological properties into proteins in live cells and organisms. To achieve this, a nonsense codon suppression system, which consists of an orthogonal aminoacyl-tRNA synthetase (aaRS) and tRNA pair that specifically decodes a nonsense codon (e.g., amber codon and quadruplet codon) with an unAA but do not “cross talk” with their endogenous counterparts, was established. This Ph.D. thesis presents our efforts on evolution and application of nonsense codon suppression systems for biochemical and biomedical investigations.

In Chapter 1, a brief overview of …

An Expedited, Regiospecific Para-Bromination Of Activated Aryls, Kathryn E. Dudley

Masters Theses & Specialist Projects

Electrophilic Aromatic Substitution (EAS) is one of the most frequently used aryl substitution methods. Aside from the fact that most EAS reactions require an acid and an oxidizer to proceed, the reactions involving activated aryls typically produce a mixture of ortho- and para- products as well as an ortho-/para- disubstituted product. Regiospecificity in aromatic substitution is key in the production of many compounds in a variety of disciplines. Since EAS is one of the most often used substitution methods, it is extremely important to develop an efficient method for regiospecific substitutions. Previous research developed a method of ortho-substitution by using …