Digital Commons Network^™

Atom Trapping And Its Role On The Nucleation & Growth Of Platinum Nanoparticles, Deepak Kunwar

Chemistry and Chemical Biology ETDs

Diesel oxidation catalysts deactivate due to Pt sintering, a major problem in automotive industries. To make sure they operate effectively throughout the lifetime of the vehicle, automotive industries are putting an excessive amount of Pt. There is a need to develop a catalyst that serves long term performance with minimal use of Pt. Jones et al^.1 demonstrated that ceria traps Pt atoms. His work generated some logical and valid questions such as what is the mechanism for the formation of anomalously large Pt particles? What is the upper limit of Pt metal loading in the form of single atoms …

Deep-Ultraviolet Laser Ablation For Biomolecular Analysis, Oluwaremilekun Omowunmi Lawal

LSU Doctoral Dissertations

New sampling and ionization techniques were developed using a deep-ultraviolet (DUV) laser at 193 nm wavelength for analysis of large biomolecules. A micrometer spatial resolution DUV laser ablation and capture system was constructed to sample tissue biomolecules. The spot size measurements of the focused beam showed that subcellular spots with ca. 2 μm diameter can be readily achieved with this wavelength. To demonstrate the extraction of tissue biomolecules with the DUV laser, regions of tissue sections were ablated and captured for offline proteomic and genomic analysis. The proteomic studies revealed that the tissue proteins were ejected without fragmentation and that …

Structure And Dynamics Of Phospholipid Vesicles And The Dependence On Nanoscale Interactions With Molecules Of Varying Complexity, Lakshapathy Widanelage Judith Upeka De Mel

LSU Doctoral Dissertations

In this dissertation, molecular interactions and changes imposed by nano-scale structures on phospholipid vesicles were investigated. 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) large unilamellar vesicles (LUVs) were used as the model system. Understanding changes of the bilayer structure, interfacial properties, lipid dynamics, and self-assembly, allows bridging relationships between biological cell membrane structure and dynamics to cellular functionalities. For example, membrane curvature changes are linked to membrane protein functions, although the exact mechanisms of control are not yet understood. Moreover, the knowledge gained from vesicle models allows exploring novel strategies for drug delivery applications. To achieve this, DOPC LUVs were synthesized and characterized by a …

Natalia Shustova Answers Questions About 15 Years Of Research On Covalent Organic Frameworks, Natalia B. Shustova Prof. Dr.

Faculty Publications

No abstract provided.

Probing The Magnetic Anisotropy Of Co(Ii) Complexes Featuring Redox-Active Ligands, Praveen Kumar, Daniel J. Santa Lucia, Kinga Kaniewska-Laskowska, Sergey V. Lindeman, Andrew Ozarowski, J. Krzystek, Mykhaylo Ozerov, Joshua Telser, John F. Berry, Adam T. Fiedler

Chemistry Faculty Research and Publications

Coordination complexes that possess large magnetic anisotropy (otherwise known as zero-field splitting, ZFS) have possible applications in the field of magnetic materials, including single molecule magnets (SMMs). Previous studies have explored the role of coordination number and geometry in controlling the magnetic anisotropy and SMM behavior of high-spin (S = 3/2) Co(II) complexes. Building upon these efforts, the present work examines the impact of ligand oxidation state and structural distortions on the spin states and ZFS parameters of pentacoordinate Co(II) complexes. The five complexes included in this study (1–5) have the general formula, [Co(Tp^{Ph2 …}

Radial Basis Densities And The Density Functional-Based Atom-In-Molecule: Designing Charge-Transfer Potentials, Godwin Amo-Kwao

Nanoscience and Microsystems ETDs

Classical potentials that are capable of describing charge transfer and charge polarization in complex systems are of central importance for classical atomistic simulation of biomolecules and materials. Current potentials—regardless of the system—do not generalize well, and, with the exception of highly-specialized empirical potentials tuned for specific systems, cannot describe chemical bond formation and breaking. The charge-transfer embedded atom method (CT-EAM), a formal, DFT-based extension to the original EAM for metals, has been developed to address these issues by modeling charge distortion and charge transfer in interacting systems using pseudoatom building blocks instead of the electron densities of isolated atoms. CT-EAM …

Development Of Next-Generation, Fast, Accurate, Transferable, And Polarizable Force-Fields For Heterogenous Material Simulations, Adam E. Hogan

USF Tampa Graduate Theses and Dissertations

Theoretical modeling is extremely useful in guiding to experiment; however quantitatively accurate modeling of energy-relevant small molecule sorption at the heterogeneous interfaces present in metal-organic materials (MOMs) is currently challenging. MOMs are an emerging class of materials consisting of inorganic clusters and organic linkers that offer great potential in the areas of gas storage, gas separation, and catalysis due to the possibility of large surface areas, complex heterogeneous surfaces, and rational designability. Efficient chemical separations involving these materials could reduce the US’s total energy consumption by approximately 10 to 15%. In this dissertation, the parameterization of small molecules and metal …

Conversion From Metal Oxide To Mof Thin Films As A Platform Of Chemical Sensing, Meng Chen

USF Tampa Graduate Theses and Dissertations

Chemical sensor is working as a widely used device which can be applied to the detection of specific chemicals that are existing in the environment especially in gas phase. The detection of combustible and toxic chemicals can be extremely important in the field of both industrial and civil activities. The chemical sensor is commonly operating by utilizing a chemical or physical interaction between the specific chemical compound and the sensing functional unit, to obtain an electronic signal caused by the property change and realize the chemical detection. Traditional chemical gas sensors such as catalytic gas sensor, thermal conductivity gas sensor, …

Rapid Evolution Of Aerosol Particles And Their Optical Properties Downwind Of Wildfires In The Western Us, Lawrence I. Kleinman, Arthur J. Sedlacek, Kouji Adachi, Peter R. Buseck, Sonya Collier, Manvendra K. Dubey, Anna L. Hodshire, Ernie Lewis, Timothy B. Onasch, Jeffery R. Pierce, John Shilling, Stephen R. Springston, Jian Wang, Qi Zhang, Shan Zhou, Robert J. Yokelson

Chemistry and Biochemistry Faculty Publications

During the first phase of the Biomass Burn Operational Project (BBOP) field campaign, conducted in the Pacific Northwest, the DOE G-1 aircraft was used to follow the time evolution of wildfire smoke from near the point of emission to locations 2-3.5 h downwind. In nine flights we made repeated transects of wildfire plumes at varying downwind distances and could thereby follow the plume's time evolution. On average there was little change in dilution-normalized aerosol mass concentration as a function of downwind distance. This consistency hides a dynamic system in which primary aerosol particles are evaporating and secondary ones condensing. Organic …

Methods For 1,2-Cis-Selective O-Glycosylation And Synthesis Of An A. Baumannii Lipooligosaccharide Core Disaccharide, Ashley Fulton

LSU Doctoral Dissertations

This dissertation focuses on the formation of organic thin films on gold surfaces and synthesis of oligosaccharides. Chapter one, is a brief introduction on the utility of thin films, as well as ways to characterize thin films, as well as, a report on the attempt to form organic thin films on Au(111) surfaces using photoredox catalysis.

Glycoconjugates on cell surfaces serve as important mediators of intercellular recognition, adhesion, and viral infection. Due to the significant role that glycoconjugates play on the surface of cells, oligosaccharide synthesis is of great interest. Chapter two, is an extensive review of oligosaccharide synthesis, its …

Synthesis And Investigation Of Amphiphilic Polypeptoids For Environmental And Biological Applications, Tianyi Yu

LSU Doctoral Dissertations

Polypeptoids are an emerging class of peptidomimetic polymers featuring N-substituted polyglycine backbones. Polypeptoids are cyto-compatible and backbone degradable, making them appealing to many biological applications. When the highly polar polyamide backbone is coupled with non-polar aliphatic side chains, polypeptoids can be considered as facial amphiphiles. Without extensive hydrogen bonding along the backbone, the conformation of polypeptoid is largely controlled by the N-substituent structures. The hydrophobicity-lipophilicity balance of polypeptoids can be readily tuned with the N-substituent structures as well as the molar ratio between the hydrophilic and hydrophobic segments in their copolymers. In view of these combined attributes, …

The Development Of Aapeptides, Lulu Wei

USF Tampa Graduate Theses and Dissertations

Non-natural peptide mimics are referred to as peptidomimetics, which contains unnatural backbones that mimic the primary peptide structure. There are a large number of peptidomimetics that have been developed including α-peptides, β-peptides, peptoids, arylamide oligomers, cationic polymers, and other peptidomimetics in the last decades. Compared to conventional peptides, these peptidomimetics have many advantages such as resistance to proteolysis, improved bioavailability, and reduced immunogenicity. However, the development of peptidomimetics is still far below the expectation due to the limitation of the availability of backbones. It is an urgent need to generate a new diverse library for novel drug discovery, design antimicrobial …

Multifunctional Metal-Organic Frameworks (Mofs) For Applications In Sustainability, Gaurav Verma

USF Tampa Graduate Theses and Dissertations

Climate change, affordable and clean energy, and responsible consumption and production are some of the important goals to be achieved for sustainable development. The current technologies used to address these challenges are energy and resource intensive. Furthermore, there are various limitations related to cost, storage, scalability and safety.Adsorbent materials are seen as a promising alternative remediation system due to their low energy consumption and minimal chemical waste production. However, most of the traditional adsorbents, such as activated carbon and zeolites lack the structural tunability to have long-term effectiveness and their use is limited. As discussed in Chapter 1, metal organic-frameworks …

Voltammetric Ph Measurements In Unadulterated Foodstuffs, Urine, And Serum With 3d-Printed Graphene/Poly(Lactic Acid) Electrodes, Fakher M. Rabboh, Glen D. O'Neil

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

The pH of a system is a critical descriptor of its chemistry—impacting reaction rates, solubility, chemical speciation, and homeostasis. As a result, pH is one of the most commonly measured parameters in food safety, clinical, and environmental laboratories. Glass pH probes are the gold standard for pH measurements but suffer drawbacks including frequent recalibration, wet storage of the glass membrane, difficulty in miniaturization, and interferences from alkali metals. In this work, we describe a voltammetric pH sensor that uses a three-dimensional (3D)-printed graphene/poly(lactic acid) filament electrode that is pretreated to introduce quinone functional groups to the graphene surface. After thoroughly …

High Level Ab Initio Study Of The Energetic And Spectroscopic Properties Of [Al,S,O]X (X=0,+1) And Its Potential For Detection In Space, Vincent J. Esposito, Tarek Trabelsi, Joseph S. Francisco

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Highly reliable molecular properties have been computed for the [Al, S, O]^x (x = 0, +1) molecular system. Spectroscopic parameters are predicted from analysis of each isomer’s 3D potential energy surface calculated using the explicitly correlated multireference configuration interaction method, including the Davidson correction (MRCI-F12+Q). These parameters provide an accurate prediction of spectroscopic data that can be used in laboratory and observational studies of these molecules. Linear-SAlO is expected to have a large permanent dipole moment suitable for detection in the circumstellar envelopes of large, evolved, oxygen-rich stars such as VY Canis Majoris, IK Tauri, and R Doradus. …

Microbiological, Physicochemical, And Immunological Analysis Of A Commercial Cashew Nut-Based Yogurt, Christopher P. Mattison, Kayanush Aryana, Kristen Clermont, Eric Prestenburg, Steven W. Lloyd, Casey .. Grimm, Richard L. Wasserman

Faculty Publications

Nut-based milks and yogurts are gaining popularity, but may not offer the same benefits as dairy yogurts to consumers. Cashew nuts often cause severe allergic reactions, and cashew nut allergens are stable to several types of processing. To compare its characteristics to dairy yogurt and characterize the effects of fermentation on the Ana o 1-3 cashew nut allergens, a commercial yogurt made from cashew nuts (Cashewgurt) was evaluated for microbiological, physiochemical, and immunological properties. Average counts for lactobacilli and Streptococcus thermophilus were greater than 10 million colony forming units per milliliter, indicating the capacity to provide a health benefit. Cashewgurt …

A Novel Mutation Of The Narrow Leaf 1 Gene Adversely Affects Plant Architecture In Rice (Oryza Sativa L.), Prasanta K. Subudhi, Richard S. Garcia, Sapphire Coronejo, Teresa B. De Leon

Faculty Publications

Plant architecture is critical for enhancing the adaptability and productivity of crop plants. Mutants with an altered plant architecture allow researchers to elucidate the genetic network and the underlying mechanisms. In this study, we characterized a novel nal1 rice mutant with short height, small panicle, and narrow and thick deep green leaves that was identified from a cross between a rice cultivar and a weedy rice accession. Bulked segregant analysis coupled with genome re-sequencing and cosegregation analysis revealed that the overall mutant phenotype was caused by a 1395-bp deletion spanning over the last two exons including the transcriptional end site …

Ion-Molecule Interactions Enable Unexpected Phase Transitions In Organic-Inorganic Aerosol, David S. Richards, Kristin L. Trobaugh, Josefina Hajek-Herrera, C. L. Price, C. S. Sheldon, J. F. Davies, Ryan D. Davis

Chemistry Faculty Research

Atmospheric aerosol particles are commonly complex, aqueous organic-inorganic mixtures, and accurately predicting the properties of these particles is essential for air quality and climate projections. The prevailing assumption is that aqueous organic-inorganic aerosols exist predominately with liquid properties and that the hygroscopic inorganic fraction lowers aerosol viscosity relative to the organic fraction alone. Here, in contrast to those assumptions, we demonstrate that increasing inorganic fraction can increase aerosol viscosity (relative to predictions) and enable a humidity-dependent gel phase transition through cooperative ion-molecule interactions that give rise to long-range networks of atmospherically relevant low-mass oxygenated organic molecules (180 to 310 Da) …

One-Pot O-Alkylation And C-C Cross-Coupling Reactions Involving Stabilized Phosphoranes, Areej Hashim Mohamed

Theses

This thesis is concerned with the one-pot reactions that are considered to be beneficial to preserve resources, save time, and are deemed a green chemistry strategy. To plan such one-pot reactions, it is important to combine two or more reactions that are compatible with each other and can be run under the same reaction conditions. In this work, possibilities of a combination of Wittig-olefination and Suzuki C-C-cross coupling reactions are explored further. Reaction sequences involve the combination of a Suzuki-reaction / Wittig olefination, a Suzuki reaction / Wittig olefination/hydrolysis, and a Suzuki-reaction / double Wittig olefination. In all cases, stabilized …

Estimation Of The Removal Of Chiral Pharmaceutical Drugs From Domestic Wastewater Using Uplc-Ms/Ms, Mohammed Khaled Al Tabaji

Theses

This thesis is concerned with the estimation of the removal of chiral pharmaceutical compounds (PCs) from domestic wastewater in Al Ain using UPLC-MS/MS. PCs are classified into many classes such as hormones, antibiotics, analgesics, cosmetic products, ꞵ blockers, and anti-inflammatory drugs. PCs do not have a guideline to describe their concentrations in treated domestic wastewater. Additionally, there is a very high demand for using PCs around the world, which results in their discharge to wastewater at relatively high masses, which could be harmful to the environment. Furthermore, very limited work has been done to estimate the removal of chiral PCs. …

Determination Of Vitamin D Metabolites And Their Epimers In Obese Emirati Population, Bashar Hiatham Alzohily

Theses

Vitamin D deficiency is a global issue, and despite all-year-round sunshine, it is a big problem in the UAE. Obesity or overweight refers to an accumulation of excessive fat that may harm health so, it is considered a worldwide health concern. The accurate measurement of vitamin D active forms is a problematic issue. This study aimed to develop and validate a UHPLC-MS/MS method for the new method for determining vitamin D levels in the obese Emirati population. The vitamin D epimers and other metabolites were determined by UHPLC-MS/MS system, model 8060. The methods include the collection of blood samples from …

Development Of Supramolecular Multicomponent Chromophores Towards Photoluminescence Switches, Rukayat Shola Bojesomo

Theses

A new fluorescent dye (4PBZC) comprises of coumarin (C), piperazine (P), and benzimidazole (BZ) was designed, prepared, and complexed to cucurbit[7]uril (CB7) to detect carnosol (CAR), an anti-breast cancer drug, in sub-nanomolar concentrations utilizing the supramolecular indicator displacement assay (IDA) strategy, the CB7-assisted pK_a shift and the CB7-retarded photoinduced electron transfer (PET) process. The host−guest complexation was confirmed by UV−visible absorption, fluorescence, and proton NMR spectroscopy, which confirm binding to 4PBZC via the BZ moiety. Also, CB7 preferentially binds the indicator dye via the protonated BZ residue compared to the neutral BZ one, demonstrated by a higher binding …

Mass Spectrometric Determination Of Retinol In Emirati Population, Israa Samir Mohamed Shawky El-Konaissi

Theses

This thesis is concerned with analyzing vitamin A deficiency. Vitamin A is crucial for several functions, including vision, growth, and cell differentiation. the main aim is to develop and validate an LC-MS/MS method for the determination of vitamin A in plasma matrix and use the new method for the determination of vitamin A levels in the obese Emirati population. Methods: A positive ion electrospray ionisation (ESI) LC-MS/MS method was used in the Multiple Reaction Monitoring (MRM) mode for quantification. It involved i) LC-MS/MS, ii) a guard column together with C18 Ascentis Express F5 column iii) Internal standard, 25-Hydroxyvitamin D3 (6, …

Increasing The Bioavailability Of Poorly Soluble Anti-Cancer Prodrugs Through Encapsulation In Platinum Based Nanocages, Salim Cesar Lutfallah

Honors Capstones

No abstract provided.

Synthesis And Ftir Characterization Of Mg-Hydroxylapatite Derived From Dolostone With High Dolomite Mineral Content, Wilson L. Mahene, Charles Gervas, Askwar H. Hilonga, Revocatus L. Machunda

Tanzania Journal of Science

We present the synthesis of magnesium-substituted hydroxylapatite starting from locally available dolostone. The apatite was prepared by a reaction between heat pre-treated dolostone powder with phosphoric acid, maintained at the pH of 12.5 using sodium hydroxide. The resultant material was then calcined at 500 °C, 600 °C, 700 °C, 800 °C and 900 °C. The precursor dolostone was characterized by organic elemental analyser (CHNS-O analyser), X-ray fluorescence (XRF) and Fourier transform infrared spectroscopy (FTIR), while the synthesized material was characterized by using FTIR. Results indicated that the dominant mineral in the carbonate rock materials was near-stoichiometric dolomite, while the synthesized …

Comparison Of Centrifugation And Solid Phase Extraction (Spe) Methods Of Sample Preparations In Determination Of Residues Of Drugs Of Abuse In Urine, John Mahugija, Anastazia Wandwi, Kessy Kilulya

Tanzania Journal of Science

Detection of drugs of abuse in urine samples depends on their composition, absorption, distribution, physical and chemical properties, concentrations, elimination properties, and the techniques employed. This study compared the performance of centrifugation and solid phase extraction (SPE) methods in the determination of levels of drugs of abuse and their metabolites in urine samples collected from drug abusers. Analysis was performed using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Calibration was done using both internal and external standards. The recovery values were generally greater in centrifugation method than in SPE method, but the recoveries in both methods were within an acceptable range. Linearity …

Development And Characterization Of Robust Methods For Field Investigations With Portable Mass Spectrometry, Ashley Rose Stelmack

Theses and Dissertations

Portable mass spectrometry (MS) has become an area of interest due to the ability to conduct chemical analyses in native environments. These instruments have the potential to increase efficiency and analytical throughput via real-time experimentation, minimizing the need for sample transportation. One drive towards the development of fieldable mass spectrometers is the potential for coupling to novel ambient ionization methods (or “ambient MS”), which can generate spectral data at ambient conditions from unprepared or minimally prepared samples of interest. Since the first introduction of the desorption electrospray ionization (DESI) technique in 2004, a myriad of novel techniques have been reported …

Population Genetics Of Rhizophora Apiculata In Peninsular Malaysia Using Microsatellite Markers, Amelia Azman

Student Works (2020-2029)

Rampant illegal logging, overharvesting and deforestation coupled with climate change, pose significant threats to the natural stands of Rhizophora apiculata, or locally known as Bakau Minyak; one of the most economically and ecologically important species of mangroves in Peninsular Malaysia. Despite being a dominant mangrove species, the reduction in the number of R. apiculata in its habitat has resulted in concerns over the long-term survival potential of the species. In Malaysia, genetic information to develop effective guidelines for the conservation and management of mangrove species has been lacking, and hence, further research should be conducted to fill this gap. The …

Electrochemical Engineering Of Carbon Nanodots, Lei Bao, Dai-Wen Pang

Journal of Electrochemistry

Aqueous batteries have been considered to be a competitive candidate for large-scale energy storage. However, most of aqueous batteries adopt inorganic electrode materials with metallic elements, which are based on the reversible insertion of metal ions, making their application being highly hindered by limited cycle life, environmental issue, high cost and low reserves. On the other hand, organic electrode materials offer the advantages of abundant reserves, tunable structures, renewability and environmental benignity. Furthermore, the wide internal space enables these organics to flexibly store various charge carriers. Organics have been investigated as the alternative to inorganic electrode materials. Herein, we review …

Porous-Electrode Theory Of Lithium Ion Battery: Old Paradigm And New Challenge, Xiao-Xiao Wang, Zi-Rui Zhou, Qiang Shan, Zeng-Ming Zhang, Jun Huang, Yu-Wen Liu, Sheng-Li Chen

Journal of Electrochemistry

A critical review on the porous electrode theory developed by Newman and his colleagues is presented. We propose several ideas for further development of this theory by analyzing its limitations. The classical Newman theory does not consider ion steric effect in describing ion transport in electrolyte solutions, which can be amended by a newly developed ion-vacancy coupled charge transfer model for ion transport in concentrated solutions. Ion transport in solid particles of active materials is essentially an ion-electron coupled transport process, and its rationality is verified by comparing the calculated and experimental diffusion coefficients of Li ⁺ ion in intercalation …