Chemistry Commons^™

Bulk Modulus Of Poly(N-Isopropylacrylamide) Microgels Through The Swelling Transition, B. Sierra-Martin, Y. Laporte, A. B. South, L. Andrew Lyon, A. Fernandez-Nieves

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report measurements of the bulk modulus of individual poly(N-isopropylacrylamide) microgels along their swelling transition. The modulus is determined by measuring the volume deformation of the microgel as a function of osmotic pressure using dextran solutions. We find that the modulus softens through the transition, displaying a nonmonotonous behavior with temperature. This feature is correctly reproduced by the theory of Flory for polymer gels, once the concentration dependence of the solvency parameter is properly incorporated.

Enhancing The Learning Experience: Learning For The Unknown Future, Barry Ryan

Conference papers

In this presentation the effects of an altered teaching methodology, in which the "student as producer" approach was adopted, are outlined. Currently, many students exist as knowledge consumers; however, Neary and Winn (2009) have suggested the positive effect on students learning through the inclusion of research-like activities at the core of the undergraduate curriculum; the students act as "producers" of knowledge.

Integrating Formative Feedback Into Individual And Group Assessments In A First Year Organic Chemistry Module, Barry Ryan, Julie Dunne

Conference papers

It is common for science undergraduates, particularly first year students, to remark that they do not receive appropriate support in their transition from second level to third level education; particularly in effective scientific laboratory report writing, new subject area preparedness and technical ‘know-how’ [1]. This is compounded by the insufficient, or inappropriate, feedback offered to students in these problem areas. The pedagogical emphasis often focuses on quantity rather than quality; both in report writing and content delivered. This publication describes an assessment methodology redesign to, firstly, incorporate on-line formative feedback and; secondly, to introduce one-to-one and one-to-group lab report feedback …

Development, Validation And Application Of Uhplc-Ms/Ms Methods For The Detection Of Veterinary Drug Residues In Food Of Animal Origin, Michelle Whelan

Theses

Ultra high pressure liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-MS/MS) technology was utilized for the development of analytical methods for the detection of veterinary drug residues in foods of animal origin. Initial work focused on the development of the mass spectrometry (MS) method for the detection of the analytes of interest and subsequent chromatographic separation. The MS method was optimised to detect both positively and negatively ionised analytes from different classes in a single injection in a 13 minute run time at μg kg^-1levels.

Sample preparation procedures were modified to extract the residues from muscle and …

Investigations On Morphology, Spectroscopy And Near-Infrared Photoresponse Sensitization Of Conjugated Polymers In Organic Photovoltaics, Zhongjian Hu

Electronic Theses and Dissertations

Conjugated polymer architecture and morphology are two of the key factors that determine corresponding opto-electronic device performance. It is well-known that conjugated polymers display a variety of conformations and exhibit aggregation in their materials and even for individual polymer chains. The intrinsic structural heterogeneity of conjugated polymers strongly complicates the active layer morphology and phase separation, which are crucial for photoinduced charge generation and transport in polymer based bulk heterojunction-organic photovoltaics device (BHJ-OPVs). Aiming to probe the molecular level correlations between conjugated polymer architecture, morphology and optoelectronic properties, single molecule spectroscopy (SMS) and single particle spectroscopy (SPS) were employed. The …

Fossil And Contemporary Aerosol Particulate Organic Carbon In The Eastern United States: Implications For Deposition And Inputs To Watersheds, Andrew S. Wozniak, James E. Bauer, Rebecca M. Dickhut

Chemistry & Biochemistry Faculty Publications

Atmospheric particulate matter samples were collected from mid-Atlantic and northeastern U. S. (Virginia and New York, respectively) sites to assess the fossil versus contemporary sources contributing to aerosol organic carbon (OC) and the implications for its deposition to watersheds. Mean particulate matter total OC (TOC) deposition rates (wet + dry deposition) were calculated to be 1.6 and 2.4 mg C m^-2 d^-1 for the Virginia and New York sites, respectively. Wet deposition of particulate TOC was determined to be the dominant depositional mode, accounting for >65% (Virginia) and >80% (New York) of total aerosol TOC deposition. Isotopic mass …

A Mini-Electrodialysis System For Desalting Small Volume Saline Samples For Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Hongmei Chen, Aron Stubbins, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

An affordable, commercially available mini-electrodialysis (mini-ED) system has been evaluated for the efficient desalting of small volume samples of seawater before analysis by electrospray Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). Mini-ED FT-ICR mass spectra were compared with spectra for samples that were treated by C₁₈ solid phase extraction, a commonly used method for rapid sample preparation for this type of analysis. In this comparison, it is clear that mini-ED provides more representative molecular information, compared with C₁₈ isolation, and recovers the overwhelming majority of peaks from salt-free samples, indicating that it adequately represents the …

Fourier Transform Emission Spectroscopy Of Yh And Yd: Observation Of New A¹Δ And B¹Π Electronic States, R. S. Ram, G. Li, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

The emission spectra of YH and YD molecules have been investigated in the 3600–12 000 cm⁻¹ region using a Fourier transform spectrometer. Molecules were formed in an yttrium hollow cathode lamp operated with a continuous flow of a mixture of Ne and Ar gases, and YH and YD were observed together in the same spectra. A group of bands observed near 1 μm have been identified as 0-0 and 1-1 bands of the A¹Δ-X¹Σ⁺ and B¹Π-X¹Σ⁺ transitions of YH and the 0-0 bands of the same two transitions …

Ace-Fts Measurements Of Trace Species In The Characterization Of Biomass Burning Plumes, K. A. Tereszchuk, G. González Abad, C. Clerbaux, D. Hurtmans, P.-F. Coheur, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

To further our understanding of the effects of biomass burning emissions on atmospheric composition, we report measurements of trace species in biomass burning plumes made by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) instrument on the SCISAT-1 satellite. An extensive set of 15 molecules, C₂H₂, C₂H₆, CH₃OH, CH₄, CO, H₂CO, HCN, HCOOH, HNO₃, NO, NO₂, N₂O₅, O-3, OCS and SF₆ are used in our analysis. Even though most biomass burning smoke is typically confined to the …

Dynamic Measurements With Scanning Probe Microscopy: Surface Studies Using Nanostructured Test Platforms Of Metalloporphyrins, Nanoparticles And Amyloid Fibrils, Wilson K. Serem

LSU Doctoral Dissertations

A hybrid imaging mode for characterization of magnetic nanomaterials has been developed, using atomic force microscopy (AFM) combined with electromagnetic sample actuation. Instead of using a coated AFM probe as a magnetic sensor; our strategy is to use a nonmagnetic probe with contact mode AFM to characterize the vibration of magnetic and superparamagnetic nanomaterials responding to the flux of an AC electromagnetic field. We refer to the hybrid imaging mode as magnetic sample modulation (MSM-AFM). An oscillating magnetic field is produced by applying an AC current to a wire coil solenoid placed under the sample stage for tuning selected parameters …

Fabrication Of Organosilane Nanostructures As Selective Sites For Surface Chemical Reactions, Kathie Lee Lusker

LSU Doctoral Dissertations

Naturally self-assembled mesospheres provide a practical route for controlling the arrangement of materials on surfaces at the nanoscale. Periodic arrays of well-defined nanostructures can be produced with different nanomaterials and interpattern spacings. Results presented in this dissertation demonstrate particle lithography methods developed for fabricating arrays of organosilane nanostructures. Surfaces were designed for the selective deposition of polymers and nanoparticles to produce multicomponent nanopatterns. The approaches for surface patterning provide new directions for studying surface chemistry at the molecular-level, and have practical application for emerging photovoltaic thin film technologies. Atomic force microscopy (AFM) provides unique capabilities for molecular visualization and ultrasensitive …

Nonuniformity In Lattice Contraction Of Bismuth Nanoclusters Heated Near Its Melting Point, A. Esmail, M. Abdel-Fattah, Hani E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The structural properties of bismuth nanoclusters were investigated with transmission high-energy electron diffraction from room temperature up to 525 ± 6 K. The Bi nanoclusters were fabricated by thermal evaporation at room temperature on transmission electron microscope grids coated with an ultrathin carbon film, followed by thermal and femtosecond laser annealing. The annealed sample had an average cluster size of ∼14 nm along the minor axis and ∼16 nm along the major axis. The Debye temperature of the annealed nanoclusters was found to be 53 ± 6 K along the [012] direction and 86 ± 9 K along the [110] …

I, An Improved Procedure For Alkene Ozonolysis. Ii, Exploring A New Structural Paradigm For Peroxide Antimalarials., Charles Edward Schiaffo

Department of Chemistry: Dissertations, Theses, and Student Research

The use of ozone for the transformation of alkenes to carbonyls has been well established. The reaction of ozone with alkenes in this fashion generates either a 1,2,4-trioxolane (ozonide) or a hydroperoxyacetal, either of which must undergo a separate reduction step to provide the desired carbonyl compound. There is considerable interest in being able to perform a reductive ozonolysis to directly provide the carbonyl. Previous reports from the Dussault lab have shown that amine N-oxides are able to perform a reductive ozonolysis. In the course of efforts to expand this reaction to other oxyanions it was realized that water was …

Fabrication And Catalytic Property Of Cerium Oxide Nanomaterials, Keren Jiang

Department of Chemistry: Dissertations, Theses, and Student Research

Cerium oxide, or ceria (CeO_x: x = 1.5 to 2), has been widely used as a heterogeneous catalyst. Ceria has several properties make it high catalytic active: the fluctuating valence of cerium, the high oxygen storage capacity and high oxygen mobility in the nonstoichiometric ceria. With the high abundance of cerium on earth crust, ceria is a highly effective alternative of the noble metal catalysts. Research has been focused on designing nanostructured ceria and ceria related materials in recent years. The catalytic activity of ceria can be enhanced by the nanoscale effect which can be applied for various …

The Reactivity Of Potassium Carbanions With Epoxides, Christina Dorado

Open Access Theses & Dissertations

The reaction of &alpha-cumylpotassium and cyclohexene oxide produces trans-cumylcyclohexanol in high yield in the presence of excess cumene. Reactions of 1.1 and 2.0 equivalents of cumene with one equivalent of n-butylpotassium to make &alpha-cumylpotassium were shown to take several days to reach a maximum yield in the subsequent reaction of &alpha-cumylpotassium and cyclohexene oxide. Although it was initially hypothesized that the high yield was attributed to the interaction of the potassium with the aromatic rings of the &alpha-cumyl anion and the excess cumene, which was confirmed by molecular modeling studies, these reactions demonstrated that no large excess of …

Quality Of Wastewater In The El Paso, Texas Region--Analysis Of Pharmaceuticals And Personal Care Products Using High Performance Liquid Chromatography Tandem Mass Spectrometry, Rodolfo Guerrero Jr.

Open Access Theses & Dissertations

Pharmaceuticals and Personal Care Products (PPCPs), such as household cleaning materials, prescription medication, and personal hygiene products, are pollutants of emerging concern that are found in 80% of our water system. Because of their applications, PPCPs are subsequently being released into wastewater; however, current wastewater treatment facilities are not regulated or designed to remove PPCPs. Therefore, these compounds are discharged into the environment on a continual basis. The effects of PPCPs on human health are not yet well known; however, recent research has found that exposure to these chemicals has some adverse developmental effects on aquatic species at low concentrations …

Photocatalytic Destruction Of Halogenated Organic Compounds In Water With A New Photocatalyst, Mabruka Hadidan

Open Access Theses & Dissertations

In this research, a newly developed high surface area semiconductor porous material was synthesized from potassium titanium niobium mixed oxide (KTiNbO5) to be used as a photo catalyst in the presence of UV light to degrade halogenated organic compounds in water. The goal of the project was to investigate the catalytic activity of the material for its effectiveness in the degradation of the halogenated organic compounds, and it is the first investigation of this new photocatalyst with halogenated compounds. Model compounds dichloromethane, 1-chlorobutane, chlorobenzene, and trifluoroacetic acid in aqueous solutions were tested with the photocatalyst under ultraviolet light irradiation, using …

On-Trap Derivatization Of Short-Chain Fatty Acids, Mace Mattieson

Master's Theses and Doctoral Dissertations

It has recently been hypothesized that gastrointestinal microbiota modulate immune response by the production of short-chain fatty acids (SCFAs). There is a need for rapid, selective analytical methodology capable of trace analysis of SCFAs in complex biological matrices. Previous studies by others using multibed-sorbent traps, solid phase microextraction (SPME), and on-fiber derivatization with SPME showed that it is possible to achieve low limits of detection (LODs) for the gas chromatographic (GC) headspace analysis of SCFAs. The goal of this project was to achieve on-trap derivatization of SCFAs by incorporating a derivatizing agent onto a sorbent trap. Preconcentration and derivatization of …

Comparison Of Standard Impedance Spectroscopy Response To Aqueous Metal Ions Using Plain Vs. Surface Derivatized Gold Interdigitated Electrodes, Sindhu Yalamanchili

Master's Theses and Doctoral Dissertations

Abstract Recent work has provided evidence that 5-amino-1, 10 –phenanthroline can react with CS2 to anchor on the gold surface of an interdigitated electrode (IDE) through a dithiocarbamate linkage, resulting in significant changes in impedance response in the presence of Cu2+ solutions. However, questions regarding the stability of the primary amine-based dithiocarbamate self-assembled monolayer, reproducibility of the raw impedance and phase angle data, and possible variation of the background response for the gold IDE array in solutions of different metal ions remain an issue. Primary experimental emphasis is on the reproducibility of standard impedance and phase angle data for the …

Study Of The Effectiveness Of Animations Used In High School Chemistry Classes, Elli Spitery

Master's Theses and Doctoral Dissertations

This chemistry education research study explores the role of computer animations in a secondary chemistry classroom setting. This study examines the effects of animation among secondary science students regarding chemical concepts and focuses on the nature of matter, atomic structure, and classes of chemical reactions. This project observes the effectiveness of animation usage in a secondary science classroom setting, which was measured through student opinions and impressions as well as performance. It was hypothesized that students would retain more information through the use of animations in the classroom. The concepts covered included linking the macroscopic world of chemistry associated with …

Theoretical Characterization Of Non-Covalent Weakly Bound Clusters Through The Application Of Sophisticated Computational Quantum Chemistry Methodologies And The Development Of Integrated Fragmentation Techniques, Desiree Bates

Electronic Theses and Dissertations

Non-covalent, weakly bound clusters have been and remain of significant interest to many researchers. However, with computational studies, accurate description of these interactions requires sophisticated electronic structure methods employing large basis sets. This methodology becomes extremely computationally demanding as the size of the system increases. This work presents benchmark data and explores methods for obtaining highly accurate ab initio results for larger systems at greatly reduced computational costs. CCSD(T) complete basis set limit interaction energies are presented for a variety of parallel-slipped π...π dimers and low-lying isomers of (h₂o)₆. The calibration of a 2-body:Many-body fragmentation method …

Isolation And Analysis Of Peptides Binding To Helix 69 Of E. Coli 23 S Rrna From M13 Phage Display, Moninderpal Kaur

Wayne State University Dissertations

Peptides binding to helix 69 of domain IV or residues 1906-1924, of 23 S rRNA of E.coli were being selected from a heptapeptide phage library. An experimental system including biotin labeling of RNA and then affinity selection through four rounds was being followed. After sequencing phage clones of the fourth round, two peptide sequences dominated the phage pool, STYTSVS and NQVANHQ. The later sequence was a unique sequence since this sequence contained an abundance of amino acid residues that are also present in the ribosome recycling factor, RRF, and known to make contacts with H69. Phage-display methodology demonstrated the rapid …

Applications Of Electronic Structure Theory To Problems In Unimolecular Dissociation And Inorganic And Biochemical Systems, Jia Zhou

Wayne State University Dissertations

In this dissertation, ab initio classical trajectory calculations have been carried out to study the dissociation of acetone radical cation, pentane-2,4-dione radical cation, and 1,3-cyclobutanedione radical cation. For acetone radical cation and pentane-2,4-dione radical cation, MP2 with bond additivity corrections generates a better potential energy surface at low cost and is thus used for molecular dynamics calculations. The dissociation of acetone radical cation is found to favor the loss of the newly formed methyl group in agreement with the experiments. The branching ratios of methyl loss were also calculated with different amount of excess energy and of specific mode excitation. …

Characterization Of Intermolecular Pi-Type Interactions Using Sophisticated Quantum Mechanical, Electronic Structure Computations, Emily Joy Carrell

Electronic Theses and Dissertations

Much like the instrumentation in an experimental lab, computational chemists use computers to solve the mathematical equations that describe the physics of electrons to understand the chemistry involved. The combination of the two main components of computational chemistry, the basis set and method, determines the ``cost'' (disk, memory, and CPU time) of a computation. A variety of basis sets and methods have been developed in the past century. The focus of this report is to accurately describe non-covalent interactions with the use of various quantum computational techniques. In Chapter 1 a brief discussion on the theory behind computational chemistry is …

Specific Incorporation Of Unlabeled Aromatic Amino Acids Into 15n-Labeled Sac7d Through Use Of Glyphosate, Paul Ferguson, Mary Catherine Hames

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Leaf Essential Oil Composition Of Citrus Japonica From Biratnagar, Nepal, Prajwal Paudel

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Gemini Metallo-Surfactants: Chemical And Physical Properties, Erich Ivan Valenzuela

Open Access Theses & Dissertations

Gemini surfactants are amphiphilic molecules that consist of two surfactant molecules chemically joined together by a spacer group. These molecules tend to self‐assemble into vesicles at much lower concentrations than traditional surfactants and have found many applications in catalysis, adsorption applications, drug‐delivery, nanoscale technology, and biotechnology. In this thesis, the synthesis, characterization and physical properties of a new type of Gemini surfactant derived from dinuclear Cu(II) metal complexes is presented. We call these molecules Gemini Metal‐Organic Surfactants (GMOs).

Three newly developed new GMOs (compounds 1‐3) are composed of Cu(II) ions ligated to a lipid‐functionalized triamine group and the metals are …

The Chemistry Of Atmosphere-Forest Exchange (Cafe) Model-Part 2: Application To Bearpex-2007 Observations, Nicole C. Bouvier-Brown

Chemistry and Biochemistry Faculty Works

In a companion paper, we introduced the Chemistry of Atmosphere-Forest Exchange (CAFE) model, a vertically-resolved 1-D chemical transport model designed to probe the details of near-surface reactive gas exchange. Here, we apply CAFE to noontime observations from the 2007 Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX-2007). In this work we evaluate the CAFE modeling approach, demonstrate the significance of in-canopy chemistry for forest-atmosphere exchange and identify key shortcomings in the current understanding of intra-canopy processes.

CAFE generally reproduces BEARPEX-2007 observations but requires an enhanced radical recycling mechanism to overcome a factor of 6 underestimate of hydroxyl (OH) concentrations observed …

Modified Chromenes As Precursors To Taar Regulators, Jonathan Lehmann, Matthew Hart

Student Summer Scholars Manuscripts

200 million people worldwide are living with a thyroid disorder related to a hormonal imbalance. Symptoms of this imbalance include deviations from normal heart rates and metabolic rates. A chemical messenger known as T3 has been shown to raise cardiac and metabolic rates, but this takes place on a timescale of hours. However, recent discoveries have revealed that a different thyroid hormone known as T1AM is capable of affecting some of these same physiological conditions in a matter of minutes. T1AM is a potent, selective agonist for the Trace Amine Associated Receptor (TAAR). Several studies have probed the structural basis …

Quantum Chemical Analysis Of The Pka's Of Alcohols And A Cellular Automata Model For The Distribution Of Gases In The Earth's Atmosphere, Edur Basha Boyinipalli

Browse all Theses and Dissertations

Alcohols play important roles in many chemical and biological processes, and their acid/base behaviors are often important for these roles. In this study we ask the question, "Can the electronic properties of these compounds offer clues to the compounds' acid/base behaviors?" The study considers whether selected quantum chemical properties can be used to find correlations with the experimental pKa's of the alcohols (aliphatic and aromatic). Calculations were carried out for these alcohols using the semi-empirical RM1 method and the more advanced density functional theory (DFT) B3LYP/6-31+G* method. Significant correlations were found for several quantum chemical descriptors. It was also found …