Physical Sciences and Mathematics Commons^™

Preparation, Structural Characterization, And Dynamic Properties Investigation Of Permalloy Antidot Arrays, Scott Whittenburg, Charles J. O'Connor

Chemistry Faculty Publications

Regular nanosized structures are considered to be promising materials for magnetic information storage media with high density of information. Recently attention was paid to static and dynamic magnetic properties arising from dimensional confinement in such nanostructures. Here we present an investigation of permalloy antidot arrays of different thicknesses. Thin permalloy films of thickness ranging from 10 to 500 nm were deposited on anoporous Al2O3 membranes with a pore size of 100 nm. It was found that additional ferromagnetic resonance peaks appear for film thicknesses below 100 nm, while films with larger thicknesses show resonance properties similar to continuous films. A …

Aldol Reactions: E-Enolates And Anti-Selectivity, Matthew Grant Anderson

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

A common structural motif in complicated natural product molecules is an alkyl group at an alpha position to a carbonyl and an alcohol at the beta position anti to each other. This arrangement occurs in bioactive molecules that are important for medical research such as spongistatin A at the C15-C16 position and in (-)-baconipyrone C at C12-C13. Bioactive molecules such as these generally occur in such a low concentration in the organism in which they originate that deriving them from the natural source for research is not practical so efficient syntheses are sought. Reactions that produce 1,2 syn aldol products …

Approaches To Uniform-Morphology: Polymer-Based Sers Substrates, Kathleen Sue Giesfeldt

Doctoral Dissertations

Polymer-nano-metallic-particle composites have demonstrated technological potential due to their unique optical and electrical properties. We report on composites prepared via physical vapor deposition of silver and gold onto pliable polydimethlysiloxane (PDMS) polymer. Rapid metal diffusion and nano-metallic-particle formation in a phase-separated surface layer of the PDMS creates unique sub-surface-based composites that vary in properties based on rate of deposition and average metal thickness. In addition, nano-metallicparticle spacing can be altered with fair reproducibility and reversibility by physically manipulating the composite. A practical technological characteristic of these composite materials arises from their potential to be molded into functional devices. Surface enhanced …

Experimental Studies Of Intra- And Intermolecular Chemical Structure, Cara Lynn Nygren

Doctoral Dissertations

The purpose of this study was two fold. The determination of hydrogen atom positions by X-ray diffraction methods is widely underused. With advances in instrument and computing technology, the use of X-ray diffraction experiments to accurately image the electron density associated with a hydrogen bond has become feasible. Secondly, general crystallographic computing programs analyze diffraction data by employing a spherical atom model. However, no such atom can be defined solely by a sphere when bound in a molecule. The use of spherical harmonics to model diffraction data enables a more complete description of the electron density in a molecular system. …

Microwave Reflectometry As A Novel Diagnostic Method For Detection Of Skin Cancers, Kundan Chand, Pratik Mehta, Daryl G. Beetner, R. Zoughi, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

More than one million people are diagnosed with skin cancer each year in the United States and more than ten thousand people die from the disease. Currently, there are some methods for early detection of skin cancers, like visual inspection, but improvements are needed. This paper presents a method involving microwave reflectometry as a diagnostic tool for detection of skin cancers. The results of measurements and simulations for normal and wet skin have been shown to distinguish among skin samples with different properties. Microwave measurements from lesions have also been presented which are used to distinguish between cancerous and benign …

The Synthesis Of Biomimetic Tungsten And Molybdenum Complexes, John Sterling Cole Iii

Honors Theses

The synthesis of novel biomimetic molybdenum and tungsten compounds that are potential model complexes for molybdenum and tungsten oxidase enzymes is being pursued. Model complexes such as these provide a better understanding of the basic chemistry of a metal center in an environment similar to that found in particular enzyme active sites. This understanding provides a good starting point for biologists or biochemists studying those biological systems. The first target complex will incorporate a tetradentate-S4 ligand (L) that features two biphenyl-S2 fragments joined by a propyl linker. The second target complex will incorporate a bidentate ligand (L') with a singly …

Inside Unlv, Erin O'Donnell, Diane Russell, Carol C. Harter

Inside UNLV

No abstract provided.

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, S. Kolesnikov, E. Shwageraus, A. Galperin

Fuels Campaign (TRP)

This report presents the results of the Task 4, defined in working program as: evaluation of reactivity feedback coefficients. Three main parameters of the Fertile-Free Fuel (FFF) lattices were evaluated: Moderator Temperature Coefficient (MTC), Fuel Temperature Coefficient due to Doppler Effect (DC), and soluble Boron reactivity worth (BW).

One of the major design challenges associated with utilization of FFF is deterioration of the temperature coefficients and control materials reactivity worth caused by high thermal cross-section of Pu and consequent hardening of the neutron spectrum. The purpose of the investigation reported in this section is to estimate the potential of addition …

Synthesis Of Novel Alkaline Earth Metal Acetylides, Eva Baker

Renée Crown University Honors Thesis Projects - All

Acetylide complexes of the heavy alkaline-earth metals were first introduced by our group. With our group being interested in how the ligand and donor affect the structural chemistry of the resulting complexes, my project was focused on the detailed analysis of past work and the extension towards new ligand and donor sets. The work required the analysis and development of synthetic procedures towards these highly reactive species.

Past synthetic work in our group had established several synthetic routes towards the target compounds including transamination and toluene elimination. Using toluene elimination, I was able to reproduce the synthesis of M(C≡CSiPh_{3 …}

Eluent Component Adsorption Properties And Chromatographic Behavior Of Reversed Phase Adsorbents With Phenyl Functionalities In Reversed Liquid Chromatography, Fred S. Chan

Seton Hall University Dissertations and Theses (ETDs)

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Dispiro-1,2,4-Trioxane Analogues Of A Prototype Dispiro-1,2,4-Trioxolane: Mechanistic Comparators For Artemisinin In The Context Of Reaction Pathways With Iron(Ii), Yuanqing Tang, Yuxiang Dong, Xiaofang Wang, Kamaraj Sriraghavan, James K. Wood, Jonathan L. Vennerstrom

Chemistry Faculty Publications

Single electron reduction of the 1,2,4-trioxane heterocycle of artemisinin (1) forms primary and secondary carbon-centered radicals. The complex structure of 1 does not lend itself to a satisfactory dissection of the electronic and steric effects that influence the formation and subsequent reaction of these carbon-centered free radicals. To help demarcate these effects, we characterized the reactions of achiral dispiro-1,2,4-trioxolane 4 and dispiro-1,2,4-trioxanes 5−7 with ferrous bromide and 4-oxo-TEMPO. Our results suggest a small preference for attack of Fe(II) on the nonketal peroxide oxygen atom of 1. For 4, but not for 5 and 6 …

Orientation Of Single Crystals Using Linear Approximations To Nmr Transits, Young-Sik Kye, Xingang Zhao, Gerard S. Harbison

Gerard Harbison Publications

We have derived analytical expressions for determining the orientation of high-symmetry single crystals from line-crossings in a single rotation plot. We demonstrate the utility of the method using the strontium-87 resonance in strontium nitrate. Employing our new method, which we call orientation of single crystals using linear approximations to NMR transits (OSCULANT), in combination with fourth-order perturbation theory, we obtain a highly accurate value for the quadrupole coupling constant, and an estimate for the chemical shielding anisotropy.

Determination Of Atrazine And Selected Respective Metabolites Using Strong Cation Exchange Resins, Cierra Cross

Masters Theses & Specialist Projects

A new solid phase extraction procedure (SPE) for the removal of atrazine and three respective metabolites including deisopropylatrazine, desethylatrazine, and didealkylatrazine from aqueous samples is presented. Octadecyl bonded silica (C18) is widely used in analytical preconcentration schemes. While C18 presents a facile method of analyte removal, a new approach is needed to achieve greater trapping for polar analytes. In this study strong cationic exchange (SCX) resins consisting of sulfonated polystyrene are investigated for their extraction capabilities of the selected analytes. By exploiting acid-base and pi-pi interactions the analytes are trapped and therefore extracted from aqueous samples. Salt solutions are used …

Studies Of Alkaline Phosphatase Inhibition By Metal Chelators Using Capillary Electrophoresis, Courtney A. Neel

Masters Theses

Alkaline phosphatase inhibition by metal chelators has been studied using capillary electrophoresis. The enzyme-inhibition assays were performed by electrophoretically mixing enzyme and inhibitor zones in a substrate filled capillary. Enzyme inhibition could be seen as a decrease in product formation as detected using laser-induced fluorescence. The enzyme-inhibition assays were adapted so they could be performed using a commercial CE system. Use of a commercial system is desirable for these assays due to ease of use and system features such as autosamplers and capillary and sample cooling. This technique could prove useful for pharmaceutical industries as a screening tool for new …

Thermodynamic Contributions Of Various Metal-Nucleotide Complexes Binding To Yeast Phosphoglycerate Kinase, Randall Allen Holzberger

Masters Theses

The purpose of this study was to determine the thermodynamic parameters of various enzyme-substrate complexes of Yeast Phosphoglycerate Kinase by using Isothermal Titration Calorimetry (ITC). The addition of metal-nucleotide substrate to a PGK solution elicited an exothermic response ranging from 0.5 kilocalories to 2.8 kilocalories. Titrations of MgATP and MgADP into PGK yielding binary complexes generated a greater amount of heat than titrations of MgADP into PGA-PGK and MgAMP-PCP into PGA-PGK yielding ternary complexes. The entropic contribution of the ternary complex formations was significantly greater than binary complex formations. Although entropic and enthalpic contributions varied, the Gibbs free energy remained …

Biomolecule Detection Via Target Mediated Nanoparticle Aggregation And Dielectrophoretic Impedance Measurement, Philip J. Costanzo, Enzhu Liang, Timothy E. Patten, Scott D. Collins, Rosemary L. Smith

Chemistry and Biochemistry

A new biosensing system is described that is based on the aggregation of nanoparticles by a target biological molecule and dielectrophoretic impedance measurement of these aggregates. The aggregation process was verified within a microchannel via fluorescence microscopy, demonstrating that this process can be used in a real time sensor application. Positive dielectrophoresis is employed to capture the nanoparticle aggregates at the edge of thin film electrodes, where their presence is detected either by optical imaging via fluorescence microscopy or by measuring the change in electrical impedance between adjacent electrodes. The electrical detection mechanism demonstrates the potential for this method as …

Search For Global Minimum Geometries For Medium Sized Germanium Clusters: Ge12–Ge20, Satya S. Bulusu, S. Yoo, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We have performed an unbiased search for the global minimum geometries of small-to-medium sized germanium clusters Ge_n (12≤n≤18) as well as a biased search (using seeding method) for Ge_n (17≤n≤20). We employed the basin-hopping algorithm coupled with the plane-wave pseudopotential density functional calculations. For each size, we started the unbiased search with using several structurally very different initial clusters, or we started the biased search with three different seeds. Irrespective of the initial structures of clusters we found that the obtained lowest-energy clusters of the size n=12–16 and 18 are the same. Among …

Isobaric Analog States Of Neutron-Rich Nuclei. Doppler Shift As A Measurement Tool For Resonance Excitation Functions, P. Boutachkov, G. V. Rogachev, V. Z. Goldberg, A. Aprahamian, F. D. Becchetti, J. P. Bychowski, Y. Chen, G. Chubarian, P. A. Deyoung, J. J. Kolata, L. O. Lamm, Graham F. Peaslee, M. Quinn, B. B. Skorodumov, A. Wohr

Faculty Publications

We present a new approach for the measurement of resonance excitation functions of neutron-rich nuclei using Doppler shift information. Preliminary data from the first application of the method is presented in the spectroscopy studies of 7He isobaric analog states in 7Li.

Bimetallic Pt-Ag And Pd-Ag Nanoparticles, Frank D. Blum, Akira Tokuhiro, Massimo F. Bertino, Carmen M. Doudna

Chemistry Faculty Research & Creative Works

We report studies of bimetallic nanoparticles with 15%-16% atomic crystal parameters size mismatch. The degree of alloying was probed in a 2-nm Pt core (smallest attainable core size) of Pt-Ag nanoparticles (completely immiscible in bulk) and 20-nm-diameter Pd-Ag nanowires (completely miscible in bulk). Particles were synthesized radiolytically, and depending on the initial parameters, they assume spherical or cylindrical (nanowire) morphologies. In all cases, the metals are seen to follow their bulk alloying characteristics. Pt and Ag segregate in both spherical and wire forms, which indicates that strain due to crystallographic mismatch overcomes the excess surface free energy in the small …

Immobilization Of Fission Iodine By Reaction With A Fullerene Containing Carbon Compound And Insoluble Natural Organic Matrix: Quaterly Report January-March 2005, Spencer M. Steinberg

Separations Campaign (TRP)

We have continued experiments on the reaction of iodate with sphagnum peat moss. We have established that iodate added to a suspension of peat moss undergoes reduction and to a significant extent is incorporated in to the peat moss. We have confirmed the incorporation of iodine into the peat matrix using pyrolysis GC/MS. In addition, we have performed a scaled up pyrolysis using the preparative GC system that was described in a previous report. This instrument consisted of a packed column gas chromatograph (SRI 8010) with a TCD detector and injector valve equipped with a thermal desorber. Pyrolysis experiments were …

Improving Performance Characteristics Of Hyphenated Preconcentrator Gc Fourier Transform Ion Cyclotron Resonance Mass Spectrometry: A "Gold Standard" For Sensor Development, Touradj Solouski

University of Maine Office of Research Administration: Grant Reports

Professor Touradj Solouki of the University of Maine at Orono is supported by the Analytical and Surface Chemistry Program to investigate cryofocusing of analytes in an Electrospray Ionization Fourier Transform Ion Cyclotron Resonance (ESI-FT-ICR) mass spectrometer. To overcome sensitivity problems of FT-ICR, Professor Solouki has added a pre-concentration (PC) gas chromatograph (GC) step to his setup. The goal of this Small Grant for Exploratory Research is to add an additional device: a cryofocuser after the GC. This is predicted to improve the detection limit by two orders of magnitude, and mass resolving power by a factor of 5-10. The PI …

Fire Retardancy Of Polystyrene - Hectorite Nanocomposites, Dongyan Wang, Bok Nam Jang, Shengpei Su, Jinguo Zhang, Xiaoxia Zheng, Grace Chigwada, David D. Jiang, Charles A. Wilkie

Chemistry Faculty Research and Publications

No abstract provided.

An Introduction To The Use Of Fillers And Nanocomposites In Fire Retardancy, Charles A. Wilkie

Chemistry Faculty Research and Publications

No abstract provided.

Relative Basicities Of Free Base Porphyrins : Understanding The Role Of Macrocyclic Distortion, Maria Ballester

FIU Electronic Theses and Dissertations

Porphyrins have been the center of numerous investigations in different areas of chemistry, geochemistry, and the life sciences. In nature the conformation of the porphyrin macrocycle varies, depending on the function of its apoenzyme. It is believed that the conformation of the porphyrin ring is necessary for the enzyme to achieve its function and modify its reactivity. It is important to understand how the conformation of the porphyrin ring will influence its properties.

In synthetic porphyrins particular conformations and ring deformations can be achieved by peripheral substitution, metallation, core substitution, and core protonation among other alterations of the macrocycle. The …

An Investigation Of Modified Superconductivity Through Structural Alteration Of Mgcni3 And Mgb2, Nathan L. Henderson

Honors Theses

No abstract provided.

The Elastic Constants And Related Properties Of Β-Hmx Determined By Brillouin Scattering, Lewis L. Stevens, Craig J. Eckhardt

Craig J. Eckhardt Publications

By scattering from a variety of acoustic phonons, a complete stiffness tensor has been determined for crystalline β-HMX. The results are compared with recent experimental and theoretical determinations of the elastic constants and bulk modulus. Reasons for disagreement are discussed in terms of experimental limitations and anharmonic effects. The observed ordering of stiffness constants, C₁₁ (18.4 GPa), C₂₂ (14.4 GPa), and C₃₃ (12.4 GPa), is qualitatively associated with physical phenomena including cleavage planes, patterns in crystal growth, and molecular packing. This interpretation is further corroborated by the linear compressibilities plotted in three crystallographic planes. The Voigt–Reuss–Hill bulk …

Chemistry & Biochemistry Newsletter, Department Of Chemistry & Biochemistry, South Dakota State University

Chemistry & Biochemistry Newsletter: 2002-2015

Inside:

Page 2-3 Forensics Project Gives Students Real Life Experience in Analytical Chemistry; 2005 Chemistry and Biochemistry Graduates

Page 4-5 Treasure Hunting at the South Pole

Page 6 Floyd Melrose Retires After 40 Years with Department

Page 7 Alumni News; Scholarship and Award Winners

Page 8 Department News; Recent Faculty Publications

Chemical Manipulation Of High-Tc Ferromagnetism In Zno Diluted Magnetic Semiconductors, Kevin R. Kittilstved, D. R. Gamelin, N. S. Norberg

Kevin R. Kittilstved

We report the use of targeted p- and n-type chemical perturbations to manipulate high-TC ferromagnetism in Mn2+∶ZnO and Co2+∶ZnO in predictable and reproducible ways. We demonstrate a clear correlation between nitrogen and high-TC ferromagnetism for Mn2+∶ZnO and an inverse correlation for Co2+∶ZnO, both as predicted by recent theoretical models. These chemical perturbations reveal rich possibilities for exerting external control over high-TC spin ordering in diluted magnetic semiconductors.

11-(2,2-Dimethylpropyl)-12-{2-[12-(2,2-Dimethylpropyl)- 9,10-Dihydro-9,10-Ethenoanthracen-11-Yl]- Ethyl}-9,10-Dihydro-9,10-Ethenoanthracene, Joseph P. Herres, Mark A. Forman, Kraig A. Wheeler, Glenn P.A. Yap

Kraig A. Wheeler

Reaction of tert-butyllithium with 11,12-dimethylene-9,10- dihydro-9,10-ethanoanthracene and 4,5-diiodopentacyclo- [4.3.0.02,4.03,8.05,7]nonane gives three products, one of which crystallizes from petroleum ether as the title compound, C44H46, (I). Molecules of (I) are positioned on inversion centers (Z0 = 0.5) in the space group P21/n and lack any discernible intermolecular interactions.

The Armstrong Chemical Bond, Armstrong Atlantic State University

Chemical Bond Newsletter (2004-2005)

No abstract provided.