Physical Sciences and Mathematics Commons^™

Mechanistic Insights And Functionalization Of Alkynes In Homogeneous Gold Catalysis., Manish Kumar

Electronic Theses and Dissertations

The focus of my dissertation work was to study the basic mechanistic insights of gold-catalyzed reactions. Although the various mechanistic pathways of gold catalysis are better understood nowadays, numerous questions still remain unanswered concerning the nature of deactivation of the catalyst's active species, high resistance towards protodeauration, and how we can solve these problems to improve the efficiency of gold catalysis. To address these challenges in gold catalysis we conducted first a detailed experimental study to understand the mechanism of deactivation of gold active species. Based on the combination of experimental data, we proposed that gold disproportionation is preferred as …

Functional Equations With Involution Related To Sine And Cosine Functions., Allison Perkins

Electronic Theses and Dissertations

Let G be an abelian group, C be the _eld of complex numbers, _ 2 G be any _xed, nonzero element and _ : G ! G be an involution. In Chapter 2, we determine the general solution f; g : G ! C of the functional equation f(x + _y + _) + g(x + y + _) = 2f(x)f(y) for all x; y 2 G. Let G be an arbitrary group, z0 be any _xed, nonzero element in the center Z(G) of the group G, and _ : G ! G be an involution. The main goals of …

Student Application Of The Fundamental Theorem Of Calculus With Graphical Representations In Mathematics And Physics, Rabindra R. Bajracharya

Electronic Theses and Dissertations

One mathematical concept frequently applied in physics is the Fundamental Theorem of Calculus (FTC). Mathematics education research on student understanding of the FTC indicates student difficulties with the FTC. Similarly, a few studies in physics education have implicitly indicated student difficulties with various facets of the FTC, such as with the definite integral and the area under the curve representation, in physics contexts. There has been no research on how students apply the FTC in graphically-based physics questions.

This study investigated student understanding of the FTC and its application to graphically-based problems. Our interest spans several aspects of the FTC: …

Nitroxide Radicals For Low Frequency Electron Paramagnetic Resonance Imaging (Epri), Joshua R. Biller

Electronic Theses and Dissertations

Optimization of nitroxides as probes for EPR imaging requires detailed understanding of spectral properties such as spin lattice relaxation times, spin packet linewidths, and nuclear hyperfine splitting. Initial measurements of relaxation times for six low molecular weight nitroxides at X-band stimulated further measurement at frequencies between 250 MHz and 34 GHz. The impact of tumbling was studied with perdeuterated 2,2,6,6-tetramethyl-4-piperidinyl-1-oxyl (PDT) in five solvents with viscosities resulting in tumbling correlation times, τ_R, between 4 and 50 ps. A set of three ¹⁴N/¹⁵N pairs of nitroxides in water was selected such that τ_R varied between …

Molecular Encapsulation In Kinetically Trapped, Hydrogen-Bonded Pyrogallolarene Hexamers, Jennifer Christine Chapin Lake

Electronic Theses and Dissertations

Pyrogallolarene and resorcinarene hexamers are hydrogen-bonded capsules that self-assemble in the solid state and can be studied in gaseous and solution phases. Guest loading within pyrogallolarene hexamers in solution has primarily been comprised of solvent molecules with some tertiary amines. A novel solvent-free method for loading guests into the interior of the hexamer has been shown to be effective for encapsulation of a variety of molecules. Aromatic and aliphatic compounds have particularly high guest loading within the hexamers and often result in kinetically stable guest-filled capsules in solution.

Kinetic studies of the encapsulation complexes of anthracene, biphenyl, fluoranthene, fluorene, naphthalene, …

Dust And Pleistocene Ice Ages: Eolian Sediments And Climate Change At Ziegler Reservoir, Snowmass Village, Colorado, Jeffrey S. Honke

Electronic Theses and Dissertations

The discovery of the Ziegler Reservoir fossil site near Snowmass Village, Colorado presents an opportunity to examine subalpine ecosystem response, during a relatively unknown period, in which climate conditions were similar to present. Finegrained sediments at Ziegler Reservoir represent continuous deposition between ~140–55 ka (thousand years before present), spanning the close of the Bull Lake glacial period [marine isotope stage (MIS) 6], the Sangamon interglacial (MIS 5) and the early stages of the Pinedale (early Wisconsin) glacial period (MIS 4). Ziegler Reservoir is positioned on top of a ridge, at an elevation of 2705 m, and has a small watershed …

The Impact Of Internet Gis On Access To Water Quality Information, Joseph H. Hoover

Electronic Theses and Dissertations

Empowering citizens to comprehend complex environmental issues affecting their daily lives is essential to sustaining a healthy and informed public. The work of many environmental nongovernmental organizations (ENGOs) and institutions of higher education (IHEs) center around helping their stakeholders become informed of, and in turn, better understand complex environmental problems. However, providing individual stakeholders with knowledge about environmental issues that is easily accessible and understandable represents a recurring challenge in today's society. As a result, a gap continues to exist between that which is known about environmental problems and the public's awareness and understanding of those issues. Arsenic contamination of …

Some New Probability Distributions Based On Random Extrema And Permutation Patterns, Jie Hao

Electronic Theses and Dissertations

In this paper, we study a new family of random variables, that arise as the distribution of extrema of a random number N of independent and identically distributed random variables X₁,X₂, ..., X_N, where each X_i has a common continuous distribution with support on [0,1]. The general scheme is first outlined, and SUG and CSUG models are introduced in detail where X_i is distributed as U[0,1]. Some features of the proposed distributions can be studied via its mean, variance, moments and moment-generating function. Moreover, we make some other choices for …

Analysis Of Snake Creek Burial Cave Mustela Fossils Using Linear & Landmark-Based Morphometrics: Implications For Weasel Classification & Black-Footed Ferret Conservation, Nathaniel S. Fox Iii

Electronic Theses and Dissertations

Two discreet methods of geometric morphometrics were applied to evaluate the taxonomic utility of each in classifying the craniomandibular region of several Mustela species. Use of both linear measurements and 2-dimensional landmarks proved successful in discriminating between extant M. nigripes (black-footed ferret) and Neovison vison (American mink), in addition to the extant North American weasel species (M. erminea, M. frenata, M. nivalis). Methods were then used to classify Late Pleistocene Mustela spp. fossils collected from Snake Creek Burial Cave (SCBC) of eastern Nevada. Data acquired for unknown predicted group memberships varied markedly among methods and specimens. …

Physiologically-Based Pharmacokinetic Model For Ertapenem, Whitney Forbes

Electronic Theses and Dissertations

Ertapenem is a carbapenem used to treat a wide range of bacterial infections. What sets ertapenem apart from other carbapenems is its longer half-life which implies it need only be administered once daily. We developed a physiologically-based pharmacokinetic model for the distribution of ertapenem within the body. In the model, parameters such as human body weight and height, age, organ volumes, blood flow rates, and partition coefficients of particular tissues are used to examine the absorption, distribution, metabolism, and excretion of ertapenem. The total and free blood concentrations found were then compared to experimental data. We then examined the sensitivity …

Very Cost Effective Domination In Graphs, Tony K. Rodriguez

Electronic Theses and Dissertations

A set S of vertices in a graph G=(V,E) is a dominating set if every vertex in V\S is adjacent to at least one vertex in S, and the minimum cardinality of a dominating set of G is the domination number of G. A vertex v in a dominating set S is said to be very cost effective if it is adjacent to more vertices in V\S than to vertices in S. A dominating set S is very cost effective if every vertex in S is very cost effective. The minimum cardinality of a very cost effective dominating set of …

Late Pleistocene And Holocene Bison Of Grand Canyon And Colorado Plateau: Implications From The Use Of Paleobiology For Natural Resource Management Policy, Jeffrey M. Martin

Electronic Theses and Dissertations

Bison spp. (bison) fossils are scarce on the Colorado Plateau, especially within the greater Grand Canyon region. Because of the poor fossil record for bison on the plateau and in Grand Canyon National Park, various resource managers have surreptitiously designated bison a nonnative and human-introduced species. The lack of evidence for bison seems to be the result of collection bias rather than a true lack of bison remains. Today, Grand Canyon National Park has a neighboring herd of 350 bison that have meandered unwantedly onto National Park lands from neighboring Forest Service and State of Arizona lands. This study spatiotemporally …

Continuous Tracking Of Lava Effusion Rate In A Lava Tube At Kilauea Volcano Using Very Low Frequency (Vlf) Monitoring, Richard A. Freeman

Electronic Theses and Dissertations

Measurement of lava effusion rates is a key objective for monitoring basaltic eruptions because it helps constrain geophysical models of magma dynamics, conduit geometry, and both deep and shallow volcano processes. During these eruptions, lava frequently travels through a single "master" lava tube. A new method and instrument for continuously monitoring the crosssectional area of lava streams in tubes and estimating the instantaneous effusion rate (IER) is described. The method uses 2 stationary very low frequency (VLF) radio receivers to measure an unperturbed VLF signal and the influence of highly conductive molten lava on that signal. The difference between these …

Inter-And Intra-Population Variability Across The Transcriptome Of Lake Baikal’S Endemic Copepod With Ramifications For Adapting To Climate Change, Larry L. Bowman Jr

Electronic Theses and Dissertations

The future of Lake Baikal’s biodiversity is uncertain in response to climate change. Unlike its diverse benthos, Lake Baikal’s zooplankton is species poor, with up to 96% of its biomass being composed of a single Calanoid copepod species, Epischura baikalensis. This study characterizes the genetic differentiation and differential gene expression of E. baikalensis. Using partial-transcriptome sequences obtained by 454 Rosche and Illumina sequencing technologies, the genetic differentiation at inferred single nucleotide polymorphism (SNP) sites and differential gene expression in populations sampled from various parts of the lake were analyzed. The functional genomics of genes showed significant differential …

Are Highly Dispersed Variables More Extreme? The Case Of Distributions With Compact Support, Benedict E. Adjogah

Electronic Theses and Dissertations

We consider discrete and continuous symmetric random variables X taking values in [0; 1], and thus having expected value 1/2. The main thrust of this investigation is to study the correlation between the variance, Var(X) of X and the value of the expected maximum E(Mn) = E(X1,...,Xn) of n independent and identically distributed random variables X1,X2,...,Xn, each distributed as X. Many special cases are studied, some leading to very interesting alternating sums, and some progress is made towards a general theory.

Permutation Groups And Puzzle Tile Configurations Of Instant Insanity Ii, Amanda N. Justus

Electronic Theses and Dissertations

The manufacturer claims that there is only one solution to the puzzle Instant Insanity II. However, a recent paper shows that there are two solutions. Our goal is to find ways in which we only have one solution. We examine the permutation groups of the puzzle and use modern algebra to attempt to fix the puzzle. First, we find the permutation group for the case when there is only one empty slot at the top. We then examine the scenario when we add an extra column or an extra row to make the game a 4 × 5 puzzle or …

Time Series Decomposition Using Singular Spectrum Analysis, Cheng Deng

Electronic Theses and Dissertations

Singular Spectrum Analysis (SSA) is a method for decomposing and forecasting time series that recently has had major developments but it is not yet routinely included in introductory time series courses. An international conference on the topic was held in Beijing in 2012. The basic SSA method decomposes a time series into trend, seasonal component and noise. However there are other more advanced extensions and applications of the method such as change-point detection or the treatment of multivariate time series. The purpose of this work is to understand the basic SSA method through its application to the monthly average sea …

Expanding The Frontier Of Gold-Catalyzed Cyclizations And Rational Ligand Design., Deepika Malhotra

Electronic Theses and Dissertations

The focus of my dissertation work is to study the gold-catalyzed intramolecular and intermolecular cyclizations involving oxonium intermediates towards the application of synthetically interesting frameworks under ambient conditions and developing a rational approach for the effective catalyst design in gold catalysis. We explored the goldcatalyzed oxygen-transfer reactions of 2-alkynyl-1,5-diketones or 2-alkynyl-5-ketoesters to furnish five-membered rings bearing a quaternary carbon tethered to a carbonyl group. The detailed mechanistic investigation on the newly proposed intramolecular [4+2] cycloaddition mechanism was performed by means of isotopic experiments and quantum chemical calculations. The reactivity of alkynylenolate was investigated in the reactions of allenic ketones and …

Kinetics Of Formation And Oxidation Of 8-Oxo-7,8-Dihydroguanine (8oxog), Derrick Ampadu Boateng

Electronic Theses and Dissertations

8-oxo-7,8-dihydroguanine (8oxoG) is one of the most important base lesions formed during oxidative damage of DNA. The aim of the present research was to investigate the effects of DNA concentration, G content, and the nature of oxidizing species on the kinetics of 8oxoG in model DNA solutions by using HPLC. The experimentally obtained yields of 8oxoG were typically in the range of 2-2.5% of total concentration of guanine. The ratios of the rate constant of hole diffusion in DNA to the rate constant of conversion of the hole into 8oxoG (k_d/k_r) were calculated from the experimental …

Comparison Of Different Methods For Estimating Log-Normal Means, Qi Tang

Electronic Theses and Dissertations

The log-normal distribution is a popular model in many areas, especially in biostatistics and survival analysis where the data tend to be right skewed. In our research, a total of ten different estimators of log-normal means are compared theoretically. Simulations are done using different values of parameters and sample size. As a result of comparison, ``A degree of freedom adjusted" maximum likelihood estimator and Bayesian estimator under quadratic loss are the best when using the mean square error (MSE) as a criterion. The ten estimators are applied to a real dataset, an environmental study from Naval Construction Battalion Center (NCBC), …

Non-Anguimorph Lizards Of The Late Oligocene And Early Miocene Of Florida And Implications For The Reorganization Of The North American Herpetofauna, Kevin Chovanec

Electronic Theses and Dissertations

Paleokarst deposits from the Oligo-Miocene of northern Florida preserve undescribed herpetofaunal remains that fill important temporal and geographic gaps in our understanding of Cenozoic lizard evolution. Here I describe and discuss the non-anguimorph lizard diversity of the Brooksville 2 (Ar2) and Miller (He1) local faunas to test for patterns of regional and latitudinal provincialism in the contemporary North American record. Collectively, the sites are significant for documenting 1) extralimital occurrences of the tropical clades Anolis and Corytophaninae, 2) a substantial temporal range extension of the modern southeastern endemic Rhineuridae, 3) the earliest record of eublepharid gekkotans from North America, and …

Synthesis Of A 4-(Trifluoromethyl)-2-Diazonium Perfluoroalkyl Benzenesuflonylimide (Pfsi) Zwitterionic Monomer For Proton Exchange Membrane Fuel Cell, Chimaroke Nworie

Electronic Theses and Dissertations

In order to achieve a more stable and highly proton conducting membrane that is also cost effective, the perfluoroalkyl benzenesulfonylimides (PFSI) polymers are proposed as electrolyte for Proton Exchange Membrane Fuel Cells. 4-(trifluoromethyl)-2-diazonium perfluoro-3, 6-dioxa-4-methyl-7-octene benzenesulfonyl imide (I) is synthesized from Nafion monomer via a 5-step schematic reaction at optimal reaction conditions. This diazonium PFSI zwitterionic monomer can be further subjected to polymerization. The loss of the diazonium N₂⁺ functional group in the monomer is believed to form the covalent bond between the PFSI polymer electrolyte and carbon electrodes support. All the intermediates and final products …

Statistical Methods For Assessing Treatment Effects For Observational Studies., Kristopher C. Gardner 1984-

Electronic Theses and Dissertations

Though randomized clinical (RCTs) trials are the gold standard for comparing treatments, they are often infeasible or exclude clinically important subjects, or generally represent an idealized medical setting rather than real practice. Observational data provide an opportunity to study practice-based evidence, but also present challenges for analysis. Traditional statistical methods which are suitable for RCTs may be inadequate for the observational studies. In this project, four of the most popular statistical methods for observational studies: ANCOVA, propensity score matching, regression with the propensity score as a covariate, and instrumental variables (IV) are investigated through application to MarketScan insurance claims data. …

Patient Rule Induction Method For Subgroup Identification Given Censored Data., Patrick James Trainor

Electronic Theses and Dissertations

The identification of subgroups in clinical studies is an important aspect of personalized medicine. In order to develop tailored therapeutics, the factors that characterize subgroups with differential prognosis, response to treatment, and incidence of adverse events or toxicities must be elucidated. We present a generalization of a statistical learning algorithm, Patient Rule Induction Method (PRIM), that is well suited for this task given a right-censored time-to-event outcome measure. This algorithm works to recursively partition a covariate space into mutually exclusive boxes that can be utilized to define subgroups. Conceptually the algorithm is similar to classification and regression trees but rather …

Functionalization Of Silica Surface Using Chan-Lam Coupling, George Appiah Kubi

Electronic Theses and Dissertations

The reaction of base-free Chan-Lam coupling was successfully used for functionalization of surface of mesoporous silica gel. Various aromatic, aliphatic, and heterocyclic compounds were immobilized by a copper-catalyzed reaction of corresponding boronic acids with surface amino groups at mild conditions. Obtained functionalized materials were mesoporous although their surface area decreased after immobilization. The reactivity of some surface functional groups was tested in their characteristic reactions.

The Impact Of World Bank’S Conditionality-Ownership Hybrid On Forest Management In Cameroon: Policy Hybridity In International Dependence Development, Asongayi Venard

Electronic Theses and Dissertations

Many developing countries depend on the World Bank for development assistance, which the Bank often provides with policy reform conditions. Resistance to World Bank’s conditionality caused the Bank to posit “ownership” as a country’s real assent to its development policies. The combination of ownership and conditionality invalidates the neocolonial, false-paradigm and dualism theses in explaining the international dependence development model. This study explains this model by investigating how the relationship between conditionality and ownership in the context of this model impacts forest management in Cameroon.

Integrating theoretical and methodological insights mainly from political science, economics, geosciences, and sociology, the study …

The Number Of Zeros Of A Polynomial In A Disk As A Consequence Of Restrictions On The Coefficients, Brett A. Shields Mr.

Electronic Theses and Dissertations

In this thesis, we put restrictions on the coefficients of polynomials and give bounds concerning the number of zeros in a specific region. Our results generalize a number of previously known theorems, as well as implying many new corollaries with hypotheses concerning monotonicity of the modulus, real, as well as real and imaginary parts of the coefficients separately. We worked with Enestr\"{o}m-Kakeya type hypotheses, yet we were only concerned with the number of zeros of the polynomial. We considered putting the same type of restrictions on the coefficients of three different types of polynomials: polynomials with a monotonicity``flip" at some …

Dust Properties Of Z~2 Infrared-Luminous Lyman Break Galaxies., Jennifer Leigh Wojno

Electronic Theses and Dissertations

Lyman break galaxies (LBGs) are well-known indicators of star formation. By analyzing the dust of moderate redshift (z ~ 2) LBGs, we can further investigate the properties of these strongly star forming galaxies at an epoch when global star formation is expected to peak. Using data observed by the Herschel satellite, we derive far-infrared fluxes for our color-selected sample of LBGs in the GOODS-S field, including a subsample of infrared-luminous LBGs (ILLBGs). This is one of the first samples of UV dropouts/partial dropouts, which are also infrared-luminous, to be studied for their far-IR properties. Fitting modified Planck curves and model …

Ligand Centered Reactivity Of Metal Stabilized Thiyl Radicals In Solution, Solid And Gaseous Phase., Rajat Rajat

Electronic Theses and Dissertations

This thesis presents ligand centered reactivity studies of metal stabilized thiyl radicals in solution, solid, and gaseous phases for catalysis and sensing based applications. Chemical oxidation of tris(2-diphenylphosphinebenzenethiolato )ruthenate(II) [Ru -1]- with ferrocenium hexafluorophosphate in the presence of ethylene yields [Ru-1·C,H.]PF6, from addition of the alkene across cis sulfur sites. In the presence of base [Ru-1·C,H.]+ is selectively deprotonated at the pseudoequatorial proton on the carbon a to the sulfur trans to phosphorus, yielding the vinyl metallosulfonium derivative [Ru-1·C,H3]. "H and 31p NMR spectra of [Ru-1'C,H3 ] are temperature dependent, associated with inversion of the sulfur lone pair at the …

Synthesis Of N-Heterocycles Through Cyclization-Triggered Tandem Additions To Alkynes And The Study Of Promoters In Ionic Reactions., Junbin Han

Electronic Theses and Dissertations

Our research mainly focused on three parts related to the rapid construction of N-heterocycles and the search for ionic reaction promoters. First, N-heterocycles of different ring sizes and with different substitution patterns constitute extremely important structure classes (e.g., alkaloids) in the search for bioactivity. A contemporary challenge in organic synthesis is the mapping of new chemical spaces through tandem or cascade reactions in an atom economical fashion. Our strategy to access these biologically important heterocycles is through a cyclization-triggered tandem addition to alkynes catalyzed by readily available alkynophilic coinage metals like copper. In this manner, a variety of functional groups …