Physical Sciences and Mathematics Commons^™

Comparing K Population Means With No Assumption About The Variances, Tony Yaacoub

Electronic Theses and Dissertations

In the analysis of most statistically designed experiments, it is common to assume equal variances along with the assumptions that the sample measurements are independent and normally distributed. Under these three assumptions, a likelihood ratio test is used to test for the difference in population means. Typically, the assumption of independence can be justified based on the sampling method used by the researcher. The likelihood ratio test is robust to the assumption of normality. However, the equality of variances is often difficult to justify. It has been found that the assumption of equal variances cannot be made even after transforming …

Elements Of Convergence Approach Theory, William D. Trott

Electronic Theses and Dissertations

We introduce two generalizations to convergence approach spaces of classical results characterizing regularity of a convergence space in terms of continuous extensions of maps on one hand, and in terms of continuity of limits for the continuous convergence on the other. Characterizations are obtained for two alternative extensions of reg- ularity to convergence-approach spaces: regularity and strong regularity. Along the way, we give a brief overview of the theory of convergence spaces and of convergence approach spaces.

Polymorphic Data Modeling, Steven R. Benson

Electronic Theses and Dissertations

There are currently no data modeling standards for modeling NoSQL document store databases. This work proposes a standard to fill the void. The proposed standard is based on our new data modeling pattern named The Polymorphic Table Pattern. The pattern embraces the “schemaless” nature of document store NoSQL while allowing the data modeler to use his or her existing skillsets. The concepts of our proposed modeling have been demonstrated against MongoDB.

Statistical Analysis Of Unreplicated Factorial Designs Using Contrasts, Meixi Yang

Electronic Theses and Dissertations

Factorial designs can have a large number of treatments due to the number of factors and the number of levels of each factor. The number of experimental units required for a researcher to conduct a $k$ factorial experiment is at least the number of treatments. For such an experiment, the total number of experimental units will also depend on the number of replicates for each treatment. The more experimental units used in a study the more the cost to the researcher. The minimum cost is associated with the case in which there is one experimental unit per treatment. That is, …

[Introduction To] Identity And Leadership In Virtual Communities: Establishing Credibility And Influence, Dona J. Hickey, Joe Essid

Bookshelf

The presence and ubiquity of the internet continues to transform the way in which we identify ourselves and others both online and offline. The development of virtual communities permits users to create an online identity to interact with and influence one another in ways that vary greatly from face-to-face interaction.

Identity and Leadership in Virtual Communities: Establishing Credibility and Influence explores the notion of establishing an identity online, managing it like a brand, and using it with particular members of a community. Bringing together a range of voices exemplifying how participants in online communities influence one another, this book serves …

Micro (Wind) Generation: 'Urban Resource Potential & Impact On Distribution Network Power Quality', Keith Sunderland

Doctoral

Of the forms of renewable energy available, wind energy is at the forefront of the European (and Irish) green initiative with wind farms supplying a significant proportion of electrical energy demand. This type of distributed generation (DG) represents a ‘paradigm shift’ towards increased decentralisation of energy supply. However, because of the distance of most DG from urban areas where demand is greatest, there is a loss of efficiency. The solution, placing wind energy systems in urban areas, faces significant challenges. The complexities associated with the urban terrain include planning, surface heterogeneity that reduces the available wind resource and technology obstacles …

Synthesis, Characterization And Electrochemical Properties Of Gold Nanomolecules, Vijay Bhaskar Reddy Jupally

Electronic Theses and Dissertations

Chapter 1 gives a brief introduction to the field of gold nanomolecules. Various synthetic protocols and analytical techniques used through out this dissertation are discussed in detail. Size dependent properties of the gold nanomolecules are described. The structure of gold nanomolecules is explained based on the crystal structure of Au25(SCH2CH2Ph)18. The theoretical basis for the stability of the gold nanomolecules is explained using the super atom complex model and geometric parameters. Chapter 2 includes ligand exchange experiments on gold nanomolecules. Ligand exchange experiments are used to modify the monolayer of nanomolecules after synthesis. Ligand exchange reactions are monitored by mass …

Investigations Towards Synthesis Of Cinnamaldehyde Semicarbazone Derivatives And Their Photochromicity By Modifying The Ring, The Linker, And The Semicarbazone, Xiao Xiao

Masters Theses

Cinnamaldehyde semicarbazone was varied in three ways, by altering the ring, the conjugated linker, and the semicarbazone, to investigate how changing the structure affects the photochomicity. The synthesis of 7 hetero- and 2 polycyclic- aromatic semicarbazone variants involved three steps, (a Wittig reaction, hydrolysis, and condensation to the semicarbazone) with cumulative yields of 15% to 52%. Generally, the pyridine series gave lower yields than other synthesized semicarbazones. The Wittig reaction gave cis/trans mixtures in ratios of 2 : 1 to 1 : 7 for the 6 acetals, except for the 3 that went directly to the aldehyde, due to the …

Effects Of Charge And Substituent On The S∙∙∙N Chalcogen Bond, U. Adhikari, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Neutral complexes containing a S···N chalcogen bond are compared with similar systems in which a positive charge has been added to the S-containing electron acceptor, using high-level ab initio calculations. The effects on both XS···N and XS+···N bonds are evaluated for a range of different substituents X = CH3, CF3, NH2, NO2, OH, Cl, and F, using NH3 as the common electron donor. The binding energy of XMeS···NH3 varies between 2.3 and 4.3 kcal/mol, with the strongest interaction occurring for X = F. The binding is strengthened by a factor of 2–10 in charged XH2S+···NH3 complexes, reaching a maximum of …

Competition Between Lone Pair-Π, Halogen Bond, And Hydrogen Bond In Adducts Of Water With Perhalogenated Alkenes C2clnf4-N (N = 0-4), U. Adhikari, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

A thorough search of the potential energy surface is carried out for heterodimers of water with C2ClnF4−n. Three different types of interactions are observed. Structures dominated by a lone pair–π interaction have the highest binding energies, and are stabilized by charge transfer from O lone pairs of H2O to the Csingle bondC π* antibonding orbital of the alkene. Halogen-bonded O⋯Cl complexes are slightly less strongly bound, followed by OH⋯X hydrogen bonds. The replacements of Cl by F atoms have only small effects upon binding energies. Inclusion of vibrational and entropic effects removes the clear energetic superiority of lp–π binding energies. …

Substituent Effects In The Noncovalent Bonding Of So2 To Molecules Containing A Carbonyl Group. The Dominating Role Of The Chalcogen Bond, L. M. Azofra, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The SO2 molecule is paired with a number of carbonyl-containing molecules, and the properties of the resulting complexes are calculated by high-level ab initio theory. The global minimum of each pair is held together primarily by a S···O chalcogen bond wherein the lone pairs of the carbonyl O transfer charge to the π* antibonding SO orbital, supplemented by smaller contributions from weak CH···O H-bonds. The binding energies vary between 4.2 and 8.6 kcal/mol, competitive with even some of the stronger noncovalent forces such as H-bonds and halogen bonds. The geometrical arrangement places the carbonyl O atom above the plane of …

Interaction Between Temozolomide And Water: Preferred Binding Sites, O. E. Kasende, A. Matondo, M. Muzomwe, J. T. Muya, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Computational methods are used to predict the most favorable site of temozolomide towards attack by a water molecule. The energetics of the various complexes are presented as well as their geometries, including perturbations of each subunit caused by the presence of the other. Molecular electrostatic potential and Natural Bond Orbital (NBO) data are used to understand the interactions which conclude the terminal amide group is the preferred attack site where water can act as simultaneous proton donor and acceptor. Other potential proton acceptor N atoms within the aromatic ring structure represent weaker binding sites. Some of the less strongly bound …

The Mtr4 Ratchet Helix And Arch Domain Both Function To Promote Rna Unwinding, Lacy L. Taylor, Ryan N. Jackson, Megi Rexhepaj, Alejandra Klauer King, Lindsey K. Lott, Ambro Van Hoof, Sean J. Johnson

Chemistry and Biochemistry Faculty Publications

Mtr4 is a conserved Ski2-like RNA helicase and a subunit of the TRAMP complex that activates exosomemiated 3-5 turnover in nuclear RNA surveillance and processing pathways. Prominent features of the Mtr4 structure include a four-domain ring-like helicase core and a large arch domain that spans the core. The ‘ratchet helix’ is positioned to interact with RNA substrates as they move through the helicase. However, the contribution of the ratchet helix in Mtr4 activity is poorly understood. Here we show that strict conservation along the ratchet helix is particularly extensive for Ski2-like RNA helicases compared to related helicases. Mutation of residues …

Electrodeposited Nickel-Sulfide Films As Competent Hydrogen Evolution Catalysts In Neutral Water, N. Jiang, L. Bogoev, M. Popova, S. Gul, J. Yano, Y. Sun

Chemistry and Biochemistry Faculty Publications

The development of low-cost, efficient, and robust electrocatalysts of the hydrogen evolution reaction (HER) is a crucial step toward the conversion and storage of sustainable and carbon-neutral energy resources, such as solar energy. Not only the HER catalysts need to be composed of inexpensive elements, they are also desirable to be prepared at low energy cost. In this work, we report that nickel-sulfide (Ni-S) films prepared by facile potentiodynamic deposition are active HER catalysts in aqueous media. Notably, the Ni-S films showed catalytic activity in water with a wide range of pH values (0 to 14), as well as in …

Complexation Of N So2 Molecules (N=1,2,3) With Formaldehyde And Thioformaldehyde, L. M. Azofra, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Ab initio and density functional theory calculations are used to examine complexes formed between H2CO and H2CS with 1, 2, and 3 molecules of SO2. The nature of the interactions is probed by a variety of means, including electrostatic potentials, natural bond orbital, atoms in molecules, energy decomposition, and electron density redistribution maps. The dimers are relatively strongly bound, with interaction energies exceeding 5 kcal/mol. The structures are cyclic, containing both a O/S⋯S chalcogen bond and a CH⋯O H-bond. Addition of a second SO2 molecule leads to a variety of heterotrimer structures, most of which resemble the original dimer, where …

Complexes Containing Co2 And So2. Mixed Dimers, Trimers And Tetramers, L. M. Azofra, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Mixed dimers, trimers and tetramers composed of SO2 and CO2 molecules are examined by ab initio calculations to identify all minimum energy structures. While AIM formalism leads to the idea of a pair of C···O bonds in the most stable heterodimer, bound by some 2 kcal mol(-1), NBO analysis describes the bonding in terms of charge transfer from O lone pairs of SO2 to the CO π* antibonding orbitals. The second minimum on the surface, just slightly less stable, is described by AIM as containing a single O···O chalcogen bond. The NBO picture is that of two transfers in opposite …

An Exploration Of The Ozone Dimer Potential Energy Surface, L. M. Azofra, I. Alkorta, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The (O3)2 dimer potential energy surface is thoroughly explored at the ab initio CCSD(T) computational level. Five minima are characterized with binding energies between 0.35 and 2.24 kcal/mol. The most stable may be characterized as slipped parallel, with the two O3 monomers situated in parallel planes. Partitioning of the interaction energy points to dispersion and exchange as the prime contributors to the stability, with varying contributions from electrostatic energy, which is repulsive in one case. Atoms in Molecules analysis of the wavefunction presents specific O⋯O bonding interactions, whose number is related to the overall stability of each dimer. All internal …

Windows Surface Rt Tablet Forensics, Asif Iqbal, Hanan Al Obaidli, Andrew Marrington, Andy Jones

All Works

Small scale digital device forensics is particularly critical as a result of the mobility of these devices, leading to closer proximity to crimes as they occur when compared to computers. The Windows Surface tablet is one such device, combining tablet mobility with familiar Microsoft Windows productivity tools. This research considers the acquisition and forensic analysis of the Windows Surface RT tablet. We discuss the artifacts of both the Windows RT operating system and third-party applications. The contribution of this research is to provide a road map for the digital forensic examination of Windows Surface RT tablets.

Geochemical Studies Of Backfill Aggregates, Lake Sediment Cores And The Hueco Bolson Aquifer, Anita Thapalia

Open Access Theses & Dissertations

This Dissertation comprises of three different researches that focuses on the application of geochemistry from aggregates, lake sediment cores and Hueco Bolson Aquifer. Each study is independent and presented in the publication format. The first chapter is already published and the second chapter is in revision phase. Overall, three studies measure the large scale (field) as well as bench scale (lab) water-rock interactions influenced by the climatic and anthropogenic factors spans from the field of environmental geology to civil engineering.

The first chapter of this Dissertation addresses the chemical evaluation of coarse aggregates from six different quarries in Texas. The …

Controls On Fault Geometry During Early Stages Of Extension In The Larkspur Hills, Northwest Basin And Range, Diana Jean Strickley

All Master's Theses

Detailed analyses of normal faults in the Larkspur Hills, CA-NV, northwest Basin and Range, offer insight into factors controlling normal fault initiation, growth, and distribution. N-trending faults in the southern portion of the study area share trends of major range-bounding structures and Pliocene linear volcanic vents; in contrast, NNW- and NNE- trending faults dominate further north and into south-central Oregon. Stress analyses and comparison with experimental and field data suggest that preexisting structures control faults in the northern Larkspur Hills, while faults form perpendicular to σ3 in the southern hills. The change in fault orientations is abrupt, occurring across a …

Function Of Several Variable, Weiting Li

A with Honors Projects

This Parkland A with Honors project discusses the function of several variables, it's limits and partial derivatives.

An Advanced Mesospheric Temperature Mapper For High-Latitude Airglow Studies, Pierre-Dominique Pautet, Michael J. Taylor, William R. Pendleton Jr., Yucheng Zhao, Tao Yuan, R. Esplin, D. Mclain

Publications

Over the past 60 years, ground-based remote sensing measurements of the Earth’s mesospheric temperature have been performed using the nighttime hydroxyl (OH) emission, which originates at an altitude of ∼87  km∼87  km. Several types of instruments have been employed to date: spectrometers, Fabry–Perot or Michelson interferometers, scanning-radiometers, and more recently temperature mappers. Most of them measure the mesospheric temperature in a few sample directions and/or with a limited temporal resolution, restricting their research capabilities to the investigation of larger-scale perturbations such as inertial waves, tides, or planetary waves. The Advanced Mesospheric Temperature Mapper (AMTM) is a novel infrared digital imaging …

Phonon Thermal Transport Through Tilt Grain Boundaries In Strontium Titanate, Zexi Zheng, Xiang Chen, Bowen Deng, Aleksandr V. Chernatynskiy, Shengfeng Yang, Jinjun Xiong, Youping Chen

Physics Faculty Research & Creative Works

In this work, we perform nonequilibrium molecular dynamics simulations to study phonon scattering at two tilt grain boundaries (GBs) in SrTiO₃. Mode-wise energy transmission coefficients are obtained based on phonon wave-packet dynamics simulations. The Kapitza conductance is then quantified using a lattice dynamics approach. The obtained results of the Kapitza conductance of both GBs compare well with those obtained by the direct method, except for the temperature dependence. Contrary to common belief, the results of this work show that the optical modes in SrTiO₃ contribute significantly to phonon thermal transport, accounting for over 50% of the Kapitza …

Symmetries Of Embedded Complete Bipartite Graphs, Erica Flapan, Nicole Lehle '09, Blake Mellor, Matt Pittluck, Xan Vongsathorn '09

Pomona Faculty Publications and Research

We characterize which automorphisms of an arbitrary complete bipartite graph K_n,m can be induced by a homeomorphism of some embedding of the graph in S³.

Topological Symmetry Groups Of Small Complete Graphs, Erica Flapan, Dwayne Chambers

Pomona Faculty Publications and Research

Topological symmetry groups were originally introduced to study the symmetries of non-rigid molecules, but have since been used to study the symmetries of any graph embedded in R³. In this paper, we determine for each complete graph K_n with n ≤ 6, what groups can occur as topological symmetry groups or orientation preserving topological symmetry groups of some embedding of the graph in R³.

Mathematical And Physical Aspects Of Complex Symmetric Operators, Stephan Ramon Garcia, Emil Prodan, Mihai Putinar

Pomona Faculty Publications and Research

Recent advances in the theory of complex symmetric operators are presented and related to current studies in non-hermitian quantum mechanics. The main themes of the survey are: the structure of complex symmetric operators, C-selfadjoint extensions of C-symmetric unbounded operators, resolvent estimates, reality of spectrum, bases of C-orthonormal vectors, and conjugate-linear symmetric operators. The main results are complemented by a variety of natural examples arising in field theory, quantum physics, and complex variables.

Novel Tuberculostatic Agents Suitable For Treatment Of Mycobacterium Tuberculosis Infections Of The Central Nervous System, Ronald Bartzatt, Preeti Sule, Suat L.G. Cirillo, Jeffrey D. Cirillo

Chemistry Faculty Publications

Aims: To demonstrate the efficacy of five small molecule compounds for inhibiting the growth of Mycobacterium tuberculosis. To present evidence that these compounds will penetrate into the central nervous system.

Study Design: Five small molecule compounds bearing a hydrazide group were synthesized utilizing microwave excitation. These compounds were then placed into tissue culture with Mycobacterium tuberculosis at various concentrations for evaluation of bacterial growth inhibition.

Place and Duration of Study: The compounds to be tested were prepared at the University of Nebraska Chemistry Department August 2013. The evaluation of antibacterial activity was determined at the Texas A&M Health Science …

Assessing Possible Cruise Ship Impacts On Huna Tlingit Ethnographic Resources In Glacier Bay, Douglas Deur, Thomas Thornton

Anthropology Faculty Publications and Presentations

This report provides a thematic summary of an ethnographic study addressing the effects of cruise ships within Glacier Bay proper on the people known as the Huna Tlingit. Occupying the heart of Glacier Bay National Park and Preserve, Glacier Bay proper is considered to be the core homeland of Huna Tlingit. The Huna occupied the Bay prior to its most recent glaciation and, though they now live nearby in Hoonah and other communities, they have continued to use, occupy, and value the lands and waters within the Bay since the glaciers began to retreat over two centuries ago. Simultaneously, since …

Comparative Analysis Of Gps Data, Kiel Von Lindenberg

Undergraduate Journal of Mathematical Modeling: One + Two

The goal of this project is to calculate the distance traveled during a bike ride around the University of South Florida using information gathered by a GPS (Global Positioning System) application on a smartphone. We calculate the route distance in two ways: from latitudes and longitudes using the haversine formula and 2) from velocities and times using the trapezoidal rule. These computed distances were compared to the distance given by the smartphone application.

Survival Analysis - Breast Cancer, Minh Hoang Pham

Undergraduate Journal of Mathematical Modeling: One + Two

In this study we used the parametric survival approach to analyze the survival time of African American breast cancer patients. In research about the survival time of patients, the Cox Proportional Hazard model, a semi-parametric method, is primarily used, but this approach does not rely on the distributional assumptions. The parametric method is more consistent with a theoretical approach compared to a semi-parametric approach. We observe that the survival time of African American breast cancer patients follows the Weibull Probability Distribution. First, we fitted the model to represent the survival ability of the general population (African American women diagnosed with …