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Physical Sciences and Mathematics Commons™

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University of Richmond

Series

2004

Articles 1 - 10 of 10

Full-Text Articles in Physical Sciences and Mathematics

Ultra-Fast Formation Of Stable Nanoparticle Film Assemblies, Dan Sheibley, Renee Szymanik, Michael C. Leopold Oct 2004

Ultra-Fast Formation Of Stable Nanoparticle Film Assemblies, Dan Sheibley, Renee Szymanik, Michael C. Leopold

Chemistry Faculty Publications

Novel assembled films of monolayer-protected clusters (MPCs) can be grown on gold and glass substrates with a 20-fold higher efficiency than established procedures. Thick MPC films grown using this new method, which can easily be scaled up or automated, are extremely stable and have properties identical to traditionally formed nanoparticle films, including unique quantized double layer charging effects. This new procedure for growing nanoparticle films shares the versatility of the traditional method but exhibits accelerated growth attributed to highly efficient sorption and mobility of metal ion linkers within swelled films and improved mass transfer of nanoparticles to assembly sites. Concentration …

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Teaching Statistics With Sports Examples, Paul Kvam, Joel Sokol Sep 2004

Teaching Statistics With Sports Examples, Paul Kvam, Joel Sokol

Department of Math & Statistics Faculty Publications

Class material for introductory and advanced statistics can be colorfully illustrated by using appropriate data and examples from sports. Specific methods, including statistical graphics (e.g., boxplots), ball-and-urn probabilities, and statistical regression are demonstrated. Examples are drawn from popular American sports such as baseball, basketball, soccer and American football. Classroom feedback indicates that most students enjoy sports examples as a way to learn abstract concepts using familiar, recreational settings.

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Tree-Like Continua And 2-To-1 Maps, Jo Heath, Van C. Nall Jan 2004

Tree-Like Continua And 2-To-1 Maps, Jo Heath, Van C. Nall

Department of Math & Statistics Faculty Publications

It is not known if there is a 2-to-1 map from a continuum onto a tree-like continuum. In fact, it is not known if there is a 2-to-1 map onto a hereditarily decomposable tree-like continuum. We show that the domain of such a map would have to contain an indecomposable continuum.

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Prolongations And Cyclic Vectors, William T. Ross, Harold S. Shapiro Jan 2004

Prolongations And Cyclic Vectors, William T. Ross, Harold S. Shapiro

Department of Math & Statistics Faculty Publications

For functions belonging to invariant subspaces of the backward shift operator Bf = (f − f(0))/z on spaces of analytic functions on the unit disk D, we explore, in a systematic way, the continuation properties of these functions.

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Zeros Of Functions With Finite Dirichlet Integral, William T. Ross, Stefan Richter, Carl Sundberg Jan 2004

Zeros Of Functions With Finite Dirichlet Integral, William T. Ross, Stefan Richter, Carl Sundberg

Department of Math & Statistics Faculty Publications

In this paper, we refine a result of Nagel, Rudin, and Shapiro (1982) concerning the zeros of holomorphic functions on the unit disk with finite Dirichlet integral.

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Common Cyclic Vectors For Normal Operators, William T. Ross, Warren R. Wogen Jan 2004

Common Cyclic Vectors For Normal Operators, William T. Ross, Warren R. Wogen

Department of Math & Statistics Faculty Publications

If μis a finite compactly supported measure on C, then the set Sμ of multiplication operators Mᵩ : L2 (μ) --> L2 (μ), Mᵩ f = ᵩ f, where ᵩ ϵ L ∞ (μ) is injective on a set of full μ measure, is the complete set of cyclic multiplication operators on L2 (μ) In this paper, we explore the question as to whether or not Sμ has a common cyclic vector

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The Backward Shift On The Space Of Chauchy Transforms, William T. Ross, Joseph A. Cima, Alec L. Matheson Jan 2004

The Backward Shift On The Space Of Chauchy Transforms, William T. Ross, Joseph A. Cima, Alec L. Matheson

Department of Math & Statistics Faculty Publications

This note examines the subspaces of the space of Cauchy transforms of measures on the unit circle that are invariant under the backward shift operator f --> z-1 (f—f (0)). We examine this question when the space of Cauchy transforms is endowed with both the norm and weak* topologies.

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Reliability Estimation Based On System Data With An Unknown Load Share Rule, Hyoungtae Kim, Paul H. Kvam Jan 2004

Reliability Estimation Based On System Data With An Unknown Load Share Rule, Hyoungtae Kim, Paul H. Kvam

Department of Math & Statistics Faculty Publications

We consider a multicomponent load-sharing system in which the failure rate of a given component depends on the set of working components at any given time. Such systems can arise in software reliability models and in multivariate failure-time models in biostatistics, for example. A load-share rule dictates how stress or load is redistributed to the surviving components after a component fails within the system. In this paper, we assume the load share rule is unknown and derive methods for statistical inference on load-share parameters based on maximum likelihood. Components with (individual) constant failure rates are observed in two environments: (1) …

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A Nonlinear Random Coefficients Model For Degradation Testing, Suk Joo Bae, Paul H. Kvam Jan 2004

A Nonlinear Random Coefficients Model For Degradation Testing, Suk Joo Bae, Paul H. Kvam

Department of Math & Statistics Faculty Publications

As an alternative to traditional life testing, degradation tests can be effective in assessing product reliability when measurements of degradation leading to failure can be observed. This article presents a degradation model for highly reliable light displays, such as plasma display panels and vacuum fluorescent displays (VFDs). Standard degradation models fail to capture the burn-in characteristics of VFDs, when emitted light actually increases up to a certain point in time before it decreases (or degrades) continuously. Random coefficients are used to model this phenomenon in a nonlinear way, which allows for a nonmonotonic degradation path. In many situations, the relative …

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Lipid-Lowering Effects Of Ethyl 2-Phenacyl-3-Aryl-1h-Pyrrole- 4-Carboxylates In Rodents, Justin M. Holub, Kathy O'Toole-Colin, Adam Getzel, Anthony Argenti, Michael A. Evans, Daniel C. Smith, Gerard A. Dalglish, Shahzad Rifat, Donna L. Wilson, Brett M, Taylor, Ulander Miott, Josephine Glersaye, Kam Suet Lam, Bryan J. Mccranor, Joshua D. Berkowitz, Robert B. Miller, John R. Lukens, Keith Krumpe, John T. Gupton, Bruce S. Burnham Jan 2004

Lipid-Lowering Effects Of Ethyl 2-Phenacyl-3-Aryl-1h-Pyrrole- 4-Carboxylates In Rodents, Justin M. Holub, Kathy O'Toole-Colin, Adam Getzel, Anthony Argenti, Michael A. Evans, Daniel C. Smith, Gerard A. Dalglish, Shahzad Rifat, Donna L. Wilson, Brett M, Taylor, Ulander Miott, Josephine Glersaye, Kam Suet Lam, Bryan J. Mccranor, Joshua D. Berkowitz, Robert B. Miller, John R. Lukens, Keith Krumpe, John T. Gupton, Bruce S. Burnham

Chemistry Faculty Publications

A series of substituted 2-phenacyl-3-phenyl-1H-pyrrole-4-carboxylates were prepared from substituted acetophenones in 6 steps. The final condensations between a chloroenal and an aminoketone were carried out under neutral conditions in parallel to yield the series listed below. Selected pyrrole derivatives proved to be potent hypolipidemic agents lowering serum triglyceride concentrations in CF-1 male mice after 14 days of I.P. administration. One agent orally lowered serum cholesterol in Sprague-Dawley male rats at 2mg/kg/day after 14 days. The agents demonstrated a lowering of mouse serum LDL- cholesterol levels and selected compounds showed an elevation of serum HDL-cholesterol levels. The cholesterol concentrations in the …

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