Digital Commons Network^™

Determination Of Best Practice Guidelines For Performing Large Eddy Simulation Of Flows In Configurations Of Engineering Interest, Adetokunbo Adelana Adedoyin

Theses and Dissertations

Large eddy simulation (LES) suffers from two primary sources of error: the numerical discretization scheme and the subgrid stress model (SGS). An attempt has been made to determine optimum combinations of SGS models and numerical schemes for use in performing practical LES for engineering-relevant problems. A formal quantification of numerical error present in finite-volume/finite-difference simulations was conducted. The effect of this error was explicitly added to a pseudospectral LES solver, and the modified pseudospectral solver was used to compute LES of decaying turbulence. In this way SGS modeling error and numerical error could be separately assessed. Verification of results was …

An Investigation Of Communication Technology Usage, Professional Development Experience, And Anxiety Among Faculty In A Community College Setting, Linda Barnes Pates

Theses and Dissertations

The purpose of the study was to determine if the use of communication technologies account for reported computer anxiety in a community college setting. Specifically, this study was designed to determine whether there was a difference in usage of communication technologies and levels of computer anxiety of faculty in relationship to their job responsibilities, gender, age, computer experience, and number of professional development activities. A descriptive research design was used in this study. Data analysis included the frequencies, means, standard deviations, t-test, crosstabs, chi-square, ANOVA, and ANCOVA. The results indicated that there was not a significant difference among faculty in …

The Relationship Between Nclb Variables And Selected Variables With High School Subject Area Test Scores, Kenyon M. Barron

Theses and Dissertations

No Child Left Behind (NCLB; 2002) requires student assessment to be reported by school districts based on certain demographic variables. Research indicated that other variables may relate to student achievement. This study calculated the relationship between average school district scores and the demographic variables required by NCLB (ethnicity, gender, socio-economic status, special needs, migrant status and English language learners) as well as literature identified variables (source of district funding, pupil-to-teacher ratio, average teacher salary, per-pupil-expenditure, school district population size.) The subject area tests used for this study were Algebra I, Biology I, English II and United States History tests for …

Optimal Hedging Strategies For Early-Planted Soybeans In The South, James Hughes Sayle

Theses and Dissertations

Agricultural producers are exposed to various types of risk in production agriculture. Price risk is one type of risk that producers need to manage. A well established method for managing price risk is the use of futures contracts. Soybean production in the south has evolved over recent years due to changes in technology. The change in production practices due to technology has created agronomic benefits as well as new possible marketing strategies. The agronomic benefits are reflected in both higher and less variable yields. This reduction in production risk may contribute to changes in optimal marketing strategies compared to traditional …

Oases In The Dark: Galaxies As Probes Of The Cosmos, Shane L. Larson

Public Talks

No abstract provided.

University Of Nebraska At Omaha, August Commencement 2007, University Of Nebraska At Omaha

Commencement Programs

No abstract provided.

Interview With Anthony Boutard, Ayers Creek Farm, 2007 (Audio), Anthony Boutard

All Sustainability History Project Oral Histories

Interview of Anthony Boutard by Magda Gaytan at Ayers Creek Farm on August 10th, 2007.

The interview index is available for download.

Persistence And Memory In Patchwork Dynamics For Glassy Models, Alan Middleton, Creighton K. Thomas, Olivia L. White

Physics - All Scholarship

Slow dynamics in disordered materials prohibits direct simulation of their rich nonequilibrium behavior at large scales. "Patchwork dynamics" is introduced to mimic relaxation over a very broad range of time scales by equilibrating or optimizing directly on successive length scales. This dynamics is used to study coarsening and to replicate memory effects for spin glasses and random ferromagnets. It is also used to find, with high confidence, exact ground states in large or toroidal samples.

Everything Stems From Nothing, Daniel Theis

All Theses

In sixteenth century Europe, mathematics was undergoing a transformation. Prominently among these changes were the switch from roman numerals to arabic numerals and the implementation of the number zero. The number zero has two main functions: to stand on its own as a symbol of nothing and to function as a placeholder. Thus, zero can be a symbol of nothing as well as a number that dramatically increases the value of the others. The dual roles of zero led to much confusion in early modern people. Shakespeare uses the different roles of zero in his plays Richard III, Hamlet, and …

Mixing And Homogenization In The Early Solar System: Clues From Sr, Ba, Nd, And Sm Isotopes In Meteorites, Rasmus Andreasen, Mukul Sharma

Dartmouth Scholarship

High-precision barium isotopic compositions of large samples of an ordinary chondrite and a eucrite are identical to the terrestrial values. In contrast, the carbonaceous chondrites reveal excesses in ¹³⁵Ba and ¹³⁷Ba of around +39 and +22 parts per million (ppm), respectively; no anomalies are resolvable in ^130,132,138Ba. High-precision Sr isotopic compositions of all meteorites are identical within error. The data are consistent with the carbonaceous chondrites having an excess in the r-process ^135,137Ba with respect to Earth, eucrite parent bodies, and ordinary chondrites. The carbonaceous chondrites, however, display no variation in the r- and …

Summer Commencement Ceremonies, University Of North Florida

Commencement Printed Materials

Program for the Summer Commencement ceremonies.

Interview With Dan J. Wilson, Sudan Farms, 2007 (Audio), Dan J. Wilson

All Sustainability History Project Oral Histories

Interview of Dan J. Wilson by Jason Keaton at Canby, Oregon on August 10th, 2007.

The interview index is available for download.

Helping Schools: Youth Development As A Form Of Supplemental Education, Jan Carroll, Jeff Goodwin, Melissa Oliver

Journal of Youth Development

This study measured the impact of 4-H Youth Development on Colorado’s youth. Active youth were compared to those who did not participate in out-of-school activities. Data were collected from 5th, 7th, and 9th grade students. Results of the study confirm active students, including 4-H Youth Development members, were less likely to engage in at-risk behaviors. 4-H Youth Development can function as a form of supplemental education, contributing to academic, civic, and social success of young people.

Search For Third-Generation Scalar Leptoquarks In Pp̅ Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Kenneth Bloom Publications

We report on a search for charge-1/3 third-generation leptoquarks (LQ) produced in pp̅ collisions at √s = 1.96 TeV using the D0 detector at Fermilab. Third-generation leptoquarks are assumed to be produced in pairs and to decay to a tau neutrino and a b quark with branching fraction B. We place upper limits on (pp̅→ LQ L̅Q̅) B² as a function of the leptoquark mass M_LQ. Assuming B^-1, we exclude at the 95% confidence level third-generation scalar leptoquarks with M_LQ < 229 GeV.

Dynamics Of Tapping Mode Atomic Force Microscopy In Liquids: Theory And Experiments, Sudipta Basak, Arvind Raman

Birck and NCN Publications

A mathematical model is presented to predict the oscillating dynamics of atomic force microscope cantilevers with nanoscale tips tapping on elastic samples in liquid environments. Theoretical simulations and experiments performed in liquids using low stiffness probes on hard and soft samples reveal that, unlike in air, the second flexural mode of the probe is momentarily excited near times of tip-sample contact. The model also predicts closely the tip amplitude and phase of the tip at different set points.

Hard/Soft-Acid/Base Principle And The Reaction Ahbs+Asbh → Ahbh+Asbs, Jerry Goodisman

Chemistry - All Scholarship

A demonstration of the hard/soft-acid/base principle involves showing that the energy change for Ah Bs + As Bh → Ah Bh + As Bs is always negative. We point out problems with assumptions made about hardness and strength of the components, but emphasize that problems with the way in which energies are calculated are even more important.

Carbon Nanomaterials In Biological Systems, Sijie Lin

All Theses

ABSTRACT


This thesis intends to present, from the biophysical viewpoint, my study on understanding carbon nanomaterials in biological and environmental systems. Carbon nanotubes and fullerenes represent a major family of carbon nanoparticles which possess distinct electrical, optical and mechanical properties. However, the major hurdle for making carbon nanomaterials bioavailable lies in their tendency toward bundling, driven by hydrophobic interaction, van der Waals force, and pi-stacking. To overcome this problem, we used non-covalent binding of zwitterionic lysophopholipids (LPL) onto the external surfaces of single-walled carbon nanotubes (SWNTs). This method affords superior SWNT solubility in aqueous solution. The stability of SWNT-LPL complex …

A Proposed Character Animation Workflow For Digital Production Arts With Preparation For Cloth Dynamics, Kent Chan

All Theses

In a fast-paced production studio, procedures and standard operating practices have been created to ensure maximum use of resources, while being flexible enough to account for problems that might arise. For the animation section of the pipeline, it is imperative to produce animation in a timely manner so that the other sections of the pipeline that are dependent on animation can begin at an appropriate time. Using 'Mileena Malign' and 'SpaceCat' as case studies, a possible workflow for computer animation--specifically as it pertains to preparation for cloth dynamics--is developed, with highlights on the advantages and challenges encountered. This thesis presents …

Nonlinear Modeling Of The Adsorption-Induced Surface Stress In Piezoelectrically-Driven Microcantilever Biosensors, Mana Afshari

All Theses

Microcantilever-based biosensors are rapidly becoming an enabling sensing technology for a variety of label-free biological applications due to their extreme applicability, versatility and low cost. These sensors operate through the adsorption of species on the functionalized surface of microcantilevers. The adsorption of biological species induces surface stress which originates from the molecular interactions such as adhesion forces of attraction/repulsion, electrostatic forces or the surface charge redistribution of the underlying substrate. This surface stress, consequently, alters the resonance frequency of the microcantilever beam.
This study presents a general framework towards modeling resonance frequency changes induced due to the surface stress arising …

Bioanalyze: A Tool For The Simulation And Analysis Of Biological Systems, James Norman

All Theses

Scientists have turned to a more systemic approach to biology in order to fully understand the complex functionality of living organisms. Biologist and Geneticist have compiled an impressive amount of experimental data for a multitude of biological systems. Modeling and simulation of these systems has become a prominent tool in the field of Systems Biology. In this paper we present a review of General Systems Theory, Systems Biology, and introduce BioAnalyze. BioAnalyze is a web application designed to simulate, and analyze, the functional dynamics of biological systems.

A Study Of Estimation Techniques And Of Mechatronic System Design And Testing, Brett Castelloe

All Theses

This thesis is a collection of two projects that the author worked on during his master's studies at Clemson University. The first project--adaptive camera calibration--involves the design and simulation of an estimator for the calibration parameters of a camera. The second project--basket drive wear testing--includes the design of a test plan for measuring wear on a mechatronic system.

A Comparison Of Class Diagram Construction At Three Different Phases Of Compilation, Robert Bailey Iii

All Theses

In maintaining, designing, and testing of OO systems, understanding the relationships between the classes and corresponding objects is imperative. Class diagrams provide program visualization that promotes easier understanding of large systems. Class diagrams are especially helpful when systems become too large to conceptualize without automated graphical illustration. There are many tools available to software developers that permit generation of class diagrams for large scale computing applications, many of which use various parsing approaches to extract information for a class diagram. In this paper, we compare and evaluate three tools that extract information for class diagrams from different phases of the …

Transmission Gate Based Dual Rail Logic For Differential Power Analysis Resistant Circuits, Srinidhi Narasimha Char

All Theses

Cryptographic devices with hardware implementation of the algorithms are increasingly being used in various applications. As a consequence, there is an increased need for security against the attacks on the cryptographic system. Among various attack techniques, side channel attacks pose a significant threat to the hardware implementation. Power analysis attacks are a type of side channel attack where the power leakage from the underlying hardware is used to eavesdrop on the hardware operation. Wave pipelined differential and dynamic logic (WDDL) has been found to be an effective countermeasure to power analysis. This thesis studies the use of transmission gate based …

Almond Skins As A Natural Antioxidant, Heather Johnson

All Theses

In this thesis, the potential for almond skins in their native state as a natural antioxidant in foods was explored. A literature review of general information on almonds, research done on almond skins, and general information on antioxidants is presented. The almond skins used in this study required an additional heat treatment step to improve their microbiological quality before further treatments and analysis could be performed. A descriptive analysis sensory panel was utilized to identify potential flavor and aroma descriptors and their intensities. The aroma descriptors identified were toasted, bran, and toasted; nutty. The flavor descriptors identified were toasted, bran, …

Pursuit-Evasion With Acceleration, Sensing Limitation, And Electronic Counter Measures, Jing-En Pang

All Theses

Abstract: The use of game theory to analyze the optimal behaviors of both pursuers and evaders originated with Isaac's work at the Rand Corporation in the 1950's. Although many variations of this problem have been considered, published work to date is limited to the case where both players have constant velocities. In this thesis, we extend previous work by allowing players to accelerate. Analysis of this new problem using Newton's laws imposes an additional constraint to the system, which is the relationship between players' velocities and allowed turning radius. We find that analysis of this relationship provides new insight into …

Standardized Power: A Rhetoric Of Performance Evaluation In Education, Michael Hedges

All Theses

South Carolina's public education system administrators and teachers need to know more about how the language used in written performance evaluations impacts the effectiveness of evaluation feedback in order to help improve the state's system for Assisting, Developing, and Evaluating Professional Teaching (ADEPT). One key to understanding this knowledge is identifying the characteristics of the language used in evaluation feedback. This study examines the rhetorical situation of written performance evaluations from a theoretical standpoint and used a survey to assess several characteristics of the language used in evaluation feedback (word usage, content inclusion, and the structural order of sentences). Results, …

Analyzing Relationships Between Lightning And Rain In Order To Improve Estimation Accuracy Of Rain , Justin Lapp

All Theses

The remote estimation of rainfall rate R is essential for the aviation industry, agriculture, and food warning. Radar, the current means of R estimation, is not available in much of the world. In addition, this measurement involves a level of inaccuracy. Using lightning to detect rain is a relatively inexpensive alternative to radar systems and can be done from existing satellites. Previous research has revealed correlations between lightning and rain, suggesting either that it is possible to estimate R using lightning, or that it is possible to use it to correct for a portion of the radar inaccuracies. These correlations …

An Efficient Asynchronous Peer To Peer Auction Using Yao Oblivious Transfer, Charles Lobo

All Theses

Distributed electronic auctions are increasingly preferred over centralized electronic auctions today. The success of peer-to-peer file sharing networks has made distributed electronic auctions a possibility. Due to trust and conflict of interest issues with centralized auctioneer systems, multiple auctioneers in distributed roles are preferred. However, there is a possibility of auctioneer node collusion [16] and auctioneer-bidder collusion and auctioneer-seller collusion in such mechanisms.
To overcome these problems, a new peer-to-peer auction protocol [17] with auctioneers forming auctioneer groups has been proposed. This protocol keeps the auctioneers honest by ensuring that no single auctioneer in the group has absolute control over …

Feeding Performance In Hawaiian Stream Goby Fishes: Morphological And Functional Analysis, Takashi Maie

All Theses

Distributions of Hawaiian stream fishes are typically interrupted by waterfalls that divide streams into lower and upper segments. Larvae hatched upstream are flushed into the ocean, and must climb these waterfalls to reach adult habitats when returning back to freshwater as part of an amphidromous life cycle. Stream surveys and studies of climbing performance show that Lentipes concolor can reach fast-flowing upper stream segments, but that Awaous guamensis reaches only slower, lower stream segments. Gut content analyses for these two species indicate that diet differs between them only by 10% or less dry weight for most major components (mostly green …

Topology-Aware Transmission Scheduling For Distributed Highway Traffic Monitoring Wireless Sensor Networks, Devang Bagaria

All Theses

Wireless sensor networks have been deployed along highways for traffic monitoring. The thesis studies a set of transmission scheduling methods for optimizing network throughput, message transfer delay, and energy efficiency. Today's traffic monitoring systems are centrally managed. Several studies have envisioned the advantages of distributed traffic management techniques. The thesis is based on previously proposed hierarchical sensor network architecture, for which the routing and transmission scheduling methods are derived.
Wireless sensor networks have a lifetime limited by battery energy of the sensors. The thesis proposes to assign schedules for nodes to transmit and receive packets and turning off their radios …