Digital Commons Network^™

On Mesh Quality Considerations For The Discontinuous Galerkin Method, Eric M. Collins

Theses and Dissertations

It is widely accepted that the accuracy and efficiency of computational fluid dynamics (CFD) simulations is heavily influenced by the quality of the mesh upon which the solution is computed. Unfortunately, the computational tools available for assessing mesh quality remain rather limited. This report describes a methodology for rigorously investigating the interaction between a flow solver and a variety of mesh configurations for the purposes of deducing which mesh properties produce the best results from the solver. The techniques described herein permit a more detailed exploration of what constitutes a quality mesh in the context of a given solver and …

On The Erdos-Sos Conjecture And The Cayley Isomorphism Problem, Suman Balasubramanian

Theses and Dissertations

We study the Erdős- Sòs conjecture that states that ever graph of average degree greater than k-1 contains every tree of order k+1. While the conjecture was studied for some graphs, it still remains open and of interest after more than 40 years. We study the conjecture for graphs with no K2,s where, s ≥ 2 and k > 12(s-1). We use the fact that as G contains no K2,s, any two distinct vertices in G have at most s-1 neighbors in common in proving the results. We have answered in the affirmative that the Erdős- Sòs conjecture is true for …

Factors Of Teacher Induction Which Impact Job Satisfaction And Attrition In Teachers, Michelle Ann Larabee

Theses and Dissertations

High quality induction for novice teachers has reduced the attrition rates for many states. The methods of implementation, components of the induction, and quality of the induction vary from district to district. The purpose of this research was to examine the components of novice teacher induction which may have a positive impact on novice teachers’ intentions to stay in that teaching position and to determine which aspects of induction will increase teacher job satisfaction by examining the commonalities among their perceptions of their induction. There is current and past research concerning the effectiveness of new teacher induction and the link …

Fracture Properties Of Concrete Containing Expanded Polystyrene Aggregate Replacement, Matthew Trussoni

Open Access Dissertations

Fracture mechanics is applied to study the behavior of concrete containing expanded polystyrene (EPS) aggregate replacement. The EPS replaces a portion of the normal weight fine aggregate. Previous research has shown EPS aggregate replacement changes the failure mode in compression from a typical instantaneous failure, as in normal weight concrete (NWC), to a more gradual dissipation of load carrying capacity. This behavior is investigated through the use of fracture mechanics. The fracture energy, critical stress intensity factor and characteristic length of EPS concrete, NWC and fiber reinforced concrete (FRC) are experimentally determined. The two types of tests used to study …

On The Green Vol. 38 No. 12 August 7, 2009, Gallaudet University

2001-2010

On the Green is an internal publication of Gallaudet College, which later became Gallaudet University. It notified employees of updates around the campus and in the broader community, including new construction and the establishment of new academic programs. Running until 2010, it was supplanted by various forms of online mass communications across multiple audiences.

Tracing The Inner Edge Of The Disk Around Hd 100546 With Rovibrational Co Emission Lines, Sean D. Brittain, Joan R. Najita, John S. Carr

Publications

In this paper we present high-resolution 4.7 μm spectra of the isolated Herbig Be star HD 100546. HD 100546 has been the subject of intense scrutiny because it is a young nearby star with a transitional disk. We observe the Δv = 1 rovibrational CO transitions in order to clarify the distribution of warm gas in the inner disk. Modeling of the CO spectrum indicates that the gas is vibrationally excited by collisions and UV fluorescence. The observed emission extends from 13 to 100 AU. The inner edge of the molecular gas emission is consistent with the inner edge of …

Interview With Rabbi Arthur Zuckerman, Shaarie Torah, 2009 (Audio), Arthur Zuckerman

All Sustainability History Project Oral Histories

Interview of Rabbi Arthur Zuckerman by Austin Rosenfeld in NW Portland, Oregon on August 7th, 2009.

The interview index is available for download.

Summer Commencement: August 7, 2009, University Of North Dakota

UND Commencement Programs

UND Summer Commencement program from August 7, 2009.

Time-Delay And Doppler Tests Of The Lorentz Symmetry Of Gravity, Quentin G. Bailey

Physics & Astronomy - Prescott

Modifications to the classic time-delay effect and Doppler shift in general relativity (GR) are studied in the context of the Lorentz-violating standard-model extension (SME). We derive the leading Lorentz- violating corrections to the time-delay and Doppler shift signals, for a light ray passing near a massive body. It is demonstrated that anisotropic coefficients for Lorentz violation control a time-dependent behavior of these signals that is qualitatively different from the conventional case in GR. Estimates of sensitivities to gravity-sector coefficients in the SME are given for current and future experiments, including the recent Cassini solar conjunction experiment.

Exploiting Bilingual Information To Improve Web Search, Wei Gao, John Bitzer, Ming Zhou, Kam-Fai Wong

Research Collection School Of Computing and Information Systems

Web search quality can vary widely across languages, even for the same information need. We propose to exploit this variation in quality by learning a ranking function on bilingual queries: queries that appear in query logs for two languages but represent equivalent search interests. For a given bilingual query, along with corresponding monolingual query log and monolingual ranking, we generate a ranking on pairs of documents, one from each language. Then we learn a linear ranking function which exploits bilingual features on pairs of documents, as well as standard monolingual features. Finally, we show how to reconstruct monolingual ranking from …

Efficient Simulation Of Fluid Flow, David Hannasch, Monika Neda

Undergraduate Research Opportunities Program (UROP)

We are computationally investigating fluid flow models for physically correct predictions of flow structures. Models based on the idea of filtering the small scales/structures and also the Navier-Stokes equations which are the fundamental equations of fluid flow, are numerically solved via the continuous finite element method. Crank-Nicolson and fractional-step theta scheme are used for the discretization of the time derivative, while the Taylor-Hood and Mini elements are used for the discretization is space. The effectiveness of these numerical discretizations in time and space are examined by studying the accuracy of fluid characteristics, such as drag, lift and pressure drop.

Baseline Microbial Characterizations Of An Imperiled Aquatic Diversity Hotspot: Ash Meadows National Wildlife Refuge, Jessica Newburn, Jim Bruckner, Jenny C. Fisher, Duane P. Moser

Undergraduate Research Opportunities Program (UROP)

Located in the discharge zone of the Death Valley Flow System, Ash Meadows National Wildlife Refuge is a spring-fed desert oasis and biodiversity hotspot about 90 miles northwest of Las Vegas. These critical wetlands are potentially threatened by groundwater pumping, exotic species invasions, and climate change. Although a major component of the lower food web, very little is known about the microbial makeup of this ecosystem. As a first step towards understanding the microbial and biogeochemical aspects of this system, a detailed molecular-based characterization of microbial communities, baseline chemistry, and physical characteristics of various springs of Ash Meadows will be …

Researching Nitrite Oxidation At High Temperatures, Dolores A. Huang, Jeremy A. Dodsworth, Brian P. Hedlund

Undergraduate Research Opportunities Program (UROP)

15N-nitrate (NO3 -) pool dilution experiments show that ammonia (NH3) is oxidized to nitrate in geothermal springs up to at least 85C; however, nitrite (NO2 -)- oxidizing microorganisms are only known to grow up to 66°C. We hypothesize that thermophilic microorganisms oxidize nitrite to nitrate at high temperatures. Alternatively, it is possible that nitrite is oxidized abiotically. We propose to test these hypotheses by setting up microbial enrichments designed to grow thermophilic nitrite oxidizing bacteria by varying incubation temperature (50, 65, 80°C), oxygen concentration (20% and 5%), and cultivation media. A negative control consisting of filtered spring water (0.1 μm) …

Martian Life Detection With Xylose Enantiomers, Arturo White, Gaosun Zhang, Henry J. Sun

Undergraduate Research Opportunities Program (UROP)

Ability of Martian soil to degrade carbohydrates, shown by the Viking mission, has two interpretations. One possibility is that the soil harbors living microorganisms. Alternatively, the soil is sterile but chemically oxidizing, i.e. it is laden with photochemical oxidants. It was shown by REU research last summer that these two possibilities can be distinguished by the use of glucose enantiomers. Life is selective: Earth organisms use D-glucose, but ignore Lglucose. This stereo selectivity is absent in chemical reactions. The goal of this project is to test if xylose, a five carbon sugar, is also suitable for chiral life detection. Mixed …

Martian Life Detection With Amino Acid Enantiomers, Ali Jamil, Gaosen Zhang, Henry J. Sun

Undergraduate Research Opportunities Program (UROP)

The Viking mission showed that Martian soil can degrade a heterotrophic medium to carbon dioxide as if live microorganisms were present. The result is considered inconclusive, however, because abiotic oxidants, such as superoxides, may also exist on Mars and would explain the Viking result. One way to resolve this ambiguity is to repeat the Viking experiment with a isomerically pure medium. The consumption of one isomer, either D or L, would indicate biological activity. Indiscriminate destruction of both isomers would indicate abiotic redox processes. This idea was validated for glucose by REU research last summer (Sun et al. 2009). The …

The Effects Of Pressure On Wide Bandgap Gan Semiconductors, William Kang, Linda Tran, Eunja Kim

Undergraduate Research Opportunities Program (UROP)

Gallium nitride (GaN) is a group-III nitride semiconductor; which may prove useful in developing optical instruments that operate under high ambient pressures. The purpose of this project is to examine the properties of GaN under varying conditions. The methods used in this experiment consist of modeling free energy as a function of lattice constants; calculating bond lengths, bond strengths, and bulk moduli; and comparing the resultant data with values in published literature. We will also compare these results with experimental data drawn from x-ray diffraction scans. By doing so, we hope to determine whether gallium nitride is suitable for use …

Temperature Links To Compositional Variations At Mutnovsky Volcano, Kamchatka, Russia, Lindsey Clark, Adam Simon, Kelly L. Robertson, Sean Mulcahy

Undergraduate Research Opportunities Program (UROP)

Full petrographic descriptions of fifty two rock samples collected from one hundred thousand year old Mutnovsky Volcano, Kamchatka, Russia are being studied to determine the magma compositions of the volcano through time. I expect that the composition will change with time owing to variation in input at the base of the volcano pluming system, above the subducting Pacific Ocean crust. This variation in composition, including the abundance of important atmospheric gases, water, and carbon dioxide, may play a key role in the abundance and type of greenhouse gases being emitted. The samples will also be analyzed by using electron probe …

Long Distance Microbial Transport In Air: Global Change Implications, Bradley J. Davey, J. C. Bruckner, Jenny C. Fisher, Duane P. Moser

Undergraduate Research Opportunities Program (UROP)

The first manifestations of global change will most likelv be observed in the Earth's atmosphere. Changing wind patterns, for example, may effect the long distance dispersal of microor-g anisms. The overall objective of this research is to correlate molecular assessments of microbial community structure from cloud water and snow samples, obtained from DRI's Storm Peak Laboratory atop Mt. Werner in Colorado, with atmospheric data and calculated air mass back trajectories. Our activities for summer of 2009 will be a focused proof-of-concept exercise to determine if intact microbial DNA and viable cells can be recovered from cloud water and alpine snow …

Point And Nonpoint Source Analysis Of Nutrients, Metals, And Pathogens In The Sediment And Water Column In Las Vegas Wash, Christine Simmons, Kumud Acharya

Undergraduate Research Opportunities Program (UROP)

Formerly an ephemeral watercourse, Las Vegas Wash is now a perennial system due to urban runoff and wastewater treatment plant (WWP) effluent. Las Vegas Wash flows into Lake Mead, where the discharge point is only a few miles upstream of Las Vegas’ main water intake. This small water cycle establishes the necessity to evaluate water quality especially due to non point sources pollution, wherein my research lies. Several points along Las Vegas Wash upstream and downstream of WWP have been chosen to represent different landuse types such as commercial, residential, wastewater treatment plants, etc. At each location, parameters including arsenic, …

Undergraduate Research Opportunities Program, University Of Nevada Las Vegas, College Of Sciences

Undergraduate Research Opportunities Program (UROP)

No abstract provided.

Mineral Content Analysis Of Atmospheric Dust Using Hyperspectralinformation From Space, A. Chudnovsky, E. Ben-Dor, A. B. Kostinski, I. Koren

Department of Physics Publications

The Bodélé depression of northern Chad is considered one of the world's largest sources of atmospheric mineral dust. Mineral composition of such transported dust is essential to our understanding of climate forcing, mineralogy of dust sources, aerosol optical properties, and mineral deposition to Amazon forests. In this study we examine hyperspectral information acquired over the Bodélé by EO‐1 Hyperion satellite during a dust storm event and during a calm clean day. We show that, for the suspended dust, the absorption signature can be decoupled from scattering, allowing detection of key minerals. Our results, based on the visible and shortwave infrared …

Copper Toxicity And Accumulation: Physiology, Chemistry, And Molecular Biology, Jonathan Blanchard

Open Access Dissertations

Our knowledge of aquatic Cu toxicity has increased greatly over the past several years culminating with the incorporation of a model (the Biotic Ligand Model (BLM)) into the regulatory framework which allows for the site specific adjustment of water quality criteria based on water chemistry. However, our understanding of Cu toxicity in the aquatic environment is limited mostly to freshwater (FW). Because of this limited knowledge, this dissertation set out to examine the affect of salinity on Cu toxicity and accumulation across salinities from FW to sea water (SW). First, this work examined tissue specific Cu accumulation in five salinities …

Algorithm To Diagnose Leaks Or Blockages Downstream Of The Secondary Air Injection Reaction (Sair) Pressure Sensor, Ian J. Mac Ewen, Martin L. Hall, Lawrence O. Murray, Julia C. Grow, Richard Van Camp, David Edward Prout, Igor Anilovich

Physics Patents

A control module and method for an exhaust system of an engine can include a secondary air intake (SAI) pressure module that monitors SAI pressure. An accumulation module can accumulate an SAI string length based on the monitored SAI pressure. A calculation module can determine an average SAI string length based on the accumulated SAI string length. A determination module can determine an operating characteristic of the vehicle exhaust based on the average SAI string length.

Obtaining Parsimonious Hydraulic Conductivity Fields Using Head And Transport Observations: A Bayesian Geostatistical Parameter Estimation Approach, Michael Fienen, R. Hunt, D. Krabbenhoft, Tom Clemo

CGISS Publications and Presentations

Flow path delineation is a valuable tool for interpreting the subsurface hydrogeochemical environment. Different types of data, such as groundwater flow and transport, inform different aspects of hydrogeologic parameter values (hydraulic conductivity in this case) which, in turn, determine flow paths. This work combines flow and transport information to estimate a unified set of hydrogeologic parameters using the Bayesian geostatistical inverse approach. Parameter flexibility is allowed by using a highly parameterized approach with the level of complexity informed by the data. Despite the effort to adhere to the ideal of minimal a priori structure imposed on the problem, extreme contrasts …

Fabrication Of Anisotropic Nanostructures On Solid Substrates For Applications As Optically Active Surfaces, Mohan Krishna Vattipalli

Dissertations and Theses

Analysis of the vibrational energy levels in molecules using Raman Spectroscopy is a popular analytical method amongst today's optical technologies. Unlike fluorescence microscopy, the Raman emission doesn't undergo the process of photobleaching, which leads to short lived signal collection. The only downside with this approach is the small absorption cross-section resulting in a low intensity of the emission signal. One of the approaches used to boost this weak signal is Surface Enhanced Raman Spectroscopy (SERS). My research efforts have been focused on how to create a novel SERS substrate with aligned patterns of Au/Ag nanoparticle deposited metals of a particular …

The Daily Egyptian, August 06, 2009, Daily Egyptian Staff

August 2009

No abstract provided.

Privacy And Geospatial Technologies, Lynn F. Brien

LSU New Orleans Theses and Dissertations

This research examines the role of geospatial and ancillary technologies in the erosion of privacy in contemporary society. The development of Remote Sensing, GIS, and GPS technologies are explored as a means of understanding both their current and predicted uses and capabilities. Examination is also made of the legal basis and current status of privacy rights in the United States. Finally, current and predicted uses and capabilities of geospatial and ancillary technologies are critically examined in light of existing privacy protections as a means of determining the ways in which these technologies are impacting privacy currently and what their effects …

A Numerical Study Of Unsteady Natural Convection In A Rectangular Enclosure -- The Effect Of Variable Thermodynamic And Transport Properties, Manohar Chidurala

LSU New Orleans Theses and Dissertations

A two-dimensional mathematical model is adopted to investigate the development of buoyancy driven circulation patterns and temperature contours inside a rectangular enclosure filled with a compressible fluid where one of the vertical walls of the enclosure is kept at a higher temperature than the opposite one. Fluid thermodynamic and transport properties are assumed to be functions of temperature. The governing equations are discretized using second order accurate differencing for spatial and temporal derivatives and then linearized using Newton's linearization method. The resulting set of algebraic equations is solved using the Coupled Modified Strongly Implicit Procedure for the unknowns of the …

A New Orleans State Of Crime: Spatio-Temporal Analysis Of Shifting Homicide Patterns In Post-Hurricane Katrina New Orleans, La, Lauren Childs

LSU New Orleans Theses and Dissertations

Dubbed the "most murderous" and "deadliest" city in the United States during 2006, 2007 and 2008, New Orleans has wrestled with crime and murder since its founding in 1718. Following Hurricane Katrina the city saw an increase in the murder rate despite a sharp decrease in population. The focus of this project was to map homicide data trends in the city of New Orleans over a period of seven years, 2002 to 2008, and compare spatial and temporal patterns via GIS. NOPD homicide location data were geocoded and analyzed in ESRI's ArcGIS geospatial software. Methodologies of hotspot detection included point …

An Analysis Of Netcdf-Fastbit Integration And Primitive Spatial-Temporal Operations, David Marks

LSU New Orleans Theses and Dissertations

A process allowing for the intuitive use of SQL queries on dense multidimensional data stored in Network Common Data Format (netCDF) files is developed using advanced bitmap indexing provided by the FastBit bitmap indexing tool. A method for netCDF data extraction and FastBit index creation is presented and a geospatial Range and pseudo-KNN search based on the haversine function is implemented via SQL. A two step filtering algorithm is shown to greatly enhance the speed of these geospatial queries, allowing for extremely efficient processing of the netCDF data in bitmap indexed form.