The 14th Annual

NC State University
Undergraduate Research Symposium

 

Physical & Mathematical Sciences Abstracts

Abstracts are listed in alphabetical order by the last name of the corresponding author.

 

 

Student Author(s): 

Baker, Adam K.

Larsen, Carrie J.

Department(s):       

Marine, Earth, and Atmospheric Sciences

Research Mentor(s): 

Gary M. Lackmann/Marine, Earth and Atmospheric Sciences

Title of Presentation:

Correlating Atmospheric Stability to Cloud Formation in Order to Provide a Website to be Used as a Teaching Aid

 

 

The purpose of our research was to develop a website for undergraduates and those new to the field of meteorology to use for the study of cloud types and the conditions for their formation.  This website will enable users to gain an idea of how atmospheric stability affects cloud formation and what types of clouds are associated with each kind of stability by viewing cloud animations.  In order to acquire good representations of cloud formations, we used the digital video cameras provided by the Digital Media Lab in D.H. Hill Library to film clouds.  The next step was digitally editing the video, which resulted in a faster and thus easier-to-visualize representation of cloud formation.  We then found Skew T log P soundings for the particular days and locations of cloud filming and linked them to the cloud animations on our website.  The website will provide users with an easy way to conceptualize the ideas of atmospheric stability and convection and how they correlate with certain cloud type formations. 

 

 

 

Student Author(s): 

Best, Kelly M.

Department(s):       

Marine, Earth, and Atmospherc Sciences

Research Mentor(s): 

Julia Clarke/Marine, Earth, and Atmospherc Sciences

Title of Presentation:

Evidence for a Possible New Species of Eocene Coraciiformes and its Significance to Early Avian Divergence

 

 

The fossil birds of the Green River Formation of Wyoming have yet to be studied in detail, yet they comprise an important assemblage.  The avifauna, from deposits in an ancient and extensive North American lake system, represents one of the best of the period following the K-T boundary extinction. It yields information on the evolution of birds after the dinosaurs and diversity in deep parts of the radiation of all birds.  We studied a rare, extraordinarily well-preserved complete bird skeleton from this deposit, found in Wyoming in oil shale deposits of the early Eocene Period (app. 50myr). Living Coraciiformes, or rollers, are medium-sized birds with colorful plumage, named for their characteristic acrobatic flight.  Three families of fossil Coraciiformes (Primobucconidae, Eocoraciidae, Geranopteridae) and 2 of extant taxa (Coraciidae, Brachypteraciidae) were considered in identification of the fossil’s group.  Extant Coraciiformes are found and two of the fossil groups are known only in the Old World, while the extinct Primobucconidae is found in both regions.  A published cladistic data matrix was used to compare features of our bird to 12 other classifications of ‘higher land birds’, including the groups above.  Our bird was supported as pan-Coraciiformes by the presence of an elongate postorbital bar, just as we hypothesized.  However, it is excluded from extant radiation by the absence of the anterior projection from this bar; meaning it does not belong to either extant group.  Of the fossil taxa, Primobucconidae is the only one found in the New World, but was eliminated due to obvious size and character differences, leaving Eocoraciidae and Geranopteridae.  Further research is needed to discern if our fossil is the first look at New World fossils of these two groups, or a new species that is more closely related to the extant birds of the Old World.

 

 

 

 

Student Author(s): 

Casulli, Matthew E.

Department(s):       

Physics

Research Mentor(s): 

Stephen P. Reynolds/Physics

Title of Presentation:

An Analysis of X-ray Emissions from Pulsar Wind Nebulae

 

 

Pulsar Wind Nebulae (PWNe) are thought to be produced by an initially relativistic "wind" of electrons (and positrons) from a pulsar.  These electrons produce X-ray synchrotron radiation. Electrons of higher energy radiate their energy faster and emit higher energy X-rays. If electrons convect hydrodynamically through the nebula, higher-energy electrons would radiate their energy closer to the pulsar than lower-energy electrons.  Because of this phenomenon, it is hypothesized that the PWN should appear smaller when viewed in higher energy bands.  It was found by qualitative methods that the hypothesis was confirmed in the PWN in the center of the supernova remnant G39.2-0.3, using data from NASA's Chandra X-ray Observatory.

 

 

Student Author(s): 

de Deugd, Casey M.

Department(s):       

Physics

Research Mentor(s): 

Laura I. Clarke/Physics

Title of Presentation:

Thin Film Growth and Characterization

 

 

The growth and characterization of thin silane films is a widely researched field and is a frequently used method to attach and examine molecules on an insulating surface. Molecular rotors are molecules with a stationary, rigid base, an axle, and a rotational group that is attached to the axle and has a torsional potential. The dynamics of the rotational group are completely determined by the torsional potential: in principle, systems can be designed to be freely rotating, hindered, or frozen at any given temperature. I plan to construct a modular system in which we can alter the torsional barrier without using synthetic chemistry, through the use of characterizing and optimizing thin film growth. In the current experiment, I have assembled thin films using two different molecules; methyltrichlorosilane and chloromethyltrichlorosilane. However, constructing a well-ordered film was challenging because it was essential to maintain humidity control.

            All experiments were conducted within a purged glove box sustained at eight percent humidity to reduce the effects of the moisture in the ambient air. After depositing onto multiple samples at varying emulsion times, I characterized all films by ellipsometry and contact angle, in order to determine the average thickness and film quality. In general, the system I constructed consists of a silane-based molecule, onto which a rotating functional group can be attached. In future experiments, I intend to attach solvachromatic probes onto my films, and characterize them via UV-vis spectroscopy. The magnitude of the absorption signal from the rotational blades will give me insight as to how many sites are available, and the breadth and position of the wavelength will provide me with more information about the local environment.

 

 

 

Student Author(s): 

Du, Shuang

Department(s):       

Physics

Research Mentor(s): 

Albert Young/Physics

Title of Presentation:

 
Muon Backing Veto forUCNA Experiment at Los Alamos 
National Labs

 

 

Muons are highly energetic charged particles originating from the upper atmosphere as a result of cosmic ray pion decay. Due to the muon's energies, they are very difficult to shield against and therefore register unwanted background in certain particle detectors. In our experiment (the UCNA experiment at Los Alamos National Laboratory) the particle detectors are designed specifically to detect beta particles from neutron decay. To solve the muon background problem, thin plastic scintillator detectors are situated essentially flush with the back of the beta detectors. Cosmogenic muons pass through both detectors without stopping, producing a "coincidence" signal that is used to reject background. Wave-shifting fluorescent scintillating fibers wrapped around the edges of our scintillators direct light into a wire mesh photomultiplier tube (PMT). Wire mesh PMTS are insensitive to the magnetic field strengths present in our spectrometer detector, which approach 1 Tesla, and prevent normal PMTs from functioning. Our muon veto systems will be installed in the UCNA experiment in the Summer of 2005.

 

 

 

Student Author(s): 

Gaither, Jeffrey B.

Department(s):       

Mathematics

Research Mentor(s): 

Ilse Ipsen/Mathematics

Title of Presentation:

Symmetrizing a Structurally Symmetric Matrix

 

 

A matrix is a rectangular array of numbers. If a matrix has the same number of rows as columns it is said to be square. Symmetric matrices are a special class of square matrices, such that when their rows and columns are switched they do not change. The purpose of this presentation will be to demonstrate a method by which a structurally symmetric matrix (which is not truly symmetric, but whose zeroes do not change position when rows and columns are interchanged) can be made to be truly symmetric. The method we will use is diagonal transformation. A diagonal matrix is a matrix which has zeroes in all positions but along the diagonal. If a diagonal matrix D has no zeroes along the diagonal it is said to be invertible, and has an inverse D^-1. Our findings deal with the circumstances in which, given an arbitrary structurally symmetric matrix S, there is a diagonal matrix D such that DSD^-1 is symmetric.  We show that the existence of such a matrix depends on there being a nonzero solution of a certain system of linear equations. We then relate this system of equations to a graph, which is a collection of points connected by lines. We show that the system has a nonzero solution if the associated graph has no circles. Why should we wish to make a structurally symmetric matrix symmetric? There are several reasons. First, the eigenvalues of structurally symmetric matrices (an eigenvalue is a very important quantity associated with a matrix) may be computed far more quickly than those of a normal matrix. Secondly, they may be computed to a higher degree of accuracy. Finally, symmetric matrices are one of the most fundamental classes of matrices and have a number of very useful properties too numerous to describe here.

 

 

 

Student Author(s): 

Hassinger, J. Peyton

Department(s):       

Chemistry

Research Mentor(s): 

Christopher B. Gorman/Chemistry

Title of Presentation:

Synthesis and Electrochemistry of Alternating Tip Iron-Sulfur Core Dendrimers

 

 

As the demand for information storage capacity continues to grow, the potential utility of unimolecular memory systems becomes evident.  Charge-stabilized dendrimers could provide such as system, forming the basis of a “0” and “1” computer language.  A dendrimer is a hyperbranching macromolecule with dendrons, or arms, branching out from a central [electroactive] core.  A variety of functional groups can be coupled onto the periphery, changing macromolecular properties such as water solubility and electron kinetics.  Attenuating electron kinetics could lead to charge stabilization.  The goal of this project was to establish an efficient synthesis scheme for an iron-sulfur cluster core dendrimer with alternating hydrophobic and hydrophilic tips, and then to investigate the encapsulating ability of the molecule by testing the electrochemical properties.  In this case, a heterogenous periphery of alternating undecane, polyethyleneglycol-12 tips was used.  A modular convergent synthesis scheme was developed, making use of a dimethoxy protecting group.  Preliminary electrochemical data suggests that the alternating undecane, polyethyleneglycol-12 dendrimer is harder to reduce than the homogenous periphery polyethyleneglycol-12 dendrimer. 

 

 

 

Student Author(s):                         Hayden, Kenneth T.

                                                            Tillman, Paul J.

                                                            Pitts, Catherine S.

Department(s):                                Statistics

Research Mentor(s):                      William F. Hunt, Jr./ Statistics

Title of Presentation:                     An Analysis of Toxic Release Trends

 

 

The U.S. Environmental Protection Agency (USEPA) created the Toxic Release Inventory (TRI) in response to the “Emergency Planning and Community Right-To-Know Act” of 1986.  The public can access the TRI Explorer on EPA’s website.  The TRI Explorer provides citizens with the means to identify industry reported routine releases of over 650 chemical materials.  The database spans the years 1988 to 2002 and includes more than 20 industry categories.  Using this database, we completed several different analyses.  First, the chemical styrene, a potential carcinogen, was studied because of its increase since 1988.  Secondly, different metropolitan areas were studied to determine if the effects of population change have an effect on the release of toxic emissions.  Lastly, the data were analyzed in order to create various models to help predict future toxic releases and to compare the rate of improvement and/or deterioration.  The goal of this research is to assist the EPA in its effort to make available useful information to the public regarding chemical releases into their communities.  

 

 

 

Student Author(s): 

Hemperly, Joshua

Department(s):       

Marine, Earth, and Atmospheric Sciences

Research Mentor(s): 

John Fountain/Marine, Earth, and Atmospheric Sciences

Title of Presentation:

Mapping Dangerous Levels of Arsenic in Gaston County Wells

 

 

High arsenic concentrations in well water have been linked to birth defects, cancer, and other health problems. NC State is collaborating with the Gaston County Health Departmment and the NC Department of Environment and Natural Resources in a study to help distinguish dangerous well water sources from innocuous ones. The categorization of aquifers and wells is important because it is impractical to test every well, so locating the watersheds with high arsenic concentrations would save valuable time and money. This is the preliminary stage of the study and has established the methodology to find such dangerous water sources. This study was conducted in the new Geology computer lab at Jordan hall at NCSU using ESRI GIS software. A geological map of Gaston County was aligned with contour maps created from DEMs, Hydrography, roads, topography, satellite photography, and well water analyses all over Gaston County. The maps are being analyzed by identifying wells with high arsenic concentrations, mapping the watersheds in which the wells are found  and deriving local ground water flow paths. Identification of dangerous watersheds and noting their similar characteristics should lead to correlations that will allow prediction of areas of potential high arsenic levels in groundwater,  and thus identifying areas in which well testing should be concentrated.

 

 

 

Student Author(s): 

 
Hopkins, Alyssa M.

Department(s): 

Marine Earth and Atmospheric Science

Research Mentor(s): 

Ping-Tung Shaw/Marine Earth and Atmospheric Science

Title of Presentation:

Ocean Topography and its Impact on Internal Wave Intensity

 

 

The ubiquitous presence of internal waves in the ocean has led to questions about how varying bottom depths on a continental shelf influences wave intensity. In this study a numerical model written in Matlab was used to simulate the behavior of internal waves propagating from deep water onto a continental shelf. Waves were first produced by tidal currents over a sill in deep water. After identifying that a  sharp thermocline produced the most visible waves, we added a continental  shelf to the topography. The depth and thickness of the thermocline were held constant to ensure best results. In each experiment, the depth of the continental shelf was modified, allowing the model to simulate the wave behavior on the shelf. The model results showed that strong waves could still form on continental shelf although some change in modal structure may occur. Taking this into account, our result suggests that internal waves generated in the deep water by a sill could well propagate onto a shallow continental shelf, as shown in observations.

 

 

Student Author(s): 

Hutchins, Alison L.

Department(s):       

Microbiology

Research Mentor(s): 

Craig Altier/Microbiology, Pathology & Parasitology

Title of Presentation:

Methods for Detecting the Effects of Low Doses of Tetracycline on Salmonella

 

 

Animals are given antimicrobials in low doses to promote their growth.  While this is beneficial for the food industry, it is harmful in that it induces resistance in animals and may be a potential problem for the people who ingest the animal meat.  The question of why antimicrobials promote growth in animals remains unanswered.  A possible suggestion may be that antimicrobials kill the resident flora of animals.  The question of why the resident flora has not become resistant to certain antibiotics is then brought up.  Another suggestion is that antimicrobials cause changes in the bacterial gene expression.  Recent work with Salmonella has shown that antibiotics can induce bacterial gene expression at sub-inhibitory concentrations.  Thus, the changes in gene expression may work to improve animal growth.  I hypothesize that antimicrobials, in addition to their ability to kill bacteria, also induce changes in bacterial gene expression when provided in sub-inhibitory concentrations.  In order to test this hypothesis I performed a conjugation, which involved transferring a lacZ plasmid from E. coli into a Salmonella chromosome.  I plated the Salmonella on agar media containing low concentrations of tetracycline and looked for colonies that turned blue in the presence of tetracycline and white in its absence.  The conjugations were not successful, either because the Salmonella was contaminated with E. coli or due to experimental error.  I also performed a transduction that involved inserting a bacteriaphage, which carried the lacZ genes, directly into the Salmonella chromosome.  This procedure proved fruitful, but due to time constraints, I never got results.  If I were to continue with this transduction experiment, I believe I could get results showing blue colonies on a tetracycline plate and white colonies on a non-tetracycline plate.  This would show that there are certain genes in the Salmonella chromosome that may in fact be turned on only in the presence of low doses of tetracycline, among other antibiotics.

 

 

 

 

Student Author(s): 

Jones, Leigh P.

Department(s):       

Marine, Earth, and Atmospheric Sciences

Research Mentor(s): 

Yuh-Lang Lin/Meteorology

Title of Presentation:

Mesoscale and Synoptic Forcing on Squall Line Propagation during MAP IOP-2a and IOP-10

 

 

We have studied mesoscale flow over the European Alps, which is of particular interest due to its potential flooding effects in surrounding valleys.  Using data from the Mesoscale Alpine Programme, a 1999 field program to gather meteorological data over the Alps, we examined one case, IOP-10, where a squall line persisted on the Alps’ northwest edge for over 12 hours past its forecast presence there.  We were interested in investigating the main forcing behind the stagnation of the squall line on the ridge.  After comparing it to a similar case, IOP-2a, in which a squall line approached the Alps and moved through within its forecast time, we found that the main forcing mechanisms behind the movement of each squall line were at the synoptic scale, rather than at the mesoscale level of the lines.  The upper-level trough upstream of IOP-10 continuously deepened into a positive tilt over the investigated time, while its eastern edge remained stagnant over the Alps.  IOP-2a’s associated upstream trough showed a more dynamic western edge with stronger upper-level forcing, while it deepened to the negative.  We concluded that the tilt of the troughs did not affect weather at the mesoscale level but that the main forcing within the larger-scale flow was most to credit.

 

 

 

Student Author(s): 

Jurss, Jonah W.

Department(s):       

Chemistry

Research Mentor(s): 

James D. Martin/Chemistry

Jaap C. Folmer/Chemistry

Title of Presentation:

How Dry are Anhydrous Materials?.The Quest to Prepare Water Free Zinc Chloride

 

 

Zinc chloride is a condensed network structure that is also a good glass former.  Zinc chloride finds numerous applications from catalysis to a host for laser materials.  A pervasive problem with this material is that trace amounts of water drastically alter the desired properties.  By solid-state NMR measurements we have found that "anhydrous" zinc chloride retains significant amounts of water.  Furthermore TGA measurements show that all the water is not lost from zinc chloride until it is heated above its melting point (317 C).  Multiple crystallizations from the vapor phase above the melt have yielded the driest materials to date.  The synthesis and structural effects of hydration will be discussed. 

 

 

 

Student Author(s): 

Madsen, Kimberly A.

Humes, Audria M.

Department(s):       

Statistics

Applied Mathematics

Research Mentor(s): 

William F. Hunt/Statistics

Title of Presentation:

Does Water Quality Differ Among North Carolina’s Watersheds?

 

 

The biotic index is a quantitative method to measure the abundance of biotic life in the North Carolina’s water systems.  The biotic index value considers different qualitative characteristics of a river and the abundance of tolerant and intolerant macro-invertebrates.  Macro-invertebrates are subject to changes in water quality, such as a decrease in dissolved oxygen, temperature, pH, etc.  This study measures the relationship between the biotic index and water quality variables over different periods for an individual watershed.  Combining location (watershed) and water quality/chemistry variables, we found that location has a significant effect on the biotic index.  There appears to be a difference between western and eastern North Carolina, which is mediated by water chemistry effects.

 

 

 

Student Author(s): 

McFarland, Amber L.

Department(s):       

Physics

Research Mentor(s): 

Stephen P. Reynolds/Physics

Title of Presentation:

Chandra X-ray Imaging and Spectroscopy of the Supernova Remnant of 1006 AD

 

 

The remnant of SN 1006 AD shows both thermal and non-thermal X-ray emission.  Thermal emission shows strong lines of O and a clumpy morphology, while the non-thermal (synchrotron) emission is concentrated in narrow arcs at the remnant edge.  We present images of SN 1006 in various lines, and localized spectral analysis, based on Chandra observations from Cycles 1 and 2.  While these observations do not cover the entire remnant, they include emission at a large range of radii and azimuthal position.  We use elemental abundance analysis to attempt to locate the reverse shock and to separate ejecta emission from emission from shocked interstellar material.  We also characterize the synchrotron component as a function of position with implications of the maximum energy to which electrons are accelerated and the mechanism limiting this energy.

 

This work was supported by NASA through award NAG5-7153.

 

 

 

Student Author(s): 

Mendenhall, Jera L.

Department(s):       

Statistics

Research Mentor(s): 

William F. Hunt Jr./Statistics

Title of Presentation:

Is There a Better Way to Define Swamplands in the Coastal Plains?

 

 

I have been asked by the North Carolina Department of Environment and Natural Resources’ (NCDENR) Water Division to examine the water quality data collected in the Coastal Plain Regions of NC to identify water quality sites as potential swamp sites based upon measured dissolved oxygen concentration data.   An essential requirement for a water area to support aquatic life is a sufficient concentration of dissolved oxygen.  When the concentration is less than 4.0 mg/L, some action is required because it is assumed that the area is polluted; the action is usually an expensive project to clean up the swamp.  However, this low concentration occurs naturally in swamp waters. Therefore, my intent is to discover which of the sites could be classified as swamp sites in order to prevent expensive clean-up projects from occurring.

            The current standard set by the EPA is that 10% of the measurements are less than 4 mg/L.  Since the water quality data is only collected monthly, I will analyze multiple years of data to avoid misclassifying a site as swamp water because of insufficient data.  Furthermore, we will identify which of the unclassified stations are strong candidates to be classified as swamp sites and which previously classified swamp sites should not be classified as such.  I also considered pH as another influencing factor; however, this revealed itself to be insignificant.  Through my analysis of the data, I noticed the lack of confidence in our estimates because of the spacing of samples over time and the influence of seasonal patterns.  After our listing of reclassifications and results, we recommend that sampling increase in the summer months and decrease in the winter, in order to increase accuracy of classifications and maintain the same costs. Also looking at reclassifications and prior classifications by region could discover trends in misclassifications.

 

 

 

Student Author(s): 

Moussa, Nader

Department(s):       

Molecular Physics Laboratory, SRI International (Menlo Park, California)

Research Mentor(s): 

Jochen Marschall/Mechanical Engineer

Kostas Kalogerakis/Chemical Physicist

Title of Presentation:

Modeling Thermal  Conductivity in Ultra-High Temperature Ceramics for  Hypersonic Vehicles

 

 

As new high-atmosphere vehicles are developed, there is a need for sharper leading-edges for vehicle control surfaces to provide greater maneuverability.  Ultra-High Temperature Ceramics (UHTC) provide a good balance between structural stability and thermal conductivity, both properties which are necessary for safe vehicle re-entry.  However, laboratory analysis of sample UHTCs show wide variation in thermal behavior between samples.  Modeling the crystal geometry and thermal properties in large computer simulations provides insight into the microscopic properties that affect required parameters.  This can be applied to the materials processing engineering, allowing for the most desirable protective materials for next-generation upper-atmosphere vehicles.

 

 

 

 

Student Author(s): 

Murray, David H.

Department(s):       

Physics

Research Mentor(s): 

Keith Weninger/Physics

Title of Presentation:

Single-molecule Fluorescence Energy Transfer Reveals the Dynamics of SNARE Proteins

 

Membrane proteins are difficult to study with traditional methods of biochemistry.  The work presented here develops single molecule fluorescence techniques to characterize the conformational dynamics of the SNARE (or soluble N-ethylmaleimide-sensitive factor attachment protein receptors) family of membrane proteins.  SNARE proteins are known to be essential for membrane fusion in a wide variety of cellular processes although a molecular-level understanding of their functional mechanisms is lacking.  Direct observations of the spontaneous fluctuations of individual SNARE proteins immobilized at a surface are described.  Cross species and mutational studies are reported.  Design and fabrication of novel instrumentation capable of high time resolution observation of protein conformational changes is described.  The methods described here will be applicable studies of a wide variety of protein systems.

 

 

 

Student Author(s): 

Queen, Ashley

White, John

Department(s):       

Meteorology 

Statistics

Research Mentor(s): 

William Hunt Jr./Statistics

Title of Presentation:

Is the Fine Particulate Matter Air Pollution "Non-Attainment" Problem in Hickory and Lexington, NC Regional or Local?

 

 

Particulate matter is one the United State’s six criteria pollutants monitored by the Environmental Protection Agency.   Specifically fine particulate matter measures 2.5 micrometers in aerodynamic diameter or less.  This type of air pollution has been shown to cause increases in premature mortality as well as cardio-pulmonary disease.  There are strict standards that each state must satisfy to be classified as an attainment area.  These states are further broken into counties or slightly larger groups of counties that must meet these pollution concentration requirements.  For an annual mean, the concentration must not exceed 15 micrograms per cubic meter.  There is a daily max limit set at 65 micrograms per cubic meter.  Two counties in North Carolina have been deemed non-attainment areas by the EPA.  Both counties’ three-year average concentration of particulate matter have exceeded the annual average standard set by the EPA.

            The North Carolina Department of Environment and Natural Resources needed to analyze concentration level data to determine if the non-attainment problems were regional or local.  Three sets of data including continuous, federal reference method and meteorological data were examined.Data management was the first step in combining all of these different forms of useful data together. Multiple statistical and graphical analyses examine whether a regional or local problem could be the cause of non-attainment.  Most of the statistical analyses show a regional and local component attributing to the concentrations in the non-attainment areas.  However, there also seems to be differences inside the town of Lexington.  This suggests a local component that could be pushing Davidson county or more specifically Lexington, NC into non-attainment.   Although a definite conclusion on the origin of influence for these monitors to be in non-attainment was not reached, several methods of examining the data show useful relationships and possible directional source locating techniques. 

 

 

 

Student Author(s): 

Reising, Sarah E.

Department(s):       

Marine, Earth, and Atmospheric Sciences

Research Mentor(s): 

Edward F. Stoddard/Marine, Earth, and Atmospheric Sciences

Title of Presentation:

Characterizing a Dipping Diabase Dike Using Magnetic Anomalies

 

 

Exploration geophysics and the emphasis on diabase dikes has recently become popular because of the large scale relationship between the dikes and ancient continental rifting as well as small scale relationships such as the influence of dikes on groundwater flow and contamination. The detection of poorly exposed dikes and the interpretation of their subsurface geometry and extent are thus of great importance.  This study was undertaken to test and examine one technique for estimating diabase dike characteristics, based upon their magnetic anomaly at the earth's surface.  The dike under study is an unusual, locally quartz-bearing diabase with plagioclase feldspar phenocrysts, and has been mapped from southern Johnston County, NC to the NC-VA border.  Magnetic intensity data from a traverse near Middleburg, NC were collected using a proton precession magnetometer, and modeled using a Gaussian method (Won, 1981).  Preliminary mapping and graphical analysis show that the dike strikes  N10E and dips steeply to the east, in good agreement with a saprolite exposure of a contact with the granitic rock that it intrudes.  Though this model is a good estimate of the attitude of the dike, technology has advanced such that parameters like magnetic susceptibility can be determined.  This will lead to an improved program that enables the user to receive output with a smaller number of variables. 

 

 

 

Student Author(s): 

Robles, Francisco E.

Department(s):       

Physics

Research Mentor(s): 

John M. Blondin/Physics

Title of Presentation:

Supernova Remnant of Cassiopeia A

 

 

The basis of this research project is to look deeper into the structure of the supernova remnant of Cassiopeia A, and to further improve our knowledge of the asymmetric structure.  In the paper “A Million-Second Chandra View of Cassiopeia A,” the authors “tentatively conclude that Cassiopeia A was formed by asymmetric explosion that produced jets of ejecta,” quickly discarding other suggestions without further exploration (Hwang).  This theory, however, provides several problems.  If the jets were induced by the ejecta, the explosion would have to be of much higher energies than it has been measured.  Moreover, to be consistent with what is known about the nature of jet explosions, it would also need to show heavy Fe ejecta in the over dense jet region, which has not been observed.

            In this project, the possibility of a symmetric explosion in an asymmetric medium was compared with Hwang’s hypothesis of an asymmetric explosion in a symmetric CSM.  Using the time dependent hydrodynamic code, several simulations were set up with different condition that correspondingly modeled a jet cause by the ejecta, and another by the Circumstellar Medium (CSM).  Equivalent relationships between the CSM and the ejecta models were derived to get a set of equations that ultimately governed the density, velocity, and pressure profiles.  Both models produced effectively identical results, which reemerged the possibility of jets being caused by a symmetric explosion in an asymmetric CSM.  Furthermore, these simulations showed that the ejecta in the SNR can be re-accelerated as it makes its way through the reverse and forward shock.  The implications of these results counter the claim that observed clumps are never decelerated, and the current believe that the reverse shock in Cas A is not energetic enough to “yield the high ionization age observed for the plasma in the jet-like region (Hwang).”

 

 

 

Student Author(s): 

Savage, L. Crosby, III

Department(s):       

Marine, Earth, and Atmospheric Sciences

Research Mentor(s): 

Yuh-Lang Lin/MEAS

Chris Hill, Heather Reeves, and Allison Hogarth

Title of Presentation:

Ideal Simulations of Genoa Cyclones Over the Apennines

 

Observations of cyclones around the world show two distinct tracks when crossing a mountain range. Some cyclones cross directly over the mountain with rather straight tracks, while others fill in the mountain and redevelop on the lee side. This study uses a simplified computer model, the NCSU GFDM, to determine whether the cyclone can cross or will be blocked by the Apennines. Three parameters were studied to determine redevelopment: vortex maximum velocity, mountain height, and the Brunt Vaisala frequency. After running several simulations a relationship was developed between deflection of the cyclone and the vortex Froude number (Vmax/Nh).  Froude numbers slightly higher than a control of 1.16 indicated a deflection of the cyclone to the north. Model output shows redevelopment on the lee side of the mountain slightly north of the cyclones previous trajectory. Froude numbers below the control of 1.16, on the other hand, dissipates showing only a wave with no redevelopment. These results suggest a weaker cyclone or higher mountain will block the cyclone, while stronger cyclones or smaller mountains will redevelop to the north. This study also shows how the angle of the Apennines does not affect the relationship of the Froude number to the cyclones redevelopment.

 

 

 

Student Author(s): 

 
Schwab, Suzanne I.

Horgan, Katherine L.

Department(s):

Marine, Earth, and Atmospheric Sciences

Research Mentor(s): 

 
Ryan Boyles/NC State Climate Office 
Sethu Raman/NC State Climate Office and Marine, Earth, and Atmospheric

Sciences

Title of Presentation:

 
Development of a Public Interface for Multi-sensor Precipitation Estimates 

 

 
Observations that are of great interest for climatological studies and for model validations are the location, amount, and timing of 
precipitation.  The current method of obtaining this data is by using cooperative observer (daily) or ASOS/AWOS (hourly) observations.  
However, the lack of adequate spatial density of surface gages forces the investigator to use observations from the closest station, which 
is often not close enough to provide an accurate representation of local precipitation. The National Weather Service’s River Forecasting 
Centers have developed a product known as Multi-sensor Precipitation Estimates (MPE) consisting of gridded radar estimated 
precipitation on a 4-km grid, corrected with quality-controlled surface observations from available gages. The estimates are available on a 
1h, 6h, and 24h basis.  The National Centers for Environmental Prediction (NCEP) provides the MPE data on a national grid in GRIB 
format, which is what was used for this research.  Using a combination of GrADS, PERL, and PHP scripting, a product was designed to 
view this data and be able to access both numerical and graphical displays of precipitation over any latitude and longitude point or range in 
the continental United States.  A website is now available through the SCO where this is possible.  Research on precipitation variability 
and flash flooding will be enhanced with convenient access to MPE through this service.  The public also can benefit from improved 
estimates of precipitation values at their specific location of interest.  
 

 

 

 

Student Author(s): 

Sigmon, Ginger

Josey, Amanda

Martin, Jim

Department(s):       

Chemistry

Research Mentor(s): 

Martin, Jim Martin/Chemistry

Title of Presentation:

The Effect of Template Disorder on the Lattice Expansion of the Sodalite Halozeotype CZX-1

 

 

CZX-1 is a metal-halide analog of the zeolite sodalite.  It is formed using a trimethyl ammonium cation template, which allows for an inorganic copper zinc chloride sodalite framework to grow around it during melt synthesis to form a cubic solid.  Inelastic neutron scattering and solid-state NMR experiments give indication that the templating cation undergoes diverse types of motion as a function of temperature.  In order to study the effect of cation motion on the lattice expansion of the inorganic network, we measured the powder X-ray diffraction of CZX1 as a function of temperature from 10K to 400K.  Changes in the rate of lattice expansion and relative charges in diffraction peak intensity support this model of template cation motion within the inorganic network.

 

 

 

Student Author(s): 

 
Smith, Barrett L., II

Department(s):

Marine, Earth, and Atmospheric Sciences

Research Mentor(s): 

 
Yuh-Lang Lin/Marine, Earth, and Atmospheric Sciences

Title of Presentation:

ECMWF Re-analysis of Cyclone Passage Over the Apennine Mountains 

 

 

Terrain is known to have a significant influence on the track of surface cyclones.  Cyclones impinging on a mountain have been observed to take different tracks, depending on several factors, such as mountain height, cyclone strength, and cyclone speed.  The Genoa cyclone, which often impinges on the Apennine Mountains in Italy, has been observed to undergo such track changes as it interacts with the mountain range.  Specifically, two tracks have been observed during the Mesoscale Alpine Program (MAP) special observing period.  One track has been observed to cross over the Apennines, with brief blocking and lee-side cyclogenesis.  The other track has been observed to deflect southward under complete blocking by the mountain range.  In addition to terrain effects, synoptic flow also contributes to cyclone track.  In conjunction with idealized simulations of the effects of the Apennine Mountains on the track of cyclones of MAP IOP-1 and IOP-8, the synoptic environmen! t was analyzed in this study, using European Center for Medium range Weather Forecasting (ECMWF) 0.5o resolution re-analysis data.  Multiple levels of atmospheric fields were analyzed, using several different parameters, including pressure and wind fields, geopotential height, streamlines, and vorticity.  From this data, two different track types were obtained.  In addition, effects of synoptic flow on the cyclone tracks were also investigated.

 

 

Student Author(s): 

 
Speller, Danielle H.

Department(s):

 
Physics

Research Mentor(s): 

 
Hans Hallen/Physics

Title of Presentation:

 
Cellular Microscopy/ Voltage Response of Nuclei to Al-Coated Probes
 
 
Stamen hair cells of the Setcresea Purpurea  (Purple Heart Plant) have been found to respond to the presence of hydrophobic surfaces 
and small voltages.  Etched fiber optic tips coated with a metal oxide and a self-assembled monolayer were inserted into the cellular walls 
and a voltage subsequently applied.  The behaviors of the nuclei in response to the different voltages were observed and are being 
modeled. Other experiments with tips have shown the easy extraction of a nucleus by a neutral tip but a more difficult replacement, despite 
applied voltage. 
 
 

 

 

Student Author(s): 

 
Stackhouse, James R.

Department(s):

Statistics

Biological Sciences

Research Mentor(s): 

Mat Alldredge / Zoology

Ken Pollock / Statistics and Zoology

Ted Simons /  Zoology

Title of Presentation:

An Assessment of Common Bird Point Count Sampling Methods

 

Point count surveys are used extensively as indices in studies of bird abundance, species diversity, habitat relationships, and responses to changing environmental conditions.  However, the traditional point count, in which an observer stands in one location and records all birds seen or heard for a set amount of time, has come under scrutiny.  In order to make valid spatial and temporal comparisons among bird populations one must assume that the proportion of the population counted is constant across all surveys.  Factors such as differing habitats, ambient noise levels, bird densities, song characteristics, and others make it doubtful that this assumption is ever valid.  Because the sampling method has never been tested on a known population, the accuracy and precision of the point count method is not known.  Our goal is to improve the validity of such methods by understanding how various sources of measurement error affect raw count data and the estimates of bird abundance and diversity.  Actual point count conditions are simulated by placing radio receivers with speakers in natural environments.  This allows for the realistic simulation of bird point counts with a known population.  It also allows for controlled experiments where factors of interest can be tested and their affect on point counts assessed.  Volunteers performed over a thousand individual point counts.  Initial findings show the potential for a number of factors to have strong effects on detection probabilities.  These findings will allow us to make practical improvements and recommendations for current point count survey techniques in the hope of increasing the validity of population assessments. 

 

 

 

Student Author(s): 

Stines, Bryan T.

Department(s):

Statistics

Research Mentor(s): 

William Hunt/Statistics

David Dickey/Statistics

Title of Presentation:

Alternative Methods of Graphically Representing Ambient Air Quality Data, by Locating Point Sources of Emissions

 

 

Graphical representation of any statistical analysis is perhaps the most difficult challenge of data analysis.  The ability to explain complex statistical results in a format that others can understand is perhaps the most challenging aspect of the analysis.  Photochemical Assessment Monitoring Station (PAMS) ambient air quality data are collected in 22 metropolitan areas across the United States.  These sites measure the concentrations of volatile organic compounds (VOC), along with nitrogen oxides (NOx), ozone and many meteorological parameters.  VOC and NOx compounds are regulated by the U. S. Environmental Protection Agency (USEPA). The PAMS sites collect massive amounts of data, but there has always been that problem of how can one represent these hourly measurements of concentration, wind speed, and wind direction to explain and better understand what sources may be influencing the concentrations measured at these sites.  I have examined two techniques to explore the relationship among concentration, wind speed and wind direction.  The first technique normalizes the data by multiplying wind speed times concentration and plotting it by direction.  It is very effective in identifying the direction of major sources in two dimensions.  The second technique takes the same data and plots it in three dimensions; this has the advantage of showing the impact of the source over time.  Is the sourcing becoming more or less of a problem?  This paper will show the advantages of these techniques in both Houston and Atlanta.

 

 

 

 

Student Author(s): 

Thomason, Leigh Ann

Department(s):       

Statistics

Research Mentor(s): 

Peter Bloomfield/Statistics

Title of Presentation:

Bankruptcy: Is it all the Economy's Fault?

 

As a way to order and organize the bonds system, each issuer is given a rating based on the financial strengths of the company.  This rating is an indicator of a company’s default risk.  But does the rating stand in a vacuum without influence from outside sources?  Are there patterns in the economy that can help explain the probability of a company going into default?  Four economic variables (GDP, GDP price deflator, and one year and five year Treasury interest rates) were examined to see if a statistically significant relationship could be found between the bond rating and economic activity.  The results will help lead to an equation to determine likelihood of default based on economic factors and initial bond rating.

 

 

 

 

 

Student Author(s): 

Thompson, Maya

Moore, Andrew

Stines. Bryan

Department(s):       

Statistics

Research Mentor(s): 

William F. Hunt, Jr./ Statistics

Roger Woodard / Statistics

Title of Presentation:

Using Statistics to Better Characterize the Residential Wood Combustion

Emissions Project

 

 

The production of wood smoke from residential wood combustion can affect both our health and quality of life.  Air pollution caused by burning wood contains many harmful chemicals as well as fine particles of dust or particulate matter.  As this particulate matter accumulates in the air, it is inhaled into the lungs and may induce or accentuate cardiovascular and respiratory illnesses.  Also, particulate matter in the atmosphere contributes to regional haze, which can drastically reduce visibility.  However, previous emissions estimates for this source of air pollution have contained a large degree of uncertainty.  To better understand the contribution of residential wood combustion to air pollution, the Mid-Atlantic Regional Air Management Association (MARAMA) contracted the services of E.H. Pechan & Associates, Inc. to develop an emissions inventory for the Mid-Atlantic/Northeast Visibility Union (MANE-VU).  Residents of the Mid-Atlantic region were surveyed in order to gain information regarding the amount and type of wood burned, burning equipment used, peak periods of activity, etc.  Pechan analyzed the data and was able to produce state-level emission summaries of pollutant emissions.  We focused on the respondents that actually burn wood and applied a log transformation to the corresponding emissions data to help normalize the data. We also found that the interaction terms used to model the data are not significant when the main effects for these factors are also included.  We will expand Pechan & Associates’ analysis by determining which wood combustion factors have significant effects on emissions and how much variability can be attributed to them.

 

 

Student Author(s): 

Timpy, Evan L.

Department(s):       

Marine, Earth, and Atmospheric Sciences

Research Mentor(s): 

William J. Showers/Marine, Earth, and Atmospheric Sciences

Title of Presentation:

Water Flow Into the Neuse River: the Influence of Basaltic Dikes

 

 

There are many factors that influence the concentration of nitrate in the Neuse River in North Carolina, and consequently the water quality of the Neuse River basin and estuary.  One such factor is the interaction between surface waters and ground waters.  This study used nitrate and silicate as chemical tracers to investigate the influence of a basaltic dike on the flow of ground water into the Neuse River.  A basaltic dike was discovered using a magnetometer that ran perpendicular to the Neuse River.  It was marked and mapped using differential GPS and GIS technology.  The surface waters surrounding the dike were analyzed for nitrate concentrations with a Lachat flow injection analysis system.  River water samples were obtained at intervals along the region of the river at which the dike intersects it.  Also in this region an in-situ ultraviolet spectrometer (ISUS) was deployed by boat which recorded absorption signals proportional to nitrate concentrations.  The samples were analyzed for silicate and nitrate concentrations using a Lachat flow injection analysis system.  The surface water samples surrounding the dike were found to contain high levels of nitrate.  In river water samples the concentrations of nitrate and silicate were found to increase significantly at the location where the dike intersects the River.  This is evidence for interaction between surface water and groundwater at the Basaltic dike.  Basaltic dikes are a subsurface hydrological route of ground water to rivers.

 

 

 

Student Author(s): 

Todd, Robert E.

Department(s):       

Marine, Earth and Atmospheric Sciences

Research Mentor(s): 

Robert C. Beardsley/Physical Oceanography, Woods Hole Oceanographic Institution

John M. Morrison/Marine, Earth and Atmospheric Sciences, NCSU

Title of Presentation:

Evaluation of WHOI and ISCCP Heat Flux Analysis Products

in the North Atlantic

 

 

The transfer of heat across the air-sea interface is an important factor in both oceanic and atmospheric phenomena. The net heat flux across the air-sea interface is the sum of the latent and sensible heat fluxes (turbulent fluxes) and shortwave and longwave radiation fluxes (radiative fluxes). Accurate estimates of each of the air-sea heat flux components with large spatial and temporal coverage are needed to parameterize oceanographic and atmospheric models for a wide range of uses. Recently, the Woods Hole Oceanographic Institution (WHOI) has developed a variational objective analysis scheme that provides daily turbulent heat flux estimates at one-degree spatial resolution over the majority of the Atlantic basin. The International Satellite Cloud Climatology Project (ISCCP) produces estimates of radiative flux components with the same spatial and temporal scales over the same portion of the Atlantic. Taken together, these two products allow us to estimate all components of air-sea heat flux and to produce an estimate of the net heat flux across the air-sea boundary. Here we evaluate these products by comparing the flux estimates to fluxes computed from in situ measurements at twelve mooring stations covering much of the North Atlantic basin. We find that, on average, the fluxes generated using the WHOI and ISCCP products capture the net heat flux across the air-sea interface to within 50 W/m^2. However, these estimates often fail to capture the daily variations in the flux components accurately, resulting in large standard deviations of the errors and low correlation coefficients.

 

 

 

Student Author(s): 

Valdez-Jasso, Daniela

Department(s):       

Mathematics

Research Mentor(s): 

Mette Olufsen/Mathematics

Mansoor Haider/Mathematics

Title of Presentation:

Viscoelastic Model Relating Blood Pressure and Area in Arteries

 

 

When deriving one-dimensional fluid dynamic models of blood flow in arteries it is necessary to include a constitutive equation. Typically such models relate cross-sectional area of the artery to blood pressure. Most previous constitutive equations are based on elastic or empirical models. However, it has long been known that arteries display viscoelatic properties. In this work we present a viscoelastic model relating blood pressure and cross-sectional area and validate this model against data obtained from pigs. Using measured pressure data as an input, we used nonlinear optimization to compute model parameters that minimized the difference between computed and measured values of the cross-sectional area. With this optimization we were able to obtain high coherence between our model and data and, furthermore, we showed that the viscoelastic model was able to predict the data significantly better than a traditional elastic model.

 

 

 

 

Student Author(s): 

Williard, Mary M.

Wang. Gongbo

Department(s):       

Physics

Biochemistry

Research Mentor(s): 

Keith R. Weninger/Physics

Title of Presentation:

Viewing Viral Infection by Single-Particle Fluorescence

 

 

Sindbis virus infects both mammalian and insect cells.  Though not pathogenic in humans, Sindbis is a model for many mosquito-borne viruses that cause human disease, such as yellow fever and dinghy fever.  Fluorescent labels were incorporated into both the viral coat proteins and the lipid envelope of the virus.  We then used real-time single particle fluorescence microscopy to observe individual Sindbis virus particles as they infect living cells.  Tracking individual viral particles allows the simultaneous determination of multiple pathways.  Kinetics characteristic of free diffusion in solution, slower diffusion on the surface of cells, and motor protein transport inside cells have been observed.  Dequenching of the membrane label is used to report membrane fusion events during the infection process.  Using these data, we have developed a proposed model for the infection pathway of Sindbis virus.

 

 

 

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Last modified February 2005 by Sharon E. Hunt, WordHunting