Physical Sciences and Mathematics Commons^™

Hydrographic Surveys Of Four Narrows Within The Namakan Reservoir System, Voyageurs National Park, Minnesota, 2011, Brenda K. Densmore, Kellan R. Strauch, Jeffrey R. Kiegweid

United States Geological Survey: Water Reports and Publications

The United States Geological Survey (USGS) performed multibeam echosounder hydrographic surveys of four narrows in the Namakan reservoir system in August 2011, in cooperation with the International Joint Commission and Environment Canada. The data-collection effort was completed to provide updated and detailed hydrographic data to Environment Canada for inclusion in a Hydrologic Engineering Centers River Analysis System hydraulic model. The Namakan reservoir system is composed of Namakan, Kabetogama, Sand Point, Crane, and Little Vermilion Lakes. Water elevations in the Namakan reservoir system are regulated according to rule curves, or guidelines for water-level management based on the time of year, established …

Comparison Of Water Consumption In Two Riparian Vegetation Communities Along The Central Platte River, Nebraska, 2008–09 And 2011, Brent M. Hall, David L. Rus

United States Geological Survey: Water Reports and Publications

The Platte River is a vital natural resource for the people, plants, and animals of Nebraska. A recent study quantified water use by riparian woodlands along central reaches of the Platte River, Nebraska, finding that water use was mainly regulated below maximum predicted levels. A comparative study was launched through a cooperative partnership between the United States Geological Survey (USGS), the Central Platte Natural Resources District, the Nebraska Department of Natural Resources, and the Nebraska Environmental Trust to compare water use of a riparian woodland with that of a grazed riparian grassland along the central Platte River. This report describes …

Emergent Sandbar Dynamics In The Lower Platte River In Eastern Nebraska: Methods And Results Of Pilot Study, 2011, Jason S. Alexander, Devin M. Schultze, Ronald B. Zelt

United States Geological Survey: Water Reports and Publications

The lower Platte River corridor provides important habitats for two State- and federally listed bird species: the interior least tern (terns; Sternula antillarum athallassos) and the piping plover (plovers; Charadrius melodus). However, many of the natural morphological and hydrological characteristics of the Platte River have been altered substantially by water development, channelization, hydropower operations, and invasive vegetation encroachment, which have decreased the abundance of high-quality nesting and foraging habitat for terns and plovers. The lower Platte River (LPR), defined as 103 miles (mi) of the Platte River between its confluence with the Loup River and its confluence with the Missouri …

Evolution Of Guano Under Different Environmental Conditions: A Mineralogical Approach, Alexandra M. Giurgiu, Bogdan P. Onac, Tudor Tămaș, Joan J. Fornos

School of Geosciences Faculty and Staff Publications

The phosphate minerals from three Romanian caves that host bat guano deposits have been investigated. The XRD and SEM analyses have revealed the presence of seven phosphates (brushite, francoanellite, hydroxylapatite, leucophosphite, taranakite, vashegyite and variscite) along with the more common gypsum, calcite and various allochthonous clay minerals. The occurrence of these phosphate minerals highlights the decomposition and various reactions that take place between the phosphate-rich solutions leaching out from the guano and different cave sediments and/or bedrock. The variation of the environmental conditions in the vicinity and within the guano accumulations is responsible for the type of mineral that is …

A New Recursion For Three-Column Combinatorial Macdonald Polynomials, Elizabeth Niese

Mathematics Faculty Research

The Hilbert series of the Garsia–Haiman module M_μ can be described combinatorially as the generating function of certain fillings of the Ferrers diagram of μ where μ is an integer partition of n . Since there are n ! fillings that generate , it is desirable to find recursions to reduce the number of fillings that need to be considered when computing combinatorially. In this paper, we present a combinatorial recursion for the case where μ is an n by 3 rectangle. This allows us to reduce the number of fillings under consideration from (3n)! to (3n)!/(3!ⁿn!).

With One Breath, Jessica Solfest

Honors Theses, 1963-2015

Biologists know that the cardiovascular and respiratory systems interact and coordinate via the baroreflex and other pathways, but there is still much to discover regarding the dynamical aspects of their communication. Synchronization patterns between the respiratory and cardiovascular systems evince their interaction. This thesis focuses on the synchronization of cardiovascular and respiratory activity. I analyze the frequency of this synchrony to determine patterns and characterize the systems’ adaptability to changes in the environment. I applied time series analysis and Markov processes to dynamical systems in an attempt to unearth meaning behind cardiorespiratory communicative mysteries. Through this research, I found that …

Coding Theory-Based Cryptopraphy: Mceliece Cryptosystems In Sage, Christopher Roering

Honors Theses, 1963-2015

Unlike RSA encryption, McEliece cryptosystems are considered secure in the presence of quantum computers. McEliece cryptosystems leverage error-correcting codes as a mechanism for encryption. The open-source math software Sage provides a suitable environment for implementing and exploring McEliece cryptosystems for undergraduate research. Using our Sage implementation, we explored Goppa codes, McEliece cryptosystems, and Stern’s attack against a McEliece cryptosystem.

Galois Representations From Non-Torsion Points On Elliptic Curves, Matthew Phillip Hughes

Senior Projects Spring 2013

Working from well-known results regarding l-adic Galois representations attached to elliptic curves arising from successive preimages of the identity, we consider a natural deformation. Given a non-zero point P on a curve, we investigate the Galois action on the splitting fields of preimages of P under multiplication-by-l maps. We give a group-theoretic structure theorem for the corresponding Galois group, and state a conjecture regarding composita of two such splitting fields.

How Differing Interpretations Of Making Mathematics Fun Influence Teaching Practice, Amanda Sawyer

Proceedings of the Annual Meeting of the Georgia Association of Mathematics Teacher Educators

I investigated an experienced teacher and a beginning teacher who held similar beliefs about making mathematics learning fun yet held different interpretations of implementation. I found when a teacher equated fun with problem solving, her classroom practice included activities with higher-level thinking skills. In contrast, a teacher who defined fun as students’ enjoyment layered manipulatives and group work on top of procedures. Therefore, teachers need opportunities to reflect on the nature of student understanding as a precursor to shaping their views of fun.

Negative phrases and attitudes toward mathematics have become commonplace in popular culture. Perhaps in response to this …

Anomalies In Sensor Network Deployments: Analysis, Modeling, And Detection, Giovani Rimon Abuaitah

Browse all Theses and Dissertations

A sensor network serves as a vital source for collecting raw sensory data. Sensor data are later processed, analyzed, visualized, and reasoned over with the help of several decision making tools. A decision making process can be disastrously misled by a small portion of anomalous sensor readings. Therefore, there has been a vast demand for mechanisms that identify and then eliminate such anomalies in order to ensure the quality, integrity, and/or trustworthiness of the raw sensory data before they can even be interpreted.

Prior to identifying anomalies, it is essential to understand the various anomalous behaviors prevalent in a sensor …

Design And Fabrication Of An Eddy Current Brake Dynamometer For Efficiency Determination Of Electric Wheelchair Motors, Wesley Brin

Browse all Theses and Dissertations

Electric wheelchairs have a considerable impact on improving the quality of life for the millions of disabled persons around the world. These modern pieces of technology offer freedom and mobility for disabled persons to interact with the world outside of their homes. The goal of this project is to assist in advancements of conventional electric wheelchairs. This includes replacing the heavy, bulky, and inefficient lead acid batteries and worm gear drive systems with lithium-ion batteries and wheel hub motors in order to decrease weight and size, and increase efficiency. This master thesis research is focused on designing, fabricating, and testing …

Landau-Zener Dynamics Of A Nanoresonator Containing A Tunneling Spin, Michael F. O'Keeffe, Eugene M. Chudnovsky, Dmitry A. Garanin

Publications and Research

We study the Landau-Zener dynamics of a tunneling spin coupled to a torsional resonator. For strong spin-phonon coupling, when the oscillator frequency is large compared to the tunnel splitting, the system exhibits multiple Landau-Zener transitions. Entanglement of spin and mechanical angular momentum results in abrupt changes of oscillator dynamics which coincide in time with spin transitions. We show that a large number of spins on a single oscillator coupled only through the in-phase phonon field behaves as a single large spin, greatly enhancing the spin-phonon coupling. We compare purely quantum and semiclassical dynamics of the system and discuss their experimental …

Mutual Information In Hawking Radiation, Norihiro Izuka, Daniel N. Kabat

Publications and Research

We compute the mutual information of two Hawking particles emitted consecutively by an evaporating black hole. Following Page, we find that the mutual information is of order exp(-S) where S is the entropy of the black hole. We speculate on implications for black hole unitarity, in particular on a possible failure of locality at large distances.

Black Hole Formation At The Correspondence Point, Norihiro Izuka, Daniel N. Kabat, Roy Shubho, Debajyoti Sarkar

Publications and Research

We study the process of bound state formation in a D-brane collision. We consider two mechanisms for bound state formation. The first, operative at weak coupling in the worldvolume gauge theory, is pair creation of W-bosons. The second, operative at strong coupling, corresponds to formation of a large black hole in the dual supergravity. These two processes agree qualitatively at intermediate coupling, in accord with the correspondence principle of Horowitz and Polchinski. We show that the size of the bound state and timescale for formation of a bound state agree at the correspondence point. The timescale involves matching a parametric …

Cft Representation Of Interacting Bulk Gauge Fields In Ads, Daniel N. Kabat, Gilad Lifschytz

Publications and Research

We develop the representation of interacting bulk gauge fields and charged scalar matter in AdS in terms of non-local observables in the dual CFT. We work in holographic gauge in the bulk, A_z = 0. The correct statement of micro-causality in holographic gauge is somewhat subtle, so we first discuss it from the bulk point of view. We then show that in the 1/N expansion CFT correlators can be lifted to obtain bulk correlation functions which satisfy micro-causality. This requires adding an infinite tower of higher-dimension multi-trace operators to the CFT definition of a bulk observable. For conserved currents the …

Reversal Of Magnetization Of A Single-Domain Magnetic Particle By The Ac Field Of Time-Dependent Frequency, Liufei Cai, Dmitry A. Garanin, Eugene M. Chudnovsky

Publications and Research

We report numerical and analytical studies of the reversal of the magnetic moment of a single- domain magnetic particle by a circularly polarized ac field of time-dependent frequency. For the time-linear frequency sweep, the phase diagrams are computed that illustrate the dependence of the reversal on the frequency sweep rate v , the amplitude of the ac field h , the magnetic anisotropy field d , and the damping parameter . It is shown that the most efficient magnetization reversal requires a non-linear time dependence of the frequency, ! ( t ) , for which an exact analytical formula is …

Excitation Modes Of Vortices In Submicron Magnetic Disks, Ricardo Zarzuela, Eugene M. Chudnovsky, Javier Tejada

Publications and Research

Classical and quantum theory of spin waves in the vortex state of a mesoscopic sub-micron magnetic disk has been developed with account of the finite mass density of the vortex. Oscillations of the vortex core resemble oscillations of a charged string in a potential well in the presence of the magnetic field. Conventional gyroscopic frequency appears as a gap in the spectrum of spin waves of the vortex. The mass of the vortex has been computed that agrees with experimental findings. Finite vortex mass generates a high-frequency branch of spin waves. Effects of the external magnetic field and dissipation have …

Diffractive Effects And General Boundary Conditions In Casimir Energy, Dimitra Karabali, V P. Nair

Publications and Research

The effect of edges and apertures on the Casimir energy of an arrangement of plates and boundaries can be calculated in terms of an effective nonlocal lower-dimensional field theory that lives on the boundary. This formalism has been developed in a number of previous papers and applied to specific examples with Dirichlet boundary conditions. Here we generalize the formalism to arbitrary boundary conditions. As a specific example, the geometry of a flat plate and a half-plate placed parallel to it is considered for a number of different boundary conditions and the area-dependent and edge dependent contributions to the Casimir energy …

Discovery Of A Magnetic Field In The Rapidly Rotating O-Type Secondary Of The Colliding-Wind Binary Hd 47129 (Plaskett's Star), J. H. Grunhut, G. A. Wade, M. A. Leutenegger, V. Petit, G. Rauw, C. Neiner, F. Martins, David H. Cohen, M. Gagné, R. Ignace, S. Mathis, S. E. De Mink, A. F.J. Moffat, S. P. Owocki, M. Shultz, J. O. Sundqvist

Physics & Astronomy Faculty Works

We report the detection of a strong, organized magnetic field in the secondary component of the massive O8III/I+O7.5V/III double-lined spectroscopic binary system HD 47129 (Plaskett's star) in the context of the Magnetism in Massive Stars survey. Eight independent Stokes V observations were acquired using the Echelle SpectroPolarimetric Device for the Observations of Stars (ESPaDOnS) spectropolarimeter at the Canada-France-Hawaii Telescope and the Narval spectropolarimeter at the Telescope Bernard Lyot. Using least-squares deconvolution we obtain definite detections of signal in Stokes V in three observations. No significant signal is detected in the diagnostic null (N) spectra. The Zeeman signatures are broad and …

In Vivo Ultrasonic Detection Of Polyurea Crosslinked Silica Aerogel Implants, Firouzeh Sabri, Merry E. Sebelik, Ryan K. Meacham, John Dudley Boughter, Mitchell J. Challis, Nicholas Leventis

Chemistry Faculty Research & Creative Works

Background:Polyurea crosslinked silica aerogels are highly porous, lightweight, and mechanically strong materials with great potential for in vivo applications. Recent in vivo and in vitro studies have demonstrated the biocompatibility of this type of aerogel. the highly porous nature of aerogels allows for exceptional thermal, electric, and acoustic insulating capabilities that can be taken advantage of for non-invasive external imaging techniques. Sound-based detection of implants is a low cost, non-invasive, portable, and rapid technique that is routinely used and readily available in major clinics and hospitals.Methodology:In this study the first in vivo ultrasound response of polyurea crosslinked silica aerogel implants …

Siguria E Internet Protokol Ipv4 Vs Ipv6, Imran Junuzi

Theses and Dissertations

Me zhvillimin e shpejtë të teknologjisë dhe përhapëjen e shpejtë të internetit, Internet Protocol versionin 4 ishte teknologji themelore që e bën të mundur që të lidhen paisjet tona në internet. Kurdo që një pajisje të hyn në internet, dhe dergon të dhëna nga një kompjuter në tjetrin me anë të internetit, një pako të dhënave duhet të transferohen në të gjithë rrjetin që përmban adresat IP të dyja pajisjet. Pa IP adres kompjuterët nuk do të jenë në gjendje të komunikojnë dhe të dërgojm të dhëna me njëri-tjetrin. IPv6 është rishikimi i gjashtë për Internet Protocol dhe pasardhës i …

Secure Design Defects Detection And Correction, Wenquan Wang

Masters Theses

"Bad design and software defects often make source codes hard to understand and lead to maintenance difficulties. In order to detect and fix such defects, researchers have systematically investigated these issues and designed different effective algorithms to tackle the problems. However, most of these methods need source codes/models for defect detection and correction. Commercial companies, like banks, may not be willing to provide their source models due to data security. Therefore, it is a huge challenge to detect software detects by a consulting company as well as to keep source models confidential. This thesis analyze security issues in existing approaches …

Confirmation Of Allelopathic Chemicals From Reed Canarygrass (Phalaris Arundinacea L.) Roots, Alexander Richard Tomes

All Graduate Theses, Dissertations, and Other Capstone Projects

Reed Canarygrass (Phalaris arundinacea) is an invasive species and a major threat to grasslands and natural wetlands on nearly every landmass (Morrison and Molofsky 1998). Methanol extracts of whole and macerated Reed Canarygrass roots have been found to reduce the germination and growth of lettuce (Lactuca sativa), radish (Raphanus sativus), and the aquatic plant, Reed Mannagrass (Glyceria maxima) (Veit and Proctor 2009). Linoleic, linolenic and palmitic acids were identified in the methanol extracts of both the whole and macerated Reed Canarygrass roots (Proctor 2011). The purpose of this research was to determine if these chemicals individually and in combination would …

The Educational Training Of Storm Chasers And Storm Spotters In Relation To Geographical Dispersion Across The United States, Paul R. Zunkel

All Graduate Theses, Dissertations, and Other Capstone Projects

When severe weather strikes, storm chasers and storm spotters confirm that what forecasters and meteorologists are seeing on a radar screen is actually occurring in the field. While some documenters are classically trained (i.e. they have a background in atmospheric science and or meteorology attained from a 4 year university) many others are not. There are currently two organizations available for the weather enthusiast to be a part of, SKYWARN and SpotterNetwork. These organizations give weather enthusiasts a background knowledge into severe weather; however, many weather enthusiasts are not classically trained and most have not taken any formal education in …

Are 34s-Enriched Authigenic Sulfide Minerals A Proxy For Elevated Methane Flux And Gas Hydrates In The Geologic Record?, Walter S. Borowski, Nancy M. Rodriguez, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

The sulfate–methane transition (SMT) zone is a diagenetic transition within anoxic marine sediments created by the metabolic activity of a consortium of sulfate-reducing bacteria and methane-oxidizing Archaea. As interstitial dissolved sulfate is consumed by microbially mediated sulfate reduction of sedimentary organic matter (SOM) and anaerobic oxidation of methane (AOM) large enrichments of ³⁴S occur in the interstitial sulfate pool. These isotopic enrichments are transmitted to the dissolved sulfide pool (∑HS⁻) and subsequently into sulfide minerals (So, ∼FeS, FeS₂).

We investigate the sulfur isotopic composition of pore-water sulfate and sulfide minerals at three sites underlain …

Theoretical Design Of Stable Small Aluminium-Magnesium Binary Clusters, Edison Osorio, Alejandro Vasquez, Elizabeth Florez, Fanor Mondragon, Kelling J. Donald, William Tiznado

Chemistry Faculty Publications

We explore in detail the potential energy surfaces of the Al_xMg_y (x, y = 1–4) systems as case studies to test the utility and limitations of simple rules based on electron counts and the phenomenological shell model (PSM) for bimetallic clusters. We find that it is feasible to design stable structures that are members of this set of small Al–Mg binary clusters, using simple electron count rules, including the classical 4n + 2 Hückel model, and the most recently proposed PSM. The thermodynamic stability of the title compounds has been evaluated using several different descriptors, including …

Dynamic Passivation With Bsa Overcomes Ltcc Mediated Inhibition Of Pcr, Jason Besecker, Kenneth A. Cornell, Greg Hampikian

Chemistry and Biochemistry Faculty Publications and Presentations

The increasing use of low temperature co-fired ceramic (LTCC) for the fabrication of biological microfluidic devices necessitates further research on LTCC biocompatibility. In this study we explore the inhibitory effect of DuPont's 951 LTCC on Polymerase Chain Reaction (PCR), and demonstrate a novel mechanism to increase biocompatibility between LTCC and PCR with the addition of a common passivation substance, bovine serum albumin (BSA). We show that DuPont's 951 LTCC binds negatively charged proteins including BSA and ovalbumin (OVA). This is a significant discovery as proteins (enzymes) are an essential component of most biological reactions, and a frequent addition to microfluidic …

A Gridded Reconstruction Of Warm Season Precipitation For Asia Spanning The Past Half Millennium, Song Feng, Q. Steven Hu, Qianru Wu, Michael E. Mann

Department of Earth and Atmospheric Sciences: Faculty Publications

The authors reconstructed May–September precipitation over the Asian continent (5°–55°N, 60°–135°E) back to AD 1470 on the basis of tree-ring data, historical documentary records, ice core records, and the few long-term instrumental data series available in the region. They employed the method of Regularized Expectation Maximization (RegEM) and applied it to 44 subregions within the continent. Verification exercises demonstrate that the reconstruction is skillful over most of the study domain, with eastern China, India, and other regions of humid climate displaying the greatest skill. Lower reconstruction skill is observed in semiarid and arid regions, which was attributable at least in …

Constraints On Aerosol Sources Using Geos-Chem Adjoint And Modis Radiances, And Evaluation With Multisensor (Omi, Misr) Data, Xiaoguang Xu, Jun Wang, Daven Henze, Wenjun Qu, Monika Kopacz

Department of Earth and Atmospheric Sciences: Faculty Publications

We present a new top-down approach that spatially constrains the amount of aerosol emissions using satellite (Moderate Resolution Imaging Spectroradiometer (MODIS)) observed radiances with the adjoint of a chemistry transport model (GEOS-Chem). This paper aims to demonstrate the approach through applying it to a case study that yields the following emission estimates over China for April 2008: 1.73 Tg for SO2, 0.72 Tg for NH3, 1.38 Tg for NOx, 0.10 Tg for black carbon, and 0.18 Tg for organic carbon from anthropogenic sources, which reflects, respectively, a reduction of 33.5%, 34.5%, 18.8%, 9.1%, and 15% in comparison to the prior …

Potential Climate Change Effects On Groundwater Recharge In The High Plains Aquifer, Usa, Russell S. Crosbie, Bridget R. Scanlon, Freddie S. Mpelasoka, Robert C. Reedy, John B. Gates, Lu Zhang

Department of Earth and Atmospheric Sciences: Faculty Publications

Considering that past climate changes have significantly impacted groundwater resources, quantitative predictions of climate change effects on groundwater recharge may be valuable for effective management of future water resources. This study used 16 global climate models (GCMs) and three global warming scenarios to investigate changes in groundwater recharge rates for a 2050 climate relative to a 1990 climate in the U.S. High Plains region. Groundwater recharge was modeled using the Soil-Vegetation-Atmosphere- Transfer model WAVES for a variety of soil and vegetation types representative of the High Plains. The median projection under a 2050 climate includes increased recharge in the Northern …