Digital Commons Network^™

Estimation Of Shelf-Slope Exchanges Induced By Frontal Instability Near Submarine Canyons, A. Jordi, John M. Klinck, G. Basterretxea, A. Orfila

CCPO Publications

The dynamics associated with the propagation of unstable waves along a density front and their interaction with submarine canyons are simulated and analyzed with a fine-resolution three-dimensional primitive equation coastal ocean model. Simulations consider flow in an alongshore density front over two bottom topographies: an idealized straight shelf and a shelf incised by a canyon. The stationary circulation over the idealized shelf exhibits a geostrophic balance that is perturbed when the canyon topography is introduced. Enhanced cross-shore and vertical motions are produced as a result of the front-canyon interaction. A second set of simulations consider the effect of a small …

Eastern Us Continental Shelf Carbon Budget Integrating Models, Data Assimilation, And Analysis, E. E. Hofmann, J. N. Druon, K. Fennel, M. Friedrichs

CCPO Publications

No abstract provided.

Otolith Chemistry Indicates Population Structuring By The Antarctic Circumpolar Current, Julian R. Ashford, Cynthia M. Jones, Eileen E. Hofmann, Inigo Everson, Carlos A. Moreno, Guy Duhamel, Richard Williams

CCPO Publications

Large-scale transport of seawater in ocean currents may generate spatially complex population structure through the advection of life stages of marine fish species. To test this, we compared the chemistry of otolith nuclei from Patagonian toothfish (Dissostichus eleginoides), presently managed as spatially discrete Populations corresponding to fishing management areas along the Antarctic Circumpolar Current (ACC), which transports water eastward around the Southern Ocean. The chemistry of otolith nuclei, laid down during early life, differed significantly between fishing areas Off South America and the Antarctic and between some Antarctic areas. However, we found significant discrepancies from expectation for a …

A Modelling Study Of Developmental Stage And Environmental Variability Effects On Copepod Foraging, Jerry D. Wiggert, Eileen E. Hofmann, Gustav-Adolf Paffenhöfer

CCPO Publications

We used a stochastic Lagrangian model to study how behaviour contributes to copepod grazing success. The model simulates distinct foraging behaviours of Clausocalanus furcatus, Paracalanus aculeatus, and Oithona plumifera. Three sets of simulations were performed to investigate the effects of (a) prey-size preference; (b) variation in prey-size spectra; and (c) turbulence intensity on these species’ grazing rates. The size preference simulations demonstrate that, compared with copepodites, mature females have cell ingestion rates that are an order of magnitude lower, while carbon uptake is reduced by 35%. A prey spectrum that is skewed towards cells ,<6 >μm promotes copepodite …

Transverse Structure Of Wind-Driven Flow At The Entrance To An Estuary: Nansemond River, Diego A. Narváez, Arnoldo Valle-Levinson

CCPO Publications

Observations of current velocity profiles were combined with an analytical solution to study the transverse partition of the wind-driven flow in an estuary, the Nansemond River, which is a tributary of the James River in the Chesapeake Bay. Observations spanned two periods of nearly 3 months in autumn-winter of 2003-2004 and spring-summer 2004. The wind-driven circulation consisted of downwind flow over the shoal and upwind flow in the channel at the entrance to the estuary. This pattern developed mainly with landward winds and provided observational evidence that sustains analytical and numerical model results. The transverse structure of the flow showed …

Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins

OES Faculty Publications

We examined the physiological responses of steady-state iron (Fe)-replete and Fe-limited cultures of the biogeochemically critical marine unicellular diazotrophic cyanobacterium Crocosphaera at glacial (19 Pa; 190 ppm), current (39 Pa; 380 ppm), and projected year 2100 (76 Pa; 750 ppm) CO₂ levels. Rates of N₂ and CO₂ fixation and growth increased in step with increasing partial pressure of CO₂ (pCO₂), but only under Fe- replete conditions. N₂) and carbon fixation rates at 75 Pa CO₂ were 1.4-1.8-fold and 1.2-2.0-fold higher, respectively, relative to those at present day and glacial pCO_{2 …}

Research Supporting Technology Education- Task Force 2.4 Final Report, Philip A. Reed, Jim Carlson, Fred Figliano, Hal Harrison, Hyuksoo Kwon, Johnny Moye, Phyllis Opare, John M. Ritz, Roger Skophammer, John Wells

STEMPS Faculty Publications

(First paragraph) ITEA's Board of Directors convened a task force in 2006 to identify research on technology teaching and learning. The resulting database is designed to help teachers, supervisors, and anyone that needs to show research support for technology education. The research was compiled by the following task force members:

Biological Networks: Modeling And Structural Analysis, Emad Y. Ramadan

Computer Science Theses & Dissertations

Biological networks are receiving increased attention due to their importance in understanding life at the cellular level. There exist many different kinds of biological networks, and different models have been proposed for them. In this dissertation we focus on suitable network models for representing experimental data on protein interaction networks and protein complex networks (protein complexes are groups of proteins that associate to accomplish some function in the cell), and to design algorithms for exploring such networks. Our goal is to enable biologists to identify the general principles that govern the organization of protein-protein interaction networks and protein complex networks. …

Cross Sections And Beam Asymmetries For E ⃗ P → Enπ+ In The Nucleon Resonance Region For 1.7 ⩽ Q2 ⩽ 4.5 Gev2, M. J. Amaryan, H. Bagdasaryan, S. Bültmann, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, A. V. Klimenko, S. E. Kuhn, J. Lachniet, R. A. Niyazov, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., The Clas Collaboration

Physics Faculty Publications

The exclusive electroproduction process e ⃗ p → e'nπ⁺ was measured in the range of the photon virtuality Q² =1.7-4.5 GeV², and the invariant mass range for the n π⁺ system of W=1.15-1.7 GeV using the CEBAF Large Acceptance Spectrometer. For the first time, these kinematics are probed in exclusive π⁺ production from protons with nearly full coverage in the azimuthal and polar angles of the nπ⁺ center-of-mass system. The nπ⁺ channel has particular sensitivity to the isospin 1/2 excited nucleon states, and together with the pπ⁰ final state will serve …

Emergent Behavior In Massively-Deployed Sensor Networks, Ekaterina Shurkova, Ruzana Ishak, Stephan Olariu, Shaharuddin Salleh

Computer Science Faculty Publications

The phenomenal advances in MEMS and nanotechnology make it feasible to build small devices, referred to as sensors that are able to sense, compute and communicate over small distances. The massive deployment of these small devices raises the fascinating question of whether or not the sensors, as a collectivity, will display emergent behavior, just as living organisms do. In this work we report on a recent effort intended to observe emerging behavior of large groups of sensor nodes, like living cells demonstrate. Imagine a massive deployment of sensors that can be in two states "red" and "blue". At deployment time …

A Follow-Up Study Of Marketing Education Graduates From Old Dominion University 2001-2007, Meghan Dowd

OTS Master's Level Projects & Papers

The problem in this study was to evaluate graduates of the marketing education program at Old Dominion University to determine the program's effectiveness in preparing them to enter the teaching profession.

A Follow-Up Study Of Technology Education Graduates From Old Dominion University 2002-2006, Johnny F. Mack

OTS Master's Level Projects & Papers

Through this follow-up study, survey data were collected toward fulfilling the following objectives: Determine whether graduates of Old Dominion University's Technology Education undergraduate program were adequately prepared to assume teaching positions; Determine what improvements can be made to the undergraduate curriculum at Old Dominion University based upon graduate's feedback; and Determine whether the standards established through the Standards of Technological Literacy framework were being attained.

Career Placement Of Graduates Who Received A Bachelor Of Science Degree In Training Specialist, Latrey E. Myrick

OTS Master's Level Projects & Papers

To determine career placement of college graduates who received a Bachelor of Science degree from Old Dominion University in the training specialist major, the following research objectives were analyzed: Determine whether Old Dominion University graduates were currently working within the training career field; Determine whether Old Dominion University graduates accepted lower occupational status positions and/or lower pay than often provided in their major; and determine whether Old Dominion University graduates were facing unemployment following a year of degree completion.

The Use Or Non-Use Of Calculators Affects On Student's Ability To Perform Basic Mathematics Problems, Christina Miles

OTS Master's Level Projects & Papers

The purpose of this study was to determine if the use or non-use of calculators in eighth grade mathematics classes affects a student's ability to solve basic mathematics equations in the Teen living (family and Consumer Science) class when working with simplistic life skill problems.

Relationship Between Workplace Skills And Grade Point Averages As Predictors For Employment, John Nelson

OTS Master's Level Projects & Papers

The problem of this study was to determine the relationship between workplace readiness skills test scores of students' with their current year grade point average in the Information Technology and Telecommunication ATC courses as a predictor of successful employment.

Using Brain Compatible Assessment To Obtain Higher Test Scores As Compared To Multiple Choice Tests, Raena Weimer

OTS Master's Level Projects & Papers

The purpose of this study was to determine whether high school students enrolled in Resource Management for Independent Living obtained higher test scores when evaluated using brain-compatible assessments.

Follow-Up Of Danville Community College Networking Track Iii Graduates Form 2005-2007, Steven Carrigan

OTS Master's Level Projects & Papers

The focus of this study was to determine the graduate job placement rate of the Networking Track III curriculum offered at Danville Community College and what impact did obtaining this training have on their success.

School District Budgeting In The Era Of Increased Accountability And No Child Left Behind: A Mixed Methods Case Study Of School District Budgeting Processes And The Correlation To Student Achievement, Scott Alan Burckbuchler

Educational Leadership & Workforce Development Theses & Dissertations

School district budgeting decisions take on added significance in light of fulfilling the objectives of No Child Left Behind Act (NCLB). If NCLB's goal of 100% student proficiency by 2014 is to be realized, school districts, as part of their improvement plans, need to focus on how to ensure that appropriate resources are available to fund proven instructional strategies which produce results. Budgeting merges resources and results. This study examines school district budgeting processes in light of NCLB. Overall, it appears that, in the school districts represented, budgeting practices have changed since the introduction of NCLB. More specifically, there has …

Swimming Dynamics And Propulsive Efficiency Of Squids Throughout Ontogeny, Ian K. Bartol, Paul S. Krueger, Joseph T. Thompson, William J. Stewart

Biological Sciences Faculty Publications

Synopsis Squids encounter vastly different flow regimes throughout ontogeny as they undergo critical morphological changes to their two locomotive systems: the fins and jet. Squid hatchlings (paralarvae) operate at low and intermediate Reynolds numbers (Re) and typically have rounded bodies, small fins, and relatively large funnel apertures whereas juveniles and adults operate at higher Re and generally have more streamlined bodies, larger fins, and relatively small funnel apertures. These morphological changes and varying flow conditions affect swimming performance in squids. To determine how swimming dynamics and propulsive efficiency change throughout ontogeny, digital particle image velocimetry (DPIV) and kinematic …

Mycobacteriosis-Associated Mortality In Wild Striped Bass (Morone Saxatilis) From Chesapeake Bay, Usa, D. T. Gauthier, R. J. Latour, D. M. Heisey, C. F. Bonzek, J. Gartland, E. J. Burge, W. K. Vogelbein

Biological Sciences Faculty Publications

The striped bass (Morone saxatilis) is an economically and ecologically important finfish species along the Atlantic seaboard of the United States. Recent stock assessments in Chesapeake Bay (USA) indicate that non-fishing mortality in striped bass has increased since 1999, concomitant with very high (>50%) prevalence of visceral and dermal disease caused by Mycobacterium spp. Current fishery assessment models do not differentiate between disease and other components of non-fishing mortality (e. g., senescence, predation); therefore, disease impact on the striped bass population has not been established. Specific measurement of mortality associated with mycobacteriosis in wild striped bass is …

Food Limitation In Larval Fish: Ontogenetic Variation In Feeding Scope And Its Potential Effect On Survival, Alexander B. Bochdansky, Peter Grønkjær, Pierre Pepin, William C. Leggett

OES Faculty Publications

We used the radiated shanny Ulvaria subbifurcataas a model species to explore the relative gut fullness from hatch to metamorphosis of wild larvae, and compared these values with those of laboratory-reared larvae fed at maximum rates. Ingestion rates of most wild larvae were above starvation levels but below the maximum feeding levels of laboratory-reared larvae. Twenty-six percent of freshly-hatched wild larvae and 11% of large, pre-settlement wild larvae had insufficient food in their stomach to satisfy metabolic requirements. These results, taken on their own, are consistent with the much hypothesized increased foraging performance and survival of larger larvae relative …

Sublethal And Killing Effects Of Atmospheric-Pressure, Nonthermal Plasma On Eukaryotic Microalgae In Aqueous Media, Ying Zhong Tang, Xin Pei Lu, Mounir Laroussi, Fred C. Dobbs

OES Faculty Publications

In-depth studies on the interaction of nonthermal plasmas with microorganisms usually focus on bacteria; only little attention has been given to their effects on more complex eukaryotic cells. We report here nonthermal plasma's effects on cell motility, viability staining, and morphology of eukaryotic microalgae, with three marine dinoflagellates and a marine diatom as major targets. The effects on motility and viability staining depended on the time of exposure to plasma and the species of microalgae. We observed a strong pH decrease in aqueous samples (marine and freshwater algal cultures, their culture media, and deionized water) after exposure to plasma, and …

Dgm-Fd: A Finite Difference Scheme Based On The Discontinuous Galerkin Method, Anne Marguerite Fernando

Mathematics & Statistics Theses & Dissertations

Accurate and efficient numerical wave propagation is important in many areas of study such as computational aero-acoustics (CAA). While dissipation and dispersion errors influence the accuracy of a method, efficiency can be assessed by convergence rates and effective adaptability to different mesh structures. Finite difference and finite element methods are commonly used numerical schemes in CAA. Finite difference methods have the advantages of ease of use as well as high order convergence, but often require a uniform grid, and stable boundary closure can be non-trivial. Finite element methods adapt well to different mesh structures but can become difficult to implement …

The Effectiveness Of One Week Of Remediation For Geometry, Martha L. Hopkins

OTS Master's Level Projects & Papers

The purpose of this study was to explore how remediation affects SOL retake scores in geometry. The following hypothesis was developed to guide this study: Students who passed high school geometry, but failed the SOL test, will pass the SOL retest after completing the one-week Geometry SOL Remediation Recovery Program.

The Effects Of Technology Education On Science Achievement, Jessica L. Filosa

OTS Master's Level Projects & Papers

The problem of this study was to determine the effect of technology education units on science achievement of third graders. To solve this problem, the following hypotheses were tested: 1) Within a third grade classroom, technology education units of instruction will affect students' achievement on the Science Tests For Higher Standards more than non-participants in such instruction. 2)Within a third grade classroom, technology education units of instruction will affect students' achievement on the Science Standards of Learning more than non-participants in such instruction.

Improved Constrained Global Optimization For Estimating Molecular Structure From Atomic Distances, Terri Marie Grant

Mathematics & Statistics Theses & Dissertations

Determination of molecular structure is commonly posed as a nonlinear optimization problem. The objective functions rely on a vast amount of structural data. As a result, the objective functions are most often nonconvex, nonsmooth, and possess many local minima. Furthermore, introduction of additional structural data into the objective function creates barriers in finding the global minimum, causes additional computational issues associated with evaluating the function, and makes physical constraint enforcement intractable. To combat the computational problems associated with standard nonlinear optimization formulations, Williams et al. (2001) proposed an atom-based optimization, referred to as GNOMAD, which complements a simple interatomic distance …

Nutrient And Carbon Dynamics In The Chesapeake Bay Outflow Plume And Their Effect On The Coastal Ocean Environment, Katherine C. Filippino

OES Theses and Dissertations

Seasonally resolved nutrient and carbon fluxes from estuaries to the coastal ocean are poorly constrained. Nutrient and carbon cycling in highly productive regions like the Chesapeake Bay outflow plume and surrounding coastal environments greatly affect our global understanding of carbon cycling. The overall questions for the research described in this dissertation stem from the need to close global carbon budgets, and obtain a fundamental understanding of nutrient dynamics in a coastal region heavily influenced by seasonality and human impacts.

Within the framework of physical characteristics of the outflow plume and through the characterization of nutrient concentrations, primary productivity rates, and …

Massive Spatiotemporal Watershed Hydrological Storm Event Response Model (Mhserm) With Time-Lapsed Nexrad Radar Feed, Changqing Song

Civil & Environmental Engineering Theses & Dissertations

Correctly and efficiently estimating hydrological responses corresponding to a specific storm event at the streams in a watershed is the main goal of any sound water resource management strategy. Methods for calculating a stream flow hydrograph at the selected streams typically require a great deal of spatial and temporal watershed data such as geomorphological data, soil survey, landcover, precipitation data, and stream network information to name a few. However, extracting and preprocessing such data for estimation and analysis is a hugely time-consuming task, especially for a watershed with hundreds of streams and lakes and complicated landcover and soil characteristics. To …

Catalytic Wet Air Oxidation Of Mono Azo Dye Orange Ii: Catalyst Selection, Reaction Kinetics, And Modeling, Pinar Ozdural

Civil & Environmental Engineering Theses & Dissertations

Wastewaters generated as byproducts of dyeing processes are not treatable with conventional methods. It has been estimated that among the 900,000 tons of different dyes produced annually in the world, approximately 10–15% are lost in wastewater streams during manufacturing and processing operations. Once in rivers and streams, dyes cause major problems, such as reducing light penetration, or displaying toxic effects on aquatic life. Therefore, it is essential that dyes are removed from wastewaters before being discharged into the environment.

This study focuses on the catalytic wet air oxidation (CWAO) of Orange II, a mono azo dye used in large amounts …

Experimental Investigation Of Active Control Of Bluff Body Vortex Shedding, Ilteris Koc

Mechanical & Aerospace Engineering Theses & Dissertations

Mean and fluctuating forces acting on a body are strongly related to vortex shedding generated behind it. Therefore, it is possible to obtain substantial reductions of at least the unsteady forces if vortex shedding is controlled or its regularity is reduced. While conventional active flow control methods are mainly concerned with direct interaction with, and alteration of, the mean flow about a body, modern techniques involve altering existing flow instabilities using relatively small inputs to obtain large-scale changes of mean flows. Aerodynamic flow control may be intended to delay or suppress boundary layer separation through creation of a boundary layer …