Physical Sciences and Mathematics Commons^™

Seasonal Variability Of Near-Surface Hydrography And Frontal Features In The Northern Gulf Of Alaska And Prince William Sound, Stephen R. Okkonen, David L. Cutchin, Thomas Royer

CCPO Publications

The meridional structure and seasonal cycles of near-surface hydrography and frontal features in the northern Gulf of Alaska and Prince William Sound are described from high-resolution measurements of near-surface temperature and salinity acquired by a vessel-mounted thermosalinograph. Near-surface temperature exhibits a well-defined seasonal cycle with little variation between basin and shelf waters. Near-surface salinity exhibits a well-defined seasonal cycle that is confined largely to the shelf waters reflecting the influence of coastal freshwater inputs. Prominent near-surface fronts at the shelf break, at the entrance to Prince William Sound, and in northern Prince William Sound intensify and weaken following the seasonal …

Nonlinear Optics And An Experimental Test Of Bell’S Inequality, Michael Herbst

Honors Papers

The purpose of this investigation is to assemble an apparatus capable of testing Bell’s inequality for a local hidden variable. The historical context and theoretical developments that led to this area of inquiry are presented. Expected experimental results stemming from two distinct physical theories are introduced. Procedures are given that outline the assembly of a device capable of testing these theories. Analysis confirming the successful completion of a majority of the steps is presented, and the final necessary steps are detailed. Finally, a laboratory prompt for this experiment’s use in Oberlin College’s advanced laboratory class is given.

Onset Conditions For Equatorial Spread F Determined During Equis Ii, D. L. Hysell, M. F. Larsen, C. M. Swenson, Aroh Barjatya, T. F. Wheeler, M. F. Sarango, Et.Al

Publications

An investigation into the dynamics and layer structure of the postsunset ionosphere prior to the onset of equatorial spread F (ESF) took place during the NASA EQUIS II campaign on Kwajalein Atoll on August 7 and 15, 2004. On both nights, an instrumented rocket measured plasma number density and vector electric fields to an apogee of about 450 km. Two chemical release rockets were launched both nights to measure lower thermospheric wind profiles. The Altair UHF/VHF radar was used to monitor coherent and incoherent scatter. In both experiments, strong plasma shear flow was detected. Periodic, patchy bottom-type scattering layers were …

Functional Response Of Six Indigenous Trichogrammatid Egg Parasitoids (Hymenoptera: Trichogrammatidae) In Kenya: Influence Of Temperature And Relative Humidity, Andrew Kalyebi, W. A. Overholt, F. Schulthess, J. M. Mueke, S. A. Hassan, S. Sithanantham

All Peer-Reviewed Publications

Laboratory tests were conducted to evaluate the functional responses of six species/strains of native Kenyan trichogrammatids using the factitious pyralid host, Corcyra cephalonica, under different temperature and relative humidity regimes. The objective was to identify promising species/strains for controlling the noctuid Helicoverpa armigera, a serious pest of vegetables in Kenya. The six species/strains of Trichogramma and Trichogrammatoidea represented collections from low (<700 m), mid (between 700 and 1200 m) and high (>1200 m) altitude locations. They were compared for parasitisation rates at six temperatures (10, 15, 20, 25, 30 and 35°C) and two relative humidity levels (40-50% and 70-80%), at five host egg densities (6, 12, 18, 24, and …

Characterisation Of An Acrylamide-Based Photopolymer For Holographic Data Storage, Hosam Sherif

Masters

An acrylamide-based photopolymer, formulated in the Centre for Industrial and Engineering Optics, was investigated as a recording material for holographic data storage applications. Holographic data storage (HDS) is an optical storage technique, which theoretically allows densities as high as tens of TB/cm2 with data transfer rates of many GB/s/. HDS has unique advantages, such as the ability to perform parallel data searches (associative recall) and implement novel encryption techniques. At present, many materials have been investigated to determine their suitability for use as HDS media. As yet, no one material possesses all the properties that are required to realise the …

An Investigation Of The Effect Of Variation In Surface Electrode Type And Placement On Action Potentials Elicited By Peripheral Nerve Simulation, Jacinta Augustine

Masters

Several experiments were designed and carried out in order to compare the performances of five commercially available EMG surface electrodes. The aim was to identify the optimal surface recording electrode from the samples examined. The particular interest was to assess the comparative performance of the electrodes routinely used in our hospital Neurophysiology laboratory. It is envisaged that the conclusions from the study might be applied to improve the quality and reproducibility of nerve conduction techniques use din our department. A literature survey was carried out to identify some of the factors that influence the recording of evoked potentials from peripheral …

On The Integrability Of A Class Of Nonlinear Dispersive Wave Equations, Rossen Ivanov

Articles

We investigate the integrability of a class of 1+1 dimensional models describing nonlinear dispersive waves in continuous media, e.g. cylindrical compressible hyperelastic rods, shallow water waves, etc. The only completely integrable cases coincide with the Camassa-Holm and Degasperis-Procesi equations.

Self-Assembly Of Ge Quantum Dots On Si(100)- 2×1 By Pulsed Laser Deposition, M. S. Hegazy, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

Self-assembled Ge quantum dots are grown on Si(100)- 2×1 by pulsed laser deposition. The growth is studied by in situ reflection high-energy electron diffraction and postdeposition atomic force microscopy. After the completion of the wetting layer, transient hut clusters, faceted by different planes, are observed. When the height of these clusters exceeded a certain value, the facets developed into {305} planes. Some of these huts become {305}-faceted pyramids as the film mean thickness was increased. With further thickness increase, dome clusters developed on the expense of these pyramids. © 2005 American Institute of Physics. [DOI: 10.1063/1.1949285]

Hydrology Of The Springs, Seeps, And Fens At The Nature Conservancy's Pigeon Point Preserve, Ransom County, North Dakota, Corey W. Askin

Theses and Dissertations

Pigeon Point lies along the Sheyenne River in the west-central part of the Sheyenne Delta Aquifer, southeastern North Dakota. Groundwater discharges along a north-facing bluff at Pigeon Point and forms springs, seeps, and fens 'hosting atypical boreal species. The Nature Conservancy owns 231 ha at Pigeon Point, a tract that also includes the largest and least disturbed spring-fed stream in the region as well as some of the finest riparian forest in the state. In response to possible future groundwater diversion, the objectives of this study are: 1) to characterize the Sheyenne Delta Aquifer up-gradient from Pigeon Point, 2) to …

Reevaluation Of Species Concepts Of Uppermost Cretaceous Unionidae (Mollusca: Bivalvia) : Hell Creek Formation, Montana, U.S.A., Marron J. Bingle

Theses and Dissertations

Species are the basic units of life relative to taxonomy, and a practical definition of species is imperative to paleontology in order to promote reproducible, unambiguous criteria for accurately interpreting past species relationships. The need for a well-defined rubric for identifying species is evident in the freshwater mussel assemblage (Family Unionidae) in the Hell Creek Formation. The Hell Creek Formation unionid species were first described by Whitfield in 1903 and 1907. His descriptions were often based on differences of a single trait. In 1976, Russell reevaluated the original species descriptions, I but still based the classification of species on only …

Iron In The Sargasso Sea (Bermuda Atlantic Time-Series Study Region) During Summer: Eolian Imprint, Spatiotemporal Variability, And Ecological Implications, Peter N. Sedwick, T. M. Church, A. R. Bowie, C. M. Marsay, S. J. Ussher, K. M. Achilles, P. J. Lethaby, R. J. Johnson, M. M. Sarin, D. J. Mcgillicuddy

OES Faculty Publications

We report iron measurements for water column and aerosol samples collected in the Sargasso Sea during July-August 2003 (summer 2003) and April-May 2004 (spring 2004). Our data reveal a large seasonal change in the dissolved iron (dFe) concentration of surface waters in the Bermuda Atlantic Time-series Study region, from ∼1-2nM in summer 2003, when aerosol iron concentrations were high (mean 10 nmol/m^-3), to ∼0.1-0.2nM in spring 2004, when aerosol iron concentrations were low (mean 0.64 nmol/m^-3). During summer 2003, we observed an increase of ∼0.6nM in surface water dFe concentrations over 13 days, presumably due to …

Rich Mesic Forests: Edaphic And Physiographic Drivers Of Community Variation In Western Massachusetts, J. Bellemare, G. Motzkin, D. R. Foster

Biological Sciences: Faculty Publications

Rich Mesic Forest, a Northeastern variant of the species-rich Mixed Mesophytic Forest association of eastern North America, is an Acer saccharum-dominated forest type typically associated with calcareous bedrock and nutrient-rich, mull soils. Rich Mesic Forest (RMF) is a priority for conservation in the Northeast due to its limited areal extent, high plant species richness, and numerous rare taxa, yet the community characteristics and environmental correlates of this forest type are incompletely understood. This study undertook a quantitative classification of RMF of the northeastern edge of the Berkshire Plateau in western Massachusetts. Cluster analysis of data from ten sites identified two …

Chemistry Of Surface Waters: Distinguishing Fine-Scale Differences In Sea Grass Habitats Of Chesapeake Bay, Emmanis Dorval, Cynthia M. Jones

OES Faculty Publications

We tested the hypothesis that the physical and chemical processes acting in sea grass habitats of the lower Chesapeake Bay are spatially structured and that dissolved elemental chemistry of sea grass-habitat surface waters have their own unique identity. We sampled surface waters from July to September 2001 in five sea grass habitats of the lower bay: Potomac, Rappahannock, York, Island (Tangier-Bloodsworth), and Eastern Shore. Dissolved Mg, Mn, Sr, and Ba concentrations were measured by sector field inductively coupled plasma-mass spectrometry. As expected, Mg, Sr, and Ba exhibited conservative behavior, but Mn exhibited nonconservative behavior along the salinity gradient. Spatial differences …

Biophysical Mechanisms Of Larval Fish Ingress Into Chesapeake Bay, Jonathan A. Hare, Simon Thorrold, Harvey Walsh, Christian Reiss, Arnoldo Valle-Levinson, Cynthia Jones

OES Faculty Publications

Selective tidal stream transport is hypothesized as a dominant mechanism by which larvae of marine animals move through estuarine openings. For larvae moving from the shelf to estuarine habitats, selective tidal stream transport proposes that larvae are higher in the water column during flood tide and lower in the water column during ebb tide. Although a number of studies conclude that selective tidal stream transport is the mechanism responsible for larval ingress, few studies consider alternative mechanisms or consider passive explanations for tidal patterns in larval distributions. We examined the biophysical mechanisms responsible for larval ingress into Chesapeake Bay using …

A Unique Seasonal Pattern In Phytoplankton Biomass In Low-Latitude Waters In The South China Sea, Chun-Mao Tseng, George T. F. Wong, I.-I. Lin, C.-R. Wu, K.-K. Liu

OES Faculty Publications

A distinctive seasonal pattern in phytoplankton biomass was observed at the South East Asian Time series Study (SEATS) station (18°N, 116°E) in the northern South China Sea (SCS). Surface chlorophyll-a, depth integrated chlorophyll-a and primary production were elevated to 0.3 mg/m³, ~35 mg/m² and 300 mg-C/m²/d, respectively, in the winter but stayed low, at 0.1 mg/m³, ~15 mg/m² and 110 mg-C/m²/d as commonly found in other low latitude waters, in the rest of the year. Concomitantly, soluble reactive phosphate and nitrate+nitrite in the mixed layer also became …

Hydrographic And Biological Changes In The Taiwan Strait During The 1997-1998 El Niño Winter, S. Shang, C. Zhang, H. Hong, Q. Liu, G. T. F. Wong, C. Hu, B. Huang

OES Faculty Publications

During the 1997–1998 El Niño event, the average sea surface temperature (SST) in the Taiwan Strait (TWS) in the winter was ~1.4°C higher than that of the winter climatological mean. The areal ratio of the warm water (≥2°C above the regional mean) to the cold water (≥2°C below the regional mean) in the TWS increased by 25% while the area of the eutrophic water (chlorophyll a >1 mg m^-3) was halved. Field observations also indicate that the mixed layer in the TWS became more nutrient-poor during this winter. These observations are consistent with a diminished advection of the …

The Effect Of Growth Rate, Phosphorus Concentration, And Temperature On N-2 Fixation, Carbon Fixation, And Nitrogen Release In Continuous Cultures Of Trichodesmium Ims101, Margaret R. Mulholland, Peter W. Bernhardt

OES Faculty Publications

With the use of continuous culture systems, rates of dinitrogen (N₂) and carbon (C) fixation and nitrogen (N)- and C-based doubling times were assessed in Trichodesmium IMS101 growing exponentially at steady state dilution rates of 0.10, 0.20, and 0.33 d^-1 (doubling times of 10, 5, and 3 d - within the range reported for natural populations). Rates of C fixation, N₂ fixation, and N release were examined in replicate culture systems with several techniques. Biomass-specific C uptake varied little with population doubling time, but N₂ fixation and N release varied markedly among treatments. Total daily …

Do Viruses Affect Fecundity And Survival Of The Copepod Acartia Tonsa Dana?, Lisa A. Drake, Fred C. Dobbs

OES Faculty Publications

Naturally occurring viruses are extremely abundant in aquatic systems, and they infect bacteria, cyanobacteria, prokaryotic and eukaryotic phytoplankton, heterotrophic nanoflagellates, fish and mammals. Viral infections of single-celled organisms have been studied intensively in the past decade, but little is known about the effects of viruses on aquatic metazoans, other than for some economically important species. Because zooplankton assemblages are often dominated in number and biomass by copepods, we used them as model organisms to study the effects of naturally occurring viruses on higher trophic levels. We attempted to induce viral infection in laboratory-reared cultures of the estuarine copepod Acartia tonsa …

Variability Of Sea Ice Cover In The Chukchi Sea (Western Arctic Ocean) During The Holocene, Anne De Vernal, Claude Hillaire-Marcel, Dennis A. Darby

OES Faculty Publications

Dinocysts from cores collected in the Chukchi Sea from the shelf edge to the lower slope were used to reconstruct changes in sea surface conditions and sea ice cover using modern analogue techniques. Holocene sequences have been recovered in a down-slope core (B15: 2135 m, 75°44'N, sedimentation rate of ~1cm kyr-¹) and in a shelf core (P1: 201 m, 73°41'N, sedimentation rate of ~22 cm kyr^-1). The shelf record spanning about 8000 years suggests high-frequency centennial oscillations of sea surface conditions and a significant reduction of the sea ice at circa 6000 and 2500 calendar (cal) …

Optimization Of Ultraviolet Emission And Chemical Species Generation From A Pulsed Dielectric Barrier Discharge At Atmospheric Pressure, Xinpei Lu, Mounir Laroussi

Electrical & Computer Engineering Faculty Publications

One of the attractive features of nonthermal atmospheric pressure plasmas is the ability to achieve enhanced gas phase chemistry without the need for elevated gas temperatures. This attractive characteristic recently led to their extensive use in applications that require low temperatures, such as material processing and biomedical applications. The agents responsible for the efficient plasma reactivity are the ultraviolet (UV) photons and the chemically reactive species. In this paper, in order to optimize the UV radiation and reactive species generation efficiency, the plasma was generated by a dielectric barrier discharge driven by unipolar submicrosecond square pulses. To keep the discharge …

Room-Temperature Atmospheric Pressure Plasma For Biomedical Applications, Mounir Laroussi, Xinpei Lu

Electrical & Computer Engineering Faculty Publications

As low-temperature non-equilibrium plasmas come to play an increasing role in biomedical applications, reliable and user-friendly sources need to be developed. These plasma sources have to meet stringent requirements such as low temperature (at or near room temperature), no risk of arcing, operation at atmospheric pressure, preferably hand-held operation, low concentration of ozone generation, etc. In this letter, we present a device that meets exactly such requirements. This device is capable of generating a cold plasma plume several centimeters in length. It exhibits low power requirements as shown by its current-voltage characteristics. Using helium as a carrier gas, very little …

Delineation Of The Fractured-Rock And Unconsolidated Overburden Ground-Water Flow Systems, On The Southern Part Of Manhattan, New York, Through Use Of Advanced Borehole-Geophysical Techniques, Frederick Stumm

Dissertations, Theses, and Capstone Projects

Advanced borehole-geophysical techniques were used to assess the geohydrology of crystalline bedrock in 31 of 64 boreholes on the southern part of Manhattan Island, N.Y. Ten wells were screened in the unconsolidated overburden (glacial aquifer) to determine water-table elevation, transmissivity, and chloride concentration. The borehole-logging techniques included natural gamma, single-point resistance, short-normal resistivity, mechanical and acoustic caliper, magnetic susceptibility, borehole-fluid temperature and resistivity, borehole-fluid specific conductance, dissolved oxygen, pH, redox, heat-pulse flowmeter (at selected boreholes), borehole deviation, acoustic and optical televiewer, and borehole radar (at selected boreholes). The boreholes penetrated gneiss, schist, and other crystalline bedrock that has an overall …

Software Development Project Risk Management: A Literature Review, Kevin Macg. Adams, C. Ariel Pinto

Engineering Management & Systems Engineering Faculty Publications

The rapid and unprecedented growth in software has brought with it some of the most spectacular and costly project failures in modern history. How risk management is presented in the scholarly journals may give insight into the risk management methods and techniques in use on software development projects. This paper provides a glimpse into the risk management methods, methodologies and techniques available to those who are responsible for software development projects by conducting a non-experimental content analysis. The findings reveal that risk management has not received sufficient attention and does not appear to be widely accepted within the software engineering …

Burial Of Terrestrial Organic Matter In Marine Sediments: A Re-Assessment, David J. Burdige

OES Faculty Publications

Calculations based on recent observations indicate that approximately one third of the organic matter presently being buried in marine sediments may be of terrestrial origin, with the majority of this terrestrial organic matter (TOM) burial occurring in muddy, deltaic sediments. These calculations further suggest that the remineralization of terrestrial organic matter in the oceans is also much less efficient than that of marine organic matter. These two underappreciated observations have important implications in terms of our understanding of the controls on the global carbon cycle. From a paleoceanographic perspective, the results presented here also suggest that changes in TOM burial …

Ridding Ships' Ballast Water Of Microorganisms, Fred C. Dobbs, Andrew Rogerson

OES Faculty Publications

( First paragraph) A complex assemblage of microorganisms exists in nearly every aquatic system on earth. In lakes and oceans, every milliliter of water contains about 10² protists (single-celled eukaryotes), 10⁶ bacteria, and 10⁷–10⁹ viruses. Therefore, billions of microorganisms inevitably enter ships’ ballast tanks during normal operations. It has been argued that microorganisms must certainly be frequent invaders of coastal ecosystems, given the high densities of bacteria and viruses in ballast water—10⁸ and 10⁹ organisms per liter, respectively (1)—their potentially high reproductive rates, broad tolerances to physical conditions, and ability to form resting …

New Standards For Reducing Gravity Data: The North American Gravity Database, William J. Hinze, Carlos Aiken, John Brozena, Bernard Coakley, David Dater, Guy Flanagan, Rene Forsberg, Thomas Hildenbrand, G. Randy Keller, James N. Kellogg, Robert Kucks, Xiong Li, Andre Mainville, Robert Morin, Mark Pilkington, Donald Plouff, Dhananjay Ravat, Daniel Roman, Jamie Urrutia-Fucugauchi, Marc Veronneau, Michael Webring, Daniel Winester

Faculty Publications

The North American gravity database as well as databases from Canada, Mexico, and the United States are being revised to improve their coverage, versatility, and accuracy. An important part of this effort is revising procedures for calculating gravity anomalies, taking into account our enhanced computational power, improved terrain databases and datums, and increased interest in more accurately defining long-wavelength anomaly components. Users of the databases may note minor differences between previous and revised database values as a result of these procedures. Generally, the differences do not impact the interpretation of local anomalies but do improve regional anomaly studies. The most …

A Self-Adaptive Evolutionary Negative Selection Approach For Anomaly Detection, Luis J. Gonzalez

CCAC Theses and Dissertations

Forrest et al. (1994; 1997) proposed a negative selection algorithm, also termed the exhaustive detector generating algorithm, for various anomaly detection problems. The negative selection algorithm was inspired by the thymic negative selection process that is intrinsic to natural immune systems, consisting of screening and deleting self-reactive T-cells, i.e., those T-cells that recognize self-cells.

The negative selection algorithm takes considerable time (exponential to the size of the self-data) and produces redundant detectors. This time/size limitation motivated the development of different approaches to generate the set of candidate detectors.

A reasonable way to find suitable parameter settings is to let an …

A Study Of The Relationships Between End-User Information Systems Problems And Helpdesk Critical Success Factors In Higher Education, Richard Dale Parrott

CCAC Theses and Dissertations

In the last fifteen years, information technology (IT) customer support has increased in importance within higher education. The pervasiveness of computers and technology on the campus has allowed students, staff, and faculty to perform a multitude of tasks by controlling their own environments and setting their own priorities. Qualified professional system and user support services have lagged demand. The problem investigated in this study was end-users' satisfaction levels of the higher education helpdesk and how end-users' satisfaction levels affected a helpdesk manager's critical success factors performance and goals. In this study, the first goal was to identify the critical success …

The Effects Of Computerized Smell Of Memory, Brandon Spencer

CCAC Theses and Dissertations

It has long been recognized that there is a major correlation between smell and memory. Until recently, commercialized multi-sensory experiences involving olfaction were limited to non-computerized mediums. Companies that manufacture computerized scent technologies tout the educational benefits of their product, yet prior to this study, there appeared to be no scholarly research in regard to the efficacy of computerized scent producing peripherals in educational environments. The aim of this research was to determine the odor memory enhancement benefits of incorporating olfactory, computerized peripherals into computerized multimedia-learning environments, from both a context dependent and context independent stand point. Specifically, within a …

Predicting Software Size And Development Effort: Models Based On Stepwise Refinement, David P. Voorhees

CCAC Theses and Dissertations

This study designed a Software Size Model and an Effort Prediction Model, then performed an empirical analysis of these two models. Each model design began with identifying its objectives, which led to describing the concept to be measured and the meta-model. The numerical assignment rules were then developed, providing a basis for size measurement and effort prediction across software engineering projects. The Software Size Model was designed to test the hypothesis that a software size measure represents the amount of knowledge acquired and stored in software artifacts, and the amount of time it took to acquire and store this knowledge. …