Physical Sciences and Mathematics Commons^™

Analysis Of Multimode Low-Probability-Of-Intercept (Lpi) Communications With Atmospheric Effects, Ala Ghordlo

Theses and Dissertations

This research expanded Low Probability of Intercept (LPI) communications analysis in two areas. First, multimode communication was included to account for ground to ground and air to ground links in addition to the standard air to air links traditionally used in LPI analysis. The propagation equations for the three modes of interest were derived and included in LPI analytic models in the form of a mode quality factor to account for multimode LPI scenarios. This new quality factor was used in studying several communication and interception link combinations. Variations due to differences between the communication and interception modes were presented …

Performance Analysis Of A Hartman Wavefront Sensor Used For Sensing Atmospheric Turbulence Statistics, Toby D. Reeves

Theses and Dissertations

Atmospheric turbulence parameters, such as Fried's coherence diameter, the outer scale of turbulence, and the turbulence power law, are related to the wavefront slope structure function (SSF). The SSF is defined as the second moment of the wavefront slope difference as a function of both time and position. Knowledge of the SSF allows turbulence parameters to be estimated. Hartmann wavefront sensor (H-WFS) slope measurements composed of both signal and noise, allow the SSF to be estimated by computing a mean square difference of H-WFS slope measurements. The quality of the SSF estimate is quantified by the signal-to-noise ratio (SNR) of …

Deconvolution From Wavefront Sensing Using Optimal Wavefront Estimators, Scott R. Maethner

Theses and Dissertations

A cost effective method to improve the space surveillance mission performance of United States Air Force (USAF) ground-based telescopes is investigated and improved. A minimum variance wavefront estimation technique is used to improve Deconvolution from Wavefront Sensing (DWFS), a method to mitigate the effects of atmospheric turbulence on imaging systems that does not require expensive adaptive optics. Both least-squares and minimum variance wavefront phase estimation techniques are investigated, using both Gaussian and Zernike polynomial elementary functions. Imaging simulations and established performance metrics are used to evaluate these wavefront estimation techniques for a one-meter optical telescope. Performance metrics include the average …

Investigation Of Ba, Bao, Sr And Sro Pulsed Laser-Induced Vapor Plumes In N2, O2, Microwave Discharged O2, And Vacuum At Low Laser Fluence, David L. Byers

Theses and Dissertations

Ba, BaO, Sr and SrO were ablated by 248 nm laser pulses at fluences ranging from 270 mJ-/sq cm to 575 mJ-/sq cm in vacuum and in 25 mtorr atmospheres of N2, O2 and microwave-discharged O2. The spectral emissions of these plumes were compared for indications of ionization due to Ba or Sr collisions with each gas. The addition of a background gas increased the ion and neutral signature across the spectrum. SrO band emission was observed at 16,600-16,900/cm and possible BaO band emissions were observed in the 18,250-18,400/cm, 19,000-19700/cm and 19,800-20,000/cm regions. A screened plate ion probe was use …

Investigation Of Radio Wave Propagation In The Martian Ionosphere Utilizing Hf Sounding Techniques, Robert J. Yowell

Theses and Dissertations

This thesis presents a preliminary design of an ionospheric sounder to be carried aboard one or more of NASA's Mars Surveyor landers. Past Russian and American probes have indicated the existence of an ionosphere, but none of these missions remotely sensed this atmospheric layer from the surface. The rationale for utilizing a surface-based Martian ionospheric sounder is discussed. Based on NASA's choice of launch vehicle and power source, a low-weight, low-powered Chirp sounder using a horizontally-polarized dipole antenna is recommended for the sounder experiment. The sounder experiment should be conducted for at least one Martian year, in order to investigate …

Trace Element Analysis Of Selected Springs In The Virgin River Basin, Mary A. Yelken

UNLV Theses, Dissertations, Professional Papers, and Capstones

Spring water from 23 springs in and near the Virgin River Basin (southwestern Utah, northwestern Arizona, and southeastern Nevada) was collected and analyzed for chemical concentrations. Trace elements and major ion chemistry was used to determine the potential for utilizing water chemistry to provide information on spring water source and flow pathways. Principal Component Analysis (PCA), rare earth element (REE) normalization patterns, and mineral equilibrium modeling (PHREEQE) techniques were used to analyze the data set. Four major spring water groups were displayed by the PCA, based on similarities in water chemistry. The analyses suggest that spring water chemistry is a …

Observation Of Shelfwater Overrunning The Southern Slope Sea, Ajoy Kumar

OES Theses and Dissertations

Analyses of two years (1992 and 1993) of high resolution (1.47 km²) sea surface temperature satellite images of the southern Mid-Atlantic Bight (MAB), showed that unusually extensive overhang of shelf water occurs episodically, and coherently over along shelf distances of several hundred kilometers. These episodes are dubbed overrunning of the Slope Sea by shelf water. The overrunning volume has a "face" and a "back" (southern and northern limit). It transports substantial quantities of shelf water southward, and does not retreat onto the shelf, but eventually joins the western edge of the Gulf Stream in the vicinity of Chesapeake …

The Effects Of Environmental Variability On The Population Structure Of The Eastern Oyster (Crassostrea Virginica): A Modeling Study, Margaret Mcmanus Dekshenieks

OES Theses and Dissertations

Three models were coupled to investigate the effects of changes in environmental conditions on the population structure of the Eastern oyster, Crassostrea virginica. The first model, a time-dependent model of the oyster population as described in Powell et al. (1992) and Hofmann et al. (1992, 1995), tracks the distribution, development, spawning, and mortality of sessile oyster populations. The post-settlement model incorporates mortality through parasitism, predation, food depletion and extremes in environmental conditions. The post-settlement model supplies the initial abundance of larvae spawned into the water column, and in turn is the recipient of cohorts of spawn which survive through metamorphosis. …

Recruitment Of Blue Crab, Callinectes Sapidus, Postlarvae To The Back-Barrier Lagoons Of Virginia's Eastern Shore, Robert D. Brumbaugh

OES Theses and Dissertations

Most research on the early life history of the blue crab, Callinectes sapidus, has been conducted in large partially stratified estuaries such as the Chesapeake Bay. In contrast, little is known about the recruitment dynamics or habitat requirements of blue crab postlarvae (megalopae) in shallow well-mixed lagoonal systems that make up a considerable part of the species' range. In Virginia's coastal lagoons, planktonic blue crab megalopae are most abundant at night on flooding tides, and are not abundant during the daytime or on ebbing tides. This appears to enhance retention within the lagoons, despite the short residence time of water …

Seasonal And Mesoscale Variability In The Distribution Of Antarctic Krill, Euphausia Superba, West Of The Antarctic Peninsula, Cathy Meyer Lascara

OES Theses and Dissertations

Observations collected between November 1991 and September 1993 during four multidisciplinary cruises were analyzed to provide a description of seasonal and mesoscale variability in the distribution and abundance of Antarctic krill, Euphausia superba, within continental shelf waters west of the Antarctic Peninsula and to investigate possible relationships between variability in krill distributions and variability in selected environmental parameters. Acoustic measurements of krill were made each season at designated locations to estimate the abundance of krill, in terms of vertically-integrated krill biomass and the number of aggregations, characterize the depth distribution of krill, and provide a quantitative description of the size, …

A One-Dimensional Model For Storm Breaching Of Barrier Islands, Cheol Shik Shin

Civil & Environmental Engineering Theses & Dissertations

A set of numerical models is developed for simulating the four stages of barrier breaching characterized by one horizontal spatial dimension.

The SBEACH model is employed for the first stage of dune/beach erosion. The Lax-Wendroff two-step explicit scheme for Stage II is developed to simulate initiation of ocean flood propagation on initially dry barrier islands and the method of characteristics (MOC), is employed to compute additional boundary data. The development of the Preissmann implicit scheme for water motion and a forward time centered space explicit scheme for sediment motion in Stages III and IV provide a tool to study the …

An Interdisciplinary Water Quality Curriculum For Middle School Students, Barbara Michelle Cleveland

All Graduate Projects

An interdisciplinary curriculum correlating water quality with the disciplines of physical science and mathematics for 6th grade middle school students was developed. Literature examined indicates that the opportunity to explore key concepts and significant issues using an integrated approach provided greater opportunity to formulate meaningful connections between disciplines studied and that achievement was enhanced. The Learning units were developed for use at Wilson Middle School in Yakima, Washington.

The Evolution Of International Fisheries Management In The North Pacific Ocean And Prospects For The Future, Paul Augustus Flynn

Theses and Major Papers

The abundant resources of the North Pacific Ocean have been the subject of international disputes and negotiations through the 20th century. The management of species which range throughout this vast area, are not under the jurisdiction of a single state. That fact has required the establishment of a framework in which allocation and conservation measures can be researched and agreed upon. This has been accomplished through various multilateral and bilateral agreements. From the voluntary Japanese suspension of a directed salmon fishery off the coast of Alaska in 1938 to recently completed multilateral treaties, significant advances have been made in Pacific …

A Policy Analysis Of The Commercial Fishing Industry Vessel Safety Act Of 1988, Peter Decola

Theses and Major Papers

During the mid-1980's, the crisis in marine insurance and growing concern over fishing vessel safety combined to stimulate passage of the Commercial Fishing Industry Vessel Safety Act of 1988. This law was enacted with the goal of improving the overall safety of commercial fishing industry vessels. However, the Act as passed by Congress contained no provisions for marine insurance reform. As a result, the commercial Fishing Industry Vessel Safety Act offered little incentive for the industry to improve upon its dubious safety record. With the exception of self-insurance clubs, the vast burden of implementing the Act has fallen upon the …

International Organizations And Tuna Management; Problems And Future Prospects, Yuh-Chen Chern

Theses and Major Papers

A large number of marine species migrate within and without national jurisdictions and a small number occur entirely outside any national jurisdiction. Thus, the species migrating through waters under the jurisdiction of coastal states to high seas beyond the jurisdiction of any single state are defined as highly migratory species (HMS). International organizations play a key role in the management of highly migratory species. Most of the international organizations concerned with HMS focus on tuna management.

Sacrificing Conservation For Pesos: An Analysis Of Select Marine Fisheries In The Political Environment Of Mexico, Sephen W. Bourgeois Jr.

Theses and Major Papers

The decline of most Mexican fisheries has occurred so rapidly that few Mexicans and Americans alike fully appreciate the loss. The major focus of this paper will examine the false impression that Mexico is engaging in marine conservation; in reality, its conservation efforts are responses to after-the-fact actions brought on by world critics and as a vehicle to pacify conservationists. The Mexican government can pass a law but lacks the resources to administer and enforce the law and subsequently manage its fisheries in an effective manner. Rather than survey the state of every fishery found in Mexican waters, this paper …

Federal Legislation Needed To Improve Towing Vessel Safety, Paul J. Keenan Jr.

Theses and Major Papers

To the casual observer, towing vessels and barges, with their low profile and unassuming presence, may seem to be an uninspiring and small part of the shipping scene. However, tank and dry cargo barges actually carry sixty-nine percent of our nation's domestic waterborne commerce. Regulations for large ships, especially oil tankers, have touched every aspect of the shipping industry, including naval architecture, engineering, damage control, manning, training, licensing, etc. Towing vessels and barges however, have largely managed to escape the proliferation of regulation. Current legislation does not provide for the inspection of sea-going towing vessels under three hundred gross tons …

Democratization Of Ocean Research: A Model For The Post-Cold War Era?, Maureen A. Kennelly

Theses and Major Papers

Since the end of World War II the field of oceanography has enjoyed the generous patronage of the federal government under the "social contract" model for the support of science. This model is based on the principles of freedom and autonomy for scientists, insulation of science from politics, and emphasis on basic research. With the recent ending of the Cold War, the simple science policies of the post-World War II years are being philosophically and politically challenged and the rationales for the support of science are being questioned. National security is no longer the driving force behind science funding in …

Integration Of Natural Hazard Mitigation Into Municipal Harbor Management Plans In The United States, Frank J. Mcneilly

Theses and Major Papers

Harbor management planning is a relatively new concept in this country. What is believed to be the first municipal level harbor management plan (HMP) in the United States originated from a need to resolve a problem of encroachments on a Federal navigation channel in Connecticut. This method of harbor planning was soon recognized as an effective management tool and was used as a model for other coastal communities in the Northeast. While early HMPs primarily focused on mooring management, today's plans address many more harbor issues. The Coastal Zone Management Act was intended to form a national coastal zone management …

Trends In Abundance Of The Gulf Of Maine Population Of Harbor Porpoise, Paula Ann Olson

Theses and Major Papers

Hundreds of harbor porpoise die each year as bycatch in the Gulf of Maine's sink gillnet fishery. In recent years, concern has arisen whether the Gulf of Maine population of harbor porpoise can sustain this level of bycatch. It is believed that the population may have declined, or is declining as a result of the incidental moralities. This paper reviews what is known about Gulf of Maine harbor porpoise demographics and how that information is incorporated into the management of the porpoise/fishery interaction. Included in this paper is a new study on the trend of relative abundance of harbor porpoise …

Protection Of Marine Fish Habitat: Towards An Integrated Approach To Management, Andrea L. Oliver

Theses and Major Papers

This paper focuses on the problems associated with marine fish habitat protection and conservation at the federal level in the United States. The intent of the study is to provide a general overview of the issues, impacts, management problems and potential solutions. Federal statutory legislation that impacts marine fish habitat and agency authority derived from those legislative mandates are examined with a view toward promoting integrated management for marine biodiversity and overall ecosystem health. The concepts of coordinated and integrated approaches to management are discussed in the context of the present management regimes. Given the fragmented authority over the policy …

The Influence Of Sea Power Upon Oceanography: A Historical And Policy Analysis Of Governmental Support For Marine Science, Daniel Stuart Schwartz

Theses and Major Papers

In a time of austere funding for national ocean science R & D programs and Congressional balanced budget constraints, marine science investigators and program managers must increasingly ponder how committed to the support of oceanography our government will continue to be. The questions might better be phrased as how, in the absence of a credible open-ocean naval threat (the traditional focus of both basic and applied research), will policy makers justify the expenditure of scarce public revenues on marine science programs? Sea Power-as broadly defined in the works of Alfred Thayer Mahan and Sergei Gorshkov-has driven, and will continue to …

Applying The Concept Of Recreational Specialization To Rhode Island Alliance Anglers, Eric Asadorian

Theses and Major Papers

Many recreationally popular marine species of fish are at or near historic lows in terms of their overall numbers. Many of these species, such as cod, summer flounder, winter flounder, and bluefish, are also commercially valuable. Fishery managers must be able to make allocation and management decisions that both protect the resource and maintain user satisfaction. The basis for achieving this goal lies in the understanding of what the users expectations, satisfactions and perceptions are related to their marine recreational fishing experience. It is often the case that a population of anglers are managed as a homogeneous group, with similar …

Volunteer Water Quality Monitoring Programs: An Assessment Of Public Participation As A Means Of Fostering Environmental Stewardship, Christopher Damon

Theses and Major Papers

Volunteer water quality monitoring organizations from across the country were surveyed (n=516) to determine the relationship between public involvement and the generation of stewardship within the community. Program coordinators were asked first to rate the level of stewardship values within the community, and then respond to questions covering four broad areas of public involvement: pre-existing conditions, public education, volunteer behavior, and communal involvement. For each question, organizations were aggregated by response, and a frequency analysis was performed to discover the most common responses in each of the four public involvement categories. the mean of perceived stewardship values was graphed as …

Limits To Private Aquaculture On Cape Cod, Kevin Robert Cute

Theses and Major Papers

This study examined the potential of social conflict related to private and public rights, to constrain aquaculture on Cape Cod. While the ability of social conflict to constrain aquaculture has been demonstrated in a few cases, its current potential to constrain aquaculture on Cape Cod had not been established prior to this study. This study was based on information gathered from town records and public hearings related to proposed aquaculture ventures. In addition, town officials were interviewed to obtain additional information related to cases. The finding of this study is that private riparian proprietors, and interests in shell-fishing tend to …

Maritime Fisheries Enforcement Analysis Of The Nmfs Northeast Region, John Thomas Davis

Theses and Major Papers

The success or failure of fishery management plans (FMP's) is dependent upon many factors. One of those factors is the level of compliance to the regulations implementing the conservation and management decisions of the FMP's that is achieved. Although compliance with regulations does not guarantee the success of management efforts, failure to ensure adequate compliance with management objectives results in failed conservation and management efforts. Enforcement is a crucial element towards achieving conservation and management goals. The objective of this paper is to analyze the maritime fisheries enforcement system in the geographic bounds of the national marine Fisheries Service's (NMFS) …

Shoreline Setbacks Vs. Regulatory Takings Law In Massachusetts, Deborah Fraize

Theses and Major Papers

this thesis examines whether the current shoreline setback scheme provided for under the Massachusetts Wetlands Protection Act may be deemed unconstitutional under the Takings Clause of the Fifth Amendment to the U. S. Constitution in light of recent holdings of the U.S. Supreme Court. In so doing, the thesis addresses what latitude regulators in Massachusetts may have under the merging case law. Because this area of law -- regulatory takings -- is still evolving, it was necessary to look at the evolution of the law in the U.S. Supreme Court and the Massachusetts appellate level courts. Research reveals that …

A Partnership For Coral Reef Protection: A Case Study Of The International Coral Reef Initiative, Karla M. Boreri

Theses and Major Papers

Coral reef are considered the most biologically diverse marine ecosystems on earth. They are a world-wide symbol of the economic and ecological importance of all types of coastal environments. The International Coral Reef Initiative (ICRI) was developed in 1994 to increase the awareness of the human and anthropogenic threats facing reefs. Initially a U.S.-focused initiative, ICRI now includes over 70 like-minded governments and a growing list of UN organizations, science and academic organizations, non-governmental organizations and the private sector as its partners. This qualitative case study was developed based on actual participation in the initiative and hundreds of pages of …

The Role Of The Federal Aid In Sportfish Restoration Program In Promoting State Marine Artificial Reef Development Activities, Loren Clark Evans

Theses and Major Papers

The passage of the Wallop-Breaux Amendments to the Federal Aid in Sportfish Restoration Program (FASRP), in 1984, significantly increased the funding available to states participating in the Program. Subsequently, the FASRP became the largest single source of funding for state marine artificial reef development activities. In recent years, there has been concern among program constituents that FASRP funds are not being utilized as intended. The principle question of the current research focused on how effective FASRP subsidies have been in providing meaningful benefits to state fisheries management programs. Specifically, the research focused on the application of FASRP monies in promoting …

The Cumulative Impacts Of Management Decisions On Nitrogen Loading To The Rhode Island Salt Ponds, Laura M. Ernst

Theses and Major Papers

Calculations and measurements of nitrogen in groundwater, stream flow and atmospheric deposition were used to see if the cumulative impacts of management decisions over a fifteen year period of time resulted in measurable changes in nitrogen loading to six of the salt ponds on the south shore of Rhode Island. The changes in the source and transmission of nitrogen were tested by comparing calculated and measured nitrogen data from 1980 and 1995. The calculated method included a nitrogen budget based on land-use and literature values for nitrogen loss to groundwater. The second method compared concentrations of nitrogen in groundwater taken …