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Articles 54571 - 54600 of 65478

Full-Text Articles in Physical Sciences and Mathematics

Anthropogenic Influences And Meteorological Effects: How They Are Changing The Sand Beaches In Southern Maine, Heather W. Heinze Dec 2001

Anthropogenic Influences And Meteorological Effects: How They Are Changing The Sand Beaches In Southern Maine, Heather W. Heinze

Electronic Theses and Dissertations

Although sand beaches in southern Maine comprise only a small segment of the coastline, they are economically important to the state. From September 1999-March 2001, volunteers made monthly topographic profiles along nine beaches in southern Maine to monitor changes. The volunteers used the Emery Method of beach profiling to take simultaneous measurements at spring low tide. The beaches are significantly different with respect to physiography, incident wave energy and direction, available sediment supply and extent of development. An average of the profiles for each category demonstrates that the undeveloped beaches experienced regular seasonal fluctuations and a consistent berm elevation from …


Solid Waste Management In Oil And Gas Pipelines Application To Asab Field, Abdulqader M Alkamali Dec 2001

Solid Waste Management In Oil And Gas Pipelines Application To Asab Field, Abdulqader M Alkamali

Theses

Managing solid waste, and any other wastes in general, is an environmental need, an economical choice and a legal requirement. Preserving the environment while lowering the cost becomes a necessity when liabilities are of concern.

Solid wastes generated from oil and gas industrial activities are very diverse in their characteristics, large in their amounts and many of which are hazardous in nature. Thus, the need to manage these wastes is an obvious mandate. Oil and gas industrial activities include exploration, drilling, production, processing, refining, manufacturing and exporting. Associated with these activities, other supporting services; such as, maintenance, civil, transportation, storage, …


Petrological And Geochemical Analyses And Economic Potential Of Some Milestones And Siliceous Rocks In Northern United Arab Emirates., Mohammed Ahmed A. Ibrahim Dec 2001

Petrological And Geochemical Analyses And Economic Potential Of Some Milestones And Siliceous Rocks In Northern United Arab Emirates., Mohammed Ahmed A. Ibrahim

Theses

Combined microscopic, heavy mineral, X-ray diffraction and chemical analyses have been carried out on the Jurassic limestone, the upper cretaceous Hawasina cherts and the coastal and inland sand dunes in several localities in the Ras Al Khaimah Emirate. The obtained results revealed that a number of represents cherts subfacies; namely: ferruginous radiolarian ribbon chert, carbonaceous radiolarian ribbon chert, colloform ribbon chert, calcareous chert and siliceous mud stone. These rocks consist of (in order of decreasing abundance): quartz, calcite, dolomite and hematite. The carbonate rocks are made up of lime mudstone, wackestone; pack stone and, rarely, crystalline limestone. Various types of …


Fluorescence And Light Scattering Studies Of Aromatic Polymers Near The Critical Concentration C*, M.Sean Healy Dec 2001

Fluorescence And Light Scattering Studies Of Aromatic Polymers Near The Critical Concentration C*, M.Sean Healy

Seton Hall University Dissertations and Theses (ETDs)

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Hazardous Materials Transportation Flow Survey: An Evaluation Of Hazardous Materials Transported In Washington County., Daniel John O'Brien Dec 2001

Hazardous Materials Transportation Flow Survey: An Evaluation Of Hazardous Materials Transported In Washington County., Daniel John O'Brien

Electronic Theses and Dissertations

This study examines the transportation of hazardous materials through Washington County, Tennessee. This study incorporates federal, state, and local data in assessing current transportation trends. Data gathering activities included local chemical inventories, hazardous materials transportation flow surveys, hazardous materials rail transportation trends, and hazardous materials incident data.

All data were compiled and then analyzed to identify hazardous materials transportation trends in Washington County, Tennessee. This information is pertinent to emergency planners for the preparation of hazardous materials transportation incidents. The data gathered further revealed the need for this type of study to identify changing trends in the transportation of hazardous …


A Meta-Analysis And Risk Assessment Of Heavy Metal Uptake In Common Garden Vegetables., Trent David Lecoultre Dec 2001

A Meta-Analysis And Risk Assessment Of Heavy Metal Uptake In Common Garden Vegetables., Trent David Lecoultre

Electronic Theses and Dissertations

Peer reviewed literature was searched to identify research pertaining to the uptake of heavy metals (As, Cd, Pb and Zn) by vegetables (cabbage, carrot, lettuce, and radish). The objectives of this research were to 1) determine the relationship between heavy metal concentrations in the soil and heavy metal concentrations in vegetables, and 2) determine the level of risk associated with exposure to heavy metals through ingestion of contaminated vegetables. Highly variable estimates and biologically implausible regression equations resulted from this meta-analysis. Exposure to arsenic through the ingestion of lettuce grown on contaminated soil significantly increases cancer risk, especially in children. …


The Suitability Of Reclaimed Agricultural Lands Along The Lower Colorado River For Native Riparian Habitat Restoration, Patti Aaron Dec 2001

The Suitability Of Reclaimed Agricultural Lands Along The Lower Colorado River For Native Riparian Habitat Restoration, Patti Aaron

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this paper is to determine the suitability of agricultural lands for use in native riparian restoration efforts under development for the Lower Colorado River Multi-Species Conservation Program. Assuming these fields are productive for crops, would they be productive for cottonwood-willow restoration? There are two aspects to consider: (1) the edaphic conditions required for three major LCR agricultural crops; alfalfa, cotton, and wheat, and (2) whether those conditions are consistent with the conditions required for the restoration of native LCR riparian habitat, primarily Fremont cottonwood (Populus fremontii) and Goodding willow (Salix gooddingii). Using the case study research approach …


On Some Optimal Tests In Finite Mixtures: Constructions And Applications., Chandranath Pal Dr. Nov 2001

On Some Optimal Tests In Finite Mixtures: Constructions And Applications., Chandranath Pal Dr.

Doctoral Theses

Mixtures of distributions are now-a-days playing very important roles in both theoretical and applied statistics. There is an abundance of real-life situations where mixture distributions are being extensively used for modelling data and drawing inference. Several books and monographs on mixtures have so far been published, e.g., Everitt and Hand (1981), Titterington et al. (1985), McLachlan and Basford (1988), McLachlan (1997) etc., which cover a wide area on different aspects of mixture distributions and their applications. The book by Titterington et al. (1985, pp. 16-21), in particular, contains a comprehensive list of references on direct applications of finite mixtures in …


Regional Variations Of Kachina Iconography In Eastern Pueblo Rock Art, Dara Leigh Saville Nov 2001

Regional Variations Of Kachina Iconography In Eastern Pueblo Rock Art, Dara Leigh Saville

Geography ETDs

This research addresses the problem of identifying patterns of regional variation in the kachina iconography of the Eastern Pueblo Province. Data produced in this study is also used to reevaluate the Rio Grande Hypothesis, which proposes a Jornada Mogollon origin for Pueblo kachinas. The author examines a sample of kachina images that are present in the rock art of the Rio Grande Valley and Eastern Mountain region of central New Mexico. The sample includes kachinas from the Lyden site on Black Mesa, Frijoles Canyon of Bandelier National Monument, Piedras Marcadas Canyon of Petroglyph National Monument, Cerro Indio at San Acacia, …


The Role Of Small And Medium Enterprises In The Economy Of Slovakia, Jaroslav Kling Nov 2001

The Role Of Small And Medium Enterprises In The Economy Of Slovakia, Jaroslav Kling

Student Work

The aim of this paper is to analyze the role of small and medium enterprises in the economy of Slovakia. The changes of 1989 brought about the changes of society and economy as well. In the period of transformation of the Slovak economy, small and medium enterprises have been often considered to be a critical element of economic revival. The study answers to what extent this expectation has been met. Legal and institutional frameworks of the small and medium enterprises development are analyzed. Popular attitudes toward entrepreneurs, views and opinions of the key representatives of entrepreneurs and state representatives are …


Bronx River Restoration: Report And Assessment, Nicole Marshall Nov 2001

Bronx River Restoration: Report And Assessment, Nicole Marshall

Student Theses 2001-2013

No abstract provided.


Genetic And Environmental Risk Factors Associated With Colon Cancer, Shamma Rashed Khalfan Al-Naili Al-Shamsi Nov 2001

Genetic And Environmental Risk Factors Associated With Colon Cancer, Shamma Rashed Khalfan Al-Naili Al-Shamsi

Theses

Colorectal cancer represents one of the most common causes of mortality in the world. A major number of populations develop an adenoma by the age of 40s. Over the past years, it has become clear that genetic factors are of crucial importance in colorectal tumorigenesis. Familial adenomatous polyposis (FAP) is responsible of developing numerous colorectal cancers cases by causing mutations in the germline in adenomatous polyposis coli (APC) genes.

Colon cancer is considered the second most frequent cause of death in most of the Western countries. Colonic cancer is common in women and rectal in men. It arise in adenomatous …


Modeling Axisymmetric Optical Precision Piezoelectric Membranes, James W. Rogers Jr. Oct 2001

Modeling Axisymmetric Optical Precision Piezoelectric Membranes, James W. Rogers Jr.

Theses and Dissertations

The US Department of Defense (DOD), as well as the National Aeronautics and Astronautics Administration (NASA) and the Jet Propulsion Laboratory (JPL) are interested in developing and deploying precise, compliant, light-weight, space-based structures. More specifically, the Air Force’s core competencies ‘Aerospace Superiority’ and ‘Information Superiority’ demand ever-increasing depth and breadth of capability. Whether used for energy transmission or optical reconnaissance, current launch restraints limit rigid space-based optical reflector size. To support this requirement, the Air Force Research Laboratory (AFRL) is developing a large space-based optical membrane telescope. Inflatable reflectors can conceptually break this barrier, but controlling such a compliant structure …


Quantitative Comparison Of Fecal Coliform And Fecal Streptococci Counts Of Six Ponds In Charlotte Sounty, Virginia, Melissa Dunn Back Oct 2001

Quantitative Comparison Of Fecal Coliform And Fecal Streptococci Counts Of Six Ponds In Charlotte Sounty, Virginia, Melissa Dunn Back

Theses & Honors Papers

Performing testing to detect for the presence of fecal coliform and fecal streptococci are the acceptable standard methods for judging the quality of water. Their presence and quantitation are presumed to be a predictive indicator of potentially more serious organisms being present. This study was initiated to look at the differences in fecal coliform counts between irrigation ponds and livestock ponds. The hypothesis was that livestock ponds would have a significantly higher count of fecal coliform and fecal streptococci than irrigation ponds. This hypothesis was accepted. Six privately owned ponds in Charlotte County, Virginia were used to evaluate for the …


The Distribution Of Airborne Coal Dust In Soil Profiles Of Norfolk, Va And Its Implication For Arsenic Loading To These Soils, William Joseph Bounds Oct 2001

The Distribution Of Airborne Coal Dust In Soil Profiles Of Norfolk, Va And Its Implication For Arsenic Loading To These Soils, William Joseph Bounds

OES Theses and Dissertations

Norfolk, Virginia is home to the Northern Hemisphere's largest coal terminal the Lamberts Point Docks. The coal loading process of this terminal creates large amounts of coal dust, which subsequently is distributed throughout the local region by atmospheric transport and deposition. While the coal dust itself poses only minor health hazards, certain trace elements within the coal, particularly arsenic, may pose environmental as well as significant health hazards. Within coal, arsenic occurs primarily in the mineral pyrite. As pyrite in the coal dust is subsequently oxidized via exposure to the atmosphere and/or meteoric water, arsenic may be released to the …


Analysis And Numerical Solution Of An Integral Equation Method For Electromagnetic Scattering From A Cavity In A Ground Plane, Eric T. Howe Sep 2001

Analysis And Numerical Solution Of An Integral Equation Method For Electromagnetic Scattering From A Cavity In A Ground Plane, Eric T. Howe

Theses and Dissertations

In this research the electromagnetic scattering of a plane wave from a two-dimensional cavity embedded in an infinite, perfectly conducting ground plane is investigated. The plane wave is assumed to be under transverse electric (TE) polarization with respect to the x-axis. The cavity may be empty or filled with an arbitrary homogeneous, lossy material. A coupled set of scalar integral equations that govern the electromagnetic scattering is implemented. An approximate solution to the scalar integral equations is found via a Method of Moments (MoM) algorithm. The algorithm is implemented in a computer code, and approximations to the total magnetic field …


Theater-Level Stochastic Air-To-Air Engagement Modeling Via Event Occurrence Networks Using Piecewise Polynomial Approximation, David R. Denhard Sep 2001

Theater-Level Stochastic Air-To-Air Engagement Modeling Via Event Occurrence Networks Using Piecewise Polynomial Approximation, David R. Denhard

Theses and Dissertations

This dissertation investigates a stochastic network formulation termed an event occurrence network (EON). EONs are graphical representations of the superposition of several terminating counting processes. An EON arc represents the occurrence of an event from a group of (sequential) events before the occurrence of events from other event groupings. Events between groups occur independently, but events within a group occur sequentially. A set of arcs leaving a node is a set of competing events, which are probabilistically resolved by order relations. An important EON metric is the probability of being at a particular node or set of nodes at time …


The Structure And Stability Of Expanding And Converging Near-Stoichiometric Flames, Raymond Addabbo Aug 2001

The Structure And Stability Of Expanding And Converging Near-Stoichiometric Flames, Raymond Addabbo

Dissertations

The stability of expanding and converging premixed flames is investigated theoretically. These configurations are inherently unsteady and represent simple examples of positively (expanding) and negatively (converging) stretched flames. A new model is employed in this study that incorporates both hydrodynamic and diffusional-thermal effects. The model expands earlier works by incorporating variable transport properties, variations in the mixture strength and a more realistic dependence on viscosity.

The expanding flame is shown to remain stable at small radii provided the thermal diffusivity exceeds the mass diffusivity of the deficient reactant. However, once the flame achieves a critical size, a cellular instability appears, …


Asymptotic Methods In Applied Waveguide Problems, Helen Martynov Aug 2001

Asymptotic Methods In Applied Waveguide Problems, Helen Martynov

Dissertations

Some of the most challenging problems in acoustics and electromagnetics involve the study of scattered fields in waveguides caused by targets of elaborate shape. The complexity of the resulting scattered field depends on the geometry of the scatterer, and exact solutions exist only for the simple geometries.

The asymptotic methods developed in this dissertation give the approximate solutions for the scattered fields in two practically important geometries: an object placed inside a stratified waveguide, and a waveguide with multiple abrupt width transitions. The solutions for these geometries are obtained by approximating the field near the target or junction by the …


Structural, Transport And Magnetic Studies Of Perovskite Bi1-X Cax Mn O3, Hyungje Woo Aug 2001

Structural, Transport And Magnetic Studies Of Perovskite Bi1-X Cax Mn O3, Hyungje Woo

Dissertations

This dissertation presents an investigation of the fundamental physics of the perovskite system Bi1-xCaxMn03. This material belongs to a group of simple perovskites called the manganites which are of technological importance for magnetic device applications as read-head sensors.

The Bi1-xCaxMnO3 system is known to exhibit charge ordering (and high sensitivity to magnetic fields) for a much broader range of x than the well-characterized La1-xCaxMnO3 system. However, the properties of Bi1-xCaxMnO3 over the entire doping range are not well understood. …


Detection Of Vapor Phase Mercury Species By Laser Fluorescence Methods, Xiaomei Tong Aug 2001

Detection Of Vapor Phase Mercury Species By Laser Fluorescence Methods, Xiaomei Tong

Dissertations

Elemental and compound mercury are often both volatile and air stable. Several mercury species emissions have been identified in off-gases from industrial processes. The high toxicity of mercury species and the presence of mercury species in municipal waste and coal have prompted a demand for a cost-effective, accurate, and rugged technique for real-time, continuous detection of mercury species vapors. Real-time, continuous emission measurements are important for process control, monitoring, and remediation. At present, there is no commercial continuous emission monitoring (CEM) technique or instrumentation to reliably monitor volatile mercury species emissions from industrial stacks. Conventional measurement methods, such as cold …


Electrostatic Micro Actuators For Mirror And Other Applications, Xingtao Wu Aug 2001

Electrostatic Micro Actuators For Mirror And Other Applications, Xingtao Wu

Dissertations

Micro-electro-mechanical systems (MEMS) based electrostatic micro actuators are becoming important building blocks for innovations in optical signal processing and computing systems due to their inherently small size, high density, high speed and low power consumption. Generally, the principle of operation in these systems can be described as: an electrostatic attractive force causes a mechanical rotation, translation or deformation of a mirror plate, controlling the power, phase or direction of a light beam while it propagates through some medium or through free space. The fast paced, competitive research and development efforts widely being undertaken, both in academia and industry, are demanding …


Computationally Efficient Search For Large Primes, Wieslawa E. Amber Aug 2001

Computationally Efficient Search For Large Primes, Wieslawa E. Amber

Theses

To satisfy the speed of communication and to meet the demand for the continuously larger prime numbers, the primality testing and prime numbers generating algorithms require continuous advancement. To find the most efficient algorithm, a need for a survey of methods arises. Concurrently, an urge for the analysis of algorithms' performances emanates. The critical criteria in the analysis of the prime numbers generation are the number of probes, number of generated primes, and an average time required in producing one prime. Hence, the purpose of this thesis is to indicate the best performing algorithm. The survey the methods, establishment of …


Reversible Melting And Crystallization Of Short And Long Flexible Chain Molecules By Temperature-Modulated Calorimetry, Jeongihm Pak Aug 2001

Reversible Melting And Crystallization Of Short And Long Flexible Chain Molecules By Temperature-Modulated Calorimetry, Jeongihm Pak

Doctoral Dissertations

Melting and crystallization of linear, flexible molecules of different lengths was studied by temperature-modulated differential scanning calorimetry, TMDSC. Various techniques for TMDSC with single and multifrequency modulations have been analyzed to optimize the conditions for the present study. The finally chosen method involved a quasi-isothermal mode with a temperature amplitude of 0.5 K and a period of 60 s (frequency = 0.167 Hz). The interpretation of the reversible and irreversible melting was developed by comparison of a variety of different modes of analysis (sinusoidal, sawtooth, and complex sawtooth). The analyzed molecules ranged from n-paraffins, oligomeric fractions of polyethylene and poly(oxyethylene) …


A Qualitative Investigation Of The Polymerization Process In The Ihss Humic Substances Extraction Procedure Using Model Phenolic Compounds, Roger J. Germay Aug 2001

A Qualitative Investigation Of The Polymerization Process In The Ihss Humic Substances Extraction Procedure Using Model Phenolic Compounds, Roger J. Germay

Masters Theses

Achard (1786) extracted peat with alkali and reported obtaining dark compounds now called humic substances. These are complex, high molecular weight, polyphenolic compounds naturally occurring in soil, in fresh-water and in marine environments. They are biodegradation products of plant materials.

The International Humic Substances Society (IHSS) adapted Achard's method to separate humic substances into three fractions: (1) humic acids (HA), soluble only at high pH; (2) fulvic acids (FA), water-soluble at any pH; and (3) humin, insoluble at any pH. The IHSS method involves contact of soil with 0.1N.NaOH solution, followed by acidification with HCl.

In this study, 0.01 N. …


Theoretical Study On The Mechanism Of Removing Nitrogen Oxides Using Isocyanic Acid., Taraneh Nowroozi-Isfahani Aug 2001

Theoretical Study On The Mechanism Of Removing Nitrogen Oxides Using Isocyanic Acid., Taraneh Nowroozi-Isfahani

Electronic Theses and Dissertations

The mechanism of RAPRENOx reactions - RAPid REduction of Nitrogen Oxides using Isocyanic acid - proposed by Robert A. Perry1 in an attempt to help control the emission of nitrogen oxides pollutant into the atmosphere, has been re-investigated theoretically. The study of reaction mechanisms was carried out using Chemist software2. All mathematically possible elementary steps have been evaluated and the chemically reasonable ones have been considered to propose new sets of reaction mechanisms. Density Functional Theory (B3LYP/6-31 G**) calculations using Gaussian 983 were made in order to study the relative energies of all species and …


Life Annuities Under Random Rates Of Interest., Lesley J. Baker Aug 2001

Life Annuities Under Random Rates Of Interest., Lesley J. Baker

Electronic Theses and Dissertations

We begin by examining the accumulated value functions of some annuities-certain. We then investigate the accumulated value of these annuities where the interest is a random variable under some restrictions. Calculations are derived for the expected value and the variance of these accumulated values and present values. In particular we will examine an annuity-due of k yearly payments of 1. Then we will consider an increasing annuity-due of k yearly payments of 1, 2, ⋯ , k. And finally, we examine a decreasing annuity-due of k yearly payments of n, n - 1, ⋯ , n - k …


Investigation Of Perceptions Of Environmental Management Systems And Its Perceived Importance In A Corporation Undergoing Iso 14001 Certification., Charlette Michelle Clark Aug 2001

Investigation Of Perceptions Of Environmental Management Systems And Its Perceived Importance In A Corporation Undergoing Iso 14001 Certification., Charlette Michelle Clark

Electronic Theses and Dissertations

The International Organization of Standardization (ISO) has created a series of voluntary standards (ISO 14000) which promote waste reduction and improve businesses’ environmental management. ISO 14001 is the Environmental Management System portion of ISO 14000 requiring employee awareness and involvement. The Robert Bosch Corporation is undergoing ISO 14001 certification.

In this study, a 23-question survey was used to evaluate Bosch employees’ awareness of ISO 14000 and their support of a waste reduction program at four plants (Johnson City, TN; Sumter, South Carolina; Ashland, Ohio; and South Bend, Indiana). Employees surveyed were not yet familiar with ISO 14000 and that their …


Lithospheric Structure Of The Basin And Range Province-Southwestern Colorado Plateau. Southeastern California, Southern Nevada, And Western Arizona, Nigel Oakley Hicks Aug 2001

Lithospheric Structure Of The Basin And Range Province-Southwestern Colorado Plateau. Southeastern California, Southern Nevada, And Western Arizona, Nigel Oakley Hicks

Open Access Theses & Dissertations

The Basin and Range Province of the western United States is an unusually wide continental rift zone and its structure and evolution have been the topic of much debate. Active source seismic surveys within the Basin and Range Province have delineated a relatively uniform crustal thickness (-30 km) despite varying magnitudes of crustal extension (<10-300 km). Large scale Cenozoic crustal extension has exhumed midcrustal rocks (from 10-20 km depth) along low angle detachment faults to create metamorphic core complexes (exposed lower plate rocks). In contrast to the extreme amounts of extension and internal deformation of the Basin and Range, the Colorado Plateau has remained a relatively rigid block, with a crustal thickness of 40-50 km, apparently resistant to the deformation processes that have shaped the Basin and Range observed today. In general, geophysical surveys reveal a significant contrast in crustal structure between the Basin and Range and it's transition into the Colorado Plateau.

The debate about the origin of the Basin and Range has underscored the need for additional geophysical constraints. Thus in this study, a regional analysis of lithospheric structure in the region of southeastern California, southern Nevada, and western Arizona that includes the Basin and Rangesouthwestern …


Empirical Spectral Analysis Of Random Number Generators, David Zeitler Aug 2001

Empirical Spectral Analysis Of Random Number Generators, David Zeitler

Dissertations

Computer simulation procedures have become a staple of research and development in many fields, including statistics. The generation of pseudo random number sequences is the core of computer simulation procedures. Validity of research results often depend on the underlying validity of the generator being used.

In this work we develop the machinery for a class of tests of spatial uniformity based on a multi-dimensional Fourier transform of the empirical probability density function. The test can be adapted to specific requirements and has the added advantage that it has computational complexity that is relatively independent of the number of data points …