Digital Commons Network^™

Mechanical Characterization Of Composite Repairs For Fiber-Glass Wind Turbine Blades, Tanveer Singh Chawla

Theses and Dissertations

While in service, wind turbine blades experience various modes of loading. An example is impact loading in the form of hail or bird strikes, which might lead to localized damage or formation of cracks a few plies deep on the blade surface. One of the methods to conduct repairs on wind turbine blades that are damaged while in service is hand lay-up of the repair part after grinding out the damaged portion and some of its surrounding area. The resin used for such repairs usually differs from the parent plate resin in composition and properties such as gel time, viscosity, …

Theoretical Studies Of Oxides Relevant To The Combustion Of Fossil Fuels, Jason Hicks

Theses and Dissertations

Anthropogenic pollution has greatly increased since the industrial revolution and continues to increase as more of the world becomes dependent upon fossil fuels for important applications like transportation and power production. In a general case, whenever a fossil fuel is consumed, a primary product of a complete combustion reaction is carbon dioxide. In a more specific case, the collection, processing and combustion of coal for power production are one of the primary ways by which trace elements, such as arsenic and selenium, are released into the environment. All of these pollutants are known to have harmful effects, whether on the …

An Investigation Of Sub-Pixel Cloud/Clear-Sky Contamination Using Hyper-Spectral Aviris Data, Celil Kaplan

Theses and Dissertations

Cloud and clear sky contamination due to sub-pixel clouds remains as a troubling issue for scientific applications that rely on remotely sensed data. Sub-pixel level clouds may not be detected by a standard cloud filtering process, and thus can cause uncertainties in satellite-based meteorological property retrievals. In this study, using collocated data from Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and Geostationary Operational Environmental Satellite (GOES) data, sub-pixel cloud and clear-sky contamination were studied over the west coast of Northern California. The hyper-spectral data from AVIRIS have a spatial resolution on the order of 11.5 m for the study case, thus can …

Performance Comparison Between Music And Esprit Algorithms For Direction Estimation Of Arrival Signals, Samira Kharel

Theses and Dissertations

This thesis examines and compares the performance of Multiple Signal Classification (MUSIC) and Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) for the estimation of Direction of Arrival (DOA) of incoming signals to the smart antenna. The comparison of these two algorithms was done on the basis of parameters like number of array elements, number of incoming signals, angle difference between the incoming signals, number of the samples taken of signal, processing time and SNR ratio.

These two algorithms were implemented with MATLAB and SIMULINK for the experimental purpose. After all the experiments performed, it was analyzed that results …

Mobile Vehicle Road And Weather Observation Quality Check Methods, Daniel Raymond Koller

Theses and Dissertations

Today State Departments of Transportation rely more and more on road weather data to make maintenance decisions. Inaccurate data can result in wrong treatment applications or inadequate staffing levels to maintain the roadway at the desired level of service.

Previous methods of road condition data reporting have been limited to static in situ sensor stations. These road weather information systems (RWIS) provide varied data about precipitation, winds, temperature, and more, but their siting does not always provide an accurate representation of weather and road conditions along the roadway. The use of mobile data collection from vehicles travelling the highway corridors …

Design And Construction Of A Fluidized Bed, Robert Ryan Mota

Theses and Dissertations

Coal combustion is responsible for the majority of electricity production in the United States. It is however, also the primary cause for carbon dioxide emissions, which contribute to global warming. With oil reaching its peak production in the near future, alternative fuel sources will be needed to meet the worlds growing energy demands. Coal is an abundant resource that has the potential to meet those demands. In contrast to coal combustion, coal gasification only partially oxidizes the coal to produce a syngas containing of hydrogen and carbon monoxide, which means less carbon dioxide emissions. Utilizing coal in gasification technologies is …

Heat Transfer Measurements On An Incidence-Tolerant Low Pressure Turbine Blade In A High Speed Linear Cascade At Low To Moderate Reynolds Numbers, Leolein Patrick Gouemeni Moualeu

Theses and Dissertations

Runway-independent aircraft are expected to be the future for short-haul flights by improving

air transportation and reducing area congestion encountered in airports. The Vehicle

Systems Program of NASA identified a Large Civil Tilt-Rotor, equipped with variable-speed

power-turbine engines, as the best concept. At cruise altitude, the engine rotor-speed will

be reduced by as much as the 50% of take-off speed. The large incidence variation in the

low pressure turbine associated with the change in speed can be detrimental to the engine

performance. Low pressure turbine blades in cruise altitude are more predisposed to develop

regions of boundary layer separation. Typical …

Variations Of E-Region Total Electron Content And Electron Density Profiles Over High Latitudes During Winter Solstice 2007 Using Radio Occultation Measurements, Kajli Agrawal

Theses and Dissertations

The space weather phenomenon involves the Sun, interplanetary space and the Earth. Different space weather conditions have diverse effects on the various layers of the Earth's atmosphere Technological advancements have created a situation in which human civilization is not only dependent on resources from deep inside the Earth, but also on the upper atmosphere and outer space region. Therefore, it is essential to improve the understanding of the impacts of space weather conditions on the ionosphere. This research focuses on the variation of total electron content (TEC) and the electron density within the E-region of the ionosphere, which extends from …

Josephson Currents In Two-Gap Superconductor-Insulator- Superconductor Junctions, Ladan Bahrainirad

Theses and Dissertations

As a way to investigate the transport property of superconductor-insulator-superconductor (SIS) junction with two-gap superconductors such as MgB2 and iron superconductors, we study the microscopic structure of the Josephson current in a tunnel junction with a very narrow quasi-classical barrier. Also, the possibility of mid-gap states in two-gap superconductor is investigated, and their effects on the current-phase relation as well as the current density characteristics are studied. In the SIS break junction, mid-gap states appear at the Superconductor-Insulator interfaces due to an abrupt change in the superconducting order parameter, indicating that the two-gap superconductor SIS junction can yield a rich …

Characterization Of Evaporative Metal Bonding In Superalloys For Use In Gasified Coal Turbine Generators, Joshua Elliot Braband

Theses and Dissertations

The diffusion bonding of Kanthal APMT, CM247LC, and Rene 80 was studied. The objective of the first part of this work was to create diffusion bonded test samples of Kanthal APMT, CM247LC, and Rene 80 using a 25μm thick zinc interlayer at varying times and temperatures. Then, using scanning electron microscopy to determine the profile of the zinc diffusing into the parent materials, the diffusion coefficients of the zinc interlayer into the materials were determined for each of the materials at each bonding time and temperature. The next objective was to create a finite element model of the bonding process …

Experimental Investigation Of The Effect Of Turbulence On Slot-Fed Film Cooling Adiabatic Effectiveness And Downstream Heat Transfer, Mitch Busche

Theses and Dissertations

Modern turbine designers are greatly concerned with power out and the efficiency of their engines. One way to increase the power output and effectiveness of the engine is to increase the hot gas temperature inside the combustion chamber. The hot gas can reach a temperature that exceeds the physical limitations of parts inside the engine, causing the parts to fail prematurely. One possible method to cool the parts is with the use film cooling. Film cooling takes cool air from the compressor, bypasses the combustor, and ducts the air to internal chambers of parts, and then ejects the cool air …

Optimization Of The Garch Model Parameters Using A Genetic Algorithm, Jonathon Patrick Cummings

Theses and Dissertations

Financial time series are often characterized by nonlinearity and volatility bunching. Standard regression analysis models cannot capture changing volatilities, potentially leading to erroneous results. The need to more completely model the characteristic volatilities inherent to financial time series eventually led to the creation of the GARCH model. Typical GARCH parameters are (1,1) incorporating a 1-period lag of the regression residual as well as a 1-period lag of the regression volatility. The primary question investigated in this paper is whether the typical GARCH(1,1) parameters are in fact optimal over all time periods and attempts to improve on the typical parameters by …

Determination Of Optimum Polymer Dose For Grand Forks Wastewater Treatment Plant Lagoon Sludge Dewatering, Dipesh Das

Theses and Dissertations

The Grand Forks Waste Water Treatment Plant (GFWWTP) is currently sending its waste activated sludge (WAS) from the activated sludge treatment process to an existing on-site wastewater treatment lagoon which has been in operation since 2003. The plant produces approximately 65,000 gallons of WAS per day. Because of this high level of loading, the existing lagoon system is no longer considered as a treatment option for the produced sludge. The Plant Authority is trying to find a sustainable solution for sludge disposal and for this reason the GFWWTP is interested in introducing screw press system for the dewatering process. As …

Does Google Search Data Aid In Predicting Unemployment?, Brennan Dyk

Theses and Dissertations

The unemployment rate is typically forecasted in the literature using initial claims for unemployment, a lagged value of unemployment, and an autoregressive component. This paper looks to improve upon existing models by adding Google search data to traditional models using initial claims or replacing initial claims with Google searches. One hypothesis is that Google searches may improve forecast accuracy due to employees knowing or getting a sense when they may become unemployed and be searching for jobs prior to filing for unemployment. Study of this is important to improve the accuracy of models and to provide more accurate out-of-sample forecasts …

A Sustainable Bio-Solids Management For The Grand Forks Wastewater Treatment Plant, Hasibul Hasan

Theses and Dissertations

The Grand Forks Waste Water Treatment Plant (GFWWTP) is currently sending its waste activated sludge (WAS) from the activated sludge treatment process to an existing on-site wastewater treatment lagoon which has been in operation since 2003. The plant produces approximately 65,000 gallons of WAS per day. Because of this high level of loading, the existing lagoon system is likely to get replaced by a more sustainable treatment option. Several methods were considered and studied thoroughly for this research, and - on site land application shows some potential. After surveying the Municipal Waste Water Treatment Facilities of the five neighboring states …

A Framework For The Integration Of Technology Into Curricula Development And Student Assessment, Washington Helps

Theses and Dissertations

The purpose of this work is to amalgamate technology and education in a manner which will prove to be beneficial to all stakeholders involved and which will allow for an improvement in the ubiquitous process of curriculum development in the teaching and learning sphere. The primary motivation surrounds the issue of limited human resources in terms of teachers and expert knowledge as well as available physical resources such as computer equipment or other classroom artifacts. It should be duly noted that it is in many developing countries where the student-teacher ratio is very high and where such a framework will …

Microwave Tomography Using Stochastic Optimization And High Performance Computing, Michael William Holman

Theses and Dissertations

This thesis discusses the application of parallel computing in microwave tomography for detection and imaging of dielectric objects. The main focus is on microwave tomography with the use of a parallelized Finite Difference Time Domain (FDTD) forward solver in conjunction with non-linear stochastic optimization based inverse solvers. Because such solvers require very heavy computation, their investigation has been limited in favour of deterministic inverse solvers that make use of assumptions and approximations of the imaging target. Without the use of linearization assumptions, a non-linear stochastic microwave tomography system is able to resolve targets of arbitrary permittivity contrast profiles while avoiding …

The Influence Of Television And Film On Interest In Space And Science, Katrina Marie Jackson

Theses and Dissertations

Entertainment media has the great potential to inspire interest in the topics it presents. The purpose of this study is to better understand how entertainment media contributes to people's interests in space and science. There is a huge variety of science communication topics in previous literature, some of which deals with television and film, but very little that specifically study how television and film can inspire interest. A historical review of pioneers in the space industry shows that many were inspired by entertainment media, which at the time consisted of science fiction novels and magazines. In order to explore the …

Tanzania Higher Education-Fifty Years After Independence, Godfrey Magoti Mnubi

Theses and Dissertations

As Tanzania celebrates fifty years of independence at the crossroads of globalization, the country has experienced a changing landscape and a major transformation in higher learning education with spectacular expansion in student enrollment rates. This requires its higher education institutions, particularly universities, to function effectively as a source of knowledge and to serve as an important partner in sustainable development by promoting effective teaching, research and service in Tanzania.

To understand the pace of globalization and the multitude of social challenges that have faced Tanzania higher education since 1961, how the policies and practices of higher education have evolved over …

Aerosol Optical Depth And Its Relationship To Radar Derived Precipitation In Mali, West Africa, David Benham Keith

Theses and Dissertations

The research goal is to determine if a relationship exists between Aerosol Optical Depth (AOD) and radar-derived precipitation in Mali, a country located in West Africa. Precipitation parameters derived from 2006, 2007 and 2008 C-band radar measurements are compared against Noon to 2 p.m. averaged AOD measurements. The AOD and Angstrom Exponent (AE) are from an Aerosol Robotic Network (AERONET) site located 240 km northeast of Bamako, and radar cell (20 dBZ threshold) tracks are generated using the Thunderstorm Identification, Tracking, Analysis and Nowcasting radar software (TITAN). Only isolated TITAN cells are used in the analysis. In addition, environmental filters …

Application Of Composite Polymeric Membranes For Efficient Regeneration Of Physical Solvents, Alireza Pesaran

Theses and Dissertations

The most dominant CO2 capture technology used for pre-combustion capture involves the application of physical solvents. Despite the low energy required to regenerate physical solvents and their high capacity for capturing and separating acid gases from the syngas produced in a gasification plant, physical solvents have some disadvantages including CO2 pressure loss and the energy required to pump the solvent to the high pressure absorber.

The primary objective of this work is to evaluate the use of composite polymeric membranes for the recovery of CO2 from CO2-rich solvent streams. To achieve this purpose, an experimental bench-scale setup was built to …

Epileptic Seizure Detection And Prediction From Electroencephalogram Using Neuro-Fuzzy Algorithms, Ahmed Fazle Rabbi

Theses and Dissertations

This dissertation presents innovative approaches based on fuzzy logic in epileptic seizure detection and prediction from Electroencephalogram (EEG). The fuzzy rule-based algorithms were developed with the aim to improve quality of life of epilepsy patients by utilizing intelligent methods. An adaptive fuzzy logic system was developed to detect seizure onset in a patient specific way. Fuzzy if-then rules were developed to mimic the human reasoning and taking advantage of the combination in spatial-temporal domain. Fuzzy c-means clustering technique was utilized for optimizing the membership functions for varying patterns in the feature domain. In addition, application of the adaptive neuro-fuzzy inference …

Cultural Identity And Behavioral Health Risk In Northern Plains American Indian Adolescents, Wanmdiwi Jessi Rose

Theses and Dissertations

The purpose of this study was to determine if Northern Plains AI adolescents identifying oneself as being "traditional' or "non-traditional" as measured by the Northern Plains Bicultural Inventory III (NPBI-III) would affect health-risk behavior scores as measured by the Youth Risk Behavior Survey (YRBS). It was hypothesized that American Indian adolescents identifying as traditional would have lower health- risk behaviors and that cultural identification would influence health-risk behaviors between males and females.

Northern Plains AI adolescents (N=60, age 14 to 19) were administered the YRBS and NPBI-III during the 2012 UNDIA Time out Wacipi Powwow in Grand Forks, ND. Results …

Wendell Berry's Philosophy Of Education: Lessons From Port William, Jane Margaret Schreck

Theses and Dissertations

In the midst of a proclaimed crisis in higher education, in the clamor and clamber to leverage technology for such innovations as mass open online courses and differentiated learning modules, in the speculative frenzy of preparing students for the careers of a fantasy future, and in the swirl of angst about funding accountability and economic relevance, Wendell Berry's philosophy of education declares that the essential element missing from most current discussions and considerations of education is love. As explained in his essays and revealed in his fiction and poetry, Berry's philosophy centers on love as the best animator of learning: …

Dinitrogen Fixation In Aphotic Oxygenated Marine Environments, Eyal Rahav, Edo Bar-Zeev, Sarah Ohayon, Hila Elifantz, Natalia Belkin, Barak Herut, Margaret R. Mulholland, Iiana Berman-Frank

OES Faculty Publications

We measured N₂ fixation rates from oceanic zones that have traditionally been ignored as sources of biological N₂fixation; the aphotic, fully oxygenated, nitrate (NO¯₃)-rich, waters of the oligotrophic Levantine Basin (LB) and the Gulf of Aqaba (GA). N₂ fixation rates measured from pelagic aphotic waters to depths up to 720 m, during the mixed and stratified periods, ranged from 0.01 nmol N L^-1 d^-1 to 0.38 nmol N L^-1 d^-1. N₂ fixation rates correlated significantly with bacterial productivity and heterotrophic diazotrophs were identified from aphotic as well as …

Development And Deployment Of A Point-Source Digital Inline Holographic Microscope For The Study Of Plankton And Particles To A Depth Of 6000 M, Alexander B. Bochdansky, Manfred H. Jericho, Gerhard J. Herndl

OES Faculty Publications

Bochdansky, A. B., Jericho, M. H., & Herndl, G. J. (2013). Development and deployment of a point-source digital inline holographic microscope for the study of plankton and particles to a depth of 6000 m. Limnology and Oceanography: Methods, 11, 28-40. doi: 10.4319/lom.2013.11.28

Recalcitrant Arguments, Kiranjeet Kaur Dhillon

Dissertations and Theses @ UNI

On January 26, 2011, Reuters photojournalist Amr Abdallah Dalsh took an image of a unknown veiled woman gesturing at Dalsh and his camera. Using TinEye, a reverse image search engine, I found that 86 circulations and 22 recirculations of the photo were primarily in the United States. US graphic artist Nick Bygon created one of the recirculations, which primarily appeared on US blogs. The photo achieved this level of circulation in the US because it is consistent with, and therefore legible within the symbolic language, of the liberal democratic order. Similar to “Migrant Mother” and “Tank Man”, the photo is …

Research About Low Permeability Measurement, Jun He

Theses and Dissertations

Petroleum exploration and production from shale formations have gained great attention throughout the world in the last decade. Producing the hydrocarbons from shale is challenging because of the low porosity and permeability. It is imperative to investigate permeability of the shale formations in order to better understand the performance of wells that are producing hydrocarbons from shale. Permeability is also one of key parameters in modeling fluids flow in matrix in reservoir simulation. Due to the low or very low permeability, the measurement of permeability is time consuming and expensive. These factors often limited the ability to perform permeability measurement …

Negotiation Stands Alone, Alexandra Crampton, Michael Tsur

Social and Cultural Sciences Faculty Research and Publications

Yes, the authors concede, “everybody” negotiates: but that’s like saying “everybody drives,” and then watching aghast when “everybody” climbs into a racing car, or an eighteen-wheeled tractor trailer. The authors draw from Tsur’s experience teaching Israeli hostage negotiators and in other high-pressure environments to argue for an entirely distinct concept of a professional negotiator, one that starts with a rather experienced “student” and builds a sharply different training regimen from there.

Assessing Behavioral Intention To Use Low Social Presence Icts For Interpersonal Task Completion Among College Students: With Special Consideration Toward Short Message Service (Sms) Text-Messaging, Jeffrey Scott Linney

CCAC Theses and Dissertations

This study sought to investigate whether the popularity of Information Communication Technologies (ICTs) would impact the behavioral intention (BI) to use of these technologies to aid in interpersonal task completion. Out of the ICTs available today, the most popular is textmessaging, especially among a sizable percentage of the college population. Approximately 600 students at a small, private junior college in eastern North Carolina were invited to participate in this study with a target of 248 responses needed to comprise an adequate sample. A total of 259 usable surveys (n = 259) were received and analyzed.

Qualitative data collection instruments consisted …