Digital Commons Network^™

Continuous Control Of Lunar Orbits Via Electric Propulsion, Sunil Aggarwal

Masters Theses

"To find definite answers for the presence of water on the poles of Moon, to facilitate selection of future lunar landing sites and aid in construction of architectural bases, to assist proper lunar resource utilization and to improve lunar gravity models there is a great interest and need for highly accurate, reliable and efficient lunar surface mapping and communication. This thesis is intended to aid in proper selection of orbits for future lunar missions by demonstrating the impact of using electric propulsion on the search space of feasible and useful lunar orbits. The requirements for future lunar mapping and communication …

Electricity Generation And Ethanol Production Using Iron-Reducing, Haloalkaliphilic Bacteria, Varun Paul

Masters Theses

"Microbial life in extreme environments has been studied primarily for their metabolic activities. Very few commercial or industrial applications have been known from these systems. In this study, the metabolic pathways and properties of bacteria from a haloalkaliphilic environment of Soap Lake, Washington were employed in two research applications related to energy production. In the first study, the bacterial cultures that were known to reduce iron (III) were used in a Microbial Fuel Cell (MFC) reactor. Iron reducing bacteria have shown to shunt their electrons on to the surface of a carbon electrode of an MFC, and the electrons can …

Development Of A One Dimensional Subsurface Contaminant Transport Model With Stochastic Applications, Benjamin Waldon Johnson

Masters Theses

"Contaminant source release history is a necessary element of contaminant mass transport simulation in the saturated zone. The source release history is unknown at many sites, and many inverse models have been developed to define finite release histories. To define a likely domain of three source history parameters, a mass balancebased one dimensional approach is developed and tested by discretizing the spatial domain into bands. By incorporating the approach in a spreadsheet model, observed data is represented by both variable length and constant length bands of analysis. Each representation of observed data was tested to determine the most appropriate band …

Exploring The Use Of A Commercial Game Engine For The Development Of Educational Software, Hussain Alafaireet

Masters Theses

"Three-dimensional visualization and simulation environments are becoming increasingly important in both industrial and educational environments. However, developing these simulations can be a difficult and expensive task. Herein we explore the use of a commercial game engine to develop a 3-D, interactive computer game designed to teach players about the anatomy of a frog. The goal of this project is threefold: 1) to develop high-fidelity virtual reality educational software with a limited budget and limited personnel, 2) to define a software development process by which similar simulations can be developed, and 3) to explore the benefits that these simulations provide to …

Modeling Of Vias And Via Arrays In High Speed Printed Circuit Boards, Arun Reddy Chada

Masters Theses

"This thesis presents modeling approaches for fast calculation of signals in dense via arrays in high speed printed circuit boards (PCBs) and model to hardware correlation study of solid and perforated disk resonators. A 2D finite difference (FD) method to extract the via capacitance which includes the via pad capacitance obtained by solving the laplace equation in the via domain in multi-layer geometries is presented and validated with analytical formulation for via capacitance. Next, closed-form expression for the impedance of an infinitely large parallel plane pair is derived and validated by comparing with cavity model for several numerical examples. The …

Stressed-Eye Analysis And Jitter Separation For High-Speed Serial Links, Nitin Radhakrishnan

Masters Theses

"As the computer and electronics industry moves towards higher data rates, the most important concern in the field of signal integrity is jitter. A data communication link path often consists of a transmitter, a channel, and a receiver. Many mechanisms can contribute to jitter, a timing uncertainty in the received signal. For example, transmitters have intrinsic noise sources that contribute to random jitter and to certain types of deterministic jitter. In addition, external coupling may cause periodic jitter. The bandwidth limitation of the channel also contributes to a fourth type of jitter, inter-symbol interference. This thesis studies the various components …

Numerical Modeling And Analysis Of Complex Electromagnetic Structures, Including Those Containing Ferrites, Andrea Orlando

Masters Theses

"Application of fast switching amplifiers in power converters, and especially in power inverters, causes unwanted radiated emission, which is a consequence of common mode (CM) currents arising in feed wire bundles. Ferrite chokes are commonly used to suppress those CM currents by increasing the CM impedance of circuits without affecting the differential mode currents, which is important for undisturbed operation of the converters or inverters. Their effective impedance is the main design concern, and it is determined by the material intrinsic properties (permeability, permittivity) and geometry. The goal of this work is to analytically correlate the geometrical and material properties …

Reliability-Based Design With System Reliability And Design Improvement, Gagandeep Singh Saini

Masters Theses

"This thesis focuses on developing a methodology for accurately estimating series system probability of failure. Existing methods for series system based design optimization are not that accurate because they assign reliability to each failure mode; as a result complete system reliability goes down. According to method proposed in this work, the user will assign required system reliability at the start and then optimizer will apportion reliability to every failure mode in order to meet required system reliability level. Detlevson second order upper bounds are used to estimate system probability of failure. Several examples have been shown to verify the results …

Fault Detection And Prediction With Application To Rotating Machinery, Gary R. Halligan

Masters Theses

"In this thesis, the detection and prediction of faults in rotating machinery is undertaken and presented in two papers. In the first paper, Principal Component Analysis (PCA), a well known data-driven dimension reduction technique, is applied to data for normal operation and four fault conditions from a one-half horsepower centrifugal water pump. Fault isolation in this scheme is done by observing the location of the data points in the Principal Component domain, and the time to failure (TTF) is calculated by applying statistical regression on the resulting PC scores. The application of the proposed scheme demonstrated that PCA was able …

Nona-Arginine Peptides Facilitate Cellular Entry Of Semiconductor Nanocrystals: Mechanisms Of Uptake, Yi Xu

Masters Theses

"Luminescent semiconductor quantum dots (QDs) have recently been used for delivering and monitoring biomolecules, such as drugs and proteins. However, QDs alone have a very low efficiency of transport across the plasma membrane. In order to increase the efficiency of QD delivery, synthetic nona-arginine (sR9) was used, a cell penetrating peptide, to facilitate uptake. Data demonstrated that sR9 could significantly increase the cellular uptake of QDs by noncovalent binding between QDs and sR9. Furthermore, the mechanisms of QD/sR9 cellular internalization were investigated. Low temperature and metabolic inhibitors markedly inhibited the uptake of QD/sR9, indicating that internalization is an energy-dependent process. …

Investment Shell Cracking, Edward A. Druschitz

Masters Theses

"Shell cracking is the single greatest problem affecting investment casters. A clearer understanding of the factors affecting the melt profile of the wax can be gained using computational fluid dynamics (CFD) to model the interaction among 1) the thermal conductivity of the wax, 2) the thermal conductivity of the shell, and 3) the temperature of the autoclave during the autoclave de-waxing cycle. The most favorable melt profile results from a high autoclave temperature (438⁰K to 458⁰K) and saturated thermal conductivity of the shell (1.36 to 1.40 Wm⁻¹k⁻¹) in conjunction with a low wax thermal conductivity (0.33 Wm⁻¹k⁻¹). These parameters reduce …

Oxidative Stress, Calcium Homeostasis, And Altered Gene Expression In Human Lung Epithelial Cells Exposed To Zno Nanoparticles, Chuan-Chin Huang

Masters Theses

"The influence of 20 nm ZnO nanoparticles on oxidative stress, intracellular calcium homeostasis, and gene expression was studied in human bronchial epithelial cells (BEAS-2B). ZnO caused a concentration- and time-dependent cytotoxicity while elevating oxidative stress and causing membrane damage (cellular LDH release). There was a remarkably steep relationship between concentration and toxicity at concentrations from 5 to 10 μg/ml. Exposure to ZnO increased intracellular calcium levels in a concentration- and time-dependent manner. Treatment with the antioxidant N-acetylcysteine prevented cell loss and diminished the increase in intracellular calcium concentration, suggesting oxidative stress mediated cytotoxicity. Exposure to a sublethal concentration of ZnO …

Maximum Likelihood Fusion For Detection Of Led Precursors Using Laser-Induced Breakdown Spectroscopy, Pratik Shah

Masters Theses

"Improvised Explosive Devices (IEDs) pose an increasing threat to the safety of soldiers and civilians in embattled areas. The use of compounds such as RDX complicates the detection of IEDs, as these compounds are often hard to identify in the presence of contaminants such as alcohol, oils and dust. Spectroscopic techniques such as Laser-Induced Breakdown Spectroscopy (LIBS) and Raman have shown promise for the detection of explosive compounds; however, their accuracy is limited, as noise can cause variations in the peak strengths and locations that they utilize for classification.

The research presented in this thesis applies signal processing to the …

Automated Offspring Sizing In Evolutionary Algorithms, André Chidi Nwamba

Masters Theses

"Evolutionary Algorithms (EAs) are a class of algorithms inspired by biological evolution. EAs are applicable to a wide range of problems; however, there are a number of parameters to set in order to use an EA. The performance of an EA is extremely sensitive to these parameter values; setting these parameters often requires expert knowledge of EAs. This prevents EAs from being more widely adopted by nonexperts. Parameter control, the automation of dynamic parameter value selection, has the potential to not only alleviate the burden of parameter tuning, but also to improve performance of EAs on a variety of problem …

Influence Of Bioirrigation On Metal Distribution Within Burrows, Terri Shattuck

Masters Theses

Bioirrigation is the increase of solute transport resulting from introduction of oxygenated water from the surface into the more reduced environment deep within the burrow. Fe and Mn hydr-(oxides) accumulate on burrow margins in response to the oxygen flux into suboxic porewaters. This has been shown to trap trace metals (Harding and Risk, 1986; Tessier and Campbell, 1988; Tessier et al., 1979, 1982). The diagenesis, mobility, and transport of metals contribute to the bioavailability of metals in the environment possibly to the extent of harming ecosystems; especially in coastal areas with buried waste. This study assesses Fe and trace metal …

Effect Of Calendering On Flexographically Printed Silver Flake Ink, Sujay Pandkar

Masters Theses

Interest in the printed electronics is increasing on a day-to-day basis. To utilize the concept of printed electronics on a wider range, printed circuit needs to perform more and more efficiently. The simplest printed circuit components include conductive traces, which can function as interconnects or contact electrodes. There are still some limitations to the conductivity of printed traces. Previous results showed an improvement in the conductivity of printed traces with a post cure treatment of 4 hours at 105°C. The present research explores a different approach towards improving conductivity using a post calendering treatment on-line.

The effects of calendering temperature, …

Optical And Electrochemical Molecular And Nanoscale Sensors For The Selective Detection Of Organophosphorus Based Pesticides, Chandrima De

Masters Theses

Organophosphorus based pesticides are highly toxic and represent serious environmental concerns. These compounds tend to easily enter ground water and cause drastic pollution. The toxicity levels of the organophosphorus pesticides however are based on their structures, and hence methods for their selective detection are in high demand. The creation of new materials for sensing and actuation requires careful manipulation of the responsive units required to control analyte selectivity. We have successfully designed and synthesized a molecular sensor based on the family of stilbenes that not only can detect organophosphorus pesticides, but also distinguish between them. Four different pesticides have been …

Origin Of Tunnel Valley And Esker Assemblages In The Saginaw Lobe, Barry County, Michigan, Caleb J. Woolever

Masters Theses

Surficial mapping, borehole analysis, and ground penetrating radar surveys are used to reconstruct conditions leading to the formation of tunnel valley and esker networks within the Dowling 7 .5 minute quadrangle. The relationship between tunnel valleys and eskers has important implications on the subglacial hydrology beneath the Saginaw Lobe of the Laurentide Ice Sheet.

Surficial mapping reveals northeast-southwest trending tunnel valleys, some containing eskers of the same orientation, in hummocky topography mapped as the Saginaw Kalamazoo Moraine. A borehole hole drilled through one such tunnel valley and esker pair reveals sand and gravel fining upwards to fine sand. Stratigraphy suggests …

Characterization Of P62, Hah1 And Their Interaction With The Wilson Disease Protein, Paul Sifuna Oshule

Masters Theses

Wilson disease is an autosomal recessive disorder resulting in the accumulation of copper in the body primarily in the liver and brain. In order to understand the pathogenesis of Wilson disease, our laboratory is studying several different proteins. Wilson disease protein (ATP7B) is a P-type ATPase which acts to remove excess copper from the cells. The p62 subunit of the dynactin complex is a protein whose function is still unknown but it has been proposed to have a copperdependent interaction with ATP7B. HAH1 is a human metallochaperone that binds copper as it comes into the cells from CTR1, a permease. …

Origin Of Size-Dependent Energy Transfer From Photoexcited Cdse Quantum Dots And Fluorescent Dyes To Gold Nanoparticles, Mariana Kondon

Masters Theses

The photoluminescence quenching of CdSe quantum dots (QD) and fluorescent dyes by hexanethiolate Mono layer Protected Clusters (MPCs) with core diameters of 1.1- 4 .9 nm is described.

The CdSe QD investigated had the following core diameters of 2.0, 2.6, 3.4 and 6.9 nm. The florescent dyes used were: Coumarin 440 (CM440), Fluorescein 548 (F548), Rhodamine 6G (R6G), Pyromethene 597 (PM597) and Lyssamine Dye (LD700). Experimental evidence suggests that the photoluminescence quenching of both CdSe QD and the fluorescent dyes occurs through energy transfer and that the AuMPCs are efficient quenchers in both cases. The larger MPCs are more efficient …

Analysis Of Pore Architecture And Correlation To Sonic Velocity Values In Silurian (Niagaran) Reefs Of The Michigan Basin, Amy Kathryn Noack

Masters Theses

Recent work has shown that there is a complex relationship among porosity, permeability, and rock fabric in carbonate rocks. Porosity/permeability transforms are of limited value when evaluating carbonate reservoirs because permeability is controlled by pore type. Vuggy, moldic, or fenestral pore types have high porosity but poor permeability; in contrast, intergranular and intercrystalline pore networks have high porosity and high permeability. Visible pore types of key facies in five Middle Silurian (Niagaran) Reef reservoirs of the Michigan Basin were evaluated to better understand related permeability. Image analysis was performed on key facies to understand pore geometries and pore connectivity. Facies …

Analysis Of Spatial Distribution Of Hazardous Wastes In Semcog Region, Michigan, Junfang Chen

Masters Theses

This research is devoted to an increasingly recognized issue: environmental injustice, that is, the distribution of environmental risks and/ hazards are disproportionably distributed in the space in terms of the effects on the victims. Specifically, this thesis focuses on an analysis of the spatial distribution of hazardous materials from fixed incidents and the characteristics of neighborhoods living near the incident sites, so as to test the hypothesized relationships that poor people and minority people live near the incident sites. SEMCOG region, Michigan is chosen as the study area due to its frequent occurrence of incidents involving environmental hazards. It is …

Mobile Phone Communication Competence (Mpcc): Development And Validation Of A New Measure, Emil Bakke

Masters Theses

More than two billion people around the world have adopted mobile phones for communication. Interpersonal communication research has found that communication competence is an essential human need required to fulfill interpersonal objectives to achieve physical and psychological satisfaction (Spitzberg and Cupach, 1984), however, mobile phone communication competence has yet to be studied. The purpose of this study is to develop and validate a new scale designed to measure Mobile Phone Communication Competence (MPCC); a principal component factor analysis uncovered the structure and dimensionality of the MPCC measure. The results from the factor analysis in this study identified six constructs: asynchronous …

The Physics Of Electron Degenerate Matter In White Dwarf Stars, Subramanian Vilayur Ganapathy

Masters Theses

White dwarfs are the remnant cores of medium and low mass stars with initial mass less than 8 times the mass of our sun. As the aging giant star expels its surface layers as planetary nebulae, the core is exposed as a white dwarf progenitor. The density of matter in white dwarfs is so high that thermal or radiation pressure no longer supports the star against the relentless pull of gravity. The white dwarf is supported by a new kind of pressure known as the degeneracy pressure, which is forced on the electrons by the laws of quantum mechanics. The …

Blocked Localized Wavefunction Analysis Of Π And Σ Bonds In The Metal Carbonyl, Kazuhito Nakashima

Masters Theses

The bonding features in group 10 and 11 metal carbonyls Ni(CO), Pd(CO), Pt(CO), [Cu(CO)]+, [Ag(CO)]+, and [Au(CO)]+ have been studied with BLW method. The carbon monoxide is well known as both a π acceptor and a σ donor. The π back bonding and o bonding are synergistic in these metal carbonyl complexes, because the π donation from the metals polarizes the metals and creates a negative force field as an additional driving force on the σ donation from the carbon end of CO vice versa. The synergistic effect in the metal-carbonyl bonds can be described by decomposing the binding energy …

The Eternality Of The Immutable God In The Thought Of Paul Helm: A Critical Analysis, Ronnie P. Campbell

Masters Theses

Paul Helm, professor of theology and philosophy at Highland Theological Institute, has written extensively on God’s relation to time. Following in the tradition of Augustine, Boethius, Anselm, and Aquinas, Helm upholds God’s temporal mode of existence as timelessness. This thesis seeks to determine whether Helm and other eternalists are justified in holding that God’s temporal mode of existence is atemporal in light of the doctrines of incarnation and creation. Central to this inquiry is whether God is strongly immutable. In conclusion, this thesis argues that while the divine timeless view is coherent, it rests on an untenable notion of strong …

Morphological Analysis Of The Charlevoix-Antrim And Northport Drumlin Fields, Michigan Using Digital Elevation Models, Alan M. Lefever

Masters Theses

The Charlevoix-Antrim and Northport drumlin fields, located in northwest Lower Michigan, lie on opposite sides of Grand Traverse Bay. Morphological measurements were derived from topographic maps and Digital Elevation Models (DEMs), combined with grain size analyses performed on collected drumlin sediments. Comparison of the morphological results demonstrates that statistical analysis of equal or better accuracy can be performed on drumlins using high resolution DEMs. The grain size analysis determined that the drumlins contain more gravel near the coast and become sandier to the south and east.

Spindle drumlins are the dominant drumlin form in both the Charlevoix-Antrim and Northport fields. …

Incorporation Of Space Syntax Theory In Determining Safe And Efficient Construction Site Layout, Minsuck Cho

Masters Theses

Facility layout is an important to determine a proper arrangement of temporary facilities in a construction site. It significantly impacts productivity and safety of construction. The objectives of layout planning are to minimize travel distance and time, to decrease the facility transportation and setup costs, and to improve site safety. Despite the importance of facility layout, it is often overlooked in the planning phase. Several models have been developed taking some of these factors into consideration; however, construction managers and site planners often regard cost as the most important factor in layout planning and pay less attention to safety and …

A Study Of Body Scent As A Social Identifier Among Members Of The Arabic Culture, Mia M. Wilson

Masters Theses

Body scent plays a major factor in how individuals interact with one another. While Americans have their own perception of what is "proper" body scent, they still remain uninformed about the various ways body scent is used to deliver social messages and form interpersonal relationships within other cultures. With many immigrants continuing to move to the United States (Frey, 2004), American societies need to become educated on other cultures' social aspects of body scent to avoid alienation of foreign communities. This qualitative research study explores how individuals of the Saudi Arabian culture use body scent as a social identifier to …

Improving Query Efficiency Of Multiresolution Data Aggregation For Analytical Exploration Of Large Relational Dataset, Yu-Ting Huang

Masters Theses

Tree structures are developed to organize the data more efficiently by using fewer resources for searching records. This thesis investigates the tree's actual structure on the hard disk to see the influence of different kinds of structures on the tree building time and query execution time. In order to improve efficiency, one multi-file structure and two reorganization structures, BFS and DFS, are examined to achieve this goal. The results indicate that two reorganization structures on KDB-tree structure can significantly improve the query execution time in large data sets and multi-file structure can slightly improve the TPIE lover level building time.