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Masters Theses

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Articles 991 - 1020 of 2634

Full-Text Articles in Physical Sciences and Mathematics

Electricity Generation And Ethanol Production Using Iron-Reducing, Haloalkaliphilic Bacteria, Varun Paul Jan 2009

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 …


Formation Of Iron-Rimmed Sandstone Nodules On Earth; Terrestrial Analogue For The Formation Of Martian Blueberries?, Katherine Charlotte Muller Jan 2009

Formation Of Iron-Rimmed Sandstone Nodules On Earth; Terrestrial Analogue For The Formation Of Martian Blueberries?, Katherine Charlotte Muller

Masters Theses

"NASA's twin Mars Exploration Rovers, MER, Spirit and Opportunity, have identified numerous geologic features that hint at a watery past on Mars noted in Malik, 2004. Prominent among these features are the "Martian Blueberries" that occur as spherical hematite (Fe₂O₃) nodules. Hematite formation is facilitated by the presence of water, although there are presently no known sources of free liquid water on Mars. Chan et al., 2004 states that these "blueberries" are also similar to nodules found in the Jurassic aged Navajo Sandstone in Utah. An understanding of the processes controlling the formation of the Utah nodules may thus be …


In Vitro Evaluation Of Bioactive Glass Scaffolds And Modified Bioactive Glasses With An Osteogenic Cell Line, Vernon C. Modglin Jan 2009

In Vitro Evaluation Of Bioactive Glass Scaffolds And Modified Bioactive Glasses With An Osteogenic Cell Line, Vernon C. Modglin

Masters Theses

"This investigation consisted of two parts focused on bioactive glasses and scaffolds for in vitro growth of bone cells for tissue engineering and bone repair. The first part involved evaluation of the ability of two new types of porous 13-93 bioactive glass scaffolds to support the growth and differentiation of mouse MLO-AS cells, an established osteogenic cell line used as a model of developing bone tissue. The two scaffold types tested included 13-93 glass fiber and trabecular-like scaffolds seeded with MLO-AS cells and cultured for intervals of 2 to 12 days. Collectively, in vitro results indicate that the 13-93 glass …


Information Flow Properties For Cyber-Physical Systems, Rav Akella Jan 2009

Information Flow Properties For Cyber-Physical Systems, Rav Akella

Masters Theses

"In cyber-physical systems, which are the integrations of computational and physical processes, security properties are difficult to enforce. Fundamentally, physically observable behavior leads to violations of confidentiality. This work analyzes certain noninterference based security properties to ensure that interactions between the cyber and physical processes preserve confidentiality. A considerable barrier to this analysis is the representation of physical system interactions at the cyber-level. This thesis presents encoding of these physical system properties into a discrete event system and represents the cyber-physical system using Security Process Algebra (SPA). The model checker, Checker of Persistent Security (CoPS) shows Bisimulation based NonDeducibility on …


Automated Offspring Sizing In Evolutionary Algorithms, André Chidi Nwamba Jan 2009

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 …


Stability Of Heme Proteins: Cytochrome C And Horseradish Peroxidase, Mini Gupta Jan 2009

Stability Of Heme Proteins: Cytochrome C And Horseradish Peroxidase, Mini Gupta

Masters Theses

No abstract provided.


Molecular Structures And Pulsed Discharge Emission Studies Of Volatile Organic Compound Derivatives, Ashley Osthoff Jan 2009

Molecular Structures And Pulsed Discharge Emission Studies Of Volatile Organic Compound Derivatives, Ashley Osthoff

Masters Theses

No abstract provided.


Electrochemical And Spectroscopic Characterization Of A Polypyridyl Ru(Ii) Complex Containing A Fused Alloxazine, Waynie Wilson Olaprath Jan 2009

Electrochemical And Spectroscopic Characterization Of A Polypyridyl Ru(Ii) Complex Containing A Fused Alloxazine, Waynie Wilson Olaprath

Masters Theses

No abstract provided.


Cloning, Overexpression, Purification And Characterization Of Gcp Ii Homologous Metalloprotein From Caulobacter Crescentus, Dilani Nilushika Gigiriwala Gamage Jan 2009

Cloning, Overexpression, Purification And Characterization Of Gcp Ii Homologous Metalloprotein From Caulobacter Crescentus, Dilani Nilushika Gigiriwala Gamage

Masters Theses

No abstract provided.


Integration Of A Gis Learning System Into Civil Engineering Curricula: An Evaluation, Basanta Tandon Jan 2009

Integration Of A Gis Learning System Into Civil Engineering Curricula: An Evaluation, Basanta Tandon

Masters Theses

"An evaluation of a web-based e-learning system to facilitate integration of Geographical Information Systems (GIS) into the Civil Engineering curriculum was conducted. The principal goals of the evaluation were to examine the effectiveness of the learning system and to develop a preliminary model to describe how students interact with the learning system. Quantitative and qualitative data were collected from 80 students who participated in a geotechnical engineering laboratory session, which covered soil borrow sites. Students rated the laboratory session as significantly more effective for learning, a nd more motivational than the class text. They also rated the lab significantly more …


Comparison Of Dashboard-Based And Balanced Scorecard-Based Corporate Performance Management System, Lin Zhu Jan 2009

Comparison Of Dashboard-Based And Balanced Scorecard-Based Corporate Performance Management System, Lin Zhu

Masters Theses

"Under current hypercompetitive and technology driven economic environment, more companies are using a corporate performance management (CPM) system to gain more accurate understandings of the company goals and strategies and to craft methods of achieving those goals and strategies. While CPM systems are generally implemented in two approaches: dashboard approach and scorecard approach, very few studies examine the effectiveness of each type of CPM systems implementation. Therefore, the main objective of this study is to assess the effectiveness of a dashboard based and a balanced scorecard based corporate performance management system. The effectiveness is examined through management effectiveness, degree of …


Environmental Geochemistry Of Metal Contaminated Sediments From The Big River System Of Southeastern Missouri, Helen Carrie Bender Jan 2009

Environmental Geochemistry Of Metal Contaminated Sediments From The Big River System Of Southeastern Missouri, Helen Carrie Bender

Masters Theses

"Geochemical analysis of stream sediments from the Big River Watershed of southeastern Missouri indicates that they contain elevated concentrations of contaminant metals such as Pb. Zn, Cu. Co, Ni and Cd. The elevated concentrations are derived from natural exposures of metal enriched strata and the numerous mine tailings piles and water seeps created as a result of about 300 years of lead-zinc mining in the “Old Lead Belt”. Galena (PbS), sphalerite (ZnS), and pyrite (FeS2) are the primary sulfides found in the tailings piles and Scanning Electron Microscopy analysis of individual metallic sediment particles collected at intervals downstream …


Oxidative Stress, Calcium Homeostasis, And Altered Gene Expression In Human Lung Epithelial Cells Exposed To Zno Nanoparticles, Chuan-Chin Huang Jan 2009

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 …


The Analogue Of The Iterated Logarithm For Quantum Difference Equations, Karl Friedrich Ulrich Jan 2009

The Analogue Of The Iterated Logarithm For Quantum Difference Equations, Karl Friedrich Ulrich

Masters Theses

"In this thesis, we consider oscillation and nonoscillation of q-difference equations, i.e., equations that arise while studying q-calculus. In particular, we prove an extension of Kneser’s theorem on q-calculus to cases in which no conclusion can be drawn by applying Kneser’s theorem. In order to accomplish this, we establish a change of variables which yields, when applied iteratively, a sequence of comparison functions. We use these comparison functions to establish our main result. Finally, we consider an analogue result for time scales which are unbounded from above"--Abstract, page iii.


The Use Of Lanthanide Triflates As A Method For Reducing Ytterbium(Iii) To Ytterbium(Ii), Latasha Michelle Garrett Dec 2008

The Use Of Lanthanide Triflates As A Method For Reducing Ytterbium(Iii) To Ytterbium(Ii), Latasha Michelle Garrett

Masters Theses

High purity lutetium (99.999%) is employed in the manufacture of cerium-doped lutetium oxyorthosilicate. Such lutetium is in high demand because the cerium-doped lutetium oxyorthosilicate is the best gamma-detecting scintillator known. Solvent extraction is the most widely used method for separating the rare earths on an industrial scale at 99.999% purity. However, this process is time consuming and requires 80-100 separation stages. The major difficulty in pure lutetium production is the separation from the adjacent element, ytterbium. If ytterbium(III) could be reduced to ytterbium(II), this would permit a different chemistry between ytterbium(II) and the trivalent state elements, allowing a more facile …


Experimental Determination Of Emissivity And Resistivity Of Yttria Stabilized Zirconia At High Temperatures, Howard Mosley Frederick Dec 2008

Experimental Determination Of Emissivity And Resistivity Of Yttria Stabilized Zirconia At High Temperatures, Howard Mosley Frederick

Masters Theses

The emissivity and resistivity of yttria stabilized zirconia (YsZ), Y2O3-ZrO2, a ceramic material that has been specially fabricated for use as an electrically powered high temperature air heater are determined for temperatures above 2000 K. Published results of measurements of emissivity and resistivity of yttria, zirconia, and their alloys at temperatures above 2000 K are rare in the technical literature. A survey of literature describing the properties of YsZ, particularly literature concerning the ionic conduction process at high temperatures, is assembled to provide a theoretical basis for the formulation of a temperature and resistivity …


A Note On Hamel Bases, Jeremy S. Higdon Dec 2008

A Note On Hamel Bases, Jeremy S. Higdon

Masters Theses

The purpose of this paper is to discuss certain properties of Hamel bases. In particular, we reprove and generalize a theorem of R. Mabry (Aequations Mathematicae 71 (2006) p. 294-299) on the non-existence of nontrivial Hamel bases closed under multiplication.


The Evaluation Of A Chemical Fingerprinting Technique For Identifying The Sources Of In-Stream Sediments, Robert Alexander Hull Dec 2008

The Evaluation Of A Chemical Fingerprinting Technique For Identifying The Sources Of In-Stream Sediments, Robert Alexander Hull

Masters Theses

Sediment is often listed as one of the main contributors to the impairment of surface waters throughout the United States. Sediment source identification is difficult in watersheds with complex combinations of land-uses and non-point sources because of the complexities involved in correlating water quality data, which are relatively easy to collect, to the source of a degrading component. The elemental properties of a particular soil on the landscape may be viewed as a “fingerprint”. A comparison of the elemental fingerprints of potential sources and in-stream sediment may be used to establish sediment source. The objectives of this investigation were to …


Environmental Analysis And White Cell Applications Ftir Spectroscopy, Maria Gabriela Oliveros Dec 2008

Environmental Analysis And White Cell Applications Ftir Spectroscopy, Maria Gabriela Oliveros

Masters Theses

The research is concerned with atmospheric chemistry & physics, and analyzing the environment with respect to the quantity of molecules is in the air we breathe. Fourier Transform Infrared Spectroscopy is used to identify the IR active molecules in our atmosphere. FTIR Spectrometer determines the intensity loss for molecules that have absorbed IR light. The FTIR spectroscopy is performed using the light from the sun or a carbon rod light source in the lab. A Sun-tracking device was employed to direct the sunlight into the spectrometer. Open-path measurements were made using multiple mirror reflections of the carbon rod light source …


Biochemical Reactions Instigating Vision – Parameter Sensitivity Analysis, Sophonie Ketcha Tchoua Dec 2008

Biochemical Reactions Instigating Vision – Parameter Sensitivity Analysis, Sophonie Ketcha Tchoua

Masters Theses

The purpose of this work is to investigate the sensitivity of parameters involved in a cascade of biochemical reactions occurring in photoreceptor cells in the retina of the eye. This cascade constitutes the first stage of the elaborate process of vision, by which light captured in a photoreceptor generates an electrical signal. It is this signal that travels to the brain enabling vision.

Sensitivity on parameters was performed on an ODE model of the biochemical cascade using two methods. One method used SimLab, a statistical sensitivity analysis program. We found that there are at most five important parameters out of …


Tree-Like Spaces With The Fixed-Point Property, Realized As Inverse Limits Of Special Finite Trees, Jennifer Katherine Aust Dec 2008

Tree-Like Spaces With The Fixed-Point Property, Realized As Inverse Limits Of Special Finite Trees, Jennifer Katherine Aust

Masters Theses

In this paper, we explore some properties of inverse limit sequences on sub-spaces of Euclidean n-space. We address some well-known examples, in particular the example by David Bellamy of the "tree-like" continuum that does not have the fixed-point property. We highlight some spaces with the fixed-point property that are between snake-like continua and Bellamy's example in their level of complexity. Specifically, we prove the fixed-point property for inverse limits of limit sequences on the unit interval and on the n-ad (in two configurations), and for inverse limits that can be mapped via a continuous function with small point pre-images to …


Heats Of Solvation Of Organic Liquids In Room Temperature Ionic Liquids, Paula Jeanette Beach Dec 2008

Heats Of Solvation Of Organic Liquids In Room Temperature Ionic Liquids, Paula Jeanette Beach

Masters Theses

Ionic liquids are of potential use in industry as reusable, non-polluting solvents. Their thermochemical properties need to be known to facilitate planning of processes and experiments using these solvents. Two ionic liquids: 1-Butyl-3-methylimidazolium hexafluorophosphate ([C4mim]PF6 or [bmim]PF6) and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([hmim]NTf2) were studied using a calorimeter. Various organic liquids were introduced into the solvents and their heats of solution were measured and tabulated. Potential effects of certain functional groups such as alcohol, amine, carboxylic acid, ketone, and aldehyde were examined as well as aromatics versus chains and saturated rings.


The Adsorption Of 2-Ketogluconate By Goethite, Jessica Suzanne Journey Dec 2008

The Adsorption Of 2-Ketogluconate By Goethite, Jessica Suzanne Journey

Masters Theses

The low-molecular-mass-organic acid, 2-ketogluconate (kG), has been found to exist in significant concentrations in the rhizosphere of agricultural soils. Adsorption of kG by constant potential mineral surfaces may influence soil chemical processes. This study examines influence of temperature, pH, and ionic environment on the adsorption of kG by goethite. When kG was present on the surface of goethite, the pHpzc decreased by approximately 0.4 pH units, from pH 7.6 to pH 7.2, suggesting that kG is chemisorbed to the goethite surface via ligand exchange mechanisms. The adsorption of kG by goethite is a function of pH and ionic strength. …


Origin Of Tunnel Valley And Esker Assemblages In The Saginaw Lobe, Barry County, Michigan, Caleb J. Woolever Aug 2008

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 Aug 2008

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. …


Optical And Electrochemical Molecular And Nanoscale Sensors For The Selective Detection Of Organophosphorus Based Pesticides, Chandrima De Aug 2008

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 …


Influence Of Bioirrigation On Metal Distribution Within Burrows, Terri Shattuck Aug 2008

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 …


Origin Of Size-Dependent Energy Transfer From Photoexcited Cdse Quantum Dots And Fluorescent Dyes To Gold Nanoparticles, Mariana Kondon Aug 2008

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 …


Relationship Between Slug-Test And Effective Hydraulic Conductivities For 2-Dimensional Heterogeneous Aquifers, Richard Walker Donat Aug 2008

Relationship Between Slug-Test And Effective Hydraulic Conductivities For 2-Dimensional Heterogeneous Aquifers, Richard Walker Donat

Masters Theses

Slug tests are one of the most common field tests used by hydrogeologists to evaluate the hydraulic conductivity of an aquifer system. Steady-state and transient (slug test) numerical simulations were run in 37, 2-dimensional randomized multifractal hydraulic conductivity fields. Each field consisted of 59,049 individual saturated hydraulic conductivity (K) values with varying numbers of hydrofacies and different degrees of spatial heterogeneity. The Keff values were determined by examining the flux in and out of the steady-state numerical model. The Kslug values were determined by adding a slug of water to the center node of the field and evaluating …


Fusion Reaction Cross-Section Measurements Near 100Sn, Elton Lewis Freeman Aug 2008

Fusion Reaction Cross-Section Measurements Near 100Sn, Elton Lewis Freeman

Masters Theses

This thesis describes the measurement of production rates of A=109 isobars produced with beams of 54Fe ions accelerated to 207 MeV bombarding 58Ni target. The reaction products have been electromagnetically separated according to their mass over charge ratio and implanted into a semiconductor detector. The spontaneous decay radiation from the implanted radioactive isobars has been measured in a detection system with known detection efficiency, enabling to determine absolute intensities of observed isotopes. Known branching ratios of alpha decays of 109Xe, 109Te, proton decay of 109I and beta delayed gamma radiation of 109Te and 109 …