Physical Sciences and Mathematics Commons^™

Wireless Passive Surface Acoustic Wave (Saw) Sensing System, Sridevi Krishnamurthy

Dissertations

Due to their small size and ruggedness, Surface Acoustic Wave (SAW) devices have been widely used as part of wireless sensing or identification system especially in inaccessible and inhospitable environments. In addition, SAW devices find widespread applications as filters in communication systems and also as physical, chemical and bio-sensors and ID tags. The passive wireless SAW sensing system mainly consists of a passive SAW sensor and an interrogation unit which sends a burst signal to the SAW sensor and processes the sensor response. Theobjectives of this work were designing, prototyping and fabricating the interrogation unit on a PCB and also …

The Effect Of Chloramphenicol On Bb88 Murine Erythroleukemia Cells, Peter K. W. Harris

Dissertations

DNA microarrays can be used to measure genome-wide transcript levels. These measurements may be useful in understanding cellular changes induced by a chemical agent. In this study, Affymetrix microarray technology has been used to study the effects of chloramphenicol, an antibiotic that inhibits bacterial and mitochondrial protein synthesis, on the transcription profile in mammalian cells. Transcript levels in BB88 murine erythroleukemia cells treated with 50 micromolar ( mu M) chloramphenicol, a concentration shown to inhibit BB88 proliferation, are measured. Using total RNA from treated cells, biotin-labeled cRNA was prepared and hybridized to Affymetrix U74Av2 microarrays. From these hybridizations, expression levels …

Modified Fenton Oxidation Of Hydrocarbon Contaminated Soils With Cao2: Microbial Survival And Surfactant Production, Abraham Matthew Northup

Dissertations

The efficacy of CaO₂ for use in modified Fenton's (MF) reactions was investigated in this study, with the goal of developing a CaO₂-based MF oxidation technology for use in in situ chemical oxidation. Traditionally, liquid H₂O₂ (HP) is used, and is injected into the subsurface in excess to ensure a sufficient radius of influence. CaO₂ was investigated as an alternative source of H₂O₂ for MF reactions.

First, the rate of dissolution of powdered CaO₂ and the yield of HP was investigated. Our results showed that the rate of dissolution …

The Global Hepatic Transcriptional Response Of Male Fisher Rats To Dietary Aroclor 1254 Exposure, Trisha M. Basford

Dissertations

Dietary intake is a primary route for biomagnification of environmentally persistent polychlorinated biphenyls (PCBs) within humans and animals. Aroclor 1254, a mixture of PCBs, is associated with a variety of toxic responses including alterations in blood and lipid biochemistry and tumor promotion. Measurement of the transcriptional responses to low-level dietary exposure to A1254 has not been reported to date, and is important given the persistence of PCBs, and range of effects associated with exposure. The aims of this study were to characterize changes in rat hepatic global gene expression due to sub-acute and sub-chronic dietary exposure to A1254, and to …

Inelastic X-Ray Scattering Studies On Organic Semiconductors And Organic Superconductors, Chaminda Nalaka Kodituwakku

Dissertations

We have measured electronic excitations and excitons in CuPc polycrystalline and single crystal samples. Measurements on the polycrystalline sample were done with 300 meV resolution and measurements on the single crystal were done using 120 meV resolution. Time dependant density functional theory (TD-DFT) calculations were done on the CuPc molecule to understand the electronic excitations in this system.

Some Applications Of Gaussian Quadrature And Neural Network Modeling In Earth Flows And Other Slow-Moving Landslides In Cohesive Slope Materials, Rennie Bwalya Kaunda

Dissertations

Geometrical changes and progressive displacements in earth flows and other slow moving landslides triggered by climatic changes may be addressed by digital modeling. Gaussian quadrature, a numerical integration technique though fixed points, is employed to compute geometrical areas defined by stratigraphic (soil or rock layering) units, vertical pole projections and a slip surface, based on kinematic admissibility. An example from the Lake Michigan coast shows that the total internal geometrical area is found to be preserved during the course of the progressive deformation. Displacement monitoring of the slope shows that it became less stable over a period of eleven years …

A New Model For Cooperative Mobility In Support If Qos In Manets With Heterogeneous Autonomy Requirements, Ghassen Ben Brahim

Dissertations

Modern mobile ad-hoc networks (MANETs) frequently consist of nodes which exhibit a wide range of autonomy needs. This is particularly true in the settings where MANETs are model compelling, i.e. battlefield, response & rescue, and contexts requiring rapid deployment of mobile users. The time-critical nature of the underlying circumstances frequently requires deployment of both manned and unmanned nodes, and a coordination structure which provides prioritized tasking to them.

In classic ad-hoc networks settings, it is assumed that all nodes are autonomous and do not depend in any case on other nodes. In this research work, contrarily to this design, we …

The Fock Space And Related Bergman Type Integral Operators, Ovidiu Furdui

Dissertations

In this thesis we study the boundedness of a general class of integral operators induced by the kernel functions of Fock spaces. More precisely, for a, b, and c real parameters we study the action of [Special characters omitted.] and [Special characters omitted.] on Lp ([Special characters omitted.] ,dv_s ), where dv_s ( z ) = [Special characters omitted.] is the Gaussian probability measure on [Special characters omitted.] . We prove that, when p > 1, respectively p = 1, these operators are bounded if and only if p satisfies a quadratic, respectively a linear, inequality. The …

Measures Of Travers Ability In Graphs, Futaba Okamoto

Dissertations

For a connected graph G of order n ≥ 3 and a cyclic ordering sc : v 1, v2,..., vn, v n+1 = v1 of vertices of G, the number d(sc) is defined by d(sc) = i=1n d(vi, vi +1), where d(vi, vi +1) is the distance between vi and vi+1 in G for 1 ≤ i ≤ n. The Hamiltonian number h(G) and upper Hamiltonian number h +(G) of G are defined as h(G) = min{d(sc)} and h+(G) = max{d(sc)}, respectively, where the minimum and maximum are taken over all cyclic orderings s c of vertices of G. For …

Laboratory Based Chemical And Isotopic Investigations On Biotic (Microbial) And Abiotic Reduction Of Iron And Oxidation Of Organic Compounds, Tsigabu Asmelash Gebrehiwet

Dissertations

Studies using chemical and isotopic techniques have been conducted to investigate experimental microbial (biotic) iron reduction and abiotic redox processes. In the microbially mediated study Fe(III) reduction and lactate oxidation at circum-neutral pH and anaerobic conditions were used to characterize the metabolic pathways followed by dissimilatory Fe⁺³ -reducing bacterium Shewanella putrefaciens strain 200R. Iron (II), Iron (III), dissolved inorganic carbon (DIC) and carbon isotope ratios were measured under bicarbonate and phosphate buffered conditions. Carbon isotope disproportionation among organic carbon substrate (lactate), biomass and respired carbon dioxide at the lag to stationary phase of the microbial growth curve showed …

Problems Related To Efficacy Measurement And Analyses, Sibabrata Banerjee

Dissertations

In clinical research it is very common to compare two treatments on the basis of an efficacy variable. More specifically, if X and Y denote the responses of patients on the two treatments A and B, respectively, the quantity P(Y>X) (which can be called the probabilistic index for the Effect Size), is of interest in clinical statistics. The objective of this study is to derive an efficacy measure that would compare two treatments more informatively and objectively compared to the earlier approaches. Kernel density estimation is a useful non-parametric method that has not been well utilized as an applied …

Prediction Of Mrna Polyadenylation Sites In The Human Genome And Mathematical Modeling Of Alternative Polyadenylation, Yiming Cheng

Dissertations

Messenger RNA (mRNA) polyadenylation plays many important roles in the cell, such as transcription termination, mRNA stability and transportation, and mRNA translation in eukaryotic cells. A large number of human and mouse genes have multiple polyadenylation sites (referred to as poly(A) sites) that lead to variable transcripts, some of which are translated into various protein products with different functions. However, the details about when and where the polyadenylation occurs, and how pre-mRNA switches from one poly(A) site to another are still unknown. This kind of 3 '-end processing can be regulated by the cell environment, cell cycle stage, and tissue …

People-Search : Searching For People Sharing Similar Interests From The Web, Quanzhi Li

Dissertations

On the Web, there are limited ways of finding people sharing similar interests or background with a given person. The current methods, such as using regular search engines, are either ineffective or time consuming. In this work, a new approach for searching people sharing similar interests from the Web, called People-Search, is presented. Given a person, to find similar people from the Web, there are two major research issues: person representation and matching persons. In this study, a person representation method which uses a person's website to represent this person's interest and background is proposed. The design of matching process …

Sifting Customers From The Clickstream : Behavior Pattern Discovery In A Virtual Shopping Environment, Peishih Chang

Dissertations

While shopping online, customers' needs and goals may change dynamically, based on a variety of factors such as product information and characteristics, time pressure and perceived risk. While these changes create emergent information needs, decisions about what information to present to customers are typically made before customers have visited a web site, using data such as purchase histories and logs of web pages visited. Better understanding of customer cognition and behavior as a function of various factors is needed in order to enable the right information to be presented at the right time. One approach to achieving this understanding is …

Ligand-Based Drug Design : I. Conformational Studies Of Gbr 12909 Analogs As Cocaine Antagonists; Ii. 3d-Qsar Studies Of Salvinorin A Analogs As Kappa Opioid Agonists, Deepangi Pandit

Dissertations

Ligand-based drug design (LBDD) techniques are applied when the structure of the receptor is unknown but when a series of compounds or ligands have been identified that show the biological activity of the interest. Generally, availability of a series of compounds with high activity, with no activity, and also with a range of intermediate activities for the desired biological target is required. It is common that structures of membrane-bound proteins (for example, monoamine transporter proteins and opioid receptor proteins) are unknown as these proteins are notoriously difficult to crystallize.

In Part I of this study, analogs of the flexible dopamine …

Long Exposure Point Spread Function Estimation From Solar Adaptive Optics Loop Data, Jose Marino

Dissertations

Adaptive optics (AG) systems provide partial correction to wavefront distortions introduced by the Earth's atmosphere. They have become an essential tool to obtain diffraction-limited observations from ground-based telescopes. However, the AG correction is only partial and post-processing with a good estimate of the point spread function (PSF) is required.

PSF estimates are impossible to measure directly during solar observations due to the lack of point sources in the field-of-view. Moreover, the highly variable day-time seeing conditions require the estimated PSF to be simultaneous with the captured image. A method is presented to estimate the long-exposure PSF of AG-corrected solar observations …

Construction Of Fasr Subsystem Testbed And Application For Solar Burst Trajectories And Rfi Study, Zhiwei Liu

Dissertations

The construction of the Frequency Agile Solar Radiotelescope (FASR) Subsystem Testbed (FST) and observational results are described. Three antennas of Owens Valley Solar Array (OVSA) have been upgraded with newly designed, state of art technology. The 1-9 GHz RF signal from the antenna feed is transmitted via broadband (45 MHz-9.5 GHz) optical fiber links to the control room. The RF is then downconverted to a 500 MHz, single-sideband signal that can be tuned across the 1-9 GHz RF band. The data are sampled with an 8-bit, 1 GHz sampling-rate digitizer, and further saved to a computer hard disk. The full-resolution …

Bioengineering Of Protein Nanotubes And Protein Nanomaterial Composites, Thilak Kumara Mudalige

Dissertations

Flagella of Mesophilic bacteria such as E. coli are extremely ordered structures consisting of self-assemblies of flagellin 11-mers resulting in protein nanotubes of 2--3 nm inner diameter, 23 nm outer diameter, several microns in length and 5.4 nm separation between 11-mer segments. They are as a result attractive scaffolds and templates for the generation of uniform nanotubes and ordered array of nanoparticles. In this study fusion protein of bacterial flagellin (Fli C) and core thioredoxin (Trx), pFliTrx was used as peptide display on bacterial flagella. This was accomplished in the current research by introducing various peptide loops such as cysteine, …

Global And Quantitative Gene Expression Analysis Of The Effects Of Drinking Water Exposure To Lead Acetate In Fisher 344 Male Rats Liver, Worlanyo Eric Gato

Dissertations

The primary objective of this research is to analyze global gene expression patterns occurring in Fisher 344 rat livers exposed to varying levels of lead and times. The hypotheses were that: (1) effects associated with Pb exposure are both dose and time dependent and (2) several genes will be over-expressed or repressed including transcripts associated with calcium signaling. Initially, the effects of Pb exposures upon morphometnc indices, liver and kidney tissue histology, Pb distribution, Pb interaction with other trace metals including Zn, Cu, Co, Fe, Ni and Ca were assessed. Results showed a significant accumulation of lead in blood, liver, …

Geophysical Monitoring Probes And Their Applications To Some Hydrogeological Problems, Laura Smart

Dissertations

Geophysical monitoring probes were constructed to monitor the vertical changes of water content and ion concentration in the subsurface. These devices contain electrodes for resistivity measurements and thermistors for temperature measurements. They are designed to monitor the resistivity and temperature of the saturated zone, the transition zone, and the vadose zone near a groundwater/surface water interface. Additional installations at the site include four monitoring wells and four Time Domain Reflectometry (TDR) access tubes, each paired with the geophysical probe installations. Pole-Pole resistivity measurements with an a-spacing of 5 cm are made using a CR1000 Campbell Scientific, Inc. datalogger. Automated data …

Late Pleistocene Climate Variability And Chemical Weathering In The Goriganga, Higher Central Himalaya, North India, Steven Paul Beukema

Dissertations

Relict lacustrine deposits in the Higher Central Himalaya, India, provide a rich repository of paleoclimate information for the period 16 ka to 11 ka. Stable isotope analysis of deposits near the village of Burfu shows the hydrologic balance between glacial meltwater and monsoon precipitation as source waters for the lake. During the period from 15.5 ka to 14 ka the Burfu lake was largely fed by melting glaciers. A warming event correlated to glacial Meltwater Pulse 1a indicates a sudden increase in carbonate weathering in the region accompanied by a gradual decrease in the ratio of glacial meltwater/monsoon precipitation feeding …

Lightweight Intrusion Detection: A Second Line Of Defense For Unguarded Wireless Sensor Networks, Vijay Subhash Bhuse

Dissertations

Wireless sensor networks (WSN) are formed of stationary nodes with stringent resources (in terms of battery power, processor speed, memory and radio range). They have specific communication and traffic patterns.

Making sensor networks secure is especially challenging because of the wireless medium and the fact that WSN is physically unguarded. The compromise of sensor nodes may lead to the loss of secret information and tampering of the software. Hence, intrusion detection techniques must be designed to detect at least some of the most dangerous attacks. Further, these techniques should be lightweight to suit resource constrained nature of WSN.

We focus …

A Collaborative, Hierarchical, Incremental, And Problem Solving Information Systems Development Model, Timothy Joseph Burns

Dissertations

The "software crisis" has been a much discussed and debated topic in Information Systems research. A core cause of the crisis is often identified as the methodologies and approaches used to develop information systems. Thus, over the years a multitude of methodologies have emerged in support of quality software. While many of these methodologies have been effective, research has shown that system development is a highly circumstantial process, and that no one methodology can be optimal in every context of every project. It is also a fact that system development practitioners have employed ad hoc approaches to modify formal methodologies …

High Resolution Studies Of Complex Solar Active Regions, Na Deng

Dissertations

Flares and Coronal Mass Ejections (CMEs) are energetic events, which can even impact the near-Earth environment and are the principal source of space weather. Most of them originate in solar active regions. The most violent events are produced in sunspots with a complex magnetic field topology. Studying their morphology and dynamics is helpful in understanding the energy accumulation and release mechanisms for flares and CMEs, which are intriguing problems in solar physics.

The study of complex active regions is based on high-resolution observations from space missions and new instruments at the Big Bear Solar Observatory (BBSO). Adaptive optics (AG) in …

Community-Based Evaluation Of The Air Toxic Provisions Of Title Iii Of The 1990 Clean Air Act Amendments : Risks, Costs And Benefits, Keith C. Silverman

Dissertations

Hazardous air pollutants (HAPs) are those pollutants that are known or suspected to cause cancer, serious health effects, or adverse environmental effects. People exposed to HAPs at sufficient concentrations and durations may have an increased risk of getting cancer or experiencing other health effects. The 1990 Amendments to the Clean Air Act (CAAA) directed the U.S. Environmental Protection Agency (USEPA) to use technology-based air pollution control measures to significantly reduce emissions of HAPs from major sources of air pollution, followed by a risk-based assessment to address any remaining or residual health risks.

This study retrospectively assessed the public health risk …

Modeling Projection Neuron And Neuromodulatory Effects On A Rhythmic Neuronal Network, Nicholas Kintos

Dissertations

Projection neurons shape the activity of many neural networks. In particular, neuromodulatory substances, which are often released by projection neurons, alter the cellular and/or synaptic properties within a target network. However, neural networks in turn influence projection neuron input via synaptic feedback. This dissertation uses mathematical and biophysically-realistic modeling to investigate these issues in the gastric mill (chewing) motor network of the crab, Cancer borealis. The projection neuron MCN1 elicits a gastric mill rhythm in which the LG neuron and INTl burst in anti-phase due to their reciprocal inhibition. However, bath application of the neuromodulator PK elicits a similar gastric …

Small And Large-Scale Magnetic Fields Involved With Solar Flares, Chang Liu

Dissertations

Solar flares are generally identified as an important source of disturbances that affect space weather, while many aspects of the basic flare process are still not well understood. The purpose of the present work has been to investigate the small and large-scale magnetic structures and their evolution associated with flares in the context of magnetic reconnection, based on which the goal of this dissertation is to further the understanding of the various properties of flares and related phenomena, including their origin, precursors, and evolution of morphology in solar atmosphere.

The research presented in this dissertation relied upon multiwavelength observations of …

Regulation Of A Dna-Compacting Plastid Nucleoid Protein, Steven William Adamson

Dissertations

DCP68, a DNA-compacting nucleoid protein, was further characterized in order to understand how plastid nucleoid proteins affect the structure and function of chloroplast DNA. Previously, DCP68 was identified as ferredoxin: sulfite reductase, an enzyme that participates in reductive sulfur assimilation and inhibits chloroplast DNA replication and transcription in vitro [1, 2]. In this study, the portion of SiR that was found to be present in soluble and plastid nucleoid-enriched fractions indicated that most SiR was stromal in Arabidopsis and soybean plants. Although SiR was detected in Arabidopsis chloroplast nucleoid-enriched fractions, the study of nucleoid dynamics proved to be difficult due …

Synthesis And Fundamental Characterization Of Nanoparticles And Their Clusters, Ke Du

Dissertations

Nanoparticles of gold derivatized with monolayers of thiocarboxylic acid ligands, core/shell nanoparticle composites of gold and silica, gold-glutathioneclusters, and titania nanoparticles were synthesized and their surface properties (extent of ligand coverage, net negative charge, and zeta potential) characterized by capillary electrophoresis as a function of pH, ionic strength, and dielectric constant for the first time. The hydrodynamic radii of thenanoparticles were determined by dynamic laser light scattering and used to calculate the net surface charge, extent of ligand coverage, and zeta potentials ofthe nanoparticles from electrophoresic mobilities. The ligand derivatized nanoparticles had similar hydrodynamic radius of about 20 nm which …

Investigation Of Oxy-Anion Legand Adsorption Onto Surfaces Of Iron Oxide And Bacteria In Groundwater Aquifers, Haile Mengistu

Dissertations

We have measured adsorption of dissolved phosphate onto synthetic hydrous ferric oxide (HFO), dissolved arsenate and chromate onto the cell membrane of a bacterium species, S. putrefaciens as a function of pH, ionic strength, and relative concentrations of the respective oxy-ligands. Our experimental data were used to constrain optimal values for surface complexation reactions involving dissolved oxi-ligands (phosphate, and chromate) and the HFO surface and the cell membrane of S. putrefaciens respectively according to the diffuse layer model.

Our results provide a more accurate fit to experimental measurements over a broader range of pH (3 - 12), ionic strength and …