Digital Commons Network^™

An Analysis Of Methodologies & Best Practices For Rapidly Acquiring Technologies To Meet Urgent Warfighter Needs, Charles D. Solomon

Theses and Dissertations

The rapidly changing global security environment that today's military operates within requires an ever-increasing ability to quickly adapt to non-traditional threats. This has forced the United States to re-examine the traditional means of equipping its forces to ensure more agile acquisition practices are available to the Science and Technology (S&T) and acquisition communities. While there have been significant efforts to look towards industry for potential solutions to this problem, the heavily bureaucratic and restrictive government environment has made applying commercial lessons learned difficult. To effectively implement rapid fielding approaches within the government context, research into organizations facing the same or …

Robust Aircraft Squadron Scheduling In The Face Of Absenteeism, Osman Bahadir Gokcen

Theses and Dissertations

Air Force fighter aircraft squadrons the world over share a unique problem. Each requires complex training schedules coupling aircraft to pilots, the duo to missions and airspaces, and then the entire combination to a feasible time slot. Creating daily and weekly flight schedules that include shifts around the clock every day of the year with a set number of pilots is a time consuming job for manual schedulers within a squadron. Complicating matters is absenteeism. If one or more pilots are unable to perform their previously assigned tasks, due to sickness, aircraft failure, or reassignment, those tasks must be performed …

Acoustic Model Adaptation For Ortolan Bunting (Emberiza Hortulana L.) Song-Type Classification, Jidong Tao, Michael T. Johnson, Tomasz S. Osiejuk

Dr. Dolittle Project: A Framework for Classification and Understanding of Animal Vocalizations

Automatic systems for vocalization classification often require fairly large amounts of data on which to train models. However, animal vocalization data collection and transcription is a difficult and time-consuming task, so that it is expensive to create large data sets. One natural solution to this problem is the use of acoustic adaptation methods. Such methods, common in human speech recognition systems, create initial models trained on speaker independent data, then use small amounts of adaptation data to build individual-specific models. Since, as in human speech, individual vocal variability is a significant source of variation in bioacoustic data, acoustic model adaptation …

Computational Models Of Tandem Src Homology 2 Domain Interactions And Application To Phosphoinositide 3-Kinase, Dipak Barua, James R. Faeder, Jason M. Haugh

Chemical and Biochemical Engineering Faculty Research & Creative Works

Intracellular signal transduction proteins typically utilize multiple interaction domains for proper targeting, and thus a broad diversity of distinct signaling complexes may be assembled. Considering the coordination of only two such domains, as in tandem Src homology 2 (SH2) domain constructs, gives rise to a kinetic scheme that is not adequately described by simple models used routinely to interpret in vitro binding measurements. To analyze the interactions between tandem SH2 domains and bisphosphorylated peptides, we formulated detailed kinetic models and applied them to the phosphoinositide 3-kinase p85 regulatory subunit/platelet-derived growth factor β-receptor system. Data for this system from different in …

Spatial Variations In Nutrient And Microbial Transport From Feedlot Surfaces, John E. Gilley, Elaine D. Berry, Roger A. Eigenberg, David B. Marx, Bryan L. Woodbury

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nutrient and microbial transport by runoff may vary at different locations within a beef cattle feedlot. If the areas making the largest contributions to nutrient and microbial transport can be identified, it may be possible to institute site‐specific management practices to reduce runoff nutrient and microbial transport. The objectives of this study were to: (1) measure selected feedlot soil properties and nutrient and microbial transport in runoff from various feedlot locations, (2) compare the effects of unconsolidated surface materials (USM) (loose manure pack) and consolidated subsurface materials (CSM) (compacted manure and underlying layers) on nutrient and microbial transport, and (3) …

Linking Embeddedness And Macroinvertebrate In Two Southwest Ohio Streams, Jonathan P. Kochersberger

Theses and Dissertations

Environmental managers utilize a variety of tools when assessing lotic systems for stressors attributed to anthropogenic sources. Stream deposited sediment has been recognized as one of the major stressors affecting streams in the U.S. The detrimental effect on aquatic biota of sediment depositing within the interstitial spaces of stream substrate (embeddedness) has been established, yet lacking is an effective in situ method of quantifying embeddedness over short time periods. The goal of this research was to develop a short-term embeddedness (EMB) quantification method that can be linked to benthic macroinvertebrate health. Such a method would be a valuable tool when …

Hydrogen Sensor Using Optical Reflectance From Porous Silicon With A Palladium Thin Film, Christopher G. Lowrie, Susan K. Earles, Maria E. Pozo De Fernandez

Electrical Engineering and Computer Science Faculty Publications

Results of a hydrogen sensor based on light scattering from a porous silicon surface coated with a thin palladium film are discussed. Reflected light scattered from the rough surface of porous silicon surface with a thin palladium film is compared before and after exposure to hydrogen gas. After exposure to hydrogen gas the sensor's optical reflectance is decreased indicating the presence of hydrogen.

Porous Silicon Surface Feature Size Estimation Using The Reflectance Spectrum, Christopher G. Lowrie, Susan K. Earles, Maria E. Pozo De Fernandez

Electrical Engineering and Computer Science Faculty Publications

In this paper we excite the surface of porous silicon with incoherent, broad band white light and observe the spectrum of colors reflected from the surface. Using an atomic force microscope images from red and green porous silicon samples are collected. In this paper we relate the optical color of the surface to the size of scattering features on the textured surface. From image segmentation using the watershed transform the height distributions of the optical scattering features are determined. The heights of these surface features are then used as input variables to a computer simulation of a reflective grating. The …

Bifidobacteria In Feces And Environmental Waters, Regina Lamendella, Jorge W. Santo Domingo, Catherine A. Kelty, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Bifidobacteria have been recommended as potential indicators of human fecal pollution in surface waters even though very little is known about their presence in nonhuman fecal sources. The objective of this research was to shed light on the occurrence and molecular diversity of this fecal indicator group in different animals and environmental waters. Genus- and species-specific 16S rRNA gene PCR assays were used to study the presence of bifidobacteria among 269 fecal DNA extracts from 32 different animals. Twelve samples from three wastewater treatment plants and 34 water samples from two fecally impacted watersheds were also tested. The species-specific assays …

Effects Of Climate Change On Energy Production And Use In The United States, Thomas Wilbanks, Vatsal Bhatt, Daniel Bilello, Stanley Bull, James Ekmann, William Horak, Y. Joe Huang, Mark D. Levine, Michael J. Sale, David Schmalzer, Michael J. Scott

United States Department of Energy: Publications

Climate change is expected to have noticeable effects in the United States: a rise in average temperatures in most regions, changes in precipitation amounts and seasonal patterns in many regions, changes in the intensity and pattern of extreme weather events, and sea level rise. Some of these effects have clear implications for energy production and use. For instance, average warming can be expected to increase energy requirements for cooling and reduce energy requirements for warming. Changes in precipitation could affect prospects for hydropower, positively or negatively. Increases in storm intensity could threaten further disruptions of the sorts experienced in 2005 …

Effects Of Climate Change On Aquatic Invasive Species And Implications For Management And Research, Roxanne Thomas, Austin Kane, Environmental Law Institute, Britta G. Bierwagen

United States Environmental Protection Agency: Publications

Global change stressors, including climate change and variability and changes in land use, are major drivers of ecosystem alterations. Invasive species, which are non-native species that cause environmental or economic damages or human-health impacts, also contribute to ecosystem changes. The interactions between stressors and invasive species, although not well understood, may exacerbate the impacts of climate change on ecosystems, and likewise, climate change may enable further invasions. This report reviews available literature on climate-change effects on aquatic invasive species (AIS) and examines state-level AIS management activities. Data on management activities came from publicly available information, was analyzed with respect to …

Externally Assembled Gate-All-Around Carbon Nanotube Field-Effect Transistor, Zhihong Chen, Damon Farmer, Sheng Xu, Roy Gordon, Phaedon Avouris, Joerg Appenzeller

Other Nanotechnology Publications

In this letter, we demonstrate a gate-all-around single-wall carbon nanotube field-effect transistor. This is the first successful experimental implementation of an off-chip gate and gate-dielectric assembly with subsequent deposition on a suitable substrate. The fabrication process and device measurements are discussed in the letter. We also argue in how far charges in the gate oxide are responsible for the observed nonideal device performance.

The Role Of Sr²⁺ On The Structure And Reactivity Of Sro-Cao-Zno-Sio2 Ionomer Glasses, Daniel Boyd, Mark R. Towler, Sally Watts, Robert G. Hill, Anthony W. Wren, Owen M. Clarkin

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of Glass Polyalkenoate Cements (GPCs) for use in orthopaedics is retarded by the presence in the glass phase of aluminum, a neurotoxin. Unfortunately, the aluminum ion plays an integral role in the setting process of GPCs and its absence is likely to hinder cement formation. However, the authors have previously shown that aluminum free GPCs may be formulated based on calcium zinc silicate glasses and these novel materials exhibit significant potential as hard tissue biomaterials. To further improve their potential and given that Strontium (Sr) based drugs have had success in the treatment of osteoporosis, the authors have …

Bifidobacteria In Feces And Environmental Waters, Regina Lamendella, Jorge W. Santo Domingo, Catherine Kelty, Daniel B. Oerther

United States Environmental Protection Agency: Publications

Bifidobacteria have been recommended as potential indicators of human fecal pollution in surface waters even though very little is known about their presence in nonhuman fecal sources. The objective of this research was to shed light on the occurrence and molecular diversity of this fecal indicator group in different animals and environmental waters. Genus- and species-specific 16S rRNA gene PCR assays were used to study the presence of bifidobacteria among 269 fecal DNA extracts from 32 different animals. Twelve samples from three wastewater treatment plants and 34 water samples from two fecally impacted watersheds were also tested. The species-specific assays …

Tem Analysis Of Apatite Surface Layers Observed On Zinc Based Glass Polyalkenoate Cements, D. Boyd, Mark R. Towler, A. W. Wren, O. M. Clarkin, D. A. Tanner

Chemical and Biochemical Engineering Faculty Research & Creative Works

The amorphous nature and composition of the surface apatite layers observed on glass polyalkenoate cements based on zinc silicate glasses (Zn-GPCs) after immersion in simulated body fluid (SBF) have been analyzed by the transmission electron microscopy (TEM). TEM was conducted using a JEOL JEM-2011 electron microscope operated at an accelerating voltage of 200 kV. The composition elements of the surface layer indicated the presence of calcium, phosphorous, zinc, and strontium within the amorphous structure. This composition, in particular the inclusion of Zn in the structure, indicates the lack of crystallinity associated with the formation of the apatite layers observed on …

Mineral Trioxide Aggregate Material Use In Endodontic Treatment: A Review Of The Literature, Howard W. Roberts, Jeffrey M. Toth, David W. Berzins, David G. Charlton

Biomedical Engineering Faculty Research and Publications

Objective

The purpose of this paper was to review the composition, properties, biocompatibility, and the clinical results involving the use of mineral trioxide aggregate (MTA) materials in endodontic treatment.

Methods

Electronic search of scientific papers from January 1990 to August 2006 was accomplished using PubMed and Scopus search engines (search terms: MTA, GMTA, WMTA, mineral AND trioxide AND aggregate).

Results

Selected exclusion criteria resulted in 156 citations from the scientific, peer-reviewed dental literature. MTA materials are derived from a Portland cement parent compound and have been demonstrated to be biocompatible endodontic repair materials, with its biocompatible nature strongly suggested by …

Development Of A Three Dimensional Prolapse Model To Simulate Physiological Haemodynamics In A Stented Coronary Artery, Jonathan Murphy, Fergal Boyle

Conference Papers

Coronary stent implantation can improve blood flow in an artery that has been narrowed by the build up of arterial plaque. However, the haemodynamic effect of stent placement is unclear and may influence arterial restenosis (re-blockage). The degree of tissue prolapse between stent struts may be an important factor in predicting the restenosis rate of a stent due to the haemodynamic influence of the protruding tissue. In this paper a mathematical model has been developed to numerically predict the tissue prolapse for an artery implanted with a coronary stent. The prolapse model has been applied to the Gianturco-Roubin II (GR-II) …

Design Of Three-Dimensional Axon Stretch Growth Device, Fayekah Assanah

Theses

Spinal Cord Injury (SCI) causes destruction and degeneration of axons in the white matter of the spinal cord, resulting in functional loss and paralysis. A successful treatment of SCI requires axons to regenerate across damaged regions. Current studies focus on identifying mechanisms to promote axon regeneration in lesions and have yet to be successful in preventing nerve degeneration due to scar tissue formation. Establishing axonal bridges over long distances of SCI lesions remains a challenge, resulting in poor functional recovery. Instead of relying on promoting axon regeneration into lesions, Pfister et al. has developed a transplantable nervous tissue construct spanned …

Pattern Recognition Of Brain Fmri Images For Various Physiological States, Priyanka Bhatt

Theses

The development of fMRI (functional Magnetic Resonance Imaging) has led many researchers to localize brain functions using different stimuli. The use of pattern recognition techniques have made it possible to predict the stimuli being presented from the corresponding brain images and activation patterns. The primary objective of the present study was to use pattern recognition methods to develop a model using available fMRJ images and then to use the model to identify the stimulus presented from a large number of unknown images. Two different experimental conditions were used involving both binary and multi-class classification. Bilateral finger tapping data which had …

Multi Well Uni-Axial Stretch Injury Device, Mridusmita Choudhury

Theses

Most diffuse brain injury is the result of uni-axial stretch of brain axons in traumatic brain injury. Traumatic injury to axons throughout the brain and is believed to be a major cause for coma, and other complications. Diffuse axonal injury is mostly multi-focal and appears throughout the deep cortical and sub-cortical regions.

Several models have tried to replicate this phenomenon. Previous models, like the Penn model, have lower throughput as they conduct experiments on one well at a time, and it has lower reproducibility as well. The other problem with these models is that they are not very user friendly, …

Mapping Inter-Subject And Inter-Regional Brain Connectivity During Free Viewing Of Novel Natural Scenes, Sheela Nagaraj

Theses

Traditional functional magnetic resonance imaging (fMRI) studies have used controlled tasks such as finger tapping to isolate function in distinct cortical. Recent studies have examined the mechanisms involved during natural conditions by asking subjects to freely view the presentation of a movie. The objective of our study was to further observe the extent to which similarities are present between subjects during natural vision. It was hypothesized that there would be a linear relationship between the percentage of region-specific overlap, which is the percent of the anatomical region of interest which contains spatial activation exhibited by all six subjects, and corresponding …

Ultra-Fine Particle Formation Using Principle Of Rapid Expansion Of Supercritical Solutions`, Miraj Minesh Sheth

Theses

There are indications in the chemical and pharmaceutical industries that the reduction in size of a crystalline particle can lead to better performance of the drug compound, particularly for water insoluble drugs, in the final dosage form. Many particle formation techniques have been investigated in recent years by researchers to obtain desired particulate sizes and size distributions. Supercritical fluid technologies have been successfully investigated for particle formation due to its unique gas/liquid properties in the supereritical state. In this report, results of particle formation using the principles of Rapid Expansion of Supercritical Solutions (RESS) have been documented.

In the RESS …

The Extraction Of Type 1 Collagen And The Fabrication Of Multi-Filament Embedded Hydrogels For Guided Nerve Regeneration, Mevan Lakmal Siriwardane

Theses

Each year, there are approximately 11,000 new cases of spinal cord injury (SCI) in the United States [2]. There have been some success in pre-clinical studies to induce axonal generation, but the reconnection of axons over large distances remains the greatest challenge. Since the development of nerve conduit to facilitate general axonal regeneration, the primary focus has changed to directing the regeneration of axons while also promoting their outgrowth over very extensive lesions to ensure functional recovery of transected nerves during in vitro experiments by using natural materials such as type I collagen, which is the largest constituent of the …

Fracture Healing : The Effects Of Local Insulin Delivery Via Calcium Sulfate And Tricalcium Phosphate, Sarah Elizabeth Buchala

Theses

Previous studies have documented the major role played by insulin in osseous healing. This is the first study to examine local intramedullary insulin delivery to the fracture site and its effect upon the normal fracture healing process. Preceding results show that when administered at the fracture site of the impaired fracture healing model of the diabetic BB Wistar rat, insulin will regulate early cellular proliferation and chondrogenesis and late mineralized tissue, cartilage content and mechanical strength.

In this study, two novel delivery vehicles have been evaluated for sustained insulin release in the normal fracture model of the BB Wistar rat. …

Dexamethasone- And Age-Sensitive Genes In Neonatal Small Intestine, Carla Cerqueira

Theses

Regulation of GLUT5 is dependent on the presence of its substrate, fructose, but it is also correlated with the developmental (aging) process of the intestine. To identify fructose-responsive genes whose expression also changes with age, intestines of 10 and 20 d old pups were perfused, by Ferraris et al., with fructose and then compared by microarray analysis. From this, a gene clustering analysis revealed that some age- and fructose-specific genes are regulated by corticosterones, which normally increase in pups ≥ 14 d old. Subsequent work indicated that priming the gut with Dexamethasone (Dex, a glucocorticoid analog) allowed fructose to precociously …

Sedimentological And Biological Analyses On Hobble Creek Prior To Restoration, Jaron Michael Brown

Theses and Dissertations

Hobble Creek is one of several inflowing streams and rivers into Utah Lake, Utah, USA. Historically, June sucker (Chasmistes liorus), a federally listed endemic fish, spawned up all the major inflowing streams and rivers but is now limited to just the Provo River. The State of Utah has recently proposed restoring the lower reaches of Hobble Creek for additional spawning and rearing needs. This restoration effort will likely involve removal of migration barriers, re-aligning the stream, and removing existing levees that prevent floodplain access. These changes have raised several questions that this study aims to answer. First, what are the …

The Average Mutual Information Profile As A Genomic Signature, Mark Bauer, Sheldon Schuster, Khalid Sayood

Department of Electrical and Computer Engineering: Faculty Publications

Background: Occult organizational structures in DNA sequences may hold the key to understanding functional and evolutionary aspects of the DNA molecule. Such structures can also provide the means for identifying and discriminating organisms using genomic data. Species specific genomic signatures are useful in a variety of contexts such as evolutionary analysis, assembly and classification of genomic sequences from large uncultivated microbial communities and a rapid identification system in health hazard situations.
Results: We have analyzed genomic sequences of eukaryotic and prokaryotic chromosomes as well as various subtypes of viruses using an information theoretic framework. We confirm the existence of a …

Mechanical Behavior And Failure Analysis Of Prosthetic Retaining Screws After Long‐Term Use In Vivo. Part 4: Failure Analysis Of 10 Fractured Retaining Screws Retrieved From Three Patients, Youssef S. Al Jabbari, Raymond Fournelle, Gerald J. Ziebert, Jeffrey M. Toth, Anthony Iacopino

Biomedical Engineering Faculty Research and Publications

Purpose: The aim of this study was to perform a failure analysis on fractured prosthetic retaining screws after long‐term use in vivo. Additionally, the study addresses the commonly asked question regarding whether complex repeated functional occlusal forces initiate fatigue‐type cracks in prosthetic retaining screws.

Materials and Methods: Ten fractured prosthetic retaining screws retrieved from three patients treated with fixed detachable hybrid prostheses were subjected to a failure analysis. In patients 1 and 2, the middle three retaining screws of the prostheses were found fractured at retrieval time after they had been in service for 20 and 19 months, respectively. In …

Preparation And Characterization Of Tapioca Starch–Poly(Lactic Acid) Nanocomposite Foams By Melt Intercalation Based On Clay Type, Siew-Yoong Lee, Han Chen, Milford Hanna

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Abstract Tapioca starch (TS), poly(lactic acid) (PLA), and four different organoclays (Cloisite 10A, Cloisite 25A, Cloisite 93A and Cloisite 15A) were used to produce nanocomposite foams by melt-intercalation. Structural, thermal, physical and mechanical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and an Instron universal testing machine, respectively. The first XRD peaks for all four nanocomposite foams, were observed to shift to lower angles, indicating that intercalation occurred. The extent of intercalation depended on the type of organoclay and was exhibited in the sequence of Cloisite 10A > 25A > 93A > 15A. Glass transition temperatures …

Simulated Effects Of Various Environmental Management Practices On Energy Consumption In Open And Confined Greenhouse Systems, Ilhami Yildiz, D. P. Stombaugh

BioResource and Agricultural Engineering

The objective of this study was to evaluate the effects of relative humidity, light management levels, minimum ventilation rates, CO₂ enrichment and canopy size on energy consumption in three different greenhouse systems (conventional, open-loop heat pump, and confined heat pump) in winter, spring, and summer months. No difference was observed in energy consumption with relative humidity set point levels in winter due to the already low relative humidity levels. Some differences were observed in spring and summer due to extra dehumidification required to maintain the inside relative humidity at lower levels. Energy consumption in summer was reduced up to …