996 matches in the database.
These are records: 1 - 30.
[1] [2] [3] [4] [5] … [34]
1.
Aab, Steven D.
Performance Analysis of the Local Area Augmentation System as the Position Sensor for the Runway Incursion Prevention System.
Degree: Master of Science (MS), Electrical Engineering (Engineering), 2005, Ohio University
► Runway incursions have become an increasing problem at airports across the country.…
(more)
▼ Runway incursions have become an increasing problem at airports across the country. The National Safety Board has listed them among their "Most Wanted" safety improvements. The Federal Aviation Administration (FAA) and National Aeronautics and Space Administration (NASA) have been developing systems intended to reduce and prevent the number of runway incursions. Both agencies have been working on systems utilizing the Local Area Augmentation System (LAAS) as the position sensor for the Automatic Dependent Surveillance and Broadcast (ADS-B). The Avionics Engineering Center of Ohio University has been involved with the development of the NASA sponsored Runway Incursion Prevention System (RIPS). The main responsibility for the Avionics Engineering Center has been the installation, operation, and maintenance of the LAAS ground facility as well as providing expertise and assessing the system’s performance. The testing for RIPS took place at the Dallas/Ft. Worth International Airport from 24 September 2000 until 26 October 2000. This thesis provides a detailed position accuracy assessment of the LAAS installation used for the NASA RIPS. This assessment provides statistical information on position accuracy as compared to industry standards for airborne LAAS receivers and recommendations for the application of Global Navigation Satellite System (GNSS) positioning equipment in supporting surface guidance.
Advisors/Committee Members: DiBenedetto, Michael F.
Keywords: avionics
More Like This
2.
Aagard, Erik A.
A Pre-Design Study Of Patient And Medical Professional Attitudes And Reactions Towards The Colors Of Medical Scrubs.
Degree: Master of Fine Arts, Art, 2008, Ohio State University
► Surgical scrubs are worn by a variety of medical professionals in various…
(more)
▼ Surgical scrubs are worn by a variety of medical professionals in various capacities all over the world. Called by the shortened name “scrubs” the one-time surgical only attire is now worn by men and wormen in every conceiveable medical capacity. Once only available in white, scrubs now come in a diverse array of color assortments, all of which carry implict meaning both for the medical professional and patient. To assess some of the possible interpretations of various scrub colors, and determine preferred colors, a three pronged approach was used. A Make-See-Do model (a hands-on, participatory experience) was employed to triangulate the data. First, nineteen medical professionals were given an in-person questionnaire asking about their color preferences, scrub color preferences, clothing preferences, and experiences wearing surgical scrubs. The professional then used a MakeTool (a toolkit to build a model) to pick their preferred color(s) and cut of scrubs by affixing small laminated colored scrub pieces to foamcore “dolls” with velcro patches. Sixteen different colors were available. Second, the identical questionnaire was also sent to 249 medical professionals who took the online survey and selected scrub configurations and preferred colors with toggle buttons. Thirdly, 341 potential patients were given an online survey asking them to guess the profession of a medical professional, based on the color of her scrubs. A list of ten possible professions was listed below her picture and the same picture was shown ten different times with the same woman wearing different colored scrubs each time. To help understand and interpret the data, a literature review of color symbolism, marketing, psychology, physiology, and history was completed. Patient and medical professional response was several times greater than initially anticipated. Both groups appeared to be quite emotionally invested in the choice of scrub colors and had strong preferences about what colors were associated with medical professionals. The most preferred color for medical professionals was light blue, light green, and then darker blue. Professionals who wore these colors were likely to be identified first as a doctor, a nurse, and then a dentist. Nurses had wider lattitude with colors and were recognized as nurses if they wore the afforementioned colors or pink, purple, gray, or red. Patient surveys demonstrated that the colors blue and green were clearly viewed as “medical” colors. If other colors were worn by professionals, patients became confused at their role. Professionals were consistent in their views on scrubs and no difference was seen between online and in-person interviews. The colors overwhelmingly preferred by medical professionals were: light blue, light green, and a darker blue. These colors were seen as the most “professional.” Darker colors and bright and light colors were considered unacceptable. Most professionals didn’t think a trim color was necessary and only 15% of them preferred two colored scrubs. A majority of the participants believed the fit of scrubs needed improvement and had various suggestions for upgrades and betterment.
Advisors/Committee Members: Mayo, Noel.
Subjects: Design; Marketing; Social research
Keywords: scrubs; color theoy; color psychology; maketool; design research; color, hues; medical clothing; color testing; surgical wear
More Like This
3.
Aarden, Bret J.
Dynamic melodic expectancy.
Degree: Doctor of Philosophy, Music, 2003, Ohio State University
► The most common method for measuring melodic expectancy is the “probe-tone” design,…
(more)
▼ The most common method for measuring melodic expectancy is the “probe-tone” design, which relies on a retrospective report of expectancy. Here a direct measure of expectancy is introduced, one that uses a speeded, serial categorization task. An analysis of the reaction time data showed that “Implication-Realization” contour models of melodic expectancy provide a good fit. Further analysis suggests that some assumptions of these contour models may not be valid. The traditional “key profile” model of tonality was not found to contribute significantly to the model. Following Krumhansl’s (1990) argument that tonality is learned from the statistical distribution of scale degrees, a tonality model based on the actual probability of scale degrees did significantly improve the fit of the model. It is proposed that the probe-tone method for measuring key profiles encourages listeners to treat the probe tone as being in phrase-final position. Indeed, the key profile was found to be much more similar to the distribution of phrase-final notes than to the distribution of all melodic notes. A second experiment measured reaction times to notes that subjects expected to be phrase-final. In this experiment the key profile contributed significantly to the fit of the model. It is concluded that the probe-tone design creates a task demand to hear the tone as a phrase-final note, and the key profile reflects a learned sensitivity to the distribution of notes at ends of melodies. The “key profile” produced by the new reaction-time design is apparently related to the general distribution of notes in melodies. The results of this study indicate that the relationship between melodic structure and melodic expectation is more straightforward than has been previously demonstrated. Melodic expectation appears to be related directly to the structure and distribution of events in the music.
Advisors/Committee Members: Huron, David B.
Subjects: Psychology, Cognitive; Music
Keywords: melodic expectancy; music theory; music cognition; music perception; tonality; key profiles; tonal hierarchy; reaction time; retrospective perception; probe tone; Implication-Realization theory; information theory
More Like This
4.
Aarnes, Turi K.
Fluid administration for the treatment of isoflurane-induced hypotension in dogs.
Degree: Master of Science, Veterinary Clinical Sciences, 2009, Ohio State University
► Isoflurane is the most commonly used inhalant anesthetic in veterinary practice. Hypotension,…
(more)
▼ Isoflurane is the most commonly used inhalant anesthetic in veterinary practice. Hypotension, a side effect of isoflurane anesthesia, increases morbidity and mortality. Intravenous (IV) fluid therapy is frequently proposed for correction of anesthetic-induced hypotension. The efficacy of fluid therapies for the treatment of isoflurane-induced hypotension has not been investigated. The objective of our study was to determine the effect of the IV administration of a crystalloid (Lactated Ringer’s Solution, (LRS)) or colloid (Hetastarch, HES) on isoflurane-induced hypotension in dogs. We hypothesized that IV fluid administration would correct isoflurane-induced hypotension and that HES administration would correct isoflurane-induced hypotension more rapidly, more effectively, and with a smaller volume than with LRS. Six Beagles were studied. Isoflurane minimum alveolar concentration (MAC) was individually determined. All dogs underwent each treatment in a random-ordered three-way cross-over design, separated by a minimum of 7 days: an infusion of HES, an infusion of LRS, and no IV fluid administration (NFA). Following propofol induction and isoflurane maintenance, dogs were instrumented. Dogs were maintained at 1.3 times MAC for an additional 30 minutes. Baseline data were collected. The isoflurane concentration was increased to achieve a systolic arterial blood pressure (SABP) of 80 mmHg (time 0). The isoflurane concentration required to attain a SABP of 80 mmHg was maintained for the duration of the experiment. Fluid administration in the HES and LRS groups began at time 0 at a rate of 80 mL/kg/hr. Fluid administration was discontinued if SABP returned to within 10% of baseline. If SABP did not return to within 10% of baseline values, fluid was administered to a pre-determined maximum volume: 40 mL/kg for HES and 80 mL/kg for LRS. Heart rate, SABP, mean ABP, diastolic ABP, mean pulmonary artery pressure, right atrial pressure, cardiac output, and blood volume change (BV) were measured and recorded at baseline, time 0, and at 15, 30, 45, 60, 90, and 120 minutes in all groups, and at 150 and 180 minutes in the fluid treatment groups. Blood gases, pH, lactate, electrolytes, packed cell volume (PCV), total protein (TP), albumin, colloid osmotic pressure (COP), and viscosity were determined at baseline, time 0, 15, 30, 60 and 120 minutes, and viscosity was also determined at 180 minutes in the fluid treatment groups. Blood was collected 24 hours after recovery for hemogram, PCV, TP, lactate, viscosity, and chemical profile analysis. Cardiac index (CI) and systemic vascular resistance (SVR) were calculated. Administration of 80 mL/kg of LRS did not increase SABP in any dog, while administration of 40 mL/kg or less of HES increased SABP in four of six dogs. SABP, DABP, and MABP were significantly increased in dogs that received HES compared with LRS. CI increased and SVR decreased with fluid administration. Viscosity was lower in dogs that received LRS compared with HES. PCV and TP decreased with LRS. COP increased with HES. Hetastarch but not LRS increased SABP despite lower volumes of HES administered. The present study supports the administration of HES over LRS for the treatment of isoflurane-induced hypotension in dogs.
Advisors/Committee Members: Bednarski, Richard.
Keywords: isoflurane, anesthesia, hetastarch, hypotension
More Like This
5.
Abada, Ahmed.
Processing, compatibility and oxidation of diboride-reinforced oxide matrix composites for ultrahigh-temperature applications.
Degree: Doctor of Philosophy, Materials Science and Engineering, 1990, Case Western Reserve University
► Promising results for the development of a ceramic/ceramic composite to be used…
(more)
▼ Promising results for the development of a ceramic/ceramic composite to be used for structural applications in the ultra high temperature range (1650-1850°C) have been obtained for alumina reinforced with titanium or zirconium diboribe coated with molybdenum disilicide. Prior to this achievement, several theoretical and experimental studies of particulate composites with (TiB2 or ZrB2) imbedded in (ZrO2, Y2O3 or Al2O3) were conducted. Calculations of the compatibility and stability of oxide matrices with the diborides in vacuum showed positive energies of formation, indicating suitability of reinforcement of alumina under vacuum conditions. Also, since the sublimation of vapor species at ultra high temperatures is very critical to the stability of substances still existing in their condensed states, a detailed thermodynamic analysis of the metal-oxygen systems, was carried out using elemental data of the TiB2, ZrB2, ZrO2, Y2O3, Al2O3, MoSi2 and their combinations (TiB2 or ZrB2)/(ZrO2, Y2O3 or Al2O3) for comparison, at 1650, 1850 and 2050°C. A comparison of the combination TiB2 and ZrB2 in Mo Si2/(Al2O3 or ZrO2) at 1650°C was also made. A stability analysis using equilibrium oxygen partial pressures for the TiB2 and ZrB2 decomposition at 1650, 1850 and 2050°C was carried out. A detailed characterization of the powders used for the oxide matrices, the diborides and the molybdenum disilicide are presented. The effects of the powder characteristics and the vacuum hot pressing parameters on the densification of the composites are discussed. Stability and chemical compatibility of the particulate and ternary composites in their as hot pressed states and following their vacuum and air oxidation treatments were characterized. Interdiffusion of elemental species across diboride/disilicide and oxide/disilicide interfaces was studies by EDS dot mapping. It is proposed that the growth of the Mo5Si3 is interface reaction controlled. It is proposed that diffusion of atmospheric gaseous oxygen through the porous texture left by the initial reaction of the oxide and diboride to form volatile B2O3 accounts for the continued erosion of the structure. (Abstract shortened with permission of author.
Advisors/Committee Members: Vedula, K. M.
Keywords: Processing compatibility oxidation diboride reinforced oxide matrix composites ultrahigh temperature application
More Like This
6.
Abahazi, Matthew A.
Tropical North Atlantic Sea Surface Temperature Reconstruction for the Last 800 Years Using Mg/Ca Ratios in Planktic Foraminifera.
Degree: Master of Science, Geology, 2009, University of Akron
► Global warming is an important scientific and cultural problem for our time.…
(more)
▼ Global warming is an important scientific and cultural problem for our time. As such, determining the historical sea surface temperatures is critical to our understanding of past, present and future climate change. In order to assess the patterns of prior climate change and establish reliable records upon which future predictions of climate change can be based, it is necessary to measure and calibrate climate change proxies. The samples used for this study come from a 56.5 cm box core retrieved in 1990 from 450 m depth in the Cariaco basin. Consecutive 1mm-thick samples were taken and processed for the planktic foraminifera species Globigerina bulloides for Mg/Ca analyses to estimate sea-surface temperature (SSTs) during the winter/spring upwelling season. The Mg/Ca values were obtained using an ICP-AES and later used in comparison with historical instrumental records to derive an equation to reconstruct sea-surface temperatures during the last 800 years. The record derived from this core indicates a high amount of variability in sea-surface temperatures over this 800 year interval. The Medieval Warm Period had considerable temperature variability that was previously not well-documented. Average sea-surface temperatures over this time period are 26.2ºC with slight cooling toward the end of the period. The Little Ice Age is marked by the coldest temperatures of the Late Holocene record, averaging approximately 25.6ºC. The coldest period within the LIA is coincident with the Maunder Minimum in the core record. Modern temperatures as recorded by instrumental records and from the proxies recovered from the core is increasing at rates greater than they have in the past 800 years represented in this sediment-core record. This study is one of the first of its kind to present a high-resolution, sea surface temperature record for the tropics. The proxy equation can be used in the region to further delineate climate variability in the Late Holocene.
Advisors/Committee Members: Chyi, Lindgren.
Subjects: Geochemistry; Geology
Keywords: Globigerina bulloides; Ciriaco Basin; Foraminifera; temperature calibration; climate change
More Like This
7.
ABASCAL, CARLOS G.
ADAPTIVE EQUALIZATION OF A RADIO FREQUENCY AMPLIFIER.
Degree: MS, Engineering : Environmental Engineering, 2001, University of Cincinnati
► With the arrival of High Definition Television and in general all spectrally…
(more)
▼ With the arrival of High Definition Television and in general all spectrally efficient modulation techniques like Eight Levels Vestigial Side Band (8VSB), whose peak to average power ratios is far greater than the traditional modulation methods, the broadcast manufacturer has encountered a new and very serious design challenge. The increased dynamic range combined with the strict maximum allowed levels of out-of-band spectral emission dictated by the Federal Communications Commission requires from all the power amplification stages more linearity than what is actually achievable by means of analog Radio Frequency design alone. In order to solve this problem a compromise solution has been proposed. It allows for some nonlinearity in the amplifiers while controlling the out of band emissions using sharp analog filtering. Unfortunately, severe degradation of the in-band signal parameters takes place as a consequence of Inter Symbol Interference caused by this analog filter, leaving no other choice but to equalize it. This thesis presents the results of Adaptive Digital Equalization of the Linear Distortion phenomena in a Television Transmitter. The characteristics of the Digital TV modulation standard used in the U.S. are examined. The design methodology of adaptive filtering is reviewed. An equalization algorithm suitable to the problem is chosen and implemented in a Digital Signal Processor. Different versions of the hardware/software implementation of the digital equalizer are reviewed and compared. Results of the final system are analyzed. Conclusions include successful applications, recommendations for improvement, as well as the foreseen conditions where the system could potentially fail.
Advisors/Committee Members: Polycarpou, Dr. Marios.
Keywords: adaptive equalization
More Like This
8.
Abate, Brianna Lynne.
The Perfect Storm: A Systemic Analysis of the Apologetic Rhetoric of Hurricane Katrina.
Degree: Master of Arts, Speech Communication, 2008, Miami University
► This thesis analyzes the rhetoric of President George W. Bush, Louisiana Governor…
(more)
▼ This thesis analyzes the rhetoric of President George W. Bush, Louisiana Governor Kathleen Blanco, and New Orleans Mayor Ray Nagin in the wake of Hurricane Katrina. Using the rhetorical methodology of apologia, six specific artifacts of federal, state, and city/local governments are examined. Analysis suggests implications for the three levels of government, the study of apologia, as well as future study of natural disaster rhetoric.
Advisors/Committee Members: Voth, Ben.
Subjects: Communication; Rhetoric
Keywords: Hurricane Katrina, apologia, rhetoric, George W. Bush, Kathleen Blanco, Ray Nagin
More Like This
9.
Abbaoui, Besma.
The Potential for Platinum-Based Heterobimetallic Paddlewheel Complexes to Fight Cancer.
Degree: Bachelor of Science, College of Arts and Sciences - Biochemistry, 2005, Miami University Honors Theses
► A thesis presented on the potential of unique metal complexes, namely Platinum…
(more)
▼ A thesis presented on the potential of unique metal complexes, namely Platinum based heterobimetallic paddlewheel complexes, to act as antitumor drugs. The goal of this work is first to present a journal review of currently present platinum and rhodium based antitumor drugs, including cisplatin and di-rhodium complexes which were instrumental in the design of our new proposed antitumor drugs. This will be followed by an introduction to the research I am currently performing in synthesizing these Pt-based heterobimettalic complexes. Finally, results and discussion of my current research findings will be presented. I hope that this work will be both informative and enjoyable to the reader.
Advisors/Committee Members: Zhou, Hong-Cai.
Subjects: Chemistry, Inorganic
Keywords: cancer, heterobimetallic, platinum, rhodium, inorganic chemistry
More Like This
10.
Abbas, Atheir Ibrahim.
PSD-95 Regulates Serotonin Receptor Function in vivo.
Degree: Doctor of Philosophy, Biochemistry, 2009, Case Western Reserve University
► The 5-hydroxytryptamine 2A (5-HT2A) receptor, a target for hallucinogens and some antipsychotics,…
(more)
▼ The 5-hydroxytryptamine 2A (5-HT2A) receptor, a target for hallucinogens and some antipsychotics, is thought to play a prominent role in regulating mood, perception, and cognition. The closely related 5-hydroxytryptamine 2C (5-HT2C) receptor is also thought to be involved in a number of central nervous system processes including mood and temperature regulation. Due to the behavioral effects that result from activation and blockade of 5-HT2A and 5-HT2C receptors, it has been suggested that these receptors can modulate glutamatergic neurotransmission, though the biochemical links between the metabotropic serotonin and ionotropic glutamate systems have remained a mystery. In the studies presented herein we show that the postsynaptic PDZ domain-containing scaffolding protein postsynaptic density protein of 95kDa (PSD-95), a 5-HT2A/2Cinteracting protein, is an important biochemical link between the serotonin and glutamate systems. We show that, in the absence of PSD-95 in vivo, 5-HT2A and 5-HT2C receptor expression is reduced due to an increase in the rate of receptor turnover. We also provide evidence that targeting to the appropriate apical dendritic compartment is impaired in neurons cultured from PSD-95 knockout mice, and that lentiviral addback of PSD-95 to knockout neurons rescues targeting. We also examine signaling at both the biochemical and behavioral level. With respect to the 5-HT2C receptor, we show that the ability of a 5-HT2C agonist to induce c-fos, a marker of neuronal activation, is greatly reduced in the absence of PSD-95. We also present data showing that 5-HT2A-mediated hallucinogen-induced head twitch is also reduced in the absence of PSD-95. Finally, we provide evidence that clozapine, which is thought to correct the abnormalities in glutamatergic neurontransmission seen in some animal models of psychosis via a 5-HT2A-dependent mechanism, is unable to exert its therapeutic efficacy in PSD-95 knockout mice. Together the data presented herein provide the first biochemical link between the metabotropic serotonin and ionotropic glutamate systems. Our studies also suggest that this link is relevant not only with respect to the regulation of 5-HT2A and 5-HT2C receptor function, but also with respect to hallucinogen action and the neurochemistry underlying psychosis.
Advisors/Committee Members: Roth, Bryan.
Subjects: Biochemistry; Pharmacology
Keywords: 5-HT2A; 5-HT2C; PSD-95; hallucinogen; antipsychotic; clozapine; serotonin receptors
More Like This
11.
Abbas, James Joseph.
Neural network control of functional neuromuscular stimulation systems.
Degree: Doctor of Philosophy, Biomedical Engineering, 1992, Case Western Reserve University
► A neural network control system has been designed for the purpose of…
(more)
▼ A neural network control system has been designed for the purpose of controlling cyclic movements in Functional Neuromuscular Stimulation (FNS) systems. The design of the control system directly addresses three problems faced in the implementation of FNS control systems: customizing the control system parameters for a particular individual, adapting these parameters to account for changes in the musculoskeletal system, and resisting mechanical disturbances. The control system is implemented by a two-stage neural network that utilizes adaptive feedforward and feedback control techniques. The first stage of the neural network, the Pattern Generator, generates a cyclic pattern of activity. The design of this stage is based upon neural models of vertebrate motor control systems. The signals from the Pattern Generator are adaptively filtered by the second stage, the Pattern Shaper. A learning algorithm that accounts for system dynamics and input time delays was developed for use in adapting the Pattern Shaper filtering properties. Computer simulated models of electrically stimulated muscles acting on one- and two-segment skeletal systems were used to assess the potential utility of the neural network control system in FNS control. Results of the evaluation demonstrated that the control system can automatically c ustomize stimulation parameters, adapt them on-line, and resist mechanical disturbances. The control system was also demonstrated to be capable of controlling movements of multi-joint systems and of utilizing biarticular muscle effectively. The success of the control system in this evaluation indicates that it may provide significant improvements to existing FNS control system technology and suggests that the technique should be investigated further. These studies also indicate that this strategy may be appropriate for other applications in the control of dynamic, nonlinear systems with input time delays. The use of biologically motivated neural networks in the Pattern Generator provides this control system with unique features that are not readily available using existing control system techniques. The learning algorithm developed for use in the Pattern Shaper is particularly well-suited for use in engineering neural network control systems because it provides the ability to account for system dynamics and input time delays.
Advisors/Committee Members: Chizeck, Howard Jay.
Subjects: Engineering, Biomedical
Keywords: Neural network control functional neuromuscular stimulation systems
More Like This
12.
Abbas, Syed Farhat.
Development of a low cost shock pressure sensor.
Degree: Master of Science (MS), Mechanical Engineering (Engineering), 1988, Ohio University
Development of a low cost shock pressure sensor.
Advisors/Committee Members: Gunasekera, Jay.
Subjects: Engineering, Mechanical
Keywords: Shock Pressure Sensor; Determination of Hugoniot Curve; Piezoelectric Polymers
More Like This
14.
Abbott, Katherine Harris.
BLENDING RESOURCES: INFORMAL NETWORKS AND HEALTH CARE UTILIZATION BY FRAIL MALE VETERANS.
Degree: Doctor of Philosophy, Sociology, 2005, Case Western Reserve University
► Social networks play an important role in monitoring symptoms and managing chronic…
(more)
▼ Social networks play an important role in monitoring symptoms and managing chronic conditions for frail elders. Elderly veteran populations are unique because they have an increased risk of chronic conditions and fewer barriers to health care treatment through the Veteran’s Affairs Medical Centers. This research focuses on the role of lay consultants in veterans’ management of their health using the concept of social networks. The purposes of this research are to; describe the characteristics of frail veterans’ informal networks, examine if there are differences between White and African-American frail male veterans’ networks, and to explore the relationship between lay health consultant network characteristics and health care utilization. Using a cross-sectional design, data were collected at the twelve-month time point of an ongoing longitudinal study. Two-hundred frail male community dwelling veterans over the age of 55 with at least 2 activities of daily living impairments were interviewed by phone. Medical chart reviews were conducted to collect data on chronic disease conditions and utilization. Socio-demographic, physical, and psychological health variables were measured as well as network structure (size and composition), network function, (instrumental aid, emotional support, health appraisal, and health monitoring), and network satisfaction. Outcome measures include days hospitalized, emergency department visits, and the receipt of home health care. Based upon logistic and maximum likelihood regression analysis, veterans with more chronic conditions were more likely to be hospitalized, but those having a larger social network were less likely to be hospitalized. Veterans having family-only social networks were more likely to be hospitalized than those who have a mixed network (family, friends, and neighbors) controlling for veteran demographics, depression, and functional health. Being African American and having a larger instrumental support network were predictive of emergency department use. Being African American, having greater functional limitations, and being in the intervention group were predictive of home care use. No moderating relationships were found. Ways in which network members impact utilization are discussed. The opportunity to identify ‘at risk’ veterans with multiple chronic conditions and few network resources can enable formal care providers to assist with monitoring or appraisal support that may prevent hospitalization.
Advisors/Committee Members: Stoller, Eleanor Palo.
Keywords: Social Network; Frail Veteran; Race Differences; Health Care Utilization
More Like This
15.
Abbott, Marianne.
Dangerous intervention: an analysis of humanitarian fatalities in assistance contexts.
Degree: Doctor of Philosophy, Sociology, 2006, Ohio State University
► Humanitarian aid agencies are challenged by a tragic aspect of their missions –…
(more)
▼ Humanitarian aid agencies are challenged by a tragic aspect of their missions – fatal attacks on assistance providers. Since the early 1990s, fatal attacks leveled at aid personnel have included a broad range of events and a large number of incidents, spanning from random violence to premeditated murder. To describe these events in the most comprehensive terms possible, I have constructed of a database of news-reported aid worker fatalities from 1991 to 2004 that identifies 1,102 deaths, almost 1,000 of which result from violent attacks. The data source validation component of this research consists of intra- and extra-source validity evaluations. While no available source of information will capture all fatality incidents, results from the intra-source analysis indicate that the coverage of humanitarian deaths provided by the news is consistent among news outlets. Results from the extra-source analysis indicate larger disparities are related to the comprehensiveness of incident coverage. In sum, these evaluations confirm that all data sources are selective, but in predictable ways. The key to this evaluation was the detection of these filters. In the descriptive section, the news dataset presents the following broad trends: (1) Insurgent actors perpetrate violent attacks on humanitarian personnel with the highest frequencies; (2) Violent attacks account for 87 percent of the humanitarian assistance deaths; (3) Fatalities are highest among international governmental organization (IGO) personnel; and (4) Fatality counts are highest in Africa. I additionally refine variables that identify the nature of these attacks, the agents involved, and the intentions behind these attacks. Implications of this research relate both to the use of events data as well as to the critical issue of humanitarian security. Analyses overwhelmingly support the assertion that news data are a valid and rich source of information. Further, results from the intentionality study suggest that news data may provide more than “who did what to whom, when and where” information. At least in the case of humanitarian fatalities, it is possible to extract “why” information from news sources by assessing details that may appear in a news report.
Advisors/Committee Members: Jenkins, J. Craig.
Subjects: Sociology, General
Keywords: humanitarian death; humanitarian fatalities; intentionality; aid worker; aid worker death; aid worker fatalities
More Like This
16.
Abbott, Maxwell Bret.
THE STRUCTURAL MECHANISM OF Β-ADRENERGIC MODULATION OF CARDIAC TROPONIN SWITCH CALCIUM SENSITIVITY.
Degree: PhD, Medicine : Molecular Genetics, Biochemistry and Microbiology, 2001, University of Cincinnati
► Cardiac troponin is the molecular switch that activates the cardiac thin filament…
(more)
▼ Cardiac troponin is the molecular switch that activates the cardiac thin filament in response to increased Ca 2+ concentrations. The sensitivity of the troponin switch to Ca 2+ is reduced in response to Β-adrenergic hormonal stimulation of the cardiac myocyte, which activates protein kinase A. Protein kinase A phosphorylation of cardiac troponin I decreases the Ca 2+ binding affinity of cardiac troponin C. The molecular mechanisms of the cardiac troponin switch were investigated by heteronuclear multidimensional NMR and fluorescence techniques. Chemical shift, 15 N relaxation and translational diffusion studies of various cardiac troponin C/cardiac troponin I complexes revealed cardiac troponin C interaction sites for the inhibitory region of cardiac troponin I and exchange between 'open' and 'closed' conformations of the cardiac troponin C regulatory domain. A cardiac troponin I molecule was engineered to contain aspartate residues at the cardiac troponin I protein kinase A phosphorylation sites to mimic the phosphorylated state. Comparison of chemical shift and dynamic data obtained with this mutant demonstrate interactions between the cardiac specific amino-terminus of troponin I and the troponin C regulatory domain. Chemical shift, dynamic and fluorescence analyses correlate chemical shift changes with conformational opening of cardiac troponin C regulatory domain upon binding the cardiac troponin I regulatory region. The unphosphorylated cardiac specific amino-terminus of troponin I stabilizes the 'open' conformation of the cardiac troponin C regulatory domain. Protein kinase A phosphorylation of cardiac troponin I weakens regulatory interactions between cardiac troponin I and cardiac troponin C. Together the data presented here further our understanding of the mechanism of the cardiac troponin switch and its modulation by protein kinase A phosphorylation.
Advisors/Committee Members: Rosevear, Paul R.
Keywords: CARDIAC TROPONIN; PROTEIN-PROTEIN INTERACTIONS; NUCLEAR MAGNETIC; STRUCTURE - FUNCTION; PHOSPHORYLATION
More Like This
17.
Abboud, Antoine A.
A high frequency digital data acquisition system.
Degree: Master of Science (MS), Electrical Engineering (Engineering), 1983, Ohio University
A high frequency digital data acquisition system
Advisors/Committee Members: Curtis, Robert.
Keywords: Sample-and-Hold Device; Analog-to-Digital Converter; Random Access Memory
More Like This
19.
Abdalla, Abdelnassir.
Torque Ripple Minimization in Direct Torque Control of Induction Machines.
Degree: Master of Science, Electrical Engineering, 2005, University of Akron
► Direct torque control (DTC) of an induction motor fed by a voltage…
(more)
▼ Direct torque control (DTC) of an induction motor fed by a voltage source inverter is a simple scheme that does not need long computation time, can be implanted without mechanical speed sensors and is insensitive to parameter variations. In principle, the motor terminal voltages and currents are sampled and used to estimate the motor flux and torque. Based on estimates of the flux position and the instantaneous errors in torque and stator flux magnitude, a voltage vector is selected to restrict the torque and the flux errors within their respective torque and flux hysteresis bands. In the conventional DTC, the selected voltage vector is applied for the whole switching period regardless of the magnitude of the torque error. This can result in high torque ripple. A better drive performance can be achieved by varying the duty ratio of the selected voltage vector during each switching period according to the magnitude of the torque error and position of the stator flux. A duty ratio control scheme for an inverter-fed induction machine using DTC method is presented in this thesis. The use of the duty ratio control resulted in improved steady state torque response, with less torque ripple than the conventional DTC. Fuzzy logic control was used to implement the duty ratio controller. The effectiveness of the duty ratio method was verified by simulation using SIMULINK, and experimentally using TMS320F240 DSP Evaluation Board.
Advisors/Committee Members: Elbuluk, Malik E.
Keywords: power electronics, motor drives, induction machines, direct torque control
More Like This
21.
Abdallah, Ayman Ahmed.
Dynamic substructuring by the boundary flexibility vector method of component mode synthesis.
Degree: Doctor of Philosophy, Civil Engineering, 1990, Case Western Reserve University
► Component mode synthesis (CMS) is a method of dynamic analysis, for structures…
(more)
▼ Component mode synthesis (CMS) is a method of dynamic analysis, for structures having a large number of degrees of freedom (D.O. F.). These structures often required lengthy computer CPU time and large computer memory resources, if solved directly by the finite-element method (FEM). In CMS, the structure is divided into independent components in which the D.O.F. are defined by a set of generalized coordinates defined by displacement shapes. The number of the generalized coordinates are much less than the original number of physical D.O.F., in the component. The displacement shapes are used to transform the component property matrices and any applied external loads, to a reduced system of coordinates. Reduced system property matrices are assembled, and any type of dynamic analysis is carried out in the reduced coordinate system. Any obtained results are back transformed to the original component coordinate systems. In all conventional methods of CMS, the mode shapes used for components, are dynamic mode shapes, supplemented by static deflected shapes. Historically, all the dynamic mode shapes used in conventional CMS are the natural modes (eigenvectors) of components. This work presents a new method of CMS, namely the boundary flexibility vector method of CMS. The method provides for the incorporation of a set of static Ritz vectors, referred to as boundary flexibility vectors, as a replacement and/or supplement to conventional eigenvectors, as displacement shapes for components. The generation of these vectors does not require the solution of a costly eigenvalue problem, as in the case of natural modes in conventional CMS, and hence a substantial saving in CPU time can be achieved. The boundary flexibility vectors are generated from flexibility (or stiffness) properties of components. The formulation presented is for both free and fixed-interface components, and for both the free and forced vibration problems. Free and forced vibration numerical examples are presented to verify the accuracy of the method and the saving in CPU time. Compared to conventional methods of CMS, the results indicate that by using the new method, more accurate results can be obtained with a substantial saving in CPU time.
Advisors/Committee Members: Huckelbridge, Arthur A.
Keywords: Dynamic substructuring boundary flexibility vector component mode synthesis
More Like This
22.
Abdelbagi, Hamdi Eltayib.
SKIN AND PROXIMITY EFFECTS IN TWO PARALLEL PLATES.
Degree: Master of Science in Engineering (MSEgr), Electrical Engineering, 2007, Wright State University
► Abdelbagi, Hamdi. M.S.Egr., Department of Electrical Engineering, Wright State University, 2007. Skin…
(more)
▼ Abdelbagi, Hamdi. M.S.Egr., Department of Electrical Engineering, Wright State University, 2007. Skin and Proximity Effects in Two Parallel Plates. Time varying currents within winding and core conductors induce magnetic fields. When more than one conductor is present the resultant magnetic field can be found by adding the individual magnetic fields by superposition. The resultant magnetic field in turn induces eddy currents within each electrical component within the vicinity of the resultant magnetic field. Eddy currents flow in the opposite direction of the primary current and increase the resistance by reducing the area in which the primary current has to travel. Eddy currents also reduce the effectiveness of the conductors to conductor high frequency currents. Skin and proximity effects were numerically investigated for two parallel plate conductors while a laminated core was designed to reduce the power losses. Maxwell’s equations were solved to obtain analytical equations for magnetic fields eddy current distribution and power losses. These equations were illustrated in MATLAB for various frequencies to validate the theoretical analysis. Results demonstrate current within an isolated conductor flows near the surface. However, when the same conductor is placed near another conductor the flow path is affected. For the case when the current is flowing in the opposite direction the magnetic fields are added in the area between the conductors and subtracted on the outer side of the conductor. This causes an increase of the current density within the conductor areas, where the conductors are close to each other. This is the proximity effect. The anti-proximity effect occurs when two conductors carry current in same direction. In this case the magnetic fields are subtracted from each other in the area between the conductors and are added to each other in the area outside the conductors resulting in a higher current density in these areas. The eddy currents can be reduced in two ways. Using a highly resistant material for the core increases the skin depth making the distribution of the magnetic flux more uniform. Laminating the core with an oxide film can be used to reduce the eddy current loss as well. The study shows that the eddy current power loss in a sold core is greater than loss in a laminated core by a factor of K2, where K is the number of the sheets in the laminated core.
Advisors/Committee Members: Kazimierczu, Marian K.
Keywords: Electrical Engineerimg; Power Electronics
More Like This
23.
Abdelfattah, Faisal A.
RESPONSE LATENCY EFFECTS ON CLASSICAL AND ITEM RESPONSE THEORY PARAMETERS USING DIFFERENT SCORING PROCEDURES.
Degree: Doctor of Philosophy (PhD), Educational Research and Evaluation (Education), 2007, Ohio University
► Test performance may have little or no personal consequences for examinees in…
(more)
▼ Test performance may have little or no personal consequences for examinees in numerous testing situations. In such situations, test administrators are likely to view the effort levels of examinees as a matter for concern. Response latency or item response time was used in an attempt to detect the occurrence of a type of guessing that is expected to occur if the examinee does not put forth adequate effort. That is, responding to an item without adequately reading it and engaging in solution-oriented behavior. The study employed response latency as an indicator of examinees rapid-guessing behavior based on response latencies lower than a particular threshold for each item. The identified responses were rescored differently using the Omitted, the Not-presented, or the Zero scoring procedures. The objective was to evaluate the use of different scoring procedures on Classical Test Theory (CTT) and Item Response Theory (IRT) parameter estimates for dichotomously scored items that were obtained from a sample of 586 ninth grade students from five high schools in Jordan who took a computer-administration of a mathematics test. The results revealed that rapid guessing may have occurred fairly early in the test. Further, it was found that examinees showed rapid-guessing behavior on every item on the test and with greater frequency on the later items. A single group within-subjects design (repeated measure) ANOVA was used to assess changes in CTT and IRT item parameter estimates across scoring procedures. Significant differences in classical item difficulty and discrimination indices for the Omitted and the Zero procedures contrasted with the default scoring procedure and there was no significant difference in difficulty and discrimination estimates between the Original scoring procedure and the Not-presented procedure. Further, there were no significant differences in IRT parameter estimates across scoring procedures except for persons’ parameter estimates. With regard to pass/fail decisions, it appears that identifying individual examinee rapid-guessing responses and rescoring them may well influence the scores and, therefore, the decision concerning performance may change accordingly.
Advisors/Committee Members: Johanson, George A.
Subjects: Education, Tests and Measurements
Keywords: Response Latency; Low-stakes Tests; Achievement
More Like This
25.
Abdel Halim, Asma Mohamed.
Honorable Daughters: The Lived Experience of Circumcised Sudanese Women in the United States.
Degree: Doctor of Philosophy (PhD), Educational Research and Evaluation (Education), 2003, Ohio University
► This is a qualitative study of the experiences of circumcised Sudanese women…
(more)
▼ This is a qualitative study of the experiences of circumcised Sudanese women in the United States. It is done to find out whether the immigration experience has affected the cultural perceptions of women, in particular their views about female circumcision (FC). Questions are focused on what exactly has changed in their lives that resulted in a change of attitude or behavior. Three focus groups of women of different age groups participated in the research. One woman of each group was interviewed in depth. Open ended questions and semi structured interviews were conducted. Participants were allowed to ask questions and answer questions during the meetings. Debates around gender relations and family relations inside the homes were quite useful to the analysis of information gathered during lengthy interviews with individual women. Literature from broad areas of immigration, human rights, FC, cultural studies and qualitative research methods and feminist theory was reviewed. The study found that there is a change in women’s perception of their culture and a high level of awareness of why the change came about. Change in gender relations inside the home is the main change for immigrant Sudanese women. Despite strong ties with the home culture these changes are accepted as good and necessary. There is an activism side to their change of attitude towards FC; it is no longer lip service to change. The married women’s group is determined to use the acquired decision-making power to protect their daughters from the practice. The study found that this activism edge stemmed from their personal experiences of humiliation and horror during childbirth. Younger unmarried women saw FC as a practice that deprived them of their bodily integrity and took away their ability to make their own decisions. Older women did not change their mind about the “benefits” of FC but saw it as detrimental to their granddaughters’ health and status in the United States.
Advisors/Committee Members: Howard, Stephen William.
Subjects: Education, General
Keywords: Female Circumcision; Immigrant Women; Sudanese Women
More Like This
26.
Abdel-Haq, Ali H.
Analysis and design of box culverts.
Degree: Master of Science (MS), Civil Engineering (Engineering), 1987, Ohio University
► Box culvert problems are a complicated example of soil structure interaction where…
(more)
▼ Box culvert problems are a complicated example of soil structure interaction where the relative stiffness between the backfill soil and the culvert materials is a critical factor in the load carrying capacity of culverts. Duncan et al proposed an equation for the design of this class of structures. This equation doesn't take into consideration the soil structure interaction phenomena. A modified form of the above equation, which is presented here, with an allowance for the soil properties and culvert stiffness provides a better agreement with the finite element solution. Furthermore, the presence of PCC relieving slabs and their action in transfering live loads is analyzed and another better agreement with the finite element method is obtained. A sophisticated computer program called SEQCON is used to verify the results obtained from CANDE. The results of both programs are compared with an experimental data on a Lane Steel Culvert.
Advisors/Committee Members: Sargand, Shad.
Subjects: Engineering, Civil
Keywords: Box culverts; Soil Structure; Backfill Soil; Culvert Materials
More Like This
27.
Abdel-Karim, Ahmad Mahmoud.
Finite element analysis of a low-profile steel culvert with field verification.
Degree: Master of Science (MS), Civil Engineering (Engineering), 1987, Ohio University
► In the first part of this study, an ARMCO multiplate, low-profile, steel…
(more)
▼ In the first part of this study, an ARMCO multiplate, low-profile, steel culvert with rib stiffeners on the outside was instrumented for strain and deflection measurements. Measured strains were converted to stresses, moments, and thrusts based on the assumption of non- composite action between the rib and plate. Deflections were computed from bench mark measurements by reducing them to rectilinear coordinates. Soil deflections were measured using four rod extensometers placed at selected locations around the culvert. Measurements were recorded during backfilling and, later, during live load testing. Composite and noncomposite moment calculations showed a noticeable tendency towards composite action as the backfill height exceeded the crown level. A lower degree of composite action was observed at the crown as opposed to the haunches. Deflection measurements indicated that the culvert displaced to the south as a result of placing the backfill material on the north side first. The finite element computer program CANDE was used to analyze the soil-culvert system in the second part of this study. The structural backfill material was modeled using Duncan's soil model which uses hyperbolic relations to express the elastic modili that relate increments of stresses to increments of strains. The soil parameters for the Duncan soil model were chosen from the CANDE material library for a similar soil. The ability of CANDE to predict the actual behavior of the culvert was examined. Comparison between the analytical and experimental results indicated that CANDE predictions are slightly conservative, and hence, are satisfactory from a design point of view. Also as part of this study, a computer program (PREP) was written for the purpose of facilitating the input procedure to CANDE, including an automatic mesh generation feature.
Advisors/Committee Members: Hazen, Glenn A.
Subjects: Engineering, Civil
Keywords: Finite Element Analysis; Low-Profile Steel Culvert; Field Verification
More Like This
28.
Abdellatif, Mohamed Moustafa.
Poly(arylene ether)s with Truly Pendant Benzene Sulfonic Acid Groups.
Degree: Master of Science (MS), Chemistry, 2008, Wright State University
► A series of new sulfonated poly(arylene ether)s containing one sulfonic acid group,…
(more)
▼ A series of new sulfonated poly(arylene ether)s containing one sulfonic acid group, located on a pendant phenyl sulfonyl moiety, at every repeat unit was synthesized using 3-sulfonated-3', 5'-difluorophenyl Sulfone, 4, and a variety of bisphenols. A conventional nucleophilic aromatic substitution (NAS) was utilized for the homopolymerization and copolymerization reactions. Polymerization reactions of 4 in NMP at 180 °C provided the corresponding linear sulfonated poly(arylene ether)s, s-PAEs, with number average molecular weight, Mn, ranging from 10,000 to 38,000 Daltons. All of the polymers were characterized by 1H and 13C NMR spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The Tg values ranged from 264 °C to 296 °C for the salt form and 183 °C to 240 °C for the acid form. The Td5% values ranged from 311 °C to 472°C for the salt form and 307 °C to 367 °C for the acid form. All of the samples possessed excellent thermal stability. Furthermore, higher accessibility of the sulfonic acid groups was evident by observing increased solubility in hot water, which is presumed to construct a more efficient conductive pass way, thus increasing the proton conductivity of the newly developed systems. The polymer samples also formed tough peelable films when DMSO solutions were slowly evaporated on a glass slide. These new sulfonated polymers possess good properties and are excellent candidates for proton exchange membrane in fuel cell applications.
Advisors/Committee Members: Fossum, Eric.
Subjects: Polymers
More Like This
29.
Abdel-Maksoud, Nahed Fahmy.
INTERACTION AS A PREDICTOR OF STUDENTS’ SATISFACTION AND STUDENTS’ GRADES IN DISTANCE EDUCATION.
Degree: Doctor of Philosophy (PhD), Computer Education and Technology (Education), 2007, Ohio University
► This study examined the relationship between students’ perceptions of interaction, gender, age…
(more)
▼ This study examined the relationship between students’ perceptions of interaction, gender, age and students’ satisfaction with course and students’ grades. The data were collected using a Web-based survey from 65 students enrolled in an online humanities course in a Midwestern community college. Multiple regression analysis was used to analyze data. Results indicated that neither perceived personal interaction (participation) nor age accounted for a significant amount of variation in the dependent variable, satisfaction with the course. The most important predictor of students’ satisfaction was perceptions of overall interaction, followed by gender. The regression model with the two predictors was significant. Male students who perceived the overall interaction in the course to be high were more satisfied with the course. No significant correlations were found between perceptions of interaction and course grades. Gender and age were not significantly correlated with course grades. The regression model with four predictors, perceptions of personal and overall interaction, gender, and age, was not significant. The key predictor of students’ satisfaction with the course was not the extent to which students participated in the interaction that was occurring in the course, but rather their perception that there was much interaction in the course. This relationship between perceived overall class interaction and course satisfaction serves as an indicator of “vicarious learning,” or learning that takes place when a student actively observes and benefits from interaction among the other students, or between students and the instructor. Students who would not initiate interaction on their own can still learn from observing class interactions.
Advisors/Committee Members: Turner, Sandra V.
Subjects: Education, Technology
Keywords: Interaction; Distance education; Online Courses; Web-based courses; Vicarious interaction; vicarious learning; Satisfaction; Grades; Personal interaction; Personal participation; Overall interaction; Class interaction
More Like This
30.
Abdel Meguid, Mona Bakry.
Measuring Arab immigrant women's definition of marital violence: creating and validating an instrument for use in social work practice.
Degree: Doctor of Philosophy, Social Work, 2006, Ohio State University
► Despite growing evidence that immigrant women are at risk of becoming victims…
(more)
▼ Despite growing evidence that immigrant women are at risk of becoming victims of domestic violence, there has been little effort until recently to address intimate partner violence in the increasing immigrant populations in the United States. Evidence in the literature indicates that the severity as well as prevalence of intimate partner violence may be higher among immigrant groups. Suffering coupled with partner violence is additionally associated with problems related to immigration and acculturation. Yet, previous studies on intimate partner violence have rarely regarded the immigration status of the victim or the specific cultural and religious background of the immigrants. The purpose of this study was to design a valid and reliable instrument, Likert-type scale that measures Arab-Muslim women’s perception of marital violence. The scale was intended to investigate how Arab-Muslim women define intimate partner violence, help-seeking sources women might ask for help in case of intimate partner violence occurring, and barriers they might perceive in seeking outside help. The study examined 224 Arab-Muslim women’s definition of marital violence, help-seeking sources preferences they might consult in case of marital violence, and barriers they might perceive in seeking outside help. The results indicated the length of stay Arab-Muslim women been in the United States and the amount of education they have received influence their perception of marital violence and their help-seeking preferences.
Advisors/Committee Members: Bronson, Denise E.
Subjects: Social Work
Keywords: Scale development; Marital violence; Physical abuse; Emotional abuse; Arab immigrant women; Arab-Muslim women; Help-seeking resources; Help-seeking barriers
More Like This
[1] [2] [3] [4] [5] … [34]