ETD Center Search

▼ The effects of an oxygen ionized gas from simulated space exposure on the toughness and fatigue properties of several aerospace aluminum alloys and aluminum composites have been analyzed. The test matrix consisted of four aluminum systems: the 6000 and 1100 series and two 8090 aluminum-lithium alloys. The test specimens were prepared as Charpy V-notched impact and disk-shaped compact fracture toughness specimens. A small specimen size is used for the compact tension specimens to facilitate exposure in a Radio Frequency (RF) Plasma Prep II unit. Radio frequency plasma, sometimes referred to as the "electrodeless plasma", is used in disassociative ionization of molecular oxygen to simulate high fluence, relatively low energy, low earth orbit (LEO) space atomic oxygen. The plasma reacts with the aluminum alloy systems and forms a thin scale of alumina a few microns thick. Monolayer sensitive Variable Angle Spectroscopic Ellipsometry (VASE) is used to determine the growth characteristics and effect on optical constants, the reflective index, n and absorption coefficient, k. Atomic Force Microscopy (AFM) was also employed to determine the effect of short exposure to the oxygen plasma environment. AFM indicates that sharp spikes of oxygen rich material are produced above the aluminum specimen surface resulting in stress concentrations with gradual roughing of the surface. After 10 years of simulated exposure, the increased roughness results in a 34% increase in the fatigue crack growth, da/dN, for the 6000 series; the crack growth rate of the aluminum-lithium material was increased about 28%. The results of instrumented Charpy V-notched impact specimens indicated that exposure reduced the energy for fracture initiation by 29%. Plane strain fracture toughness effects could not be established because the influence of oxygen was concentrated at the surface of the specimens. Advisors/Committee Members: Wallace, John F.

▼ The purpose was to find a relationship between eating behaviors of female adolescent ballet dancers and nutritional knowledge and attitudes of their parents. Four ballet schools agreed to participate. Female dancers ages 10 through 18 who took two ballet classes per week and the parent most responsible for meal preparations were selected as participants. One hundred and nine parent/dancer matched surveys were collected. Parental surveys tested nutritional attitudes and knowledge on components of a diet and daily allowances. Dancer surveys scored eating behaviors. Frequencies and correlations were computed to determine scores and found a general lack of parental knowledge. The only statistically significant finding in this study was the relationship between the dancer’s eating behaviors and their body mass index. In fact the parental knowledge and attitude scores were not found to be related to the dancer’s eating behaviors. Advisors/Committee Members: Wilson, Dr. Bradley.

▼ The purpose of this investigation was to design and build a test rig to investigate the heat generated by a high speed sprag clutch assembly. The parameters used to design the test rig were to apply the cyclic torsion load at a level of 756 inch-pounds at 5000 rpm. The test rig was designed using a four square arrangement, which utilizes the circulation of power principle, a well known method commonly used in load testing power transmissions and has the advantage that only lost power must be supplied to the test rig. The sprag clutch test unit was placed between the high speed pinions of the circulating power loop. The test unit was designed to have replaceable inner and outer races, which contain the instrumentation to monitor the sprag clutch, to allow for cost effective replacement and versatility to test different sprag clutch designs. The oil supply system for the sprag clutch was developed to have the ability to lubricate the clutch from the inner race or through the sides of the sprag clutch and the oil flow rate could be changed by changing the size of the supplying orifice. The torque loading device was chosen to be a water cooled magnetic clutch, which is controlled either manually or through a computer. A DC electric motor, which will be used to supply the lost power to the four square loop, was chosen with a speed range of 0 to 2800 rpm, which allows testing at various speeds. The electric motor was coupled to the four square test loop by an increaser belt system, which will allow the high speed gear shafts to have a maximum speed of 5000 rpm. The data obtained from this investigation will be used to verify the results from a computer model and provide the ability to test present and future sprag clutch designs. Advisors/Committee Members: Kicher, Thomas P.

▼ Tumor metastasis, the leading cause of cancer deaths, is a multistep process with a few key steps believed to be rate limiting. The final step of metastasis, the growth of tumor cells at distal sites, is one key step. Both experimental and clinical data suggest that dispersed tumor cells can remain dormant for many years before developing into malignant tumors. However, little is known about how the growth of such metastatic cells is regulated. This switch from dormancy to malignancy could be attributed to manipulation of tumor cell behavior by the adjoining stromal cells. In this study we have demonstrated an Ets2-specific mechanism in tumor associated macrophages (TAMs) involved in promoting aggressive metastatic growth. Elevated expression of Ets2, a member of the Ets family of transcription factors, has been correlated with breast cancer, putatively by its activity in the stroma. It is also an important effector molecule in the CSF-1 mediated pro-inflammatory pathway in macrophages. Additionally, Ets2 activates or represses transcription of target genes in a context dependent manner. Mouse modeling results described here demonstrate that Ets2 activity in TAMs creates a favorable angiogenic environment, in part, by repressing a set of genes that negatively regulate angiogenesis, resulting in metastatic growth. We also observe similar Ets2-dependent molecular changes in the immature myeloid precursors in bone marrow of tumor-bearing mice. Thus, this Ets2-mediated program is involved in ‘educating myeloid cells even before their physical association with tumor cells. The mouse Ets2-TAM signature could also distinguish between lymphocyte/ leukocyte infiltration positive and negative human breast tumor samples. A subset of this profile was sufficient to retrospectively predict disease free survival among breast cancer patients. Interestingly, the Ets2-TAM signature stratified estrogen receptor negative patient samples into two distinct survival groups, in contrast to other existing mammary tumor gene signatures developed to predict patient survival. Our approach uncovered molecular mechanisms that regulate metastatic tumor growth and identified potential stromal biomarkers for human breast tumor metastasis. Advisors/Committee Members: Ostrowski, Michael.

▼ The consequences of a first order QCD phase transition in the protoneutronstar remnant of core collapse supernova are presented with a special focus on the effects on neutrino transport. A secondary focus is the detection of these neutrinos in terrestrial detectors. Hybrid stars are constructed such that a coexistence region of QCD-confined and deconfined phases forms in the protoneutronstar interior with possibly a pure deconfined phase in the center. The resulting Coulomb lattice (1D,2D and 3D) in the coexistence region is shown to crystallize for temperatures relevant in supernova cores seconds after bounce. Droplet deformation modes freeze out in the same range. For the outermost ~1 km of the coexistence region, the stability of the 3D lattice to shear stresses falls below the critical range of mechanical energy densities provided by hydrodynamical flow. This can lead to a non-spherical relief structure which, together with the enhanced neutrino opacity of the coexistence lattice, can result in anisotropic neutrino transport and therefore neutron star kicks. A computer model for neutrino diffusion coupled with quasistatic evolution of a solid lattice phase and hydrodynamical treatment of the confined matter envelope was developed to address the kick model and other problems. The state of newly formed hybrid stars is determined using a self-consistent approach of integrating the stellar structure equations with the constraint of heat flow equilibrium, resulting in relatively cool energy spheres (T~1MeV) compared to T~10MeV in the interior. Typical cooling timescales of hybrid stars are then ~100 seconds. This is shown to result in a statistically significant signal in a Pb-neutron spallation detector. In exploratory calculations, observed kick speeds were reproduced and the presence of a sustainable convective flow pattern to maintain a crater in the coexistence region was verified. The Pb and Fe components of a proposed neutron spallation neutrino detector concept were optimized with respect to cost-efficiency. DAMOCLES, a transport code for neutrons, capture gamma rays and scintillation photons was developed for that purpose. The detection efficiency for liberated neutrons for the optimum configurations in both detectors is 38%. The available sensitivity to sparse neutrino signals is ~1/(second,kT) for expected radioactive background rates. Advisors/Committee Members: Boyd, Richard N.

▼ This dissertation concerns the field of values of the inverse of a matrix. Techniques of approximation of this set are considered for large, sparse matrices, and applications are discussed. A new method is presented that is similar in computational cost to previous methods, but may yield better approximations in practice. Also, a new technique for finding eigenvalue inclusion regions is presented, developed from the relationship between the field of values of the inverse and the eigenvalue extraction technique known as harmonic Rayleigh-Ritz. By intersecting these eigenvalue inclusion regions, a new characterization of the spectrum of a matrix is obtained. The technique for generating these regions can be generalized by replacing the field of values with other eigenvalue inclusion sets, and this is demonstrated using the Geršgorin region of a matrix. Advisors/Committee Members: Singer, David A.

▼ Complicated healing of articular fractures represents a clinical challenge and a financial burden on the health care system. Bone marrow-derived mesenchymal stem cells (BMDMSC) hold promise for targeted osteogenic differentiation and can be augmented by delivery of genes encoding bone morphogenetic proteins (BMP). Osteogenic differentiation of BMDMSC was investigated using two BMP genes. Cultured BMDMSC were transduced with adenoviral vectors containing human BMP2 or BMP6 in either sustained in monolayer or suspended in alginate for 22 days. Adenovirus (Ad)-BMP-2 and Ad-BMP-6 transduction resulted in abundant BMP-2 and BMP-6 mRNA and ligand expression in monolayer culture and BMP-2 ligand expression in alginate. Ad-BMP-2 and Ad-BMP-6 transduced BMDMSC in monolayer had earlier alkaline phosphatase-positive staining and mineralization and were sustained for a longer duration than untransduced or Ad-ß-galactosidase-transduced cells. Gene expression studies at day 2 confirmed an inflammatory response to the gene delivery process. Up-regulation of genes consistent with response to BMP exposure and osteogenic differentiation occurred in BMP-transduced cells. These data support that transduction of BMDMSC with Ad-BMP-2 or Ad-BMP-6 can accelerate osteogenic differentiation and mineralization of stem cells. BMP-2-transduced stem cells suspended in alginate culture may be a practical carrier system to support bone formation in vivo. A distal femoral articular osteotomy model was created in the nude rat to study articular fracture healing. Osteotomies were treated with BMDMSC, wild-type (NoAd) or transduced with Ad-BMP-2. Cells were delivered in alginate (ALG) or injected in saline. Controls were empty ALG, saline injections, direct Ad-BMP-2 injection, and untreated osteotomies. Healing was compared using quantitative micro-computed tomography, fluorescent labeling, and histology. At day 14, osteotomy gap area in the Ad-BMP-2 ALG group was significantly greater than other groups (P < 0.0003). The group treated with Ad-BMP2-transduced cells injected in saline (Ad-BMP-2 cells) healed with less osteotomy gap area (P < 0.0001) and volume (P < 0.02) than untreated controls. In ALG groups, bone healing was impeded by development of a chondroid mass most pronounced in the Ad-BMP-2 ALG group. Injection of Ad-BMP2-transduced BMDMSC in saline accelerated bone healing and reconstituted the articular surface in this distal femoral osteotomy model of articular fracture healing. Advisors/Committee Members: Bertone, Alicia L.

▼ The sport of ice hockey is a unique blend of anaerobic power and aerobic capacity. These athletes perform short bouts (90 sec) of powerful skating, shooting, and body hits. While these are anaerobic bouts of exercise, the effect of repeated on-ice shifts results in a cumulative endurance exercise. The purpose of this study was to analyze the body's physiological responses, such as maximal oxygen consumption and ventilatory threshold, of National Collegiate Athletic Association (NCAA) Division I level hockey players. Twenty-four male hockey players (n=14 forwards, n=8 defensemen, n=2 goalies; age=20.9 ± 1.18 yrs.) were measured for VO2max and ventilatory threshold (Tvent) on a treadmill, utilizing a progressive, graded exercise test protocol. The measures were collected using the Oxycon Mobile® gas analysis system. The subjects ran on the treadmill for 3-minute stages during which speed and grade increased, until exhaustion. VO2max was expressed in relative terms (ml/kg/min), and Tvent was recorded as a percent of VO2max (%VO2max). Heart rate (bpm) and rating of perceived exertion (RPE) were also measured. VO2max for these subjects were significantly higher than the average for this demographic, 57.2 ± 5.04 ml/kg/min (range: 68.0-48.4 ml/kg/min). Tvent for these subjects was also significantly higher than average, untrained individuals, 80.7 ± 9.6% VO2max (range: 91.9%-54.0%). Also, VO2 at stage 4 (p=0.068, d=2.42) and Tvent (p=0.68, d=0.19) were not shown to be dependent on position. Advisors/Committee Members: Morgan, Amy L.

▼ The purpose of this descriptive field study was to investigate the meaning of loneliness from the adult, hospitalized, dying person's perspective. Participant observation, intensive interviewing, and review of records were the central techniques of data collection. Data were collected over a nine-month period, with the researcher in the role of a clinical nurse specialist at a large university medical center. The purposive sample consisted of 18 primary participants who were recognized as having limited life spans by virtue of their diagnosis of metastatic cancer or AIDS and a prognosis of approximately one year or less. The interpretation of loneliness meanings relied on data from these primary participants. Field notes comprised the data for analysis. A thematic and pattern analysis was performed. The data supported the existence of three meaning dimensions of loneliness: relational, existential, and emotional. These dimensions overlap and a common core of experiences, termed "poverty of self," was identified. The meaning dimensions are expressive of and based in two affiliative contexts, others and self. From the perspective of the adult, hospitalized, dying person, loneliness is an unpleasant feeling of separateness, aloneness, and/or emptiness in response to qualitative or quantitative deficits in relationships with others and a perceived inability to adequately express one's complete self with others. The data also revealed that a person may feel lonely in the presence of others or he/she may be alone and not feel lonely. The intensity of the feeling may be lessened by the knowledge that the separation from important persons or things is temporary. From the dying person' s perspective, although it is a frightening and distressing experience, there is potential for self-growth. A comparison of data from the lonely and not lonely suggested three associated conditions: (a) deficits in relationships that provide a sense of attachment and the opportunity for nurturance; (b) the absence of a spiritual belief system; and (c) a pattern of living-dying characterized by fear and uncertainty about illness and/or treatment outcomes. The majority of these dying persons expressed at least a minimal or temporary experience of loneliness. The potential usefulness of nursing interventions aimed at self-enrichment were suggested. Advisors/Committee Members: Wykle, May.

Advisors/Committee Members: Sciulli, Paul W.

▼ This four-chapter report describes the work I completed as a technical writer/trainer intern at The Normandy Group (TNG). It provides an overview of TNG; an overview of my role and the projects I worked on at TNG; a description of the user guide I created as my major writing project at TNG; and an analysis and application of the Problem Solving Model for Technical Communicators in regards to my major project and an exploration of the internship regarding the expectations I had before the internship began, the reality of the internship, and the hindsight gained from the internship. Advisors/Committee Members: Durack, Katherine.

Strength and hydraulic conductivity characteristics of roller compacted concrete Advisors/Committee Members: Hazen, Glenn.

▼ A current priority of the National Highway Traffic Safety Administration (NHTSA) is to decrease stopping distances of commercial vehicles. It has been found that longer stopping distances during panic stops increase the chances of collision with other vehicles. By using ABS modulated air-disk brakes in conjunction with electronic actuation (Electronic Control Braking System, ECBS) on the prime mover (i.e. the tractor), the stopping distance can be decreased by as much as 30 %. However, due to fiscal reasons in the trucking industry and the nature of ECBS of adding a fourth line to the system, it has not been implemented on the trailer(s). Thus, there are compatibility issues between the tractor and trailer(s). Previous brake-in-turn studies have been done with single-trailer commercial vehicles. This study investigated the jackknife stability of double tractor-trailer combination vehicles in brake-in-turn maneuvers with varying loads and surface conditions, and brake configurations. TruckSimTM was used to model the vehicle dynamics of the vehicle and MATLAB®’s Simulink®, in parallel, ran NHTSA’s ABS model. A sanity check was performed on TruckSimTM’s doubles package with the aid of experimental data obtained by the University of Michigan Transportation Research Institute (UMTRI) at the Transportation Research Center Inc (TRC). In the Brake-In-Turn studies the tractor utilized a 4s/4m ABS configuration with pneumatic drum, pneumatic disc or ECBS disc brakes. The trailers and dolly utilized a 2s/1m select-high or low ABS control algorithm with pneumatic drum brakes. Conditions with ABS ON for the entire vehicle (and select-high control algorithm on the trailers and dolly) found that instabilities were exhibited under a surface friction coefficient of 0.3. Lane excursions occurred in the dolly and 2nd trailer or a jackknife occurred between the 1st and 2nd trailer. It was demonstrated that these instabilities could be avoided while utilizing a select-low control algorithm on the trailers and dolly. Conditions with ABS OFF for the tractor and on for the rest of the vehicle (with a select-high control algorithm on the trailers and dolly) found instabilities under every condition with the exception of one. The instabilities exhibited were either a lane excursion or jackknife. The difference between a jackknife and lane excursion situation was realized when investigating the discrepancy in time between steer and drive wheel lock-up. The greater difference in lock-up between the steer and drive wheels on a high friction coefficient resulted in a jackknife situation. On a low or medium friction coefficient, the smaller time difference in wheel lock-up increased the jackknife stability, but a lane excursion still occurred. A greater number of jackknife situations occurred on a tractor equipped with pneumatic drum brakes for this same reasoning. The tradeoff between the vehicle equipped with disc and drum brakes was discussed. Simulation results (with ABS OFF on the tractor) showed that a tractor equipped with disc brakes (ECBS or Pneumatic) had greater jackknife stability. However, the vehicle left the intended path at an earlier moment in the maneuver than a tractor equipped with pneumatic drum brakes under the same simulated conditions. A comparison showed that the dolly was the least stable unit in the vehicle with the ABS ON conditions; whereas, with the ABS OFF, the tractor was the least stable unit. A current priority of the National Highway Traffic Safety Administration (NHTSA) is to decrease stopping distances of commercial vehicles. It has been found that longer stopping distances during panic stops increase the chances of collision with other vehicles. By using ABS modulated air-disk brakes in conjunction with electronic actuation (Electronic Control Braking System, ECBS) on the prime mover (i.e. the tractor), the stopping distance can be decreased by as much as 30 %. However, due to fiscal reasons in the trucking industry and the nature of ECBS of adding a fourth line to the system, it has not been implemented on the trailer(s). Thus, there are compatibility issues between the tractor and trailer(s). Previous brake-in-turn studies have been done with single-trailer commercial vehicles. This study investigated the jackknife stability of double tractor-trailer combination vehicles in brake-in-turn maneuvers with varying loads and surface conditions, and brake configurations. TruckSimTM was used to model the vehicle dynamics of the vehicle and MATLAB®’s Simulink®, in parallel, ran NHTSA’s ABS model. A sanity check was performed on TruckSimTM’s doubles package with the aid of experimental data obtained by the University of Michigan Transportation Research Institute (UMTRI) at the Transportation Research Center Inc (TRC). In the Brake-In-Turn studies the tractor utilized a 4s/4m ABS configuration with pneumatic drum, pneumatic disc or ECBS disc brakes. The trailers and dolly utilized a 2s/1m select-high or low ABS control algorithm with pneumatic drum brakes. Conditions with ABS ON for the entire vehicle (and select-high control algorithm on the trailers and dolly) found that instabilities were exhibited under a surface friction coefficient of 0.3. Lane excursions occurred in the dolly and 2nd trailer or a jackknife occurred between the 1st and 2nd trailer. It was demonstrated that these instabilities could be avoided while utilizing a select-low control algorithm on the trailers and dolly. Conditions with ABS OFF for the tractor and on for the rest of the vehicle (with a select-high control algorithm on the trailers and dolly) found instabilities under every condition with the exception of one. The instabilities exhibited were either a lane excursion or jackknife. The difference between a jackknife and lane excursion situation was realized when investigating the discrepancy in time between steer and drive wheel lock-up. The greater difference in lock-up between the steer and drive wheels on a high friction coefficient resulted in a jackknife situation. On a low or medium friction coefficient, the smaller time difference in wheel lock-up increased the jackknife stability, but a lane excursion still occurred. A greater number of jackknife situations occurred on a tractor equipped with pneumatic drum brakes for this same reasoning. The tradeoff between the vehicle equipped with disc and drum brakes was discussed. Simulation results (with ABS OFF on the tractor) showed that a tractor equipped with disc brakes (ECBS or Pneumatic) had greater jackknife stability. However, the vehicle left the intended path at an earlier moment in the maneuver than a tractor equipped with pneumatic drum brakes under the same simulated conditions. A comparison showed that the dolly was the least stable unit in the vehicle with the ABS ON conditions; whereas, with the ABS OFF, the tractor was the least stable unit. Advisors/Committee Members: Guenther, Dennis A.

▼ The Gory Sowie Block (GSB), of SW Poland’s Sudete Mountains, contains numerous ultra-high temperature granulites (UHT) and small relict ultra-high pressure (UHP) eclogites enveloped within amphibolite-facies gneisses and amphibolites. The GSB is bounded by ductile fault zones, bisected by the Sudetic Boundary fault and partially overlies ophiolitic sequences. The GSB experienced a polyphase metamorphic history spanning Caledonian and Variscan accretionary events (440 - 330 Ma) with peak metamorphic conditions of 1000°C and >20 kbar occurring ca. 400 Ma, indicated by U-Pb zircon ages on garnet peridotites and felsic granulites. This project involved 40 Ar/ 39 Ar hornblende and mica plateau ages from primarily GSB host gneisses. The results indicate that the western GSB experienced a diachronous cooling event with the northern region cooling from upper amphibolite-facies (sillimanite/kyanite zone) ca. 385 Ma and southern region from middle to lower amphibolite-facies (garnet/biotite zone) ca. 375 Ma with cooling rates ranging from 40 – 25°C m.y. -1 . U-Th total-Pb monazite geochronometric results obtained during this study reveal both amphibolite-facies metamorphism at 385 Ma, concordant with the 40 Ar/ 39 Ar cooling ages, and homophazation of the gneisses and late-fluid mobilization along tectonic boundaries associated with large scale metamorphism of the surrounding Sudetic terranes at ca. 360 Ma. Additionally, concordant 40 Ar/ 39 Ar hornblende and biotite plateau ages obtained along the far eastern margin indicate a regional heating event at 336.8 ± 0.8 Ma., most likely associated with Niemcza shearing. Advisors/Committee Members: Schneider, Dave.

▼ Children with chronic illnesses have a unique set of health and illness experiences. The purpose of this research was to investigate how children with juvenile diabetes (IDDM) explain, manage and cope with their illness. Three sets of interviews were administered to twenty-six children who were diagnosed as diabetic for at least six months. Theoretical perspectives were gathered in initial and follow-up interviews. Weekly interviews, gathered by telephone, investigated health maintenance activities and actual response patterns to illness episodes. Results indicate that although juvenile diabetes is a fully recognized entity in the realm of professional biomedicine, it is the popular sector of care which has the greater influence on diabetic illness beliefs, management behaviors, and coping strategies. The children's responses also indicate that they view their condition from two perspectives. The first is a disease orientation in which juvenile diabetes is seen as a complex, life-threatening, medical condition which is caused by a malfunctioning pancreas. This disease orientation is mediated by an illness orientation, which has management as the focal point. The diabetic management tasks of insulin injections, blood or urine checks and vigilance in diet and exercise are clearly delineated in the professional sector of care, b ut are carried out in the popular sector of care. By successfully participating in self-care, these children learn that they can become responsible for their health. Since several of the prescribed diabetic management tasks are recommended for all health-conscious individuals, the paradigm of care for these children becomes one of health maintenance as opposed to diabetic illness prevention. Advisors/Committee Members: Korbin, Jill E.

▼ In summer 2002, face-to-face interviews were carried across Lebanon with seventeen nursery managers. Production of woody plants from propagation to finished product does not commonly occur. Most frequently, woody taxa are imported from Italian and Spanish nurseries. Fertilizer studies were carried out on three species native to Lebanon that have ornamental attributes: Cercis siliquastrum, Acer syriacum and Malus trilobata. The fertilizer study aimed at determining the production potential of six sources of Cercis, two sources of Malus and one source of Acer, by exploring their growth, N, P, K nutrient uptake efficiency and partitioning under two fertilizer rates. Seedlings of all sources of Cercis grown under 25 had greater dry weight than those grown at 100 mg N per L. those of Malus under the low fertilizer rate were taller than those at the high fertilizer rate. Growth of Acer was not affected by fertilizer rates. Nutrient loading occurred in Cercis and Malus plants under the high fertilizer rate, although total plant N, P, and K content was not affected by fertilizer rate. Water use of container-grown plants and the impact of fertilization on water use were studied in these species. Water use estimates were made by saturating the containers early in the morning, allowing them to drain for one hour, weighing them and re-weighing approximately five hours later. Seedlings at the low fertilizer rate used more water per cm height than plants at the high fertilizer rate. In addition, there were differences in water use among and within seed sources of Cercis and Malus. One way to preserve these species is by propagation and reintroduction into appropriate habitats. Therefore, the relationship of nine species to soil and climatic conditions in eight sites along an altitudinal gradient was studied. Climatic data was collected and soil samples were taken and analyzed for soil texture, soil pH, EC, CaCO3, organic matter content and the following nutrients: Ca, Mn, Na, Fe, P, K, Cu, Mg, and Zn. Each ecosystem had a unique environment. Some species’ densities were affected by soil conditions while climatic conditions explained the densities of species. Advisors/Committee Members: Struve, Daniel.

Experimental study of a quench process. Advisors/Committee Members: Alam, M. K.

▼ The primary objective of this thesis is to address an understudied area of the political geography scholarship, initiative voting and referendum voting. Initiative and referendum voting was adopted by the state of Ohio in 1912, and this thesis will present a historical analysis of the outcomes these votes in the state of Ohio from 1928 to 2006. This work will describe the distributions of these votes through mapping and statistical methods. Using these above methods, this research will address the following problems: Are the outcomes of the vote’s similar dependent upon the type of measure or the when the measure was voted on? Does dropoff have a unique spatial distribution? Advisors/Committee Members: McTague, Dr. Colleen.

▼ In Ohio, fish and macroinvertebrates are the organisms of choice for assessment of biological condition in wadable streams. Macroinvertebrates are used to calculate the invertebrate community index (ICI) in order to assign a site score of 0-60, and classification of Excellent, Good, Fair, or Poor. This study aimed to show the utility of the diatom community in classifying streams as well as the ICI, evaluate sensitivity of potential diatom metrics and the diatom index of biotic integrity (DIBI) to acid mine drainage pollution (AMD), and assemble promising metrics into an index that could be used to characterize health of AMD stressed streams. To accomplish this task, macroinvertebrates, diatoms and water samples were collected from 41 stream segments in southeastern Ohio. Water samples were analyzed for nutrients (P04, N03,), alkalinity, pH, conductivity, and AMD indiators (Fe, Mn, and SO4). The ICI metrics showed significant (p < 0.05) correlations with many stream chemistry variables. Four DIBI metrics showed significant correlations with more than two chemical variables. Several ICI metrics showed correlations with DIBI metrics and DIBI scores were significantly correlated with ICI scores. Classification and regression tree (CART) analysis produced a tree using five DIBI metrics to characterize streams based on their ICI narrative grouping (Excellent, Good, Fair, and Poor). A modified DIBI (AMD-DIBI) was created using 3 original metrics plus six additional metrics that were determined to be more sensitive to AMD stress. The AMD-DIBI proved to have a much-improved relationship with the ICI (r = 0.72, p < 0.0001). This AMD-DIBI may be a useful tool for assessing biotic integrity when obtaining an ICI score is not feasible. Advisors/Committee Members: Vis, Morgan L.

▼ Solid oxide fuel cells have been investigated frequently with models predicated on linear electrical circuit elements, ignoring finer details of electrochemical transport. To gain better understanding of the operation of solid oxide fuel cells based on their underlying physics, the most simple system of fundamental equations, consistent with solid oxide fuel cell thermodynamics, has been constructed. The system includes the continuity equation for mass/charge transport, the Poisson equation relating electrostatic potential and charge density, and interface flux expressions reflecting activated state processes. The driving force of all transport processes is the electrochemical potential gradient of mobile species. This potential includes entropic interaction and electrostatic energies. Gas phase mass transport was not considered in this work. The equation system governed calculations simulating various electrical and electro-chemical measurement experiments, specifically: equilibrium open-circuit cell voltage measurement, cell voltage measurement with increasing dc current density, and electrochemical impedance spectroscopy. The 1-D solid oxide fuel cell system investigated is composed of two dense mixed-conducting electrodes and a dense purely ion-conducting electrolyte. Relaxing the system from initial non-equilibrium, the calculated equilibrium cell voltage agreed O(10 −9%) with the theoretical Nernst voltage. Also, non-thermodynamic and non-material parameters did not affect this agreement, validating the thermodynamics of the equation system. The effects of kinetic and geometric variables on the behavior of the investigated system were clearly observed in both dc current density and electrochemical impedance simulations. As the perturbation amplitude was increased, the onset of nonlinear impedance response was seen. Advisors/Committee Members: Verweij, Henk.

▼ Interval boundary element method (IBEM) is developed allowing computation of the worst case behavior of the system due to numerical errors on the point-wise variable level. Three sources of error due to numerical analysis are considered; 1) errors occurring due to numerical integration, 2) errors occurring due to floating point number truncation, and 3) errors occurring due to the discretization of the integral equation resulting from boundary element formulation. The impact of uncertainty in the applied boundary conditions was also examined. Boundary element method is a technique used to solve partial differential equations. This numerical scheme obtains approximate solutions which have been shown to converge on the global scale. However, the accuracy of the solutions on the local level has not been studied and needs to be considered for reliable engineering analysis. This work obtains the enclosure of the boundary integral equations, which result from boundary element formulation, via interval methods. The interval boundary integral equations are then solved using the conventional boundary element procedure. The resulting is the enclosure of the true solution of the boundary values. Form the worst case bounds on the boundary values the worst case bounds in the domain of the problem are computed. Interval analysis is used to treat errors due to numerical integration and floating point number truncation. An illustrative numerical scheme is considered to demonstrate the formulation and the rounding error is accounted for in the iterative scheme used to solve the resulting interval linear system of equations. The treatment of uncertainty in the boundary conditions is explored using interval concepts resulting in exact worst case bounds for the boundary values. Advisors/Committee Members: Mullen, Robert.

▼ A sensitive Cavity Ringdown Spectroscopy (CRDS) apparatus has been successfully developed to study reactive intermediates in the near IR region. Many interesting species can be observed in this chemical fingerprint spectral region. Peroxy radicals (RO2), a class of important intermediates in atmospheric chemistry and low temperature combustion, have been investigated via IR A - X electronic transition. Moderate resolution (0.2 cm−1 ) absorption spectra of the near IR electronic transition have been obtained for several members of the alkyl peroxy radical family: methyl (CH3O2), ethyl (C2H5O2) and isopropyl (2-C3H7O2) peroxy. CRDS spectra of the acetyl peroxy radical (CH3C(O)O2), a key irritant in smog, has been investigated. A sharp, structured electronic spectrum of A - X electronic transition for the fluorinated methyl peroxy (CF3O2) radical has been observed. Extensive ab initio calculations have been carried out to help assign spectral carrier, predict and analyze observed spectroscopic features such as rotational contours, vibrational hot bands and frequencies for the A state fundamental vibrations. Structured spectral signatures of the transition contain information sufficient to distinguish the detailed nature of the R group, even when they are quite similar, providing an opportunity to easily identify different peroxy radicals and develop species specific diagnostics. The absorption cross sections for several peroxy radicals has been determined using CRDS observations and radical recombination kinetic measurements. Advisors/Committee Members: Miller, Terry A.

▼ My intention in this study is to provide insight into the problem of representing the trauma of the Holocaust in Italian cinema. In the tradition of Neorealism, in which filmmakers investigated socio-political issues of contemporary and historical Italy, the paucity of Italian films that deal with the Final Solution is remarkable. I will explore this contradictory attitude of Italian filmmakers towards a particularly obscure and unpleasant past, and while focusing on the ambiguous filmic representations of the Shoah, mainly through the study of liminal figures (in particular the Muselmann and the kapo) in a selection of Italian Holocaust films. My study will be divided into 4 chapters. It will include an introduction, in which I will briefly examine the notion of trauma from a critical perspective and introduce the idea of liminality. Then, I will examine five Italian films (Kapò by Gillo Pontecorvo, 1959, The Night Porter by Liliana Cavani, 1974, Seven Beauties by Lina Wertmüller, 1975, Look to the Sky by Roberto Faenza, 1993 and Life is Beautiful by Roberto Benigni, 1997) which depict the Holocaust experience, and will focus my attention on the ambiguous figures produced by the concentration camp experience. Advisors/Committee Members: Renga, Dana.

▼ The Ohio Department of Transportation Bridge Management System (BMS) currently uses Organizational Performance Indices (OPI) to track bridge performance each year. Currently, ODOT makes decisions based on four OPI ratings. The goal is to keep bridge deficiency levels below specified levels for OPI ratings, on which the bridge performance is evaluated. First, the historical data from disparate sources is extracted, cleaned and transformed taking into consideration data quality issues. A suitable schema is implemented to construct a data warehouse. Secondly, a stochastic Markov chain model is built to study the effect of geographical location, bridge type material and age on the degradation rate of over 45,000 bridges. The results give an insight into bridge performance issues, ability to study bridge performance with time and degradation rates. Bridges in northern and southern districts and bridges with concrete and steel material have different degradation rates. Three age groups of new, middle and old aged bridges exhibit different degradation rates (three piece-wise stationary) indicating age is an important factor that affects degradation. The bridge prediction and performance model developed will facilitate inspection scheduling, cost analysis and budget optimization. This will aid in management and decision making activities. Advisors/Committee Members: Helmicki, Arthur.

▼ Gel network technology in conditioning shampoo represents an advantage over traditional silicone 2-in-1 technology due to its main benefits: dry conditioning, wet feel and lower cost. The purpose of this study was to do a proof of principle investigation and to study the main factors that affected partitioning of PRMs into the gel network system shampoos and determine the effect that perfume incorporation had on the shampoo stability of the different formulations . Gel network premixes (literally a conditioner) were formulated then incorporated into a standard shampoo base. Changes in formulation of the gel network such as chain length of fatty alcohols and fatty alcohol ratios were done and its effect on stability and perfume migration studied. A technical accord with 25 PRMs with a very wide range of physical properties was used as a marker. Other perfume variables studied were hydrophobicity of the perfume, hydrophobically modified accords, and other user practices such as combing/wetting. The formulations were evaluated for stability using microscopy and differential scanning calorimetry. Compositional analysis was done using GC/MS and headspace analysis. Consumer acceptance was evaluated using sensory panel. The compositional analysis partition data was used in a QSAR model to predict future PRMs tendency to partition into the gel network. Three main conclusions were reached: 1) Hydrophobically modified accords partition favorably into the gel network, however, whether that translates into greater consumer benefit will need to be further tested. 2) PRMs that partition favorably into the gel network follow a structure-property relationship of lipophilicity and rigidity. 3) Changes in processing parameters influence the partitioning of PRMs into the gel network and can be stronger levers than formulations parameters for enhancing perfume bloom and longevity. Advisors/Committee Members: Kasting, Dr. Gerald B.

▼ Previous studies on the Italian-American reaction to the Ku Klux Klan in Niles, Ohio primarily discussed the Knights of the Flaming Circle, an anti-Klan organization whose efforts and activities news writers well documented in local papers. Some completed oral interviews of those who experienced the presence of the Klan to supplement the information obtained from newspaper accounts. However, most of these interviews took place in the 1980s, nearly sixty years after the riot between the Knights of the Flaming Circle and the Klan. Furthermore, the age of the interviewees limited the validity of the oral histories. Only one local newspaper, Il Cittadino Italo-Americano, provided an account of the events in the Mahoning Valley through the perspective of Italian-Americans. The newspaper, written in Italian, had scarcely been analyzed for research. It contained valuable information regarding Italian-American attitudes toward the Klan, the United States, and the Mahoning Valley. Most importantly, the newspaper provided evidence of another Italian reaction to the Klan, separate from the Knights of the Flaming Circle. Il Cittadino Italo-Americano called Italian-Americans to participate in the American political process and prove their American citizenship by contributing to Niles society. Il Cittadino Italo-Americano served as the most significant primary source to determine the Italian-American reaction to the Ku Klux Klan. Information gathered from other local newspapers, oral histories, census data, and secondary literature supplemented that obtained from Il Cittadino Italo-Americano. Using these sources, the study proved that another Italian-American reaction against the Klan existed. These Italians were politically active, literate, educated, and considered themselves American citizens. Advisors/Committee Members: Pallante, Martha.

▼ The porphyrins are an important class of chromophores with high stability and efficient light absorption ability in the visible and near-infrared regions of the optical spectrum. They find uses in optoelectronics, magnetic materials, photoconductive materials, non-linear optical materials and photo tumor therapeutic drugs. Porphyrins have a set of highly delocalized ð-orbitals situated on the carbon-nitrogen framework. When such a ligand is coordinated to a centrally-located metal atom of the transition series, having incompletely filled d-orbitals (Ni, Co, Fe, Cu, etc.), the ð- and d-manifolds can interact. As a result the excited state deactivation dynamics becomes very dependent on the electronic nature of the central metal. Advisors/Committee Members: Rodgers, Michael A J.

▼ A nonlinear strain energy based failure model is proposed for fiber reinforced polymer composites. A new strain energy based failure theory is developed to predict matrix failure for a unidirectional laminate. It is shown that the proposed model complies with energy conservation principles for elastic materials. A correction factor is incorporated into the formulation to take into account the influence of transverse stress on the inplane shear resistance. The maximum longitudinal strain criterion is adopted to predict fiber failure. An incremental constitutive model is developed to predict stress-strain response of the material under multiaxial loading, unloading, and reloading conditions. The failure model is extended to multidirectional laminates, using classical lamination theory. An empirical exponential stiffness reduction model is proposed to represent transverse and shear moduli of the laminae embedded in a multidirectional laminate. Model parameters are evaluated using experimental data from the literature. The proposed model is used to predict stress-strain response and failure of unidirectional and multidirectional laminates with various material properties and lay-ups. The predictions are shown to be in agreement with available experimental data. Additional experimental data are obtained by testing S-glass and carbon fiber specimens under combined axial and torsional loads. The experimental observations show that the measured values from different strain gages installed on the same specimen, as well as those installed on similar specimens tested under the same loading conditions are generally in agreement. For some cases the measured strains from different strain gages installed on the same specimen were somewhat different. The proposed model is shown to be capable of predicting stress-strain responses as well as initial and final failures for the tested specimens. Advisors/Committee Members: Wolfe, William E.

▼ Laser light scattering has been used to investigate the structure and hydrodynamic properties of proteoglycans. Two species of proteoglycans have been studied in this work. The first proteoglycan species is that isolated from bovine skin, and is called proteodermatan sulfate (PDS). The second proteoglycan species is isolated from bovine nasal septum cartilage, and exists in two forms: the subunit or monomeric form (PGS), and the aggregate form (PGA), in which PGS units are non-covalently attached to a linear strand of hyaluronic acid (HA). Static light scattering was used to determine the weight-average molecular weight, Mw, z-average radius of gyration, Rgz, and the second virial coefficient, A2. Dynamic light scattering was used to obtain the z-average translational diffusion coefficient, Dtz, which at infinite dilution allows the frictional hydrodynamic radius, Rhf, to be determined using the Stoke's equation. PDS was determined to have a Mw = 62,000 in 4M guanidine hydrochloride (GndHCl), which increased to 610,000 in 0.15M NaCl. The core protein was found to have a Mw = 39,000 in GndHCl, and this also significantly increased to 650,000 in 0.15M NaCl. In contrast, the dermatan sulfate chain (DS) was determined to have a Mw = 24,000 in 0.15M NaCl, indicating minimal self-association. Comparison of the observed translational diffusion coefficient with various hydrodynamic models indicates that PDS has a "lollipop" conformation in dilute solution. The Rgz for PDS (53 nm) and core protein (34 nm) are significantly above expected values for their respective molecular weights. This discrepancy is consistent with a small degree (<5%) of self-association of PDS and core protein in 4M GndHCl. The dilute solution hydrodynamic behavior of PGS and PGA were found to deviate from conventional hydrodynamic theory. Initially, experimental error in the light scattering results was suspected. However, upon further review of proteoglycan literature, as well as literature on star- and comb-branched polymers, it was noted that similar deviations from conventional theory also occurred. Following this observation, a review of more recent hydrodynamic theories was performed, which showed that branched molecular systems are not adequately explained by conventional theory. Finally, the thermal stability of both the PGS and link-stabilized PGA was evaluated. This represents the first time the thermal stability of the subunit was investigated. Advisors/Committee Members: Blackwell, John.

▼ Crystal packing is important in many areas of science. Recent interest in nonlinear optical (NLO) properties have increased the need for the prediction of crystal structures. Yet, the prediction of the crystal packing of small organic molecules had eluded scientists until recently. The highly vectorized computer algorithm ICE9 was developed in our laboratory to aid in the prediction of the crystal packing of such molecules. The program has had good success in the past for predicting the crystal packing of saturated and nearly saturated molecules containing only carbon and hydrogen atoms. In this work, the expansion of the program to allow it to predict the packing of structures also containing oxygen atoms is described. The expanded program provided some insight into the packing of molecules containing oxygen atoms. The importance of the electrostatic interactions involving the oxygen atoms, however, somewhat overwhelmed one of the underlying premises of the program: that the dominant crystallizing forces were due to van der Waals forces and not coulombic forces. As a result, the accuracy of the program was not that achieved previously with the saturated carbons; however, the program is still valuable in showing the general packing patterns and in predicting the most likely structures. Advisors/Committee Members: Klopman, Gilles.