Digital Commons Network^™

Increasing The Corrected Field Of View Of An Adaptive Optical Telescope, Dustin C. Johnston

Theses and Dissertations

Current adaptive optical telescope designs use a single deformable mirror (DM) to compensate for atmospheric distortion. The corrected field of view (FOV) of an adaptive optics system could be increased through the use of multiple DMs optically conjugated to corresponding planes which sample the turbulence region in altitude. Often, the atmospheric turbulence responsible for the degradation of telescope images is concentrated in several layers. Each DM would correct for the component of the total wavefront in the pupil contributed by one or more layers. If the atmosphere does not possess a layered structure, the best fit of the turbulence profile …

Collisional Detachment Of Anions Using Fourier Transform Mass Spectrometry, Kevin B. Riehl

Theses and Dissertations

Fourier Transform Mass Spectrometry (FTMS) is used to make energy resolved ion-neutral reaction measurements at high translational energies (up to several hundred eV). The technique is demonstrated for collisional detachment of anions, and should be easily applied to other inelastic reactions. Collisional detachment cross sections of iodine anions onto gas phase targets of neon, xenon, and trifluoromethyl iodide are measured for 1-300 eV (lab frame). Peak detachment cross sections are roughly 2, 8.5, and 7 Ų, respectively. Ion kinetic measurements show the iodine anion is unreactive in trifluoromethyl iodide at thermal energies. Positive ion chemistry is consistent with …

Factors Influencing Recruitment Of Collegiate Basketball Players In Institutions Of Higher Education In The Upper Midwest, Lori Ulferts

Theses and Dissertations

The purpose of the study was to examine the factors that influenced college basketball players to choose to attend a certain institution of higher education. The secondary purpose was to learn if the perceptions of head college basketball coaches as to reasons for student athletes to choose a college were the same as the student athletes' stated reasons. The study sought to determine what factors influence athletes' decisions and whether those factors differed for female and male athletes, female and male coaches, athletes from different divisions, and coaches from different divisions. The study was intended to contribute to knowledge in …

Inservice Training And Accessing Knowledge: The Perceived Needs Of Parents And Educators Of Children With Special Needs In North Dakota, Randal W. Eckart

Theses and Dissertations

Purpose and procedure. The purpose of this study was to provide a detailed analysis of needs assessment data regarding inservice training and accessing knowledge as perceived by parents, special education teachers, general education teachers, related services providers, and administrators in the state of North Dakota. These five groups were surveyed by the Bureau of Educational Services and Applied Research at the University of North Dakota. Resulting data were statistically analyzed utilizing frequency distributions and percentages to identify perceived needs for accessing knowledge or skills in special education and inservice training.

Conclusions and recommendations. Educators prioritized concerns over programming and instruction …

The Effects Of Chronic Migraine And Tension Headache On Neuropsychological Functioning, Kerri J. Lamberty

Theses and Dissertations

The present study was designed to examine possible neuropsychological deficits in migraine and tension headache subjects. Past research has been inconclusive, with some studies indicating that chronic migraine headache sufferers do exhibit some neuropsychological deficits such as short-term memory difficulties, gross motor slowing, and verbal memory deficits, while other studies have indicated that no deficits are seen in this group Also examined were headache precipitant and headache-related behaviors that these groups partake in when experiencing headache pain. Past research has suggested that migraine headache sufferers tend to deal with their headache pain differently than tension headache sufferers.

Ninety undergraduate psychology …

Excitation And De-Excitation Mechanisms Of Er-Doped Gaas And Algaas, David W. Elsaesser

Theses and Dissertations

Electrical and optical characterization have been performed on GaAs and Al_xGa_1-xAs samples doped with Er either by ion implantation or during Molecular Beam Epitaxial (MBE) growth. Deep Level Transient Spectroscopy (DLTS) and Temperature-Dependent Hall Effect (TDH) measurements indicated the presence of two hole traps in Er-doped GaAs, at 35 and 360 meV above the valence band maximum. The former (shallower) center was thought to be due to Er substituting for a Ga atom (Er_Ga) and giving rise to an isoelectronic impurity potential. The second center was attributed to an Er atom occupying an interstitial …

Identification Of The Initial Transient In Discrete-Event Simulation Output Using The Kalman Filter, Mark A. Gallagher

Theses and Dissertations

Data truncation is a commonly accepted method of dealing with initialization bias in discrete-event simulation. Algorithms for determining the appropriate initial-data truncation point for univariate and multivariate output are proposed. The techniques entail averaging across replications and estimating a steady-state output model in a state-space framework. Using the estimated model, Multiple Model Adaptive Estimation (MMAE), which uses Kalman filters with different parameter vectors, is applied. Based on the filters' residuals, the conditional probabilities of each filter's specific parameter vector being correct are determined. The MMAE parameter estimates are the probabilistic- weighted average of the filters' assumed parameter vectors. The estimated …

A Study Of Ninth Grade Students' Satisfaction With School And Self-Esteem In Two Grade Organization Patterns, Marcia Jane Brokenik Fivizzani

Theses and Dissertations

This study focused on ninth grade students attending school in two grade organization patterns, 7 through 9 and 9 through 12. Students' satisfaction levels with school as measured by the NASSP Student Satisfaction Survey and students' self-esteem measures on the Coopersmith Self-Esteem Inventory were assessed to determine whether a relationship between grade organization, gender, satisfaction with school, and self-esteem existed. Ninth graders from one upper midwest community who attended a four-year high school (N=317) or a 7 through 9 junior high school

Findings revealed that both schools scored within the average range on all subscales of the Student Satisfaction Survey. …

Perceptions About Strategies And Processes Necessary In Minnesota To Integrate Systems To Increase Services To Children And Families, Harold King Larson

Theses and Dissertations

This Minnesota study was intended to obtain, describe, and analyze legislator, state commissioner, and local service providing agency director perceptions of the change strategies and processes which might permit integrated delivery systems and services to increase and improve services to children and families. The specific research questions asked were (1) How do the policymakers and stakeholders perceive the issues which led to the 1990 legislative initiative in Minnesota? (2) Are there consensual perceptions among the policymakers regarding these issues? (3) What are the policymaker and stakeholder perceptions regarding the efficacy of certain (a) change strategies and (b) change processes? Are …

Fantasy Proneness And Psychological Coping, Kenneth D. Huff

Theses and Dissertations

In this study, objective measures of self-esteem, satisfaction with life, trait anxiety, and schizotypal psychopathology were administered to 493 subjects representing the full range of fantasy proneness as determined by their scores on the Inventory of Childhood Memories and Imaginings (ICMI); in addition, subjects selected for high, medium, and low levels of fantasy proneness were administered measures of state anxiety and coping skills during a stressful laboratory condition. This was done in order to contribute to the construct validity of fantasy proneness and to provide empirical inquiry into the nature of fantasy proneness as a psychological coping strategy.

In replication …

Congress And Early Federalist Military Policy: An Examination Of Defense Related Roll Calls In The Second United States Congress, 1792-1793, Elbert S. Barker Iii

Theses and Dissertations

The legislators of the Second United States House of Representatives faced a set of challenging military and political problems when they met in November 1791. The issue of what would be the primary means of the young nation's defense had not yet been determined. The old British and colonial precedents of a militia as the first line of defense were firmly rooted in the minds of most congressmen meeting in Philadelphia. Many of the legislators had been indelibly imprinted with a fear of a large standing army in peacetime from their own personal experiences in the pre-Revolutionary days. Many of …

Competency For Execution: Factors Affecting The Judgement Of Forensic Psychologists, Sharon Brown

Theses and Dissertations

The determination of a death-row inmate's competency to be executed is a compelling ethical issue for mental health professionals. It has been suggested that forensic psychologists who offer such services to the courts may tend to approach the problem of determining competency by diverse and unstandardized methods (Grisson, 1986). Heilbrun (1986) has questioned the effect of the psychologist's potential death penalty bias on the outcome of the evaluation process.

Death penalty attitudes have a demonstrated effect on the decision-making processes of capital jurors who are death-qualified, (willing to impose the death penalty under some circumstances) or excludable (unwilling to consider …

A Morphophonology Of Komo: Non-Tonal Phenomena, John Paul Thomas

Theses and Dissertations

Komo, a sub-Bantu language spoken in northeastern Zaire, exhibits a number of interesting interactions between the morphology and phonology during the process of word derivation. A framework using parametric rule description, underrepresentation of morphemes, and lexical phonology is used in describing non-tonal phenomena of the language. Use of this framework results in optimalizing the description of lexical entries and simplifying the derivation of forms exhibiting complex phonological alternations. Complete paradigms of verbs in a number of tense-aspect-mood configurations are included, even though they may go beyond the requirements of the analysis. This brings to light a language that has not …

Extended Lyapunov Exponents For Second Order Systems, Janice M. Horn

Theses and Dissertations

It is shown that the concept of the Lyapunov exponent can be extended to include an imaginary part. A numerical technique used to calculate these extended Lyapunov exponents for second order systems is presented. There are two requirements to make this extension possible: the definition of a coordinate frame on the tangent space of the differential equation, and an extension of the classical limit, called the limit of the mean. An application of the technique to the van der Pol equation for the constant coefficient and periodic coefficient cases is given. The extended Lyapunov exponents found using this technique totally …

An Approximate Solution For The Linearized Spinup Dynamics Of A Dual-Spin Spacecraft, David L. Kinney

Theses and Dissertations

An approximate solution is obtained for the linearized equations of motion for the spinup dynamics of a dual-spin spacecraft. The approximation is obtained from the WKB (Wentzel, Kramers, and Brillouin) method, which usually generates a divergent series. Comparison between the WKB solution and the numerically integrated solution are used to study the effects of spinup torque magnitude and the number of WKB terms used on the accuracy of the approximation. The WKB method generates accurate approximations for small spinup torques using as few as two terms in the series when no singularities are present in the WKB terms during the …

An Experimental Determination Of The Effects Of Blending Collocated And Non-Collocated Sensor Measurements To Control A Flexible Structure, Richard G. Cobb

Theses and Dissertations

An experimental investigation was performed controlling a cantilevered beam in bending using proportional feedback on a blend of collocated and non-collocated sensor measurements using a single actuator. Exact transfer functions between the control input and the measurements were developed and compared to the finite element method. By analyzing the open loop pole-zero locations as a function of the measurement blending, insight into the closed loop behavior is obtained. Minimum phase behavior can be maintained for a range of the blending ratio. Results using blended control were compared to both proportional collocated feedback and compensated collocated feedback using LQG methods. The …

Solving Nonlinear Composite Material Problems Using The Automated Structural Optimization System (Astros), Robert Bolha

Theses and Dissertations

Most advanced composite materials have nonlinear stress versus strain curves--grossly so in the laminas shear direction. If linear approximations are used, overly conservative design will result. This thesis expands the usefulness of the Automated Structural Optimization System (ASTROS) finite element (FE) program by incorporating a newly developed capability to include material nonlinearities. By dividing a FE problem into several intervals, and incorporating the changing nature of the nonlinear material properties within each element, a good approximation of the laminate's actual stresses and strains can be obtained without the undue experimentation involved in testing every individual configuration. Each material property is …

An Electromagnetically-Controlled Precision Orbital Tracking Vehicle (Potv), Richard E. Lawrence Jr.

Theses and Dissertations

A propulsion configuration it defined for a precision orbital tracking vehicle (POTV) that employs electrodynamic forces to control vehicle attitude and position with respect to another spacecraft. A pair of electrically powered thrusters assist the POTV in position control. The vehicle can maintain continuous standoff at close range from another spacecraft in any direction, has docking capability, and has gross orbital transfer capability. These capabilities and the specific design derived for the POTV have been defined by the requirements of a postulated space facility (ASSET) that salvages structural aluminum from the external fuel tank of the space shuttle. Precision control …

Power Analysis In Flexible Automation, Nathan A. Titus

Theses and Dissertations

The performance of an automation or robotic device can be measured in terms of its power efficiency. Screw theory is used to mathematically define the task instantaneously with two screws. The task wrench defines the effect of the device on its environment, and the task twist describes the motion of the device. The tasks can be separated into three task types: kinetic, manipulative, and reactive. Efficiency metrics are developed for each task type. The output power is strictly a function of the task screws, while device input power is shown to be a function of the task, the device Jacobian, …

Canonical Floquet Perturbation Theory, David J. Pohlen

Theses and Dissertations

Classical Floquet theory is examined in order to generate a canonical transformation to modal variables for periodic system This transformation is considered canonical if the periodic matrix of eigenvectors is symplectic at the initial time. Approaches for symplectic normalization of the eigenvectors had to be examined for each of the different Poincare eigenvalue cases. Particular attention was required in the degenerate case, which depended on the solution of a generalized eigenvector. Transformation techniques to ensure real modal variables and real periodic eigenvectors were also needed. Periodic trajectories in the restricted three-body case were then evaluated using the canonical Floquet solution. …

Rewet Performance Of A Rectangular Grooved Heat Pipe Wick After Gravitationally Induced Dryout, Lowell S. Hawthorne

Theses and Dissertations

The effects of increased acceleration forces on the transient dryout and rewet performance of an axial groove heat pipe wick were experimentally studied using inclination to simulate increased acceleration forces. Two durations of increased acceleration were investigated, one being less than the time required for the groove to reach steady-state dryout conditions, the other being sufficient to ensure the groove had reached steady-state dryout conditions. The groove's extent of dryout was found to be greater at increased levels of acceleration. The period of time required for the groove to rewet after an acceleration induced dryout increased as acceleration increased. The …

Data Reduction With Least Squares Differential Correction Using Equinoctial Elements, Michael S. Wasson

Theses and Dissertations

This study investigates earth satellite orbit estimation on a track of range, azimuth, and elevation data from a single tracking station. The estimation routine is a least squares batch filter based solely on two-body orbital motion. Using equinoctial elements for the reference orbit avoids the numerical difficulties of the classical elements at eccentricities near zero and inclinations near zero or 90 degrees. Orbits for Mir, DMSP, Explorer, Cosmos, and GPS are investigated. The goal of this study is to reduce orbit information from observations (range, azimuth, and elevation) to an element set and a covariance matrix without considering perturbation effects. …

Effect Of Transverse Vibration On The Capillary Limit Of A Wrapped Screen Wick Copper/Water Heat Pipe, Mark C. Charlton

Theses and Dissertations

The effect of transverse vibration on the capillary limit of a copper/water heat pipe with a tightly wrapped screen wick was investigated. The capillary limit was measured over a range of operating temperatures under static conditions. A bench-top shaker was used to provide vibration normal to the longitudinal axis of the pipe, and the capillary limit was measured at vibration frequencies of 30, 250, and 1000 Hz. At each of these frequencies, tests were run at vibration levels of 1.0, 2.5, and 5.0 G. The pipe was maintained at a zero degree inclination angle and power throughput was increased until …

Passive Damping Of A Solar Array, Mark A. Scharpen

Theses and Dissertations

This study was an attempt to conceptualize, design, build, and test a constrained layer damping device that uses mechanical advantage for the purpose of increasing the damping of transient vibration of a five-bay planar truss. The aluminum truss was clamped to a fixed support and simulated a solar array. A conventional constrained layer treatment was designed, built, and tested to serve as a benchmark for comparison. For the conventional treatment, Plunkett and Lee's segmented constraining layer technique was used. The improved device, two three-layer sandwich beams spanning the two bays nearest the built-in end, were supported several inches away from …

Nonlinear Large Displacement And Moderate Rotational Characteristics Of Composite Beams Incorporating Transverse Shear Strain, Stephen G. Creaghan

Theses and Dissertations

This research was directed toward the investigation of nonlinear large displacements and moderate rotations of composite beam structures considering a finite element potential energy approach incorporating through the thickness shear strain as an analytical function. This approach was compared to large rotation theories. Test cases were run to evaluate numerical algorithms Riks method and displacement imposed techniques were employed. The limitations and advantages of both methods were considered. Loading arrangements included concentrated forces as well as moments.

Baseline Experiments On Coulomb Damping Due To Rotational Slip, John P. Santacroce

Theses and Dissertations

Two experimental pin-type joint models are developed to study the effects of Coulomb Damping due to rotational slip. Model One is an inverted beam allowed to pivot at one end as a pendulum. Model Two is a horizontally mounted beam allowed to pivot about its center. The equations of motion for the joint geometries, considering only macro-slip friction, are developed and solved. Theoretical and experimental results for the response of the models in vibration are presented showing energy dissipation versus clamping force for the joint(s).

A Study Of Heat Flux Induced Dryout In Capillary Grooves, Timothy J. Murphy

Theses and Dissertations

This is an experimental study of ethanol flowing in the narrow grooves of a copper plate which is subjected to heat fluxes sufficient to evaporate more liquid than can be replaced by capillary pumping. Three groove geometries are used: square, rectangle, and trapezoid. The objective is to simulate aspects of liquid flow in heat pipes with axial grooves. In order to validate analytical models of capillary flow in grooves, the capillary limit, dryout front location, and dryout front movement in response to power draw downs are documented. The results show the rewet performance of the groove is dependent on geometry. …

Comparative Educational Policies Between The United States And Japan, Mieko Kurihara

Theses and Dissertations

No abstract provided.

Childhood Sexual Abuse As An Antecedent Of Problem Drinking And Sexual Dysfunction In Women, Sue Ann Russell

Theses and Dissertations

A number of studies have linked childhood sexual abuse to problems with alcohol and sexual dysfunction in adult women. Moreover, some researchers suggest temporal sequences in which either (a) early sexual abuse increases women's risks of sexual dysfunction, which in turn leads to increased alcohol use, or (b) the reverse, in which sexual abuse contributes to excessive drinking, which in turn impairs sexual functioning.

Most studies of these issues to date have had serious methodological problems (e.g., small samples, often from clinical populations lacking control groups). Additional limitations have been the limited range of variables measured and the lack of …

Affixes Of Salasca Quichua With Special Attention To Derivational Affixes Which Attach To Verbs, Kristine E. Waskosky

Theses and Dissertations

This thesis is a synchronic description of the morphology of Salasaca Quichua (SQ) with extensive examples in interlinear texts. The meaning of each suffix and its order relative to other suffixes is described. A more expanded description is given for each of the deverbalizers (suffixes which create non-finite verbs), especially their use in subordinate clauses.

SQ is a member of the family of languages called Quechua A or Quechua II. It is an agglutinating language with up to six suffixes possible on a single root. Derivational suffixes, of which there are 15 possible for verb formation and 16 for noun …