• 2 μm Pulsed Fiber Laser Sources and Their Application in Terahertz Generation

      Fang, Qiang (The University of Arizona., 2012)
      In this dissertation, an all-fiber-based single frequency nanosecond pulsed laser system at ~ 1918.4 nm in master-oscillator-power-amplifier (MOPA) configuration is present. The nanosecond pulse seed is achieved by directly modulating a continuous wave (CW) single frequency fiber laser using a fast electro-optical modulator (EOM) driven by an arbitrary waveform generator (AWG). One piece of single mode, large core, polarization-maintaining (PM) highly thulium-doped (Tm-doped) germanate glass fiber (LC-TGF) is used to boost the pulse power and pulse energy of these modulated pulses in the final power amplifier. This laser system can work in both high power and high energy regime: in high power regime, to the best of our knowledge, the highest average power 16 W and peak power 78.1 kW are achieved for single frequency transform-limited ~2.0 ns pulses at 500 kHz and 100 kHz repetition rate, respectively: In high energy regime, nearly 1 mJ and half mJ pulse energy is obtained for ~15 ns pulses at 1 kHz repetition rate and 5 kHz repetition rate, respectively. Theoretical modeling of the large-core highly Tm-doped germanate glass double-cladding fiber amplifier (LC-TG-DC-FA) is also present for 2&mum nanosecond pulse amplification. A good agreement between the theoretical and experimental results is achieved. The model can simulate the evolution of pump power, signal energy, pulse shape and the amplified stimulated emission (ASE) in the amplifier. It can also be utilized to investigate the dependence of the stored energy in the LC-TGF on the pump power, seed energy and repetition rate, which can be used to design and optimize the LC-TG-DC-FA to achieve higher pulse energy and average power. Two channel of high energy nanosecond pulses (at 1918.4 nm and 1938 nm) are utilized to generate THz wave in a quasi-phase-matched (QPM) gallium arsenide (GaAs) based on difference frequency generation. THz wave with ~ 5.4μW average power and ~18 mW peak power has been achieved. Besides, one model is built to simulate a singly resonated THz parametric oscillator. The threshold, the dependence of output THz energy on pump energy has been investigated through this model. One pump enhanced THz parametric oscillator has been proposed. The enhancement factor of the nanosecond pulses in a bow-tie ring cavity has been calculated for different pulse duration, cavity length and the transmission of the coupler. And the laser resonances in the ring cavity have been observed by using a piezo to periodically adjust the cavity length. We also build an all-fiber thulium-doped wavelength tunable mode-locked laser operating near 2&mum. Reliable self-starting mode locking over a large tuning range (>50 nm) using fiber taper based carbon nanotube (FTCNT) saturable absorber (SA) is observed. Spectral tuning is achieved by stretching another fiber taper. To the best of our knowledge, this is the first demonstration of an all-fiber wavelength tunable mode-locked laser near 2&mum.
    • Accessing the mental lexicon in spoken word production: Masked priming effects in picture naming.

      Xing, Kongliang. (The University of Arizona., 1995)
      This dissertation investigated the process of lexical access in spoken word production by using a picture naming task which involves very similar processes. Experiment 1 showed that significant repetition priming effect was obtained in this task when the prime was heavily masked and was unavailable to conscious report. In addition, the repetition effect was independent of word frequency. However, a pattern of frequency attenuated priming effects was obtained in Experiment 2 when the prime was unmasked and was named about 10 minutes previously. These results suggest that the masked repetition effect is lexical in nature, whereas the unmasked effect is contaminated by non-lexical sources, such as auditory episodic memory. Experiment 3 showed that the masked repetition effect was independent of the neighborhood density of target names, but the masked form-priming effect was highly constrained by the density. Further, Experiment 4 showed that once the form-related prime became phonologically identical to the picture name the form-priming effect was no longer constrained by the density. In order to distinguish which processing component (lexicalization or production) was responsible for the elimination of the constraint, a picture-fragment matching task was used. Experiment 5A showed that in the matching task, repetition effects were significant and independent of neighborhood density. In contrast with Experiment 4, Experiment 5B showed that the form-priming effect was highly constrained by the density in the matching task. These experiments suggest that (1) the process of phonological encoding is automatic and extremely fast; and (2) the phonological encoding is a necessary process for production but not for lexicalization. In addition, no masked associative priming was obtained in either a picture naming task (Experiment 6) or a picture categorization task (Experiment 7), suggesting that masked priming effects obtained in the present picture processing tasks were not due to facilitation occurring at the semantic or conceptual level. Finally, the robust frequency effects established in picture naming tasks were severely weakened when a picture-fragment matching task was used (Experiment 8). This pattern of results suggests that frequency influences mainly name production rather than name retrieval in picture naming.
    • The accretionary history of the Alexander terrane and structural evolution of the Coast Mountains batholith: Evidence from geologic, geochronologic, and thermobarometric studies in the Petersburg region, central southeastern Alaska.

      McClelland, William Cabell. (The University of Arizona., 1990)
      Rocks west of the Coast Mountains batholith in central southeastern Alaska include the Alexander terrane, Gravina belt, Taku terrane, and newly defined Ruth assemblage. Geologic, geochronologic and thermobarometric studies of these rocks in the Petersburg region provide new constraints on the accretionary history of the Alexander terrane and structural evolution of the Coast Mountains batholith. Paleozoic and Upper Triassic strata of the Alexander terrane were deformed within the Duncan Canal shear zone. Dextral shear in this zone during Early or Middle Jurassic time is inferred to reflect deformation along the eastern margin of the Alexander terrane and record the juxtaposition of the Alexander terrane with the North American margin. Deposition of the Upper Jurassic-Lower Cretaceous Gravina belt occurred within a transtensional back-arc to intra-arc basin that evolved during the northward translation of the Alexander terrane. The Ruth assemblage and Taku terrane were structurally emplaced over the Gravina belt and Alexander terrane along the Sumdum-Fanshaw fault system during mid-Cretaceous time. West-vergent thrusting of the Ruth assemblage was accompanied by metamorphic P,T conditions of 6.8 kb, < 450°C in the Gravina belt and 6.9 to > 7.4 kb, > 550°C in the Ruth assemblage. The age of deformation is constrained by syntectonic and post tectonic intrusive bodies that yield U-Pb lower intercept apparent ages of 92.3 ± 3 Ma and 91.3 ± 6.3 Ma, respectively. Late Devonian-Mississippian orthogneiss and felsic metavolcanic rocks in the Ruth assemblage suggest correlation of the assemblage with continental margin rocks of the Yukon-Tanana and Nisling terranes east of the Coast Mountains batholith. Thus the mid-Cretaceous Sumdum-Fanshow fault system marks the fundamental boundary between the Alexander terrane and inboard fragments. This deformation records the final structural accretion of the Alexander, Wrangellia, and Peninsular terranes to the western margin of North America. The mid-Cretaceous thrust system is truncated to the east by the LeConte Bay shear zone: a complex zone of Late Cretaceous-early Tertiary fabrics that occur within and west of the Coast Mountains batholith. This zone has apparently accommodated both west-side-up and east-side-up displacement during the collapse of the overthickened crust developed during mid-Cretaceous time.
    • ACQUISITION OF CLINICAL INTERVIEWING SKILLS OF STUDENTS PREPARING FOR THE MEDICAL PROFESSION.

      BURPEAU-DI GREGORIO, MICHELE YOUNG. (The University of Arizona., 1982)
      The ability to gather accurate and complete information is important in scientific endeavors and the field of medicine is no exception. The medical interview is one of the primary methods by which the physician gathers information. His/her method should be no less than that used by the scientist. There are two components to the medical interview: The content, or the specific information, and the process, or the method by which the information is obtained. Traditional methods for teaching interviewing skills to medical students emphasized an on-the-job type of experience with students going out on the wards to interview actual patients. The method had several problems including lack of standardized methods of teaching and evaluating. This dissertation looks at a competency-based method of teaching and evaluating medical interview skills used at The University of Arizona College of Medicine. It uses patient instructors (PIs) to objectively evaluate interviewing skills. PIs are highly trained non-physicians who have been trained to function as patients, teachers, and evaluators. Analysis of the data collected on student interview performance from the classes of 1982-1984 indicated that there was no significant difference in content or process scores due to sex or prior occupational experience in a health-related profession. However, significant differences were found in content and process scores due to the age of the interviewer with students older than the class average scoring higher than the younger students.
    • Actual and Ideal Roles of Music Teachers in Community Schools of the Arts Pertaining to Community, School, and the Profession

      Fischler, Gail (The University of Arizona., 2007)
      The purpose of the study was:1. To develop an inventory of music teacher roles which pertained to the setting, community schools of the arts (CSAs).2. To discover how music teachers perceive their actual job roles vs. their ideal job roles in CSAs.An instrument was structured using the roles found in the work of Onderdonk (1995), Barnes (1972), Moller (1981), White (1964), and input from experts. Roles were categorized into three areas: community, school, and professional. The population of teachers was drawn from member schools of the National Guild of Community Schools of the Arts (NGCSA) for the year 2005-2006. The final study population consisted of 139 CSA teachers from 16 schools across the USA.Overall, teachers indicated that roles in the professional category were and should be performed more often than community and school roles. The school and community categories were deemed equal to each other (actually and ideally). Teachers indicated that community, school, and professional roles in CSAs were complex, consisting of 31 roles (7 community, 10 school, and 14 professional). A ranked and tiered inventory of the 31 valid roles and a portrait of the CSA music teacher were created. As an aggregate, teachers ideally desired to increase the frequency with which they performed the following roles: Advocate, Attendee of Faculty/Committee Meetings, Attendee of School Activities, Performer/Demonstrator/Coach, and Student/Lifelong Learner. As an aggregate, teachers desired to decrease the frequency with which they performed the role of School Leader. Teachers indicated balance in regard to modeling, performing, parental education, discipline, tradition, and leadership.Implications for CSA administrators, personnel of the National Guild of Community Schools of the Arts, teacher educators and trainers, and future research include: finding paths to develop part-time leaders, developing content for coursework and professional development specific to CSA teachers, and promoting awareness that investment in current/future teachers should be given similar value and energy to fundraising efforts. In order to educate/train future CSA teachers, coursework which includes preparation as instrumental/pedagogical experts, as well as content which provides training in educational philosophy, history, curriculum development, role modeling, culture, and technology were recommended.
    • AdaptiSPECT: a Preclinical Imaging System

      Chaix, Cécile (The University of Arizona., 2015)
      This dissertation addresses the design, development, calibration and performance evaluation of a pre-clinical imaging system called AdaptiSPECT. Single-Photon Emission Computed Tomography (SPECT) systems are powerful tools for multiple applications in small-animal research, ranging from drug discovery to fundamental biology. Traditionally, pinhole SPECT systems are designed with fixed imaging characteristics in terms of sensitivity, resolution and size of the field of view, that are dictated by the hardware configuration of the system. The SPECT system described in this dissertation can change its hardware configuration in response to the subject data it is acquiring in order to improve the imaging performance. We employed 16 modular gamma-ray detectors, each of which consists of a NaI:Tl scintillation crystal, a fused silica lightguide, and an array of 9 PMTs. The camera is designed to work with maximum-likelihood position estimation methods. These detectors are arranged into 2 rings of 8 detectors around an adjustable pinhole aperture. The aperture itself comprises three cylinders of different diameters, each with pinholes of different diameters. The three aperture cylinders are stacked together along the imager axis, and selection of the appropriate ring of pinholes is carried out by translating the entire aperture assembly. In addition, some sections of the aperture are fitted with shutters to open or close additional pinholes that increase sensitivity. We reviewed the method used to calibrate AdaptiSPECT, and proposed a new interpolation scheme specific to adaptive SPECT imaging systems where the detectors can move to multiple locations, that yields system matrices for any configuration employed during adaptive imaging. We evaluated the performances of AdaptiSPECT for various configurations. The magnification of the system ranges from 1.2 to 11.1. The corresponding resolution ranges from 3.2 mm to 0.6 mm, and the corresponding transaxial field-of-view ranges from 84 mm to 10 mm. The sensitivity of the system varies from 220 cps/MBq to 340 cps/MBq for various configurations. Imaging of a mouse injected with a bone radiotracer revealed the finer structures that can be acquired at higher magnifications, and illustrated the ability to conveniently image with a variety of magnifications during the same study. In summary, we have brought the concept of an adaptive SPECT imaging system as it was originally described by Barrett et al. in 2008 to life. We have engineered a system that can switch configurations with speed, precision, and repeatability suitable to carry out adaptive imaging studies on small animals, thus opening the door to a new research and medical imaging paradigm in which the imager hardware is adjusted on the fly to maximize task-performance for a specific patient, not, as currently, an ensemble of patients.
    • Adult Outcomes, Reported Self-Aptitude, and Perceived Training: A Follow-up Study of Individuals with Visual Impairment

      Lawson, Holly Michelle (The University of Arizona., 2010)
      The purpose of this study was to examine factors that relate to successful adult outcomes for 28 individuals with visual impairment ages 23-30. The primary dependent variable was current employment. Independent living and completion of postsecondary educational program were secondary, related outcome measures. A secondary goal of this research was to explore self-perceived aptitude in specific skills that are related to adult outcomes and to understand how and how well participants learned these skills.A mixed-methods design was implemented and quantitative and qualitative data were collected using a highly structured 151-item telephone survey. A series of Fisher's Exact and Mann Whitney-U tests were run to explore statistically significant relationships between variables. Past employment experience was positively related to current employment. Receipt of Social Security benefits and profound vision loss were negatively related to current employment. The longer a participant had been out of high school, the more likely he/she was to have a postsecondary educational degree.Eight essential skills were examined: daily living, college preparation, social, self-advocacy, technology, transportation management, and job seeking. Overall on a scale of 1-10, participants rated their aptitude and training in essential skills areas high. Job seeking was scored the lowest and those who had worked in the past five years rated their job seeking skills higher than those without past work experience. Adults who had completed a postsecondary educational degree rated their college preparation skills higher than those who had not completed a degree program. Those who were living independently rated their overall daily living skills higher than those who were living with a parent or parents.Qualitative data suggest that some skills, such as transportation management and technology, were taught primarily by professionals in the field of visual impairment. In contrast, daily living, social and self-advocacy skills were often learned from the support of family or friends. Many adults reported that they did not receive direct instruction in social and self-advocacy skills; instead they learned them on their own. Further empirical research is needed to understand best practices for integrating effective instruction in compensatory training and their relationship to successful adult outcomes.
    • Aging and Behavioral Health: Power and Accountability in Outsourced Public Policy Implementation

      Fry, Melissa Sue (The University of Arizona., 2005)
      Devolution of the welfare state brings with it problems of democratic accountability to taxpayers, equality and uniformity in services, and the protection of vulnerable service populations. This research contributes to discussions of devolution and outsourcing by exploring the role of service populations in shaping the relationship between policy formation and implementation and the implications of this relationship for accountability in public policy implementation. A comparative analysis of community based services in aging and behavioral health illuminates the role of political power, professional interests, and organized advocacy in policy formation and implementation. The study pools evidence from legislative histories, newspaper archives, field observations, and surveys to provide a detailed account of the relationship between legislation and implementation. The findings suggest that the political power of service populations affects public policy formation, and written policies structure implementation organizations. Strengths and weaknesses of legislation are transferred to the organizations of implementation as state policies determine the constraints and resources that structure implementation organizations.
    • ALCOHOL CONSUMPTION AMONG IRISH-AMERICANS AND JEWISH-AMERICANS: CONTRIBUTIONS FROM ARCHAEOLOGY.

      STASKI, EDWARD. (The University of Arizona., 1983)
      Archaeological methods can contribute to the understanding of current human issues, including the use and abuse of alcohol in American society. Popular stereotypes concerning drinking have influenced scholarly descriptions and interpretations. There is, for instance, widespread and questionable acceptance by researchers that ethnic identification often correlates strongly with rates of alcohol consumption. Through refuse analysis, this study suggests that no such correlation exists, at least as far as household alcohol use is concerned. Instead, it is found that the degree of social heterogeneity within households, causing stress among individuals, is positively associated with consumption rates. Ethnicity might be related more closely to expressed attitudes about drinking, though results are inconclusive. The archaeological investigation of late 19th century drinking habits is possible, and might contribute to historical studies in a way similar to how this study contributes to sociological and psychological approaches.
    • Almost Poisson Brackets for Nonholonomic Systems on Lie Groups

      Garcia-Naranjo, Luis Constantino (The University of Arizona., 2007)
      We present a geometric construction of almost Poisson brackets for nonholonomic mechanical systems whose configuration space is a Lie group G. We study the so-called LL and LR systems where the kinetic energy defines a left invariant metric on G and the constraints are invariant with respect to left (respectively right) translation on G.For LL systems, the equations on the momentum phase space, T*G, can be left translated onto g*, the dual space of the Lie algebra g. We show that the reduced equations on g* can be cast in Poisson form with respect to an almost Poisson bracket that is obtained by projecting the standard Lie-Poisson bracket onto the constraint space.For LR systems, we use ideas of semidirect product reduction to transfer the equations on T*G into the dual Lie algebra, s*, of a semidirect product. This provides a natural Lie algebraic setting for the equations of motion commonly found in the literature. We show that these equations can also be cast in Poisson form with respect to an almost Poisson bracket that is obtained by projecting the Lie-Poisson structure on s* onto a constraint submanifold.In both cases the constraint functions are Casimirs of the bracket and are satisfied automatically. Our construction is a natural generalization of the classical ideas of Lie-Poisson and semidirect product reduction to the nonholonomic case. It also sets a convenient stage for the study of Hamiltonization of certain nonholonomic systems.Our examples include the Suslov and the Veselova problems of constrained motion of a rigid body, and the Chaplygin sleigh.In addition we study the almost Poisson reduction of the Chaplygin sphere. We show that the bracket given byBorisov and Mamaev is obtained by reducing a nonstandard almost Poisson bracket that is obtained by projecting a non-canonical bivector onto the constraint submanifold using the Lagrange-D'Alembert principle.The examples that we treat show that it is possible to cast the reduced equations of motion of certain nonholonomic systems in Hamiltonian form (in the Poisson formulation) either by multiplication by a conformal factor, by the use of nonstandard brackets or simply by reduction methods.
    • ALTERATIONS OF SUBSTANCE P-CONTAINING NEURONS AS CLUES TO THE ROLE OF THE PEPTIDE IN THE MAMMALIAN PERIPHERAL NERVOUS SYSTEM.

      BUCK, STEPHEN HENDERSON. (The University of Arizona., 1982)
      The effects of capsaicin, the major pungent component of hot peppers, were assessed on neuropeptide levels and on sensory function in neonatal and adult rats and in adult guinea pigs. Systemic doses of capsaicin in rats treated while neonates or while adults produced marked depletion of substance P (SP) in dorsal roots plus ganglia (DRG) and in dorsal spinal cord without altering tail-flick latencies in the treated animals. Guinea pigs had several-fold higher levels of SP than did rats in DRG and dorsal cord. In adult guinea pigs, systemic doses of capsaicin as low as 2.5 mg/kg depleted SP in DRG while a 10 mg/kg dose depleted the peptide maximally in DRG (85% decrease) and in the dorsal cord (35% decrease). High doses of capsaicin in guinea pigs had no consistent effects on levels of radioimmunoassayable cholecystokinin (CCK), vasoactive intestinal polypeptide, or somatostatin although a transient decrease in CCK levels was observed four days after dosing in DRG and in ventral cord. A single 5 mg/kg dose of capsaicin rendered animals completely insensitive to chemical irritation of the cornea without affecting sensitivity to noxious heat. Higher doses of capsaicin produced a marked insensitivity to nociceptive and non-nociceptive heat as well as to chemical irritation without affecting other sensory modalities. The SP depletion and sensory deficits produced by a single 50 mg/kg dose of capsaicin were still evident ten weeks later. The pattern of selectivity of the sensory deficits produced by capsaicin differed from that produced by morphine which was active against all forms of nociceptive stimuli. High doses of capsaicin also induced skin lesions and corneal opacities in guinea pigs. The syndrome of sensory effects produced by capsaicin in guinea pigs closely resembles the pattern of sensory deficits in familial dysautonomia, an autosomal recessive disorder in which there is a disappearance of SP from the substantia gelatinosa of the spinal cord. The results indicate that in the guinea pig capsaicin is potent at producing a unique, long-lasting syndrome of peripheral sensory deficits that may result from an action of the compound on SP-containing primary afferent neurons. Capsaicin is a valuable pharmacological tool for investigation of the neurochemistry and neurophysiology of primary afferent neurons and animals treated with the agent may be useful laboratory models of some forms of peripheral neuropathy.
    • AN ALTERNATIVE APPROACH TO INFLATION MEASUREMENT.

      KINONEN, RICHARD EUGENE. (The University of Arizona., 1982)
      The major economic policy issue of the 1980s is inflation. Although economists have been writing about inflation for several decades, little work has been done on the theory of inflation measurement. There is an extensive literature dealing with the statistical aspects of price indices and the inflation phenomenon. However, statistical discussions ignore the economic theory behind inflation measures and inflation discussions fail to address the practical aspect of measurement of inflation. This dissertation develops an inflation measure that overcomes these failings. By combining the principles of price formation found in microeconomic literature with the macroeconomic theory of inflation, an economically appropriate measure of inflation is presented. The measure adopts the Marshallian view that producers fix prices and vary output in response to market conditions. Recognizing that production takes time which leads to uncertainty about the forward delivery market, the measure stresses both labor and material input costs as the prime price determinants. Contracts fix these costs. Current or spot market demand influences prices only in the service sector. This influence is measured and added to the price forming factors determined in oligopoly, monopoly and competitive sectors. The four sectors are combined with a measure of government price influence to generate the measure of inflation. A highly stylized model of this measure is tested monthly for the 1965-78 period. The theoretical measure and the model results are then compared to conventional inflation measures. The CPI, GNP deflator and WPI are discussed and their problems as measures of inflation are assessed. The measure proposed and tested here eliminates much of the sampling bias, substitution bias, and quality bias plaguing the others. Being designed as a measure of inflation in the general price level, the proposed measure actually incorporates the broad economic base necessary for a macroeconomic measure. It provides a useful policy guide for inflation management and an appropriate measure of the policy's success.
    • Alternative economic institutions to motivate managerial disclosure of private information: An experimental markets examination.

      Wallin, David Ernest. (The University of Arizona., 1990)
      A central consideration in constructing a theory of the firm is the divergent preferences of managers and investors. Managers have incentives to take actions (shirk, consume perquisites) not in the best interests of the firm. Accounting reports are a primary method by which managers make assertions about their actions or the results of their actions. Auditing is a mechanism by which managers can purchase external verification of their disclosures. This dissertation develops the demand for auditing in two multiperiod environments. The first environment allows the manager to disclose with impunity. In such a case the manager's demand for auditing depends on the ability of the manager to obtain the cooperative solution without auditing. The second environment permits the investors to bring suit against a manager suspected of issuing fraudulent disclosures. In that environment, a cooperative solution can be obtained without auditing. The results of 16 experiments designed to test the analytical assertions suggests that there is a demand for auditing, regardless of whether or not legal recourse is present. Both the availability of auditing and the availability of legal recourse induces a higher level of managerial effort. The highest level of managerial effort was seen when both auditing and legal recourse were available, despite the prediction that the presence of a legal system would make auditing useless. The investors tended to overbid and the markets with auditing reduced that tendency. Truthful disclosures were generally only seen when legal recourse was available.
    • American foreign policy: Arms transfers to the Middle East, 1960-1990: Testing competing theories.

      Hayajneh, Adnan Mohammad Hussin. (The University of Arizona., 1995)
      This study investigated American arms transfer policy in the Middle East from 1960 to 1990. Five independent hypotheses have been formulated using explanations for arms transfers drawn from the academic theoretical literature on international relations as well as policy and popular interpretations. The dissertation tested all five hypotheses for their respective explanatory power in understanding United States arms transfers to the Middle East during a key thirty-year period, using a mix of techniques including a comprehensive overview of each factor, historical and objective grounding for each factor and a systematic inquiry using both qualitative and quantitative methods. The five individual hypotheses focus on Soviet arms transfers to the region, the regional balance of power, the "Israeli factor," the Arab-Israeli peace process and the "Oil factor". Data was collected to test each of these hypotheses. The results include the following: a modest action-reaction pattern in superpower arms transfer to the region does exist, with more support for a US reactionary policy to the Soviet Union than the opposite; US transferred arms to the hegemon's challengers to maintain a balance of power system in the Middle East; US arms transfers to Arab states were not strongly related as leads to US arms transfers to Israel; it was found that US peace attempts are moderately correlated with US arms transfers to the involved states; and, finally US arms transfers were strongly correlated with the oil factor. The dissertation concluded that political considerations and economic factors are equally salient depending on the type of cases studied. The results provided insights on the multiple explanations for understanding United States arms transfer policies to the Middle East and produced findings that will have policy implications for policy toward a volatile region of the world in the post-Cold War era, as well as for our understanding of a key component of United States foreign policy in general.
    • ANAEROBIC - AEROBIC TREATMENT OF DOMESTIC SEWAGE

      Banihani, Qais Hisham (The University of Arizona., 2009)
      Domestic wastewater is the most abundant type of wastewater. Direct discharge of untreated domestic wastewater has environmental and public health risks due to the presence of organics, nutrients and pathogens. Application of anaerobic processes for the treatment of domestic sewage, which at present is largely treated by aerobic processes, has drawn considerable attention recently. Anaerobic processes can be applied for the removal of organic matter (methanogenesis) and nitrogen (anaerobic ammonium oxidation (Anammox)).The toxicity of fluoride to methanogenesis was investigated. The results indicate that acetoclastic were more susceptible to fluoride than hydrogenotrophic methanogens. The concentration of fluoride causing 50% inhibition (IC50) to acetoclastic ranged from 18.1 to 155.7 mg L-1 while for hydrogenotrophic methanogens was > 400.0 mg L-1.The feasibility of a combined system consisting of anaerobic up-flow anaerobic sludge blanket (UASB) followed by aerobic activated sludge (AS) reactor for removal of carbonaceous and nitrogenous contaminants from strong synthetic sewage (2.5 g chemical oxygen demand (COD) L-1) was also studied. The average combined removal of total COD, volatile fatty acids (VFA) and protein was higher than 89.0%, 99.0% and 97.0%; respectively. Extensive nitrification (96.0%) was observed when dissolved oxygen (DO) concentration was > 2.0 mg L-1. In contrast, only partial nitrification occurred when the AS received high organic loads and/or the DO level was below 2.0 mg L-1.The inhibitory effect of nitrite and nitrate on methanogenesis was evaluated. Methanogenic activity was inhibited by the presence of NOx- compounds (i.e., nitrite and nitrate). The inhibition imparted by nitrate was not due to the nitrate itself, but rather to its reduced intermediate, nitrite. The toxicity of NOx- to methanogens was found to be reversible after all the NOx- were reduced during denitrification.Moreover, the development of Anammox enrichment cultures was evaluated. Anammox cultures were successfully developed using sludge samples collected from municipal wastewater treatment plants (WWTPs) as inocula but not from methanogenic granular sludges. Return activated sludge (RAS) collected from WWTP operating for biological nitrogen removal had the highest intrinsic level of Anammox activity. RAS Anammox culture was developed rapidly within 40 days with a doubling time of 6.8 days.
    • Analysis and Informative Interviews to Aid in the Performance Practice of the Concerto for Marimba and String Orchestra by Eric Ewazen

      Latta, Jonathan Ryan (The University of Arizona., 2009)
      ANALYSIS AND INFORMATIVE INTERVIEWS TO AID IN THE PERFORMANCE PRACTICE OF THE CONCERTO FOR MARIMBA AND STRING ORCHESTRA BY ERIC EWAZENThe research found in this document will assist in a performer's preparation of Dr. Eric Ewazen's Concerto for Marimba and String Orchestra. In order to give an informed performance of the work, it is this author's belief that an understanding of the collaboration between the composer and the premiering artist, Ms. She-e Wu, as well as the impact Ms. Wu's artistry had on Dr. Ewazen is paramount. Also, knowledge of Dr. Ewazen's compositional style, reference to his other works for percussion, and an understanding of the structure of the work will assist future performers in demonstrating a well-versed and rewarding performance of the piece. This study presents insightful interviews from both the composer and the premiering artist. These interviews offer a wealth of understanding into the composition and performance of the work. The performance practice suggestions offer tools to interpret and prepare the piece. Though the Concerto may be a challenge for many marimbists, this author hopes that future performers find the rewards in this well-constructed and exciting work after reading this document.
    • Analysis and optimal design of a resonant switching converter for space applications.

      Quintero, Francisco Javier. (The University of Arizona., 1990)
      The design of converters for space applications is subject to a number of unusual constraints, such as low volume and weight, high efficiency operation, minimum components stress, low noise interference and resistance to ionizing radiation. The diode clamped series resonant converter (DCSRC) can be designed to satisfy some of the design constraints. A new approach in the analysis of the DCSRC, and a systematic way of designing for high efficiency and minimum component stress is presented. The direct relationship between the phase plane and the resonant wave shapes allows us to synthesize the closed-form solution and generate the output plane, which relates the normalized output current to the normalized output voltage for any load and any ratio of switching to resonant frequencies. The converter operation is optimized by superimposing the functions that describe the transistor stress and resonant tank component stress on the output plane. Experimental results are in good agreement with both the mathematical model and simulation. The effects of ionizing radiation on the converter performance under simulated space radiation conditions is also investigated.
    • Analysis of queueing systems requiring resequencing of customers.

      Chowdhury, Shyamal (The University of Arizona., 1990)
      This dissertation describes queueing-theoretic analysis of shared service systems that require that customers leave the system in the sequence in which they arrived. This requirement makes it necessary to resequence customers before they leave the system. Resequencing adds new complications to the analysis of queueing systems. While waiting time is still important, resequencing results in a new type of "non-working" delay of a customer called the resequencing delay. This dissertation presents primarily analytical and numerical methods to determine the distribution and mean value of resequencing delay, and of total delay. In the simplest models closed form analytical expressions have been obtained, but in more complex models numerical methods have been developed to compute the distribution and mean of resequencing delay, and of total delay. This enables us to study the behavior of resequencing and total delay as system parameters are changed. For several composite server models we present expressions for the distribution and mean of resequencing delay, and of total delay. In particular we consider the M/M/∞ composite server model, the M/H(K)/∞ composite server model, the G/M/∞ composite server model, the M/M/m composite server model, and the G/M/m composite server model. The formulas are interpreted using asymptotic approximation or bounding techniques. For more general composite server models, it is difficult to obtain closed form expressions for resequencing and total delay. We develop numerical methods based on matrix-geometric methods to compute resequencing and total delay. In particular, we develop numerical methods for the computation of the mean resequencing delay, and mean total delay for the M/H₂/m composite server model, and the M/Hypo₂/m composite server model.
    • Analysis of stiffened membranes by the finite element method

      ABDEL-DAYEM, LAILA HASSAN. (The University of Arizona., 1983)
      A survey for the different variational principles and their corresponding finite element model formulations is given. New triangular finite elements for the analysis of stiffened panels are suggested. The derivation of the stiffness matrix for these elements is based on the hybrid stress model. The boundary deflections for these elements are assumed linear. These elements are different in two aspects, the degree of the internal stress polynomials and the number and location of the stiffeners. Numerical studies are carried out and results are compared to the theoretical solutions given by Kuhn as well as to results of the compatible model. Convergence of the stress in stiffeners to the actual solution through mesh refinement is studied. Jumps in the stiffener stresses given by the new elements exist. The use of special Lagrangian elements at the interelement boundaries to eliminate some of these jumps is studied.
    • Analysis of the implementation of noxious weed policy on Bureau of Land Management and Forest Service lands in Arizona.

      Cramer, Gary Clark. (The University of Arizona., 1995)
      Noxious weeds are harmful plants that are regulated by law. It is their regulation that makes them unique from other weeds. At least 14 noxious weed species are known to occur in Arizona. The Federal Noxious Weed Act of 1974, as amended in 1990, directs all federal agencies to develop, coordinate, fund, and implement noxious weed programs on land that they manage. This dissertation describes and evaluates the implementation of federal noxious weed policy by the Forest Service and the Bureau of Land Management in Arizona. Policy design methodology is used to construct a model of federal policy. Policy elements evaluated include statutes, implementing agents, target audiences, and the policy rules and tools that link these players to policy outcomes. Interviews with agents and targets revealed that there are no noxious weed programs being conducted on Forest Service or BLM lands in Arizona. Also, there is an insignificant amount of funding being provided for such programs. Policy design methods are used to assess the context of the implementation problem. Policy tools are recommended to address the lack of knowledge about infestation levels and management options. Additional support building tools are recommended to address the adaption of integrated weed management techniques.