Now showing items 29091-29110 of 39117

    • The Q-sort as a measure of self concept in children

      Hurston, Mary Victoria Selser, 1938- (The University of Arizona., 1967)
    • Q-switched and Mode-locked Mid-IR Fiber Lasers

      Peyghambarian, Nasser; Zhu, Gongwen; Peyghambarian, Nasser; Norwood, Robert A.; Zhu, Xiushan (The University of Arizona., 2015)
      Mid-infrared (IR) lasers (2-12 μm) have found tremendous applications in medical surgeries, spectroscopy, remote sensing, etc. Nowadays, mid-IR emissions are usually generated from semiconductor lasers, gas lasers, and solid-state lasers based on nonlinear wavelength conversion. However, they usually have disadvantages including poor beam quality, low efficiency, and complicated configurations. Mid-IR fiber lasers have the advantages of excellent beam quality, high efficiency, inherent simplicity, compactness, and outstanding heat-dissipating capability, and have attracted significant interest in recent years. In this dissertation, I have studied and investigated Q-switched and mode-locked fiber lasers in the mid-IR wavelength region. My dissertation includes six chapters: In Chapter 1, I review the background of mid-IR lasers and address my motivation on the research of mid-IR fiber lasers; In Chapter 2, I present the experimental results of microsecond and nanosecond Er³⁺-doped and Ho³⁺-doped fiber lasers in the 3 μm wavelength region Q-switched by Fe²⁺:ZnSe and graphene saturable absorbers. In Chapter 3, Q-switched 3 μm laser fiber amplifiers are investigated experimentally and theoretically and their power scaling are discussed. In Chapter 4, a graphene mode-locked Er³⁺-doped fiber lasers at 2.8 μm with a pulse width < 50 ps is presented. In Chapter 5, extending the spectral range of mid-IR fiber lasers by use of nonlinear wavelength conversion is addressed and discussed. I have proposed 10-watt-level 3-5 μm Raman lasers using tellurite fibers as the nonlinear gain medium and pumped by our Er³⁺-doped fiber lasers at 2.8 μm. In the last chapter, the prospect of mid-IR fiber laser is addressed and further research work is discussed.
    • QoS Improvement Schemes for Real-Time Wireless VoIP

      Rodriguez, Jeffrey J.; McNeill, Kevin M.; Liu, Mingkuan; Rodriguez, Jeffrey J.; McNeill, Kevin M.; Hariri, Salim (The University of Arizona., 2006)
      There is a tremendous demand on real-time multimedia delivery over wireless Internet due to the dramatic increase in wireless communication and the growth of the Internet. However, real-time multimedia over wireless Internet poses many challenges. First of all, the inherent best-effort characteristic of packet-switched networks makes it difficult to provide guaranteed QoS for real-time multimedia delivery. Secondly, wireless channels have much higher packet-loss rate, bit-error rate, and channel instability compared to wired channels due to noise, path loss, multi-path fading and shadowing, which result in fluctuating communication channel statistics. Thirdly, the real-time communication demands strict time limitations on the network end-to-end delay and delay jitter.In this dissertation, an intelligent application architecture and several QoS improvement mechanisms are proposed to timely estimate the current wireless network statistics and dynamically take smart actions to improve the overall performance of a real-time wireless Internet telephony system. An online network traffic modeling method based on time series analysis was used to estimate the dynamic wireless network statistics such as end-to-end packet delay and delay jitters. Using this real-time updated information, the application's sender side can take some adaptive actions such as voice codec selection and forward error-correction schemes for packet-loss concealment to improve the QoS under current available network resources. Also, a novel adaptive playout jitter buffer adjustment algorithm is proposed. The proposed algorithm achieved 11%-15% performance improvement compared to traditional adaptive playout adjustment algorithms using the ITU-E model measurement metric.
    • QoS routing in packet networks

      Krunz, Marwan; Korkmaz, Turgay (The University of Arizona., 2001)
      The current best-effort service of the Internet is not sufficient to meet the demands of emerging real-time network applications (e.g., video conferencing, Internet telephony). This has motivated the development of new networking technologies (e.g., Intserv, Diffserv, MPLS) that are geared towards providing quality-of-service (QoS) guarantees (e.g., bandwidth, delay, fitter, reliability) to prospective flows. Various aspects of these technologies are being extensively investigated in the research community. In this dissertation, we focus on the routing aspect, with the objective of providing scalable and computationally efficient solutions. The QoS routing problem involves two tasks: (a) capturing and disseminating the state information of the underlying network; and (b) using this information to compute resource-efficient constrained paths. In the presence of multiple constraints (QoS link parameters), these two tasks become notoriously challenging. We investigate several key issues in QoS routing and discuss how to integrate the provided solutions into evolving state-dependent and hierarchical routing protocols (e.g., PNNI and QoS-extended OSPF). First, we develop a hybrid mechanism based on both flooding and tree-based broadcasting for reliable and efficient dissemination of dynamic link-state parameters, such as bandwidth. Second, we present a scalable, source oriented state aggregation methodology for hierarchical networks. Third, we introduce several heuristics and approximation algorithms for path selection under multiple QoS constraints. Fourth, we consider the path selection problem under inaccurate (probabilistically modeled) state information, and provide a heuristic for a special yet important case of this problem, namely, routing under bandwidth and delay constraints. Finally, we evaluate the performance of the proposed methods through simulations.
    • QR Codes For Good

      Redford, Gary; Miner, Corey Justin (The University of Arizona., 2019)
      This project is a payment transaction system based on QR codes. The purpose of the project is to create a system where you can donate to homeless people electronically. 70% of people today no longer carry cash, so homeless people are no longer getting the donations that they once got. Using QR codes, the homeless person can go to the public library and print a QR code, and then any person who wants to donate only needs to scan the QR code to donate. By having the money electronically, by partnering with homeless shelters or EBT program, the recipient of the donation can be restricted in what they can purchase. Not allowing them to buy alcohol or drugs can make people donating feel better about their donations as well. Overall, people are donating less and cash can be spent anywhere, but with this project, donations can be sent quickly and painlessly through a QR code.
    • QSO Pairs and the Lyman-alpha Forest: Observations, Simulations, and Cosmological Implications

      Impey, Chris D.; Marble, Andrew R; Impey, Chris D.; Schmidt, Gary; Dave, Romeel; Fan, Xiaohui (The University of Arizona., 2007)
      This dissertation addresses two cosmological applications of the Lyman-alpha (Ly ɑ) forest observed in QSO pairs separated by several arcminutes or less. The Ly ɑ flux autocorrelation and cross-correlation provide a measurement of cosmic geometry at z > 2, via a variant of the Alcock-Paczyński test. I present the results of an observing campaign to obtain moderate resolution spectroscopy of the Ly ɑ forest in QSO pairs with small redshift differences (Δz < 0.25) and arcminute separations (θ < 5'). This new sample includes 29 pairs and one triplet suitable for measuring the cross-correlation and 78 individual QSO spectra for determining the autocorrelation. Continuum fits are provided, as are seven revisions for previously published QSO identifications and/or redshifts. Using a suite of hydrodynamic simulations, anisotropies in the Ly ɑ flux correlation function due to redshift-space distortions and spectral smoothing are investigated for 1:8 ≤ z ≤ 3, further enabling future applications of the Alcock-Paczyński test with Ly ɑ correlation measurements. Sources of systematic error including limitations in mass-resolution and simulation volume, prescriptions for galactic outflow, and the observationally uncertain mean flux decrement are considered. The latter is found to be dominant. An approximate solution for obtaining the zero-lag cross-correlation for arbitrary spectral resolution is presented, as is a method for implementing the resulting anisotropy corrections while mitigating systematic uncertainty.
    • Quadrat frequency sampling in a semi-desert grassland

      Yavitt, Joseph Benjamin (The University of Arizona., 1979)

      Ogden, Kimberly; Gautier, Marissa Ann (The University of Arizona., 2018)
      The overall goal of this project is to produce 50 million doses of a quadrivalent flu vaccine each year to reduce the outsourcing of vaccines from other countries. The facility being designed is an add-on to the existing Sanofi Pasteur plant located in Swiftwater, Pennsylvania. The process of producing a flu vaccine begins with obtaining the predicted flu strain from the Centers for Disease Control and Prevention (CDC). Then the flu virus is injected into fertilized eggs, which serve as bioreactors. The eggs are incubated for 3 days and then the allotonic fluid is harvested, purified with multiple chromatography columns and tangential flow filtration columns, and then packaged to become the final flu vaccine. In order to produce 50 million doses the plant requires 928,000 fertilized chicken eggs. The facility is profitable at $70.5 million annually. The cost to make each vaccine is $0.25 and they are sold for $1.66, resulting in a $1.41 profit per vaccine. Since the number of people who receive the flu vaccine each year has been increasing over the past seven years, adding 50 million vaccine doses to the U.S market would be beneficial in case of outbreak or prediction of an incorrect flu strain.

      Fitzsimmons, Kevin; WAGNER, MITCHELL HAROLD (The University of Arizona., 2016)
      First introduced in Western United States waters in 2007, the quagga mussel (Dreissena rostriformis bugensis) has rapidly spread throughout the Lower Colorado River and other bodies of water. Along the way, they have caused severe ecological and economical damage through ecosystem transformation and biofouling of water systems. To date, they have proved impossible to eradicate after colonization of a system. The best way to control quagga mussels is to prevent them from spreading to other waters. Once established, a combination of physical, chemical, and biological control methods need to be developed for that specific body of water. Continued research on best management practices and optimal facility designs are needed in order to control existing populations. Even though a solution for complete eradication of D. Bugensis has not been found to date, with public support and proper government funding, the effect of the quagga mussel in Western U.S. waters can be minimized.

      Matsumori, Barry Alan. (The University of Arizona., 1985)

      COWELL, MITZI JO (The University of Arizona., 2008-05)
    • The qualifying examination in English at the University of Arizona

      Brown, Francis, 1903- (The University of Arizona., 1937)
    • Qualitative Analysis of Erythro-Methylphenidate Isomers Contained within Methylphenidate HCl Capsules using TLC

      Durazo, Enrique; Nakai, Jodi S.; College of Pharmacy, The University of Arizona (The University of Arizona., 2005)
      Objective: The goal of this study was to determine the presence of erythro-methylphenidate (erythro-MPH) isomers contained within methylphenidate HCl (Metadate CD®) capsules. Methods: This experiment was conducted at a pharmaceutical manufacturing facility located in Tucson, Arizona. Methylphenidate HCl (MPH) capsules by Celltech Pharmaceuticals, Inc. were analyzed and compared to a reference standard. Thin-layer chromatography (TLC) was the technique used to qualitate the samples. The main outcome measure was the Rf values which were used to determine whether or not the MPH capsules contained erythro-MPH. Results: The study included ten, 20 mg MPH capsules and a reference standard (50 mg strength USP MPH related compound). The Rf value of the reference standard was 0.073 while the Rf value of the MPH samples ranged from 0.42 - 0.85. Conclusion: In this qualitative analysis of MPH capsules, there was no erythro-MPH isomers present in the MPH capsules.
    • A Qualitative and Quantitative Analysis of Quality Improvement Education in Colleges of Pharmacy

      Warholak, Terri; Cooley, Janet; Montoya, Amber; Walsh, Angela; Warholak, Terri; Cooley, Janet; College of Pharmacy, The University of Arizona (The University of Arizona., 2015)
      Objectives: To analyze the state of quality improvement (QI) education across ACPE-accredited pharmacy schools in the United States. Methods: Stage one of data collection consisted of an inspection of each pharmacy school website to reveal the presence of published QI curriculum or other related content. In the second stage, an e-mail questionnaire was sent to one representative of each of the 129 accredited schools in the U.S. who was interested in or who teaches QI at his/her school. Respondents could complete the questionnaire via: 1) electronic; 2) paper; or 3) phone. Later, the questionnaire was shortened and a raffle was initiated to increase response rate. The survey instrument contained both multiple choice and open-ended items. Results: Sixty responses were returned from the 129 accredited schools (47% response rate). The least-covered QI topics in respondents’ QI curricula were: Quality dashboards and sentinel systems (30%); Six-sigma, or other QI methodologies (45%); Measures of safety and quality (57%); Medicare Star measures (a national measurement program) and payment incentives (58%); and How to implement changes to improve quality (60%). More private schools covered Adverse Drug Events than public schools (p=0.039). Requiring a specific QI class was more likely in private schools (p=0.003) while requiring a QI project was more often reported by public schools (p=0.014). Conclusions: To the investigators’ knowledge, this is the first national study to map QI education in U.S. pharmacy schools. These results will inform pharmacy and other health-related professional programs in the integration of QI concepts into their curriculum.
    • Qualitative aspects of memory performance in depressed versus demented elderly

      Kaszniak, Alfred W.; Nussbaum, Paul David, 1963- (The University of Arizona., 1987)
      This study investigated quantitative and qualitative aspects of memory in three age-and-education-matched groups (1) 38 normal elderly, (2) 15 patients with dementia of the Alzheimer's type (DAT), and (3) 26 depressed elderly. Three clusters of dependent variables were used to examine group differences: (1) standard psychometric (Wechsler Memory Scale logical memory and visual reproduction subtests), (2) verbal recall measures (free recall measures of primary memory, secondary memory, prior item intrusions and extra list intrusions), and (3) verbal recognition memory measures (true positive, false positive, true negative, and false negative responses). Analyses of variance, with specified contrasts, found the DAT patients to demonstrate a pervasive memory impairment affecting both the qualitative and quantitative memory indices compared to depressed and normal elderly. The depressed elderly demonstrated impairment, compared to normal elderly, on tasks requiring effortful processing. Findings support pervasive memory loss in DAT patients and do not support clear memory impairment in the present depressed sample.
    • Qualitative assessment of successful individuals who have a learning disability

      Sales, Amos; McDonnell, Daniel Michael, 1948- (The University of Arizona., 1996)
      This study used qualitative methods to investigate successful individuals who had a learning disability. Six participants, three men and three women, along with their family members and significant others were interviewed. A participant observation was also conducted during each participant's typical day at work. Four common characteristics were found among the participants. These characteristics were organizational skills, drive, a match between strengths and career, and interpersonal competence. The characteristics identified by the study were similar to those found by Gerber and Ginsberg (1990); however, it was noted that over-reliance on one characteristic and an inability to adjust to success often created difficulties. Further, job satisfaction and eminence in one's field did not always mean self-fulfillment, happiness, and psychological maturity. A definition of success which suggests a balance between career, family, and social activities was given. The study noted that a key element in coping with a learning disability was that the individuals understood both their strengths and weakness. Family members indicated that the transition from school to adult life was critical and that the role of parent and family members' perceptions about the participants usually needed to be adjusted. Older participants indicated that having a son or a daughter who had a learning disability helped them to come to terms with their disability. They also noted the importance of having a diagnosis, so they could reframe their self-perception in terms of a condition rather than a sense of mental incompetence or laziness. Recommendations for future research in this field were presented.
    • Qualitative changes in serum lipid fractions from the isolated perfused bovine liver

      Haugebak, Clayton Deane, 1946- (The University of Arizona., 1970)
    • Qualitative Content Analysis of Political Rhetoric and Victim Perceptions in the United States

      Sullivan, Daniel; Huang, Anthony (The University of Arizona., 2018)
      Victimhood rhetoric, through which victims of crimes request recompense as a result of their suffering, is easily observed in modern media. This observation poses the possibility that societal perceptions of victims over time may have changed. This study investigates, in all 58 of the United States Presidents’ inaugural speeches, the chronological shift of rhetorical themes associated with victim perception. The themes being evaluated were determined by their relevance to positive and negative valuations of victimhood status. Themes were then separated into several codes: duty to help others and true victimhood codes represented positive victim perceptions; Protestant Work Ethic, isolationism, and untrue victimhood codes represent negative victim perceptions. These codes were applied on a sentence-by-sentence basis to develop initial impressions of trends. Isolationism and untrue victimhood were not correlated with the passage of time. However, associations were found between passage of time and three themes: Protestant Work Ethic, duty to help others, and true victimhood.
    • A Qualitative Evaluation by Focus Group of Pharmacists on Patient Counselling on Inhaler Technique

      Lee, Jeannie; Tate, Jared; Avila, Sena; Day, Kendall; College of Pharmacy, The University of Arizona (The University of Arizona., 2018)
      Specific Aims The purpose of this study was to describe the barriers that exist at the pharmacy level in providing appropriate patient education on inhaler technique. Methods A focus group was used for this study, approved by the University of Arizona Institutional Review Board. De-identified demographic information was collected to describe the characteristics of the study participants and their experiences with inhaler education. During the focus group, conducted by student pharmacists, data were collected by note taking and audio recording. Descriptive data about the participants were reported using summary means, and standard deviations. Audio recording and researcher notes were analyzed by content analysis to extract common barriers that limit appropriate patient education on inhaled medication use. Results Ten pharmacists participated in the focus group discussion. The average age of participants was 46 years (SD=11.1, Range=29-61) and the majority were female (80%). The main themes identified centered on patient- and practice-specific factors for instituting patient education on inhaler technique. Conclusions Prioritizing common barriers identified by practicing pharmacists as a focus of pharmacist training and process implementation within pharmacies may help improve patient education, and in turn adherence to inhaled medications and outcomes.
    • A qualitative evaluation of multicultural art curricula at primary levels

      Greer, W. Dwaine; Borin, Meredith Dawn, 1971- (The University of Arizona., 1997)
      Today, a large number of multicultural publications and resources are available for elementary classroom use. The purpose of the study was to examine existing multicultural elementary art curricula and resources to evaluate their adequacy and availability to the classroom art teacher, according to criteria, methods, and materials recommended by scholars in art education. The examination included price range and adaptability of material, audiovisual resources, art production, art criticism, art history, aesthetics, sequential organization, developmental appropriateness, cultural integrity, and multicultural content level. Upon completion of this study, two of the five curriculum publishers proved to consistently produce multicultural art education curriculum at a high quality level. Crizmac and Crystal Publications offer a number of curriculum settings that comply with current NAEA standards as well as the criteria set forth in this paper. Supplementary resources and the future of multicultural art education in respect to curriculum and classroom implementation are also discussed.