Now showing items 39084-39103 of 39117

    • The z-transform as a general tool in approximation

      Pendleton, Freeman Luke, 1928- (The University of Arizona., 1960)
    • The Zanj Revolt (869-883) in the Abbasid Era

      Muhammad, Suad Mustafa (The University of Arizona., 1981)
    • Zapotec language shift and reversal in Juchitan, Mexico

      Hill, Jane H.; Saynes-Vazquez, Floria E. (The University of Arizona., 2002)
      This dissertation documents the process of language shift from Zapotec to Spanish in urban Juchitan, a Zapotec community in southern Mexico. The work also analyzes the current strategies Juchitecos are developing to stop the replacement of their local language. The work first provides a sociohistorical overview of the community, which helps us to understand its current sociolinguistic situation. Oral and written materials, the ways in which ethnic symbols are manipulated, and the sociopolitical dimensions of the indigenous language are analyzed in order to elucidate the tensions that define the current bilingual situation of Juchitan. The work also addresses the broader aspect of language policies in Mexico, and shows how linguistic policies in the country have promoted the loss of the Mexican languages, and the replacement of Zapotec by Spanish. After describing how these linguistic policies negatively impacted the reproduction of the Zapotec language, the study presents some of the actions Juchiteco people are currently putting into practice in order to restore mother tongue transmission and reverse the process of language shift. The salient ethnic identity of JuchitAn is explored and helps to understand the linguistic profile of the community, as well as the current actions that are being developed towards the reversal of the Zapotec language shift. This study argues, following Fishman's theory, that the reproduction of the Zapotec language and an effective reversal of the language shift depend mostly on the speakers themselves and on the resources locally developed.
    • Zebrafish Video Analysis System for High-Throughput Drug Assay

      Rodríguez, Jeffrey J.; Todd, Douglas Wallace; Rodríguez, Jeffrey J.; Powers, Linda S.; Tharp, Hal S. (The University of Arizona., 2016)
      Zebrafish swimming behavior is used in a new, automated drug assay system as a biomarker to measure drug efficiency to prevent or restore hearing loss. This system records video of zebrafish larvae under infrared lighting using Raspberry Pi cameras and measures fish swimming behavior. This automated system significantly reduces the operator time required to process experiments in parallel. Multiple tanks, each consisting of sixteen experiments are operated in parallel. Once a set of experiments starts, all data transfer and processing operations are automatic. A web interface allows the operator to configure, monitor and control the experiments and review reports. Ethernet connects the various hardware components, allowing loose coupling of the distributed software used to schedule and run the experiments. The operator can configure the data processing to be done on the local computer or offloaded to a high-performance computer cluster to achieve even higher throughput. Computationally efficient image processing algorithms provided automated zebrafish detection and motion analysis. Quantitative assessment of error in the position and orientation of the detected fish uses manual data analysis by human observers as the reference. The system error in orientation and position is comparable to human inter-operator error.
    • The Zen Horseman

      Oberman, Hester; Andelora, Joshua Francis (The University of Arizona., 2017)
      This creative honors thesis, The Zen Horseman, explores the possible correlation between equine interaction and meditation. Through methods such as practicing Zen meditation, working with equine assisted psychotherapists, neurosurgeons, and academic researchers in the field of mind-body physiology this thesis suggests that heart rate variability is the physiological link correlating meditation and equine interaction. Through a review of multiple studies occurring within the past ten years, both equine interaction and meditation have been found to boost immunity, decrease negative affect, decrease anxiety, depression, and stress. The core focal point of these studies is heart rate variability (HRV), which is the foundational physiological phenomenon, which indicates a mind-body connection. By using HRV, evidence based data allows speculation that Zen meditation and equine interaction are linked through their health-promoting effects on the human body.
    • Zen in the Art of Teaching: Contemplative/Mindfulness Practice in the Professional Development of Teachers

      Vorndran, Kenneth R.; McAllister, Ken; McAllister, Ken; Warnock, John; Miller, Thomas P. (The University of Arizona., 2009)
      This dissertation uses a Zen koan as a foundation for discussing teacher training and development. It suggests that teacher training attends to issues of theory, pedagogy, and technology, and it contends that teacher training and development does not adequately attend to the intrapersonal aspect of teaching. In spite of the use of reflective techniques in teacher education, teachers are not trained in a significant way to navigate, negotiate, or manage the issues of identity, the issues of self-belief, the patterns of thought, and/or the emotional patterns, which affect their teaching and their classrooms. This work looks at research regarding the importance of the intrapersonal aspect of teaching in relation to teacher effectiveness and classroom climate; it considers current practices in pre-service and in-service teacher training; and it reviews research related to the efficacy of mindfulness and contemplative practices, such as meditation. It argues that the intrapersonal aspect of teaching is relevant to teacher effectiveness and classroom climate; that contemplative and mindfulness practices may offer systems that support and sustain teachers as they navigate, negotiate, and manage the intrapersonal aspect of teaching; and that pre-service and in-service professional development may provide vehicles to deliver this training.
    • The zero dispersion limits of nonlinear wave equations.

      Levermore, C. David; Tso, Taicheng.; Palmer, John; Greenlee, W. Martin (The University of Arizona., 1992)
      In chapter 2 we use functional analytic methods and conservation laws to solve the initial-value problem for the Korteweg-de Vries equation, the Benjamin-Bona-Mahony equation, and the nonlinear Schrodinger equation for initial data that satisfy some suitable conditions. In chapter 3 we use the energy estimates to show that the strong convergence of the family of the solutions of the KdV equation obtained in chapter 2 in H³(R) as ε → 0; also, we show that the strong L²(R)-limit of the solutions of the BBM equation as ε → 0 before a critical time. In chapter 4 we use the Whitham modulation theory and averaging method to find the 2π-periodic solutions and the modulation equations of the KdV equation, the BBM equation, the Klein-Gordon equation, the NLS equation, the mKdV equation, and the P-system. We show that the modulation equations of the KdV equation, the K-G equation, the NLS equation, and the mKdV equation are hyperbolic but those of the BBM equation and the P-system are not hyperbolic. Also, we study the relations of the KdV equation and the mKdV equation. Finally, we study the complex mKdV equation to compare with the NLS equation, and then study the complex gKdV equation.
    • The Zero Energy Evolution

      Brown, Caitlin C.; College of Architecture, Planning and Landscape Architecture; Smith, Robert L.; Iuliano, Joey; Keith, Ladd (The University of Arizona., 2014-12-17)
      This study is an analysis and definition of green building design and zero energy building. This distinguishes the different components that go into net zero building, and the feasibility of making it happen on current buildings, as well as ones in design. The study identifies a building currently in construction on the University of Arizona campus, and identifies its possibility of zero energy and how zero energy would affect the cost and performance of the building. Ultimately it is found that net zero is feasible for the Environmental Natural Resources Building 2 and the University of Arizona, and should be a component in the design and building process of future buildings on campus.
    • Zero-Emissions Solar Power Plant

      Ogden, Kimberly; Rabbani, Michael (The University of Arizona., 2017)
      With energy demand continuously increasing in the United States, renewable energy development is critical to combatting the effects of global climate change. The objective of the project was to create a design for a zero-emissions solar plant. The project group designed a plant to provide electricity to all of residential Chandler, a city with about 100,000 homes. An estimated 543,880 metric tons of carbon dioxide equivalent is produced to power residential Chandler. In contrast, the proposed solar plant will produce zero emissions. Unfortunately, the proposed process is not currently economically feasible. The proposed process is a concentrating solar power (CSP) tower plant. A central receiver on top of a 175 meter tower absorbs heat reflected off of a field of reflective heliostats. A chloride molten salt mixture flows to the receiver where it is heated to approximately 1000°C. The heated molten salt flows back into a tank where it can be stored for later use or pumped directly to a series of heat exchangers. The working fluid, supercritical carbon dioxide (s-CO2), gains heat from the heat exchanger and powers highly efficient turbines. Waste heat is recovered from the turbines using the closed-loop Brayton Cycle and the s- CO2 is recompressed.
    • ZERO-ONE PROGRAMMING ANALYSIS OF MINE PRODUCTION SCHEDULING PROBLEMS.

      Cai, Wenlong. (The University of Arizona., 1985)
    • ZERO/ONE DECISION PROBLEMS WITH MULTIPLE RESOURCE CONSTRAINTS: ALGORITHMS AND APPLICATIONS.

      RASSENTI, STEPHEN. (The University of Arizona., 1982)
      Two complex resource allocation problems motivate the algorithms and applications discussed in this dissertation. The Public Broadcasting Service (PBS), a cooperative of television stations with independent budgets, must decide which programs to purchase from various producers and at what cost to its member stations. The airports of America must decide how to allocate limited takeoff and landing slots to competing airlines. Both problems are recognized as zero/one decision problems with multiple resource constraints. A computer aided allocation mechanism is proposed as an alternative to the currently practiced decision procedures. Bid information, solicited in an auction phase, provides values to parameterize a mathematical model. An optimization phase is then used to generate the best solution for the given information. The integer programming algorithms required to solve the particular models suggested are explored in detail. A best bound enumeration strategy which uses a surrogate knapsack relaxation is developd. Computer storage requirements are curtailed by using a new greedy heuristic for general integer programming problems. The PBS model has a structure closely related to certain fixed charge problems. This allows the use of necessary conditions for the existence of a solution of capacitated transportation problems to test the feasibility of candidate solution vectors. In the SLOT model feasibility testing is a trivial matter of maintaining running row sums. The bound provided by the knapsack relaxation is further enhanced with the addition of a set of generalized choice constraints. An efficient polynomial algorithm and proof of optimality are given for the linear relaxation of this problem. A procedure for generating a set of generalized choice constraints from any set of logical constraints is also given. The viability of the approach developed and the effects of parameter variation are computationally tested in both PBS and SLOT contexts. Some further computational results for project selection, set covering, and multiple knapsack problems are reported. A broad class of mixed integer linear programming problems is defined (e.g., capital expenditure and network design problems) and a suitable relaxation for a similar approach is developed. Finally, several new directions for research in algorithmic development and application are proposed.
    • Zhiyi's interpretation of the concept "dhyana" in his Shi chan boluomi tsidi famen

      Gimello, Robert M.; Wang, Huei-hsin (The University of Arizona., 2001)
      This study is an analysis of Zhiyi's interpretation of the concept of "dhyana" in his Shi chanboluomi cidi famen (An Exposition of Methods to Achieve the Stages of Meditative Perfection, hereafter, The Stages of Meditative Perfection). In the studies of Chinese Buddhism, dhyana , translated into Chinese "chan," is commonly associated with the Chan school (Chan zong ) developed in China in the seventh and the eighth century. In Zhiyi's The Stages of Meditative Perfection, however, dhyana is generally understood as the Four Dhyanas. In the "Four Dhyanas" chapter of The Stages of Meditative Perfection, Zhiyi specifically defines dhyana as "zhilin (dhyana factors)" and "gongde tsonglin (an array of meritorious qualities)." The Stages of Meditative Perfection is Zhiyi's systemization of the various dhyana methods practiced by Chinese Buddhists from the second to the sixth centuries A.D. A general sketch of The Stages of Meditative Perfection is made in the first three chapters of this study. In the first chapter I make a brief textual review and discuss some general features of this text. In chapter two, I discuss some of the important terms related to meditation practices used inThe Stages of Meditative Perfection. The third chapter is an analysis of some of Zhiyi's dhyana classification systems that appear in the first five chapters of The Stages of Meditative Perfection , which comprises Zhiyi's theoretical systemization of Dhyana-paramita . Among Zhiyi's discussion of the actual practice of the fifteen dhyana methods discussed in the sixth and seventh chapters of The Stages of Meditative Perfection, two dhyana practices, the Four Dhyanas and the Tongming guan (The Contemplation Leading to [Six] Supernormal Powers and [Three Illuminating] Insights) are the most crucial for our understanding of Zhiyi's concept of dhyana. Therefore, these two dhyana practices are selected as the subject of detailed analysis. Four aspects of Zhiyi's interpretation of dhyana will be examined in my analysis: Zhiyi's definitions of dhyana, his concepts of "Mundane Dhyana" and "Supramundane Dhyana," the role of intellect and physiology in the meditative states in Zhiyi's interpretation of dhyana, and Zhiyi's method of synthesizing practice and doctrine in his interpretation of dhyana.
    • Zhoukoudian: A synthesis of research to date

      Olsen, John W.; Della Croce, Anthony (The University of Arizona., 1995)
      The site of Zhoukoudian has been studied for over 70 years. During this time, a great deal of change has occurred in both analytical methodology and paradigmatic models concerning human prehistory. Zhoukoudian presents an opportunity to study both issues of early hominid behavior and the evolution of palaeoanthropological, geological, dating methodology and palaeoenvironmental research over the last eight decades. Zhoukoudian was the first site to exhibit verifiable evidence for the presence of early hominids in East Asia (more than 45 individuals). The site has been established as containing Middle and Upper Pleistocene components. The majority of these (e.g., Locality 1) fall within a Middle Pleistocene context, while the Upper Cave represents an Upper Pleistocene occupation of the site. Modem studies are suggested in light of the recent reworking of some fundamental concepts at Zhoukoudian. These include evidence for hunting vs. scavenging, fire usage and duration of occupation of the site by early hominids, all of which need reevaluation.
    • Zika Outbreak Concern in Border Communities: Zika Virus Dissemination Prevention Program

      Parker, Sheila; Neel, Kelly Lynn (The University of Arizona., 2017)
      The rapid and vast expansion of Zika virus in the Americas has heightened interest in members of the health sciences community, including public health agencies and officials. Concern of a future Zika outbreak in the United States is imminent. Prior studies, in combination with surveys administered by the author, suggest that mosquito avoidance behaviors could use improvement, especially in areas of high susceptibility of mosquito-borne illness dissemination. Border communities often face more health-related complications due to lack of appropriate resources, indicating the need for preventive education in these areas. The purpose of this thesis is to bring awareness to this outbreak potential, as well as providing a comprehensive health educational unit plan for high school students on the Tohono O’odham reservation in Southern Arizona. Focusing on awareness and emphasis on mosquito avoidance behaviors are crucial methods that must be implemented in these communities to reduce the chances of both travel-related and autochthonous Zika development and transmission.
    • Zika Virus: Patient Education Recommendations

      Goldsmith, Melissa; Towers, Victoria (The University of Arizona., 2017)
      As the current growing threat to maternal-fetal health, the most recent and largest outbreak of the Zika virus has introduced the devastating fetal effects of microcephaly and other central nervous system deficits. Therefore, the need for appropriate recognition, treatment, management, and prevention of the Zika virus prompts the necessity for further education and high quality level research to be conducted and utilized. A search of the literature using the databases PubMed, UptoDate, and CINAHL was conducted for articles published between 2009 and 2016. In addition, key informant interviews from various specialties including clinical genetics and public health were conducted. The proposed best practice recommendations for education regarding the Zika virus and appropriate prevention and treatment methods are outlined in an electronic education module that would be delivered to patients and their families prior to visiting their healthcare providers. As the Zika virus continues to spread and further research is conducted regarding its teratogenic effects, the need for concise and effective education is critical in order to raise awareness and conversely decrease the potential for maternal exposure and adverse fetal outcomes.
    • ZINC ADSORPTION AND DESORPTION IN CALCAREOUS SOILS

      Udo, Eno Jumbo, 1937- (The University of Arizona., 1968)
    • Zinc status and functional correlates in preschool and school-aged children in Egypt.

      Harrison, Gail G.; Mohs, Mary Ellen.; Berry, James W.; Ritenbaugh, Cheryl; Stini, William A.; Weber, Charles W. (The University of Arizona., 1989)
      Zinc status of Egyptian children 18-30 months and 6-10 years of age was characterized in relation to morbidity, growth, and socioeconomic variables. In a pilot study of children whose general nutrition ranged from adequately nourished to moderately malnourished, mean hair zinc was 135 ug/g (63-230 ug/g), with suboptimal zinc status suggested for 44%. Predictors of hair and serum zinc levels were explored for 23 school-aged and 40 preschool children. Included in models were weaning age for preschool children, body size (length- or height- and weight-for-age Z scores), current growth over 6 months or longer, illness experience over 10 to 12 months, demographic variables affecting food availability and distribution, sex, and season. Data were collected by Egyptian workers as part of a larger field project. Hair and serum samples were analyzed for zinc content by atomic absorption spectrophotometry. Results showed no difference in hair zinc levels by color, presence or absence of louse egg fragments and mucilage, or presence or absence of henna dye. In multiple regression models, the best predictor of hair zinc in preschool children was season of year, with zinc lower in summer. Season, negative effect of percent of weeks ill with diarrhea, and positive effects of socioeconomic status (SES) based on father's education/literacy and economic subsistence base excluding agriculture (ESB-A) predicted 23% of total hair zinc variation in preschool children. In preschool children serum zinc was lower in summer. Season, positive effect of rate of weight increase, and negative effects of rate of height increase, SES based on father's occupation(s) (SES2), and ESB-A predicted 53% of total serum zinc variation in preschool children. Serum zinc was higher in summer in school-aged children. Season, negative effect of SES2 and ESB-A, and positive effects of percent weeks ill with diarrhea and height for age Z scores predicted 60% of total serum zinc variation in school-age children. Negative effects of percent weeks ill with diarrhea and parents' age and child:adult ratio predicted 29% of hair zinc in school-aged children.
    • ZINC SULFATE SUPPLEMENTATION IN CHRONIC RENAL FAILURE PATIENTS REQUIRING HEMODIALYSIS.

      THOMPSON, JOAN SILVERMAN. (The University of Arizona., 1983)
      The effects of 18 milligrams elemental zinc as zinc sulfate were investigated in 24 hemodialysis patients during a double blind study. The study was conducted at two different dialysis centers in Utah. Each patient was evaluated for a 12 week period. The effects of zinc supplementation were evaluated using the parameters of serum zinc, hair zinc, dialysate zinc, and objective and subjective taste evaluation procedures. To possibly clearify the above determination in zinc status, copper determination were made of the same parameters. In addition, determinations of serum ferritin, transferrin and iron levels were made. A three day diet record was used to document the dietary intakes of calories, protein, and zinc as well as indicate the balance of food groups in the diets. Patients were evaluated biweekly throughout the study period. There were a total of six evaluations made on each participant during the investigation. Complete data were collected on six patients in the treatment group, and on ten patients in the control group. Even though the sample size was small, results were very steady and values fell within narrow ranges for most parameters examined. The mean baseline serum zinc value (n = 24) was 56 micrograms per deciliter. Patients, by this value would be classified as zinc deficient. However, the hair zinc levels were within the normal range, and no other signs or symptoms of zinc deficiency were evident in any patient, other than altered taste. There were no differences between pre and post dialysis serum zinc levels, nor were there any consistent increases in zinc levels cleared from the plasma during dialysis. There were no increases seen in the serum zinc or hair levels in response to zinc supplementation. Furthermore, there was no significant improvement in the taste acuities of the treatment group patients compared to the controls. The low serum levels maintained were probably due to the redistribution of body zinc known to occur in uremia. Most patients improved their taste test scores. This displayed the learning phenomena that was inherent in the taste testing technique. Furthermore, hemodialysis patients and the failure of many subjects to identify all four tastants (sweet, sour, bitter, and salt) correctly. Daily dietary intakes of high bioglogical value protein and zinc by the patients were less than the amounts recommended by the National Dietary Counsil and the physicians. However, the daily intakes of protein (55 grams) and zinc (7.9 milligrams) were not limited to the level where deficiency signs or symptoms of either nutrient were seen. Copper serum levels were all within the normal range. The mean baseline level for all patients was 113 micrograms per deciliter. Copper status appeared unaffected by uremia or hemodialysis. Body stores of iron, determined by serum ferritin levels, ranged from possibly indicating iron deficiency to iron overload. The body iron stores did not correlate with patients’ responses to the oral zinc supplementation.
    • Zircon (U-Th)/He Dates from Radiation Damaged Crystals: A New Damage-He Diffusivity Model for the Zircon (U-Th)/He Thermochronometer

      Reiners, Peter; Guenthner, William Rexford; Reiners, Peter; Ketcham, Richard; Ganguly, Jibamitra; DeCelles, Peter (The University of Arizona., 2013)
      Zircon (U-Th)/He (zircon He) dating has become a widely used thermochronologic method in the geosciences. Practitioners have traditionally interpreted (U-Th)/He dates from zircons across a broad spectrum of chemical compositions with a single set of ⁴He diffusion kinetics derived from only a handful of crystals (Reiners et al., 2004). However, it has become increasingly clear that a "one-size-fits-all" approach to these kinetics is inadequate, leading to erroneous conclusions and incongruent data. This dissertation develops a more grain-specific approach by showing the fundamental role that intracrystalline radiation damage plays in determining the He diffusivity in a given zircon. I present three appendices that seek to quantify the radiation damage effect on He diffusion in zircon, explain how this effect manifests in zircon He dates, and show how to exploit such manifestations to better constrain sample thermal histories. Of particular importance, this dissertation represents the first comprehensive study to concentrate on the entire damage spectrum found in natural zircon and also the first to show that two different mechanisms affect He diffusion in zircon in different ways across this spectrum. In the first appendix, I and my fellow co-authors describe results from a series of step-heating experiments that show how the alpha dose of a given zircon, which we interpret to be correlated with accumulated radiation damage, influences its He diffusivity. From 1.2 × 10¹⁶ α/g to 1.4 × 10¹⁸ α/g, He diffusivity at a given temperature decreases by three orders of magnitude, but as alpha dose increases from ~2 × 10¹⁸ α/g to 8.2 × 10¹⁸ α/g, He diffusivity then increases by about nine orders of magnitude. We parameterize both the initial decrease and eventual increase in diffusivity with alpha dose with a function that describes these changes in terms of increasing abundance and size of intracrystalline radiation damage zones and resulting effects on the tortuosity of He migration pathways and dual-domain behavior. This is combined with another equation that describes damage annealing in zircon. The end result is a new model that constrains the coevolution of damage, He diffusivity, and He date in zircon as a function of its actinide content and thermal history. The second and third appendices use this new model to decipher zircon He datasets comprising many single grain dates that are correlated with effective uranium (eU, a proxy for the relative degree of radiation damage among grains from the same sample). The model is critical for proper interpretation of results from igneous settings that show date-eU correlations and were once considered spurious (appendix B). When applied to partially reset sedimentary rocks, other sources of date variability, such as damage and He inheritance, have to be considered as well (appendix C).
    • Zola's theory and practice in the genealogical novel

      Wright, Grace, 1901- (The University of Arizona., 1939)