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Modeling and testing of a milliwatt hydrokinetic turbine for pressure energy harvesting
Get PDFTechnologies such as telemetry and remote sensing systems are commonly used to gain information that is not easily obtainable by the researcher. The challenge, however, is that these systems do not have access to an external power supply once deployed in a desolate location. This limits their lifespan to the energy density of an on-board battery and creates a constraint on their sensing capabilities and data resolution. Often times the batteries are not rechargeable and need to be replaced, which is especially difficult and costly for marine telemetry systems, as they are typically encased in epoxy resin to withstand high pressures at depth. Such systems would benefit greatly from energy harvesting. In the marine environment, the great pressures that are experienced at depth provide a vast amount of potential energy that can be harvested. Marine animals equipped with telemetry tags are the perfect candidates as many species make frequent dives while foraging or migrating. This energy can be converted to mechanical and electrical energy with the use of a turbine, which is commonly used for small to large-scale energy production. However, turbines on the scale needed for this application is not readily available. There has been an increase in the research of millimeter-scale turbines for small power generation, but they are usually air or gas powered and few provide an in-depth analysis of the efficiencies of these systems. This thesis focuses on the development and testing of a millimeter-scale hydrokinetic turbine for harvesting energy for marine telemetry tags and like-systems. An analytical model is developed using common turbomachinery concepts and compared to experimental results of a turbine prototype to identify and quantify sources of loss. Each identified loss is thoroughly explained as it is applied to the model and suggested design improvements are discussed. The model is used to make predictions of turbine performance given a higher input pressure for assessment of the viability of this transduction method for the intended application. The model and design presented provides useful information for future exploration of miniature turbine technology for powering remote micro-systems and insight into pressure energy harvesting capabilities
Severe thermoregulatory deficiencies in mice with a gene deletion in titin
Get PDFMuscular dystrophy with myositis (mdm) mice, which carry a deletion in the muscle protein titin, shiver at a lower than expected frequency for their body size, have body temperatures that decrease below ambient temperatures of 34°C, and have reduced active muscle stiffness in vivo compared to their wild type siblings. The impairment in shivering thermogenesis could be due to the N2A deletion in the titin protein leading to more compliant muscles and lower shivering frequency. I hypothesized that the ability of mdm mice to use the other heat production mechanism, nonshivering thermogenesis (NST), may also be impaired and contribute to their hypothermic state. To assess the response to cold exposure, body temperature and metabolic rate were measured in wild type and mdm mice using open-flow respirometry at four ambient temperature ranges: 19-21°C, 23-25°C, 27-30°C, and 33-35°C. Following the temperature experiment, NST was maximally stimulated by administering 1.2 mg kg-1 of norepinephrine subcutaneously. In the temperature experiment, there was a significant interaction between genotype and temperature, with mdm mice having significantly higher metabolic rates at 27-30°C and lower metabolic rates at 23-25°C compared to wild type mice. After correcting metabolic rate for Q10 effects, mdm mice had lower metabolic rates compared to size-matched Perognathus longimembris (little pocket mouse). In addition, the capacity for NST estimated by area underneath the metabolic response curve was also reduced in mdm mice compared to wild type littermates. When comparing mdm mice to other mice with similar body mass (7g), the effects of low metabolic rate and capacity for NST were exacerbated because predicted values of metabolic rate and capacity for NST are larger for smaller animals. These results indicate that a deletion in N2A titin causes severe thermoregulatory defects at every level of thermoregulation, including NST. Direct effects of the titin mutation likely lead to the lower shivering frequency observed. Indirect effects likely lead to a lower capacity for NST and metabolism in general. Future studies should investigate effects on oxidative phosphorylation or other signaling pathways
Nations united through discourse: a corpus analysis of UN general assembly addresses
Get PDFThe overarching goal of this dissertation is to investigate the linguistic features of United Nations (UN) General Assembly (GA) General Debate addresses delivered in English during 2015. In order to describe UNGA addresses with the greatest accuracy, breadth, and depth, the study explores typical linguistic features across texts as well as variation within the register. Thus, the dissertation also examines the geographic, political, economic, and social profile of the countries represented in the UNGA in order to identify any country-related characteristics associated with systematic linguistic variation. The dissertation uses two corpus-informed methodologies: register analysis and Corpus-Assisted Discourse Studies (CADS), with a secondary goal of discerning the ways in which methodology affects the nature of findings.
The study is based on a corpus of all 92 UNGA addresses delivered in English during the General Debate in 2015. In the examination of linguistic features across UNGA addresses, the UN texts are contrasted with the British National Corpus as well as four comparable registers: prepared speeches, spontaneous speeches, official documents, and conversation. The analysis begins with a description of situational characteristics for the UNGA and the four comparison registers. Then keywords and Multi-Dimensional scores for the five principal dimensions found in Biber (1988) reveal the lexical and grammatical features that characterize the UNGA. The second part of the investigation looks at variation among UNGA addresses, with texts divided into groups based on country-specific characteristics such as region and Gross Domestic Product. Keyword analysis, key feature analysis, and Multi-Dimensional analysis are used to identify systematic variation of linguistic features based on country group. The final analysis is a CADS study of three frequent and politically salient terms (terrorism, Security Council, and women) with keyword and collocational analyses to determine how the terms are conceptualized generally in the UNGA and also whether any variation can be identified for country groups.
Results show a remarkable consistency across the UNGA not only in what lexical and grammatical features are preferred and dispreferred but also in how they are used. Lexical features reveal the importance of topic, purpose, and discourse structure. Grammatical features are greatly influenced by written-to-be-spoken production circumstances and purpose. In spite of the large number of features (126) and country groups (31) explored, very few exhibit any systematic patterns of variation. The variation that does occur is primarily associated with level of development and region. The CADS analysis supports the register analysis, showing that UNGA texts tend to conceptualize politically charged terms in similar ways with only occasional variation based on country group. These findings have important implications for the field of political discourse analysis, furthering our understanding of the linguistic features of international organization spoken discourse. In addition, the CADS analysis demonstrates some important methodological considerations, with consequences for the design of future corpus-informed research
Radial and Non-radial Numerical Solutions to the Non-linear Elliptic BVP on the Disk
No full textIn the last few decades, much research has gone into proving the existence
of solutions to the non-linear elliptic partial differential equations (PDEs) with
0 - Dirichlet boundary conditions on the unit disk. Following the work of Luna
and Swift in [15], we seek to find numerical solutions to a PDE of this type
and investigate certain salient accompanying questions. We concentrate on find-
ing radial-only solutions and investigating the behavior of secondary solution
branches bifurcating from those radial ones
An analysis of culturally significant plants, springs, and archaeology at Grand Staircase-Escalante National Monument, Utah
No full textLaws protecting cultural and natural heritage help ensure that important places are respected and protected. The Antiquities Act of 1906, in protecting places of significance, from Grand Canyon, Arizona, to Grand Staircase, Utah, reminds us of the importance of preserving the best of our natural and cultural heritage, for benefit of all. Places of significance are integral to our cultural identity, have garnered appreciation cross-culturally, and provide opportunity for learning how to live sustainably in a healthy world.
The responsibility of protecting important places has been led by historians and archaeologists, creating bias toward sites identified as a result of historical or archaeological study. People who emphasize this configuration of responsibility often neglect to consider natural places of significance that lack archaeology or historical documentation. Traditional Cultural Place theory guides us back toward the intent of the Antiquities Act, that we may ensure due consideration of natural places, as informed by the communities that value them.
The purpose of this thesis is to draw attention to the importance of natural places from Indigenous perspectives, with focus on plants and springs sites. Toward this end, I conducted two seasons of ethnobotanical and archaeological surveys in vicinity of springs sites on Grand Staircase-Escalante National Monument, Utah. These data were used to explore and analyze patterns of interest to the studies of ethnobotany, ecological anthropology, archaeology, biology, hydrology, and environmental sustainability. The results of this thesis demonstrate the central importance of springs to human settlement and subsistence, for the majority of human history in the southwestern United States. The goal of this project is to help better respect and protect places of traditional and continuing importance, for generations to come
Scattered, smothered, and covered: the cultural significance of terminal classic deposits at Baking Pot, Belize
Get PDFThroughout the Maya lowlands, archaeologists have identified deposits associated with the final activities in ceremonial and domestic spaces that date to the Terminal Classic period (AD 700-1000). These features include concentrations of cultural material deposited in the corners of plazas and courtyards. At the site of Baking Pot, Belize, the Belize Valley Archaeological Reconnaissance (BVAR) project has identified several of these peri-abandonment deposits. This thesis will shed light on the types of artifacts that were deposited during these final events to answer questions related to the nature of abandonment activities. I also employ these data to identify the cultural significance of ritual deposition of cultural materials to ascertain how distinct combinations of artifact classes can yield information on human behavior, and to demonstrate how the peri-abandonment deposits at Baking Pot offer additional information about abandonment activity in the Maya lowlands
The role of content-rich visuals in the L2 academic listening assessment construct
Get PDFDespite the growing recognition that second language (L2) listening is a skill incorporating the ability to process visual information along with the auditory stimulus, standardized L2 listening assessments have been predominantly operationalizing this language skill as visual-free (Buck, 2001; Kang, Gutierrez Arvizu, Chaipuapae, & Lesnov, 2016). This study has attempted to clarify the nature of the L2 academic listening assessment construct regarding the role of visual information.
This goal was achieved by developing an interpretive argument for including video-based visuals in L2 academic listening tests. Particular attention was paid to the role of content-related visuals that provided graphical illustration, description, or explanation of the auditory listening message. Using Kane’s validity framework, the explanation inference was of primary concern to this study because it is used to justify the measured construct (Kane, 1992; 2004; 2006; 2013).
The explanation inference was supported by two types of evidence. First, the performances of 143 English as a second language (ESL) and English as a foreign language (EFL) students on an academic English listening comprehension test were quantitatively analyzed for the effect of delivery mode (i.e., audio-only vs video-based) and its relationships with test-takers’ listening proficiency (i.e., lower vs higher), item video-dependence (i.e., whether or not an item was cued by video), item type (i.e., local vs global), and viewing behavior (self-reported on a scale from 1-did not watch the video to 5-watched all of the video). Analyses were based on both classical test theory (i.e., ANOVA and correlations) and item response theory (i.e., Rasch analysis). In the video-based version of the test, content-rich videos were used, defined as videos containing relevant graphical content-related visual cues for 60% of the video length.
The findings showed that video-dependent items were easier with videos than without for both lower-level and higher-level test-takers, regardless of item type. Video-independent items were unexpectedly harder with videos in general. In particular, video-independent global items were harder in the video-based mode than in the audio-only mode for lower-level test-takers. Viewing behavior had a weak positive relationship with listening comprehension, regardless of proficiency.
Second, stakeholders’ perceptions about using content-rich videos were investigated. Using a questionnaire, the same 143 test-takers provided their perceptions of test difficulty, motivation towards listening, listening authenticity, and whether content-rich videos should be used in high-stakes academic listening tests. The effects of mode and proficiency on these perceptions were examined. Similarly, 310 ESL and EFL teachers provided their opinions about the effects of content-rich videos on listening difficulty, motivation, authenticity, and using content-rich videos in L2 listening tests. The effects of teachers’ background (i.e., professional location, education level, and teaching-related experience) on their perceptions were examined.
Test-takers found the video-based mode easier than the audio-only mode; however, their perceptions of motivation, authenticity, and using videos in tests were not affected by mode. Regarding video use perceptions, test-takers were in favor of including content-rich videos in L2 academic listening tests. Teachers were more favorable towards the video-based mode than the audio-only mode in terms of listening difficulty, motivation, authenticity, and using videos in L2 academic listening tests.
The study has discussed how these findings supported the interpretive argument for including content-rich video-based visual information into the assessment construct of L2 academic listening comprehension. Challenges revealed by the findings were also addressed, with limitations acknowledged. The study also offered theoretical and practical implications for the field of L2 assessment. As its primary implication, the study recommends that test developers start using content-rich visual information in L2 academic listening tests
The bioaccumulation of uranium in sheep heart and kidney: the impact of contaminated traditional food sources on the Navajo Reservation
No full textUranium ore was mined on the Colorado Plateau, which overlaps the majority of the Navajo Nation. There were various mining sites all across the Navajo Nation including Cameron, AZ where open pit mining occurred. The purpose of this study is to investigate uranium contamination of sheep on the Navajo Nation collected near Cameron and Leupp, AZ. Navajo rely on sheep as part of their traditional diet. This research seeks to characterize uranium exposure and accumulation with respect to grazing on or near abandoned uranium mine sites. The sheep tissue samples were analyzed using inductively coupled plasma mass spectrometry (ICPMS).
Sheep exposed to uranium near the mine sites in Cameron are compared to a control group that grazes in areas that were not mined on the reservation (Leupp), and an overall control site off the reservation (Eagar). The request was made from the communities of Cameron and Leupp to study the sheep for uranium. The results indicate that there are measurable levels of uranium in the meat and tissue of sheep from both Leupp and Cameron. The organs analyzed were the kidney and heart; the uranium levels ranged from 50 to 200 ppb. The results from Cameron and Leupp were relatively similar, a t-test confirmed inclusiveness, due to variation in the sample. The next step is incorporating an additional site off the reservation, Eagar, AZ. The results suggest the reservation sites (Cameron and Leupp) are statistically higher than the off-reservation site (Eagar). The results of our research will be used to develop policy for the Navajo Nation with respect to contamination of traditional foods
Acute stress response to the "panel-out" Trier Social Stress Test and encounters of racial discrimination in African American and White college students
No full textEncounters of racial discrimination are appraised as chronic stressors and activate the hypothalamic-pituitary-adrenocortical (HPA) axis. Members of racial minority groups experience significantly more racial discrimination and disproportionately high prevalence rates of chronic illnesses, both associated with chronic HPA axis activation. To date, much is unknown about stress responses among healthy African Americans. The present study investigated acute HPA axis activation to the "panel-out" Trier Social Stress Test (TSST) among healthy African American and White college students. Salivary cortisol and blood pressure (BP) were measured before and after the TSST, and participants were asked about their encounters with racial discrimination. It was hypothesized that there would be differences between African American and White participants in encounters with racial discrimination, baseline cortisol, and cortisol and BP measurements post-TSST. Results indicated that compared to White participants (n = 24), African American participants (n = 9) experienced significantly more racial discrimination. There were no significant differences in baseline cortisol, and cortisol and BP in response to the TSST between groups. There were significant increases in cortisol and BP following the TSST, indicating successful implementation of the panel-out protocol. Due to the small sample, cautious interpretation of the analyses for the cortisol data are suggested as the obtained power for these analyses ranged from .080-.321. Adequate power was obtained for the analyses of the discrimination measure and the BP data. The findings for the discrimination measures may support the cumulative nature of allostatic load, and suggest nuances in cognitive appraisal and coping mechanisms suggested by Lazarus and Folkman (1984). Future research should account for factors associated with a blunted stress response, investigate whether blunted stress responses are seen in members of other racial minority groups, and be more critical of the responder criteria applied to cortisol data
Urban Agriculture: Food, Connection, Community Restoring Resilience in Phoenix, Arizona
No full textAgriculture in the US is dominated by corporate ownership of food and industrial agriculture. Industrial ag utilizes practices, like monocropping and pesticide use, that undermine the long-term ecological health of food systems. Agriculture is a social-ecological system, meaning it has ecological and social implications. Food is a powerful confluence of culture, community, and identity and the way our corporately owned, industrial food system operates, undermines these relationships. Large cities, like Phoenix Az, are already experiencing ecological degradation, social inequity, food insecurity, and other negative impacts related to industrial agriculture and our food system. Climate change is projected to exacerbate these impacts with changes in water availability and increased temperatures. Urban agriculture has been used a mechanism for increasing the resilience or adaptability of nations in response to crisis.
Semi-structured interviews and participant observations were utilized for this study. The study was comprised of eleven semi-structured interviews, 26 informal interviews, four events of participant observations, observed 42 garden participants in six gardens, three of which were “bottom-up, community-based, collaborative effort” and three non-profit gardens. Each garden was located within a sixteen mile radius of Central City Phoenix and the furthest distance between study gardens was 25 miles. The data was coded and four themes emerged: resources, ecology, food security, and community. Resources was the most comprehensive theme with three codes including time, infrastructure, and knowledge. The theme of ecology is referring to the growing practices at each garden. Food security was discussed by all respondents either through donations to the local food bank, volunteer harvests, and knowledge sharing. Community was challenging to define, but evident through every interview and observational experience. The sense of community was unique to each garden.
Urban agriculture is happening throughout Phoenix as community gardens, non-profit organizations, for-profit entities, or educational platforms. Based on my data and experiences, I do believe that urban agriculture in Phoenix is helping to promote social-ecological resilience and food security, but these efforts are still in their infancy. The scale of these efforts are small and the relationships made in the gardens appear to be more surface level remaining primarily in the garden. One respondent described having a sense of tribe with other garden participants. This deep sense of relationship with members of their community it important to the development of socio-ecological resilience in response to changing circumstances. There were many barriers discussed throughout my research, but the four most significant were culture, economy, political, and time