Dynamic and thermal analysis of high speed tapered roller bearings under combined loading

The development of a computer program capable of predicting the thermal and kinetic performance of high-speed tapered roller bearings operating with fluid lubrication under applied axial, radial and moment loading (five degrees of freedom) is detailed. Various methods of applying lubrication can be considered as well as changes in bearing internal geometry which occur as the bearing is brought to operating speeds, loads and temperatures

Effects of management practices on reflectance of spring wheat canopies

The effects of available soil moisture, planting date, nitrogen fertilization, and cultivar on reflectance of spring wheat (Triticum aestivum L.) canopies were investigated. Spectral measurements were acquired on eight dates throughout the growing season, along with measurements of crop maturity stage, leaf area index, biomass, plant height, percent soil cover, and soil moisture. Planting date and available soil moisture were the primary agronomic factors which affected reflectance of spring wheat canopies from tillering to maturity. Comparisons of treatments indicated that during the seedling and tillering stages planting date was associated with 36 percent and 85 percent of variation in red and near infrared reflectances, respectively. As the wheat headed and matured, less of the variation in reflectance was associated with planting date and more with available soil moisture. By mid July, soil moisture accounted for 73 percent and 69 percent of the variation in reflectance in red and near infrared bands, respectively. Differences in spectral reflectance among treatments were attributed to changes in leaf area index, biomass, and percent soil cover. Cultivar and N fertilization rate were associated with very little of the variation in the reflectance of these canopies

NASA ROVER, Tackling Citizen Science With Grand Challenges and Everyday Problems

ROVER is the Citizen Science arm of the NASA Clouds and the Earth's Radiant Energy System (CERES) Students' Cloud Observations On-Line (S'COOL) Project. Since 2007, participants around the world have been making and reporting ground truth observations of clouds to assist in the validation of the NASA CERES satellite instrument. NASA scientists are very interested in learning how clouds affect our atmosphere, weather, and climate (relating to climate change). It is the clouds, in part, that affect the overall temperature and energy balance of the Earth. The more we know about clouds, the more we will know about our Earth as a system and citizen scientists are an important piece of that puzzle! As a ROVER cloud observer, all participants follow simple online tutorials to collect data on cloud type, height, cover and related conditions. Observations are sent to NASA to be matched to similar information obtained from satellites and sent back to participants for comparison and analysis. The supporting ROVER website houses a searchable database archiving all participant reports and matching satellite data. By involving Citizen Scientists in cloud observations and reporting we can gain a valuable set of data that would have been previously unavailable to science teams due to funding, manpower, and resource limitations or would have taken an unreasonable amount of time to collect. Reports from a wide range of Citizen Scientist locations are helpful to assess the satellite data under different conditions. With nothing more than their eyes and an internet connection participants provide a different perspective and analysis of clouds, adding to a more complete picture of what's happening in the atmosphere in which we live

Lichtenberger and The Three Bears: Getting the Private Search Exception and Modern Digital Storage Just Right

Finding a happy medium is hard. Often, it is a challenge to find a workable balance between two unworkable extremes. Known as the “Goldilocks Principle,” this phenomenon has been observed in fields as diverse as developmental psychology and astrobiology. As Goldilocks found in the Three Bears’ house, “just right” may not come on the first attempt. We may have to explore the extremes of the spectrum—“too hot” and “too cold”—before we can settle on “just right. Goldilocks also discovered that this process is all the more difficult in a new environment—like the Three Bears’ house. Goldilocks persevered, however, until she found “just right.” Federal courts face a similar dilemma in the private search exception to warrant requirements under the Fourth Amendment. On one hand are legitimate individual privacy interests and on the other, the legitimate interests of law enforcement to protect society. Courts must not handcuff law enforcement agents in their duties in the name of individual privacy (“too cold”), but neither should they unreasonably curtail individual liberty by giving too much latitude to legitimate government interests (“too hot”). It is no small task to identify an appropriate compromise between the competing principles of protecting the privacy of American citizens and protecting American citizens from crime. Like Goldilocks, courts today also face this challenge in an unfamiliar world. What is the “just right” application of the private search exception in the world of digital storage devices, which hold staggeringly large amounts of data and whose structure challenges traditional Fourth Amendment concepts

Natural histories of Yup'ik memoirs

Thesis (M.A.) University of Alaska Fairbanks, 2017This thesis explores how cultural knowledge is committed to textual form and circulated within and outside of linguistically marginalized communities. Working within a Central Yup'ik context, I have focused my research on collections of Yup'ik elders' memoirs housed within the Alaska Native Language Archive. Published Yup'ik elders' memoirs offer rich descriptions of Yup'ik cultural histories, epistemologies and statements about language, the expression and inclusion of which varies based on the interactional contexts, participant frameworks and funding institutions through which they were produced. This study incorporates both Indigenous and non-Indigenous theoretical frameworks related to the process of entextualization, or text creation, and the transmission of cultural knowledge. Drawing from archival materials and interviews with participants involved in their production and circulation, I identify the relevant linguistic ideologies and participant frameworks involved in the creation of these publications or "text artifacts" and frame my analysis with respect to the following research questions: How have published memoirs of Yup'ik elders emerged as a culturally salient genre of text? Who are the primary participants in the production, publication and circulation of Yup'ik memoirs? How do issues of identity, agency, authenticity and essentialism shape the form, thematic content and circulation of Yup'ik memoirs in Alaska? This thesis seeks to identify the primary participants and ideologies contributing to the publication of Yup'ik elders' memoirs, as well as the visibility or erasure of these actors within the published text of the memoirs. I further explore the specific ways in which individual voices, tribal, political and academic institutions and their ideological goals presuppose and contribute to broader cultural processes and shape the linguistic structure and content of textual artifacts produced. Although the documentation, description and analysis of Yup'ik language and culture has received sustained attention both within and outside the academy, this project is the first to investigate the processes and participant frameworks through which traditional Yup'ik cultural knowledge is entextualized and circulated as contemporary published text. This research offers significant insights into the collaborative efforts of Native and non-Native participants in the production of Yup'ik textual materials, while also contributing to a broader understanding of ideological goals and obstacles relative to processes of entextualization within communities facing marginalization or language endangerment within, and outside of, the circumpolar north. An analysis of the participants and ideologies shaping the production and circulation of Yup'ik memoirs provides and empirical framework for understanding the relationship between text artifacts and ongoing cultural processes, and contributes to an increasingly reflexive approach to anthropological and sociolinguistic research concerning identity, authenticity and the entextualization of traditional knowledge

Role of vascular hyperpolarization in muscle blood flow regulation in healthy humans

2013 Spring.Includes bibliographical references.The following investigation composes a series of experiments with the overall aim of determining the role for vascular hyperpolarization via activation of inwardly-rectifying potassium (KIR) channels and Na+/K+-ATPase in the regulation of vascular tone in response to muscle contractions and ischaemia in young, healthy humans. We tested the general hypothesis that activation of KIR channels and Na+/K+-ATPase contributes in large part to the vasodilatory, hyperaemic, and sympatholytic responses observed in these conditions and this contribution is greater than that of other vasodilators, specifically nitric oxide (NO) and prostaglandins (PGs). The specific aims of each experiment were: 1) to determine whether K+-stimulated vascular hyperpolarization via activation of KIR channels and Na+/K+-ATPase mediates contraction-induced rapid vasodilatation in the human forearm; 2) to determine whether vascular hyperpolarization via activation of KIR channels and Na+/K+-ATPase contributes to the hyperaemic response at the onset of repeated muscle contractions, as well as to steady-state forearm blood flow during rhythmic handgrip exercise; 3) to determine whether vascular hyperpolarization via activation of KIR channels and Na+/K+-ATPase contributes to the observed blunting of sympathetically-mediated vasoconstriction that occurs during moderate intensity rhythmic forearm exercise; and 4) to determine whether vascular hyperpolarization via activation of KIR channels and Na+/K+-ATPase contributes to the observed reactive hyperaemia that occurs in the human forearm following release of temporary ischaemia. Our collective findings demonstrate a significant contribution of KIR channels and Na+/K+-ATPase activation to rapid vasodilatation following a single muscle contraction, the onset of exercise hyperaemia in response to repeated muscle contractions, steady-state muscle blood flow during rhythmic handgrip exercise and reactive hyperaemia following temporary ischaemia. In contrast to our hypothesis, we did not observe a significant contribution of KIR channels and Na+/K+-ATPase to the observed blunting of sympathetic α-adrenergic vasoconstriction that occurs during handgrip exercise. In all studies, any role of NO and PGs was modest, if present at all. Taken together, our findings indicate that during a variety of vasodilatory stimuli, there is a large contribution of pathways that are independent of NO and PGs, specifically activation of KIR channels and Na+/K+-ATPase. Hyperpolarization via activation of KIR channels and Na+/K+-ATPase represents a novel mechanistic pathway in the understanding of in vivo regulation of muscle blood flow in response to contractions and ischaemia. These findings may provide insight into understanding impaired vascular function in patient populations and as such, could represent a novel therapeutic target for reversing microvascular dysfunction

From Professor to Patient X

I walked into the classroom feeling nervous. It wasn\u27t my first time teaching undergraduate students about human endocrine physiology. I knew the material well. But today\u27s lecture was different. I pulled up slides depicting a hypothetical cancer patient and told them, “Patient X had a biopsy that detected invasive carcinoma in her breast.” I described the many months of chemotherapy, surgery, and radiation treatments she went through before going into remission. Then I taught the students about the hormonal therapy she was prescribed—drugs her doctor hoped would limit the growth of any remaining cancer cells and prevent a recurrence. On the final slide, I showed them a picture of me on my last day of chemotherapy. “I am patient X,” I revealed

Implementation of a speed sensorless vector controlled induction motor drive with zero speed start-up

In this thesis the implementation of a speed sensorless vector controlled induction motor drive with start-up from zero speed is studied. Both indirect vector control and direct vector control methods are used in the drive operation and are reviewed in chapter 2. A new control strategy using a hybrid vector control method is described. This new method allows the drive to start from zero speed without a speed sensor using indirect vector control and then transition to direct vector control. The hybrid vector control method and the outstanding features of this method are described in chapter 3. The drive was implemented in hardware using a 5 horsepower (HP) insulated gate bipolar transistor (IGBT) inverter, 5HP induction motor, and a Texas Instruments TMS320C30 digital signal processor (DSP). The hardware detail and DSP software implementation are described in chapter 4. The results from the experimental study are presented in chapter 5