BASS Code Development

The BASS computational aeroacoustic code solves the fully nonlinear Euler equations in the time domain in two-dimensions. The acoustic response of the stator is determined simultaneously for the first three harmonics of the convected vortical gust of the rotor. The spatial mode generation, propagation and decay characteristics are predicted by assuming the acoustic field away from the stator can be represented as a uniform flow with small harmonic perturbations superimposed. The computed field is then decomposed using a joint temporal-spatial transform to determine the wave amplitudes as a function of rotor harmonic and spatial mode order. This report details the following technical aspects of the computations and analysis. 1) the BASS computational technique; 2) the application of periodic time shifted boundary conditions; 3) the linear theory aspects unique to rotor-stator interactions; and 4) the joint spatial-temporal transform. The computational results presented herein are twofold. In each case, the acoustic response of the stator is determined simultaneously for the first three harmonics of the convected vortical gust of the rotor. The fan under consideration here like modern fans is cut-off at +, and propagating acoustic waves are only expected at 2BPF and 3BPF. In the first case, the computations showed excellent agreement with linear theory predictions. The frequency and spatial mode order of acoustic field was computed and found consistent with linear theory. Further, the propagation of the generated modes was also correctly predicted. The upstream going waves propagated from the domain without reflection from the in ow boundary. However, reflections from the out ow boundary were noticed. The amplitude of the reflected wave was approximately 5% of the incident wave. The second set of computations were used to determine the influence of steady loading on the generated noise. Toward this end, the acoustic response was determined with three steady loading conditions: design, low-loading, high-loading. The overall trend showed significant (approximately 10 dB) increases in the generated noise for the highly loaded stator

The politics of reliability a sociological examination of the State of Vermont's response to peak oil & climate change

The problems of global peak oil and global climate change are unlike any yet faced by modern industrial societies: every ecosystem and social system on the planet will be impacted. The U.S. Federal government appears to have abdicated responsibility for dealing with climate change and peak oil. So called “sub-national” forces–states, regions, and cities–subsequently have tried to pick up the slack. State efforts to help citizens prepare for, mitigate against, and adapt to peak oil and climate change have varied greatly. This dissertation examines the State of Vermont, which consumes the least amount of fossil fuels and generates the least amount of greenhouse gases of any state in the country. The thesis that Vermont, the “greenest state in the country,” is not acting reliably to help its citizens prepare for, mitigate against, or adapt to peak oil and climate change was largely borne out over the course of interviews with high ranking government employees and nonprofit organizations. Despite being the “greenest state in the country,” Vermont creates, in the words of one interviewee, “a dull tool,” for dealing with problems. Except for domain consensus that climate change is a problem,the majority of the characteristics of “high reliability organizations”–‘big picture’ communication and coordination, domain consensus, decentralized decision-making, extensive training, aggressive information seeking, and strong leadership–are not apparent in Vermont’s response to peak oil and climate change. This dissertation explains how the environment of organizations (e.g., sunk costs), organizationalcharacteristics (e.g., combinations of resources and schemas), and the cognitive practicesof individuals within organizations (e.g., political ideologies) undermines the characteristics of high reliability organizations. Although the details of this dissertation are specific to Vermont, the problems are likely endemic in other U.S. states and other forms of government. As state governments learn, shift gears, and recalibrate their activities to address the twin challenges of peak oil and climate change, it isimportant to recognize that the veneer of “greenness,” “high policy,” official representations of leadership, and technological infatuations, may mask underlying unreliable structures

Experimental Investigation of Drag Reduction by Trailing Edge Tabs on a Square Based Bluff Body in Ground Effect

This thesis presents an experimental investigation of drag reduction devices on a bluff body in ground effect. It has previously been shown that the addition of end-plate tabs to a rectangular based bluff body with an aspect ratio of 4 is effective in eliminating vortex shedding and reducing drag for low Reynolds number flows. In the present study a square based bluff body, both with and without tabs, will be tested under the same conditions, except this time operating within proximity to a ground plane in order to mimic the properties of bounded aerodynamics that would be present for a body in ground effect

Broadband Access for Students at East Tennessee State University

The purpose of this study was to determine the availability of Internet access for students attending East Tennessee State University during the fall semester 2013. It has been unknown to what degree broadband access is available in the East Tennessee State University service area that includes counties in East Tennessee, Southwest Virginia, and Western North Carolina. The research was conducted during the fall semester 2013 including the months of August, September, and October of 2011. Data were gathered by surveying currently enrolled students of the university. Seven hundred eighty-four students responded to the survey. The survey instrument covered areas of demographics and Internet connection type from home. In addition, the instrument covered usage of 3G/4G Mobile Broadband Service, ETSU computer labs, and high-speed Internet service for coursework. The results of the data analysis provided insight into the availability, frequency of use, and perceived importance of high-speed Internet access for students at ETSU. For example, over 95% of the respondents had either a high-speed Internet connection or 3G/4G Mobile Broadband Service at their place of residence. Fifteen percent were dissatisfied with their current high-speed Internet service. Approximately 70% reported that high-speed Internet service was very important in completing coursework. This study provided an increase in the body of knowledge related to Internet access for ETSU students and the counties surrounding the university

Effects of Hearing Loss on General Cognitive Health and Social Auditory Lifestyle within the Older Population

Hearing loss is a common medical condition associated with the elderly. Its impact on general cognitive health has been extensively studied, along with its association with social auditory lifestyle. Hearing loss has been associated with a decline in both aspects (Lin, 2011a; Wu and Bentler, 2012), however, studies involving all three of these factors have yet to be performed. Further research is needed to encompass how these three facets, when combined, affect the elderly population. A literature review of 21 articles was conducted in order to reveal how hearing loss is associated with general cognitive health and social auditory lifestyle

Grieving Without God: Comparing Posttraumatic Growth, Complicated Grief, and Psychological Distress in Believers and Atheists During Bereavement

The purpose of this dissertation was to examine coping and outcomes of grief for atheist individuals during bereavement. The landscape of grief research has significantly changed since the days of Freud, and widely accepted stage theory models of grief have not held up to empirical review (Wortman & Silver, 1989). Emerging research examines factors that may lead to positive changes as a result of loss or trauma, known as posttraumatic growth. However, atheist individuals continue to be an understudied group in the psychological and bereavement literature, while people with religious beliefs continue to receive the most focus (Brewster, Robinson, Sandil, Esposito, & Geiger, 2014; D’Andrea & Sprenger, 2007). This study explored how cognitive (e.g., assumptions about the world), existential (e.g., meaning), and behavioral (active and emotional) coping methods are associated with posttraumatic growth, complicated grief, and psychological distress in a believer and atheist sample after the death of a close friend or family member. Specifically, posttraumatic growth, complicated grief, and psychological distress were regressed onto the three types of coping (cognitive, existential, and behavioral) using a hierarchical regression analysis. The first analysis controlled for demographic variables and the second analysis consisted of matched groups on demographic variables that were found to be associated with grief outcomes in prior research (e.g., Bonanno et al., 2008; Bonanno, Galea, Bucciarelli, & Vlahov, 2007). Exploratory bivariate correlations were conducted to assess interrelations between the variables of interest. Additionally, MANOVA was used to assess differences in demographic variables between the believer and atheist sample. Significant cognitive, existential, and behavioral coping methods were found to be associated with posttraumatic growth, complicated grief, and psychological distress. Furthermore, the endorsement of a belief in God(s) was significantly and positively associated with posttraumatic growth, but also significantly and positively associated with complicated grief and psychological distress. Results from this study can be used to identify appropriate clinical strategies for counselors working with grieving atheists, and will deepen the breadth of literature on bereavement and coping within diverse populations. Limitations and directions for future research are also discussed

Measuring current consumption of locally grown foods in Vermont: Methods for baselines and targets

Numerous studies have measured the economic impact of increased consumption of locally grown foods, and many advocates have set goals for increasing consumption of locally grown foods to a given percentage. In this paper, we first apply previously developed methods to the state of Vermont, to measure the quantity and value of food that would be consumed if the USDA Dietary Guidelines were followed. We also assess the potential of locally grown foods to meet these guidelines, finding that meeting dietary guidelines with a local, seasonal diet would bring economic benefit, in this case, US$148 million in income for Vermont farmers. A missing piece of information has been: what is the current percentage of locally grown food being consumed in a given city, state, or region? The Farm to Plate Strategic Plan, a 10- year plan for strengthening Vermont’s food system, attempted to answer this question. To date, we know of no credible set of methods to precisely measure the percentage of food consumed that is locally grown. We collect data from a variety of sources to estimate current local consumption of food. We were able to measure and account for about US$52 million in local food expenditures, equal to about 2.5% of all food expenditures in Vermont. We then discuss limitations and suggestions for improving measurement methods moving forward

Pathfinder Technology Demonstrator: Demonstrating Novel CubeSat Technologies in Low Earth Orbit

NASA\u27s Pathfinder Technology Demonstrator (PTD) project will test the operation of a variety of novel CubeSat technologies in low-Earth orbit, providing significant enhancements to the performance of these small and effective spacecraft. Each Pathfinder Technology Demonstrator mission will consist of a 6-unit (6U) CubeSat weighing approximately 12 kilograms and measuring 30 centimeters x 25 centimeters x 10 centimeters. The PTD project led by NASA\u27s Ames Research Center at Moffett Field, California, in collaboration with NASA\u27s Glenn Research Center in Cleveland, Ohio and a commercial partner will benefit future missions by demonstrating the operation of new subsystem technologies on orbit. These technologies include propulsion systems that provide the capability to maneuver small science platforms and send small spacecraft to deep space; novel technologies to stabilize spacecraft, and laser communications systems that will greatly increase the amount of data that can be transmitted from the spacecraft to the ground. As small spacecraft increase mobility and capability, NASA benefits by flight-qualifying these subsystems, providing access to low cost, highly capable, science and technology platforms that can operate from the near-Earth to the deep space environment. The PTD mission is funded through NASA\u27s Small Spacecraft Technology Program (SSTP), which is chartered to develop and mature technologies to enhance and expand the capabilities of small spacecraft with a particular focus on communications, propulsion, pointing, power, and autonomous operations. The SSTP is one of nine programs within NASA\u27s Space Technology Mission Directorate. This paper will include an overview of the PTD project, the PTD spacecraft bus interfaces and capabilities as an adaptable, commercially developed small satellite bus for LEO technology demonstration, potential types of payloads, expected timeframe and flights, and how the PTD project will be a pathfinder for novel small spacecraft technologies to be flight demonstrated for science, commercial, and governmental use