Matching Items (6)
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- All Subjects: Sustainability
- All Subjects: Audio amplifiers--Design and construction.
- All Subjects: efficiency
- Member of: ASU Electronic Theses and Dissertations
- Status: Published
Description
Research has shown that the ability to smell is the most direct sense an individual can experience. With every breath a person takes, the brain recognizes thousands of molecules and makes connections with our memories to determine their composition. With the amount of research looking into how and why we smell, researchers still have little understanding of how the nose and brain process an aroma, and how emotional and physical behavior is impacted. This research focused on the affects smell has on a caregiver in a simulated Emergency Department setting located in the SimET of Banner Good Samaritan Medical Center in Phoenix, Arizona. The study asked each participant to care for a programmed mannequin, or "patient", while performing simple computer-based tasks, including memory and recall, multi-tasking, and mood-mapping to gauge physical and mental performance. Three different aromatic environments were then introduced through diffusion and indirect inhalation near the participants' task space: 1) a control (no smell), 2) an odor (simulated dirty feet), and 3) an aroma (one of four true essential oils plus a current odor-eliminating compound used in many U.S. Emergency Departments). This study was meant to produce a stressful environment by leading the caregiver to stay in constant movement throughout the study through timed tasks, uncooperative equipment, and a needy "patient". The goal of this research was to determine if smells, and of what form of pleasantness and repulsiveness, can have an effect on the physical and mental performance of emergency caregivers. Findings from this study indicated that the "odor eliminating" method currently used in typical Emergency Departments, coffee grounds, is more problematic than helpful, and the introduction of true essential oils may not only reduce stress, but increase efficiency and, in turn, job satisfaction.
ContributorsClark, Carina M (Author) / Bernardi, Jose (Thesis advisor) / Heywood, William (Committee member) / Watts, Richard (Committee member) / Rosso, Rachel (Committee member) / Arizona State University (Publisher)
Created2013
Description
ABSTRACT Recent studies indicate that top-performing companies have higher-performing work environments than average companies. They receive higher scores for worker satisfaction with their overall physical work environment as well as higher effectiveness ratings for their workspaces (Gensler, 2008; Harter et al., 2003). While these studies indicate a relationship between effective office design and satisfaction they have not explored which specific space types may contribute to workers' overall satisfaction with their physical work environment. Therefore, the purpose of this study is to explore the relationship between workers' overall satisfaction with their physical work environments and their perception of the effectiveness of spaces designed for Conceptual Age work including learning, focusing, collaborating, and socializing tasks. This research is designed to identify which workspace types are related to workers' satisfaction with their overall work environment and which are perceived to be most and least effective. To accomplish this two primary and four secondary research questions were developed for this study. The first primary question considers overall workers' satisfaction with their overall physical work environments (offices, workstations, hallways, common areas, reception, waiting areas, etc.) related to the effective use of work mode workspaces (learning, focusing, collaborating, socializing). The second primary research question was developed to identify which of the four work mode space types had the greatest and least relationship to workers' satisfaction with the overall physical work environment. Secondary research questions were developed to address workers' perceptions of effectiveness of each space type. This research project used data from a previous study collected from 2007 to 2012. Responses were from all staff levels of US office-based office workers and resulted in a blind sample of approximately 48,000 respondents. The data for this study were developed from SPSS data reports that included descriptive data and Pearson correlations. Findings were developed from those statistics using coefficient of determination.
ContributorsHarmon-Vaughan, Elizabeth (Author) / Kroelinger, Michael D. (Thesis advisor) / Bernardi, Jose (Committee member) / Ozel, Filiz (Committee member) / Arizona State University (Publisher)
Created2013
Description
Efficiency of components is an ever increasing area of importance to portable applications, where a finite battery means finite operating time. Higher efficiency devices need to be designed that don't compromise on the performance that the consumer has come to expect. Class D amplifiers deliver on the goal of increased efficiency, but at the cost of distortion. Class AB amplifiers have low efficiency, but high linearity. By modulating the supply voltage of a Class AB amplifier to make a Class H amplifier, the efficiency can increase while still maintaining the Class AB level of linearity. A 92dB Power Supply Rejection Ratio (PSRR) Class AB amplifier and a Class H amplifier were designed in a 0.24um process for portable audio applications. Using a multiphase buck converter increased the efficiency of the Class H amplifier while still maintaining a fast response time to respond to audio frequencies. The Class H amplifier had an efficiency above the Class AB amplifier by 5-7% from 5-30mW of output power without affecting the total harmonic distortion (THD) at the design specifications. The Class H amplifier design met all design specifications and showed performance comparable to the designed Class AB amplifier across 1kHz-20kHz and 0.01mW-30mW. The Class H design was able to output 30mW into 16Ohms without any increase in THD. This design shows that Class H amplifiers merit more research into their potential for increasing efficiency of audio amplifiers and that even simple designs can give significant increases in efficiency without compromising linearity.
ContributorsPeterson, Cory (Author) / Bakkaloglu, Bertan (Thesis advisor) / Barnaby, Hugh (Committee member) / Kiaei, Sayfe (Committee member) / Arizona State University (Publisher)
Created2013
Description
Class D Amplifiers are widely used in portable systems such as mobile phones to achieve high efficiency. The demands of portable electronics for low power consumption to extend battery life and reduce heat dissipation mandate efficient, high-performance audio amplifiers. The high efficiency of Class D amplifiers (CDAs) makes them particularly attractive for portable applications. The Digital class D amplifier is an interesting solution to increase the efficiency of embedded systems. However, this solution is not good enough in terms of PWM stage linearity and power supply rejection. An efficient control is needed to correct the error sources in order to get a high fidelity sound quality in the whole audio range of frequencies. A fundamental analysis on various error sources due to non idealities in the power stage have been discussed here with key focus on Power supply perturbations driving the Power stage of a Class D Audio Amplifier. Two types of closed loop Digital Class D architecture for PSRR improvement have been proposed and modeled. Double sided uniform sampling modulation has been used. One of the architecture uses feedback around the power stage and the second architecture uses feedback into digital domain. Simulation & experimental results confirm that the closed loop PSRR & PS-IMD improve by around 30-40 dB and 25 dB respectively.
ContributorsChakraborty, Bijeta (Author) / Bakkaloglu, Bertan (Thesis advisor) / Garrity, Douglas (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2012
Description
ABSTRACT
Recent studies indicate that there is a positive influence of nature and nature integrated built environments on human health and wellness in various physical, physiological and social domains. This thesis critically reviews formally and contextually three distinct residential typologies designed by renowned architects Frank Lloyd Wright (1867-1959), Lina Bo Bardi (1914-1992), and Ryue Nishizawa (1966-), in different periods and countries; the United States of America (USA), Brazil and Japan. Yet, the buildings analyzed in the research are relatively connected by means of nature and the natural elements in their constructed essence. This research focuses on the features of the buildings that characterize the Biophilic Design, along with theoretical and practical ideas of the architects behind each building in their own process of formation.
The Biophilic Design Framework has been developed out of the Biophilia Hypothesis (Fromm, 1973; Wilson, 1984) which puts forward an explanatory suggestion that human affinity and affiliation with nature are based on genetic and environmental adaptation processes. This research is designed to display how specific natural phenomena apply to the built environment within the Framework of Biophilic Design (Kellert, & Calabrese, 2015) and how the Biophilia Hypothesis translates into the built environment. To accomplish this, two primary and three secondary research questions were developed for the study. The research will provide an understanding of the Biophilia Hypothesis and its impact on the built environment through the evaluation of research variables on the case studies using the ‘twenty-four attributes’ indicated in the ‘three experiences’ of Biophilic Design.
These architects’ approaches and the methods applied theoretically and practically to these research sites were unveiled and analyzed through three case studies. A positive correlation regarding the success of the case studies and their Biophilic characteristics is found by analyzing the research sites and critiques from the authorities in written literature. The applicability of the ‘Biophilic Design Framework’ was found and evidenced by the findings from these case studies designed by master architects and located in different climates, regions and contexts.
Recent studies indicate that there is a positive influence of nature and nature integrated built environments on human health and wellness in various physical, physiological and social domains. This thesis critically reviews formally and contextually three distinct residential typologies designed by renowned architects Frank Lloyd Wright (1867-1959), Lina Bo Bardi (1914-1992), and Ryue Nishizawa (1966-), in different periods and countries; the United States of America (USA), Brazil and Japan. Yet, the buildings analyzed in the research are relatively connected by means of nature and the natural elements in their constructed essence. This research focuses on the features of the buildings that characterize the Biophilic Design, along with theoretical and practical ideas of the architects behind each building in their own process of formation.
The Biophilic Design Framework has been developed out of the Biophilia Hypothesis (Fromm, 1973; Wilson, 1984) which puts forward an explanatory suggestion that human affinity and affiliation with nature are based on genetic and environmental adaptation processes. This research is designed to display how specific natural phenomena apply to the built environment within the Framework of Biophilic Design (Kellert, & Calabrese, 2015) and how the Biophilia Hypothesis translates into the built environment. To accomplish this, two primary and three secondary research questions were developed for the study. The research will provide an understanding of the Biophilia Hypothesis and its impact on the built environment through the evaluation of research variables on the case studies using the ‘twenty-four attributes’ indicated in the ‘three experiences’ of Biophilic Design.
These architects’ approaches and the methods applied theoretically and practically to these research sites were unveiled and analyzed through three case studies. A positive correlation regarding the success of the case studies and their Biophilic characteristics is found by analyzing the research sites and critiques from the authorities in written literature. The applicability of the ‘Biophilic Design Framework’ was found and evidenced by the findings from these case studies designed by master architects and located in different climates, regions and contexts.
ContributorsOrman, Pinar (Author) / Bernardi, Jose (Thesis advisor) / Harmon-Vaughan, Elizabeth (Committee member) / Zygas, Kestutis Paul (Committee member) / Heywood, William (Committee member) / Arizona State University (Publisher)
Created2017
Description
For most of our history humans have been closely tied to energy provided by the sun. Phases of light and dark initiate major biological functions within each day and regulate patterns of sleep and heightened alertness. Daylight was historically synonymous with sophisticated architecture, providing a mysterious play of light and illuminating productive tasks. It is only within the last 150 years that humans have sought to improve upon daylight, largely replacing it with artificially fueled systems. A new scientific approach to providing interior light has focused on the visible spectrum, negating the remainder of energy from our lives. This thesis considers the full spectrum of natural daylight, and its potential for improving human health, and well being. The literature review explores a brief history of solar architecture leading into the 21st century. A case study of the award winning Arabian Library in Scottsdale Arizona reveals four methods of passive daylight integration. A phenomenological ethnographic methodology assessed the impact of these four strategies on interior lighting quality, documented from the designer's perspective. As the science of photobiology continues to advance, it has become clearly evident that natural daylight provides more than mere illumination, and should be considered an essential element of the interior built environment.
ContributorsMarotta, Nickolas A (Author) / Bernardi, Jose (Thesis advisor) / Rowen, Marthe (Committee member) / Bauer, Kelly (Committee member) / Arizona State University (Publisher)
Created2013