Matching Items (10)
Description
In this thesis, an approach to develop low-frequency accelerometer based on molecular electronic transducers (MET) in an electrochemical cell is presented. Molecular electronic transducers are a class of inertial sensors which are based on an electrochemical mechanism. Motion sensors based on MET technology consist of an electrochemical cell that can be used to detect the movement of liquid electrolyte between electrodes by converting it to an output current. Seismometers based on MET technology are attractive for planetary applications due to their high sensitivity, low noise, small size and independence on the direction of sensitivity axis. In addition, the fact that MET based sensors have a liquid inertial mass with no moving parts makes them rugged and shock tolerant (basic survivability has been demonstrated to >20 kG).
A Zn-Cu electrochemical cell (Galvanic cell) was applied in the low-frequency accelerometer. Experimental results show that external vibrations (range from 18 to 70 Hz) were successfully detected by this accelerometer as reactions Zn→〖Zn〗^(2+)+2e^- occurs around the anode and 〖Cu〗^(2+)+2e^-→Cu around the cathode. Accordingly, the sensitivity of this MET device design is to achieve 10.4 V/G at 18 Hz. And the sources of noise have been analyzed.
A Zn-Cu electrochemical cell (Galvanic cell) was applied in the low-frequency accelerometer. Experimental results show that external vibrations (range from 18 to 70 Hz) were successfully detected by this accelerometer as reactions Zn→〖Zn〗^(2+)+2e^- occurs around the anode and 〖Cu〗^(2+)+2e^-→Cu around the cathode. Accordingly, the sensitivity of this MET device design is to achieve 10.4 V/G at 18 Hz. And the sources of noise have been analyzed.
ContributorsZhao, Zuofeng (Author) / Yu, Hongyu (Thesis advisor) / Zhang, Junshan (Committee member) / Jiang, Hanqing (Committee member) / Arizona State University (Publisher)
Created2015
Description
In many systems, it is difficult or impossible to measure the phase of a signal. Direct recovery from magnitude is an ill-posed problem. Nevertheless, with a sufficiently large set of magnitude measurements, it is often possible to reconstruct the original signal using algorithms that implicitly impose regularization conditions on this ill-posed problem. Two such algorithms were examined: alternating projections, utilizing iterative Fourier transforms with manipulations performed in each domain on every iteration, and phase lifting, converting the problem to that of trace minimization, allowing for the use of convex optimization algorithms to perform the signal recovery. These recovery algorithms were compared on a basis of robustness as a function of signal-to-noise ratio. A second problem examined was that of unimodular polyphase radar waveform design. Under a finite signal energy constraint, the maximal energy return of a scene operator is obtained by transmitting the eigenvector of the scene Gramian associated with the largest eigenvalue. It is shown that if instead the problem is considered under a power constraint, a unimodular signal can be constructed starting from such an eigenvector that will have a greater return.
ContributorsJones, Scott Robert (Author) / Cochran, Douglas (Thesis director) / Diaz, Rodolfo (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor) / School of Mathematical and Statistical Sciences (Contributor)
Created2014-05
Description
Noise abatement is a current and ever-changing issue that leaves some groups satisfied and others dissatisfied. Given that noise is a natural byproduct of aviation, it is the duty of the Federal Aviation Administration (FAA) to mitigate noise pollution and the effects that it has on the surrounding community. With the FAA currently progressing to modernize the National Airspace System, communities around the United States have expressed their concerns regarding changes of flight paths, notably the City of Phoenix. Public unrest has increased intensively since the implementation of Performance Based Navigation (PBN) departure procedures in September of 2014. The unrest has allegedly stemmed from a lack of consultation from the Federal Aviation Administration to the City of Phoenix and surrounding communities. Documented complaints have not only been filed by the City, but also by National Prehistoric Preservation areas within the valley. The City of Phoenix and the State of Arizona filed a lawsuit against the FAA to dispute the flight path changes. The court ruled in favor of Arizona and required the FAA to revert to the flight paths that were in place before the changes. This paper is an immersion into the current state of what has occurred within the Phoenix Terminal Airspace (PTA), the effects that the changes have had on the natural and social environment, the FAA, and the NextGen initiative which the FAA is said to be implementing. This paper will also inform the reader of how a departure procedure is created, how the public can stay better informed of what the FAA is planning, and possible long-term solutions that will satisfy both the environmental and modernization requirements placed on the PTA.
ContributorsCharles, Kyle (Author) / Wallmueller, Katherine (Thesis director) / Delugt, H. (Committee member) / Aviation Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Dogs in animal shelters are subjected to a number of stressors during their stay, including barking which can reach 120 dB. Music has been suggested as a way to reduce this stress, however, the properties of music that result in reduced stress behavior have not been examined. An affective response to music, like that found in humans, is unlikely due to human higher cognitive function. Masking, reducing the magnitude of volume change with the presence of another sound, is one property that may be responsible for this observed stress reduction. Using white and pink noise, we examined the effects of auditory masking on stress behaviors in shelter dogs. Overall, we observed no difference in the amount of sitting, lying, head resting, or barking between the control and treatment conditions. Limitations and future directions of studies are listed.
ContributorsRedmond, Domenic Xavier Wendell (Author) / Wynne, Clive (Thesis director) / Glenberg, Arthur (Committee member) / Steele, Kenneth (Committee member) / School of Social Transformation (Contributor) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
This document introduces the need for the Rest Egg system and defines an accessible method of smartphone integration. Excessive noise can prevent recovering patients and special needs persons from resting correctly. The Rest Egg was designed for these people- people who are in critical need of quality rest but are often unable to eliminate stressors themselves. This system ensures their environment is calm by alerting caretakers' smartphones if noise reaches abrasive levels. Smartphones were the preferred device due to the wide spread of such devices in today's market. After making open sourcing a goal, something ubiquitous and affordable \u2014 yet usable and dependable \u2014 was necessary for the alert system. These requirements lead to the election an online alert service: Pushover, a trademark and product of Superblock, LLC.
ContributorsJennings, Tyler Blake (Author) / Goryll, Michael (Thesis director) / Kozicki, Michael (Committee member) / Barrett, The Honors College (Contributor) / Electrical Engineering Program (Contributor)
Created2016-05
Description
An investigation of phase noise in amplifier and voltage-controller oscillator (VCO) circuits was conducted to show that active direct-current (DC) bias techniques exhibit lower phase noise performance than traditional resistive DC bias techniques. Low-frequency high-gain amplifiers like those found in audio applications exhibit much better 1/f phase noise performance and can be used to bias amplifier or VCO circuits that work at much higher frequencies to reduce the phase modulation caused by higher frequency devices. An improvement in single-side-band (SSB) phase noise of 15 dB at offset frequencies less than 50 KHz was simulated and measured. Residual phase noise of an actively biased amplifier also exhibited significant noise improvements when compared to an equivalent resistive biased amplifier.
ContributorsBaldwin, Jeremy Bart (Author) / Aberle, James T., 1961- (Thesis advisor) / Bakkaloglu, Bertan (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2010
Description
This paper analyzes existing literature regarding how excessive aggravating stimuli in a hospital environment can reduce the quality and quantity of sleep. The sick and injured are most sensitive to aggravating stimuli and the most vulnerable to poor sleep conditions. For individuals with anxiety, stress, hypersensitivity, or conditions such as Autism Spectrum Disorder (ASD), as additional stress during rest periods could seriously harm development and overall well-being. While solutions have been proposed and tested, there is no one solution to the problem. One possible solution is to design a device that monitors a patient's room and alerts a nurse or parent of aggravating stimuli so that it can be removed.
ContributorsKhan, Zarah Noor (Author) / Goryll, Michael (Thesis director) / Adams, James B. (Committee member) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Procedural content generation refers to the creation of data algorithmically using controlled randomness. These algorithms can be used to generate complex environments and geological formations as opposed to manually creating environments, using photogrammetry, or other means. Geological formations and the surrounding terrain can be created using noise based algorithms such as Perlin noise. However, interpreting noise in this manner has a number of challenges due to the pseudo-random nature of noise. We will discuss how to generate noise, how to render noise, and the challenges in interpreting noise.
ContributorsLi, Michael L (Author) / Hansford, Dianne (Thesis director) / Kobayashi, Yoshihiro (Committee member) / Computer Science and Engineering Program (Contributor, Contributor) / School of Art (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
In a Mirror Dimly… is an autobiographical work that follows my mental development from my teen years into my mid-20s and offers a way forward into the future. First comes legalism: a canon, which represents a rule-based thought process. Next is freedom and individuality: indeterminate methods and textures. Finally, the piece concludes with unity and wholeness, using quoted and composed hymns in chorale settings. The conceptual content is taken from Hermann Hesse’s Siddhartha, a story of a Hindu man’s life through the development of his own ideology into Buddhism. He begins by following the rules of his faith obsessively, then he decides that the rules themselves don’t matter as much as the spirit behind them, and finally he begins to see the interconnectedness of nature through the flow of a river and gains a fuller picture of all that is. I have also included an anxiety motif which begins as an interruption or nuisance; it then takes over in the form of a panic attack but is quelled by a hymn: “Be Still My Soul,” with text written by Katharina von Schlegel set to the tune of Sibelius’ Finlandia. Finally, the anxiety is contained and molded to help the overall texture rather than disrupting it. The anxiety is never truly eradicated, but it is transformed.
ContributorsChesney, Jacob Andrew (Author) / Temple, Alex (Thesis advisor) / Bolanos, Gabriel (Committee member) / Rockmaker, Jody (Committee member) / Arizona State University (Publisher)
Created2022
Description
Human activity produces ambient noise that potentially alters species’ abilities to communicate with each other—among other impacts. Given that birds are known to be sensitive to structural changes in habitat and highly communicative through sound, it is beneficial to understand how changing acoustic ecologies and ambient noise impact birds’ ability to communicate in their respective environments. In this study, mockingbird calls from an urban, desert, and intermediate study site were recorded and analyzed for differences in acoustic properties. Acoustic properties such as frequency and amplitude differed significantly across sites as it was determined that mockingbirds in urban areas increase both the peak frequency and amplitude of their calls in order to communicate. This study identifies what these changes in acoustic properties mean in relation to the survival and conservation of birds and concludes with recommendations for novel research.
ContributorsReynolds, Bailey Susana (Author) / Pearson, David (Thesis director) / Walters, Molina (Committee member) / School of Sustainability (Contributor) / School of Life Sciences (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05