Matching Items (12)
Description
A new analytical method is proposed for measuring the deuterium to hydrogen ratio (D/H) of non-stoichiometric water in hydrous minerals via pyrolysis facilitated gas-chromatography - isotope ratio mass spectrometry (GC-IRMS). Previously published analytical methods have reported a poorly understood nonlinear dependence of D/H on sample size, for which any accurate correction is difficult. This sample size effect been variously attributed to kinetic isotope fractionation within the mass spectrometer and peripheral instruments, ion source linearity issues, and an unstable H_3^+-factor or incorrect H_3^+-factor calculations. The cause of the sample size effect is here identified by examinations of individual chromatograms as well as bulk data from chromatographic peaks. It is here determined that it is primarily an artifact of the calculations employed by the manufacturer's computer program, used to both monitor the functions of the mass spectrometer and to collect data. Ancillary causes of the sample size effect include a combination of persistent background interferences and chromatographic separation of the isotopologues of molecular hydrogen. Previously published methods are evaluated in light of these findings. A new method of H_3^+-factor and D/H calculation is proposed which makes portions of the Isodat software as well as other published calculation methods unnecessary. Using this new method, D/H is measured in non-stoichiometric water in chert from the Cretaceous Edwards Group, Texas, as well as the Precambrian Kromberg Formation, South Africa, to assess hydrological conditions as well as to estimate the maximum average surface temperature during precipitation of the chert. Data from Cretaceous chert are consistent with previously published data and interpretations, based upon conventional analyses of large samples. Data from Precambrian chert are consistent with maximum average surface temperatures approaching 65°C during the Archean, instead of the much lower temperatures derived from erroneous methods of sample preparation and analysis. D/H is likewise measured in non-stoichiometric water in silicified basalt from the Precambrian Hooggenoeg Complex, South Africa. Data are shown to be consistent with D/H of the Archean ocean similar to present day values.
ContributorsSheehan, Michael Robert (Author) / Knauth, Leroy P (Thesis advisor) / Anbar, Ariel (Committee member) / Farmer, Jack (Committee member) / Arizona State University (Publisher)
Created2011
Description
Characterization of particulate process and product design is a difficult field because of the unique bulk properties and behaviors of particles that differ from gasses and liquids. The purpose of this research is to develop an equation to relate the angle of repose and flowability, the ability of the particle to flow as it pertains to particulate processes and product design. This research is important in multiple industries such as pharmaceuticals and food processes.
ContributorsNugent, Emily Rose (Author) / Emady, Heather (Thesis director) / Marvi, Hamidreza (Committee member) / Materials Science and Engineering Program (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This thesis investigates the effects of differing diameters, removal of antistatic forces, and varying moisture content on the shear stress properties of granular glass beads through use of a Freeman FT4 Powder Rheometer. A yield locus results from plotting the experimental shear stress values (kPa) vs. the applied normal stress value (kPa). From these yield loci, Mohr’s Circles are constructed to quantitatively describe flowability of tested materials in terms of a flow function parameter.
By testing 120-180 µm, 120-350 µm, 250-350 µm, and 430-600 µm dry glass bead ranges, an increase in diameter size is seen to result in both higher shear stress values and an increasing slope of plotted shear stress vs. applied normal stress. From constructed Mohr’s Circles, it is observed that flow function is quite high amongst tested dry materials, all yielding values above 20. A high flow function value (>10) is indicative of a good flow.1 Flow function was observed to increase with increasing diameter size until a slight drop was observed at the 430-600 µm range, possibly due to material quality or being near the size limitation of testing within the FT4, where materials must be less than 1000 µm in diameter.However, no trend could be observed in flowability as diameter size was increased.
Through the use of an antistatic solution, the effect of electrostatic forces generated by colliding particles was tested. No significant effect on the shear stress properties was observed.
Wet material testing occurred with the 120-180 µm glass bead range using a deionized water content of 0%, 1%, 5%, 15%, and 20% by mass. The results of such testing yielded an increase in shear stress values at applied normal stress values as moisture content is increased, as well as a decrease in the resulting flow function parameter. However, this trend changed as 20% moisture content was achieved; the wet material became a consistent paste, and a large drop in shear stress values occurred along with an increase in flowability.
By testing 120-180 µm, 120-350 µm, 250-350 µm, and 430-600 µm dry glass bead ranges, an increase in diameter size is seen to result in both higher shear stress values and an increasing slope of plotted shear stress vs. applied normal stress. From constructed Mohr’s Circles, it is observed that flow function is quite high amongst tested dry materials, all yielding values above 20. A high flow function value (>10) is indicative of a good flow.1 Flow function was observed to increase with increasing diameter size until a slight drop was observed at the 430-600 µm range, possibly due to material quality or being near the size limitation of testing within the FT4, where materials must be less than 1000 µm in diameter.However, no trend could be observed in flowability as diameter size was increased.
Through the use of an antistatic solution, the effect of electrostatic forces generated by colliding particles was tested. No significant effect on the shear stress properties was observed.
Wet material testing occurred with the 120-180 µm glass bead range using a deionized water content of 0%, 1%, 5%, 15%, and 20% by mass. The results of such testing yielded an increase in shear stress values at applied normal stress values as moisture content is increased, as well as a decrease in the resulting flow function parameter. However, this trend changed as 20% moisture content was achieved; the wet material became a consistent paste, and a large drop in shear stress values occurred along with an increase in flowability.
ContributorsKleppe, Cameron Nicholas (Author) / Emady, Heather (Thesis director) / Vajrala, Spandana (Committee member) / Chemical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
This thesis focuses on the effects of an engine's induction and exhaust systems on vehicle fuel efficiency, along with the challenges accompanying improvement of this parameter. The aim of the project was to take an unconventional approach by investigating potential methods of increasing fuel economy via change of these systems outside the engine, as finding substantial gains via this method negates the need to alter engine architectures, potentially saving manufacturers research and development costs. The ultimate goal was to determine the feasibility of modifying induction and exhaust systems to increase fuel efficiency via reduction of engine pumping losses and increase in volumetric efficiency, with the hope that this research can aid others researching engine design in both educational and commercial settings. The first step toward achieving this goal was purchasing a test vehicle and performing experimental fuel efficiency testing on the unmodified, properly serviced specimen. A test route was devised to provide for a well-rounded fuel efficiency measurement for each trial. After stock vehicle trials were completed, the vehicle was to be taken out of service for a turbocharger system installation; unfortunately, challenges arose that could not be rectified within the project timeframe, and this portion of the project was aborted, to be investigated in the future. This decision was made after numerous fitment and construction issues with prefabricated turbo conversion parts were found, including induction and exhaust pipe size problems and misalignments, kit component packaging issues such as intercooler dimensions being too large, as well as manufacturing oversights, like failure to machine flanges flat for sealing and specification of incorrect flange sizes for mating components. After returning the vehicle to stock condition by removing the partially installed turbocharger system, the next step in the project was then installation of high-flow induction and exhaust systems on the test vehicle, followed by fuel efficiency testing using the same procedure as during the first portion of the experiment. After analysis of the quantitative and qualitative data collected during this thesis project, several conclusions were made. First, the replacement of stock intake and exhaust systems with high-flow variants did make for a statistically significant increase in fuel efficiency, ranging between 10 and 20 percent on a 95% confidence interval. Average fuel efficiency of the test vehicle rose from 21.66 to 24.90 MPG, an impressive increase considering the relative simplicity of the modifications. The tradeoff made was in noise produced by the vehicle; while the high-flow induction system only resulted in increased noise under very high-load circumstances, the high-flow exhaust system created additional noise under numerous load conditions, limiting the market applicability for this system. The most ideal vehicle type for this type of setup is sports/enthusiast cars, as increased noise is often considered a desirable addition to the driving experience; light trucks also represent an excellent application opportunity for these systems, as noise is not a primary concern in production of these vehicles. Finally, it was found that investing in high-flow induction and exhaust systems may not be a wise investment at the consumer level due to the lengthy payoff period, but for manufacturers, these systems represent a lucrative opportunity to increase fuel efficiency, potentially boosting sales and profits, as well as allowing the company to more easily meet federal CAFE standards in America. After completion of this project, there are several further research directions that could be taken to expand upon what was learned. The fuel efficiency improvements realized by installing high-flow induction and exhaust systems together on a vehicle were experimentally measured during testing; determining the individual effects of each of these systems installed on a vehicle would be the next logical research step within the same vein. Noise, vibration, and harshness increases after installing these systems were also noticed during experimental trials, so another future research direction could be an investigation into reducing these unwanted effects of high-flow systems. Finally, turbocharging to increase a vehicle's fuel efficiency, the original topic of this thesis, is another very important, contemporary issue in the world of improving vehicle fuel efficiency, and with manufacturers consistently moving toward turbocharged platform development, is a prime research topic in this area of study. In conclusion, the results from this thesis project exhibit that high-flow induction and exhaust systems can substantially improve a vehicle's fuel efficiency without modifying any internal engine components. This idea of improving a vehicle's fuel economy from outside the engine will ideally be further researched, such as by investigating turbocharger systems and their ability to improve fuel efficiency, as well as be developed and implemented by others in their educational projects and commercial products.
ContributorsCurl, Samuel Levi (Author) / Trimble, Steven (Thesis director) / Takahashi, Timothy (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Unmanned aerial vehicles have received increased attention in the last decade due to their versatility, as well as the availability of inexpensive sensors (e.g. GPS, IMU) for their navigation and control. Multirotor vehicles, specifically quadrotors, have formed a fast growing field in robotics, with the range of applications spanning from surveil- lance and reconnaissance to agriculture and large area mapping. Although in most applications single quadrotors are used, there is an increasing interest in architectures controlling multiple quadrotors executing a collaborative task. This thesis introduces a new concept of control involving more than one quadrotors, according to which two quadrotors can be physically coupled in mid-flight. This concept equips the quadro- tors with new capabilities, e.g. increased payload or pursuit and capturing of other quadrotors. A comprehensive simulation of the approach is built to simulate coupled quadrotors. The dynamics and modeling of the coupled system is presented together with a discussion regarding the coupling mechanism, impact modeling and additional considerations that have been investigated. Simulation results are presented for cases of static coupling as well as enemy quadrotor pursuit and capture, together with an analysis of control methodology and gain tuning. Practical implementations are introduced as results show the feasibility of this design.
ContributorsLarsson, Daniel (Author) / Artemiadis, Panagiotis (Thesis advisor) / Marvi, Hamidreza (Committee member) / Berman, Spring (Committee member) / Arizona State University (Publisher)
Created2016
Description
This project is a small scale investigation of various factors concerning "Flow" in Piano Performance. "Flow" is the sweet spot where ability and challenge are about equal, and usually high (Csikszentmihalyi 1990). Piano performance is a state of playing the piano with some intent to perform. In this case, the intent is to create something new or improvise. Improvisation is one form of expressive creativity on the piano stemming from some knowledge and extrapolation upon that knowledge (Nachmanovitch 82). Creativity is essential to the development of new music, and though extensive literature exists on both creativity and music independently, there is a gap in research regarding links between the two (Macdonald et al. 2006). This project aims to address some of these gaps by working with piano players and non-musicians of various technical skill levels to examine the "Flow" state in improvisation as well as potential factors affecting creative performance. Factors such as listening, self-confidence, frustration in methodology, and meditation practices were found to correlate positively with technical skill. Participants who completed the practice program were able to reconstruct challenges and enter the "Flow" state in improvisation regardless of high or low technical scores.
ContributorsDorr, Alexander Nathan (Author) / Kaplan, Robert (Thesis director) / Parker, John (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Finding Flow was inspired by a previous research project, Zen and the Art of STEAM. The concept of flow was developed by Mihaly Csikszentmihalyi and can be described as "being in the zone." The previous research project focused on digital culture students and whether they could find states of flow within their coursework. This thesis project aimed to develop a website prototype that could be used to help students who struggled to find flow.
ContributorsDredd, Dominique (Author) / Jayasuriya, Suren (Thesis director) / Barnett, Jessica (Committee member) / Barrett, The Honors College (Contributor) / Arts, Media and Engineering Sch T (Contributor)
Created2023-05
Description
Finding Flow was inspired by a previous research project, Zen and the Art of STEAM. The concept of flow was developed by Mihaly Csikszentmihalyi and can be described as "being in the zone." The previous research project focused on digital culture students and whether they could find states of flow within their coursework. This thesis project aimed to develop a website prototype that could be used to help students who struggled to find flow.
ContributorsDredd, Dominique (Author) / Jayasuriya, Suren (Thesis director) / Barnett, Jessica (Committee member) / Barrett, The Honors College (Contributor) / Arts, Media and Engineering Sch T (Contributor)
Created2023-05
Description
Finding Flow was inspired by a previous research project, Zen and the Art of STEAM. The concept of flow was developed by Mihaly Csikszentmihalyi and can be described as "being in the zone." The previous research project focused on digital culture students and whether they could find states of flow within their coursework. This thesis project aimed to develop a website prototype that could be used to help students who struggled to find flow.
ContributorsDredd, Dominique (Author) / Jayasuriya, Suren (Thesis director) / Barnett, Jessica (Committee member) / Barrett, The Honors College (Contributor) / Arts, Media and Engineering Sch T (Contributor)
Created2023-05
Description
This work describes the development of a device for measuring CO2 in breath, which has applications in monitoring a variety of health issues, such as Chronic Obstructive Pulmonary Disease (COPD), asthma, and cardiovascular disease. The device takes advantage of colorimetric sensing technology in order to maintain a low cost and high user-friendliness. The sensor consists of a pH dye, reactive element, and base coated on a highly porous Teflon membrane. The transmittance of the sensor is measured in the device via a simple LED/photodiode system, along with the flow rate, ambient relative humidity, and barometric pressure. The flow is measured by a newly developed flow meter described in this work, the Confined Pitot Tube (CPT) flow meter, which provides a high accuracy with reduced flow-resistance with a standard differential pressure transducer. I demonstrate in this work that the system has a high sensitivity, high specificity, fast time-response, high reproducibility, and good stability. The sensor has a simple calibration method which requires no action by the user, and utilizes a sophisticated, yet lightweight, model in order to predict temperature changes on the sensor during breathing and track changes in water content. It is shown to be effective for measuring CO2 waveform parameters on a breath-by-breath basis, such as End-Tidal CO2, Alveolar Plateau Slope, and Beginning Exhalation Slope.
ContributorsBridgeman, Devon (Author) / Forzani, Erica S (Thesis advisor) / Nikkhah, Mehdi (Committee member) / Holloway, Julianne (Committee member) / Raupp, Gregory (Committee member) / Emady, Heather (Committee member) / Arizona State University (Publisher)
Created2017