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- Creators: Arizona State University
- Creators: Nullmeyer, Robert
Description
Trenchless technology is a group of techniques whose utilization allows for the installation, rehabilitation, and repair of underground infrastructure with minimal excavation from the ground surface. As the built environment becomes more congested, projects are trending towards using trenchless technologies for their ability to quickly produce a quality product with minimal environmental and social costs. Pilot tube microtunneling (PTMT) is a trenchless technology where new pipelines may be installed at accurate and precise line and grade over manhole to manhole distances. The PTMT process can vary to a certain degree, but typically involves the following three phases: jacking of the pilot tube string to achieve line and grade, jacking of casing along the pilot bore and rotation of augers to excavate the borehole to a diameter slightly larger than the product pipe, and jacking of product pipe directly behind the last casing. Knowledge of the expected productivity rates and jacking forces during a PTMT installation are valuable tools that can be used for properly weighing its usefulness versus competing technologies and minimizing risks associated with PTMT. This thesis outlines the instrumentation and monitoring process used to record jacking frame hydraulic pressures from seven PTMT installations. Cyclic patterns in the data can be detected, indicating the installation of a single pipe segment, and enabling productivity rates for each PTMT phase to be determined. Furthermore, specific operations within a cycle, such as pushing a pipe or retracting the machine, can be observed, allowing for identification of the critical tasks associated with each phase. By identifying the critical tasks and developing more efficient means for their completion, PTMT productivity can be increased and costs can be reduced. Additionally, variations in depth of cover, drive length, pipe diameter, and localized ground conditions allowed for trends in jacking forces to be identified. To date, jacking force predictive models for PTMT are non-existent. Thus, jacking force data was compared to existing predictive models developed for the closely related pipe jacking and microtunneling methodologies, and the applicability of their adoption for PTMT jacking force prediction was explored.
ContributorsOlson, Matthew P (Author) / Ariaratnam, Samuel T (Thesis advisor) / Lueke, Jason S (Committee member) / Zapata, Claudia E (Committee member) / Tang, Pingbo (Committee member) / Arizona State University (Publisher)
Created2013
Description
The Federal Flight Deck Officer (FFDO) program was mandated legislatively, as part of the Homeland Security Act of 2002. This study replicated earlier research that investigated pilots’ opinions of the current state of the FFDO program based on interviews. A Likert survey was created to allow simpler quantitative collection and analysis of opinions from large groups of pilots. A total of 43 airline pilots participated in this study. Responses to the Likert questions were compared with demographics, searching for significance through a Pearson chi-square test and frequencies were compared to earlier research findings. Significant chi-square results showed that those familiar with the program were more likely to agree the program should continue, it was effective, the screening and selection process of program applicants was adequate and the Federal Air Marshal Service’s management of the FFDO program was effective. Those with Military experience were more likely to disagree it was reasonable that FFDOs were required to pay for their own room and board during training or train on their own time. All those who shared an opinion agreed there should be a suggestion medium between FFDOs and their management. Unlike the prior study, all those familiar with the program agreed the weapons transportation and carriage procedures were adequate. Furthermore, all those who shared an opinion found the holster locking mechanism adequate, which was another reversal of opinion from the prior study. Similar to the prior study, pilots unanimously agree FFDOs were well trained and agreed that the program was effective and should continue.
ContributorsFerrara, Marc, M.S (Author) / Niemczyk, Mary (Thesis advisor) / Nullmeyer, Robert (Committee member) / Branaghan, Russell (Committee member) / Arizona State University (Publisher)
Created2017
Description
There are many computer aided engineering tools and software used by aerospace engineers to design and predict specific parameters of an airplane. These tools help a design engineer predict and calculate such parameters such as lift, drag, pitching moment, takeoff range, maximum takeoff weight, maximum flight range and much more. However, there are very limited ways to predict and calculate the minimum control speeds of an airplane in engine inoperative flight. There are simple solutions, as well as complicated solutions, yet there is neither standard technique nor consistency throughout the aerospace industry. To further complicate this subject, airplane designers have the option of using an Automatic Thrust Control System (ATCS), which directly alters the minimum control speeds of an airplane.
This work addresses this issue with a tool used to predict and calculate the Minimum Control Speed on the Ground (VMCG) as well as the Minimum Control Airspeed (VMCA) of any existing or design-stage airplane. With simple line art of an airplane, a program called VORLAX is used to generate an aerodynamic database used to calculate the stability derivatives of an airplane. Using another program called Numerical Propulsion System Simulation (NPSS), a propulsion database is generated to use with the aerodynamic database to calculate both VMCG and VMCA.
This tool was tested using two airplanes, the Airbus A320 and the Lockheed Martin C130J-30 Super Hercules. The A320 does not use an Automatic Thrust Control System (ATCS), whereas the C130J-30 does use an ATCS. The tool was able to properly calculate and match known values of VMCG and VMCA for both of the airplanes. The fact that this tool was able to calculate the known values of VMCG and VMCA for both airplanes means that this tool would be able to predict the VMCG and VMCA of an airplane in the preliminary stages of design. This would allow design engineers the ability to use an Automatic Thrust Control System (ATCS) as part of the design of an airplane and still have the ability to predict the VMCG and VMCA of the airplane.
This work addresses this issue with a tool used to predict and calculate the Minimum Control Speed on the Ground (VMCG) as well as the Minimum Control Airspeed (VMCA) of any existing or design-stage airplane. With simple line art of an airplane, a program called VORLAX is used to generate an aerodynamic database used to calculate the stability derivatives of an airplane. Using another program called Numerical Propulsion System Simulation (NPSS), a propulsion database is generated to use with the aerodynamic database to calculate both VMCG and VMCA.
This tool was tested using two airplanes, the Airbus A320 and the Lockheed Martin C130J-30 Super Hercules. The A320 does not use an Automatic Thrust Control System (ATCS), whereas the C130J-30 does use an ATCS. The tool was able to properly calculate and match known values of VMCG and VMCA for both of the airplanes. The fact that this tool was able to calculate the known values of VMCG and VMCA for both airplanes means that this tool would be able to predict the VMCG and VMCA of an airplane in the preliminary stages of design. This would allow design engineers the ability to use an Automatic Thrust Control System (ATCS) as part of the design of an airplane and still have the ability to predict the VMCG and VMCA of the airplane.
ContributorsHadder, Eric Michael (Author) / Takahashi, Timothy (Thesis advisor) / Mignolet, Marc (Committee member) / White, Daniel (Committee member) / Arizona State University (Publisher)
Created2016
Description
There are significantly higher rates of pilot error events during surface operations at night than during the day. Events include incidents, accidents, wrong surface takeoffs and landings, hitting objects, turning on the wrong taxiway, departing the runway surface, among others. There is evidence to suggest that these events are linked to situational awareness. Improvements to situational awareness can be accomplished through training to instruct pilots to increase attention outside of the cockpit while taxiing at night. However, the Federal Aviation Administration (FAA) night time requirements are relatively low to obtain a private pilot certification. The purpose of this study was to determine the effect of flight training experience on conducting safe and incident-free surface operations at night, collect pilot opinions on night training requirements and resources, and analyze the need for night time on flight reviews. A survey was distributed to general aviation pilots and 239 responses were collected to be analyzed. The responses indicated a higher observed incident rate at night than during the day, however there were no significant effects of night training hours or type of training received (Part 61, Part 141/142, or both) on incident rate. Additionally, higher total night hours improved pilot confidence at night and decreased incident rate. The overall opinions indicated that FAA resources on night flying were effective in providing support, but overall pilots were not in support of or against adding night time requirements to flight reviews and found night training requirements to be somewhat effective.
ContributorsWhittard, Megan (Author) / Niemczyk, Mary (Thesis advisor) / Nullmeyer, Robert (Committee member) / Hampshire, Michael (Committee member) / Arizona State University (Publisher)
Created2020
Description
Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that are detected ubiquitously in the aquatic environment, biota, and humans. Human exposure and adverse health of PFAS through consuming impacted drinking water is getting regulatory attention. Adsorption using granular activated carbon (GAC) and ion exchange resin (IX) has proved to be efficient in removing PFAS from water. There is a need to study the effectiveness of commercially available sorbents in PFAS removal at the pilot-scale with real PFAS contaminated water, which would aid in efficient full-scale plant design. Additionally, there is also a need to have validated bench-scale testing techniques to aid municipalities and researchers in selecting or comparing adsorbents to remove PFAS. Rapid Small-Scale Column Tests (RSSCTs) are bench-scale testing to assess media performance and operational life to remove trace organics but have not been validated for PFAS. Different design considerations exist for RSSCTs, which rely upon either proportional diffusivity (PD) or constant diffusivity (CD) dimensionless scaling relationships.
This thesis aims to validate the use of RSSCTs to simulate PFAS breakthrough in pilot columns. First, a pilot-scale study using two GACs and an IX was conducted for five months at a wellsite in central Arizona. PFAS adsorption capacity was greatest for a commercial IX, and then two GAC sources exhibited similar performance. Second, RSSCTs scaled using PD or CD relationships, simulated the pilot columns, were designed and performed. For IX and the two types of GAC, the CD–RSSCTs simulated the PFAS breakthrough concentration, shape, and order of C8 to C4 compounds observed pilot columns better than the PD-RSSCTs. Finally, PFAS breakthrough and adsorption capacities for PD- and CD-RSSCTs were performed on multiple groundwaters (GWs) from across Arizona to assess the treatability of PFAS chain length and functional head-group moieties. PFAS breakthrough in GAC and IX was dictated by chain length (C4>C6>C8) and functional group (PFCAs>PFSAs) of the compound. Shorter-chain PFAS broke through earlier than the longer chain, and removal trends were related to the hydrophobicity of PFAS. Overall, single-use IX performed superior to any of the evaluated GACs across a range of water chemistries in Arizona GWs.
This thesis aims to validate the use of RSSCTs to simulate PFAS breakthrough in pilot columns. First, a pilot-scale study using two GACs and an IX was conducted for five months at a wellsite in central Arizona. PFAS adsorption capacity was greatest for a commercial IX, and then two GAC sources exhibited similar performance. Second, RSSCTs scaled using PD or CD relationships, simulated the pilot columns, were designed and performed. For IX and the two types of GAC, the CD–RSSCTs simulated the PFAS breakthrough concentration, shape, and order of C8 to C4 compounds observed pilot columns better than the PD-RSSCTs. Finally, PFAS breakthrough and adsorption capacities for PD- and CD-RSSCTs were performed on multiple groundwaters (GWs) from across Arizona to assess the treatability of PFAS chain length and functional head-group moieties. PFAS breakthrough in GAC and IX was dictated by chain length (C4>C6>C8) and functional group (PFCAs>PFSAs) of the compound. Shorter-chain PFAS broke through earlier than the longer chain, and removal trends were related to the hydrophobicity of PFAS. Overall, single-use IX performed superior to any of the evaluated GACs across a range of water chemistries in Arizona GWs.
ContributorsVenkatesh, Krishishvar (Author) / Westerhoff, Paul (Thesis advisor) / Sinha, Shahnawaz (Committee member) / Lind, Marylaura (Committee member) / Arizona State University (Publisher)
Created2020
Description
Nicotine and tobacco use, whether it be through cigarette smoking or other devices, creates negative health conditions in pilots. The literature that was reviewed pertained to nicotine withdrawal symptoms and their negative impact on pilot performance. There have been studies conducted in order to explore how these symptoms impact pilot performance using cigarettes as the only nicotine device and does not specify the nicotine levels or the frequency of use. This thesis extends this work to examine the relationship between the nicotine withdrawal symptoms and the nicotine behaviors of pilots. It was hypothesized that the extent of withdrawal symptoms may differ by device and by nicotine levels and frequency of use, with higher levels and more frequent use being associated with more severe withdrawal symptoms. These behaviors included the device they use to take nicotine whether it be cigarettes, vaporizers, e-cigarettes, or smokeless tobacco. The behaviors also included exploration of how nicotine levels relate to withdrawal symptoms whether the nicotine level is as low as 3mg or high as 36mg. The last relationship that was explored was that between the withdrawal symptoms presented in pilots and how often they used nicotine, whether it be often as every day or less frequent as 1-2 times a year. It was found that there is no statistical relationship between nicotine withdrawal symptoms and the nicotine habits such as device used, nicotine level used, and frequency of use.
ContributorsBartlowe, Halie Marie (Author) / Cooke, Nancy J. (Thesis advisor) / Nullmeyer, Robert (Committee member) / Wende, Anthony (Committee member) / Arizona State University (Publisher)
Created2019