Browsing by Subject "power"

Now showing 1 - 7 of 7
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    Airgap-less Electric Motor
    (2021-08) Alibeik, Maryam; dos Santos, Euzeli; King, Brian; Li, Lingxi; Rovnyak, Steven
    This dissertation focuses mainly on the airgap-less electric machine. An extensive literature review has been presented along with a systematic study that included analytical modeling, simulation with both steady-state and transient analysis, prototype building, and experimental validation. In this type of device, the rotor is allowed to touch the stator at a contact point, which maximizes the internal flux and therefore the electromagnetic torque. A higher torque density motor is proposed in this dissertation due to a reduced reluctance caused by zero airgap situation. A comparison with other high torque density electric machines demonstrates the advantages of the proposed machine. Switched reluctance motor for hybrid vehicle, integrated magnetic gear, induction machines, are some examples of the machines with lower torque density than the airgap-less electric machine. This machine will maximize the generated torque allowing these type of machines to be competitive in applications where hydraulic motors are prevalent, i.e., low-speed and high-torque requirements. Hydraulic motor systems face two major problems with their braking system and with low efficiency due to a large number of energy conversion stages (i.e., motor-pump, hydraulic connections and the hydraulic motor itself). The proposed electric motor, unlike hydraulic motors, converts electrical energy directly to mechanical energy with no extra braking system necessary and with higher efficiency. The evolution of the airgap-less electric machine from three poles to 9 bi-poles is discussed in this dissertation. The modeling of this machine with a minimum number of poles is discussed before a generalization is presented. The simulation and analysis of the airgap-less electric motor has been done using Euler integration method as well as Runge Kutta 4th order integration method due to its higher precision. A proof-of-concept electric machine with nine magnetic bipoles is built to validate the theoretical assumptions.
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    Enhancing Separation and Constriction of Ion Mobility Distributions in Drift Tubes at Atmospheric Pressure Using Varying Fields
    (American Chemical Society, 2022-03-31) Chen, Xi; Latif, Mohsen; Gandhi, Viraj D.; Chen, Xuemeng; Hua, Leyan; Fukushima, Nobuhiko; Larriba-Andaluz, Carlos; Mechanical and Energy Engineering, School of Engineering and Technology
    A linearly decreasing electric field has been previously proven to be effective for diffusional correction of ions in a varying field drift tube (VFDT) system, leading to higher resolving powers compared to a conventional drift tube due to its capacity to narrow distributions midflight. However, the theoretical predictions in resolving power of the VFDT were much higher than what was observed experimentally. The reason behind this discrepancy has been identified as the difference between the theoretically calculated resolving power (spatial) and the experimental one (time). To match the high spatial resolving power experimentally, a secondary high voltage pulse (HVP) at a properly adjusted time is used to provide the ions with enough momentum to increase their drift velocity and hence their time-resolving power. A series of systematic numerical simulations and experimental tests have been designed to corroborate our theoretical findings. The HVP-VFDT atmospheric pressure portable system improves the resolving power from the maximum expected of 60–80 for a regular drift tube to 250 in just 21 cm in length and 7kV, an unprecedent accomplishment.
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    Having Responsible Power Leads to Sexual Harassment? The Explanatory Role of Moral Licensing
    (2020-10) Dinh, Tuyen K.; Stockdale, Margaret S.; Ashburn-Nardo, Leslie; Salyers, Michelle P.
    Feeling powerful or possessing power over someone is often shown in the sexual harassment literature as an antecedent. Indeed, power can be construed in a self-focused manner or in a responsibility-focused manner. Tost (2015) theorized that powerholders who construe their power as responsibility should then act for the benefit of others. However, a recent study by Stockdale, Gilmer, and Dinh (2019) found the opposite effect. Specifically, they found that priming responsibility-focused power increased the intention to sexually harass, speculating that priming such powers may have created a “moral license” (Miller & Effron, 2010) to engage in sexual harassment. The purpose of the present study is to extend their findings by examining the role of moral licensing. I hypothesize that participants who are in the responsibility-focused power priming condition will engage in sexual harassment proclivities through a serial mediation of communal feelings and moral licensing (moral crediting and moral credentialing). Results confirm that communal feelings and moral crediting serially mediate the relationship between responsibility-focused power and sexual harassment proclivities. The hypothesized role of moral credentialing was not supported. Findings in this study provides a potential explanation for the paradoxical findings of responsibility-focused power in Stockdale et al. (2019)’s study. This study also emphasizes the importance of understanding responsibility-focused power in sexual harassment indices and the potential the ironic effects of having such power via moral crediting.
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    Living with Serious Mental Illness, Police Encounters, and Relationships of Power: A Critical Phenomenological Study
    (2021-12) Quiring, Stephanie Q.; Kim, Hea-Won; Starnino, Vincent; Sullivan, Patrick; Kennedy, Sheila
    The criminalization of mental illness has drawn and kept a disproportionate number of people living with mental illness in jails and prisons across the United States. The criminal legal system is ill-equipped or unequipped to provide meaningful mental health care. Police often serve as gatekeepers to the criminal legal system in the midst of encounters involving people living with serious mental illness. The literature that examines police decision-making amid these highly discretionary encounters has been primarily situated in post-positivist, quantitative methodologies focused on police perspectives. There is a dearth of research with the direct involvement of people living with serious mental illness that employs more advanced qualitative methodologies. The purpose of this study was to understand the lived experience of police encounters from the perspective of people living with serious mental illness through multi-level analysis of the interpersonal and structural contexts which underpin these encounters. This critical phenomenological study used interpretative phenomenological analysis as process. A sample of 16 adults were recruited using purposive and snowball sampling and completed semi-structured interviews. The findings reported two descriptive areas for participants—aspects of serious mental illness and contemplations of power. The findings also included the interpretive analysis organized around six themes that emerged regarding the lived experience of police encounters: (a) significant context, to include serious mental illness, was made invisible, (b) the carceral response to serious mental illness and interpersonal issues, (c) law enforcement’s power to force submission, (d) facets of escalation, (e) law enforcement encounters lacked essential care, and (f) law enforcement encounters served as a microcosm of the criminal legal system. The implications of the study’s findings on police encounters as they are currently framed in the largely post-positivist, quantitative body of research are discussed. In addition, the current wave of national police response models and reform are considered and connected to implications for social work practice. Finally, culminating in the findings’ implications for a growing edge of critical phenomenology that incorporates intersectionality and disciplinary power and the central role of an abolition feminist praxis at the nexus of mental health, crisis response, and collective care.
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    PV Based Converter with Integrated Battery Charger for DC Micro-Grid Applications
    (2014) Salve, Rima; Santos Jr., Euzeli C. dos
    This thesis presents a converter topology for photovoltaic panels. This topology minimizes the number of switching devices used, thereby reducing power losses that arise from high frequency switching operations. The control strategy is implemented using a simple micro-controller that implements the proportional plus integral control. All the control loops are closed feedback loops hence minimizing error instantaneously and adjusting efficiently to system variations. The energy management between three components, namely, the photovoltaic panel, a battery and a DC link for a microgrid, is shown distributed over three modes. These modes are dependent on the irradiance from the sunlight. All three modes are simulated. The maximum power point tracking of the system plays a crucial role in this configuration, as it is one of the main challenges tackled by the control system. Various methods of MPPT are discussed, and the Perturb and Observe method is employed and is described in detail. Experimental results are shown for the maximum power point tracking of this system with a scaled down version of the panel's actual capability.
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    The Transformational Relationship Evaluation Scale II (TRES II) Reflection Framework: Version 2
    (2022-04) Clayton, Patti H.; Camo-Biogradlija, Jasmina; Kniffin, Lori E.; Price, Mary F.; Bringle, Robert G.; Pier, Alyssa A.
    The Transformational Relationship Evaluation Scale Reflection Framework (TRES II Reflection Framework, Version 2) is a critical reflection tool designed for all participants in community-campus relationships to generate actionable learning regarding their collective work and to serve as an intervention to deepen those relationships. This tool was designed to accompany the Transformational Relationship Evaluation Scale II (TRES II), which on its own has documented utility to enhance partnership inquiry and practice (Kniffin et. al., 2020). The TRES II Reflection Framework broadens and deepens the scale with intentionally-designed prompts structured using the DEAL Model of Critical Reflection (Ash & Clayton, 2009). Authors’ Note: This version of the TRES II Reflection Framework was last updated in April, 2022, and a PDF file can be accessed at the link provided in the recommended reference. Contact Patti Clayton, patti.clayton@curricularengagement.com, for an editable Word file and/or future versions.
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    Women’s experiences of participation in mass participation sport events
    (Frontiers, 2022-10) Mirehie, Mona; Tourism, Conventions, and Event Management, School of Physical Education and Tourism Management
    Mass participation sport events (MPSEs) have become a popular form of recreational sport participation. Understanding experiences of participants is pivotal to designing and implementing socially just and sustainable events. Applying constructivist grounded theory methodology, this inquiry explored experiences of participation in MPSEs, with particular attention to the impact of gender on participation experiences. In-depth interviews were conducted with 13 women who participated in MPSEs. Fear and power were two core themes in interviewees’ experiences. Fear of sexual assault, injury, and “something bad” was a significant element in women’s experiences which related to perceptions of place and time. The second theme, power, was generated from strong sport identities, camaraderie among female runners, all-women races, and finishing mixed-gender races. The findings provide some guidelines for practitioners to enhance experiences of female participants and encourage repeated participation that is key to sustainability of the events.