Dissertation Defense Announcements

Candidate Name: Elnaz Haddadi
Title: Mechanical behavior of the materials
 December 11, 2023  3:30 PM
Location: DUKE-308
Abstract:

Materials science aims to explore the properties and behaviors of different materials, from metals to advanced carbon structures. This dissertation focuses on three distinct areas of study: Inconel Alloy 740H, polycrystalline graphene, and tetragraphene (TG).
The first part of this work concentrates on developing and validating a Chaboche unified constitutive model. This model incorporates both nonlinear isotropic and kinematic hardening rules to accurately predict the stress-strain behavior of Inconel Alloy 740H, a high-temperature nickel-based superalloy. The material parameters of the model are determined and its accuracy validated through experimental data obtained from uniaxial strain-controlled loading tests across a wide temperature and strain ranges.
The second part explores the mechanical properties of polycrystalline graphene, bridging scales from nanoscale to macroscale through a multiscale molecular dynamics (MD)–finite element (FE) modeling approach. By studying the behavior of graphene sheets with different grain boundaries and atomic structures, insights are gained into the influence of grain size on mechanical properties like the Young modulus and fracture stress.
The third part of this dissertation investigates the mechanical properties of tetragraphene (TG), a quasi-2D semiconductor carbon allotrope, with a focus on addressing graphene's limitations in electronic applications. Through MD simulations, the research examines TG's fracture properties under mixed mode I and II loading, considering variables such as loading phase angle, crack structure, and temperature.



Candidate Name: Kristin M. Villanueva
Title: Examining the Research-Practice Collaborative Model as a Framework for Bolstering Implementation Fidelity of Educational Policy Initiatives: A Case Study of the North Carolina Early Learning Inventory
 December 01, 2023  8:30 PM
Location: CATO College of Education: Mebane Hall - Room 259
Abstract:

The expectation for educators to engage in evidence-based decision-making has become standard protocol in public education, yet translating research into effective practice can often be mired with implementation challenges. Research-practice partnerships (RPP) support research-informed practice by engaging key stakeholders to address real and contextual problems encountered by K-12 educators. This qualitative critical realist case study investigated the inner workings and attributes of a teacher-centric RPP formed to address ongoing implementation challenges with the North Carolina Early Learning Inventory. Data sources included observations of RPP meetings, teacher interviews, communications, and analysis of artifacts. Thematic findings suggest that teacher-centric RPP models strengthen trust and credibility between educational agencies through a series of preconditions: Expanding access, diversifying perspectives, developing alliances, and deepening knowledge. This resulted in increased implementation practices and enhanced the production of usable information to address implementation fidelity. Simultaneously, this framework also heightened teachers’ sense of professional identity. This study contributes to a dearth of literature on applying RPP models to support evidence-based policy mandates and offers a new model for leveraging classroom practitioners. This investigation contributes to the field of evaluation by providing a sustainable model to maintain implementation fidelity and strengthen teachers’ perceptions of their professional identity and agency.



Candidate Name: Kristin M. Villanueva
Title: Examining the Research-Practice Collaborative Model as a Framework for Bolstering Implementation Fidelity of Educational Policy Initiatives: A Case Study of the North Carolina Early Learning Inventory
 December 14, 2023  10:30 AM
Location: CATO College of Education: Mebane Hall - Room 259
Abstract:

The expectation for educators to engage in evidence-based decision-making has become standard protocol in public education, yet translating research into effective practice can often be mired with implementation challenges. Research-practice partnerships (RPP) support research-informed practice by engaging key stakeholders to address real and contextual problems encountered by K-12 educators. This qualitative critical realist case study investigated the inner workings and attributes of a teacher-centric RPP formed to address ongoing implementation challenges with the North Carolina Early Learning Inventory. Data sources included observations of RPP meetings, teacher interviews, communications, and analysis of artifacts. Thematic findings suggest that teacher-centric RPP models strengthen trust and credibility between educational agencies through a series of preconditions: Expanding access, diversifying perspectives, developing alliances, and deepening knowledge. This resulted in increased implementation practices and enhanced the production of usable information to address implementation fidelity. Simultaneously, this framework also heightened teachers’ sense of professional identity. This study contributes to a dearth of literature on applying RPP models to support evidence-based policy mandates and offers a new model for leveraging classroom practitioners. This investigation contributes to the field of evaluation by providing a sustainable model to maintain implementation fidelity and strengthen teachers’ perceptions of their professional identity and agency.



Candidate Name: Morgan Pullium
Title: Intraoperative Dosing of Dexamethasone In Type II Diabetics Undergoing Genitourinary Procedures
 December 08, 2023  10:00 AM
Location: CHHS 131
Abstract:

The purpose of this quality improvement project was to identify trends in the intraoperative dosing of dexamethasone in type II diabetic patients undergoing genitourinary procedures at a full-service community hospital and to determine impact of dosage level on postoperative glycemic response compared to preoperative blood glucose levels. Dexamethasone is a corticosteroid that has many dose-dependent benefits when administered perioperatively to surgical patients. It is often withheld in the type II diabetic population out of concern for effects on postoperative glycemic control due to the side effect of hyperglycemia.

The method of this quality improvement project consisted of a retrospective chart review of patients with type II diabetes undergoing genitourinary procedures. Data inclusion criteria included patients who: are type II diabetics, had procedures that lasted less than four hours, had a documented preoperative hemoglobin A1C reading within the last twelve months ranging from 6.5-8.9%, are non-pregnant, are not taking oral steroidal medications, and had an ASA classification of I, II, or III.

Forty-nine charts were reviewed and overall there was no significant change in blood glucose in the postoperative period (t = 0.92, p = 0.361). The dose of dexamethasone (4, 8, or 10 mg) had no effect on the change in blood glucose levels (t =-1.14, p = 0.263). Additionally, changes in blood glucose were not found to be associated with age, HbA1C, or ASA status.

Dexamethasone administration for patients undergoing genitourinary procedures had no significant impact on blood glucose levels in the postoperative period. These findings may be a result of the shorter length of surgery, in that all 49 charts in this sample consisted of different cystoscopy procedures and had an average surgery length of 66 minutes. Further study is needed to help facilitate anesthesia provider’s decision-making for dexamethasone dosing in type II diabetics.



Candidate Name: Pouria Karimi Shahri
Title: Designing Hierarchical Infrastructure-based Traffic Control Frameworks for Large-Scale Heterogeneous Traffic Networks
 December 08, 2023  1:00 PM
Location: https://charlotte-edu.zoom.us/j/97702163883
Abstract:

Autonomous vehicles have gained huge interest across private industry, academia, government, and the public because they promise higher road efficiency, improved safety, better energy consumption, and improved emissions. However, the widespread adoption of autonomous vehicle technology will likely take place over several years (if not decades) as the technology becomes more widely accepted by the general public and more cost-effective. Therefore, there will be a long period of time when we have both autonomous and human-driven vehicles sharing the same road and it is essential to develop traffic management strategies that take the uncertainty associated with the heterogeneity in the traffic networks into account. Furthermore, it is crucial to understand the extent to which these control strategies improve the performance of the traffic network.
This research aims to develop, enhance, and validate hierarchical infrastructure-based control framework designs for improving the mobility of large-scale heterogeneous traffic networks. In this work, heterogeneity is defined as a multi-vehicle traffic network consisting of Human-Driven Vehicles (HDVs) and Autonomous Vehicles (AVs), distinguished by their operational characteristics and controllability. To capture the realistic nature of large-scale heterogeneous traffic networks, we adopt the heterogeneous (multi-class) METANET model wherein the density and velocity dynamics of each vehicle class in each cell are described mathematically.
Moreover, in this research, we propose a hierarchical distributed infrastructure-based control framework to manage large-scale heterogeneous traffic networks. At the lower-level, we employed the Distributed Filtered Feedback Linearization (D-FFL) controller which only requires limited information from the plant model. The purpose of this controller is to track the desired density of each vehicle class in the target cells which is set by the upper-level controller. D-FFL tracks the reference density by controlling the suggested velocity of vehicles in the target cell and its upstream cell. At the upper-level, in our initial design, a Distributed Extremum-Seeking (D-ES) controller is designed and implemented to find the optimal operating densities of each vehicle class in the target cells over time. Gradient-based D-ES is a model-free, real-time adaptive control algorithm that is useful for adapting control parameters to unknown system dynamics and unknown mappings from control parameters to an objective function. To improve the performance of the designed hierarchical controller and reduce the convergence time, we designed and implemented Lyapunov-based Switch Newton Extremum Seeking (LSNES) at the upper level of the hierarchy to feed the optimal density of each vehicle class in the target cells to the lower-level controller. One of the key distinctions between the Newton algorithm and the gradient algorithm is that the convergence of the former is not solely contingent on the second derivative (Hessian) of the cost map and it is user-assignable.
Finally, we established a MATLAB-VISSIM COM interface that allows closed-loop control of a simulated traffic scenario in PTV-VISSIM to test and validate the effectiveness of the distributed control approaches in large-scale traffic networks. The simulation results show that our control framework design can effectively reduce congestion and prevent congestion back-propagation during peak hours in large-scale traffic networks.



Candidate Name: Natalie Gabhart
Title: Intraoperative Dosing of Dexamethasone in Type II Diabetics Undergoing Bariatric Surgery
 December 08, 2023  10:00 AM
Location: CHHS 436
Abstract:

Purpose: Identifying trends in the intraoperative dosing of dexamethasone in type II diabetic patients undergoing bariatric procedures at a community hospital to determine impact of the dose received on perioperative glycemic control.

Background: Dexamethasone is a corticosteroid and despite its many documented benefits when administered perioperatively to surgical patients, it is often withheld in the type II diabetic population out of concern for postoperative hyperglycemia.

Methods: Retrospective chart reviews of 36 type II diabetics receiving dexamethasone undergoing bariatric procedures was completed. Inclusion criteria: type II diabetics, procedures <4 hours, patients with a HbA1C reading 6.5-8.9%, patients who are non-pregnant, patients with an ASA classification of I, II, or III, and who are not taking chronic steroids.

Results: Of the 36 perioperative glycemic trends reviewed, there was a significant increase (t = 8.72, p<0.001) between the preoperative and immediate postoperative blood glucose readings for dexamethasone doses 4-10 mg (p <0.011). This increase was not associated with age, HbA1C, or surgery length. The dose level itself did not influence actual BG level changes (t = -.87, p = .390).

Conclusion: Dexamethasone increases postoperative BG significantly in DMII patients undergoing bariatric surgery in the immediate postoperative period. However, it should be noted that there was not a significant difference between preoperative BG and the 24-hour postoperative BG level. Two patients who did not receive dexamethasone also showed an increase in BG that approached significance (p = .060). These results suggest that further study on the effects of dexamethasone dosing and perioperative glycemic control is necessary.

Key words: Hemoglobin A1C (HbA1C), dexamethasone, diabetic II, type 2, bariatric, intraoperative



Candidate Name: Mara Hannigan Leavitt
Title: An Educational-Based Approach to Prevent Corneal Abrasions at a Trauma I Level Hospital
 December 08, 2023  1:00 PM
Location: CHHS 436
Abstract:

Corneal abrasions are one of the most common anesthesia-related adverse events. There is limited evidence about the effect of virtual education on anesthesia providers’ knowledge regarding corneal abrasion prevention. The purpose of this study project was to assess if a web-based educational module effectively improved anesthesia providers’ awareness of evidence-based preventative measures of corneal abrasions. This was a quasi-experimental pretest-posttest study design. All participants completed a questionnaire regarding their knowledge of corneal abrasion prevention before and after the educational module. A student T-test was used to compare the differences in pre- and post-education knowledge scores. There were 55 participants in the study. Among them, 23.6% were anesthesiologists and 76.4% were certified registered nurse anesthetists. There was a significant pretest-posttest difference in the total knowledge score (6.49±1.23 vs. 8.24± 1.08, p< .001). The average number of correct answers increased from 6.49 ± 1.23 to 8.24 ± 1.108 (t = 9.94, p < .001) Overall, the web-based educational module was effective in enhancing anesthesia providers’ knowledge in preventing surgical-induced corneal abrasions. The finding may add evidence for developing effective guidelines and standardizing provider education in corneal abrasion prevention.



Candidate Name: Madison Gallo
Title: Scholarly Project: Sugammadex and Hormonal Birth Control Education
 December 01, 2023  10:00 AM
Location: CHHS 436
Abstract:

Background
Sugammadex is one of the most used agents to reverse surgery induced neuromuscular blockade. It also reduces hormonal contraceptive effectiveness. There is limited evidence about developing effective education of the interaction between Sugammadex and birth control pills in post anesthesia care unit (PACU) nurses who are responsible to provide discharge education to patients taking hormonal contraceptives.

Purpose
The purpose of the project is to examine the effect of a web-based education on PACU nurses’ awareness and knowledge about the interaction between Sugammadex and hormonal contraceptives.

Methodology
A quasi-experimental study with pretest posttest design was conducted in a southeast healthcare facility. An animated educational video was designed to enhance the knowledge about the interaction between Sugammadex and hormonal contraceptives. An online survey was performed to assess the change of pre and post education knowledge score.

Results
The study included 27 PACU nurses. Age was associated with pretest score (b = 0.04, p = .010). Older participants were likely to have higher pre-intervention score. There was a significant pretest -posttest difference on Question 1 (the mechanism of action of Sugammadex) (χ2 = 7.72, p = .005) and total score (3.93± 1.00 vs. 4.55 ± 0.67, t = 2.81, p = .011).

Conclusion
The web-based education is effective to improve PACU nurses’ knowledge of the drug interaction between Sugammadex and hormonal contraceptives. The finding may help the development of discharge teaching in surgical patients taking hormonal contraceptives.



Candidate Name: Justice L. Edmond
Title: SCHOLARLY PROJECT: SUGAMMADEX AND HORMONAL BIRTH CONTROL EDUCATION
 December 01, 2023  10:00 AM
Location: CHHS 436
Abstract:

Background
Sugammadex is a useful reversal agent of neuromuscular blockade during surgery. However, its interaction with hormonal contraceptives could lead to undesirable outcomes in surgical patients using birth control pills. The feasibility and effectiveness of web-based education targeting post-anesthesia care unit (PACU) nurses are limited. PACU nurses are responsible for patient education related to the interaction between Sugammadex and hormonal contraceptives.
Purpose
The purpose of the project is to examine the effect of a web-based education on PACU nurses’ awareness and knowledge about the interaction between Sugammadex and hormonal contraceptives.
Methods
A quantitative, quasi-experimental, pre-/post-test design study was conducted among PACU nurses who work at a healthcare facility located in the southeast region of the United States. An online survey was used to investigate the effect of web-based education on PACU nurses’ knowledge about the interaction between Sugammadex and hormonal contraceptives.
Results
Among 27 PACU nurses, their years of experience ranged from 0 to 26 years (4.43 ± 6.65). There was a significant pretest-posttest difference on Question 1 (the mechanism of action of Sugammadex) (χ 2 (1) = 6.22, p = .013). The average number of correct answers increased from 4.00 ± 0.87 to 4.70 ± 0.54 (t = 3.99, p < .001).
Conclusion
The web-based education was effective in improving PACU nurses’ knowledge of drug interactions. This finding may contribute to the development of a standardized online education program for anesthesia providers, enhancing their skills and competence in providing patient education on anesthetic agents.



Candidate Name: Ashley Burch
Title: SCHOLARLY PROJECT: SUGAMMADEX AND HORMONAL BIRTH CONTROL EDUCATION
 December 01, 2023  10:00 AM
Location: CHHS building, room 436
Abstract:

Background
Sugammadex is an effective and safe drug to reverse surgery induced neuromuscular blockade. However, the interaction of Sugammadex and hormonal contraceptives may lead to unintended effects in surgical patients who are using hormonal birth control. There is insufficient evidence regarding the effectiveness of online education among post-anesthesia care unit (PACU) nurses, who are responsible for delivering discharge education.

Purpose
The purpose of the project is to examine the effect of a web-based education on PACU nurses’ awareness and knowledge about the interaction between Sugammadex and hormonal contraceptives.

Methods
We conducted a quasi-experimental study with pre-/post-test design. The study was conducted in a surgical center located in the southeastern region of the United States. A digital survey was given both prior to and following the online educational session. The effects of web-based education was examined by comparing the differences of the pre and post-educational survey knowledge scores.

Results
Among 19 PACU nurses, their years of experience ranged from 0 to 33 years (M = 5.67, SD = 8.81, Mdn = 3). There was a significantly increased number of corrections between pre- and post-test from 4.37 ± 0.90 to 4.81 ± 0.40 (t = 2.52, p = .023).

Conclusion
The online education proves to be both feasible and effective in enhancing the knowledge of drug interactions among PACU nurses. This finding could contribute to the development of a standardized educational framework for ongoing drug education in nurses.