Advisor: Dr. Fateme Rezaei
Date & Time: Friday March 24, 2023 at 12:00PM
Location: https://umsystem.zoom.us/j/98030258488?pwd=ejQ0T3M4YjZqTm9DdDIzNVZyZzdTUT09
Abstract: This research focuses on the In-Situ CO2 capture and utilization in the oxidative dehydrogenation of ethane (ODHE) for ethylene production, and a subsequent ethylene purification through adsorptive separation process. In particular, several dual-function materials (DFMs) were developed, formulated into 3D-structure, and investigated for ODHE reaction to ethylene under various process conditions using CO2 as a mild oxidant. The DFMs materials were consisted of CaO and metal oxides (e.g., Cr2O3 and V2O5) supporting H-ZSM-5. The results indicated that higher cell densities lead to better performance due to kinetic enhancement, and the optimum configuration is separate stacking of the adsorbent and catalyst phases.
In the second part of the research, an induction swing adsorption process was designed, and a series of novel magnetic-responsive sorbents were developed for ethylene purification. The results indicated that both sets of sorbents (Fex/MOF-74 and Fex/13X) had high ethylene adsorption capacity, selectivity, and regeneration when exposed to an electromagnetic field. With a 20% Fe3O4 /13X, the highest energy absorption was observed with the greatest ethylene desorption rate of 0.69 mmol/g.min. Interestingly, using induction heating, the cooling rate is 71% faster than the conventional heating method. Furthermore, the selectivity of C2H4/C2H6 was constant at 4.10 even in the presence of impurity gases (e.g., CH4, H2) as in ternary and multicomponent gas mixtures. Overall, novel DFMs formulations for CO2 capture-conversion processes, in particular for the production of light olefins, are developed, along with magnetic sorbents that facilitate the capture and purification of olefins from paraffins via induction heating.
Advisor: Dr. Ming Leu
Date & Time: Friday March 24, 2023 at 12:00PM
Location: https://umsystem.zoom.us/j/7033107533?pwd=V0lmWFRRL0R6Tm56QTdRUHNoMWI3QT09
Abstract: This research was conducted to characterize the powder properties using different characterization techniques to enhance the powder behavior in the Laser Powder Bed Fusion (LPBF) process. One of the shortcomings of LPBF process is the high cost of gas-atomized powder feedstock. To overcome this downside, the cheaper water-atomized powder was characterized and used in LPBF process, and its performance was compared with those of gas-atomized powder. Also, the plasma spheroidization process was used to improve the powder characteristics; if the spheroidized powder could function as well as the virgin powder, plasma spheroidization process could be applied to the used powders to recycle them to a virgin-like state. In addition, due to the recent increasing implementation of copper powder in LPBF, the impact of plasma spheroidization on the copper powder used in LPBF was investigated, both numerically and experimentally. Furthermore, a powder spreading setup was designed and fabricated to study the fundamental characteristic of powder spreadability, which plays an important role in the efficiency of LPBF process.
This research addressed challenging topics regarding the powder behavior in LPBF process. The powder characteristics were identified and improved so that the parts fabricated using LPBF can show higher mechanical properties. The results of this study can be extended to other materials and powder-based AM processes. The results of this study indicated the commercial profit that can be provided through utilization of a cheaper powder, deployment of plasma spheroidization process, and identifying and enhancing the powder spreadability metric in LPBF process.
Advisor: Dr. Suzanna Long
Date & Time: Monday March 27, 2023 at 9:00AM
Location: https://uidaho.zoom.us/j/84922500011
Abstract: The healthcare system in the United States is complex and dynamic. The emergency department (ED) is a unique environment within the health-care system that bridges the gap between outpatient and inpatient care. According to the Centers for Disease Control and Prevention nearly 130 million people visited emergency rooms in the United States in 2018. The ED, like any other large system, has various subunits and components, making it complex and difficult to understand. As a result, in this study, various engineering analysis methods were used. This combination of methodologies aided in identifying and better understanding issues in the ED. Findings from this study can be used by healthcare stakeholders to support ED-related decisions.
The first contribution of this research involved data collection through the utilization of job shadowing of human entities at the Phelps Health Emergency Department in Rolla, Missouri, allowing the identification of issues impacting patient flow and wait times. A Model Based Systems Engineering model was developed to represent and comprehend the structure, activities, and use cases in the ED. The model aided in gaining a better understanding of the complex system of the ED and helped identify the factors influencing patient wait time and satisfaction.
The second contribution of this research involved the development of a small-scale discrete event simulation model to gain an understanding of the factors that influence resource utilization and the average patient total time in the ED. By comparing the results of the day and night shift simulations, the impact of staffing and other factors on ED performance during different shifts was identified.
The third contribution of this research involved the development of a discrete event model based on the data collected from the job shadowing process at the Phelps Health Emergency Department in Rolla, Missouri. A multi-objective optimization was conducted to minimize patient total wait time and maximize resource utilization. The effectiveness of different strategies for improving ED performance was evaluated through the comparison of DES and MOO results. The contributions in this study significantly advanced the understanding of ED operations, and important implications for improving ED performance were identified.
The challenges affecting the ED were identified and analyzed by utilizing a combination of methods. This approach provided insights that could aid healthcare organizations in their efforts to improve patient outcomes. The study's results demonstrated the potential benefits of using job shadowing and engineering analysis methods to address the challenges in the ED.
Advisors: Dr. Honglan Shi
Dr. Casey Burton
Dr. Paul Nam
Date & Time: Monday March 27, 2023 at 9:00AM
Location: https://umsystem.zoom.us/j/98433988594?pwd=SGtYclVWRzFiT1QrT3B3Wm8wNW0wdz09
Abstract: Pathological processes often involve complex biochemical changes which can be assessed using advanced mass spectrometry techniques. In this present dissertation, two significant public health concerns were studied: traumatic brain injury (TBI), and water contamination by L. pneumophilia.
TBI is a pressing public health concern, with both acute and long-term consequences in affected individuals. Current clinical tools used to assess TBI remain inadequate to fully assess the impact of TBI over time. Growing evidence suggests that biochemical markers are altered following a head injury, and may prove to be a powerful tool for future clinicians to assess TBI severity. This dissertation presents newly developed high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) methods to access key metabolites associated with brain injury caused by repeat blast exposure. We applied these methods to the serum and urine of military personel conducting training which involves exposure to multiple explosive blasts. Significant changes in urinary homovanillic acid (P < 0.0001), linoleic acid (P = 0.0030), glutamate (P = 0.0027), and serum N-acetylaspartic acid (P = 0.0006) were all observed between pre- and post-blast specimens. Homovanillic acid was also decreased further following additional blast exposures. These changes point to the possibility of a biomarker panel which may be able to assess the severity of blast related TBI non-invasively and without the need for advanced neuroimaging.
L. pneumophilia is a pathogenic bacteria implicated in the majority of cases of Legionairre’s disease around the world. As this opportunistic pathogen can infect domestic water supplies, its control and prevention in these systems is of major public health consequence. We have developed a novel single cell-inductively coupled plasma-mass spectrometry (SC-ICP-MS) method and applied this method to investigate L. pneumophilia treatment efficiency by copper (Cu) in drinking water. We applied this method to L. pneumophilia populations dosed with Cu in both varied concentrations and over a time delay experiment. Interestingly, while high concentrations (800-1200 ppb) of Cu ions were found to have a high disinfection rate in drinking water, some cells persisted and even returned to a normal state 24 hours after the initial exposure to Cu. These likely vaiable but non-culturable cells were detectable by SC-ICP-MS but not by colony forming unit count analyses. They may have actively expelled Cu, or never had any Cu uptake, providing resistance to disinfection. This is the first study to our knowledge which explores the relationship between copper dosing over time of L. pneumophilia in drinking water by SC-ICP-MS.
Advisor: Dr. Muthanna H. Al-Dahhan
Date & Time: Monday March 27, 2023 at 12:00PM
Location: https://umsystem.zoom.us/j/91208326475
Abstract: The new generations of nuclear plants are increasingly gaining interest due to their high efficiency and inherent safety. In this study, the thermal hydraulics and especially the convective heat transfer is investigated for a pebble bed reactor (PBR) which is a High Temperature Gas-cooled Nuclear Reactor (HTGR). The convective heat transfer between the TRISO pebbles and the coolant gas (Helium) is the main criteria by which the throughput of these reactors is assessed and gathering a reliable databank of local heat transfer measurements is essential for the design and safety of PBRs. In the different parts of this study, the objective was to investigate the variation of the local convective heat transfer coefficients inside the pebble bed at various flow conditions, corresponding to laminar and turbulent flow conditions, as well as to directly link these variations in the local heat transfer coefficients with the variations of the local gas velocities in the pebble bed, which is also directly related to the bed structure and the void fractions in the bed.
All the parts of this study are conducted with a pebble diameter of 5 cm and a pebble-to-
diameter ratio (aspect ratio) of 6. Despite the small aspect ratio of this bed, the size of the pebbles allows us to approximately assess the effect of the wall on the local convective heat transfer coefficients in a real PBR. In the first part, the local actual gas velocities were measured at different radial locations in the pebble bed, from the center of the bed to the region near the wall (r/R =0, 0.33, 0.67, 0.9) using a sophisticated hot wire anemometry (HWA) technique, which was
supported with a novel probe-protector case that protected the probe, allowing the measurements of the local gas velocities to be taken at the center of the pebble bed for the first time. In the second part, the local convective heat transfer coefficients were measured using a cartridge heated probe pebble, a microfoil heat flux sensor and a thermocouple at various radial locations, axial locations, and angular orientations and under different superficial inlet gas velocities that correspond to both laminar and turbulent flow conditions. This comprehensive study of the local heat transfer by convection presents a valuable databank for the validation of CFD simulations with integrated heat transfer calculations. In the third part, to further enhance the databank of the local convective heat transfer measurements inside the pebble bed, new measurements were conducted using the same setup and technique, with the addition of taking three measurements at the different locations in the void of the bed, by changing the orientation of the probe pebble and the location of the thermocouple, accordingly. This allowed us to assess the reliability of the measurements that are taken at the center of the void, compared to the average of the measurements taken at different locations in the void. This also allowed us to confirm the reproducibility of the local heat transfer measurements using our measurement technique as well as to confirm the patterns of the variation of the local heat transfer coefficients along the diameter of the pebble bed.
Advisor: Dr. Joshua P. Schlegel
Date & Time: Wednesday March 29, 2023 at 1:00PM
Location: https://umsystem.zoom.us/j/94453024096
Abstract: Due to the complexity of multiphase flow phenomena, numerical analysis for multiphase turbulent flow is not as reliable as single-phase computational fluid dynamics (CFD). A literature review has revealed that the current efforts on multiphase flow simulation have focused on small diameter channels under very restricted flow conditions and have been conducted without identifying some important procedures. To expand CFD applications to a wide range of two-phase flow conditions in large diameter channels, this study aims to validate the current CFD models for vertical concurrent air-water two-phase flow simulations beyond bubbly flows. First, a numerical model developed to describe dynamical changes of interfacial area concentration (IAC) of bubbles, known as two-group interfacial area transport equation (2G IATE), is evaluated for a wide range of flow regimes in a large diameter pepe. This evaluation includes examinations of mass and momentum exchange, and interaction mechanisms between gas phases and between gas and liquid phases. Second, the interfacial force closure models, which are a key for the accurate prediction of two-phase flow parameters on the Eulerian-Eulerian framework, are validated and an appropriate choice of closure models for a wide range of flow regimes is proposed. Third, CFD models affecting the turbulence mixing effect were compared and the effect of bubble-induced turbulence (BIT) generated by large bubbles was investigated. The three important aspects addressed for the validation of the CFD models for high void fraction and high velocity flow conditions in a large diameter pipe are the first effort to validate the current CFD models for beyond bubbly flows and for a large diameter pipe.
Advisor: Dr. Baojun Bai
Dr. Thomas Schuman
Date & Time: Monday April 3, 2023 at 1:00PM
Location: McNutt Hall Conference Room 124
Abstract: Recrosslinkable Preformed Particle Gel (RPPG), a preformed particle gel of which particles can bond together to form a strong bulk gel system after being placed inside the target formation. This technology, which was invented at MST, has been successfully applied to control conformance problems for water flooding projects in the North slope of Alaska. In this research, we have systematically evaluated the feasibility of using this novel technology in improving gas flooding performance in mature reservoirs. Two types of RPPG systems were investigated in this research, including acrylamide (AM) and 2-acrylamide-2-methylpropane sulfonate acid (AMPS) based RPPG (CR-RPPG) and acrylamide-co-acrylic acid based RPPG (LT-RPPG). Different experimental apparatuses were designed to quantify and visualize the RPPGs phase stability under static and dynamic gel-gas interactions. The RPPGs phase stability were evaluated under a different range of injection pressure, gas exposure time and swelling ratio. Also, the RPPGs stability were compared to conventional polymer gel systems (HPAM/Cr (III)) which has been applied in oilfields to control gas injection conformance. The RPPGs plugging efficiency were evaluated using open fractured cores with different apertures. The results showed that the RPPG systems were stable under both static and dynamic gel-natural gas interactions and were stable when being exposed to an acidic environment with an insignificant total percentage weight loss. The coreflooding experiments results demonstrated that the RPPGs exhibited excellent plugging performance, which was closely related to the swelling ratio and the fracture aperture. The CR-RPPG could achieve a higher plugging performance especially for treating big fractures. with a sealing pressure exceeding 300 psi/ft. The robustness of the RPPGs system make it a viable candidate for improving the gas flooding processes in mature reservoirs dominated by conformance problems such as void space conduits, fractures, and high permeability channels.
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