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Optimization of metal organic frameworks design for CO2 capture through machine learning and molecular dynamic simulation
No full textThe efficiency of carbon dioxide (CO2) capture is strongly governed by the physical and chemical characteristics of the adsorbent, which determine its adsorption uptake, selectivity, and regeneration performance. As a performance benchmark, desorption kinetics were experimentally evaluated by thermogravimetric analysis (TGA) for activated carbon and zeolite, revealing desorption activation energies of 141.14 and 28.11 kJ mol−1, and CO2 uptakes of 5.79 and 2.90 mg g−1, respectively, at 0.04% CO2 concentration. These results motivate the exploration of metal–organic frameworks (MOFs) for their tunability in pore structures and surface functionality for CO2 adsorption. In this work, machine learning and molecular simulations were integrated to model and predict carbon dioxide/nitrogen (CO2/N2) selectivity in MOFs. A neural network trained on 400 ideal MOFs from the Topologically Based Crystal Constructor (ToBaCCo) dataset, using categorical descriptors of topology, node and edge building blocks, and functional groups, was developed to predict CO2 selectivity. The model was subsequently applied to an external dataset of 9,146 computation-ready experimental (CoRE) MOFs described by geometric descriptors, yielding an ��2 score of 0.999 for predicted selectivity. SHAP analysis identified chemical functionalization and network connectivity as the influential contributors to adsorption behavior. Monte Carlo perturbation and Bayesian calibration produced mean selectivity values of 6.25 and 6.33, confirming the model’s robustness, stability and interpretability. GCMC simulations under flue-gas conditions demonstrated that charged Cu-BTC and Zr-DMBD MOFs achieved CO2 uptakes of 1.499 and 2.985 mmol g−1, respectively, outperforming their neutral counterparts. Molecular dynamics (MD) simulations further demonstrated that the charged frameworks possessed enhanced electrostatic cohesion and structural stability, indicating that framework polarization strengthens CO2 binding without compromising rigidity. Together, these findings establish a unified computational framework for predicting adsorption behavior and guiding the design of next-generation MOFs for both Direct Air Capture (DAC) and post-combustion CO2 separation
Improvement of spot spraying treatments using precision application technologies
No full textChemical plant protection is widely adopted in agriculture and plays a crucial role in maximizing plant production. Several developments for site-specific applications have been implemented in chemical plant protection, driven by economic, social, and environmental considerations. Spot spraying technology, which utilizes single nozzles or a limited number of nozzles to treat specific areas, is now available and gaining market penetration. However, its performance depends on carefully optimized application parameters to ensure consistent coverage and efficacy, thereby mitigating both under- and overdosing. To address concerns including reduced efficacy, resistance evolution, and environmental impacts, this work researches the effects of nozzle selection on lateral distribution quality under laboratory conditions. In 2021, the Pesticide Application Technology Lab at the University of Nebraska Lincoln was used to evaluate the effects of boom height, nozzle spacing, fan angle, and nozzle orientation in combination with different nozzle types. A new evaluation standard was developed to assess the distribution patterns in spot spray applications. The effects of varying nozzle types on spot spray herbicide application and subsequent savings were investigated in field trials with a Fendt Rogator Smart Sprayer prototype. Randomized strip trials with four replicates were set up on eight agricultural fields in corn and grain stubble between 2021 and 2023. Results indicate that nozzle type influences savings, and that boom height, nozzle spacing, fan angle, and nozzle type impact lateral distribution for single nozzle applications. This study also introduced a novel method, the In-Spot Out-Spot (ISOS) standard, which has proven to quantify spraying quality in single nozzle applications. Therefore, application equipment is a crucial factor in evaluating site specific pesticide applications, and the findings from this study should be considered when calibrating spot sprayers
Growing Pains: Assessing the Strategic Organizational Communication Approaches of an Expanding Extension Organization
No full textAs social structures evolve, strategic organizational communication (SOC) must also evolve for organizations to best meet the ever-changing needs of stakeholders. Assessing communications can guide the direction of an organization while also elevating the organization to the next level. For this study, researchers assessed the SOC strategy of the Extension Disaster Education Network (EDEN) through qualitative focus groups. Results of this study revealed internal communication and resources provided by the organization were perceived as positive communication approaches, while external communication and visibility were identified as negative communication approaches. Other Extension organizations could benefit from the results of this research as they work to prioritize organizational communication goals
Men in Family Science Courses: Perspectives of Family Science Faculty and Administrators
No full textThe goal of this qualitative study is to describe the perspectives of higher education family science faculty and administrators regarding men’s enrollment in family science courses. University family science courses educate students on how to promote developmental potential for individuals, couples, and families. Information from these classes can assist students’ personal and professional development regardless of gender, yet there are far fewer men enrolled in these courses compared to women. Data come from 78 faculty members and 12 administrators from randomly selected universities using the National Council on Family Relations’ Degree Programs in Family Science directory. Using coding reliability thematic analysis, three broad themes were identified: (1) Men’s enrollment in family science is impacted by broader societal forces; (2) “Family science is for EVERYONE”; and (3) Consequences of increasing men’s enrollment in family science courses. Results illustrate that men could benefit from family science courses, but societal influences are likely to inhibit men’s enrollment. Increasing men’s enrollment could alter the current structure of family science courses. Based on these results, strategies are proffered to recruit students across gender and other identities into family science courses
Bipyridine-containing, bio-inspired ligand to support manganese for oxidative catalysis
No full textMetalloenzymes have garnered significant interest in bioinorganic research due to their ability to use earth-abundant metals (i.e., iron, copper, manganese) to conduct reactions in an environmentally friendly manner. Manganese-catalyzed reactions have been extensively studied for O2 activations, superoxide disproportionation, and water oxidation. Additionally, manganese catalysts have been investigated in alkene oxidative cleavage, an essential process in the pharmaceutical and synthetic industries. The primary industrial method employed for this reaction is ozonolysis, a stoichiometric approach that utilizes harsh and toxic conditions. For example, (+)-artemisinin and 24(S)-hydroxyvitamin D2 are two pharmaceutical drugs that utilize ozonolysis in the synthetic procedure to cleave the alkene to the final product or to produce the intermediate for the final product. In addition to ozonolysis, KMnO4, photocatalysis, and several stoichiometric or catalytic methods have also been developed to circumvent the high waste of ozonolysis. While these methods are effective, some still depend on harsh and toxic conditions. In addition, there is a lack of selectivity between the thermodynamically favored cleaved product and the kinetically favored product, epoxide. The biological system TM1459 is a metalloprotein that has been shown to oxidatively catalyze alkenes in vitro in the presence of manganese, utilizing a four-histidine metal binding site. Previously, our group developed a tetradentate ligand to model this enzyme with two pendant imidazoles. However, when applied to water oxidation catalysis, the complex proved unstable under catalytic conditions, and the ligand was weakly bound to manganese. Subsequently, we aim to incorporate pyridinol donors into the ligand to enhance stability under catalytic conditions, as they can deprotonate to the pyridonate, thus making the ligand a more substantial donor.
This thesis details the synthetic efforts to produce this ligand. The first step involves a lithium halogen exchange with 6-bromo-2,2-bipyridine to facilitate a nucleophilic attack on the ketone. This step is analyzed under various temperatures, metal-halogen exchange sources, and reaction time conditions. 1H NMR and gas chromatography-mass spectroscopy (GC-MS) were utilized to analyze each attempt to determine whether the product was formed and identify any side products generated during the reaction
Empowering Community Through Extension: Identifying Community Health and Wellness Strengths and Needs
No full textHealth and wellness are foundational to thriving communities, yet many Americans face barriers that impact their access to essential health education and services. This study used a community-based participatory research (CBPR) approach to assess the perceived strengths and needs of health and wellness resources of rural and urban Texas communities. Data were collected through a statewide survey (n = 9,418), targeting key aspects of health and wellness. The results identified critical strengths, including school lunch programs and grocery stores accepting electronic benefit transfers (EBT), while reducing obesity and addressing mental health emerged as top community needs in both urban and rural areas. Rural communities showed a greater need for emergency healthcare services, whereas urban participants prioritized suicide prevention and mental health services. These findings highlight the vital role of Extension in bridging health education gaps and providing targeted programming to address diverse community needs. By leveraging its existing infrastructure, Extension can facilitate sustainable interventions, strengthen community health outcomes, and build resilience in both rural and urban populations. Future research should aim to expand these insights into broader populations and refine programming strategies
An investigation of non-persistence of second and third year engineering students at a midsize research university in the South
No full textApproximately 25% of engineering students drop out during their 1st year of school, with nearly that many leaving during their second or third years. A meta-analysis of engineering non-persistence literature led to the development of an Engineering Non-persistence Model, which incorporates both quantitative and qualitative factors. While previous research primarily focused on factors of non-persistence of engineering students as a whole, this study aims to fill the gap in existing literature by examining factors within the model that contribute to non-persistence among 2nd- and 3rd-year engineering students. The goal is to provide tailored support to second and third year students who have a desire to remain in engineering yet have obstacles to overcome. During Stage 1, institutional quantitative data were analyzed for the 2014 cohort of engineering students at a midsize Southern research university. Statistical analysis revealed several key factors linked to nonpersistence among second and third year students, including low ACT Math subscore, low high school GPA, poor grades in calculus and physics, and engineering course failures. Gender and ethnicity were not found to be significant factors. During Stage 2, to gain a deeper understanding of the perspectives of students who did not persist and chose to switch to other programs, qualitative, in-depth interviews were conducted. This approach aims to strengthen the data collected from the students\u27 academic records. Six nonpersisting students - two female and four male - who were enrolled at the university in 2024, participated. Analysis of the data uncovered several themes related to nonpersistence, such as lack of involvement in extracurricular activities, poor peer and professor relationships, inadequate study habits, and unpreparedness for rigor or time commitment. With these new insights, engineering schools can narrow their focus and provide customized solutions for the targeted population of second and third year engineering students who are at risk of nonpersistence. Engineering schools should prioritize fostering stronger relationships among peers. Engineering schools should also incorporate time management skills and study skills tailored to the demands of engineering. These goals could be accomplished with the implementation of small group mentoring practices run by the college of engineering
The Lucky Ones
No full textMany fictional stories featuring adoption, written from the perspective of non-adoptees, lack the authenticity required to resonate with adoptees who want to see themselves accurately represented. These narratives often perpetuate harmful stereotypes of adoptees and must be challenged by more genuine and respectful portrayals in fictional stories. In a series of short stories, I developed characters who provided realistic representations of unique feelings and experiences regarding loss, belonging, and family. Across various genres, six short stories were written from the perspective of adoptees to include multiple pathways to adoption and define the term “family.” A richer and more nuanced perspective of adoptees in fictional stories, as seen in these stories, offers a voice for those who struggle to find themselves accurately represented
A cloud of witnesses: Captivity among the Society People of colonial Pennsylvania
No full textIn 1760, Jean McCord Lowry published a journal detailing her three years of captivity among the Delawares of Pennsylvania and the French Catholic authorities in New France during the Seven Years’ War. Lowry was a member of a religious community known as the Society People that strictly adhered to the codes, rules, and ordinances of the Scottish National Covenant of 1638 and the Solemn League and Covenant of 1643. This sect emerged from a series of European imperial conflicts that led to internal divisions within the Covenanter community. The Society People in Scotland, Ireland, and colonial America believed themselves the “representatives of the true Presbyterian Church & Covenanted Nation of Scotland.” As the only surviving account of the captivity experiences of a female member of the Society People of colonial Pennsylvania, with deep spiritual roots in Scotland and Ireland, Lowry’s published journal deserves a prominent place in the historiography of captivity narratives. This research positions Lowry’s journal as a Covenanter text, in the same way the Covenants executed in the seventeenth century, and the later writings and published testimonies by the Society People of those martyred for the faith, demonstrated the peculiar beliefs of a persecuted people. This transatlantic study places women in the foreground of larger historical events from the English Civil Wars to the Seven Years’ War and centers them in the history of the Scottish Presbyterian covenanting movement. Women often placed themselves in harm\u27s way and used their voices, their wit, their bodies, and their courage to cling to their covenanting beliefs and those of their ancestors. As a captive and a Covenanter, Lowry viewed the imperial war that surrounded her community for control of the North American continent, not as a contest against flesh and blood, but as a religious war. Lowry, and the story of Society People of Pennsylvania are transatlantic threads that connect this extreme religious group of adherents to the ancient Covenants in Scotland and Ireland to colonial America
Impact of circular and non-circular nozzle exit geometries on jet flow propagation and turbulence characteristics
No full textThis thesis aims to investigate the impact of nozzle exit geometry on jet flow propagation and turbulence characteristics. Computational fluid dynamics simulations were performed using ANSYS Fluent, employing the Reynolds-Averaged Navier-Stokes (RANS) approach, to compare circular, elliptic, and rectangular nozzle geometries. The analysis focused on velocity distributions, turbulence characteristics, and cross-flow interactions. Results indicate that circular jets have the longest potential core and slowest velocity decay, reflecting lower mixing rates. In contrast, elliptic and rectangular jets have shorter potential cores, faster velocity decay, and elevated TKE peaks, suggesting enhanced turbulence and mixing. These findings highlight the significant role of nozzle geometry in shaping jet behavior, offering insights for designing efficient nozzle systems for specific applications. The study paves the way for future research on the axis-switching phenomena in non-circular jets and the effects of higher aspect ratios on jet flows properties