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Direct Air Capture of Carbon Dioxide from the Atmosphere and Sequestration: Developing A new Class of Regenerable Hybrid Ligand Exchanger
No full textClimate change is a major obstacle to sustainable development, and the suffering inflicted on marginalized populations is disproportionately high in both the developed and developing world. As a result of global warming, it is anticipated that the frequency, intensity, and consequences of some types of extreme weather events, such as ice melting, water scarcity, and sea level rise, would increase. The elevated atmospheric CO2 concentration from anthropogenic emissions is singularly responsible for global warming and is regarded as humanity\u27s worst existential threat. The magnitude of the crisis is enormous, with approximately 36.3 Gt/year of global CO2 emission, necessitating urgent actions from tens of countries for carbon mitigation. Direct air capture (DAC) is important to achieve net-zero greenhouse gas emissions by 2050. However, the ultra-dilute atmospheric CO2 concentration (~ 400 ppm) poses a formidable hurdle for high CO2 capture capacities using sorption-desorption processes. Therefore, for increased uptake, point-source flue gas streams with orders of magnitude higher CO2 concentrations have been desirable targets for enhanced CO2 removal. Previous studies have demonstrated that the overall economics and energy efficiency of DAC are greatly enhanced when the sorbent exhibits a high sorption capacity and can be regenerated efficiently. In this study, we present for the first time a Lewis acid-base interaction derived hybrid sorbent with a polyamine-Cu(II) complex enabling over 5.0 moles CO2 capture per kilogram of the new sorbent, nearly 2-3 times greater capacity than most of the DAC sorbents reported to date. The hybrid sorbent is mechanically strong, chemically stable, and like other amine-based sorbents, is amenable to thermal desorption at less than 90 °C. Additionally, seawater was validated as a viable regenerant, and the desorbed CO2 is simultaneously sequestered as innocuous, chemically stable alkalinity (NaHCO3). The dual-mode of regeneration offers an unprecedented flexibility in using oceans as decarbonizing sinks to widen DAC application opportunities. Furthermore, this study reveals for the first time that seawater has the potential to be used both as a regenerant and a sink for direct air capture of CO2 and thus can eliminate the need for underground geological storage simultaneously in agreement with the recent National Academies of Sciences (NAS) recommendations
On Non-Energy Uses of Anthracite Coal
No full textNon-energy applications of coal and their by-products such as manufactured activated carbon and recovered rare earth elements have been paid a lot of attention of lately due to the declining uses of coal power generation and emerging new carbon-based industries and renewable energy technologies. There is increasing interest from government agencies, research laboratories and universities, and private companies in research and development of technology aligned with this space. In this dissertation, three different non-energy uses of anthracite coal were studied. Specifically, rare earth elements extraction from anthracite acid mine discharge was investigated to determine the feasibility of a novel process for recovery of these critical materials. An anthracite coal-based activated carbon was developed and tested at laboratory and slip-stream scale to assess the feasibility of this product in removing mercury emissions from flue gas. In addition, anthracite coal-based porous carbon materials were developed, characterized and utilized as electrodes for high-performance supercapacitor applications. The higher ash content of anthracite among all types of coal represents a higher inorganic compound content that bonds valuable rare earth elements which are in high demand in the world. A study on the feasibility of a novel extraction process was performed, which included the selection of an extractant ligand as a key factor for high rare earth elements extraction efficiency. A detailed analysis was performed in this study to select proper organic ligands for different configurations of rare earth elements static/dynamic extraction from anthracite coal acid mine drainage. The optimal rate of rare earth elements extraction was determined to increase with the atomic number of the rare earth elements. Process improvements for enhancing rare earth elements\u27 extractability were discussed and suggested. Anthracite coal has the highest carbon content and the least amount of volatile matter of all ranks of coal, making it beneficial to utilize as a carbon resource due to its porous carbon structure. The characterization of a newly developed anthracite activation process, including alkali to coal ratio, activation temperature, etc. were investigated for mercury adsorption. The mercury adsorption performance of selected anthracite coal-based activated carbon samples was evaluated. Anthracite coal-based activated carbon achieved good results in terms of mercury adsorption at elevated temperatures in simulated flue gas, comparable to a commercial activated carbon. In addition, an analysis of manufacturing anthracite coal-based activated carbon was performed to confirm the experimental data. Following laboratory tests, the lab-scale Hg adsorption experiment was expanded to a field test campaign to evaluate the mercury removal efficiency of anthracite coal-based activated carbon in a slipstream apparatus at a waste-to-energy plant. The obtained adsorption results were very encouraging. The mercury removal efficiency of the anthracite coal-based activated carbon reached up to 80%, which was comparable to the removal efficiency of the commercial activated carbons used at the plant for mercury emissions compliance. Finally, the research also focused on developing anthracite coal-based porous carbon materials as a carbon electrode for high-performance supercapacitor applications using a multi-stage activation method. A theoretical analysis of characterization of anthracite-based porous carbon materials was conducted for understanding the performance and these materials and to outline a methodology of electrode fabrication optimization. The electrochemical performance of anthracite coal-based porous carbon electrodes in a specific electrode system was fully characterized using specialized instrumentation. It was found that all lab-made anthracite coal-based porous carbon materials resulted competitive in terms of supercapacitor electrical performance when compared to commercially available porous carbons
The Impact of Virtual Arts Experiences on Student Interest in the Arts
No full textThis research study used quantitative data analysis techniques to examine if participation in a live, virtual arts experience increased student interest in the arts. The study explored three key research questions: What is the impact of a live interactive virtual arts experience on student interest in the arts? Does participating in an interactive virtual arts experience in one domain (visual arts, music, dance, theater) increase students\u27 desires to engage in and participate in a second experience, either in the same or different arts domain (visual arts, music, dance, theater)? Are there comparable effects in outcomes across student subgroups in regards to students\u27 desire to engage in and participate in the arts? Participants included 186 students in grades 6-8 in the tri-state area. Using a randomized-control study, participants either received a live, virtual arts experience or a static, recorded arts experience. Data was collected using the Student Interest in the Arts Questionnaire (SIAQ) and a behavioral measure of participation in a follow-up arts experience. Data was analyzed through regression analysis and t-tests. Findings were statistically significant for several demographics. Females reported lower interest than males in all four domains of the SIAQ. Black or African American students as well as Students with Disabilities demonstrated lower interest in Dance. In the domain of Theater, students who were treated expressed more interest in taking lessons in this art-form outside of school as compared to those in the control group. For music, students who identified as Asian and received treatment demonstrated more interest than the reference group. Implications for future research include repeating the study once more time has elapsed from the intense virtual learning experiences of the pandemic era as well as comparing the effect of live, virtual experiences to physical visits to a cultural museum on student interest in the arts
Investigating Helium Diffusion Systematics with Continuous Ramped Heating Analysis: New Insights and an Application in the Altai Mountains
No full textApatite (U-Th)/He (AHe) thermochronology is an important tool in addressing questions in earth sciences, especially in tectonics and surface processes. However, the application of AHe thermochronology has been hindered by an incomplete understanding of diffusion systems that result in the single-grain age dispersion observed in natural samples, particularly those from old, slowly cooled geologic settings. This dissertation has three interrelated chapters that include advances in the understanding of helium diffusion systematics in apatite and the application in studying the mountain-uplift in the Altai mountains in Mongolia.In the first chapter, I used continuous ramped heating (CRH) to examine varying helium diffusion behavior using an apatite suite from the Transantarctic Mountains. The result shows that CRH analysis can be used as a screening tool for AHe dating and offers a chance in revealing first-order kinetic variations (i.e., helium transport that can be explained by simple volume diffusion versus those that show complex behaviors, which are characterized by systematic gas-release at high temperatures). This work also proposes that diffusion sinks exist in some apatites and can trap helium, resulting in altered helium retention and observed complex degassing behavior. In the second chapter, I performed CRH analysis on apatites from KTB boreholes (German Continental Deep Drilling). These samples have distinctively different thermal histories, allowing a chance to explore helium retention in the proposed diffusion sinks inside an active partial retention zone. Results demonstrate that He-release from the proposed diffusion sinks is temperature sensitive. In the third chapter, I used the CRH method to screen apatites from bedrock in the Altai mountains and utilized combined AHe ages, thermal-history modeling, and channel longitudinal-profile modeling to learn the timing of intracontinental uplift of the Altai mountains. The result shows that the Cenozoic rock uplift-related exhumation has started in the Gobi Altai by ~35 Ma, much earlier than previously thought. In addition, compared to the observed thermal stability of Gobi Altai in a large part of the Mesozoic, the Mongolian Altai have experienced relatively fast exhumation in the Jurassic – Cretaceous time, suggesting possible spatially varying geodynamics of the Altai
Conservation Complexities in the Mount Elgon Region, Uganda
No full textAbstractMargaux Petruska: Conservation Complexities in the Mount Elgon Region, Uganda Under the Direction of Karen Pooley This study utilizes prior research done in theories of development, institutions, militarization and environmental services to analyze the Mount Elgon Region of Uganda. By combining literature and qualitative research done in the region, the primary goal of the study is to determine and explore the connection between conservation policies and economic practices in the region as impacted by the creation of a National Park in 1993. Findings conclude that the region faces various environmental challenges perpetuated by population pressure, lacking environmental education, and conflicts between conservation authorities and the local communities. Potential solutions propose that shifting from primarily agricultural practices to formal jobs through sustainable development may lead to increased economic opportunities for the rural region. Additionally, increased coordination between the government and locals about proper environmental management can help reduce environmental impacts like landslides and soil degradation
Staging the Impossibilities of Conversion in the Early Modern Theater
No full textDuring the Early Modern period, conversion remained a complex phenomenon that involved not only religious beliefs but also political, social, and cultural aspects. Theatrical representations of conversion reflect this complexity and provide valuable insights into the ways in which people understood religious conversion. This thesis employs a translational and comparative lens to explore and interrogate The Tempest and Auraco Domado as two theatrical works that capture social perceptions of conversion in early modern England and Spain. It also considers how these two works present two similar, yet distinguishable models of conversion. By analyzing these representations, this thesis aims to shed light on the multiple ways in which English and Spanish societies negotiated with the possibilities of religious conversion as a tool of colonial domination
"Really listen this time:" Searching for Alternative Archival Practices in Gloria Naylor\u27s Archive
No full textThis thesis is a draft that will hopefully have a final form in the future, and thus is meant to be read as a work in progress. This paper explores a small section of Naylor\u27s archive—the research materials for Mama Day—in individual vignettes that each focus on one or two archival documents in conversation with passages from Mama Day and Black feminist criticism from the likes of Hazel Carby, Saidiya Hartman, Alice Walker, Katherine McKittrick, and Jean-Christophe Cloutier. Section one grows from an annotation that Naylor made on a travel brochure into a discussion of the ways in which Naylor uses her fiction to subvert racist organizational and cataloging systems of institutional archives. The next section focuses on Naylor as an ethnographer via her inclusions of an interview she conducted with folk healer and midwife Eva McKinney. The inclusion of the interview connects to her treatment of Reema\u27s boy, a fictional ethnographer in Mama Day, and how he is perhaps a warning to readers about the racist methodologies that weave their way into academic fields. The last two sections of the thesis center on the various types of maps included in Naylor\u27s archive. The first of these sections examines how, through reading the context in which the maps are placed in Mama Day, the archival maps should actually be read counter to the reason they were originally produced. The next and final section explores a hand drawn map by Naylor, one that leads to more questions than answers, highlighting the speculative nature of the archive. All together, these sections will hopefully coalesce into an insight into how Naylor was thinking about her archive and her research methods. Hopefully, by exploring the spaces between Naylor\u27s archive and her fiction new alternatives for engaging with the archive and performing archival research can be found
Sensor Selection Without Inter-sensor Communication Based on Observed Sensor Data
No full textReducing the number of transmissions in a wireless sensor network (WSN) to improve itsenergy efficiency has always been of great interest. We consider a new approach where only a fixed number of sensors will send data to the fusion center. We provide proofs and numerical results on the optimality of this approach in the case of selecting one out of two sensors. We also demonstrate numerically, the significant gains of this approach in the case of selecting 1 out of N sensors when compared to random selection, in terms of the perspective of the accuracy of decision making. We also show the performance of an approach for selecting m out of N sensors
The Standardization of Blockchain Benchmarking
No full textA benchmark is a measurement of a systems performance against another systems performance. A proper workload is relevant, reproducible, fair, verifiable, and usable [24]. A proper workload is also standardized between the systems being measured, as to produce comparable results. The Transaction Processing Performance Council (TPC) provides a range of database benchmarks including standardized benchmarks for transaction processing, decision support, and virtualization. These benchmarks provide external parties with results that are comparable between systems and lead to informed decisions when choosing the best system for a given task. This standardization of benchmarks across the blockchain industry is necessary for the adoption of blockchain technology. Currently, blockchain organizations benchmark in-house using their own workloads, runtime environments, and definition of metrics. As such, the results of a given blockchain organization are not comparable to the results of another blockchain organization. In this thesis we explore the problems within blockchain benchmarking, our proposed framework for developing standardized blockchain benchmarks, and our implementation of this framework in a web3 focused benchmark for layer-1 blockchains