Ion Selective Electrochemical Process for Pollutant Removal and Resource Recovery

Water scarcity worldwide has prompted the complete utilization of every drop of water sources by removing pollutants and recovering resources from multiple water sources. Electrified water treatment technologies such as electrocatalysis and electrodialysis are promising technologies to achieve such targets by consuming renewable energy, causing no secondary pollution and requiring no harsh chemicals. However, the efficiency of electrified technology is not satisfied due to complicated water matrix and high salinity in some water sources, where competing ions may decrease the product purity and waste more energy during major process. High selectivity is a key parameter to improve electrified technology efficiency in a multi-solute water matrix via high energy efficiency, fast kinetics, and low by-product production or less by-process. The selectivity towards certain ions can be achieved by its size, electrostatic force, chemical affinity and even design of operation. In this work, We reported several approaches including process design, membrane development and material synthesizing to deliver a comprehensive strategy of achieving ion selectivity by multiple mechanisms. The removal efficiency of nitrate as a pollutant and the recovery of Lithium as a resource were evaluated and compared with commercial or conventional design

Convergence Results and a New Preconditioner for Spectral Collocation in Time

Spectral collocation methods provide a systematic construction for the approximate solution of ordinary differential equations (ODEs) of arbitrarily high order. These methods approximate the solution with a piecewise polynomial, which is determined by requiring the residual of the ODE to vanish at collocation points. This thesis presents three algebraically equivalent forms of the collocation method corresponding to different choices of polynomial bases. The convergence of global collocation for linear problems is analyzed from the viewpoint of projection methods, in which the projection operator represents interpolation by polynomials. This analysis is extended to nonlinear problems using the Kantorovich Theorem. Finally, a new preconditioner is presented that facilitates the efficient implementation of Chebyshev collocation methods. Numerical experiments demonstrate that the solution time of preconditioned spectral collocation behaves like O(K log K), where K is the number of collocation points, allowing for solves with over a million points

Understanding and Leveraging the Temperature-Dependent Curing of Silicone Elastomers

Silicone elastomers offer a wide range of mechanical properties, and their inherent compliance renders them suitable for use in applications including medical devices, shock absorbers, water-repellant surfaces, and cookware. Moreover, in the past decade, silicone elastomers have facilitated significant progress in the field of soft robotics. However, knowledge of the curing duration at a given temperature for thermally polymerizable elastomers often relies on empirical trends, and furthermore, the curing parameters—typically determined through trial and error—are limited to specific geometries and elastomers. Additionally, over-curing elastomeric parts at elevated temperatures consumes excess energy and contributes to device failure due to subsequent weak adhesion between components. The lack of understanding of the curing behavior limits the accessible design space of elastomers. Building on a framework introduced in my prior research quantifying the inactivation reaction of viruses, in this thesis, I present a modeling framework based on thermo-rheological experiments and the Arrhenius equation to provide a new understanding of the temperature-dependent curing of platinum catalyzed elastomers. The experimental results reveal that the curing behavior exhibits self-similarity upon normalizing with the gelation time, and the reaction is characterized by a dimensionless reaction coordinate that represents the extent of curing. Next, I leverage this understanding of the curing kinetics to study the adhesion between elastomer layers only as a function of the extent of curing, which accounts for both duration and temperature, and demonstrate the utility of the reaction coordinate to pinpoint failure regimes. Adhesion between elastomeric components represents a longstanding problem in the field of soft robotics and soft lithography. New insight into improving adhesion will enable new fabrication methodologies. Finally, I investigate the effects of curing silicone elastomers at temperatures beyond room temperature on the mechanical properties. The corresponding experimental results highlight the feasibility of using temperature to control the speed of curing while maintaining the desired mechanical behavior. Overall, my thesis aims to understand and leverage the curing behavior of elastomers as a function of time and temperature, informed by reaction kinetics, to broaden elastomer processing beyond traditional casting, and expand the accessible design space for the manufacturing of elastomeric devices

Evolution of Holiness Camp Kwali, Abuja: Gnosis and History Exemplifying a shift from Church-Centric to Community-Centric Christianity

Abstract Historically, the Evangelical Revival and the Great Awakenings of the eighteenth century primarily resulted in the establishment of church institutions through rituals. This work is going to demonstrate that while the early history of revivalism is well documented in Nigeria, the contrast today is that the current revival leaders have also expanded the scope of their vision to create Nigerian Pentecostal camp meeting revivals beyond church institutions into creating Christian neighborhoods governed according to the teachings and doctrines of specific movements. This research focuses on the Holiness Camp, Abuja. Ruth Marshall's observation that "In Nigeria, the line between the city and the church is rapidly vanishing" underscores the transformation of the Redemption Camp into the Redemption City of the Redeemed Christian Church of God, highlighting significant real estate investments that have turned the camp into a residential area. Despite the extensive literature on Nigerian Pentecostalism, a significant gap remains in understanding the connection between Pentecostalism and neighborhood development through the tradition of Pentecostal revival camps and their evolution into exclusive Christian enclaves. This dissertation addresses how daily spiritual devotions transform a camp space into a new and settled community by examining the Holiness Camp in Abuja, Nigeria, as a case study of a diastolic camp. It categorizes Pentecostal revival camps in Nigeria into three types: systolic, equilibrium, and diastolic (residential) camps. The research posits the perspective that the frequency and constancy of spiritual devotion, large expanse of land, and founder’s residence in the camp, are crucial for an equilibrium or seasonal camp to transition into a Holiness Revival Movement Worldwide’s camp into a diastolic or residential camp. Key activities for neighborhood development shift from seasonal to daily or weekly devotions, with four quarterly conferences hosted at the camp. I demonstrate that the presence of the founder's residence, internal security system, large expanses of land available for sale or gift to members, the administrative headquarters being located within the camp, and the emergence of socio-economic activities such as commercial laundry, printing press, mechanic workshops, restaurants, medical clinics, schools, and factories for block and water production, all guided by the doctrines of the movement, endow the camp with the features of a neighborhood with a religious worldview. This research employs descriptive analysis methods and Anthony Wallace’s event-analysis methodological principle to examine the spiritual and doctrinal systems addressing everyday needs in the Holiness Camp. The study is grounded in comprehensive fieldwork, utilizing diverse data sources, including field notes, diaries, devotional tracts, oral and telephone interviews, participant observation, and an extensive collection of over fifty books authored by Paul Rika, the founder of HOREMOW. Additionally, it incorporates the analysis of multimedia sources such as photographs, YouTube and Facebook videos, audio and video disks, websites, maps, Zoom meetings, and academic journal articles. This dissertation contributes to the understanding of the evolving nature of Pentecostal revival camps in Nigeria, providing insights into the complex interplay between Pentecostalism and neighborhood development

Towards Fine-Grained Isolation Mechanisms for Intraprocess Isolation

Memory safety has long been a significant challenge in computer software security. In this thesis, we propose a set of methods to mitigate memory safety issues. Our approach allows for isolation of different functions and modules within an application at the granularity of individual functions, thereby preventing the spread of memory safety issues between these modules. With our thread-safe security monitor, developers can specify untrusted code and data requiring extra protection, thereby restricting access to sensitive information in two key ways. The first, called a sandbox, isolates error-prone components, such as those used for computation, protocol state machines, and parsers. The second, called a safebox, protects sensitive data or security-critical elements, including privilege flags, access tokens, and ACLs. This model enhances data protection and supports the incremental isolation of critical parts at minimal cost. We introduce an innovative combination of memory safety with contextual re- sources, allowing the allocation of isolation contexts for temporarily created resources. For instance, this enables the isolation of communication contents between connec- tions from different users, with sharing permitted only through securely isolated mod- ules. A typical example is a chat server where each client has its own context for handling user connections and encryption keys, preventing attackers from accessing other users’ information. The received data is shared among receiving users through a shared memory within a safe module which include sufficiently small TCB code (containing only the minimal code required for memory copying). Finally, develop- ers can set additional system resource policies for these contexts, thus limiting their access to file systems, networks, and other resources. By utilizing alias mapping, we map the same physical memory to multiple vir- tual memory addresses, allowing different modules to share data structures without frequent copying. We embed this alias into the higher bits of the virtual address, which enables efficient address translation across domains with minimal overhead and facilitates the seamless use of shared memory across function calls. We simplify the process by allowing developers to express intentions rather than operations through code annotations, improving maintainability. This information can coexist with regular software code and be dynamically enabled or disabled through our tools, optimizing the use of limited hardware resources while balancing security and performance. Our system demonstrated 95% compatibility in LTP testing, indicating its ca- pability to support most applications developed for the Linux platform, including those that utilize signals and multithreading, without requiring additional porting. We conducted several micro-benchmarks for the implementation mechanisms our sys- tem relies on, better illustrating the system’s overhead sources and providing clearer guidance for users. We implemented module isolation in real applications like NGINX and Redis and created separate isolation contexts for user connections. These evaluations demon- strate that our system can be easily and progressively applied in practical software. Our overhead for individual module isolation ranged from 3% to 10%. When isola- tion was performed on both dimensions simultaneously, our overhead reached 10% to 40

Beyond Dollars and Cents: Exploring Budgeting, Saving, and Financial Security in the Houston Area

This study explores Harris County residents’ financial security, looking at their budgeting and saving practices, barriers people face to budgeting and saving, and how these practices relate to someone being able to withstand economic shocks

A kinetic Monte Carlo simulation of solid-electrolyte interphase formation and dendrite growth during electroplating

The formation of 3D structures such as dendrite, filament, and moss during electroplating is an obstacle to the development of a number of battery systems vital to a sustainable future, particularly lithium metal batteries. The morphological evolution of lithium metal electrode is strongly affected by the presence of passivating species formed by electrolyte decomposition, known as solid-electrolyte interphase (SEI). A 2D kinetic Monte Carlo (kMC) algorithm on a hexagonal grid was developed to account for the competing effects of deposition, diffusion, and surface passivation, providing an elementary understanding of electrodeposition systems with passivation. Growth from flat electrode and from hemispherical nucleus were both investigated. Morphological information and shape statistics were found to be strongly controlled by both SEI initiation time and current density, and a phase map was constructed over both parameters to demonstrate the distribution of results. Spherical deposits formed at high passivation time and high flux, filaments and whiskers at low flux and high passivation time, and dendrites and mosses at high flux and low passivation time. SEI formation is also observed to exacerbate nascent diffusion instabilities on pristine electrode. In the limit of no cross-SEI diffusion, we obtain a scaling relation of filament lengthscale as flux^(0.35) t_pass^(2.17). When cross-SEI diffusion was considered, a contrast is observed between low and high flux regimes: traditionally, thickness decreases with current, but at high fluxes after SEI cracking, we observe that growth from a single active tip can sustain larger thicknesses with larger flux, shedding light on an SEI-free ultrahigh flux regime. These findings provide foundational yet novel understanding of complex SEI phenomena, potentially streamlining the design of next-generation batteries

Nineteenth-Century Virtuosic Transcriptions of Vocal Music: A New Typology

The development of the piano into a highly virtuosic instrument in nineteenth-century Europe led to a proliferation of repertoire exploiting its new mechanical capabilities. A significant portion of the repertoire comprises works that transform existing music into solo piano compositions. Vocal music like art song, oratorio, and opera frequently provided source material for these works. Since the nineteenth century, terms like “transcription,” “fantasy,” “arrangement,” and “paraphrase” have been used to refer to works of this sort, but they are often used imprecisely, inconsistently, and interchangeably. To address the categorical difficulty, a new typology is proposed in this document. The proposed types are based on the qualities and traits of existing repertoire, as revealed by analysis of representative pieces. Aspects of compositional design and various pianistic idioms are among many characteristics which contribute to the transformation of source material, and which will serve as a basis for study. As a final demonstration of the proposed types, three newly composed solo piano works are included as an appendix, the final chapter serving as an explanation of their methodology and connection to the existing repertoire

Flash Joule Heating for Materials Production

Flash Joule heating has been widely used as an ultrafast, scalable, and versatile synthesis method, most prominently in the synthesis of flash graphene and other carbon materials. Whereas most chemical synthesis methods transfer heat through a medium into which most heat is lost, flash Joule heating reactions utilize the target feedstock itself as the heating medium, enabling near optimal heating efficiency and consequently extremely high heating rates. Herein, I present an overview of the use of flash Joule heating for materials production, including graphene, graphite, carbon nanotubes, doped graphene, silicon carbide, and p-block metal dichalcogenides. I present different engineering and reaction techniques to facilitate the kilogram-scale production of these materials while performing life cycle assessments and technoeconomic analyses of these processes. I further highlight the impact that the passage of electrical current through the reactant feedstock has on the mechanics of the flash Joule heating technique, finding that this phenomenon can reduce reaction activation energy. I finally discuss the historical foundations of graphene production and provide evidence that Thomas Edison may have synthesized graphene as early as 1879