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Effects Of Confinement On Ionic Liquids And Deep Eutectic Solvents For The Design Of Catalytic Systems, Electrochemical Devices, And Separations, Andrew Drake

Theses and Dissertations--Chemical and Materials Engineering

Confinement of ionic liquids (ILs) and deep eutectic solvents (DESs) within mesoporous materials such as silica helps to control the local environment within the pores for applications such as catalysis, electrochemistry, and absorption. Silica thin films with 2.5 and 8 nm pores and micron-sized silica particles with pore diameters of 5.4 and 9 nm were synthesized to study the effect of nanoconfinement on ILs 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF₆]), 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), and DESs reline and ethaline (choline chloride and urea or ethylene glycol). Silica thin films with vertically aligned, well ordered, and accessible pores were synthesized via the evaporation-induced …

Tracing The Path Of Technology Diffusion: The Case Of Nturumenti, Narok, Kenya, Paul N. Katiku, R. Kimitei, S. Amboga, G. A. Keya, B. Korir, J. Nginyi

IGC Proceedings (1997-2023)

An array of technologies; growing improved wheat varieties, bulking and collective marketing of wheat grains, sheep breed improvement, ram sharing, feedlot sheep fattening for market, strategic sheep deworming, pasture establishment and conservation practices; were introduced to members of a community based organization (CBO) in Nturumenti, anti-female genital mutilation and anti-poverty organization (AFAPO) in 2014. The CBO members, composed of youthful 19 men and 7 females, were intensively exposed and involved in the new skills both theoretically and practically in the farmers’ field school model. Even though the 8 farming technology options were suitable for the study environment, their adoption and …

Understanding The Role Of Charge On Particle Transport Within Semidilute And Concentrated Biopolymer Solutions And Tau Protein Condensates, Kanthi Nuti

Theses and Dissertations--Chemistry

Biological polymer networks such as mucus, extracellular matrix, nuclear pore complex, and bacterial biofilms, play a critical role in governing the transport of nutrients, biomolecules and particles within cells and tissues. The interactions between particle and polymer chains are responsible for effective selective filtering of particles within these macromolecular networks. This selective filtering is not dictated by steric alone but must use additional interactions such electrostatics, hydrophobic and hydrodynamic effects to control particle transport within biogels. Depending on chemical composition and desired function, biogels use selective filtering to allow some particles to permeate while preventing others from penetrating the biogel. …

Identifying Opportunities For Improved Adoption Of New Grazing Innovations, Geoff Kuehne, Rick Llewellyn, Pannell Pannell, Perry Dolling, Roger Wilkinson, Mike Ewing

IGC Proceedings (1997-2023)

Those aiming for high levels of adoption of grazing-related innovation are often frustrated at low and slow uptake by farmers. This paper describes a new tool, ADOPT (Adoption and Diffusion Outcome Prediction Tool), that can be used to evaluate the potential adoptability of grazing innovations (Kuehne et al. 2012). ADOPT aims to: (1) predict an innovation’s likely peak level of adoption and likely time for reaching that peak; (2) encourage users to consider factors affecting adoption during project design; and (3) engage R, D & E managers and practitioners by making adoptability knowledge and considerations more transparent and understandable.

Capillary Flow Of Liquid Aluminum Alloy In Wetting And Wetting/Non-Wetting Systems, Yangyang Wu

Theses and Dissertations--Mechanical Engineering

In this dissertation, the capillary flow of liquid aluminum alloy in both wetting and wetting/non-wetting systems is investigated.

The impact of gravity and surface topography on the capillary flow has been studied in a wetting/non-wetting assembly (an AA3003/Al₂O₃ wedge-tee configuration). The research includes (i) kinetics of liquid Al-Si-K_xAl_yF_z alloy triple line movements and dynamic macro advancing and receding contact angles and (ii) free surface profiles of the molten alloy driven by surface tension and impacted by gravity. A trade-off between the surface tension and gravity force has been found by calculating the …

Multi-Scale Computational Studies Of Calcium (Ca2+) Signaling, Bin Sun

Theses and Dissertations--Chemistry

Ca²⁺ is an important messenger that affects almost all cellular processes. Ca²⁺ signaling involves events that happen at various time-scales such as Ca²⁺ diffusion, trans-membrane Ca²⁺ transport and Ca²⁺-mediated protein-protein interactions. In this work, we utilized multi-scale computational methods to quantitatively characterize Ca²⁺ diffusion efficiency, Ca²⁺ binding thermodynamics and molecular bases of Ca²⁺-dependent protein-protein interaction. Specifically, we studied 1) the electrokinetic transport of Ca²⁺ in confined sub-µm geometry with complicated surfacial properties. We characterized the effective diffusion constant of Ca²⁺ in a cell-like environment, which helps to understand …

Understanding Electrical Conduction In Lithium Ion Batteries Through Multi-Scale Modeling, Jie Pan

Theses and Dissertations--Chemical and Materials Engineering

Silicon (Si) has been considered as a promising negative electrode material for lithium ion batteries (LIBs) because of its high theoretical capacity, low discharge voltage, and low cost. However, the utilization of Si electrode has been hampered by problems such as slow ionic transport, large stress/strain generation, and unstable solid electrolyte interphase (SEI). These problems severely influence the performance and cycle life of Si electrodes. In general, ionic conduction determines the rate performance of the electrode, while electron leakage through the SEI causes electrolyte decomposition and, thus, causes capacity loss. The goal of this thesis research is to design Si …

Diffusion-Mediated Deposition Of Proteins, Ruiqian Zhan

Theses and Dissertations--Mechanical Engineering

Gradients of proteins play a prominent role in many biological processes, from development of multicellular organisms to chemical signaling in the immune system. Deposition of surface gradients is a way to permanently modifying a surface’s properties, resulting in the creation of novel materials which have widespread applications in biologically relevant fields, such as directed cell growth, production of biocompatible implantable materials, and creation of functional biosensors. These types of surfaces can also be used as an ex vivo tool to help understand many biological processes by mimicking the environment in gradient-related phenomena in a controllable way. However, despite the large …

Derivation Of An Analytical Solution To A Reaction-Diffusion Model For Autocatalytic Degradation And Erosion In Polymer Microspheres, Ashlee N. Ford Versypt, Paul D. Arendt, Daniel W. Pack, Richard D. Braatz

Pharmaceutical Sciences Faculty Publications

A mathematical reaction-diffusion model is defined to describe the gradual decomposition of polymer microspheres composed of poly(D,L-lactic-co-glycolic acid) (PLGA) that are used for pharmaceutical drug delivery over extended periods of time. The partial differential equation (PDE) model treats simultaneous first-order generation due to chemical reaction and diffusion of reaction products in spherical geometry to capture the microsphere-size-dependent effects of autocatalysis on PLGA erosion that occurs when the microspheres are exposed to aqueous media such as biological fluids. The model is solved analytically for the concentration of the autocatalytic carboxylic acid end groups of the polymer chains that comprise the microspheres …

Who’S Following Twitter? Coverage Of The Microblogging Phenomenon By U.S. Cable News Networks, Deborah S. Chung, Mina Tsay-Vogel, Yung Soo Kim

Journalism and Media Faculty Publications

Through data captured in a digital content analysis (DCA) lab, we examine coverage of Twitter across three 24-hour U.S. cable news channels: CNN, Fox News Channel, and MSNBC. This investigation tracked Twitter coverage from its initial stage, followed by its rise to a massively used tool and its subsequent diffusion into society, evident through its plateauing coverage. News stories covering Twitter, as it penetrated into society, were more likely to use benefit/gain frames when discussing the technology, highlighting its positive social, communicative, political, and participatory impact. Benefit frames were also likely to associate Twitter with journalism. Patterns …

Nanoparticle Behavior In Biological Gels And Biofluids: The Impact Of Interactions With Charged Biogels And The Formation Of Protein Coronas On Nanoparticles, Xiaolu Zhang

Theses and Dissertations--Chemistry

With the rapid growth of nanotechnology, situations where nanomaterials will interact with biological systems will unquestionably grow. Therefore, it is increasingly understood that interactions between nanomaterials and biological environments will play an essential role in nanomedicine. Biological polymer networks, including mucus and the extracellular matrix, serve as a filter for the exchange of molecules and nanoparticles. Such polymer networks are complex and heterogeneous hydrogel environments that regulate transport processes through finely tuned particle-network interactions. In chapters 3 and 4, we investigate the role of electrostatics on the basic mechanisms governing the diffusion of charged molecules inside model polymer networks by …

Understanding Degradation And Lithium Diffusion In Lithium Ion Battery Electrodes, Juchuan Li

Theses and Dissertations--Chemical and Materials Engineering

Lithium-ion batteries with higher capacity and longer cycle life than that available today are required as secondary energy sources for a wide range of emerging applications. In particular, the cycling performance of several candidate materials for lithium-ion battery electrodes is insufficient because of the fast capacity fading and short cycle life, which is mainly a result of mechanical degradation.

This dissertation mainly focuses on the issue of mechanical degradation in advanced lithium-ion battery electrodes. Thin films of tin electrodes were studied where we observed whisker growth as a result of electrochemical cycling. These whiskers bring safety concerns because they may …

Synthesis Of Multi-Wall Carbon Nanotubes Using Unseeded Hydrocarbon Diffusion Flames, Kozo Saito, Forman A. Williams, Alvin S. Gordon, Liming Yuang

Mechanical Engineering Faculty Patents

A method is provided for synthesizing carbon nanotubes from unseeded methane-air diffusion flames. A novel stainless steel and Ni—Cr wire probe is also provided for collecting carbon nanotubes from those diffusion flames.

Characterization Of Water Movement Into And Through Soils During And Immediately After Rainstorms, C. T. Haan

KWRRI Research Reports

The movement of water into and through soils in the unsaturated state is basic to many water resources problems including rainfall-runoff models, ground water recharge, irrigation, drainage, evapotranspiration and the movement of pollutants in soils. This study was conducted in an effort to determine if the flow equation based on Darcy's Law and the continuity equation could be used to describe watershed infiltration and thus be incorporated into hydrologic models.

The results of the study indicate that even on apparently uniform soils there is a great deal of variability in soil water properties. Handling this variability plus the difficulty of …