Development of a Rational Modeling Approach for the Design, and Optimization of the Multifiltration Unit

This thesis includes the development and verification of an adsorption model for analysis and optimization of the adsorption processes within the International Space Station multifiltration beds. The fixed bed adsorption model includes multicomponent equilibrium and both external and intraparticle mass transfer resistances. Single solute isotherm parameters were used in the multicomponent equilibrium description to predict the competitive adsorption interactions occurring during the adsorption process. The multicomponent equilibrium description used the Fictive Component Analysis to describe adsorption in unknown background matrices. Multicomponent isotherms were used to validate the multicomponent equilibrium description. Column studies were used to develop and validate external and intraparticle mass transfer parameter correlations for compounds of interest. The fixed bed model was verified using a shower and handwash ersatz water which served as a surrogate to the actual shower and handwash wastewater

Dynamic Imaging of the Effector Immune Response to Listeria Infection In Vivo

Host defense against the intracellular pathogen Listeria monocytogenes (Lm) requires innate and adaptive immunity. Here, we directly imaged immune cell dynamics at Lm foci established by dendritic cells in the subcapsular red pulp (scDC) using intravital microscopy. Blood borne Lm rapidly associated with scDC. Myelomonocytic cells (MMC) swarmed around non-motile scDC forming foci from which blood flow was excluded. The depletion of scDC after foci were established resulted in a 10-fold reduction in viable Lm, while graded depletion of MMC resulted in 30–1000 fold increase in viable Lm in foci with enhanced blood flow. Effector CD8+ [CD8 superscript +] T cells at sites of infection displayed a two-tiered reduction in motility with antigen independent and antigen dependent components, including stable interactions with infected and non-infected scDC. Thus, swarming MMC contribute to control of Lm prior to development of T cell immunity by direct killing and sequestration from blood flow, while scDC appear to promote Lm survival while preferentially interacting with CD8+ [CD8 superscript +] T cells in effector sites.National Institutes of Health (U.S.) (Grant P01AI-071195

A model for predicting contaminant removal by adsorption within the international space station water processor: 1. Multicomponent equilibrium modeling

A thermodynamic model is developed to predict adsorption equilibrium in the International Space Station water processor\u27s multifiltration beds. The model predicts multicomponent adsorption equilibrium behavior using single- component isotherm parameters and fictitious components representing the background matrix. The fictitious components are determined by fitting total organic carbon and tracer isotherms with the ideal adsorbed solution theory. Multicomponent isotherms using a wastewater with high surfactant and organic compound concentrations are used to validate the equilibrium description on a coconut-shell-based granular activated carbon (GAC), coal-based GAC, and a polymeric adsorbent

Correlation of aqueous-phase adsorption isotherms

A correlation was developed to estimate the adsorption equilibrium capacity of various adsorbents and organic compounds using a combination of Polanyi potential theory and linear solvation energy relationships (LSERs). Polanyi theory provided the basic mathematical form for the correlation. LSERs were used to normalize the Polanyi theory based on the fundamental interaction forces between the solvent, adsorbate, and adsorbent expected in aqueous-phase adsorption. The correlation was developed using 56 organic compounds and eight adsorbents. The following classes of organic compounds were used: (i) halogenated aliphatics, (ii) aromatics and halogenated aromatics, (iii) polyfunctional organic compounds and (iv) sulfonated aromatics. The adsorbents were (i) three coal-based activated carbons (F-300, F-400, and APA), (ii) one coconut shell based activated carbon (580-26), (iii) one unspecified activated carbon, and (iv) three synthetic polymeric adsorbents (XAD-4, XAD-7, and XEN-563). The proposed correlation, which considers the fundamental solvent-adsorbate-adsorbent interaction forces, showed a significant improvement in predicting the adsorption capacity over a correlation that considered only van der Waals forces. However, the correlations did not predict the adsorption capacities of highly soluble organic compounds such as polysulfonated aromatics and polyfunctional organic compounds

An Electrochromic Painter’s Palette: Color Mixing via Solution Co-Processing

Electrochromic polymers (ECPs) have been shown to be synthetically tunable, producing a full palette of vibrantly colored to highly transmissive polymers. The development of these colored-to-transmissive ECPs employed synthetic design strategies for broad color targeting; however, due to the subtleties of color perception and the intricacies of polymer structure and color relationships, fine color control is difficult. In contrast, color mixing is a well-established practice in the printing industry. We have identified three colored-to-transmissive switching electrochromic polymers, referred to as ECP-Cyan (ECP-C), ECP-Magenta (ECP-M), and ECP-Yellow (ECP-Y), which, via the co-processing of multicomponent ECP mixtures, follow the CMY color mixing model. The presented work qualitatively assesses the thin film characteristics of solution co-processed ECP mixtures. To quantitatively determine the predictability of the color properties of ECP mixtures, we estimated mass extinction coefficients (ε_mass) from solution spectra of the CMY ECPs and compared the estimated and experimentally observed color values of blends via a calculated color difference (Δ<i>E</i>_ab). The values of Δ<i>E</i>_ab range from 8 to 26 across all mixture compositions, with an average value of 15, representing a reasonable degree of agreement between predicted and observed color values. We demonstrate here the ability to co-process ECP mixtures into vibrantly colored, visually continuous films and the ability to estimate the color properties produced in these mixed ECP films

Application of short-time stochastic subspace identification to estimate bridge frequencies from a traversing vehicle

© 2020 Elsevier Ltd This study establishes a short-time stochastic subspace identification (ST-SSI) framework to estimate bridge frequencies by processing the dynamic response of a traversing vehicle. The formulation uses a dimensionless description of the response that simplifies the vehicle-bridge interaction (VBI) problem and brings forward the minimum number of parameters required for the identification. With the aid of the dimensionless parameters the analysis manages to successfully apply ST-SSI despite the time-varying nature of the VBI system. Further, the proposed approach eliminates the adverse effect of the road surface roughness using a transformed residual vehicle response obtained from two traverses of a vehicle at different speeds over the bridge. The study verifies the proposed ST-SSI approach numerically: it first performs the dynamic VBI simulations to obtain the response of the vehicle, and then applies the proposed ST-SSI method, assuming the dynamic characteristics of the vehicle are available. The numerical experiments concern both a sprung mass model and a more realistic multi-degree-of-freedom (MDOF) vehicle model traversing a simply supported bridge. The results show that the proposed approach succeeds in identifying the first two bridge frequencies for test-vehicle speeds much higher (e.g., 10 m/s = 36 km/h and 20 m/s = 72 km/h) than previously considered, even in the presence of high levels of road surface roughness