Chemical Engineering Commons^™

Aging Study Of Silver-Exchanged Mordenite And Silver-Functionalized Silica Aerogel In Dry Air, Humid Air, No And No2, Seungrag Choi

Dissertations - ALL

Iodine-129 (129I) is one of the volatile radioactive species in the off-gas streams generated from the spent nuclear fuel reprocessing system, and it is essential to remove 129I vapor because 129I has a long half-life (1.6 x 107 years) and can be fatal to the human body if released to the environment. Radioactive iodine vapor can be effectively captured by silver containing adsorbents such as silver exchanged mordenite (Ag0Z) and silver functionalized silica aerogel (Ag0-aerogel) used in this study. However, the aging impact of off-gas streams on the adsorbents is one of major issues in the removal of radioactive iodine …

Rational Design Of Supported Metal Catalysts For Carbonyl Reduction During Biomass Upgrading, Xin Gao

Dissertations - ALL

Ketone hydrogenation:A model system of carbonyl (ketone) hydrogenation, acetone hydrogenation over supported Pt catalysts in the gas-phase fixed bed reactor was investigated to understand both the mechanism and rate controlling steps in a fundamental level. The experiments and outcomes include the detailed macro- and micro-kinetic analysis of hydrogenation of acetone. The apparent reaction orders of hydrogen and acetone, apparent activation energies, and observed kinetic isotope effects over a large range of temperatures and concentrations (compound partial pressures) are reported in this document. Generally speaking, the ketone hydrogenation over metal surfaces in vapor phase comply with the mechanism that hydrogen atoms …

Substrate Delivery Of Embedded Liposomes, Srivatsan Kidambi, Stephen L. Hayward

Department of Chemical and Biomolecular Engineering: Faculty Publications

This invention relates to compositions useful for localized and sustained release of therapeutic agents, and more particularly to functionalized liposomes embedded in a poly electrolyte multilayer. Methods of preparing the compositions, methods of treating diseases, devices, and pharmaceutical compositions comprising the compositions are also provided.

Real-Time Monitoring Of Cell Death Progress Using Capacitance Spectroscopy, Suyang Wu

Electronic Theses and Dissertations

Biologics, including the monoclonal antibody (mAb), has experienced rapid development in the last decade. However, the price of biologics is often prohibitively high because of the low process efficiency. Delaying the inevitable cell death improves the productivity of upstream bioprocessing, whose success relies on monitoring the cell death onset that indicates the timing for preventive actions.

This study proposes to develop a real-time monitoring model that quantifies the dying cell percentage in lab-scale bioreactors using capacitance spectroscopy. The capacitance spectroscopy contains cell death-related information due to various physical properties changes during the cell death process, e.g., cytoplasmic conductivity change. The …

Development Of Polymeric Cxcr4 Targeting Carriers For Sirna Delivery To Treat Acute Kidney Injury, Weimin Tang

Theses & Dissertations

Acute kidney injury (AKI) is a major kidney disease that is characterized by a sudden loss of renal function which manifests by a decrease in urine output and an increase in serum creatinine. AKI is a global healthcare burden associated with high morbidity, mortality, and increasing cost. Currently there are no effective pharmacological treatments available. Apoptosis induced by p53 has been demonstrated as an important pathological mechanism for the development of AKI. Meanwhile, CXCR4/SDF-1 axis has been associated with the inflammation during AKI, and CXCR4 is overexpressed on injured tubules. This dissertation hypothesized that polycations with CXCR4 targeting ability could …

Advancements In Pressurized Oxy-Combustion Process: Pollutant Control And Process Development, Piyush Kumar Verma

McKelvey School of Engineering Graduate Student Theses & Dissertations

The emission of carbon dioxide from the power industry is one of the major causes of climate change. However, it is well established that the development of human societies across the globe depends on reliable and dispatchable power, which are generally the source of these emissions. There has been a recent growth in the integration of intermittent sources such as wind and solar which are carbon free. But these intermittent sources have significant temporal changes in power production and thus lack reliability and dispatchablity. This is a complicated problem to solve. However, flexible power plants with carbon capture and storage, …

Interfacial Engineering And Photoelectrochemistry Of Patterned Metal/Semiconductor Heterostructures, Che Tan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Photoelectrochemical (PEC) cells enable the conversion of solar energy into storable fuels, which is critical in overcoming the intermittent nature of this largest renewable source. However, the majority of semiconductors used as photoelectrodes in these cells have low conversion efficiencies and/or stabilities. Silicon (Si) is an attractive semiconductor material for photoelectrodes, but the development of efficient Si-based photoanodes is challenging due to their instability in alkaline solutions. Thus, one focus of this dissertation is the design and fabrication of highly stable nickel (Ni)-patterned Si photoanodes through interfacial engineering of the barrier heights. Recently, hot carriers in plasmonic metal nanostructures have …

Quantifying Components Of Protein Translation And Metabolite Heterogeneity In Isogenic Microbial Populations, Alexander Schmitz

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cell-to-cell variation in gene expression and metabolite levels have a significant impact on ensemble productivity of microbial bioproduction. New metabolic engineering tools and approaches are needed that consider cell cultures as an amalgam of uniquely behaving individuals to improve the slow commercialization of metabolically engineered systems. Stochastic cellular process including gene expression, metabolism, and growth lead to phenotypic variation between genetically identical cells. Understanding and the ability to control microbial phenotypic variation is key to improving microbial bioproduction metrics. During protein translation, codon usage strongly influences ensemble gene expression but the effect on the variation of gene expression was not …

Anion Exchange Membranes In Electrochemical Energy Systems, Yunzhu Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Non-CO2-emitting sources of renewable energy, such as solar and wind, have become quite popular in recent years, and their electricity generation cost at scale has become comparable with that of gas- and coal-fired power plants. However, their intermittent output makes the resultant electricity hard to dispatch in a reliable manner in the absence of grid-scale electrical energy storage (EES) technologies. Redox-flow batteries (RFBs) are promising devices for medium- to large-scale electric energy storage. They are safe, reliable, and portable, and are designed with decoupled power and energy modules, which makes it easy and cost-effective to scale their output to meet …

Polymeric Nanofibers Supported Metal Oxides For Electrochemical Energy Storage Devices, Rutul Patel

Electronic Theses & Dissertations

With increasing demand for energy, there is an increased need to find effective ways to store the available energy to sustain current and future generations. Thus, the research investigates whether polymetric nanofibers support metal oxide are a good solution to store energy. The materials used for synthesis includes N-dimethylformamide, nickel nitrate, cobalt nitrate and polyacrylonitrile.

These fibers are developed three phases. First, a homogenous mixture is prepared, followed by electrospinning of the mixture. Next, calcination of the prepared nanofibers was done to generate the 1D nanofibers embedded with metal oxides. The samples are primarily tested for supercapacitor applications, hydrogen evolution …

Catalytic Light Alkanes Selective Conversion Through Ammonia-Assisted Reforming, Siavash Fadaeerayeni

Theses and Dissertations

The fact that hydrogen is a clean and versatile fuel offers an attractive carbon-free source of energy and leverages the U.S. economy toward long-term sustainable economic growth. At an industrial scale, hydrogen production is mostly relying on methane steam reforming producing stoichiometric amounts of carbon oxides (CO and CO2), which imposes economic and environmental concerns. To mitigate the issue, we propose NH3 assisted anaerobic reforming of natural gas liquids (ethane and propane) as an alternative approach to produce COx free hydrogen. Here, in the first chapter, through comprehensive performance evaluation, characterization, and transient kinetic studies, it is shown that the …

Effect Of Feed Amount And Composition On Blaine And Residue In Cement Mill, Ahmed Mubarak Alsobaai

Hadhramout University Journal of Natural & Applied Sciences

This study investigates the effect of the amount and composition of cement ball mill feed on Blaine fineness and cement residue. The collected data were obtained using a ball mill for grinding clinker and additive materials (pozzolana and gypsum) at different amounts and composition of feed. The fineness of cement was measured as a specific surface by the air permeability method (Blaine Method) and the residue was calculated as cumulated residue on a 45 microns sieve. It was found that the cement residue increased with an increase in the amount and composition of feed while the Blaine fineness decreased. The …

Activity Performance And Stability Of Functionalized Sba -15 Mesoporous Silica For Lipase Immobilization, Ahmed Mubarak Alsobaai Dr

Hadhramout University Journal of Natural & Applied Sciences

SBA -15 Mesoporous Silica was synthesized and functionalized with aminopropyl-, phenyl- and chloropropyl- using post-synthesis method. The esterification of citronellol with lauric acid in batch mode at 37 ◦C was used to measure the performance of the immobilized enzymes. Characterization of the supports revealed the satisfactory development of mesoporosity with uniform internal channels distribution. Pure SBA-15 showed the typical hexagonal pore and straight channels while the functionalized SBA-15 with triethoxysilane caused pore size to decrease and the distortion of internal channels occurred to subsequently improved the degree of immobilization. The best support among the four was the 3-aminotriethoxysilane functionalized SBA-15 …

Discovery Of Phosphotyrosine-Binding Oligopeptides With Supramolecular Target Selectivity, Ana S. Pina, Leonor Morgado, Krystyna L. Duncan, Sara Carvalho, Henrique F. Carvalho, Armenio J. M. Barbosa, Beatriz De P. Mariz, Ines P. Moreira, Daniela Kalafatovic, Bruno M. Morais Faustino, Vishal Narang, Tong Wang, Charalampos G. Pappas, Isabel Ferreira, A. Cecılia A. Roque, Rein V. Ulijn

Advanced Science Research Center

We demonstrate phage-display screening on self-assembled ligands that enables the identification of oligopeptides that selectively bind dynamic supramolecular targets over their unassembled counterparts. The concept is demonstrated through panning of a phage-display oligopeptide library against supramolecular tyrosine-phosphate ligands using 9-fluorenylmethoxycarbonyl-phenylalanine-tyrosine-phosphate (Fmoc-FpY) micellar aggregates as targets. The 14 selected peptides showed no sequence consensus but were enriched in cationic and proline residues. The lead peptide, KVYFSIPWRVPM-NH2 (P7) was found to bind to the Fmoc-FpY ligand exclusively in its self-assembled state with KD = 74 ± 3 μM. Circular dichroism, NMR and molecular dynamics simulations revealed that the peptide interacts with Fmoc-FpY …

Investigation Of Human Adipose-Derived Stem-Cell Behavior Using A Cell-Instructive Polydopamine-Coated Gelatin-Alginate Hydrogel., Settimio Pacelli, Aparna R Chakravarti, Saman Modaresi, Siddharth Subham, Kyley Burkey, Cecilia Kurlbaum, Madeline Fang, Christopher A Neal, Adam J Mellott, Aishik Chakraborty, Arghya Paul

Chemical and Biochemical Engineering Publications

Hydrogels can be fabricated and designed to exert direct control over stem cells' adhesion and differentiation. In this study, we have investigated the use of polydopamine (pDA)-treatment as a binding platform for bioactive compounds to create a versatile gelatin-alginate (Gel-Alg) hydrogel for tissue engineering applications. Precisely, pDA was used to modify the surface properties of the hydrogel and better control the adhesion and osteogenic differentiation of human adipose-derived stem cells (hASCs). pDA enabled the adsorption of different types of bioactive molecules, including a model osteoinductive drug (dexamethasone) as well as a model pro-angiogenic peptide (QK). The pDA treatment efficiently retained …

Nonmetallic Jet Impingement Thermal Management For Power Electronics Via Additive Manufacturing, Reece Whitt

Graduate Theses and Dissertations

The increase in energy demanded by transportation and energy sectors has necessitated highly efficient thermal management for reliable power electronics operations. Conventional cooling techniques are limited by their inability to target switching location hot spot temperatures, leading to non-uniform thermal gradients. These devices, such as cold plates and heat sinks, also utilize heavy metallic structures that can accentuate electromagnetic interferences generated by high voltage switching processes. This work proposes a non-metallic jet impingement cooler for more customized thermal management, while simultaneously reducing the harmful effects of electromagnetic interferences. Additive manufacturing is utilized to enable jet impingement zones to target individual …

Complete Modeling Of The Chondrogenic Environment Under Continuous Low-Intensity Ultrasound, Heather Newell

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Articular cartilage is an avascular tissue that requires therapeutic intervention methods. This work answers the following: determine transducer operation to optimize the bioeffects; calculate the magnitude of pressure exerted on chondrocytes at an injury site; and confirm the theoretical findings by an animal model.

Earlier work has shown that cellular response to US is maximized at the resonance frequency of the cells. Resonance frequencies were calculated for chondrocytes in various layers. The latter configuration closest resembles in vivo conditions and the resonance occurred at 3.8±0.3 ������. The 3D model of US propagation in a rabbit knee was constructed from MRIs …

Extraction Methodologies And Physicochemical Characterizations Of Nanocellulose Isolated From Kudzu For Potential Sustainable Packaging Applications, Elliott Love

All Theses

Flexible packaging is an integral part of the food supply chain due to its unique thermal, mechanical, and barrier properties. The many advantages (e.g., lightweight, product protection, reduction in food waste, communication medium, etc.) come with certain drawbacks (low recyclability rate, pollution of ecosystems, etc.). Still, the heavy reliance of the food industry on these products, many of them being non-sustainable polyolefins, is unlikely to diminish in the foreseeable future. Thus, more sustainable alternatives that do not sacrifice performance (machinability, shelf-life, etc.) are needed before pollution becomes irreversible and public outcry insurmountable. Nanocellulose, especially in the form of cellulose nanocrystals …

Water Recovery From Bioreactor Mixed Liquors Using Forward Osmosis With Polyelectrolyte Draw Solutions, Calen Raulerson

All Theses

The objective of this research was to test the feasibility of using forward osmosis (FO) with polyelectrolyte draw solutions to recover water from bioreactor mixed liquors. When combined with an Anaerobic Osmotic Membrane Bioreactor (AnOMBR), such a system could process fecal and food waste from astronauts aboard the International Space Station (ISS) and reclaim important nutrients and water. This project focused on measuring the obtainable water recovery rates from bioreactor effluent, and the identifying challenges associated with the operation.

AnOMBRs feature several advantages over aerobic bioreactors, and non-osmotic anaerobic membrane bioreactors (AnMBR). Anaerobic bioreactors avoid the significant energy costs of …

Greenhouse Tomatoes: Process Simulation, Juan Gabriel Marin Jr.

Graduate Theses and Dissertations

Growing population demand and challenges brought on by climate change have spurred the need for more resilient fruit and vegetable supply chains. One agricultural technology of significant interest is the use of greenhouses for food production. Greenhouses create a stable and adaptable environment for crops such as tomatoes to grow year-round. Fresh tomatoes are the second most consumed vegetable per capita in U.S. diets, currently averaging 20.7 pounds. The growing consumption of fresh tomatoes has been the result of increasing cultural diversity in the United States.

To meet the growing demand, Venlo-type greenhouses have been frequently used by growers. It …