Digital Commons Network^™

Understanding Inhibition Of A Biodesulfurization Enzyme To Improve Sulfur Removal From Petroleum, Yue Yu

Theses and Dissertations--Chemical and Materials Engineering

The biodesulfurization 4S-pathway is a promising complementary enzymatic approach to remove sulfur from recalcitrant thiophenic derivatives in petroleum products that remain from conventional hydrodesulfurization method without diminishing the calorific value of oil. The final step of this pathway involves the carbon-sulfur bond cleavage from HBPS, and the production of the final products 2-hydroxybiphenyl (HBP) and sulfite, has been recognized as the rate-limiting step, partially as a result of product inhibition. However, the mechanisms and factors responsible for product inhibition in the last step have not been fully understood. In this work, we proposed a computational investigation using molecular dynamic simulations …

Application Of Process Systems Engineering Tools And Methods To Fermentation-Based Biorefineries, Kwabena Darkwah

Theses and Dissertations--Chemical and Materials Engineering

Biofuels produced from lignocellulosic biomass via the fermentation platform are sustainable energy alternatives to fossil fuels. Process Systems Engineering (PSE) uses computer-based tools and methods to design, simulate and optimize processes. Application of PSE tools to the design of economic biorefinery processes requires the development of simulation approaches that can be integrated with existing, mature PSE tools used to optimize traditional refineries, such as Aspen Plus. Current unit operation models lack the ability to describe unsteady state fermentation processes, link unsteady state fermentation with in situ separations, and optimize these processes for competing factors (e.g., yield and productivity). This work …

The Development Of Microfluidic Devices For The Production Of Safe And Effective Non-Viral Gene Delivery Vectors, Jason Matthew Absher

Theses and Dissertations--Chemical and Materials Engineering

Including inherited genetic diseases, like lipoprotein lipase deficiency, and acquired diseases, such as cancer and HIV, gene therapy has the potential to treat or cure afflicted people by driving an affected cell to produce a therapeutic protein. Using primarily viral vectors, gene therapies are involved in a number of ongoing clinical trials and have already been approved by multiple international regulatory drug administrations for several diseases. However, viral vectors suffer from serious disadvantages including poor transduction of many cell types, immunogenicity, direct tissue toxicity and lack of targetability. Non-viral polymeric gene delivery vectors (polyplexes) provide an alternative solution but are …

Synthesis Of Biologically-Inspired Nanofiltration Membranes Using Protected, Mutated, And Simulated Aquaporins, Priyesh Ashokrao Wagh

Theses and Dissertations--Chemical and Materials Engineering

Gram-negative bacterial cells are surrounded by a cell membrane which protects the cell and controls the transport of nutrients and waste products in and out of the cells at a fast rate. This rapid transport of nutrients and wastes through the cell membrane is made possible by channel proteins called porins. Various types of porins present in the cell membrane have specific functions depending on their selectivity towards different nutrients, and channel proteins selective towards water are called aquaporins. These proteins restrict the passage of all entities except water molecules and they provide a fast transport rate of water molecules …

Design And Analysis Of Curcumin Conjugated Poly(Beta-Amino Ester) Networks For Controlled Release In Oxidative Stress Environments, Carolyn T. Jordan

Theses and Dissertations--Chemical and Materials Engineering

Oxidative stress, the imbalance of free radical generation with antioxidant defenses, leads to cellular inflammation, apoptosis and cell death. This compromised environment results in debilitating diseases, such as oral mucositis (OM), atherosclerosis, and ischemia/reperfusion injury. Antioxidant therapeutics has been a proposed strategy to ameliorate these imbalances and maintain homeostatic environments. However, the success of these approaches, specifically curcumin, has been limited due to characteristics such as hydrophobicity and high reactivity when released as bolus doses to contest to oxidative stress induced diseases. The development of a controlled release system to aid in protection of the antioxidant capacity of curcumin, as …

Mixed Matrix Flat Sheet And Hollow Fiber Membranes For Gas Separation Applications, Nicholas W. Linck

Theses and Dissertations--Chemical and Materials Engineering

Mixed matrix membranes (MMM) offer one potential path toward exceeding the Robeson upper bound of selectivity versus permeability for gas separation performance while maintaining the benefits of solution processing. Many inorganic materials, such as zeolites, metal-organic frameworks, or carbon nanotubes, can function as molecular sieves, but as stand-alone membranes are brittle and difficult to manufacture. Incorporating them into a more robust polymeric membrane matrix has the potential to mitigate this issue.

In this work, phase inversion polymer solution processing for the fabrication and testing of asymmetric flat sheet mixed matrix membranes was employed with CVD-derived multiwall carbon nanotubes (MWCNTs) dispersed …

Surface Engineering And Monomer Design For Light-Mediated Ring Opening Metathesis Polymerization, Ishan A. Fursule

Theses and Dissertations--Chemical and Materials Engineering

Stimuli-responsive materials are changing the landscape of actuated materials, optoelectronics, molecular machines, solar cells, temporary memory storage, and biomedical materials. Specifically, photo-responsive polymers have gained acceleration in research and application since the last two decades in the form of a surface coating and micro-patterns. Light as a stimulus can be coherent, mono or polychromatic, tunable for power (intensity) and energy (wavelength), and has precise spatiotemporal control. Conventional surface coating techniques such as spin coating are unable to impart properties to the coatings in terms of sturdiness, homogeneity, uniformity over the complex surface, post deposition modification, and process efficiency. Also, in …

Understanding Carbohydrate Recognition Mechanisms In Non-Catalytic Proteins Through Molecular Simulations, Abhishek A. Kognole

Theses and Dissertations--Chemical and Materials Engineering

Non-catalytic protein-carbohydrate interactions are an essential element of various biological events. This dissertation presents the work on understanding carbohydrate recognition mechanisms and their physical significance in two groups of non-catalytic proteins, also called lectins, which play key roles in major applications such as cellulosic biofuel production and drug delivery pathways. A computational approach using molecular modeling, molecular dynamic simulations and free energy calculations was used to study molecular-level protein-carbohydrate and protein-protein interactions. Various microorganisms like bacteria and fungi secret multi-modular enzymes to deconstruct cellulosic biomass into fermentable sugars. The carbohydrate binding modules (CBM) are non-catalytic domains of such enzymes that …

Surface Functionalization Via Photoinitiated Radical Polymerization For Rare Cell Isolation And Mechanical Protection, Calvin Frank Cahall

Theses and Dissertations--Chemical and Materials Engineering

Surface functionalization of living cells for cell therapeutics has gained substantial momentum in the last two decades. From encapsulating islets of Langerhans, to cell laden gels for tissue scaffolds, to individual cell encapsulation in thin hydrogels, to surface adhesives and inert surface camouflage, modification of living cell surfaces has a wide array of important applications. Here we use hydrogel encapsulation of individual cells as a mode of protection from mechanical forces for high throughput cell printing, and chemical stimuli for the isolation of rare cells in blood.

In the first study, we review methods of surface functionalization and establish a …