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2020

Chemical Engineering

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Full-Text Articles in Engineering

Development Of Novel Inks And Approaches For Printing Tissues And Organs, Shen Ji Dec 2020

Development Of Novel Inks And Approaches For Printing Tissues And Organs, Shen Ji

Dissertations

Tissue engineering is a multidisciplinary field that investigates and develops new methods to repair, regenerate and replace damaged tissues and organs, or to develop biomaterial platforms as in vitro models. Tissue engineering approaches require the fabrication of scaffolds using biomaterials or fabrication of living tissues using cells. As the demands of customized, implantable tissue/organs are increasing and becoming more urgent, conventional scaffold fabrication approaches are difficult to meet the requirements, especially for complex large-scale tissue fabrication. In this regard, three-dimensional (3D) printing attracted more interest over the past decades due to its unrivaled ability to fabricate highly customized tissues or …

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The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu Dec 2020

The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu

Dissertations

The main goal of this dissertation is to generate data and parameterizations to accurately represent soot aerosols in atmospheric models. Soot from incomplete combustion of fossil fuels and biomass burning is a major air pollutant and a significant contributor to climate warming. The environmental impacts of soot are strongly dependent on the particle morphology and mixing state, which evolve continuously during atmospheric transport via a process known as aging. To make predictions of soot impacts on the environment, most atmospheric models adopt simplifications of particle structure and mixing state, which lead to substantial uncertainties. Using an experimentally constrained modeling approach, …

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Modeling Mass Transfer And Chemical Reaction In Industrial Nitrocellulose Manufacturing Processes, Francis Patrick Sullivan Dec 2020

Modeling Mass Transfer And Chemical Reaction In Industrial Nitrocellulose Manufacturing Processes, Francis Patrick Sullivan

Dissertations

A series of models are proposed to describe the production of military grade nitrocellulose from dense cellulose materials in mixtures of nitric acid, sulfuric acid, and water. This effort is conducted to provide a predictive capability for analyzing the rate and extent of reaction achieved under a range of reaction conditions used in the industrial nitrocellulose manufacturing process for sheeted cellulose materials. Because this capability does not presently exist, nitrocellulose producers have historically relied on a very narrow range of cellulose raw materials and resorted to trial and error methods to develop processing conditions for new materials. This tool enables …

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Development Of Novel Membranes For Nanocarbon Enhanced Separation With Application In Biofuels And Solvent Recover, Oindrila Gupta Dec 2020

Development Of Novel Membranes For Nanocarbon Enhanced Separation With Application In Biofuels And Solvent Recover, Oindrila Gupta

Dissertations

Pharmaceutical industries historically have had one of the highest amounts of solvent waste generated per unit of drug manufactured. Energy requirements and carbon footprint of current solvent recycling processes tend to be quite high, and the incineration of the solvents for waste disposal produces toxic air emissions. Also, rapidly increasing demand for energy and strict regulation on engine pollutant emissions have necessitated the use of alcohol as carbon-neutral fuels. Thermal distillation is one of the most common methods for the separation of alcohol-water mixtures. However, its application is limited due to energy requirements and high operating costs, and heating to …

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Preparation And Characterization Of Reactive Composites Combining Boron With Mixed Oxides, Purvam Mehulkumar Gandhi Dec 2020

Preparation And Characterization Of Reactive Composites Combining Boron With Mixed Oxides, Purvam Mehulkumar Gandhi

Theses

Thirteen liquids have been explored as Process Control Agents (PCAs) for high-energy mechanical milling of two metal oxide powders, CuO and Bi2O3, with the practical purpose to reduce the sizes of powder particles and refine their crystal structure. Multiple liquid properties have been considered to analyze their effect on evolution of both particle and crystallite sizes during milling for each oxide. Experimental data were analyzed using the δ-AICc (Akaike Information criterion) correlation function applied to linear relations between liquid properties and powder characteristics. Multiple linear correlation models were ranked based on the highest log-likelihood and the …

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Optimal Conditions Of Fermentation Of The Pichia Pastoris Yeast Expressing The Recombinant Pres2-S Protein (M-Hbsag) Of Hepatitis B Virus (Hbv), Sasmakоv Sobirdjan, Ashirоv Оybek, Abdurakhmanоv Jaloliddin, Xasanоv Shuhrat Dec 2020

Optimal Conditions Of Fermentation Of The Pichia Pastoris Yeast Expressing The Recombinant Pres2-S Protein (M-Hbsag) Of Hepatitis B Virus (Hbv), Sasmakоv Sobirdjan, Ashirоv Оybek, Abdurakhmanоv Jaloliddin, Xasanоv Shuhrat

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of this study is determination of optimal fermentation conditions of the Pichia pastoris yeast expressing the recombinant Pres2-S protein of hepatitis B virus (HBV). For this purpose we investigated the main factors influencing for the cultivation of recombinant strain of the yeast Pichia pastoris pPIC3,5-S-HBsAg - the composition of the nutrient medium, pH and dissolved oxygen (DO). As a result, by enzyme-linked immunosorbent assay (ELISA) the optimal concentration of methanol ≈1.0 %, which is the initiator and the only source of carbon for protein expression in the Mut+ phenotype Pichia pastoris yeast cells was determined. In the selected …

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Waste Engine Oil Regeneration With Bentonite From The Navbahor Deposit, Azimova Shodiyakhon, Arslanov Sharafutdin, Turakhujayev Saidakbar, Azimov Dilmurod Dec 2020

Waste Engine Oil Regeneration With Bentonite From The Navbahor Deposit, Azimova Shodiyakhon, Arslanov Sharafutdin, Turakhujayev Saidakbar, Azimov Dilmurod

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the study was the regeneration of used oils. The change in the conditions for the regeneration of used engine oil as a result of adsorptive cleaning with alkaline earth clay from the Navbakhor deposit has been studied. The carried-out regeneration allows almost completely removing mechanical impurities, moisture from the waste oil and helps to clarify it. The optimal conditions for regeneration have been established. The removal of secondary products formed during the use of engine oil while retaining the main components that determine the serviceability of the product has been established. By means of IR spectroscopy, as …

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Mixed Complex Compounds Of Palmitate, Oleate Calcium With Acetamide, Nicotinamide And Thiocarbamide, Ibadullaeva Tursunoy, Azizov Tokhir, Ibragimova Мavluda Dec 2020

Mixed Complex Compounds Of Palmitate, Oleate Calcium With Acetamide, Nicotinamide And Thiocarbamide, Ibadullaeva Tursunoy, Azizov Tokhir, Ibragimova Мavluda

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of the study was the synthesis and study of the structure of mixed complexes of palmitate, calcium oleate with acetamide, nicotinamide and thiocarbamide. The mixed coordination compounds of palmitate and calcium oleate were synthesized. The composition, individuality, thermal behavior, methods of coordinating the palmitate and oleate fragments, acetamide, nicotinamide and thiocarbamide molecules have been established. Comparison of the diffraction patterns of calcium palmitate and oleate, free ligand molecules and synthesized compounds showed the mismatch of the diffractograms, conseqently that the synthesized complexes have an individual crystal lattice different from the starting materials. The method of coordination of amide …

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Synthesis Of Esters Of Halogenoacetic Acids, Yuldasheva Muxabbat, Turaev Sherzod Dec 2020

Synthesis Of Esters Of Halogenoacetic Acids, Yuldasheva Muxabbat, Turaev Sherzod

CHEMISTRY AND CHEMICAL ENGINEERING

Amidoalkylating reagents containing a phthalimide group are used in the synthesis of hard-to-reach primary amines and complex heterocyclic compounds. These types of amidoalkylating compounds are suitable reagents for nucleophilic substituted reactions in acidic media due to their resistance to acids. Result of reactions of amidoalkylating reagents-N-hydroxyethylphthalimide and N-hydroxymethylphthalimide with aliphatic carbonic acids can also produce new bactericidal and fungicidal esters. In this study, halogen acids reacted with N-hydroxymethylphthalimide monochloric acetic acid, monobromic acetic acid, monoiodic acetic acid, trifluoric acetic acid and trichloroacetic acid, as well as, N-b-hydroxyethylphthaleidyl monohydric acid. As a result of the reactions, new phthalimidomethyl and phthalimidoethyl esters …

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Carbon Nanotube–Liposome Complexes In Hydrogels For Controlled Drug Delivery Via Near-Infrared Laser Stimulation, S. Zahra M. Madani, Mohammad Moein Safaee, Mitchell Gravely, Carolynn Silva, Stephen Kennedy, Geoffrey D. Bothun, Daniel E. Roxbury Dec 2020

Carbon Nanotube–Liposome Complexes In Hydrogels For Controlled Drug Delivery Via Near-Infrared Laser Stimulation, S. Zahra M. Madani, Mohammad Moein Safaee, Mitchell Gravely, Carolynn Silva, Stephen Kennedy, Geoffrey D. Bothun, Daniel E. Roxbury

Chemical Engineering Faculty Publications

Externally controllable drug delivery systems are crucial for a variety of biological applications where the dosage and timing of drug delivery need to be adjusted based on disease diagnosis and progression. Here, we have developed an externally controllable drug delivery system by combining three extensively used platforms: hydrogels, liposomes, and single-walled carbon nanotubes (SWCNTs). We have developed carbon nanotube–liposome complexes (CLCs) and incorporated these structures into a 3D alginate hydrogel for use as an optically controlled drug delivery system. The CLC structures were characterized by using a variety of imaging and spectroscopic techniques, and an optimal SWCNT/lipid ratio was selected. …

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Effect Of Reaction Conditions On Cu⁃Catalyzed Co2 Electroreduction, Chang Zhu, Wei Chen, Yan-Fang Song, Xiao Dong, Gui-Hua Li, Wei Wei, Yu-Han Sun Dec 2020

Effect Of Reaction Conditions On Cu⁃Catalyzed Co2 Electroreduction, Chang Zhu, Wei Chen, Yan-Fang Song, Xiao Dong, Gui-Hua Li, Wei Wei, Yu-Han Sun

Journal of Electrochemistry

Electrochemical conversion of carbon dioxide (CO2) driven by renewable electricity that can meet both carbon emission reduction and renewable energy utilization has been rapidly developed in recent years. Copper (Cu) catalyst has long been a promising candidate for CO2 electroreduction applications because of its natural abundance and specific capability of producing a substantial amount of C2 products. However, various metallic Cu electrodes reported have been significantly influenced by the adsorption of certain cation/anion ions, resulting in wide-span catalytic activities and selectivity for various products. In addition, a recent report demonstrated that by virtue of gas-diffusion flow cell …

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Numerical Simulations Of Current And Temperature Distribution Of Symmetrical Double-Cathode Solid Oxide Fuel Cell Stacks Based On The Theory Of Electric-Chemical-Thermal Coupling, Cheng-Rong Yu, Jian-Guo Zhu, Cong-Ying Jiang, Yu-Chen Gu, Ye-Xin Zhou, Zhuo-Bin Li, Rong-Min Wu, Zheng Zhong, Wan-Bing Guan Dec 2020

Numerical Simulations Of Current And Temperature Distribution Of Symmetrical Double-Cathode Solid Oxide Fuel Cell Stacks Based On The Theory Of Electric-Chemical-Thermal Coupling, Cheng-Rong Yu, Jian-Guo Zhu, Cong-Ying Jiang, Yu-Chen Gu, Ye-Xin Zhou, Zhuo-Bin Li, Rong-Min Wu, Zheng Zhong, Wan-Bing Guan

Journal of Electrochemistry

Solid oxide fuel cell (SOFC) is a high-efficient clean conversion device for future energy management. Because of the low antioxidant reduction ability and complex thermal stress, the structure of traditional asymmetrical thin anode-supported planar SOFC is easily to be broken under stack operating conditions. To overcome these defects, a new complete symmetrical SOFC based on double-sided cathodes was developed. To study the influences of gas flow direction and current collection mode on the cell performance inside stack, a numerical model was established by finite element method based on the theory of electro-thermo-chemo multiphysical coupling. By applying this model, the molar …

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Core-Shell Structured Ru@Ptru Nanoflower Electrocatalysts Toward Alkaline Hydrogen Evolution Reaction, Xue-Liang Wang, Yuan-Yuan Cong, Chen-Xi Qiu, Sheng-Jie Wang, Jia-Qi Qin, Yu-Jiang Song Dec 2020

Core-Shell Structured Ru@Ptru Nanoflower Electrocatalysts Toward Alkaline Hydrogen Evolution Reaction, Xue-Liang Wang, Yuan-Yuan Cong, Chen-Xi Qiu, Sheng-Jie Wang, Jia-Qi Qin, Yu-Jiang Song

Journal of Electrochemistry

Water electrolysis for hydrogen production is beneficial for solving the problem of energy crisis and environmental issues. It is necessary to study highly active and cost-effective catalysts toward hydrogen evolution reaction (HER) to reduce the consumption of noble metals. Herein, we report the synthesis of core-shell structured Ru@Pt0.24Ru nanoflowers electrocatalyst by stepwise reduction of Ru and Pt precursors in the mixture of oleylamine and benzyl alcohol at 160 oC. The average diameter of the resultant Ru@Pt0.24Ru was 16.5±4.0 nm with a bulk atomic ratio between Pt and Ru of 0.24:1 and a surface ratio of 3.3:1 …

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Reduction Of Copper And Iron Oxide Mixture With Local Reducing Gases, Shokhrukh Khojiev Dec 2020

Reduction Of Copper And Iron Oxide Mixture With Local Reducing Gases, Shokhrukh Khojiev

Acta of Turin Polytechnic University in Tashkent

The article analyzes the scientific problems of the copper industry. In particular, the main problem with the classical production of copper is the causes of large amounts of slag and the negative impact of these wastes on the environment. Accordingly, the main component that forms the slag is iron, and the higher its content in the original copper concentrate, the more slag is formed, and at the same time a large amount of copper metal is released into the waste. The departure is indicated by evidence. To prevent this problem, a technology has been proposed to reduce copper sulfide concentrates …

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Effect Of Microcapsule Content On Diels-Alder Room Temperature Self-Healing Thermosets., Sadella C Santos, John J La Scala, Giuseppe R Palmese Dec 2020

Effect Of Microcapsule Content On Diels-Alder Room Temperature Self-Healing Thermosets., Sadella C Santos, John J La Scala, Giuseppe R Palmese

Henry M. Rowan College of Engineering Faculty Scholarship

A furan functionalized epoxy-amine thermoset with an embedded microcapsule healing system that utilizes reversible Diels-Alder healing chemistry was used to investigate the influence of microcapsule loading on healing efficiency. A urea-formaldehyde encapsulation technique was used to create capsules with an average diameter of 150 µm that were filled with a reactive solution of bismaleimide in phenyl acetate. It was found that optimum healing of the thermoset occurred at 10 wt% microcapsule content for the compositions investigated. The diffusion of solvent through the crack interface and within fractured samples was investigated using analytical diffusion models. The decrease in healing efficiency at …

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Effect Of Surfactant Addition On The Dispersion And Antioxidant Performance Of Pyrogallol In Biodiesel, Silvya Yusri, Mohammad Nasikin, Hery Sutanto Dec 2020

Effect Of Surfactant Addition On The Dispersion And Antioxidant Performance Of Pyrogallol In Biodiesel, Silvya Yusri, Mohammad Nasikin, Hery Sutanto

Makara Journal of Science

Biodiesel is one of the most feasible energy sources that can be used as a replacement for fossil fuel. Biodiesel has several advantages over conventional fuels because of its availability, renewability, and high combustion efficiency. However, biodiesel that contains unsaturated fatty acid methyl esters is prone to oxidation during the blending process and storage period. The complete oxidation reaction of biodiesel produces insoluble gums that could potentially plug the fuel engines. This reaction has become the main barrier for biodiesel to compete with other biofuels. Among several methods, the addition of antioxidants is the most cost-effective method to prevent the …

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Detection Of Nucleotides In Hydrated Ssdna Via 2-D H-Bn Nanopore With Ionic-Liquid/Salt-Water Interface, Jungsoo Lee Dec 2020

Detection Of Nucleotides In Hydrated Ssdna Via 2-D H-Bn Nanopore With Ionic-Liquid/Salt-Water Interface, Jungsoo Lee

Multidisciplinary Studies Theses and Dissertations

Accomplishing slow translocation speed with high sensitivity has been the greatest mission for solid-state nanopore (SSN) to electrically detect nucleobases in single-stranded DNA (ssDNA). In this study, a method to detect nucleobases in ssDNA using a SSN is introduced by considerably slowing down the translocation speed and effectively increasing its sensitivity. The ultra-thin titanium dioxide (TiO2) coated hexagonal boron nitride (h-BN) nanopore was fabricated, along with an ionic-liquid [bmim][PF6]/2.0 M KCl aqueous (cis/trans) interfacial system, to increase both the spatial and the temporal resolutions. As the ssDNA molecules entered the nanopore, a …

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Bridging Thermochemical And Biochemical Conversion: Impact Of Biochar Addition On The Anaerobic Digestion Of Aqueous Pyrolysis Condensate, Neha Batta Dec 2020

Bridging Thermochemical And Biochemical Conversion: Impact Of Biochar Addition On The Anaerobic Digestion Of Aqueous Pyrolysis Condensate, Neha Batta

Electronic Thesis and Dissertation Repository

Profitable treatment of low value waste biomass is one of the biggest challenges of the industry. Where most of the current treatment strategies, such as pyrolysis, are efficient in complete breakdown of hard to synthesize, low value waste biomass such as lignocellulosic wastes, it leads to the generation of secondary waste thereby compromising its efficiency. The aim of this research is to utilize the aqueous pyrolysis condensate as a feedstock for anaerobic digestion, previously adapting the microbial consortia to the acidity and other potential organic inhibitors present in the APC, to produce energy in the form of biogas following the …

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Experimental Study Of Viscoelastic Fluid-Structure Interactions, Anita Anup Dey Dec 2020

Experimental Study Of Viscoelastic Fluid-Structure Interactions, Anita Anup Dey

Doctoral Dissertations

It is well known that when a flexible or flexibly-mounted structure is placed perpendicular to a Newtonian fluid flow, it can oscillate due to the shedding of vortices at high Reynolds numbers. Unlike Newtonian fluids, viscoelastic fluid flow can become unstable even at infinitesimal Reynolds numbers due to a purely elastic flow instability occurring at large Weissenberg numbers. This thesis focuses on exploring the mechanisms of viscoelastic fluid-structure interactions (VFSI) through experimental investigations on several different combinations of flexible and flexibly-mounted circular cylinders, micro and macro-scale cantilevered beams and viscoelastic fluids such as wormlike micelle solutions and polymer solutions. VFSI …

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Encapsulation And Stabilization Of Biomacromolecules, Whitney Blocher Blocher Mctigue Dec 2020

Encapsulation And Stabilization Of Biomacromolecules, Whitney Blocher Blocher Mctigue

Doctoral Dissertations

Recent work in the area of protein encapsulation has turned away from traditional methods of sequestration toward gentler, purely aqueous techniques. Among them, complex coacervation has become a topic of discussion. Complex coacervation is an all-aqueous liquid-liquid phase separation phenomenon dominated by electrostatic interactions and entropic gains. The use of coacervates as protein encapsulants has garnered much attention, but there has been little headway in determining a set of design rules. We considered coacervation between two oppositely-charged polypeptides and a biomacromolecule cargo to investigate the effects of changing aspects of the coacervating polymers and/or various solution parameters. We characterized the …

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Modeling Residence Time Distribution Of Chromatographic Perfusion Resin For Large Biopharmaceutical Molecules: A Computational Fluid Dynamic Study, Kevin Vehar Dec 2020

Modeling Residence Time Distribution Of Chromatographic Perfusion Resin For Large Biopharmaceutical Molecules: A Computational Fluid Dynamic Study, Kevin Vehar

KGI Theses and Dissertations

The need for production processes of large biotherapeutic particles, such as virus-based particles and extracellular vesicles, has risen due to increased demand in the development of vaccinations, gene therapies, and cancer treatments. Liquid chromatography plays a significant role in the purification process and is routinely used with therapeutic protein production. However, performance with larger macromolecules is often inconsistent, and parameter estimation for process development can be extremely time- and resource-intensive. This thesis aimed to utilize advances in computational fluid dynamic (CFD) modeling to generate a first-principle model of the chromatographic process while minimizing model parameter estimation's physical resource demand. Specifically, …

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Understanding Biomass Upgrading Through Hydrogenolysis Reactions: Kinetics And Mechanism, Jalal Tavana Dec 2020

Understanding Biomass Upgrading Through Hydrogenolysis Reactions: Kinetics And Mechanism, Jalal Tavana

Electronic Theses and Dissertations

This dissertation involves several hydrogenolysis reactions but is mainly focused on hydrodechlorination (HDC) of chlorobenzene (PhCl) and hydrodeoxygenation (HDO) of 2-furancarboxylic acid (FCA). Hydrodechlorination of PhCl has been the subject of research for some time. Here, we used a Pd/C catalyst to study this reaction though rigorous kinetics and mechanistic analyses in a CSTR reactor. The H2/D2 kinetic isotope effect (KIE) experiment revealed that H2 is not involved in a rate controlling step. The kinetics data are in agreement with similar systems reported before and follow a first-order dependence on chlorobenzene, half order for hydrogen and …

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Reaction Kinetics And Mechanism Investigations Of Renewable Chemicals Production From Biomass, Hussein Talib Abdulrazzaq Dec 2020

Reaction Kinetics And Mechanism Investigations Of Renewable Chemicals Production From Biomass, Hussein Talib Abdulrazzaq

Electronic Theses and Dissertations

The development of the technologies and the improved processes for the production of high value bio-based chemicals is one of the most important challenges at the present time. This new movement is not only important from an environmental perspective, but also it is a profitable approach to provide affordable and efficient processes. Therefore, the chemical catalytic upgrading processes over various homogenous and heterogeneous catalysis could be an outstanding modification to upgrade biomass-derived platform molecule to high value applications. In this dissertation, we highlight our recent progress in developing new chemistries and processes for upgrading biomass-derived molecules and address the challenges …

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Micro-Physiological Models To Mimic Mucosal Barrier Complexity Of The Human Intestine In Vitro, Abhinav Sharma Dec 2020

Micro-Physiological Models To Mimic Mucosal Barrier Complexity Of The Human Intestine In Vitro, Abhinav Sharma

Doctoral Dissertations

The mucosal barrier in the intestine is vital to maintain selective absorption of nutrients while protecting internal tissues and maintaining symbiotic relationship with luminal microbiota. This bio-barrier consists of a cellular epithelial barrier and an acellular mucus barrier. Secreted mucus regulates barrier function via in situ biochemical and biophysical interaction with luminal content that continually evolves during digestion and absorption. Increasing evidence suggests that a mucus barrier is indispensable to maintain homeostasis in the gastrointestinal tract. However, the importance of mucus barrier is largely underrated for in vitro mucosal tissue modeling. The major gap is the lack of experimental material …

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Evolution And Flow Of Vapors In A Fluidized Bed, Hansen Mangaranap Silitonga Dec 2020

Evolution And Flow Of Vapors In A Fluidized Bed, Hansen Mangaranap Silitonga

Electronic Thesis and Dissertation Repository

Vaporization of injected liquid is a key process in many industrial fluidized beds. In Fluid Cokers, for example, quicker vaporization would increase liquid product yield and reduce fouling. A new experimental method was developed to measure the vaporization rate by injecting liquid for a certain duration to reach a constant vaporization rate while monitoring changes in pressure and vapor composition in the exhaust pipe of the fluidization column. Three processes can delay vaporization in a fluidized bed: heat flux from hot-dry particles to wet particles, vapor saturation, and wet agglomerate formation. Operating a spray nozzle at a very high atomization …

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Use Of Food Waste Activated Carbons For Wastewater Treatment, Abigale Monasterial Dec 2020

Use Of Food Waste Activated Carbons For Wastewater Treatment, Abigale Monasterial

Honors Scholar Theses

Activated carbons are often used to remove phenol from wastewater. However, they are usually derived from expendable resources, such as coal and have high regeneration costs. In this work, the adsorption of phenol on activated carbon derived from food waste was studied to understand its kinetics, determine its maximum adsorption capacity, and compare it to commercial activated carbons. Adsorption experiments were performed at 298 K for 48 hours at various pHs and initial phenol concentrations. The adsorption data was then fit to the pseudo-first order, pseudo-second order, and intraparticle diffusion models to understand the kinetics and to the Langmuir and …

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Value-Added Lipids Extraction From Wet Microalgae Using Ionic Liquids, Yujie Zhang Dec 2020

Value-Added Lipids Extraction From Wet Microalgae Using Ionic Liquids, Yujie Zhang

Electronic Thesis and Dissertation Repository

Microalgae have gained interest as sources of renewable lipids in the biofuel sector due to their ability to sequester carbon dioxide into triacylglycerol (TAG), a biodiesel feedstock. However, industrial-scale production of microalgae exclusively for fuel production is limited by technical and economic challenges. Some marine microalgae can accumulate large amounts of polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and other unsaturated fatty acids, which are high-value compounds linked to the prevention of various cardiovascular diseases. This thesis therefore examines the extraction of lipids and DHA from two microorganisms (Chlorella vulgaris, a model organism for lipid production, …

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Copper Electrodeposition In Full Wafer Thickness Through-Silicon Vias, Rebecca P. Schmitt Dec 2020

Copper Electrodeposition In Full Wafer Thickness Through-Silicon Vias, Rebecca P. Schmitt

Chemical and Biological Engineering ETDs

Through-silicon vias (TSVs) are a key interconnect technology for advanced packaging of microelectronic devices, and full wafer thickness TSVs are required for certain microelectromechanical systems (MEMS) applications. In this work, electrolytes containing copper sulfate, an acid, chloride, and Tetronic 701 suppressor were implemented for Cu filling of high aspect ratio (10:1), full wafer thickness TSVs. For each electrolyte system, rotating disk electrode voltammetry was used to identify a voltage range for bottom-up Cu filling in the TSVs. Die level feature filling was performed using voltage ramping, which moved active deposition through the vias to yield void-free Cu features. During voltage-controlled …

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The Effect Of Moox Reducibility On Its Activity For Anisole Hydrodeoxygenation, Chantal Walker Dec 2020

The Effect Of Moox Reducibility On Its Activity For Anisole Hydrodeoxygenation, Chantal Walker

Electronic Thesis and Dissertation Repository

Catalytic hydrodeoxygenation (HDO) is a process for upgrading crude bio-oil as it has a high oxygen content which causes several undesirable properties. Current methods for HDO use sulfided NiMo and CoMo or supported noble metal catalysts which hydrogenate aromatic rings, leading to less valuable products and increasing the hydrogen consumption. Using 10 wt. % MoO3 supported on ZrO2, TiO2, γ-Al2O3, SiO2 and CeO2, we investigated the atmospheric HDO of anisole, a model compound, at 350 °C. All catalysts achieved C – O bond cleavage, preserving the aromatic ring. In situ UV-Vis spectroscopy showed a peak corresponding to intervalence charge transfer …

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Understanding The Role Of Atom Trapping In The Evolution Of Hydrocarbon Transformation Catalyst Morphology, Griffin Canning Dec 2020

Understanding The Role Of Atom Trapping In The Evolution Of Hydrocarbon Transformation Catalyst Morphology, Griffin Canning

Chemistry and Chemical Biology ETDs

Converting alkanes to other, more chemically and economically valuable molecules requires catalysts that can survive elevated temperatures and highly reducing environments. These environments can cause many metal-nanoparticle based catalysts to sinter rapidly, causing a loss of activity. They must also tolerate the coke formation, as well, since coke can restrict access to active sites by gas phase molecules, thus lowering catalytic activity. While there are routes to improve both the sinter and coke resistance of catalysts, an alternative strategy is to develop a protocol for regenerating the activity of the catalyst in question when coke formation or sintering becomes problematic. …

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