Chemical Engineering Commons^™

Pore-Confined Carriers And Biomolecules In Mesoporous Silica For Biomimetic Separation And Targeting, Shanshan Zhou

Theses and Dissertations--Chemical and Materials Engineering

Selectively permeable biological membranes composed of lipophilic barriers inspire the design of biomimetic carrier-mediated membranes for aqueous solute separation. This work imparts selective permeability to lipid-filled pores of silica thin film composite membranes using carrier molecules that reside in the lipophilic self-assemblies. The lipids confined inside the pores of silica are proven to be a more effective barrier than bilayers formed on the porous surface through vesicle fusion, which is critical for quantifying the function of an immobilized carrier. The ability of a lipophilic carrier embedded in the lipid bilayer to reversibly bind the target solute and transport it through …

Marketing Strategies To Enhance Profitability Among International Oil And Gas Service Companies, Hesameddin Zafari

Walden Dissertations and Doctoral Studies

A significant drop in oil price in 2014 resulted in enormous pressure on marketing managers of international oilfield service companies to address new market expectations. In such competitive conditions, some marketing managers lack strategies to leverage profitability during downturns. The purpose of this multiple case study was to explore strategies that senior marketing managers of international oilfield service companies in the Middle East successfully used to enhance sales performance, revenues, and profits during periods of declining oil prices. Theory of market segmentation, targeting, and positioning formed the conceptual framework for this study. Data were collected through semistructured interviews of 5 …

Biochemical Variation In Caribbean Sponges Of The Genus Aplysina, Sarah L. Criddle

Honors Theses

Sponges are among the simplest multicellular organisms, consisting of groupings of cells with similar functions rather than true tissues. Nonetheless, sponges are ecologically significant in many marine environments, including coral reefs. They are sedentary organisms that feed by filtration from the water column, which contributes to the numerous roles they play on coral reefs, including upkeep of the reef, production of usable energy, and recycling of nutrients. Like all multicellular organisms, sponges are made up of biologically significant macromolecules. These macromolecules provide the energy for the sponge, and their relative concentrations determine how sponges can store and access the energy …

The Evaluation Of Az66, A Highly Selective Sigma-1 And Sigma-2 Receptor Antagonist, For Its Anti-Convulsive Effects In C57bl/6 Mice, Jamie Stone

Honors Theses

The Evaluation of AZ66, A Highly Selective Sigma-1 and Sigma-2 Antagonist, for Anticonvulsive Effects in C57Bl/6 Mice (Under the direction of Lisa Wilson and Dr. Christopher McCurdy) Sigma receptors have become a popular subject for research the past few decades, but there is still much mystery behind these receptors and how they work. Researchers have found that sigma receptor antagonists can attenuate cocaine induced convulsions, however, limited research has been conducted on the effects of these antagonists on convulsions that mimic the types of seizures associated with epilepsy. Therefore, the aim of the current study was to evaluate AZ66 (20 …

The Effects Of Ultrasonic And Photochemical Pretreatment On Heating Value And Carbon Capturing Ability Of Fast Pyrolysis-Derived Biochars, Jordan Houry, Dong Joon Kim, Cary Roy

Honors Theses

Slow pyrolysis biochar has been shown to be receptive to ultrasonic and photochemical pretreatment that raises the heating value, surface area, and carbon content of the samples. This experiment was designed to test the feasibility of substituting fast pyrolysis derived biochar in place of slow pyrolysis biochars in order to reduce production times. Furthermore, new biomasses (switchgrass, rice husk, and rice straw) were tested for their receptiveness to pretreatment methods. It was ultimately determined that fast pyrolysis biochars that were exposed to pretreatment increased their carbon content and surface area but did not experience a heating value increase to the …

Hot-Fire Testing Of An Af-M315e 1-Newton Thruster, Alex Mcgee

Honors Theses

AF-M315E is a green monopropellant currently being investigated for use as a potential replacement for hydrazine in low-thrust spacecraft propulsion applications. To support devel- opment e↵orts, a series of hot-fire tests were conducted to assess the performance of AF-M315E in a 1N thruster. Preliminary design and analysis shows an increase in performance versus a comparable hydrazine system. Testing was conducted with a 1N TZM (titanium, zinc, and molybdenum alloy) thruster in late July 2016 in collaboration with the Spacecraft Propulsion Systems o ce (ER23) at Marshall Space Flight Center (MSFC). Testing focused on character- izing the transient behavior of the …

Cellulose Nanocrystal Stabilized Pickering Emulsions, Sangeet Adhikari

Honors Theses

The use of Pickering Emulsions in place of conventional surfactants has opened new doors in fields like pharmacy, cosmetology, and oil and gas industry. Pickering emulsions using Cellulose Nanocrystals (CNCs) are generally stable to heating in a wide range of temperatures and show great stability against salt and pH changes. The management of water resources in the United States has been a challenge. The injection of water in aging oil fields and unconventional tight-gas, shale-gas, and coal bed-fields often generate substantial amounts contaminated wastewater. This research project is expected to help future efforts in promoting oil biodegradation in emulsified mixtures. …

Utilizing The Zebrafish Model To Determine Anti-Epileptic Properties Of Mistletoe And Cannabis, Collin Dietrich

Honors Theses

Epilepsy affects around 50 million people in the world, therefore improving treatment efficacy and safety for epileptics is imperative. In this study we sought to screen the effectiveness and safety of cannabis constituents (delta-9-tetrahydrocannabinol and cannabidiol) and Tapinanthus globiferus extracts in treating epilepsy. We used a zebrafish model wherein seizures were induced by treatment with pentylenetetrazol. Our results showed that Tapinanthus globiferus dose-dependently reduced seizure activity, and no toxicities were seen at the concentrations used. In contrast delta-9-tetrahydrocannabinol and cannabidiol did not significantly reduce seizure activity and some toxicities were seen at the higher concentrations tested. We conclude that extracts …

Determination And Validation Of High-Pressure Equilibrium Adsorption Isotherms Via A Volumetric System, Hind Jihad Kadhim Shabbani

Theses and Dissertations

Adsorption equilibrium isotherms for N2, CO2, and CH4 on zeolite 13X were investigated at three different temperatures (25.5, 50.5 and 75.5 ̊ C) and a pressure range of (0-6.89475) MPa for CH4 and N2 and in the range of (0-4.82633) MPa for CO2 using built in volumetric apparatus. The results were validated using with a volumetric system (ASAP) at the same temperatures and a pressure up to (160-110) KPa respectively. The experimental results were correlated using three process Langmuir (TPLM). The correlated isotherms were then used to calculate the isosteric heat of adsorption for the three gases on 13X. The …

Stilbenes: Therapeutic Interventions Targeting Amyloid Β Protein Aggregation In Alzheimer’S Disease, Yiying Wang

Theses and Dissertations

Alzheimer’s disease (AD) is the most common form of dementia and accounts for 60-80 % of all dementia cases. In the United States, AD is ranked as the 6th leading cause of death and it is the only one among the top 10 that cannot be prevented, treated or even slowed. All FDA approved drugs focus on attenuating the symptoms for a limited time by regulating neurotransmitters without any intervention with the underlying disease process. A major player in the initiation and development of this debilitating disorder is the misfolding and subsequent aggregating of amyloid-β (Aβ) peptide. This aggregation process …

Statistical Mechanics Of Lipid-Liquid Crystal Systems: From Fundamentals To Sensing Applications, Donya Ohadi Kabir Maghsudlu

Theses and Dissertations

Understanding the thermodynamics of small systems has a well-established history. The non-intuitive behavior of the intensive properties of small systems comprised of less than a few hundred particles has important implications in many areas of engineering and materials science. Nevertheless, many open questions about the thermophysical properties of systems not in the thermodynamic limit remain unanswered. In the first part of this work, we explore the consequences of the coupling of two small subsystems that together make up a larger isolated system through the use of statistical mechanics and molecular dynamics simulations of Lennard-Jones particles in two dimensions. The results …

Pollutant Formation In Oxy-Coal Combustion, Nujhat Choudhury

Theses and Dissertations

With the increasing levels of carbon dioxide (CO2) in the atmosphere, researchers are driven to seek cleaner combustion techniques to burn coal for power generation. Oxy-coal combustion is a promising technique to cut down CO2 emissions. This technology requires the introduction of a pure oxygen (O2) stream and a recycled flue gas stream into the boiler instead of air. Flue gas stream generated from the system will be low in volume and highly concentrated in CO2. Thus, the capture and sequestration process will be facilitated. But, one of the concerns of adopting this technology is the altered chemistry of pollutants …

Co2 Capture From Flue Gas By A Psa Process Using A Novel Structured Adsorbent, Nima Mohammadi

Theses and Dissertations

First adsorption equilibrium isotherms for N2, O2, Ar and CO2 on zeolite 13X were measured at three temperatures (25, 50, 75 °C) and pressures up to 110 kPa with a volumetric method and validated by also measuring the same isotherms with a gravimetric system.

Then a comprehensive 2-D mathematical model was developed to study the fundamentals of adsorption processes in parallel channel structured adsorbents. The results clearly indicated that under studied circumstances the plug flow condition can be assumed and therefore the system is not subject to premature breakthrough.

The pressure drop of corrugated structured adsorbents with narrow triangular channels …

Supercritical Carbon Dioxide Treatment Of Natural Biomaterials For Tissue Engineering Applications, Dominic M. Casali

Theses and Dissertations

The number of people requiring an organ transplant in the United States has increased considerably over the past 25 years, but the number of organ donations has stagnated; over 8,000 people now die annually while awaiting a transplant or become too sick to receive one. Tissue engineering (TE), the design and production of artificial tissues and organs in vitro, has been proposed to alleviate this problem. Though synthetic polymers offer tunable mechanical and biochemical properties, natural biomaterials have recently garnered attention in TE for their high degree of biocompatibility and ability to direct cell proliferation and constructive tissue remodeling. Yet …

Rational Synthesis Of Catalysts For Biomass Conversion, Qiuli Liu

Theses and Dissertations

With climate change due to global warming, the production of hydrocarbon fuels and chemicals from renewable biomass resource has become more pressing in recent decades. The biggest challenge in biomass conversion is to develop active, selective and stable catalysts for particular applications. The objective of this research is to optimize catalytic performance for hydrodeoxygenation (HDO) and hydrogenation reactions by enhancing the stability of the support, tuning metal particle size, and controlling surface composition.

The high content of water in bio-oil and the aqueous environment of the upgrading process requires a hydrothermally stable catalyst. The hydrothermal stability has been effectively improved …

Synthesis And Characterization Of Cross-Linked Polyimide Film Using Tolylene Diisocyanate, Sirichai Reeyakad

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cross-linked polyimide films were synthesized by the reaction between diisocyanate groups and hydroxyl functional groups in polyimide structure, which was confirmed by IR. During the thermal treatment of the cross-linked polyimide, the thermal labile component (CO₂) in the urethane segments was decomposed which might generate pores in the film. The presence of the pores was confirmed from the dielectric constant of the film. The dielectric constant of the films decreased with the increase of TDI loading. By comparing the properties of the films, the PI50-C1.0 exhibited optimum mechanical and good dielectric properties. The cross-linked structure was also confirmed by DMA. …

Catalytic Ethanol Dehydration To Diethyl Ether Over Palladium-Modified Phosphorus Gamma Alumina Catalysts, Chakkrit Khaochartchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

The gamma alumina (γ-Al2O3) catalyst was modified with phosphorous (P) by acid activation technique and palladium (Pd) by the incipient wetness impregnation technique. The obtained catalysts were characterized with various techniques including X-ray diffraction (XRD), inductively coupled plasma (ICP), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX), N2 physisorption, ammonia temperature-programmed desorption (NH3-TPD), and thermogravimetric analysis (TGA). In addition, these modified catalysts were tested in ethanol dehydration reaction in a fixed-bed microreactor to determine ethanol conversion and product yield at the atmospheric pressure with temperatures ranging from 200-400oC. From the results, the phosphorous modification diminished the amount of …

Co2 Methanation Over Nial2o4 Spinel - Based Catalysts, Chanya Thamma

Chulalongkorn University Theses and Dissertations (Chula ETD)

In the present work, a series of NiO/NiAl2O4 catalysts were prepared by co-precipitation method with molar ratio of Ni/Al equal 1/2 at different precipitation temperatures (30 and 80oC) and calcination temperatures (500, 700, 900, and 1200oC). The catalyst properties were characterized by using N2 physisorption, X-ray diffraction, H2 - TPR, SEM, and TEM. The NiO/NiAl2O4 precipitated at 80oC and calcined at 900oC showed the best activity in CO2 methanation at 350oC with conversion 92% and 100% methane selectivity without CO formation. The optimal of NiO and NiAl2O4 composition at 24.7% and 75.3%wt could provide a stabilizing effect preventing the metal …

Dehydration And Oxidative Dehydrogenation Of Ethanol Over Sba-15 Based Catalysts Prepared By Sol-Gel And Hydrothermal Methods, Chaowat Autthanit

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this present study, characteristics and catalytic properties of zirconium (Zr) and bimetal (Zr and La) containing in SBA-15 catalysts and different VOx/SBA-15 catalysts were determined and well related. The study was divided into three parts. Regarding to the first part, zirconium (Zr) and bimetal (Zr and La) containing in SBA-15 synthesized by sol-gel and hydrothermal methods were compared. The results showed that the incorporation of Zr and bimetal (Zr and La) had an effect on the textural properties of both synthesized SBA-15 catalysts. Surface acidity in the SBA-15 suggests new active sites, especially Brønsted acid type. In the second …

Functionalization Of Carbon Nanohorns And Their Catalysis Applications, Chompoopitch Termvidchakorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Carbon nanohorns (CNHs) synthesized by gas-injected arc-in-water method were functionalized in this study. Metal (Ni, Cu, Fe, Pd, and Pt) and their alloy (NiCu, NiFe, NiPd, and NiPt) hybridized with CNHs were successfully produced. In addition, thermal and acid treatment was applied on the hybridized materials. Effect of metal loading and functionalizing conditions on characteristics of CNHs and functionalized CNHs was examined based on transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), N2 sorption, Raman spectroscopy, Fourier transform infrared (FT-IR) spectrometer, temperature programmed desorption of ammonia (NH3-TPD) analysis. The functionalized CNHs were applied as a catalyst in …