Chemical Engineering Commons^™

Structures Of The Insecticidal Toxin Complex Subunit Xpta2 Highlight Roles For Flexible Domains, Cole L. Martin, David W. Chester, Christopher D. Radka, Lurong Pan, Zhengrong Yang, Rachel C. Hart, Elad M. Binshtein, Zhao Wang, Lisa Nagy, Lawrence J. Delucas, Stephen G. Aller

Markey Cancer Center Faculty Publications

The Toxin Complex (Tc) superfamily consists of toxin translocases that contribute to the targeting, delivery, and cytotoxicity of certain pathogenic Gram-negative bacteria. Membrane receptor targeting is driven by the A-subunit (TcA), which comprises IgG-like receptor binding domains (RBDs) at the surface. To better understand XptA2, an insect specific TcA secreted by the symbiont X. nematophilus from the intestine of entomopathogenic nematodes, we determined structures by X-ray crystallography and cryo-EM. Contrary to a previous report, XptA2 is pentameric. RBD-B exhibits an indentation from crystal packing that indicates loose association with the shell and a hotspot for possible receptor binding or a …

Liquid Crystalline Coacervates Composed Of Chromonic Mesogens And Polyelectrolytes, Elizabeth Adeogun

Graduate Theses and Dissertations

Complex coacervates are formed by liquid-liquid phase separation of an aqueous solution of oppositely charged ions. Although several mixtures of molecules of natural and synthetic macro-ion have been shown to form complex coacervates, the formation of liquid crystalline (LC) coacervates are sparsely reported. LC coacervates have a unique property in that they can change their shape and optical property in response to external stimuli such as changes in temperature, pH, or the presence of specific molecules. This property makes LC coacervates useful as a sensor, as they can be engineered to respond to specific stimuli and generate a measurable signal …

Novel Breath Collection Techniques For Detection Of Covid-19., James Morris

Electronic Theses and Dissertations

Volatile Organic Compounds (VOC) generated endogenously in the human body can be used to detect diseases that induce oxidative stress and inflammation. Breath analysis has been used for the detection of diseases such as COPD, Depression, Lung Cancer and most recently COVID-19. Methods such as Exhaled Breath Condensate (EBC), Sorbent Tubes, Solid Phase Microextraction (SPME), and silicon microreactors have shown considerable capability in extracting and concentrating trace VOC’s present in human breath. Silicon microreactors functionalized with capture agents to derivatize carbonyl compounds are effective but the overall maximum flow rate of breath sample possible during analysis is low, making direct …

Wind Tunnel Modeling Of The Jack Rabbit Ii Mock Urban Environment Chlorine Releases Based On Comparison With Field Scale Video Record, Samuel Gallimore

Graduate Theses and Dissertations

Unintentional releases of hazardous gases have led to significant injuries and fatalities in severe cases. Field tests can be used to release hazardous gases to document and evaluate the behavior of the gases. Chlorine is an especially hazardous gas due to its toxicity. The Jack Rabbit II Phase I field tests released chlorine within a mock urban environment (MUE) consisting of Conex containers arranged in rows to simulate buildings and streets. The number of field tests is limited by both expense and time. Simulation of a field test using a wind tunnel model can provide additional data and opportunity for …

Experimental And Numerical Investigation Of Fluid Flow Behavior Through Fractured Wellbore Cement, Mahya Hatambeigi

Civil Engineering ETDs

Leakage from wellbores has been a major challenge in the energy industry, leading to groundwater contamination, reduced productivity, safety hazards, and increased operating costs. Cemented annulus fractures are a common type of leakage pathway in wellbores that can form due to various physical and chemical conditions. The number of wellbore leaks continues to increase globally, making it imperative to develop a better understanding of the complex mechanisms governing fluid flow through fractured wellbore cement. Understanding the behavior of fluid flow through a leaky cemented annulus is crucial for evaluating the leakage potential and risk assessments in wellbore systems, as well …

Treating High Salinity Produced Water Using Hybrid Membrane Processes: Electrocoagulation-Microfiltration/Ultrafiltration-Membrane Distillation-Crystallization, Mahmood Gheni Jebur

Graduate Theses and Dissertations

Produced water (PW) is considered the largest industrial wastewater stream in the world. PW generated from oil and gas operations generally contains a range of contaminants including high total dissolved solids, high total suspended solids, polar and nonpolar organic compounds, and low surface tension dissolved species. Treating PW is very challenging and applying only membrane-based technologies is not sufficient due to membrane fouling, which affects their long-term performance. Hence, integrated membrane processes are required to treat PW effectively. Hybrid membrane processes, which may result from combining a conventional process with a membrane separation, could be used to address the issues …

Investigation Of The Flow Field In The Jack Rabbit Ii Mock Urban Environment Field Tests Using A 1:50 Scale Wind Tunnel Model, Paulo Victor De Freitas Lopes

Graduate Theses and Dissertations

Accidental release of toxic chemicals can put workers and nearby populations at significant risk. Consequence assessment of accidents in urban environments is of particular interest. Urban geometries create wind channels between buildings, along with particularly dangerous areas downwind of buildings, where near-stagnant flow is present. Furthermore, recirculation zones can be formed between buildings, trapping high concentrations of toxic gases at ground level, particularly for denser-than-air gases. In 2015, the Department of Homeland Security conducted the Jack Rabbit II Field Test (JR-II) at Dugway Proving Ground, UT. During JR-II, chlorine was released at the center of a Mock Urban Environment (MUE) …

Multiscale Modeling And Gaussian Process Regression For Applications In Composite Materials, Joshua Arp

All Dissertations

An ongoing challenge in advanced materials design is the development of accurate multiscale models that consider uncertainty while establishing a link between knowledge or information about constituent materials to overall composite properties. Successful models can accurately predict composite properties, reducing the high financial and labor costs associated with experimental determination and accelerating material innovation. Whereas early pioneers in micromechanics developed simplistic theoretical models to map these relationships, modern advances in computer technology have enabled detailed simulators capable of accurately predicting complex and multiscale phenomena.

This work advances domain knowledge via two means: firstly, through the development of high-fidelity, physics-based finite …

Mil-53(Fe) Derived Magnetic Cufe2o4/Fe2o3 Composite For Catalytic Oxidation Of Sulfamethoxazole Via Peroxymonsulfate Activation, Abdul H. Asif, Nasir Rafique, Rajan A. K. Hirani, Lei Shi, Yantao Wang, Xiaoguang Duan, Yu Yin, Hongqi Sun

Research outputs 2022 to 2026

Design of metal–organic framework (MOF) derived metal oxides is an effective approach for environmental remediation. The current study describes the fabrication of MIL-53-derived perforated CuFe2O4/Fe2O3 using a facile, one-step, post-thermal solid-state approach by varying Cu/Fe ratios. Herein, the release of CO2 and H2O during the thermal treatment facilitates the incorporation of Cu2+ onto the Fe2O3 structure, forming a perforated hollow CuFe2O4/Fe2O3 composite via an in-situ ion-exchange mechanism. The optimised catalyst CF-0.5 displays a high degradation efficiency for the removal of sulfamethoxazole (SMX) by heterogeneous activation of peroxymonsulfate (PMS), ascribing to the better textural, morphological, and elemental properties of the novel …

Effects Of Cobalt Salts On Biomass Conversion To Functional Carbon-Based Catalysts For Peroxymonosulfate Activation, Zhihao Tian, Qianru Chen, Shiying Ren, Huayang Zhang, Wenjie Tian, Hongqi Sun, Shaobin Wang

Research outputs 2022 to 2026

Metal functionalization is an effective structure-engineering strategy for preparing biomass-derived carbon materials, whereas the influences of different metal precursors on the structure and catalytic performance remain unclear. Herein, an investigation of four typical cobalt salts for pyrolytic biomass conversion is performed. The melting points and anion species of cobalt salts are found to be critical factors. Co-salts (cobalt nitrate (Co(NO3)2), cobalt acetate (Co(OAc)2), cobalt acetylacetonate (Co(acac)2)) melted at low temperatures ( ≤ 165 °C) could promote mesopore formation and catalyze the graphitization process of a biomass flower during the carbonization, finally forming mesoporous graphitic carbon matrixes with Co@graphitic-C nanoparticles and …

Investigation Of Cyclic Gaseous Solvent Injection For Enhanced Oil Recovery In Unconventional Formations, Samuel Asante Afari

Theses and Dissertations

Unconventional resources have been known to hold vast quantities of hydrocarbons. However, exploiting the oil and gas they hold was previously challenging due to their low permeabilities. Recent advances in horizontal well drilling and hydraulic fracturing have enabled oil and gas production from these reservoirs, leading to significant increases in energy supply to meet the growing energy demand. However, despite the relative technological success, considerable obstacles persist; oil production from unconventional wells often declines by more than 20% of their initial production rate within the first two years, leaving significant volumes of residual oil trapped in the formations. This overarching …

Removing Ilmenite-Based Filter Cakes Using Hydrochloric Acid And Chelating Agent – Experimental Study, Jianping Su, Omar Mahmoud, Hisham A. Nasr-El-Din

Future Engineering Journal

Ilmenite is often used as a weighting agent in drilling fluids to increase the fluid density, but the formation of a filter cake on the borehole wall can impact cementing operations and reduce well productivity. To remove the filter cake, various techniques can be employed such as chemical treatments, mechanical methods, or a combination of both. The goal of this study is to evaluate the effectiveness of chemical removal of ilmenite-based filter cake using 7.5 wt.% hydrochloric acid (HCl) and hydroxyethyl ethylenediamine triacetic acid (HEDTA) – chelating agent. The filter cakes were generated using API filter press under harsh conditions …

Recent Progress Of Bifunctional Electrocatalysts For Oxygen Electrodes In Unitized Regenerative Fuel Cells, Tian-Long Zheng, Ming-Yu Ou, Song Xu, Xin-Biao Mao, Shi-Yi Wang, Qing-Gang He

Journal of Electrochemistry

Unitized regenerative fuel cells (URFCs), which oxidize hydrogen to water to generate electrical power under thefuel cells (FCs) mode and electrolyze water to hydrogen under the water electrolysis (WE) mode for recycling, areknown as clean and sustainable energy conversion devices. In contrast to the hydrogen oxidation reaction (HOR) andhydrogen evolution reaction (HER) on the hydrogen electrode side, the sluggish kinetics of oxygen reduction reaction(ORR) and oxygen evolution reaction (OER) on the oxygen electrode side requires highly efficient bifunctional oxygencatalysts. Conventional precious metal oxygen catalysts combine Pt and IrO₂ with excellent ORR and OER activities toachieve bifunctional electrocatalysis performance, but …

Band Alignments Of Metal/Oxides-Water Interfaces Using Ab Initio Molecular Dynamics, Yong-Bin Zhuang, Jun Cheng

Journal of Electrochemistry

Band alignments of electrode-water interfaces are of crucial importance for understanding electrochemical interfaces. In the scenario of electrocatalysis, applied potentials are equivalent to the Fermi levels of metals in the electrochemical cells; in the scenario of photo(electro)catalysis, semiconducting oxides under illumination have chemical reactivities toward redox reactions if the redox potentials of the reactions straddle the conduction band minimums (CBMs) or valence band maximums (VBMs) of the oxides. Computational band alignments allow us to obtain the Fermi level of metals, as well as the CBM and VBM of semiconducting oxides with respect to reference electrodes. In this tutorial, we describe …

Comparing Fishbone Drilling And Hydraulic Fracturing In Ultra-Low Permeability Geothermal Reservoirs, Aimene Aihar, Nassim Bouabdallah, Ghoulem Ifrene, Doina Irofti

Petroleum Engineering Posters and Presentations

Harnessing geothermal energy through Enhanced Geothermal Systems (EGS) offers a sustainable and renewable means of tapping the Earth's subsurface heat. However, in ultra-low permeability formations like those found in the Williston Basin, the effectiveness of conventional hydraulic fracturing techniques is limited. This study evaluates the potential of fishbone drilling technology as an alternative approach, focusing on the efficiency and engineering aspects of both methods in the context of geothermal reservoirs with extremely low permeability.

We carried out an extensive literature review, numerical simulations, and case studies to compare fishbone drilling and hydraulic fracturing in EGS applications. Fishbone drilling, which involves …

Evaluation Of Hybrid Prediction Models For Accurate Rate Of Penetration (Rop) Prediction In Drilling Operations, Abdelhakim Khouissat, Mohamed Riad Youcefi, Ghoulem Ifrene, Doina Irofti

Petroleum Engineering Posters and Presentations

The precise prediction of the rate of penetration (ROP) is of utmost importance for optimizing drilling operations and minimizing costs while increasing efficiency. However, the complex and nonlinear nature of the drilling process can pose significant challenges in achieving accurate ROP predictions. To address this challenge, multiple hybrid prediction models have been developed, and their accuracy in ROP prediction has been compared.

To accomplish this objective, we created three different hybrid models, including Artificial Neural Network – Genetic Algorithm (ANN-GA), Artificial Neural Network-Particle Swarm Optimization (ANN-PSO), and Support Vector Regression (SVR) to estimate ROP. These models were trained and tested …

Liposomes For The Treatment Of Brain Cancer—A Review, Richu Raju, Waad H. Abuwatfa, William G. Pitt, Ghaleb A. Husseini

Faculty Publications

Due to their biocompatibility, non-toxicity, and surface-conjugation capabilities, liposomes are effective nanocarriers that can encapsulate chemotherapeutic drugs and facilitate targeted delivery across the blood–brain barrier (BBB). Additionally, strategies have been explored to synthesize liposomes that respond to internal and/or external stimuli to release their payload controllably. Although research into liposomes for brain cancer treatment is still in its infancy, these systems have great potential to fundamentally change the drug delivery landscape. This review paper attempts to consolidate relevant literature regarding the delivery to the brain using nanocarriers, particularly liposomes. The paper first briefly explains conventional treatment modalities for cancer, followed …

Investigation Of The Performance Of Anti-Corrosive Coating Materials Derived From Bio-Based Feedstocks, Sarah Anne Salazar

Theses and Dissertations

Corrosion is a costly phenomenon that is largely responsible for the deterioration of various infrastructures. While there are many corrosion prevention techniques, polymeric coatings are the most cost-effective and frequently used methods for protection of metal surfaces. The most commonly employed polymeric coatings are non-renewable BPA-based epoxide resins. Common curing agents are also the derivatives of hazardous amines such as ethylene di-amine and methylene dianiline. Therefore, there is a growing demand to develop renewable and less-harmful precursors from biomass to replace rapidly depleting petrochemicals. This thesis focuses on the characterization and optimization of anti-corrosive polymeric coating formulations derived from renewable …

A Review On Membrane Fouling Prediction Using Artificial Neural Networks (Anns), Waad H. Abuwatfa, Nour Al Sawaftah, Naif Darwish, William G. Pitt, Ghaleb A. Husseini

Faculty Publications

Membrane fouling is a major hurdle to effective pressure-driven membrane processes, such as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO). Fouling refers to the accumulation of particles, organic and inorganic matter, and microbial cells on the membrane’s external and internal surface, which reduces the permeate flux and increases the needed transmembrane pressure. Various factors affect membrane fouling, including feed water quality, membrane characteristics, operating conditions, and cleaning protocols. Several models have been developed to predict membrane fouling in pressure-driven processes. These models can be divided into traditional empirical, mechanistic, and artificial intelligence (AI)-based models. Artificial neural networks …

Physiologically Relevant Fluid Shear Stress Induced Receptor Conversion In Hormone Receptor-Positive (Hr+) Breast Cancer, Jonathan James Cuccia

LSU Doctoral Dissertations

Breast cancer is the most common type of cancer among all people in the United States as of 2023 and often has devastating impacts on afflicted patients. Although some treatments show great efficacy against primary breast tumors, none have been able to significantly reduce the mortality rate of breast cancer once it has metastasized to distant sites. In primary, hormone receptor-positive (HR+) breast cancers, endocrine therapies are often used as first-line treatments and are generally well-tolerated. However, as the disease progresses, these previously sensitive cancers can become resistant to endocrine therapies and continue proliferating despite them. Therefore, there is a …