Chemical Engineering Commons^™

Random Trilobe Packing Using Rigid Body Approach And Local Gas-Liquid Hydrodynamics Simulation Through Cfd With Experimental Validation, Binbin Qi, Sebastián Uribe, Omar Farid, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

It is quite difficult to measure the local information of the gas/liquid flow inside random packed extrudate catalyst beds in a large scale. Obtaining the local information through computational fluid dynamic (CFD) simulations in such system is also difficult due to the complexity of random particle packing and two-phase flow simulation. An efficient packing scheme was implemented to randomly pack 2917 trilobe particles (10 cm in height) in a 2-inch column to represent the trickle bed reactor (TBR) based on the rigid body approach. The generated geometry was used to define the computational domain for the two-phase hydrodynamics simulation based …

Liquid And Solids Phase Backmixing In A Bubble And Slurry Bubble Column Using A Virtual Tracer Response Methodology Based On The Trajectory Data Of The Radioactive Particle Tracking (Rpt) Technique, Lu Han, Premkumar Kamalanathan, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Virtual tracer response methodology developed based on the trajectory data of the computer aided radioactive particle tracking (CARPT) technique was demonstrated. The demonstrated virtual tracer technique has advantages of non-invasiveness, near perfect injection/sampling, and flexibility in choosing the sampling/injection boundaries in a specific spatial pattern. With the developed virtual tracer technique, liquid and solids back mixing was investigated at the conditions mimicking Fischer-Tropsch synthesis. Experiments were conducted at different pressure, solids loading, and superficial gas velocity. The axial dispersion model (ADM) and recirculation and cross flow dispersion (RCFD) models were used to model the liquid mixing. Transient sedimentation dispersion model …

Review Of Biomechanical Studies And Finite Element Modeling Of Sternal Closure Using Bio-Active Adhesives, Amatulraheem Al-Abassi, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The most common complication of median sternotomy surgery is sternum re-separation after sternal fixation, which leads to high rates of morbidity and mortality. The adhered sternal fixation technique comprises the wiring fixation technique and the use of bio-adhesives. Adhered sternal fixation techniques have not been extensively studied using finite element analysis, so mechanical testing studies and finite element analysis of sternal fixation will be presented in this review to find the optimum techniques for simulating sternal fixation with adhesives. The optimal wiring technique should enhance bone stability and limit sternal displacement. Bio-adhesives have been proposed to support sternal fixation, as …

A New Look At Landslides Of The Vermilion And Echo Cliffs, Northern Arizona, Conor M. Watkins, J. David Rogers

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Vermilion and Echo Cliffs form a nearly continuous escarpment more than 160 km long within the Colorado Plateau physiographic province of North America. The cliffs overlie the Marble Platform in northern Arizona and are located along the Colorado River, just upstream of the Grand Canyon. Large rotational block landslides mantle the erosional escarpment along most of its extent. Although these landslides have been noted for over 100 years, their likely origin has never been explained. Landslide failure surfaces appear to be influenced by the Petrified Forest Member of the Triassic Chinle Formation, a shale layer containing smectite clay weathered …

Drug-Facilitated Sexual Assault At The University Of Arkansas, Barrett Weidman

Chemical Engineering Undergraduate Honors Theses

This work was written to fulfill two main purposes. First, to help survivors of Drug-Facilitated Sexual Assault (DFSA) process their experience by compiling the toxicological, pharmacological, and distribution of the three most used date-rape drugs. Second, to gauge the knowledge and interest of University of Arkansas students regarding drug impairments, sexual assault education, and bystander intervention training. A survey was conducted for the latter and revealed that 91.6% of students believe the University’s existing sexual assault prevention education and bystander intervention training have room for improvement. Also, 37.1% of students who have received this education report that the programming does …

Free Convection Heat Transfer From Plates, Alexa Moreno

Chemical Engineering Undergraduate Honors Theses

The purpose of this honors thesis is to create an experiment for the CHEG Lab I course. This report explains the motivation for creating this heat convection experiment, the results of performing the experiment, and provides recommendations for future work on this experiment. Multiple experiments were performed to assess materials and parameters to be investigated. It was determined that a 0.5” plate has smaller percent error and accommodates for the desired timeframe for a Lab I experiment compared to the first plate used (1.5” thickness). Recommendations for expanding on this project include adding experiments using vertical geometry for heat convection …

Quantification Of Slit-Like Pores Through Using Liquid Crystals As A Template, Dominique Savage

Chemical Engineering Undergraduate Honors Theses

The purpose of this research is to manufacture a membrane with slit-like pores to achieve particle filtration. Slit-like pore membranes are preferred over conventional membranes with cylindrical pores since slit-like pores have two length scales that can be manipulated to better control cut off and flux through the membrane. This project focuses on manufacturing slit-like pore membranes through the use of two liquid crystals, 1,4-bis[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene (RM257) and 4-Cyano-4′-pentylbiphenyl (5CB). This method for making slit-like pores has not been widely investigated nor has the morphology of the membrane pores and mechanical properties of such a membrane been addressed. It was found …

Synthesis And Phase Transition Characterization Of Liquid Crystal Membranes With Slit-Like Pores, Isaac Hopwood

Chemical Engineering Undergraduate Honors Theses

Membranes with slit-like pores have been of interest for some time due to their ability to reject smaller particles than traditional cylindrical-pored membranes at the same fluid flux. However, using liquid crystals as a template for this sort of membrane has not been thoroughly investigated. In this study, the liquid crystal mixture of RM257 (2-Methyl-1,4-phenylene bis(4-(3-(acryloyloxy)propoxy)benzoate)) and 5CB (4-Cyano-4'-pentylbiphenyl) for the purpose of manufacturing membranes with slit-like pores, the phase transition behavior of this LC mixture at various mole fractions of RM257, and the impact of mole fraction of RM257 in the liquid crystal (LC) mixture and membrane manufacturing conditions …

Diffusion Of A Salt In An Aqueous Media, Aldaly Pineda Hernandez

Chemical Engineering Undergraduate Honors Theses

Diffusion is defined as the net transfer of a molecule from a high concentration region to a low concentration region. The concept of diffusion is used in a very important process called "desalination." Desalination is a separation process used to reduce the salt content dissolved in brackish water to make it suitable for human consumption, irrigation, and industrial use.

In desalination plants, it is important to monitor the constantly changing salt content of water, partly due to the diffusive effect. The main purpose of this experiment was to study the diffusion of NaCl in water at two NaCl concentrations. The …

Phonon Thermodynamics Of Bcc Zirconium With Machine Learning, Vanessa Judith Meraz

Open Access Theses & Dissertations

First principles-based simulations have allowed us to explore emerging phenomena in a variety of systems. Its steadfast practicality has led to an increase in molecular and materials design ranging from drug discovery to planetary formation. However ubiquitous in its field, one of its biggest drawbacks is its computational cost, notably so in molecular dynamics simulations. To counter this setback, there have been many leading efforts in machine learning methods, whether it be in algorithms or network architectures. Our contribution uses an active learning algorithm paired with a tensor field network, e3nn. By steadily feeding new data points to our model, …

Development Of Porous Solid Acid Catalysts For Lignocellulose And Plastic Upcycling., Mohammad Shahinur Rahaman

Electronic Theses and Dissertations

My goal is to develop chemical processes for transforming waste to solve environmental problems and enhance sustainability. Environmental problems such as pollution and massive amounts of waste are the main drivers that stimulate my research ideas. I focused on creating novel, efficient catalytic processes for converting polymeric waste "feedstocks" into high-value chemicals by integrating my expertise in catalysis, materials science, and synthetic chemistry to develop porous solid catalytic materials. During my Ph.D., I focused on two polymeric feedstocks, lignocellulose, and discarded plastic.

Early in my Ph.D. journey, I focused on catalytic upcycling of lignocellulose. Lignocellulosic biomass is cost-effective, abundant, and …

Materials And Interfaces For Electrocatalytic Hydrogen Production And Utilization., Alexander Jiya Gupta

Electronic Theses and Dissertations

Mass industrialization over the last few centuries has created a global economy which is dependent upon fossil fuels to satisfy an exponentially increasing demand for energy. Aside from the possible depletion of this finite resource, the combustion of fossil fuels releases greenhouse gases into the atmosphere which cause the global temperature to rise – a phenomenon which has already begun to create geologic and geopolitical instability and shows no signs of abatement. One proposed method to rid humanity of its dependence on fossil fuels is to use green hydrogen as an energy carrier. In this scheme, excess electricity from a …

Effects Of Continuous In Situ Low-Dose Ionizing Radiation On Microorganisms, Molly E. Wintenberg

All Dissertations

Precise detection and monitoring of nuclear fuel cycle, enrichment, and weapon development activities are critical for supporting warfighter preparation in chemical, biological, radiological, nuclear, and explosives (CBRNE) operations, clandestine activities, and nuclear compliance. A biological sensing system could serve as an alternative to traditional detection methods by using organic material naturally present in the environment to discreetly detect residual trace nuclear material. Microorganisms provide an optimal platform for an alternative sensing system; however, their response to low levels of ionizing radiation is poorly characterized. Combining the power of next-generation sequencing and transcriptomic analysis, this dissertation takes an approach to obtain …

Extractive Membranes For The Detection And Screening Of Waterborne Plutonium, James Foster

All Dissertations

The development of rapid screening tools for special nuclear materials remains a crucial focus for nonproliferation efforts. Traditional approaches for the analysis of trace-level Pu isotopes in water requires tedious and time-consuming sample preparation steps that do not lend well to expeditious screening. Therefore, a novel analytical method that combines both Pu concentration and source preparation into a single detection system would make for an invaluable tool for nuclear security applications. Extractive membranes absorbers can help to fulfill this role as they are capable of concentrating Pu to detectable limits while subsequently serving as alpha spectrometry sample sources. In Chapter …

Establishing Pteridine Metabolism In A Progressive Isogenic Breast Cancer Cell Model – Part Ii, Lindsey Rasmussen, Zachary Foulks, Jiandong Wu, Casey Burton, Honglan Shi

Chemistry Faculty Research & Creative Works

Introduction: Determining the biological significance of pteridines in cancer development and progression remains an important step in understanding the altered levels of urinary pteridines seen in certain cancers. Our companion study revealed that several folate-derived pteridines and lumazines correlated with tumorigenicity in an isogenic, progressive breast cancer cell model, providing direct evidence for the tumorigenic origin of pteridines. Objectives: This study sought to elucidate the pteridine biosynthetic pathway in a progressive breast cancer model via direct pteridine dosing to determine how pteridine metabolism changes with tumorigenicity. Methods: First, MCF10AT breast cancer cells were dosed individually with 15 pteridines to determine …

Membrane Bioreactor For Enhanced Enzymatic Hydrolysis Of Cellulose, Saleha Abdullah Al-Mardeai

Dissertations

With the rising environmental concerns related to fossil fuels utilization and the depletion of these resources, interest in bioethanol from lignocellulosic waste as an alternative, sustainable energy source has been increasing. Date palm waste is considered a good feedstock for bioethanol production, especially in countries of large date palm plantations, such as the United Arab Emirates.

In the lignocellulose to bioethanol process, the enzymatic hydrolysis of celluloses to produce simple sugars that can be converted to bioethanol by fermentation is the most challenging step, and enhancing it is essential for efficient and feasible operation. Enzyme inhibition by the products is …

Desalination Waste Revitalization Using Carbon Capture: Process Optimization Using Machine Learning, Ahmed Mohamed Elsayed

Theses

Over the next five to ten years, desalination will play an ever-important role in our society. Developing nations will look at desalination from the point of water scarcity, while developed nations will consider the perspective of the Water-Energy-Food nexus. With current technology, for every liter of freshwater produced, one and a half liters is thrown away as waste. This body of research proposes to employ chemical precipitation in ammoniated brine solutions, that have reasonably high ionic concentrations. CO2 absorption in Bubble Column Reactors can reduce sodium ions by precipitating NaHCO3. Also, the absorbed CO2 can reduce chloride ions and induce …

Koh-Based Modified Solvay Process: Optimization And Kinetics Studies, Aya Abdel-Hamid Mourad

Dissertations

While desalination of seawater is important for meeting the water demand, the technology produces large volumes of reject brine and CO₂, causing environmental pollution. Solvay process (based on ammonia, NH₃) and modified Solvay process (based on calcium oxide, CaO) try to manage these wastes. However, more attention is needed to overcome different limitations of these processes such as, alkaline solubility, operating temperature, maintaining high pH value, and low sodium (Na⁺) removal efficiency, which does not exceed 35%. The aim of this work is to introduce an alternative alkaline, namely potassium hydroxide (KOH) and investigate …

Integration Of Dynamic Growth Modeling And Hydrodynamics In An Internal-Loop Split Photobioreactor, Laith S. Sabri, Aastha Ojha, Abbas J. Sultan, Muthanna H. Aldahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this study, new high-quality experimental data for culturing green microalgae Scenedesmus in tubular and cylindrical split airlift photobioreactors were obtained under different operating conditions. The obtained experimental data of culturing microalgae Scenedesmus in a tubular photobioreactor were used for determining the kinetic parameters of the photosynthetic reaction. On the other hand, the culturing of green microalgae in a split airlift photobioreactor was used to measure the microalgae cell trajectory using an advanced radioactive particle tracking (RPT) technique. The obtained results in terms of kinetic parameters of the photosynthetic reaction and microalgae cell trajectory were integrated for the first time …

Comprehensive Evaluation Of Self-Healing Polyampholyte Gel Particles For The Severe Leakoff Control Of Drilling Fluids, Lili Yang, Chunlin Xie, Tian Ao, Kaixiao Cui, Guancheng Jiang, Baojun Bai, Yongwei Zhang, Jun Yang, Xingxing Wang, Weiguo Tian

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Lost circulation has been a serious problem to be solved in many drilling practices during oil, gas and geothermal well drillings. Many materials have been developed and evaluated for the purpose. However, their performance to plug severe leakoff is very limited. Herein, an injectable self-healing hydrogel based on polyampholyte with sulfonated and quaternary ammonium functionalities (P(MPTC-co-NaSS)) was developed and comprehensively evaluated to prevent the severe loss of fluids to formation. By incorporating cation-π (π is for aromatic residues) interaction, the hydrogel shown self-healing property and robustness in severe environment (temperature, salt) by comparison with other hydrogels merely consisting of cation-anion …