Engineering Commons^™

Dynamic Metabolic Flux Analysis Amidst Data Variability: Sphingolipid Biosynthesis Case Study In Arabidopsis Thaliana Cell Cultures, Abraham Boluwatife Osinuga

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Sphingolipids are pivotal for plant development and stress responses. Growing interest has been directed towards fully comprehending the regulatory mechanisms of the sphingolipid pathway. In this study, we explore its de novo biosynthesis and homeostasis in Arabidopsis thaliana cell cultures, shedding light on fundamental metabolic mechanisms. Employing ¹⁵N isotope labeling and quantitative dynamic modeling approach, we obtained data with notable variations and developed a regularized and constraint-based Dynamic Metabolic Flux Analysis (r-DMFA) framework to predict metabolic shifts due to enzymatic changes. Our analysis revealed key enzymes such as sphingoid-base hydroxylase (SBH) and long-chain-base kinase …

Development Of A Large Format Additive Manufacturing System Based On An Off-The-Self Pellet Extruder, Aywan Das

Theses and Dissertations

Large Format Additive Manufacturing (LFAM), or Big Area Additive Manufacturing (BAAM), was introduced to resolve the limitations of the low deposition rate, low scalability, and therefore long print times, of traditional 3D printing methods when applied to the manufacturing of large structures and tooling. LFAM can be used to overcome the high conventional tooling costs of large structures. However, even with robotic setups, LFAM still mainly relies on quasi-planar, 2.5D printing strategies. This fails to reap the advantages of multi-axis printing, such as improved adhesion, reduced support material use, and the ability to create complex curved surfaces. In this research, …

Applications Of Catalytic Ammonia Chemistry: From Low-Pressure Ammonia Synthesis To The Decomposition Of Tritiated Ammonia As A By-Product Of Magnetically Confined Nuclear Fusion, Jennifer Kules Naglic

Theses and Dissertations

Ammonia is the 2nd most produced chemical in the world with vital importance for its use in fertilizer as the global population has grown in accordance with the industrialization of NH3. While 80% of NH3 produced goes to fertilizer, it has gained attention recently as a hydrogen storage and transportation vessel. Industrially, NH3 is produced at high temperatures and pressures which in turn require high electrical input. Turning to a green NH3 cycle with low temperature and pressure membrane reactors for both NH3 synthesis and decomposition would allow for much lower energy input as well as a renewable energy to …

Investigation Of Ethane Dehydrogenation And Hydrogenolysis On Pt(111), Pt(211) And Pt(100): Bayesian Quantification And Correction Of Dft-Based Enthalpic And Entropic Uncertainties, Mubarak Bello

Theses and Dissertations

Computational investigations of heterogeneously catalyzed reactions using density functional theory (DFT) are often inaccurate, largely due to uncertainties in the choice of DFT functional (enthalpic uncertainty) and approximations for modeling adsorbate movement along the catalyst surface (entropic uncertainty). This work illustrates that both uncertainties are significant in the investigation of the ethane dehydrogenation (EDH) and hydrogenolysis on Pt catalysts by considering the complete deconstruction of ethane on Pt(111), Pt(211), and Pt(100) using microkinetic modeling (MKM). Hence, this work uses both non-calibrated and Bayesian calibrated MKMs to quantify and correct inaccuracies in macroscopic properties due to both uncertainties. A Bayesian approach …

Surface Acoustic Waves-Based Point-Of-Care Biosensor, Debdyuti Mandal

Theses and Dissertations

A biosensor is an analytical tool consisting of biologically active material used in close conjunction with a device that converts a biochemical signal into a quantifiable electrical signal. The early detection of the disease biomarkers can enhance the increased curability of the disease, reduce healthcare costs, and finally, improve the quality of life for patients. Thus, for the following purpose, there is always a need for an effective biosensor as a diagnostic device. The biosensor typically consists of an actuator, a bio-recognition component, and a transducer that converts captured signals into a meaningful display. The bio-recognition component uses biomolecules to …

Design And Development Of A Direct Medium Voltage Solar Pv Resonant Inverter, Parthkumar Sureshkumar Bhuvela

Theses and Dissertations

In a grid-tied photovoltaic (PV) system connected to a medium voltage (MV) grid, an inverter is generally employed with a line frequency transformer (LFT) to connect to the grid. These LFTs are large in size and weight, exhibit high cost and losses. In recent studies, the LFTs replaced by are by (high frequency transformer) HFT embedded in DC-DC converters. These DC-DC converters are used to boost voltage levels and DC-AC inverters are employed for MV inversion. This leads to high frequency switching at MV which increases losses in inversion stage. In this study, a novel MV grid-connected solar PV inverter …

Exploring Shape Dependency Of Catalysts For Chemical Reactions, Kaveh Shariati

Theses and Dissertations

Recent advancements in the synthesis of nanoparticles, particularly one-dimensional (1D) nanoparticles, have significantly enhanced the catalytic activity of various processes by enabling precise control over their morphologies and exposing unique crystallographic facets. The shape of nanoparticles is closely linked to their chemical, physical, electrical, optical, magnetic, and catalytic properties. This dissertation investigates the impact of 1D nanoparticle catalysts on two distinct and well-known chemical reactions. In the first part of the study, we explore the catalytic activity and selectivity of silver catalysts in the ethylene epoxidation reaction, which are intrinsically linked to their faceting. Silver nanowire catalysts representing Ag(100) and …

Multidimensional Simulation Of Cool Diffusion Flame, Ejaz Ahmed

Theses and Dissertations

Understanding the behavior of spherical cool diffusion flames in microgravity conditions is crucial for advancing combustion research. This knowledge has significant implications for both fundamental science and practical applications, such as spacecraft fire safety and the development of advanced, high-efficiency engines that benefit from low-temperature chemistry. Spherical cool diffusion flames are typically characterized by peak temperatures between 500 and 1000K and are often followed by the radiative extinction of a hot flame. Some low-temperature ignitions can sustain indefinitely at around 700K, leading to chain-branching pathways that produce intermediate species such as C2H4, H2O2, HO2, CH2O, CH3O, and HCO. In some …

Accelerating Numerical Modeling And Optimization Of Structural Mechanical Systems, Fatemeh Hashemian

Theses and Dissertations

This research proposal presents Bayesian optimization and reduced order modeling methods to accelerate numerical analysis and design of structure mechanical system. First, a holistic framework of Bayesian optimization (BO) based on parameterized numerical models and genetic algorithm-guided adaptive sampling is developed to automate and accelerate the design of a front-loading washing machine. The research aims to address challenges associated with the model parameterization and global optimization and design. A multibody dynamics model of the washing machine incorporating a set of 9 key design variables is developed. The design variables are implemented to enable automated modifications of the dynamics model for …

Enabling Novel Nanopore Sensing Approaches For Personalized Medicine Through Chemical Modifications To Analytes, Zehui Zhang

Theses and Dissertations

Nanopore sensors have garnered significant attention recently, not only for their groundbreaking advancements in single-molecule DNA sequencing but also for their diverse applications in stochastic sensing, single-molecule chemistry, and protein unfolding. The interaction of single molecules with the nanopore sensing interface leads to characteristic ionic current modulations, reflecting the composition, charge, distribution, structure, and sequence of the translocating molecule. With the electrical resistive pulse nanopore sensing, its single-molecule sensitivity and specificity have opened doors to numerous potential applications in personalized medicine. I will discuss recent advancements in the sensitivity and specificity of personalized medicine using nanopore sensors, focusing on proteomic …

Jme 4110: Washer To Dryer Clothes Transfer Device, Scott Diep, Jared Edwards, Catherine Mcdonnell, Patrick Geldmeier

Washington University / UMSL Mechanical Engineering Design Project JME 4110

For those leading busy lives or facing mobility challenges, this project involve a custom device can transfer clothes from washer to the dryer automatically when the person is not home. This solution eliminates the need to manually move clothes from the washer, preventing formation of mildew, and ensuring that the laundry is fresh and ready to wear when you return.

Jme 4110: Patient Mat Mover, Muhammad Mughal, Seth Gallamore, Gabriel Monte, Marcos Navas Gallardo, Jamie Barvian

Washington University / UMSL Mechanical Engineering Design Project JME 4110

The idea of an improved patient mat mover was suggested to help make the life of patients and their care givers easier. The typical method of using brute force to lift a patient and slide a mat under them can be very challenging and tasking on both the patient and their care giver. It is a large inconvenience in the medical field and makes the process of patient care difficult and uncomfortable. Our value is designing a solution that will eliminate pain and difficulty for both our patients and their nurses/care givers by simplifying patient transport from bed to bed. …

Jme 4110: Stand-Up Pedicure Final Report, Heather Burt, Brian Hinkle, Jonathon Riggle, Anna Domingo Garcia

Washington University / UMSL Mechanical Engineering Design Project JME 4110

This project focuses on designing a pedicure device specifically for individuals who struggle with bending down to cut their toenails. While many people may not give this task a second thought, for some, it is a daily challenge. The goal is to create a device that allows users to safely and comfortably cut their toenails without needing to bend down or visit a nail salon, saving them time, effort, and money. This innovative design will cater to those with physical limitations, enabling them to maintain their nail care independently.

Additively Manufactured Flexible Piezoelectric Wave-Based Multifunctional Sensor, Rishikesh Srinivasaraghavan Govindarajan

Doctoral Dissertations and Master's Theses

The demand for acoustic wave-based sensors has rapidly increased in the aerospace, chemical, gas, and biological fields due to their versatility in sensing measurands. This study aims to develop a flexible piezoelectric sensor exhibiting enhanced piezoelectric properties using additive manufacturing techniques that can detect mechanical strains and gas or volatile organic compounds (VOCs) by incorporating functional material into the sensing layer. This research explores piezoelectric substrate fabrication through diverse additive manufacturing techniques, including new material development made of polymer/nano-fillers with electrodes that are filled using different printing techniques. Notably, the design of the interdigital transducer (IDT) in the piezoelectric sensor …

Patient-Specific Hemodynamic Modeling For Optimizing Left Ventricular Assist Device And Right Heart Health, Holly Felice Grant

Theses and Dissertations

LVAD speed optimization is essential for efficient LVAD therapy and to minimize complications. However, the ideal LVAD speed is unknown and must be tailored for each patient. The interplay between the LVAD, systemic, and pulmonary circulations is critical and should be considered during optimization. A computational hemodynamic model that can be tailored for each patient may provide clinicians with useful guidance and reduce the need for repeated invasive studies. This study sought to customize and evaluate a patient-specific LVAD hemodynamic optimization model.

We conducted a retrospective analysis on 25 patients implanted with HM3 and who underwent right heart catheterization (RHC) …

Increasing Optical Channel Capacity By Integrating Pam4 Modulation With Wavelength Division Multiplexing And Spatial Domain Multiplexing, Swaroopini Harish

Theses and Dissertations

Spatial division multiplexing (SDM) is a technique used in telecommunications and networking to increase data transmission capacity over optical fiber communication channels. This multiplexing technique spatially reuses optical frequencies by allocating different spatial locations for inputs based on their inject angles. The signals travel in a helical pattern within the carrier fiber and exit as concentric rings. SDM enables more efficient utilization of available bandwidth and improved communication performance. In four-level pulse amplitude modulation (PAM4), each symbol represents a combination of four possible signal levels instead of the two levels in binary modulation. The four levels are denoted in different …

Parallel Communications In Single-Core Optical Fibers Utilizing Spatial Domain Multiplexing And Wavelength Division Multiplexing, Mingxuan Tu

Theses and Dissertations

This endeavor proposes a hybrid parallel optical communication architecture in single-core fibers combining WDM in O-band (1270 nm, 1310 nm, 1310 nm, and 1330 nm) and two-channel SDM. The proposed architecture applies carefully designed delays in each propagating channel to achieve synchronization and, therefore, realizes parallel transmission in single-core fibers without the help of Serializer/De-serializers (SerDes). A mathematical model of SDM, calculations on delays between each optical channel, simulation of the hybrid architecture, experimental setup, and the testing and analysis of channel performance have been provided. A design of a photonic integrated circuit based on thin film lithium niobate electro-optic …

Engine Performance Of An Electric Airplane With Partial Battery Capability, Hannah Yasmine Scrivens

Theses and Dissertations

As electric aircraft are developed and certified, knowledge of electric aircraft performance during complete or partial battery failures can be useful to determine an aircraft’s limitations and capabilities of completing an emergency landing, especially during takeoff and low-altitude climbs, as well as fully characterizing the potential aircraft performance. The results of this research will be useful in developing regulations and procedures pertaining to energy reserves and emergencies. This paper presents the results of a Pipistrel electric airplane climb power ground test that was conducted by the author and Florida Tech faculty. In the test, one of the airplane’s batteries was …

Characteristics Of Pyrolysis Products Of California Chaparral And Their Potential Effect On Wildland Fires, Mahsa Alizadeh, David R. Weise, Thomas H. Fletcher

Faculty Publications

The aim of this study was to investigate the pyrolysis of selected California foliage and estimate the energy content of the released volatiles to show the significance of the pyrolysis of foliage and its role during wildland fires. While the majority of the volatiles released during the pyrolysis of foliage later combust and promote fire propagation, studies on the energy released from combustion of these compounds are scarce. Samples of chamise (Adenostoma fasciculatum), Eastwood’s manzanita (Arctostaphylos glandulosa), scrub oak (Quercus berberidifolia), hoaryleaf ceanothus (Ceanothus crassifolius), all native to southern California, and sparkleberry …

Improving Performance Of Tpu By Controlled Crosslinking Of Soft Segments, Lucivan P. Barros Jr., Lucio R. De Souza, Rasoul Rahimzadeh, Ica Manas-Zloczower

Faculty Scholarship

Thermoplastic polyurethanes (TPUs) are a family of thermoplastic elastomers with great properties such as high elongation and excellent chemical and abrasion resistance, which are processable by conventional melting methods. Nevertheless, TPUs lose mechanical properties and thermal stability at higher temperatures. In this work, we designed and synthesized a new TPU with limited crosslinking of the soft segments in order to improve its performance at high temperatures while preserving processability. Additionally, the new TPU maintains its transparency. With the incorporation of 10% trifunctional polyol, the T was increased by 7°C, the storage modulus at room temperature (25°C) was improved by 412 …

Understanding And Tuning Magnetism In Layered Ising-Type Antiferromagnet Fepse3 For Potential 2d Magnet, Rabindra Basnet, Taksh Patel, Jian Wang, Dinesh Upreti, Santosh Karki Chhetri, Gokul Acharya, Md Rafique Un Nabi, Joshua Sakon, Jin Hu

Chemistry & Biochemistry Faculty Publications and Presentations

Recent developments in 2D magnetic materials have motivated the search for new van der Waals magnetic materials, especially Ising-type magnets with strong magnetic anisotropy. Fe-based MPX₃ (M = transition metal, X = chalcogen) compounds such as FePS₃ and FePSe₃ both exhibit an Ising-type magnetic order, but FePSe₃ receives much less attention compared to FePS₃. This work focuses on establishing the strategy to engineer magnetic anisotropy and exchange interactions in this less-explored compound. Through chalcogen and metal substitutions, the magnetic anisotropy is found to be immune against S substitution for Se whereas …

Exploring Performance-Based Contracts: A Good Option To Address Long-Term Road Maintenance In California?, Maria Calahorra-Jimenez, Richard Poythress

Mineta Transportation Institute

Performance-based contracts (PBCs) used in road maintenance provide flexibility for considering new materials, design, and technology to achieve predetermined performance targets. Several states in the U.S. have already used these types of contracts in road maintenance, and their experience can inform the use of PBCs in California. The objectives of this research are twofold. First, identify the benefits and challenges of PBCs compared to traditional contracts. Second, explore the main aspects of PBCs implementation for road maintenance and relate them to California's context. To this end, deductive-inductive content analysis was conducted on 84 peer-reviewed articles published between 1998 and 2023. …

Experimental Investigation Of The Self-Healing Potential Of Bacteria For Sustainable Concrete Structures Phase 2, Andrea Calabrese, Pitiporn Asvapathanagul, Nisarg N. Patel, Nanubala Dhruvan, Austin Adams, Michael Hernandez, Douglas S. Lopez-Cruz

Mineta Transportation Institute

Concrete is a critical component of so much of the modern construction industry. This material, well known for its versatility, robustness, longevity, and strength, is well-suited for a wide range of structural applications. Nonetheless, the widespread occurrence of cracks in concrete structures, primarily attributed to its limited tensile strength, shrinkage, and overstain, imposes a considerable economic and environmental challenge when it comes to retrofitting these fissures. This study tackles this problem by harnessing bacteria tolerant to high alkaline conditions to enable Microbially Induced Calcium Carbonate Precipitation (MICP) for the self-repair of concrete. This is achieved through an external application method, …

Battery Management System Development For Electric Vehicles And Fast Charging Infrastructure Improvement, Yu Yang, Hen-Geul Yeh, Cesar Ortiz

Mineta Transportation Institute

The electric vehicle (EV) has become increasingly popular due to its being zero-emission. However, a significant challenge faced by EV drivers is the range anxiety associated with battery usage. Addressing this concern, this project develops a more efficient battery management system (BMS) for electric vehicles based on a real-time, state-of-charge (SOC) estimation. The proposed study delivers three modules: (1) a new equivalent circuit model (ECM) for lithium-ion batteries, (2) a new SOC estimator based on the moving horizon method, and (3) an on-board FPGA implementation of the classical Coulomb counting method for SOC estimation. The research team extends the traditional …

Geometrically Exact Beam Theory For Gradient-Based Optimization, Taylor Mcdonnell, Andrew Ning

Faculty Publications

Decades of research have progressed geometrically exact beam theory to the point where it is now an invaluable resource for analyzing and modeling highly flexible slender structures. Large-scale optimization using geometrically exact beam theory remains nontrivial, however, due to the inability of gradient-free optimizers to handle large numbers of design variables in a computationally efficient manner and the difficulties associated with obtaining smooth, accurate, and efficiently calculated design sensitivities for gradient-based optimization. To overcome these challenges, this paper presents a finite-element implementation of geometrically exact beam theory which has been developed specifically for gradient-based optimization. A key feature of this …

Ductape: A Steady-State, Axisymmetric Ducted Fan Analysis Code Designed For Gradient-Based Optimization, Judd Mehr, Andrew Ning

Faculty Publications

Electric ducted fans have become an intriguing option for the propulsion systems of clean, quiet advanced air mobility technologies due to their potential benefits in both aerodynamic efficiency and reduced noise profiles compared to open rotor systems. Exploration of conceptual electric ducted fan design in the context of novel, and often complex, applications may be greatly aided by the use of optimization techniques. Specifically, gradient-based optimization lends itself to the exploration of large, complex, multi-disciplinary systems due to its inherent scalability. Despite ducted fans/propellers having been relatively well studied for the last century, modern, gradient-based, optimization-ready analysis tools for ducted …

Explainable Artificial Intelligence: Methods And Evaluation, Gayane Grigoryan

Engineering Management & Systems Engineering Theses & Dissertations

A wide array of techniques within explainable artificial intelligence (XAI) have been developed to measure the importance of features in machine learning models. A notable portion of these methods draws upon principles of cooperative game theory (CGT), with the Shapley value emerging as a widely used solution concept. Despite the rising prominence of the Shapley value, other promising solutions from cooperative game theory—such as the Nucleolus, Banzhaf power index, Shapley-Shubik power index, and solutions to conflicting claims problems—have been comparatively overlooked, even though they hold significant potential. In this dissertation, multiple XAI methods based on these other CGT solutions are …

Alternative Applications Of Composite Materials To Reduce Radar Cross Section, Mark Patterson

Mechanical & Aerospace Engineering Theses & Dissertations

The use of carbon nanoparticles and graphene in composite materials has created a foundational shift in enhancing performance across mechanical, thermal, and electrical properties. Such applications are vital in the aerospace industry. However, there has not been such a focus on the material use for reducing radar cross section (RCS). Historically, RCS is minimized by designing sharp geometric shapes to deflect or dissipate the incoming electromagnetic waves away from the receiving antenna. However, these designs are not always optimized for aerodynamics. The goal of this research is to understand the application of composite materials and specifically carbon nanotubes (CNTs) to …

T. Boudieri Extract Potentiates The Effects Of Capecitabine Treatment In Human Colon Cancer Cells, Katia Sawaya, Mahmoud Khalil, Ghada Khawaja

BAU Journal - Science and Technology

Resistance to chemotherapy remains a major challenge for colorectal cancer patients worldwide, hence the persistent need to uncover alternative treatments as well as new adjunct therapies in the fight against cancer. Natural extracts constitute an excellent source of bioactive substances that have a promising potential in that regard, with minimal negative side effects. We have previously demonstrated that both the ethanolic as well as the water extracts of Terfezia boudieri, a black desert truffle abundant in and part of the cuisine of the Mediterranean region, have significant antiproliferative effects against colon cancer cells. Our aim in this study was …

A Strategic Framework For Attaining Golden Leed Certification For Resorts, Mohamad Soliman, Hadi Jawad, Mariam Younes, Oussama El Hamaoui, Saadeddine Ramadan

BAU Journal - Science and Technology

The contemporary landscape of engineering is witnessing a pivotal shift towards sustainability, encapsulated in the catchphrase "GO GREEN". This global trend underscores a strategic emphasis on sustainable design, where engineering projects prioritize a delicate balance among environmental, societal, and economic considerations.” However, a persistent challenge in construction projects lies in their tendency to neglect environmental impact, contributing to increased contamination levels. This paper aims to introduce the "Lodge in the Green" project, meticulously aligned with LEED Certification principles. LEED, or Leadership in Energy and Environmental Design, stands as the foremost green building rating system, highlighting its relevance in contemporary sustainable …