Digital Commons Network^™

Technology For Obtaining Aliphatic Amines Based On Liquid By-Products Of Polymerization Processes, Kamila Sabirbaevna Allanazarova, Ulugbek Komiljonovich Urinov

Technical science and innovation

Polymerization processes generate considerable amounts of liquid secondary by-products, which are often underutilized despite their significant chemical potential. Addressing the need for sustainable resource use, this study aims to develop a technological method for converting these by-products into valuable aliphatic amines. The experimental approach involved the pre-treatment of liquid polymerization by-products through fractional distillation to isolate C3–C10 fractions, followed by catalytic amination using Raney nickel under controlled temperature (160°C) and pressure (12 atm) conditions. Analytical methods including gas chromatography-mass spectrometry (GC-MS) and Fourier-transform infrared spectroscopy (FTIR) were employed to characterize the reaction products. The results demonstrated the successful formation of …

Investigation Of Energy Efficiency Of An Autonomous Mobile Photovoltaic-Thermal (Pv/T) System With A Polycarbonate Absorber, Sanjar Kodir Ugli Shoguchkarov, Anvar Rakhmat Ugli Rakhmatov, Rushana Husen Kizi Abdullaeva, Orazbek Maratbay Ugli Temirbaev

Technical science and innovation

This study analyzes the enhancement of energy efficiency in photovoltaic-thermal (PV/T) systems, which enable the simultaneous generation of electrical and thermal energy from solar radiation. The research focus is an autonomous mobile unit based on multi-channel polycarbonate heat collectors with a hydraulic diameter of 8 mm, characterized by their lightweight nature and superior corrosion resistance compared to conventional metal absorbers. Experimental investigations were conducted at the solar testing field of the Physical-Technical Institute of the Academy of Sciences of Uzbekistan under extreme continental climatic conditions to determine the system's stable thermophysical indicators. The results demonstrated that active water cooling using …

Modeling Of Terpolymerization Kinetics And Determination Of Reactivity Ratios In The Tdma–Styrene–Maleic Anhydride System, Shohrux Boboxon Ugli Mavlonov, Sadriddin Fayzullayevich Fozilov

Technical science and innovation

In this study, the kinetics of terpolymerization, compositional evolution, and monomer reactivity ratios in the TDMA–styrene–maleic anhydride system were comprehensively investigated. Increasing the initiator concentration from 16.8×10⁻⁶ to 51.3×10⁻⁶ mol•L⁻¹ led to an increase in conversion from 6.4% to 15.2% and reaction rate from 4.075×10⁻⁶ to 8.965×10⁻⁶ mol•L⁻¹•s⁻¹. At low conversion (Xw≈0.02–0.09), the terpolymer composition remained close to the initial feed, although deviations due to differences in monomer reactivity were observed. With increasing conversion, some systems exhibited stable composition (±0.02), while others showed compositional drift (increase of MA fraction from 0.50 to 0.70). The determined reactivity ratios (rTDMA/St≈0.99; rSt/TDMA≈1.62; rTDMA/MA≈2.02; …

Adaptive – Compositional Method For Coordinating Subsystems At Different Levels In Hierarchical Control Systems, Husan Zakirovich Igamberdiyev, Uktam Farxodovich Mamirov Mr, Inomjon Ilxom Ugli Abdukaxxarov Mr

Technical science and innovation

This paper examines the problem of synthesizing algorithms for the composition of subsystems at various levels within complex hierarchical control systems under conditions of uncertainty and resource constraints. It is demonstrated that classical composition algorithms, which rely on the intersection of admissible sets and the use of local optimality criteria, suffer from several significant drawbacks. These include a combinatorial increase in complexity, dependence on the expert selection of parameters, and limited applicability in dynamic environments. To overcome these shortcomings, an adaptive-compositional method is proposed. This method is based on the dynamic recalculation of coordination parameters, the integration of model predictive …

Calculation Of The Basic Parameters Of The Hybrid Power Plant (Hpu) On The Spark Car, Rustam Raximovich Tillahodjaev, Jamoliddin Pardaboy Ugli Turdiev

Technical science and innovation

This article presents one of the effective ways to improve fuel efficiency and reduce emissions of toxic substances, the use of internal combustion engines with the use of an electric drive in their designs. In recent years, two directions in the development of cars with electromechanical drives have been clearly identified, the first is the creation of a pure electric car, the second is the development of an electromechanical drive with a combined (hybrid) power plant. Due to the lack of efficient energy storage available for mass production, pure electric vehicles have relatively low mileage on a single charge. This …

Chi Meta-Project Ecosystem Overview - Spring 2026, David B. Smith

Publications and Research

This paper offers a high-level account of the Center for Holistic Integration’s (CHI) meta-project ecosystem as visualized in the included system map. CHI provides an organizational structure framed around persistent meta-projects that support and extend individual initiatives across curriculum, scholarly and applied research, infrastructure, artistic production, AI development, cultural inquiry, and external partnerships. Rather than presenting the map as a static inventory of projects, the paper examines how its core domains function as living systems through which knowledge, tools, documentation, participants, and collaborations can accumulate over time. It also considers how CHI-mediated connectivity, institutional integration, and external funding allow the …

Higher-Order Statistical Analysis Of Inter-Arrival Times For Radiation Detector Deadtime Characterization And Paralysis Factor Determination, Abdallah Wazzan, Shoaib Usman, Tayfun Akyurek

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

All real detectors exhibit hybrid behavior that combines both paralyzable and non-paralyzable which requires improved characterization techniques. This study investigates the relationship between detector deadtime parameters and higher-order statistical for inter-arrival time distributions to develop advanced detector characterization. Two comprehensive Monte Carlo simulation approaches were employed using MATLAB: a full radioactive decay curve analysis spanning approximately 4.5 half-lives of Cobalt-60 and Vanadium-52 sources, and a fixed count rate analysis covering practically achievable laboratory conditions (440 to 1,000,000 counts per second). The hybrid deadtime model was implemented with deadtimes ranging from 2.5 to 50 μs for the full simulation and from …

Magnetic Field-Induced Transformation In Polycrystalline Ni2mnal Heusler Type Magnetic Shape Memory Alloy, Choji J. Daches, Joseph W. Newkirk, Mario Buchely, Laura N. Bartlett

Materials Science and Engineering Faculty Research & Creative Works

The martensitic and magnetic transformations, as well as the mechanical properties, of Ni₂MnAl alloys in as-cast (AC) and heat-treated (HT) conditions were investigated. Magnetic-field-induced strain was evaluated via magnetostriction, with reversible strains of 0.14% and 0.2% achieved in the martensitic phase at 2 K for the AC and HT alloys, respectively. Transformation temperatures and Curie temperatures were determined under constant applied magnetic field, revealing that γ-phase inclusions in the AC microstructure suppress antiferromagnetic domain response, yielding a lower magnetization (∼8.4 emu g⁻¹) compared to the HT alloy (∼13.4 emu g⁻¹). Both alloys exhibited hysteretic behavior in the martensitic state and …

Tailoring Crushing Responses Of Hexagonal Crash Box Filled With Additively Manufactured Lattice Structures By Assessing The Influence Of Material Parameters, L. D. Lumanauw, A. Jusuf, M. H. Jarwadi, L. Gunawan, T. Sebaey, A. Yudhanto

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Hexagonal crash boxes offer superior crashworthiness compared to other cross-sectional geometries, and their performance can be further enhanced by integrating additively manufactured lattice fillers. This study investigates the quasi-static crushing behavior of hexagonal crash boxes filled with hexagonal close-packed (HCP) lattice structures fabricated via stereolithography (SLA). Finite element models developed in ABAQUS/Explicit, validated against quasi-static compression experiments, show discrepancies below 5%, indicating that polymeric lattice fillers provide modest performance gains, achieving a crushing force efficiency (CFE) of 20%–25%. Replacing polymeric lattices with metallic fillers, namely 316L stainless steel and Ti–6Al–4V titanium alloy, substantially increases energy absorption, with Ti–6Al–4V delivering the …

Nascent Titanium-/Silicon-Containing Particle Formation In Corona-Discharge-Assisted Combustion, Chanakya Bagya Ramesh, Frank Daoru Han, Yang Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Adding plasmas to a flame has been shown to introduce high concentrations of charges, ions, and radicals to the said flame. This technique of adding plasma to a flame is called plasma-assisted combustion (PAC), and this addition has been shown to make a flame more stable and efficient. At the same time, PAC has also been shown to alter particle formation during combustion. Here, we investigate the effect of a high-frequency (∼21 kHz) alternating current (AC) corona discharge on particle formation and growth in a premixed flame, especially at the initial stages (with particle sizes below 10 nm). We first …

Multi-Parametric Nonlinear Programming For Lossy Lmp Sensitivity Analysis Using Outer Progressive Cuts, Yuhan Huang, Tao Ding, Chenggang Mu, Rui Bo, Pengwei Du

Electrical and Computer Engineering Faculty Research & Creative Works

Accurate sensitivity analysis of locational marginal price (LMP) is crucial for risk hedging and market management. This paper proposes multiparametric nonlinear programming for sensitivity analysis of LMP with nonlinear network loss, also known as lossy LMP. Global analytical solutions for lossy LMP and the corresponding critical regions are derived. An outer progressive cut algorithm is developed to constrain the network loss error within a specific range for the whole parametric domain. Case studies show the improved accuracy over methods with lossless or fixed loss factors, and a two-order-of-magnitude online speedup over Monte Carlo methods while maintaining lower total computational time.

Unveiling Corrosion Behavior And Passive Film Performance Of L12-Strengthened Ni28cr15cu8ti8fe26-Xco15+X Multi-Principal Element Alloys, Liran Huang, Zhiqiang Fu, Chenliang Chu, Shiyu Liu, Xiaohui Qin, Yunzhu Shi, Yongxiang Tan, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

L12 precipitates are usually induced into face-centered cubic (FCC) multiple-principal element alloys (MPEAs) to improve their moderate yield strength; however, the precipitation also influences the corrosion resistance. This study investigated the corrosion behavior and passive film performance of a series of L1₂-strengthened Ni₂₈Cr₁₅Cu₈Ti₈Fe_26-xCo_15+x (x = 0, 3, 6, and 9 at.%) MPEAs in 3.5 wt.% NaCl solution. The size and density of the L1₂ nanoprecipitates were regulated via tuning Fe and Co content. With decreasing Fe/Co ratio, the radii of these nanoprecipitates gradually increased within the …

Classification Of Aircraft Checklist Usability Problems Using Natural Language Processing, Borvorn Kasemtanakul

Doctoral Dissertations and Master's Theses

The use of checklists has been identified as a recurring issue in aviation accident investigations, highlighting the need for continued improvement in aircraft checklist design. However, existing aviation safety taxonomies do not systematically address checklist usability problems. Therefore, a systematic classification of these problems is needed to support the extension of existing aviation safety taxonomies and to facilitate safety data analysis for checklist design improvements. Furthermore, applications of Natural Language Processing (NLP) techniques in aircraft checklist research remain underexplored, despite their potential to identify meaningful patterns in textual safety data.

This exploratory research aimed to develop a data-driven classification of …

How Does Competitive Adsorption Between Vma And Pce Influence Yield Stress Of Cement Paste? A Novel Insight From Interparticle Forces And Percolation Threshold, Huamin Sun, Le Teng, Xiaohan Yu, Xin Shu, Zhangli Hu, Jiaping Liu, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Viscosity modifying admixture (VMA) and polycarboxylate superplasticizer (PCE) are often combined to optimize rheological properties of cement-based materials. However, the competitive adsorption of these complex admixtures can greatly influence rheological properties. Many studies have investigated the variation of yield stress due to competitive adsorption between VMA and PCE; but the mechanisms are not fully understood. This study aims to shed a new light on this question in cement paste systems prepared with low water-to-binder ratios of 0.16–0.30. The competitive adsorption of VMA and PCE was quantitatively assessed using the Total Organic Carbon and Ultraviolet-Visible Spectroscopy measurements. The effect of competitive …

Managing Risks Under Nuclear Power Plant Projects: A Latent Similarity-Guided Contract Customization, Mariam Elazhary, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Global energy is transforming, with nuclear power emerging as a pivotal player in achieving sustainable and low-carbon energy goals. The nature of nuclear technology introduces unique challenges, such as stringent safety and environmental requirements. Existing studies focus on general risk identification, such as supply chain delays, cost overruns, and public perception issues. However, these studies fail to address integrating these risks into tailored contractual provisions, which are critical for navigating the unique challenges of nuclear projects. The goal of this paper is to examine how standard construction contracts can be tailored to better accommodate the risks inherent in nuclear power …

Interpretable Machine Learning Of Plasma Proteomics Reveals Stage-Specific Signatures Across The Alzheimer's Disease Continuum, Hemshankar Laugi

2026 Spring Honors Capstones Projects

Alzheimer’s pathology begins years before clinical symptoms, starting early with amyloid-β accumulation, followed by tau deposition and neurodegeneration. Although existing tools, such as cerebrospinal fluid (CSF) screening and PET/MRI imaging, can accurately track disease progression, they are invasive, expensive, and not scalable for population-level screening. So, there is a growing interest in using blood-based plasma biomarkers as a scalable alternative. While recent studies demonstrate strong predictive performance with plasma biomarkers, most rely on a small set of canonical blood-based protein biomarkers such as amyloid-β, p-tau, and neurofilament light. These biomarkers primarily reflect downstream brain pathology and may fail to capture …

Thermal And Mechanical Properties Of Zirconium Carbide Manufactured Via Ceramic On-Demand Extrusion, Clare Sabata, Yue Zhou, Jeremy L. Watts, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

Zirconium carbide (ZrC) was fabricated by material extrusion additive manufacturing (AM) followed by pressureless sintering at 2000°C for two hours, achieving a relative density of 90.3 %. SEM analysis revealed grains of 4.6 ± 1.8 μm; XRD confirmed single phase ZrC. A stoichiometry of ZrC_0.92 was determined by XPS. Four-point flexure testing exhibited a strength of 331.3 ± 57.1 MPa and Young's modulus of 232.8 ± 13.1 GPa. Vickers hardness was 13.6 ± 1.0 GPa and 11.6 ± 0.5 GPa at 4.91 and 9.81 N, respectively. Indentation fracture resistance was 2.9 ± 0.2 MPa⋅m^1/2; Griffith analysis confirmed …

Distinct Regulatory Dna Methylation Signatures Across Multiple Sclerosis, Neuromyelitis Optica, And Neurological Post-Acute Sequelae Of Covid-19, Syed Ilyas Munzir, Daniel B. Hier, Michael D. Carrithers

Electrical and Computer Engineering Faculty Research & Creative Works

Background/Objectives: Our prior epigenome-wide association study (EWAS) on multiple sclerosis (MS) identified myeloid-associated methylation signatures and an association with enhancer regions. Here we compared differential DNA methylation across three central nervous system inflammatory disorders: MS, neuromyelitis optica (NMO), and neurologic post-acute sequelae of COVID-19 (neuro-PASC). Methods: Whole-blood DNA was profiled on Infinium MethylationEPIC arrays. Analyses included EWAS at the CpG level, differentially methylation region (DMR) analysis, and gene regulatory-element enrichment using Locus Overlap Analysis (LOLA). Limma linear models were adjusted for race, EPIC array version, age, sex, disease-modifying treatment class, and blood cell composition. Results: All three diseases were associated …

Jme 4110: Drill-Powered Beach Umbrella Anchor, Matthew Barton, Tanin Ramnath, Marquan Bailey, Zachary Van-Horn, Kaelin Mendoza

Washington University / UMSL Mechanical Engineering Design Project JME 4110

A common and potentially hazardous situation faced by beachgoers is when standard umbrella anchors fail to hold during wind gusts, causing the umbrella to potentially go airborne and injure nearby people. Existing anchors require manual operation, leading to inconsistent grip and no resistance to different wind directions. Our project is a motorized three anchor system that drives augers into the sand to ensure a consistent grip and security against the wind.

Jme 4110: Drill Powered Pressure Washer, Kathryn Keele, Ashley Givance, Reagan Grass, Andrew Ellis, Jacob Thebeau

Washington University / UMSL Mechanical Engineering Design Project JME 4110

This project focuses on developing a drill-powered pressure washer attachment that connects to a standard cordless drill and garden hose. The device uses the drill as its only power source to pressurize water for cleaning applications. This portable design provides a convenient, low-cost alternative to traditional electric or gas-powered pressure washers.

Study Of Onshore And Offshore Upwind And Downwind Wind Turbine Configurations: Performance Differences And Aerodynamic Characteristics, Ahmed Ismail

Mechanical Engineering Theses

The aerodynamic performance and loading behavior of large- scale wind turbines depend heavily on atmospheric inflow conditions and rotor orientation. While upwind turbines remain the most common design in the industry, recent progress in materials, aeroelastic modeling, and control systems has sparked renewed interest in downwind configurations. This study aims to assess how ABL characteristics and rotor orientation affect the aerodynamic performance of a utility- scale wind turbine. A CFD framework was built in ANSYS Fluent to model the NREL 5 MW Reference Wind Turbine. Transient simulations employed the SST k–ε turbulence model under various inflow conditions: uniform, onshore, and …

Constrained Assortment Optimization Under The Mixed-Logit Model, Hoang Giang Pham, Tien Mai

Research Collection School Of Computing and Information Systems

In this paper, we study the assortment optimization problem under the mixed-logit customer choice model. While assortment optimization has been a central topic in revenue management for decades, the mixed-logit model is widely regarded as one of the most general and flexible frameworks for modeling and predicting customer purchasing behavior. The assortment optimization problem is known to be NP-hard to be approximated to any constant factor, even in the unconstrained case. To address this challenge, we first explore the submodularity properties of a simplified version of the objective function to derive novel semi-constant factor approximation solutions for assortment problems under …

Late-Night And Early-Morning Train Scheduling With Non-Traffic Hour Maintenance Window In Urban Rail Transit Systems, Yaochen Ma, Hai Yang, Hai Wang

Research Collection School Of Computing and Information Systems

Regular maintenance during non-traffic hours (NTH) is vital for the resilience of urban rail transit (URT) systems, yet an insufficient NTH maintenance window poses a challenge for URT systems in various cities. For instance, the Hong Kong MTR Corporation has noted that the required NTH maintenance time often exceeds the available window, prompting service adjustments such as earlier late-night closures and/or later early-morning starts. To address this challenge, this study develops an optimal scheduling framework that links late-night and early-morning URT services through the NTH maintenance window requirement to maximize public welfare. A Decoupled Optimization Model (DOM) first derives closed-form …

The Neuropsychological Analysis Of The Effect Of Shame And Traumatic Memories In Paranoia: A Network Analysis, Anwesha Maitra

Clinical Psychology Dissertations

Paranoia is increasingly recognized as a multidimensional psychological phenomenon influenced by trauma-related distress, shame, maladaptive interpersonal experiences, and emotional functioning. Although these factors have been extensively associated with paranoia, their relationships with neurocognitive functioning, social cognition, and global functioning remain less well understood. The present study examined these relationships using traditional statistical analyses, network analysis, and machine-learning approaches in a non-clinical sample of 42 adults.

Participants completed self-report measures assessing trauma-related distress, childhood interpersonal experiences, shame, paranoia, depressive symptoms, fear of negative evaluation, self-esteem, and hostile attribution bias, in addition to a comprehensive neurocognitive battery, an emotion recognition task, and …

A System Dynamics Model For Analyzing Customer Satisfaction Drivers In A Manufacturing Context, Mahnaz Asgari Sooran, Venkat Allada, Adewole Adegbola

Engineering Management and Systems Engineering Faculty Research & Creative Works

Customer satisfaction offers economic benefits and competitive advantage to manufacturing enterprises. However, a gap exists in understanding how to achieve customer satisfaction due to the complexities involved in coordinating various subsystems of an enterprise in an efficient manner. In this paper, we identified four internal and external-to-the-firm customer satisfaction drivers which include: government policies, supply chain reliability, knowledge management, and manufacturing performance criteria such as on-time delivery, quality and cost. We then developed a conceptual framework to define the non-linear mathematical relationships between drivers using system dynamics modeling. We conducted "what-if "scenario analyses for a base case, optimistic case and …

Leveraging Data Science And Analytics For Next-Generation Transportation And Logistics: Literature Review And Regional Analysis, Kazi Humayra Shams

Graduate Theses and Dissertations

The increasing integration of data science and analytics into next-generation transportation and logistics planning and operations offers improved system performance but requires managing and interpreting vast and complex datasets. The Arkansas Smart Transportation Research, Infrastructure and Data-Driven Engineering Systems (AR-STRIDES) program (NSF Award No. 2445877) is working to develop data science solutions and data-driven supply chain technologies for next-generation transportation and logistics systems. This thesis supports AR-STRIDES by providing a comprehensive literature review of recent literature studying data science and analytics in transportation and logistics systems and conducting a regional analysis of Arkansas to create a database of companies, higher …

Analysis Of Inhibitor Supply Control Systems To Prevent Hydrate Formation In A Low-Temperature Gas Separation Unit And A Method For Solving The Problem, Shakhzod Nurmuhammadovich Amirov Mr, Erkin Xxx Uljayev

Technical science and innovation

The article examines and analyzs patents, published scientific works, and currently used scientific and practical methods and devices for regulating the parameters of the low-temperature separation process in production. However, the conducted analysis showed that one of the main causes of hydrate formation in the device is the lack of continuous comprehensive control over parameters such as the pressure of the inhibitors supplied to the injectors at each stage and the moisture content of the total gas, i.e., the moisture content of the total gas at the system inlet, the gas temperature at the device outlet, and the pressure and …

Comparative Catalytic Pyrolysis Of Wheat Straw For Enhanced Bio-Oil Production, Nourhan H. Khashaba, Noura F. Abdelsalam, Hany A. Elazab, Mamdouh A. Gadalla, Thokozani Majozi, Fatma H. Ashour

Chemical and Biochemical Engineering Faculty Research & Creative Works

Catalytic fast pyrolysis of lignocellulosic biomass is a promising thermochemical route for producing renewable biofuels and value-added chemicals. Many African countries have abundant underutilized agricultural residues whose reuse can improve waste management while reducing reliance on fossil fuels. This study used wheat straw as a representative residue to examine how two catalysts—zinc oxide (ZnO) and cement kiln dust (CKD)—affect bio-oil yield and quality. Bench-scale experiments were performed in a fixed-bed reactor under an inert nitrogen atmosphere at 500–600 °C. Each catalyst was tested separately at loadings from 0 to 7 g per 500 g of biomass to evaluate impacts on …

Veribrief: A Multi-Agent Retrieval-Augmented Generation System For Policy Decision Support, Imane Bahji

Electrical and Computer Engineering ETDs

VeriBrief is a multi-agent retrieval-augmented generation (RAG) system for evidence-grounded economic policy analysis. The system orchestrates a five-stage LangGraph pipeline, retrieval, research, analysis, synthesis, and critique, to produce cited, structured responses while detecting out-of-scope queries. An empirical evaluation on eight questions drawn from official U.S. macroeconomic releases compared VeriBrief against a single-pass RAG baseline. The multi-agent system achieved 100% refusal precision on unanswerable analytical queries versus 0% for the baseline. Unsupported claims fell substantially on answerable factual questions. A context-propagation defect discovered during evaluation was diagnosed and corrected. Limitations include failure of the evidence gate on policy-counterfactual queries and a …

Robust Generator Maintenance Schedule For Frequency-Secure Power Systems, Yang Yang, Qiuzhuang Sun, Jimmy Chih-Hsien Peng, Loon Ching Tang, Zhisheng Ye

Research Collection College of Integrative Studies

Problem definition: Normal operations of a power system require that alternating current frequency be maintained at a nominal value, for example, 50 Hz, whereas severe deviation from this value due to power deficiencies can cause cascading generator trips. Maintaining the frequency requires adequate inertia and frequency regulation reserve, which are primarily provided by online generators. In daily operations, generators due for preventive maintenance must be taken offline, and thus an improper maintenance schedule could jeopardize frequency security, as exemplified by the recent Texas power blackout. However, this natural nexus between frequency security and maintenance has been over-looked largely in the …