Chemical Engineering Commons^™

Biocrude From Organic Waste And Its Conversion To Hard Carbon: Experimental And Modeling Study, Isamu Umeda

Civil & Environmental Engineering Theses & Dissertations

This study establishes a technical and theoretical foundation for the efficient conversion of organic waste into biocrude and high-value carbon materials, aiming to facilitate the industrialization of hydrothermal and solvothermal liquefaction. The dissertation research is structured as follows:

Chapter 2 developed a novel chemical kinetic model for the HTL of corn stover based on elemental balances (C, H, N, and O). By incorporating temperature, residence time, solid loading as an independent variable, the model successfully predicted product yields and properties, revealing that there was non-pseudo-first-order reaction pathways in the conversion of water soluble organics in aqueous phase (AP) to hydrochar. …

Ion-Imprinted Polymer-Based Sensors For Toxic Metal-Ion Detection In Water: Coordination Chemistry, Transduction Strategies, And Environmental Applications, Ghita Yammouri, Gymama Slaughter

Center for Bioelectronics Publications

Toxic metal contamination in aquatic environments remains a persistent threat to human health and ecosystems. Yet, the high cost, infrastructure demands, and centralized nature of conventional analytical methods constrain routine monitoring. Ion-imprinted polymers (IIPs), a subclass of molecularly imprinted polymers, have emerged as promising synthetic recognition materials for metal-ion sensing because they generate coordination-defined binding sites with high selectivity, chemical stability, low cost, and reusability. This review summarizes recent advances in Ion-imprinted polymer (IIP)-based sensing technologies for toxic metal-ion detection in water from 2016 to 2026. It examines the fundamental recognition chemistry of IIPs, major synthesis strategies used to generate …

Selective Lithium Extraction Using Ion-Sieves From Geothermal Brine, Agyare Asante, Abigail Berardi, Jayla Standin, Elliott Walker, Ujjwal Pokharel, Sandeep Kumar

Graduate Student Government Association Research Conference

Lithium (Li) is a critical component in modern green energy technologies, serving as the cornerstone for advanced batteries used in electric vehicles, renewable energy storage, and portable electronics. To address the increasing global demand for lithium, this study explores the synthesis and performance of ion-sieve novel adsorbents derived from the spinel-type precursor Li₄Mn_4.5Zr_0.5O₁₂ (LMZO). The precursor was produced using an economical solid-phase reaction that involved lithium, manganese, magnesium, and zirconium salts. This was followed by a two-stage calcination process involving 200 K for 2 hours and 450 K for 24 hours. Acid activation …

Polymorphism And Mechanical Behavior In Hot-Pressed 3d-Printed Polyamide Composite: Effects Of Pressure And Temperature, John Barber, Patricia Revolinsky, Jimesh Bhagatji, Diego Pedrazzoli, Sergii Kravchenko, Oleksandr Kravchenko

Mechanical & Aerospace Engineering Faculty Publications

The aim of this work is to study the effect of high-temperature compaction (HTC) upon the polymorphism and the mechanical behavior of an additively manufactured (AM) carbon fiber-reinforced polyamide (PA6). Different pressure and temperature levels during HTC were tested to determine the overall effect on the mechanical behavior and material crystalline composition. Treated, carbon fiber-reinforced PA6 samples were analyzed using differential scanning calorimetry, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and three-point bending testing. When considered with respect to as-printed samples, an HTC temperature of 190 °C combined with 80 psi pressure resulted in an increased flexural modulus and strength …

A Comprehensive Review Of Piezoelectric Pvdf Polymer Fabrications And Characteristics, Nadia Ahbab, Sidra Naz, Tian-Bing Xu, Shihai Zhang

Mechanical & Aerospace Engineering Faculty Publications

Polyvinylidene fluoride (PVDF) polymer films, renowned for their exceptional piezoelectric, pyroelectric, and ferroelectric properties, offer a versatile platform for the development of cutting-edge micro-scale functional devices, enabling innovative applications ranging from energy harvesting and sensing to medical diagnostics and actuation. This paper presents an in-depth review of the material properties, fabrication methodologies, and characterization of PVDF films. Initially, a comprehensive description of the physical, mechanical, chemical, thermal, electrical, and electromechanical properties is provided. The unique combination of piezoelectric, pyroelectric, and ferroelectric properties, coupled with its excellent chemical resistance and mechanical strength, makes PVDF a highly valuable material for a wide …

Electrical Homeostasis Of The Inner Mitochondrial Membrane Potential, Peyman Fahimi, Lázaro A. M. Castanedo, P. Thomas Vernier, Cherif F. Matta

Bioelectrics Publications

The electric potential across the inner mitochondrial membrane must be maintained within certain bounds for the proper functioning of the cell. A feedback control mechanism for the homeostasis of this membrane potential is proposed whereby an increase in the electric field decreases the rate-limiting steps of the electron transport chain (ETC). An increase in trans-membrane electric field limits the rate of proton pumping to the inter-membrane gap by slowing the ETC reactions and by intrinsically induced electroporation that depolarizes the inner membrane. The proposed feedback mechanism is akin to a Le Chatelier's-type principle of trans-membrane potential feedback control.

Metathesis Or Isomerization: Counteranion Directed Reactivity Of Grubbs I, Paul D. Miller, Joe B. Calkins, Craig A. Bayse, Trandon A. Bender

Chemistry & Biochemistry Faculty Publications

Catalytic isomerization of alkenes has garnered interest for many years, but there are remaining challenges when it comes to thermodynamic selectivity and uncontrolled isomerization. Nonbiased substrates, be it sterically or thermodynamically, remain challenging for many catalysts, with a few examples available in the more modern literature. Herein, we present the controlled isomerization of linear alkenes with a cocatalytic mixture of commercially available catalyst and reagents: Grubbs I, tris(pentafluorophenyl)borane, and triethylsilane. DFT calculations indicate that an observed alkylidyne hydride intermediate is in rapid equilibrium with an alkylidene that binds the alkene substrate. This combination results in a pi-acidic metal and a …

Flipped Classroom Techniques In A Thermodynamics Course In Engineering Technology, Nathan Luetke, Orlando Ayala, Vukica Jovanovic

Engineering Technology Faculty Publications

Teaching undergraduate thermodynamics presents numerous challenges to educators due to its inherently complex and abstract nature. The vast array of applications in engineering requires educators to strike a balance between theoretical principles and practical examples, thereby creating a meaningful and applicable learning experience. This paper presents an approach to teaching an undergraduate thermodynamics course in engineering technology developed over four consecutive semesters blending traditional lecture-based teaching with flipped classroom techniques. The teaching methods used, and modifications made each semester are presented along with student performance.

Pla Polymer Binder In Core Production - Influence On Final Casting Dimensions, Artur Soroczyński, Krzysztof Rechowicz

Virginia Digital Maritime Center (VDMC) Faculty Publications

The foundry industry is seeking an ecological alternative to synthetic molding resins. This study evaluates the technological properties of core sands bonded with biodegradable polylactide (PLA). Cores prepared on a 2% quartz sand matrix were subjected to casting processes using two alloys with extremely different pouring temperatures: gray cast iron (approx. 1200 °C) and AK11 silumin (approx. 710 °C). The research methodology included macroscopic assessment, dimensional analysis using 3D scanning (GOM Inspect), and qualitative knock-out assessment supported by numerical temperature field simulation. The results showed that the high crystallization temperature of cast iron leads to complete thermal degradation of the …

Investigations Of Conjugate Heat Transfer And Fluid Flow In Partitioned Porous Cavity Using Darcy-Forchheimer Model: Finite Element-Based Computations, Nasir Yasin, Shafee Ahmad, Muhammad Umair, Zahir Shah, Narcisa Vrinceanu, Ghadah Alhawael

Mathematics & Statistics Faculty Publications

The conjugate heat transfer and fluid flow has vast applications in thermal engineering, particularly for cooling in thermal devices, and automobile engines. This study investigates conjugate heat transfer in 2D enclosures, featuring thin solid fins attached to a porous bottom wall. The porous medium is considered isotropic and homogeneous by the Darcy-Forchheimer model, with fluid phases in local thermal equilibrium. The boundary conditions at the porous fluid interface ensure continuity of the velocities, stresses, temperature, and heat flux. The phenomenon is mathematically modelled by obtaining a set of partial differential equations. The finite element method (FEM) is used to perform …

Incorporating Insulin Into Alginate-Chitosan 3d-Printed Scaffolds: A Comprehensive Study On Structure, Mechanics, And Biocompatibility For Cartilage Tissue Engineering, Afsaneh Jahani, Mohammad Sagdegh Nourbakhsh, Ali Moradi, Marzieh Mohammadi, Lobat Tayebi

Electrical & Computer Engineering Faculty Publications

Osteoarthritis is a leading cause of disability worldwide, challenging current treatments to limited cartilage self-healing capacity. Cartilage tissue engineering (CTE) integrates cells, scaffolds, and signaling molecules, with Insulin being utilized as a differentiation biomolecule due to cost-effectiveness, dose-dependent influence on chondrogenesis, suitable biological activity, and ability to activate relevant receptors. Yet, administering differentiation biomolecules through conventional scaffolds poses a persistent challenge. Alginate (Alg) is commonly employed in CTE for its biocompatibility, though it lacks sufficient mechanical properties. Chitosan (Cs), while enhancing scaffold mechanical properties, but does not independently provide optimal support for chondrogenesis. While Alg-Cs scaffolds have garnered attention, challenges …

Quasi-Static And Impact Load Response Of Bfrp-Reinforced Concrete Beams And Post-Terrorist-Attack Sub-Assemblages, José Luis Carrasquillo

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of a theoretical and experimental study of Basalt Fiber Reinforced Polymer (BFRP) reinforced concrete beams and post-terrorist-attack subassemblages subjected to either quasi-static or impact load. Both BFRP reinforcement as well as BFRP fabric are used in this investigation. The sub-assemblage consists of an otherwise two-span beam converted to a fixed-end single-span one owing to the loss of a middle column blasted off during the terrorist attack. The simply supported beams are subjected to a midspan quasistatic or an impact load. However, each sub-assemblage is subjected to a quasi-static load up to collapse to simulate the …

Thermo-Elasto-Plastic Stability Of Biaxially Loaded Hollow Rectangular Section Steel Beam-Columns With Applied Torsion, George Adomako Kumi

Civil & Environmental Engineering Theses & Dissertations

Presented herein is an experimental and theoretical study of biaxially loaded hollow rectangular section steel beam-columns with applied torsion at elevated temperatures. The theoretical analysis is based on a system of simultaneous materially nonlinear differential equations of equilibrium for which an iterative semi-analytic solution approach is formulated. Although the primary goal of this research is to study the influence of elevated temperatures on the steel member with the complex loading, rigorous analysis is also conducted of the member at ambient temperature for comparison. The experimental part of the study involves conducting tests on the members at both ambient and high …

Triphlapan: Predicting Hla Molecules Binding Peptides Based On Triple Coding Matrix And Transfer Learning, Meng Wang, Chuqi Lei, Jianxin Wang, Yaohang Li, Min Li

Computer Science Faculty Publications

Human leukocyte antigen (HLA) recognizes foreign threats and triggers immune responses by presenting peptides to T cells. Computationally modeling the binding patterns between peptide and HLA is very important for the development of tumor vaccines. However, it is still a big challenge to accurately predict HLA molecules binding peptides. In this paper, we develop a new model TripHLApan for predicting HLA molecules binding peptides by integrating triple coding matrix, BiGRU + Attention models, and transfer learning strategy. We have found the main interaction site regions between HLA molecules and peptides, as well as the correlation between HLA encoding and binding …

Type-B Energetic Processes: Introduction And Invitation To Special Issue Of Energies, James Weifu Lee, Daniel P. Sheehan

Chemistry & Biochemistry Faculty Publications

[First paragraph] Currently, there is substantial scientific evidence for the existence of Type-B energetic processes on Earth, such as the naturally occurring transmembrane-electrostatically localized protons (TELP) thermotrophic properties in life [1]. A number of groundbreaking human-made Type-B energetic processes, including (but not limited to) “asymmetric function-gated isothermal electricity production” [2], “epicatalysis generating a temperature difference between catalysis-asymmetric filaments” [3], “artificially made asymmetric membrane concentration cell” [4,5], “Fu’s experiment on heat–electric conversion using surface electron emission under a static magnetic field” [6], and the “dynamic processes in superconductors indicating Type-B energetic process” [7,8,9] have been invented and/or experimentally demonstrated. The innovative …

Synthetic Approaches Of Carbohydrate Based Self-Assembling Systems, Guijun Wang, Anji Chen, Pramod Aryal, Jonathan Bietsch

Chemistry & Biochemistry Faculty Publications

Carbohydrate-based self-assembling systems are essential for the formation of advanced biocompatible materials via a bottom-up approach. The self-assembling of sugar-based small molecules has applications encompassing many research fields and has been studied extensively. In this focused review, we will discuss the synthetic approaches for carbohydrate-based self-assembling (SA) systems, the mechanisms of the assembly, as well as the main properties and applications. This review will mainly cover recent publications in the last four years from January 2020 to December 2023. We will essentially focus on small molecule self-assembly, excluding polymer-based systems, which include various derivatives of monosaccharides, disaccharides, and oligosaccharides. Glycolipids, …

Role Of Nitrogenous Functional Group Identity In Accelerating 1,2,3- Trichloropropane Degradation By Pyrogenic Carbonaceous Matter (Pcm) And Sulfide Using Pcm-Like Polymers, Han Cao, Jingdong Mao, Paul G. Tratnyek, Wenqing Xu

Chemistry & Biochemistry Faculty Publications

Groundwater contamination by 1,2,3-trichloropropane (TCP) poses a unique challenge due to its human toxicity and recalcitrance to degradation. Previous work suggests that nitrogenous functional groups of pyrogenic carbonaceous matter (PCM), such as biochar, are important in accelerating contaminant dechlorination by sulfide. However, the reaction mechanism is unclear due, in part, to PCM's structural complexity. Herein, PCM-like polymers (PLPs) with controlled placement of nitrogenous functional groups [i.e., quaternary ammonium (QA), pyridine, and pyridinium cations (py⁺)] were employed as model systems to investigate PCM-enhanced TCP degradation by sulfide. Our results suggest that both PLP-QA and PLP-py⁺ were highly effective …

Type-B Energetic Processes: Their Identification And Implications, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

We have now identified two thermodynamically distinct types (A and B) of energetic processes naturally occurring on Earth. Type-A energy processes, such as classical heat engines, apparently well follow the second law of thermodynamics; Type-B energy processes, such as the newly discovered thermotrophic function that isothermally utilizes environmental heat energy to perform useful work in driving ATP synthesis, follow the first law of thermodynamics (conservation of mass and energy) but do not have to be constrained by the second law, owing to their special asymmetric functions. Several Type-B energy processes such as asymmetric function-gated isothermal electricity production and epicatalysis have …

Effects Of Electron Beam Irradiation On Crmnv And Crmntiv High Entropy Alloys: Nano-Mechanical, Structural, And Thermodynamic Perspectives, N. A. Sultana, Y. S. Mohammed, S. J. Pendleton, J. Vennekate, G. Ciovati, X. Li, H. Baumgart, A. A. Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

Beam exit windows are crucial components of any particle accelerator as they provide an interface between the beamline vacuum and target material at atmospheric media. For high beam power machines, special materials and designs are required to withstand high radiation and mechanical loads, while minimizing energy loss during transition and maximizing window lifetime. This research investigates the impact of electron beam exposure to bulk CrMnV and CrMnTiV high entropy alloys (HEAs) with the primary goal of identifying suitable candidate materials for the design of robust and durable exit window settings. The selection criteria include intrinsic characteristics, power dissipation, and mechanical …

Parametrization Of Fluid Models For Electrical Breakdown Of Nitrogen At Atmospheric Pressure, Shirshak K. Dhali

Electrical & Computer Engineering Faculty Publications

In the transient phase of an atmospheric pressure discharge, the avalanche turns into a streamer discharge with time. Hydrodynamic fluid models are frequently used to describe the formation and propagation of streamers, where charge particle transport is dominated by the creation of space charge. The required electron transport data and rate coefficients for the fluid model are parameterized using the local mean energy approximation (LMEA) and the local field approximation (LFA). In atmospheric pressure applications, the excited species produced in the electrical discharge determine the subsequent conversion chemistry. We performed the fluid model simulation of streamers in nitrogen gas at …

Fugacity-Based Lattice Boltzmann Method For Multicomponent Multiphase Systems, Muzammil Soomro, Luis F. Ayala, Cheng Peng, Orlando M. Ayala

Engineering Technology Faculty Publications

The free-energy model can extend the lattice Boltzmann method to multiphase systems. However, there is a lack of models capable of simulating multicomponent multiphase fluids with partial miscibility. In addition, existing models cannot be generalized to honor thermodynamic information provided by any multicomponent equation of state of choice. In this paper, we introduce a free-energy lattice Boltzmann model where the forcing term is determined by the fugacity of the species, the thermodynamic property that connects species partial pressure to chemical potential calculations. By doing so, we are able to carry out multicomponent multiphase simulations of partially miscible fluids and generalize …

Outstanding Advantages, Current Drawbacks, And Significant Recent Developments In Mechanochemistry: A Perspective View, Silvina Pagola

Chemistry & Biochemistry Faculty Publications

Although known since antiquity, mechanochemistry has remained dormant for centuries. Nowadays, mechanochemistry is a flourishing research field at the simultaneous stages of gathering data and (often astonishing) observations, and scientific argumentation toward their analysis, for which the combination of interdisciplinary expertise is necessary. Mechanochemistry’s implementation as a synthetic method is constantly increasing, although it remains far from being fully exploited, or understood on the basis of fundamental principles. This review starts by describing many remarkable advantages of mechanochemical reactions, simplifying and “greening” chemistry in solutions. This description is followed by an overview of the current main weaknesses to be addressed …

More On The Demons Of Thermodynamics, Daniel P. Sheehan, Garret Moddel, James W. Lee

Chemistry & Biochemistry Faculty Publications

No abstract provided.

Design, Synthesis And Characterization Of Triazole Based Glycoconjugates And 4,6-Acetal Protected D-Glucosamine Derivatives As Low Molecular Weight Gelators, Pooja Sharma

Chemistry & Biochemistry Theses & Dissertations

Low molecular weight gelators (LMWGs) are small molecules that can form gels in either organic solvents or water in their pure form or as mixtures. LMWGs self-assemble through noncovalent interactions such as hydrogen bonding, halogen bonding, van der Waals interactions and hydrophobic forces in solvents. They have shown great potential in biomedical industry, catalysis and environmental remediation to name a few. Moreover, the formation of metallogels can be used for detection of various ions as well as catalysis, which adds a new dimension to their applications. Among many classes of LMWGs based on the type of functional groups used, carbohydrate …

Fabrication Of Nb3Sn By Magnetron Sputtering For Superconducting Radiofrequency Application, Md Nizam Sayeed

Electrical & Computer Engineering Theses & Dissertations

Particle accelerators are considered as an important device that has wide applications in cancer treatment, sterilizing waste, preserving foods, ion implantation in semiconductor industry, and in production of isotopes for medical applications. Superconducting radiofrequency (SRF) cavities are the building blocks of a linear particle accelerator. Current particle accelerators use niobium (Nb) superconductors as the sheet material to fabricate a single SRF cavity for particle acceleration. With better superconducting properties (critical temperature T_c ~ 18.3 K, superheating field H_sh~ 400 mT), Nb₃Sn is considered a potential candidate in SRF technology. Magnetron sputtering is a promising deposition …

Development Of High Quantum Efficiency Strained Superlattice Spin Polarized Photocathodes Via Metal Organic Chemical Vapor Deposition, Benjamin Belfore

Electrical & Computer Engineering Theses & Dissertations

Spin polarized photocathodes are necessary to examine parity violations and other fundamental phenomena in the field of high energy physics. To create these devices, expensive and complicated growth processes are necessary. While integral to accelerator physics, spin polarized electrons could have other exciting applications in materials science and other fields of physics. In order to explore these other applications feasibly, the relative supply of spin polarized photocathodes with a high rate of both polarization and photoemission needs to be increased. One such way to increase this supply is to develop the means to grow them faster and at a larger …

4,6-O-Phenylethylidene Acetal Protected D-Glucosamine Carbamate-Based Gelators And Their Applications For Multi-Component Gels, Pooja Sharma, Guijun Wang

Chemistry & Biochemistry Faculty Publications

The self-assembly of carbohydrate-based low molecular weight gelators has led to useful advanced soft materials. The interactions of the gelators with various cations and anions are important in creating novel molecular architectures and expanding the scope of the small molecular gelators. In this study, a series of thirteen new C-2 carbamates of the 4,6-O-phenylethylidene acetalprotected D-glucosamine derivatives has been synthesized and characterized. These compounds are rationally designed from a common sugar template. All carbamates synthesized were found to be efficient gelators and three compounds are also hydrogelators. The resulting gels were characterized using optical microscopy, atomic force microscopy, …

A Local Mode Study Of Ring Puckering Effects In The Infrared Spectra Of Cyclopentane, Edwin L. Sibert Iii, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

We report and interpret recently recorded high-resolution infrared spectra for the fundamentals of the CH₂ scissors and CH stretches of gas phase cyclopentane at −26.1 and −50 ^○C, respectively. We extend previous theoretical studies of this molecule, which is known to undergo barrierless pseudorotation due to ring puckering, by constructing local mode Hamiltonians of the stretching and scissor vibrations for which the frequencies, couplings, and linear dipoles are calculated as functions of the pseudorotation angle using B3LYP/6-311++(d,p) and MP2/cc-pVTZ levels of theory. Symmetrization (D_5h) of the vibrational basis sets leads to simple vibration/pseudorotation Hamiltonians whose solutions …

Recent Advancements In Electrochemical Conversion Of Carbon Dioxide, Nandan Nag, Amit Kumar, Sumit Sharma, Sandeep Kumar, Amit K. Thakur

Civil & Environmental Engineering Faculty Publications

Electrochemical reduction of carbon dioxide into eco-friendly and clean products is a promising approach to eradicate pollution. Although carbon dioxide emission is inhibited by the advent of renewable sources of energy, it is present in the atmosphere and needs to be cleaned. The reduction of carbon dioxide from atmospheric gases can be accomplished by its adsorption and subsequent transportation to electrolytic chambers, where it is reduced to hydrocarbons, organic acids or carbonates. This review focuses on developing a three compartment electrochemical cell to reduce carbon dioxide used as a catholyte. Various factors affecting the electrochemical reduction of carbon dioxide and …

Reducing Print Time While Minimizing Loss In Mechanical Properties In Consumer Fdm Parts, Long Le, Mitchel A. Rabsatt, Hamid Eisazadeh, Mona Torabizadeh

Mechanical & Aerospace Engineering Faculty Publications

Fused deposition modeling (FDM), one of various additive manufacturing (AM) technologies, offers a useful and accessible tool for prototyping and manufacturing small volume functional parts. Polylactic acid (PLA) is among the commonly used materials for this process. This study explores the mechanical properties and print time of additively manufactured PLA with consideration to various process parameters. The objective of this study is to optimize the process parameters for the fastest print time possible while minimizing the loss in ultimate strength. Design of experiments (DOE) was employed using a split-plot design with five factors. Analysis of variance (ANOVA) was employed to …