Engineering Commons^™

A Fuzzy Based Framework For Sustainable Technology Selection In Small-Scale Gold Mining Operations, John M. Kafuku

Tanzania Journal of Engineering and Technology (TJET)

Small-scale gold mining (SSGM) operations in Tanzania has been operating inefficiently due to inadequate mining processing technologies, poor working tools, lack of enough capital, and insufficient electricity. Despite the efforts made by different stakeholders in boosting the sustainability of SSGM yet the sector has not reached the expected goal. This paper proposes a framework for appropriate technology selection to help small scale gold miners in evaluating various gold mineral processing technologies. The framework utilizes the fuzzy logic set theory for technology evaluation and selection. The developed framework for technology selection upon validation provided results that technology adequacy of more than …

Dust Analyses In Ventilation Ducts, Karolina Vyhlidalova, Petr Vlček, Olga Rubinová, Jiří Bernard

Journal of Sustainable Construction Materials and Technologies

The paper describes the importance of monitoring the dust in the atmosphere of human life. It deals with the issue of dust in air ducts, approaching the methods that can be used to detect the amount of dust. For conditions for buildings in the Czech Republic there is created the methodology of quantitative and qualitative evaluation of dust sediment for the needs of HVAC and other building surfaces. The scale for visual evaluation was created and it has been elaborated the assessment of kind of particles contained in dust.

Assessment Of Long Time Approximation Equation To Determine Thermal Conductivity Of High Porous Materials With Nss Probe, Hussein Humaish, Bastien Ruet, Laurent Marmoret, Hassen Beji

Journal of Sustainable Construction Materials and Technologies

Recent economic changes have increased the focus on energy conservation in buildings. Improve insulation represents one of the biggest challenge to save energy. The TP02 Huksefux® Non Steady State Probe (NSSP) has been used to determine the thermal conductivity of the building insulation materials. Usually, the long term approximation equation (linear form) is applied to determine the thermal conductivity when using hot wire techniques. Long term approximation has been successfully used to characterize glycerol: a fluid which doesn’t present contact resistance and porosity. But, an S-shaped appears for more porous materials. So to generalize the possibility of using this method, …

Variation Of Membrane Electrode Assembly Catalyst Layer In Unitized Regenerative Fuel Cell, Yollanda Nurcholifah, Dedi Rohendi, Edy Herianto Majlan, Nirwan Syarif, Addy Rachmat, Dwi Hawa Yulianti, Nyimas Febrika S

Journal of Electrochemistry

A unitized regenerative fuel cell (URFC) is a device that may function reversibly as either a fuel cell (FC) or water electrolysis (WE). An important component of this device is the Membrane electrode assembly (MEA). Therefore, this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers. This study measured Electrochemical Surface Area (ECSA), Electrochemical Impedance Spectroscopy (EIS), X-ray Diffraction analysis (XRD), and X-ray Fluorescence (XRF). Furthermore, the round-trip efficiency (RTE) of the MEA, as well as the performance in FC and WE mode, was measured. In comparison, The ECSA values of Pt-Ru/C …

Integrating Environmental Analyses And Awareness To The Senior Chemical Plant Design Course Che 4233, Lucie I. Leblanc

Honors Theses

The EPA has implemented and increased environmental regulations and safeguards for carbon dioxide (CO2) and volatile organic compound (VOC) emissions for the past 70 years. These regulations have affected the technology and methodology used in industrial chemical production processes. As newly graduated engineers enter the work field, they will encounter current and future EPA regulations, and they will have to adjust their production units to meet these safeguards. This report loosely follows the structure of the Plant Design Course (CHE 4233) to show the process of designing a conventional cumene production plant. The conventional process is compared to a new …

Electrocatalytic Nitric Oxide Reduction To Yield Ammonia Over Fe3C Nanocrystals, Sen Lin, Lang Zhang, Tong Hou, Jun-Yang Ding, Zi-Mo Peng, Yi-Fan Liu, Xi-Jun Liu

Journal of Electrochemistry

Nitric oxide (NO), which generally originates from vehicle exhaust and industrial flue gases, is one of the most serious air pollutants. In this case, the electrochemical NO reduction reaction (NORR) not only removes the atmospheric pollutant NO but also produces valuable NH₃. Hence, through the synthesis and modification of Fe₃C nanocrystal catalysts, the as-obtained optimal sample of Fe₃C/C-900 was adopted as NORR catalyst at ambient conditions. As a result, the Fe₃C/C-900 catalyst showed an NH₃ Faraday efficiency of 76.5% and an NH₃ yield rate of 177.5 μmol·h^–1·cm^{–2 …}

Ordering Degree Regulation Of Pt2Nico Intermetallics For Efficient Oxygen Reduction Reaction, Chen-Hao Zhang, Han-Yu Hua, Jun-Hao Yang, Qian Zhang, Chang Yang, De-Li Wang

Journal of Electrochemistry

Alloying transition metals with Pt is an effective strategy for optimizing Pt-based catalysts toward the oxygen reduction reaction (ORR). Atomic ordered intermetallic compounds (IMC) provide unique electronic and geometrical effects as well as stronger intermetallic interactions due to the ordered arrangement of metal atoms, thus exhibiting superior electrocatalytic activity and durability. However, quantitatively analyzing the ordering degree of IMC and exploring the correlation between the ordering degree and ORR activity remains extremely challenging. Herein, a series of ternary Pt₂NiCo intermetallic catalysts (o-Pt₂NiCo) with different ordering degree were synthesized by annealing temperature modulation. Among them, the o-Pt …

Performance Of Co2/H2O Co-Electrolysis In A Flat-Tube Solid Oxide Electrolysis Cell Stack Under Air-Free Environment, Xiao-Hui Zhong, Fei Wang, An-Qi Wu, Bei-Bei Han, Jian-Xin Wang, Wan-Bing Guan

Journal of Electrochemistry

This work investigates the transient performance and stability of CO₂/H₂O co-electrolysis in an air-free environment using a flat-tube solid oxide electrolysis cell (SOEC) stack. The results show that the transient behavior of the stack with and without blowing gas in the air electrode is almost the same. With a current density of 0.67 A·cm⁻²@750 °C, the stack operated for over 200 h under co-electrolysis conditions with no air blowing, and the voltage drop rate of the stack was approximately 0.203%/100 hours. Microstructure analysis reveals significant loss of Ni particles and formation of an insulating …

Small-Scale Production Of Bespoke Accelerated Aging Plutonium Alloy, K. S. Holliday, A. M. Parkes, Devin Rappleye, D. J. Roberts, K. J. Kondrat, S. A. Simpson, A. J. Swift, U. Mehta, R. M. Kissinger, D. L. Rosas, L. S. Ripplinger, E. R. Tardiff, S. L. Harris, S. Perkins, C. Hawkins, N. J. Gibbs, R. J. P. Driscoll, A. T. Sidambe, R. A. Cole, T. T. Roehling, J R. Jeffries

Faculty Publications

This study demonstrates the 100 g scale manufacture of a plutonium alloy that ages at an accelerated rate. The resulting alloy ages six times faster than typical weapons-grade plutonium due to the addition of ²³⁸Pu. As a major innovation, the process involved using a partial direct oxide reduction technique. This method was achieved by developing a new, complex geometry stirrer using additive manufacturing to reduce the ²³⁸Pu oxide and efficiently incorporate it into weapons-grade plutonium metal. The material was then purified by molten salt extraction and electrorefining before being alloyed with gallium. The alloy was then cold-rolled and …

Methods For Rotating Electrodes In High-Temperature Molten Salts, Ranon Fuller, Eloise Cluff, Edward Mercado, Carlos Mejia, Devin Rappleye

Faculty Publications

In this paper, we describe and validate a custom apparatus for performing high-speed (250-3,500 rpm) rotating electrode and dilatometer density experiments in molten salts. The reported details can aid in decreasing the difficulty and increasing the quality of such experiments. We discuss the design challenges and the solutions identified. We investigate methods for accurately measuring the solution resistance using electrochemical impedance spectroscopy (EIS), calculating the working electrode area using cyclic voltammetry (CV), and measuring the mass transfer-limited current of rotating electrodes using a series of chronoamperometry (CA) pulses. We further demonstrate the efficacy of our methods in producing accurate results.

Porous Hierarchically Ordered Hydrogels Demonstrating Structurally Dependent Mechanical Properties, Elisabeth C. Lloyd, Sujata Dhakal, Shahrouz Amini, Rami Alhasan, Peter Fratzl, Douglas R. Tree, Svetlana Morozova, Robert J. Hickey

Faculty Publications

While hierarchical ordering is a distinctive feature of natural tissues and is directly responsible for their diverse and unique properties, efforts to synthesize biomaterials have primarily focused on using molecular-based approaches with little emphasis on multiscale structure. Here, we report a bottom-up self-assembly process to produce highly porous hydrogel fibers that resemble extracellular matrices both structurally and mechanically. Physically crosslinked nanostructured micelles form the walls of micrometer-sized water-rich pores with preferred orientation along the fiber direction. Low elastic moduli (< 1 kPa), high elasticity (extending by more than 12 times the initial length), non-linear elasticity (e.g., hyperelasticity), and completely reversible extension are derived from unevenly distributed strain between the micrometer-sized pores and the polymer chains, which is reminiscent of cellular solids. Control of the material microstructure and orientation over many orders of magnitude (e.g., nm–μm), while holding the nanostructure constant, reveals how the multiscale structure directly impacts mechanical properties.

Effect Of Precursors On Trimetallic Ruthenium-Based Catalysts Supported On Γ‑Al2O3 Pellets For Low-Temperature Ammonia Decomposition, Christopher J. Koch, Jennifer Naglic, Logan Kearney, Daniel Clairmonte, Binod Rai, Jochen A. Lauterbach, Lucas M. Angelette, Tyler Guin

Faculty Publications

Ammonia is a promising candidate as a liquid hydrogen energy storage medium, but it requires catalytic decomposition (ammonia cracking) to regenerate hydrogen. Recently developed trimetallic ruthenium−potassium-promoter (RuKM) ammonia decomposition catalysts have exceptionally low ammonia decomposition temperatures, able to perform the decomposition as low as 250 °C, which is significantly lower than other known catalysts that require temperatures above 500 °C. However, the effects of the RuKM precursor on the catalytic activity have not been investigated. We report the observed differences of 3% ruthenium/12% potassium/1% yttrium (RuKY) catalysts on γ-alumina synthesized from chloride-, nitrate-, and acetate-based precursors. Catalysts synthesized from chloride-based …

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 …

Continuous Purification Of A Parvovirus Using Two Aqueous Two-Phase Extraction Steps, Natalie Nold, Sheridan Waldack, Grace James, Trisha Colling, Lynn M. Manchester, Taravat Sarvari, Amanda P. Bekkala, Seth Kriz, Madison Baldwin, Emily Agustin-Mazariegos, Michael J. Betenbaugh, Caryn Heldt

Michigan Tech Publications

Aqueous two-phase systems (ATPS) are a liquid–liquid extraction method that offers low-cost, continuous-adaptable virus purification. A two-step ATPS using polyethylene glycol (PEG) and sodium citrate that recovered 66% of infectious porcine parvovirus with 2.0 logs of protein removal and 1.0 logs of DNA removal in batch has now been run continuously. The continuous system output of < 10 ng/mL DNA regardless of starting DNA titer agreed with batch studies. However, the continuous system had a five-fold higher contaminating protein titer than batch studies, likely because of incomplete mixing or settling. Turbidity was tested as a measure of mixing and settling efficiency. Monitoring in-line absorbance at 880 nm directly after mixing and before collection in the settling reservoir could track both mixing and settling during operation. Settling time was reduced by changing the settling line material from PVC to PTFE, which is more hydrophobic. A flow-through AEX filter tested to make impurity removal more robust recovered 90% of PPV and removed an additional 87% of host cell DNA. The filter did not add any additional protein removal. In the future, in-line absorbance sensors could be implemented along with conductivity sensors to measure salt concentration, refractive index sensors to track the PEG-citrate interface, and scales to track mixer and reservoir volumes to enable automated, continuous ATPS. Our vision is to integrate continuous ATPS into a fully continuous end-to-end production for viral vectors.

Modular Molecular Design Of Polymerized Pro-Estrogen Materials Enables Controlled Astrocyte Response, Devan L. Puhl, Alexis Ziemba, Samuel A.T. Ellman, Alex Hsu, Jayant Saksena, Penelope Phillips Falcone, Bailey Balouch, Deniz Rende, Tanner Fink, R. Helen Zha, Ryan J. Gilbert, Edmund F. Palermo

Chemical and Biochemical Engineering Faculty Research & Creative Works

The hormone 17β-estradiol (estrogen or "E2") has demonstrated robust neuroprotective properties in countering oxidative stress-induced neurotoxicity, as well as strong neurotrophic properties to promote axonal growth, following injury to the central nervous system (CNS). However, oral or injected E2 is a suboptimal drug, as systemic administration fails to achieve a therapeutic dose at the injury site, in addition to being contraindicated in most male patients. Polymerized pro-drug biomaterials can mitigate these issues by locally releasing small quantities of drug over vastly extended timescales. We sought to study the effect of the biomaterial properties of poly(pro-E2) on astrocyte-surface interactions because astrocytes …

Evaluating The Potential For Reusing Process Waste Fiber, Elisha Ewing

Honors Theses

This study was born out of curiosity around the potential use of reject materials from the papermaking screening system for molded fiber product development. The team sought to explore the technical feasibility of this concept and develop a proposed design for mill implementation. The project supports the common papermaking objective of reducing fiber loss from the stock preparation process.

The project assessed first the technical feasibility through laboratory testing and trials. The team dedicated time to characterizing screen reject samples from local mills and running trials using the good fibers extracted from the samples. Molded fiber products were successfully created …

Nanostructured Transition Metal Oxides For Electrochemical Co2 And Methane Conversion, Olumide O. Oladoyin

Chemical and Biological Engineering ETDs

Rising atmospheric CO₂ and CH₄ drive climate change, prompting research into their electrochemical conversion to valuable products. This study investigates electrodeposited nanostructured transition metal oxides (TMOs), unary (CuO, Co₃O₄) and dual (Cu-Co oxide) as catalysts for CO₂ reduction and CH₄ oxidation under ambient conditions. Fabricated on various substrates (Cu foil, SS316, carbon paper) and characterized by SEM, their electrochemical performance was evaluated via cyclic voltammetry.

Cu-Co oxide showed superior CO₂ reduction, leveraging the strengths of individual oxides. Co₃O₄ exhibited higher current densities for CH₄ oxidation, with SS316 proving the best substrate. Catalyst composition, morphology, and substrate significantly influenced efficiency. While …

Analysis Of Pistachio Shell-Derived Activated Porous Carbon Materials For Hydrogen Adsorption, Setareh Elyasi, Nishar Hameed, Peter J. Mahon, Saulius Juodkazis, Alireza Keshavarz, Stefan Iglauer, Tawanda Matamba, J. Vongsvivut, Nisa V. Salim

Research outputs 2022 to 2026

Developing efficient storage materials is critical for advancing the hydrogen economy. In this study, we aim to utilize plant-based biomass as a sustainable source for fabricating porous carbon (PC) and subsequently employing it for hydrogen adsorption. For the first time, we synthesize highly porous carbon materials from pistachio shells as precursor materials for efficient hydrogen storage. Experiments were conducted to chemically activate pistachio shells using two different agents, sodium chloride (NaCl) and potassium chloride (KCl), at varying ratios. This study evaluates the effectiveness of these chemical activation agents in enhancing the surface area of PC and, consequently, its hydrogen adsorption …

Enhancing Oil Recovery With Novel Nano-Particle-Infused Surfactant Biopolymer Composite: A Comprehensive Investigation, Attia Attia, Amira Shafaay Dr., Michael Sami Alfonse Eng., George Azmi Eng., Rania Ramadan

Petroleum Engineering and Gas

The oil industry worldwide is searching for a new way to increase oil recovery. Chemical flooding has been used worldwide to improve oil recovery. In this research, the study of Enhanced Oil Recovery was carried out by using an Egyptian oil of API 42◦; the experiments were done by using Xanthan biopolymer (XG) gum with sodium dodecylbenzene sulfonate (SDBS) as a composite for the EOR process and studying the impact of different composite concentrations on oil recovery. Design Expert software was used to determine the optimum concentrations of the composite. 500 ppm concentration of graphene cobalt samarium ferrite nanoparticles (NP) …

Aerosol Technology For Carbon Capture And Utilization, Onochie Chinedum Okonkwo

McKelvey School of Engineering Graduate Student Theses & Dissertations

The CO2 concentration in the atmosphere has continued to increase over the past century and now poses an increasing potentially catastrophic effect to human life and the environment via global warming and the concomitant effect of climate change. Anthropogenic carbon dioxide emissions due to fossil fuel combustion for increasing energy demand is the main driver for the increased carbon dioxide in the atmosphere. A multifaceted approach including carbon dioxide capture and utilization is required to mitigate anthropogenic carbon dioxide emissions. Aerosol science and technology, an enabler for clean combustion technologies and nanomaterial synthesis, can contribute significantly to the advancement of …

Metabolite Analysis To Understand Factors Limiting Microbial Fermentation At High Substrate Concentrations, Bishal D. Sharma

Dartmouth College Ph.D Dissertations

Clostridium thermocellum, a thermophilic anaerobic bacterium, holds promise as a biocatalyst for conversion of lignocellulosic biomass into biofuels. This microbe has been subjected to various metabolic engineering strategies, including the deletion of genes encoding secondary fermentation products such as H₂, formate, acetate, and lactate, as well as the expression of heterologous genes to redirect carbon flux toward ethanol production. Despite these efforts, achieving economically viable ethanol titers remains a challenge. We hypothesized that studying how intracellular metabolite concentrations change as fermentation stops could reveal metabolic bottlenecks or regulatory mechanisms limiting ethanol production at high titers. However, metabolomics studies at …

Enhancing Co₂ Sweep And Storage Efficiency: Development And Evaluation Of A Hydrogel For Co₂ Storage And Enhanced Oil Recovery, Maryaam Sharifi Paroushi, Baojun Bai

Miners Solving for Tomorrow Research Conference

No abstract provided.

Preliminary Assessment Of Non-Volatile Particulate Matter And Gaseous Emissions From A Premixed Pre-Vaporized Combustor Designed For Civil Supersonic Transport, Ugochukwu Ewuzie, Godwin Ifeanyi Ogbuehi, Steven Achterberg, Monday Uchenna Okoronkwo, Philip D. Whitefield

Miners Solving for Tomorrow Research Conference

No abstract provided.

Carrier Analysis Of Alc Lipid Nanoparticles With Lung Cancer Drug, Noah Sparks, Lei Xu, Hu Yang

Miners Solving for Tomorrow Research Conference

No abstract provided.

A High-Temperature Lithium-Aluminum Alloy/Oxygen Or Air Fuel Cell, Sarwan S. Sandhu

Chemical and Materials Engineering Faculty Publications

This paper is in support of our current effort in the development of an experimental hybrid (lithium- aluminum alloy/electrolyte/oxygen or air) fuel cell for the acquisition of the experimental data required to characterize its performance behavior. The literature-based assembled formulation provided in this paper can be used to predict the cell open-circuit electric potential, lithium amount in the cell anode alloy, and g-atom ratio of lithium to aluminum in the cell anode as a function of time at any cell discharge current level. The ohmic voltage losses can also be computed in the cell cathode, anode, and two electrolytes at …

The Interplay Between Endothelial Glycocalyx Maturity And Both The Toxicity And Intracellular Uptake Of Charged Nanoparticles, Claire A. Bridges, Lu Fu, Jonathan Yeow, Xiaojing Huang, Miriam Jackson, Rhiannon P. Kuchel, James D. Sterling, Shenda M. Baker, Megan S. Lord

Business and Information Technology Faculty Research & Creative Works

Nanoparticles are widely studied for delivering treatments to target tissues, but few have reached clinical use. Most nanoparticles encounter blood vessels on their way to target tissues. The inner surface of these vessels is lined with endothelial cells covered by a glycocalyx, an extracellular matrix rich in anionic glycans. The role of the glycocalyx in nanoparticle interactions is not well understood. Here, we demonstrate that endothelial cells need extended culture times to synthesize a mature glycocalyx. Our research shows that branched polyethyleneimine functionalized gold nanoparticles bind to endothelial cells expressing either a developing or mature glycocalyx, with the interaction involving …

Ultrasonic Spray Coating Of Carbon Fibers For Composite Cathodes In Structural Batteries, Thomas Burns, Liliana Delatte, Gabriela Roman-Martinez, Kyra Glassey, Paul Ziehl, Monirosadat Sadati, Ralph E. White, Paul T. Coman

Faculty Publications

Structural batteries, also known as “massless batteries”, integrate energy storage directly into load-bearing materials, offering a transformative alternative to traditional Li-ion batteries. Unlike conventional systems that serve only as energy storage devices, structural batteries replace passive structural components, reducing overall weight while providing mechanical reinforcement. However, achieving uniform and efficient coatings of active materials on carbon fibers remains a major challenge, limiting their scalability and electrochemical performance. This study investigates ultrasonic spray coating as a precise and scalable technique for fabricating composite cathodes in structural batteries. Using a computer-controlled ultrasonic nozzle, this method ensures uniform deposition with minimal material waste …

Josephson Junctions: Fabrication And Applications For The Axion Dark Matter Experiment, Jonah M. Sachs

Senior Honors Papers / Undergraduate Theses

The observation of axions could revolutionize the world of physics. Through microwave frequency cavity readout of the photons associated with these axions, the ADMX project at WashU utilizes multiple different forms of the Josephson junction (JJ), a superconductive circuit element. The physics behind the JJ are essential to understanding its operation for resonant cavity readout in addition to parametric amplification. Parametric amplifiers produced using JJs can approach the signal-to-noise ratio set by quantum mechanics, and prove essential for the amplification chain used by the ADMX experiment for axionic detection. The limits of these amplifiers are set by the noise tuning …

Experimental And Numerical Analysis Of Fluidization Of Pelletized Activated Carbon Columns: Effects Of Glass Bead Retention Layer, Amin Nemati Tamar

Theses and Dissertations

In pressure swing adsorption (PSA) processes there is always a desire to process as much gas as possible in the smallest beds possible. This necessarily leads to velocities that, especially during pressure-changing steps, may exceed the adsorbent particle fluidization velocity within the bed. To prevent the possibility of bed expansion and fluidization bed retention systems are usually employed at the top of the bed in the form of dense beads, bags of the same or springs, otherwise the mechanical integrity of the adsorbent might become compromised. PSA process simulation, based on Archimedes’ force balance involving weight, buoyancy and the drag …

Multiscale Modeling Techniques For Electrodynamic Systems, Hunter Teel

Theses and Dissertations

In order to rapidly develop better electromagnetic and electrochemical systems, approaching these complicated topics from multiple perspectives is necessary. The use of mathematical models and numerical simulation offers the ability to evaluate and predict the performance of these systems based off the principles of electrodynamics in an ideal setting. Through the use of Computational Fluid Dynamics (CFD), representative geometries of scales can be created and evaluated to provide insight into the behavior of these systems. Simulation offers a modifiable environment that can approach the relevant physics from both the microscale and macroscale. Conclusions, results, boundary conditions, or other information from …