Digital Commons Network^™

Concerted Proton Transfer In Homogeneous And Heterogeneous Cyclic Hydrogen-Bonded Clusters Of H2o, Hf, And Hcl, Max R. Tucker, Yuan Xue, Nathan R. Speake, Eden Nickolson, Jeremy M. Carr, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

This work examines various homogeneous and heterogeneous clusters of hydrogen-bonded (HF)x(H₂O)y(HCl)z complexes, where x + y + z = 3 or 4. For each unique cyclic structure associated with the xyz permutations, the geometries of the reactant, product, and transition state (TS) for concerted proton transfer (CPT) were fully optimized using second-order Møller-Plesset perturbation theory (MP2) with a mixed basis set consisting of cc-pVTZ for H atoms and aug-cc-pVTZ for O, Cl, and F atoms (denoted haTZ). Harmonic vibrational frequencies were also computed at the same level of theory to verify the nature of the stationary points. Intrinsic …

Lessons Learned In Teaching Electrochemistry, Alanah Fitch, Ingrid Fritsch, Carol Korzeniewski, Shelley D. Minteer, Johna Leddy

Chemistry Faculty Research & Creative Works

Students frequently encounter difficulties in learning the vast landscape of electrochemistry. Here are shared examples of methods to demystify electrochemistry based on the extensive experience of the authors. Topics include a perspective on the shape of a voltammogram viewed as Ohm's Law, an extrapolation to electrochemical impedance spectroscopy (EIS), potential axes to identify spontaneous reactions, and select examples from organic and biological electrochemistry. Explained is the rationale behind certain Go To molecules used in electrochemical experiments such as ferrocene, ferricyanide, and other inorganic and organic electroactive molecules. Finally, more than sigmoidal curves are needed to confirm electrocatalysis. The domain of …

Evaluating The Use Of Machine Learning For Road Maintenance Cost Estimation, Shahla Shirinzad, David Enke

Engineering Management and Systems Engineering Faculty Research & Creative Works

Accurate estimation of highway maintenance costs is essential for efficient resource allocation and long-term infrastructure sustainability. This study evaluates the effectiveness of advanced machine learning models, including ResNet, Transformer, and other neural network architectures, for forecasting maintenance costs using historical data from the Highway Maintenance Improvement Program (HMIP) provided by the North Carolina Department of Transportation (NC DOT). A comprehensive comparative analysis is conducted across multiple models using standard performance metrics, including R², MAE, RMSE, and MSE. The results demonstrate that advanced architectures, particularly ResNet and Transformer, consistently outperform traditional statistical approaches and baseline machine learning models, achieving …

The Effect Of Reviewer Heterogeneity Between One-Time And Multi-Review Reviewers, Price Sentiment, And Pre-Purchase Information On Star Ratings For Amazon Subscription Boxes, Jikhan Jeong

Economics Faculty Research & Creative Works

This study examines the presence, prevalence, and negative polarity of one-time reviewers compared to those who have left multiple reviews across all categories, based on an analysis of 571,544,746 Amazon product reviews. Since sellers and consumers may be interested in specific products relevant to their business or purchasing interests within a category rather than across all categories, this research focuses on the Subscription Boxes category for econometric analysis. This category exhibits an unusual rating distribution, likely presents fewer incentives for promotional reviews, and faces fewer constraints. However, price data is unavailable in this category. Therefore, this study develops price sentiment …

Volatile Organic Compound Analysis Of Humboldt Penguin (Spheniscus Humboldti) Preen Oil: A Pilot Study, Dante E. Rojas, Mitchell M. Mccartney, Eva Borras, Michael O. Eze, Abigail Pietrow, Jennifer J. Valvo, Cristina E. Davis

Chemistry Faculty Research & Creative Works

Avian olfaction has gained prominence in recent decades for its roles in social communication and behavior. In penguins, the chemical characterization of preen oil remains limited. In this exploratory study, we characterized the volatile organic compound (VOC) profile of preen oil from Humboldt Penguins (Spheniscus humboldti). Preen oil from 12 captive individuals was analyzed using headspace sorptive extraction (HSSE) coupled to gas chromatography–mass spectrometry (GC–MS). Chemometric analyses examined variation in VOC profiles by sex, age class, and breeding activity. We detected 54 compounds (20 tentatively identified), including linear alcohols, methyl ketones, carboxylic acids, saturated hydrocarbons, oxygenated and nitrogen-containing organics, prenolipids, …

Soft-Chemical Scalable One-Pot Aqueous-Medium Synthesis Of Na3(Vo)2(Po4)2f-Based Cathodes: Compositional Tuning And Electrochemical Performance In Na- And Li-Ion Batteries, Prashanth Sandineni, Subal Chandra Manna, Sutapa Bhattacharya, Santhoshkumar Sundaramoorthy, Ramesh Deokate, Milad Aghayi-Anaraki, George E. Sterbinsky, Kartik Ghosh, Amitava Choudhury

Chemistry Faculty Research & Creative Works

One of the most important cathode materials for Na-ion batteries, Na₃(VO)₂(PO₄)₂F, and its compositional variants have been synthesized using four different and facile one-step soft chemical routes. The as-synthesized compounds, Na_2.95(VO)₂(PO₄)₂F (I), Na_2.93(VO)₂(PO₄)₂F (II), and Na_2.58(VO)₂(PO₄)₂F (IV), crystallize in the tetragonal crystal system in the P4₂/mnm space group, while Na₃(VO)₂(PO₄)₂F (III) crystallizes in the orthorhombic crystal system in …

Age-Related Hearing Loss Involves Mitochondrial Dna Instability And Copy Number Depletion In The Cochlea: Insights From In Vivo And In Vitro Models, Akil Turner, Bo Ding, Xiaoxia Zhu, Tam Nguyen, Parveen Bazard, Robert D. Frisina

Chemical and Biochemical Engineering Faculty Research & Creative Works

Age-related hearing loss (ARHL) is a highly prevalent sensory neurodegenerative disorder that involves various molecular mechanisms. The present study investigated if age-related oxidative stress (OS) induces alterations in mitochondrial DNA (mtDNA) copy number and heteroplasmy, using complementary in vivo and in vitro models. Aged (30-month) CBA/CaJ mice have elevated auditory brainstem response (ABR) thresholds amplitudes vs. young (3-month) CBA/CaJ mice, a key physiological characteristic of ARHL The in vitro experiments employed the strial SV-K1 cochlear cell line treated with hydrogen peroxide (H₂O₂). Both the aged cochleae and H₂O₂-treated cells exhibited a significant …

Insights Of Quantitative Imaging And Instantaneous Heat Transfer Coefficient Measurement In Spouted Bed Column, Hasan A. Abdulwahab, Abbas J. Sultan, Amer A. Abdulrahman, Haydar A.S. Aljaafari, Ali A. Yahya, Zahraa W. Hasan, Malik M. Mohammed, Laith S. Sabri, Bashar J. Kadhim, Jamal M. Ali, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this study, the heat transfer behavior of a conical spouted bed column was imaged for the first time across its entire cross-sectional area and at multiple axial heights. To achieve this, a custom-built quantitative imaging approach was developed. This method combined FluxTeq heat flux sensors with an Arduino-based data acquisition system. The experimental setup enabled instantaneous, spatially resolved measurements of surface temperature, heat flux, and local heat transfer coefficients (LHTC) under various operating conditions. Measurements at different radial locations, angles, and heights provided a comprehensive view of heat transfer behavior throughout the column. The obtained cross-sectional images show that …

Temperature Compensation In Loop And Patch Fss Strain Sensors: Analysis And Experimental Validation, Swathi Muthyala Ramesh, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Frequency selective surfaces (FSSs) are arrays of conductive elements or apertures that exhibit frequency-dependent reflection and transmission properties. Their electromagnetic response is influenced by geometry and environmental conditions, making them attractive for wireless strain-sensing applications. However, temperature variations can produce frequency shifts similar to those caused by strain, reducing measurement accuracy. This work investigates the effects of intrinsic temperature compensation on two common FSS unit cell geometries—loop and patch—through comprehensive simulation analysis. The results show that loop-based cells offer superior thermal stability, while patch-based cells provide greater strain sensitivity, illustrating the trade-off between thermal robustness and mechanical responsiveness. A patch-type …

Safety Aware Continual Reinforcement Learning-Based Output Tracking Control Of Nonlinear Continuous-Time Systems, Irfan Ganie, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

An output feedback (OF)-based control scheme utilizing both a scalable multilayer neural network (MNN) observer and actor–critic MNN via integral reinforcement learning (IRL)/adaptive dynamics programming (ADP) approach for a class of nonlinear systems with output constraints is introduced. The proposed observer, critic, and actor MNN weight updates are derived using a singular value decomposition (SVD) of MNN activation function gradient along with output error, Bellman and control input errors, respectively. Next, the approach incorporates continual learning (CL), utilizing a penalty function in the weight update laws for both actor–critic MNNs to consolidate knowledge from previous tasks and enhance learning in …

Corrections To: Enhancing Measurement Accuracy: The Impact Of Missing Data On Parameter Estimation In Mass-Spring-Damper Systems (Ieee Transactions On Instrumentation And Measurement (2026) 75 (1–12) Doi: 10.1109/Tim.2026.3676091), Michkath Omanda Bouraima, Steven Thompson, Maciej J. Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

In the above article [1], a wording ambiguity appears in Proposition 4 regarding the description of the missing at random (MAR) mechanism. The published sentence states that the probability of observing the kth sample depends on the realized measurement value. This wording may be interpreted as dependence on the current unobserved value y[tk], which could suggest a missing not at random (MNAR) mechanism. The intended MAR mechanism is that the observation probability for the kth sample depends only on previously observed measurement information, such as y[tk-1], and not on the current unobserved value y[tk]. Therefore, the corrected wording clarifies that …

Exploring New Poly-Anion Based Materials For Lithium – Ion Battery Cathodes, Sutapa Bhattacharya

Doctoral Dissertations

The escalating global demand for sustainable energy storage solutions has driven intensive research into novel electrode materials. Polyanion-based cathode materials have emerged as promising candidates due to their structural stability, safety, and voltage tunability enabled by the inductive effect of polyanionic groups. This research explores the synthesis, crystal structure, and electrochemical performance of new polyanion-based cathode materials featuring vanadium, molybdenum, and iron within phosphate and selenite frameworks.

Novel selenite-based materials, such as LiFe(SeO₃)₂ and Li₀.₂₅V₂O₃(SeO₃)₂, were synthesized and characterized, revealing stable electrochemical cycling associated with Fe2+/Fe3+ and V⁴⁺/V⁵⁺ transitions. Additionally, a systematic investigation was conducted on molybdenum phosphate compounds, including …

Adaptive Machine Learning Framework For Microstructural Optimization And Mechanical Performance Prediction In Steels, Henry Adekola Haffner

Doctoral Dissertations

Evolution of microstructures, such as polygonal ferrite, acicular ferrite, bainite, and martensite, plays a pivotal role in determining the final microstructural and mechanical properties of steel products. Given the established inter-relationship between processing parameters, microstructure, properties, and performance, precise control of phase transformation is essential to achieve pre-determined properties. To understand transformation routes in different steel grades, time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams are necessary and can be described using the Johnson-Mehl-Avrami-Kolmogorov equation and Scheil’s additivity rule. This study presents a comprehensive computational framework for predicting and optimizing microstructure and mechanical properties in advanced high-strength steels (AHSS) using adaptive machine …

Advancing Coal Rib Support Design Through The Integration Of Field Studies And Numerical Simulations, Alper Kirmaci

Doctoral Dissertations

Coal rib stability remains a major safety concern in U.S. underground coal mines, with rib failure-related injuries and fatalities still occurring. A key challenge is the lack of a standardized methodology for designing rib support systems that can address varying geological conditions. As a result, many mines rely on trial-and-error or traditional practices, leading to inconsistent designs. This research aims to develop a systematic methodology for rib support design to improve coal rib stability in U.S. mining operations.

The study consists of: i) field monitoring in active room-and-pillar coal mines, ii) in-situ pull-out tests on coal ribs, iii) numerical model …

Geometric Effects Of Warfighters On Body Armor Fit And Protective Capabilities Against Shock Wave Energy, Melissa Lynn Sutter

Doctoral Dissertations

Body armor is a vital piece of protective equipment for warfighters to defend against threats, necessitating continued development to improve comfort, weight, and protection. However, female warfighters often wear unisex body armor, designed primarily for the male torso. Current research has evaluated the short- and long-term detriments of female warfighters wearing these armors, focusing on comfort and performance. However, these studies do not comprehensively consider how a non-form-fitting armor compromises warfighter safety from battlefield threats. This research examines the geometric effects of female warfighters on armor protection level when defending against shock threats by evaluating the energy distribution on a …

Structured Decomposition And Efficient Adaptation For Scientific Data Movement: From Transfer Concurrency To Genomic Data Acquisition, Rasman Mubtasim Swargo

Masters Theses

"The end-to-end performance of scientific data movement is increasingly limited not by raw network capacity but by whichever resource along the path is momentarily slowest, a bottleneck that no single static configuration can track. This thesis argues that the right response is to decompose each problem along the resource or workflow axis where bottlenecks vary, adapt only the genuinely dynamic control variables at runtime, and make that adaptation efficient through utility-guided or offline-learned control rather than expensive online search. The thesis develops this principle through four systems of widening scope. AutoMDT decomposes a transfer by operation, assigning separate concurrency levels …

Moth Assemblages Of Fort Leonard Wood, Missouri, Kimberly Anne Steese

Masters Theses

"Moths (Lepidoptera) are ecologically important insects that function as herbivores, pollinators, prey resources, and indicators of ecosystem integrity. Despite their ecological significance, moth communities in the Missouri Ozarks remain poorly documented, particularly within military-managed landscapes. This thesis examined patterns of moth diversity, assemblage structure, and environmental drivers at Fort Leonard Wood (FLW), Missouri, while also assessing the distribution and genetic diversity of species within the genus Papaipema.

Field surveys were conducted from 2019 through 2021 across prairie, savanna, forest, and restoration habitats at FLW using UV bucket traps, sheet trapping, and targeted larval surveys. Across all sampling efforts, 29,116 individual …

Sapphire Optical Fiber Bragg Grating Sensors Based On Dispersive Microwave-Photonic Frequency-Time Domain Analysis, Ruimin Jie, Chen Zhu, Farhan Mumtaz, Koustav Dey, Bohong Zhang, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Sapphire fiber Bragg gratings (SFBGs) have attracted growing interest for high temperature sensing in harsh environments, yet their interrogation typically relies on optical spectrum measurements, demanding a high-resolution optical spectrum analyzer (OSA) that is bulky, expensive, and constrained in acquisition speed. Moreover, the inherently multimode nature of sapphire fiber further complicates spectrum-based demodulation, thereby limiting the achievable sensing resolution. In this paper, we propose and experimentally demonstrate a microwave-photonic interrogation approach for SFBG sensors. Instead of measuring the optical reflection spectrum, the complex frequency response in the microwave domain of an SFBG is acquired using a vector network analyzer (VNA) …

Lidar-Based Framework For Detecting Suspicious Human Activities, Ahd Aljumah, Charalampos Antoniadis, Hakim Ghazzai, Nawfal Guefrachi, Ahmad Alsharoa, Gianluca Setti

Electrical and Computer Engineering Faculty Research & Creative Works

This study explores the development of Human Activity Recognition (HAR) systems capable of identifying suspicious activities to enhance security in public spaces. We propose an innovative solution that integrates LiDAR sensors with deep learning technologies. Our method employs advanced models operating on LiDAR point cloud, PV-RCNN for human detection, and LidarGait++ for classifying activities into categories such as standing or walking (non-suspicious) and sneaking or fighting (suspicious). Due to the scarcity of suitable real-world datasets for training such systems, we utilize a 3D simulation tool, Blender, to create realistic environments and generate labeled point cloud data. This synthetic dataset allows …

Deep Learning Approach For Microwave Imaging Based On Deep Convolutional Asymmetric Encoder-Decoder Structure And Physics-Induced Loss, He Ming Yao, Shiji Song, Michael Kwok Po Ng, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we introduce an innovative deep learning (DL) methodology designed for real-time quantitative microwave imaging (MWI). Our approach is centered around the utilization of a deep convolutional asymmetric encoder-decoder structure (DCAEDS), which requires only a single-frequency far-field measurement of the electromagnetic (EM) scattered field as input and subsequently predicts the contrasts (permittivities) of the target materials. During the offline training process, we incorporate an EM forward solver specifically crafted to compute the EM scattered field generated by the predicted target contrasts (permittivities) produced by the DCAEDS. The DCAEDS is seamlessly integrated with this EM forward solver to optimize …

Instrument Response Functions Of The Antarctic Demonstrator For The Advanced Particle-Astrophysics Telescope (Adapt), Wenlei Chen, James H. Buckley, Marion Sudvarg

Computer Science Faculty Research & Creative Works

The Antarctic Demonstrator for the Advanced Particle-astrophysics Telescope (ADAPT) gamma-ray/cosmic-ray instrument serves as a precursor to the proposed APT mission. The APT mission is designed to improve sensitivity in the MeV-TeV gamma-ray range by an order of magnitude compared to current missions and is optimized for dark-matter and multimessenger research. The ADAPT instrument uses scintillating fibers for particle tracking and sodium-doped cesium iodide (CsI:Na) tiles read out with wavelength shifting (WLS) fibers for imaging, with solid-state silicon photomultipliers (SiPMs) for calorimetry. It includes four layers of imaging calorimeter detectors and scintillating-fiber trackers, functioning both as a Compton and Pair telescope …

Real-Time Likelihood Map Generation To Localize Short-Duration Gamma-Ray Transients, Jeremy Buhler, Marion Sudvarg

Computer Science Faculty Research & Creative Works

High-energy transient astrophysical phenomena, such as supernovae and binary neutron star mergers, benefit from a multi-wavelength investigation in which a space- or balloon-based omnidirectional telescope detects and localizes early high-energy emissions (such as a gamma-ray burst), then alerts a narrow-field follow-up instrument to observe the source. The high-energy telescope must provide a map that assigns to each sky location a likelihood that the source appears there. To issue prompt alerts despite limits on communication bandwidth and latency, it is desirable to compute this map aboard the high-energy telescope, but doing so requires rapid response while computing under stringent size, weight, …

Polyminhash: Efficient Area-Based Minhashing Of Polygons For Approximate Nearest Neighbor Search, Alima Subedi, Sankalpa Pokharel, Satish Puri

Computer Science Faculty Research & Creative Works

Similarity searches are a critical task in data mining. As datasets grow larger, exact nearest neighbor searches quickly become unfeasible, leading to the adoption of approximate nearest neighbor (ANN) searches. ANN has been studied for text data, images, and trajectories. However, there has been little effort to develop ANN systems for polygons in spatial database systems and geographic information systems. We present PolyMinHash, a system for approximate polygon similarity search that adapts MinHashing into a novel 2D polygon-hashing scheme to generate short, similarity-preserving signatures of input polygons. Minhash is generated by counting the number of randomly sampled points needed before …

Tunable Phase-Change Metasurfaces Coupled With Mid-Infrared Molecular Vibrations, Haotian Tang, Liliana Stan, David A. Czaplewski, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Chiral optical meta surfaces have emerged as a promising platform in coupling with molecular vibrational fingerprints through the enhanced light-matter interaction under different circularly polarized light illumination. This work reports the mode coupling between the mid-infrared phonon vibrations of polymethyl methacrylate (PMMA) molecules, and the thermally tunable chiral meta surfaces based on the phase-change material Ge₂Sb₂Te₅ (GST-225). Phase-change chiral meta surfaces with high circular dichroism (CD) in absorption and tunable plasmonic resonance in the frequency range of 48-56 THz are demonstrated, which covers the phonon vibrational frequency of PMMA molecules at 52 THz. The mode splitting features are observed in …

Accessing Cation And Anion Redox In Mixed-Valent One-Dimensional Iron-Chalcogenides, Na1.5fe1s2–Xsex(X = 0, 1, And 2), For Na-Ion Batteries, Santhoshkumar Sundaramoorthy, Milad Aghayi-Anaraki, Sutapa Bhattacharya, Amitava Choudhury

Chemistry Faculty Research & Creative Works

Sodium-ion batteries (NIBs) have attracted considerable attention as a cost-effective and sustainable alternative to lithium-ion batteries (LIBs), owing to the abundance and low cost of sodium resources. Here, we investigate previously reported mixed-valent (Fe^3+/2+) one-dimensional (1D) iron chalcogenides: Na1.5FeS2, its selenide analogue Na1.5FeSe2, and newly developed solid solution Na1.5FeSSe, focusing on their synthesis, structural characterization, and electrochemical performance in NIBs. While the full Fe²⁺sulfide version (NaFeS2) of the compound is explored in solid-state cells for its dual cation–anion redox mechanism, we reveal the effect of anion substitution on the electrochemical behavior of Na1.5FeS2–xSex(x = 0, 1, …

Engineered Multifunctional Drug-Loaded Dendrimer Nanoparticles For Glaucoma: Triple Mechanism Via Antioxidant Activity, Iron Chelation, And Enhanced Ocular Transport, Burhan Ates, Ashish Trital, Vimalin Jeyalatha Mani, Lei Xu, Jonathan Kenlee, Nuran Ercal, Hu Yang

Chemistry Faculty Research & Creative Works

In this study, we developed multifunctional nanoparticles based on polyamidoamine (PAMAM) dendrimers functionalized with caffeic acid (CA) and poly (ethylene glycol) maleimide (PEGM) for the topical delivery of hydrophobic antiglaucoma drugs brimonidine (BM) and betaxolol (BX). The PAMAM-CA and PAMAM-CA-PEGM conjugates exhibited antioxidant and iron-chelating activities in a dose-dependent manner. BM- and BX-loaded dendrimer nanoparticles produced using a multi-inlet vortex mixer showed uniform spherical morphology (∼80 nm by TEM) and hydrated sizes of ∼135-144 nm by DLS. Both nano formulations demonstrated high cytocompatibility with human corneal epithelial cells and were nonirritant in the HET-CAM assay, with PEGM further improving cytocompatibility. …

Using Insecticidal Compounds To Elucidate The Potential Role Of Neurotransmitters In Lepidoptera Pupal Ecdysis, Niranjana Krishnan, Cassandra Gorman, Jillian Stewart, Steven Bradbury, Russell Jurenka

Biological Sciences Faculty Research & Creative Works

Previously, we reported final-instar lepidopteran larvae exposed to low doses of imidacloprid, clothianidin, and thiamethoxam had arrest in pupal ecdysis, which is a novel adverse outcome for neonicotinoid insecticides. Since neonicotinoids disrupt acetylcholine signaling, we hypothesized that the excitatory neurotransmitter acetylcholine plays a critical role in regulation of pupal ecdysis, likely by modulating the release of peptides from crustacean cardioactive peptide (CCAP) neurons. In this paper, using two lepidopteran species, we undertook studies with five additional nicotinic acetylcholine receptor (nAChR) agonists and three muscarinic acetylcholine receptor (mAChR) agonists to hypothesize the putative nAChR subunits that mediate pupal ecdysis. We also …

Wacsaw: An Adaptive, Statistical Method To Classify Movement Into Sleep And Wakefulness States, Austin Vandegriffe, V. A. Samaranayake, Matthew S. Thimgan

Mathematics and Statistics Faculty Research & Creative Works

Wearable actimeters can improve our understanding of sleep in the natural environments. Current algorithms may produce inaccuracies in specific individuals and circumstances, such as quiet wakefulness. New hardware allows data collection at higher frequencies enabling sophisticated analytical methods. We have developed a novel statistical algorithm, the Wasserstein Algorithm for Classifying Sleep and Wakefulness (WACSAW), to identify behavioral states from recordings of everyday movement. WACSAW employs optimal transport techniques to identify segments with differing activity variability. Functions characterizing the segments' movement distributions were clustered into two groups using a k-nearest neighbors and labeled as sleep or wake based on their proximity …

Experimental Determination Of Tnt Equivalence Values For Binary Energetic Materials, Gracie May M. James, Rachel L. Bauer, Emily M. Johnson, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

TNT equivalency quantifies the impact of energetic materials relative to TNT, aiding in safety guidelines and performance evaluations. Despite widespread use in industry, military, and research, many binary energetics lack published TNT equivalence values. This study experimentally determines TNT equivalency values for Helix, Texpak, Rimfire, Tannerite, and Kinepak using three tests: (1) plate dent, (2) reaction velocity and (3) air blast. Each test evaluates distinct aspects of energetic performance, addressing both close-in destructive power and downstream effects. Helix produced TNT equivalence values from 0.64 to 1.10, comparable to TNT, while Kinepak had lower values (0.18 to 0.58) indicating limited brisance, …

Unlocking The Potential Of Copper Sulfide Tailings As A Secondary Source For Tellurium And Precious Metals: A Comprehensive Characterization Study, Fardis Nakhaei, Lana Alagha, Gary Wyss

Mining Engineering Faculty Research & Creative Works

This study investigated historical copper sulfide tailings as an unconventional source of tellurium (Te), gold (Au), and silver (Ag). Advanced analytical studies were conducted to determine the geochemical and mineralogical properties of the tailing samples. The results showed that tetradymite (Bi2Te2S) was the predominant Te-bearing mineral, while hessite (Ag2Te) was a minor Te carrier, both notably occurring within fine-grained (< 8 μm) inclusions in pyrite. Gold was present as native Au, electrum (Au-Ag), and within complex silver tellurides hosted primarily in chalcopyrite and pyrite. Froth flotation studies showed that the 180 to 38 μm size range was the optimum feed size that yielded recoveries of 59 %, 37 %, and 27 % for Te, Au, and Ag, respectively. These findings suggested that froth flotation is a feasible method for concentrating Te-Au-Ag-bearing phases. Given the strong association between Te, Au, Ag, and Cu, the co-extraction of these metals should significantly enhance the economic viability of tailings' processing.