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Influence Of Metal-Coordinating Comonomers On The Coordination Structure And Binding In Magnetic Poly(Ionic Liquid)S, Kayla Foley, Lucas Condes, Keisha B. Walters

Chemical Engineering Faculty Publications and Presentations

A poly(ionic liquid) (PIL), poly(acrylamide-co-diallyl dimethylammonium chloride), was systematically complexed with Co²⁺, Fe³⁺, and Co²⁺/Fe³⁺ (mixed) at different molar equivalencies to form a series of magnetic PILs (MPILs). These novel MPILs were utilized to examine molecular structure and binding between the polymer and metal species using comprehensive spectroscopic studies in both dry and liquid states. FTIR, X-ray photoelectron, UV-vis, and Raman spectroscopies showed evidence of metal coordination of both the iron and cobalt chloride species with the acrylamide comonomer. Using AC susceptibility measurements, the MPILs were found to have magnetic properties …

The Role Of Membrane Porosity In Ion Removal By Ro/Nf Membranes And Development Of A Regenerable Pac-Loaded Membrane, Yizhi Hou

Dissertations (1934 -)

Reverse osmosis (RO) and nanofiltration (NF) membranes are widely used for water treatment applications. They are charged porous materials, in which size exclusion and charge exclusion work together to dictate solute transport. In this study, membrane porosity was primarily determined by pore size. Thicker, more porous membranes with smaller pores had higher NaCl removal and less permeate water flux. Higher porosity membranes have greater inner pore surface area available to support a greater number of functional groups, thereby rejecting ion flux and increasing ion removal. The Donnan steric pore model (DSPM) was used to determine that the contribution of diffusion …

Influence Of Feedstock And Moisture Content In A Continuous Feed Screw Torrefier, Anna H. Partridge, Isabella Casini, Denise A. Mckahn, David Carter, Charles Chamberlin, Arne Jacobson, Kyle Palmer, Yaad Rana, Mark Severy

Engineering: Faculty Publications

This paper investigates the parameters impacting product quality in a pilot scale biomass torrefaction reactor. The system analyzed in this work was designed and manufactured by Norris Thermal Technologies for use in Big Lagoon, California at a remote mill site. The torrefaction unit was a continuous feed reactor with an electrically heated screw, which served the dual purpose of heating and biomass conveyance. The energy and mass yields were found to be highly correlated in this analysis. The best predictor of both energy and mass yield in this study was the steady state temperature measurement in the biomass product closest …

Upscaling Wetland Methane Emissions From The Fluxnet-Ch4 Eddy Covariance Network (Upch4 V1.0): Model Development, Network Assessment, And Budget Comparison, Gavin Mcnicol, Etienne Fluet-Chouinard, Zutao Ouyang, Sara Knox, Zhen Zhang, Tuula Aalto, Sheel Bansal, Kuang Yu Chang, Min Chen, Kyle Delwiche, Sarah Feron, Mathias Goeckede, Jinxun Liu, Avni Malhotra, Joe R. Melton, William Riley, Rodrigo Vargas, Kunxiaojia Yuan, Qing Ying, Qing Zhu, Pavel Alekseychik, Mika Aurela, David Billesbach, David I. Campbell, Jiquan Chen, Housen Chu, Ankur R. Desai, Eugenie Euskirchen, Jordan Goodrich, Timothy Griffis, Manuel Helbig, Takashi Hirano, Hiroki Iwata, Gerald Jurasinski, John King, Franziska Koebsch, Randall Kolka, Ken Krauss, Annalea Lohila, Ivan Mammarella

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Wetlands are responsible for 20%–31% of global methane (CH4) emissions and account for a large source of uncertainty in the global CH4 budget. Data-driven upscaling of CH4 fluxes from eddy covariance measurements can provide new and independent bottom-up estimates of wetland CH4 emissions. Here, we develop a six-predictor random forest upscaling model (UpCH4), trained on 119 site-years of eddy covariance CH4 flux data from 43 freshwater wetland sites in the FLUXNET-CH4 Community Product. Network patterns in site-level annual means and mean seasonal cycles of CH4 fluxes were reproduced accurately in tundra, boreal, and temperate regions (Nash-Sutcliffe Efficiency ∼0.52–0.63 and 0.53). …

Towards Agile Academia: An Approach To Scientific Paper Writing Inspired By Software Engineering, Tyler Procko

Doctoral Dissertations and Master's Theses

The construction of scientific papers is performed in service of the greater scientific community. This iterative process is, in effect, an academic economy, where all members benefit from well-written papers. However, many published scientific papers are poorly written; they often lack sufficient detail to allow replication, there is improper usage of citations or a lack of regard to relevant work, reporting is vague or without linked empirical data to allow verification, figures do not correspond to text or are non-sensical, literary elements, e.g., bulleted lists, are used ineffectively, formatting renders certain sections unreadable, and grammatical errors abound. The issues of …

Investigation And Analysis Of Circular Economy Indicators In The Manufacturing Industry, Dina Al Jamal

Theses

In the pursuit of sustainable development, the concept of the Circular Economy (CE) has emerged as a compelling and transformative alternative to the traditional linear economic model (i.e., take, make, use, dispose). The limitations of the linear economy in addressing contemporary global challenges have highlighted the urgency of adopting a more regenerative approach. Simply put, the circular economy aims to maximize the value extracted from available resources over their lifecycle, thereby ensuring the fulfillment of both current and future generations' needs. This thesis sheds light on a pivotal solution for effectively integrating circular economy principles into enterprises, thereby reinforcing sustainability. …

Balanced Blended Space: Proposing A Universal Theoretical Framework For Combinative Reality, David Smith, Frederick Bianchi

Publications and Research

In today's fragmented societies, a unified framework for communication and collaboration across different realities is crucial. We introduce Balanced Blended Space (BBS) as a framework for describing combinative reality, encompassing virtual, physical, and conceptual realms, all intrinsically connected. Interactions within these environments shape our perceptual space. This paper outlines key axiomatic assumptions, criteria for a universal framework, and fundamental terminology. We identify deep symmetries enabling the BBS framework, including Cognitive and Computational Symmetry, Physical and Virtual Symmetry, Mediation Pathway Symmetry, Space-Time Symmetry, and Sensory Symmetry. We propose tests to determine its viability, emphasizing virtual intelligence as a collaborative partner. We …

Creating An Automatic Lowering Function For Quarter-Scale Tractor Pulling Sled, Sam Wilkins

Honors Program: Senior Projects (Public)

As the agricultural industry works to continuously integrate innovative technology and improve production efficiency, improved on-board data acquisition and transmission will be necessary for all agricultural machines. To make this a reality, the utilization of controller area network (CAN) technology will be crucial. Therefore, it is important for all agricultural engineers to have foundational knowledge of CAN bus systems and the standards that govern their use in industry. The UNL quarter-scale tractor team regularly utilizes CAN buses on their tractors and testing equipment. One such testing machine is the team’s pulling sled, which uses CAN messages to transport important information …

Floodplain And In-Channel Sedimentation In The Bedrock Congaree River, Sc, Mahsa Ahmadpoor

Theses and Dissertations

The Congaree River planform is characterized by an abrupt increase in channel sinuosity in the downstream direction. Such a change is not typical of alluvial meandering rivers but has been observed in mixed bedrock-alluvial rivers. This motivated the first study of this dissertation, specifically designed to determine if the Congaree River is indeed a mixed bedrock-alluvial river in its low sinuosity (upstream) reach. To test this hypothesis, sonar-based measurements of channel bed and sublayer elevation were performed from Columbia to the Congaree River-Wateree River confluence. The sublayer is here defined as the first surface visible in the sonar measurements underneath …

Particle-Free High Spatial Resolution Velocimetry For Slip Flow Detection, Malhar Prasad Joshi

Theses and Dissertations

Microfluidic systems have a wide range of applications, including biomedical devices, lab-on-a-chip technologies, and aerospace propulsion. Understanding and quantifying the slip flow phenomenon in these microscale and nanoscale channels is of paramount importance for precise control and optimization of fluidic processes. Our study presents a novel approach to directly measure the velocities in a microchannel using Laser Induced Fluorescence Photobleaching Anemometer (LIFPA) and Travel Time After Photobleaching Velocimetry (TTAPV). In this experimental study, microchannels with micrometer dimensions were used, and slip flow conditions controlled. The LIFPA-TTAPV approach was applied to measure slip velocities in the near wall regime, providing accurate …

Water Quality Monitoring And Mapping Using Rapidly Deployable Sensor Nodes, Mohamed Abdelwahab

Theses and Dissertations

Efficient and continuous monitoring of water quality parameters plays a pivotal role in responding to pollution incidents and ensuring the safety of both human consumption and ecological resources. This research introduces an affordable and dependable in-situ water quality sensor package designed for seamless continuous monitoring, providing essential data to facilitate informed decision-making in water resource management. The sensor package enables comprehensive on-site assessment of key water characteristics, including pH, temperature, turbidity (measured in NTU), and total dissolved solids (TDS, measured in ppm). Spatial interpolation techniques, specifically Kriging, are employed to extrapolate variable values at unobserved locations based on nearby measurements. …

Studies Of Damage Tolerance In Automated Fiber Placement Based Heterogeneous Meso-Architectured Carbon/ Epoxy Composite Laminates., Karan Kodagali

Theses and Dissertations

Traditional unidirectional (UD) carbon fiber-reinforced polymer matrix composites manufactured via automated fiber placement (AFP) are widely used in aerospace structures. While heterogeneous at the micro-scale, these materials are homogeneous at the meso-scale (ply-scale). The major limitation is its limited toughness, poor damage tolerance/impact resistance capability and the inability to sufficiently redistribute stresses, resulting in strength-toughness tradeoffs, making them susceptible to impact damage. From previous studies, there is an understanding that fiber architecture has a first order effect on the damage tolerance. Introducing new discontinuous/heterogeneous meso-scale architectures, through an optimal merger of material and structure, can result in unprecedented property improvements …

Virus Control Aboard A Commuter Bus, Hamid Rahai, Jeremy Bonifacio

Mineta Transportation Institute

A major health concern for public transit users is exposure to viruses from other passengers. This numerical study examines virus containment aboard a public bus with changes to the bus ventilation system. The virus was modeled as a 2.5 µm round solid particle released from the mouth of the infectious passenger at a rate of 21 particles per second at a mouth velocity of 0.278 m/sec. The air delivery to the cabin was two linear ceiling slots spanning the length of the bus delivering 59.38 m3/min (2,097 CFM) of air at a mean velocity of 1 m/sec. Two different axial …

Cheiloscopy Examination And Classification Of Lip Prints With And Without Parafunctional Oral Habits: A Cross-Sectional Observation Study, Emily Smith Regan

Dental Hygiene Theses & Dissertations

Problem: Lip prints are unique and have potential for use as a human identifier. The purpose of this study was to observe possible cheiloscopy differences of individuals with and without parafunctional oral habits. Additionally, inter-rater reliability (IRR) of lip print examiners was observed. Methods: This IRB approved blinded cross-sectional observational study collected lip prints from sixty-six individuals using lipstick and adhesive tape to transfer lip prints to white bond paper for viewing purposes. Each set of included lip prints was divided into quadrants and dichotomized as those with or without an oral parafunctional habit. Each quadrant sample was manually analyzed …

Pulsed Electric Field Ablation: Mechanisms Of Differential Cell Sensitivity And Methods To Mitigate Neuromuscular Excitation, Emily Gudvangen

Biomedical Engineering Theses & Dissertations

Ablation therapies aim to destroy tumors while maintaining minimal damage to surrounding healthy tissue. Pulsed electric field (PEF) ablation targets the cell membrane during the destruction of tissues, which consequently spares extracellular structures such as ducts and blood vessels, leaving the framework for tissue regeneration. However, the utility of PEF is limited by neuromuscular excitation, causing pain and involuntary muscle contraction. To identify PEF protocols that efficiently ablate tissue while minimizing neuromuscular stimulation, various PEF protocols differing in pulse duration, shape, and repetition rate were tested. The ratio of cell death and nerve excitation thresholds, which determines the range of …

Investigation Of Nanosecond Pulsed Electric Fields (Nspef) Induced Anti-Cancer Mechanism And Enhanced B16f10 Melanoma Cancer Treatment, Kamal Asadipour

Biomedical Engineering Theses & Dissertations

The use of nanosecond pulsed electric fields (nsPEF) has emerged as a promising area of research with vast implications across various scientific disciplines. The ability to generate ultra-short, high-voltage electric pulses has paved the way for numerous applications, ranging from fundamental investigations of biological phenomena to the development of innovative medical therapies. The aim of this thesis is to highlight the importance of nsPEF in two critical areas: 1) Understanding the impact of subtle postpulse waveforms through a comprehensive analysis of two common pulse generators and 2) using this knowledge to advance melanoma treatment by enhancing the therapeutic effect of …

Machine Learning Approach To Activity Categorization In Young Adults Using Biomechanical Metrics, Nathan Q. C. Holland

Mechanical & Aerospace Engineering Theses & Dissertations

Inactive adults often have decreased musculoskeletal health and increased risk factors for chronic diseases. However, there is limited data linking biomechanical measurements of generally healthy young adults to their physical activity levels assessed through questionnaires. Commonly used data collection methods in biomechanics for assessing musculoskeletal health include but are not limited to muscle quality (measured as echo intensity when using ultrasound), isokinetic (i.e., dynamic) muscle strength, muscle activations, and functional movement assessments using motion capture systems. These assessments can be time consuming for both data collection and processing. Therefore, understanding if all biomechanical assessments are necessary to classify the activity …

Fabrication Of Smooth Sac305 Thin Films Via Magnetron Sputtering And Evaluations Of Microstructure, Creep, And Electrical Resistivity, Manish Ojha

Mechanical & Aerospace Engineering Theses & Dissertations

SAC305 (96.5%Sn-3%Ag-0.5%Cu) is the leading alternative to the traditional Sn-Pb solder eutectic alloy owing to its low melting temperature, better compatibility with other components, and excellent mechanical/structural properties. In the realm of modern electronics, where devices are increasingly miniaturized, the design and characterization of thin solder joints become paramount. The orientation and size of the grains within the solder can influence its ability to withstand mechanical stresses. However, research on SAC thin films remains sparse, and these films present unique challenges and characteristics compared to their bulk counterparts, influenced by factors like interfaces, stresses, thickness, microstructure, and the nature of …

Development Of Pullulan/Chitosan/Salvianolic Acid Ternary Fibrous Membranes And Their Potential For Chemotherapeutic Applications, Salahuddin Ahmed, Megan Keniry, Victoria Padilla, Narcedalia Anaya-Barbosa, Md Noushad Javed, Robert Gilkerson, Kithzia Gomez, Acharan S. Narula, Karen Lozano

Mechanical Engineering Faculty Publications

This study investigates the feasibility of centrifugal spinning for producing fibrous membranes containing pullulan, chitosan, and danshen extract. The danshen extract is composed of 20 wt% salvianolic acid B (SA). Citric acid was added to the mixture as a crosslinking agent to promote its use in the aqueous medium. The influence of the danshen concentration (25 wt% and 33 wt%) on fiber morphology, thermal behavior, and the biochemical effect was analyzed. Developed fiber-based membranes consist of long, continuous, and uniform fibers with a sparse scattering of beads. Fiber diameter analysis shows values ranging from 384 ± 123 nm to 644 …

Enhanced Cell Viability And Migration Of Primary Bovine Annular Fibrosus Fibroblast-Like Cells Induced By Microsecond Pulsed Electric Field Exposure, Prince M. Atsu, Connor Mowen, Gary L. Thompson Iii

Henry M. Rowan College of Engineering Departmental Research

This study is the first to report the enhancement of cell migration and proliferation induced by in vitro microsecond pulsed electric field (μsPEF) exposure of primary bovine annulus fibrosus (AF) fibroblast-like cells. AF primary cells isolated from fresh bovine intervertebral disks (IVDs) are exposed to 10 and 100 μsPEFs with different numbers of pulses and applied electric field strengths. The results indicate that 10 μs-duration pulses induce reversible electroporation, while 100 μs pulses induce irreversible electroporation of the cells. Additionally, μsPEF exposure increased AF cell proliferation up to 150% while increasing the average migration speed by 0.08 μm/min over 24 …

Extraction And Characterization Of Fibres From The Bark Of Ficus Nekbudu Tree, Liberato V Haule

Tanzania Journal of Engineering and Technology (TJET)

This paper investigates the extraction and characterization of fibres from the bark of the ficus nekbudu tree. The Ficus Nekbudu Fibres (FNF) was extracted from the bark by retting in water and then treatment with sodium hydroxide solution. The extracted FNF was analysed for chemical composition, physical, tensile, surface, structural and thermal stability properties. Findings on the chemical composition indicated that FNF has cellulose (49.9 %), lignin (13.4%), ash (7.1%) and water content (8.1%). From the physical investigation it was found that FNF has density (1.42 ± 0.005 g/cm3) and moisture regain (9.2 ±0.3%). From mechanical investigation it was found …

Engineered Exosomes For The Multimodal Imaging Directed Photo-Immunotherapy Of Colorectal Cancer, Deepak S. Chauhan, Meena Jaggi, Subhash C. Chauhan, Murali M. Yallapu

Research Symposium

Background: Rio Grande Valley experience severe cancer health disparity. A novel therapeutic modality may serve as better therapeutic option. Nanohybrids endowed with multifunctionality, longer circulation time, large surface area have emerged as an active preference for cancer research. However, rising concern of nanomaterials toxicity and scalability issues has slowed their translation to clinics. Exosomes (Exo) are endogenous endocytic origin 40-100 nm vesicles found in various body fluids, which in comparison to synthetic nanoparticles, are biodegradable, highly biocompatible as well as immunocompatible in nature. Although bulk isolation of exosomes from human body fluids is still a problem and engineering of exosomes …

Recognizing Handwritten Digits Using Spiking Neural Networks With Learning Algorithms Based On Sliding Mode Control Theory, Yeşi̇m Öni̇z, Mehmet Ayyildiz

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a spiking neural network (SNN) has been proposed for recognizing the digits written on the LCD screen of an experimental setup. The convergence of the learning algorithm has been ensured by using sliding mode control (SMC) theory and the Lyapunov stability method for the adaptation of the network parameters. The spike response model (SRM) has been utilized in the design of the SNN. The performance of the proposed learning scheme has been evaluated both on the experimental data and on the MNIST dataset. The simulated and experimental results of the SNN structure have been compared with the …

A Machine Learning Approach For Dyslexia Detection Using Turkish Audio Records, Tuğberk Taş, Muhammed Abdullah Bülbül, Abas Haşi̇moğlu, Yavuz Meral, Yasi̇n Çalişkan, Gunay Budagova, Mücahi̇d Kutlu

Turkish Journal of Electrical Engineering and Computer Sciences

Dyslexia is a learning disorder, characterized by impairment in the ability to read, spell, and decode letters. It is vital to detect dyslexia in earlier stages to reduce its effects. However, diagnosing dyslexia is a time-consuming and costly process. In this paper, we propose a machine-learning model that predicts whether a Turkish-speaking child has dyslexia using his/her audio records. Therefore, our model can be easily used by smart phones and work as a warning system such that children who are likely to be dyslexic according to our model can seek an examination by experts. In order to train and evaluate, …

Cognitive Load Detection Using Ci-Ssa For Eeg Signal Decomposition And Nature-Inspired Feature Selection, Jammisetty Yedukondalu, Lakhan Dev Sharma

Turkish Journal of Electrical Engineering and Computer Sciences

Cognitive load detection is eminent during the mental assignment of neural activity because it indicates how the brain reacts to stimuli. The level of cognitive load experienced during mental arithmetic tasks can be determined using an electroencephalogram (EEG). The EEG data were collected from publicly available datasets, namely, mental arithmetic task (MAT) and simultaneous task workload (STEW). The first phase comprises decomposing the electroencephalogram (EEG) signal into intrinsic mode functions (IMFs) using circulant singular spectrum analysis (Ci-SSA). In the second phase, entropy-based features were evaluated using IMFs. After that, the extracted features were fed to nature-inspired feature selection algorithms: genetic …

Adaptive Octree Meshes For Simulation Of Extracellular Electrophysiology, Christopher Bc Girard, Dong Song

Engineering Faculty Articles and Research

Objective. The interaction between neural tissues and artificial electrodes is crucial for understanding and advancing neuroscientific research and therapeutic applications. However, accurately modeling this space around the neurons rapidly increases the computational complexity of neural simulations. Approach. This study demonstrates a dynamically adaptive simulation method that greatly accelerates computation by adjusting spatial resolution of the simulation as needed. Use of an octree structure for the mesh, in combination with the admittance method for discretizing conductivity, provides both accurate approximation and ease of modification on-the-fly. Main results. In tests of both local field potential estimation and multi-electrode stimulation, dynamically adapted meshes …

L(D)-Tyrosine-Mediated One-Step Chiral Graphene Production For Chirality-Dependent Sensing, Fnu Pranav, Ali Ashraf, Meena Jaggi, Subhash C. Chauhan, Murali M. Yallapu

Research Symposium

Background: Chirality has been the most iconic phenomenon that occurred in nature. The idea of mirror-image asymmetry associated with the biological entity is still unsolved The emergence of 2D layered nanomaterials which have already shown amazing properties and a wide range of applications, especially in the areas of sensing.Amino acids enantiomers have similar physical and chemical properties however their physiological responses get changed based on the enantiomers. For example, L from amino acids helps body in protein formation, and generation of biological signals etc. whereas the D-form may cause toxic effects. We have developed a novel and facile synthesis method …

Modeling Leaf-Level Transpiration: Exploring The Consequences Of Assumed Saturated Vapor Pressure In Leaves, Danlyn L. Brennan

Dissertations and Theses

Understanding the dynamics of water transport through leaf intercellular airspaces (IAS) and its impact on transpiration is crucial for accurate predictions of plant water use and ecosystem response to changing climates. This study investigates the implications of assuming undersaturation of water vapor in the IAS for transpiration predictions and explores potential modifications to standard modeling approaches.

A dynamic 1D soil-plant-atmosphere continuum using a stomatal optimization model (SPAC-SOT) framework was used to simulate the response of tree species, P. edulis, to prolonged drought and varying environmental conditions. Comparisons between two model assumptions (saturated vs. undersaturated IAS) reveal notable differences in …

Hydrophobicity Optimization Of Cathode Catalyst Layer For Proton Exchange Membrane Fuel Cell, Hao-Jie Chen, Mei-Hua Tang, Sheng-Li Chen

Journal of Electrochemistry

Hydrophobicity of the cathode catalyst layers (CCLs) crucially determines the performance of proton exchange membrane fuel cells (PEMFCs) by affecting the transports of oxygen and liquid water. In this regard, polytetrafluoroethylene (PTFE) is usually used as a hydrophobic additive to facilitate the oxygen and water transports in CCLs. So far, there remains lacking systematic effort to optimize the addition methods of PTFE in CCLs and the mechanisms behind. In this work, the effects of the approaches for PTFE addition and the distribution of PTFE on the mass transport of oxygen and the proton conduction in CCLs were studied by using …

Dependence Of Heat Transfer Model On The Structure Of Electrically Coil-Heated Microelectrodes, Ju Li, Sen Yang, Jian-Jun Sun

Journal of Electrochemistry

Electrically heated microelectrodes have gained much attention in electroanalytical chemistry in recent years. It has been shown that the promotion of mass transport and reaction kinetics at high-temperatures often results in increased current signals. However, there is no study about the heat transfer inner the microelectrodes which is necessary for the design and operation for microsensors. This report introduces a finite element software (COMSOL) to analyze the factors that influence the surface temperature (T_s), which is crucial for the heating ability of micro-disk electrodes with coils. Distances between the electrode surface and the bottom of the heated copper …