Engineering Commons^™

Solution To Exide Technologies Inbatec Inefficiency, Reagan Gilker, Mary Fairley, Spencer Christain, Shixuan Hou, Covenson Latouche

Chemical Engineering Undergraduate Honors Theses

The inefficiency of the battery charging time in Inbatec Units 1 and 2 in the Exide Technologies Fort Smith was initially investigated by a student team in Fall 2019, and the investigation was continued into Spring 2020. The Exide Technologies facility in Fort Smith, Arkansas utilizes 13 Inbatec units to charge the lead-acid batteries.

The Inbatec systems circulate the sulfuric acid solution through a cooling tower to maintain to optimal charging temperature. Previous analysis of the charging process for Inbatec Units 1 and 2 show the cooling tower have the capacity to quickly remove the excess heat in the sulfuric …

Improvement Of Geometric Quality Inspection And Process Efficiency In Additive Manufacturing, Yu Jin

Graduate Theses and Dissertations

Additive manufacturing (AM) has been known for its ability of producing complex geometries in flexible production environments. In recent decades, it has attracted increasing attention and interest of different industrial sectors. However, there are still some technical challenges hindering the wide application of AM. One major barrier is the limited dimensional accuracy of AM produced parts, especially for industrial sectors such as aerospace and biomedical engineering, where high geometric accuracy is required. Nevertheless, traditional quality inspection techniques might not perform well due to the complexity and flexibility of AM fabricated parts. Another issue, which is brought up from the growing …

Improving Pv Module Efficiency Through Cooling, Brandon Conrad, Blake Bradley, Ashley Cox, Donhy Mai, Harrison Dawson, Megan Reynolds, George Hill

Chemical Engineering Undergraduate Honors Theses

The Solarbacks researched and designed a variety of cooling methods that could be used to improve the efficiency of photovoltaics. These cooling methods can be separated into two categories: active and passive methods. The active cooling method of hydraulic cooling and the passive cooling methods of heat sinks (fins), optical coatings, thermosyphons, phase change materials, and thermoelectric generators were all taken into consideration as potential cooling methods. Passive cooling methods were preferred because the use of electricity required for the cooling mechanism would reduce the net electricity and subsequent profit from the panels.

Two variations of hydraulic cooling were researched: …

Removal Of Fluoride From Mine Water Via Adsorption For Land-Applied Soil Amendment, Kevin Le, Adrian Damian, Mary Johnson, Ethan Phan, Courtney Golman, Michelle Dopp, Jacqueline Payne

Chemical Engineering Undergraduate Honors Theses

The team researched, designed, and economically analyzed a full-scale adsorption column system to be applied in mining processes that leave high amounts of fluoride in their effluent. This system was designed to remove fluoride from water saturated with calcium sulfate, as calcium sulfate is present in high amounts in certain mining processes. Currently, high density sludge (HDS) is commonly employed to reduce fluoride concentrations, but due to solubility limits the sludge treatment cannot lower fluoride below 10 mg/L (ppm). The current enforceable EPA standard for discharged water is at 4 mg/L (ppm), although mining companies anticipate that this standard will …

Improving Pv Module Efficiency Through Cooling, Ashley Cox

Chemical Engineering Undergraduate Honors Theses

The Solarbacks researched and designed a variety of cooling methods that could be used to improve the efficiency of photovoltaics. These cooling methods can be separated into two categories: active and passive methods. The active cooling method of hydraulic cooling and the passive cooling methods of heat sinks (fins), optical coatings, thermosyphons, phase change materials, and thermoelectric generators were all taken into consideration as potential cooling methods. Passive cooling methods were preferred because the use of electricity required for the cooling mechanism would reduce the net electricity and subsequent profit from the panels.

Two variations of hydraulic cooling were researched: …

Removal Of Fluoride From Mine Water Via Adsorption For Land-Applied Soil Amendment, Adrian Damian, Kevin Le, Mary Johnson, Ethan Phan, Courtney Golman, Michelle Dopp, Jacqueline Payne

Chemical Engineering Undergraduate Honors Theses

The process of mining minerals and elements from ores and rocks creates acid rock drainage (ARD). This drainage is water that contains heavy metals and minerals that can be dangerous for human consumption or damaging to the environment. The mining industry has employed various water treatment methods to prevent these metals and minerals from being discharged into water sources such as ponds, lakes, and streams. Currently, the most used treatment process in the mining industry is a cost-effective highdensity sludge (HDS) process. This method reduces the concentration of metals and elements with the use of lime/limestone. However, the concentration of …

Removal Of Fluoride From Mine Water Via Adsorption For Land-Applied Soil Amendment, Michelle Dopp, Kevin Le, Ethan Phan, Mary Johnson, Jacqueline Payne, Adrian Damian, Courtney Golman

Chemical Engineering Undergraduate Honors Theses

The Moo Pig Sooie’s researched, designed, and economically analyzed a full-scale adsorption column system to be applied in mining processes that leave high amounts of fluoride in their effluent. This system was designed to remove fluoride from water saturated with calcium sulfate, as calcium sulfate is present in high amounts in certain mining processes. Currently, high density sludge (HDS) is commonly employed to reduce fluoride concentrations, but due to solubility limits the sludge treatment cannot lower fluoride below 10 mg/L (ppm). The current enforceable EPA standard for discharged water is at 4 mg/L (ppm), although mining companies anticipate that this …

Removal Of Fluoride From Mine Water Via Adsorption For Land-Applied Soil Amendment, Courtney Golman, Kevin Le, Michelle Dopp, Adrian Damian, Mary Johnson, Jacqueline Payne, Ethan Phan

Chemical Engineering Undergraduate Honors Theses

The process of mining minerals and elements from ores and rocks creates acid rock drainage (ARD). This drainage is water that contains heavy metals and minerals that can be dangerous for human consumption or damaging to the environment. The mining industry has employed various water treatment methods to prevent these metals and minerals from being discharged into water sources such as ponds, lakes, and streams. Currently, the most used treatment process in the mining industry is a cost-effective highdensity sludge (HDS) process. This method reduces the concentration of metals and elements with the use of lime/limestone. However, the concentration of …

Elucidating Basis Of Rice Discoloration And Developing Prevention Strategies, Zeinab Mohammadi Shad

Graduate Theses and Dissertations

Economically, discolored rice kernels have less market value, which can seriously impact farm net profit. The reasons for rice discoloration during storage have not been studied extensively and many questions remain. Therefore, the primary goal of this study was to improve understanding of the role and contributions of storage practices on rice quality degradation and discoloration. In this study, three rice cultivars including XL753 (hybrid), Roy J (pureline), and Titan were assessed for changes in quality and microbial kinetics. The rice samples at a high moisture content (MC) of 21% w.b. and a low MC of 16% were stored at …

An Fpga-Based Hardware Accelerator For The Digital Image Correlation Engine, Keaten Stokke

Graduate Theses and Dissertations

The work presented in this thesis was aimed at the development of a hardware accelerator for the Digital Image Correlation engine (DICe) and compare two methods of data access, USB and Ethernet. The original DICe software package was created by Sandia National Laboratories and is written in C++. The software runs on any typical workstation PC and performs image correlation on available frame data produced by a camera. When DICe is introduced to a high volume of frames, the correlation time is on the order of days. The time to process and analyze data with DICe becomes a concern when …

Stay-At-Home Motor Rehabilitation: Optimizing Spatiotemporal Learning On Low-Cost Capacitive Sensor Arrays, Reid Sutherland

Graduate Theses and Dissertations

Repeated, consistent, and precise gesture performance is a key part of recovery for stroke and other motor-impaired patients. Close professional supervision to these exercises is also essential to ensure proper neuromotor repair, which consumes a large amount of medical resources. Gesture recognition systems are emerging as stay-at-home solutions to this problem, but the best solutions are expensive, and the inexpensive solutions are not universal enough to tackle patient-to-patient variability. While many methods have been studied and implemented, the gesture recognition system designer does not have a strategy to effectively predict the right method to fit the needs of a patient. …

Investigations Of New Fault-Tolerant Methods For Multilevel Inverters, Haider Mhiesan

Graduate Theses and Dissertations

The demands of power electronics with high power capability have increased in the last decades. These needs have driven the expansion of existing power electronics topologies and developing new power electronics generations. Multilevel inverters (MLI) are one of the most promising power electronics circuits that have been implemented and commercialized in high-voltage direct current (HVDC), motor drives, and battery energy storage systems (BESS). The expanding uses of the MLI have lead to creation of new topologies for different applications. However, one of the disadvantages of using MLIs is their complexity. MLIs consist of a large number of switching devices, which …

Structure And Deformation Of Carbyne Deposited On A Nickel Substrate, Abigail Eaton

Mechanical Engineering Undergraduate Honors Theses

Carbyne is a nanomaterial of great interest due to its ability to withstand high forces similarly to other carbon allotropes such as graphene or carbon nanotubes. However, it is currently difficult to synthesize and maintain without the assistance of a composite material substrate that the carbyne can be integrated with, which will affect its reaction to varying conditions. This thesis focuses on studying the effects of carbyne on a nickel surface and its mechanical properties to predict its future usages and potential for applications in varying fields. We perform a three-point bending test simulation using molecular dynamics with pure Ni …

A History And Status Of Wind Energy Potential In Arkansas, Pre And Post Covid-19, Will Blasingame

Mechanical Engineering Undergraduate Honors Theses

Historically, wind-generated electricity has been the largest renewable energy sources in the United States. Wind-rich regions like Oklahoma and Texas have fueled growth and sold that electricity to electric utilities located in wind-poor states like Arkansas in the form of Power Purchase Agreements. Future technologies such as Vertical Axis Wind Turbines, small wind turbines, and Tesla turbines designed to generate electricity from wind show promise in unlocking more expensive wind resources in regions like Northwest Arkansas by mitigating concerns about low wind speeds and noise. However, more factors than just feasibility influence the growth of wind power. Governmental policies such …

Construction Of A Hyperspectral Imager Using 3d-Printed And Off-The-Shelf Components, Joshua Moorhouse

Mechanical Engineering Undergraduate Honors Theses

The Arkansas Center for Space and Planetary Sciences is working in collaboration with the Mechanical Engineering department to create a relatively cheap and modifiable hyperspectral imager. It is constructed using 3D-printed and off-the-shelf components from Edmund Optics and Amazon. The iteration created in this paper delivers spectrograms in the visible spectrum. The long-term goals of the camera are to create hyperspectral images from these spectrograms and to advance the imager into the infrared and near-infrared spectra. This imager is being developed to be used in the Arkansas Center for Space and Planetary Sciences environmental test chambers to further the scientific …

Sub-/Surface Evaluation Of Industry-Grade Endodontic File Micro-/Nanoscale Structures And Low-Cost, Low-Energy Methods Of Rapidly Annealing And Nitriding Titanium, Nicholas Broadbent

Mechanical Engineering Undergraduate Honors Theses

Because of their unique mechanical properties, shape memory capabilities and biocompatibility, Nickel-titanium alloys are frequently used in the medical industry for a variety of applications including endodontic files. Until now, the performance of industry-standard endodontic files has been characterized by this alloying property and a limited set of macroscale surface structures and features. In this work, High Resolution Transmission Electron Microscopy (HRTEM), Low Resolution Transmission Electron Microscopy (LRTEM), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDX) analyses are conducted at both the surface and sub-surface levels of a wide selection of industry-grade endodontic files currently offered on the …

Enhancement Of Phase Change Material Sorbitol By Nanoparticle Inclusion For Improving Thermal Energy Storage Capabilities, Joshua Kasitz

Mechanical Engineering Undergraduate Honors Theses

Thermal management of electronic devices has become an increasingly vital field of study with the rapid miniaturization of many key electrical components. With the significant improvement of semiconductor manufacturing and intensified focus on interconnects, electronic devices have decreased in size at an incredible rate. Decreasing spatial requirements is essential to improving device capabilities as the electronic system is able to incorporate more components. Currently, electronic systems are drastically limited by the capabilities of their cooling mechanisms. Smaller devices lead to large increases in the energy density of the system and require more powerful cooling systems to maintain proper component operating …

Locating Emergency Shelters While Incorporating Spatial Factors, Justin Taylor

Graduate Theses and Dissertations

In the immediate response phase of a natural disaster, local governments and nonprofit agencies often establish shelters for affected populations. Decisions regarding at which locations to open shelters are made ad hoc based on available building inventory, and may result in high travel impedance to reach shelters and congestion. This thesis presents a shelter location optimization model based on the two-step floating catchment area (2SFCA) method. The 2SFCA method creates a shelter accessibility score for each areal unit (e.g., census block group) which represents the ability for persons in the unit to access shelter capacity with low travel impedance, relative …

Applying Performance Engineered Mixture Design To Permeable Concrete, Rachel Pohl

Civil Engineering Undergraduate Honors Theses

The scope of research and application related to permeable pavements has recently broadened. The desire to significantly reduce the environmental impact of large paved areas makes the permeable pavement concept more desirable (American Concrete Institute, 2018). Although research and interest are increasing, the actual application of permeable pavement is still very limited and has not reached the airfield arena. In airfields, permeable pavement could possibly be used for aircraft aprons - which currently require substantial measures to control stormwater runoff. Permeable pavements are typically used in low-traffic-volume / lightly loaded applications; questions remain regarding a permeable pavement’s ability to hold …

Design Of Submicron Structured Guided-Mode-Resonance Near-Infrared Polarizer, Marzia Zaman

Graduate Theses and Dissertations

The objective of this research is to design a larger submicron linear polarizer in the near-infrared wavelength range with a wide bandwidth which can be fabricated using the conventional thin-film microfabrication technology to reduce cost. For this purpose, a gold (Au) wire-grid transmission-type transverse-magnetic (TM) polarizer and a silicon (Si) wire-grid reflection-type TM polarizer, were designed using the guided-mode-resonance filter. The Au wire-grid TM polarizer of 700nm grating width and 1200nm grating period has 95% transmittance at 2400nm, more than 1000nm resonance peak bandwidth, and an extinction ratio (ER) of around 300 with a moderated level of sidebands. The 700nm …

Design And Simulation Of Power Electronics Modules, Haonan Jia

Graduate Theses and Dissertations

Silicon carbide (SiC), a wide-bandgap semiconductor material, greatly improves the performance of power semiconductor devices. Its electrical characteristics have a positive impact on the size, efficiency, and weight of the power electronics systems. Parasitic circuit elements and thermal properties are critical to the power electronics module design. This thesis investigates the various aspects of layout design, electrical simulation, thermal simulation, and peripheral design of SiC power electronic modules. ANSYS simulator was used to design and simulate the power electronic modules. The parasitic circuit elements of the power module were obtained from the device parameters given in the datasheet of these …

Low Latency Anomaly Detection With Imperfect Models, Samrat Nath

Graduate Theses and Dissertations

The problem of anomaly detection deals with detecting abrupt changes/anomalies in the distribution of sequentially observed data in a stochastic system. This problem applies to many applications, such as signal processing, intrusion detection, quality control, medical diagnosis, etc. A low latency anomaly detection algorithm, which is based on the framework of quickest change detection (QCD), aims at minimizing the detection delay of anomalies in the sequentially observed data while ensuring satisfactory detection accuracy. Moreover, in many practical applications, complete knowledge of the post-change distribution model might not be available due to the unexpected nature of the change. Hence, the objective …

Study Of A Symmetrical Llc Dual-Active Bridge Resonant Converter Topology For Battery Storage Systems, John K. George

Graduate Theses and Dissertations

A symmetrical LLC resonant converter topology with a fixed-frequency quasi-triple phase-shift modulation method is proposed for battery-powered electric traction systems with extensions to other battery storage systems. Operation of the converter with these methods yields two unique transfer characteristics and is dependent on the switching frequency. The converter exhibits several desirable features: 1) load-independent buck-boost voltage conversion when operated at the low-impedance resonant frequency, allowing for dc-link voltage regulation, zero-voltage switching across a wide load range, and intrinsic load transient resilience; 2) power flow control when operated outside the low-impedance resonance for integrated battery charging; 3) and simple operational mode …

Peptoid And Antibody-Based Gfp Sensors, Solomon Isu

Graduate Theses and Dissertations

In this work, we have made and characterized a pair of immunobiosensors for detecting the green fluorescent protein (GFP) in an aqueous matrix. An anti-GFP antibody-based biosensor was assembled to detect GFP, while a novel peptoid (N-substituted oligomers of glycine designated as IOS-1) biosensor was also assembled for GFP detection. A quartz crystal microbalance (QCM) gold sensor was used as the supporting substrate for self-assembly of the immunobiosensors. Gravimetric measurements of the QCM gold sensor during immunobiosensor construction and operation were available in real-time using a QCM instrument. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Fluorescence microscopy were used …

A Power Constrained 433-Mhz Low Noise Amplifier, Pablo Alvarez Arellano

Graduate Theses and Dissertations

Within wireless communication systems, low noise amplifiers are critical for the performance of receivers. They are primarily responsible for providing enough gain while adding little noise to overcome the noise of the subsequent stages. The LNA presented here is part of a battery-powered transceiver meant to measure crop nutrient data and relay the information. Therefore, power consumption and area become import considerations. To design for a specific power level, a power-constrained noise optimization method is used. The method sizes the amplifying transistor for a fixed source impedance, power dissipation, technology, and operating frequency. The chosen topology is the cascode stage …

Built-In Self-Test (Bist) For Multi-Threshold Null Convention Logic (Mtncl) Circuits, Brett Sparkman

Graduate Theses and Dissertations

This dissertation proposes a Built-In Self-Test (BIST) hardware implementation for Multi-Threshold NULL Convention Logic (MTNCL) circuits. Two different methods are proposed: an area-optimized topology that requires minimal area overhead, and a test-performance-optimized topology that utilizes parallelism and internal hardware to reduce the overall test time through additional controllability points. Furthermore, an automated software flow is proposed to insert, simulate, and analyze an input MTNCL netlist to obtain a desired fault coverage, if possible, through iterative digital and fault simulations. The proposed automated flow is capable of producing both area-optimized and test-performance-optimized BIST circuits and scripts for digital and fault simulation …

A Novel Three-Level Isolated Ac-Dc Pfc Power Converter Topology With Reduced Number Of Switches, Obaid Aldosari

Graduate Theses and Dissertations

The three-level isolated AC-DC power factor corrected (PFC) converter provides safe and more efficient power conversion. In comparison with two-level, three-level PFC converter has the advantages of low total harmonic distortion, low device voltage rating, low di/dt, better output performance, high power factor, and low switching losses at higher switching frequencies. The high frequency transformer (HFT) grants galvanic isolation, steps up or down secondary voltage, and limits damage in case of a fault current.

The existing three-level converter based on solid-state transformer (SST) topologies convert ac power from the electrical grid to a dc load while maintaining at least the …

Area Efficient Device Optimization For Esd Protection In High Speed Interface Ics, Dan Thomas Jarard

Graduate Theses and Dissertations

Electrostatic discharge (ESD) protection is considered as a vital step in integrated circuit (IC) manufacturing process. IC chips are unable to overcome the effects of transient events without adequate discharge protection. Recent trend in the industry has seen the incorporation of system level ESD protection within the IC chip. Incorporating system level on-chip ESD protection often increases cost, degrades circuit performance and consumes layout area which could otherwise be used for improving the circuit performance. These design challenges could be easily overcome if the parasitic components in a circuit were used for ESD protection. Despite the various design challenges, on-chip …

Characterization Of Avidin And Case9 Single Protein Molecules By A Solid-State Nanopore Device, Haopeng Li

Graduate Theses and Dissertations

The shape and charge of a protein play significant roles in protein dynamics in the biological system of humans and animals. Characterizing and quantifying the shape and charge of a protein at the single-molecule level remains a challenge. Solid-state nanopores made of silicon nitride (SiNx) have emerged as novel platforms for biosensing such as diagnostics for single-molecule detection and DNA sequencing. SSN detection is based on measuring the variations in ionic conductance as charged biomolecules translocate through nanometer-sized channels driven by an external voltage applied across the membrane. In this paper, we observe the translocation of asymmetric cylindrical structure CRISPR-Cas9 …

Cybersecurity Methods For Grid-Connected Power Electronics, Stephen Joe Moquin

Graduate Theses and Dissertations

The present work shows a secure-by-design process, defense-in-depth method, and security techniques for a secure distributed energy resource. The distributed energy resource is a cybersecure, solar inverter and battery energy storage system prototype, collectively called the Cybersecure Power Router. Consideration is given to the use of the Smart Green Power Node for a foundation of the present work. Metrics for controller security are investigated to evaluate firmware security techniques. The prototype's ability to mitigate, respond to, and recover from firmware integrity degradation is examined. The prototype shows many working security techniques within the context of a grid-connected, distributed energy resource. …