Engineering Commons^™

Improving Pv Module Efficiency Through Cooling, Megan Reynolds

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: …

Solution To Exide Technologies Inbatec Inefficiency, Shixuan Hou, Reagan Gilker, Mary Fairley, Spencer Christian, 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 …

Re-Evaluating Coverage Metrics For Wireless Sensor Network Border Security Applications, Kevin Haney

Industrial Engineering Undergraduate Honors Theses

Wireless sensor networks are an emerging technology used to monitor an environment over time. One specific application of the wireless sensor network is the border security application. Researchers have adapted coverage metrics from general wireless sensor network literature to fit the border security application. While some of the adapted metrics count the number of sensors detecting a potential target, others measure the distance between a potential target and its nearest sensor. No existing metric accounts for both of these factors. To take advantage of this gap and to attempt to increase the accuracy to which coverage is measured in this …

Promoting The Sustainable Utilization Of Groundwater Resources In Ethiopia Using The Integrated Groundwater Footprint Index, Xinyu Lin

Honors Scholar Theses

The country of Ethiopia is highly vulnerable to human-caused climate change and is already suffering from the effects. The predominately rural population relies heavily on small-scale agriculture, with 78% of households having at least one member engaged in the field, yet staple crops are highly susceptible to droughts and other weather shocks. Total and agricultural GDP growth in the country have been strongly linked to inter-annual rainfall variability, of which Ethiopia has among the highest in sub-Saharan Africa. A decrease in rainfall since the 1970s has been one of the primary causes of low crop yields, and stresses the immediate …

Melamine-Derived Graphene Foam As A Thermal Additive For Water Harvesting Applications, Emily Chase

Honors Theses

This project proposes the use of a novel melamine-derived graphene foam formed by high temperature pyrolysis under inert conditions for use as a thermal additive to absorbent crystals. The high thermal conductivity of graphene foam makes it an ideal candidate for use as a cheap, flexible, and light-weight alternative to previously used copper foam and metal organic frameworks. Following surface functionalization, graphene foam may be saturated with hydrophilic absorbent crystals. The primary objectives of this research are to optimize the synthesis process of such a graphene foam to obtain the highest purity product while maintaining foam flexibility and to study …

Synthesizing And Modeling The Optical Properties Of Silica Aerogel, Hannah Margavio

Honors Theses

Silica aerogel has attracted the attention of researchers for decades for its applications in insulation materials, storage, and solar-thermal devices. The appeal surrounding silica aerogel is attributed to its unique combination of physical and chemical properties. Silica aerogel is a highly porous, optically transparent nano-polymer with a low thermal conductivity. Additionally, the material boasts a super-low density, high specific surface area, and low dielectric constant. The following report proposes a viable method of synthesizing polyvinylpolymethylsilane (PVPMS) aerogel as well as a model for determining the optical performance of TMOS aerogel by determining its radiative properties. First, the report will explore …

The Problem-Solving Workshop: Adapting Process Improvement Methodologies For K-12 Educators, Madison Chan

Honors Theses

Lean and Six Sigma have been lauded in the manufacturing sector for their ability to streamline processes, reduce waste, minimize variation and defects, and improve the bottom line. Although these methodologies have begun to spread to other industries, their impact has been relegated to certain areas and has largely missed others. One area that bears strong consideration is education. Education is heavily process-based and notoriously tight on resources. It is hypothesized that if educators were taught the basics of these strategies and were able to implement them in the classroom setting, the effectiveness of both teaching strategies and classroom operations …

An Investigation Of Diode Failure, Nicholas James Adams

Physics

Solar electricity can be used to cheaply cook food and charge electronic devices. We investigate the viability of using diodes as heating elements for insulated solar electric cooking (ISEC). In addition, information on designing and constructing ISEC compatible phone chargers and rechargeable LED lighting systems is included.

Characterization Of Mechanical, Thermodynamic And Surface Properties Of The Butterfly Proboscis, Tatiana Stepanova

All Theses

The butterfly proboscis is a fascinating fiber designed to probe and transport fluids. The built-in sensors and actuators make this fiber multifunctional. The proboscis consists of 2 hollow C-shaped tubes that are united when the butterfly comes out of the pupa. A single galea consists of a solid cuticular wall, muscles, nerves, and tracheae. The proboscis cuticular wall is mainly composed of polymers and small amounts of metals and non-metals. The proboscis is a porous material, and its water content is high, up to 50%. When the butterfly is not hungry, its proboscis is tightly coiled; when the butterfly is …

A High Frequency Photoacoustic System For Colorectal Cancer Imaging, Kexin Huang

McKelvey School of Engineering Graduate Student Theses & Dissertations

While colorectal cancer is the second largest cause of cancer-related deaths in the United States, early detection is a key factor in its survival rate. Compared to conventional imaging modalities, photoacoustic imaging offers benefits in providing angiographic images which are valuable for early-stage tumor detection. This thesis presents the design of a 32-channel 80 MHz photoacoustic image system, whose relatively high frequency offers particular advantages. The system comprises several modules, including a laser system, ultrasound probe, AD convertor, microcontroller (FPGA), and a computer. The system requires programs for the FPGA and the data receiver on the computer. The data transportation …

Computational Imaging Methods For Analysis Of Datscan Spect Images, Hae Sol Moon

McKelvey School of Engineering Graduate Student Theses & Dissertations

There is an important need to develop biomarkers to improve the diagnosis and assess the severity of Parkinson’s disease (PD). The potential to derive such biomarkers from quantitative dopamine transporter scan (DaT-Scan) single-photon emission computed tomography (SPECT) imaging, in particular the uptake of DaT in the caudate, putamen, and globus pallidus regions, is highly appealing as imaging is non-invasive and DaTScan is already used in the management of patients with PD. However, reliable quantification requires reliable segmentation of these regions in these images. Reliable segmentation is challenging due to the limited spatial resolution and high image noise in SPECT images …

Micro Distillery Process Design And Business Plan, Nolan Hughes

Graduate Theses - Engineering Management

This integrated project investigates entry into the growing distillery market. The specific entry point will be a craft distillery focusing on the artisanal production of rum in Houston, Texas and the surrounding regions. A flexible design of a distillation process implementing a hybrid pot still with a total capital investment of $391,000 was generated. A business model incorporating this process design develops the consumer basis, value proposition, key activities, and cost structure of the artisanal distillery. Following the proposed business model incorporating the maximization of initial cash flow, the resulting NPV at a discount rate of 10% after 10 years …

Wait A Minute! Reducing Campus Eatery Wait Times, Yewande Ade-Arigbabuwo

Graduate Theses - Engineering Management

The purpose of this study was to reduce meal wait times at Chauncey’s, a pub-style eatery for students at Rose-Hulman Institute of Technology. Chauncey’s re-opened in Fall 2018-19 after the student union was redesigned in Summer 2018. With its refreshed look and menu, its popularity grew, and so did its customers’ wait times. Despite Chauncey’s staffs’ efforts to reduce wait times in the fall and winter quarters, the waits still fluctuated at peak times and were often longer than customers considered reasonable. Consequently, dissatisfied customers sometimes gravitated towards other campus dining options, such as the student cafeteria. Not only does …

Post-Impact Flexural Behavior Of Carbon-Aramid/Epoxy Hybrid Composites, A. Wagih, T. A. Sebaey, A. Yudhanto, G. Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Hybrid polymeric composites are currently used in aerospace structures due to their specific strength and stiffness as well as larger design space. This paper presents an experimental study on residual flexural strength of impacted Carbon-aramid/Epoxy hybrid composite laminates. Specimens are designed in a sandwich form in which plies of aramid/epoxy represent the core and carbon/epoxy plies play the role of face sheets. This design is expected to take advantage of the high energy absorption capabilities of aramid/epoxy composites. We pre-damage such composites by performing low-velocity impact at different energy levels. Three-point bending tests then are used to measure the residual …

Static Pressure Recovery Effects Of Conical Diffusers With Swirling Inlet Flow, James Ray Wright Iii

All Theses

Conical diffusers are used in hundreds of engineering applications in various industries. Some of the operating conditions that they operate under cause swirling flow to enter the diffuser. It is generally well documented that the addition of swirl to the flow of a diffuser allows for greater divergence angles without wall separation, resulting in better overall performance of the diffuser and the machine it’s attached to. It is also known that as swirl strength is increased, the flow will eventually breakdown, resulting in internal flow recirculation and decreased diffuser performance. However, the relationship between the diffuser geometry and its performance …

Enhancing Cellular Communications For Uavs Via Intelligent Reflective Surface, Dong Ma, Ming Ding, Mahbub Hassan

Research Collection School Of Computing and Information Systems

Intelligent reflective surfaces (IRSs) capable of reconfiguring their electromagnetic absorption and reflection properties in real-time are offering unprecedented opportunities to enhance wireless communication experience in challenging environments. In this paper, we analyze the potential of IRS in enhancing cellular communications for UAVs, which currently suffers from poor signal strength due to the down-tilt of base station antennas optimized to serve ground users. We consider deployment of IRS on building walls, which can be remotely configured by cellular base stations to coherently direct the reflected radio waves towards specific UAVs in order to increase their received signal strengths. Using the recently …

Delineating The Relationship Between Cardiovascular Physiology And Subject Characteristics Using Computational Modeling And Systemic Review, Aseem Pradhan

All Theses

Lumped Parameter Networks (LPN) are computational models that can capture the systemic responses of the cardiovascular system. An LPN describes the systemic behavior by providing outputs such as the blood pressure, flowrate, and heart chamber volume at the points defined in the network. To use the LPN for medical applications, it needs to provide output values that represent the physiology of realistic subjects. The cardiovascular system exhibits short-term and long-term adaptations to factors such as aging, weight gain, exercise, etc. Therefore, subject characteristics such as age, height, weight, etc. affect the output values of the LPN. Current literature reports the …

Impact Of Compactive Effort On Soil Strength Of Glacial Lake Columbia Soils, Alexander M. Navarra, Dwight Hendrickson, Jaremy Shaw

2020 Symposium Posters

Glacial Lake Columbia (GLC) existed from 15,550 (+/- 450) to 13,050 (+/- 650) years ago (Atwater, 1986) as a result of the Okanagan Lobe of the Cordilleran Ice Sheet damming the Columbia River near present-day Grand Coulee Dam. The lake deposited a fine-grained basal layer that had interbeds of coarse Missoula Flood deposits and later lake deposits above. Because these GLC deposits are present around most of the Spokane area, they are important to civil engineering and development. We sampled the basal layer of GLC soils from the Peone Prairie, WA. We performed prerequisite testing before the main experiment, with …

Additive Manufacturing And How 3d Printing Is Fighting Covid-19, Raghavan Srinivasan, Ahsan Mian, Joy Gockel, Laura M. Luehrmann

Mechanical and Materials Engineering Faculty Publications

This is the fourth installment in the Shelter in Place (SiP) Lecture series. This installment covers the creative ways that 3D printing has supported efforts to combat the pandemic. It covers the basics of what 3D printing is, some of the various creative projects that have used 3D printing to combat the pandemic, among other topics and questions by the pandemic.

Microwave Nondestructive Detection Of Influenc Of Alkali-Silica Reaction (Asr) In Materials Properties Of Concrete Specimens, Reza Zoughi, John R. Gallion, Nolan W. Hayes

Electrical and Computer Engineering Faculty Research & Creative Works

Alkali-silica reaction has been identified to be a cause deterioration in concrete structures. This reaction takes place when alkalis (e.g., potassium and sodium), hydroxyl ions in the pore solution and certain siliceous minerals (present in some aggregates) are present, resulting in what is known as the ASR gel. Expansion of this gel, in the presence of heat and moisture, causes stresses that lead to microcracking and deterioration of concrete. The criticality of this problem has been particularly highlighted in recent past with respect to nuclear power plant containment concrete structures. Although there have been many studies devoted to examining and …

Impact Of Large-Scale Correlated Failures On Multilevel Virtualized Networks, Max G. Medina, Mohammed J.F. Alenazi, Egemen K. Cetinkaya

Electrical and Computer Engineering Faculty Research & Creative Works

Communication network architectures have been evolving with increased programmability and virtualization of physical infrastructures. While this evolution enables a faster introduction of new services and efficient utilization of resources, the complexities and interdependencies among the physical and virtual infrastructures, as well as the control and management planes, hinder a complete understanding of the system at hand. It is imperative, therefore, to model and study these evolving virtualized infrastructures. We propose a multilevel virtualized network embedding model and study its performance against correlated failures. Our analysis of multiple synthetic network models identified that grid-like infrastructures capture the realistic Internet2 structure the …

Investigating The Effect Of Hydrophilic Block Length On The Co-Assembly Behavior Of Amphiphilic Triblock Copolymers, Alexandra M. Garrett

Honors Theses

Polymer vesicles and micelles have been of interest in the scientific community for the past few decades due to potential biomedical applications in areas such as drug delivery, nanoreactors, and biosensing. Polymer vesicles and micelles are formed through the self-assembly of amphiphilic block copolymers. The objective of this project is to gain a better understanding of the influence of hydrophilic block copolymer length and composition in controlling the resulting morphologies from the co-assembly of triblock copolymers. First, a hydrophobic block composed of poly(methyl acrylate) was synthesized using reversible addition-fragmentation chain-transfer (RAFT) polymerization mediated by a difunctional chain-transfer agent. The block …

Thiol-Induced Degradation Of Hydrogels Utilizing Multiresponsive Dithiomaleimides Crosslinkers, Kundu Thapa

Honors Theses

Hydrogels are hydrophilic, three-dimensional materials used as platforms for various biomedical applications such as drug delivery, biosensors, or as scaffolds in tissue engineering. The ability to degrade on demand in response to biological cues is particularly attractive whether dealing with microgels or if one aims to release an active ingredient from a scaffolding material. For instance, many cancer-remediation drug delivery platforms leverage the high concentration of glutathione, a thiol-containing tripeptide, found in cancerous cells. In this work, poly(ethylene glycol) acrylate hydrogels were fabricated using dithiomaleimide (DTM) moieties. DTMs are known to undergo thiol-exchange reactions favoring the dissolution of the hydrogel …

Selfsame Epoxide-Amine Microparticle Systems: Investigation Of Crosslink Density, John J. Peyrefitte

Honors Theses

Epoxide-amine matrix materials containing microparticles with the same chemical composition provide a model system to study interphase formation in highly crosslinked epoxide-amine matrix materials. The epoxide monomer was varied between three different monomer systems to study the model system’s relationship with crosslink density. The same amine monomer, cure procedure, and stoichiometric ratio of epoxide and amine groups were used to prepare each type of microparticle and matrix material. The differences in the epoxide monomer structure affected the crosslink density of the unmodified matrix material, which was concluded to influence the effect of microparticle presence on crosslink density. For the unmodified …

Tailoring Photodegradation Rates Of Acetal-Containing Polymer Networks, Michael Sandoz

Honors Theses

In this thesis, we explore the degradation of poly (thioether acetal) thermosets via a photoinduced thiol-catalyzed ß-scission of acetal linkages incorporated as network crosslink junctions. Specifically, a library of bis-allyl acetal-containing monomers derived from para-substituted benzaldehydes was synthesized and formulated into photopolymerizable thiol-ene resins with commercially available thiol monomers. By varying the electron donating or withdrawing nature of the monomer substituent, we explored the impact of substituent effects on the rate of polymer degradation. Furthermore, we compare the results to those expected from a classical Hammett-type relationship of substituent electronic effects. FTIR was employed to track the appearance of the …

Spherical Cavity Expansion Approach For The Study Of Rigid-Penetrator’S Impact Problems, Mario Buchely, Alejandro Marañon

Materials Science and Engineering Faculty Research & Creative Works

In recent years, Spherical Cavity Expansion (SCE) theory has been extensively utilized to model dynamic deformation processes related to indentation and penetration problems in many fields. In this review, the SCE theory is introduced by explaining the different mathematical features of this theory, its solution, and a potential application to model the penetration of a rigid penetrator into a deformable target. First, a chronologically literature review of the most common models used to study this kind of penetration problems is introduced, focusing on the SCE theory. Then, the engineering model of penetration is presented using the SCE approach. The model …

Passive And Active Battery Balancing Methods Implemented On Second Use Lithium-Ion Batteries, Walter Bartek

Masters Theses

As the number of electric vehicles (EVs) increases, the number of used battery packs that require disposal increases; however, many of these packs still have useful capacity and can be repurposed. When using repurposed large lithium-ion battery packs, deviations between cells within a pack become problematic. These deviations result in a pack that is unbalanced, affecting performance and proving potentially hazardous when charging. Consequently, a battery management system (BMS) is needed. To provide safety, the BMS in this paper monitors and controls the operation of the battery pack. In addition, it controls the redistribution of charge between the cells within …

A Virtual Space Vectors Based Model Predictive Control For Three-Level Converters, Waleed Saad S. Alhosaini

Graduate Theses and Dissertations

Three-phase three-level (3-L) voltage source converters (VSC), e.g., neutral-point clamped (NPC) converters, T-type converters, etc., have been deemed to be suitable for a wide range of medium- to high-power applications in microgrids (MGs) and bulk power systems. Compared to their two-level (2-L) counterparts, adopting 3-L VSCs in the MG applications not only reduces the voltage stress across the power semiconductor devices, which allows achieving higher voltage levels, but also improves the quality of the converter output waveforms, which further leads to considerably smaller output ac passive filters.

Various control strategies have been proposed and implemented for 3-L VSCs. Among all …

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 …

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 …