Engineering Commons^™

The Surrogate Fold Catalog: A Design Tool For Origami-Inspired Mechanical Systems, Larry L. Howell, Ivy Running, Phebe Ramsdell, Carolina Wright, Spencer P. Magleby

Faculty Publications

Origami has inspired work in many fields of science and engineering. However, it can be difficult to transfer the motion of an origami design from folded paper to thicker, stiffer materials. When using engineering materials, creases from an origami fold pattern are usually replaced with “surrogate folds”. While many different surrogate folds have been developed, it is challenging for a designer to quickly survey and compare potential surrogate folds. Surrogate folds can improve many origami-inspired designs and applications by changing how the designs are manufactured and how they behave. This work categorizes compliant mechanisms that may be effective as surrogate …

Characterization Of Magnetically Stabilized Hinges For Origami-Inspired Mechanisms, Larry L. Howell, H T. Pruett, Philip Klocke, Spencer Magleby

Faculty Publications

Origami-inspired mechanisms provide opportunities for deployable systems, including reflectarray antennas. There is a need for approaches to deploy and stabilize such arrays. Magnetic mechanisms show promise for meeting those needs and methods for modeling their behavior would facilitate their design and analysis. We demonstrate the existence of bistability in select configurations of magnetically stabilized hinges and characterize their equilibrium positions as a function of parameters estimated from simulation data for these mechanisms. Other relevant information such as potential energy, axial force data, angular position of unstable equilibria, and transition values from bistability to monostability are also modeled. The results are …

Draft Makerspace Optimization And Procedure For The University Of Northern Iowa And Cedar Falls, Andrew Nii Anang

Graduate Research Papers

The University of Northern Iowa (UNI) Makcrspace is a dynamic, communal setting created to encourage members of the community at large to be creative, innovative and engage in hands-on learning. Access to a variety of hand and power tools as well as state-of-the-art technologies is available at this cutting-edge facility. The Makerspace promotes a culture of experimentation and entrepreneurship while offering assistance for multidisciplinary initiatives. The Makerspace incorporates real-world, project-based learning experience, greatly improving UNI's educational environment. It enhances the university's reputation for encouraging innovation and research by drawing in potential students and community members who are interested in cutting-edge …

Experimental Investigation And Performance Analysis Of The Transformational Challenge Reactor (Tcr) System Under Various Temperature And Pressure Conditions, Ahmed Mohamed Ali Soliman

Dissertations and Theses

The Transformational Challenge Reactor (TCR) represents a significant advancement in nuclear reactor technology, taking into consideration modularity, efficiency, and safety. This study explores the coupling between thermal behavior and the coolant gas flow behavior of the TCR’s 3D-printed ceramic core under various operating conditions. Using nitrogen as a coolant, experiments were performed at pressures ranging from 20.4 bar to 40.8 bar (300 to 600 psi) and temperatures from 100°C to 300°C. The main parameters including gas inlet and outlet temperatures, the TCR wall temperature at the inlet and outlet, and flow rates, were analyzed to evaluate heat transfer efficiency and …

An Optical Aptamer-Based Carbon Nanosensor For Cortisol Detection, Jessica Kretli Zanetti

Dissertations and Theses

Cortisol is a hormone related to numerous biological functions. This hormone is primarily associated with regulating the body’s stress response, including its effects on metabolism, immune function, and energy balance. Additionally, it plays a critical role in maintaining physiological homeostasis during periods of physical or psychological stress. Consequently, it is critical to monitor levels of this hormone to understand different vital processes it can impact. This work presents the development of an optical aptamer-based carbon nanosensor for the detection of cortisol. The sensor utilizes single-walled carbon nanotubes (SWCNTs) functionalized with a specific DNA aptamer to achieve high specificity and sensitivity. …

Change Of Metal Oxidation State At High Temperature, Impact Of Temperature And Reactive Gases, Yegor Nikitin

Dissertations and Theses

The fundamental understanding of gas-solid reactions enables a wide range of applications to be developed and improved. Specifically, the use of metal-based materials is critical to ensuring robust, safe, and long-term operations. For example, in power systems where boilers are used to generate steam for heat or electricity generation the use of stainless metal alloys is critical to allow high quality steam to be produced in a very harsh environment. Alternatively, in catalysis, the use of metal doped heterogeneous catalysts are essential in achieving selectivity and conversion performance for chemical synthesis to emissions abatement. Typically, these metal alloys must withstand …

Blockchain Based Framework For Secure And Decentralized Energy Trading - Transforming Local Energy Markets For Sustainable Communities, Saurabh Sachdeva

Dissertations and Theses

The emergence of prosumers provides an opportunity for the setup of a local energy market (LEM) where individual households with distributed energy resources (DERs) can produce, store, and trade energy. Peer-to-peer(P2P) and decentralized energy trading (ET) can be implemented between the participants within or across microgrids. Several solutions based on the existing technologies have been proposed worldwide for the integration of prosumers in the existing energy setup and to enable and support ET, but these solutions present the issues of centralization, data integrity, and confidentiality, user and anonymity, and transparency. The applications of blockchain technology have recently become fascinating for …

Using Mechanical Interventions To Enhance Drug Transport To Bone Tumors, Michelle Gelbs

Dissertations and Theses

Bone metastasis occurs when cancer cells spread from a primary site to a secondary location in bone. Current treatments for metastatic bone tumors typically involve systemic chemotherapy, bisphosphonates, radiotherapy, or surgery; however, due to morphological changes in the tumor microenvironment and elevated interstitial fluid pressure, tissue penetration of therapeutic agents is often more limited in cancerous tumors compared to normal tissue. Weight-bearing mechanical loading applied to bone, as well as other mechanical stimulations such as vibration, have been shown to cause loading-induced bone deformations that increase convective transport via interstitial fluid flow. We hypothesize that mechanical loading can increase the …

Optimizing Transcranial Focused Ultrasound: Calibration, Neuro Navigation, And Bold Fmri Evidence Of Neuromodulation, Amilcar J. Malave

Dissertations and Theses

This thesis presents the development, calibration, and initial implementation of transcranial focused ultrasound (tFUS) for neuromodulation in a human study. The primary objectives were to design a system capable of delivering precise and safe ultrasound stimulation to targeted brain regions and to conduct preliminary trials to assess its effects on brain activity. A custom calibration device was developed to ensure accurate measurement of acoustic pressure, addressing challenges such as voltage alterations caused by changes in system impedance. Additionally, a neuro-navigation tool was created to facilitate precise targeting of the right subgenual anterior cingulate cortex (right sgACC), enabling accurate placement of …

Nanoparticle Stabilized Interfaces And Their Effect On Foam Stability, Nicole T. Donovan

Dissertations and Theses

No abstract provided.

On The Understanding Of The Coastal-Urban Nexus Of Weather, Air Quality And Energy, Harold Gamarro

Dissertations and Theses

Urban environments exhibit complex interactions between atmospheric processes, building energy consumption, and air quality, particularly during periods of seasonal extremes such as summer ozone peaks and winter heating. Accurate representation of these interactions in urban modeling is crucial for understanding and addressing air pollution and energy management challenges in cities. This research presents a comprehensive study that advances urban atmosphere simulations by integrating building energy dynamics, air quality, and robust multi-source observational evaluation. Leveraging the Weather Research and Forecasting (WRF) model, coupled with a multilayer building environment parameterization (BEP) and a building energy model (BEM), with an improved boundary layer …

Analysis Of Energy Savings And Feasibility Of Retrofitting New York City Midrise Multifamily Buildings With Air Source Heat Pump Technology, Samuel Chussid

Dissertations and Theses

Motivated by reducing impacts of climate change due to greenhouse gas emissions, many dense urban cites throughout the United States have set into law ambitions decarbonization policies that will require buildings to replace fossil fuel space and water heating systems with electric powered alternatives. In many cities, especially in the northeast, fossil fuel space and water heating systems are used in a vast majority of buildings and significantly contribute to citywide carbon emissions. In New York City (NYC), it is estimated that over 40 percent of citywide emissions come from space heating and water heating systems that run on fossil …

Implementation Of Acid/Gas Digestion Approach To Maximize Volatile Fatty Acids Production From Municipal Sludge And A Techno-Economic Feasibility Study, Aykut Sayin

Dissertations and Theses

Acid digestion, which is the first step of two-phase acid/gas anaerobic digestion process, was studied to identify the optimum operating conditions that would maximize the production of volatile fatty acids (VFAs). Batch and semi-continuous acid digesters were operated using combined primary sludge and waste-activated sludge as the feedstock from New York City (NYC)’s Wards Island water resource recovery facility (WRRF). Operating conditions tested in batch acid digesters for maximizing VFAs production included temperature (35-70°C), inoculum-to-substrate ratio (0.0-0.5 mgVS/mgVS), thickening (3-13%TS), and contact time (0-10 days), while simultaneously inhibition mechanisms on VFAs production were investigated. Once the optimum operating conditions for …

Modulation Of Motor Learning With High-Intensity Transcranial Electric Stimulation, Gavin Hsu

Dissertations and Theses

Research thus far on noninvasive, transcranial electric stimulation have produced mixed results from in vivo human experiments. This work tests the hypothesis that applying higher stimulation intensities would induce intracranial electric fields that more closely match the higher magnitudes used in animal and in vitro studies and subsequently yield more robust effects. As done commonly in the literature, we targeted the motor cortex (M1), specifically in the context of neuroplastic changes taking place during motor learning in healthy adult humans. This work also seeks a better understanding of the neural correlates underlying motor skill learning.

Through multiple large-sample studies, this …

The Racial Disparities Of The Gamma-Secretase/Notch Pathway And Inhibition In Triple Negative Breast Cancer, Jobin Joseph

Dissertations and Theses

Triple Negative Breast Cancer (TNBC) continues to be a formidable challenge in oncology, characterized by its aggressive phenotype and limited treatment options. Alarming racial disparities in TNBC outcomes persist, with underrepresented populations experiencing disproportionately higher rates of mortality and poorer prognoses. This master's thesis aims to delve into the molecular intricacies that contribute to these disparities, with a specific focus on gamma secretase activity, a key regulator of cellular processes.

The research methodology encompasses a multi-faceted approach, amalgamating clinical data analysis with extensive in vitro and in vivo experimentation. The study employs cutting-edge molecular profiling techniques and gene expression analysis …

Ring Resonators Intergrating With Dichoric Materials And In Spin-Valley Controlled Photonic Topological System, Yuma Kawaguchi

Dissertations and Theses

Photonic technology plays an important role in the development of diverse applications, ranging from optical telecommunications to sensing and imaging. The utilization of photonic circuits emerges as a promising platform for the establishment of advanced communication systems characterized by high speed and large capacity. This advancement is crucial to facilitate fast and efficient data transfer while concurrently managing multiple devices. It is imperative that essential components such as lasers, modulators, and isolators exhibit compactness without incurring significant losses.

Non-reciprocal devices represent a valuable addition to photonic circuits, enabling the creation of unidirectional waveguides that function as optical isolators, preventing signals …

Alkaline Potassium Polyacrylate Electrolytes For Rechargeable Zinc-Manganese Dioxide Batteries, Jungsang Cho

Dissertations and Theses

Zinc (Zn)–manganese dioxide (MnO₂) rechargeable batteries have high specific theoretical capacity as well as being environmentally friendly, intrinsically safe and low-cost. Liquid electrolytes, such as potassium hydroxide (KOH), are historically used in these batteries; however, many failure mechanisms of the Zn–MnO₂ battery chemistry result from the use of liquid electrolytes, including the formation of electrochemically inactive compounds and shape change of Zn electrodes during charge and discharge cycling. This led to incorporation of an alkaline polymer electrolyte as an alternative to the liquid KOH electrolyte in Zn-MnO₂ rechargeable batteries, with the aim of making them non-spillable …

Surface Activity At The Air-Water Interface And Self-Stratification Of Silica Nanoparticles Functionalized With Tri-Methoxy Poly(Ethylene Glycol) Silane, Hyeongoo Jung

Dissertations and Theses

Aggregated silica nanoparticles (SNPs) have been functionalized with tri-methoxy poly(ethylene glycol) silane (mPEG silane), end-capped with a methyl group. This functionalization imparts surface activity at the air-water interface due to the hydrophobic nature of the end-capped methyl group. To determine the surface coverage of silane on the particle surface, solution-state ¹H-NMR spectroscopy was utilized for characterization, and surface tension measurements were conducted to assess their tension-lowering ability. Solutions containing 10 wt% of the functionalized SNPs reduced the quasi-static surface tension to approximately 53 mN/m, regardless of the amount of reacted mPEG silane. However, the quantification of mPEG silane influenced …

Hydrodynamics Of Drops And Particles Driven By Marangoni And Diffusiophoretic Forces, Subramaniam Chembai Ganesh

Dissertations and Theses

This study investigates the hydrodynamics of particles and drops driven by forces generated by an asymmetrical physical and chemical surrounding environment. In the first part, a novel colloidal motor design driven by surface tension forces is proposed, utilizing an active Janus particle encapsulated in an immiscible liquid drop to form a compound drop/particle. Marangoni forces induced by asymmetric solute adsorption at the liquid-liquid interface of the drop propels the compound system. The propulsion speeds of the motor are analyzed for various relative sizes and configurations of the Janus particle and the encapsulating drop and the effects of varying the transport …

Hyperspectral And Polarimetric Imaging Of The Ocean For The Characterization Of The Surface Effects And Measurement Uncertainties, Mateusz Malinowski

Dissertations and Theses

Ocean and coastal waters are monitored by Ocean Color satellite sensors to determine concentrations of chlorophyll and water properties and identify areas of algal blooms and other events. The light radiance from the ocean is weak in comparison with the sky radiance, which requires very accurate atmospheric correction of the radiance measured at the top of the atmosphere (TOA) on the satellite and heavy validation of the derived water leaving radiance by field measurements from the ships and ocean platforms. For TOA and especially above water radiance the skylight reflected from the ocean surface represents one of the main sources …

Orbit Determination Demonstration Using Onboard One-Way Radiometrics From The Iris Radio On The Capstone Mission, Todd A. Ely, Anthony Zara, Dana Sorensen, Zaid J. Towfic, Connor Ott, Alec Forsman, John D. Baker

Space Dynamics Laboratory Publications

Onboard one-way radiometric tracking from an Iris Radio paired with a Chip Scale Atomic Clock (CSAC) on NASA’s CAPSTONE mission has been collected and demonstrated to be able to determine its near rectilinear halo orbit. This is a first-ever demonstration of one-way radiometric tracking originating from the DSN and being collected onboard a spacecraft. For CAPSTONE, the tracking data from the Iris/CSAC pair are shown to have sufficient accuracy to enable future autonomous radio navigation for missions with modest navigation requirements. This work will compare the space-based data with prior ground-based test results, as well as assess CAPSTONE’s orbit solution …

Target Size Estimation Through Sensor Fusion, Morgan Davidson, Cory Brinck, Kori Moore, Tanner Chase

Space Dynamics Laboratory Publications

Target size is an important quantity in both classification and multi-sensor target tracking applications, but it is often an unknown. In some imaging applications, target size is assumed based on classification results. This assumed size is sometimes used in the synthesis of range measurements from monocular imagery, based on the apparent target size that is observed. Range-from-apparent-size measurements may be the only range measurements available during times when sensors that produce range information (such as radar) are not available. This range-from-apparent-size approach is typically plagued by range bias in the resulting measurements due to several factors. In this work, we …

Advancements And Challenges In Additively Manufactured Functionally Graded Materials: A Comprehensive Review, Suhas Alkunte, Ismail Fidan, Vivekanand Naikwadi, Shamil Gudavasov, Mohammad Alshaikh Ali, Mushfig Mahmudov, Seymur Hasanov, Muralimohan Cheepu

Engineering Technology Faculty Publications

This paper thoroughly examines the advancements and challenges in the field of additively manufactured Functionally Graded Materials (FGMs). It delves into conceptual approaches for FGM design, various manufacturing techniques, and the materials employed in their fabrication using additive manufacturing (AM) technologies. This paper explores the applications of FGMs in diverse fields, including structural engineering, automotive, biomedical engineering, soft robotics, electronics, 4D printing, and metamaterials. Critical issues and challenges associated with FGMs are meticulously analyzed, addressing concerns related to production and performance. Moreover, this paper forecasts future trends in FGM development, highlighting potential impacts on diverse industries. The concluding section summarizes …

Energy Efficiency In Additive Manufacturing: Condensed Review, Ismail Fidan, Vivekanand Naikwadi, Suhas Alkunte, Roshan Mishra, Khalid Tantawi

Engineering Technology Faculty Publications

Today, it is significant that the use of additive manufacturing (AM) has growing in almost every aspect of the daily life. A high number of sectors are adapting and implementing this revolutionary production technology in their domain to increase production volumes, reduce the cost of production, fabricate light weight and complex parts in a short period of time, and respond to the manufacturing needs of customers. It is clear that the AM technologies consume energy to complete the production tasks of each part. Therefore, it is imperative to know the impact of energy efficiency in order to economically and properly …

Ground Tire Rubber As A Sustainable Additive: Transforming Desert Sand Behavior, Nabil Ismael, Dalya Ismael, Asmaa Al-Ahmad

Engineering Technology Faculty Publications

Managing waste tires presents a significant challenge globally, particularly in regions experiencing high temperatures and shortage of landfill sites. This issue is affecting countries like Kuwait, where the abundance of waste tires is a major source of environmental and safety risks, particularly during the intensely hot summer months. This extreme heat has sparked numerous fires, leading to substantial air pollution due to thick black smoke. Given the limited disposal options, recycling waste tires and finding practical applications for ground tire rubber (GTR) is essential. To address the challenge, a comprehensive laboratory testing program was conducted, using locally produced rubber aggregates …

Immersive Visualization In Infrastructure Planning: Enhancing Long-Term Resilience And Sustainability, Dalya Ismael

Engineering Technology Faculty Publications

Infrastructure decisions today significantly impact future generations' quality of life, especially as severe storms and rising sea levels increasingly threaten communities across the United States. Decision-makers at all levels, including those involved in disaster prevention and response, must address climate change. However, those in infrastructure design and construction often prioritize immediate gains over long-term resilience. Engineering teams typically employ decision tools to manage complexity, but these methods may not highlight the long-term consequences of their choices. This study tests whether integrating Virtual Reality (VR) technology with engineering decision-making tools, can enhance engineers’ ability to visualize the future impacts of their …

Uncertainty Quantification In Large Language Models Through Convex Hull Analysis, Ferhat Ozgur Catak, Murat Kuzlu

Engineering Technology Faculty Publications

Uncertainty quantification approaches have been more critical in large language models (LLMs), particularly high-risk applications requiring reliable outputs. However, traditional methods for uncertainty quantification, such as probabilistic models and ensemble techniques, face challenges when applied to the complex and high-dimensional nature of LLM-generated outputs. This study proposes a novel geometric approach to uncertainty quantification using convex hull analysis. The proposed method leverages the spatial properties of response embeddings to measure the dispersion and variability of model outputs. The prompts are categorized into three types, i.e., ’easy’, ’moderate’, and ’confusing’, to generate multiple responses using different LLMs at varying temperature settings. …

Long-Term Impact Of A Semester-Long Multidisciplinary Service-Learning Assignment In A Fluid Mechanics Course, Orlando M. Ayala, Kristie Gutierrez, Isaac Koduah Kumi, Francisco Cima, Stacie I. Ringleb, Krishnanand Kaipa, Danielle M. Rhemer, Pilar Pazos, Jennifer Jill Kidd

Engineering Technology Faculty Publications

Seventy-three students who enrolled in a senior-year level fluid mechanics course during spring semesters from 2019-2023 were asked about their perceptions on the impact in their professional preparation of a semester-long multidisciplinary service-learning assignment. This paper aims to evaluate their current perceived impact of the assignment (long-term impact) and whether it might have changed from when they took the course (short-term impact). The project tested their creativity, knowledge of fluid mechanics concepts, and skills to work with people from other disciplines. They were told that they were working for a hypothetical company, “Engineering is for all,” and were assigned to …

Federated Learning: Overview, Strategies, Applications, Tools And Future Directions, Betul Yurdem, Murat Kuzlu, Mehmet Kemal Gullu, Maliha Tabassum

Engineering Technology Faculty Publications

Federated learning (FL) is a distributed machine learning process, which allows multiple nodes to work together to train a shared model without exchanging raw data. It offers several key advantages, such as data privacy, security, efficiency, and scalability, by keeping data local and only exchanging model updates through the communication network. This review paper provides a comprehensive overview of federated learning, including its principles, strategies, applications, and tools along with opportunities, challenges, and future research directions. The findings of this paper emphasize that federated learning strategies can significantly help overcome privacy and confidentiality concerns, particularly for high-risk applications.

Four Decades Of Distance Learning Instruction In An Electrical Engineering Technology Program, Otilia Popescu, Isaac L. Flory Iv, John R. Hackworth, Murat Kuzlu

Engineering Technology Faculty Publications

Online instruction is no longer a new or seldom used modality. It has grown over the last few decades, reaching a pinnacle during the recent pandemic. Different institutions and different programs chose different approaches for the online delivery of courses, adopting either synchronous or asynchronous deliveries for online students, and hybrid delivery for mixed groups of campus and online students attending the classes in a live or synchronous manner. This paper’s main goal is to present the history of over 40 years of distance learning in an Electrical Engineering Technology program and how the delivery mode progressed over time. While …