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Faculty Publications

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Articles 421 - 450 of 3293

Full-Text Articles in Engineering

Bringing The Analysis Of Electrodeposition Signals In Voltammetry Out Of The Shadows, Devin Rappleye, Ranon G. Fuller Jun 2023

Bringing The Analysis Of Electrodeposition Signals In Voltammetry Out Of The Shadows, Devin Rappleye, Ranon G. Fuller

Faculty Publications

Voltammetry studies of electrodeposition are growing rapidly. Yet, relations for the analysis of electrodeposition reactions in voltammetry remain relatively obscure in the literature. The existing cyclic and square wave voltammetry relations for electrodeposition and their limitations are discussed to increase awareness. A retrospective analysis is performed to demonstrate the impact of model selection in improving the analysis of electrodeposition behavior with voltammetric data. A repository for voltammetry models of electrodeposition is proposed to further increase familiarity and application of the most appropriate models, which would support a rapidly growing area of research and technological development.

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Imparting Systems Engineering Experience Via Interactive Fiction Serious Games, Thomas C. Ford, David Long, Echo Ford Jun 2023

Imparting Systems Engineering Experience Via Interactive Fiction Serious Games, Thomas C. Ford, David Long, Echo Ford

Faculty Publications

Serious games for education are becoming increasing popular. Interactive fiction games are some of the most popular in app stores and are also beginning to be heavily used in education to teach analysis and decision-making. Noting that it is difficult for systems engineers to experience all necessary situations which prepare them for the role of a chief engineer, in this paper, we explore the use of interactive fiction serious games to impart systems engineering experience and to teach systems engineering principles. The results of a cognitive viability, qualitative viability, and replayability analysis of 14 systems engineering serious games developed in …

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Estimating Intermittency Significance By Means Of Surrogate Data: Implications For Solar Wind Turbulence, Eliza Teodorescu, Marius Mihai Echim, Jay Johnson Jun 2023

Estimating Intermittency Significance By Means Of Surrogate Data: Implications For Solar Wind Turbulence, Eliza Teodorescu, Marius Mihai Echim, Jay Johnson

Faculty Publications

Introduction: Intermittency is a property of turbulent astrophysical plasmas, such as the solar wind, that implies irregularity and fragmentation, leading to non-uniformity in the transfer rate of energy carried by nonlinear structures from large to small scales. We evaluated the intermittency level of the turbulent magnetic field measured by the Parker Solar Probe (PSP) in the slow solar wind in the proximity of the Sun during the probe’s first close encounter. Methods: A quantitative measure of intermittency could be deduced from the normalized fourth-order moment of the probability distribution functions, the flatness parameter. We calculated the flatness of the magnetic …

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Modeling Potential Damages Of Hurricanes At The Facility Scale: A Case Study Of Eglin Air Force Base, Alexander J. Baldwin, Christopher M. Chini, Steven J. Schuldt, Justin D. Delorit Jun 2023

Modeling Potential Damages Of Hurricanes At The Facility Scale: A Case Study Of Eglin Air Force Base, Alexander J. Baldwin, Christopher M. Chini, Steven J. Schuldt, Justin D. Delorit

Faculty Publications

Tropical cyclones have intensified and are expected to strengthen throughout the 21st century due to climate change impacts. Storm intensification poses a serious threat to coastal municipalities and infrastructure that are not designed to withstand future wind and storm surge potential. Coupled modeling software has been widely used to replicate extreme weather events and simulate climate change effects to understand the magnitude of vulnerability coastal regions face. However, these studies are often conducted at too coarse resolutions to provide decision makers with actionable information for facility-level adaptation. This study addresses this limitation using a coupled modeling approach by simulating climate-intensified …

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User Guide For Urban Canopy Modeling In Wrf. Version 1.0, Corey L. Smithson, Natalie J. White, Hans R. Klomp, Eric C. Monson, Bradley R. Adams Jun 2023

User Guide For Urban Canopy Modeling In Wrf. Version 1.0, Corey L. Smithson, Natalie J. White, Hans R. Klomp, Eric C. Monson, Bradley R. Adams

Faculty Publications

Researchers at Brigham Young University (BYU) have developed this guide for running a WRF simulation using a single layer urban canopy model (UCM). This was developed specifically for the Greater Salt Lake Area but is adaptable to other urban areas. This guide includes information on running WRF simulations to study theoretical urban growth scenarios.

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Effects Of Individual Strategies For Resource Access On Collaboratively Maintained Irrigation Infrastructure, Jordan L. Stern, Afreen Siddiqi, Paul N. Grogan Jun 2023

Effects Of Individual Strategies For Resource Access On Collaboratively Maintained Irrigation Infrastructure, Jordan L. Stern, Afreen Siddiqi, Paul N. Grogan

Faculty Publications

Built infrastructure for water and energy supply, transportation, and other such services underpins human well-being and socioeconomic development. A fundamental understanding of how infrastructure design and user strategies interact can guide important design decisions as well as policy formulation for ensuring long-term infrastructure viability in conjunction with improved individual user benefits. In this work, an agent based model (ABM) is developed to study this issue for the specific case of irrigation canals. Cooperatively maintained irrigation canals serve essential roles in sustaining agriculture-based economies in many regions. Canal system design can strongly affect benefits derived by distributed users, regional agricultural output, …

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Nonsolvent-Induced Phase Separation Inside Liquid Droplets, Rami Alhasan, Tanner A. Wilcoxson, Dakota S. Banks, Sion Jung, Douglas R. Tree Jun 2023

Nonsolvent-Induced Phase Separation Inside Liquid Droplets, Rami Alhasan, Tanner A. Wilcoxson, Dakota S. Banks, Sion Jung, Douglas R. Tree

Faculty Publications

Nonsolvent-induced phase separation (NIPS) is a popular method for creating polymeric particles with internal microstructure, but many fundamental questions remain surrounding the kinetics of the complex coupled mass transfer and phase separation processes. In this work, we use simulations of a phase-field model to examine how (i) finite domain boundaries of a polymer droplet and (ii) solvent/nonsolvent miscibility affect the NIPS process. To isolate the effects of phase separation kinetics and solvent/nonsolvent mass transfer on the NIPS process, we study two different cases. First, we investigate droplet concentrations that originate inside the two-phase region, where phase separation kinetics alone governs …

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Vortex Particle Method For Electric Ducted Fan In Non-Axisymmetric Flow, Eduardo Alvarez, Cibin Joseph, Andrew Ning Jun 2023

Vortex Particle Method For Electric Ducted Fan In Non-Axisymmetric Flow, Eduardo Alvarez, Cibin Joseph, Andrew Ning

Faculty Publications

The vortex particle method has been reformulated in recent work as a large eddy simulation (LES) in a scheme that is both meshless and numerically stable, solving long-standing issues of numerical stability. In this study, we build upon this meshless LES scheme to create a simulation framework for electric ducted fans. This poses the challenge of introducing solid boundaries in the vorticity form of the Navier-Stokes equations without a mesh. Rotor blades are introduced in our computational domain through an actuator line model (ALM) following well-established practices for LES. A novel, vorticity-based, actuator surface model (ASM) is developed for the …

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Hierarchical, Porous Hydrogels Demonstrating Structurally Dependent Mechanical Properties, Elisabeth Lloyd, Rami Alhasan, Sujata Dhakal, Svetlana Morozova, Douglas R. Tree, Robert Hickey May 2023

Hierarchical, Porous Hydrogels Demonstrating Structurally Dependent Mechanical Properties, Elisabeth Lloyd, Rami Alhasan, Sujata Dhakal, Svetlana Morozova, Douglas R. Tree, Robert Hickey

Faculty Publications

While hierarchical ordering is a distinctive feature of natural tissues and is directly responsible for their diverse and unique properties, research efforts to synthesize biomaterials have primarily focused on using molecular-based approaches without considering multiscale structure. Here, we report a bottom-up self-assembly process to produce highly porous hydrogels that resemble natural tissues both structurally and mechanically. Randomly oriented, physically crosslinked nanostructured micelles form the walls of aligned, polymer-rich pore walls that surround water-rich cavities. Extremely soft elastic modulus (<  1 kPa), highly stretchability (greater than 12-times), strain-hardening, and completely reversible deformation result from the hierarchical structure. Independent control of nano and macroscales is realized through the combination of polymer macromolecular parameters and processing conditions, directly impacting the resulting phase behavior. Here, we demonstrate precise control of the material structure and structure orientation over many orders of magnitude (e.g., nm – µm), and reveal how the multiscale structure directly impacts mechanical properties.

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Fate And Transport Of Per- And Polyfluoroalkyl Substances (Pfas) At Aqueous Film Forming Foam (Afff) Discharge Sites: A Review, Jeffery T. Mcgarr, Eric G. Mbonimpa, Drew C. Mcavoy, Mohamad R. Soltanian May 2023

Fate And Transport Of Per- And Polyfluoroalkyl Substances (Pfas) At Aqueous Film Forming Foam (Afff) Discharge Sites: A Review, Jeffery T. Mcgarr, Eric G. Mbonimpa, Drew C. Mcavoy, Mohamad R. Soltanian

Faculty Publications

Per- and polyfluorinated alkyl substances (PFAS) are an environmentally persistent group of chemicals that can pose an imminent threat to human health through groundwater and surface water contamination. In this review, we evaluate the subsurface behavior of a variety of PFAS chemicals with a focus on aqueous film forming foam (AFFF) discharge sites. AFFF is the primary PFAS contamination risk at sites such as airports and military bases due to use as a fire extinguisher. Understanding the fate and transport of PFAS in the subsurface environment is a multifaceted issue. This review focuses on the role of adsorbent, adsorbate, and …

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Design And Performance Of A Laboratory Scale Pressurized Oxy-Coal Reactor, Scott Gardner, Cody Carpenter, Jacob Tuia, Aaron Skousen, Dustin Badger, Sandra Thomas, Bradley R. Adams, Dale R. Tree, Andrew R. Fry May 2023

Design And Performance Of A Laboratory Scale Pressurized Oxy-Coal Reactor, Scott Gardner, Cody Carpenter, Jacob Tuia, Aaron Skousen, Dustin Badger, Sandra Thomas, Bradley R. Adams, Dale R. Tree, Andrew R. Fry

Faculty Publications

A pressurized oxy-coal (POC) reactor has been designed, built and tested to investigate key technologies related to oxy-coal combustion including a dry coal feed system, an oxy-coal burner, and a slagging ash management system. The coal feed system utilized a fluidized bed to convey pulverized coal with CO2 from a coal bed into the reactor. The reactor has diagnostic capabilities including optical access, embedded thermocouples, fuel and gas flow rates, exhaust gas analysis (CO2, CO, NO, O2) and heat flux. At 13.6 atm and a firing rate of 89 kWth a mean feed rate of 12.5 kg/h was …

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Experimental And Numerical Behavior Of Encased Pultruded Gfrp Beams Under Elevated And Ambient Temperatures, Enas M. Mahmood, Teghreed H. Ibrahim, Abbas A. Allawi, Ayman El-Zohairy May 2023

Experimental And Numerical Behavior Of Encased Pultruded Gfrp Beams Under Elevated And Ambient Temperatures, Enas M. Mahmood, Teghreed H. Ibrahim, Abbas A. Allawi, Ayman El-Zohairy

Faculty Publications

In this research, experimental and numerical studies were carried out to investigate the performance of encased glass-fiber-reinforced polymer (GFRP) beams under fire. The test specimens were divided into two peer groups to be tested under the effect of ambient and elevated temperatures. The first group was statically tested to investigate the monotonic behavior of the specimens. The second group was exposed to fire loading first and then statically tested to explore the residual behavior of the burned specimens. Adding shear connectors and web stiffeners to the GFRP beam was the main parameter in this investigation. Moreover, service loads were applied …

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Decision Support Issues In Automated Driving Systems, William N. Caballero, David Ríos Insua, David Banks May 2023

Decision Support Issues In Automated Driving Systems, William N. Caballero, David Ríos Insua, David Banks

Faculty Publications

Machine learning and computational processing have advanced such that automated driving systems (ADSs) are no longer a distant reality. Many automobile manufacturers have developed prototypes; however, there exist numerous decision support issues requiring resolution to ensure mass ADS adoption. In the coming decades, it is likely that production ADSs will only be partially autonomous. Such ADSs operate within predetermined conditions and require driver intervention when they are violated. Since forecasts of their 20-year market penetration are relatively low, ADSs will likely operate in heterogeneous traffic characterized by vehicles of varying autonomy levels. Under these conditions, effective decision support must consider …

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Numerical Modeling And Analysis Of Strengthened Steel–Concrete Composite Beams In Sagging And Hogging Moment Regions, Ayman El-Zohairy, Suzan Mustafa, Hesham Shaaban, Hani Salim Apr 2023

Numerical Modeling And Analysis Of Strengthened Steel–Concrete Composite Beams In Sagging And Hogging Moment Regions, Ayman El-Zohairy, Suzan Mustafa, Hesham Shaaban, Hani Salim

Faculty Publications

Strengthening of composite beams is highly needed to upgrade the capacities of existing beams. The strengthening methods can be classified as active or passive techniques. Therefore, the main purpose of this study is to provide detailed FE simulations for strengthened and unstrengthened steel–concrete composite beams at the sagging and hogging moment regions with and without profiled steel sheeting. The developed models were verified against experimental results from the literature. The verified models were used to present comparisons between the effect of using external post-tensioning and CFRP laminates as strengthening techniques. Applying external post-tensioning at the sagging moment regions is more …

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Discriminating Wirelesshart Communication Devices Using Sub-Nyquist Stimulated Responses, Jeffrey D. Long, Michael A. Temple, Christopher M. Rondeau Apr 2023

Discriminating Wirelesshart Communication Devices Using Sub-Nyquist Stimulated Responses, Jeffrey D. Long, Michael A. Temple, Christopher M. Rondeau

Faculty Publications

Reliable detection of counterfeit electronic, electrical, and electromechanical devices within critical information and communications technology systems ensures that operational integrity and resiliency are maintained. Counterfeit detection extends the device’s service life that spans manufacture and pre-installation to removal and disposition activity. This is addressed here using Distinct Native Attribute (DNA) fingerprinting while considering the effects of sub-Nyquist sampling on DNA-based discrimination. The sub-Nyquist sampled signals were obtained using factor-of-205 decimation on Nyquist-compliant WirelessHART response signals. The DNA is extracted from actively stimulated responses of eight commercial WirelessHART adapters and metrics introduced to characterize classifier performance. Adverse effects of sub-Nyquist decimation …

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Semi-Differentiation Of Reversible, Soluble-Insoluble Potential Sweep Voltammograms, Tyler Williams, Ranon Fuller, Cameron Vann, Devin Rappleye Apr 2023

Semi-Differentiation Of Reversible, Soluble-Insoluble Potential Sweep Voltammograms, Tyler Williams, Ranon Fuller, Cameron Vann, Devin Rappleye

Faculty Publications

Semi-differentiation, or convolution as it is sometimes known, is a mathematical technique commonly used to disentangle overlapping peaks in cyclic or linear sweep voltammograms. However, this technique is often misapplied due to misunderstandings of fractional calculus. Additionally, rigorous treatment and validation of the theory of semi-differential analysis of reversible, soluble-insoluble electrochemical reactions is lacking. Peculiarities of semi-differentiation are explored; theoretical relations for semi-differentiated voltammograms are given; the exponential nature of the theoretical curve is explored; theoretical relations are compared to experimental voltammograms for AgNO3 in 1 M nitric acid at 298 K, NiCl2 in LiCl at 974 K, …

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Information Horizon Of Solar Active Regions, Jay R. Johnson, Simon Wing, Carson O'Ffill, Bishwa Neupane Apr 2023

Information Horizon Of Solar Active Regions, Jay R. Johnson, Simon Wing, Carson O'Ffill, Bishwa Neupane

Faculty Publications

Information theory is used to characterize the solar active region periodicities and memories from the Carrington map images 1974–2021. The active regions typically evolve and move from one map to the next. In order to track these active region structures in sequences of images, an innovative method based on information theory is developed. Image entropy provides a measure of the organization of structures in the images. The entropy can also be used as a filter to identify structures and partition the active regions, which are then registered for each image. The partitions are used to compute the mutual information and …

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Microcanonical Thermodynamics Of Small Ideal Gas Systems, David S. Corti, Donya Ohadi, Ricardo Fariello, Mark J. Uline Apr 2023

Microcanonical Thermodynamics Of Small Ideal Gas Systems, David S. Corti, Donya Ohadi, Ricardo Fariello, Mark J. Uline

Faculty Publications

We consider the thermal, mechanical, and chemical contact of two subsystems composed of ideal gases, both of which are not in the thermodynamic limit. After contact, the combined system is isolated, and the entropy is determined through the use of its standard connection to the phase space density (PSD), where only those microstates at a given energy value are counted. The various intensive properties of these small systems that follow from a derivative of the PSD, such as the temperature, pressure, and chemical potential (evaluated via a backward difference), while equal when the two subsystems are in equilibrium are nevertheless …

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Human Microbiome Transfer In The Built Environment Differs Based On Occupants, Objects, And Buildings, Andrew J. Hoisington, Christopher E. Stamper, Katherine L. Bates, Maggie A. Stanislawski, Michael C. Flux, Teodor T. Postolache, Christopher A. Lowry, Lisa A. Brenner Apr 2023

Human Microbiome Transfer In The Built Environment Differs Based On Occupants, Objects, And Buildings, Andrew J. Hoisington, Christopher E. Stamper, Katherine L. Bates, Maggie A. Stanislawski, Michael C. Flux, Teodor T. Postolache, Christopher A. Lowry, Lisa A. Brenner

Faculty Publications

Compared to microbiomes on other skin sites, the bacterial microbiome of the human hand has been found to have greater variability across time. To increase understanding regarding the longitudinal transfer of the hand microbiome to objects in the built environment, and vice versa, 22 participants provided skin microbiome samples from their dominant hands, as well as from frequently and infrequently touched objects in their office environments. Additional longitudinal samples from home environments were obtained from a subset of 11 participants. We observed stability of the microbiomes of both the hand and built environments within the office and home settings; however, …

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Utilizing The System Engineering Trade Study Analysis Method To Analyze Patient Aeromedical Evacuation, Sara Shaghaghi, Jeremy M. Slagley, Michael E. Miller, Gaiven Varshney Apr 2023

Utilizing The System Engineering Trade Study Analysis Method To Analyze Patient Aeromedical Evacuation, Sara Shaghaghi, Jeremy M. Slagley, Michael E. Miller, Gaiven Varshney

Faculty Publications

The US Air Force has gone through many aeromedical patient isolation transport system designs. The first designs were developed in response to the Ebola outbreak in 2014 and, more recently, the COVID-19 pandemic. The trade study analysis part of the system engineering design method was used to analyze the historic and current aeromedical patient contamination control transport systems. A trade study is a process that evaluates alternatives based upon various “-ilities”, such as reconfigurability, flexibility, durability, cost, and more, and performs a systematic analysis to aid designers in producing a ‘good’ design alternative given the large set of possible solutions. …

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Measuring Radiation Protection: Partners From Across The Nuclear Enterprise Evaluate The Radiation Protection Of Us Army Vehicles, Andrew W. Decker, Robert Prins Apr 2023

Measuring Radiation Protection: Partners From Across The Nuclear Enterprise Evaluate The Radiation Protection Of Us Army Vehicles, Andrew W. Decker, Robert Prins

Faculty Publications

Recent mounting nuclear threats and postures from adversary nation-states, such as Russia, China, North Korea, and Iran, represent a clear danger to the interests and security of the United States of America and its Allies. To meet these threats, the 2022 Nuclear Posture Review requires the Department of Defense (DoD) to design, develop, and manage a combat-credible U.S. military which, among other prioritizations, is survivable. A survivable force can generate combat power despite adversary attacks. As such, the US Army must prepare today to set the conditions for successful conventional warfare on the nuclear battlefields of tomorrow. Our Army cannot …

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Large Eddy Simulation For Empirical Modeling Of The Wake Of Three Urban Air Mobility Vehicles, Denis-Gabriel Caprace, Andrew Ning Apr 2023

Large Eddy Simulation For Empirical Modeling Of The Wake Of Three Urban Air Mobility Vehicles, Denis-Gabriel Caprace, Andrew Ning

Faculty Publications

Recent advances in urban air mobility have driven the development of many new VTOL concepts. These vehicles often feature original designs departing from the conventional helicopter configuration. Due to their novelty, the characteristics of the super-vortices forming in the wake of such aircraft are unknown. However, these vortices may endanger any other vehicle evolving in their close proximity, owing to potentially large induced velocities. Therefore, improved knowledge about the wakes of VTOL vehicles is needed to guarantee safe urban air mobility operations. In this work, we study the wake of three VTOL aircraft in cruise by means of large eddy …

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Experimental Investigation Of Self-Compacting Concrete With Recycled Concrete Aggregate, Sayed Ahmed, Ayman El-Zohairy, Ahmed S. Eisa, Mohamed Abd El-Aziz Badran Mohamed Mar 2023

Experimental Investigation Of Self-Compacting Concrete With Recycled Concrete Aggregate, Sayed Ahmed, Ayman El-Zohairy, Ahmed S. Eisa, Mohamed Abd El-Aziz Badran Mohamed

Faculty Publications

Due to the depletion of natural aggregates and raw materials for contemporary construction, the construction and demolition waste existing in old concrete structures is an imperative problem. Cutting down on exploiting natural aggregates and reusing construction and demolition waste in the concrete industry are solutions to this problem. This paper investigated the replacement of natural coarse aggregate (NCA) with recycled concrete aggregates (RCA) with different ratios (0%, 50%, 75%, and 100%) in producing self-compacting concrete (SCC). Different components of supplementary cementitious materials (SCMs), such as nano-silica (NS), fly ash (FA), and metakaolin (MK), as well as PVA fibers, were incorporated …

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Control Education For Societal-Scale Challenges: A Community Roadmap, John Anthony Rossiter, Christos G. Cassandras, João Hespanha, Sebastian Dormido, Luis De La Torre, Gireeja Ranade, Antonio Visioli, John Hedengren, Richard M. Murray, Panos Antsaklis, Francoise Lamnabhi-Lagarrigue, Thomas Parisini Mar 2023

Control Education For Societal-Scale Challenges: A Community Roadmap, John Anthony Rossiter, Christos G. Cassandras, João Hespanha, Sebastian Dormido, Luis De La Torre, Gireeja Ranade, Antonio Visioli, John Hedengren, Richard M. Murray, Panos Antsaklis, Francoise Lamnabhi-Lagarrigue, Thomas Parisini

Faculty Publications

This article focuses on extending, disseminating and interpreting the findings of an IEEE Control Systems Society working group looking at the role of control theory and engineering in solving some of the many current and future societal challenges. The findings are interpreted in a manner designed to give focus and direction to both future education and research work in the general control theory and engineering arena, interpreted in the broadest sense. The paper is intended to promote discussion in the community and also provide a useful starting point for colleagues wishing to re-imagine the design and delivery of control-related topics …

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Simulations Of Morphology Control Of Self-Assembled Amphiphilic Surfactants, Qinyu Zhu, Douglas R. Tree Mar 2023

Simulations Of Morphology Control Of Self-Assembled Amphiphilic Surfactants, Qinyu Zhu, Douglas R. Tree

Faculty Publications

One of the grand challenges of amphiphilic self-assembly is the design of ordered structures whose morphology or shape can be explicitly and dynamically controlled by adjusting the properties of the amphiphiles or their surroundings. Such a capacity would enable researchers to create synthetic systems with functionality that meets or exceeds biological cells, and provide a robust platform for a broad range of engineering applications such as artificial tissues, drug delivery, and separation membranes. Despite significant progress, important fundamental questions remain unanswered, due in part to the limited resolution and the restricted parameter spaces that are readily accessible in experiments. Computational …

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Simulations Of Morphology Control Of Self-Assembled Amphiphilic Surfactants, Qinyu Zhu, Douglas R. Tree Mar 2023

Simulations Of Morphology Control Of Self-Assembled Amphiphilic Surfactants, Qinyu Zhu, Douglas R. Tree

Faculty Publications

One of the grand challenges of amphiphilic self-assembly is the design of ordered structures whose morphology or shape can be explicitly and dynamically controlled by adjusting the properties of the amphiphiles or their surroundings. Such a capacity would enable researchers to create synthetic systems with functionality that meets or exceeds biological cells, and provide a robust platform for a broad range of engineering applications such as artificial tissues, drug delivery, and separation membranes. Despite significant progress, important fundamental questions remain unanswered, due in part to the limited resolution and the restricted parameter spaces that are readily accessible in experiments. Computational …

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Large Deflection Analysis Of General Beams In Contact-Aided Compliant Mechanisms Using Chained Pseudo-Rigid-Body Model, Mohui Jin, Collin Ynchausti, Xianmin Zhang, Zhou Yang, Benliang Zhu, Larry L. Howell Mar 2023

Large Deflection Analysis Of General Beams In Contact-Aided Compliant Mechanisms Using Chained Pseudo-Rigid-Body Model, Mohui Jin, Collin Ynchausti, Xianmin Zhang, Zhou Yang, Benliang Zhu, Larry L. Howell

Faculty Publications

The nonlinear analysis and design of contact-aided compliant mechanisms (CCMs) are challenging. This paper presents a nonlinear method for analyzing the deformation of general beams that contact rigid surfaces in CCMs. The large deflection of the general beam is modeled by using the chained pseudo-rigid-body model. A geometry constraint from the contact surface is developed to constrain the beam’s deformed configuration. The contact analysis problem is formulated based on the principle of minimum potential energy and solved using an optimization algorithm. Besides, a novel technique based on the principle of work and energy is proposed calculate the reaction force/moment of …

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A Model For Multi-Input Mechanical Advantage In Origami-Based Mechanisms, Jared Butler, Adam Shrager, Timothy Simpson, Landen Bowen, Mary Frecker, Robert Lang, Eric Wilcox, Paris Von Lockette, Larry L. Howell, Spencer P. Magleby Mar 2023

A Model For Multi-Input Mechanical Advantage In Origami-Based Mechanisms, Jared Butler, Adam Shrager, Timothy Simpson, Landen Bowen, Mary Frecker, Robert Lang, Eric Wilcox, Paris Von Lockette, Larry L. Howell, Spencer P. Magleby

Faculty Publications

Mechanical advantage is traditionally defined for single input and single-output rigid-body mechanisms. A generalized approach for identifying single-output mechanical advantage for a multiple-input compliant mechanism, such as many origami-based mechanisms, would prove useful in predicting complex mechanism behavior. While origami-based mechanisms are capable of offering unique solutions to engi neering problems, the design process of such mechanisms is complicated by the interaction of motion and forces. This paper presents a model of the mechanical advantage for multi input compliant mechanisms and explores how modifying the parameters of a model affects their behavior. The model is used to predict the force-deflection …

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Developable Mechanisms On Regular Cylindrical Surfaces, Jacob R. Greenwood, Spencer P. Magleby, Larry L. Howell Mar 2023

Developable Mechanisms On Regular Cylindrical Surfaces, Jacob R. Greenwood, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Developable mechanisms can provide high functionality and compact stowability. This paper presents engineering models to aid in the design of cylindrical developable mechanisms. These models take into account the added spatial restrictions imposed by the developable surface. Equations are provided for the kinematic analysis of cylindrical developable mechanisms. A new classification for developable mechanisms is also presented (intramobile, extramobile, and transmobile) and two graphical methods are provided for determining this clas sification for single-DOF planar cylindrical developable mechanisms. Characteristics specific to four-bar cylindrical developable mechanisms are also discussed.

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Membrane-Enhanced Lamina Emergent Torsional Joints For Surrogate Folds, Guimin Chen, Spencer P. Magleby, Larry L. Howell Mar 2023

Membrane-Enhanced Lamina Emergent Torsional Joints For Surrogate Folds, Guimin Chen, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Lamina emergent compliant mechanisms (including origami-adapted compliant mechanisms) are mechanical devices that can be fabricated from a planar material (a lamina) and have motion that emerges out of the fabrication plane. Lamina emergent compliant mechanisms often exhibit undesirable parasitic motions due to the planar fabrication constraint. This work introduces a type of lamina emergent torsion (LET) joint that reduces parasitic motions of lamina emergent mechanisms (LEMs), and presents equations for modeling parasitic motion of LET joints. The membrane joint also makes possible one-way joints that can ensure origami-based mechanisms emerge from their flat state (a change point) into the desired …

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