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Full-Text Articles in Engineering

Revealing Driver Psychophysiological Response To Emergency Braking In Distracted Driving Based On Field Experiments, Ying Li, Li Zhao, Kun Gao, Yisheng An, Jelena Andric Jul 2022

Revealing Driver Psychophysiological Response To Emergency Braking In Distracted Driving Based On Field Experiments, Ying Li, Li Zhao, Kun Gao, Yisheng An, Jelena Andric

Department of Civil and Environmental Engineering: Faculty Publications

Purpose – The purpose of this paper is to characterize distracted driving by quantifying the response time and response intensity to an emergency stop using the driver’s physiological states.

Design/methodology/approach – Field tests with 17 participants were conducted in the connected and automated vehicle test field. All participants were required to prioritize their primary driving tasks while a secondary nondriving task was asked to be executed. Demographic data, vehicle trajectory data and various physiological data were recorded through a biosignalsplux signal data acquisition toolkit, such as electrocardiograph for heart rate, electromyography for muscle strength, electrodermal activity for skin conductance and …


An Acoustofluidic Scanning Nanoscope Using Enhanced Image Stacking And Processing, Geonsoo Jin, Joseph Rich, Jianping Xia, Albert J. He, Chenglong Zhao, Tony Jun Huang Jul 2022

An Acoustofluidic Scanning Nanoscope Using Enhanced Image Stacking And Processing, Geonsoo Jin, Joseph Rich, Jianping Xia, Albert J. He, Chenglong Zhao, Tony Jun Huang

Faculty Publications

Nanoscale optical resolution with a large field of view is a critical feature for many research and industry areas, such as semiconductor fabrication, biomedical imaging, and nanoscale material identification. Several scanning microscopes have been developed to resolve the inverse relationship between the resolution and field of view; however, those scanning microscopes still rely upon fluorescence labeling and complex optical systems. To overcome these limitations, we developed a dual-camera acoustofluidic nanoscope with a seamless image merging algorithm (alpha-blending process). This design allows us to precisely image both the sample and the microspheres simultaneously and accurately track the particle path and location. …


A Distributed Trust Model Simulator For Energy Grid Of Things Distributed Energy Resource Management System, Abdullah Barghouti Jul 2022

A Distributed Trust Model Simulator For Energy Grid Of Things Distributed Energy Resource Management System, Abdullah Barghouti

Dissertations and Theses

The evolution of networks into more distributed, self-reliant nodes has mitigated single-point failures that plagued traditional centralized networks. Applied to power grids, distributed systems can increase the integrity and availability of grid services while also offering a power management solution. However, while distributed networks provide scalability, security, and sustainability compared to centralized networks, their distributed nature makes them harder for anomaly detection and prevention. Incorporating a Distributed Trust Model (DTM) System into an Energy Grid of Things Distributed Energy Resource Management System (EGOT DERMS) allows grid participants to be characterized and their communication to be analyzed for possible attacks. A …


Tensile Testing Of 3d Printed Tpu Samples For Pediatric Biomaterial Applications, Sheridan C. Perry, Rodriguez M. Rafael, Victor Huayamave, Bryan M. Gonzalez, Kim Dae-Won, Zachary R. Nadeau Jul 2022

Tensile Testing Of 3d Printed Tpu Samples For Pediatric Biomaterial Applications, Sheridan C. Perry, Rodriguez M. Rafael, Victor Huayamave, Bryan M. Gonzalez, Kim Dae-Won, Zachary R. Nadeau

PanaSoMM

Additive Manufacturing (AM) has, in recent years, become one of the most widespread and preferred prototyping methods. The most popular additive manufacturing method is Fused Deposition Modeling. FDM’s popularity is primarily attributed to its 3 major strengths of rapid prototyping, variability in material choice, and subject specific nature. The medical industry is one of the larger industries that has benefited from 3D printing especially in the terms of medical trainers. Unfortunately, most medical trainers that are developed (either being 3d printed or through traditional manufacturing processes) are poor substitutes for the human body. This can be attributed to either a …


Statistical Shape Model (Ssm) Of Infant Femurs And The Relationship With Severity Of Hip Dysplasia, Tamara Chambers, Penny Atkins, Victor Huayamave, Andrew Anderson, Charles Price Jul 2022

Statistical Shape Model (Ssm) Of Infant Femurs And The Relationship With Severity Of Hip Dysplasia, Tamara Chambers, Penny Atkins, Victor Huayamave, Andrew Anderson, Charles Price

PanaSoMM

The objective is to assess the morphology of infant femurs using a statistical shape model (SSM). The Ortolani collection is used in this study and consists of untreated infant cadaveric specimens with both healthy and dysplastic hips. Computed Tomography (CT) scans of 4 of the 14 specimens in the collection were taken at the University of Padua. Manual and semi-automatic segmentation techniques were used to reconstruct the 2D slices of femurs and generate 3D surface models. The SSM model of the infant femurs will be developed using an open-source software called ShapeWorks developed by the University of Utah. The SSM …


Introducing Modeling To First-Year Engineering Students For Effective Implementation In The Engineering Design Process, Carolina Barriento, Juan F. Granizo Jul 2022

Introducing Modeling To First-Year Engineering Students For Effective Implementation In The Engineering Design Process, Carolina Barriento, Juan F. Granizo

PanaSoMM

Introducing Modeling to First-Year Engineering Students for Effective Implementation in the Engineering Design Process

Carolina Barriento and Juan Francisco Granizo

Embry-Riddle Aeronautical University

Abstract

Modeling and Simulation are fundamental skills for all engineering students [1]. However, students are usually introduced to these concepts during their junior or even as late as their senior year. Our research aims at familiarizing students with Modeling and Simulation tools in their first year of engineering studies. We consider the fact that proper learning involves using long-term memory (in contrast with working memory) and this is accomplished by the gradual introduction and practice of the …


Incorporation Of Trajectory Behaviors In The Vicinities Of Different Planetary Moons Using Finite-Time Lyapunov Exponent Maps, David Canales Garcia, Kathleen C. Howell, Elena Fantino Jul 2022

Incorporation Of Trajectory Behaviors In The Vicinities Of Different Planetary Moons Using Finite-Time Lyapunov Exponent Maps, David Canales Garcia, Kathleen C. Howell, Elena Fantino

PanaSoMM

There is an increasing interest in future space missions devoted to the exploration of key moons in the Solar system. These many different missions may involve libration point orbits as well as trajectories that satisfy different endgames in the vicinities of the moons. To this end, an efficient design strategy to produce low-energy transfers between the vicinities of adjacent moons of a planetary system is introduced that leverages the dynamics in these multi-body systems. Such a design strategy is denoted as the moon-to-moon analytical transfer (MMAT) method. It consists of a general methodology for transfer design between the vicinities of …


Combination Of Statistical Shape Modeling And Statistical Parametric Mapping To Quantify Cartilage Contact Mechanics In Hip Dysplasia, Penny R. Atkins Phd, Shireen Y. Elhabian Phd, Jeffrey A. Weiss Phd, Ross T. Whitaker Phd, Christopher L. Peters Md, Andrew E. Anderson Phd Jul 2022

Combination Of Statistical Shape Modeling And Statistical Parametric Mapping To Quantify Cartilage Contact Mechanics In Hip Dysplasia, Penny R. Atkins Phd, Shireen Y. Elhabian Phd, Jeffrey A. Weiss Phd, Ross T. Whitaker Phd, Christopher L. Peters Md, Andrew E. Anderson Phd

PanaSoMM

Finite element models can predict subject-specific chondrolabral stresses and help to elucidate the effect of under-coverage and incongruency of the hip joint in patients with dysplasia. However, complex stress patterns are difficult to generalize and evaluate statistically. With an established correspondence across shapes from statistical shape modeling (SSM), statistical parametric mapping (SPM) allows for evaluation of local variability while preserving model subject-specificity. Herein, we evaluated the combined application of SSM and SPM to compare cartilage contact stress between control subjects and patients with dysplasia.

Previously published hip joint contact stresses were mapped onto chondrolabral surface meshes and incorporated into an …


Application Of Statistical Shape Modeling To Predict Clinical Metric Of Femoral Head Coverage In Patients With Developmental Dysplasia, Penny R. Atkins Phd, Praful Agrawal Phd, Joseph D. Mozingo Phd, Keisuke Uemura Md, Phd, Kunihiko Tokunaga Md, Christopher L. Peters Md, Shireen Y. Elhabian Phd, Ross T. Whitaker Phd, Andrew E. Anderson Phd Jul 2022

Application Of Statistical Shape Modeling To Predict Clinical Metric Of Femoral Head Coverage In Patients With Developmental Dysplasia, Penny R. Atkins Phd, Praful Agrawal Phd, Joseph D. Mozingo Phd, Keisuke Uemura Md, Phd, Kunihiko Tokunaga Md, Christopher L. Peters Md, Shireen Y. Elhabian Phd, Ross T. Whitaker Phd, Andrew E. Anderson Phd

PanaSoMM

Developmental dysplasia of the hip (DDH) is described as under-coverage of the femoral head by the acetabulum, resulting in mechanical instability. Though DDH is often diagnosed using plain film radiographs, these images cannot adequately capture 3D joint coverage. Herein, we applied a 3D statistical shape model (SSM) to the femur and hemi-pelvis of patients with DDH to objectively measure shape variation and evaluated whether SSM outputs could predict measurements of joint coverage.

The femur and hemi-pelvis were semi-automatically segmented from CT images (83 hips from 47 females with DDH). Surfaces of each hip were reconstructed from segmentations, aligned, and input …


Ci Asteroid Regolith As An In Situ Plant Growth Medium For Space Crop Production, Steven J. Russell, Sherry Fieber-Beyer, Kathryn A. Yurkonis Jul 2022

Ci Asteroid Regolith As An In Situ Plant Growth Medium For Space Crop Production, Steven J. Russell, Sherry Fieber-Beyer, Kathryn A. Yurkonis

Biology Faculty Publications

Human expansion into the solar system is currently at the forefront of space research. For our astronauts to survive, they will need to be fed a healthy and nutritious diet on a consistent basis. Right now, our current method of feeding astronauts consists of resupplied prepackaged food from Earth, which is unsustainable for long-term missions. Using planetary resources via in situ resource utilization to grow crops is the next step toward sustainability in space. Asteroids are an abundant space resource and should not be overlooked when considering crewed missions. In particular, the primordial CI carbonaceous asteroids are of interest because …


A Pilot Study On The Nanoscale Properties Of Bone Tissue Near Lacunae In Fracturing Women, Wen Qian, Roman Schmidt, Joseph A. Turner, Sue P. Bare, Joan M. Lappe, Robert R. Recker, Mohammed P. Akhter Jul 2022

A Pilot Study On The Nanoscale Properties Of Bone Tissue Near Lacunae In Fracturing Women, Wen Qian, Roman Schmidt, Joseph A. Turner, Sue P. Bare, Joan M. Lappe, Robert R. Recker, Mohammed P. Akhter

Department of Mechanical and Materials Engineering: Faculty Publications

The goal of this study is to investigate the causes of osteoporosis-related skeletal fragility in postmenopausal women. We hypothesize that bone fragility in these individuals is largely due to mineral, and/or intrinsic material properties in the osteocyte lacunar/peri-lacunar regions of bone tissue. Innovative measurements with nanoscale resolution, including scanning electron microscope (SEM), an atomic force microscope that is integrated with infrared spectroscopy (AFM-IR), and nanoindentation, were used to characterize osteocyte lacunar and peri-lacunar properties in bone biopsies from fracturing (Cases) and matched (Age, BMD), non-fracturing (Controls) postmenopausal healthy women. In the peri-lacunar space, the nanoindentation results show that the modulus …


Bioremediation Of Petroleum-Based Contaminants By Alkane-Degrading Bacterium Alcanivorax Borkumensis, Amber Julaine Pete Jul 2022

Bioremediation Of Petroleum-Based Contaminants By Alkane-Degrading Bacterium Alcanivorax Borkumensis, Amber Julaine Pete

LSU Doctoral Dissertations

The world’s dependence on petroleum hydrocarbons has led to significant environmental implications. For example, oil spills cause lasting environmental damage, and the increase of plastics in the marine environment has been growing, specifically, microplastics that can be difficult to detect due to their small size. Petroleum hydrocarbons occur naturally in nearly all marine environments, which has allowed hundreds of microorganisms to evolve to utilize these hydrocarbons as their primary energy source. These microbes are classified as hydrocarbonoclastic and are utilized to remove spilled oil biodegradation. Over the last ten years, progress has been made in the biodegradation of oil spills …


Investigating The Performance Of A Novel Multi-Element Airfoil Concept Using Numerical Analysis, Ahmed Elbaz Jul 2022

Investigating The Performance Of A Novel Multi-Element Airfoil Concept Using Numerical Analysis, Ahmed Elbaz

Mechanical Engineering

Separation control is one of the trending topics recently for Vertical Axis Wind Turbine (VAWT) applications, flow separation that occur on the suction side of an airfoil is a major limitation for VAWTs starting and power coefficient; passive control of flow separation has been attracting wind energy research community recently. The principle objective of this paper is to investigate the effect of the multi-element airfoil on the aerodynamic characteristics at wide range of angles of attack at a Reynolds number of 140,000. The multi element airfoil modification has been implemented by replacing the baseline airfoil with two airfoil members within …


Control And Planning For Mobile Manipulators Used In Large Scale Manufacturing Processes, Joshua T. Nguyen Jul 2022

Control And Planning For Mobile Manipulators Used In Large Scale Manufacturing Processes, Joshua T. Nguyen

LSU Master's Theses

Sanding operations in industry is one of the few manufacturing tasks that has yet to achieve automation. Sanding tasks require skilled operators that have developed a sense of when a work piece is sufficiently sanded. In order to achieve automation in sanding with robotic systems, this developed sense, or intelligence, that human operators have needs to be understood and implemented in order to achieve, at the minimum, the same quality of work. The system will also need to have the equivalent reach of a human operator and not be constrained to a single, small workspace. This thesis developed solutions for …


Interfacial Interactions Of Uranium And Hdpe In Agricultural Soil And Their Bioacummulation In Mentha Arvensis, Casey Miller, Andrew Neidhart, Kendra Hess, Abdul-Mehdi S. Ali, Angelica Benavidez, Michael Spilde, Laura Green, José M. Cerrato, Jorge Gonzalez Estrella, Eliane El Hayek Jul 2022

Interfacial Interactions Of Uranium And Hdpe In Agricultural Soil And Their Bioacummulation In Mentha Arvensis, Casey Miller, Andrew Neidhart, Kendra Hess, Abdul-Mehdi S. Ali, Angelica Benavidez, Michael Spilde, Laura Green, José M. Cerrato, Jorge Gonzalez Estrella, Eliane El Hayek

Civil Engineering ETDs

We investigated the adsorption, precipitation, and phytoavailability of uranium after reactions with soil, high-density polyethylene particles, and Mentha arvensis through the integration of batch experiments, plant exposure, microscopy, and spectroscopy. Soluble U (initially 100 µM) decreased by 98.6% (1.09 µM) at pH 5 and 86.2% (13.81 µM) at pH 7.5 after 0.1 h of reaction with 10 g of soil in solution. Heterogenous U precipitates were observed in weathered HDPE surfaces for experiments without soil at both pH conditions. This suggests the weathering of the microplastic surfaces enhanced the nucleation of the U precipitates. Plants exposed to both U and …


Towards Multiplexed And Multimodal Biosensor Platforms In Real-Time Monitoring Of Metabolic Disorders, Sung Sik Chu, Hung Anh Nguyen, Jimmy Zhang, Shawana Tabassum, Hung Cao Jul 2022

Towards Multiplexed And Multimodal Biosensor Platforms In Real-Time Monitoring Of Metabolic Disorders, Sung Sik Chu, Hung Anh Nguyen, Jimmy Zhang, Shawana Tabassum, Hung Cao

Electrical Engineering Faculty Publications and Presentations

Metabolic syndrome (MS) is a cluster of conditions that increases the probability of heart disease, stroke, and diabetes, and is very common worldwide. While the exact cause of MS has yet to be understood, there is evidence indicating the relationship between MS and the dysregulation of the immune system. The resultant biomarkers that are expressed in the process are gaining relevance in the early detection of related MS. However, sensing only a single analyte has its limitations because one analyte can be involved with various conditions. Thus, for MS, which generally results from the co-existence of multiple complications, a multi-analyte …


Development Of A Configurable Derms Test System In Gridapps-D, Sean James Keene Jul 2022

Development Of A Configurable Derms Test System In Gridapps-D, Sean James Keene

Dissertations and Theses

Distributed Energy Resources and their increased penetration within the power grid are a suitable method to provide essential reliability services. In order to do so, they must operate in aggregate. Aggregation of a wide variety of systems with varying standards and protocols is a complex task, which could benefit from rules and standards to support interoperability. To this end, the Portland State University Power Lab has developed the Energy Grid of Things project, which includes a Distributed Energy Resource Management System to provide aggregation and demonstrate the usage of an Energy Services Interface: a set of rules governing the interface …


Learning From Machines: Insights In Forest Transpiration Using Machine Learning Methods, Morgan Thornwell Jul 2022

Learning From Machines: Insights In Forest Transpiration Using Machine Learning Methods, Morgan Thornwell

Dissertations and Theses

Machine learning has been used as a tool to model transpiration for individual sites, but few models are capable of generalizing to new locations without calibration to site data. Using the global SAPFLUXNET database, 95 tree sap flow data sites were grouped using three clustering strategies: by biome, by tree functional type, and through use of a k-means unsupervised clustering algorithm. Two supervised machine learning algorithms, a random forest algorithm and a neural network algorithm, were used to build machine learning models that predicted transpiration for each cluster. The performance and feature importance in each model were analyzed and compared …


Pulsatility Is A Predictive Marker Of Improved Cardiac Function In Patients With Liquid Matrix-Treated Left Ventricular Assist Devices, Philemon Mikail, Rinku Skaria, Marvin Slepian, Janny Garcia, Richard Smith, Zain Khalpey Jul 2022

Pulsatility Is A Predictive Marker Of Improved Cardiac Function In Patients With Liquid Matrix-Treated Left Ventricular Assist Devices, Philemon Mikail, Rinku Skaria, Marvin Slepian, Janny Garcia, Richard Smith, Zain Khalpey

The VAD Journal

Objective: Left ventricular assist devices (LVADs) are utilized as a bridge to transplant or as destination therapy for patients with end-stage heart failure. Although cardiac offloading from these devices rarely leads to complete remodeling and functional recovery, the use of mesenchymal cells to modulate heart failure has been explored in recent years due to its intrinsic regenerative properties. Current methods of evaluating cardiac function have too much variability, difficulty of access, or require too frequent follow up to create universal weaning protocols. We hypothesized that the administration of amniotic allograft liquid matrix (LM) containing amnion-derived mesenchymal stem cells (aMSCs) in …


Control Implemented On Quantum Computers: Effects Of Noise, Nondeterminism, And Entanglement, Kip Nieman, Keshav Kasturi Rangan, Helen Durand Jul 2022

Control Implemented On Quantum Computers: Effects Of Noise, Nondeterminism, And Entanglement, Kip Nieman, Keshav Kasturi Rangan, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Quantum computing has advanced in recent years to the point that there are now some quantum computers and quantum simulators available to the public for use. In addition, quantum computing is beginning to receive attention within the process systems engineering community for directions such as machine learning and optimization. A logical next step for its evaluation within process systems engineering is for control, specifically for computing control actions to be applied to process systems. In this work, we provide some initial studies regarding the implementation of control on quantum computers, including the implementation of a single-input/single-output proportional control law on …


Improving The Factual Accuracy Of Abstractive Clinical Text Summarization Using Multi-Objective Optimization, Amanuel Alambo, Tanvi Banerjee, Krishnaprasad Thirunarayan, Mia Cajita Jul 2022

Improving The Factual Accuracy Of Abstractive Clinical Text Summarization Using Multi-Objective Optimization, Amanuel Alambo, Tanvi Banerjee, Krishnaprasad Thirunarayan, Mia Cajita

Computer Science and Engineering Faculty Publications

While there has been recent progress in abstractive summarization as applied to different domains including news articles, scientific articles, and blog posts, the application of these techniques to clinical text summarization has been limited. This is primarily due to the lack of large-scale training data and the messy/unstructured nature of clinical notes as opposed to other domains where massive training data come in structured or semi -structured form. Further, one of the least explored and critical components of clinical text summarization is factual accuracy of clinical summaries. This is specifically crucial in the healthcare domain, cardiology in particular, where an …


A Comparative Study On Representativeness And Stochastic Efficacy Of Miniature Tensile Specimen Testing, Sreekar Karnati, Sriram Praneeth Isanaka, Yunlu Zhang, Frank W. Liou, Jason L. Schulthess Jul 2022

A Comparative Study On Representativeness And Stochastic Efficacy Of Miniature Tensile Specimen Testing, Sreekar Karnati, Sriram Praneeth Isanaka, Yunlu Zhang, Frank W. Liou, Jason L. Schulthess

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this article, a miniature dog bone tensile coupon design was tested against the existing ASTM standard specimen design. Specimens were prepared from commercially sourced austenitic stainless steel 304 alloy, and a defect-ridden additively manufactured 304L alloy was studied. By utilizing a tensile specimen design that is 1/230th volume of the smallest ASTM E8-04 (2016), Standard Test Methods for Tension Testing of Metallic Materials, dog bone specimen, coupled to a digital image correlation (DIC) setup, case studies were performed to compare tensile property measurements and strain field evolution. Whereas yield strength measurements were observed to be similar, post-yield, the ultimate …


Application Of Probabilistic Methods To Turbine Engine Disk Life Prediction And Risk Assessment, Paul Copp, Ashley Whitney-Rawls, Jace Carter, Tarun Goswami Jul 2022

Application Of Probabilistic Methods To Turbine Engine Disk Life Prediction And Risk Assessment, Paul Copp, Ashley Whitney-Rawls, Jace Carter, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Turbine engine disk life prediction and understanding the associated risk remains a significant challenge for today’s designer. Despite advances made in materials testing and characterization, as well as, the application of damage tolerance and linear elastic fracture mechanics modeling, there remains a void in properly assessing loading, geometry, and material design property variability. Add to this the application of advanced hybrid and composite material systems and the need to accurately deal with material variability is even greater. There still remain incidents of failure of critical components which were not properly accounted for by the existing analytical methods, testing, and inspections …


Demonstrating Configuration Of Software Defined Networking In Real Wireless Testbeds, Saish Urumkar, Gianluca Fontanesi, Avishek Nag, Sachin Sharma Jul 2022

Demonstrating Configuration Of Software Defined Networking In Real Wireless Testbeds, Saish Urumkar, Gianluca Fontanesi, Avishek Nag, Sachin Sharma

Conference papers

Currently, several wireless testbeds are available to test networking solutions including Fed4Fire testbeds such as w-ilab. t and CityLab in the EU, and POWDER and COSMOS in the US. In this demonstration, we use the w-ilab.t testbed to set up a wireless ad-hoc Software-Defined Network (SDN). OpenFlow is used as an SDN protocol and is deployed using a grid wireless ad-hoc topology in w-ilab.t. In this paper, we demonstrate: (1) the configuration of a wireless ad-hoc network based on w-ilab.t and (2) the automatic deployment of OpenFlow in an ad-hoc wireless network where some wireless nodes are not directly connected …


Experimenting An Edge-Cloud Computing Model On The Gpulab Fed4fire Testbed, Vikas Tomer, Sachin Sharma Jul 2022

Experimenting An Edge-Cloud Computing Model On The Gpulab Fed4fire Testbed, Vikas Tomer, Sachin Sharma

Conference papers

There are various open testbeds available for testing algorithms and prototypes, including the Fed4Fire testbeds. This demo paper illustrates how the GPULAB Fed4Fire testbed can be used to test an edge-cloud model that employs an ensemble machine learning algorithm for detecting attacks on the Internet of Things (IoT). We compare experimentation times and other performance metrics of our model based on different characteristics of the testbed, such as GPU model, CPU speed, and memory. Our goal is to demonstrate how an edge-computing model can be run on the GPULab testbed. Results indicate that this use case can be deployed seamlessly …


Predictive Thermal Modeling And Characterization Of Ultrasonic Consolidation Process For Thermoplastic Composites, Madeline Kirby Jul 2022

Predictive Thermal Modeling And Characterization Of Ultrasonic Consolidation Process For Thermoplastic Composites, Madeline Kirby

LSU Master's Theses

Ultrasonic consolidation (USC) of thermoplastic composites (TPCs) is a highly attractive and promising method to manufacture high-performance composites. This work focuses on USC of dry carbon fiber (CF) fabrics with high-temperature polyphenylene sulfide (PPS) films. Experimental trials to assess feasibility of the process are time-consuming. Consequently, a predictive thermal model would facilitate process parameters selection to reduce expensive trial-and-error approaches. This paper presents a 2D finite element model of samples under consolidation, incorporating equations for viscoelastic heating, matrix phase change, and material properties. Theoretical temperature profiles for nodes of interest were compared to the corresponding experimental temperature curves for various …


Influence Of Aluminum Addition On The Laser Powder Bed Fusion Of Copper-Aluminum Mixtures, Nada Kraiem, Loic Constantin, A. Mao, Fei Wang, Bai Cui, Jean-François Silvain, Yongfeng Lu Jul 2022

Influence Of Aluminum Addition On The Laser Powder Bed Fusion Of Copper-Aluminum Mixtures, Nada Kraiem, Loic Constantin, A. Mao, Fei Wang, Bai Cui, Jean-François Silvain, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

The high optical reflectivity of copper (Cu) in the near infrared (NIR) domain and its elevated heat dissipation make Cu a challenging metal for laser powder bed fusion (LPBF), even with high energy densities (EDs). In this study, we demonstrated that adding aluminum (Al) powder by as little as 0.75, 1.5, and 3 wt.% substantially enhances Cu processability, leading to denser (up to 98%) and smoother (Ra = 3.3 𝜇m) Cu-Al parts as compared to 95% and 18 𝜇m, respectively, for the parts printed using pure Cu. In addition, this method reduces the ED required by a factor of two …


Enabling Successful Human-Robot Interaction Through Human-Human Co-Manipulation Analysis, Soft Robot Modeling, And Reliable Model Evolutionary Gain-Based Predictive Control (Mega-Pc), Spencer W. Jensen Jul 2022

Enabling Successful Human-Robot Interaction Through Human-Human Co-Manipulation Analysis, Soft Robot Modeling, And Reliable Model Evolutionary Gain-Based Predictive Control (Mega-Pc), Spencer W. Jensen

Theses and Dissertations

Soft robots are inherently safer than traditional robots due to their compliance and high power density ratio resulting in lower accidental impact forces. Thus they are a natural option for human-robot interaction. This thesis specifically looked at human-robot co-manipulation which is defined as a human and a robot working together to move an object too large or awkward to be safely maneuvered by a single agent. To better understand how humans communicate while co-manipulating an object, this work looked at haptic interaction of human-human dyadic co-manipulation trials and studied some of the trends found in that interaction. These trends point …


Simulation And Localization Of Autonomous Underwater Vehicles Leveraging Lie Group Structure, Easton Robert Potokar Jul 2022

Simulation And Localization Of Autonomous Underwater Vehicles Leveraging Lie Group Structure, Easton Robert Potokar

Theses and Dissertations

Autonomous underwater vehicles (AUVs) have the potential to dramatically improve safety, quality of life and general scientific knowledge. Our coasts, lakes and rivers are filled with various forms of marine infrastructure including dams, bridges, ship hulls, communication lines, and oil rigs. Each of these structures requires regular inspection, and current methods utilize divers, which is dangerous, expensive, and time consuming. AUVs have the potential to alleviate these difficulties and enable more regular inspection of these structures. Furthermore, there are significant scientific discoveries in the fields of geology, marine biology and medicine that AUV exploration of our oceans will enable. Since …


Surface-Wave Coupling In Double Floquet Sheets Supporting Phased Temporal Wood Anomalies, Ya-Wen Tsai, Yao-Ting Wang, Emanuele Galiffi, Andrea Alù, Ta-Jen Yen Jul 2022

Surface-Wave Coupling In Double Floquet Sheets Supporting Phased Temporal Wood Anomalies, Ya-Wen Tsai, Yao-Ting Wang, Emanuele Galiffi, Andrea Alù, Ta-Jen Yen

Advanced Science Research Center

We investigate symmetry-selective surface-mode excitation in a general periodically time-modulated double-layer system, where the modulation of the two layers has a constant phase difference. By deriving a semi-analytic transfer matrix formalism of a Drude-dispersive double-layer structure with periodic time-modulation, we calculate the scattering amplitudes and the corresponding transmission coefficient. Our results show that the phase-difference between the modulation of the two sheets plays an essential role in significantly enhancing and selectively exciting either the even or odd surface mode with high efficiency. We verify our calculations with full-wave time-domain simulations, showing that efficient switching between the surface-wave excitation of the …