Engineering Commons^™

Tunable, Reconfigurable, And Programmable Acoustic Metasurfaces: A Review, Ali Zabihi, Chadi Ellouzi, Chen Shen

Henry M. Rowan College of Engineering Departmental Research

The advent of acoustic metasurfaces (AMs), which are the two-dimensional equivalents of metamaterials, has opened up new possibilities in wave manipulation using acoustically thin structures. Through the interaction between the acoustic waves and the subwavelength scattering, AMs exhibit versatile capabilities to control acoustic wave propagation such as by steering, focusing, and absorption. In recent years, this vibrant field has expanded to include tunable, reconfigurable, and programmable control to further expand the capacity of AMs. This paper reviews recent developments in AMs and summarizes the fundamental approaches for achieving tunable control, namely, by mechanical tuning, active control, and the use of …

Comparisons Of Cooling Performance And Flow Characteristics Of A Combustor Liner Plate With Compound Angle And Simple Angle Effusion Holes, Hwabhin Kwon, Phillip M. Ligrani, Sneha R. Vanga, Heesung Park

PRC-Affiliated Research

The present investigation considers a unique compound angle arrangement, never previously considered, with α = 30°, β = ±30°, such that the compound angle of the effusion holes changes from β = +30° to β = −30°, as adjacent rows of effusion holes are encountered. Also provided are data for comparison from a simple angle configuration with α = 30°, β = 0°. Coolant is supplied to both effusion hole arrays using arrays of impingement cooling jets. The results of the numerical simulations are obtained using the ANSYS FLUENT V 21.1 numerical code, with a shear stress transport (SST) k–ω …

The Impact Of Case Management Intervention For Insured Asthma Patients In Louisiana, An Empirical Study, Mohamed Mohamed Ohaiba

LSU Doctoral Dissertations

Asthma is a chronic condition whose symptoms are managed/prevented using medication and interventions. The overarching objective of this study was to evaluate the impact of patients' demographics on case management enrollment and healthcare utilization, as well as to develop machine learning models to predict high-cost patients.

To accomplish these goals, the Man-Whiteness test, the chi-squares test, logistic regression and odds ratios, and machine learning models were implemented. The average cost of the non-enrolled CM group was significantly higher than the enrolled group (p-value .0001). In addition, the non-enrolled groups had considerably more visits to the emergency department than the other …

How A Higher Education Aviation Faculty Perceived The Challenges Of An Online Emergency Transition During The Covid-19 Pandemic And Identifies Recommendations For Future Emergency Online Transitions, Victor Miguel Fraticelli Rivera

Doctoral Dissertations and Projects

The purpose of this case study is to discover the perceived challenges and identify future recommendations for emergency online learning transition as a result of the COVID-19 pandemic at a major aeronautical higher education institution in the southeast region of the United States. For this study, emergency online learning transition is defined as the period in which higher education faculty members were required to pivot to an online methodology in response to a global pandemic in the spring and fall academic semesters of 2020. The theories guiding this study are the theory of planned behavior (TPB) by Icek Ajzen and …

An Evaluation Of A Computational Technique For Measuring The Embeddedness Of Sustainability In The Curriculum Aligned To Aashe-Stars And The United Nations Sustainable Development Goals, Philippe Lemarchand, Cormac H. Macmahon Dr, Mick Mckeever, Philip Owende

Articles

Introduction: SDG 4.7 mandates university contributions to the United Nations (UN) Sustainable Development Goals (SDGs) through their education provisions. Hence, universities increasingly assess their curricular alignment to the SDGs. A common approach to the assessment is to identify keywords associated with specific SDGs and to analyze for their presence in the curriculum. An inherent challenge is associating the identified keywords as used in the diverse set of curricular contexts to relevant sustainability indicators; hence, the urgent need for more systematic assessment as SDG implementation passes its mid-cycle.

Method: In this study, a more nuanced technique was evaluated with notable capabilities …

Deep Learning Methods For Prediction Of And Escape From Protein Recognition, Bowen Dai

Dartmouth College Ph.D Dissertations

Protein interactions drive diverse processes essential to living organisms, and thus numerous biomedical applications center on understanding, predicting, and designing how proteins recognize their partners. While unfortunately the number of interactions of interest still vastly exceeds the capabilities of experimental determination methods, computational methods promise to fill the gap. My thesis pursues the development and application of computational methods for several protein interaction prediction and design tasks. First, to improve protein-glycan interaction specificity prediction, I developed GlyBERT, which learns biologically relevant glycan representations encapsulating the components most important for glycan recognition within their structures. GlyBERT encodes glycans with a branched …

Applied Machine Learning In Development Of Geospatial Information Tools For Sustainable Groundwater Management, Saul Gallegos Ramirez

Theses and Dissertations

Groundwater plays an important role in sustainable water resource management. Globally, the development of groundwater resources for irrigation provides a stable water source and enhances food security. However, developing groundwater resources is difficult, requiring the collection, synthesis, analysis, and dissemination of information about groundwater in an accessible, effective manner so decision makers have the knowledge and tools to implement sustainable management strategies. In this dissertation, I present solutions to assist with the paucity of groundwater data. The first problem I explore is extending the Palmer Drought Severity Index to near present day. This dataset is crucial to current groundwater imputation …

Rehabilitation Technologies To Abate Infiltration In Sanitary Sewers, Steve Youssef

USF Tampa Graduate Theses and Dissertations

In urban coastal environments, sewer infrastructure is plagued by infiltration which seeps into aging and compromised pipes. Infiltration increases pumping costs, reduces treatment efficiency, and may trigger release of partially treated wastewater at water reclamation facilities. To restore pipes and abate infiltration, local utilities rely on structural and non-structural trenchless rehabilitation technologies. These methods are commonly used throughout the United States and the world due to their numerous benefits compared to traditional open-cut construction. However, limited data is available regarding their efficacy in reducing infiltration in sewer systems. In this study, we analysed infiltration in a small urban sewershed in …

Turning Dead Leaves Into An Active Multifunctional Material As Evaporator, Photocatalyst, And Bioplastic, Siyuan Fang, Xingyi Lyu, Tian Tong, Aniqa Ibnat Lim, Tao Li, Jiming Bao, Yun Hang Hu

Michigan Tech Publications, Part 1

Large numbers of leaves fall on the earth each autumn. The current treatments of dead leaves mainly involve completely destroying the biocomponents, which causes considerable energy consumption and environmental issues. It remains a challenge to convert waste leaves into useful materials without breaking down their biocomponents. Here, we turn red maple dead leaves into an active three-component multifunctional material by exploiting the role of whewellite biomineral for binding lignin and cellulose. Owing to its intense optical absorption spanning the full solar spectrum and the heterogeneous architecture for effective charge separation, films of this material show high performance in solar water …

Zero Torque Compliant Mechanisms Employing Pre-Buckled Beams, Pietro Bilancia, Samuel Porter Smith, Giovanni Berselli, Spencer P. Magleby, Larry L. Howell

Faculty Publications

The concept of a statically balanced mechanism with a single rotational degree of freedom is presented. The proposed device achieves static balancing by combining positive stiff- ness elements and negative stiffness elements within a nuclear domain. Two designs are discussed. The first is composed of an Archimedean spiral and two pinned-pinned pre-buckled beams. The overall mechanism is modeled via an analytical approach and the element dimensions are optimized. The optimal configuration is then tested through finite element analysis (FEA). A second approach replaces the spiral beam with elastic custom-shaped spline beams. An FEA optimization is performed to determine the shape …

Conceptualizing Stable States In Origami-Based Devices Using An Energy Visualization Approach, Jacob Greenwood, Larry L. Howell, Alex Avila, Spencer P. Magleby

Faculty Publications

In many origami-based applications, a device needs to be maintained in one or more fold states. The origami stability integration method (OSIM) presented in this paper pro- vides an approach for graphically combining various techniques to achieve stability. Existing stability techniques are also categorized into four groups based on whether they are intrinsic or extrinsic to the origami pattern and whether they exhibit gradual or non-gradual energy storage behaviors. These categorizations can help designers select appropriate techniques for their applications. The paper also contains de- sign considerations and resources for achieving stability. Finally, two case studies are presented that use …

Reflect To Connect, Sophia Rae Guzules

Liberal Arts and Engineering Studies

Engineering statics is an important course and a prerequisite for many subsequent courses for many engineering majors. It is often students’ first exposure to technical engineering sciences. Most statics concepts are addressed in ways disconnected from students’ prior experiences and interests. Utility Value Interventions (UVIs) have been employed in fields like biology and chemistry to help students connect concepts in class and their lives outside the classroom. However, UVI usage in engineering so far has been limited. In this Senior Project paper, I will describe the process that the team Critical Research in Engineering and Technology Education (CREATE) and I …

Private Pete Fights Illiteracy At Fort Ontario: The Men In Charge, Christian Wright, Adrian Mandzy

2023 Celebration of Student Scholarship - Poster Presentations

From June of 1943 to February of 1944, the 1210th Special Training Unit at Fort Ontario in Oswego, New York taught pre-basic military training to thousands of illiterate, slow learning, and non-English-speaking soldiers in the United States Army. The training center at Fort Ontario conducted programs in disciplinary barracks, specialized military, technical, academic and vocational education.

Classification Of Road Objects Using Convolutional Neural Networks, Mann Patel, Heba Elgazzar

2023 Celebration of Student Scholarship - Poster Presentations

Driving is the primary means of transportation for many people around the world. Whether the use is to assist human drivers or create autonomous driving, the use of machine learning can create safer road conditions. Drivers must consider other objects on the road, most commonly other vehicles and pedestrians. These three components, road signs, pedestrians, and vehicles, make up a large majority of objects that a driver will encounter when on the road. This research applies machine learning algorithms, specifically Convolutional Neural Networks (CNN), to classify these road objects. The goal is to create a classification model that can reliably …

The Afit Engineer, Volume 5, Issue 1, Graduate School Of Engineering And Management, Air Force Institute Of Technology

AFIT Documents

In this issue:

• 2023 Graduation
• WMD research at AFIT
• NOAA aerosol research at AFIT
• AFIT Model Shop

Bipolar Membrane Electrodialysis For Sustainable Utilization Of Inorganic Salts From The Reverse Osmosis Concentration Of Real Landfill Leachate, Hao-Ran Yang, Chi-Qian Zhang, Bing Li, Jia-Cheng Yang, Yu-Ming Zheng, Mohammad Younas, Zhi-Hua Zheng

Faculty Publications

Developing an effective resource utilization method for landfill leachate reverse osmosis concentrate (LLRC) remains a challenge because of the high concentrations of inorganic salts and refractory organic compounds. This study applied a bipolar membrane electrodialysis (BMED) to separate inorganic salts from real LLRC while simultaneously reclaiming inorganic acids and bases. The performance of BMED was affected by operating parameters, such as operating voltage, membrane surface flow velocity, and initial acid-base concentration. With optimized operating parameters, the reclaimed acid-base concentrations, desalination rate, and current efficiency were higher with less energy consumption. Ultimately, 0.41 mol/L acids and 0.40 mol/L bases were reclaimed …

Pan-Arctic Soil Moisture Control On Tundra Carbon Sequestration And Plant Productivity, Donatella Zona, Peter M. Lafleur, Koen Hufkens, Beniamino Gioli, Barbara Bailey, George Burba, Eugénie S. Euskirchen, Jennifer D. Watts, Kyle A. Arndt, Mary Farina, John S. Kimball, Martin Heimann, Mathias Göckede, Martijn Pallandt, Torben R. Christensen, Mikhail Mastepanov, Efrén López-Blanco, Albertus J. Dolman, Roisin Commane, Charles E. Miller, Josh Hashemi, Lars Kutzbach, David Holl, Julia Boike, Christian Wille, Torsten Sachs, Aram Kalhori, Elyn R. Humphreys, Oliver Sonnentag, Gesa Meyer, Gabriel H. Gosselin, Philip Marsh, Walter C. Oechel

Daugherty Water for Food Global Institute: Faculty Publications

Long-term atmospheric CO₂ concentration records have suggested a reduction in the positive effect of warming on high-latitude carbon uptake since the 1990s. A variety of mechanisms have been proposed to explain the reduced net carbon sink of northern ecosystems with increased air temperature, including water stress on vegetation and increased respiration over recent decades. However, the lack of consistent long-term carbon flux and in situ soil moisture data has severely limited our ability to identify the mechanisms responsible for the recent reduced carbon sink strength. In this study, we used a record of nearly 100 site-years of eddy covariance …

The Role Of Year And Animal Origin On Key Determinants Of Ewe Longevity, Audrey Burton, Annika Weaver, Rebekah Mills, Flint Herrelson, Patricia Harrelson

2023 Celebration of Student Scholarship - Poster Presentations

The MSU sheep flock is an Innovation Flock in the Sheep GEMS project through the University of Nebraska-Lincoln. The Sheep GEMS project is a national, multi-breed project that is focused on evaluating different sheep breeds and their longevity in different climates. As a participant, we collect/send raw data that is compiled. Our preliminary data from the 2022 (Year 1) and 2023 (Year 2) lambing season has been included. We collected measurements from Katahdin ewes (n = 38; 1-4.5 years old). We measured fecal egg counts (FEC), FAMACHA scores, body condition scores (BCS), teat and udder scores. Using the MIXED procedures …

Reference Frames In Human Sensory, Motor, And Cognitive Processing, Dongcheng He

Electronic Theses and Dissertations

Reference-frames, or coordinate systems, are used to express properties and relationships of objects in the environment. While the use of reference-frames is well understood in physical sciences, how the brain uses reference-frames remains a fundamental question. The goal of this dissertation is to reach a better understanding of reference-frames in human perceptual, motor, and cognitive processing. In the first project, we study reference-frames in perception and develop a model to explain the transition from egocentric (based on the observer) to exocentric (based outside the observer) reference-frames to account for the perception of relative motion. In a second project, we focus …

Deep Learning For Power Flow Estimation And High Impedance Fault Detection, Kun Yang

Electronic Theses and Dissertations

My thesis is divided into two parts.

The first part is: “Optimal Power Flow Estimation Using One-Dimensional Convolutional Neural Network [1]“. Optimal power flow (OPF) is an important research topic in power system operation and control decisions. Traditional OPF problems are solved through dynamic optimization with nonlinear programming techniques. For a large power system with large amounts of variables and constraints, the solving process would take a long time. This paper presents a new method to quickly estimate the OPF results using a one-dimensional convolutional neural network (1D-CNN). The OPF problem is treated as a high-dimensional mapping between the load …

Unsupervised Learning Algorithm For Noise Suppression And Speech Enhancement Applications, Abdullah Zaini Alsheibi

Electronic Theses and Dissertations

Smart and intelligent devices are being integrated more and more into day-to-day life to perform a multitude of tasks. These tasks include, but are not limited to, job automation, smart utility management, etc., with the aim to improve quality of life and to make normal day-to-day chores as effortless as possible. These smart devices may or may not be connected to the internet to accomplish tasks. Additionally, human-machine interaction with such devices may be touch-screen based or based on voice commands. To understand and act upon received voice commands, these devices require to enhance and distinguish the (clean) speech signal …

Integrating Quality Assurance In Balance Mix Designs For Durable Asphalt Mixtures: State-Of-The-Art Literature Review, Yizhuang David Wang, Jun Liu, Jenny Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Delivering durable asphalt concrete within a reasonable cost is one of the great ambitions of pavement material engineers. This state-of-the-art review article documents the efforts spent in the past two decades to ensure the durability and performance of asphalt mixtures in mix design and production. A perspective with the attempt to integrate laboratory mix design, plant production quality assurance, and field place acceptance is applied in the review. The development of the performance specification and performance mix design is summarized. The paper categorizes performance specification into index-based performance specification and predictive performance specification that include performance-related specification and performance-based specification. …

Thermal Analysis Of Si-Igbt Based Power Electronic Modules In 50kw Traction Inverter Application, Mohammad Shahjalal, Tamanna Shams, Sadat Bin Hossain, Md Rishad Ahmed, Mominul Ahsan, Julfikar Haider, Rajib Goswami, Syed B. Alam, Atif Iqbal

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Estimation of Accurate IGBT Junction Temperature is Crucial for Reliability Assessment. the Well-Known RC Lumped Approach Can Help Predict Junction Temperature. However, This Method Suffers from Inaccuracy While Characterizing the Thermal Behavior of Several IGBT Modules Mounted to the Liquid-Cooled Heatsink. Specifically, the Thermal Challenge Originates from the Thermal Cross-Coupling and Module-To-Module Heat Spreading and the Converter Cooling Condition. This Article Demonstrates a Methodology to Study the Impact of Heat Spreading, Thermal Interface Material, and Massive Size Liquid Cold-Plate on the overall Thermal Behavior. a Case Study of 50 KW Traction Inverter is Chosen to Demonstrate the Benefit of Early …

Are Natural Fractures In Sandstone Reservoir: Water Wet – Mixed Wet – Or Oil Wet?, Salah Almudhhi, Laila Abdullah, Waleed Al-Bazzaz, Saleh Alsayegh, Hussien Alajaj, Ralph E. Flori

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This study accurately measures the wettability contact angle of native Kuwaiti sandstone reservoir that hosts mixed pore size distributions in both the tight sandstone matrix as well as the natural fracture (NF) embedded in it. Also, this study, effectively, investigates the geometrical size and shape of natural available voids whether matrix voids or NF voids captured in the rock 2D image frame system. Correspondingly, this study is, successfully, measure tight matrix, NF Pore wall, and NF pore opening wettability performance and recovery efficiency contributions inside the sandstone reservoir. A model pore/ grain contact angle wettability is generated. Therefore, this study …

Measuring Ground Surface Elevation Changes In A Slow-Moving Colluvial Landslide Using Combinations Of Regional Airborne Lidar, Uav Lidar And Uav Photogrammetric Surveys, Sarah E. Johnson, William C. Haneberg, L. Sebastian Bryson, Matthew M. Crawford

UK CARES Faculty Publications

Slow-moving, chronically destructive landslides are projected to grow in number globally in response to precipitation increases from climate change, and land disturbances from wildfire, mining and construction. In the Cincinnati and northern Kentucky metropolitan area, USA, landslides develop in colluvium that covers the steep slopes along the Ohio River and its tributaries. Here we quantify elevation changes in a slow-moving colluvial landslide over 14 years using county- wide lidar, uncrewed aerial vehicle (UAV) structure-from-motion (SfM) surveys and a UAV lidar survey. Because the technology and quality differ between surveys, the challenge was to calculate a threshold of detectable change for …

Closed-Loop Recyclable Plastics From Poly(Ethyl Cyanoacrylate), Allison J. Christy, Scott T. Phillips

Materials Science and Engineering Faculty Publications and Presentations

Ethyl cyanoacrylate is a highly reactive monomer that has been used nearly exclusively to make Super Glue and related fast-setting adhesives. Here, we describe transformation of this highly abundant, readily available monomer into a closed-loop recyclable plastic that could supplant currently used (and often unrecycled/unrecyclable) plastics, such as poly(styrene). We report polymerization conditions, plastic-processing methods, and plastic-recycling protocols for poly(ethyl cyanoacrylate) plastics that make the Super Glue monomer a viable starting material for a next generation of closed-loop recyclable plastics. The processes described are scalable, and the plastics can be recycled in a closed-loop process with >90% yields, even when …

Effect Of Substituent Location On The Relationship Between The Transition Dipole Moments, Difference Static Dipole, And Hydrophobicity In Squaraine Dyes For Quantum Information Devices, Maia Ketteridge, Austin Biaggne, Ryan Rau, German Barcenas, Olga A. Mass, William B. Knowlton, Bernard Yurke, Lan Li

Materials Science and Engineering Faculty Publications and Presentations

Aggregates of organic dyes that exhibit excitonic coupling have a wide array of applications, including medical imaging, organic photovoltaics, and quantum information devices. The optical properties of a dye monomer, as a basis of dye aggregate, can be modified to strengthen excitonic coupling. Squaraine (SQ) dyes are attractive for those applications due to their strong absorbance peak in the visible range. While the effects of substituent types on the optical properties of SQ dyes have been previously examined, the effects of various substituent locations have not yet been investigated. In this study, density functional theory (DFT) and time-dependent density functional …

Design, Determination, And Evaluation Of Gender-Based Bias Mitigation Techniques For Music Recommender Systems, Sunny Shrestha

Electronic Theses and Dissertations

The majority of smartphone users engage with a recommender system on a daily basis. Many rely on these recommendations to make their next purchase, download the next game, listen to the new music or find the next healthcare provider. Although there are plenty of evidence backed research that demonstrates presence of gender bias in Machine Learning (ML) models like recommender systems, the issue is viewed as a frivolous cause that doesn’t merit much action. However, gender bias poses to effect more than half of the population as by default ML systems are designed to cater to a cisgender man. This …

Enhancement Of Heat-Cured Cement Paste With Tannic Acid, Jinrui Zhang, Ziye Kang, Youzhi Yang, Biqin Dong, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Improvement of Cement-Based Materials' Performance by Natural Organic Compounds Can Greatly Promote the Green and Sustainable Development of the Construction Industry. However, Such Compounds Are Not Widely Used Yet Because of their Retarding Effect on Cement. in This Study, the Retardation Effect of Tannic Acid (TA, a Well-Known Retarding Compound) is overcome and the Enhancing Effect is Achieved by Adding Less Than 0.1% Content and Curing Samples in Thermal Regime. Then the Mechanism of TA Enhancing Heat-Cured Cement Pastes is Studied Systematically. Mechanical Properties Results Suggest that Addition of 0.025% TA Can Reduce the Compressive and Flexural Strengths of …

Assessing Hardware Security Threats Posed By Hardware Trojans In Power Electronics, Quinn Kinzie

All Theses

This study investigates the threat of hardware Trojans (HTs) in power electronics applications, a rising concern due to the growing demand for cost-effective embedded solutions in power systems. With the supply chain for electronic hardware devices expanding globally, particularly to low-cost foundries in foreign locations, there is an increasing risk of HT attacks. While there has been extensive research on HTs in computer applications, little consideration has been given to their threat in power electronics. This study demonstrates the effectiveness of a power electronics HT by implementing a novel HT design into a gate drive circuit. Additionally, the research proposes …