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2023

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Articles 301 - 330 of 9777

Full-Text Articles in Engineering

Network Layer Reliability And Security In Energy Harvesting Wireless Sensor Networks, Jing Yang Dec 2023

Network Layer Reliability And Security In Energy Harvesting Wireless Sensor Networks, Jing Yang

Theses and Dissertations

Wireless sensor networks (WSNs) have become pivotal in precision agriculture, environmental monitoring, and smart healthcare applications. However, the challenges of energy consumption and security, particularly concerning the reliance on large battery-operated nodes, pose significant hurdles for these networks. Energy-harvesting wireless sensor networks (EH-WSNs) emerged as a solution, enabling nodes to replenish energy from the environment remotely. Yet, the transition to EH-WSNs brought forth new obstacles in ensuring reliable and secure data transmission.

In our initial study, we tackled the intermittent connectivity issue prevalent in EH-WSNs due to the dynamic behavior of energy harvesting nodes. Rapid shifts between ON and OFF …


Moisture Effects On Visible Near-Infrared And Mid-Infrared Soil Spectra And Strategies To Mitigate The Impact For Predictive Modeling, Francis Hettige Chamika Anuradha Silva Dec 2023

Moisture Effects On Visible Near-Infrared And Mid-Infrared Soil Spectra And Strategies To Mitigate The Impact For Predictive Modeling, Francis Hettige Chamika Anuradha Silva

Theses and Dissertations

Instrumental disparities and soil moisture are two of the key limitations in implementing spectroscopic techniques in the field. This study sought to address these challenges through two objectives. The first objective was to assess Visible-near infrared (VisNIR) and mid-infrared (MIR) spectroscopic approaches and explore the feasibility of transferring calibration models between laboratory and portable spectrometers. The second objective addressed the challenge of soil moisture and its impact on spectra. The portable spectrometers demonstrated comparable performance to their laboratory-based counterparts in both regions. Spiking with extra-weight, was the most effective calibration transfer method eliminating disparities between instruments. The samples were rewetted …


Cement Stabilization Of Poorly Graded Sand, Lana Grayson Brown Sisung Dec 2023

Cement Stabilization Of Poorly Graded Sand, Lana Grayson Brown Sisung

Theses and Dissertations

Stabilization of poorly graded sand in full-scale applications is challenging. This thesis evaluated cement-stabilized sand and had two objectives: (1) evaluation of stabilized material using the PM device to quantify engineering properties for future comparison to alterative materials and to investigate the effectiveness of the device with sand and (2) investigation of the merits of alternative application of cement to sand to benchmark against other topically applied materials. The PM device was successfully used to recommend 10% cement for field studies with one sand, successfully allowed data collection in laboratory and field applications, and its potential in sand seems promising …


Traffic Light Detection And V2i Communications Of An Autonomous Vehicle With The Traffic Light For An Effective Intersection Navigation Using Mavs Simulation, Mahfuzur Rahman Dec 2023

Traffic Light Detection And V2i Communications Of An Autonomous Vehicle With The Traffic Light For An Effective Intersection Navigation Using Mavs Simulation, Mahfuzur Rahman

Theses and Dissertations

Intersection Navigation plays a significant role in autonomous vehicle operation. This paper focuses on enhancing autonomous vehicle intersection navigation through advanced computer vision and Vehicle-to-Infrastructure (V2I) communication systems. The research unfolds in two phases. In the first phase, an approach utilizing YOLOv8s is proposed for precise traffic light detection and recognition, trained on the Small-Scale Traffic Light Dataset (S2TLD). The second phase establishes seamless connectivity between autonomous vehicles and traffic lights in a simulated Mississippi State University Autonomous Vehicle Simulation (MAVS) environment resembling a small city with multiple intersections. This V2I system enables the transmission of Signal Phase and Timing …


Soft Robot Trajectory Generation: Enabling Soft Robot Arms To Reliably And Effectively Perform Real World Tasks Through Optimization, Haley P. Sanders Dec 2023

Soft Robot Trajectory Generation: Enabling Soft Robot Arms To Reliably And Effectively Perform Real World Tasks Through Optimization, Haley P. Sanders

Theses and Dissertations

The robotic platform presented in this thesis is underdamped with high inertia and can store potential energy in its compliant joints, making it ideal for many different types of real-world tasks for which traditional rigid-robots are ill-suited. Some real-world tasks suited to soft robots include high impact tasks like hammering a nail into a wall or moving heavy objects with other robot or human teammates while using relatively little power. Some of the same characteristics which make soft robots useful, such as their underdamped, highly compliant joints, also make motion planning and control for soft robots difficult. In this thesis, …


A Review On Ship Recycling Industry In Bangladesh From Global Perspective, Ahammad Abdullah, Zobair Ibn Awal, M Ziauddin Alamgir, Md. Jobayer Mia, Farihatul Mim, Utpal K. Dhar Dec 2023

A Review On Ship Recycling Industry In Bangladesh From Global Perspective, Ahammad Abdullah, Zobair Ibn Awal, M Ziauddin Alamgir, Md. Jobayer Mia, Farihatul Mim, Utpal K. Dhar

Journal of Ocean and Coastal Economics

At present, the global center of the ship breaking and recycling industry is in South Asia, specifically Bangladesh, India, and Pakistan. These three countries account for 70–80 percent of the international recycling market for ocean-going vessels, with China and Turkey covering most of the remaining market. Only about 5 percent of global volume is scrapped outside these five countries. Bangladesh has environmentally beneficial coastal region and affordable labor that make the shipbreaking and recycling business as a potential sector for the country. In addition, ship recycling and its related businesses are helping to solve our nation’s unemployment issues at all …


Thermally Rearranging Polyimide Networks For High-Temperature Applications, William Guzman Dec 2023

Thermally Rearranging Polyimide Networks For High-Temperature Applications, William Guzman

Dissertations

High-performance polymers can retain functional properties when exposed to long-term or short-term durations of harsh conditions, such as mechanical action, at elevated temperatures (>177 °C). A mixture of intramolecular and intermolecular forces of and between polymer chains provide excellent property retention at elevated temperatures. Specifically, the highly aromatic nature of high-performance polymer backbones provides outstanding thermal stability, which is typically attributed to π-π stacking. However, the interrelationship between thermal stability and high aromaticity creates a challenging structure-processing relationship paradigm, which causes poor polymer processability in most high-performance polymers. Herein, it was demonstrated that rationally designing a crosslinking phenylethynyl imide …


Using Afm-Ir To Study Nanoscopic Phase Behavior Of Polymer Blends And Photovoltaic Bulk Heterojunctions, Nathaniel L. Prine Dec 2023

Using Afm-Ir To Study Nanoscopic Phase Behavior Of Polymer Blends And Photovoltaic Bulk Heterojunctions, Nathaniel L. Prine

Dissertations

Conjugated polymers (CPs) and polymer blends harbor the potential for high-performance organic solar cells (OSCs) due to their short energy payback time, low cost, solution processability, lightweight attributes, and flexibility. However, OSCs suffer from poor thermal stability compared to their inorganic equivalents. This study explores the thermal instability of OSCs, focusing on phase separation of the photoactive layer under heat, resulting in morphology changes and degradation of power conversion efficiency (PCE). Utilizing atomic-force microscopy coupled with infrared spectroscopy (AFM-IR) and differential scanning calorimetry (DSC), we delve into thermal stability-morphology relationships to devise strategies to improve OSC blend durability under thermal …


Timeseries Forecasting Of U.S. Housing Price Index Using Machine Learning And Deep Learning Models, Krishna Chaitanya Nunna Dec 2023

Timeseries Forecasting Of U.S. Housing Price Index Using Machine Learning And Deep Learning Models, Krishna Chaitanya Nunna

Dissertations

Time series forecasting is a promising technique for various applications which predicts future values or patterns by taking historical data as base. Forecasting future trends is very beneficial for different industries to make valuable decisions and strategies. One such industry is housing market; it has biggest influence on U.S. economy. Housing price index (HPI) is a one of the crucial economic indices published by various government funded and private agency to benefit several industries and individuals for better analysis of future trends of housing market.

Several factors influence the HPI, economical, geographical, and demographic features. Development of traditional time series …


Intelpvt And Opt-Stvit: Advances In Vision Transformers For Object Detection, Classification And Video Recognition, Divya Nimma Dec 2023

Intelpvt And Opt-Stvit: Advances In Vision Transformers For Object Detection, Classification And Video Recognition, Divya Nimma

Dissertations

Since the advent of Transformers, followed by Vision Transformers (ViTs), great success has been achieved by researchers in the field of computer vision and object detection. The difficult mechanism of splitting images into fixed patches posed a serious challenge in this arena and resulted in the loss of useful information at the time of object detection and classification. We propose an innovative Intelligent-based patching mechanism to overcome the challenges and integrate it seamlessly into the conventional Patch-based ViT framework. The proposed method enables the utilization of patches with flexible sizes to capture and retain essential semantic content from input images, …


2023 Fall Engr333 Section B Final Report, Ally Gauss, Stuart Johnston, Zachary Rozendal, Nora Terbeek, Samantha Bush, Daniel Cordeiro, David Harris, Nathan Zylstra, Mikayla Bindon, David Schmurr, Zachary Swart, Micah Vandeburg, David Conhoff, Mitchell Cook, Yonggi Kim, Mark Schultz Dec 2023

2023 Fall Engr333 Section B Final Report, Ally Gauss, Stuart Johnston, Zachary Rozendal, Nora Terbeek, Samantha Bush, Daniel Cordeiro, David Harris, Nathan Zylstra, Mikayla Bindon, David Schmurr, Zachary Swart, Micah Vandeburg, David Conhoff, Mitchell Cook, Yonggi Kim, Mark Schultz

ENGR 333

Calvin University is currently committed to being carbon neutral by 2057. However, by 2057 the earth will see irreversible damage due to global warming. Because of the constant rise in global carbon emissions, President Boer tasked the students of ENGR-333 to find an earlier date for Calvin to become carbon neutral. Carbon net neutrality involves eliminating the emissions associated with heating and electricity. To have the most immediate impact, it was desired to reduce the most carbon as fast as was cost effective. Starting immediately, Calvin would start buying carbon free electricity from Consumer’s Energy, continuing until 2040 when Consumer’s …


2023 Fall Engr333 Section A Final Report, Owen Kalsbeek, Panashe Makuvaro, Luke Penning, Caleb Gaffner, David Visser, Jared Skaggs, Stephen Langerak, Kyle Borror, Caleb Clark, Michael Lanning, Brayden Raches, Sam Mennega, Seth Devries, Kyle Vandusen, Hayden White Dec 2023

2023 Fall Engr333 Section A Final Report, Owen Kalsbeek, Panashe Makuvaro, Luke Penning, Caleb Gaffner, David Visser, Jared Skaggs, Stephen Langerak, Kyle Borror, Caleb Clark, Michael Lanning, Brayden Raches, Sam Mennega, Seth Devries, Kyle Vandusen, Hayden White

ENGR 333

On 6 December 2017, then-president Michael Le Roy signed the President’s Climate Commitment, which committed Calvin University to carbon neutrality by 2057. Within a global scope, humanity has already emitted approximately 83% of its carbon allowance before causing global warming of 1.5°C. The Paris Climate Accords stated this temperature increase as the point at which humanity’s damage to the planet becomes irreversible. Given this, the year 2057 seemed like a dangerously late date for Calvin to achieve carbon neutrality. These concerns led President Boer to task the students of Engineering 333 with the following question: what earlier year should Calvin …


Cobalt Chromium In Biomedical Applications And The Development Of A Pspp Map, Nouralhouda Jamal Dec 2023

Cobalt Chromium In Biomedical Applications And The Development Of A Pspp Map, Nouralhouda Jamal

BCoE Publications

During the world wars, Cobalt-Chromium (Co-Cr) alloys gained prominence for their use in aircraft engine components, where they exhibited high temperature strength and durability. They are used in a wide range of industries due to their unique set of qualities, particularly strength, corrosion resistance, and biocompatibility. They have emerged as versatile materials with a broad spectrum of applications, from aerospace and automotive components to biomedical implants.

This paper presents a thorough analysis of its composition, processing techniques, microstructure, mechanical properties, and performance characteristics. The primary goal of this project is to develop a PSPP (Process, structure, properties, and performance) map …


Quantification Of Intervertebral Disc Strain From High-Resolution Ultrasound Imaging During Dynamic Loading, Diya Sakhrani Dec 2023

Quantification Of Intervertebral Disc Strain From High-Resolution Ultrasound Imaging During Dynamic Loading, Diya Sakhrani

Discovery Undergraduate Interdisciplinary Research Internship

High-resolution ultrasound imaging employs high-frequency sound waves that can be used to noninvasively visualize the structures within the body, facilitating medical diagnosis without the need for open surgery. The widespread utilization of ultrasound is attributed to its affordability, non-invasive characteristics, and use of non-ionizing radiation. Nevertheless, ultrasound is prone to artifacts originating from the surrounding environment, gas-liquid interfaces, or dense tissue. These artifacts are common in ultrasound images and can cause dropout, noise, and degraded resolution. In this study we analyzed intervertebral disc (IVD) strain during two axial compression testing cycles of bovine intervertebral discs with a 2-dimensional direct deformation …


Drop Retention And Departure In Shear Flow On Structured Superhydrophobic Surfaces, Blake Morgan Lyons Dec 2023

Drop Retention And Departure In Shear Flow On Structured Superhydrophobic Surfaces, Blake Morgan Lyons

Theses and Dissertations

Water is often found adhering to surfaces in droplet form. Droplets can develop as a result of precipitation, condensation, or chemical reactions. Drops are retained or held on a surface due to a retention force exerted on the drop by the surface. This retention force is a function of the surface tension of the liquid, drop geometry, and the contact angle between the drop and the surface. When external or body forces exceed this retention force the drop begins to move. This thesis seeks to understand and quantify the forces present at the point of droplet departure once it begins …


Development Of A Submerged Hydraulic Jump Prediction Method Using Documented Fatal Incidents At Low-Head Dams, Caleb Mccurry Dec 2023

Development Of A Submerged Hydraulic Jump Prediction Method Using Documented Fatal Incidents At Low-Head Dams, Caleb Mccurry

Theses and Dissertations

Low-head dams are known to be dangerous due to a recirculating current that, when formed, drowns recreationalists who become trapped in the current. Efforts to mitigate the hazard of low-head dams have led to the compilation of a database of low-head dams with proven fatalities. Additionally, flume-based experiments along with well-known hydraulic equations have been used to create a spreadsheet-based system for predicting the occurrence of the dangerous recirculating current, otherwise known as a submerged hydraulic jump. The premise of the spreadsheet is that if the normal depth calculated with the Mannings Equation for the downstream reach is between the …


Protecting Zn Anodes By Atomic Layer Deposition Of Zro2 To Extend The Lifetime Of Aqueous Zn-Ion Batteries, Shichen Sun, Yeting Wen, Aiden Billings, Roya Rajabi, Boyu Wang, Kangkang Zhang, Kevin Huang Dec 2023

Protecting Zn Anodes By Atomic Layer Deposition Of Zro2 To Extend The Lifetime Of Aqueous Zn-Ion Batteries, Shichen Sun, Yeting Wen, Aiden Billings, Roya Rajabi, Boyu Wang, Kangkang Zhang, Kevin Huang

Faculty Publications

Aqueous rechargeable Zn-ion batteries (ARZIBs) are a newly emerged class of electrochemical cells suited for large-scale stationary energy storage applications due to their unique advantages in safety, cost, and supply chain. To advance ARZIB technology toward commercialization, the corrosion problem of Zn anodes in aqueous electrolytes must be adequately addressed. Here we report our efforts to tackle this issue by using atomic layer deposition (ALD) to coat the Zn anode surface with a protective nanoscale ZrO2 thin film, collectively denoted as ALD-ZrO2@Zn in this study. We show the pertinent properties of ALD-ZrO2@Zn in aqueous Zn-salt …


Artificial Intelligence & Aviation: A Content Analysis, Victor E. Morales, Jonathan Escalera, Jose Sanchez, Brooke Wheeler, Vivek Sharma Dec 2023

Artificial Intelligence & Aviation: A Content Analysis, Victor E. Morales, Jonathan Escalera, Jose Sanchez, Brooke Wheeler, Vivek Sharma

Aeronautics Student Publications

The aviation industry has explored the integration of artificial intelligence (AI) into its unique aspects. This study aimed to identify the trends in publications that discuss AI and aviation within 2013-2023. A content analysis is used to identify any regressions in the trends of publication counts discussing AI and aviation. The study collected publication data from the Advanced Technologies & Aerospace Database (ATAD) using specific search terms, “AI and aviation,” “artificial intelligence and aviation,” “AI and aircraft,” and “AI and aircraft safety,” to accurately obtain publications. The collected data is then categorized by publications per year and is represented in …


Analyzing Flight Delays: Legacy And Low-Cost Carriers In The U.S., Kwangyeol Yang, Dae Keun Jeon, Nawaf Nasser M. Alsubaie, Vivek Sharma, Brooke Wheeler Dec 2023

Analyzing Flight Delays: Legacy And Low-Cost Carriers In The U.S., Kwangyeol Yang, Dae Keun Jeon, Nawaf Nasser M. Alsubaie, Vivek Sharma, Brooke Wheeler

Aeronautics Student Publications

This study analyzed flight delays between legacy and low-cost carriers in the U.S. from 2013 to 2022. The study found a higher average percentage of flights delayed among low-cost carriers than legacy carriers and identified a significant difference in the percentage of total flights delayed by airline type.


Change In Air Cargo Revenue Before Vs During The Covid-19 Pandemic, Ali Abushal, Timothy R. Buchal, Ethan Noto, Brooke Wheeler, Vivek Sharma Dec 2023

Change In Air Cargo Revenue Before Vs During The Covid-19 Pandemic, Ali Abushal, Timothy R. Buchal, Ethan Noto, Brooke Wheeler, Vivek Sharma

Aeronautics Student Publications

This study aimed to investigate the changes in revenue experienced by cargo airlines before and during the COVID-19 pandemic. To gather the necessary data, information was sourced from the Securities and Exchange Commission's (SEC) databases and the websites of the specific airlines. The findings of this study revealed significant shifts in revenue for cargo airlines during the pandemic. Some airlines experienced an unexpected rise in revenue, challenging our previous understanding of the industry dynamics. These findings highlighted the importance of conducting a comprehensive analysis that includes a larger view of the aviation sector.

The COVID-19 pandemic had a profound impact …


Wildlife Strikes By Damage Category In The U.S. From 2013-2022, Malek Alharbi, Catherine Meechan, Brooke Wheeler, Vivek Sharma Dec 2023

Wildlife Strikes By Damage Category In The U.S. From 2013-2022, Malek Alharbi, Catherine Meechan, Brooke Wheeler, Vivek Sharma

Aeronautics Student Publications

The FAA provides the public with a database containing reports of wildlife strikes. We gathered data on the reported types of damage and concluded there was a difference in the annual strike rate by damage category with no damage as the most reported damage category.


A Human Factors Approach To Improve Layout Design For A Virtual Reality-Based Training Platform, Md Humaun Kobir, Taufiq Rahman, Yiran Yang, Shuchisnigdha Deb Dec 2023

A Human Factors Approach To Improve Layout Design For A Virtual Reality-Based Training Platform, Md Humaun Kobir, Taufiq Rahman, Yiran Yang, Shuchisnigdha Deb

SAGE Open Access Agreement Publications-Archive

In manufacturing industries, equipment arrangement, and layout design are critical factors that directly influence productivity, workplace safety, and workers’ performance. Link analysis, as a human factors approach, has been widely used in industries for many years to improve layout design and machinery arrangement. This approach considers humans' physical and cognitive capabilities and movement limitations to find an optimal design. Virtual reality significantly impacts our society from product design to worker training. Hence, effective virtual training platforms require the same attention to layout design as manufacturing work settings which offer efficient testing of multiple layouts. This research focuses on developing a …


Comparison Of Methods For Estimating Instantaneous Turn Radius Of Ackermann Steering Vehicles, Kenneth Gennaro Stutts Dec 2023

Comparison Of Methods For Estimating Instantaneous Turn Radius Of Ackermann Steering Vehicles, Kenneth Gennaro Stutts

Doctoral Dissertations and Master's Theses

The instantaneous turn radius of an Ackermann steering vehicle is the distance to a point in space about which the vehicle will travel in an arc during a turn. There are at least six ways to estimate instantaneous turn radius and each method uses different inputs and has distinct advantages and disadvantages. In this thesis, six different methods will be used to estimate the instantaneous turn radius of a vehicle traveling on a closed circuit. This testing will clarify similarities and differences between the methods. This thesis clarifies which method will be the most appropriate for a given set of …


Shop & Speak: The Hottest Eye-Phone App On The Market, Angelo N. Ledonne Dec 2023

Shop & Speak: The Hottest Eye-Phone App On The Market, Angelo N. Ledonne

Honors Capstones

In the U.S, approximately 20 million individuals (8% of the population) are partly or completely visually impaired. This disability makes some everyday tasks such as reading, writing, shopping, traveling, etc., difficult. But, with the advancement of technology over the past few decades, design products and software have been created that help level the playing field for those in need. The only hurdle that still exists today is the cost and availability of these products, leaving many affected individuals with very little or no assistance in their everyday lives. This project was inspired by my grandmother’s disability. She was born with …


Climate Change Impact On Bridge Scour Risk In Ny State: A Gis-Based Risk Analysis Model, Muhammad Hassan Butt Dec 2023

Climate Change Impact On Bridge Scour Risk In Ny State: A Gis-Based Risk Analysis Model, Muhammad Hassan Butt

Publications and Research

Bridge scour, the primary cause of bridge failure in the United States, escalates post-severe storms, necessitating effective mitigation. This study employs a GIS-based risk analysis model to assess climate change's impact on bridge scour and associated risks in New York State. Data from the National Bridge Inventory, climate hazard maps, and geospatial data are integrated.


A Series Of Improved And Novel Methods In Computer Vision Estimation, James J. Adams Dec 2023

A Series Of Improved And Novel Methods In Computer Vision Estimation, James J. Adams

Theses and Dissertations

In this thesis, findings in three areas of computer vision estimation are presented. First, an improvement to the Kanade-Lucas-Tomasi (KLT) feature tracking algorithm is presented in which gyroscope data is incorporated to compensate for camera rotation. This improved algorithm is then compared with the original algorithm and shown to be more effective at tracking features in the presence of large rotational motion. Next, a deep neural network approach to depth estimation is presented. Equations are derived relating camera and feature motion to depth. The information necessary for depth estimation is given as inputs to a deep neural network, which is …


Effectiveness Of Intelligent Transportation Systems On Utah Roadways, Matthew Cline Davis Dec 2023

Effectiveness Of Intelligent Transportation Systems On Utah Roadways, Matthew Cline Davis

Theses and Dissertations

This thesis presents the findings of a comprehensive research study conducted for the Utah Department of Transportation (UDOT) to evaluate the effectiveness of commonly deployed Intelligent Transportation System (ITS) treatments in Utah, with a focus on Variable Message Signs (VMS), traffic cameras, and Road Weather Information System(s) (RWIS) sites. The study aimed to determine the impact of these ITS treatments on mobility and safety for Utah's unique road conditions and configurations. Three primary analyses were performed: a diversion rates analysis to assess the effectiveness of VMS on Utah freeways during incidents; a weather analysis to evaluate the effectiveness of VMS …


Advancements In Levitated Optomechanics: Exploring Plasmon-Enhanced Light-Matter Interactions In Optical Trapping, Siavash Mirzaei Ghormish Dec 2023

Advancements In Levitated Optomechanics: Exploring Plasmon-Enhanced Light-Matter Interactions In Optical Trapping, Siavash Mirzaei Ghormish

Theses and Dissertations

Optical trapping of metallic nanoparticles investigates phenomena at the interface of plasmonics and optical micromanipulation. This thesis combines ideas from the optical properties of metals, originating in solid-state physics, with the force mechanisms resulting from optical trapping. I explore the influence of enhanced light-matter interaction due to the plasmon resonances of gold particles on their trapping properties. I present theories for trapping mechanisms of gold metallic particles and then verify these theories through experiments. Optical trapping of metallic nanoparticles is considered challenging, especially in air, as they are highly absorbing and reflecting at optical wavelengths. Yet the optical levitation of …


Measuring Gas Discharge In Contact Electrification, Hongcheng Tao, James Gibert Dec 2023

Measuring Gas Discharge In Contact Electrification, Hongcheng Tao, James Gibert

Purdue University Libraries Open Access Publishing Fund

Contact electrification in a gas medium is usually followed by partial surface charge dissipation caused by dielectric breakdown of the gas triggered during separation of the surfaces. It is widely assumed that such discharge obeys the classical Paschen’s law, which describes the general dependence of the breakdown voltage on the product of gas pressure and gap distance. However, quantification of this relationship in contact electrification involving insulators is impeded by challenges in nondestructive in situ measurement of the gap voltage. The present work implements an electrode-free strategy for capturing discrete discharge events by monitoring the gap voltage via Coulomb force, …


Investigating The Effects Of Unfused Powder Damping In Laser Powder Bed Fusion, Samuel Hao Teng Dec 2023

Investigating The Effects Of Unfused Powder Damping In Laser Powder Bed Fusion, Samuel Hao Teng

Theses and Dissertations

This study uses Additive Manufacturing (AM) processes to fabricate 316L stainless steel beams with pockets of unfused powder for increased damping. Modal testing was completed to compare damping factors of beams with varying pocket geometries as well as number of pockets and pocket location. For the first three bending modes that were tested, an initial damping increase was observed when pocket height is greater than powder diameter. Following the initial increase there is a height threshold, which is mode dependent, that is required to achieve a statistically significant increase in damping.