Journal of Extension

Accepted versio

Ion-Currents in Oxyfuel Cutting Flames Exposed to External Bias Voltages

Computational Fluid Dynamics (CFD) and predictive models are presented in this dissertation that illustrates the detailed electrical characteristics, and the current-voltage (i-v) relationship throughout the preheating process of premixed methane-oxygen (CH4-O2) oxyfuel cutting flame subject to electric bias voltages. As such, the equations describing combustion, electrochemical transport for charged species, and potential are solved through a commercially available finite-volume CFD code. The reactions of the methane-oxygen (CH4 – O2) flame were combined with the GRI 3.0 mechanism and a 25-species reduced mechanism, respectively, and additional ionization reactions that generate three chemi-ions, H3O+, HCO+, and e– , to describe the chemistry of ions in flames. The electrical characteristics such as ion migrations and ion distributions are investigated for a range of electric potential, V ∈ [−10V, +10V ]. Since the physical flame is comprised of twelve Bunsen-like conical flame, inclusion of the third dimension imparts the resolution of fluid mechanics and the interaction among the individual cones. As for developing the predictive models, four different supervised machine learning (ML) algorithms, decision tree (DT), random forest (RF), K-nearest neighbors (KNN), and artificial neural network (ANN), were employed to predict the i-v relationship. An experimental dataset of ≈ 10050 was utilized where a 60:20:20 split was adopted, allocating 60% for training, 20% for validation, and 20% for testing. It was concluded that charged 'sheaths' are formed at both torch and workpiece surfaces, subsequently forming three distinct regimes in the i-v relationship. The i-v characteristics obtained have been compared to the previous experimental study for premixed flame. In this way, the overall model generates a better understanding of the physical behavior of the oxyfuel cutting flames, along with a more validated i-v characteristics. Such understanding might provide critical information towards achieving an autonomous oxyfuel cutting process.Doctor of PhilosophyOxyfuel flame cutting is a century-old technique having widespread applications in heavy industries, including, but not limited to, building construction, defense, shipyards, etc. However, the mechanized oxyfuel cutting process has never benefited from the degree of autonomy due to contemporary sensing technologies' limitations at high-temperature working conditions. As a result, an experienced labor force is required to operate the system, thereby lowering the efficacy associated with this cutting process. A potential solution to this problem is motivated by preliminary measurements demonstrating that electrical events called 'ion currents' associated with the flame itself can reliably indicate vital process states. Provided that an autonomous process is achieved, this work could realize reliable cost-effective control of the oxyfuel cutting process, a capability of great interest to many core US industries involved in construction, and major equipment manufacture for defense and energy applications. Critical parameters (standoff, F/O ratio, flow rate, etc.) must be detected during operation to ensure an autonomous oxyfuel cutting process. The motivation stems from the fact that by measuring such co-dependence between critical parameters and electrical characteristics through a data acquisition unit (DAQ) and power supply, the shortcomings of sensing suites in a harsh operating environment can be compromised. Experimental data in the literature indicated the current-voltage (i-v) relationship with different critical parameters of oxyfuel flame to be the salient electrical characteristic in the preheating process when cutting steel. A comprehensive two-dimensional computational simulation using StarCCM+ only with the reduced combustion chemical mechanism with ion-exchange reactions has already been completed to elucidate the experimental results and to investigate the electrical characteristics such as ion migrations and ion distributions. Nonetheless, the findings exhibit some magnitude of differences compared to the experimental results. Thereby to further improve the results and better understand the underlying physics, further computational models using ANSYS FLUENT are proposed herein, having the reduced surface chemical mechanism considered. In addition, predictive models were developed based on machine learning (ML) algorithms. Four supervised ML algorithms - decision tree (DT), random forest (RF), Knearest neighbors (KNN), and artificial neural network (ANN) - were adopted to predict the current-voltage (i-v) relationship at different process states. ML offers a more data-driven, adaptable, and scalable approach to prediction compared to traditional methods. Its ability to handle large, noisy, and complex data makes it especially powerful for tasks that are challenging for conventional analytical techniques. The results of this study illustrate the detailed electrical characteristics of premixed methane-oxygen (CH4 – O2) oxyfuel cutting flame subject to an electric field, for both the computational fluid dynamics (CFD) and ML models. Since the physical flame is comprised of twelve Bunsen-like conical flame, inclusion of the third dimension will impart the resolution of fluid mechanics and the interaction among the individual cones. Moreover, the chemical activity at the work surface will also be considered, however, with a substantial simplification of the three-dimensional model as a cost. The overall model will generate a better understanding of the physical behavior of the oxyfuel cutting flames, along with a more validated currentvoltage (i-v) relationship. Consequently, this relationship could then be embedded into a control algorithm to detect the critical process parameters that may facilitate a step towards achieving an autonomous oxyfuel cutting process

Enhancing the User Experience and Decision-Making of Green Building Certification Resources through Usability Testing Methods

Doctor of PhilosophyGreen building is defined as a building providing users with healthy and comfortable living space that also implements efficient use of energy and resources. Guidelines and manuals called green building certification resources help project teams construct green buildings and earn certifications. By focusing on technical aspects, green building certification resource developers overlook usability and likely impact ease of use and overall experience. EarthCraft Multifamily (ECMF) is a green building certification program that has had many years of success in Virginia and Georgia. While ECMF resources have contributed to its success, there is room for improvement. The objective of this research was to investigate ways to improve the user experience and usability of green building certification resources and enhance user decision-making. This research utilized various qualitative and quantitative methods to analyze and discuss various ways that green building certification resources can be improved. Results from this study are based on numerous ways that ECMF resources can be enhanced. Data sources include data from Jefferson et al. (2021), project specifications, developer interview data, stakeholder interview data, and builder interview data. Interviews were conducted with professional architects, builders, and stakeholders that had previous experience with the ECMF program and resources. Interviews were also conducted with members of past development teams that worked on ECMF resources in the past. A comparative analysis following an A/B testing format was conducted on original and alternate versions of ECMF resources. The findings from this study demonstrate that user experiences and usability improvements to ECMF resources can contribute to enhance decision-making. Interview data showed that architects, builders, and stakeholders' experience with ECMF resources were affected by the usability issues present in the resources. Understanding how ECMF resources are utilized and perceived by users allows for the appropriate content and options to be strategically framed to enhance user decision-making in future iterations of ECMF. This research also sets the stage for developers of other green building certification programs such as LEED and Enterprise to replicate this form of study and further enhance their resources which are critical to the development of affordable sustainable housing

Agronomy

Maize (corn) (Zea mays L.) yield is influenced by complex factors, including abiotic and biotic stress and inconsistent nutrient use efficiency, which challenge optimal yield. Standard management recommendations often fall short, prompting interest in intensive management strategies within an Adaptive Maize Management System (ACMS). To investigate this, we employed an addition/omission technique within a randomized complete block design (RCBD) to compare standard maize management recommendations with an intensive management protocol aimed at identifying yield-limiting factors. Our intensive management approach combined early-season biostimulant applications with mid-season supplementation of phosphorus (P), potassium (K), and nitrogen (N) at the V7 stage, followed by foliar fungicides and additional foliar N at the R1 stage. Field trials spanned five Virginia locations over 2022 and 2023 under both irrigated and non-irrigated conditions, yielding ten site-years of data. Analysis via ANOVA in JMP® Version 18 with Dunnett’s test revealed that the intensive management approach significantly increased grain yield in 3 of 10 experiments. Under non-irrigated conditions, the intensive management practices averaged 5.9% higher yield than the standard management check. We observed a higher response to irrigation in standard management check (34%) than in intensive management check (8.9%). Site-specific irrigation impacts ranged from 14% to 61%. Results emphasize site-specific input recommendations for yield enhancement.Published versio

Traffic Visualization Dashboard

Currently, the dashboard contains some key features such as: a user authentication and login system, a file collection upload mechanism to populate the database, and a base visualization environment that loads automatically upon selecting a data collection. After meeting with the client, Professor Mohamed Farag, the proposed updates interactive dashboard will contain a second-by-second simulation review that can display the plain data and a new graph visualization that displays the change in metrics over time, new navigation/help features that will allow easier usability of the system, and updates to the login/landing page.The Traffic Visualization Dashboard project, led by the Virginia Tech Transportation Institute (VTTI), is a project created last semester by a team of students that seeks to improve the accessibility and user-friendliness of the Integration Traffic Simulation Tool. The aim of last semester’s project is to improve the usability of the simulator by creating a comprehensive visualization dashboard. This dashboard would take complex raw data and transform it into intuitive, meaningful visualizations, allowing users to gain insights into traffic behavior and patterns

Sankofa: A virtual Exploration of the Besease Shrine

As a teenager growing up in Ghana, whenever I traveled to my hometown, I saw old, abandoned traditional buildings made of earth and timber frames. I have always wanted to know why old traditional buildings look so unique and different from our present-day buildings. They usually appear to be weak as rain erodes some portions of them. While most have been abandoned, some have been preserved to serve their purpose. This ignited my curiosity as an artist to use visual forms to learn more about these buildings. In this project, I use virtual reality to explore the purpose and importance of these buildings in their prime. The Besease Shrine, located in Ejisu Besease, which has been serving as a spiritual ground since the 19th century, is being used as a case study and reimagined in a virtual space to learn about the architectural forms and motifs of these buildings. Virtual reality is an artistic medium that can visualize historic sites and places remotely to give a firsthand perspective and appreciation. The paper further discusses how virtual reality can be used to preserve and document these historical places.Master of Fine ArtsWith the rise of modern emerging technologies, you can be close to distant places that seem far from you. With VR technology, I invite participants to feel like they are in the presence of the Besease Shrine without having to travel to its location in the Ashanti Region of Ghana. The project uses Maya 3D, Adobe Substance Painter, ZBrush, MakeHuman, and Unity Game Engine to give life to old traditional buildings that have existed for years. Eventually, the experience will be made available on Steam and built for the web, allowing others to download and explore it from anywhere in the world

Examining the Relationships Between Urban Heat Island Effect and the Spatial and Racial Dimensions of Inequality

This research addresses the relationship between the spatial and racial dimensions of housing inequality in New York City and Washington, D.C. This research aims to demonstrate the influence of historical policies on present day public housing and the impacts of continuously rising temperatures resulting from climate change on residents. To do so, this work relies on spatial mapping to examine the overlaps of three indicator variables to determine the relationship between housing and racial-spatial inequality , locations of public housing, HVI/HSI scores, and count of Black or African American residents per census tract, . Hot spot analysis was conducted to identify areas of high concentration for each variable and their overlapping regions.. Both Washington, D.C., and New York City demonstrated strong correlations between high heat vulnerability, racial disparities, and public housing locations, emphasizing the influence of historical urban policies on cities today. These findings highlight the need for all three variables to be used in housing and heat inequality research. Additionally, this research shows that public housing data is a good source for understanding the racial and spatial patterns of inequalities related to urban heat. Future work should focus on expanding the research to other cities burdened by heat, housing, and racial inequalities in other of U.S. cities to inform climate policy.Master of Urban and Regional PlanningThis research explores the connection between housing, race, and heat inequality in New York City and Washington, D.C. Due to past policies and systemic inequalities, many Black communities in these cities live in public housing. Uurban areas with public housing are typically more vulnerable to rising temperatures, making heat exposure major challenge for its predominantly Black residents. To better understand these relationships, this study maps where public housing is located, how heat affects different neighborhoods, and where Black residents are most concentrated. By identifying areas where these variables overlap, the research highlights how historical housing decisions continue to impact communities today and how racial, spatial and heat inequalities are interconnected. In both cities, neighborhoods with higher numbers of public housing and Black residents also experience greater heat risk, emphasizing how racial and environmental inequality are connected. This work shows that public housing data is a useful tool for studying inequality, particularly in relation to climate and racial disparities. Future research should expand this approach to other cities facing similar challenges. By doing so, researchers can identify broader patterns and help shape better policies to address housing, racial, and environmental justice on multiple scales

Pocahontas, VA: Conceptual Redevelopment Plan for the Fuel Building

Pocahontas, Virginia, once a thriving center of coal mining in Tazewell County, is today a community deeply engaged in preserving its rich history. This report summarizes the conceptual vision for the revitalization of the historic Fuel Building, a notable structure within the Pocahontas Historic District. Located near the heart of Pocahontas, the Fuel Building was once part of the bustling industrial infrastructure that powered the town’s mining operations in the late 19th and early 20th centuries. Though no longer in active use, the building stands as a testament to the town’s legacy as the first coalfield town in Virginia, and as a symbol of the ingenuity and resilience that defined the region’s workforce and way of life. Spearheading efforts to preserve and reinterpret Pocahontas’ historical assets is Historical Pocahontas Incorporated (HPI), a dedicated community group that has long advocated for the conservation of the town’s architectural and cultural heritage. Their continued leadership and collaboration with local and state partners have been crucial in shaping the vision for the Fuel Building and other significant structures in the area. This report outlines Pocahontas’ historic significance, the background of the Fuel Building, and the collaborative planning process underway to develop a meaningful and sustainable future for this site—one that respects the town’s coal mining roots while creating new opportunities for education, tourism, and community engagement

12th Annual Hume Center National Security Colloquium

The Ted & Karyn Hume Center for National Security and Technology, part of the Virginia Tech National Security Institute, welcomes you to the 12th annual Hume Center National Security Colloquium! This event is made possible through our Intelligence Community Centers for Academic Excellence (IC CAE) grant and our Academic Affiliates Program (AAP). We are excited to host Dr. Aaron Weiner, the Director for Advanced Systems & Technology (AS&T) at the National Reconnaissance Office (NRO) for our keynote where he will discuss opportunities and challenges for the agency. As in past years, the colloquium will highlight our student’s research and experiential learningprograms, and will include presentations and posters from students across multiple departmentsand colleges at Virginia Tech. In addition to highlighting the achievements of our outstandingstudents and their faculty mentors, we will be hosting a series of roundtables so that studentshave an opportunity to engage directly with some of our industry and government sponsors.This event is made possible through our Intelligence Community Centers for Academic Excellence (IC CAE) grant and our Academic Affiliates Program (AAP)

A Digital Library for CS4624 Projects

This project was done in fulfilling a requirement for the CS 4624 Capstone Course. The team has been tasked with creating a web application that displays information and files of all previous projects that were originally uploaded to the VTechWorks website under the tag Multimedia, Hypertext & Information Access. This project is to be usable on all OS types and support user authentication and differing permission levels and accesses based on said authentication. Furthermore, the web application should allow for users to search the database for projects based on specified search criteria. It will also allow users of higher permissions to create and upload projects to the database based on a form that requests information and files regarding the project. The web application should also have the ability to run any project on the discovery portal with the press of one button. The resulting docker container should have full project functionality.CS4624 is one of many capstone courses a student within the CS curriculum is able to take. The multimedia and hypertext course delves into the diverse range of multimedia content such as images, audio, video, as well as any information retrieval and access relating to it. With this course comes the capstone project, a semester-long project given to us students to allow a display of mastery within our discipline. It has so far been a pleasure to work with Dr. Farag’s guidance with the project. An insight into real-world applications as well as a diverse approach to different problems has allowed us to grow as both people and developers. The current discovery portal for CS4624 student projects serves as a platform for students working within the course to submit and hold their projects. Details included within the pages on the discovery portal consist of abstract, date, author, presentation, final report, source code, and collections. Additionally, the discovery portal contains filtering features to allow users to specifically search for any project dependent on recent submissions, issue semester, author, title, subject, content type, and department. The discovery portal also provides three separate home views depending on the user's permissions. Current supported user roles are admin, client, and student. This allows teachers to easily access desired projects as well as a safe holding for semester long projects that students worked hard on. Rather than discarding prior work, we have extended and enhanced it by integrating backend support in Python/Flask to interface with Docker and dynamically assign ports for each running container. With this comes the purpose of our project this semester. After reviewing the previous semester’s project as well as discussing with our client and professor Dr. Mohammad Farag, it was concluded that the current largest issue with the discovery portal was the lack of an easy way to run projects. As it stood, to run a project from the discovery portal, the user would have to manually download the code and configure codebases themselves. This is an issue for all types of users. Students want an easier way to run previous semesters’ projects, and to view other projects from the same semester. The client desired a way to run projects within the discovery portal without the need for manual configuration. After analyzing the discovery portal, we concluded that the most important feature for the discovery portal would be a “run” button on each project page. This would allow any user to have a one-click solution for running a project’s code, instead of manually having to download and configure codebases. Clicking the run button would deploy a docker instance to run on a dedicated port, unless an image of the specific project was already running. This provides the user with an easy way to run any project they desire and interact with it in the discovery portal. Upon completion of the project, we hope to have provided future CS4624 students and staff an easier and more efficient tool to complete their projects with