PhD Update #1: The End of The Beginning

As I write this, I've been in the PhD program in chemical engineering at the University of Florida for 16 months.

I passed my candidacy exam on November 13. Preparing for it took up most of the last two months, not to mention the full year of work on theoretical understanding and experiment construction.

This update is about the process so far. I will not share the exact details of my research here until it's formally published (see here for an explanation).

How It Started

Unlike most of my peers, I did not enter the PhD program directly from my undergraduate degree. My bachelor's is in physics, so when I first applied to UF's chemical engineering department in 2018, they put me in the Master of Engineering (ME) program so I could learn the fundamentals of chemical engineering first. I completed it in 2022 and did well enough that I was asked back to do a PhD in a specific project - the exact project I wanted.

That sounds simple, does it? It wasn't.

I had no guarantee that I'd get upgraded to the PhD program or if my desired project would get the funding it needed. At that time, there was no funding and I struggled in a couple of crucial classes. At the graduate level, anything below a B-minus is considered "failing". We also had COVID-19 to deal with.

Why didn't I quit? Because even in the worst case, I would get a masters in chemical engineering which is a very employable degree. My goal isn't to become a professor. It's to work on interesting problems that have commercial potential, and I could do that in industry as well as in academia.

I persevered and passed the classes and applied again to the PhD program in 2022. They told me my desired projects did not exist and so they could not admit me. So I switched my application to the Mechanical and Aerospace Engineering department and talked with professors there. Some of them had projects I was interested in... but their funding didn't come through.

The first half of 2023 was an uncertain time for me. I worked at a hydrogen production research lab at University of North Florida in Jacksonville, commuting 176 miles a day. I was looking for jobs and making plans to move out of Gainesville when the fateful email came in May. Ranga Narayanan said, "I have funding to do your project, are you available?" It took me all but 30 minutes to check in with myself before replying: Of course I'm in.

I didn't get the official offer letter until June because my application had to be switched back to the chemical engineering department. I started in August 2023 as a direct hire into the lab, not in the pool of students waiting to be matched to a lab.

At the orientation, they talked a bit about why PhD students should only work on funded projects and that they shouldn't wait for their dream project to be funded. It made me realize just how lucky I was that funding came through for the project I desired at this specific time. It really was a close thing.

The Research Lab

I work in Ranga Narayanan's Nonlinear Instability and Bifurcation Laboratory. We study novel transport phenomena in fluids under flow and acceleration environments, including microgravity. My research is funded by a couple of grants from NASA and the Florida Space Grant Consortium.

Why is this particular area interesting? Understanding little-known transport phenomena unlocks new ways to control fluid and heat transfer in microgravity, which can be applied to future space hardware (and some Earthly applications). Our lab is very space-focused, as evidenced by the number of times I've seen my colleagues take their experiments out on microgravity parabolic flights with NASA.

Nonlinear Instability and Bifurcation Laboratory at the University of Florida

about us

We work in a nice lab room in one of the newest buildings on campus, just south of the chemical engineering building. The door is electronically locked, and we have large computer screens and 3D printers on each table.

Accommodations

I am the only deaf person in my PhD program, and the whole chemical engineering department at University of Florida. While I know of other deaf students at UF in other engineering departments and the medical school, we don't run into each other very often.

The overwhelming majority of my interactions at UF is with hearing people, both faculty and peers.

UF has two staff interpreters living in Gainesville or nearby. They are reserved for high-level situations such as a PhD candidacy exam. These are the ones I worked with before and during my exam. The other interpreters who work my seminars and UF-related social activities are contract interpreters, on hire from agencies across the state. Some of them come from Jacksonville, St. Augustine, and even as far as Tampa.

This support extends to conferences, too. We attended the American Institute of Chemical Engineers (AIChE) annual meeting in Orlando in November 2023. The interpreter coordinator at UF worked with the conference organizers to ensure that I had services whenever I needed it, and I successfully networked with multiple experts in the field.

Who pays for all of this? UF does. The Americans with Disabilities Act, passed in 1990, requires all institutions of higher learning receiving federal funds to provide reasonable accommodations to disabled students and employees. This was a huge step forward for disabled people in America, but it doesn't cause complete equality - no law can do that. UF is a wealthy public school, but there is still a national shortage of qualified interpreters, especially in Florida. So we (both me and the person who coordinates interpreters) have to prioritize.

I can't use interpreters all the time in my day-to-day work. This is not a money issue - this is an availability issue. I often go for hours without talking and other deaf students need interpreters too. In this case, I use speech-to-text apps on my phone and the iPad that I used lab funding to buy (at Dr. Narayanan's request).

The effectiveness of these apps vary - I've had to stop using some in favor of others. A select few were extremely effective for my environment and scientific/technical jargon. Discussing them is probably worth another blog post.

Theoretical Understanding

Each field of study has theories with varying correspondence to reality. Examples in the social sciences might be empowerment theory, Skinner's theory of operant conditioning, or Marx's labor theory of value. Theories explain why things happen and help identify relationships between variables. In chemical engineering, theory is based on the known laws of physics and chemistry.

The study of novel fluid transport phenomena is in fact extremely mathematical. This is going to intimidate some readers, but it needs to be said: without a solid grounding in partial differential equations and Bessel functions, it's going to be hard to understand what's going on in the device more than superficially.

The math is a guide to how you design your experiment. Assuming that I did the math right (and I'm pretty sure it's correct), I can predict how the outputs of the system will change when the inputs are changed. I have written Python code to plot these theoretical predictions. Once I begin trials on my experimental rig, I can log the data from the sensors and compare them against the theoretical predictions.

Experiment Construction

Dr. Narayanan is big on both theory and experiment. It's rare that a PhD student goes through his mentorship without doing experiments. So at least half of my time is devoted to designing the experiment rig in CAD software (in my case, Autodesk Fusion 360), buying each part, and testing them out in the system. My colleagues are doing the same with their experiments.

Our experiments are built from hardware ordered from online catalogs such as McMaster-Carr, but we have also ordered custom-machined metal items from Xometry. Our 3D printers aren't just for fun. We have used them to print custom parts from PLA plastic and transparent resin to use in our projects.

So far, my experiment has over 200 parts, not including nuts and bolts. The total cost is over $10k. It will be ready for testing in early 2025.

The Candidacy Qualification Exam

A few years before the dissertation defense exam, there is the candidacy qualification exam. During the exam, you demonstrate your knowledge of the material and the topic you're about to research. The qualification exam is a presentation to your peers, followed by a cross-examination from a committee of professors who are experts in the specific area you are researching.

How did I prepare, given that I need sign language interpreters for this and they might not know the content?

To be blunt, I taught my interpreters. Not the math, of course, but the concepts and vocabulary. They were quick studies, and that's rare. I don't often get interpreters who are STEM-trained or otherwise comfortable with advanced STEM material.

I was graded on the following rubric:

• Ability to identify a problem. Are you able to observe phenomena and extract interesting problems from the observations?
• Ability to formulate a problem. In other words, can you convert the identified problem into a mathematical formula?
• Ability to solve engineering problems. Can you solve a formulated problem, i.e., a mathematical formula that's already set up?
• Ability to critically read engineering literature. Can you find relevant papers, read the papers, and utilize the papers in research?
• Ability to use the techniques, skills, and modern engineering tools necessary for engineering practice at an advanced level. Can you use CAD/CAE software? Can you code? And so on...
• Ability to communicate effectively. Did you demonstrate your technical/ academic writing skills in your proposal, and did you give an amazing presentation?

Suffice to say, I passed with flying colors.

Stay tuned for the next update!