Thursday, January 29, 2015

Video Motivation for Chemical Reaction Engineering Course

The main motivation for the course I'm teaching this semester is to learn how to design industrial equipment for chemical reactions that economically produce desired products with highest priority given to safety. I showed this video on the first day of class to show what can happen when economics and disregard for engineering best practices can lead to horrible safety breaches and devastating accidents.


Video Resources for Chemical Reaction Engineering Course

This semester I'm teaching CHE 3123 at Oklahoma State University. I'm always looking for great videos. Here are two that were enlightening for the chemical engineering juniors in my course but also approachable for a non-scientist (my husband Joel) or students of general introductory chemical courses.


Chemistry's Demolition Derby


Reaction Kinetics in Blue

Wednesday, March 6, 2013

Computational Modeling Can Bring Better, Cheaper Medicines to a Pharmacy Near You

Check out the two parts of my blog series on the impact of the research that I do in computational modeling for pharmaceutical device design and manufacturing. See my previous blog post for my reflection on communicating my science and engineering to others.

Part 1: Reducing Pharmaceutical Production Costs Using Continuous Manufacturing and Computational Modeling

Part 2: Computational Modeling to Design Pharmaceuticals that Require Fewer Dosages for Same Treatment

Reducing Pharmaceutical Production Costs Using Continuous Manufacturing and Computational Modeling

Continuous manufacturing is the typical industrial practice characterized by a flow of materials through an assembly line often operating 24/7 to produce a product. I have been familiar with continuous manufacturing most of my life: my dad builds tires in 12-hour rotating shifts at a Goodyear factory, and I spent a summer as a chemical engineering intern in continuous manufacturing for refining oil into fuels. A striking exception to the rule of using continuous manufacturing to produce chemical products is the pharmaceutical industry, which uses batch manufacturing. Like bakeries that bake many batches of different pastries using regular or jumbo-sized kitchen equipment like mixers and ovens to accommodate the varied tastes of many customers, the pharmaceutical industry uses jumbo-sized organic chemistry lab techniques for producing batches of specialty chemicals with a range of demands. These techniques do not necessarily scale well to larger production. The differences between batch and continuous manufacturing can be illustrated by sub sandwiches. Subway’s highly successful marketing campaign for the $5 foot long has made them the go-to restaurant for affordable, made-to-order sandwiches. Subway uses an assembly line to create customized sub sandwiches in bulk (continuous manufacturing). One of my friends on a tight budget did an experiment in the economics of creating a sandwich at home (batch manufacturing) with quality on par with Subway. His question: is it cost effective to make your own sandwich versus buying Subway’s foot long? His answer was a resounding no. Not only did it cost a lot for the groceries, but he had to go shopping, prepare the veggies, and think of ways to eat all the groceries before they spoiled or eat the same type of sandwich repeatedly. (A similar case study is available online.) Compared to continuous manufacturing the batch method of manufacturing a sandwich has more expensive raw ingredients, can create a lot of waste, and takes more time. Also, product quality may vary widely between batches. The same things are typical of the pharmaceutical industry. The Novartis-MIT Center for Continuous Manufacturing (CCM) focuses on shifting the pharmaceutical industry to the more cost effective practice of continuous manufacturing (for more on the CCM click here and here).

In my research in the CCM, I have developed a computational model to describe a chemical assembly line for making pharmaceuticals. We add medicines and flavors to a liquid mixture, which is spread on a conveyor belt. This thin liquid layer has to be carefully dried to form an edible film like Listerine Pocketpaks breath strips or Fruit Roll-Ups before it leaves the equipment, and the film must have uniform concentrations of medicine and precise physical properties. I use mathematical descriptions of the time-varying processes involved in drying the film (heating, evaporation, motion of water molecules, and movement along the conveyor belt) to aid in design and quality control of the system. We use computational tools to monitor changes to the input conditions and undesirable disturbances, quickly calculate how these changes should affect the output using my model, and make corrections to the temperatures or speeds within the equipment to ensure that the final product reliably meets its quality specifications, preventing waste of materials, time, and energy. Thus, fabrication of high quality pharmaceuticals through continuous manufacturing is enabled by computational science and applied mathematics and should lower production costs.


Computational Modeling to Design Pharmaceuticals that Require Fewer Dosages for Same Treatment

Controlled release drug delivery is a category of pharmaceutical dosage techniques where the level of medicine in a patient's body is sustained for a long period of time with a single dose. Examples of controlled release delivery include skin patches for nicotine or estrogen that work for days or weeks and intrauterine birth control devices that release a constant supply of hormones for years. These devices are wonderful improvements over traditional dosages forms like pills or injections that require repeated doses. The daily birth control pill is an example of a traditional dosage form that has life-altering consequences for a single forgotten dose. Controlled release drug delivery alleviates pressure on patients to remember every one of the frequent doses. For a chronically forgetful person like me, this is great news. Currently, controlled release drug delivery is only available for a few medicines and generally involves a material (usually plastic) that has to be removed from the skin or from inside the body after all the medicine has been released. I study biodegradable materials that decompose into natural products that are not harmful to the body and do not require removal. The hope is that many types of medications could be delivered with these materials to improve patient convenience for care of chronic conditions and mental illnesses with major consequences of forgetfulness such as schizophrenia and Alzheimer's disease.

I develop mathematical models to design how medicines are released from biodegradable polymer spheres that contain medicine. I use computational experiments to explore conditions that may give the optimal design. Thomas Edison was a prolific American inventor credited with the invention of the light bulb, phonograph, and motion picture camera. Just imagine Edison's impact if he had mathematical models or computer simulations that predicted the best design, saving him hundreds of experiments. Then he might have been able to be as productive as Nikola Tesla (see The Oatmeal for a striking, humorous comparison of Edison and Tesla).

My models combine the biodegradation chemical reactions and transport of the medicine as the spheres dissolve. Because many conditions change in an interdependent manner, the equations describing them cannot be solved through simple calculations. Instead, I use advanced computational recipes or algorithms for accurately approximating the solutions to equations in the model. More computational power enables more sophisticated algorithms, better spatial resolution, and increases in the length of time that can be simulated. These contribute to more accurate predictions for the timing of drug release, which in turn enable more realistic computational experiments to identify best designs for the spheres.


Saturday, February 16, 2013

Communicating My Science and Engineering

Communicating about my science and engineering allows me to combine two important facets of my life. If you've know me very long, you know that I love talking, telling stories, and connecting with people. You also probably know that I love being an engineer and am really excited to work at the intersection of several fields: chemical engineering, computational science and engineering, applied mathematics, biomedical engineering, and pharmaceutical sciences. If you're reading this, you also know that I enjoy blogging about everything from books and exercise to writing and vacations. Recently, I've been inspired to use my blog more to combine my story telling with my research endeavors. Here's a little of the motivation:

This week I've been attending a conference in Boston for the American Association for the Advancement of Science. It's very different from most others science conferences where grad students, post docs, and professors give presentations about the details of their current research projects to others in their narrow subfields. Is this one, mostly very senior researchers and other scientific professionals discuss the impacts of their work to science, society, and public policy and address very diverse audiences with people with advanced degrees in every possible field of STEM including Nobel Prize winners, students, educators, policy making, funding agencies, science writers, and even lay audiences from the general public. Additionally, the well-attended, well-run expo had hands-on science demos for kids and adults of all backgrounds.  It's a been phenomenal experience, and I have three favorite sessions so far: 1) an engaging session about science communication secrets presented by science writers Brian Lin and Andy Torr (key slide), 2) the science of the kitchen presented by Nathan Myhrvold, author of the Modernist Cuisine tomes about why cooking works (acclaimed as "the greatest cookbook achievement of all time" with stunning photography) and that features my favorite equation from heat transfer (what I study) written with flames, and 3) a great talk by Sherry Turkle about how humans have are growing to be more connected with life-like machines and robots while sacrificing connections with other humans.


I've recently discussed my work with a senior citizens group, science writers, and a microscope salesman, besides with other science professionals from a variety of fields. I have upcoming appointments to reach out to other groups and show why they should care about my work: computational researchers in Boston, middle school girls in a math club, and high school girls in an engineering mentoring program. This is all in addition to my corporate research sponsors, current research colleagues, and, in the near future, potential employers and colleagues. While these are all verbal communications, I want to try to engage with my blog readers and friends who live in other areas of the country and the world through this written forum. In the next few weeks, I plan to write two blog posts to tell about my graduate and postdoctoral research and how computational science and applied mathematics have really enabled the work in designing advanced drug delivery devices that can give medicines for extended periods of time with a single dose and in improving pharmaceutical manufacturing practices to lower the cost of medicines. I'm eagerly looking forward to starting conversations with my readers about the tools that I use for my research and the societal benefits of the work and about how this kind of information can be shared effectively with non-technical audiences, including students. Please share your feedback with me either directly on this blog or on facebook.

Stay tuned for the next episode: How computational science and applied mathematics can bring better, cheaper medicines to a pharmacy near you.

Friday, September 14, 2012

Creative Writing in Engineering


I'm a postdoctoral researcher in chemical engineering. My youngest sister is a creative writing major in college. To most, these fields seem very disparate. However, I've been reflecting a lot on my writing, and it has occurred to me that for success in my career I need to have similar levels of being intentional, focused, efficient, and prolific in my writing as my sister should for a successful career in her field. My content is simply different--chemical engineering instead of vampire fiction. Over the course of my career, I may produce more words than she does through communicating my science and mathematics via presentations, articles, theses, reports, essays, research statements, and proposals. Including smaller items such as emails, blog posts, and writing related to teaching or outreach only increases the total. My research productivity is measured by publications and awards/funding based on my ability to convince people that my ideas are interesting or that I know what I'm talking about. I get paid to write and translate complex ideas and topics into content that others can interpret. My writing has to be well-written and original, and unlike my sister's chosen genres of science-fiction and fantasy, it must be scientifically sound.

My training through three engineering degrees and two minors at two universities has prepared me technically. Now I'm focusing on honing my writing skills, efficiency, and disciplined habits.  I've always been a decent writer with a nice grasp on English grammar (I'm by no means perfect, so don't judge if there are typos in this post!); currently, I'm focused on becoming a more efficient, productive writer (I should take lessons from myself from my non-academic blogging that has been prolific in the past). Towards this aim, I've joined a writing group with other individuals who have committed to writing productively. I've prioritized writing tasks over research tasks that can crowd out writing. I've also been reading books such as Scientific Writing and Communication: Papers, Proposals, and Presentations; Writing Science: How to Write Papers that Get Cited and Proposals that Get Funded; How to Write a Lot: A Practical Guide to Productive Academic Writing; and How to Write Fast Under Pressure. I'm putting all this great written advice into practice by scheduling writing time, setting goals, rewarding progress, fostering a positive attitude, and just doing it! 

My immediate goal is to get a full review paper to my advisor tomorrow for submission to a journal. According to my outline, I have 8-10 more paragraphs remaining. I will celebrate completing this goal by running a 10k on Sunday at Orchard House, home of Louisa May Alcott--one of my favorite authors as a child. I'm also reading Little Men by Alcott and am looking forward to seeing her home that was the inspiration for the setting of her novels.