Chemical and Biomolecular Engineering

Official blog of the Lehigh University Chemical Engineers

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Dr. Aditya Khair of Carnegie Mellon Holds Seminar at Iaccoca

In an effort to better characterize nonnewtonian fluids, Dr. Aditya Khair is pushing the limits of rheometry at Carnegie Mellon. He came all the way up the mountain last Wednesday to discuss his ideas before an audience of professors and students convened at Iaccoca. Professor Khair’s visit was sponsored by the Department of Chemical and Biomolecular Engineering as part of their Fall Seminar Series.


Dr. Aditya Khair speaks before an audience of students and professors convened at Iaccoca.

Rheology, the science of the deformation and flow of matter, has enabled the prediction of a fluid’s behavior via measurement of its intrinsic properties. Of the various methods of measurement implemented in pursuit of this goal, oscillatory rheometry has been of particular interest in respect to Dr. Khair’s recent ideas. In this method, a fluid is pressed between two horizontal plates. The top plate is held stationary as the bottom plate is rotated sinusoidally, imposing a time dependent strain on the fluid, by which the fluid then enacts a quantifiable torque upon the top plate. A comparison of the frequency of oscillation and the measured stress response can then be used to infer properties of the fluid in question. This allows for calculations of viscosity and elasticity to be extrapolated and applied to a wide range of conditions – at least, that’s what we tend to assume.

As Dr. Khair demonstrated to us, in the case of conditions under which either strain or oscillation rates are very high, the stress is no longer directly proportional to the strain, creating a gap between our assumed extrapolations and the reality of a nonnewtonian fluid’s behavior.

In order to better understand this reality, Dr. Khair applied mathematical models to two types of fluids: those characterized at the molecular level as rigid rods and those seen as flexible coils, enabling the interpretation of rheometric data from the region beyond ideal conditions. In this way, the use of the rheometer itself as a platform for fluid mechanics experimentation has enabled Khair to better define and more accurately explain the behavior of these fluids under nonlinear conditions.

dsc_0731Extensive discussion followed Dr. Khair’s presentation. From the questions raised by Lehigh’s ChemE faculty, a sentiment of cautious skepticism was made clear – after all, as Dr. Anthony McHugh remarked, “I’ve always used a rheometer as a rheometer,” reflecting some doubt in being able to learn something new about a fluid from applications of a rheometer outside its typical range of use. He also mentioned, however, that there’s always been a “problem of extrapolating [rheometric] data to nonlinear conditions,” and that deeper understanding of a fluid’s behavior at high strain levels/oscillation rates might lead to industrial applications concerning fluids under highly turbulent conditions.

Despite his unconventional approach, the potential of Dr. Khair’s ideas to yield new information concerning the properties of nonnewtonian fluids is certainly something to be optimistic about.


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Friendly Reminder

With finals in full swing, it’s easy to get carried away in the heat of it all and forget to do things for yourself. While studying and working hard is very important, you need to remember to take some stress relieving measures. Stress can wreak havoc on your body, your success, and your motivation.

Here is a list of things you can do to help keep your stress down and your motivation high!

  1. Give yourself an hour of netflix. Take that time to relax, give your mind a break, and have some fun. Studying for 92873423 hours on end will not help you, it will only burn you out. The hour of a show will refresh your brain and rejuvenate your spirits.
  2. Take 30 minutes to eat. Your brain needs food too! Take thirty minutes to kick back, eat some food, and not stare at a textbook or screen.
  3. Phone a friend. Call your best friend at home or another school and talk for 15 minutes about your day. It will give you a mental break and connecting with friends is never bad! And if nothing else, you’ll have someone to complain too.
  4. Talk a walk. When you’re super frustrated or have a lot on your mind, take a quick lap. Getting your blood flowing will help keep you alert and in the zone.
  5. Get a good night of sleep! Nothing beats this. You can’t perform if you’re exhausted.

Keep up the good work.

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Try Not to Memorize

One issue I have faced throughout my college career is really KNOWING something versus MEMORIZING something. Two super different concepts, with one being far superior to the other. Memorizing may get you an okay grade, however, when that final rolls around the memorization from mid-semester probably won’t still be there. If you take the time to learn it the first time around, going back to review could almost be fun!

Here are some key differences between memorization and acquiring knowledge.

1.Memorization: You learn something word for word and can repeat it as such.

Knowing: You understand the full definition but can express it in your own words.

2.Memorization: You do the same problem so many times, that you eventually memorize it.

Knowing: You learn the logic behind the problem and can apply it to other problems.

3.Memorization: Your understanding is very superificial. You can’t go into much detail.

Knowing: People can ask you questions about something and you feel confident in answering.

Some ways to expand learning versus memorizing is to allow yourself many different outlets of learning. Rereading your textbook and repeating the same problem isn’t going to help. You need to read different explanations and try different problems. I personally like buying the “Insert Subject Here” for Dummies books. They usually coincide nicely as a summary to the textbook and come with a slew of new problems to try. Sometimes this is a cheaper alternative than buying the solutions manual to your textbook.

Study hard friends. Finals are almost over!

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Switching Majors

Sometimes in college you have some really nice crises where you don’t know why you chose your major or what you’re going to do with your life. My friends and I decided to combat this by investigating what exactly goes into switching your major should you ever decide to do so. Some colleges have restrictions about how late in your career you can switch, but with Lehigh, you can do it through the end of junior year.

If you really think about it, this is actually pretty great. For a fair number of majors, such as chemical engineering, the curriculum doesn’t get into the meat of their classes until junior year. So the first two years of college are mostly prerequisites. You don’t really get to experience the heart and soul of your major until it’s almost too late. What if you take the classes first semester junior year and don’t like them??

Any engineering would have about the same first two years of curriculum, but often times important classes are only offered in either spring or fall, not both. This usually introduces problems with graduating on time if you’re interested in switching.

Another important aspect of deciding to switch is having an adviser who is very interested in helping you make this choice. One switch that isn’t very difficult is from chemical to bio engineering. Another switch is from chemical engineering to chemistry. Both options allow you to graduate in the same amount of time. Material science may also be doable, but we didn’t really look into that.

The last bit of advice is that if you are truly interested, Lehigh offers an audit on the banner that allows you to see how close you are to a particular major based on every class you have taken thus far. It’s interesting to say the least! If you are curious, take a shot and see what it would take!

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What to Do While Studying

Studying can often be a struggle. What can you do when people around you are talking or there’s construction outside driving you crazy?

I have come up with a few alternative solutions.

1. Music. Your favorite music. For me personally, this is a bit too distracting and prohibits me from reading, but I can enjoy music when I am doing math problems.

2. Music you don’t know. This can be good because you can’t sing along and you can’t necessarily distinguish the words on the first listen. It won’t distract you as much.

3. Classical or instrumental music. This can almost act as white noise. You can’t be distracted if there aren’t any lyrics! But again, for me, classical music doesn’t always work.

4. My personal favorite is white noise such as rain. There are websites that play thunderstorm sounds on loop that make me feel like I’m in my own world cozied up with my textbooks. It’s one of the only things I can listen to and be completely productive with.

5. Silence. It’s honestly the best. It allows your brain to fully focus on and absorb what it is you’re doing. So go search for that empty spot!

When the silence is too much to bare or those girls won’t stop whispering, you can’t let that stop you from succeeding! So find what background noise works best for you.



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What I Like about Finals

Many people dread finals week as the worst time in the semester, however, there are a few reasons why I actually..wait for it..ENJOY the week.

1. There are no classes. This is glorious. You have an additional 4-5 hours a day, if not more. You don’t have to wake up at a certain time. You don’t even need to leave your room if you don’t feel so inclined. There are no lectures to listen to or notes to take. At this point in the game, you have been exposed to all of the information that you need to know.

2. You have all of the time. An added benefit to no classes is that your only responsibility is to study hard for the final. You can wake up at 9:00 am and hit the books till 9:00 pm with no time constraints by homework or assignments due the next day.

3. You’ve already been tested on 90% of the material. Finals are not that terrible!! You have already been tested on most of it and the important stuff was probably placed on a test you’ve taken. Go back and review the stuff you’re amazing at to boost the confidence, then spend the time to learn what you need to know.

4. If you do it right, finals boost your grade. This semester, literally every one of my finals is worth 40% of my grade. THAT’S INSANE. It could boost you from a C to a B or a B to an A. Finals are your golden ticket if you don’t slack off.

I believe in you. I believe in me. I believe in the power of finals. One more week kids, then we are home free!



Sometimes as a chemical engineer, you feel a little down. I mean, you’re taking the most difficult classes, you have homework sets that take over 15 hours each, you forget to eat sometimes (might be a joke also might not be a joke.) Life is hard. It gets especially frustrating when you feel like you’re putting in a ton of effort and are seeing no results.

I was talking to my best chemE friend about this today, because we were both feeling particularly defeated. His response was motivating. He said “Think about it like this: we may not be getting the best grades in this room, but the fact that we are even able to do it, makes us special. There are thousands and thousands of people in the world who wouldn’t be able to get as far as we have gotten or be doing as well as we are doing. If you ever need to be motivated, think about those people. Don’t think about the people who are doing better than you.”

That my friends is a very valuable lesson. You can’t compare yourself to that genius in the front row who can solve complex integrations in his head. He is a rare specimen. Would it be nice if I could do that? Yeah, 100%. But that’s not me, so comparing myself to him will always make me feel down. I am just a dedicated student who has to really commit and really try to get the grades that I’ve been getting. You need to evaluate yourself and your progress by itself with these types of questons “Am I budgeting all of my time adequately?,” ‘Did I study as much as I possibly could?,” “What more can I be doing?” and grow from those types of questions, as opposed to killing your motivation with “WHY DIDN”T I GET A 97 ON THAT TEST I OBVIOUSLY NEED TO DROP OUT.”

Chemical engineering is hard. Not in the “Oh, this person told me it was hard but I bet they just didn’t apply themselves” kind of way. Chemical engineering is hard in the “This person was in the top of their class in high school and is performing average or below in their classes now” kind of hard. It can be a blow to the ego, but it’s worth the struggle. This is why chemical engineering is such a respected and prestigious major. Not everyone can do it, but I believe if you really want to, you can.