Thermopia: class notes on thermodynamics

Problem 8 on PS7

2011-11-20T13:18:00.000-08:00

There is a typo in that some of the distributions read P(x) when it should be P(z).
Cheers,
MSS

No more Monday make-up lectures

2011-11-09T12:59:00.000-08:00

Dear class,

We will not need to hold any more make-up lectures, so Monday we will only meet at the regular time (2-3pm) from hereon out.

Cheers,
MSS

Thought problems for phase equilibrium

2011-11-06T17:32:00.000-08:00

Class,

There is a typo in problem 2 for these thought problems. It should read f/P instead of f.

Cheers,
Scott

PS4

2011-10-21T15:14:00.000-07:00

Hi class,

For PS4, question number 6, you can also assume that in analogy with the usual fundamental equation, the quantities Cv = (dE/dT)_L and Cp = (dH/dT)_tau are both positive. Similarly, the equivalent of the compressibility (dL/dtau)_T is always positive.

Cheers,
MSS

Final grades

2011-03-21T13:31:00.000-07:00

Dear class,

We have finished grading the final and your course grades have been computed. I will endeavor to return these to you at the start of ChE110B. Alternatively, you may stop by my office if you do not get yours back in class next week.

The statistics for the final are:

average - 61% (62% with bonus from problem session)
standard deviation - 13% (13% with bonus)
maximum score - 84% (87% with bonus)

The statistics for the course grade are (with bonus):

average - 70%
standard deviation - 10%
maximum score - 90.7%

The letter grade distributions are as follows:

A - 27%
B - 37%
C - 23%
D - 8%
F - 5%

A detailed plot of these distributions can be found on the course webpage.

I enjoyed teaching you all this quarter and wish you the best of success in your future endeavors!

Cheers,
MSS

Study break

2011-03-15T21:54:00.000-07:00

Here's an interesting little mathematics / statistical analysis of the NCAA tournament that you may find to be a nice reprieve from your finals studying:

http://fivethirtyeight.blogs.nytimes.com/2011/03/15/when-15th-is-better-than-8th-the-math-shows-the-bracket-is-backward/?hp

These authors show that lower-ranked seeds actually have a higher probability of making it to the sweet sixteen, elite eight, and final four than mid-ranked teams. It's a problem ripe for population balances and rate equations, in truth not really all that different from mass balances and chemical kinetics.

Go Gauchos!

MSS

Office hours tomorrow

2011-03-14T23:12:00.000-07:00

Hi class,

Just a small update to my office hours tomorrow. In the afternoon I will be available 4-5:30pm, not 3:30-5:30 as originally indicated.

Cheers,
MSS

Common mistakes on HW9

2011-03-14T13:29:00.001-07:00

Dear class,

If you would like your HW9 back, you can retrieve it at the review session tonight or see me in my office tomorrow. Here are a few common mistakes we noticed in grading it:

Problem 49:

Some students did not realize that entropy increases for the nonideal compressor case. The corresponding curve in the Mollier diagram should start at the same place as the ideal case, but then move both up and over to the right, in the direction of increasing entropy. The endpoint will not be the same, although it will intersect the same isobar.

Problem 50:

Some students calculated for the turbine:

W_real = W_isentropic / efficiency
This is the right expression for a pump or compressor, but for a turbine it should instead be:
W_real = W_isentropic * efficiency

Cheers,
MSS

HW9

2011-03-08T10:41:00.000-08:00

Hi class,

Please do attach the Mollier diagram that you work in problem 49 to your solutions. If you would like another copy, you can print one out from the online pdf of the homework assignment.

Cheers,
MSS

Final and review session

2011-03-07T14:24:00.000-08:00

Dear class,

The final will be Wednesday, March 16, from 12-3pm. It will be open book and one page of notes, similar to the midterm. You should bring a calculator, your book, writing utensils, and your notes page. If you would like to use the first page of the fundamentals handout, and write your additional equations on the back, that would be fine as well -- but in total you should only have one page of notes to bring. The format of the final will be very similar to the midterm, but longer in proportion with the three hour time block.

I will hold an open question-and-answer review session on Monday, March 14 from 6-8pm in Engineering II 1519. Feel free to stop by whenever is convenient during that time to ask questions.

I will also be available to chat during office hours on Tuesday, March 15, from 10am-12pm and from 3:30-5:30pm. My office is Engineering II 3321.

In addition, I will be handing out grade statistics sheets for each student on Friday at the end of class so that you will be able to see how you are doing in the course going into the final.

Cheers,
MSS

Common mistakes on HW6 and HW8

2011-03-07T14:22:00.000-08:00

Dear class,

We noticed that there were a number of mistakes on HW6 and 8 involving unit conversions. It is essential that you carry units throughout all of your calculations so that can keep tabs on conversion issues. To avoid a lot of writing, you can keep your equations in analytical form until the final step when you plug in actual values of variables.

Cheers,
MSS

Common mistakes on HW7

2011-03-02T11:30:00.001-08:00

Hi class,

Here are some common mistakes that were made on HW7. Please check to see if you made these so as to avoid them in the future.

Problem 32: "well-insulated" implies "adiabatic" - which means Q = 0, not necessarily that delta(T) = 0 (although with an ideal gas in a process that also does no work, delta(T) will equal zero).

Problem 33: need to use absolute temperatures with the efficiency, Qc, and Qh equations.

Problem 34: need to use consistent units with the Q=n*cp*delta(T) equation

Problem 38: constants in table c.1 have units (e.g. B has units of 1/Kelvin and C has units of 1/Kelvin^2); basically another reminder to take care with units and make sure that they match up.

Cheers,
MSS

HW8, problem 42

2011-02-26T12:00:00.000-08:00

A slight correction to the problem statement:

In part (b), please calculate the entropy change for the world, i.e., that due to both the system and environment entropy change. The point is to show you that supercooled water freezes, the entropy of the world increases and thus this process does not violate the second law, even though "disorder" may seem to be decreasing.

Cheers,
MSS

Some Notes on Homework #6

2011-02-15T17:37:00.000-08:00

Problem 28

When calculating the percent error, compare your calculated enthalpy at 25 °C to the tabulated value at 0 °C (1189.5 J/g). Please ignore the fact that this tabulated value is not at the same temperature as your results. You do not need to rescale the tabulated value to 25 °C.

Problem 31-b

For this problem, assume that no phase changes occur - all components remain gases over all temperatures. Also assume that the heat capacity coefficients given in Appendix C.1 are valid over all temperatures. There is a typo in the problem, so don't worry if your answer seems off, just approach the problem the same way you've learned in class.

Monday morning office hours cancelled

2011-02-13T20:40:00.000-08:00

I have a conflicting appointment tomorrow and won't be able to keep my office hour Monday morning. If you have questions on the homework, please email me, stop by my office (Eng. II, room 3218), or come to Anthony, Kate, or Prof. Shell's office hours. I apologize for any inconvenience.

Brandon

Review sessions

2011-02-01T21:54:00.000-08:00

Dear class,

Just a quick reminder that I will hold review sessions Wed and Thursday evenings from 5:30-6:30pm in Engineering II 1519.

Also, I have extended the deadline for HW5 to Wednesday, Feb 9.

Cheers,
MSS

Midterm exam

2011-01-26T16:04:00.000-08:00

Dear class-

To summarize what we discussed today in class, the midterm exam will be on Friday, February 4th in class. You will have approximately one hour to work the exam, which will cover Chapters 1-3 in the book. Bring a pencil and calculator. The exam will be open book, but closed notes. HOWEVER, you may bring one 8.5 x 11" page of handwritten notes, front and back. This should give you the opportunity to organize the course equations for quick reference during the exam.

Also, note that HW5 is not due until Monday, February 7.

Cheers,
MSS

Lost calculator

2011-01-24T14:08:00.001-08:00

Did anyone leave a calculator in class today? One was turned in to me. Please contact me if you believe it is yours, and let me know what type of calculator it is.

Cheers,
MSS

Office hours update and HW2 solutions

2011-01-14T15:56:00.000-08:00

Dear class,

The office hour time on Mondays that was 5-6pm has been moved to 6-7pm because of a room schedule conflict.

Also, solutions to HW2 can be found on the course webpage.

Cheers,
MSS

Office hours

2011-01-03T14:32:00.000-08:00

Dear ChE110a,

We have secured locations for the office hours for this course, and note that there are different locations depending on the day:

TA office hours
Monday 10:30-11:30am, Engineering II 3301
Monday 5:00-6:00pm, Engineering II 3301
Tuesday 12:20-2:20pm, Engineering II 1519

My office hours
Thursday 11am-12pm, Engineering II 3321 (my office)
Friday 2-3pm, Engineering II 3321 (my office)

Office hours will begin next week. If you need to meet with someone this week, please email one of the TAs as I will be in travel most of the week.

Cheers,
MSS

final exams and final grades

2010-12-13T12:13:00.000-08:00

Dear ChE170,

Your final exams have been graded and course grades have been assigned. You can find information on grade distributions here. If you would like to pick up your exam, please stop by my office any time this quarter or at the start of the next.

I enjoyed the class this quarter, and we'll leave up the gallery for a while for all to admire your work. Good luck in your future courses and endeavors!

Cheers,
MSS

HW 5 pickup

2010-12-08T12:10:00.000-08:00

Hi all,

If you would like to pick up graded HW5, I will be available in my office (or the lab next door) from 2-4 PM. (Chemistry 3219)

Sunyia

Review session for final

2010-12-02T12:08:00.000-08:00

Hi class,

I will hold a question-and-answer review session for the final exam on Monday from 2-3pm in 1519.

Cheers,
MSS

Movies

2010-12-02T11:55:00.000-08:00

Class-

If you're interested, here is a link to the website with the movies that I showed today in class:

http://multimedia.mcb.harvard.edu/

Also, I was able to find the NY Times article that Sam mentioned that describes the efforts to produce these movies (Thanks, Sam):

http://www.nytimes.com/2010/11/16/science/16animate.html

Cheers,
MSS

Cancer rates

2010-11-30T14:09:00.001-08:00

In class today someone asked about cancer incidents and deaths over time. Here are several telling charts from the NIH:

http://www.ncbi.nlm.nih.gov/books/NBK20811/figure/A5099/?report=objectonly

http://www.ncbi.nlm.nih.gov/books/NBK20811/figure/A5100/?report=objectonly

http://www.ncbi.nlm.nih.gov/books/NBK20811/figure/A5101/?report=objectonly

As you can see from this data, death rates from stomach cancer have decreased over time, likely due to improved food practices (refrigeration, food storage and handling). On the other hand, lung cancer deaths increased dramatically in the 20th century, peaking around 1990. Other cancer rates have fluctuated somewhat.

Cheers,
MSS

Protein gallery

2010-11-29T18:17:00.001-08:00

Dear class,

Your bonus projects have been posted in the hallway outside of 3301. They turned out quite nice! I encourage you to take a look at the gallery.

Cheers,
MSS

Guest lecture

2010-11-28T13:11:00.000-08:00

Class,

I posted Prof. Doyle's slides from last Tuesday online at the course website.

Cheers,
MSS

Final reading assignment

2010-11-26T15:30:00.001-08:00

Dear class,

I was just alerted of a typo in the course syllabus. The final reading assignment should be Chapters 17 and 20, not Chapters 7 and 20.

Cheers,
MSS

HW5 clarifications

2010-11-22T12:00:00.000-08:00

Dear class,

A few clarifications about HW5:

Problem 2c - In the second part, it should ask you to find the time dependence of [U], not [U]SS.

Problem 3d - It is asking for the total concentration of the site, [S]0. You should express your concentration in molarity (or millimolar or micromolar units as appropriate).

Problem 4 - Insulin is NOT taken up by the cells; only glucose is. Also, when applying your pssa approximation, you should use it for insulin, not glucose.

Hope that helps,
Cheers,
MSS

Problem 3

2010-11-17T10:40:00.000-08:00

Class,

I just found another small typo in problem 3. It should ask you to look for a maximum, not a minimum, in drug concentration, which will be higher than the buffer concentration. Chances are that this did not affect your solutions, however.

Cheers,
MSS

HW4, Problem 3

2010-11-15T15:52:00.001-08:00

Dear class,

There is a typo in the problem set for problem 3. The typical surface tension of a bilayer should be 70 mJ/m^2 (milliJoules per meter squared). In the original problem set, it appears as microNewtons instead, which is an incorrect set of units for surface tensions.

Cheers,
MSS

Office hours

2010-11-08T07:17:00.000-08:00

Dear class,

Due to my presence at the AIChE meeting this week, I will not be holding office hours. However, Sunyia will still be having hers. She also has an additional time this afternoon (see previous post).

Cheers,
MSS

Friday Office Hours moved to Monday

2010-11-04T10:17:00.000-07:00

Hello class,

I will not be having my regular office hour this Friday, and will move it to Monday afternoon at 4 PM.

Sunyia

HW3 and HW4

2010-11-02T23:56:00.000-07:00

Dear class,

Per the vote today, the due dates for HW3 and HW4 have changed:

HW3 due Tuesday 11/9 (formerly Thursday 11/4)
HW4 due Thursday 11/18 (formerly Tuesday 11/16)

I will distribute HW4 this coming Thursday so that it is given with two weeks advance of the due date.

Keep in mind your final two quizzes have not changed from their dates indicated in the syllabus, and will be on Tuesdays:

Quiz 4 on Tuesday 11/9 (covering Chapters 11-12)
Quiz 5 on Tuesday 11/23 (covering Chapters 15, 8, &16)

Cheers,
MSS

Drug discovery seminar

2010-10-29T12:48:00.001-07:00

Dear class,

The Technology Management Program has a seminar next week from Roger Perlmutter, the Executive Vice President of Research and Development at Amgen. The title of the talk is "Building Better Medicines: Drug Discovery in the 21st Century" and it may be of interest to many of you who are thinking about careers in biotechnology and medicine. I imagine that you will be well-equipped to understand the content of the talk with what we've discussed in class so far.

http://www.tmp.ucsb.edu/outreach/pdf/LSPoster_Perlmutter_HR.pdf

Cheers,
MSS

HW1 solutions

2010-10-21T17:28:00.001-07:00

Dear class-

The solutions to HW1 are now posted on the course website.

Cheers,
MSS

HW 1 pickup

2010-10-19T14:01:00.000-07:00

Hi everyone,

If you would like to pick up your graded first homework before Thursday class, I will be available in my office (Chemistry 3219) from 3-5 PM tomorrow (Wednesday).

Sunyia

Problem 5 on HW2

2010-10-18T13:26:00.001-07:00

Dear class,

At some point in this problem it asks you to prove that DeltaS(Ts) = 0. One approach would be to go back to the derivation for the free energy of folding with temperature that you did in HW1, where you had explicit expressions for DeltaS and DeltaH. Another approach might be to use a thermodynamic identity that you learned in your ChE110 classes. Hint: if you know G(T,P) then what is (dG/dT)_P, by definition?

Cheers,
MSS

Question

2010-10-01T07:33:00.000-07:00

I was reading my Biochem book and it states that a closed system exchanges energy, but not matter. I though you said the opposite in class. Also, for today's lecture, I was confused on where the lecture is taking us. Are we studying the probability of empty sites that will later translate to sites on enzymes or some other typing of bonding in the cell?

Closed systems are those that can exchange energy, but not mass. Isolated systems are those that exchange neither.

The example worked in class was just a simple case to illustrate the properties of Boltzmann probabilities. We will not connect this specific example to any biomolecular process; however, the final, general equations that we arrived at, namely the connection between state probabilities and free energies, will be used quite extensively.

HW1, question 4b

2010-09-29T17:31:00.000-07:00

Dear class,

There is a typo in part b of question 4 on the homework. It should say that the transfer free energy is N * (0.2 kcal/mol) and not N * (0.1 kcal/mol). An updated HW is posted online. Sorry for the confusion.

Cheers,
MSS

ChE170 logistics

2010-09-24T11:44:00.001-07:00

Dear class,

Just a reminder from the syllabus: your current reading assignment is Chapters 1-2 in ECB3. Our first quiz will be next Thursday, 9/30, at the start of class, and it will cover this material.

Below I am also posting the complete office hours schedule for this quarter:

Mondays 11am-12pm, MSS - Eng. II 3321
Tuesdays 3-4pm, Sunyia - Eng. II 3201
Wednesdays 10-11am, MSS - Eng. II 3321
Fridays 12-1pm, Sunyia - Eng. II 3201

Cheers,
MSS

TA Office Hours this Quarter

2010-09-24T11:17:00.000-07:00

My ChE 170 office hours this quarter will be in EngII, Room 3201, Tuesdays 3-4 PM, and Friday 12-1 PM, starting next week (9/28)! This room is the ChemE TA room, and it's on the third floor outside by one of the the stairs.

Sunyia

Final grades

2010-03-23T13:13:00.000-07:00

Dear class,

We have finished grading the final and your course grades have been computed.

The statistics for the final are:

average - 59% (63% with bonus)
standard deviation - 16% (17% with bonus)
maximum score - 92% (98% with bonus)

The statistics for the course grade are (with bonus):

average - 68%
standard deviation - 13%
maximum score - 92%

The letter grade distributions are as follows:

A - 23.6%
B - 29.1%
C - 27.3%
D - 9.1%
F - 10.9%

A detailed plot of these distributions can be found on the course webpage.

I enjoyed teaching you all this quarter and wish you the best of success in your future endeavors!

Cheers,
MSS

Final review problem solutions

2010-03-13T11:06:00.001-08:00

Dear class,

The numerical answers to the review problems suggested for the final are posted online.

MSS

Problem #48

2010-03-10T21:47:00.000-08:00

On problem #48, since we are given that the gas is ideal (not steam, or methane, etc.) with a constant heat capacity and that the expansion is adiabatic, can we use deltaH = Cp*delta T to find the shaft work? But since this is also the expression to find the isentropic work, would the efficiency be 1.00?

The efficiency measures the work relative to the isentropic work. In the isentropic case, the exit temperature will be different from the actual temperature given. So, to compute the efficiency you will need to compute the new output temperature.

MSS

Review session

2010-03-10T18:46:00.000-08:00

Class,

I will hold a question-and-answer review session for the final on Monday from 5:30-6:30pm in our usual classroom.

Cheers,
MSS

Problem #47

2010-03-09T15:30:00.000-08:00

When solving for V in terms of V-vap and V-liq, is it ok to assume that V-liq will be negligible?

This is probably a pretty good assumption that will simplify your calculations, provided the temperature is sufficiently sub-critical and V-vap and V-liq differ quite a bit in magnitude (e.g., V-vap is ~1000 times as large).

MSS

HW9 question

2010-03-08T21:02:00.000-08:00

For problem number 47 once 25% of the steam has condensed do we use the evap. column in the steam table to find the volume and pressure of the new state?

Think about what kind of process this is. It states that the condensation takes place in a rigid vessel. That means that the *overall* molar volume of the system must remain constant. That places a constraint on the overall molar volume of the final state, which is a combination of liquid and vapor molar volumes (via the quality). The other constraint is that the system is on the saturation curve. Those two constraints should help you find the final state, using the steam tables.

You will also need to apply the first law to figure out how the heat removed relates the properties of the system. Note that Delta H = Q / n does not apply here because it is not a constant pressure process.

-MSS

HW 8 Problem 40

2010-03-01T11:09:00.000-08:00

Dear Class,

You should assume that the device in problem 40 operates adiabatically.

-Nathan

HW8

2010-02-28T18:35:00.000-08:00

For number 40 on the homework, can we assume that the system is isochoric because in the book it says that for a steady state process, the mass and entropy of the fluid in the control volume is constant. Are we allowed to use isochoric equations to solve for q of the process?

You could use the equations for an isochoric process only if the volume per mole of the fluid stays the same throughout the process, not the control volume. Thus, if the conditions indicated suggest a constant volume per mol of the flowing streams, you can use isochoric expressions. If not, you will need to use more general expressions.

MSS

Problem 43

2010-02-28T16:01:00.000-08:00

Dear Class,

There is a typo in Problem 43.
Problem 43 should read:
"Superheated steam at 500 kPa and 300 deg. C ..."
The online version has been corrected.

-Nathan

AIChE membeship

2010-02-28T14:57:00.000-08:00

Dear Class,

Several student had problems with AIChE's membership website when attempting to join AIChE for assignment 6. As a result you may attach proof of membership to Problem Set 8 or 9 to receive bonus points for the final if you have not done so already.

-Nathan

HW8, problem 39

2010-02-28T13:39:00.000-08:00

I am doing problem 39 on the homework and I am not sure how to calculate T2.

Remember that you now have multiple thermodynamic laws that you can apply to any process. Think about solving problems systematically by applying all of these laws. If you are still confused, go back to HW6 where you have solved problems for T2 exactly like this before.

-MSS

Problem 33 on Problem Set 7

2010-02-23T10:28:00.000-08:00

Dear Class,

There is a typo in the problem set. For Problem 33 parts (c) and (d) the efficiency (eta) is 70% of the Carnot efficiency as it was in parts (a) and (b).

-Nathan

Hints for Problem Set 6

2010-02-17T15:14:00.000-08:00

Dear Class,

Here are some hints for Problem Set 6.

Problem 29
You should assume that air is at 1 atm. You should be able to model air as an ideal gas to acceptable accuracy.

Problem 30
Propane is usually stored as a saturated liquid.

The equations used in this assignment generally offer good agreement with tabulated data for the conditions of interest. If you find that your |%error| is large (ie more than 10%) you have probably made an error.

-Nathan

Extension for HW6

2010-02-16T11:46:00.000-08:00

Dear class,

I received a request to extend the HW6 deadline. I am willing to do this, but mainly because I believe it is very important after the midterm for you catch up to material that you did not understand. As such, you may turn in HW6 this Friday at the beginning of class.

However, HW7 will still be given out tomorrow (Wed) and it will still be due a week later (the next Wed). There will be no other extensions for homework given, except of course in extenuating circumstances on an individual basis. I expect that you should be starting on your homework sets well-before the Monday or Tuesday before they are due, in order to time-manage this course's workload with your other courses.

Cheers,
MSS

Antoine’s Equation and the Clausius-Clapeyron Equation

2010-02-15T13:18:00.000-08:00

Dear Class,

When Antoine’s equation is combined with the Clausius-Clapeyron Equation DeltaH becomes:

DeltaH=BRT²/(C’+T)²

There may have been a missing exponent when this equation was presented in class. Note that B, C’, and T have units of Kelvin. The US edition of SVA gives C in Celsius in Table B.2, therefore C’=C-273.15. International editions of SVA may already give C in Kelvin.

-Nathan

Questions regarding HW6

2010-02-13T13:59:00.000-08:00

Some questions and answers-

The table C.1 has values of B divided by 10^3, but the examples in the book have 10^-3. Could that be a typo?

What the book is reporting is the value of B times 10^3, so that the actual value of B is a factor of 10^3 smaller. Think of the number listed in the table as a value x. Then, we have B*10^3 = x so that B = x * 10^-3. Similar for C and D.

I am trying to work on problem 4.2 part a, using the example 4.3 as a guide. So for the iteration of the mean heat capacity over R, how can I compute it without having a value for tau? Should I assume first it equals to 1, starting with T = Tzero, then getting a value for heat capacity, plug it into T = deltaH/Cp + Tzero. Then using the new T, with new tau , get another value for Cp, then another value for T and so on?

Yes, exactly. Remember, the mean heat capacity depends on both the initial and final temperatures. Consider constant pressure heating where the heat duty is specified. In this case, the first law is:

Delta H = Q/n

We can rewrite Delta H using the mean heat capacity and the temperature change:

(Tf - T0) Cpavg = Q/n

We can solve this for Tf, but it is highly nonlinear in Tf. Why? This is because Tf not only appears in the temperature difference, but it is part of the expression for (by way of tau). Setting up an iteration helps us solve this nonlinear equation:

Tf = (Q/n) /Cpavg + T0

You start with a guess for Tf and plug it in. The easiest guess is just to use T0. Then, you use this equation to continue to get new guesses for Tf until you converge on one value. At that point, you have found the value of Tf that solves the original equation.

Cheers,
MSS

Office hours on Monday 2/15/10

2010-02-12T15:25:00.000-08:00

Dear Class,
I will have regular office hours on Monday (2/15/10) from 10-11am in Engr. II 3301.
-Nathan

Problem Set 5

2010-02-09T14:08:00.000-08:00

Dear Class,

If you turned in Problem Set 5 on Monday and would like to work on it during your extension, you can pick up your Problem Set from me in my office (Engr. 3218) until 5:00 pm today or during office hours from 5-6 pm in Engr. II 3301.

Cheers,
Nathan

Classroom change reminder

2010-02-08T10:28:00.001-08:00

Dear class,

This is a reminder that today's class will be our first in the new classroom, EII 1519. It is located in the new construction of the EII quad, on ground level immediately to the right of the large stairway as you walk up to Chemical Engineering.

MSS

Extension on HW5

2010-02-08T09:15:00.000-08:00

Dear class,

Since there are a number of midterms this week and last, I will extend the deadline for turning in HW5 until Wednesday at the beginning of class. However, I will still hand out HW6 today.

Cheers,
MSS

Questions and answers

2010-02-05T10:11:00.000-08:00

Here are a few questions that I received through email and responses that may be useful to you.

I was just wondering how much of the virial expansion we will need to know. I am assuming everything we learned, to be safe. But I was wondering if there was a certain emphasis you wanted us to have, such as where the equation comes from or solving a problem like the example we had in class.

What we covered in lecture should be sufficient for understanding the virial equation. Generally, anything presented in lecture is what you should know very well, especially since we are covering a lot of material in just 10 weeks.

When do you know where to use the virial expansion? In the book example and the one in lecture the values for B and C were given, indicating that the virial equation would be used. Is there a table in the book for the values?I couldn't find one. Or would we be given the values if they were needed?

Second (and sometimes third) virial coefficients are tabulated for a wide range of systems because they are often easy to measure experimentally, but I don't think the book has a table. Generally if we work a problem these values will be given. In your later courses, you may see a lot more of the virial equation because it is frequently used to model dilute suspensions and colloidal solutions. But for the purposes of modeling fluids, the cubic equations of state and, even more so, the generalized correlations are usually more accurate.

Are the isothermal compressibility and the thermal volume expansivity generally constant for a specific material, or do they vary with temperature and pressure? For an ideal gas can we assume they are constant?

In general, these parameters are state-dependent, and thus depend on the specific pressure and temperature of the system. They do depend on state for an ideal gas. I believed we derived the ideal gas expressions for these parameters in lecture, but it should also be in the book if you want a second perspective.

MSS

Review session for midterm

2010-02-01T21:44:00.000-08:00

Dear class-

We will have a question and answer review session on Wednesday 7-8pm in room 3301, Engineering II.

Cheers,
MSS

Midterm Exam

2010-01-25T15:27:00.000-08:00

Per our discussion in class, we will aim to have the midterm on Friday, Feb. 5 in class. If you have problems with this date, please email me before class on Wednesday. Otherwise, there will be no make-up midterms except for exceptional circumstances.

Cheers,
MSS

Correction to HW3, problem 10

2010-01-19T14:08:00.000-08:00

Dear class,

There is a typo in problem 10 on HW3. The heat capacity for the vessel should be expressed in terms of pound-mass, not pound-mole.

Cheers,
MSS

Office hours on Monday (1/18/10) are canceled

2010-01-13T13:08:00.000-08:00

Dear Class,

Office hours on Monday (1/18/10) are canceled since the power will be out in Engr. II and it is also a holiday. I will have extended office hours on Tuesday from 5:00-6:50 PM.

-Nathan

Office hours on 1/11/10 are canceled

2010-01-10T14:37:00.000-08:00

Dear Class,

Office hours for Monday 1/11/10 are canceled. I will still have regular office hours on Tuesday in Engr. II 3301. You are also welcome to stop by my office, Engr. II 3218 on Tuesday. I should be available all day (9:00 AM - 5:00 PM).

Sorry for the inconvenience,
Nathan

Ch E 110A Office Hours

2010-01-04T13:46:00.001-08:00

Dear class,

Office hours for Ch E 110A are as follows:

Prof. Shell (3321 Engr II)
Thursday 11:00 AM-12:00 PM
Friday 2:00-3:00 PM

Nathan (3301 Engr II)
Monday 10:00-10:50 AM
Tuesday 5:00-6:00 PM

-Nathan

Final exams and final grades

2009-12-11T12:30:00.000-08:00

Dear ChE170,

Your final exams have been graded and course grades have been assigned. You can find information on grade distributions at the course website. You can also find solutions to the final exam problems there as well. If you would like to pick up your exam, please stop by my office sometime.

I enjoyed the class this quarter, and we'll leave up the gallery for a while for all to admire your work. Good luck in your future courses and endeavors!

Cheers,
MSS

HW5

2009-12-07T19:56:00.001-08:00

Dear class,
If you haven't picked up HW5 (or any other HWs), I will be bringing them to the art gallery at 5pm on Tues or you can pick them up at my office in ESB 3413.
Good luck on your finals,
Brad

Old HWs or Quizzes

2009-12-04T13:27:00.000-08:00

Hi class,
If you have not gotten back any HWs or quizzes you can stop by my office in ESB 3413 anytime to pick them up. I will also be bringing them to the review session on Monday.
Thanks,
Brad

Some notes before finals

2009-12-04T13:06:00.000-08:00

Dear class,

Just a few new announcements before the final on Thursday:

The final is closed notes and closed book, but you will be provided with the equation sheet given out in class today (handout 7, also on the web). Please bring pencils and a calculator. The final will cover all the material on the quizzes and problem sets.
A question-and-answer session will be held on Monday, 4-5pm in the chemical engineering conference room, EII 3319. We were unable to book the small classroom at this time, but with the small number of students that indicated interest in class, this room should be adequate.
A "gallery opening" will be held on Tuesday, 5-6pm, for your bonus projects. I will also invite the graduate students that were judges, and bring snacks. Feel free to stop by and take a study break.
The quizzes and their answer keys have been posted online.

Cheers and happy studying,
MSS

HW5

2009-11-24T13:22:00.000-08:00

Dear class,

Please excuse the typo on HW5 - it is due Friday, 12/4, not Monday.

Cheers,
MSS

Problem 6c

2009-11-20T12:32:00.000-08:00

Dear class,

In problem 6c on HW4, you may compute a faster rate of diffusion of the protein than for active transport. This is not an error -- I should have chosen a larger protein here.

Cheers,
MSS

Quiz and HW statistics

2009-11-18T08:27:00.000-08:00

Dear class,

Here are the course averages thus far:

quiz 1: 81.1 +- 10.9%
quiz 2: 72.5 +- 16.5%
quiz 3: 78.6 +- 16.3%
quiz 4: 89.5 +- 8.9%

HW1: 81.6 +- 14.1%
HW2: 78.3 +- 12.8%
HW3: 87.0 +- 11.4%

Cheers,
MSS

Notational clarifications in HW4

2009-11-16T10:54:00.000-08:00

Dear class-

I realized that there might be some notational confusion throughout HW4 regarding different R's - some of which specify the gas constant, some the cell radius, and some a protein radius. I have re-tooled the notation to be clearer so as to delineate these different quantities. I also made some clarifications on a number of problems: please check in particular the new problems 3 and 6c.

Cheers,
MSS

No office hours today or tomorrow

2009-11-16T10:06:00.000-08:00

Dear class-

I will not be having office hours today due to travel to an NSF panel in DC. However, should you have questions about HW4, feel free to email me, stop by Wed or later in the week, or see Brad in his office hours.

Cheers,
MSS

Quiz 3 & HW2 avg scores

2009-11-13T11:11:00.000-08:00

Class,
The average on Quiz 3 was a 78.6% and the average on HW2 was a 79.6%. I hope to be able to hand back HW3 by Wednesday's class. I have office hours today (Friday 11/13) at 3pm if you have any questions on the recently handed back HW or quizzes.
-Brad

Grading with bonus project

2009-11-08T17:58:00.000-08:00

Class-

There may be some confusion about the bonus project and how it will figure into your grade. Here's how we will compute your final grade.

At the end of the quarter after the final, we will first compute your grade as if there were no bonus project, but still dropping your lowest quiz score. From these grades we will compute the final grading scale (typically looking for natural breaks in the distribution) and assign you a letter grade.

Then, if you completed the bonus project satisfactorily, we will then recompute your grade two ways: one in which your second lowest quiz score is replaced with a 100% and one in which your final letter grade is bumped up by one +/- increment. Whichever of the two results in a higher final grade will be what we assign you.

In this scheme, missed quizzes will count as zero, but since we are dropping your lowest quiz score and since the bonus project gives you a second way to make up a quiz, this should permit you sufficient flexibility if you are unable to make a quiz for some reason. The purpose of the bonus project is to accomodate students who could not make a quiz due to conflicts and the rescheduling of the dates. As a result, we won't hold any make-up quizzes.

Hope that clarifies things,

Cheers,
MSS

HW4

2009-11-08T17:57:00.000-08:00

Class-

HW4 is now posted online at the course website.

Cheers,
MSS

Bonus project question

2009-11-05T17:03:00.000-08:00

I was asked the following:

Does the project need to pertain only to one protein or can we use multiple proteins (i.e. DNA and a DNA polymerase)? Also, say we choose a small protein, can the artwork be a collage of multiple repeated units of that particular protein even if it isn't found like that in nature?

You can certainly include more than one molecule, especially if the function of them is best illustrated by a complex. As far as the layout, you can choose any way of displaying the protein that you like (collage, etc) so long as you are able to illustrate some kind of function within your project.

MSS

Updated course schedule

2009-11-05T12:44:00.000-08:00

Dear class-

As discussed yesterday, there are some updates to the course schedule:

today, 11/5 -- Brad's office hours extended 3-5pm
tomorrow, 11/6 -- quiz 3 (Chapters 5-7, 10), also office hours canceled
Monday, 11/9 -- class canceled due to AIChE meeting, HW4 posted online
Tuesday, 11/10 -- Brad will be available for HW3 questions 11am-12pm
Thursday, 11/12 -- HW3 is due on Thursday, Nov 12 by 12pm in Brad's box
Friday, 11/13 -- HW4 will be handed out on paper
Monday, 11/23 -- HW4 due (normal due date)
Monday, 11/30 -- Quiz 5 will likely be moved to this date due to a guest lecture by Frank Doyle on Wednesday, 12/2

Also, the solutions to HW2 have been posted.

Cheers,
MSS

Office Hours Change and HW Mistake

2009-11-04T10:15:00.000-08:00

Hello everyone,

As discussed in lecture this morning, I will not hold my normal Friday afternoon office hours this week and they've been rescheduled for Thursday at 4pm. That means I'll have office hours from 3pm-5pm on Thursday this week only. Also, feel free to email me any questions you have and we could arrange a time to meet sometime before the homework is due next Thursday, Nov 12 at noon (in my mailbox).

On number two of HW2 I misread the question as T>Tfold so if I took off points for your graph being wrong, please either show me your HW on Friday or place it in my mailbox and I'll give you the two points back. Sorry for the error.

Thanks,
Brad

Quiz moved again -> Friday

2009-10-30T11:07:00.001-07:00

Class-

I received note from several students that will be taking the GRE next Wednesday morning. Therefore, as voted on in class this morning, we will have the quiz on the Friday of next week.

Cheers,
MSS

Quiz next week moved to Wed

2009-10-28T10:20:00.000-07:00

Per the near-unanimous vote of the class, I will move the quiz from next Monday to next Wednesday. If this will cause a problem for you, please let me know immediately.

Cheers,
MSS

HW2 notes

2009-10-22T17:19:00.000-07:00

Hi class-

A couple of notes on HW2:

On problem 3, when you look at the description of the structure on the PDB website, there will be three different chains - two for thrombin and one for hirugen (a hiruden mimic). Hirugen will be about 12 residues long.

On problem 4, keep in mind that what is given is the fraction of the total that is folded ([F]/[F]+[U]), not the ratio of folded to unfolded ([F]/[U]).

On problem 6b, assume T = 300 K.

Cheers,
MSS

Talk on how to job interview

2009-10-22T13:46:00.000-07:00

Hi class-

I received a note from Prof. Seborg that two ChE almuni will present a talk on "How to Succeed When Interviewing for an Industrial Job" today at 5pm in the Multicultural Center Theater:

The two speakers, Marc Privatera and Christina Borgese, were both AIChE Student Chapter presidents at UCSB. Marc was the UCSB recruiter for Clorox for several years and has had considerable experience interviewing ChE students. Recently, he moved to a biodiesel startup company, Biofuelbox, where he is the chief Technology Officer. Christina is a 2006 graduate who has worked at both Clorox and Biofuelbox.

Cheers,
MSS

Grade distributions thus far

2009-10-21T10:05:00.000-07:00

Hi class-

Here are some statistics on grades for the first two quizzes and first homework:

Quiz 1
average +- std dev: 81% +- 11%
max: 96%
min: 52%

Quiz 2
average +- std dev: 73 +- 17%
max: 100%
min: 33%

Homework 1
average +- std dev: 82% +- 14%
max: 100%
min: 18%

Keep in mind that homework assignments count for 35% of your grade and quizzes 25%. In addition, remember that the lowest quiz grade will be dropped.

Cheers,
MSS

Interesting video

2009-10-16T12:38:00.000-07:00

Dear class-

I highly suggest you take a look at this wonderful animation, entitled "The Inner Life of the Cell":

http://multimedia.mcb.harvard.edu/anim_innerlife_hi.html

It gives a molecular picture of most of the processes and compartments inside of a cell that we have been discussing. Although some of these are highly dramatized (for example, actin and tubulin assembly), the video does do an excellent job of integrating most of the major cellular processes and might make it easier for you to visualize the topics discussed in class.

Cheers,
MSS

Hints on HW1

2009-10-07T15:49:00.000-07:00

Dear class-

Here are some hints on HW1 for the problems.

Problem 1:
In this problem, you are tackling a problem of combinatorics. The problem essentially asks you how many spots there must be in a DNA sequence that are variable (i.e., one of the four possible bases) in order to have 10^10 unique sequences.

Problem 2:
To compute how far proteins are from each other, you want to assume each protein sits in a little cube of volume. The distance between proteins is then V^(1/3). Therefore, to solve this problem, you have to first compute the volume per protein.

Problem 3:
For part b, first sketch out what the Coulombic interaction looks like. Then, sketch what the total LJ + Coulombic interaction would look like for small q, medium q, and large q. At some point, as you increase q, the minimum in the net potential should vanish. What are the mathematical criteria for the vanishing of a minimum? In other words, what two conditions involving the derivatives of a function must apply when a minimum becomes and inflection point? This provides two equations... what are the two unknowns?

Problem 6:
(b) Imagine that the protein is fixed at the origin. What conformations must the ligand give up when it binds?

Problem 7:
(a) To get from heat capacities to entropies and enthalpies, you will have to integrate from a reference temperature. What are the definitions of CP?

(b) To eliminate DeltaS(Tf) from your final expressions, you will need to let T = Tf and DeltaG= the value at the folding temperature, then solve your expression for DeltaS.

(d) You will want to use either the slope or intercept of some line to estimate DeltaH(Tf)

Problem 8
You are going to first want to write all of your equations in terms of K1, K2, K3, K4 where K1=exp(-DeltaG1/RT) and so on and so forth. Next, express the concentrations of the various bound hemoglobin species in terms of equilibrium constants, [O2], and [H]. What constraint governs the total concentration of hemoglobin? Write down a mass balance on concentrations of hemoglobin. Let [H]0 be equal to the total amount. Then, f0 = [H]/[H]0, f1 = [HO2]/[H]0 and so on and so forth.

Problem 9
This problem amounts to finding the probability of one molecular state relative to another one, using Boltzmann populations, P ~ exp(-U/kB T). Be sure to normalize the probabilities such that they sum to one.

That's all the hints for now. Good luck,

MSS

Problem

Hints on problem set 1

2009-10-04T15:14:00.000-07:00

Hi class-

If you're having a little bit of trouble getting started with PS1, here are a few hints for some of the more challenging problems.

On problems 6,7, and 9, you are using the Boltzmann population rules that we discussed in class. These may be new concepts for you, but these problems will help you grow comfortable in applying them. When you are working on these problems, you need to start by thinking about states: what are the possible states the system can have (e.g., folded or unfolded, bound or unbound, correct or incorrect nucleotide)?

Write down a list of all states.
Next, you need to assign a probability to each of the states, and that probability is given by the Boltzmann rule. You need to know the list of all of the states in order to normalize the probabilities, i.e., to ensure that they sum to one over all states.
Keep the following in mind for the Boltzmann rule. If your state consists of multiple possible molecular configurations, you want to use a free energy in the Boltzmann exponential. If it consists of only one, you can use the internal energy.

On problem 8, you will be using concepts from your earlier chemistry courses that should be more than familiar to you. Keep in mind that the equilibrium constant for a reaction relates to the reaction free energy by:

K = exp( - DeltaG0/ R T )

We'll eventually derive this rule in class this week. You will need to know this relationship in order to solve problem 8. Also keep in mind for problem 8 that the total concentration of hemoglobin molecules is constant, [H] + [H(O2)] + [H(O2)2] + [H(O2)3] + [H(O2)4] = const = [H]0. What you are trying to find is f0 = [H]/[H]0, f1 = [H]/[H]1, and so on and so forth.

Cheers,
MSS

Updated course website

2009-10-02T10:19:00.001-07:00

Dear class-

I have posted the slides for the first three lectures and my notes for the lecture on thermodynamics on the course website. The thermo notes in particular may be helpful to you in thinking about and digesting today's lecture, and as you are working on the homework.

Cheers,
MSS

Updated office hours

2009-09-30T11:51:00.001-07:00

Dear class-

The updated office hours for the course are as follows:

me (3321 Engr II)
Monday 3-4pm
Tuesday 11am-12pm

Brad (3201 Engr II)
Thursday 3-4pm
Friday 3-4pm

Cheers,
MSS

HW1

2009-09-27T15:32:00.000-07:00

Dear class,

If you have taken a look at the first problem set, be aware that some of the problems will relate to material that we will be getting to this week. Problems 1-5 relate to material that we will discuss on Monday and Wednesday, and Problems 6-9 to material discussed Friday and perhaps also next Monday. However, if you are eager to start these problems, the book reading assignment (Ch. 103) also provides background material that will be pertinent to them.

Cheers,
MSS

TA Office Hours

2009-09-25T11:44:00.000-07:00

Dear ChE170 students,

As discussed in today's lecture, my office hours are Tuesdays & Fridays at 3PM in room 3201 ENGRII. Also, there was a typo in the syllabus: my email is spatola@umail.ucsb.edu, with an o, NOT spatula like the kitchen utensil.

Thanks,
Brad Spatola

ChE170

2009-09-25T11:38:00.000-07:00

Dear class-

Welcome to the course announcements blog for ChE170: Molecular and Cell Biology for Engineers. To receive announcements automatically by email, I encourage you to add your email to the subscription box to the right. Your email will be removed at the end of the course.

Cheers,
MSS

Final project gallery

2009-06-19T14:15:00.000-07:00

Dear ChE210D class members,

I have completed turning your final projects and movies into an online gallery at the course website. You can find it at this link:

http://www.engr.ucsb.edu/~shell/che210d/gallery/index.html

Enjoy!

MSS

Final projects

2009-06-12T13:45:00.000-07:00

Dear ChE210D-

Great job on the final projects! I was thoroughly impressed with what you all were able to do in such a short period of time. I will be away next week at a workshop, but the following week I will compile the projects into a web page for you all to view and vote on your favorites.

Also, I placed your graded final project back in your mailbox if you are a ChE graduate student. Otherwise, you can stop by my office the week after next to pick them up if you want them.

I hope you all enjoyed the class. From the look of the projects, it seems that you learned a great deal. Down the road, I'd be greatly appreciative if you would let me know how your projects develop (if you continue them) and, in particular, what parts of the course turn out to be the most useful for you.

Have a happy and productive summer,

MSS

Final project CDs

2009-06-09T16:12:00.000-07:00

Dear class-

I have a group meeting from 4-5pm tomorrow, but you can submit your final project either by: putting it in my mailbox or by sliding it under my office door. The former is preferred so that I don't inadvertently step on any CDs.

Cheers,
MSS