Category Archives: Uncategorized

More analysis of files downloaded from RESOURCES

We analyzed the raw log from October 31 through November 11 of 2021, subtracting web bots and spiders.

Of 764 unique users who accessed at least one PDF, only 80 did anything on the site other than access a PDF (view or download).

Two reasons probably contribute to this result: (1) some users are accessing single pages found in a browser search, and (2) some instructors are posting direct links to individual PDFs in the RESOURCES section.

That is easy to do in making reading assignments but deprives students of seeing all the other material on this web site.

I request that instructors post a link to our Home Page with each assignment and encourage students to look around the site.

Maybe even ask students to turn in a response to a question, such as what the conversion of reactant is when the temperature is set to 300 for the home page reactor.

A big THANK YOU to instructors who do this!

Top files downloaded from RESOURCES

We were interested in which notes in the RESOURCES section are being used. The data here are for the month of October, 2021.

We are happy the notes in Resources are being found useful. Please let us know your thoughts via email to

The top 10 countries for download bandwidth are, in order most to least: USA, India, Mexico, Brazil, Canada, Philippines, Japan, Great Britain, Russia, Germany.

Top 20 files accessed (viewed or downloaded):

# Downloads, File
221, CRE Notes 13 – intro to PFRs
217, CRE Notes 7 – data analysis
216, CRE Notes 14 – intro to CSTRs
213, CRE Notes 16 – more reactors
181, CRE Notes 9 – thermal effects
139, CRE Notes 12 – multiple reactions
106, CRE Notes 15 – CSTR thermal effects
104, COCO simulator, Part 1 – flash drum
83, Matlab, material balances
80, CRE Notes 11 – semi-batch
72, GRAD CRE Notes, oregonator description
67, GRAD CRE Notes, Reaction and diffusion in porous catalysts
60, Matlab, array vs matrix ops
54, Matlab, bouncing ball eqns
48, CRE Notes 4 – integration
47, CRE Notes 13-A – methanol reactor model
47, GRAD CRE Notes, ammonia synthesis kinetics
39, Matlab, hex 15_12.txt
38, Control notes, 4. transfer functions
38, GRAD CRE Notes, effectiveness greater than one

The Web Labs are being used each day

We counted the number of runs in each of the Web Labs for the 13.4 days of Mon, 18 Oct 2021 21:16 to Mon, 1 Nov 2021 11:00

The reactor on the Home Page is seeing an average of 45 runs per day.

Lab 7, the Plug Flow Reactor is seeing an average of 30 runs per day during this period. Every Web Lab has been used.

We are happy the Web Labs are being found useful. Please let us know your thoughts via email to

600 runs, Home Page reactor
406 runs, Lab 7, Plug Flow Reactor, including 7 Quiz for this period
271 runs, Lab 9, Hysteresis and multiple steady states in catalytic CSTRs in series
103 runs, Lab 13, Batch reactor, isothermal, nth order reaction
101 runs, Lab 3, Reactor T control with Tj inlet
83 runs, Lab 1, Water Tank Level Control
63 runs, Lab 14, CSTR, isothermal, nth order reaction
52 runs, Lab 15, PFR reactor, isothermal, nth order reaction
47 runs, Lab 5, Bioreactor Control
35 runs, Lab 18, Teddy Token blockchain
22 runs, Lab 000, Artificial Zoo, with the Dragon most popular
16 runs, Lab 00, Pendulum
10 runs, Lab 17, Cryptographic hash
9 runs, Lab 2, Dynamic diffusion and reaction in a porous solid catalyst
8 runs, Lab 8, Plug Flow Reactor + Heat Exchanger
7 runs, Lab FF, Forest fire
6 runs, Lab 0, Swarm of Objects
6 runs, Lab 16, RSA encryption
2 runs, Lab 1A, Level Control, two tanks in series
2 runs, Lab 4, Reactor T control with Tj
2 runs, Lab 6, Heat Exchanger

Web Labs now have the capability of desktop Reactor Lab

With the addition today of Web Lab 13, batch reactor with n-th order reaction, Web Labs now have examples of all the types of labs and plots in the desktop Reactor Lab.

In Dynamic lab types, the simulation runs continuously in time, with the student being able to change inputs during the simulation. In non-dynamic labs, individual experiments are run, which produce one or more plots for that experiment. In quizzes, such as the current Lab 7 Quiz, students can run and analyze experiments to determine unknown input values.

Plot types include profile, single, strip, and color canvas. A profile plot shows how an output has changed with time or space. Single type plots show results of non-dynamic experiments as x,y points as inputs are changed between experiments, with the student being able to select which inputs and outputs are shown on both the x and y axes.

A strip plot is like a lab strip chart (do they have those anymore?) which continuously scrolls in time as outputs are plotted. A color canvas plot shows how a color-coded output varies in two dimensions, e.g., time and space.

Graphics can also be dynamically drawn with SVG graphics, such as in Web Lab 00, a simulation of a pendulum. Several labs change the size and color of HTML div elements to show fluid levels and concentrations changing.

Do you have any suggestions for new labs? Please let us know by sending email to

Open source SimzLab

We uploaded an open-source version of SimzLab to our github project at

SimzLab was an extension of the concept of ReactorLab to enable different types of labs, or “courses,” to be distributed from a single platform. Originally, one of the courses in SimzLab was ReactorLab. We later took ReactorLab out of SimzLab and stopped development on SimzLab due to lack of development resources.

The current SimzLab includes PureWaterLab, a project about water purification, a process Control Lab, and a Heat Exchanger simulation.

The Download section of this web site has a standalone version of SimzLab for Windows OS. For other platforms, you can download and use the open-source version with the LiveCode development tool, which can be obtained at

My advice to students for succeeding at the university

1) Study with at least one other student in each class. Get study buddies.

Don’t do it all alone. You will learn from other students, even when you show them how you figured things out. They will keep you honest when studying for a test: no peeking at notes when they ask a potential test question.

2) Schedule plenty of time to study and do homework. Do not overcommit.

Do not get too involved with work, student organizations, athletics, gaming, or partying. There are lots of interesting things to do at the university other than study.

Note: Not following (1) and (2) are almost always the reasons I have seen students struggle at UCSD. Everyone who gets admitted is smart enough. Don’t worry about that.

3) Talk to your professors and TAs.

A couple times during the term, ask them about topics in class or their research.

Do not always ask them about points on homework and tests. That will leave a negative impression of you. It is fine to ask about points, just not as the first question nor the only question.

At their office door, always remind them of your name, and ask them if they have a minute to talk about (fill in something interesting, not points). Do not ask, “are you busy?” Stupid question. Prof’s are always busy! Best not to approach them right before class.

Don’t wait until you are struggling in a class. Always talk to them if you do start to struggle for any reason, even if you haven’t talked to them before. Get help early!

If they know you, then you are more likely to get “the benefit of the doubt” during grading, e.g., drawing the grade line just below you instead of just above you.

4) Aim for A grades. Try to get at least B grades.

To keep open the option of going to grad school or professional school, you need to graduate with at least a 3.0 GPA overall. Also, you need at least 3.0 (B) average in your major if you want to continue in that major in grad school.

Most schools won’t admit a student to grad school with less than a 3.0 GPA, except in unusual, extenuating circumstances and with a sponsoring professor. Don’t rely on that. With less than a 3.0, your options are schools with lower standards, lower reputations, and higher costs.

5) The day before your first day of class, walk around campus and locate your classrooms.

Before serving on an advising panel one day, I asked a barista at Muir Woods the most important thing to tell new students. This is her advice. Sounds good to me.