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Please state dimensional units!

I have been looking into developing a Web Lab simulation of a fluidized bed gasifier. Reaction rate equations are needed.

Trying to get rate equations from research papers has been frustrating because the dimensional units of terms in equations are often not stated.

To an editor or peer reviewer, it may look like the author has given all the required equations to duplicate their work, but you learn the truth when you try to use those equations, not just read them!

Please make sure you explicitly state the dimensional units for all terms in all equations, or example units if more than one set of consistent units can be used. Stating dimensional units is mandatory for equations with numerical constants. If equations are dimensionless, please state that.

Reviewers and editors, please check to make sure authors have done this.

On a related note, I ask that chemists reporting reaction rates please state for which type of reactor those rates and equations apply. Usually, a chemist is using a batch reactor, e.g., a test tube or flask but we should not have to assume that. Some chemists might even use a continuous stirred tank (beaker) reactor.

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 https://github.com/RichardHerz.

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 LiveCode.com.

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.