Teaching
Development
Report

UniServe Science News Volume 11 November 1998

An Electronic Text for Environmental Engineering

The discipline of Environmental Engineering has in the last twelve years emerged from Civil, Chemical and other engineering schools with major contributions from the Applied Sciences. While the origin of the subject is rooted in the traditions of these older disciplines, the freshness of the subject has fostered new approaches to teaching. To the traditional lecture, laboratory and field teaching, technology allows us to add computer based methods. At the moment there is nothing offered in this area that specifically targets environmental technology. Our aim has been to make a start in plugging that gap.

In teaching environmental engineering to classes at the Australian Defence Force Academy, the first author started to develop MATLAB simulations to help explain the basic concepts of pollutant dispersion in the environment. These simulations, displayed to a screen from a computer seemed to spark the interest of the students some of whom even wanted copies of their own. However the value of the simulations diminished as standalone learning aids because they needed the classroom interaction of the teacher posing questions, getting responses from students and then testing among options using the simulations. A need for a more interactive product was apparent. The first edition of such an interactive electronic text has now been released under the name - Envetext.

Using familiar development tools

In considering how to develop the product we had several goals in mind - the software should be intuitive to use, it should be attractive enough to entice students to pick it up, the content should not be shallow, and lastly it should be completely open, so the student who wishes to can explore exactly how it works and can even add their own content.

Because of this last goal we settled on a combination of Microsoft Word and MATLAB by MathWorks. The choice of MATLAB was natural, partly because some elements of the product were already in place, but mostly because it was a tool already well known to our students. It is commonly used in engineering and science schools as a programming language and has, in addition to advanced computational features, a well engineered graphics interface. It does fall short however in the area of textual presentation - for example it has only rudimentary ability to display scientific notation, and therefore the MATLAB applications were to be embedded in a Word framework.

The choice of Word was also dictated in part for the requirement of openness. All students have access to Word and hence any document can be completely under the student's control.

Envetext architecture

All Word, MATLAB and ancillary files reside on the student's computer or in his or her directory on a network. Operation requires the student to open a Word document that includes the introduction and highest level navigation in the form of a table of contents. Navigation within and between Word documents makes use of the inbuilt bookmarks and hyperlinks now provided as standard with Microsoft Word (We currently use Word 97 under Windows 95).

Within a topic area (Chapter) the student is stimulated with some posed questions (Figure 1) and invited to invoke a MATLAB application that we call a 'breakout' in analogy to the breakout boxes of magazines that typically provide more in-depth information (Figure 2). Colour coding within text gives ready identification for such breakouts.

Figure 1. Sample Chapter page for Envetext

Figure 2. Sample MATLAB breakout for Envetext

The breakout then takes the student on a journey of the topic using simulations and tutorials to guide him or her to an understanding. The emphasis is on interactivity so that the student is constantly trying things out, answering questions or even writing snippets of MATLAB code.

On returning to the Word document there are hints on what answers were expected to the questions as well as pointers to reference material.

The content

The first release of Envetext focuses on physical dispersion of pollutants in a fluid environment such as the atmosphere, coastal waters, groundwater etc. Four topics in dispersion theory are covered before embarking on a design exercise:

dispersion fundamentals, which shows how a simple statistical model leads to the basic differential equation for dispersion of a pollutant;

behaviour of turbulent jets, which includes a simulation of the mixing process in an expanding jet or plume;

models for concentrations and velocities in jets, which uses the laws of conservation of mass and momentum to develop expressions for the concentration and velocity at points near where a pollutant might be discharged;

environmental dispersion, which examines the dispersion due to turbulence and currents in the receiving environment; and

Monte Carlo simulation of an outfall design, which takes components from each of the other breakouts and allows the student to design an outfall for discharging a pollutant safely into the environment.

Evaluating the efficacy of the electronic text

Full evaluation on the version as released is yet to be undertaken on a statistically significant number of students however the results in formal examinations show some promise. On questions related to the subject matter of Envetext, the students who had use of Envetext performed better than all of the three previous years and on average this improvement was 40%. It is too early however to be conclusive about the results of these assessments.

Conclusions

A first release of an electronic text for environmental engineering is now available via the World Wide Web address given at the end of this article. In a unique way it makes use of the standard Windows programs - Microsoft Word and MATLAB by MathWorks. The text is a highly interactive facility which aims to help the student increase their understanding of some important fundamentals and design principles in design engineering. Early feedback suggests that the text is an effective addition to the armoury of the environmental engineering teacher.

Acknowledgments

The development of this teaching aid was supported by the Committee for University Teaching and Staff Development. The contribution of the many other individuals and organisations is gratefully acknowledged on the Envetext web page http://www.ce.adfa.edu.au/research/Envetext/envetext.html

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