Dissolved Oxygen Activity

Documentation Review: I reviewed Cynthia Lanius'Lessons for Fun with Math. I found the collection very extensive. There was a good short description of each activity on the Homepage with course and grade level information. The exercises were easy to start without extensive instrution. The applications ranged from kindergarten to adult. Many of the algebra examples could also be used in Math Modeling Problem(s) annotations: The Ratio activities needed a way for the student to input the answer before they checked it. The current check answer radial lets the student get the answer without inputing an answer for evaluation. The Pattern Block Fraction exercise was similar to the Fraction exercise in Project Interactivate. Recommendations: Keep adding resources and possibly give a way to sort them by subject and grade level on the home page.

There is plenty of documention and explanation. The applet was a little confusing as to how to run it. The platform and browser were fine.

It looked like everything was properly documented and was explained very well. The model was easy to figure out and run. It explained how to use the model and what it meant.

Problem(s) annotations: The material seems like it is a little too challenging for middle school students. It seems to be more appropriate for more experienced students. The concepts and presentation would make it difficult for younger students to process the impact of the results. They may be able to go through an exercise, but I find it unlikely that a large majority would truly "understand" the meaning/value of the experience. The interface in the model has a few flaws as well. Units are not displayed on the slide bars or graph. The graph is also laid out poorly. It lacks units and the label for the Y-axis is unclear. It seems that a model provided for use by students, learning about the importance of well-labeled material, should follow appropriate format. The task itself is worded in a way that may make it difficult for all but the highest-level students to work through without significant aid form the teacher. It really requires a rewrite by the classroom teacher to make it fit their class. Recommendations: This resource is an excellent tool to discuss the issues related to water quality. The level of dissolved oxygen can be used to jump start learning in all areas related to water quality. The simulation does a good job of linking to the types of concepts we as educators want to cover in a class that is investigating the environment, water, pollution, systems engineering, etc. Its broad appeal across disciplines makes it a powerful resource. The only caveat is that it will require significant teacher prep time to prepare it for specific use or to make it accessible to lower performing students. The Stella model interface needs to be modified to match the way we teach our students to present these types of material. This specifically refers to labels and units. The recommendation of appropriate level should be changed to exclude middle school grades.

Documentation Review: The theory part is incomplete (Application/Algorithm) to be able to do the documentation review at this point of time. Problem(s) annotations: 1. The graph in the applet does not seem to match the graph from the Stella model for the same parameters (as far as can be seen from the model) 2. The applet gives fewer parameters to change than the Stella Model. (For example BOD sewage, BOD decay, sewage volume, ...) 3. Text field of the parameters in the applet are truncated making it hard to identify the particular parameter (Channel_Dept, Channel_Velo....). 4. The x-axis and y-axis labels are missing in the applet graph. 5. The multiple graph comparing BOD and DO is not available in the applet 6. The text output from applet does not correspond to the Table output in the Stella model for the same parameters. 7. The "Close Window" button in the text output window is too narrow to recognize it as a button.

Documentation Review: I am not quite familiar with what the model is addressing. Problem(s) annotations: Specify how to download the model. Indicate that in order to use the Stella version, one needs to install Stella.

Documentation Review: The Stella version of the model downloaded fine but had the extension .stm.htm and had to be changed to be readable to Stella. The model worked fine with Stella Research version 7.0.3. The model components were labelled appropriately and the model appeared to give results that were sensible given the inputs. Problem(s) annotations: There is a major problem with the Java version of the model. The graph does not match the form of the DO curve. The slider bars are the wrong ones to allow one to test the scenarios given in the exercise. This version needs to be fixed or deleted. Recommendations: Revise the Java version pending further testing. Pass the Stella version on for validation.

Test Case(s): I followed the instructions and was able to vary the parameters as indicated in the Stella version to arrive at a comparison of the impacts of the sewage treatment plant on DO levels under a range of conditions. The model appears to behave correctly across these conditions - producing lower levels with higher temperatures or increased loads higher levels otherwise. Problem(s) annotations: Java applet version does not work correctly. Recommendations: I would recommend the exercise on model using the Stella version. It teaches the principles of the major relationships associated with DO in a stream and a relevant decision that is to be made based on the simulation results.

Problem(s) annotations: This may be somewhat difficult for grades 7-9 but is certainly appropriate for grades 10-12 and undergraduate students. For undergraduates or K-12 students with pre-calculus, one could add the differential equations represented by the difference functions in the current model. A couple of the equations may be hard to track down. In particular, the equation for reaeration is incompletely documented and some students may have trouble understanding the exponentiation and where it came from. Recommendations: Recommended that this accredited at the 10-12 and undergraduate grade levels.

Documentation Review: Theory and Algorithm sections promised to Come Soon. In the Introduction: The SI unit abbreviation for liter (litre) is cap L, not lc l. It would be nice to convert ppm at 0oC to mg/L also. Problem(s) annotations: Java applet needs to be redone. The Java curve appears to be nearly quadratic starting at 0 and increasing without the "dip" discussed whereas the Stella curve appears similar to the curve described in the Introduction. The DO_effluent doesn't seem to do anything in the Java applet. I cannot read all of the Channel_Dept??? or Channel_Veloc??? because the words are blocked by the values. Recommendations: Verify the Java applet. Try a different font size or reduce the name length

Problem(s) annotations: More directions in the check box area for the graph to be display- What is the purpose of the red box next to the check line box? Recommendations: Get rid of the bar graph option- Doesn't seem to generate as much useful info as the line-

Recommendations: The applet could use short instructions. The graph should have labeled axes.