Use of Living Systems to Teach Basic Engineering Concepts - Web-Based Engineering Education: Critical Design and Effective Tools - page 99

Gas Transfer verse Osmosis, Ultrafiltration and Ion Exchange.

Specifically they work on an experiment on de-
termining the adsorption coefficient of activated
carbon in removing organic pollutants.

This experiment exposes students to the principles
of gas transfer. Students will conduct a visual
simple batch experiment with various commercial
diffusers to transfer oxygen into the water and
compare diffuser efficiencies.

2. Instrumentation and control

These experiments focus on the use of remote
sensing, real time data and images on the WWW.
A 100 gallon marine aquarium that is maintained
at the NJAAS distance learning classroom has
been instrumented with a webcam and sensors to
display real time images and water quality data
through the project website. This instrumented
aquarium is titled R~QUARIUM. A web-camera
and a sensor system are used to instrument the
marine aquarium. The sensor system allows real
time values of water pH, Dissolved Oxygen,
Conductivity and Temperature.

Respiration

Students also investigate the differences in air
and water as respiratory environments. The most
significant difference is that water contains only
1/13 as much O 2 as air does, or 1% to 21% (water
to air) by volume. The energy that is required to
move water into and out of a respiratory organ
is much more than that used to move air because
water is more dense and viscous.

Hydraulics

Data Acquisition and Remote Control

Water pressure in an aquarium is a major param-
eter in design considerations. Students conduct
experiments to determine the pressure distribu-
tion and net forces on the aquarium walls using
conventional hydraulics equipment. They also
conduct experiments on head losses in pipes and
porous media such as sand.

This module exposes students to data acquisition
techniques. Students' prototype a relatively simple
but representative example of a technologically
complex feedback control system to monitor water
quality parameters (e.g., aquarium temperature,
pH, Conductivity, and Dissolved Oxygen). Stu-
dents also identify all relevant electronic com-
ponents (e.g., sensors, amplifier, A/D, and D/A,
etc.) and their interrelations.

Light

Light intensity is of utmost importance in the
operation of an aquarium. Students design a light-
ing system to simulate day and night, while the
temperature is maintained within a certain range.
Students also learn to use timers to conduct open
loop control, and use thermostats as sensors for
feed-back control. Simulink is used to simulate
various lighting scenarios.

WWW and Networking

One important feature of the R~Quarium is on-line
real-time data acquisition. This module focuses
on the basic networking technology in support of
this theme. Students are introduced to a seven-
layer networking model, distributed systems as
exemplified in the Internet, and database funda-
mentals with emphasis on their application to the
aquarium. A website has also been dedicated for
rapid information dissemination 5 .

Water Treatment Processes

Students observe demonstrations of various water
treatment processes such as Sand Filtration, Re-