In this Issue

- Membrane Permeability
  Experiment
- ISE-100 pH Electrode
  Tech Note
- Web resources
- Clearance Items

------------------------------

The iWorx newsletter is a FREE monthly publication dedicated to sharing teaching laboratory techniques and other useful information with educators in the fields of Anatomy and Physiology. We will also be sending you technical information and info on new developments at iWorx that we feel may be of use to you in your teaching and research activities.

About iWorx
iWorx has everything you need to add excitement and distance learning to any physiology teaching program. Our products include data acquisition hardware, professionally -developed physiology courseware, innovative web tools, and a full selection of transducers, cables, front ends and accessories.

iWorx/CB Sciences
One Washington St.
Suite 404
Dover, NH 03820
P: 800-234-1757
F: 603-742-2455
info@iworx.com

© 2006 CB Sciences, Inc. Patent pending. iWorx is a trademark of CB Sciences, Inc.

December 2006

 Experiment:  Water Quality

The acidity, salinity, conductivity, and many other properties of natural water systems depend on the conditions of the environment that surround the water systems.  These properties determine the organisms that can live in the water system.  To maintain aquatic life in a water system, the properties of water quality need to be within a narrow range of values.  For example, the water that fills natural water systems may begin as rain that is slightly acidic, and becomes more acidic as it seeps through the leaves littering the forest floor.  As the water percolates through the soil, it reverts to being less acidic and becomes basic as it moves through deposits of minerals, like limestone. These compounds in the ground usually balance each other, so that natural water systems have a pH between 4 and 9.

The interactions of humans with the environment can alter the quality of water dramatically and affect the survival of aquatic life.  Many natural water systems are surrounded by agricultural land.  Nutrients in the soil and fertilizers applied to the land can alter the abundance of aquatic life in the water system.  When these chemicals reach the water system, they can stimulate the growth of organisms, like algae, that actually deplete the water system of dissolved oxygen and affect the survival of fish in that water.

In this experiment, students will collect water samples from a variety of sources, like streams and ponds, around their community. They can also collect samples of tap water, water from swimming pools and drinking fountains, and deionized or distilled water for testing. Students will measure the temperature of the water at the site where it is collected.  When the water samples are brought back to the laboratory, the students will measure the pH, dissolved oxygen concentration, and specific gravity of their samples.  The values of these four parameters for each sample will be entered into a table for comparison.

Download Water Quality experiment.

Download screen optimized or press optimized Water Quality experiment.

ISE-100 pH Electrode

The ISE-100 is an easy-to-use pH electrode that is capable of measuring the acidity of solutions over a pH range of 0 to 12.  The ISE-100 is a combination electrode with both the recording and reference electrodes included in the same housing.  The plastic housing at the end of the electrode protects the glass membrane and reduces the probability of the electrode breaking as it is handled. 

View a Tech Note here.

ISE-100 pH Electrode

ISE-100

pH Electrode

$155

$125

Download the updated settings group for this month’s experiment and the other experiments published in the iWorx Newsletter.

Whether you plan to download any of the experiments announced in recent editions of the iWorx Newsletter or a new copy of the LabScribe Installation CD, you need a password and an ID to access the download sites for these items. 

To register for a new ID and password, please go here.   After you receive confirmation that user account has been activated, return to the same site and click on the Enter link. 

Registered users can log-in here.

To download screen or press optimized copies of the latest lab experiments and Tech Notes published in the iWorx Newsletters, go here and select the lab experiment of interest.

If you plan to use any of the experiments or manuals announced in recent editions of the iWorx Newsletter, you should obtain a copy of the settings group used to configure LabScribe for these experiments.  To download the settings file, right click here and choose "Save Target As" in the Internet Explorer browser or "Save Link As" in the Firefox browser.  Save the file in your LabScribe Folder.  When you launch LabScribe, the settings group will be available from Load Group command in the Settings menu.

The write-ups and the settings files for the blood pressure experiments in the iWorx Physiology Manual have been updated.  The latest version of the LabScribe Installer CD that contains the updates, is available for free on the iWorx Users Area.

Learn more about water quality by going to the external Web resources page.

On this page we have also accumulated a host of links to informative, external physiology Web sites and conveniently categorized them into major sub categories for easy reference.

Clearance Items

iWorx has a large supply of new and trade-in items at up to 70% discount.  Also check with us about trade in allowances for your older Powerlab or Biopac equipment.  Customers in the U.S. and Canada can order directly online. See specials