The two main
applications of IRIS are educational and professional. Iris is designed as interactive teaching
tool for use in the class room and in teaching laboratories; however, it is
equally well suited for the professional work of material scientists:
(1) IRIS for
Teaching Using IRIS with a standard projector attached to the PC, the
instructor enriches his/her teaching with interactive graphics in class. For
example, the IRIS program allows you to perform time-temperature superposition
in real time, to calculate the relaxation time spectrum immediately after that,
and then to graph of all kinds of material functions. All of this is done
within minutes so that teaching proceeds at normal pace. Predictions from analytical
expressions (Rouse, Doi-Edwards, BSW) can be pulled in and graphed next to the
data for comparison. In this way, the students directly participate in the data
processing and then can be asked to follow up with a reading assignment in the
accompanying text. Teacher and student jointly explore the beauty and
usefulness of linear viscoelasticity. Many variations are possible depending on
topic and advancement of the class.
The program is
designed so that students with minimal training are able shift and further
evaluate experimental data by themselves.
This ‘hands-on’ approach allows the student to get a feeling for
rheological data, their analysis, and their application. The experiments become tangible and 'real'.
IRIS for the Professional With IRIS, you can analyze and scrutinize
rheological data from a wide range of rheometers, design effective experiments,
determine the rheological parameters, and use these parameters for flow
predictions of interest. The resulting
data are the starting point for flow calculations (Polyflow modeling, for
instance). The interactive graphics of IRIS visualize differences and common
features of materials, detect systematic trends in the relaxation patterns (see
for instance the study of Baumgärtel, Schausberger, and Winter, Rheologica Acta
29, 400, 1990), monitor phase transitions, or single out specific relaxation
modes. Rheological data get scrutinized
for inconsistencies (Winter, 1997). As inconsistencies in the data become
apparent, methods can be devised to improve the rheometrical experiment. Large sections of IRIS are devoted to
time-temperature superposition, conversion of dynamic data into relaxation time
spectra, and linear viscoelastic modeling.
Recent additions in IRIS compare these experimental findings with
theoretical predictions for well defined classes of materials.
The IRIS program
is written with the intention of navigating the user without much reading of a
manual. The help-buttons in the toolbar provide sufficient explanation without
disrupting the work with IRIS. At all times, a help text appears in the status
bar at the lower edge of your screen (if absent, go to ‘view’ and activate
‘status bar’). Its help text will give direct guidance. You will find many
details by opening the program and by just starting to work with IRIS. Only
some basic directions are given in the following few manual pages. In the
manual, we encourage further explorations with occasional tutorials. Answers to some frequently asked questions
can be found in the back of the manual. You will also find a ‘picture tour’
(.PPT file) on the CD. It shows typical graphs which you might encounter during
your work with IRIS.
The major part of the IRIS program concerns
mechanical spectroscopy as explained in a book chapter on Mechanical Spectroscopy
by Mours and Winter (2000), see reference on bottom of this page and copy on
CD. The IRIS program together with this
book chapter constitutes an effective teaching tool and simultaneously a 'work
horse' for the rheology laboratory. Many details are explained systematically
in the book chapter and are not repeated here. Some sections of IRIS, however,
exceed the realm of mechanical spectroscopy and lead you into a full dialog
with viscoelasticity, an all encompassing investigation of the viscoleastic
properties of your materials. The data from mechanical spectroscopy are the
starting position for this dialog.
Reference: Mours M, Winter HH (2000) Mechanical
Spectroscopy. Tanaka T, Ed,
Experimental Methods in Polymer Science: Modern Methods in Polymer Research and
Technology, Academic Press, San Diego CA. p. 495-546.
dialog with viscoelasticity starts with an experimental data set (left) or with
a theoretical prediction (center). Each
step in the dialog is accompanied with a graph, and each graph can be converted
into a spreadsheet (if so desired) or into an endless array of further graphs.