The videos demonstrate the basic capabilities of the model, and how to use it.
They include:
A short summary of the contents of the E-AIM home page.
Demonstrations of several types of calculation.
Examples showing the different types of model output (verbose, column, and graphical).
The selection and inclusion of organic compounds in the modelled system(s),
and viewing and changing the thermodynamic data that describe them.
The videos are organised into six sections, below. Click on a numbered link to open a viewer
in another browser tab and watch the video. (Checking the "show details" box after any
title will display instructions to enable you to reproduce the content of the video.)
I. Introduction
This video shows the home page, and the links to basic information about the model
including how to get started, and frequently asked questions.
Video 1: the home page. This video introduces the main sections of the home page, including the Model II description page as an example of description pages for all models.
From the E-AIM home page:
Click the News link to view the E-AIM news page.
Click the Project link to view the E-AIM project description page.
Click the Chemical System link to see the description of the chemical
systems modelled by E-AIM.
Click the Quick Start link to see the E-AIM Quick Start Guide.
Click the FAQ link to see the E-AIM Frequently Asked Questions page.
On the home page click the Model II link to go to the E-AIM Model II page.
And from the Model II page, click the
Description and Abstract link to see the Model II Summary and Abstract page.
From there, click on the model description link to see the pages that describe the thermodynamics of all the models.
That completes our overview tour of the informational pages within E-AIM.
II. Different Types of Calculation (Normal Output)
These demonstrations introduce the different types of calculation that
the model can do, and need not be viewed in order.
2.
Properties of an aqueous solution of specified concentration, and the main E-AIM results page.
( show details)
Video 2: the properties of an aqueous solution.E-AIM can either fix the water content of the solution, and calculate the properties of that solution, or determine the water content for a desired relative humidity (entered by the user). In this video, we demonstrate the aqueous solution feature,
which fixes the water content, and calculate the
thermodynamic properties of a 5 molal solution of ammonium sulfate.
On the E-AIM home page, click the Model II link.
Select the Aqueous Solution page from the list.
Enter 10.0 for NH4+
and 5.0 for SO42−.
Scroll down and click the Run button.
On the E-AIM Model Results page you will see summary information about P,
V, RH, and T, followed by the calculated thermodynamic
properties of the aqueous, gas, and solid phases. (There is no solid phase in
this example.)
3.
A simple chemical system at a fixed relative humidity (water activity), including
the partitioning of volatile species (NH3 and HNO3) into the gas phase.
( show details)
Video 3: a calculation at fixed relative humidity (RH). For
atmospheric calculations, investigators typically want to understand systems at fixed
relative humidity, which is equivalent to water activity in the particle when the system
is at equilibrium. This example shows a calculation
for a case where there is significant partitioning of species between the
gas and particle phases.
On the E-AIM home page, click the Model III link.
Click the Comprehensive link.
Enter a humidity of 70% as 0.70 in the "relative humidity or
moles of water" box. Note that humidity scales are 0–1 (fractions) in E-AIM, not percentages.
Next, enter 0.1E-6 for H+,
0.9E-6 for NH4+,
and 1.0E-6 for NO3− in the
boxes provided. You can click in each box or use the tab key to move between them. Values can be
entered in scientific notation, where for instance 1e-6 means 1×10-6.
Scroll down and click the Run button.
On the E-AIM Model Results page you will see similar summary information to
that in Video 2. Sections for the aqueous, gaseous and solid phases follow.
There is no solid phase in this case: the saturation ratio, here 0.70991,
has to reach 1.0 before a solid phase will form. Substantial partitioning of
ammonia (NH3) and nitric acid (HNO3) to the gas phase has occurred.
4.
The formation of a solid salt at low relative humidity, using (NH4)2SO4 as an example,
and a calculation for a supersaturated solution.
( show details)
Video 4: the formation of solids.E-AIM can determine if a compound will form a solid phase (at low RH) or not, and can provide information about supersaturation in cases where the solid phase cannot form because it has been "switched off" by the user.
On the E-AIM home page, click the Model III link. We
will do this example on the Simple Calculation page.
Enter a humidity of 75% as 0.75 in the relative humidity box.
Enter 2.0 for NH4+ and
1.0 for SO42−.
Scroll down and click the Run button.
Notice that there are no aqueous or gaseous phases – only pure ammonium sulfate in the solid phase. Now try
a second calculation:
Press the Back button on the browser
to return to the data entry page, and enter 0.75 for relative humidity.
Enter 2.0 for NH4+
and 1.0 for SO42−.
Under Solid Phases, check the box for ammonium sulfate ((NH4)2SO4) to prevent that solid from forming.
Scroll down and click the Run button.
Now there is an aqueous phase, but no gas or solid phases. Also notice in the solid phase
report that the saturation ratio is 1.77427, showing that the solution is supersaturated
with respect to ammonium sulphate (any value above 1.0 means supersaturation).
In aerosols, the very small amount of
solution in a droplet often does not contain a pre-existing solid phase, or if it does that
solid phase may not promote the formation of a new solid phase until substantial
supersaturations occur. This example demonstrates
E-AIM's ability to examine such supersaturations.
5.
The partitioning of a fixed amount of water (per m3 of atmosphere) between the
gas phase and an aqueous salt aerosol.
( show details)
Video 5: amounts of water in the gas and aerosol phases. In most atmospheric calculations, but
not necessarily in clouds, we can assume that the RH is fixed and independent of the
aerosol water content. This is reasonable because the amount of water in the gas phase is
large compared to that in the particle phase. This example illustrates water partitioning
between the gas and particle phases:
On the E-AIM home page, click the Model II link.
Click the Comprehensive link.
Click the Constant total water link and enter the amount of water as 1.183 moles.
Enter 15.14E-9 for the moles per m3 of NH4+ and
7.57E-9 for SO42−.
Click the Show Options radio button which then displays the option to
not calculate the equilibrium between NH4+ and NH3 (i.e.,
all ammonium is assumed to be present as NH4+ if the
box is checked). Click in the check box.
It is more realistic to include the NH4+ / NH3 equilibrium, especially in
basic (pH > 7) solutions. We turned this off for this example to simplify
interpretation of the results – it has an insignificant effect on the output.
Scroll down and click the Run button.
Result: in 1.0 m3 of air, there are 0.1379E-6 moles of water
in the aqueous phase
and 1.183 moles of water in the gas phase. This illustrates the point that
there is insignificant water in the particle phase compared to that
in the gas phase. Consequently, the RH can be assumed constant for
gas to particle equilibration in atmospheric systems containing typical
amounts of soluble components ((NH4)2SO4 in this example).
6.
A calculation for an H+ –
NH4+ –
SO42− –
NO3− –
H2O system, for which there
is an aqueous phase, gases, and a solid present at equilibrium.
( show details)
Video 6: a more complex system at fixed RH. In this example,
we will illustrate what you can find in the E-AIM output for an
acid ammonium sulfate - nitrate system.
On the E-AIM home page, click the Model II link.
Click the Comprehensive link.
Enter an RH of 0.65.
Enter 0.2
for H+,
3.0 for NH4+,
1.1 for SO42−,
and 1.0 for NO3−.
Scroll down and click the Run button.
In the output you can see that there are entries under all three sections:
Aqueous Phase, Gases and Solids. At equilibrium, the system consists of
0.63225 moles of solid (NH4)2SO4,
3.6139E-6 moles of HNO3 gas,
1.3284E-8 moles of NH3 gas, and 2.7E-19 moles of H2SO4 gas, all in
equilibrium with an aqueous phase.
In the Solids section it can be seen that the system is about 77%
saturated with respect to the double salt 2NH4NO3·(NH4)2SO4
(and 100% saturated
with respect to (NH4)2SO4). In the Gases section the
actual partial pressures of
the gases (for the numbers of moles present) can be compared with the
same quantities further below which have been calculated from the thermodynamic
properties of the aqueous phase and the appropriate Henry's law constants.
The numbers should of course be the same, and the system tests for this.
III. Column and Graphical Output of Results, Using Deliquescence as an Example
These demonstrations show how to calculate the properties of chemical systems
over a range of relative humidities, and display the results in different ways.
7.
The uptake of water by NH4NO3
at a characteristic relative humidity to form a saturated solution, which becomes more dilute as
relative humidity is increased (the results are displayed in column format).
( show details)
Video 7: calculations for a range of RH, and "column" output. So far we have done single calculations, with only one set of input values, but frequently investigators want to see how the output changes as a function of one variable. We will use the "parametric" capabilities of E-AIM to illustrate this feature. Also, for parametric calculations it is more convenient to view the output in a table format. This example illustrates both features.
On the E-AIM home page, click the Model II link.
For Parametric (item 5), click on the relative humidity or total water link.
Press the Column radio button to select output in column format.
Enter a Start Value of 0.1, an
End Value of 0.9, and 17 for "No. of Points".
Enter 1.0 for NH4+,
and also 1.0 for NO3−.
Click the Show Options radio button which displays the option to
switch off the calculation of the equilibrium
between NH4+ and NH3.
Click on the check box (so that all ammonium remains as NH4+).
Scroll down and click the Run button.
The output will appear in the browser window in column format.
There are 17 rows, for humidities evenly spaced between 0.1 (10%)
and 0.9 (90%). The first report concerns the aqueous phase. Notice that
for RH less than 60%, there is no aqueous phase (i.e., Volume(aq) and
n_H2O(aq) are zero). Correspondingly, the particle phase contains 1
mole of the first solid (moles_s01) which is identified as NH4NO3 in
the last column.
Further down the page, the next set of columns shows additional
thermodynamic information including activity coefficients and partial
pressures. Still further down the page there is information about the
total composition, where it can be seen note that the total amount of water in the system
increases as the RH increases. Finally, at the bottom of the page are
more detailed descriptions of the contents of these tables.
8.
A further example of deliquescence, using (NH4)2SO4 (the results are shown as a graph).
( show details)
Video 8: plotting graphs.E-AIM output may also be viewed graphically. This example illustrates the feature in a calculation of the deliquescence behavior of ammonium sulfate.
On the E-AIM home page, click the Model II link.
Under Parametric (item 5), click on the
relative humidity or total water link.
Press the Graph radio button to set the output to graphical format.
For the range of RH enter a Start Value of 0.5,
an End Value of 0.95, and 50
for "No. of Points".
Next, enter 2.0 for NH4+,
and 1.0 for SO42−.
Click the Show Options radio button which displays the option to switch
off the calculation of the equilibrium between NH4+ and NH3.
Click on the check box (so that all ammonium remains as NH4+).
Scroll down and click the Run button.
At this point the E-AIM Graphics page is displayed. The controls are displayed down the
left hand side of the page. Graphs that you plot will be displayed in the grey area on the right.
As you can see from the drop-down boxes for X and Y variables, a variety of
different quantities can be plotted.
For X select relative humidity, and
for Y select moles of H2O(aq), then
click on Draw the Graph.
For RH less than 81% (or 0.81, as a fraction), the
particle is composed of solid ammonium sulfate with no water. At 82%,
the particle deliquesces, taking up water to form a solution, and then
continues to take up more water as the RH rises further. The graph was
not continued to 100% because the water content is theoretically infinite
at 100% RH (corresponding to an infinitely dilute solution containing 1.0
moles of (NH4)2SO4).
9.
Deliquescence in a more complex system, containing two salts, and showing both
the water content and amounts of the different solids present (the results are shown as graphs).
( show details)
Video 9: a graph of deliquescence. Let's use the graphical output feature to look at the
deliquescence behavior of a more complex system than that above.
On the E-AIM home page, click the Model II link.
Under Parametric (item 5), click the relative
humidity or total water link.
Press the Graph radio button to select output in graphical format.
Enter a Start Value of 0.5, an
End Value of 0.95, and 50
for "No. of Points".
Next, enter 3.0 for NH4+,
1.0 for SO42−, and 1.0
in the NO3− box.
Click the Show Options radio button which displays the option to switch off
the calculation of the equilibrium between NH4+ and NH3. Click
the check box (so that all ammonium remains as NH4+).
Scroll down and click the Run button.
You are now on the E-AIM Graphics page. You can plot
a range of variables against each other on the X and Y axes.
Select relative humidity
for X, and moles of H2O(aq)
for Y, and then click Draw the Graph.
Notice on the graph a deliquescence point at about 67% RH (or 0.67, as a
fraction), and an inflection at about 75% RH. What causes this behaviour?.
To find out:
Select relative humidity for X,
and moles of (NH4)2SO4 for Y, and
then click Draw the Graph.
For RH below 67%, the particle contains 0.5 moles of
ammonium sulfate (the rest is an ammonium nitrate-sulphate
double salt, as we'll see in a moment). Between RHs of 67%
and 74% the amount of ammonium sulfate solid first grows to
0.8 moles then drops to nothing as the solid phase completely dissolves.
To learn more about this behaviour:
Select relative humidity for X,
and moles of 2NH4NO3·(NH4)2SO4 for Y, and
then click Draw the Graph.
For RH below 67%, the particle contains 0.5 moles of the
2:1 ammonium nitrate-ammonium sulphate double salt, in addition to ammonium sulphate. Above 67% RH, the
double salt is no longer a stable solid so it dissolves, and much
of the ammonium sulfate formerly in the double salt becomes solid
(NH4)2SO4 (thus increasing the amount present,
as seen above) AS RH rises, the remaining ammonium sulfate and the ammonium
nitrate dissolve into the aqueous phase.
10.
The properties of aqueous (NH4)2SO4 at low relative humidities,
for which the solution is supersaturated with respect to the solid salt (the results are shown as a graph).
( show details)
Video 10: graphs of deliquescence and supersaturated solutions. In video 8, we used the
graphical output feature of E-AIM to show the deliquescence behavior of ammonium sulfate.
In this example, we show a similar example but this time (as in Video 4), we will also show supersaturation.
On the E-AIM home page, click the Model II link.
Under Parametric (item 5), click on the relative humidity or total water link.
Press the Graph radio button to select output in graphical format.
Enter a Start Value of 0.2, an End
Value of 0.9, and 50
for "No. of Points".
Next, enter 2.0 for NH4+,
and 1.0 for SO42−.
Click the Show Options radio button which
displays the option to switch off the calculation of the equilibrium between
NH4+ and NH3. Click on the check box (so that
all ammonium remains as NH4+).
In the Solid Phases section, click the check box for (NH4)2SO4
so that the solid is prevented from forming in the system.
Scroll down and click the Run button.
At this point you can plot a range of variables against each other on the X and Y axes.
For X select relative humidity and
for Y select moles of H2O(aq), and then click on
Draw the Graph.
Notice on the graph that there is no sharp deliquescence since the solid
phase of ammonium sulfate was prohibited from forming. Instead, at RH
below the 82% deliquescence point there is a smooth decrease in
particle water content at RH falls.
IV. Selecting and Creating Organic Compounds
These videos show how to: (i) select an organic compound to include in a calculation;
(ii) view and change its thermodynamic properties, and (iii) create new organic
compounds and define their properties. These demonstrations should be viewed in the
order they are listed.
11.
Select an organic compound from the pre-defined public list, and
calculate the properties of a system containing both organic and inorganic compounds
((NH4)2SO4 and malonic acid).
( show details)
Video 11: selecting and using an organic compound.E-AIM has a number
of capabilities for modeling the thermodynamics of organic compounds in particles in
addition to the inorganic electrolytes already covered in prior examples.
E-AIM assumes that the particle can be composed of:
a liquid aqueous phase that may dissolve inorganic
electrolytes and water soluble organic compounds,
multiple solid phases of solid inorganic electrolyte
crystals, and
one organic phase (containing hydrophobic organic compounds, but no water or inorganic compounds).
In this example, we illustrate some of the capabilities of E-AIM
for modeling the organic compounds, water soluble or not, in particles.
On the E-AIM home page, click the Model II link.
Click the Manage Compounds link.
Click on the down arrow at the right of the select box in section 2 of
the page to see the list of organic compounds currently in the E-AIM
library. The (public) designation indicates that this compound is in the
public library, and accessible to all. (You can also create compounds in
the library that are private or share them with others.)
Select (public) Malonic acid (UNIFAC) and click
the Add to system button. This adds the UNIFAC
model of malonic acid that is in the public library to the set
of E-AIM compounds (both inorganic and organic) that are
being modeled. Notice that a box now appears between sections 2 and 3
listing malonic acid and its ions. In this Malonic acid section,
roll over the HELP on the right to learn more about the links.
Click on Return to Calculation in section 3 to return to
the Model II data entry page.
Enter an RH of 0.8.
Under Inorganic Composition, enter 2.0 for
NH4+ and 1.0 for
SO42−.
Notice that this page now includes "Malonic acid (UNIFAC)" in the
list of chemical components. Enter 1.0 (moles) for the amount of malonic acid.
Scroll down and click on the Peng et al. radio
button to select that UNIFAC parameter set. To read more about the differences
between parameter sets, roll over the HELP button. Notice that Malonic acid also
appears in the list of solid phases.
Click the Run button.
The output includes malonic acid and the bimalonate and malonate anions in the aqueous phase,
its equilibrium vapor pressure in the gas phase, and the calculated saturation ratio with respect to
the solid acid. The solution is subsaturated with respect to both the solid acid and to solid ammonium
sulphate.
12.
View and change the thermodynamic properties of an organic compound, and save
the results so they can be used in a calculation.
( show details)
Video 12: changing the properties of an organic compound. This video is
a continuation of Video 11, so run Video 11 first before starting this one.
In Video 11, we added malonic acid and its ions to the list of compounds that
E-AIM models and ran a sample calculation. Here, we modify the characteristics
of malonic acid to explore how that changes thermodynamic behaviour.
From the end of the Video 11 example, use the back button of the
browser to return to the Model II data entry page
and click on the Manage Compounds link. You should see a
box between sections 2 and 3 that lists malonic acid.
Click on View/Edit.
The organic data page has ten sections. Roll over the
HELP box on the right side of section 5 to
learn more about the options for this section. Section 5 lets you select
which liquid phases the malonic acid can reside in: aqueous only,
hydrophobic only, or both (which is the default).
Below section 5 are unnumbered boxes with options pertaining
to the activity model employed. Roll over the HELP link on the right side
of the box just below section 5 to learn more about the option regarding
the choice of activity equation. Click this HELP link to obtain a
detailed description of what is going on inside E-AIM and what
the various options mean. Click the Back link on the help page (do NOT
use the browser back button) to return to the data page.
Scroll down to the unnumbered box just below section 8. Change the
liquid vapor pressure from 6.61E-9
to 6.61E-10,
to lower the vapor pressure by one order of magnitude.
Roll over the HELP link on the right
side of section 10. You can create your own organic compounds
or alter the properties of organic compounds, but these will generally only
last for the current session when you save them. If you would like
to save them permanently, you must first have logged in (creating a
username and password if necessary). Work that you save
permanently will be associated with your username so that, when you
return, the compounds and their properties are available for you
to continue using. You can also share these compounds with other
users. This help box and link summarizes these capabilities.
Finally, click Save the data to save
this modification to malonic acid. You will be given the option to overwrite
the vapor pressure value malonic acid in your current session, or to change
the compound name to indicate that it is different from the public version
of malonic acid in the library. Click Overwrite existing compound to
select the former.
The data for malonic acid that you have just saved will be used for all
new calculations in Models I–IV.
13.
Create a new organic compound, define its properties, and save the results
so that the compound can be used in a calculation.
( show details)
Video 13: creating a new organic compound. Now we will make a custom organic compound.
(This is a continuation of Videos 11 and 12 so they should be performed first.)
On the E-AIM home page, click the organic compounds
link (just below the one for Model IV).
Click the Create compound link.
In the Name box enter "test" and in
the Molar mass box enter 100.
Click Save the data at the bottom of the page.
A message in red
appears because we didn't complete the form. Scroll up to
see that there is also an error message in section 1 because we neglected
to specify a "Short name" for this compound. Enter "test" in
the Short name box too.
Scroll down and click Save the data again.
The Available Compounds page appears with malonic acid present from the previous
examples and the new compound, "test", from this example.
V. Calculations That Include Organic Compounds
Here we show example calculations for chemical systems that include an organic acid, an amine, and the
new organic compound created in the last video in section IV. Unless you
are familiar with E-AIM the demonstrations here should be
viewed after those above.
14.
A calculation for a chemical system containing (NH4)2SO4 and
the new organic compound (called "test") created in Video 13.
( show details)
Video 14: a calculation with the new organic compound. Now we will do
a calculation that employs the compound "test", and also malonic acid
with its pure liquid vapour pressure reduced by a factor of 10. (This is
a continuation of Videos 11-13, so they should be performed first.)
On the E-AIM home page, click the Model II link.
Click on the Comprehensive link.
Enter a relative humidity of 0.8.
Enter 2.0 for NH4+,
and 1.0 for SO42−.
Click the Show Options radio button which
displays the option to switch off the calculation of the equilibrium between
NH4+ and NH3. Click the check box (so that all
ammonium remains as NH4+).
Scroll down and enter a value of 1.0 for
the number of moles of the compound test. Do not
enter anything for malonic acid, so that its amount will be zero.
Scroll down and click the Run button.
The results page includes the test compound in the list of
species. One of the default properties for any new compound is that it is water soluble (and that it obeys
Raoult's law in a pure aqueous solution) so all of test
is in the aqueous phase.
15.
The creation of a hydrophobic compound (decane), the selection of an amine
from a library, and calculations for a system containing these compounds and
(NH4)2SO4. The result is a chemical system containing two liquid phases.
( show details)
Video 15: create an organic compound, and include an amine in the system. Here we
create an organic compound, select an amine from the library that is
provided, and then perform a calculation using inorganic electrolyte compounds,
the amine and the newly-created organic compound. (This is a continuation of
Videos 11 – 13, so they should be performed first.) At the end of Video 14, you
should be on the Available Compounds page, which is where we start.
Click on the Create compound link.
Enter Decane in the Name and
Short Name
boxes (section 1), in the Molar mass box (section 2)
enter 142.0, and in the Molar volume
box (section 3) enter 194.0.
In section 5, click on Hydrophobic phase only,
for Activity equation select UNIFAC, then enter
this UNIFAC group description for Decane: 2*CH3 8*CH2.
Finally click on Save the data.
We have now returned to the Available Compounds page. At the bottom
is a note describing how you can add a library of amine compounds to the
list of compounds to choose from. Copy the code 729efd
from the note, paste
it into the Library Code box, and click the button
Get library compounds.
Click the down arrow at the right of the select box in section 2 to
see the list of organic compounds currently in the E-AIM library. In
addition to the original list of organic acids, there is now also a list of
amines.
Select (729efd) Diethylamine from the list and
click on Add to system.
The list of compounds below section 2 should now include four compounds: malonic
acid, test, Decane and Diethylamine.
In the Diethylamine box, click on View/Edit and then scroll down to
two boxes below section 6. Click the nitrate
check box and enter an
Activity product in saturated solution value
of 14.65. This step lets
E-AIM know that we are permitting the reaction of the
diethylaminium ion with nitrate to form the diethylaminium nitrate salt,
which has an activity product of 14.65 mol2
kg−2 in a saturated aqueous
solution.
Scroll down and click on Save the data, and then
Overwrite existing compound on the page that appears, to make the
modified diethylamine – now with the ability to form a nitrate salt –
available in your session. Next, use these compounds to perform a
calculation. At this point you should be on the Available Compounds page.
Click on Model II at the top of the page.
For relative humidity enter 0.6.
For H+, NH4+,
SO42−,
NO3−, enter 0.1E-6,
1.9E-6, 0.75E-6,
and 0.5E-6, respectively.
Enter 1.0E-6 for the amount of compound "test".
Enter 1.0E-6 for the amount of Decane.
Enter 0.1E-6 for the amount of Diethylamine.
Scroll to the bottom of the page and notice that solids DEA
and DEA-nitrate are now included on the list. Click Run.
On the results page the Aqueous Phase section contains information
about the inorganic electrolytes in the modeled system, the
aminium cation DEA+, the neutral (uncharged) species "test", and DEA
(which is the undissociated amine).
We did not equilibrate species
between the gas and particle phases in this calculation so there
are no species present in the gas phase. However, the equilibrium vapor
pressures of the compounds, including DEA, above the aqueous phase are
reported. In the Solids section you can see that 3.77E-7 moles of solid
ammonium sulfate have formed. Saturation ratios, all less than unity, are
listed further below for the other possible solid phases.
VI. Website Help
This is a survey of the "help" pages on the website. They include the Quick Start
guide, and the page that contains explanations and notes on the thermodynamic properties
of organic compounds in the model (and also lists the UNIFAC parameter set).
Video 16: help on the website.E-AIM has a wide range of help facilities
to answer questions and assist you with using the various E-AIM tools. Here we briefly
review them:
On the E-AIM home page, click the Quick start link.
This page describes the E-AIM modelling platform and how to start
using it. In the top section there are links to four other useful pages.
The contents of the Quick Start page itself are listed below (5 items). These can be
clicked on to go directly to the topics.
Click on the model description link. The contents of
this page are listed near the top, and can be clicked on to go
directly to the topics in the same way as on the Quick Start page. In the first
section – on the chemical system treated by E-AIM –
scroll down to the figure which illustrates the various equilibria modelled
by E-AIM.
Use the browser back button to return to the Quick Start page and
click on the help page link to view
the "Thermodynamic Properties of Organic Compounds" page. This is a
complete description of the properties of organic compounds within
E-AIM, how to work with organic compounds, and especially
what information E-AIM needs for new organic compounds. As
with the previous help pages, this one also has a contents list with links
that can be clicked on to jump to the relevant part of the page.
For example, click on item 6e to learn
more about the equilibria associated with amine salts.
For a second example, return to the top of the page, and then
click on item 12 to see a description of the two
UNIFAC parameter sets available in E-AIM: standard and that due to Peng et al.(2001).
Scroll down to Table 1 which shows all the structural groups that
UNIFAC employs to estimate activity.
Hit the Back button of the browser twice to return to the
Quick Start page.