diff --git a/caimira/apps/simulator.py b/caimira/apps/simulator.py
index 6f1fd789..1a0b55d0 100644
--- a/caimira/apps/simulator.py
+++ b/caimira/apps/simulator.py
@@ -10,15 +10,10 @@ import matplotlib.lines as mlines
 import matplotlib.patches as patches
 from .expert import collapsible, ipympl_canvas, WidgetGroup, CAIMIRAStateBuilder
 
-# ventilation=models.MultipleVentilation(
-#             ventilations=[
-#                 models.AirChange(active=models.PeriodicInterval(period=120, duration=120), air_exch=100),
-#             ],
-#     ),
 baseline_model = models.CO2ConcentrationModel(
     room=models.Room(volume=75, inside_temp=models.PiecewiseConstant((0., 24.), (293.15,))),
     ventilation=models.SlidingWindow(
-        active=models.PeriodicInterval(period=120, duration=15),
+        active=models.PeriodicInterval(period=120, duration=15, start=8.),
         outside_temp=models.PiecewiseConstant((0., 24.), (283.15,)),
         window_height=1.6, opening_length=0.6,
     ),
@@ -496,8 +491,8 @@ class ModelWidgets(View):
         toggle_window(window_w.value)
 
         number_of_windows= widgets.IntText(value= 1, min= 0, max= 5, step=1)
-        period = widgets.IntSlider(value=node.active.period, min=0, max=240)
-        interval = widgets.IntSlider(value=node.active.duration, min=0, max=240)
+        frequency = widgets.IntSlider(value=node.active.period, min=0, max=120)
+        duration = widgets.IntSlider(value=node.active.duration, min=0, max=frequency.value-1)
         opening_length = widgets.FloatSlider(value=node.opening_length, min=0, max=3, step=0.1)
         window_height = widgets.FloatSlider(value=node.window_height, min=0, max=3, step=0.1)
 
@@ -506,8 +501,9 @@ class ModelWidgets(View):
         
         def on_period_change(change):
             node.active.period = change['new']
+            duration.max = change['new'] - 1
 
-        def on_interval_change(change):
+        def on_duration_change(change):
             node.active.duration = change['new']
 
         def on_opening_length_change(change):
@@ -518,8 +514,8 @@ class ModelWidgets(View):
 
         # TODO: Link the state back to the widget, not just the other way around.
         number_of_windows.observe(on_value_change, names=['value'])
-        period.observe(on_period_change, names=['value'])
-        interval.observe(on_interval_change, names=['value'])
+        frequency.observe(on_period_change, names=['value'])
+        duration.observe(on_duration_change, names=['value'])
         opening_length.observe(on_opening_length_change, names=['value'])
         window_height.observe(on_window_height_change, names=['value'])
 
@@ -558,12 +554,12 @@ class ModelWidgets(View):
                     window_height,
                 ),
                 (
-                    widgets.Label('Interval between openings (minutes)', layout=auto_width),
-                    period,
+                    widgets.Label('Frequency (minutes)', layout=auto_width),
+                    frequency,
                 ),
                 (
-                    widgets.Label('Duration of opening (minutes)', layout=auto_width),
-                    interval,
+                    widgets.Label('Duration (minutes)', layout=auto_width),
+                    duration,
                 ),
                 (
                     widgets.Label('Outside temperature scheme', layout=auto_width),
diff --git a/caimira/apps/simulator/caimira.ipynb b/caimira/apps/simulator/caimira.ipynb
index 13501bfd..259328ac 100644
--- a/caimira/apps/simulator/caimira.ipynb
+++ b/caimira/apps/simulator/caimira.ipynb
@@ -1,25 +1,35 @@
 {
  "cells": [
+  {
+   "attachments": {},
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "<div style=\"text-align: center;\" align=\"center\" >\n",
+    "<img src=\"./files/static/images/header_image.png\" style=\"height:5em\"></img></div>\n",
+    "<p style=\"text-align: center;\">\n",
+    "Please see the <a href=\"https://caimira.web.cern.ch/\">CAiMIRA homepage</a> for details on the methodology, assumptions and limitations of CAiMIRA.</p>"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 1,
-   "metadata": {
-    "pycharm": {
-     "name": "#%%\n"
-    },
-    "scrolled": false
-   },
+   "metadata": {},
    "outputs": [
     {
-     "ename": "AttributeError",
-     "evalue": "module 'caimira.apps' has no attribute 'CO2Application'",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[0;31mAttributeError\u001b[0m                            Traceback (most recent call last)",
-      "Cell \u001b[0;32mIn[1], line 3\u001b[0m\n\u001b[1;32m      1\u001b[0m \u001b[39mimport\u001b[39;00m \u001b[39mcaimira\u001b[39;00m\u001b[39m.\u001b[39;00m\u001b[39mapps\u001b[39;00m\n\u001b[0;32m----> 3\u001b[0m app \u001b[39m=\u001b[39m caimira\u001b[39m.\u001b[39;49mapps\u001b[39m.\u001b[39;49mCO2Application()\n\u001b[1;32m      4\u001b[0m app\u001b[39m.\u001b[39mwidget\n",
-      "\u001b[0;31mAttributeError\u001b[0m: module 'caimira.apps' has no attribute 'CO2Application'"
-     ]
+     "data": {
+      "application/vnd.jupyter.widget-view+json": {
+       "model_id": "888611458e044cd3b7cda7dfcf1fdbe4",
+       "version_major": 2,
+       "version_minor": 0
+      },
+      "text/plain": [
+       "HBox(children=(Tab(children=(VBox(children=(VBox(children=(Button(button_style='success', description='Duplica…"
+      ]
+     },
+     "execution_count": 1,
+     "metadata": {},
+     "output_type": "execute_result"
     }
    ],
    "source": [
diff --git a/caimira/apps/simulator/static/images/header_image.png b/caimira/apps/simulator/static/images/header_image.png
new file mode 100644
index 00000000..5f2a2702
Binary files /dev/null and b/caimira/apps/simulator/static/images/header_image.png differ