Archive for July 2012

Reconnecting with Ton Ellermeijer at WCPE

July 30th, 2012 by Bob Tinker

I recently attended the modestly named World Conference on Physics Education in Istanbul. One of the highlights of the meeting was connecting with my old friend Ton Ellermeijer and meeting his colleague, André Heck.

Some of the most innovative developments in educational technology have been made during the last 25 years at the AMSTEL Institute at the University of Amsterdam, The Netherlands, under the direction of Ton Ellermeijer. At this university, Ph.D. students in physics and other sciences could specialize in education at the Institute, which was on a par with more traditional areas of physics research. Sadly, a new dean eliminated AMSTEL in 2010. Ton soldiers on from a nonprofit he founded in 1987 (Foundation CMA), but with a reduced staff.

AMSTEL developed extensive probeware for real-time data acquisition, as well as several generations of COACH, software for analyzing these data, modeling, control, video data capture and animations. This technology has been integrated into STEM instruction using well-designed and tested materials. One area in which they have done particularly interesting work is sports physics using video analysis. Widely used in Europe, this material is unknown in the U.S., which is a great loss.

André Heck worked with Ton for a decade and published nearly 60 scholarly articles on various aspects of this research. This wealth of material has recently been collected in André’s Ph.D. thesis.The print version of the thesis comes with a CD ROM that includes all these articles as well as considerable student materials.

 

Thermostats in Energy2D

July 27th, 2012 by Charles Xie
A thermostat is a controller that maintains a system's temperature near a fixed point. The simplest thermostat does this by switching a heater or AC on and off to maintain the desired temperature (known as the bang-bang control). I spent a couple of days adding thermostats to Energy2D and developing a simple GUI for setting up thermostats.

In Energy2D, a thermostat is a connection between a power source and a thermometer. A thermometer can be linked to any number of power sources, but a power resource can only be linked to one thermometer. In the property window of a thermometer, the user can select the power sources it will control.

This Energy2D model demonstrates how a thermostat works. Turn on the temperature graph. Let the simulation run for a few cycles and then turn on the sunlight. Compare the behavior of the temperature graph. You can also try to move the temperature sensor around to examine how the on/off time of the thermostat depends on its location.

You should discover from this simulation that, when the sun shines on the house, it ends up using less energy to maintain the inside temperature because the time that the heater is on is shorter (see the differences of the two graphs in the first two images of this post). You should also find out why we should not put the sensor of a thermostat near a window.

The third image shows multiple thermostats at work to create different heating zones. This Energy2D simulation has four heaters in three rooms, each of which is controlled by a thermostat. 

From these demos of thermostats in Energy2D, you can see the richness of the software. I will add more useful features like this to make Energy2D even better. Stay tuned!

Two Interactive Features Added to Energy2D

July 23rd, 2012 by Charles Xie
Energy2D is our signature software for heat transfer and fluid dynamics simulations. Written in Java, it runs speedily either as a standalone app on your desktop or an embedded applet within a browser. It is actively being developed to meet the need of energy education to have an interactive and constructive learning environment based on rigorous scientific principles. Energy2D is already a highly interactive system--you can change anything that is allowed to change by the author of a simulation while it is running. Recently, I have added two new features to make it even more interactive. Both features apply to all existing Energy2D simulations I (or you) have created.

The first one is a "heat dropper," a mode in which the user can click or drag the mouse to add or remove heat from the location in the model that the mouse points to. If you have a touch screen, you can touch or swipe your finger across it and the heat dropper works as if your finger could give heat to the virtual space in the simulation. The first video in this blog post shows how it works.

The second one is a "field reader," a mode in which the user can move the mouse to read the value of a property distribution field at the location the mouse points to. Currently, the supported property fields include temperature, thermal energy, and fluid velocity (which will be zero in a solid). The second video shows how it works.

If a web page that embeds an Energy2D applet doesn't already have a drop-down menu on the page for you to switch to these modes, you can always access them through the View Options dialog window. The View Options menu can be found if you right-click on a spot in the simulation window that is not occupied by a model component (like a polygon or a sensor).

Molecular Workbench used at University of Ottawa Medical School to teach molecular simulations

July 18th, 2012 by Charles Xie
The Molecular Workbench software has been widely used in middle and high schools. It is relatively unknown that many colleges and universities around the world use it in their classrooms as well.

Recently, the software was used in the Summer School in the Systems Biology of Neurodegenerative Disease offered by the Ottawa Institute of Systems Biology. Students in this Summer School learned about the basics of molecular dynamics simulations using tools including our "intuitive" Molecular Workbench. They then applied their new knowledge to either model and simulate bilayer membranes made of various lipid species or strictly model a lipid using three different approaches.

For the Molecular Workbench, we have developed a set of unique simulation techniques that can render a dynamic cartoon view of biomolecular processes that are usually too complicated to show all the fine details (see the images to the right for a cartoonized simulation of micelle formation in water and oil, respectively). This capability turns what used to be static illustrations in a biology textbook dynamic and interactive and provide opportunities of exploration to students. This is the key why the coarse-grain modeling techniques developed for MW based on soft body dynamics and particle dynamics looks so promising for the current wave of digitization of chemistry and biology textbooks.

Flexible textbooks

July 6th, 2012 by Dan Barstow

We’re in the midst of a remarkable transition in education – a change that will give teachers more flexibility in the resources they use in their classroom.

The growing role of digital textbooks is gaining momentum. Major publishers are not just converting their textbooks to digital format, they’re also reconceptualizing them, adding a more diverse array of embedded interactives and providing states and districts with the option to pick and choose sections to meet local educational goals.

Think about this for a moment.

We are used to the monolithic textbook package – a basal textbook, lab manuals, CDs and other ancillaries. Each major publisher offers its package. States and districts decide which publisher’s package to purchase. End of story.

But that world is changing. A district might choose several chapters from one publisher and other chapters from a second publisher. From a third publisher, they might select a lab manual that is especially engaging for their students. And they might select multiple online resources to extend student learning.

From the teacher’s perspective, this is potentially liberating. Instead of working through the standard textbook and its aligned support materials, teachers have a richer set of options. They can select resources based on personal expertise, knowledge of their students, teaching style and familiarity with the growing array of digital interactives.

How does Molecular Workbench fit in? MW helps students understand fundamental principles of physics, chemistry and biology, yet it hasn’t always been clear how to fit this into the classroom, as it might seem a diversion from the flow of the textbook.

With a more flexible approach to teaching and learning, science teachers will be able to easily integrate the power of atomic and molecular simulations into their classrooms. This will not be an aberration, but the new norm.

This change will take a few years to fully play out, but it is a welcome transition away from the dominance of the standard, one-size-fits-all textbook and towards freedom to use a robust set of resources – including Molecular Workbench.

A simple IR experiment to prove that the North Carolina Sea Level Rise Bill is just flat wrong

July 5th, 2012 by Charles Xie
Last month, North Carolina's Senate passed a bill that would have required the state's Coastal Resources Commission to base predictions of future sea level rise along the state's coast on a steady, linear rate of increase. This has sparked controversies across the nation amid the record heat waves in many states.

If the lawmakers had done our very simple IR experiment on visualizing thermohaline in a cup, published in the July issue of last year's Journal of Chemical Education (see the image to the left), they would have had a better understanding about the possibility of the nonlinear acceleration of ice shelf melting: The less salty the seawater is, the faster the ice shelf above it melts. And the faster ice melts, the less salty the seawater will become. This creates a positive feedback loop that accelerates the melting process. If the speed of ice melting in systems as simple as a cup of saltwater is not as nice as the "steady, linear" rate some of the lawmakers would like to see, who can be sure that systems as complex as the Earth would follow a "steady, linear" trajectory of change?

If you bother to read on, this experiment uses just a cup of tap water, a cup of salt water, and some ice cubes. The two cups are placed next to each other on a table for comparison. (a) An IR image right after an ice cube was added to a cup of freshwater (left) and a cup of saltwater (right). (b) An IR image taken after four minutes showing a downwelling column in the freshwater. (c) An IR image taken after nine minutes showing the tabletop was cooled significantly near the freshwater cup. (d) An IR image taken after 16 minutes showing that the bottom of the freshwater cup became cooler than the top whereas the bottom of the saltwater cup remained warmer than the top.

To see the entire process caught under an IR camera, you can watch the embedded YouTube videos in this blog post. Feel free to send these videos to your representatives if you happen to live in the coastal area of North Carolina. Or send to a science teacher in North Carolina in the hope that the bill will be revised in the future to consider the possibility of nonlinear acceleration.

Note that these videos do not represent any political view and should not be considered as in support of any agenda, my purpose is only to provide a humble scientific demonstration to prove that things do not always go smoothly as we wish.

Investigating thermoimaging in augmented multisensory learning about heat transfer

July 2nd, 2012 by Charles Xie
Jesper Haglund from Linköping University presents a poster about our Sweden-US collaborative research on thermal visualization at the 2012 World Conference on Physics Education held in Istanbul, Turkey. Below is the abstract of the poster:

"Infrared (IR) thermal imaging is a powerful technology which holds the pedagogical potential of ‘making the invisible visible’, and is becoming increasingly affordable for use in educational contexts. Science education research has identified many challenges and misconceptions related to students’ learning of thermodynamics, including disambiguation of temperature and heat, and a common belief that our sense of touch is an infallible thermometer. The purpose of the present study was to explore how thermal imaging technology might influence students’ conceptual understanding of heat and temperature. This was carried out by investigating three different conditions with respect to students exploration of the thermal phenomena of different objects (e.g. wood, metal and wool), namely the effect of students’ use of real-time imaging generated from a FLIR i3 IR camera, students’ interpretation of static IR images, and students’ deployment of traditional thermometer apparatus. Eight 7th-grade students (12-13 years old) worked in pairs across the three experimental conditions, and were asked to predict, observe and explain (POE) the temperature of a sheet-metal knife and a piece of wood before, during and after placing them in contact with their thumbs. The participants had not been exposed to any formal teaching of thermodynamics and the ambition was to establish if they could discover and conceptualise the thermal interaction between their thumbs and the objects in terms of heat flow with minimal guidance from the researchers. The main finding was that a cognitive conflict was induced in all three conditions, as to the anomaly between perceived ‘hotness’ and measured temperature, with a particular emotional undertone in the real-time IR condition. However, none of the participants conceptualised the situation in terms of a heat flow. From the perspective of establishing a baseline of the understanding of thermal phenomena prior to teaching, extensive quantities, e.g. ‘heat’ or ‘energy’, were largely missing in the participants’ communication. In conclusion, although an unguided discovery or inquiry-based approach induced a cognitive conflict, it was not sufficient for adjusting the students’ conceptual ecologies with respect to the age group studied here. Future research will exploit the promise of the cognitive conflict observed in this study by developing a more guided approach to teaching thermal phenomena that also takes full advantage of the enhanced vision offered by the thermal camera technology."

If you happen to be at WCPE 2012, drop by his poster: Session - 1.04, Date & Time: 7/3/2012 / 13:00 - 14:00, Room: D406 (3rd Floor).

If you don't know what thermal visualization is, visit our InfraredTube website.