Friday, September 30, 2011

Swedish newspaper reported IR research with pupils

Swedish newspaper Norrköpings Tidningar reported today our international collaboration with Konrad Schönborn and Jesper Haglund at Linköping University on educational research that is aimed at uncovering the cognitive power of IR imaging for science education. If you don't understand Swedish, the title translates into “The heat camera can become important in school physics.” Jenny Sajjadi, a teacher in math and physics, was quoted as saying: “Physics is seen as an ‘old’ subject and this is a bit of new thinking that can increase the students’ interest. For me as a teacher, it is an entrance to deeper teaching.”

Modern handheld IR cameras deliver tremendous power equivalent to thousands of temperature sensors. This kind of Very Large Scale Integrated Sensing System (VLSISS, my coinage in parallel to VLSI circuits that have revolutionized computing) is about to change the landscape of scientific inquiry in the classroom. It opens up learning opportunities that have never been seen before. This US-Sweden collaboration will advance this agenda. As the first step, the collaborative project will provide some pivotal data for how augmented visualization (to the sense of touch) could be a good intervention to notoriously hardy misconceptions related to heat and temperature. See my earlier blog post about this.

Tuesday, September 27, 2011

An online gas lab simulation

Go to simulation.
You probably know the Ideal Gas Law well. An ideal gas is a hypothetical gas made of randomly moving particles that do not have a volume and do not interact with one another. Have your students ever asked questions such as "What about non-ideal gases? How good is the Ideal Gas Law for real gases?" I don't know about other people's experience, but I myself was intrigued by those questions when I learned the gas laws. Unfortunately, I couldn't go too deeply in trying to answer them because just thinking about the complexity of the motion and interaction quickly intimidated me.

Before computer simulation was widely accessible, you probably would have to pull out the Van der Waals Equation and pray that doing the math would do the trick.

Now, there is a good way to teach this. Using an online molecular dynamics simulation--made using the Molecular Workbench software, investigating non-ideal gases is a piece of cake. This simulation uses a pair of gas containers side by side and allows the user to explore how six variables affect the volume of  a gas: temperature, pressure, number of particles, particle mass, particle size, and particle attraction. It basically covers all the variables in the Van der Waals equation--without saying them explicitly. And there is a variable that is not included in the Van der Waals equation. The simulation reveals exactly why it is not there.

Saturday, September 24, 2011

An online simulation for studying states of matter

Go to the simulation
Have you wondered why some light elements form solids at room temperature whereas some heavy elements form liquids (e.g., mercury) or gases (e.g., radon) at room temperature? Many people tend to associate "heavy" with "solid." But that is not true.

Using an online 3D molecular dynamics simulation--made using the Molecular Workbench software, you can investigate if or how atomic mass, atomic size, interatomic attraction, and temperature affect the formation of a phase. This investigation allows for deeper exploration about what determines a phase.

Java is required to run this simulation in your browser as an applet.

Thursday, September 1, 2011

Designing solar hot air collectors

Engineering design is a lot of fun. The variety of engineering systems students can realistically design and build in classrooms is, however, limited by the constraints of time, resources, and student preparedness.

Currently, construction toys and computer programming are perhaps the most frequently adopted student projects for learning engineering design. These applications cover a number of domains such as robotics and software engineering. 

In our Engineering Energy Efficiency project, we have been working on adding a new option of engineering project that students and teachers can choose to learn and teach engineering.

This Green Building Kit we are developing needs only paper, cardstock, foam board, among other typical office supplies and widely available sensors. Yet, it will allow students to design, build, and test energy-efficient model houses with considerable green features.

An example I am working on is a hot air collector (HAC, also known as the Trombe wall). This is actually very easy to construct (hence a popular DIY project for those who are "green"-minded and handy). It is not difficult for students to add an HAC unit to the sun-facing wall of a model house.

In order for students to have fun with this design challenge, we need to show them that there are a variety of things that they can learn, emulate, test, and invent.

HAC units are usually installed to the part of the sun-facing wall that is not occupied by windows. Windows are necessary to a house because they let light in, but they generally lose more heat than an insulated wall. An insulated wall keeps the heat inside the house, but it does not do anything to collect the heat from the sun and give it to the house. The idea of hot air collector is to use the surface area of the wall that is exposed to the sun to collect some solar energy for warming up the house.

If you think about this engineering design task, it is really a problem about the optimal use of the sun-facing wall surface. So where should we put windows and HAC units and what is the best way of using them? The above images show a variety of designs. Click each image to enlarge it and see the details of each design.

The fourth design combines the benefits of windows and HAC units. It is basically a large HAC unit with the middle part replaced by a window. On the one hand, sunlight still can shine into the house through the two layers of glazing (we automatically have a double-pane window). On the other hand, as the HAC unit is tall, the convective heat exchange between the HAC unit and the room will be more significant. I haven't seen an HAC design like this, so this is my little "invention." Well, I am pretty sure some guy has thought of this before and there is probably a pending patent for this, but never mind about this, I am just demonstrating how an engineering design process in the classroom could be made more inventive.

Our next step is to make it possible for students to add these green architectural elements (HAC is just one of them) in one of our flagship products: Energy3D. Energy3D already has a powerful heliodon for solar design.