Monthly Archives: September 2015

The National Science Foundation awards grant to study virtual worlds that afford knowledge integration

The Concord Consortium is proud to announce a new project funded by the National Science Foundation, “Towards virtual worlds that afford knowledge integration across project challenges and disciplines.” Principal Investigator Janet Kolodner and Co-PI Amy Pallant will explore how the design of project challenges and the contexts in which they are carried out can support knowledge integration, sustained engagement, and excitement. The goal is to learn how to foster knowledge integration across disciplines when learners encounter and revisit phenomena and processes across several challenges.

Aerial Geography and Air QualityIn this model, students explore the effect of wind direction and geography on air quality as they place up to four smokestacks in the model.

We envision an educational system where learners regularly engage in project-based education within and across disciplines, and in and out of school. We believe that, with such an educational approach, making connections across learning experiences should be possible in new and unexplored ways. If challenges are framed appropriately and their associated figured worlds (real and virtual) and scaffolding are designed to afford it, such education can help learners integrate the content and practices they are learning across projects and across disciplines. “Towards virtual worlds” will help move us towards this vision.

This one-year exploratory project focuses on the possibilities for knowledge integration when middle schoolers who have achieved water ecosystems challenges later attempt an air quality challenge. Some students will engage with EcoMUVE, where learners try to understand why the fish in a pond are dying, and others will engage with Living Together from Project-Based Inquiry Science (PBIS), where learners advise about regulations that should be put in place before a new industry is allowed to move into a town. A subset of these students will then encounter specially crafted air quality challenges based on High-Adventure Science activities and models. These, we hope, will evoke reminders of experiences during their water ecosystem work. We will examine what learners are reminded of, the richness of their memories, and the appeal for learners of applying what they are learning about air quality to better address the earlier water ecology challenge. Research will be carried out in Boston area schools.

Sideview Pollution Control Devices In this model, students explore the effects of installing pollution control devices, such as scrubbers and catalytic converters, on power plants and cars. Students monitor the level of primary pollutants (brown line) and secondary pollutants (orange line) in the model over time, via the graph.

The project will investigate:

  1. What conditions give rise to intense and sustained emotional engagement?
  2. What is remembered by learners when they have (enthusiastically) engaged with a challenge in a virtual figured world and reflected on it in ways appropriate to learning, and what seems to affect what is remembered?
  3. How does a challenge and/or virtual world need to be configured so that learners notice—while not being overwhelmed by—phenomena not central to the challenge but still important to making connections with content outside the challenge content?

Our exploration will help us understand more about the actual elements in the experiences of learners that lead to different emotional responses and the impacts of such responses on their memory making and desires.

Lessons we learn about conditions under which learners form rich memories and want to go back and improve their earlier solutions to challenges will form some of the foundations informing how to design virtual worlds and project challenges with affordances for supporting knowledge integration across projects and disciplines. Exemplar virtual worlds and associated project challenges will inform design principles for the design and use of a new virtual world genre — one with characteristics that anticipate cross-project and cross-discipline knowledge integration and ready learners for future connection making and knowledge deepening.

Simulating the Hadley Cell using Energy2D

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Although it is mostly used as an engineering tool, our Energy2D software can also be used to create simple Earth science simulations. This blog post shows some interesting results about the Hadley Cell.

The Hadley Cell is an atmospheric circulation that transports energy and moisture from the equator to higher latitudes in the northern and southern hemispheres. This circulation is intimately related to the trade winds, hurricanes, and the jet streams.

As a simple way to simulate zones of ocean that have different temperatures due to differences in solar heating, I added an array of constant-temperature objects at the bottom of the simulation window. The temperature gradually decreases from 30 °C in the middle to 15 °C at the edges. A rectangle, set to be at a constant temperature of -20 °C, is used to mimic the high, chilly part of the atmosphere. The viscosity of air is deliberately set to much higher than reality to suppress the wild fluctuations for a somehow averaged effect. The results show a stable flow pattern that looks like a cross section of the Hadley Cell, as is shown in the first image of this post.

When I increased the buoyant force of the air, an oscillatory pattern was produced. The system swings between two states shown in the second and third images, indicating a periodic reinforcement of hot rising air from the adjacent areas to the center (which is supposed to represent the equator).

Of course, I can't guarantee that the results produced by Energy2D are what happen in nature. Geophysical modeling is an extremely complicated business with numerous factors that are not considered in this simple model. Yet, Energy2D shows something interesting: the fluctuations of wind speeds seem to suggest that, even without considering the seasonal changes, this nonlinear model already exhibits some kind of periodicity. We know that it is all kinds of periodicity in Mother Nature that help to sustain life on the Earth.

Simulating geometric thermal bridges using Energy2D

Fig. 1: IR image of a wall junction (inside) by Stefan Mayer
One of the mysterious things that causes people to scratch their heads when they see an infrared picture of a room is that the junctions such as edges and corners formed by two exterior walls (or floors and roofs) often appear to be colder in the winter than other parts of the walls, as is shown in Figure 1. This is, I hear you saying, caused by an air gap between two walls. But not that simple! While a leaking gap can certainly do it, the effect is there even without a gap. Better insulation only makes the junctions less cold.

Fig. 2: An Energy2D simulation of thermal bridge corners.
A typical explanation of this phenomenon is that, because the exterior surface of a junction (where the heat is lost to the outside) is greater than its interior surface (where the heat is gained from the inside), the junction ends up losing thermal energy in the winter more quickly than a straight part of the walls, causing it to be colder. The temperature difference is immediately revealed by a very sensitive IR camera. Such a junction is commonly called a geometric thermal bridge, which is different from material thermal bridge that is caused by the presence of a more conductive piece in a building assembly such as a steel stud in a wall or a concrete floor of a balcony.

Fig. 3: IR image of a wall junction (outside) by Stefan Mayer
But the actual heat transfer process is much more complicated and confusing. While a wall junction does create a difference in the surface areas of the interior and exterior of the wall, it also forms a thicker area through which the heat must flow through (the area is thicker because it is in a diagonal direction). The increased thickness should impede the heat flow, right?

Fig. 4: An Energy2D simulation of a L-shaped wall.
Unclear about the outcome of these competing factors, I made some Energy2D simulations to see if they can help me. Figure 2 shows the first one that uses a block of object remaining at 20 °C to mimic a warm room and the surrounding environment of 0 °C, with a four-side wall in-between. Temperature sensors are placed at corners, as well as the middle point of a wall. The results show that the corners are indeed colder than other parts of the walls in a stable state. (Note that this simulation only involves heat diffusion, but adding radiation heat transfer should yield similar results.)

What about more complex shapes like an L-shaped wall that has both convex and concave junctions? Figure 3 shows the IR image of such a wall junction, taken from the outside of a house. In this image, interestingly enough, the convex edge appears to be colder, but the concave edge appears to be warmer!

The Energy2D simulation (Figure 4) shows a similar pattern like the IR image (Figure 3). The simulation results show that the temperature sensor placed near the concave edge outside the L-shape room does register a higher temperature than other sensors.

Now, the interesting question is, does the room lose more energy through a concave junction or a convex one? If we look at the IR image of the interior taken inside the house (Figure 1), we would probably say that the convex junction loses more energy. But if we look at the IR image of the exterior taken outside the house (Figure 3), we would probably say that the concave junction loses more energy.

Which statement is correct? I will leave that to you. You can download the Energy2D simulations from this link, play with them, and see if they help you figure out the answer. These simulations also include simulations of the reverse cases in which heat flows from the outside into the room (the summer condition).