Jan 6th- 101's- Weekly preeenations

Weekly group presentations-

Algae group-

Bioreactor- difficult to keep the algae in the tubes- may need syringe.

What components and materials will you need to get to build the bioreactor?

What have been the color changes in the algae? You need to log how much food you are giving them.

How will you verify how much light you are actually giving them?

Discussed issue of urea nitrogen vs. nitrate; nitrifying bacteria.

Plants Group-

Ben and Sarah and Joelle met with Principal Turner, who ok'd putting the plants in the window.

Next Project- Mycelium-

Will need an enclosed table space and a way of keeping the mycelium sterile- can utilize a glove bag.

Could use a pressure cooker to kill bacteria. Get advice from Tharun( senior).

Mycelium could be stored in science refrigerator when not in use.

Will make more planters for the window unit. May want to have plants with longer lifespans such as Basil.

Bikes Group-

Has build bikestand and LED lights. Still waiting for a motor- will try Craig's List(?) Freecycle(?). Also- Wireless Router?

Add pictures of the bikestand to the Wiki post- how did you build it.

Aquaponics Group-

Try to grow pea plants--some are collapsing under their own weight.

The ammonia levels are too high-

Overall objective- to successfully grow useful amounts of plants. 

What is the growing capacity of your system? What are you trying to grow? How much food would you need to grow to be useful for a homeless shelter?

What the the regulations for what kind of food they are allowed to accept- do they accept fresh produce? See for example:

http://www.pinestreetinn.org/site/assets/docs/Food%20Donation%20Criteria.pdf

Will it be useful for them?

Or come up with an alternative goal-

• Teach them how to set up their own system- this can be researched while growing your plants

See template and instructions.

When you're trying to figure something out, such as the ideal nutrient chemistry-

• You need to measure and quantify the change you make ( i.e., light, nutrients, temperature, etc) and the system's response-- don't add something w/o measuring the change it produced and recording it.

You should record the essence of your presentation( words and pictures) in the wiki, and use this when giving your presentation.

January 5th- 201's- Arrival of the Tilapia; Bike Shelter Model

The tilapia arrived, and were welcomed to their new home, except for Arduino, RIP

Meanwhile, the bike group modeled the bike shelter

January 4th- GRNG 101's- Updates

The 101's returned from X-mas break.

Dr. T-

You should now be well on your way with the 'Core 4' projects.

We will now have weekly presentations on what you have accomplished, and what you are planning to do.

Each group needs to post at least weekly to the wiki detailing your progress and plans, including pictures. You will be graded on your posts- no post, no credit. If there are two of you in a group, one can write the post.

If you are feeling unsure about what to do next, I will give you guidance on what you should investigate; but I will not tell you what to do.

ALGAE GROUP-

Came in to find the lights were not functioning. One light had been switched off, the other had a burned out bulb, which was replaced. The algae itself may have died over break, as indicated by the pale green color.

New algae is being ordered.

BIKE GROUP-

Bike group needs to begin doing wiki posts.

Tried out Neopixels; however, these need an Arduino to be driven.

Wired up the 12V LED strips, and cut them to a reasonable length. Added Stacon connectors to attach them to the battery.

Attached bicycle to stand with lights and tested- quite nice.

PLANTS GROUP-

Plants seemed to survive over break. Plants were watered. There is concern that using a pump would lead to unsightly wires.

AQUAPONICS GROUP-

Turned on air pump.


Discussion-

How do we get students to take initiative?

January 3rd- Xplorers- Wind Turbines

Back from Xmas break, the Xplorers continued working on their wind turbines, with mixed success:

Excellent workmanship and attention to detail. However, when tested with the fan, it failed to rotate, lacking sufficient power to overcome the friction in the motor. Needs much larger/longer blades, since power available from the wind is proportional to swept area.

This team constructed a full size version of their previous smaller unit,

which was conceptual only; it would not turn,  and which was not tested for functionality.

This larger version used  CD cases to catch the wind. It was not tested.  However, unit would likely catch the wind in both directions, so would not turn.

This turbine turned a little bit; however, the blades would not hold a fixed angle. The student did not appear to understand why the blade angle mattered.

 I suggested that the blades be taped to better hold the correct angle.

This group worked on their large rotor, attempting to construct a post to hold the system.

Another group had previous built this rotor using cup-shaped blades:

Although this previous version would not turn, they spent the period making metal versions of the cup-shaped blades for their final version:

In the new version(above), they have eliminated the bearing entirely, so that there is no possible way for the turbine blades to rotate.

I pointed out that the turbine system is really 3 different subsystems:

• The wind turbine blade system itself
• The motor and gearbox system
• the tower

Each of these contains very different technical issues, which has tended to lead each design team in several different directions at once.

To make this challenge more effective and achievable, one could:

• provide the tower and gearbox system to the students, and limit the design or
• assign different teams to different problems.

In this design challenge, students built various prototypes, which in most cases were not tested for functionality. Nor did the class hold a design reviews to get feedback.

In most school-based design challenges, students are provided with a standard menu of materials. In this case, there was no standardization; every design used very different materials.

For the turbine portion of the design, Kidwind( the most common windpower educational system), has students methodically determine the optimum blade angle, length, and number. This was not done in this case, so the students had no empirical basis for the design of their turbine.

For the motor and gearbox portion of the challenge, students had been given no introductory experiences assembling Lego gear systems. They did not appear to understand the difference between gearing up or gearing down, the trade-off between speed and torque, or the frictional effects of long gear trains. Students also seemed confused by the concept of bearings, as being devices which restrict motion to a single axis.

For the tower system, again, different groups used very different materials. No prototypes were constructed of the towers; the full-size tower was the only unit constructed. All towers were different heights; some used PVC pipe, others a cardboard tube,  another a hand-built cardboard box, another a wooden stick, another just held the motor in their hand.

Dec 23rd- Planning for Spring Term for Xplorers

Discussed plans for spring term of XPlorers-


Introductory Design Challenges
https://dschool.stanford.edu/groups/k12/wiki/332ff/Curriculum_Home_Page.html

Design Thinking

Design Process

• Projects Need regular Peer Review/critique

Plastics types/recycling/fleece

Upcycling

Composting

Making cloth items, etc.

Vision/Marketing

Logo Design-- the "What Next?"

Can we have a teaching model with distributed expertise-- problem design/prototyping/engineering/marketing?

Define skills we want students to have-
  Researching/independent learning
 critiques - positives/negatives, suggestions/connections

Dec 23rd- 101's- Wind turbines( continued)

Groups continued to assemble and test their designs.

The design below, by Sam, had 3 large blades based on the smaller prototype which had used helicopter blades. The blades did spin, but were not evenly balanced.

Below-- cup-shaped blades made from aluminum. Not clear whether the group had tested it.

Lego-based design had two sets of small blades. Not clear whether it has enough power to turn a motor.

Groups have focused almost entirely on fabrication, with very little actual testing of prototypes.

Are their rationale for design decisions grounded in reality?

Dec 23rd- 201's- electronics, wood planking, chain fixtures

Aquaponics group- attached 1x2's to the wall with expansion anchors.

Dis-assembled planking from pallets to make paneling. Oak was very difficult to cut. Will stain but will otherwise leave rough.

Speencer solder on right-angle connector onto LCD display. System should probably be re-designed once prototype design is finished.