Our Environmental STEM classes launch, record and track weather balloons at least twice a year. Following are measurements and photos captured from the launch in February 2019.

• Max altitude: 84,449 feet, or 16 miles, just short of our record height (airplanes generally have a max altitude of 7.5 miles)
• Lowest temperature reached: -54.7 C, or -66.5 F
• Lowest pressure reached during flight: 0.019 atm (normal atmospheric pressure is around 1.00 atm)
• Lowest % oxygen measured: 0.345 (normal % oxygen at ground level is 21%)

Students investigated hydroelectric power and wind turbines as part of an energy unit. Since the majority of our electricity is produced with a turbine turning a generator, it made sense to start with generators. This gave the students a hands-on opportunity to investigate the relationships between electricity, magnetism, generators and motors.

Once the fundamentals of electromagnetism were understood, the students applied this knowledge to the construction of a simple hydroelectric generator, using water to turn the turbine, which in turn turned the generator, thus producing electricity. Current (amps) and potential (volts) were measured using Vernier probes and software, which allowed students to calculate the power output (Watts).

Lastly, students investigated the variables in wind turbine design, specifically how the number of blades, the pitch of the blades, the length of the blades, and wind speed effect power output. The students used this knowledge to compete against each other to design the wind turbine that would have the greatest power output. Once they had decided on an initial design, they would test it, evaluate the results, modify the design, and continue to test, evaluate, and modify until they were satisfied with their results.

SLUH’s Environmental STEM class learned firsthand on November 16, 2016 with waste oil from the school’s food service.

First the students filtered the waste oil to remove the "chunkles" (a term coined by the Searle Biodiesel Program at Loyola Chicago), essentially all the solid particles and gunk that remains in the oil after cooking. Then, they titrated the waste oil to determine the amount of free fatty acids in the oil. The free fatty acids are produced when the cooking process breaks down the triglycerides (oil). Free fatty acids would interfere with the catalyst used to produce the biodiesel and the amount of catalyst needs to be adjusted accordingly. The students then prepared the catalyst, added the waste oil, and shook the mixture for 10 minutes to carry out the reaction (in Mason jars). The mixture was then poured into a separatory funnel. The biodiesel rose to the top and the glycerin settled to the bottom. The glycerin was removed and can be used to make soap.

The students will also measure the density, viscosity, heat of combustion, and soot production of their biodiesel and compare those results to commercial diesel and biodiesel they prepared earlier using virgin vegetable oil.