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Judges’ Queries and Presenter’s Replies

  • February 23, 2015 | 05:44 p.m.

    Hello Linh and Desai, I’m interested in understanding how you measured productivity in your different algae samples grown under lights of different color. Did you measure weight gain? How did you do this? Did you have a control sample that was grown in the dark?

  • Icon for: Desai C

    Desai C

    Presenter
    February 27, 2015 | 07:54 p.m.

    Hello Ms. Leschine, were not able to measure weight gain because the growth was not enough to give us accurate measures of weight. Instead, we based the productivity solely on visual observations. Before measuring, we shook the cap containing water and algae so that the algae was spread distributed in the water, then we let the water evaporate and based our observations on the darkness of the green of the algae with darker greens representing more algae.

  • Icon for: Brian Drayton

    Brian Drayton

    Judge
    February 24, 2015 | 03:30 p.m.

    I especially enjoyed your poster, which laid out your thinking carefully. Algae are certainly an interesting target — and some kinds might even be edible after creating the biomass (have you tried any algae recipes?).

    Do you know what wavelengths of light are favored by your algae for photosynthesis?

  • Icon for: Desai C

    Desai C

    Presenter
    February 27, 2015 | 08:01 p.m.

    Thank you Mr. Drayton. Unfortunately we have not tried any algae recipes, although I will definitely look up a few now that you have mentioned it. As to what wavelengths of light are favored, we believe that blue light, which has shorter wavelengths are slightly favored over the longer wavelength red light. But neither light is capable of maximizing the efficiency of the photosynthetic pigments in the algae cells because there are highly specialized pigments that only absorb one wavelength. So in order to allow all pigments to be activated, helping the cell create more sugars, white light, which contains every wavelength should be used.

  • Icon for: Gillian Puttick

    Gillian Puttick

    Judge
    February 24, 2015 | 03:42 p.m.

    You poster was clear and concise, and you made a good case for why fossil fuels are not sustainable in the video. Can you speculate about the “carbon budget” of a biofuel system using algae – energy in to the system required to support algal growth and energy “saved” in chemical bonds in the algae? In other words, what factors would you need to consider were you to scale your system up to produce biofuel?

  • Icon for: Desai C

    Desai C

    Presenter
    February 27, 2015 | 08:38 p.m.

    Hello, Ms. Puttick. Carbon enters the system as carbon dioxide and leaves in the same form, so we believe that the net increase of carbon in the atmosphere would be either zero or very close to it. If the algae is grown in open air, there would be no carbon released in the production of algae. But in our case, white light requires energy, which means carbon production. But the energy required to produce light is very minimal, so we do not believe that it will upset the amount of energy saved from using biofuels. But if this project was to be scaled up, we would also need to factor in the energy required to run the facilities, pump carbon dioxide, and other processes. But according to the Oregon Department of Environmental Quality, it is estimated that the total impact of CO2 on global warming is reduced by almost 80% by using biodiesel. So even if huge facilities and large amounts of energy are used to produce great amounts of algae, it still should be enough that there would still be a net decrease in the emission of carbon dioxide.

  • Icon for: Sara Lacy

    Sara Lacy

    Judge
    February 26, 2015 | 10:23 a.m.

    Thanks for presenting this interesting project. I apologize for leaving a message so late in the process. Could you help me understand the difference between the flow of carbon and the flow of energy in this process? Where is the carbon in each step of the process? And, on the other hand, where is the energy?

  • Icon for: Desai C

    Desai C

    Presenter
    February 27, 2015 | 08:17 p.m.

    Thank you for your question. The carbon first enters the system when the algae absorbs it in the photosynthetic process, in which carbon dioxide, water, and light are used to make sugars for the plant. The plant then uses the sugar to produce energy to grow and make lipids, which will be used to make biofuel. Lipids are organic molecules that contain carbon and after treatment, can be used to power engines. The burning of this biofuel then releases energy and carbon into the atmosphere. So in a way, the flow of energy is tied to the flow of carbon. The carbon flows in as carbon dioxide, transitions to lipids for a while, and flows out as carbon dioxide. Chemical energy is created in the plant from cellular respiration and is released when the biofuel is burned and is turned into mechanical energy to power our engines.

  • Further posting is closed as the competition has ended.

Presentation Discussion

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    Anonymous

    Guest
    February 26, 2015 | 02:23 p.m.

    Nice job, Dry Ice Cubes! I have a couple question about your experiment — what other factors do you think could affect the algae growth besides light wavelengths? How different were the weights of the different treatments? If you repeated the experiment, do you think you would get the same results?

  • Icon for: Desai C

    Desai C

    Presenter
    February 27, 2015 | 08:59 p.m.

    Thank you for your questions. We believe that temperature may also have an effect. Besides that, the amount of carbon dioxide exposure and the amount of light all affect the growth. We were not able to measure the actual weight of the groups, but from our visual observations, it was determined that the white light group clearly had more growth, followed by blue light, followed by red light. If we repeated this experiment, I believe that we would get the same results because we believe that only white light, which contains all frequencies of light is able to maximize the photosynthetic productivity of algae by activating all of the photosynthetic pigments.

  • Further posting is closed as the competition has ended.

  1. Desai C
  2. Presenter’s INNOVATETOMITIGATE
  3. The Dry Ice Cubes
  1. Abigail D
  2. Presenter’s INNOVATETOMITIGATE
  3. The Dry Ice Cubes
  1. Linh H
  2. Presenter’s INNOVATETOMITIGATE
  3. The Dry Ice Cubes

Colored Lights and Algae to Generate Biofuels

Algae are currently one of the most important and promising sources of biofuel for the future. Compared to other agricultural products such as corn or soybeans, algae contain much higher lipid content and are more likely to produce a higher amount of biodiesel at a less expensive and more efficient rate. Algae’s growth and development depend on the photosynthetic process, which uses carbon dioxide, water, and light to produce energy. This experiment studies how different colored lights affect the growth of algae. One control group grows under regular sunlight, one group grows under red light, which has low frequency and long wavelength, and one group grows under blue light, which has high frequency and short wavelength. Each group is exposed to its respective light color for sixteen hours each day and growth is recorded. The light color group with the most growth is determined.