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Variable Changes

By: Justin Tan

Photo Credit : Templeton Times

Photo Credit :

www.bestoninternet.com

Photo Credit :

Magic Microbes

Welcome everyone. My name is xxx. Today we are going to talk about Microbial Fuel Cell. But Microbial Fuel Cell sounds serious and rather boring.

{Click}

Lets call it a Mudwatt instead.

The slides provided in this presentation has been designed to give you the background and instruction necessary to engage in your own exploration of microbial fuel cells. Each slide builds upon the learning in the preceding activity and it is recommended that the slides be done sequentially.

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Notes for teachers:

The progression of slides provided in this presentation has been designed to give students the background and instruction necessary to engage in their own exploration of microbial fuel cells. Each slide builds upon the learning in the preceding activity and it is recommended that the slides be done sequentially.

Teacher’s Materials:

00 MudWatt MainModule

04 MudWatt Workshop Presentation

Student’s Materials:

04-S1 MudWatt Workshop Student Handout Background: One week before the presentation

04-A Mudwatt Workshop PreAssessment: At the start of the workshop

04-S2 Mudwatt Workshop Student Handout Instruction Guide: At the start of Activity 1

04-S3 Mudwatt Workshop Student Handout Activity 1: At the start of Activity 1

The reading material and lab activities help provide concrete learning opportunities for abstract concepts. Students with minimal background knowledge can perform these activities.

Sub-Module 1: Meet the Microbes

Sub-Module 2: Electricity and Circuits.

Sub-Module 3: Soil Ecology

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What is your Role?

Predictions

(Today)

When will the MudWatt LED begin blinking?

Day: ?

What will be the maximum LED blinking rate in 20 days?

No. of blinks per minute: ?

Data Collection

(Next 20 days)

Check each day if the LED is blinking

At the start of the day
At the end of the day

Record the value in a table

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Day	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
Blinks / Minute
Blinks / Minute

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Tell me what happened

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Team Results

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Team Name	Day LED started blinking	Maximum Blink Rate

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Experiment Parameters

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Team Name	Day	Rate	Soil Additive	Other Parameter	Other Parameter

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Experiment Ideas

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Activity

Procedure

Set up a control unit
Change only one variable in each of the other units
Everything else should be kept the same.
Follow the Scientific Method
Evaluate data for a cause and effect relationship

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In this investigation, you will manipulate variables to determine cause and effect between the variables with the goal of optimizing the amount of power output from the MudWatt™.

You would usually have at least 2 MudWatts™ to conduct an experiment using a control. You select one independent variable (of their own choosing) to change in one MudWatt™ while keeping the second MudWatt™ unchanged to serve as the control. You may also select the dependent variable to measure and record.

Use the Scientific Method to guide you in your investigations.

For Teachers:

In this lesson, students will:

• Gain familiarity with how MFCs respond to different conditions

• Conduct a controlled experiment while manipulating variables

• Make accurate observations and record data

• Use indirect evidence to make predictions

• Practice analyzing data results

• Evaluate data for a cause and effect relationship

Students may design your own investigations using Activity 2 or the Experiment Design Template, depending on their previous experience with experimental design.

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Design a new experiment with the MudWatt

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What can you change in the MudWatt?

List all possible ideas (e.g. different soil type, temperature of soil, …)
Choose one idea from the list
This will be your Independent Variable
The others are your Controlled Variables

What are all the parameters you could measure on the MudWatt?

List all possible ideas (e.g. when the LED blinks, rate of LED blinks, …)
Choose one idea from the list
This will be your Dependent Variable

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Design a new experiment with the MudWatt

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What can you change in the MudWatt?

List all possible ideas (e.g. different soil type, temperature of soil, …)
Choose one idea from the list
This will be your Independent Variable
The others are your Controlled Variables

What are all the parameters you could measure on the MudWatt?

List all possible ideas (e.g. when the LED blinks, rate of LED blinks, …)
Choose one idea from the list
This will be your Dependent Variable

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Examples of Experiments

Experiment A

Testable Question: Does the type of soil used impact how much power is produced?
Independent Variable: Soil Type, as varied by color, texture, depth, and/or smell
Dependent Variables: Voltage, Current, Power

Experiment B

Testable Question: How can multiple MudWatts be configured to increase the amount of Voltage or Current, or both, in order to power different things?
Independent Variable: The method of connecting multiple MudWatts together (in series vs parallel)
Dependent Variables: Voltage, Current, Power

Experiment C

Testable Question: Does the distance between electrodes affect the amount of power being produced?
Independent Variable: The distance between the electrodes (i.e. the amount of soil between them)
Dependent Variable: Power

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Design your own MFC

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Thank You!!

Justin Tan

Email: tanjustin121@gmail.com