Cs382/Diffusion Experiment - Revision history

Brad: /* Results */ - equation update

2007-11-05T02:39:01Z

Results: - equation update

← Older revision		Revision as of 02:39, 5 November 2007
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	* Determine the dye's rate of diffusion for the two soil mediums in the simulator.		* Determine the dye's rate of diffusion for the two soil mediums in the simulator.
	** The rate of diffusion in this experiment is defined as the speed at which the dye at the edge of the plume travels from one time interval to another.		** The rate of diffusion in this experiment is defined as the speed at which the dye at the edge of the plume travels from one time interval to another.
	** <math>r(n)</math> = radius of plume at time interval <math>n</math> (radius = diameter / 2)		** <math>r(t)</math> = radius of plume at time interval <math>t</math> (radius = diameter / 2)
	** rate of diffusion = <math>(r(n2)-r(n1))/(n2-n1)</math>		** rate of diffusion = <math>(r(t2)-r(t1))/(t2-t1)</math>
	** Does the rate of diffusion change over time?		** Does the rate of diffusion change over time?
	** Does the rate of diffusion differ between sand and gravel?		** Does the rate of diffusion differ between sand and gravel?

Brad: /* Procedure */ fixed spacing

2007-11-05T02:21:27Z

Procedure: fixed spacing

← Older revision		Revision as of 02:21, 5 November 2007
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	# Fill the groundwater simulator with fresh water This yields the greatest contrast between the dye plume and surrounding clean water.		# Fill the groundwater simulator with fresh water This yields the greatest contrast between the dye plume and surrounding clean water.

	# Make sure the pump is off. If the pump was recently circulating water, make sure that the water table's level has had enough time to stabilize. This ensures that the dye's plume will only be affected by diffusion and not water movement.		# Make sure the pump is off. If the pump was recently circulating water, make sure that the water table's level has had enough time to stabilize. This ensures that the dye's plume will only be affected by diffusion and not water movement.
	# Fill the pipette at least halfway full with dye.		# Fill the pipette at least halfway full with dye.

Brad: link update

2007-11-05T02:20:24Z

link update

← Older revision		Revision as of 02:20, 5 November 2007
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	This is a detailed description of one experiment listed on the CS382 [~~http://wiki.cs.earlham.edu/index.php/~~Cs382 course page]		This is a detailed description of one experiment listed on the CS382 [[Cs382\|course page]]
	----		----
	== Goal ==		== Goal ==

Brad: /* Considerations for a Computer Based Simulation */

2007-11-05T02:10:01Z

Considerations for a Computer Based Simulation

← Older revision		Revision as of 02:10, 5 November 2007
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	* If NetLogo is your computational tool of choice, how does the diffuse function (patch based) compare to the results you observed?		* If NetLogo is your computational tool of choice, how does the diffuse function (patch based) compare to the results you observed?
			* Would it be better to simulate this with a cell or agent based simulation?
	* Would it be better to

Brad: /* Results */

2007-11-05T02:08:44Z

Results

← Older revision		Revision as of 02:08, 5 November 2007
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	* Determine the dye's rate of diffusion for the two soil mediums in the simulator.		* Determine the dye's rate of diffusion for the two soil mediums in the simulator.
	** The rate of diffusion in this experiment is defined as the speed at which the dye at the edge of the plume travels from one time interval to another.		** The rate of diffusion in this experiment is defined as the speed at which the dye at the edge of the plume travels from one time interval to another.
	** <math>d(n)</math> = ~~diameter~~ of plume at time interval <math>n</math>		** <math>r(n)</math> = radius of plume at time interval <math>n</math> (radius = diameter / 2)
	** rate of ~~plume growth~~ = <math>(d(n2)-d(n1))/(n2-n1)</math>		** rate of diffusion = <math>(r(n2)-r(n1))/(n2-n1)</math>
	** Does the rate of diffusion change over time?		** Does the rate of diffusion change over time?
	** Does the rate of diffusion differ in sand and gravel?		** Does the rate of diffusion differ between sand and gravel?
	* Do the properties of the plume change over time?		* Do the properties of the plume change over time?
	** Is the dye concentration consistent throughout the plume? Is there less of a concentration at the edges or center?		** Is the dye concentration consistent throughout the plume? Is there less of a concentration at the edges or center?
	** Does the plume's overall shape change over time?		** Does the plume's overall shape change over time?
	** Is there a difference in plume behavior in sand and gravel?		** Is there a difference in the plume's behavior in sand and gravel?

	== Considerations for a Computer Based Simulation ==		== Considerations for a Computer Based Simulation ==

Brad: /* Procedure */

2007-11-05T02:04:28Z

Procedure

← Older revision		Revision as of 02:04, 5 November 2007
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	== Goal ==		== Goal ==

	The goal of this experiment is to ~~determine~~ the ~~rate of~~ diffusion of dye in the groundwater simulator and ~~to observe~~ the ~~form taken by~~ the dye ~~as it~~ travels through ~~the~~ sand or gravel.		The goal of this experiment is to observe the diffusion of a dye plume in the groundwater simulator and note the plume's properties as it the dye travels through sand or gravel. The data gathered here will be used to verify a computer simulation of dye diffusion.

	== Equipment ==		== Equipment ==
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	# Make sure the pump is off. If the pump was recently circulating water, make sure that the water table's level has had enough time to stabilize. This ensures that the dye's plume will only be affected by diffusion and not water movement.		# Make sure the pump is off. If the pump was recently circulating water, make sure that the water table's level has had enough time to stabilize. This ensures that the dye's plume will only be affected by diffusion and not water movement.

	# Fill the pipette at least halfway full with dye.		# Fill the pipette at least halfway full with dye.

	# Insert the pipette completely into well number 3 (sand).		# Insert the pipette completely into well number 3 (sand).

	# Inject enough dye into the well to create a quarter sized plume.		# Inject enough dye into the well to create a quarter sized plume.

	# Keep the pipette's bulb depressed until after it is removed from the well to avoid creating a vacuum and sucking dye from the plume back into the well. A little of this may occur as the water level in the well rises to fill the space formerly occupied by the pipette's barrel.		# Keep the pipette's bulb depressed until after it is removed from the well to avoid creating a vacuum and sucking dye from the plume back into the well. A little of this may occur as the water level in the well rises to fill the space formerly occupied by the pipette's barrel.

	# Measure the plume's diameter in the horizontal plane and start the timer. Describe the properties of the plume (shape, distribution of dye concentration, etc.)		# Measure the plume's diameter in the horizontal plane and start the timer. Describe the properties of the plume (shape, distribution of dye concentration, etc.)

	# Continue to measure the diameter of the plume at regular intervals until the plume has doubled it's original diameter. Make note of the plume's properties at each measurement.		# Continue to measure the diameter of the plume at regular intervals until the plume has doubled it's original diameter. Make note of the plume's properties at each measurement.
			# Repeat this experiment in well number 5 (gravel)
	# Repeat this experiment in well number 5 (gravel) ~~and compare your results.~~

	== Results ==		== Results ==

	* Determine the rate of diffusion		* Determine the dye's rate of diffusion for the two soil mediums in the simulator.
			** The rate of diffusion in this experiment is defined as the speed at which the dye at the edge of the plume travels from one time interval to another.
			** <math>d(n)</math> = diameter of plume at time interval <math>n</math>
			** rate of plume growth = <math>(d(n2)-d(n1))/(n2-n1)</math>
			** Does the rate of diffusion change over time?
			** Does the rate of diffusion differ in sand and gravel?
	* Do the properties of the plume change over time?		* Do the properties of the plume change over time?
	** Is the dye concentration consistent throughout the plume? Is there less of a concentration at the edges or center?		** Is the dye concentration consistent throughout the plume? Is there less of a concentration at the edges or center?
	** Does the plume's overall shape change over time?		** Does the plume's overall shape change over time?
			** Is there a difference in plume behavior in sand and gravel?

	== Considerations for a Computer Based Simulation ==		== Considerations for a Computer Based Simulation ==

	* If NetLogo is your computational tool of choice, how does the diffuse function (patch based) compare to the results you observed?		* If NetLogo is your computational tool of choice, how does the diffuse function (patch based) compare to the results you observed?

			* Would it be better to

Brad: Diffusion Experiment Page Created

2007-11-05T01:38:10Z

Diffusion Experiment Page Created

New page

This is a detailed description of one experiment listed on the CS382 [http://wiki.cs.earlham.edu/index.php/Cs382 course page]
----
== Goal ==

The goal of this experiment is to determine the rate of diffusion of dye in the groundwater simulator and to observe the form taken by the dye as it travels through the sand or gravel.

== Equipment ==

* enVision sand and gravel groundwater simulator
* dark water soluble dye
* pipette
* water
* ruler
* kitchen timer or some other time measurement device

== Procedure ==

# Fill the groundwater simulator with fresh water This yields the greatest contrast between the dye plume and surrounding clean water.

# Make sure the pump is off. If the pump was recently circulating water, make sure that the water table's level has had enough time to stabilize. This ensures that the dye's plume will only be affected by diffusion and not water movement.

# Fill the pipette at least halfway full with dye.

# Insert the pipette completely into well number 3 (sand).

# Inject enough dye into the well to create a quarter sized plume.

# Keep the pipette's bulb depressed until after it is removed from the well to avoid creating a vacuum and sucking dye from the plume back into the well. A little of this may occur as the water level in the well rises to fill the space formerly occupied by the pipette's barrel.

# Measure the plume's diameter in the horizontal plane and start the timer. Describe the properties of the plume (shape, distribution of dye concentration, etc.)

# Continue to measure the diameter of the plume at regular intervals until the plume has doubled it's original diameter. Make note of the plume's properties at each measurement.

# Repeat this experiment in well number 5 (gravel) and compare your results.

== Results ==

* Determine the rate of diffusion
* Do the properties of the plume change over time?
** Is the dye concentration consistent throughout the plume? Is there less of a concentration at the edges or center?
** Does the plume's overall shape change over time?

== Considerations for a Computer Based Simulation ==

* If NetLogo is your computational tool of choice, how does the diffuse function (patch based) compare to the results you observed?