Earth Science Regents Performance Test Bead Drop:

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Earth Science Regents Performance Test Bead
DropSettling it once and for all!
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Bead Drop Research Team -SUNY Oneonta

• Dr. Jim Ebert, Earth Sciences Dept.
• Ron Chapin
• Trish Emmons
• Don Zaengle
• Gerald Jones
• Tom Sansone

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Student Participants

• Student participants in the Station 5 research
  project were Secondary Education/Earth Science
  Students enrolled in ESCI 315 Laboratory
  Techniques in Earth Science in the Spring
  semesters of 1999 and 2000

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Variables investigated in 1999

• Variation in bead density with temperature
• Variation in fluid density with temperature
• Changing time to terminal velocity with fluid
  height in column
• Variation in fluid viscosity with temperature

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Research in 2000

• Focus on viscosity change with temperature
• Construct correction curves?
• Examine other fluids with less temperature-depende
  nt viscosity

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Lets drop some Beads!!
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ESCI 315 data for Red Beads
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ESCI 315 data - Green Beads
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ESCI 315 data Orange Beads
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Settling Time expanded scale
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Settling Time expanded scale
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Range of settling timeswith temperature
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Viscosity and settling time

• Water-based solutions show significant changes in
  viscosity with changes in temperature
• Settling time may vary by up to 50 over range of
  typical classroom temperatures
• Vegetable oil shows very slight changes in
  viscosity and therefore settling time with
  changes in temperature

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Channelingand water-based solutions

• Water-based solutions displayed an unexpected
  channeling effect
• A visible channel was observed in the fluid
  column
• Beads entering this channel settled significantly
  faster than beads outside the channel
• Settling times in water-based solutions may vary
  by up to 6 seconds at a single temperature!

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CONCLUSIONS

• Use Vegetable Oil for Station 5
• Viscosity and therefore settling time is less
  affected by temperature during administration of
  the practical
• With vegetable oil, it should be possible to make
  up a single key for each set-up and not have
  different keys for different times of
  day/temperatures.

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Helpful hints for Station 5

• USE VEGETABLE OIL instead of water-based
  solutions. Oil is less susceptible to
  temperature-induced changes in viscosity.
  Therefore there will be less drift in settling
  time. Also, channeling is not a problem.
• Be aware that settling times in oil are faster
  than water-based solutions. Adjust timing marks
  on columns to give appropriate settling times.

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Helpful hints for Station 5

• Use Number 7 or 8 rubber stoppers in the bottoms
  of columns. They give a better seal than the
  plastic fittings.
• Place the bottom of the tube in a plastic beaker
  or whipped topping container to ease clean-up in
  the case of minor leaks.

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Helpful hints for Station 5

• Place a film-cannister bailer at the bottom of
  the tube to retrieve beads. Holes in the
  cannister allow fluid to drain out.
• Bent pieces of coat hanger are good for the
  hook and straightened coat hangers work well to
  retrieve the bailer.
• Thanks to Irv Soden for this suggestion.

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Helpful Hints for Station 5

• Plastic petri (culture) dishes work well for
  holding the beads at each station.
• Use masking tape to anchor the dishes to the
  table top to minimize the chances of students
  spilling beads (of course, this NEVER happens!)

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Helpful Hints for Station 5

• Glue beads onto the station directions so that
  there is no ambiguity over which beads the
  students should use for each trial.
• Use plastic page protectors for the station
  instructions. This prevents students from writing
  on them, shields them from spills and preserves
  them for future use.

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CLEAN UP

• Hot soapy water works well for removing oil from
  beads, tubes and stoppers. You can even use the
  detergent from previous years!
• Oil can be kept in the original bottles
  indefinitely.

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