Amount of Time Compacted Soil in Layers Holds Back Water

Purpose

The purpose of this experiment was to determine the effect of dirt compaction on the ability of dirt to hold water in a simulated levee.

I became interested in this idea when I read in the newspaper that New Orleans had been flooded and destroyed because a levee had broken.

The information gained from this experiment could protect people from getting their homes destroyed and being killed by floods because levees weren’t compacted in layers enough. Lots of people would care, especially engineers trying to build or protect people with levees.

Hypothesis

My first hypothesis was that the more compacted layers there were, the longer it would hold back water.

I based my hypothesis on the fact that earthen dams and levees are usually built layer by layer with compaction of each layer before the next one is added.

Experiment Design

The constants in this study were:

•    Width of PVC pipe

•    Length of PVC pipe

•    Amount of water put in PVC pipe

•    Type of water put in PVC pipe

•    Amount of dirt put in PVC pipe

        •    Type of dirt put in PVC pipe

•    Temperature where testing

•    Time brick compacted dirt

The manipulated variable was the number of layers that were compacted.

The responding variable was the amount of time it took before the dirt plug broke.

To measure the responding variables, I used a stopwatch and started it when I put the water in and stopped it when plug broke.

Materials

Procedures

1.    Build system

a.    Connect the 133cm in length of PVC pipe to the 2in PVC pipe elbow

b.    Connect PVC pipe valve to the elbow

c.    Build plugs

i.    Put 473ml of dirt in the 30.5cm length of 2in (5cm) PVC pipe

ii.    Place compactor in PVC pipe on dirt then place a 16.78kg brick

for 4 seconds on the circle to compact the dirt.

iii.    Repeat steps i. - ii. until an 8 layer plug is created with 8 compactions.

iv.    Repeat steps i. - iii. until 5 plugs are created

v.    Repeat steps i. – iv., reducing layers by half and doubling the time the brick sits on the circle compactor

1.    For the first repetition, reduce the layers to 4 and double the compaction times to 8 seconds

2.    For the second repetition, reduce the layers to 2 and double the compaction times to 16 seconds

3.    For the third repetition, reduce the layers to 1 and double the compaction times to 32 seconds

2.    Ready Experiment

a.    Place plug tube horizontally into PVC valve so that side with the dirt is away from the valve.

b.    Make sure the valve is shut

c.    Support so the long pipe is vertical

3.    Conduct Experiment

a.    Fill vertical pipe, 133cm with tap water to the top

b.    Start the stopwatch when you turn the valve

c.    Stop the stop watch when the plug breaks and record

4.    Repeat with other dirt plugs in this compaction group

5.    Repeat with other compaction groups

6.    Average results within each group

Results

The original purpose of this experiment was to determine the effect of dirt compaction in layers on the ability to hold water.

The results of the experiment were inconsistent because there is no recognizable trend. The results were low then high having no recognizable relationship.

Conclusion

My hypothesis was that the more compacted layers there were the longer it would hold back water.

The results indicate that this hypothesis should be rejected, because of the inconsistence results. The problem is that the harder you compact it the plug is compacted so great there is no path of air for it to follow instead of the plug breaking it is pushed out by the pressure. Though if you are compacting the plug little air cracks will be left. If the cracks are found by the water it will lead it out when you start to see the water come out it erodes half of the plug in one second. The problem is that the air cracks maybe harder to find.

After thinking about the results of this experiment, I wonder if the type of material used as a plug would make a difference in the time it held water. I also wonder if the amount of time the soil was being compacted would matter at all.  For example if each compaction lasted 64 seconds instead of 32, would that improve the water resistance?  What if the dirt was dry, damp, or frozen?  One could also test the amount of dirt used in the plug.  Would twice as much dirt double the time water was held?

If I were to conduct this project again I would conduct more trials probably ten or 12.  I would also test a plug with a larger number of layers, perhaps 16.

Researched by Connor H

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Deicer Salt on the Growth of Barley

Purpose :- :-

       The purpose of this experiment was to determine the effect of deicer salt on the growth of barley.

       I became interested in this idea when I saw people putting deicer on the roads and sidewalks in the winter. I wondered if the salt dissolved and got into the soil, would it affect how much plants grew. My family and I grew a garden, so salt in the soil could cause problems.  

        The information gained from this experiment could be of interest to gardeners, farmers, the Department of Transportation employees who salt the roads and homeowners who use deicer on their sidewalks and driveways. If salt damages plant growth, then this study could act as a warning. 

Hypothesis

My first hypothesis was that the barley plants with more deicer salt would grow more slowly than the plants without it.

My second hypothesis was that as the amount of deicer increased, the percent of surviving plants would decrease.  

       My third hypothesis was that as the amount of deicer salt increased, the weight of the plants would decrease.

       I based my hypothesis on an Internet article called “Sources of Soil Salinity”.  The article said that salt doesn't affect how plants grow much, unless a high amount of salt is present.

Experiment Design

The constants in this study were:

•    The amount of water given to the plants (5cc)

•    The amount of soil in each cell

•    The type of soil

•    The amount of light given (14 hours a day)

•    The temperature the plants were grown at (20°C)

•    The type of plant seed (barley)

•    The depth of the plant seed (1 cm)

The manipulated variable was the amount of deicer salt used. 

         The responding variables were the growth of the barley and the survival rate. 

         To measure the responding variables, I measured the weight of the barley using a triple beam balance and counted the number that survived. 

Materials

Quantity	Item Description
2	Planting trays with 72 cells
1	Triple Beam Balance
432	Barley Seeds
1	Bag of potting soil
1	Bag of deicer rock salt
	Tap Water
1	Growing Light
1	Syringe
2	Plastic Clear Domes
1	Timer
5	Plastic Jugs

                          

Procedures

1.    Planting seeds

A. Fill all of the cells in both planting trays 1/2 full with potting soil.

B. Add 15cc of water to each cell using the syringe.

        C. Place 3 barley seeds evenly spaced into each cell.

        D. Cover the barley seeds with a layer of potting soil.

        E. Add another 15cc of water. 

        F. Place a plastic, clear dome over each of the planting trays.

G. Set the timer for the fluorescent light to turn on for 14 hours every day and make sure the light is placed 30 centimeters above the soil.

2.    Label Groups

A. Divide up the cells so you have 3 groups of 24 cells in each tray (a total of 6 groups).

        B. Label the first group “no salt”.

        C. Label the second group “2.25 grams of salt”.

        D. Label the third group “4.5 grams of salt”.

        E. Label the fourth group “9 grams of salt”.

        F. Label the fifth group “18 grams of salt”.

        G. Label the sixth group “36 grams of salt”.

3.   Creating Saltwater Solutions

A. Put 2.25 grams salt into a plastic jug, add 1 liter water, label it “2.25 grams”.

B. Put 4.5 grams salt into a plastic jug, add 1 liter water, label it “4.5 grams”.

C. Put 9 grams salt into a plastic jug, add 1 liter water, label it “9 grams”.

D. Put 18 grams salt into a plastic jug, add 1 liter water, label it “18 grams”.

E. Put 36 grams salt into a plastic jug, add 1 liter water, label it “36 grams”.

4.    Experimental Treatments

A. Every other day add 5cc of salt solution to each cell using the syringe. Use the correct jug of water for each group.

B. At the end of the experiment, uproot and weigh all of the plants in each group using a triple beam balance. 

 C. Find the total mass for each group, then find the average mass for each group by taking the total mass for each group and dividing it by the number of plants in that group.

Results

The original purpose of this experiment was to determine the effect of deicer salt on the growth of barley.

The results of the experiment were that the groups with more deicer salt weighed less than the groups with less deicer salt.

The group with no salt had an average mass of .25 grams.

The group with 2.25 grams of salt had an average mass of .23 grams.

The group with 4.5 grams of salt had an average mass of .20 grams. The group with 9 grams of salt had an average mass of .17 grams. 

The group with 18 grams of salt had an average mass of .12 grams. The group with 36 grams of salt had an average mass of .09 grams. 

The group with no salt had 100% surviving and the group with 36 grams of salt had 22% surviving.

Conclusion

        My first hypothesis was that the barley plants with more deicer salt would grow more slowly than the plants without it. 

       The results indicate that my first hypothesis should be accepted, because once the salt concentrations were applied, the groups with the higher amounts of salt grew the least. 

       My second hypothesis was that as the amount of deicer increased, the percent of surviving plants would decrease.

      The results indicate that my second hypothesis should be accepted, because once the salt concentrations were applied, the groups with more salt had fewer surviving plants.

      My third hypothesis was that as the amount of deicer salt increased, the weight of the plants would decrease. 

      The results indicate that my third hypothesis should be accepted, because the groups with the more deicer salt have a lower average mass.

        After thinking about the results of this experiment, I wonder if a different type of deicer would affect how much barley grows. For example, the Department of Transportation sprays a special type of deicer on the roads. I wonder if that deicer would affect barley. Also, there are a lot of different types of plants that could be tested. I wonder if what the effect of deicer would be on wheat, soybeans, apple trees, or any other type of plant.

        If I were to conduct this project again I would have used six different syringes so I would have had one for each group, because the next time I watered the plants, some of the salt could still have been in the syringe from last time. I also would have grown the plants in natural sunlight outside in the summer instead of using an artificial light inside in the winter because that would be more natural. I also would have used more plants in each group and more variations of salt concentrations to discover the smallest amount of salt having a negative effect. 

 Researched by ----- Ashley B

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Wind Speed, Air Humidity, and Air Temperature on Evaporation Rate

Purpose :- :- :- :- 

            The purpose of this experiment was to compare the effect of wind speed, air humidity, and water temperature on the evaporation rate of water.

            I became interested in this idea because I knew that water evaporation could be helpful when it cooled you down and harmful when it dehydrated both plants and people, so I decided to learn more about what affected evaporation. 

           The information gained from this experiment could help food producers who dehydrate fruit, vegetables, or meat.  It could also help coaches and athletes who need to keep cool during strenuous exercise, and people who are interested in outdoor activities, such as camping, hiking, or swimming.

Hypothesis

My hypothesis was that the temperature of the air would affect evaporation rate most.

        I based my hypothesis on a diagram I found in Young Scientist Encyclopedia.  The diagram showed that the warmer the water, the more molecules escaped as vapor.

         I also based my hypothesis on a slideshow I saw on the movie “Bill Nye the Science Guy: The Water Cycle.”  It showed that boiling water’s molecules have more energy and escape as vapor at a much faster pace than molecules at room temperature.

Experiment Design

The constants in this study were

•    The type of water (tap)

•    The amount of water 

•    The location the water is placed 

•    The size of the container

•    The ruler

•    The number of trials conducted

•    The type of the container

•    How long the water has to evaporate

        The manipulated variables were air humidity, wind speed, and water temperature.

           The responding variable was the amount of water evaporated in 150 minutes.  I measured the water in a graduated cylinder before and after the evaporation occurred.

          To measure the responding variable, I measured the water in milliliters before and after the evaporation occurred.

Materials

Quantity	Item Description
1	Small room fan
3	Liters tap water
5	Small dishes
1	Small air humidifier
1	100 ml. graduated cylinder
1	Humidity meter
1	Room thermometer
1	Lab thermometer
1	Plastic jug (approx. 4 liters)

 Procedures

1.    Collect materials.

        2.    Stabilize and maintain the humidity in testing room using a small air humidifier as needed.  For the first phase of testing, the humidity should be about 34%.

        3.    Stabilize and maintain the temperature in testing room.  For the first trials the room temperature should be 10º C.

        4.    Stabilize and maintain the air speed in testing room using a small fan as needed.  For the first trials the wind speed should be “dead calm”.

        5.    Place a jug of tap water in the testing room so it adjusts to the room temperature.  Whenever the water temperature is the same as the air temperature, the experiment can continue.

       6.    Pour 100 ml. of tap water from the jug at the current temperature into each of 5 identical small dishes using a graduated cylinder.

        7.    Place the dishes so they are being equally affected by room temperature, humidity, and air movement.

       8.    Using a timer, let the water sit in the testing room for 180 minutes.

       9.    Using a graduated cylinder, measure the water remaining from each dish and subtract each from the original 100 ml.

       10.    Record this as how many milliliters evaporated for that trial.

      11.    Repeat steps 4-10, except turn the fan on to its high-speed setting.  Be careful when placing the dishes that all are equally affected by the moving air.

     12.    Repeat steps 3-11, but stabilize and maintain the temperature at 20º C.

     13.    Repeat steps 3-11, but stabilize and maintain the temperature at 30º C.

       14.    Repeat steps 2-13, but stabilize and maintain the humidity at about 65%      for the entire series of trials.

Results

The original purpose of this experiment was to compare the effect of wind speed, air humidity, and water temperature on evaporation rate of water. 

           The results of the experiment were that wind speed affected evaporation rate most.  The difference between the two wind speeds evaporated water is 4.4 ml.

Conclusion

My hypothesis was that the temperature of the air would affect evaporation rate most.

The results indicate that this hypothesis should be rejected, because wind speed affected evaporation rate most.  The temperature of the air did not matter nearly as much as the wind speed and air humidity in the room when you are testing evaporation rate.

After thinking about the results of this experiment, I wonder if the size of the room would affect how much water was evaporated.  Water in dishes set in a closet might evaporate very differently than in a gymnasium.  All liquids can evaporate but they do so at varying rates. It would be interesting to see what happens to a fast evaporating liquid like rubbing alcohol using my same procedures.

If I were to conduct this project again, I would do many more trials of each variation.  I would still use five dishes at a time, but I would do at least three different batches of five for each temperature, wind speed, and humidity condition.  I am sure that each evaporation trial should have been much longer, probably five to eight hours long.  That would have given a better idea of what happened with each condition.  It would also have been better to add an intermediate wind speed, about halfway between high and zero.

Researched by ------ Kaiti D

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