The National Student Research Center

E-Journal of Student Research: Science

Volume 8, Number 1, September, 1999


The National Student Research Center is dedicated to promoting student research and the use of the scientific method in all subject areas across the curriculum, especially science and math.

For more information contact:

John I. Swang, Ph.D.
Founder/Director
National Student Research Center
2024 Livingston Street
Mandeville, Louisiana 70448
U.S.A.
E-Mail: nsrcmms@communique.net
http://youth.net/nsrc/nsrc.html


TABLE OF CONTENTS

  1. Building Materials and Acid Rain
  2. Title: How Does Color Affect The Human Heart Rate?
  3. Testing Ice Cream for Bacterial Contamination
  4. Fading Rate of Naturally-Dyed Cloth
  5. Freezing Time of Ice Cream With Different Amounts of Sugar
  6. Blind Spot In Your Eye



Title:   Building Materials and Acid Rain

Student Researcher:   Neil Pacheco
School Address:   Del Norte High School
                  Del Norte, CO 81132
Grade:   12
Teacher:   Mrs. Stuemky


I.  Purpose/Hypothesis

Many of today's buildings and statues are being eroded by acid 
rain.  This is a problem all around the world.  Buildings, 
bridges, and statues have no defense against acid.  I decided to 
see which building material resisted acid rain the best.  This 
can be a valuable information to architectural engineers because 
the information would save millions of dollars in repairs.  I 
also wanted to prove that acid rain does more damaged to 
structures than just plain rain.  If this is true there needs to 
be an effort to reduce acid rain pollution.  I think that copper 
of the metals will be least affected by acid rain.  I also think 
that the smooth cut of granite will be least affected by the 
acid rain.  Lastly, I think that acid rain will cause more 
damage than regular water.

II.  Methodology

Procedure:
1.  Mass each piece of test material (three of each).
2.  Record these numbers.
3.  Make and record observations about each piece of 
testing material.
4.  Take a picture of each testing material.
5.  Place 500 mL of acid rain (sulfuric acid) with a pH of 
two into a spray bottle and label the bottle "Acid Rain".
6.  Place 500 mL of distilled water into a spray bottle 
and label the bottle "Water". 
7.  Place one piece of plastic wire screen at the bottom 
of three buckets.
8.  Place one piece of testing material onto a piece of 
wire screen.  (There should be five total pieces of testing 
material on each screen).
9.  Label one bucket "A", a second bucket "B" and the last 
bucket "C".
10.  Bucket "A" will receive five sprays of acid rain per 
day.
11.  Bucket "B" will receive five sprays of water per day.
12.  Bucket "C" will receive zero sprays of anything and 
will serve as a control.
13.  Repeat steps 10 and 11 every day for twenty days 
while recording observations on days one, six, eleven, sixteen, 
and twenty.
14.  Retake pictures of each material.
15.  Brush off each piece of testing material.
16.  Remass each material and record those results.
17.  Clean up testing area and dispose of acid rain 
accordingly.

Materials:
1.  Three pieces of flat 2 inch by 2 inch steel.
2.  Three pieces of flat 2 inch by 2 inch brass.
3.  Three pieces of flat 2 inch by 2 inch copper.
4.  Three pieces of smooth cut granite, 2 cubic inch.
5.  Three pieces of rough cut granite, 1 cubic inch.
6.  Three pieces of plastic wire screen.
7.  Two spray bottles.
8.  500 mL of sulfuric acid pH 2. 
9.  500 mL of distilled water.
    10.  Three buckets.

III.  Analysis of Data

Staring mass of materials in grams.
                            A        B        C
Copper                    1.55     1.38     1.61
Brass                     1.27     1.19     1.65
Steel                     0.44     0.56     0.45
Rough granite            28.37    46.51    36.42
Smooth granite           74.47   106.8     95.88

Final mass of materials in grams.

                            A        B        C
Copper                    1.46     1.36     1.61
Brass                     1.13     1.14     1.65
Steel                     0.30     0.50     0.45
Rough granite            26.46    45.59    36.41
Smooth granite           73.23   105.1     95.87


Difference in mass in grams.

Copper                    0.09     0.02     0.00
Brass                     0.14     0.05     0.00
Steel                     0.14     0.06     0.00
Rough granite             1.91     0.92     0.01
Smooth granite            1.24     1.70     0.01

IV.  Conclusion

In conclusion, my hypothesis was correct.  Copper was not 
affected by the acid rain as much as the other metals.  The 
smooth cut of granite also was less affected than rough granite.  
I was also correct in that the acid rain did erode more material 
than water.  I feel that brushing off each piece of material 
after the experiment only removed material eroded by the acid 
rain.  This is key to show a change in mass for each material, 
otherwise, all of the mass would still be on the object even 
though it is not connected.  I would like to repeat this 
experiment for a longer amount of time to see if, in the long 
run, water and acid rain did the same amount of damage.  I would 
also like to test more metals and stones to see if there are 
even more resistant materials to acid rain.  I also would 
increase the amount of sprays per day because that would better 
represent a rain storm.

V.  Application

I think that what I have learned can be used to make acid rain 
resistant buildings and statues.  I also think that all exposed 
metal surfaces in buildings should be copper or brass plated.  
This is so they can resist acid rain.  I think that all granite 
applications should be that of a smooth cut to help reduce 
erosion.



Title:  How Does Color Affect The Human Heart Rate?

Student Researcher:  Michelle Blackmon
School Address:  Del Norte High School 
                 Del Norte, CO  81132
Grade:  Tenth Grade
Teacher:  Mrs.  Stuemky


I.  Statement of Purpose and Hypothesis:

I feel the need to pursue how color affects heart rate by seeing 
how much a human's pulse increased or decreased with the 
influence of colors. 
 
I feel that the human heart rate will react to red by speeding 
up.  I also think blue will make the human heart rate change by 
slowing down.  My hypothesis also states that orange and yellow 
will increase the heart rate.  I also feel white, silver and 
black will make the heart rate decrease from the normal average 
heart rate.

II.  Methodology:

In order to conduct this experiment I will need 8, 22x94 by 
28x94 poster board ranging in colors: red, blue, green, yellow, 
white, black, silver and orange.  At least 20 middle school 
students will also be needed.  In order to make the experiment 
conclusive, one ordinary white room containing one desk and 
chair will be used.  The setting should stay the same to 
eliminate some of the variables. To make the data easier to 
collect and record, at least 20 data sheets will be used.  

First, have the color cards stacked one upon another in a 
specific order, on the table.  Call one person at a time into 
the room.  The volunteer will then be asked if they mind people 
touching their wrists.  If not, they will then be asked what 
their favorite color is.  This will be recorded on the data 
sheet.  The subject will then be seated and their resting heart 
rate will be taken and recorded.  (To take heart rate:  for 15 
seconds, place middle and index fingers on the inside of the 
subjects wrist.  Count these beats and multiply that number by 4 
to get the actual heart rate.)  Then continue to show the 
subject the color cards one at a time for 30 seconds.  After 
each time interval, take the subjects heart rate and record it 
on the data sheet.
  
After all 8 color cards are shown to the subject they may be 
dismissed and another called.  The steps will stay the same for 
all participants.

III.  Analysis Of Data:  

I found that the average resting heart rate was 80.  Orange, 
red, green, yellow, white, black and silver raised  the average 
heart rate.  Orange raised the average heart rate to 87, red to 
85, green to 84, yellow and white to 82, and black and silver to 
81.  Blue in my experiment was the only color to that lowered 
the heart rate below the average.  Blue lowered the heart rate 
to 79.

IV.  Summary And Conclusion:

I found that blue lowered the resting heart rate the most.  
Orange raised it the most.  The other colors were too close to 
conclude anything.  I rejected my hypothesis because I didn't 
really take in consideration what some of the other colors would 
do.  I felt orange wouldn't have as much affect as red, but in 
actuality orange caused more of a change.  I was right when I 
purposed that blue would lower the humans resting heart rate the 
most.

V.  Applications:

I feel my project can be applied to many topics in the outside 
world.  If a medical patient is known to have hereditary heart 
problems in their earlier years, I conclude that if they were to 
spend much of their time in blue surroundings it may cause a 
positive change in their heart rate.  Even when a person comes 
into the hospital with a heart attack, a blue room may help.  In 
the fitness world, if people were to exercise in a orange or red 
room they may be able to raise their heart rate levels even more 
than normal.  This would result in more fat burning.  My 
experiment would also help an inactive or overactive child be 
accepted by society.  If an inactive child could play in a red 
or orange room they may become more active, because their heart 
rate has been increased.  The exact opposite goes for an over 
active child.  If the over active child were to play in a blue 
room their heart rate may decrease enough so that hyperactivity 
is subdued.



TITLE:  Testing Ice Cream for Bacterial Contamination

STUDENT RESEARCHERS:  Aaron Abbott, Amanda Arvin, Ben McChesney, 
Ben Peters, Ben Robinson, Ben Soule, Caleb Baron, Dylan 
McGuffin, Harold Jones, Josh Hanrahan, Lucas Hanowitz, Mackenzie 
Hussman, Mason Mills, Owen Carey-Hatch, Travis Webster-Booth, 
Zach Benton

SCHOOL:  Sant Bani School 
         Sanbornton, NH  03269
GRADE:  6
TEACHER:  Robert Schongalla


STATEMENT OF PURPOSE AND HYPOTHESIS:

When our teacher told us about feeling sick after eating ice 
cream, we wanted to see if we would find bacteria in it.  This 
ice cream had several parts:  ice cream, a fruit swirl or purée, 
and some chocolate.  We hypothesized that we would find higher 
amounts of bacteria in one of the parts of the ice cream.  

METHODOLOGY:    

1.  Our teacher ordered sterile droppers and "Coliscan Easygel 
pour plates" manufactured by Microbiology Laboratories of 
Goshen, Indiana.  
2.  We followed the directions carefully and took 1 ml samples 
of the ice cream, fruit swirl, and chocolate.The samples were 
mixed in with the Coliscan bacteria food / (media) and poured 
into the culture plates.  We took samples of drinking water and 
contaminated water as "controls." 
3.  The class worked as a research team and broke into groups of 
three to test specific parts of the ice cream and set up the 
controls.  We repeated the tests four times in total (at four 
levels in the ice cream container from the near the top to near 
the bottom). 
4.  The culture plates were incubated for 24 hours.  To read the 
plates, our teacher taped them to a window, and we compared them 
to an interpretation chart provided by Coliscan.  We recorded 
our results on a data table and discussed them right away.

Safety note:  The contaminated water was from a toilet, and our 
teacher took this sample.  The plates were taped shut.  All of 
us washed our hands carefully after the sampling.  After 
incubation, only our teacher handled the plates, and as soon as 
they were read, he poured bleach over them. 

SUMMARY AND CONCLUSION:  

We found a great amount of coliform bacteria in the fruit swirl, 
and therefore we accepted our hypothesis that we would find at 
least one part of the ice cream with high amounts of bacteria.  
The amount of bacteria in the swirl was greater than the amount 
we found in the contaminated water sample!  The ice cream 
contained some bacteria -- not coliform.  The tap water and 
chocolate had no bacteria.  The high level of coliform bacteria 
found in the fruit swirl was near the top of the container.  No 
bacteria was seen in the purée we tested at lower points in the 
container.

APPLICATION:

We learned a lot from doing this research project and our 
discussions.  The wrong bacteria in food can make a person very 
sick.  We talked about several ways bacteria could have gotten 
into the fruit purée.  We were surprised to see how fast 
bacteria can grow in 24 hours when given the
right conditions.  We saw how culture plates could help someone 
determine the cause of food poisoning.  We learned about how 
important it is to prepare and handle foods carefully and 
hygienically to avoid contamination.  Our teacher had called the 
ice cream company when he became sick.  Later, he called again 
during class to report our
results.  

We respect bacteria a little more after doing this project
since we learned in discussions how bacteria are all around us, 
and how they can be both good and harmful.  Our teacher was 
careful with them.  The ice cream company sent us two coupons 
for free ice cream which we enjoyed!



Title:  Fading Rate of Naturally-Dyed Cloth

Student Researcher:  Kimber Melton
School Address:  Belleville Middle School,
                 Belleville, Kansas
Grade:  8
Teacher:  Jean Jensby


I.  Statement of Purpose and Hypothesis

The purpose of my investigation is to determine which cloth, 
dyed naturally, fades faster: those dyed in vinegar, mordants, 
or neither.  My hypothesis states that cloth dyed in mordants 
will fade the least.

II.  Methodology

Independent variable: different dying aides

Dependent variable: fading time of clothes

Controls: same cloth, where placed, amount of sunshine, time in 
sunshine, amount of natural dye used, same dying method.

Materials: calendar, same muslin, red onion skins, coffee beans, 
water (two quarts for each color), two-quart pot, oven, data 
sheet, vinegar, mordants, six bowls, 14 six inch muslin squares, 
tape for labeling, two Rubbermaid plastic containers with lids.

Procedure:

1. Gather materials.
2. Make the natural dye bringing to a simmer in a two-quart pot 
the red onion skins and water, secure the red onion skins in a 
muslin pouch.  In the pot also put two squares of muslin to be 
dyed in neither vinegar or mordants.  This will take from 20 
minutes to three hours.
3. Repeat step #2 one more time (making each natural dye to be 
used).
4. Separate each of the dyes into halves, adding vinegar to one, 
and mordants to another. Label each bowl carefully.
5. Dye two six-inch squares of muslin in red onion skin dye. 
Label carefully.
6. Repeat step #5 with each of the two variations of each dye to 
be used.
7. Dry the six pieces of dyed cloth by laying them flat on a 
waterproof surface.
8. Place one cloth of every color, of every variation, in an 
airtight container, out of sunlight. I used Rubbermaid 
containers and stored them under our kitchen counter.
9. Place the other cloths of every color of every variation in a 
place where they will receive direct sunlight but no weathering 
effects.
10. When cloths have been in sunlight for a prolonged period of 
time, compare them with their partners.
11. Record results periodically.  Make any comments you feel 
due.

Definition of Terms

1. mordant- a chemical that serves to fix a dye in or on a 
substance by combining it with a dye to form a insoluble 
compound

2. muslin- any of various sturdy, plain woven, cotton fabrics, 
used especially for sheets

3. natural dye- dye found 'in nature, such as the roots, leaves, 
bark, stems, and blossoms of plants

4. synthetic dye- any substance used to color materials which 
are made by man

5. alum- any of various double sulfates of a trivalent metal 
such as, aluminum, chromium, or iron and a univalent metal such 
as potassium or sodium, especially aluminum potassium sulfate.

III.  Analysis of Data

My research had the results as follows: the mordant/red onion 
skins dye and the mordant/coffee dye both faded the least in 
their respective categories.

Ranking second in most faded was the vinegar/red onion skins and 
the vinegar/coffee dyes.  The group of dyes that had faded the 
most at the end of the four months was the cloth that was dyed 
in neither of each category.

IV.  Summary and Conclusion

The information I found led me to accept my hypothesis. The 
cloth dyed in mordants in each category faded the least, 
although the cloth dyed in coffee and mordants had faded more 
than the red onion/mordant combination. I was surprised that the 
rankings ended up the same in each category.  I thought they 
would not end up the same because they did not stay the same 
during the experiment.  Also, on one of the samples a piece of 
metal in the window blocked sunlight from the cloth so there is 
a dark spot on it.  If I were to repeat this experiment I would 
make sure there were no pieces of metal or bars in the window 
that would block the sunlight from the cloth.

V.  Application

I believe the data I conjured in my experiment could be a 
benefit to the textile industry.  If a mordant was added to a 
cloth it would be less likely to fade and therefore be able to 
keep its natural color longer, This information would in turn 
benefit the fashion industry since natural fibers and dyes are 
very important.



Title:  Freezing Time of Ice Cream With Different Amounts of
        Sugar

Student:  Krystal Hergott
School Address:  Belleville Middle School
                 Belleville, Kansas
Grade: 8
Teacher: Mrs. Jean Jensby


I.  Statement of Purpose and Hypothesis

The purpose of my investigation is to determine how the amount 
of sugar affects the freezing time of ice cream.  My hypothesis 
states that the more sugar you add the longer the freezing time 
will be.

II.  Methodology

Manipulated variable: the amount of sugar I put in ice cream

Responding variable: the amount of time the ice cream takes to 
freeze

Controls: the recipe of the ice cream, the amount of ice and ice 
cream salt used to make the ice cream, the ice cream freezer

Materials: ice cream ingredients already mixed up, a gallon 
electric ice cream freezer, 10 pounds of ice, one cup of ice 
cream salt, timer

Procedure:

1. Gather the materials.
2. Put mixed ingredients into the ice cream freezer freezing 
compartment.
      6 C. whole milk      4 C. whipping cream
      2 1/4 C. sugar       2 T. Vanilla
      1/2 tsp. salt
Pour milk and cream into gallon freezer.  Gradually add sugar, 
stirring constantly until sugar is dissolved. Stir in vanilla 
and salt.  Freeze.
3. Surround it with 10 pounds of ice and one cup of ice cream 
salt.
4. Start the timer and the ice cream freezer at the same time.
5. When the ice cream freezer stops turning, turn the timer off.  
Record the time in a data table.
6. Repeat steps 1-5 four more times using 2 1/4 cups sugar.
7. Repeat steps 1-6 using different amounts of sugar- 1 1/4 cup, 
2 1/4 cup, and 3 1/4 cup.
8. Calculate average freezing time for each of the sugar 
amounts.
9. Compare average by ranking the freezing time from least to 
most in your data table.
10. Analysis of Data

III.  Analysis of Data

My data shows that the ice cream with 1 1/4 cup of sugar froze 
the fastest on an average of 24.2 minutes. The 2 1/4 cups of 
sugar in the ice cream was the second fastest, freezing on an 
average of 34.4 minutes. The slowest freezing time came with the 
ice cream with 3 1/4 cups sugar in it and it froze on an average 
of 123.6 minutes.

IV.  Summary and Conclusions

My hypothesis was accepted, it stated that the more sugar you 
add the longer the freezing time will be.  All the ice cream I 
made was edible, but the ice cream with 2 1/4 cups of sugar was 
the best tasting. The ice cream with 1 1/4 cups of sugar wasn't 
sweet enough and the ice cream with 3 1/4 cups of sugar was too 
sweet.

V.  Application

This science project applies to whether regular or diet (less 
sugar) soda pop in a can or bottle will freeze faster if left in 
a car in freezing temperatures.  This also tells the ice cream 
industry about how long they need to freeze their ice cream 
before it is ready to eat.  It also tells the people who develop 
and use the recipes how long it takes the ice cream to freeze 
and how, if they vary the sugar, they need to change the time, 
too.  High sugar content does slow freezing time down and could 
be used in some future unknown situation.



Title:  Blind Spot In Your Eye 

Student Researcher:  Jon Chatfield 
School Address:  Belleville Middle School
                 Belleville, Kansas 
Grade:  8 
Teacher:  Mrs. Jean Jensby


I.  Statement of Purpose and Hypothesis

The purpose of my investigation is to determine if 13-year old 
males' and females' blind spots are different distances in 
length.

My hypothesis states that different people have blind spots at 
different distances in length.

II.  Methodology

Independent variable (manipulated variable): Different 13-year 
old males and females

Dependent variable (responding variable): length of the blind 
spot

Controls: lighting in the room, using same chart, giving same 
directions

Materials: Your Eyes book, ruler, different 13 year-old males 
and females with good vision (with glasses on)

Procedure

1. Get materials together.
2. Take photocopy page 9 out of Your Eyes (blind spot chart)
3. Cut out picture diagram. You will use that to find out where 
your subjects' blind spots are.
4. Then get one of your 13-year old friends.  Have them hold the 
picture diagram as far from their face as they can and 
concentrate on the x on the left side.  Their chin should be on 
one end of the meter stick (0 cm) and the picture diagram X 
should be directly above the meter stick.
5. Have your friend bring the picture diagram slowly toward 
their face until he can no longer see the dot.  Note the 
distance on meter stick,
6. Record how far away the picture diagram is now.
7. Have your friend continue to bring the picture diagram slowly 
toward their face until the dot reappears. Record. Calculate 
length of blind spot.
8. Repeat steps #4-#7 with same person.  Calculate average 
distance for that person.
9. Repeat steps #4-#8 with remaining subjects.

III.  Analysis of Data

I found that the boys had a smaller Blind Spot, except one boy 
who was the first to be tested had a slightly larger Blind Spot, 
than two of the girls.  The largest Blind Spot of any boy was 
10.5 centimeters compared to the largest of any girl to be 15.5 
centimeters.  The smallest Blind spot of any boy was 8 
centimeters compared to the smallest girls was 10 centimeters.

IV. Conclusion and Summary

My results caused me to accept my hypothesis.  The research 
showed that the individuals Blind Spots varied in distance.  
Those people whose blind spots were the same distance started 
and stopped at different points.  If I could of done on thing 
different, it would have been to use a larger group of subjects.  
If my results varied in a group of 9 people, it would of been 
interesting to test a greater number of people.

V.Application

I feel blind spots have a lot to do in everyday life.  If you 
have a fairly large blind spot it could interfere with a task 
such as driving your car.  I hope my research will help people 
become aware of blind spots so they can make necessary 
adjustments.  The only suggestion I have for future research 
done on this topic is to research a larger group of people.