Science Projects

PHEOC Write Up

Problem: Which kind of cheese can grow mold the slowest and which can grow mold the fastest?


Hypothesis: I predict that the mold will grow on the Muenster cheese last because it is rinsed so mold won't grow on it.

Experiment
Materials

1. Three different cheeses, Muenster, Swiss and American
2. Three Petri Dishes
3. Webcam Toy

Process
The process for mold to grow is to get three different cheeses and put them in the Petri dishes, so the oxygen can’t escape, put the cheese somewhere safe where no one will open the cheese and let the mold that is growing escape, and a picture of each of the cheeses will be taken every day.

I selected three different cheeses, all having different qualities: Muenster cheese, a washed rind cheese, a cheese rinsed with chemicals to prevent mold growth; Swiss cheese a hard, low moisture cheese, a cheese that has a low amount of moisture and is harder than some other cheese; American, a processed cheese, a cheese that is made using a variety of ingredients.


There are certain things that mold needs for it to grow.
What mold needs to grow is...

• An organic matter - the cheese
• Moisture - On the cheese
• A Temperature between 40 and 100 degrees - the cabinet
• Oxygen - trapped in the petri dish
• Time - letting the cheese sit in the cabinet for a few weeks

Variables
Dependent Variables, the variables that change - The cheese
Independent Variables, the variables that cause something to change - The moisture
Constant Variables, the variables that don’t change - The Petri Dish, temperature, oxygen and the time

Observation:

Muenster Cheese - It took 6 days for mold to grow on the cheese.
American Cheese - It took 15 days for mold spores to grow on the cheese
Swiss Cheese - It took 7 days for mold to start developing on the cheese

Conclusion:

I did this experiment to see which kind of cheese could grow mold the fastest. The cheese that grew mold the fastest was the Muenster cheese, because it is washed so mold won’t grow on it, but because the cheese was placed in a Petri dish and placed in a warm cabinet for 15 days. The chemicals that it was washed with wore off because the chemicals are meant to be placed in a cold place, like a refrigerator, but because it had been in a warm place for a longer amount of time than the chemicals are supposed to.

The Swiss cheese started to develop mold after the Muenster cheese because the heat of the cabinet had eventually started to make the cheese melt, so it gave the mold moisture because the Swiss cheese was starting to melt.

The American cheese didn't grow mold because of the ingredients it is made with, and one of the ingredients is a variety of different salts, and salt affects mold growth because salt absorbs the moisture on food. Because there are a variety of salts in the cheese, some of the moisture was absorbed into the salt, the moisture sank into the cheese. Also, salt is a natural preservative.

Tornadoes

The family flees from the house to the safe room, and when they get there they see the giant tornado suck up their house and fling it up into the air like it was made of paper. The family exited the safe room half an hour later when the tornado was gone. There was an incredible amount of damage. There were trees everywhere. The whole suburb was completely destroyed. Tornadoes are the most powerful and feared forces of nature.

Tornadoes can occur in any climate, as long as a different air mass collides with the climate’s. But for a tornado to occur, it needs wind current. Wind current is caused by the Earth’s rotation. If the Earth wasn't moving, the air would just stay in one place. The circular motion of a tornado is caused by two different air masses colliding. The warm air rises and cold air goes down. The different air is colliding and twisting around the other air mass so it can get past the different air. The air swirls around the other air while it is moving. The circular motion is caused by cold air swirling around the warm air while trying to escape. 

Tornado Alley is where tornadoes occur the most. Tornado Alley is in between the Rocky Mountains and the Mississippi River. Tornadoes occur here because cold and dry air from the Rocky Mountains meet the warm and moist air from the Gulf of Mexico, which are perfect conditions for a tornado to occur. While Tornado Alley is where tornadoes occur the most, Antarctica is where tornadoes occur the least, tornadoes don’t even occur in Antarctica, because of the year – long cold. The Great Plains are in a small part of Tornado Alley.

Some tornadoes can be slow, around 30 - 40 miles. Some tornadoes can be faster than a cheetah. Tornadoes were more dangerous in the past. Sometimes you could predict them easily. Sometimes you couldn't tell a tornado was coming, but sometimes you might not know that there is a tornado coming until it was too late. Now people have radars that scan the area to look for a tornado, or conditions that could cause a tornado, so they can warn the people in the area that there is a tornado nearby. 

Tornadoes are the most powerful and feared forces of nature. They are made from two differing air masses colliding. Things were much more dangerous in the past because they didn't have all the technology that we have today. Things would be very different in the present, if they had all of the machines that we have today. If tornadoes could occur in Antarctica, they would move the same speed as all of the other tornadoes. Tornadoes could not occur without warm air colliding with cold air.

Sewage Treatment Plants and their affect on Ecosystems

Society depends on many different things and processes. One process that is very important people don’t usually think about. People just think that when they throw something away, or flush something down the toilet that it just goes away. One of these processes is the sewage treatment plant process. Even though the process that it takes to get the water clean and back to the river, the process is actually really complex.

The first step in the sewage treatment process is to get all giant objects out of the water, like a tissue box, and other items that are big. In the second step the water is put into tanks so all of the solid particles (like sand and dirt) can sink to the bottom. They are then removed and sent to holding tanks for further processing and eventually thrown into a landfill or used as a fertilizer for farmland. The third step is to put a micro – organism in the water to remove organic matter out of the water, and it does this by using the organic matter as a food substance to remove the organic matter. The fourth step is to remove all of the harmful micro – organisms out of the water, and the clean water is sent into a river or any body of water nearby.

Sewage treatment plants positively impact the environment because it provides clean water for rivers. They can also negatively impact the environment, because building the plant requires cutting down plant life, like trees and bushes, which can destroy homes for animals. Human actions can affect the environment in many ways. Sewage treatment plants help the environment because they also provide a disposable effluent that doesn’t affect the environment. Effluent is used to feed bacteria used in biofilters, which are used to reduce pollutants.

Even though the process that it takes to get the water clean and back to the river, the process is actually really complex. The process provides clean water for environments, and an effluent which can help biofilters reduce pollutants.  It can also help humans, because it provides clean water for rivers or lakes, so kids can swim in cleaner water.