Showing posts with label 2015-2016. Show all posts
Showing posts with label 2015-2016. Show all posts

Renewable Materials

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Image source: www.pinterest.com
In class, I've been studying sustainability in the various components of green architecture. This week we read article about how to choose a renewable material based on a lot of different factors. This article relates to what I'm learning because it's important to know what makes a material green when choosing which material to use in a green home design. It is important to think and learn about these things because they enable us to begin to reverse the damage we've done to our environment.

Image source: www.arup.com
When choosing what material to use in an environmentally friendly home, there are many different factors and ideas to consider. For example, all products made from petrochemicals have a  large environmental impact not only during their use but also as they remain in the environment - in landfills, mostly - long after their actual use. Heat should also be considered because the more heat used in the production of a material, the higher its impact -they consume more fuel, therefore creating more pollution. Manufacturing is another fairly straightforward idea - the more complex the manufacturing process, the more environmental impact it has. Products tat contain toxins are,, for obvious reasons, both unhealthy and non-renewable. These products will have effects both during the manufacturing process and after their use in the building.

Image source: blog.wallstreetsurvivor.com
Planned obsolescence, complexity, and human vs. machine labor should also be considered. Planned obsolescence is when companies produce consumer goods that will become obsolete, or age and break down in such a way that they can't be repaired, only replaced. "Maintenance-free" products do require no maintenance - because after a while they become obsolete beyond repair. Those products that aren't maintenance-free do require regular refurbishment but because of this they can last centuries. Complexity is, in this case, quite a common-sense principle: the more parts a product has, the more opportunity there is for it to malfunction or breakdown, becoming waste. As far as human vs. machine-labor goes in environmental terms, human labor is much less impactful than a machine's. A person applying by hand a product made locally is much more sustainable than having to ship a machine-manufactured product from a distant factory. 

Image source: www.millergrpva.com
Overall design is a "green consideration that is often overlooked when it comes to designing a sustainable home - a well-built conventional home will probably outlast a poorly built sustainable one. Another pretty obvious thing you should consider doing when designing a green home is setting sustainable goals and making informed choices about your chosen material. If a material earns many green points in one area, it probably has drawbacks in others. The best way to find the right or the "greenest" material is to take advantage of third-party certification. As well, even if a building is extremely green/sustainable/uses only renewable materials and resources, if it's ugly or not likely to make people care about it, it won't be cared for through future generations, once again outlived by more beautiful conventional homes. When picking a material, you should also look out for greenwashing. Greenwashing is falsely advertising products as green, and has a very negative effect on the environment, because people motivated to make green choices may, as a result of greenwashing, think they are making those choices when they aren't. Overall, there are three categories environmental merit can be judged in:
  • low overall energy consumption, which can be achieved by using energy-efficient appliances and systems.
  • reduced toxins or environmental impacts, a large category which includes recycling, responsibly harvesting producing, durability, reduced waste, and more.
  • creation of a non-toxic indoor environment, which is just what it sounds like - keeping harmful toxins our of the inside of your house.
Transportation impacts are also important to think about. The distance your material must travel, the weight of that material, and mode of transportation all contribute towards the transportation impact. The lower the transportation impact, the better.

Image source: cleantechnica.com
An interesting concept mentioned in the article was "Comparing Like To Like." This means that once you've chosen your renewable material, its impact can still vary based on the supplier you choose. Whether or not the chosen material was harvested and/or processed sustainable should definitely affect a material's overall "green points" With the current trend towards green home design, a lot of new products are entering the market. They all share a common goal - to improve upon their competitors' environmental performance, affordability, durability, and ease of installation. It is up to each individual buyer to judge for themselves, with the help of trustworthy third-party certifications, which material is green enough to use in a sustainable home design.

The Race to Carbon Neutral

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 Image credit: www.transsolar.com
In class I've been designing green homes and choosing the city where my home would be located. This week we read an article about carbon neutral cities and the cities that aspire to that title. This article relates to what I'm learning because a city's carbon footprint should be factored into a decision about the location of a green home.

To become a completely green city, with absolutely no carbon footprint is the ultimate environmental goal for any city. Right now, in Abu Dhabi, the United Arab Emirates, Masdar City is being built to fulfill these requirements, which include using only renewable energy sources like solar and wind energy and relying solely on smart design elements. Abu Dhabi was chosen specifically for develop
ment because the country has made it's fortune on fossil fuels like oil, but the country's officials are well aware that their oil wells will run out and are therefore highly in favor of using their money to invest in the construction of the environment-friendly Masdar City. Because of this development, green city design organizations have decided Abu Dhabi is a perfect place to build a completely carbon-neutral city.

Image credit:  www.masdar.ae
However, building a completely carbon-neutral city is a complicated process, with lots to consider. One major consideration for the city planners of Abu Dhabi is the city's heat - they had to come up with dozens of small solutions whose collective impact replaced the need for air conditioners.Another consideration was water conservation, because of Abu Dhabi's arid climate. The solution to the water conservation difficulties was to purify then recycle greywater, or the water left over from washing machines, sinks, baths, and showers. Another solution that helped conserve both water and energy was the decision to replace faucet handles and switches with motion-activated sensors. Another innovation implemented by the city planners, this time to reduce air pollution, is to ask that no cars be used in the city, to be replaced by underground electric pod shuttles. Solving these difficulties was an expensive but effective undertaking, which was only made possible because of the city's oil drilling fortune and determination to "go green."

Image credit: inhabitat.co
As I mentioned, building carbon-neutral cities like Masdar City is an extremely expensive process. This is because of all the practices and renovation that must be implemented citywide for each problem. However, each of these practices could be individually implemented in older cities to make them more sustainable with minimal trouble.

Thge South Australian government has set themselves a new goal - to make Adelaide the world's first carbon-neutral city. Their hope is to remedy the federal Coalition's approach to environmental issues by implementing a variety of different renewable energy projects. These include a focus on transportation, efficiency (for example, a trial of driverless cars) and better waste managements and recycling. These are all excellent ways to make their city energy efficient, and, if successful, will be a role model for green cities everywhere.

Rooftop Views

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In class, I have been studying different types of green roofs. this week we read an article about the growth and benefits of rooftop farms and gardens in Chicago. This article relates to what I'm learning because rooftop gardens and farms are excellent examples of green roofs. It is important to learn about these topics so we can be properly informed while designing our own homes, whether for a project or real life, as well as generally understanding what may well be the future of agriculture.

Green Roofs for Healthy Cities (GRHC), an organization that promotes green roofs, has decided to target the city of Chicago for development for a number of reasons. One reason is that Chicago was already known for its green development and rooftop gardens, so the organization had a start to work from. Another reason is that there were already green organizations reaching out to the city and they could be even more successful in their green developments by forming partnerships. These reasons, among others, were deciding factors in GRHC’s choice of Chicago.

The phenomenon known as the Urban Heat Island Effect describes how an urban area is warmer than a rural one. It is caused by a variety of factors, including lack of vegetation that would otherwise filter and cool the air, artificial materials and vibrant colors that absorb and radiate heat, and the exhaust from our cars and factories. The Urban Heat Island Effect affects humans by amplifying the amount of energy we need to cool our buildings, which in turn has a significant effect on our economy and by increasing health hazards such as heatstroke. It also affects the environment as a whole, since the increased need of energy uses up resources and the overall increase in heat contributes to global warming.

Albedo is the amount of light or radiation reflected by a surface. The albedo of a surface ranges from 0 to 1, 0 representing a surface that absorbs all the light that reaches it while 1 represents a surface that reflects all the light that reaches it. Albedo affects communities in relation to the Urban Heat Effect - a rooftop or wall with lower albedo will absorb heat, contributing to a warmer urban area, while a surface with higher albedo will reflect it. So, if as a builder and/or consumer you are designing or choosing the roof of your house, it makes sense to consider the albedo of the surface material you choose.

A rooftop farm is pretty much what it sounds like - a green way to grow food on your roof. There are many benefits to having them, such as much greater efficiency in food production, opportunity for city-dwellers to reconnect with nature and agriculture, and reduced seasonal limitations. Because of these reasons, rooftop farms are becoming more and more popular. 

Overall, rooftop gardens and farms and a firm understanding of how the Urban Heat Effect and the concept of albedo affect these green rooftops is a great way to learn how to improve the green quality of the home you're buying or designing. 

Why Green Homes Matter

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In class I have been studying green architecture. This week I read an article about why green homes matter. This article relates to what I'm learning because it's important to understand why the green homes you're designing matter and how affect the world we live in. It is important to learn about these topics because they teach us how to contribute to the conservation of our resources and our environment.

Image credit: www.casaverdenm.com
There are many ways in which living in a green home or building benefits human health. One reason is indoor air quality - a green home contains less allergens, pollutants, and environmental contaminants than a non-green home, which enables the resident of a green home to be less likely to contract asthma, allergies, or other respiratory diseases. A second reason is that it has been proven that living or working in a green building can also impact mental health, because it has been shown that working a green building results in higher productivity and a lower rate of employee turnover. The only area green homes did not score well on was acoustics, which means they don't usually have good sound quality. This is because it's sacrificed to allow better insulation, efficiency, and general sustainability. The two positive reasons are just two among many, but they show that even with sub-optimal sound quality, it is much healthier to live in a green home than a conventional one.

Image credit: www.opuc.texas.gov
There are five main ways you can enhance 'green' qualities in your home. These are energy efficiency, water conservation, indoor air quality, resource conservation, and livable communities. Three areas we should particularly focus on are livable communities, energy efficiency, and resource conservation. We should focus on livable communities because it is both an important and easy change that minimizes greenhouse gas emissions - it can implemented easily by simply living in a well-clustered community with close access to stores, schools, parks, and restaurants where you can walk or bike to most necessities. Energy efficiency should also be a focus because it both conserves valuable energy sources and lessens the amount due for people's utility bills. We can implement this by checking the energy performance of our appliances and using renewable energy sources like solar heating when we can. Resource conservation is another area we should focus on because it once again reduces initial  and maintenance costs, as well as preventing deforestation and keeping waste our of landfills. It can be implemented while building your home by using less wood and reusing existing materials. Implementing each of these areas is a great way to begin making our home sustainable and environmentally friendly.

I've heard in many places different ways I can make sustainable choices, but one memorable suggestion was at my first overnight camp, where I was asked to minimize my food waste as much as possible, during my duration at the camp as well as afterwards.I choose to make an effort to do that as much as possible, because I think it is a reasonable way to contribute to resource conservation. My choice impacts the environment positively, because it is conserving all the resources that would be wasted in uneaten food.

Chemoluminescence

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In class I've been studying different chemical reactions through a number of different labs. This week we read an article about chemoluminescence, especially in glow sticks. This article relates to my learning because chemoluminescence is a particularly useful and efficient tool in everything ranging from emergency workers to crime scene investigators to medical researchers. It is important to learn about Chemoluminescence because of both the efficient and helpful uses for it that we've already found, as well as the possibly life-saving prospects of what it could be used for in the future.

Because of how important Chemoluminescence is, it's also to understand the words used to describe it. To fully understand the topic, you need to know the terms defined below:

Chemoluminescence: Light emitted by the decaying of an unstable product of a chemical reaction.

Product: A substance formed by a chemical reaction.

Stable: When a system is in it's lowest energy state and isn't going to decay.

Unstable: Liable to decay and to deteriorate.

Emitted: Exuded or produced.

Next, I will discuss the following topics: early uses of chemoluminescence, glow sticks, chemoluminescence in forensics and efficiency, and how chemoluminescence is being used to help diabetics.

All Chemoluminescence reactions create an unstable product that decays, producing light. For example, when the element phosphorus is exposed to damp air, an atom of phosphorus is released and absorbed into the air. This causes the molecules to return to a more stable state, emitting a greenish light while it does so. The light is formed by the atoms being released.

Glow sticks, also known as light sticks, are used by a number of different people, such as emergency workers, military personnel, rave dancers, and Halloween trick-or-treaters. They are generally used when it would be impractical or unsafe to use electricity to generate light. There are two chemicals in glow sticks — usually hydrogen peroxide and cyalume — separated by a glass separator. To 'activate' the glow stick, you 'snap' the separator, allying the two chemicals to mix, causing a chemical reaction.  This excites the dye inside the stick, which then causes the stick to glow the color of the dye in the stick.

Chemoluminescence can also be used for forensics by crime scene investigators. One chemical, luminal, is used to detect blood at crime scenes. This is because it reacts on contact with hemogoblin (red blood cells), glowing a greenish-blue color. This means that the investigators can simply sweep the area with luminal, and if it glows greenish-blue anywhere, they've detected blood. Chemoluminescence is also surprisingly efficient compared to our electric lights. For example, a light bulb has 10% efficiency in transferring energy to light, while a firefly has 88% efficiency.

Chemoluminescence can even be used in medical science. Researchers have been recently experimenting with alternatives to what is currently the only way to diabetics' health - constant finger pricks to test glucose levels and inject insulin. What they've come up with utilizes Chemoluminescence, and looks like it may be a much less irritating and safer alternative. Tiny implants can be injected into the skin without surgery, where they monitor glucose levels by immediately reacting and glowing if blood pressure increases. They're estimated to last about 140 days, because that's how long they've lasted in mice before requiring replacement. The implants can be replaced as easily as they're implemented, with no surgery - quickly and fairly painlessly removed with tweezers. It looks like they'll be a safe alternative for humans, as long as they use well-sealed, with  safe chemicals in the implants.

Overall, Chemoluminescence is an important and useful concept to understand, with a variety of current and possibly uses, all of which are interesting to learn and write about.



Pancakes

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In class, I've been learning about chemical formulas and how to determine them, as well as continuing to cover types of bonds. This week we read an article about pancakes and the chemical reactions that make them what they are. It relates to my learning because it gives me a deeper understanding of various aspects of chemical reactions.

The article we read this week talked about a number of compounds with several different chemical bonds. I have chosen two compounds, sugar and salt, to go into more detail about. Salt is an ionic bond, because chlorine steals sodium's valence electron to form the bond. Sugar forms a covalent bond because oxygen, carbon, and hydrogen share their valence electrons equally between them.

Pancakes rise, like my other baked goods, because carbon dioxide gets trapped in the batter when you mix it, helping fluff the pancakes out. In pancakes, most of the protein comes from eggs and the gluten in flour. The chewable texture is formed by the carbon dioxide bubbles trapped in the batter by mixing, and the tenderness formed by the sugar and butter. It is mainly the fluids in the batter tat allow all the chemical reactions to occur.

Sodium bicarbonate (NaHCO3) is made up of both ionic and covalent bonds, which occurs when positively charged sodium bonds with the negatively charged oxygen and carbon. When you mix acid with a carbonate (such as baking soda with vinegar) you get lots of fizzing as the two react. It is important to remember when adding buttermilk to pancakes that since buttermilk is slightly acidic, it will react with the carbonates. Because of this, if you leave buttermilk pancake batter out for a while, the batter will go flat, like soda when it's left out.

The Maillard reaction is caused by a chemical reaction bet
ween hot sugar and amino acids. During the reaction, small molecules are let out, creating the delicious smells that reach our noses. Two examples of the Maillard reaction or furanones and thiophenes. Furanones create a sweet, caramelly burnt smell while thiophenes generate more of a meaty, burnt smell. An example of something that undergoes the Maillard reaction is onions when they are caramelized - they exude furanones.

All in all, pancakes have a lot of chemical reactions to thank - the ingredients in the batter, the properties of sodium bicarbonate, and the browning process caused by the Maillard reaction. Together, they make pancakes look, smell, and taste good.

Why Do We Care About Chemicals?

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Image credit: www.saltopiasalts.com

     In STEM we've been continuing to learn about subatomic particles and how they help atoms form ionic and covalent bonds. This week we read an article about salt: its chemical makeup, positive and negative effects on health, and how much of it the average human needs to stay healthy. This topic is important because it is important to understand the structure and effects of something we eat every day.

 Image credit: www.health.com
     Besides making food taste salty, salt also enhances sweetness and rounds out the flavor in other foods. However, even though it makes food taste better, it can have negative effects on your health. In the article, it says that "taking to much salt has been associated with high blood pressure, which can damage the heart and blood vessels and increase the risk of a heart attack and stroke." These are all detrimental effects salt can have on your health. People aren't usually very effective at reducing the sodium in their diets because they are still exposed to the same amounts of salt in processed and restaurant foods, which is where 77% of the average person's salt comes from, according to the article.

   
Image credit: www.chemistry.wustl.edu 
 A salt molecule is made out of two elements, sodium and chloride.  Sodium is a very reactive element because it has only one valence electron, which it readily loses to form an ionic bond with another element, such as chloride. Chloride has 7 electrons and six additional protons, so it readily accepts sodium's single valence electron to bring the amount of electrons in it's outer shell to the optimal eight. This makes sodium and chloride very compatible and able to form a very strong ionic bond.



Image credit: www.oreida.com

While it's fairly commonly known that too much salt is bad for you, low-sodium diets can actually be just as harmful. In the article, it states that "Salt, especially the sodium ions (Na+) present in it's NaCl structure, is essential to the functioning of every cell in our bodies." The article then goes on to explain this by describing electrolytes.Electrolytes are solutions that conduct electric currents, the same electric currents that help your brain communicate with the rest of your body. As well, the amount of sodium in your body determines the osmolarity of your bodily fluids. Osmolarity means "the concentration of a solution expressed as the total number of solute particles per liter." If your sodium is low, the osmolarity if your blood could become imbalanced, and the total volume of liquid per cell would decrease, This could cause dehydration, low blood pressure, and even death. Because sodium/salt is also lost when we excrete it through urine and sweat, we need to continually replenish it by consuming salt.

     It is important to balance the amount of salt in your diet. When adding salt to your food, it is important to remember that there's often already food added, especially if the food is processed or made in a restaurant. While having too much salt is definitely bad for your, causing things like high blood pressure, heart attacks, and strokes, low sodium levels can also have negative effects such as dehydration, low-blood pressure, or even death. The key to salt consumption is balance. It shouldn't even be too hard. According to the article, "people may somehow regulate the amount of salt they eat." This means that as long as you let your body tell you when it needs salt and when it doesn't, you should be fine.






Subatomic Particles

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     In class we've been learning about the subatomic particles that make up atoms: protons, neutrons, and electrons. This week we read a a series of comics about subatomic particles and their positive, negative, or neutral charges. It is important to learn about subatomic particles because they make up atoms and atoms make up everything in the world around us.
 
     In the first comic I read, the two characters, Bill and Tim discussed what an atom and its components are. Bill defines an atom as "the smallest component of an element." The comic describes an isotope as the same element with different mass. An example of an isotope is a carbon atom with an atomic number of 6 and a mass of 12 and a carbon atom with an atomic number of 6 and a mass of 10. The comic also stated that the subatomic particles that make up most of the mass of an atom are the protons and neutrons, and the subatomic particles that make up most of the volume are the electrons.

     The second comic discussed the components that make up the human body. The four main elements inside us are oxygen, carbon, hydrogen, and nitrogen. There are also smaller amounts of calcium, phosphorous, and iron inside your body. If you removed all the empty space within all the atoms inside your body, what remained would be smaller than a grain of sand. All this shows that the human body is mostly empty space, water, and a few other different elements.

     The third article talked about how electrons cause static electricity by switching between two atoms. You can harness static electricity by rubbing atoms together, for example such as when your rub your feet against the rug. This makes you negatively charged, so when you next touch someone, they feel a tiny electric shock. This happened in the Protons, Neutrons, and Electrons stations lab we did in class - I negatively charged myself and a piece of plastic by rubbing the plastic against my hand.

     The above comic shows the two atoms talking after an electron switches from one atom to another, negatively charging the latter. The atom that lost the electron says to another "I'm positive!" because it's no longer negatively charged.

New Elements Within The Periodic Table

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     In class we've been learning about different aspects of the Periodic Table of the Elements, such as how and why it's organized the way it is. This week we read an article talking about four new super-heavy elements that will be added to the Periodic Table, about how they are made and named. It is important to read articles like this so we can understand how any new elements can be discovered, named, and eventually added to the table.

    In the article I read this week there were a number of new scientific terms mentioned in the text. Knowing the full definition of these terms is important to fully understanding my blog post, so they're defined below.

An element is something that cannot be broken down into a different substance.

Matter is something that takes up space.

An atom is the smallest possible unit of an element.

A nucleus is the positively charged center of an atom.

Protons are positively charged particles.

Neutrons are neutrally charged particles.

When something is unstable, it is unbalanced, or can lose mass quickly.

Decay means to fall apart.

     The four elements, discovered in January 2016 by the Joint Institute for Nuclear Research and a Japanese team led by Kosuke Morita, the new elements were originally known as ununtrium (113), ununpentium (115), ununseptium (117), and ununoctium (118). Later, element 116 was renamed Livermorium, after the name of the lab where it was created. It can be hard for scientists to tell whether the elements they discover are truly new, because they only exist for less than a second. As well, it is not the element itself that the researchers study. In the article, it says that "Scientists never observe unstable elements directly. Rather, they know they briefly existed because they are able to measure their decay products." This means that scientists can only use the decay product of their element to determine whether their element is new, which is why it could be hard to interpret their results.

     Two of the characteristics that make super-heavy elements such as 113, 115, 117, and 118 unique are their unstability, and how they are created in specialized laboratories. They are made by smashing two particles together, both of which are specially selected for their amount of protons and neutrons. The two particles rarely stick, so it can take 10 quintillion tries for the experiment to succeed.

     Elements names are traditionally chosen by the scientist who discovers them, However, before they receive their names, their names are the Latin word equivalent of their number. In the article, it says that "...these elements have been known by their generic names... Their confirmation paves the way for them to get permanent names. Traditionally, this honor falls to the researchers who first found them." This means that the researchers have to wait until their element is confirmed before they can replace it's Latin name with one of their own choosing.

    Overall, understanding how new elements are created and named is very important to fully understanding the different aspects of the Periodic Table. Learning about elements such as 113, 115, 117, and 118 is helpful for reaching this understanding.

Hydraulics vs. Pneumatics

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This week I read an article on pneumatics vs. hydraulics. Once interesting fact I learned was that both pneumatics create a mechanical advantage, which is why they are both commonly used in machines. It is important to read articles like this so we can understand many of the systems that power the machines and vehicles that we see and use in every day life.

Image credit: www.designnews.com
In STEM we've been learning about two different pressure systems, hydraulics and pneumatics. The two systems are similar in that they are both pressure systems used to utilize force. The difference is between them is that hydraulics involve liquids and pneumatics involve gases. Because of how spread out gas molecules are, gas can be compressed, or made more compact. Liquids, on the other hand, are incompressible. For example, if you filled a water bottle all the way to the top and tried to screw on the cap, some of the water would spill out, because the cap would take up a tiny bit of space previously occupied by water, and since water is incompressible and can't be forced to become compact enough to fit in the smaller space, it spills.

Image credit: hendrix2.uoregon.ed
Pressure is defined as the amount of force per unit area. Atmospheric pressure varies depending on how close or far you are from the cor of the Earth. If you are closer to the core of the Earth, then the atmospheric pressure will be greater, because the gravitational pull on the air molecules is stronger and the mass of the air molecules higher up also contribute to the pressure.

Pressure also changes based on the state of the container the substance is in. For example, the pressure in an open container containing liquid only pushes down, and as with the air molecules causing atmospheric pressure, the pressure in an open container increases deeper in the water because of the mass of the water above it. In a closed container, the water is occupying less space than it wants so, so the pressure it applies is spread evenly in all directions.

Mechanical advantage is how a tool or machine can be used to amplify the force put into it. When relating to mechanical advantage, the relationship between cylinder size and force is proportional - applying a small force to the small cylinder results in a large force applied to the large cylinder. However, the relationship between cylinder size and distance is different. The small cylinder has to move a greater distance for the large cylinder to move a smaller distance.

It is important to think about mechanical advantage when we want to create a hydraulic arm so that we can understand and utilize it to increase the efficiency of the arm, and so we can use it to move heavier objects with less force When building the arm, it is useful to use syringes of the same size and differing sizes. If you want the amount of force you put in to be equal to the output force, use two syringes that are the same size. If you want to put in a smaller force for a greater distance to get a greater output force for a shorter distance, use two syringes of differing sizes.

Boat Building

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Image credit: www.teachengineering.org
Three objects that look the same in size and shape may not float in the water in the same way. For example, For example, if there were three blocks that were exactly the same size, one made of Styrofoam, one made of hollow wood, and one made of solid wood, each would float, but they would all float in different ways. The Styrofoam would float high in the water, the solid wood float low in the water, and the hollow wood block would float somewhere in between. This is because of how gravity and water pressure affect each block. The Styrofoam block isn't very dense and contains a lot of air, so it doesn't contain much matter. Since its mass is so low, gravity doesn't affect it very much and the water pressure at the surface of the water is enough to keep it afloat.The hollow wood block would be heavier, so it would have to sink farther down in the water before it would find enough water pressure to make it float. The solid wood block would have to sink still further before it would find enough water pressure to counteract the amount of gravity acting on it.

The reason why ships float although they often are made of a material that naturally sinks is mainly due to their shape. When a ball of steel, for example, is dropped in the water, it sinks, because all the force of gravity acting on it focused on one point in the water, so no amount of water pressure can counteract the ball's gravity. But when that same volume of steel is flattened out and shaped into a boat, the amount of gravity acting on it is spread out over a larger surface area, so the water pressure is able to counteract it.

Due to buoyancy, objects displace the same amount of water as their mass and the volume of however much of the object is in the water. If an empty canoe floating on the water weighed 120 pounds, it would displace 120 pounds of water. However, if that same canoe sank, it would displace more than 120 pounds because the canoe would have to weigh more that it did when it floated to sink. The same is true for if the canoe tipped over or filled with water - if it filled with water, that is obviously adding more weight, and if it tipped over it would float lower in the water and therefore displace more water as well.

This week, to show our understanding of buoyancy, density, and particles, we created boats using aluminum foil, modelling clay, and/or Play-doh, all of which are denser than water. The first challenge was to create a boat that floated, but then we were given the additional challenge of making it carry as much weight as possible without sinking. While building my boat, I decided that aluminum foil was the best material, higher sides made the boat stay afloat longer, and larger boats held more weight.

When testing and redesigning my boat I made a number of different changes, including making the shape more elongated, the bottom flatter (it distributed the weight better), the sides higher, and I added a couple extra layers to hold extra air and prevent leaks in the main body of the boat. The design that worked best was my final product. It was the largest yet so that the gravity acting on it was spread over a greater surface area, and higher sides let it sink lower in the water before filling with water. The boat design I tried that worked least well was one of my earliest designs, one that had a more traditional boat bottom, because it forced all the gravity acting on it to focus on less surface area. This made the design sink faster.

During class, we learned about volume, mass, density, and buoyancy through many different types of exploration. After all that we learned, I think it's important to remember these three central points:

  1. Materials that would usually sink in water can be made to float by shaping the material, so that the amount of gravity acting on the material is spread out over a greater surface area.
  2. Where something floats in the water is determined by how far down in the water there is enough water pressure to counteract the gravity acting on the object.
  3. The volume and mass of an amount of water displaced by an object is equal to the volume and mass of the object itself.
These three points can be used to determine how an object floats, why an object floats, and how to make an object float or sink.

Moving Things

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Image credit: www.britannica.com
This week I read a selection from books 7 and 8 of Aristotle's Physics. One thing I found interesting was how Aristotle talked about change, and how he said that weight is basically an upward or downward tendency. It is important to read texts like this because it tells us about what some of the first philosophers thought about the subjects we learn about in school.

According to Aristotle, fiery particles naturally move upwards and earthy particles tend to move downwards. Therefore, downwards would be an unnatural direction of movement for something fiery, and upwards would be an unnatural direction of movement for earthy particles.

Image credit: weknowyourdreams.com
Something can be potentially light in one situation and potentially heavy in another situation. This is because of a number of reasons, such as gravity, mass, or, in Aristotle's words, upward or downward tendencies. An example of fluctuating weight would be a pool of water - with the force of gravity acting on it, it remains pulled downward, but if the force of gravity was lessened or removed, it would float upwards.

Image credit: www.public-domain-image.com
 When Aristotle spoke of fire and earth having natural movements, I think he is offering an explanation based on principles and causes. He mentioned that they are "forcibly moved by something," which could be a cause, and also says that natural tendencies are caused only by what they already possess in potential, which could be seen as a cause from the fire or earth itself.

Overall, this text was very interesting, because it was intriguing to see a philosopher from such a long time ago thought about the topics he wrote about, and how that related to things like gravity, mass, and density.

To better understand the text, our class put together actions for each paragraph in the excerpt we read, and the complete video can be found below:

Oobleck Lab

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Image credit: www.albionlibrary.org
This week I experimented with Oobleck. In class, I have been studying mass, volume, density, and particles. I made Oobleck from cornstarch and water, adding 200 mL of cornstarch to 100 mL of water a little bit at a time. This relates to my learning because we've been learning about how the density of particles affects the state of matter of a substance, and Oobleck is unusual because it has properties of both a solid and a liquid matter.

When you move Oobleck around or apply pressure, the Oobleck feels solid, but when it's still, it melts into liquid. When I looked at the Oobleck, it looked like a blue (because of added food coloring) liquid, and when I shook the plastic bag I had it in, it moved like a liquid. The Oobleck smelled like cornstarch, predictably, but its most interesting feature was definitely how it felt. Through the bag, it felt liquidy, but when I squeezed it, it felt kind of doughy. Once I took some of it out, though, I could make it solid by moving it around but when I set it down, it melted into a waxy puddle.

When I was playing with the Oobleck, the results were mixed. When I poked my finger into the Oobleck slowly, it felt like I was sticking my finger in a liquid. When I poked it quickly, it felt like I was poking a solid. When I was transferring it from one bag to another, it poured like a liquid. I succeeded in rolling the Oobleck into a ball by keeping it constantly in motion, but when I stopped touching it, it became a liquid again. Bouncing the Oobleck was unsuccessful - it melted as soon as it touched the table.

Image credit: www.utwente.nl
My experiments have shown me that Oobleck is a non-Newtonian substance, which means that it's neither a solid nor a liquid, but possesses properties of both. When pressure was applied, or it was kept in motion, the Oobleck was a solid, but when it was left alone, it was more of a liquid. From what I learned in class, I can hypothesize that by applying the pressure that makes it feel solid, I'm actually pushing the particles of the substance closer together. That would explain why it seems to switch between the states of matter. It is a very intriguing substance, and interesting to experiment with.

Effects of Turbidity on Living Things

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This week in class we explored how plants react to changes in the amount of sunlight that they receive. I was surprised to learn that bacteria photosynthesize too, the process is not limited to plants and algae. It is important to investigate water quality indicators and tell others about my results because a lot of us take good quality water for granted, and don't always think about people for whom finding good or even just fair quality water is a challenge.

The reason we used "sunlight" and "lack of sunlight" to explore how successfully a plant grows was to further explore how turbidity can affect water quality. In my experiment, my results showed that the plant without light, the plant with a higher level of "turbidity" did much worse than the plant with light, with a lower level of "turbidity." In my hypothesis, I originally stated that the plant with light would do better than the one without, because the one without wouldn't get the nutrients it needed from the light. I therefore proved myself correct through this investigation, because my results matched my hypothesis,

Image credit: en.wikipedia.org

During photosynthesis, oxygen and sugars (glucose) are produces. They are both the result of photosynthesis because the oxygen is the by-product of the water, carbon dioxide, and nutrients during the process and the glucose is specifically produced to help the plant grow. I think this investigation is related to photosynthesis because turbidity is the amount of suspended particles, or murkiness, in the water, and suspended particles block and absorb sunlight before it can reach many water plants. So, when we compared plant growth with light and no light, we were also comparing what could have been two levels of turbidity,


Changing other influences on plant growth, such as the amount of water or nutrients, affects the plants because a plant needs the correct amount of all its influences to grow properly. High turbidity in a river causes changes in a plant's ability to photosynthesize. Other water quality indicators that signal a problem for photosynthesis in plants include lack of nutrients (specifically, nitrates and phosphates) in the water, because nutrients are one of the key components for photosynthesis.

Image credit: fish-notes.blogspot.com
The following might happen to other living things in the ecosystem if a plant cannot complete
photosynthesis:the plant species might die, causing a collapse in the ecosystem and a scarcity of DO, which they use up as they decompose. It would also not use up carbon dioxide and give oxygen, which would affect nearby life.

It is important to know how specific water quality indicators impact the water and living organisms with the water because then when there is a problem with a body of water or life within a body of water, we can use our knowledge of specific indicators to locate and stop the source of the problem.

The River Continuum

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Image credit: nsismke.blogspot.com
This week I read "The River Continuum." The article was about the four functional feeding groups of macroinvertebrate aquatic insects: shredders, collectors, scrapers (also called grazers), and predators. It also showed where each group lives within a river. Their purpose within the river or stream is to help decompose the natural debris in the water. Below are some of the words and terms from the article and their definitions.

Specialized adaption is when an organism adapts because of a specific circumstance or surrounding. For example, black fly larvae use a fan to capture their tiny food particles.

Organic materials are the natural matter found in a river such as leaves, twigs, branches, and dead aquatic life. Macroinvertebrate aquatic insects eat and grow on them.

Shredders are the group of aquatic insects which eat pre-softened food with large mouthparts. Their job is to take care of the larger pieces of of the organic material.

Collectors are the group that eat the little pieces of is the suttter that shredders leave behind. They have special adaptations too, like how the free-living caddisfly spins a net to catch their food.

Scrapers eat algae from the surface of rocks. They build homes out of stones and stick to them with suction cups and stickiness on their abdomens.

Predators eat the other types of aquatic insects. Their job is to keep the other groups' populations down. 

Geomorphology is basically the study of the shape of the earth's structures. It relates to our blogging and classwork because the geomorphology of a stream affects the quality of its water, which affects the aquatic life, including the four groups of insects.

Riparian means of or around water. For instance, vegetation growing by a river could be called riparian vegetation.

Substrate is something on which something else grows. For example, the algae the scrapers eat grows on rocks. Those rocks would be substrate.

Image credit: www.stroudcenter.org
Shredders, collectors, scrapers, and predators are found at the headwaters of a river. These functional feeding groups are found in this location because there is a wide variety of organic material found there, so the shredders and collectors are particularly abundant.

As well, all four groups are found at the mid reaches of a river. However, the abundance of shredders decreases, because most of the large organic material is found at the headwaters. The collectors still have plenty of smaller food, though, and scrapers have plenty of algae-ey rocks to feed off of too.

Collectors and predators are found in the lower reaches of a river. Collectors thrive because there is still no shortage of tiny pieces of organic material, even in the wider part of a river, Predators also live there because they can eat the collectors.

It is important to know which macroorganisms are present in a source of water because they affect the water quality too, just like all the other indicators I posted about. They affect the amount of natural matter in the water, as well as the other microorganisms that live in it too. 

How Water Quality Affects Ecology of a Community

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I hypothesize that the water from Jar 5 (left) came from a forest stream. One indicator is its turbidity, which is fairly high, as you might find in a shallow natural stream. It's DO is also pretty high too, which suggests that it was probably a moving water source, like a stream, and can support small aquatic life. Finally, it's pH level  is slightly alkaline, so it would be good to drink, but not perfect. Taken together, I would rate this good quality water, because while it doesn't have unhealthy levels of anything, but it isn't filtered.
Sign that could be posted by culvert                 
This water could also be from a culvert, because the same indicators could apply to both locations. While they may not seem particularly similar, the actually do have some similarities. Most of the water in a culvert is rainwater, and it flows, which could explain the fairly high level of DO. Also, both locations are shallow, and could turn up bottom sediment, which would lead to a level of turbidity. Since rainwater is usually alkaline (except where there are high levels of air  pollution), the pH levels would make sense too. While I wouldn't recommend drinking this water, if you did, you would probably be okay.

   Image credit: gardenpool.org
In my experiment to determine how fertilizer concentration affects the growth of duckweed plants (pictured left), I determined that the lowest concentration of fertilizer, 0.25%, was best for the duckweed growth. That water's duckweed grew many more fronds (leaf like protuberances on the surface of the water) than the other four concentrations. The two highest percentages, 1% and 2%, were bad for the plants, leaving most of the plants dead within five days. The duckweed plants with the concentration of 0.5% and the control were okay for the duckweed, too. This leads me to think that when we use fertilizer in our gardens and yards to help our own plants grow, we are actually affecting the outside environment. When it rains, the rainwater mixes with the soil, then flows down to the nearest body of water. My experiment shows that even 1-2% of fertilizer concentration in the water can make it a worse environment for plants like duckweed to grow, and it's possible that the fertilized soil-infused water collectively could reach that percentage, affecting the body of water's aquatic plant growth. All in all, the concentration level of phosphates and nitrates impacts water quality and plant growth positively in moderation, but negatively in excess.

Image credit: bjsilliman.wordpress.com
If I were to come across a body of water like the one pictured right, I would determine the quality of the water by using many but not all of the tests we've learned about so far. Specifically, I would include turbidity, pH level, check for organisms and parasites like amoeba, and its temperature. My reasoning is fairly simple - the tests I chose would determine whether it's quality was good for humans only, other types of organisms, or none. For instance, if the pH level was very acidic, I would be able to tell that the water quality wasn't very good for any type of life. If there were organisms or parasites in the water, I would know that it wouldn't be good for humans to drink, but maybe okay for other animals, as with the turbidity. Finally, its temperature would tell me how good it was for both humans and animals, because warm water is both a less good environment for aquatic life, and more likely to host things that are bad for humans too. Judging from the picture of this water alone, I would rate it's turbidity level pretty high, and guess that there would be a fair amount of organisms within it. I would recommend it for boating and canoeing, but not necessarily for swimming, and definitely not for drinking unfiltered.

Beneath MN's Surface

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 Image credit: www.mustesielu.deviantart.com
     This week I read the article "Beneath MN's  Surface." I was surprised to learn that there were any deadly water amoeba as far north as Minnesota, because I had heard that they needed especially warm conditions to survive, like in Florida or Texas. While it can definitely be disturbing or depressing to read articles like this, it is still important to know about the things they describe, and sometimes so we can remedy them.

Video credit: www.youtube.com/watch?v=7pR7TNzJ_pA      
     One water parasite that Minnesota's waters may  be becoming more hospitable towards is deadly water amoeba, or Naegleria fowleri. The amoeba causes amebic meningoencephalitis, by basically  traveling up your nose and living in, eating, and infecting your brain. While I haven't yet learned about deadly water amoeba's effects on non-human organisms, it does change our environment by making us more wary of swimming in warm water. As far as what is creating a space for deadly water amoebas to show up in Minnesota, it is probably because of global warming, and the summer heat waves which increase the risk of contracting amebic meningoencephalitis.
                                                                                 

      Around August 31st, a mysterious oily red film appeared on the surface of Richfield Lake. It resembles no natural algae or plant product, and is currently unidentified. It's appearance was noted by many people living nearby, and one Brigit Johnson said "It was shiny and red. I just thought it looked scary." Initial tests by scientists did not identify the substance, and even now it has not been identified. Personally, from how it has been described, I have some ideas as to what it is. Since it is on the surface of the lake, it is probably lighter than water, and hydrophobic. My guess is that it's either some sort of discarded chemical substance or an oil-based paint or something similar, but it could always be taken to an analytic chemist to know for sure. The article does not suggest that it probably won't affect humans, because Richfield's drinking water does not come from the  lake. However, it still may affect some of the aquatic life in the lake. Hopefully, though, since it isn't a naturally produced substance, it should be a one-time occurrence.

     The importance of determining water quality is so that we can know how pure and good the water we are using to drink and swim in is, as well as the water we use for other things, like boating or sailing. As water-conscious citizens, I think all should be aware of the quality of water that is their community. If a source of water is compromised it could negatively affect the health of both humans (especially those who are less wealthy, because they may not be affording personal house filters or purified bottles water)and many other animals. Finally, one way I could advocate for clean water is by working with my family to buy less toxic products, knowing that some of it will end up in the groundwater.

     
    

Water Quality Indicators

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Image credit: http://www.nihonsolid.co.jp

     This week I read an article about water quality indicators. The term communities is a good term to use when thinking about aquatic ecosystems because the organisms in the ecosystems depend on each other and the state of the water they live in to survive and thrive. One thing I learned more about was the effect of phosphates and nitrates on water, and how that directly affects the growth of water plants. I was slightly surprised to learn that many types of aquatic life prefer cooler water to warmer water.

     Temperature is one big indicator of water quality because it directly affects the amount of dissolved oxygen, or DO, in the water. Cooler water higher levels of DO, and warmer water has lower levels of DO. If temperature in the water increases, many of the aquatic organisms inhabiting it leave or die, because the water is too warm for them to thrive. Often, warm-water organisms will replace them. One big reason for temperature change like that is humans, and the many things we dump into lakes, rivers, and streams. Temperature changes caused by humans are called thermal pollution. Scientists and aquatic environmentalists can check for thermal pollution by testing the temperature of a river, lake, or stream at its source. Then, they move to a different point in the river, lake, or stream, and test the temperature again. If there is a big difference, then the water is probably thermally polluted. Generally, excellent quality water is 0-4 °F, and poor quality water is 18°F or greater.

     Another indicator of water quality is turbidity. Turbidity is basically the measure of how clear the water is. Turbid water has things like clay, silt, and bottom sediment suspended in it, which makes the water brownish or murky. Turbidity affects the quality of water because it affects the temperature of the water - suspended particles block and absorb sunlight. Then, of course, all of the effects of temperature start to occur. Turbidity levels are mainly affected by soil erosion, bottom sediment disturbance, and urban runoff.

     The last indicator of water quality I'm going to write about is plant growth. Algae and other water plants need a small amount of phosphates to grow. Too many phosphates or nitrates, however, increase the plant growth drastically. When there is too much algae, from increased amounts of phosphates and nitrates, it's called an algal bloom. The algal blooms are not good for the waterway, because they block sunlight from the roots of water plants, and when they decompose, the DO levels decrease. The main human sources of phosphates and nitrates in the water are fertilizer, laundry detergent, and sewage. The way to stop water quality decreasing from human-affected plant growth, is to be more effective about stopping phosphates and nitrates from entering the water. This can be done at farms, by building a barrier to stop large quantities of fertilized earth entering the water, and by watching were we dump our sewage.

     In class I have been studying water quality, and how fertilizer concentration affects the growth of duckweed. The article I read relates to my learning because knowing the indicators of water quality will help me understand other things about water quality. I would like to learn more about turbidity, and what natural levels of it are good for common aquatic life.


The Face of a Spider

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Image Credit: http://www.tarantulaspider.net

The Face of a Spider by David Quammen is a story about one day when the author returns home to find his living room filled with black widow spiders - baby ones. Spawned by a single female that Quammen had been avoiding dealing with, the article is about his minor moral crisis, and the major question: How should humans act towards members of the other species? His solution is eye contact.

I participated in the discussion around the question "What is importance if eye contact with other species, according to Quammen?" Before the discussion, I thought that Quammen says it is important to make eye contact because by doing so, we are respecting the other creature as we might another human, and respecting that they may have emotions too. After the discussion, I thought mostly the same thing, but now I thought Quammen emphasized more the emotional aspect over the respect aspect.
 The part of the text that led me to thinking was, "Look for signs of embarrassment, rancor, or guilt. Repeat the following formula like a mantra 'This is some mother's darling, this is some mother's child."

When I was listening to the discussion around the question "How should humans behave toward members of the other living species?" I was intrigued when someone expressed the view that humans should seriously empathize with other species, think of them like human beings, and then still kill them. If I could have added a comment to the discussion, I would have replied to a question posed: "In the end, why does the spider hide it's face in 'distrust'?" and said that, in my opinion, Quammen was over-personifying - that it was highly unlikely that a random arachnid should feel distrust at a face that is just one of many goggling through the glass throughout the day.

I think, when a person has to make the decision to kill or not to kill, it definitely makes them a better person, or at least more comfortable as themselves with their views, because it forces them to reflect on themselves. What do they care about more? What, to them, is right or wrong?" At the end of such a reflection, after having make a decision, I feel like a person would feel more comfortable with their views.

Humans, as a species, have made a pretty indecisive choice in this decision. We go all out trying to protect some species, such as polar bears and spotted animals, but practically ignore many others. Why? Well, we can't practically go to either extreme - saving all endangered species or saving none - so we make choices. People are more willing to fund protection for animals that they know about, like a bear or an owl, and an animal that appeals to them, whether it's considered 'cute,' 'cool,' or 'beautiful.' 

There have been groups of people who've gone an extreme, like the Jainist religion of India, whose central belief is ahimsa, do no harm. Rigorously devout Jains would do things like refrain from cutting their hair, to avoid hurting lice, and cover their mouth with a cloth, to avoid inhaling gnats. Personally, I think it is a nice idea - sharing the earth without harming other life - but just, in the end, wishful thinking. To exert that much energy against such a natural, relentless instinct, to kill, if necessary, to survive - I just don't think that works,