PDS APES 5th Period 2009-10

1. Power

Power is the rate at which Energy is used or being created. Its base unit is in Watts where 1W=(1Joule)/(1second). Power is the basis for rating the amount of energy appliances use over time, like a 100 Watt light bulb will use twice as much energy at any period of time than a 50 Watt bulb.The equation for Power is:

P=E/t

This equation can also be rearranged to find Energy produced: P*t=E

2. Heat transfer

The most common method of turning any Energy in heat, is to transfer heat into steam which will turn a turbine and generator shaft. We can use Heat transfer equations to show how much Energy we need to boil water.

The heat equation uses several variables: Q=Heat energy(calories/BTU’s); m=Mass(grams);c=specific heat, the higher the harder to heat up a material [cal/(J*C)]; and T refers to the change in Temperature. The equation goes like this:

Q=mcT

(remember T is change in temperature!)

3. Price

Calculating Price is the same process as calculating Power, minus the  science! Instead of power we refer to number units bought(units), individual price($/unit) to get the total Price($). Instead of power, price uses a ‘price rate’ or the individual price. Equation:

#Units*Individual Cost= Total Cost

4. Efficiency

Last but not least, we need to be able to calculate efficiency. It doesn’t matter how much Energy we use, if we aren’t using it properly, thats what efficiency is about. Sadly, due to reality all appliances aren’t a 100% efficient so we need to see how much energy we are wasting. For efficiency, we focus on the Input energy, the total energy we put into say a light bulb, multiply that by the efficiency to get an output, an alternate form of energy from what we started (say light/heat). The equation is straight forward:

Input*%efficiency=Output

We are what we eat. For Americans that means we eat a lot of processed foods. When you pick up a bag of potato chips, its easy to see that the product is unnatural, the chip didn’t fry itself and dip it in oil man did that. But what about the meat we eat? In class today we talked about how the meat production industry has changed since the early 1980′s, about the mechanism that replaced the stereotypical small farmer, CAFO’s.

CAFO’s, or Condensed Agriculture Feed Operations is brain child of antibiotics and genetically modified corn. GM corn allows for cheap feed for cows, while antibiotics allows for livestock to bypass population density inhibitors along with an increased growth rate. What this means is that we can now feed more cows, aka produce more meet in less room. That may sound like a simple achievement, but these adjustments allowed for a much higher rate of meat production than other farming methods by fencing animals as tightly as possible, and fattening them as fast as possible.

Just because the CAFO business is booming doesn’t mean that grass fed cattle operations don’t exist. There are still farmers who feed livestock on open pastures or fenced ranged land. But compared to CAFO, the output is so low, increasing pricing that grass fed operations only operate a small consumer niche of the market. Although economic incentives are virtually nonexistent in this market, there are ecological and personal incentives to eat grass fed.

As mentioned in King Corn, the ratio of saturated fat per t-bone in grass fed to corn fed is 5 to 9, almost double, which helps explain rising obesity rates. This along with the fact that cows aren’t meant to eat corn brings up some potential health issues. Other than health issues, by using feedlots, though we are conserving biodiversity by using less land, we promote other environmental issues. With high production of meat comes high production of manure, and methane(global warming gas). Although manure could be a plus since it could be used for fertilizer, with the sheer amount of manure produced by all the cattle, shipping all the manure is not possible and a fair amount of manure will end up traveling down watersheds and causing algae bloom in bodies of water. With high antibiotic use, people worry about the potential of feedlots breeding super drug resistant strains of bacteria also.

Criticism of CAFO’s are different in every country. In Europe, the precautionary principle came first, so GMO’s have been banned along with use of steroids on cattle, destroying CAFO’s. America on the other hand, has embraced the technology producing tons upon tons of corn beef. With no strong health benefits there is no clear winner. I just hope China has grass fed beef, so I don’t have to worry about ulcered cow stomach meat.

Made by KC.

So, reviewing my tests and study guides and I came across a conflict. On the test, it says that green house gas effect is caused when gasses trap infrared light, yet two of the gasses listed, water vapor and ozone are absorbers of UV rays. So I have two questions from this.

1. are all green houses bad? With the formation of ozone holes in the stratosphere, isn’t having more ozone and water in the troposphere good since it can absorb UV rays?

2. How does water and ozone absorb infrared energy? Is it simply a physical reaction versus the 3/2 steps ozone uses to change UV rays into infrared.

So after doing the island simulation, I remembered something. In the packet which explained to us how to use the rule of 70, there one of the practice questions taled about at which day did should the lilies be removed so they don’t overpopulate the pond (I don’t have the packet with me but I’ll edit the post to clarify the question when the next opportunity arises). Does that refer to the inflection point? Or the period of doubling before the lilies completely occupy the pound?

Studying for the test, and was looking at the lovely diagrams in the book and well, like last time I came across another sinkhole that kind of bothers me. This time its on page 78, figure 5-4, where it shows heat released and radiates to the atmosphere. I find this a little bit confusing partially because of discussion of how the only atoms that really escape into space are around the mass of Helium, and well given the air’s composition, doesn’t really seem like much of a heat sink. Is that how it really works? I’m not worried about knowing this for the test, but I want to know whats happening…

So, looking over the cycles in the book, and I realized that the Nitrogen Cycle isn’t complete, at least in the book. On page 57, the cycle shows Nitrogen traveling from soil and runoff of fertilizers into the ocean into “deep ocean sediments”. It does not cycle back, but is depicted as determinately lost, thus shown a hole in the cycle. What happens to the life Nitrogen that gets stuck in the sediments? Is it absorbed by organisms? or slowly weathered?

Today in APES we learned about the base unit of Ecology, Ecosystems.

We started class trying to define what an ecosystem is, and ended up with a definition like this: an Ecosystem is the community of organisms in an area and their interactions, as well as their interactions with the non-living environment.

In order to further hone our understanding of ecosystems, we also discussed the levels of organization of life, the chart of which I will type bellow:

Levels of Organization of Life:

Cell

tissue

Organ

Organ System

Organism (if you noticed, organism and above are concepts mainly dealt with in Biology)

Population (same species) (The rest of the concepts in the chart are concepts dealt in Biology)

Community( All Different populations in ecosystem)

Ecosystem

Biome (ex. tundra, dessert)

Biosphere (earth)

We pointed out that at the end, below ecosystems, the organizations of life also included land, and abiotic (nonliving) elements into their definitions.

Lastly, we ended our lecture talking about one type of interaction between organisms in the ecosystem, predator prey, using ecological tools like the Ecological pyramid, and Food webs.

An Ecological Pyramid is like a food chain, and describes feeding relations in a ecosystem. It consists of tropic levels (generally 4-5 levels) and looks something like this:

The lower level is always eaten by the level above it (accept for omnivores, which may eat a level lower, and from the base/first level of the pyramid). An important issue to note is that most Ecological food pyramids leave of decomposers, or consider it Trophic level 0 (which isn’t consistent since plants don’t eat decomposers like fungi and bacteria) despite their important task of recycling nutrients, since they can decompose/eat organisms from every level. The example pyramid also shows some of the other conclusions we came up with, like how the second trophic level is composed of herbivores (since the first level contains plants 99% of the time).

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Our last topic of today’s lecture dealt with the food web, which is a series of food chains(a chain of predator prey relationships that starts from the bottom of the trophic level and works to the top) that are connected together. Here is an example of a food web:

Food Web

(arrows point to the prey’s predator in this picture).

And all the ideas we learned about in APES today. If you have any questions, or need clarification post a comment.

(credit pictures of:

Ecological Pyramid-http://www.tutorvista.com/search/trophic-levels

Food Web-http://www.mrsoshouse.com/envirothon/foodweb.html)

So I was re-reading the packet that talked about U.S. environmental movement history, and I’m a little uneasy with how they did not strongly differentiate Romanticists and Preservationists. From what I learned in English 2, I know that Romanticists did not do many movements to protect nature, they just valued nature, and individuality. Is that all they contributed? The “revolutionary idea” that nature might be important? Which would lead to the Preservationists? Or did they do more.