PDS AP Environmental Science 5th Period 2010-11

When you hear the words “Nuclear Superpower” the first thing you’d probably think about would be an image from the Cold War with stockpiles of nuclear warheads to kill off the planet earth several times over. But that was then – come to the 21′s century, bud. Sure we still have big bombs in commission, but ironically we have also adapted the most destructive weapon for non destructive purposes – Energy.

So y’all are probably thinking “whoa, is that possible? Is its power level over 9000???” Sure it is! but you need to know how electricity is typically generated in order to understand how nuclear energy works. Heres a simplified rundown of how we get most of our electrical energy (in reverse).

• Electrical energy always comes from spinning magnets, or spinning some sort of shaft. thus: “Super merry-go-round” + magic = Electricity =
• We power this super super merry-go-round not with electricity (because that would be stupid) but my moving some sort of gas or fluid through a turbine. its like holding a propeller and blowing into it — more magical moving particles + turbine + more magic =  super merry-go-round
• In most power plants this fluid is pressurized steam that is forced though tight chambers to get them moving fairly quickly. we get steam though the magic of heating water. — magical water + something that has hot air (like Mr. W, JK!) + even more magic = moving steam (moving particles)

http://www.freeinfosociety.com/images/science/nuclearenergy1.jpg

So thats how we generate most electricity in a nutshell. its 1 part basic physics and 3 parts awesome magic. The only thing that differs between most typical power plant designs is how we heat the water. Obviously with a nuclear plant we use a nuclear reaction (not nukes). Here, instead of burning coal, we have a reactor core that is filled with radioactive material. This material can easily fission (the whole atom can be broken, yeah they told you atoms couldnt do that, well they can.) into smaller parts, however in such a reaction, although the number of particles is conserved, mass is not. the mass is converted into energy (heat). Here’s how that works:

• Fissionable Uranium 235 is fairly stable by itself, but with the addition of a free nutron it becomes Uranium 236 which is highly unstable. — Uranium 235 + magical nutrons = really angry Uranium 236
• The pissed off Uranium 236 decides it doesnt like itself so it splits into two smaller atoms in a bloody civil war creating smaller Krypton and Barium atoms as well as 3 nutron Al-Quida radicals. (this is a really hot situation so there is a lot of heat released)
• The 3 free radicals run around and upset other happy Uranium 235 and repeats this process. Its like a positive feedback loop, except it gets VERY hot. Enough to make many pots of coffee.

Here’s a video that shows how this works.

But enough wharbl garbl, if its so good, why dont we use it?

Unfortunately, the Al-Quida radicals overcome Uranium 235 and cause too many of them to fission too fast creating too much heat. This situation in a nuclear power plant is called a Meltdown or where the core gets too hot and the whole thing basically “melts down” into a a soupy mixture that spews out radiation unsafely; just like the one in Chernobyl in the 20th century when they couldnt shut down their reactor in time. But even today, we are still having problems avoiding potentially catastrophic events from nuclear power. A recent tsunami that hit Japan has crippled safety features in a power plant that has become unstable. Here, like Chernobyl, they cannot seem to stop their reactor completely, but they are making every effort to keep it cool with seawater. HERE’S a link to what is really going on out in Japan.

Aside from these “minor” problems in today’s current events, Nuclear power has a lot to offer us in terms of energy. FIND OUT MORE TOMORROW IN CLASS!

Ok mates,
So contrary to popular belief, floods are not things that happen when the Norse gods get angry with the world. They are actually natural phenomena and can help restore nutrients to floodplains. For those of you who have never seen a flood, its when too much water collects in the floodplains because of excessive rain, runoff (and godly actions). Generally, these floods are not exclusively destructive as portrayed by many movies – They actually help stir up the rich silt and nutrients contained at the bottom of bodies of water and dump them around the floodplain to create fertile soils.

Define – Floodplains: Sorta what it implies, its a flat area next to a river that will flood when the water lever rises in the river.

The lighter blue areas are the floodplains. (The farmer in the house over there probably has great crops)

See? natural flooding is good… its just the unnatural ones that gives us problems. Surprise, surprise, it is almost directly caused by human actions.

Unnatural Flooding:

As  humans, we like moving things. If it is in our way, we will put it somewhere else. This is the case for water. We erect structures to divert the alter the natural flow of water to our bidding, such as adding levees (earth made, parallel to flow of water to regulate water levels), dams (completely stop the water) and floodwalls (like a dam, but only for preventing flooding), or even laying down asphalt and other ground coverings that prevent natural infiltration of water into the ground. These artificial structures do not prevent flooding, but rather, almost always magnify the impending disaster. Why? because levees and dams can fail and magnify major flooding from all the built up water, and also the addition of concrete and other artificial, impervious coverings prevent water from infiltraitng naturally into the soil thus causing it to remain above ground and run around the area carrying your Mercedes with it. Furthermore, due to artificial blocking of waterways, we prevent natural renewal of soils in the floodplains due to floods and thus plants and biodiversity will decrease no wonder the Norse gods want to punish us.

Still think that human engineering is flawless and all of this is just blasphemy??? Well, remember Katrina that caused just a small problem for New Orleans? I know its a far off theory, but that might have happened because water built up behind the levees and floodwalls and when a not so small storm hit, it overwhelmed the artificial barriers and rushed into the city. Unable to make it into the ground, it settled for your houses instead.

Solutions to flooding problems???

Well, we could just simply make better dams and levees but as shown, that only makes the gods even more mad and floods worse. But recently we have been pioneering to combat the problem at the source–the river source. Because flooding is caused by excessive runoff from heavy rains that feed into the floodplains, by diverting or stopping this water from collecting too fast (perhaps with plants or trees to stabilize the water flow), we might be able to minimize  the effects of flooding.

So thats how flooding works. Im Jason Yang, and THATS how stuff works.

Floodplains pic: http://rfcd.pima.gov/fpm/hazard.htm

On Friday October 1st, the Environmental Science classes took the day off from school and traveled down to Davidson College for a hands on experience in creating controlled experiments and data gathering in the field. We started off with a presentation on Bernese pythons and how they are ravaging the southern parts of Florida. Although we do not know the source of the problem, we do know that these foreign species of giant snakes (adults can get more than 9 feet long) are procreating very readily and consuming native wildlife with seemingly no natural predators in the area, possibly toppling over an otherwise delicately balanced ecosystem. Although the topic of the presentation was interesting, the main points that we left with (or should have left with) were, field research makes a huge difference in understanding the ecological systems around us, and designing controlled experiments, regardless of the seemingly uncontrollable nature of nature, is completely possible.

From there, we went into the ecological preserve to look into methods for sampling nature. The first that we looked at was a technique called drift fencing. This approach primarily targets small creatures, but has been adapted for slightly larger animals with varying degrees of success. The underlying idea behind this approach is as follows: An animal encounters a large fence, large enough such that it cannot burrow under nor fly over it. In order to get past the obstacle, it must traverse the perimeter of the fence, which while doing so, may fall into a 5 gallon bucket ‘trap’ or larger animals might get stuck in boxes with one way doors. Using this method, we can get an idea of what creatures inhabit the immediate surroundings.

Another method was much simpler: Coverboards were placed in open areas, providing shade to cold blooded animals to help regulate their metabolism. By lifting these coverboards during sunny times, we might be able to observe and document critters who might be taking refuge underneath and, again, get an idea of what animals are around us.

Finally, we tried our hands at acquiring a representative sample of an ecosystem for controlled experiments. Our lab required samples from both pine and oak forests, but acquiring these samples raises two questions: where do we get our samples from, and how much do we get? The inherent laziness of people might cause us to only sample the outer edge of the forest; what lives there might not be the same as what lives slightly deeper. also, we had no method of regulating the sizes of each sample collected. To solve this, we have a device called a quadrat, and transect. A quadrat is merely a rigid square that is placed on the floor of the area in study such that we can analyze what is inside it. It sets boundaries and keeps our sample size constant. A transect is a method to randomly sample parts of the area in question such that we get a representative sample. there are two measuring tapes; one going down the middle of the area, and another placed perpendicular to the first, essentially creating a coordinate-grid system. using a random two digit number generator, or a phone book, we can randomly pick ‘coordinates’ and sample them. the first digit tells us how far down the first tape measure to go, and the second digit indicates how far left or right we move from the first tape measure. We alternate sides (left/right) each sample. For example, if the number was 45, we would travel out 4 meteres and then to the right 5 meteres, place our quadrat at that location and sample whatever was contained within.

The small white frame is a quadrat. We sample only what is contained within its boundaries and take it back to the lab

Drift Fencing is merely a fence that critters must travel around the perimeter to get across, hopefully falling in a trap such that we can count them

Finally, we also looked into how to sample rapidly moving insects that might be on long stemmed plants. Using a large net called a sweep net, we can ‘sweep’ the tops of the stems and catch whatever might be living on them at the moment. By controlling the number of ‘sweeps’ done by the net and sweep area, we can keep the sample size constant and acquire a representative sample size.

The biggest environmental problem is the lack of research and enthusiasm towards fixing such problems. sure, we have technologies to address such problems, such as the energy problem but most of these solutions have a lot more potential to do more than they are doing right now. Solar energy from solar panels could be much more efficient if we could put funding towards research in looking for a wider wavelength band that can excite electrons thus increasing overall efficiency.