PDS AP Environmental Science 8th Period 2011-12

I think I lost the sheet that compares fossil fuels. Can someone post what it is called so I can find it online or post the most important stuff on it?

Before Mr. Thompson, the CEO of a Biodiesel fuel company, came to speak to us on Friday, what did our class know about Biodiesel fuel or even just diesel fuel? We knew that diesel fuel was more expensive at gas stations than gasoline, that trucks and other large vehicles often run on diesel fuel, and that diesel fuel would destroy a gasoline engine. But that was about it.

The first thing Mr. Thompson want to make clear to us was that BIODIESEL IS NOT ETHANOL. Ethanol is a corn-based fuel that is made by distilling the sugars and starches into alcohol. It is then mixed with gasoline. Ethanol is not only less efficient than gasoline but it also takes away from our food supply. Basic rule of economics: when the supply of a product decreases the price increases. On top of its lack of efficiency and the fact that it increases the price of food, because it is corn-based all the same fossil fuel inputs and environmental impacts associated with farming. When you add up all these costs ethanol is energy negative (it takes more energy to make it than it provides) and in the eyes of Mr. Thompson and many others to be a bad fuel.

Mr. Thompson went on to explain what biodiesel fuel actually is and does. Biodiesel is fuel made from natural oils (soy, canola, poultry, algae, or Mr. Thompson’s company made fuel from used cooking oil) that can be used in a diesel engine. It can be combined with petroleum-based diesel fuel in any percentage and still run a diesel engine. In fact, the main reason biodiesel even needs to be mixed with petrodiesel fuel is that it tends to congeal when it is cold and block up engines. Petrodiesel’s lower freezing point prevents this tendency when the two are mixed. Compared to regular diesel fuel biodiesel fuel can also reduce carbon emissions by as much as 75%.

Biodiesel: 30 PSA

Just a couple of videos to show you how biodiesel fits into our country today

Mr. Thompson finished his lesson by telling us what biodiesel is not. Again IT IS NOT ETHANOL. It is not simply waste vegetable oil taken from someones kitchen and dumped into a gas tank. It has to be processed first or else it would eventually ruin your engine. On the downside, in most places it is not cheaper than regular diesel fuel or gasoline or available in as great quantities… yet. But on the upside it is not flammable, hazardous, carcinogenic, and since it is just natural oils, it biodegrades very quickly.

Biodiesel fuel has many exiting possibilities and in a few decades it could be one of our major sources of fuel.

Mr. Willard's picture

Tags: biodiesel, biofuel, biomass, energy, renewables

Pikachu, quick use thunderbolt!

Critical Hit!

Foe’s Blastoise fainted.

For the millions of you that have played Pokemon, it seems obvious that electricity is water’s kryptonite; they don’t mix! But in the world of modern science, nearly twenty percent of all electricity comes from hydroelectric plants (imagine that Ash!). Source: Friedland and Relyea Environmental Science for AP

To illustrate the vast potential of Hydroelectricity as an alternative energy source, check out this brief video of China’s Three Gorges Damn, the largest in the world.

Here’s a current article about the dam!

Hydroelectric power uses dammed reservoirs to direct the flow of water through a penstock and then past a turbine that generates electricity. Watch this short video to see what I’m talking about, and if you don’t have time for the video, check out the diagram.

Diagram

Hydro electricity takes “hydro” and a substantial initial investment, and not all countries have the water and resources to make hydroelectric dams. The good new is that hydroelectricity emits no pollutants once constructed, and there are other ways to generate the hydroelectricity without a large river such as, run-o-the-river and tide. These use the same concepts, but don’t have reservoirs to direct the flow.

Get it? Got it? Good.

P.S.

Things to consider:

fish ladders: for migratory fish during their mating season.

Siltation:  the plague o’ hydroelectric dams! Silt from the water builds up behind the dam and has the potential to clog the penstock.

Tags: energy, renewables, water

At Davidson we learned how to conduct out-door experiments through use of a line transect, quadrats, sweep nets, drift fences, and cover boards. To take random samples of detritus from the forest floor, we had to represent the area as a grid to use a method called a grid transect. Next we used a random number generator to decide which part of the grid we would choose samples from. The random number generator was a piece of paper with numbers randomly placed across it. Someone would close their eyes and point to a number. We would then measure the distance of the chosen number and repeat to get a measurement to the right or left. We did this because humans naturally are going to choose a place that is out in the open and easy to get a sample from. That is not the goal. We want samples from anywhere in the given  are, and that includes briar patches or any other hard to get to place. So to be fair we use the random number generator.

After we chose the spot we placed a quadrat on the ground and collected all detritus within it.  We repeated until we had seven samples, which was roughly ten percent of the area we were sampling. Always aim to collect ten percent of the target area.

We also learned how to collect samples of bugs. We used the same random number generator and grid transect to choose an area to use a sweep net. Once you choose the spot, you walk ten steps forward swing the net back and forth evenly with each pace to beat the plants and collect the bugs clinging to them. Then dump the nets on a mat and bottle the samples.

The way to sample reptiles and amphibians starts with a drift fence. It is a silt fence place near a water source. As amphibians approach the water source they hit the fence and walk along it until they hit one of the pitfall traps. A pitfall trap is a bucket buried right at surface level. When they amphibians fall in, it is too steep to get out. For reptiles it is similar. They hit the fence and walk along until they hit one of the wood boxes with inward slanting chain-link fence on each side. They slide in but can not figure out the way out. They are trapped until people come and collect the samples.

The last way we learned to collect samples was by using a cover board. Place a board of plywood on the ground and leave it there a few days. Many types of bugs like to live under things like that. Then collect the bugs that have gathered underneath the board.

Tags: ecology, fieldwork

The biggest Environmental problem facing us is finding how to feed and water an ever increasing human population, without overusing the soil and destroying too much natural habitat.