Reflections Upon Others' Blogs

First, I visited James’ blog concerning nanotechnology. His blog mentioned that nanotechnology has both positive and negative effects on products and our environment. I found his sunscreen example very interesting. In it, he discussed how the tiny particles in sunscreen protect our skin, but they can also penetrate the skin, harming the user of the sunscreen. Also, his list of nanotechnology vocabulary was very useful in providing me with an intro to nano-tech. It is interesting that “nanoshells,” very small nano-particles, can be given different physical properties by varying their sizes. For example, some nanoshells can absorb harmful light rays, which is useful for medical procedures.

I then entered McLovin Cohen’s Pasteurization blog. His entry began with a definition of ‘pasteurization,’ which I learned is the process of heating an edible product to destroy microorganisms which may cause disease. Evan discussed how without pasteurization, food would spoil much more quickly. He focused some of his entry discussing how the wine industry is dependent upon pasteurization to preserve their products while aging. Without pasteurization, microorganisms would multiply in their respective wines, during aging, contamination the final product. Therefore, pasteurization, like all of chemistry, helps our national economy. Also, although not mentioned in his blog, I thought that milk also underwent pasteurization. I am not positive whether I am confusing ‘pasteurization’ with another long work, but maybe Evan could answer this in a future post for me.

After Evan’s blog, I arrived at Laura’s blog on college’s affect on chemical imbalances, (i.e. stress). Although interesting, her blog was also quite frightening, for it reminded me of the bad side of college. She mentioned that college students were more prone to depression, schizophrenia, and eating disorders due to chemical imbalances. These imbalances are caused by the stress of a new environment and unfamiliarly with the college lifestyle. Her blog also discussed how there is still much that scientists do not know about these chemical imbalances. However, some medicines exist to help remedy this problem.

~Rick

How do Car Engines Work? (How does gasoline make our cars ‘go places’)?

(Although the topic for my blog is nuclear energy, I am going to focus this post on car engines/combustion engines and improving their miles per gallon/efficiencies. I will compare combustion to nuclear energy processes in later posts.)

To start off, cars are powered by internal combustion engines. As the name suggests, these engines are powered by the combustion of gasoline. (During combustion, gasoline is ignited, releasing large amounts of energy to power a car). There are four steps to a car’s combustion cycle (commonly known as the Otto cycle). In the first step, air and gasoline enter the engine to be used in the combustion reaction; chemically speaking, combustion reactions require a hydrocarbon and oxygen to produce carbon dioxide, water, and energy. For this reaction, the oxygen comes from the air, and the gasoline serves as our hydrocarbon. In the second step, the engine compresses to increase the energy which will be produced in the explosion (HowStuffWorks, 2). During the third step, a spark ignites the gasoline, causing a reaction (the combustion reaction). The energy from this reaction forces down the engine’s turbine. The turbine then transforms this energy into rotational motion to be used by our cars. In the fourth step, the byproducts of the combustion reaction, mostly carbon dioxide and carbon monoxide, are released as exhaust. And then the cycle repeats.

While reading about car engines, I also came across an interesting article discussing ethanol’s usefulness in improving the combustion reaction. When ethanol is added to gasoline, the ethanol “enhances” the gasoline, increasing the distance that the gasoline will last your car (Journey to Forever, 3). The ethanol also decreases carbon monoxide products in the combustion reaction. Overall, the ethanol increases the efficiency of your car’s engine by a few percent, yet this reaction is still very inefficient. A lot energy is lost to heat, exhaust, and friction, making the reaction only 20% efficient (Wikipedia, 3).

It appears that combustion and gasoline are not a very efficient method of producing energy. In later research, I will compare combustion’s 20% with statistics concerning nuclear and other types of energy.

Without knowledge of chemistry, it would be difficult to describe the combustion reaction that takes place in a car’s engine. As mentioned earlier, this particular reaction requires oxygen, a hydrocarbon, and something to ignite the hydrocarbon so that it can take place. An understanding of chemistry is useful in recognizing the products of the reaction. Also, chemistry can help explain that in incomplete reactions, carbon monoxide is formed instead of carbon dioxide. Furthermore, if one understands the bonding of carbon monoxide, it is easy to see why this molecule can be dangerous.

Works Cited

Ethanol Fuel. Journey to Forever. 28 January 2008.

____http://journeytoforever.org/ethanol.html.

How Car Engines Work. HowStuffWorks. 28 January 2008.

____http://auto.howstuffworks.com/engine1.htm.

Internal Combustion Engine. 28 January 2008. Wikipedia. 28 January

____2008. http://en.wikipedia.org/wiki/Internal_combustion_engine.

*Ms. V, I had difficulty formatting the indentations and '<>' s in my citations.