Tran,+Faith

Polymers in the Field - 1 September 2011

I found it quite interesting to know that it is actually the green blades of grass that absorb the most heat, rather than the black rubber that lies beneath since normally one avoids wearing black on a hot summer day. Although, I suppose the green blades are more exposed to the sunlight than the rubber granules. I did not know that the field was measured at a mere 0.5 percent slope to allow runoff. I never really thought about it, but I kind of assumed that the water just got absorbed into the sand and evaporated later on. 0.5 percent is hardly anything, but it makes a load of difference when it rains. I also did not know that the field was raked every few games to level out. I would poke holes in the turf with my finger when I got the chance to and I often wondered what happened when enough holes were poked. Now I know that those holes just disappeared when raked. I am curious as to how it's done. Is it like a Zamboni that runs up and down the field? And if that's the case, then wouldn't the small slope eventually disappear? I think that the vulcanized rubber that is used to make the track is something that is pertinent to chemistry class since it's reconstructing the rubber at a molecular level in order to change its properties.

Good post. I like your scientific references. 5 huge stars! MW

Stearic Acid - 13 May 2012

Also known as octadecanoic acid. C18H36O2 Stearic acid is a saturated fatty acid that has 18 carbons in a long chain with an acid group at the end. It is prepared by treatment of water at high pressures and temperatures, which is then distilled.
 * Melting point || 69.6 °C ||
 * Boiling point || 383 °C ||
 * Solubility || 3mg/L (at 20 °C) ||
 * Density || 0.847g/cubic cm ||

Stearic acid is most usually used as a thickener or used to something waxy in everyday products like candles, soap, lotion and margarine.

In candles, it is used to make the wax thicker and melt at a higher temperature. For soap, it is an additive because it is not that soluble in water. It makes soap white and is the main "active" ingredient that makes you squeaky clean by binding the dirt so that water can wash it away. In lotion, it is used to thicken the lotion and allow the application to be smooth. It also lengthens shelf life. For margarine, it makes the margarine stable during cooking.

It is also used to make oil pastels, cosmetics, fireworks (increases shelf life) and shampoos.

When mixed with other compounds, it can be used to make lubricants for playing cards and is used in the plastering process. It is mainly extracted from animal or plant fats, which means that it is fairly cheap. There is a lot more stearic acid in animal fat than in plant fat, but cocoa butter and shea butter is the exception (about 28-45% of which is stearic acid).

http://www.wisegeek.com/what-are-the-different-uses-of-stearic-acid.htm http://en.wikipedia.org/wiki/Stearic_acid