Spread spectrum. In telecommunication and radio communication, spread-spectrum techniques are methods by which a signal (e.g., an electrical, electromagnetic, or acoustic signal) generated with a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth.
Lipids are one of the four major groups of organic molecules; the other three being proteins, nucleic acids (DNA), and carbohydrates (sugars). Lipids are made up of the same elements as carbohydrates: carbon, hydrogen, and oxygen.
There are different types of lipids, but what they all have in common is that they do not dissolve in water. Fatty acids are lipids made of long chains of hydrogen and carbon. Waxes are made of fatty acids and alcohols. Sphingolipids may have fatty acids, alcohol, phosphate and nitrogen, while triacylglycerides are made of a substance called glycerol and three fatty acids. Fats are triacylglycerides that are solid at room temperature, but when the triacylglycerides are liquid, they are called oils.