.... make them in the second half of the nineteenth century, long before we really even knew what a polymer was. The very first came about when a scientist reacted cellulose, in the form of cotton, with nitric acid. The result was cellulose nitrate. Cellulose nitrate, also called gun cotton, turned out to be a powerful explosive. It soon replaced common gunpowder as the explosive charge in the ammunition for rifles and artillery. Cellulose nitrate was also used to make an early polymer containing composite material, safety glass. This was a sandwich made of a sheet of cellulose nit .....

.... therefore combining to form a wave that has an amplitude equal to the sum of the individual amplitudes of the original waves. Stimulated emission is the process that the laser works on, which was first proposed by Albert Einstein in 1917. When a sufficient number of atoms, either gas solid or liquid, absorb energy so that they are in an excited state of higher energy stimulated emission can occur. Light of a specific wavelength can produce more light with the same phase and direction these light waves will be coherent. Stimulated emission amplifies the coherency of thi .....

.... been many uses for calcium over the years, but calcium has not been available on a large scale until the twentieth century. Calcium is a metallic element, which is fifth in abundance in the Earth’s crust. It is essential for forming leaves, bones, shells, and Portland Cement. Calcium occurs in many highly useful compounds such as marble, limestone, and chalk. Plants and animals must have calcium to live. A plant cannot grow without a good supply of calcium. A lack of calcium prevents bones from developing properly. Calcium is the major component of teeth and bones. .....

.... and nervous system, they are classified under the Mollusca phylum. It then goes under the classification of Cephalopod along with squids and chambered nautilus. From there it is ordered as Octopoda, (Family) Octopodidae, (Genus) Octopus. Then its species differ to differentiate one octopus from another. A common octopus's species is labeled as vulgaris. A common octopus's scientific name: Kingdom: Animalia Phylum: Mollusca Classification: Cephalopoda Order: Octopoda Family: Octopodidae Genus: Octopus Species: (common octopus) vulgaris Physiology: external .....

.... which lacks clotting factor nine. An extremely small number of hemophiliacs lack yet another kind of clotting factor. Both A and B forms have also been called the royal disease. Hemophilia was inherited by decedents of England's Queen Victoria and introduced into the royal houses of Spain, Germany, and Russia. Hemophilia A and B are caused by genes that are sex linked and recessive. A defective gene on the X chromosome, one of the two chromosomes, that determine a person's sex. The Y chromosomes which has no genes for clotting is the other chromosome. Males have one .....

.... parts of most continents. The world’s grasslands are vast areas covered with grass and leafy plants. They generally have a dry climate, little vegetation, and most grasslands receive only about twenty to thirty inches of rain each year, with most of it coming in the same season. Some grasslands may even receive up to thirty to forty inches of rain a year! For example, since the grasslands of the United States have hot summers and mild winters, most of the rain comes from the summer thunderstorms. With this limited amount of rain, only grasses and shrubs can grow. Bu .....

.... so it can reach the advanced users.Other computer system is Macintosh Power PC that is used by graphical designers,press companies and advertising companies, can be run with Linux. The others are Sun Sparc&Sun Ultra, Amiga, 3Com Palm Pilot which are rarely used. This capability of Linux provides a large user number and user kind that makes Linux more popular.(www.linux.org) Linux has a powerful security system.It is almost impossible to write a virus for Linux because it must be 30-40 Mbytes.Also it has firewall system to protect the network from the hackers.If we think th .....

.... Multimedia Encyclopedia 1990). Tigers usually live and hunt alone. When they hunt they can leap 5 to 6 or jump as far as 10 meters. Tigers do not usually prey on people, but some do become man eaters. If a Tiger becomes a man eater it is because of a wound, weakness, or just because it is to old. The young accompany their mother on the hunt when they are 5 to 6 months of age. Tigers begin to hunt alone when they are just eleven months old. Before the young can hunt alone, the mother will demonstrate how it is done(Comptons Interactive Encyclopedia 1993). Tigers usua .....