.... steam-power plants made it obvious that only very large and costly hydroelectric installations could compete effectively, and that the federal government would have to assume a major share in their construction. Motivated by the search for the multiple use of water resources, including navigation, flood control, and irrigation, in addition to power production, the Tennessee Valley Authority, or TVA, started government participation in large-scale waterpower development in 1933. Most major installations depend on a large water-storage reservoir upstream of the dam where .....

.... processes. Since the cell membrane of an eukaryotic cell is its only source of nutrition, its surface area must be large enough to allow the cell’s organelles to receive the material it needs or it will die. The eukaryotic cell does this by maximizing the surface area to volume ratio. By using the surface area and volume equations for a sphere you can estimate the surface area of a small cell. By modeling the growth rate of the surface area and volume of a sphere on a linear graph its easily discernible that as the size of the sphere increases the ratio of surface area to .....

.... observed. The Steady State model says that the universe does not evolve or change in time. There was no beginning in the past, nor will there be change in the future. This model assumes the perfect cosmological principle. This principle says that the universe is the same everywhere on the large scale, at all times.2 It maintains the same average density of matter forever. There are observational evidences found that can prove the Big Bang model is more reasonable than the Steady State model. First, the redshifts of distant galaxies. Redshift is a Doppler effect w .....

.... and therefore caused the dinosaurs' birth rate to drop. The birth rate became smaller than the death rate and the dinosaurs died out. This, however, is not a plausible scenario. This would only account for the dinosaurs, but not all the other creatures of that time. Paleontologists needed to come up with a more plausible and devastating theory that would include the other creatures that died out 65 million years ago. There have been several major theories that have come about that can all be substantiated. Any one of these events, theorized by paleontologists, could hav .....

.... infected person over into illness. In his study of 72 married white men for a period of 12 weeks, in which they kept daily diaries of their stress. Researchers then measured the subjects' saliva for a substance called secretary immunoglbulin-A antibody, the less they had of it, the more likely it was that the subject would come down with the cold. This may be true according with Dr. Stone, but an argument made by Dr. Gwaltney, "You see, you could have a ton of immunoglobulin-A and you could still get sick. If you don't have a specific antibody for the cold virus that's after y .....

.... used tests used for detecting breast cancer among women today. The self exam is a simple exam that women can perform on their own with a few simple steps. Another way of detecting breast cancer is with a mammography. This is an X-ray that scans in make up of the breast to show whether there are and tumors. This is the most effective type of detection to date. (Cancer Facts, Detection. National Cancer Institute) One disadvantage to using mammography is that with mammography, the x-ray picture sometimes detects substances in the breast that are not recognizable. (NCI .....

.... alcohol content of the beverage consumed, the more alcohol will enter the bloodstream. The amount and type of food in the stomach also affect the absorption rate. Drinking when the stomach is filled is less intoxicating than when it is empty; the foods in the stomach, which contain fat and protein, delay alcohol absorption. Body weight is also a factor; the heavier the person, the slower the absorption of alcohol. After alcohol passes through the stomach, it is rapidly absorbed through the walls of the intestines into the bloodstream and carried to the various organ systems of .....

.... There are several species of these animals. The Six-banded Armadillos were good burrowers and massive devourers of insects. They also ate vegetable matter and were useful for devouring carrion. One specie called the Peludo was clumsy bet was effective in getting a snake to its armored hide and grinding the life out of it. It then eats the snake not effected by the poison. The king of the tribe is the Great Armadillo. It is a big creature in appearance, a yard in length from nose to tail covered with the armor. It even has armor on its legs. Its claws .....