Archives September 2013

"... only thirty years ago [its functions] would have filled the entire floor of an office building." Marshall Brain, How Stuff Works By the early 1980s analog cellular telephone systems were attracting ever more customers. Each country, however, was developing its own standard, which was often incompatible with others. Standardization seemed essential, and so, in 1982, the Groupe Special Mobile (GSM) was established by a consortium of thirteen telecommunications interests to develop a common cell phone system throughout Europe. (Appropriately, 'the" "acronym was later changed to represent the ''words" Global System for Mobile Communications.") The first GSM phone call was made on the Finnish Radiolinja network in 1991, and by 1997 100 countries had implemented a GSM capable network. GSM strove to produce a standard for all the elements of a cellular mobile phone call, including the particular frequencies to be used for receiving and transmitting calls. Since the signaling more...

"Look well to your seat, 'tis like- taking an airing/On a corduroy road, and that out of repairing." James Russell Lowell, "A Fable for Critics" Nicknamed corduroy roads, log-laid roads consist of whole logs, or logs split down the middle, that are laid across the roadway, one tightly against the next, to create a resistant road surface over swampy or muddy land. Sand is used to cover the surface and reduce the discomfort of traveling over the corduroy-like surface. Despite enabling easier travel through once inaccessible places, corduroy roads could be dangerous for the user. In the best of conditions the ride was already bumpy and uncomfortable, but if rain washed away the sandy cover or logs became loose or wet, the surface became highly hazardous to horses and any vehicles that were attached to them. The first known log-laid road was constructed in 4000 B.C.E. Evidence of corduroy roads, more...

A fiber with half the density of fiberglass and five times stronger, weight for weight, than steel, Kevlar8 is now globally recognized and widely used. It is best known for its use in bulletproof and stabproof vests, where it has saved thousands of lives. After graduating from the Carnegie Institute of Technology in 1946, American chemist Stephanie Kwoleck (b. 1923) was employed by DuPont to research high-performance chemicals. Her work on polymers yielded a number of successful discoveries. Kwoleck, who holds twenty-eight U.S. patents, specialized in developing polymers at low temperatures and in the 1960s discovered a new group called liquid crystalline polymers. Kwoleck's invention of Kevlar fibers in 1965 stemmed from an interest in the chemicals produced during the process of polymer synthesis. These substances are sensitive to moisture and heat and easily undergo hydrolysis and self-polymerization. She discovered that, in cool conditions, these chemicals created an aramid polymer more...

“I never drink coffee at lunch. I find it keeps me awake for the afternoon." Ronald Reagan, U.S. President 1981-1989 Melitta Bentz (1873-1950) invented the coffee filter to solve a simple household need, and it resulted in a hugely successful company and her filter being used throughout the world. Bentz wanted to find a way to produce coffee without the grounds in it and began to experiment with passing the coffee through various types of filters, eventually trying the blotting paper that her children used when doing homework. By putting a circle of the blotting paper into a metal cup with holes in it, Bentz could pass hot water over the coffee, then let it drain into another cup, with the grounds left behind in the filter. In 1908, Bentz filed a patent for her invention and, with her husband, formed the Melitta Bentz Company to promote it. The invention more...

"Industrial wind energy is a symptom of, not a solution to, our energy problems" Eric Rosenbloom, National Wind Watch Windmills had been been in use for some 2,000 years before, in 1888, Charles F. Brush (1849-1929) linked a wind-powered turbine and a generator to provide power for the lights on his estate in Ohio, The 144- bladed rotor was based on wind-driven water pumps, and bore little resemblance to today's turbines. Perhaps more familiar would be the turbines developed by Paul LaCour who, from 1891, developed wind power as a means of supplying farms and villages in his native Denmark. His four-bladed turbines could provide up to 25 kilowatts of power and were generating in their hundreds by 1910. In the early twentieth century, propeller-like turbines with only two or three blades appeared, in 1931 the first large- scale turbine, a 100-kilowatt Russian device, was connected directly into an existing more...

“He gave me a skin-bag flayed from an ox… and therein he bound… the blustering wind”. Homer, The Odyssey The ability to extract metals from their ores is one of the most significant discoveries in antiquity. Until the invention of bellows, furnace fires were stoked by breath alone. Teams of men, using blowpipes, would blow on the charcoal to supply the oxygen required to increase its temperature. The teams could achieve temperatures high enough to smelt copper and tin and melt metals such as bronze, silver, and gold. Bellows improved this process not least because arm and leg power is considerably less exhaustible than lung power. They also enabled much larger furnaces to be used; one man with bellows could generate heat around seventy times faster than one with a blowpipe. A pan found in Talla, Mesopotamia, dated around 2500 B.C.E., is believed to be the earliest evidence of bellows, more...

"With advanced hemorrhage control ...20 to 30 percent of all combat deaths can be prevented." Kenton W. Gregory, MD Imagine a bandage that not only covers up a wound and soaks up blood but also causes the blood to form a clot once it comes into contact with it. This is exactly what the chitosan bandage does. Chitosan is a compound found in shrimp shells. Its molecules carry a positive charge and are therefore able to interact with negatively charged red blood cells to create a clot. Research on chitosan was first conducted at Oregon Medical Laser Center in the United States. Initial results in animals showed great promise for the bandages, and the Food and Drug Administration (FDA) approved their use in 2002. The development and manufacture of the bandages was undertaken at HemCon, a company that develops technology for trauma injuries. The implications for the battlefield, as well more...