Archives April 2013

Acrylic glass, or Perspex® under its commonly used trade name, is a transparent material that has been found to have many advantages over traditional glass. It is a polymer of methyl methacrylate, a simple organic compound, and is called by a number of monikers, including plexiglass, acrylic, and, properly, poly (methyl 2-methylpropenoate). It is a simple polymer, formed from chains of carbon, hydrogen, and oxygen. Despite its simplicity, Perspex® is a versatile material. Durable, yet easily molded, it found early use as a safe alternative to glass, with particular utility during World War II in Spitfire canopies, and later in visors and shields. At about half the weight of glass, but seventeen times its strength under constant load, Perspex® is also useful in aquariums, skylights, and anywhere else a transparent material under pressure is required. Medical uses include contact lenses, dentures, and bone cement. Furthermore, when suspended in water, it more...

"A rather unusual advantage of the syphon bottel was its use as a fire extinguisher." Bryan Grapentine, antique collector Carbonated drinks were known in France as early as 1790, but the soda syphon or seltzer bottle was developed by Deleuze and Dutillet in 1829. This featured a hollow corkscrew that allowed some of the contents to be dispensed, via a valve, while keeping the bottle under pressure and its contents fizzy. The modern bottle, which remains essentially unchanged today, was patented by Antoine Perpigna in 1837 and was known as the "Vase Syphoide." In an improvement on the earlier design, the head featured a valve that was closed by a spring. The drink is carbonated by pressurized carbon dioxide. The excess pressure causes more of the gas than usual to dissolve in the liquid. When the liquid is returned to atmospheric pressure in the glass, this gas comes out of more...

"Before ...the flying ambulance, we seldom saw men who had lost both legs and arms..." Dominique-Jean Larrey, surgeon Ambulances first began to appear on the Napoleonic battlefields of France in 1792. Their inventor, surgeon Dominique-Jean Larrey (1766-1842), had grown frustrated with regulations requiring him to stay to the rear. After observing how the mobility of the French artillery helped it to quickly disengage from an advancing enemy, Larrey proposed to the military hierarchy what he called an ambulance volante, or "flying ambulance," that would follow the artillery into battle and tend to the wounded where they fell. Larrey devised a horsedrawn wheeled carriage with a central compartment able to transport two patients comfortably on leather-covered horsehair mattresses; windows on either side provided good ventilation. Inside, patients could be moved in and out easily on floors seton rollers. Recessed areas contained medicines and medical equipment, and ramps at the rear doubled as more...

Around 300 million people have asthma across the planet. For more than fifty years, many of these have benefited from the metered dose inhaler. But the idea to create a device that delivers measured particles of aerosol medicines into the lungs did not come from a scientist, but from a thirteen-year-old girl. Susie Maison asked her father why her asthma spray could not be put into a hairspraylike device instead of the bulky, glass nebulizer she struggled with. Mr. Maison, then president of Riker Laboratories (acquired by 3M Pharmaceuticals in 1970), took the idea to the company where a team looked into making it a reality. They examined devices used for aerosol perfumes and tried mixing the medications, isoprotenerol or epinephrine with alcohol, ascorbic acid, and chlorofluorocarbon propellants. Early trials showed the effectiveness of this method of drug delivery and the first pressurized metered dose inhalers were launched in March more...

Virtual reality (or VR) is a system that allows individuals to interact with a computer-simulated environment. There is much debate about the origin of the term, although it seems to have come into popular usage in the 1970s. Ivan Sutherland [b. 1938), an American engineer, was one of the first to explore the potential of computers to enable people to have experiences that are unavailable to them in real life. In 1960 cinematographer Morgan Heilig built a single-user console called the Sensorama, which stimulated all the senses of the user in an all- surrounded environment. Heilig's concept involved only passive viewing, but many of his initial ideas were used by Harvard postgraduate student Sutherland. Sutherland wanted to develop a head-mounted display that enabled the wearer to look into a virtual world that would appear completely real. The user could fully interact with this virtual world, which would be maintained by more...

It was a Saturday. I had seen the movie on TV the previous night that was telecast from 11.30 PM to 1 30 AM. I went to sleep after 2 AM, My mother had prepared breakfast and was taking her bath. She had thought that I was getting ready in my room. She was surprised when she saw me sleeping as she came out. She woke me up with great difficulty. I prepared myself hastily and rushed to the bus stop. There was no student waiting for the school bus. I realized at once that I would have to reach the school by the local bus. The buses were overcrowded and 'some commuters were hanging on doors. As the bus stopped, I entered from the front door. The driver was nice. He did not object when I requested him to let me stand in a corner. The conductor asked me more...

It was the 1st of April. 1st of April is known as 'All Fools Day'. But I had forgotten it. Early in the morning, my younger brother shook me awake. "What's the matter?" I asked him. "Your teacher has come to see Papa." I hurriedly got up and put on clothes and asked, "Where is she?" My younger brother said, "At the door." I hurried to the door and opened it. No one was there. I looked around. Just then, my younger brother yelled from behind, "April fool, April fool." I ran after him, caught him and laughed loudly. After some time we went to school. I wanted to take revenge with my younger brother. In the afternoon we returned from school. My younger brother sleeps in the afternoon for a short while. When I saw him fast asleep, I patted him awake and said, "You're late for school. Hurry more...

The exact date and location of the initial historic transition from simpler bridges to arch-supported types is now lost to us. The development and use of the arched bridge has been attributed variously to the Indus Valley Civilization of around 2500 B.C.E. the Mesopotamians, Egyptians, Sumerians, and Chinese; and the Etruscans and Romans, who built most of the surviving early arch-based architecture in Europe. Early arches were corbeled, not really an arch as we understand the term today. A corbel is a projecting, stone supporting piece. It is a simple example of a cantilever. Such an arch is constructed by progressively corbeling from the two sides with horizontal joints until they meet at a midpoint. At the top, where the two sides meet, a capstone is placed. The Romans, aided by their invention of a cement material to bind stone together, refined the technigues of arch construction. Arch-based Roman bridges more...

"Before ...the flying ambulance, we seldom saw men who had lost both legs and arms..." Dominique-Jean Larrey, surgeon Ambulances first began to appear on the Napoleonic battlefields of France in 1792. Their inventor, surgeon Dominique-Jean Larrey (1766-1842), had grown frustrated with regulations requiring him to stay to the rear. After observing how the mobility of the French artillery helped it to quickly disengage from an advancing enemy, Larrey proposed to the military hierarchy what he called an ambulance volante, or "flying ambulance," that would follow the artillery into battle and tend to the wounded where they fell. Larrey devised a horsedrawn wheeled carriage with a central compartment able to transport two patients comfortably on leather-covered horsehair mattresses; windows on either side provided good ventilation. Inside, patients could be moved in and out easily on floors seton rollers. Recessed areas contained medicines and medical equipment, and ramps at the rear doubled as more...